No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Search Is a Time-Critical Event: When Search and Rescue Missions May Become Futile
Abstract
The purpose of this study was to derive and validate a rule for duration of search (ie, search time) that maximizes survivors and after which a search and rescue (SAR) mission may be considered for termination.
This was a retrospective cohort study of all SAR missions initiated in Oregon over a 7-year period, which were documented in a population-based administrative database. The following types of search missions were excluded from analysis: redundant reports of a single search; lost helicopters and airplanes; support of organized events; law-enforcement searches; searches for persons actively avoiding rescue; body recovery missions; and cases without outcome information. The cohort was divided into a derivation cohort (searches from 1997-2000) and a validation cohort (2001-2003). The primary outcome was survival. Variables considered in the model included age, gender, minimum and maximum daily temperatures, precipitation, search time, and whether the search involved an air or water incident. Missing data were handled using multiple imputation. Classification and regression tree (CART) methods were used to derive the model.
The derivation cohort included 1040 searches involving 1509 victims, 70 (4.6%) of whom died. The validation cohort included 1262 searches involving 1778 victims; 115 (6.5%) died. Search time was the only variable retained in the final model, with a cut-point of 51 hours. The derivation model was 98.9% sensitive; the same model run using the validation cohort was 99.3% sensitive.
This time-based model may aid search managers in the decision about starting a search or changing search tactics for missing persons.
... Koester and Stooksbury (1995) speak of a "search window" of 24 h for persons with dementia. After that, the survival rate rapidly falls (Adams et al., 2007;Rowe et al., 2011). ...
... Six out of ten people with dementia report becoming lost (American Alzheimer's Association, 2011). Persons with dementia wandering off, with increased risk of becoming disoriented and getting lost is a well-known phenomenon (Adams et al., 2007;Bantry White and Montgomery, 2015). A total of 38% of those persons are expected to go missing more than once (Tarling and Burrows, 2003;Gibb and Woolnough, 2007;Ferguson and Picknell, 2021). ...
... Adapting the missing person checklists for eldercare was quickly done by the eldercare managers when they realised that the time factor and swiftly alerting the police were paramount (Koester and Stooksbury, 1995;Adams et al., 2007;Rowe et al., 2011). Such coordination is free of cost and will likely save resources if there is awareness of the need for change. ...
Purpose
The purpose of this paper is to give an account for preparative collaboration between the police and municipal eldercare in Sweden concerning missing persons with dementia.
Design/methodology/approach
Design/methodology/approach used was a qualitative case study design, consisting of one focus group with representatives for the participating organisations, followed by directed content analysis.
Findings
The findings showed a lack of current collaboration and reluctance to new collaborative initiatives. However, when focussing on preparative collaboration of coordinated responses to missing incidents, possibilities for improvement could be identified. The improvements concerned updated personnel response checklists, along with suggestions for an elaborate life story document in eldercare, with police access. Finally, better coordination of the return of the found person and a follow up were proposed.
Research limitations/implications
It is suggested that collaboration must be given different meanings and use different approaches adapted to the different phases in a rescue operation. In the preparation and the response phase, the focus should be on coordination of the resources available. In the pre-planning and prevention phases, as well as in evaluation and learning, horizontal collaboration is more suitable. The amount of data in this study is a research limitation which calls for further research.
Practical implications
It is suggested that collaboration must be given different meanings and use different approaches adapted to the different phases in a rescue operation. In the preparation and the response phase, the focus should be on coordination of the resources available. In the pre-planning and prevention phases, as well as in evaluation and learning, horizontal co-operation is more suitable.
Originality/value
The originality/value of this paper can be found in the novelty of missing person research in Sweden, and in practical suggestions for preparative collaboration concerning persons with dementia who go missing. Finally, it can be found in the suggested need for a more dynamic and process-sensitive view of collaboration in SAR or rescue operations.
... GPS localization with important cost in terms of energy consumption). With this approach we can satisfy accurate localization (for SAR needs) and at the same time wearable device can last enough for the majority of the SAR operations, as mentioned in paper [3] , even the battery life is not 100%. ...
... This mechanism is able to extend the battery life to a significant extent, so that the SAR workers can be able to reach the lost people. The data used in order to proof that the results are sufficient is presented in [3] . According to [3] , the information accumulated in a 7-year study of all SAR operations, conducted in the state of Oregon, concluded that in order for a lost person to have moderate to high possibility of survival, the person must be found within 50 h from the time he was lost. ...
... The data used in order to proof that the results are sufficient is presented in [3] . According to [3] , the information accumulated in a 7-year study of all SAR operations, conducted in the state of Oregon, concluded that in order for a lost person to have moderate to high possibility of survival, the person must be found within 50 h from the time he was lost. Taking this into consideration, we describe both the architecture of the system and the energy efficient mechanism that aims to reach this target. ...
Internet of Things (IoT) is the ability of communication between objects and refers to a wide range of applications, such as the Search and Rescue (SAR) operations. SAR applications need long distance connectivity, thus can be benefited by Low Power Wide Area Networks (LPWAN). One LPWAN technology is called LoRa (Long Range). In this context, the WeSAR project has been created that provides a system for locating and rescuing people, especially those who belong to population groups with a very high probability of getting lost. The energy consumption of the wearable devices is important factor in the SAR operations, as the battery should last more than 50 hours. Therefore, the proposed system is based on LoRa technology, the user localization is based on LoRa using trilateration and Time Difference of Arrival (TDoA) instead of Geolocation Positioning System (GPS), as GPS increases the energy consumption, and we created an energy-efficient mechanism to tackle the problem of energy consumption. In this paper, an energy efficient mechanism for LoRa networks is presented, that is based on the user's state and the battery level of the wearable device. Realistic simulations have been conducted to evaluate the system for both one wearable device, and multiple wearable devices, using different mobility models. The results from the simulations have shown a decrease in the energy consumption in various node mobility models that were tested, without compromising the delivery ratio of the network, something important as the LoRa packets are used for the localization of the lost person.
... Examine the study [3] to grasp the significance of the long battery lifetime and, as a result, the energy usage. The study [22] investigates the existence of a criteria for selecting SAR operations depending on search time length, with the goal of maximizing the rescue of surviving missing individuals. The average search length for a significant number of survivors (n = 1439) is 7.9 hours, with a maximum duration of 323 hours, or almost 13 days. ...
... The average search length for a significant number of survivors (n = 1439) is 7.9 hours, with a maximum duration of 323 hours, or almost 13 days. Specifically, at an expected cut-off point of 51 hours, virtually all survivors had been found, and by 100 hours, nearly all lost victims, dead or alive, had been found (but not rescued) [22]. As a result, the battery life must be sufficient to provide rescuers ample time to find and rescue the people. ...
Nowadays, IoT has been introduced in different aspects of our lives giving solutions to several problems, one of which is the Search and Rescue (SAR) operations. People that suffer from dementia or people with disease in the autism spectrum tend to elope from their caretaker’s attention, a fact that can lead to serious problems. Thus, a system that takes into consideration of the multiple requirements is of paramount importance. In this paper, a LoRa based SAR system is proposed in order to help in the localization of people with high risk of going missing. In contrast to most of the related systems, in this research article a different approach has been followed. Instead of focusing on the technology, in our approach a human-centered design has been used, leveraging the knowledge of Human-Computer Interaction (HCI) domain. Thus, the technologies used, are an outcome of the initial study. Finally, the system is evaluated using heuristic evaluation and questionnaires.
... On the other hand, in natural disaster crises such as earthquakes, there is a need to supply blood to affected patients promptly [13,14]. Overall, a cut-point of 51 hours-less than 3 days-is suggested for the more than 2200 search and rescue processes studied [15]. This time is far less than a week shelf life suggested for the whole blood [16]. ...
... Calculate the value of using Equations (15) or (16) given ′ ...
The problem of blood delivery has been a critical concern in past decades. However, the unsteady behavior of blood donors, along with the uncertainties associated with demands in a crisis imposes several challenges for resource management. In this research work, we analyze the blood delivery behavior in a crisis modeled by coupled queues of patients and blood sources. Using Markovian modeling and results associated with G-network, we derive two critical probabilities, namely lack of unit of blood (unit of donations) or not having any storage capacity left to accept new donors' blood. We propose a closed-form solution to calculate the optimal blood storage size, and also we suggest sufficient conditions that guarantee the feasibility of the model. Finally, we conduct a sensitivity analysis to investigate the impact of model parameters on storage size and the proportion of time that storage is full.
... The ability for robots to effectively balance time against the thoroughness of search in strict time conditions is vital for providing timely assistance in many search and rescue applications [1,2]. For example, it is often desired to have robots quickly survey large areas in minimal time and then execute a refined search based on any information gathered. ...
... where v ≤ n, and L i are the bounds of the workspace W which we denote as the exploration space. 1 The map g then takes us from state space X to exploration space W. ...
... The ability for robots to effectively balance time against the thoroughness of search in strict time conditions is vital for providing timely assistance in many search and rescue applications [1,2]. For example, it is often desired to have robots quickly survey large areas in minimal time and then execute a refined search based on any information gathered. ...
... where v ≤ n, and L i are the bounds of the workspace W which we denote as the exploration space. 1 The map g then takes us from state space X to exploration space W. ...
Robots with the ability to balance time against the thoroughness of search have the potential to provide time-critical assistance in applications such as search and rescue. Current advances in ergodic coverage-based search methods have enabled robots to completely explore and search an area in a fixed amount of time. However, optimizing time against the quality of autonomous ergodic search has yet to be demonstrated. In this paper, we investigate solutions to the time-optimal ergodic search problem for fast and adaptive robotic search and exploration. We pose the problem as a minimum time problem with an ergodic inequality constraint whose upper bound regulates and balances the granularity of search against time. Solutions to the problem are presented analytically using Pontryagin's conditions of optimality and demonstrated numerically through a direct transcription optimization approach. We show the efficacy of the approach in generating time-optimal ergodic search trajectories in simulation and with drone experiments in a cluttered environment. Obstacle avoidance is shown to be readily integrated into our formulation, and we perform ablation studies that investigate parameter dependence on optimized time and trajectory sensitivity for search.
... Autonomous drones or unmanned aerial vehicles (UAVs) represent promising advantages over conventional humanintervened target detection methods due to their fast deployment, autonomous mobility capability, low cost, and easier reachability to the hard-to-reach areas. In a typical scenario, UAVs will be deployed in an area of interest, perform sensory operations to collect evidence of the presence of a target, and report their collected information to a remote ground station or a rescue team [1], [2]. ...
... (2) The UAV is deployed in a forest area in surveillance mode to detect a potential fire spot 1 . This scenario is referred to as the fire surveillance. ...
Utilizing autonomous drones or unmanned aerial vehicles (UAVs) has shown great advantages over preceding methods in support of urgent scenarios such as search and rescue (SAR) and wildfire detection. In these operations, search efficiency in terms of the amount of time spent to find the target is crucial since with the passing of time the survivability of the missing person decreases or wildfire management becomes more difficult with disastrous consequences. In this work, it is considered a scenario where a drone is intended to search and detect a missing person (e.g., a hiker or a mountaineer) or a potential fire spot in a given area. In order to obtain the shortest path to the target, a general framework is provided to model the problem of target detection when the target's location is probabilistically known. To this end, two algorithms are proposed: Path planning and target detection. The path planning algorithm is based on Bayesian inference and the target detection is accomplished by means of a residual neural network (ResNet) trained on the image dataset captured by the drone as well as existing pictures and datasets on the web. Through simulation and experiment, the proposed path planning algorithm is compared with two benchmark algorithms. It is shown that the proposed algorithm significantly decreases the average time of the mission.
... Injury risk is influenced by the composition of rural areas, with rural populations being relatively older, having a higher proportion of males, an increased proportion of Indigenous Australians, a different occupation profile, increased prevalence of chronic disease morbidity, and higher levels of a socio-economic disadvantage when compared to metropolitan populations [4]. Lack of access to medical services [5], unreliable telecommunications [6], and higher rates of risky alcohol consumption have also been highlighted as factors impacting the risk of injury in rural Australia [7]. ...
... From the 108 studies identifying injury risk factors, 26 (24.1%) showed risk factors relating to the increased burden of rural injury [6,25,26,28,29,43,48,51,75,79,88,92,112,122,130,134,139,140,153,154,156,158,160,164,171,177] ( Table S6). The increased morbidity, mortality, and burden of rural injury related directly to the severity of the incident, access to medical services, definitive care management received, and some demographical features (i.e., socio-economic disadvantage, private health insurance, being an Aboriginal and Torres Strait Islander person, etc.). ...
Rural populations experience injury-related mortality and morbidity rates 1.5 times greater than metropolitan residents. Motivated by a call for stronger epidemiological evidence around rural injuries to inform prevention, a systematic review of peer-reviewed literature published between January 2010 and March 2021 was undertaken to explore the epidemiology of rural injury and associated risk factors in Australia. A subsequent aim was to explore definitions of rurality used in injury prevention studies. There were 151 papers included in the review, utilizing 23 unique definitions to describe rurality. People living in rural areas were more likely to be injured, for injuries to be more severe, and for injuries to have greater resulting morbidity than people in metropolitan areas. The increase in severity reflects the mechanism of rural injury, with rural injury events more likely to involve a higher energy exchange. Risk-taking behavior and alcohol consumption were significant risk factors for rural injury, along with rural cluster demographics such as age, sex, high socio-economic disadvantage, and health-related comorbidities. As injury in rural populations is multifactorial and nonhomogeneous, a wide variety of evidence-based strategies are needed. This requires funding, political leadership for policy formation and development, and implementation of evidence-based prevention interventions.
... E Mergency situations that require Search And Rescue (SAR) operations have been increasing on a yearly basis [1]. These situations may happen due to natural or man-made [2] causes and require an immediate response, as time is a key element for the success of SAR operations [3]. Therefore, improving communication efficiency in SAR teams can be beneficial for the success of time-critical rescue operations. ...
... It is a broad term and has many sub-fields, usually depending on the search area, such as Mountain Rescue [33], Cave Rescue [34], Urban Search and Rescue (USAR) [35] and Wilderness Search and Rescue (WSAR) [36]. Regardless of the type of SAR, time is always a critical factor [3]. Thus, fast and efficient communication among SAR team members can be a deciding factor in whether or not the SAR team will succeed in saving people's lives. ...
Emotions can provide a natural communication modality to complement the existing multi-modal capabilities of social robots, such as text and speech, in many domains. We conducted three online studies with 112, 223, and 151 participants to investigate the benefits of using emotions as a communication modality for Search And Rescue (SAR) robots. In the first experiment, we investigated the feasibility of conveying information related to SAR situations through robots' emotions, resulting in mappings from SAR situations to emotions. The second study used Affect Control Theory as an alternative method for deriving such mappings. This method is more flexible, e.g. allows for such mappings to be adjusted for different emotion sets and different robots. In the third experiment, we created affective expressions for an appearance-constrained outdoor field research robot using LEDs as an expressive channel. Using these affective expressions in a variety of simulated SAR situations, we evaluated the effect of these expressions on participants' (adopting the role of rescue workers) situational awareness. Our results and proposed methodologies provide (a) insights on how emotions could help conveying messages in the context of SAR, and (b) evidence on the effectiveness of adding emotions as a communication modality in a (simulated) SAR communication context.
... All types of SAR operations have the following requirements in common: they must be addressed quickly and efficiently to prevent further injury or death because any delay can have direct, dramatic consequences for human life [4]. In many cases, rescue efforts are hampered by the simple inability to pinpoint the location of the lost person, which means that the first step of this process (locating the missing person) results in valuable time being wasted. ...
... As it is difficult to determine which β parameter is optimal, this stable growth contributes to the advantage of this algorithm because it shows its low dependence on the value of the β parameter (for each β parameter, the F score value is quite high). Furthermore, the advantage of this algorithm is in its simplicity of execution, because any further analysis of the detected objects and its environment is not required, thereby reducing execution time, which plays a crucial role in saving lives [4]. Thus, it can be concluded that the proposed algorithm RFCCD+DV is the most optimal for use in SAR operations. ...
Recent results in person detection using deep learning methods applied to aerial images gathered by Unmanned Aerial Vehicles (UAVs) have demonstrated the applicability of this approach in scenarios such as Search and Rescue (SAR) operations. In this paper, the continuation of our previous research is presented. The main goal is to further improve detection results, especially in terms of reducing the number of false positive detections and consequently increasing the precision value. We present a new approach that, as input to the multimodel neural network architecture, uses sequences of consecutive images instead of only one static image. Since successive images overlap, the same object of interest needs to be detected in more than one image. The correlation between successive images was calculated, and detected regions in one image were translated to other images based on the displacement vector. The assumption is that an object detected in more than one image has a higher probability of being a true positive detection because it is unlikely that the detection model will find the same false positive detections in multiple images. Based on this information, three different algorithms for rejecting detections and adding detections from one image to other images in the sequence are proposed. All of them achieved precision value about 80% which is increased by almost 20% compared to the current state-of-the-art methods.
... All these variables, when incorporated, influence team's performance intensity and their direction towards mission accomplishment. In addition, Adams, Schmidt, Newgard, Federiuk, Christie, Scorvo, and DeFreest (2007) stressed that it is essential for the team, especially the aid and recovery unit, to have an adequate time arrangement as it gives a significant impact on their performance. Hence, this research has included team time management in the framework to understand how it can impact the performance of the search and recovery team. ...
... Team time management plays a vital role in determining the victim's survival. Adams et al. (2007) found that the first 51 hours of the search time increase 1% of the probability for the victim to found alive. Hence, the team must act fast to reduce the loss of life. ...
Teamwork is a cooperative process that encourages personnel to achieve specific aims, whereby the members work together to achieve shared goals. The practice of teamwork is vital in any organization. One of many organizations that utilize teamwork is the Fire and Rescue Department of Malaysia (FRDM). FRDM'S most prominent activities involve Search and Rescue (SAR) teams. A SAR team refers to a group of individuals with the necessary skills and knowledge to find people in distress due to natural disasters or getting into difficulty in distress mountainous or desert regions. Several studies suggested that the SAR team's main issue is poor communication between the leader and members, leading to problems tracing accidents, team movements, and the incident location. There is still a lack of study focus on team performance, specifically in the SAR team context. Most of the previous scholars addressing team performance in military and business organizations. This study proposes to examine the relationship between team communication, team leadership, and team time management on the team performance of SAR teams. A total of 100 SAR team members from nine selected states in Peninsular Malaysia participated in this study. Data was collected using a set of questionnaires which were distributed to the SAR team of FRDM. The hypotheses were analyzed using Partial Least Squares (PLS) and the Statistical Package for the Social Sciences (SPSS). The results indicated a significant and positive relationship between communication, leadership, and time management towards team performance. This study would provide valuable inputs for the team, especially the search and rescue squad.
... The first hours of a rescue operation are widely recognized as the most critical [1]- [6]. Studies across thousands of Search and Rescue (SAR) missions have shown that survival rates drop exponentially during the first 18 hours after the onset of rescue efforts, and this rate reaches nearly zero percent after 20 hours [6]. ...
... The first hours of a rescue operation are widely recognized as the most critical [1]- [6]. Studies across thousands of Search and Rescue (SAR) missions have shown that survival rates drop exponentially during the first 18 hours after the onset of rescue efforts, and this rate reaches nearly zero percent after 20 hours [6]. Other guides and evidence have speculated that key time-frames are within the first 24-72 hours or less [2]- [5]. ...
... The goal of SAR operations is to maximise the likelihood of success as swiftly as possible using available resources. The decision to terminate SAR efforts, if a victim is not found timeously, or to change to a search and recovery operation should be made based on the probability of survival [6]. Abandoning search and rescue efforts as the likelihood of survival diminishes, may reduce the risk to rescuers and conserve resources [6]. ...
... The decision to terminate SAR efforts, if a victim is not found timeously, or to change to a search and recovery operation should be made based on the probability of survival [6]. Abandoning search and rescue efforts as the likelihood of survival diminishes, may reduce the risk to rescuers and conserve resources [6]. ...
Background:
Injuries remain a major contributor of morbidity and mortality worldwide, with drowning accounting for 7% of all injury-related deaths with rates of between 4 and 8 per 100,000. The African region has death rates comparable to most low-income countries. Non-fatal drowning in Africa remains unquantified but it is estimated to be ten times higher than the fatal drowning rate. Timely search and rescue, initial resuscitation and rapid transportation to definitive care play a crucial role in preventing injury- related morbidity and mortality. The National Sea Rescue Institute (NSRI) of South Africa is a non-profit organisation responsible for ~97% of maritime search and rescue operations in South Africa (including inland navigable waters). The aim of the study was to describe the epidemiology of operations performed by the NSRI of South Africa over a 5-year period.
Materials and methods:
The NSRI operational database was analysed from 1 January 2010 to 31 December 2014. Summary statistics are presented.
Results:
The NSRI launched 3281 operations over the study period. Marked seasonal variation were noticeable with peak periods in December and January, corresponding to the South African summer holiday season. Water-based operations (67.6%) were the most frequent operation performed. The NSRI assisted 3399 individuals of which 77% were male. The mean age of rescued persons was 42 years. Eight hundred and thirty-six (25%) individuals had non-fatal injuries or illnesses requiring medical assistance. Medical emergencies (35%), traumatic injuries (32.8%), and non-fatal drownings (23%) were the most common types of injury and illness. The majority of the 184 (18%) deaths recorded were due to drowning (75%).
Conclusions:
Injury and illness, specifically drowning utilise a large proportion of search and rescue services. The results suggest further preventative measures and public health strategies be implemented to minimise traumatic and medical incident severity and subsequent casualties at sea.
... In Australia, volunteer search and rescue teams within the State Emergency Services (SES) during a recent calendar year have dedicated more than 50,000 hours to performing search and rescue operations (ACSES 2012). In addition to technical and skill proficiencies, and necessary qualifications, personnel operating in search and rescue must demonstrate a minimal physical competency, since job tasks are physically arduous and stressful (Adams et al. 2007;Hung et al. 2007). Identifying and characterising the physical job demands of search and rescue roles establishes a platform on which organizations can screen personnel on their physical capacity to meet job demands, which can help improve the health and safety of the workforce. ...
... Few studies have documented the physical demands of search and rescue operations, however, some insights can be gleaned from the small pool of available literature. Search teams are often required to cover large distances and traverse challenging terrain for durations of 8-12 hours in a typical search day (Denver et al. 2007;Adams et al. 2007;Hung et al. 2007), highlighting the need for a high level of cardiovascular fitness. Upon location of a person, task performance is then seemingly dependent on a workers' muscular strength and strength endurance capacity, since stretcher carries are typical amongst the majority of rescues (Richmond et al. 2003). ...
Search and rescue operations are necessary in locating, assisting and recovering individuals lost or in distress. In Australia, land-based search and rescue roles require a range of physically demanding tasks undertaken in dynamic and challenging environments. The aim of the current research was to identify and characterise the physically demanding tasks inherent to search and rescue operation personnel within Australia. These aims were met through a subjective job task analysis approach. In total, 11 criterion tasks were identified by personnel. These tasks were the most physically demanding, frequently occurring and operationally important tasks to these specialist roles. Muscular strength was the dominant fitness component for seven of the 11 tasks. In addition to the discrete criterion tasks, an operational scenario, was established. With the tasks and operational scenario identified, objective task analysis procedures can be undertaken so that practitioners can implement evidence-based strategies, such as physical selection procedures and task-based physical training programs, commensurate with the physical demands of search and rescue job roles.
Practitioner Summary
The identification of physically demanding tasks amongst specialist emergency service roles predicates health and safety strategies which can be incorporated into organizations. Knowledge of physical task parameters allows employers to mitigate injury risk through the implementation of strategies modelled on the precise physical demands of the role.
... When a person is missing outside of a city, or in a wilderness area, SAR personnel face the task of locating them. This challenge involves limited resources and the possibility of a long search period, which can reduce the survival chances of the missing person [6]. The most common method for locating a missing individual is to create probability maps depicting potential locations. ...
Every year, hundreds of people go missing in the wilderness of Saudi Arabia. There is an urgent need to examine modern geographic techniques for finding such people. Geographical information systems, for example, play a crucial role in wilderness search and rescue (WiSAR), not only in mapping probability areas but also in applying further analysis and modeling methods to reduce time and effort and to guide life-saving task forces in the right direction. In this study of a hypothetical missing-person case in Saudi Arabia, two standard WiSAR models are compared: ring and mobility. In the presented study situation, both models can be used. However, the new approach used in the mobility model drastically reduces the extent of the possible search area, from 101,787 km² in the ring model to 335.34 km of likely trails and unpaved roads, and also provides exact directions to where the missing person may be found.
... Search and Rescue operations operate under the assumption, that the longer it takes to find lost people, the less likely their survival is [1], [2]. This emphasises the need for fast exploration in unknown environments. ...
Multi-robot exploration is a field which tackles the challenge of exploring a previously unknown environment with a number of robots. This is especially relevant for search and rescue operations where time is essential. Current state of the art approaches are able to explore a given environment with a large number of robots by assigning them to frontiers. However, this assignment generally favors large frontiers and hence omits potentially valuable medium-sized frontiers. In this paper we showcase a novel multi-robot exploration algorithm, which improves and adapts the existing approaches. Through the addition of information gain based ranking we improve the exploration time for closed urban environments while maintaining similar exploration performance compared to the state-of-the-art for open environments. Accompanying this paper, we further publish our research code in order to lower the barrier to entry for further multi-robot exploration research. We evaluate the performance in three simulated scenarios, two urban and one open scenario, where our algorithm outperforms the state of the art by 5\% overall.
... In contrast, other critical missing cases usually occur outside urban areas in the wilderness (WiSAR Cases) and involve hikers, riders, tourists, etc. (Heth & Cornell, 1998;Koster, 2008) When a person is missing outside of a city, search and rescue personnel in the wilderness, confront the task of locating them. This challenge must consider limited resources and a long search period, which can reduce a person's chances of surviving (Adams et al., 2007). The most common method for locating a missing individual is to create probability maps depicting potential locations. ...
Every year, hundreds of people go missing in the wilderness of Saudi Arabia. There is an immediate need to examine modern geographic techniques for finding these people. Geographical information systems (GIS), for example, play a crucial role in WiSAR, not only in mapping probability areas but also in applying further analysis and modeling methods to reduce time and effort and guide life-saving task forces in the right direction. In a hypothetical case study conducted in Saudi Arabia, this study compares two standard WiSAR models, ring and mobility. In these situations, both models can be used. However, the new approach in the mobility model drastically reduces the possible search areas, from 101,787 km2 in the ring model to 335.34 km of likely trails and unpaved roads, and gives exact directions to where a missing person may be.
... For instance, during winter and mountain operations, SAR personnel can carry packs weighing approximately 30 kg and may carry them for up to 10 hours (45). Furthermore, the ability to perform and complete these tasks is often time-critical (2), and personnel need to be physically and cognitively capable of treating a patient on arrival. ...
Search and rescue (SAR) personnel may be required to wear and carry external loads during a task. These external loads may be carried in austere environments across unpredictable terrain. Like other tactical occupations (military, law enforcement, fire, and rescue), SAR loads can range from 20 to 45 kg. Not only are these loads known to cause a variety of injuries to the musculoskeletal, integumentary, and neurological systems of the carrier, but these loads are also known to impede task performance and have ultimately led to mission failure. Ensuring personnel are physically capable of carrying external loads on tasks is critical to mitigating these potential risks of injury and performance decrements. Optimal load carriage conditioning, following the known frequency, intensity, time, and type of training formula would see SAR personnel conduct a load carriage specific session every 7 to 14 days, with load weights, walking speeds, and durations akin to those typical of their SAR requirements. The terrain types (inclusive of grade and nature of terrain) should likewise form part of this conditioning process. In addition to load carriage-specific sessions, improving strength (notably relative strength) and aerobic fitness should also optimize the load carriage conditioning of SAR personnel.
... These difficulties should not be overlooked. WiSAR operations often have limited resources, and past two days, or about fifty hours of search, the lost person's chances of survival decrease significantly (Adams et al, 2007). ...
... Moreover, given the changes caused by global warming, the number of disasters, their severity, and complexity have gradually increased over the last years [3]. Thereby, if such a disaster occurs, the first 51 hours are crucial for rescue teams [1], however, the unstructured environment of disaster sites makes it often difficult to work quickly, efficiently, and -in particular -safely. ...
... task allocation in the first few hours of the search can make a significant difference to the success of the search. As time progresses, the survivability of the lost person decreases rapidly, especially so if the LP is not found within the first 51 hours; in other words, effective planning can mean life or death 10 . Thus, the quality of the predicted locations of the LP is critical to search operations. ...
Thousands of people are reported lost in the wilderness in the United States every year and locating these missing individuals as rapidly as possible depends on coordinated search and rescue (SAR) operations. As time passes, the search area grows, survival rate decreases, and searchers are faced with an increasingly daunting task of searching large areas in a short amount of time. To optimize the search process, mathematical models of lost person behavior with respect to landscape can be used in conjunction with current SAR practices. In this paper, we introduce an agent-based model of lost person behavior which allows agents to move on known landscapes with behavior defined as independent realizations of a random variable. The behavior random variable selects from a distribution of six known lost person reorientation strategies to simulate the agent’s trajectory. We systematically simulate a range of possible behavior distributions and find a best-fit behavioral profile for a hiker with the International Search and Rescue Incident Database. We validate these results with a leave-one-out analysis. This work represents the first time-discrete model of lost person dynamics validated with data from real SAR incidents and has the potential to improve current methods for wilderness SAR.
... For different foraging problems, the desired t e (n, N ) may differ. Consider a search and rescue mission as an example, in which t e (n, N ) may be determined by how long a missing person can stay alive [2]. To save as many as possible, it is important to determine the appropriate N to minimize t e (n, N ) without having to run a large number of experiments. ...
The exploration time for a swarm of robots doing object gathering depends on the specific task, environment, number of objects, and number of robots. Hence, it is important to understand how different properties affect the exploration time. To address this practical challenge, we present a theoretical analysis of the expected exploration time for a swarm of robots that are searching for objects in an arena and present experimental results obtained with different swarm sizes. The experimental results are consistent with the theoretical analysis.KeywordsSwarm roboticsForagingExploration time estimate
... • Manage resources (ensure autonomy: eat/drink/rest, charge batteries, refuel, etc.) Of all the influencing factors, time is arguably the most important in deciding whether SAR operations turn out successful or not (Adams et al. 2007). In fact, according to the aforementioned study, the probability of finding survivors decreases exponentially as time passes, and drops to nearly 0% after only 24 hours. ...
In an attempt to solve search-and-rescue problematics such as rescue time and difficulty in accessing certain search areas, a cognitive swarm of drones system is proposed, using artificial intelligence techniques interacting with cognitive components.
The system’s various elements (drones’ cognition, pathfinding, policies, but also humans-swarm interactions) are elaborated, implemented and evaluated using a simulator custom-built for this dissertation.
Evaluation outcomes show that cognitive functions can be beneficial to non- cognitive drone components, and vice versa. Possible improvements are discussed.
... The fundamental role of time in search and rescue activities was highlighted by Adams et al. [49], who emphasized it in their work: "Search is a time-critical event: when search and rescue missions may become futile". Although they did not only focus on Alzheimer's disease patients, but conducted a much wider study, their Kaplan-Meier estimator predicted the survival status as a function of search time, and determined the cut-off point of 51 h (in accordance with Koester and Stooksbury [48], mortality among Alzheimer's disease patients grows to 62% if a person remains un-found for longer than 48 h). ...
Recent advances in search and rescue methods include the use of unmanned aerial vehicles (UAVs), to carry out aerial monitoring of terrains to spot lost individuals. To date, such searches have been conducted by human observers who view UAV-acquired videos or images. Alternatively, lost persons may be detected by automated algorithms. Although some algorithms are implemented in software to support search and rescue activities, no successful rescue case using automated human detectors has been reported on thus far in the scientific literature. This paper presents a report from a search and rescue mission carried out by Bieszczady Mountain Rescue Service near the village of Cergowa in SE Poland, where a 65-year-old man was rescued after being detected via use of SARUAV software. This software uses convolutional neural networks to automatically locate people in close-range nadir aerial images. The missing man, who suffered from Alzheimer’s disease (as well as a stroke the previous day) spent more than 24 h in open terrain. SARUAV software was allocated to support the search, and its task was to process 782 nadir and near-nadir JPG images collected during four photogrammetric flights. After 4 h 31 min of the analysis, the system successfully detected the missing person and provided his coordinates (uploading 121 photos from a flight over a lost person; image processing and verification of hits lasted 5 min 48 s). The presented case study proves that the use of an UAV assisted by SARUAV software may quicken the search mission.
... Therefore, researchers proposed new approaches for search and rescue missions in outdoor environments, based on the RF source's signals, as introduced in [5,6]. In such cases, time is critical, and S&R missions may become worthless and futile [7]. ...
Due to its low implementation cost, the combination of the Received Signal Strength (RSS) with the Angle of Arrival (AOA) measurements is one of the solutions for Radio Frequency (RF) source localization, especially in a Non-Line of Sight (NLOS) environment. It is critical to determine the search space for a person who is lost in rural areas where the mobile network is unavailable due to a lack of Base Tower Stations (BTS) in order to reduce search time. In this paper, we introduce a new beacon-based approach for RF source localization, where the RF signal is received in NLOS after 1-bounce reflection, by combining the information coming from both the RSS-AOA sensors and the beacons, which are used as helpers- that move along a determined path. The proposed approach relies on determining the reflector’s pose first, after which the RF source is localized. The work has been verified in simulation and the Root Mean Square Error (RMSE) is used as a performance metric for RF source localization. Results show that our proposed approach has the lowest RMSE among localization methods mentioned in the literature under the same conditions. HIGHLIGHTS A new beacon-based approach for RF source localization in Non-Line Of Sight (NLOS) condition A reflector’s pose is determined based on the signal received from beacons The reflector’s pose is used to determine the location of the RF source One bounce reflection is considered since the chance of receiving RF signal with more reflections is very low GRAPHICAL ABSTRACT
... Moreover, people who are lost in the wilderness might sustain a state of disorientation for as long as it takes until they get rescued, whether it be several hours or several days. The only thing that makes spatial disorientation episodic rather than sustained is that we tend to solve spatial disorientation swiftly, 3 because the costs of not solving it can be extremely severe (Adams et al., 2007). The difference between episodic and sustained states is not a difference between spatial and non-spatial forms of disorientation. ...
One of the chief features of this global crisis is that we find ourselves in a shifting landscape. The resulting disorientation extends beyond health research and into many domains of our individual and collective lives. We suffer from political disorientation (the need for a radical shift in economic thinking), from social disorientation (the rearrangement of social dynamics based on distancing measures), and from temporal disorientation (the warping of our sense of time during lockdown), to name but a few. This generalised state of disorientation has substantial effects on wellbeing and decision making. In this paper, we review the multiple dimensions of disorientation of the COVID-19 crisis and use state-of-the art research on disorientation to gain insight into the social, psychological and political dynamics of the current pandemic. Just like standard, spatial cases of disorientation, the non-spatial forms of disorientation prevalent in the current crisis consist in the mismatch between our frames of reference and our immediate experience, and they result in anxiety, helplessness and isolation, but also in the possibility of re-orienting. The current crisis provides a unique environment in which to study non-spatial forms of disorientation. In turn, existing knowledge about spatial disorientation can shed light on the shifting landscape of the COVID-19 pandemic.
Key messages
Growing evidence suggests that the COVID-19 crisis has been disorienting across domains.
Disorientation is a metacognitive feeling monitoring both spatial and non-spatial tasks.
Temporal disorientation was fostered by the pandemic’s counterintuitive temporality.
Disorientation mitigation can facilitate new social and political frames of reference to emerge. </ul
... In such scenarios, the survival time under the snow of the casualties is approximately calculated not to exceed 20 minutes [66], so the ground crew has a very short time in tracking victims. Consequently, mission response time in ASR operations is highly considered for optimization to help rescuing victims' lives [67]. 1. Network Performance: e.g., packet delay, packet loss ratio [70], and throughput [71]. ...
In the last few decades, Information and Communication Technology (ICT) has been introduced which aims to bring more comfort to human life by integrating smartness into daily objects, yields to the idea of the smart city. Guaranteeing the well-being of residents and assessing industry and urban planning from an ecological and sustainable perspective are the main goals for the smart city. Great potentials are brought to the public and civil areas by the Aerial Ad Hoc Network (AANET) concept, especially in applications that are risky to human lives. AANET, like any emerging technology, comes with many challenges that have to be overcome to be employed efficiently. In this paper, we make a detailed survey on current literature, standards, and projects of self-organizing AANET in smart cities. Also, we intend to present a profound knowledge of this active research area by identifying features, design characteristics, architectures, routing protocols, and security aspects for the design and implementation of self-organizing AANET. Furthermore, we discuss existing solutions, indicate assessment metrics along with current applications, finally we highlight the main research scope for further developments. This article surveys the work done toward AANET-related outstanding issues, intending to encourage further research in this field.
... 4 The rural population is relatively older, has a higher percentage of males, higher Aboriginal and Torres Strait Islander populations, increased prevalence of chronic disease morbidity and higher levels of socio-economic disadvantage when compared to major cities, all factors which contribute to increased injury risk. 4 Lack of access to major services, including medical care 5 and telecommunications, 6 and higher rates of risky alcohol consumption are also factors impacting the risk of an injury. 7 Like other injury mechanisms, rural populations also experience higher rates of drowning, which are positively correlated as rurality increases. ...
Objective: To examine unintentional drowning by remoteness in Australia.
Design: A systematic review of both peer‐reviewed and grey literature published between January 1990 and December 2019 (inclusive).
Method: Using Preferred Reporting Items for Systematic Reviews and Meta‐Analysis guidelines, MEDLINE (Ovid), PubMed, EMBASE, Scopus, PsycINFO (ProQuest), SPORTDiscus and Google Scholar were searched for studies exploring fatal and non‐fatal unintentional drowning by remoteness. Epidemiological data, common factors and prevention strategies were extracted and mapped to Australian standard geographical classifications (major cities, inner regional, outer regional, remote and very remote). Level of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation and prevention strategies aligned to the hierarchy of control.
Result: Thirty‐two studies satisfied inclusion criteria (66% reporting epidemiology; 59% risk factors; and 44% prevention strategies). All (100%) included studies were assessed very low against Grading of Recommendations Assessment, Development and Evaluation. Findings indicate rural populations (ie, excluding major cities) have higher rates of drowning positively correlated with increasing remoteness. Common factors included age (child), natural water bodies, undertaking boating and watercraft activities and alcohol consumption. While a range of prevention strategies has been proposed, only one study outlined a rural drowning prevention strategy which had been implemented and evaluated. Strategies were generally low on the hierarchy of control.
Conclusion: Rural populations are proportionately over represented in drowning statistics. Proposed prevention strategies have unknown efficacy. Greater research into rural drowning of Australians is needed especially exploring behavioural motivations, program delivery, cost‐effectiveness and evaluation. Development and use of a standard definition for remoteness are recommended. Rural populations use water extensively; therefore, there is an urgent need to keep them safe.
... Generally, SAR operations are conducted over large areas. As survival chances are negatively correlated with time to detection [1], finding people in need of rescue needs to happen as fast as possible. ...
Search and rescue (SAR) is a vital line of defense against unnecessary loss of life. However, in a potentially hazardous environment, it is important to balance the risks associated with SAR action. Drones have the potential to help with the efficiency, success rate and safety of SAR operations as they can cover large or hard to access areas quickly. The addition of thermal cameras to the drones provides the potential for automated and reliable detection of people in need of rescue. We performed a pilot study with a thermal-equipped drone for SAR applications in Morecambe Bay. In a variety of realistic SAR scenarios, we found that we could detect humans who would be in need of rescue, both by the naked eye and by a simple automated method. We explore the current advantages and limitations of thermal drone systems, and outline the future path to a useful system for deployment in real-life SAR.
... Recent statistical studies show that the survival rate, for example, of trapped victims in collapsing buildings, falls within 72 hours of the disaster (Tomotani, 2015). In non-urban SAR operations, if a person is not found within 51 hours of being lost, his chances of survival are significantly reduced ( Adams et al., 2007). This time period is even shorter (24 hours) for patients with Alzheimer's disease (Koester & Stooksbury, 1995). ...
The technology of small unmanned aerial vehicles, also known as UAVs, are currently on the up rise. This research wants to evaluate if the capabilities of UAVs could be exploited to provide valuable contributions in search and rescue efforts-and if so-what challenges would arise. The research will serve as a suggestion for what benefits the UAV platform can provide, as well as considering the challenges for implementation. Through a thorough literature review, state-of-the-art for search and rescue, UAV platforms and sensor technology is investigated to establish a theoretical frame of reference. This framework is the foundation for evaluating how to improve the current search and rescue efforts, what capabilities current UAV and sensor technology has, and how to best apply UAVs to satisfy the needs of a rescue. The subject of UAVs in search and rescue is still in its initial stages, and the amount of research and knowledge is therefore limited. The main challenges identified and discussed in this research is under the categories of adverse meteorological conditions and technological challenges. There were also identified some challenges regarding compliance to regulations and in relation to human and organization, however these were less precarious for the implementation. Furthermore, it was established that UAVs are not yet capable of replacing manned aircrafts, but could still be a unique and valuable asset to a rescue operation. There were identified some hazards due to implementation of UAVs, none of which were believed to pose and excessive risk, especially when considering the expected benefit for the rescuers.
... These difficulties should not be overlooked. WiSAR operations often have limited resources, and past 2 days, or about 50 h of search, the lost person's chances of survival decrease significantly (Adams et al. 2007). ...
Nowadays, Wilderness Search and Rescue (WiSAR) operations revolve around the creation of probability maps using GIS planning tools (Doherty et al, Appl Geogr 47:99–110, 2014). Although this method has proven effective, there is a missing link between WiSAR theory and advances in other fields related to disorientation (e.g. psychology and neuroscience). A unified conceptualisation of disorientation is a crucial element for understanding the mind and behaviour of disoriented subjects. The central aim of this chapter is to explore how a unified conceptualisation of disorientation can contribute to GIS-informed WiSAR theory. The paper will open with a review of the work on disorientation coming from different fields, to then introduce the conceptual work that is needed for a unified account of disorientation. We will discuss two different approaches to WiSAR theory: a ring model and a Bayesian model. We end on a discussion on how conceptual work on disorientation and GIS-informed WiSAR theory can help each other advance.
... To support successful applicability of UAVs, there are time sensitive issues in the system with UAVs including minimizing total movement distance of UAVs, minimizing maximum distance of UAVs, minimizing mission completion time by UAVs, etc [9]. In particular, the system with multiple small-sized UAVs should be considered carefully to handle those time critical issues because the small-sized UAV has a limited flight time [10], [11] and those limitations may affect the performance of the whole UAV system. ...
Thanks to recent enormous advance of mobile and vehicular technology, it is highly expected that Unmanned Aerial Vehicles (UAVs) are used for various applications in smart cities as well as the number of flying UAVs in the sky is increasing explosively. However, such a proliferation of UAVs accompanies additional critical issues to be considered for efficient, secure use of UAVs. One of important issues should be a privacy of people. When the UAVs fly to perform specific objectives, minimizing movements of UAVs is an important issue to minimize mission completion time and to maximize the network lifetime of UAVs. To do so, one intuitive solution is that UAVs may pass through private area of citizens whereas people do not want any penetration into own area without a permission. For those situations, we may take into account a compromise so that people can decide whether they give a differential, temporal permission for each UAV to access their areas depending on specific benefits by use of UAVs or emergent situation for public safety. In this study, we introduce a framework for privacy preserving movements of UAVs with differential UAVs' permissions given by citizens, which is called as UDiPP (UAVs' Differential Privacy Preserving movements). Then, using ILP, we formally define a problem whose objective is to minimize total movements of UAVs with preserving privacy of citizens. To solve the problem, we propose a novel approach with a creation of UDiPP graph and then evaluate its performance through extensive simulations.
... According to analyses of the 2011 Tōhoku tsunami in Japan, the first 24 h was the most critical (Editorial Office of the Ishinomaki Kahoku 2014). Studies across more than 1000 SAR missions show a survival rate dropping exponentially during the first 18 h after the onset of SAR efforts, dropping to a survival rate that levels off near 0% after 20 h (Adams et al. 2007). ...
Abstract A swarm of autonomous flying robots is implemented in simulation to cooperatively gather situational awareness data during the first few hours after a major natural disaster. In computer simulations, the swarm is successful in locating over 90% of survivors in less than an hour. The swarm is controlled by new sets of reactive behaviors which are presented and evaluated. The reactive behaviors integrate collision avoidance, battery recharge, formation control, altitude maintenance, and a variety of search methods to optimize the coverage area of camera and heart-beat locator sensors mounted on the robots. The behaviors are implemented in simulation on swarms of sizes from 1 to 20 robots. The simulation uses actual location data, including post-disaster satellite imagery, real locations of damaged and inundated buildings, and realistic victim locations based on personal interviews and accounts. The results demonstrate the value of using behavior-based swarming algorithms to control autonomous unmanned aerial vehicles for post-disaster search and assessment. Three examples of algorithms that have been effective in simulation are presented.
... Yet another similarity between our findings and conclusions drawn by Goodrich et al. (2009) is the partial success of UAV-assisted field search. Since search time is a key factor that controls survival (Adams et al., 2007), both F I G U R E 8 SARUAV report for image IMG_8894.JPG (Krobica) F I G U R E 9 SARUAV report for image IMG_8901.JPG (Krobica) field experiments measured time until a person was found. Although Goodrich et al. (2009) worked with time span beginning at the moment of UAV launch and we measured the time differently-that is, in two ways: (1) between reporting a missing person and finding the lost individual or (2) between disseminating the SARUAV report to ground searchers and finding a lost person-both the experiment confirmed that it was possible to find the persons within a few hours. ...
This paper reports on the performance of a novel system for supporting search and rescue activities, known as SARUAV (search and rescue unmanned aerial vehicle), in a field experiment during which a real-world search scenario was simulated. The experiment took place on March 2–3, 2017, at two sites located in southwestern Poland. Three groups acted in the experiment: (1) SARUAV and unmanned aerial vehicle (UAV) operators, (2) ground searchers, and (3) participants who simulated being lost. In the uncomplicated topography without snow cover, the system identified the lost persons, and ground searchers found them 31 min after the SARUAV report had been disseminated. In the mountainous area covered with snow, one person was found within 9 min after searchers received the SARUAV report; however, the other two persons were not identified by SARUAV. The field experiment served as a proof of concept of the SARUAV system, confirmed its potential in person identification studies, and helped to identify numerous scientific and technical problems that need to be solved to develop a mature version of the system.
... Search and rescue operation (SAR) is time critical -only a small window of opportunity exists to search out and rescue the disaster victims who are trapped [1]. Currently only a few rescue teams have access to specialized rescue robots that are durable and resilient to hazardous environments available in such disaster sites e.g. ...
Mission criticality in disaster search and rescue robotics highlights the requirement of specialized equipment. Specialized manipulators that can be mounted on existing mobile platforms can improve rescue process. However specialized manipulators capable of lifting heavy loads are not yet available. Moreover, effect of joint friction in these manipulators requires further analysis. To address these issues, concepts of model based design and concurrent engineering are applied to develop a virtual prototype of the manipulator mechanism. Closed loop manipulator mechanism actuated by prismatic actuators is proposed herein. The mechanics model of the manipulator is presented here as a set of equations and as multibody models. Mechanistic simulation of the virtual prototype has been conducted and the results are presented. Combined friction model that comprises Coulomb, viscous and Stribeck friction is used to compute frictional forces and torques generated at each one degree of freedom translational and rotational joints. Multidisciplinary approach employed in this work improves product design cycle time for complex mechanisms. Kinematic and dynamic parameters are presented in this paper. Friction forces and torques from simulation are also presented in addition to the visual representation of the virtual prototype.
... 3,13 Remotely piloted aerial systems, which are nowadays commonly used by geoscientists, become powerful tools for supporting medical activities in a sense that they may reduce search time. Since the time remains a critical issue in SAR missions, 14,15 the use of popular UAVs in a near real-time fashion may have a significant impact on a probability of surviving. Indeed, survival time -which is controlled by many factors such as air temperature, wind and clothing 16,17 -may drop below 24 h if a worn lost person is exposed to low temperatures (less than -20˚C). ...
A new method, named as the nested k-means, for detecting a person captured in aerial images acquired by an unmanned aerial vehicle (UAV), is presented. The nested k-means method is used in a newly built system that supports search and rescue (SAR) activities through processing of aerial photographs taken in visible light spectra (red-green-blue channels, RGB). First, the k-means classification is utilized to identify clusters of colors in a three-dimensional space (RGB). Second, the k-means method is used to verify if the automatically selected class of colors is concurrently spatially clustered in a two-dimensional space (easting-northing, EN), and has human-size area. The UAV images were acquired during the field campaign carried out in the Izerskie Mountains (SW Poland). The experiment aimed to observe several persons using an RGB camera, in spring and winter, during various periods of day, in uncovered terrain and sparse forest. It was found that the nested k-means method has a considerable potential for detecting a person lost in the wilderness and allows to reduce area to be searched to 4.4 and 7.3% in spring and winter, respectively. In winter, land cover influences the performance of the nested k-means method, with better skills in sparse forest than in the uncovered terrain. In spring, such a relationship does not hold. The nested k-means method may provide the SAR teams with a tool for near real-time detection of a person and, as a consequence, to reduce search area to approximately 0.5–7.3% of total terrain to be visited, depending on season and land cover.
... Intensity and duration of the recorded heat signatures lead to the idea of using them as a source of heat and radiation for locating insect infested human remains days or even weeks post-mortem. However, this topic has been virtually unstudied so far [15,16]. Only one publication [16] covers this topic and showed that pigs infested by insects can be detected by TI up to distances of ca. ...
One of the most common techniques applied for searching living and even dead persons is the FLIR (Forward Looking Infrared) system fixed on an aircraft like e.g. a helicopter, visualizing the thermal patterns emitted from objects in the long-infrared spectrum. However, as body temperature cools down to ambient values within approximately 24 h after death, it is common sense that searching for deceased persons can be just applied the first day post-mortem. We postulated that the insect larval masses on a decomposing body generate a heat which can be considerably higher than ambient temperatures for a period of several weeks and that such heat signatures might be used for locating insect infested human remains.
We examined the thermal history of two 70 and 90 kg heavy pig cadavers for 21 days in May and June 2014 in Germany. Adult and immature insects on the carcasses were sampled daily. Temperatures were measured on and inside the cadavers, in selected maggot masses and at the surroundings. Thermal imaging from a helicopter using the FLIR system was performed at three different altitudes up to 1500 ft. during seven day-flights and one night-flight.
Insect colonization was dominated by blow flies (Diptera: Calliphoridae) which occurred almost immediately after placement of the cadavers. Larvae were noted first on day 2 and infestation of both cadavers was enormous with several thousand larvae each. After day 14 a first wave of post-feeding larvae left the carcasses for pupation. Body temperature of both cadavers ranged between 15 °C and 35 °C during the first two weeks of the experiment, while body surface temperatures peaked at about 45 °C. Maggot masses temperatures reached values up to almost 25 °C above ambient temperature. Detection of both cadavers by thermal imaging was possible on seven of the eight helicopter flights until day 21.
Introduction:
There is no published information on the epidemiology of wilderness rescues in California outside of national parks. The objective of this study was to investigate the epidemiology of wilderness search and rescue (SAR) missions in California and identify risk factors for individuals requiring rescue due to accidental injury, illness, or navigation errors in the California wilderness.
Methods:
A retrospective review of SAR missions in California from 2018 to 2020 was conducted. This was done from a database of information collected by the California Office of Emergency Services and the Mountain Rescue Association from SAR teams, who submitted voluntarily. The subject demographics, activity, location, and outcomes of each mission were analyzed.
Results:
Eighty percent of the initial data were excluded because of incomplete or inaccurate data. Seven hundred forty-eight SAR missions involving 952 subjects were included in the study. The demographics, activities, and injuries of our population were consistent with those reported from other epidemiological SAR studies, and there were significant differences in outcomes based on the subject's activity. For example, water activities were highly correlated with a fatal outcome.
Conclusions:
The final data show interesting trends, but it is difficult to draw firm conclusions because so much of the initial data had to be excluded. A uniform system for reporting SAR missions in California may be helpful for further research, which may aid both SAR teams and the recreational public in understanding risk factors. A proposed SAR form for easy entry is included in the discussion section.
Emotions can provide a natural communication modality to complement the existing multi-modal capabilities of social robots, such as text and speech, in many domains. We conducted three online studies with 112, 223, and 151 participants, respectively, to investigate the benefits of using emotions as a communication modality for Search And Rescue (SAR) robots. In the first experiment, we investigated the feasibility of conveying information related to SAR situations through robots' emotions, resulting in mappings from SAR situations to emotions. The second study used Affect Control Theory as an alternative method for deriving such mappings. This method is more flexible, e.g. allows for such mappings to be adjusted for different emotion sets and different robots. In the third experiment, we created affective expressions for an appearance-constrained outdoor field research robot using LEDs as an expressive channel. Using these affective expressions in a variety of simulated SAR situations, we evaluated the effect of these expressions on participants' (in the role rescue workers) situational awareness. Our results and proposed methodologies (a) provide insights on how emotions could help conveying messages in the context of SAR, and (b) show evidence on the effectiveness of adding emotions as a communication modality in a (simulated) SAR communication context.
Objectives:
Older people are vulnerable to becoming lost from home, especially if alone and in unfamiliar environments. Incidents of older persons becoming lost are frequently reported and often requiring a search and rescue (SAR) response. Becoming lost is distressing to the person concerned, their carer, and family and may result in physical injury and/or death. This study examined what factors are associated with death among older persons reported lost from home.
Methods/design:
A retrospective cross-sectional study. Data were obtained from the International Search and Rescue Incident Database from 1985 to 2013. Participants comprised persons aged 65 years and older living in the United States. Individual, SAR incident, and environmental factors were analysed. The primary outcome of this study was lost person found alive or found dead on arrival. Relationships between categorical variables and outcome were summarised with contingency tables, chi-squared test p-values (or Fisher's-exact-test), and odds ratios (OR) with 95% confidence intervals (CI). Association between continuous variables and outcome were examined using multiple logistic regression. p-value of <0.05 was considered significant.
Results:
Among the 5242 SAR incidents, 1703 met the inclusion criteria, of which 87.8% (n = 1495) were found alive and 12.2% (n = 208) were found dead. Factors associated with death included: male gender (OR 1.46; CI 1.01-2.13; p = 0.048), cognitively intact (OR 0.32; CI 0.22-0.47; p < 0.001), prolonged SAR duration (OR: 1.028; CI: 1.021-1.035; p < 0.001), found in water/wetlands (OR 7.40; CI 3.37-16.24; p < 0.001), and extreme weather (OR: 2.06; 95% CI: 1.10-3.86; p = 0.024).
Conclusions:
Older people have a fundamental human right to protection from preventable deaths. Findings indicate these rights are not being protected with deaths occurring frequently among older people who have become lost from home. To minimise fatalities, knowledge of factors associated with death could inform the development suitable assessment and intervention strategies for SAR teams and caregivers.
This work continues a line of research examining the relationship between drone sensor swarm characteristics and performance of the swarm as a holistic system. A swarm of autonomous Unmanned Aerial Vehicles (UAVs) was implemented in simulation to cooperatively perform a Wide Area Search for survivors in a post-disaster scenario. The sensor swarm was controlled through a behavior-based artificially intelligent paradigm whereby each UAV executes one of three sets of simple, uncoupled search behaviors - Social Searcher, Antisocial Searcher, Relay. The relationship between proportions of these behavior sets and time to find 90% of survivors was examined in swarms of 10–50 UAVs. 100 different swarm size and role distributions were generated using Design and Analysis of Computer Experiments (DACE) methodology. 1000 (100 swarm size x 10 replications) simulation runs revealed an effective distribution pattern which drones could follow to automatically reallocate roles based on current swarm size. Simulations also revealed multiple configurations of role distributions at various swarm sizes that could consistently locate over 90% of survivors in under 20 minutes.
Unmanned Aerial Vehicles (UAVs) have attracted significant interest in recent years, as they have shown to be effective in supporting a wide range of applications in many different areas, including logistics, search and rescue (SAR) [3], public safety communications [8], infrastructure monitoring [9], precision agriculture [4], forestry [5], and telecommunications [2]. Specifically we focus on those of search and exploration in the context of search and rescue. In our presented work, success is measured in an agents ability to find all transmitters in as small a time as possible. Through the use of a challenging discretized simulation environment, we investigate the practicality of an empowerment-driven exploration behaviour (EEB) in order to locate an unknown number of wireless transmitters with minimal prior knowledge about the locations of obstacles, transmitters and their properties. With problem specific adaptations to the algorithm, including the ability to detect non-identifying signals from transmitters, when compared with a random walk agent and an idealistic Bayesian agent, the empowerment algorithm performs near to that of the Bayesian agent with unrealistic information about the environment. We show that our empowerment-driven algorithm has practical potential and lays a foundation for future work in this area.
Geospatial data and tools are key in locating lost or missing persons in as short a time as possible. In this study, we used a geographic information system (GIS) to analyze four years of search and rescue (SAR) mission data from Colorado to determine the appropriate use of GIS for volunteer-based SAR organizations with limited resources and GIS expertise. GIS can provide more sophisticated analyses of geospatial data than simple mapping technologies, but our findings indicated that complex spatial analysis might not be required on all missions, because the majority of missions were completed within six to ten hours. Instead, new technologies such as tablets with mapping software and online GIS systems that provide quick and easy access to up-to-date geospatial data such as imagery offer capabilities that could improve mission planning. Here we provide a framework in which SAR missions can apply geospatial technologies to aid with missions, identify critical “hotspots,” and enhance postanalysis and training. The work here is highly applicable for nonprofit SAR groups when deciding on what GIS technologies to consider for their areas.
A recent proliferation of UAVs accompanies several critical issues to be considered for efficient, secure use of UAVs. One of those issues should be a privacy of people. Also, when the UAVs fly to perform specific objectives, minimizing movements of UAVs is a big issue to provide a minimum mission completion time and a maximum network lifetime. One intuitive solution is that UAVs may pass through private area of citizens whereas people do not want any penetration into own area without a permission. Then, we may take into account a compromise between those situations by giving a differential permission for each UAV to access citizens' areas depending on specific benefits by use of UAVs or emergent situation for public safety. In this paper, we introduce a framework for privacy-preserving movements of UAVs with differential UAVs' permissions given by citizens. Then, we formally define a problem whose objective is to minimize total movements of UAVs with preserving privacy of people. To solve the problem, we create a new graph type called as UDiPP graph and propose a novel priority-based approach. Furthermore, we discuss future issues and directions for differential privacy-preserving movements by UAVs.
The prediction of survival time (ST) for cold exposure is speculative as reliable controlled data of deep hypothermia are unavailable. At best, guidance can be obtained from case histories of accidental exposure. This study describes the development of a mathematical model for the prediction of ST under sedentary conditions in the cold. The model is based on steady-state heat conduction in a single cylinder comprised of a core and two concentric annular shells representing the fat plus skin and the clothing plus still boundary layer, respectively. The ambient condition can be either air or water; the distinction is made by assigning different values of insulation to the still boundary layer. Metabolic heat production (M) is comprised of resting and shivering components with the latter predicted by temperature signals from the core and skin. Where the cold expousure is too severe for M to balance heat loss, ST is largely determined by the rate of heat loss from the body. Where a balance occurs, ST is govedrned by the endurance time for shivering. End of survival is marked by the deep core temperature reacing a value of 30 degrees C. Th emodel was calibrated against survival data of cold water (0 to 20 degrees C) immersion and then applied to cold air exposure. A sampling of ST predictions for the nude exposure of an average healthy male in relatively calm air (1 km/h wind speed) are the following: 1.8, 2.5, 4.1, 9.0, and > 24 h for -30, -20, -10, 0 and 10 degrees C, respectively. With two layers of loose clothing (average thickness of 1 mm each) in a 5 km/h wind, STs are 4.0, 5.6, 8.6, 15.4, and > 24 h for -50, -40, -30, -20, and -10 degrees C. The predicted STS must be weighted against the extrapolative nature of the model. At present, it would be prudent to use the predictions in a relative sense, that is, to compare or rank-order predicted STs for various combinations of ambient conditions and clothing protection.
Introduction Assumptions EM and Inference by Data Augmentation Methods for Normal Data More on the Normal Model Methods for Categorical Data Loglinear Models Methods for Mixed Data Further Topics Appendices References Index
The relationship between a response variable and one or more continuous covariates is often curved. Attempts to represent curvature in single- or multiple-regression models are usually made by means of polynomials of the covariates, typically quadratics. However, low order polynomials offer a limited family of shapes, and high order polynomials may fit poorly at the extreme values of the covariates. We propose an extended family of curves, which we call fractional polynomials, whose power terms are restricted to a small predefined set of integer and non-integer values. The powers are selected so that conventional polynomials are a subset of the family. Regression models using fractional polynomials of the covariates have appeared in the literature in an ad hoc fashion over a long period; we provide a unified description and a degree of formalization for them. They are shown to have considerable flexibility and are straightforward to fit using standard methods. We suggest an iterative algorithm for covariate selection and model fitting when several covariates are available. We give six examples of the use of fractional polynomial models in three types of regression analysis: normal errors, logistic and Cox regression. The examples all relate to medical data: fetal measurements, immunoglobulin concentrations in children, diabetes in children, infertility in women, myelomatosis (a type of leukaemia) and leg ulcers.
An account is given of a recently devised method of prediction based on sample reuse techniques. It is most useful in low structure data paradigms that involve minimal assumptions. A series of applications demonstrating the technique is presented.
Introduction General Conditions for the Randomization-Validity of Infinite-m Repeated-Imputation Inferences Examples of Proper and Improper Imputation Methods in a Simple Case with Ignorable Nonresponse Further Discussion of Proper Imputation Methods The Asymptotic Distribution of (Q̄m, Ūm, Bm) for Proper Imputation Methods Evaluations of Finite-m Inferences with Scalar Estimands Evaluation of Significance Levels from the Moment-Based Statistics Dm and Δm with Multicomponent Estimands Evaluation of Significance Levels Based on Repeated Significance Levels
To determine injury and illness patterns and occurrence rates during wilderness recreation.
Prospective injury and illness surveillance study.
Wilderness areas throughout the Western hemisphere.
All students and instructors on National Outdoor Leadership School courses over a five-year period.
A single fatality occurred, resulting in a death rate of 0.28 per 100,000 person-days of exposure. Injuries occurred at a rate of 2.3 per 1,000 person-days of exposure. Sprains and strains and soft tissue injuries accounted for 80% of the injuries. The illness rate was 1.5 per 1,000 person-days of exposure. Sixty percent of illnesses were due to nonspecific viral illnesses or diarrhea; hygiene appeared to have a significant impact on the incidence of these illnesses. Thirty-nine percent of the injuries and illnesses required evacuation (1.5 per 1,000 person-days of exposure).
The injury and illness patterns indicate that wilderness medical efforts should concentrate on wilderness hygiene and management of musculoskeletal injuries and soft tissue wounds. The data also indicate that wilderness activities can be conducted relatively safely, but the decision to participate should be individualized, with an understanding of risks versus benefits.
This paper describes a reliable test method for measuring and comparing the heat-transfer characteristics of outdoor garments and sleeping bags. The procedure involves the use of an electrically heated mannequin located in a climate-controlled chamber. Unlike instruments that evaluate small samples of fabric, the mannequin technique reflects the effects of fabric overlap and garment design, shape, fit, and layering in the measurements. This paper also discusses the textile and human factors that affect the heat exchange between the body and a cold environment.
The prediction of survival time (ST) of individuals stranded at sea is particularly difficult since reliable controlled data are unavailable. An individual's rate of body cooling is governed by the difference between heat loss and heat production. It has been suggested that the rate of deep body cooling can be extrapolated to estimate ST. The observed linearity of this cooling rate against water temperature is consistent with the predictions of an independently-developed mathematical model of ST. This model has been extended to simulate conditions of partial immersion and wet clothing, and subsequently calibrated against observed human cooling rates. The resultant modification allows a much broader range of ST predictions involving calm and rough seas, and non-immersion wet conditions. Predictions are presented for lean vs. fat individuals, a "worst" case scenario where shivering is absent, and partial immersion. While these predictions must be considered speculative and subject to change as better information becomes available, the model can be useful as a decision aid. It would be prudent, however, to consider the predictions in a relative vs. absolute sense; i.e., for comparative purposes.
The medical literature is limited regarding current wilderness morbidity and mortality statistics. Available studies concentrate on selected wilderness activities. This study retrospectively examines wilderness injuries, illnesses, and mortality based on case incident report files from eight National Park Service parks within California over a three-year period. Data were extracted regarding type of illness or injury, body area affected, age, gender, month in which the event occurred, and activity in which the victim was involved at the time of the event. The overall occurrence of nonfatal events was 9.2 people per 100,000 visits. More than 70% of all nonfatal events were related to musculoskeletal or soft-tissue injury. The most frequently involved body area was the lower limbs (38%). Seventy-eight mortalities occurred during the three years studied, resulting in an overall mortality rate of 0.26 deaths per 100,000 visits. Men accounted for 78% of the deaths. Heart disease, drowning and falls were the most common causes of death. The information and statistics on morbidity and mortality in California wilderness areas that this study provides may be used to guide future wilderness use, education, and management. A standardized, computerized database would greatly facilitate future evaluations, decisions, and policies.
To determine the causes and characteristics of pediatric recreational wilderness deaths.
All deaths of children between 12 months and 20 years of age involving a wilderness recreational activity in 5 western Washington counties between 1987 and 1996 were identified by medical examiners' logs. Univariate analysis was used to examine variables such as age, gender, activity, mechanism of injury, adult presence, blood alcohol level, safety equipment, and mode of evacuation.
Of 40 cases meeting inclusion criteria, 90% involved male subjects and 83% of victims were 13 to 19 years old. Hiking (33%), swimming (20%), and river rafting (10%) were the most common activities. Death was most often by drowning (55%) or closed head injury (26%). No victim was alone. All children younger than 10 years of age were accompanied by an adult, in contrast to only 26% of individuals 10 years or older. Only 4 victims had drugs or alcohol in their system. No victim wore a personal flotation device or helmet, and only 5% had foul weather gear. Although nearly one third of victims were transported by airlift, more than half of the victims were dead at the scene.
Males and teenagers were the 2 major risk groups for recreational wilderness deaths. Traditional activities such as hiking and swimming were the most common causes of death. Children younger than 10 years died despite the presence of an adult, whereas teenagers were usually with groups of peers. The majority of victims were not prepared for adverse events with basic safety equipment.
To analyze the epidemiology of wilderness mortalities in a localized area with diverse terrain.
We conducted a retrospective review of the Pima County (Arizona) Sheriff's Office (PCSO) search and rescue logs and case reports, hospital records, and autopsy reports for all wilderness deaths from 1980 to 1992. The study group comprised all victims of injury or illness in Pima County wilderness who died during a 13-year period in a location remote enough so that standard ground-based emergency medical services units could not extract the body.
One hundred fatalities occurred during the 13-year study period. There were 59 unintentional traumas, 18 suicides, 9 homicides, 12 medically related deaths, and 2 deaths of unknown causes. Toxicology tests performed on body fluids yielded positive findings for alcohol in a total of 50 (50%) cases and positive findings for drugs of abuse in 12 (12%) cases. It was estimated that alcohol was "a very probable" or "a probable" causative factor in 23 (40%) of the 59 unintentional trauma deaths, and in 1 (8.3%) of the 12 medically related deaths. Fifty-five (55%) deaths were witnessed events, with 45 (80%) of these victims reported as dying immediately or before arrival of search and rescue personnel. Ten (10%) victims received resuscitation in the field, and according to a review of hospital charts and autopsy reports, only 2 victims had a potentially survivable injury or illness.
Many wilderness mortalities are related to incidents involving alcohol. Once the accident or injury has occurred, the majority of deaths are immediate, or at least before the arrival of medical personnel. Higher levels of medical care would not have improved the outcomes of those who did survive long enough to receive medical care. Therefore, primary efforts to reduce mortalities in the wilderness should be directed toward prevention, especially diminishing alcohol use in wilderness areas.
This paper describes field injury, illness, near miss, and evacuation profiles of the National Outdoor Leadership School (NOLS).
The NOLS incident database is used to record injuries, illnesses, near-miss incidents (close calls), evacuations, and nonmedical incidents. The database has been used continually since 1984.
During the period September 1, 1998, through August 31, 2002, there were 630,937 program days on which 1940 incidents were reported involving 1679 students and 233 staff. Athletic injuries account for 50% of all injuries, and soft-tissue injuries account for 30%. Athletic injuries are most often sprains and strains of knees (35%), ankles (30%), and backs (13%). Falls and slips around camp or while hiking are the leading contributing factors. The most common illnesses are gastrointestinal symptoms such as nausea, vomiting, and diarrhea (26.4%) and all flu-like illness, including flu symptoms and respiratory symptoms (16.6%). Rock fall was the leading near-miss incident. Two hundred fifty-seven (53%) medical evacuees received treatment and were able to rejoin and finish their course. There was one fatality from 1999 to 2002. The fatality rate for this period is 0.002 per 1000 program days.
The number of injuries and, specifically, the number of athletic injuries have declined. The number and rate of near-miss incidents increased as a result of better reporting; the rate of nonmedical incidents held steady. Motivation continues to be our leading category of nonmedical incident. Efforts at collecting incident data provide a useful measurement from which we can gauge our risk-management performance.
To describe the epidemiology of wilderness search and rescue in a region with easily accessible, heavily used wilderness areas.
We conducted a retrospective review of New Hampshire Fish and Game Department wilderness search-and-rescue reports between January 1999 and December 2001. The study group consisted of all the subjects of the New Hampshire Fish and Game Department search and rescue in the state of New Hampshire during the study period. Demographics, types of incidents, type and location of injuries, environmental factors, fatalities, and use of medical services for all the subjects were analyzed.
Three hundred twenty-one incidents involving 457 subjects were analyzed. The mean age of the subjects in the incidents was 35.6 years, with 64.5% men and 35.4% women; 73% of the subjects resided in New Hampshire and Massachusetts. At the time of the incident, 57.3% of the subjects were hiking. Injuries precipitated 39.3% of the rescues, whereas lost and missing persons accounted for 41.4%. Fractures accounted for 33.7% of the reported injuries; 49.7% of the injuries were to the lower extremities. Sixty-four of the subjects (14%) died; 32.8% drowned, and 23.4% died from cardiac events. Volunteers were used in 53.3% of the rescues, a rescuer was injured in 2.5% of the incidents, and at least 36.4% of the subjects were transported to a hospital.
The most prevalent demographic group requiring search-and-rescue efforts in New Hampshire was men aged 30 to 40 years who were hiking and who resided within a 4-hour drive of the area where they encountered difficulty. To decrease the number of people involved in most search and rescue, efforts should be focused on preventing wilderness users from getting lost and preventing lower extremity musculoskeletal injuries. Wilderness deaths may be prevented by focusing attention on cardiac health in wilderness users older than 50 years and on water safety.
Oregon county climate data Available at: http://www.ocs.oregonstate.edu/pagelinks/ climatedatazones/climatedata.html Rubin DB. Multiple Imputation for Nonresponse in Surveys
- Oregon
- Service
Oregon Climate Service. Oregon county climate data. Available at: http://www.ocs.oregonstate.edu/pagelinks/ climatedatazones/climatedata.html. Accessed October 19, 2005. 7. Rubin DB. Multiple Imputation for Nonresponse in Surveys. New York, NY: Wiley; 1987.
The jackknife, the bootstrap and other resampling plans. Paper presented at: Regional Conference Series in Applied Mathematics
- B Efron
Efron B. The jackknife, the bootstrap and other resampling plans. Paper presented at: Regional Conference Series in Applied Mathematics; 1982; Philadelphia, PA.
Search Is an Emergency
- P Lavalla
- Stoffel
LaValla P, Stoffel R. Search Is an Emergency. 2nd ed. Olympia, WA: The Emegency Response Institute, Inc.; 1987.
Oregon county climate data Available at
- Oregon Climate
- Service
Oregon Climate Service. Oregon county climate data. Available at: http://www.ocs.oregonstate.edu/pagelinks/ climatedatazones/climatedata.html. Accessed October 19, 2005.
Search and rescueWilderness Medicine: Management of Wilderness and Environmental Emergencies
- Dc Cooper
- La Valla
- Ph Stoffel
Cooper DC, La Valla PH, Stoffel RC. Search and rescue.
In: Auerbach PS, ed.Wilderness Medicine: Management of
Wilderness and Environmental Emergencies. St. Louis,
MO: Mosby-Year Book; 1995:506–534.