Takehiro Kashiyama

The University of Tokyo | Todai · Institute of Industrial Science

This paper summarizes the Crowdsensing-based Road Damage Detection Challenge (CRDDC), a Big Data Cup organized as a part of the IEEE International Conference on Big Data’2022. The Big Data Cup challenges involve a released dataset and a well-defined problem with clear evaluation metrics. The challenges run on a data competition platform that mainta...

This paper summarizes the Crowdsensing-based Road Damage Detection Challenge (CRDDC), a Big Data Cup organized as a part of the IEEE International Conference on Big Data'2022. The Big Data Cup challenges involve a released dataset and a well-defined problem with clear evaluation metrics. The challenges run on a data competition platform that mainta...

Analyzing vehicle movement trajectories is essential for understanding urban mobility and traffic flow patterns. Obtaining a reliable estimate of vehicle trajectory is challenging as it requires the vehicle to be observed and re-identified at different locations and times. Recently, a scalable citywide traffic flow estimation method has been propos...

Traffic flow estimation is required for road infrastructure management tasks such as road development planning, routing, and navigation. Determining traffic flow on a citywide scale is challenging because of the expensive costs and portability of current devices. Portable sensing devices such as drive cams and smartphones are an effective source of...

People flow data are utilized in diverse fields such as urban and commercial planning and disaster management. However, people flow data collected from mobile phones, such as using global positioning system and call detail records data, are difficult to obtain because of privacy issues. Even if the data were obtained, they would be difficult to han...

Using medium altitude footage in various image based pedestrian detection and tracking tasks have several advantages as opposed to low altitude footage. For instance, much larger covered area, or weaker perspective distortions and occlusions. Furthermore, it does not pose privacy issues. However, it also has a disadvantage that is the irregular cam...

Analysis of traffic flow parameters is necessary for Intelligent Transportation Systems (ITS) and autonomous driving research. Deep learning-based vehicle detection techniques have been widely used in reconstructing traffic flow parameters from video images. This research proposes a novel cross-sectional traffic flow estimation algorithm to reconst...

Many municipalities and road authorities seek to implement automated evaluation of road damage. However, they often lack technology, know-how, and funds to afford state-of-the-art equipment for data collection and analysis of road damages. Although some countries, like Japan, have developed less expensive and readily available Smartphone-based meth...

The use of drones and other unmanned aerial vehicles has expanded rapidly in recent years. These devices are expected to enter practical use in various fields, such as taking measurements through aerial photography and transporting small and lightweight objects. Simultaneously, concerns over these devices being misused for terrorism or other crimin...

This paper summarizes the Global Road Damage Detection Challenge (GRDDC), a Big Data Cup organized as a part of the IEEE International Conference on Big Data’2020. The Big Data Cup challenges involve a released dataset and a well-defined problem with clear evaluation metrics. The challenges run on a data competition platform that maintains a leader...

This paper summarizes the Global Road Damage Detection Challenge (GRDDC), a Big Data Cup organized as a part of the IEEE International Conference on Big Data'2020. The Big Data Cup challenges involve a released dataset and a well-defined problem with clear evaluation metrics. The challenges run on a data competition platform that maintains a leader...

Many municipalities and local road authorities seek to implement automated evaluation of road damage. However, they often lack technology, know-how, and funds to afford state-of-the-art data collection equipment for collection and analysis of road deficiencies. The paper describes the development of a localized road damage detection model using the...

Many municipalities and road authorities seek to implement automated evaluation of road damage. However, they often lack technology, know-how, and funds to afford state-of-the-art equipment for data collection and analysis of road damages. Although some countries, like Japan, have developed less expensive and readily available Smartphone-based meth...

Continually improving crowd counting neural networks have been developed in recent years. The accuracy of these networks has reached such high levels that further improvement is becoming very difficult. However, this high accuracy lacks deeper semantic information, such as social roles (e.g., student, company worker, or police officer) or location-...

Understanding individual and crowd dynamics in urban environments is critical for numerous applications, such as urban planning, traffic forecasting, and location-based services. However, researchers have developed travel demand models to accomplish this task with survey data that are expensive and acquired at low frequencies. In contrast, emerging...

Machine learning can produce promising results when sufficient training data are available; however, infrastructure inspections typically do not provide sufficient training data for road damage. Given the differences in the environment, the type of road damage and the degree of its progress can vary from structure to structure. The use of generativ...

Shortages of engineers and financial resources have made it difficult for municipalities to identify and address problems with aging road infrastructures. To resolve these problems, numerous studies have focused on automating road inspection, including a study in which we developed a smartphone-based road inspection system. For efficient operation...

Over the past few years, researchers have presented many different applications for convolutional neural networks, including those for the detection and recognition of objects from images. The desire to understand our own nature has always been an important motivation for research. Thus, the visual recognition of humans is among the most important...

Western Japan was hit by heavy rain from June 8 to July 28, 2018. Record-breaking rain caused nearly all rivers to flood in Hiroshima and other areas. Over 200 people died following this disaster. Authorities attempted to understand why evacuation was not conducted swiftly enough to stop these deaths. They mentioned that normalcy bias and cognitive...

This paper describes the development of the “My City Report” open source platform as a tool to encourage citizens to solve problems themselves as well as actively hearing and carefully considering citizens’ opinions. This was accomplished by conducting demonstration experiments utilizing data from several domestic municipalities. The development wa...

Both in the Tokyo metropolitan area and rural areas in Japan, the number of development projects being undertaken by private companies and local governments has been increasing. Under these circumstances, there is need for a system to estimate the rent paid by tenants and consider the features of living areas from several perspectives. This informa...

Mobile Phones are near ubiquitous. We introduce a sensing technique to count how many people flow into and out of an urban area in an average weekday and weekend by combining subscribers billing records, road infrastructure network, and population data. Furthermore, trips are disaggregated by entry region and validated to the most recent available...

Research on damage detection of road surfaces using image processing techniques has been actively conducted. This study makes three contributions to address road damage detection issues. First, to the best of our knowledge, for the first time, a large‐scale road damage data set is prepared, comprising 9,053 road damage images captured using a smart...

Japan has suffered significant damage from countless earthquakes throughout its history. Thus, it is important to take prompt and effective measures against major future earthquakes predicted. Among the components of damage, measures against tsunamis are a top priority, as demonstrated by the catastrophic losses caused by the Great East Japan Earth...

Research on damage detection of road surfaces using image processing techniques has been actively conducted, achieving considerably high detection accuracies. Many studies only focus on the detection of the presence or absence of damage. However, in a real-world scenario, when the road managers from a governing body need to repair such damage, they...

Understanding people flow at a citywide level is critical for urban planning and commercial development. Thanks to the ubiquity of human location tracking devices, many studies on people mass movement with mobility logs have been conducted. However, high cost and severe privacy policy constraints still complicate utilization of these data in practi...

Infrastructure maintenance requires extensive financial and human resources, and a lack of these resources---and, in particular, a shortage of experts---is a problem in many countries and regions around the world. In response to such circumstances, there is considerable research on infrastructure damage-detection methods using camera images and mac...

In recent years, there has been remarkable development in unmanned aerial vehicle UAVs); certain companies are trying to use the UAV to deliver goods also. Therefore, it is predicted that many such objects will fly over the city, in the near future. This study proposes a system for monitoring objects flying over a city. We use multiple 4K video cam...

Real-time estimation of human mobility following a massive disaster will play a crucial role in disaster relief. Because human mobility in massive disasters is quite different from their usual mobility, real-time human location data is necessary for precise estimation. Due to privacy concerns, real-time data is anonymized and a popular form of anon...

Recently, infrastructure monitoring in developing countries is not enough, though it becomes very important based on the development of social capital. In this study, we asked to collect road state data, especially road bump and hourly traffic link speed from GPS and acceleration data, for the person in developing countries by smartphones using cro...

Recently, an understanding of mass movement in urban areas immediately after large disasters, such as the Great East Japan Earthquake (GEJE), has been needed. In particular, mobile phone data is available as time-varying data. However, much more detailed movement that is based on network flow instead of aggregated data is needed for appropriate res...

Real-time estimation of people distribution immediately after a disaster is directly related to disaster reduction and is also highly beneficial in society. Recently, traffic estimation research has been actively performed using data assimilation techniques for observation data obtained from mobile phones. However, there has been no research on dat...

Recently, malware has become a major security threat to computers. Responding to threats from malware requires malware analysis and understanding malware behavior. However, malware analysts cannot spend the time required to analyze each instance of malware because unique variants of malware emerge by the thousands every day. Dynamic analysis is eff...

We can measure depth of rivers quite efficiently by using ALB (Airborne Laser Bathymetry) technology. But in order to use ALB we must fly very low at 400 meters by airplane. So ALB is not usable anywhere. In this study, we developed a method for estimating the area where we can use ALB technology under topographical restriction. We simulated the ap...

The Great East Japan Earthquake, which took place in East Japan area on the 11 March 2011, had a broad impact on land and infrastructure as well as human life. City Bureau, MLIT, Japan has made a survey of the tsunami damage for the local government systematically and comprehensively. This study develops data archiving of this survey result using v...

The speed and direction of coastal ocean surface currents are very important elements in examining land reclamation or establishment of coastal levees. Measuring the speed of sea surface currents generally employs a radar system using Doppler effect. However, there is a problem that it is unable to measure the current in a wide area because the sys...

Recently, incidents in which data such as private information has leaked have occurred frequently. In many cases, the main causes of data leakage are as follows: taking data out illegally or unfairly, erroneous operation by a user with authority to access the data. We developed the operating system Salvia for the purpose of preventing data leakage...

Recently, with the development of information technology, Construction CALS/EC is being promoted at a high speed. In order to introduce Construction CALS/EC smoothly, the originality of the 2D-CAD data (SXF: SCADEC data eXchange Format) delivered electronically must be protected. Up until now, when determining if two CAD data are identical, one oft...

A standard specification of enhanced DM-SXF conversion is settled on aiming to use the enhanced DM data made as a result of measurement in design phase. And, there are some conversion systems in accordance with the standard specification, but there are two problems. First, it is necessary to take much time for processing DM-SXF conversion. Second,...

Recently, the research on the traffic analysis is actively done, and it is used to decide the maintenance plan of the bridge and strategy of the commercial operation to the road coast region. However, a large cost is required in an existing analysis, because traffic information collected in a road traffic census and the Origin Destination Survey is...