Hamad bin Khalifa University

The growing number of publications on Operating Room Scheduling (ORS) in recent years reflects the rapid advancements in the field. This review aims to comprehensively analyze the historical developments and evolving trends in operating room scheduling by systematically examining the literature from 2000 to 2023. A multi-database search, including Scopus, Web of Science, PubMed, ProQuest and IEEE Xplore was employed to ensure the inclusion of key studies. This paper presents a review of the factors, descriptive fields, and key issues in operating room scheduling. It also focuses on optimization techniques and solution approaches for both deterministic and uncertain conditions. Special attention is given to real-world constraints, such as resource limitations, staff availability and patient variability which significantly impact scheduling. The review identifies that ORS research covers a broad spectrum of problems and solutions, with no singular research trend dominating the field. This indicates that researchers are tackling diverse challenges across various contexts. The final section outlines the significant pitfalls and proposes future research directions, including the integration of emerging technologies and sustainability considerations. This review is a valuable resource for researchers, practitioners, and academicians in healthcare operations and hospital management, offering insights into current practices and future opportunities for innovation in ORS.

Purpose This study examined the effect of 3 and 6 weeks of intensity domain-based exercise training on ${\dot{\text{V}}\text{O}}_{{2}}$ kinetics changes and their relationship with indices of performance. Methods Eighty-four young healthy participants (42 M, 42 F) were randomly assigned to six groups (14 participants each, age and sex-matched) consisting of: continuous cycling in the (1) moderate (MOD)-, (2) lower heavy (HVY1)-, and (3) upper heavy-intensity (HVY2)- domain; interval cycling in the (4) severe-intensity domain (i.e., high-intensity interval training (HIIT), or (5) extreme-intensity domain (i.e., sprint-interval training (SIT)); or (6) control (CON). Training participants completed two three-week phases of three supervised sessions per week, with physiological evaluations performed at PRE, MID and POST intervention. All training protocols, except SIT, were work-matched. Results There was a significant time effect for the time constant ($\tau {\dot{\text{V}}\text{O}}_{{2}}$) between PRE (31.6 ± 10.4 s) and MID (22.6 ± 6.9 s) (p < 0.05) and PRE and POST (21.8 ± 6.3 s) (p < 0.05), but no difference between MID and POST (p > 0.05) and no group or interaction effects (p > 0.05). There were no PRE to POST differences for CON (p < 0.05) in any variables. Despite significant increases in maximal ${\dot{\text{V}}\text{O}}_{{2}}$ (${\dot{\text{V}}\text{O}}_{{{\text{2max}}}}$), estimated lactate threshold (θLT), maximal metabolic steady state (MMSS), and peak power output (PPO) for the intervention groups (p < 0.05), there were no significant correlations from PRE to MID or MID to POST between $\Delta \tau {\dot{\text{V}}\text{O}}_{{2}}$ and $\Delta {\dot{\text{V}}\text{O}}_{{{\text{2max}}}}$ (r = – 0.221, r = 0.119), ΔPPO (r = – 0.112, r = – 0.017), ΔθLT (r = 0.083, r = 0.142) and ΔMMSS (r = – 0.213, r = 0.049)(p > 0.05). Conclusion This study demonstrated that (i) the rapid speeding of ${\dot{\text{V}}\text{O}}_{{2}}$ kinetics was not intensity-dependent; and (ii) changes in indices of performance were not significantly correlated with $\Delta \tau {\dot{\text{V}}\text{O}}_{{2}}$.

It is unclear whether physiological responses, such as muscle oxygen saturation (SmO2), can be considered symmetrical during cycling. This knowledge has important practical implications for both training and performance assessment. The aim of this study was to determine whether oxygenation profiles in the three active muscles of both legs were symmetrical during cycling at different intensities. Twenty‐six trained cyclists and triathletes completed a graded exercise test (GXT) and an 8‐min functional threshold power estimation test (8MTT) on a cycle ergometer over two nonconsecutive days. SmO2 was bilaterally assessed using NIRS technology in the vastus lateralis, gastrocnemius medialis, and tibialis anterior. Symmetry was compared between legs in both tests, and reliability and agreement between the measurements were quantified. The main results were that SmO2 in the three muscles assessed did not differ between legs during the GXT and 8MTT (p > 0.05). Reliability of the measures was poor to good in the vastus lateralis (ICC = 0.83–0.37), moderate to excellent in the tibialis anterior (ICC = 0.92–0.73), and poor to good for the gastrocnemius medialis (ICC = 0.80–0.24). Overall, the group variability in SmO2 showed a narrower distribution at lower intensities, with data dispersion increasing at higher intensities. In conclusion, the SmO2 was similar and showed symmetrical responses in both the preferred and nonpreferred limb in different muscles assessed during cycling at different intensities within a range of 10%–20%. Although individual physiological differences that might be relevant in some clinical/performance settings should not be disregarded, these findings indicate that measuring a single lower limb provides an accurate approximation of the responses in both lower limbs.

This research explores the contribution of Blockchain Technology and Industry 5.0 in driving sustainability within Bangladeshi Ready-Made Garments (RMG) industry, with a focus on alignment with key Sustainable Development Goals (SDGs). The study employs Interpretive Structural Modeling (ISM) and fuzzy Decision-Making Trial and Evaluation Laboratory (DEMATEL) methods to identify and analyze 14 critical synergies that can drive sustainability. The ISM analysis categorizes the synergies into independent, dependent, and linkage variables, providing insights into their roles and significance within the system. Fuzzy DEMATEL further refines this understanding by evaluating the direct and indirect relationships among the linkage synergies. Key findings reveal the importance of synergies such as reverse logistics and recycling, supply chain collaboration & visibility and ethical practices in driving sustainability. This research contributes by offering a detailed analysis of how the synergy between Blockchain technology and Industry 5.0 can enhance sustainability practices in the RMG industry, providing actionable insights into the technological transformation of supply chain dynamics in support of global sustainability targets.

Quantum walks (QW) offer a speed-up advantage over random walks in quantum search applications. We present an experimental study of the transition from quantum-to-classical random walk using an emulation of the decoherence process for polarization qubits that exploits maximally non-separable spin–orbit modes of an intense laser beam for the first, to the best of our knowledge, time. We are able to continuously control the input polarization mode in an all-optical quantum walk circuit to observe transitions associated with quantum, quantum stochastic, and classical random walk distributions. The results are in agreement with theoretical expectations.

Although affecting both sexes, loss of sex hormones and consequently increased risk for cardiovascular disease (CVD) render particular features to vascular aging in females. More importantly, while the female’s vasculature is more sensitive to CVD risk factors, CVD is often underdiagnosed in women. In the present study, we investigated vascular function in the arm and leg skeletal muscle microvasculature and conduit artery in young and older females. We also applied a mixed-effect regression analysis to examine the relationship between vascular function and CVD risk factors in women. We showed that the detrimental effects of age in conduit artery vascular function, as assessed by flow-mediated dilation (%FMD), was more evident in the lower limb (Older, 2.6 ± 0.5 vs. Young, 7.2 ± 0.9%, p=0.0116). compared to the upper limb (Older, 5.3 ± 0.5 vs. Young, 7.3 ± 0.4%, p=0.175) In addition, we demonstrate that CVD risk factors, mainly plasma lipid levels (VLDL-c: r ² =0.415, p=0.007; HDL-c: r ² =0.313, p=0.024; triglycerides: r ² =0.422, p=0.006) and insulin sensitivity index (HOMA-IR: r ² =0.635, p<0.001; QUICKI: r ² =0.792, p<0.001), were exclusively associated with upper limb skeletal muscle microvascular function in older females. In aggregate, our findings provide novel evidence that impairments in conduit artery function in older females are more pronounced in the lower limb vasculature compared to the upper limb. Also, we demonstrate that older women’s upper limb microvasculature function may be more susceptible to the impact of CVD risk factors than lower limb microvasculature function and both limb’s conduit arteries.

This paper explores the intersection of public administration and its administrative state, transnational and global policy, and international sports governance. We start by exploring autonomy and self-governance in international sport before sharing the structures, legal personalities, and nature of transnational private law interaction with international sport. The implications are illustrated through three examples. The first is the legal-policy interactions of the FIFA World Cup 2022 with Qatar. The second are new interactions of human rights with future World Cups and future Olympics. The third is the role of the Court of Arbitration for Sport and the World Anti-Doping Agency. This leads to three implications for administrative scholarship: lex sportiva implications for public administration, a stretching of the autonomy and self-governance concepts, and expanding the evaluation stage of a policy cycle to include the governance legacies of mega sports events.

To address the short-lived battery lifetime of Bluetooth low energy (BLE) beacons, researchers proposed solar-powered designs, equipped with rechargeable energy storage such as a supercapacitor. However, accurately monitoring the energy status - an essential step for device maintenance - has shown to be a major concern. Existing energy status monitoring methods, which are either crowd-assisted or require on-site data collection, suffer from severe losses of energy status information. This paper presents an energy status recovery framework with support vector regression (SVR) to address this issue. The proposed framework leverages recurrence training of SVR with lost energy status information to capture features from discharge behavior, achieving high accuracy while minimizing training and prediction time. Multiple real-life BLE beacon energy level records are evaluated to demonstrate that our proposed framework can recover the energy information with at least 98% accuracy under a data loss rate of up to 99%.

High altitude platforms (HAPs)-aided terrestrial-aerial communication technology based on free-space optical (FSO) and Terahertz (THz) feeder links has been attracting notable interest recently due to its great potential in reaching a higher data rate and connectivity. Nonetheless, the presence of harsh vertical propagation environments and potential aerial eavesdroppers are two of the main challenges limiting the reliability and security of such a technology. In this work, a secrecy-enhancing scheme for HAP-aided ground-aerial communication is proposed. The considered network consists of HAP-assisted communication between a ground station and a legitimate user under the threat of an aerial and ground eavesdropper. Thus, the proposed scheme leverages (i) HAP diversity by exploiting the presence of multiple flying HAPs and (ii) the use of a hybrid FSO/THz transmission scheme to offer better resilience against eavesdropping attacks. An analytical secrecy outage probability (SOP) expression is derived for the scheme in consideration. Results manifest the notable gain in security of the proposed scheme with respect to both (i) the single-HAP and (ii) THz feeder-based benchmark ones, where the proposed scheme's SOP is decreased by four orders of magnitude using 4 HAPs with respect to the first benchmark scheme, while a 5-dB secrecy gain is manifested with respect to the second benchmark one.

This article addresses the consensus tracking control of multiagent systems (MASs) via a quadratic programming (QP) optimization framework, where the control Lyapunov function (CLF) condition serves as a constraint. The optimal controllers, derived through the QP solver, not only ensure the tracking control objective but also minimize the cost functions of agents. To enhance energy efficiency, discontinuous control methods, such as intermittent control strategy and event-triggered mechanism, are employed in the control framework. The CLF-based QP controllers are only updated at specific time instants, in order to reduce the frequency of QP problem-solving. In addition to considering optimization, the proposed methods are extended to uncertain MASs to enhance robustness, where the uncertainty is modeled by Gaussian process regression. In the end, simulation results are provided to demonstrate the feasibility of the theoretical analysis.

The rapid increase in global energy demand and the depletion of fossil fuels highlight the importance of biomass as a renewable energy source. Biomass, especially agricultural by-products rich in hemicellulose, cellulose, and lignin, offers a sustainable alternative for producing fuels and value-added products. The generation of power, heat, and biofuels from biomass has gained increasing significance in today’s energy landscape. This review explores the potential of advanced biomass conversion technologies, with a focus on thermochemical and biochemical processes as key methods for optimizing agricultural waste management strategies. It examines these technologies for converting agricultural wastes into bioenergy, such as biogas, syngas, bio-oil, biochar, and digestate, while detailing their operational parameters, technological principles, and implementation prospects. While biological processes are limited by long processing times and low yields, thermochemical methods are challenged by high processing costs and temperature requirements. The review also compares the advantages and challenges of each method to assess their overall effectiveness and suitability. Further research in feedstock pretreatment, catalyst development, and system optimization is essential for advancing biofuel production.

Digital twins (DT) are digital copies of tangible assets and operations utilised in some industries to improve efficiency and foster creativity, accuracy, and decision making. Although beneficial, they have brought up some of the most critical security issues due to the complexity of their implementation and how they are incorporated into strategic systems. In this study, the security aspects of DTs that deal with challenges relating to data integrity, privacy, and secrecy are covered: potential vulnerabilities. For example, data used for malicious reasons, gaining unauthorised access, and interference with authorised network activities are considered in the planned attempt. In this study, the authors provide a secure and efficient protocol based on elliptic curve cryptography (ECC) to address security, privacy, and associated concerns in vehicular digital twins (VDT) networks. In addition, the paper discusses formal and informal security analysis based on the random oracle model, Burrows-Abadi Needham (BAN) logic, and Scyther verification tool. The proposed protocol ensures security, privacy, and other related security attacks and attributes in VDT networks. Furthermore, in the performance analysis section, we compare the communication and computation costs of the proposed protocol and related protocols. The proposed framework is secure and efficient in VDT network systems. Our analysis shows that the proposed protocol may apply to future VDT networks.

The Groundwater Module within the Sustainability Nexus Analytics, Informatics, and Data (AID) Programme of the United Nations University (UNU) addresses critical challenges in sustainable groundwater management. Groundwater resources around the world are under increasing stress from overextraction and pollution, threatening water and food security for billions. Groundwater governance is not one-dimensional but multi-faceted, and central to the management of environmental, social, and economic systems worldwide. In line with the Nexus Approach, the goal of the UNU Sustainability Nexus AID Programme's Groundwater Module is improving access to data and information tools that help scientists and decision-makers address interdisciplinary groundwater problems that affect humans and nature. Here, we describe the critical need for a Nexus Approach to groundwater-related issues and highlight current challenges involving data and information gaps and data-model operability. The Groundwater Module can help address these challenges by offering a central hub for data, analytics, and informatics for addressing groundwater-related issues. By integrating dispersed datasets and modeling tools, this module aims to enable analysis and new insights. We showcase some of the tools in the Groundwater Module and discuss future opportunities in the global pursuit to fulfill the UN Sustainable Development Goals (SDGs).

Objectives Scant data are available on syphilis infection within migrant populations worldwide and in the population of the Middle East and North Africa region. This study investigated the prevalence of both lifetime and recent syphilis infections among migrant craft and manual workers (MCMWs) in Qatar, a diverse demographic representing 60% of the country’s population. Methods Sera specimens collected during a nationwide cross-sectional survey of SARS-CoV-2 seroprevalence among the MCMW population, conducted between 26 July and 9 September 2020, were analysed. Treponema pallidum antibodies were detected using the Mindray CL-900i Chemiluminescence Immunoassay Analyzer. To differentiate recent infections, rapid plasma reagin (RPR) testing was performed, with an RPR titre of ≥1:8 considered indicative of recent infection. Logistic regression analyses were employed to identify factors associated with lifetime syphilis infection. Sampling weights were incorporated into all statistical analyses to obtain population-level estimates. Results T. pallidum antibodies were identified in 38 of the 2528 tested sera specimens. Prevalence of lifetime infection was estimated at 1.3% (95% CI 0.9% to 1.8%). Among the 38 treponemal-positive specimens, 15 were reactive by RPR, with three having titres ≥1:8, indicating recent infection. Prevalence of recent infection was estimated at 0.09% (95% CI 0.01 to 0.3%). Among treponemal-positive MCMWs, the estimated proportion with recent infection was 8.1% (95% CI: 1.7 to 21.4%). The adjusted OR for lifetime infection increased with age, reaching 8.68 (95% CI 2.58 to 29.23) among those aged ≥60 years compared with those ≤29 years of age. Differences in prevalence were observed by nationality and occupation, but no differences were found by educational attainment or geographic location. Conclusions Syphilis prevalence among MCMWs in Qatar is consistent with global levels, highlighting a disease burden with implications for health and social well-being. These findings underscore the need for programmes addressing both sexually transmitted infections and the broader sexual health needs of this population.

This scoping review explores mobile health (mHealth) technologies and their features affecting medication adherence in cancer patients. Among 11 selected studies, predominantly from the USA, mHealth tools, particularly smartphone apps, were examined for their features in managing cancer patient’s medication adherence. The studies highlighted the importance of adherence in continuous cancer therapy, with mHealth tools offering reminders and interactive features, that aim to enhance patient engagement. However, the review identified research gaps, emphasizing the need for broader investigations into diverse mHealth tools beyond apps, including electronic capsules and smart pill dispensers. Additionally, it underscored the absence of information on costs, user input, integration with electronic health records, and data management. While acknowledging potential positive impacts on adherence, the review calls for more comprehensive research to substantiate these findings in clinical oncology.

Lamb wave resonators (LWRs) based on lithium niobate on insulator (LNOI) substrates operating in an A1 mode at frequencies above 5 GHz typically exhibit high electromechanical coupling coefficients (K²) ranging from 20% to 30%. This makes them promising candidates to replace current bulk acoustic wave technology in next-generation broadband RF filters. However, the K² of conventional LWRs still struggles to meet application requirements for bandwidths exceeding 1 GHz, such as WiFi-6E. This paper presents an analytical optimization approach for rapid and comprehensive scanning of the full 3D Euler space to find the maximum effective K² of LWR devices. Such a full scan is difficult to achieve by the conventional time-consuming finite element method (FEM). The K² results for a selected subset of Euler angles obtained through this analytical approach align with FEM simulation results. The optimized results show that LWRs on LNOI can achieve the highest K² of 59.92% at Euler angles of (0, −151°, −60°), providing bandwidths exceeding 1 GHz at 5 GHz. To validate this optimization approach, LWRs with various orientations were fabricated on both 41° YX-cut and Z-cut LNOI wafers, with measured K² values at different Euler angles agreeing well with both analytical and FEM results. The proposed K² optimization method serves as a valuable guideline for selecting substrate cuts and device orientations in the design of ultra-broadband filters for next-generation telecommunications.

Electric vehicles (EVs) are playing a pivotal role in transportation systems to conform to the rising exigencies for enhanced performance with safety and hindered environmental impact. Thus, to improve the efficiency and downsize the maintenance cost of EVs, an early fault diagnosis (FD) framework is crucial. Bearing and stator winding faults, which account for approximately 78% of induction machine (IM) incipient faults in EVs, remain rather elusive for conventional sensors to accurately classify them and their incipient values. To this end, this paper presents a novel Attention-enhanced Autoencoder-Gated Recurrent Unit (AAGRU) model that improves the accuracy and efficiency of fault analysis in IMs. Moreover, since bearing faults are usually captured through vibration sensors, which are expensive and require direct coupling with the IM, a hybrid signal re-constructor is devised based on merely stator current signals. The proposed model leverages Empirical Mode Decomposition (EMD), Fast Fourier Transform (FFT), and Discrete Wavelet Decomposition (DWT) to process the electric current data, which are then used by the AAGRU model to identify, detect, and classify the fault patterns. Experimental results demonstrate that the proposed model offers a 1%–6% improvement in fault detection and an 8%–28% improvement in inter-turn short-circuit fault severity classification relative to different shallow and deep-based benchmark models. The proposed model was also tested on different load conditions to ensure its applicability in practice.