Tactical Decisions Research Articles

Design and planning of global sustainable bio-hydrogen supply chain with uncertainty: A transportation-oriented robust model

Among renewable energy systems, hydrogen-based ones are promising options towards the “clean fuel” because they do not produce greenhouse gases during combustion. By utilizing the supply chain concept, it is possible to develop the use of hydrogen as a fuel in the transportation industry. As the first stage, in this study a MILP model is developed to configure the hydrogen supply chain network, including strategical and tactical decisions, while minimizing costs and carbon emission across the network. And, in the second stage, it investigates the excess hydrogen exportability to regional countries, based on which an economic objective function maximizes the related profit. Dealing with hydrogen demand uncertainty, the present study has been used the robust possibilistic programming method. Results of a related case study in Iran show that: 1) The sensitive analysis of carbon tax parameter shows a small value can reduce carbon emissions significantly, 2) Among hydrogen production technologies, “coal gasification with carbon capture-emission facilities” is an optimal decision, and 3) exporting produced hydrogen did not have any economic justification due to its high cost/unit production.

Optimal planning of an urban ferry service operated with zero emission technology

While passenger-only ferries can be an effective instrument in mitigating road congestion in urban areas, they are among the most polluting modes of transportation. This paper studies technical and economic feasibilities of a battery-powered high-speed ferry service in Oslo, Norway. An urban ferry planner problem that minimizes ferry operator and passenger costs and external costs of road transport subject to strategic (fleet selection and infrastructure location), tactical (service frequency) and operational (vessel speed) decisions is proposed. While the results show that zero emission technologies can pass the cost-benefit test for a short-range service, competitiveness hinges on energy costs and capacities and on the performance of the existing service. Counterfactual scenarios show substantial cost reductions from altering the current ferry route. Anticipated increase in external costs of road transport from closing the ferry service is also much smaller than the system costs of maintaining the urban ferry connection.

Capacitated vertiport and charging station location-allocation problem for air taxi operations with battery and fleet dispatching considerations: a case study of New York city

Set to begin operations in the coming years, air taxi is an emerging ride-sharing aviation service that plans to commute millions of customers in metropolitan cities every day. However, existing literature has not holistically investigated the impact of the various strategic, tactical, and operations decisions pertaining to air taxi services (ATS). This research adopts a simulation-based framework to address the capacitated infrastructure location and demand allocation problems associated with ATS. Specifically, we determine the following decisions: (i) location and size of operating facilities and charging stations (strategic), (ii) air taxi fleet required to serve the expected demand at a specified service level (strategic), (iii) threshold minimum charge required for efficient air taxi operations (tactical), and (iv) real-time allocation of customer demand (operational). The proposed approach identifies the infrastructure locations using a clustering algorithm, and subsequently addresses the capacitated location-allocation problem for ATS by employing a simulation-based model. To test the effectiveness of the proposed approach, we consider a case study of New York City. We leverage the estimated air taxi demand and evaluate the proposed model by considering the weighted sum of fleet utilization and customer waiting time.

Benchmarking an allocation to the foreign Sub-portfolio from a South African perspective

This paper responds to the recent (2022) change to Regulation 28 of the South African Pension Funds Act which now permits an increased allocation (raised from 30% to 45%) in foreign investments. Our primary aim is to establish a strategic (long-term) benchmark weight for the allocation to foreign assets. Our secondary aim is to assist in building intuition on potential tactical (shorter-term) foreign allocation decisions. To ensure rigour in our study, we use a novel dataset dating back to the 1930s and we utilise methodologies in recent academic literature in the mean-variance framework. Our optimisation evidence supports a strategic foreign benchmark allocation of 39% (with 61% allocated to local asset classes). We highlight that this strategic foreign benchmark of 39% (probably for the first time) enables managers to potentially take on meaningful tactical overweight foreign positions. We establish that this strategic foreign benchmark would have reduced the risk (standard deviation of returns) of the local-only optimal portfolio significantly from 10% p.a. down to 8.7% p.a. over the 92 year period analysed, whilst increasing the return by an additional 1.1% p.a. over the local-only portfolio. Lastly, we provide guidance on tactical foreign allocation decisions based on four potential local economic regimes.

Investigating different manual picking workstations for robotized and automated warehouse systems: Trade-offs between ergonomics and productivity aspects

Robotized and Automated Warehouse Systems are widely used in logistics systems due to their efficiency and compactness. Among all aspects to include during tactical and strategic decisions, the number and the design configuration of the picking workstations represent the most critical decision since they influence the conveyor system path and length and the efficiency and productivity of the entire logistics system. Further, the proper workstation design reduces ergonomics risks and, thus, ensures a better quality of work and safety. Nevertheless, many studies on parts-to-picker systems have focused on global system performance, while ergonomics and their influence on system efficiency have often been neglected.For these reasons, in this paper, we aim to close the gap by investigating both ergonomic assessment and picking workstation configurations in an integrated way. Based on the results obtained, managerial guidelines are provided by highlighting the pros and cons of each configuration. Results demonstrate that the suitable solution depends heavily on the delivery order profile and on the time necessary to pick a customer order line. Configurations with the storage bins placed inclined, placed above the order bin and in front of the worker lead to better posture and lower picking time. Further, additional parameters, such as the time required to change the storage bin, the number of items to pick from each storage bin, strongly influence the choice of the most suitable configuration. The results of this paper represent fundamental guidelines to allow managers to carry out correct feasibility studies in terms of expected costs, performance and required spaces.

Hardware accelerated ray-tracing in ocean acoustics

Due to the expense and complexity of real-world data collection, machine learning applications in ocean acoustics demand ever-faster and more realistic models for training. In this talk, I discuss some recent GPU technologies which support hardware accelerated ray tracing and how they can be exploited to boost the throughput of certain types of calculations. Firstly, I describe RTX-Prop, which is a large-scale range-dependent Gaussian beam model which benefits from hardware-acceleration of bounding volume hierarchy searches and geometry intersection calculations. Designed to ingest oceanographic forecasts from the Royal Australian Navy’s Bluelink system, RTX-Prop has been developed as an embedded model to support tactical decisions by autonomous underwater vehicles. In the second application, I discuss hardware acceleration in the context of high-frequency sonar simulation. By synthesising fine-scale environmental detail, we have previously shown that simulated imagery can be almost indestinguishable from real data. Simulated sidescan and SAS imagery from our S4 model has recently become the basis of a machine-learning pipeline for training detectors and classifiers for naval mine countermeasures. [Work supported by the Trusted Autonomous Systems Defence Coorperative Research Centre.]

The vehicle routing problem with underground logistics: Formulation and algorithm

Recognizing the pressure on urban logistics and the overcapacity of urban public transportation systems during off-peak hours, this study investigates a subway-assisted delivery model. This is a system in which part of the goods to be delivered into a city can be transferred to specific subway stations in advance (e.g., during the night) using underground logistics. During the day, vehicles can then be replenished at these subway stations. In our study, we investigate how a system of this kind affects the decisions to be made by a logistics service provider. We introduce the vehicle routing problem with underground logistics to model how to find the best vehicle routes and goods transfer plan in this system. First, we formulate this problem as a mixed integer linear model. Then, we propose a problem-customized adaptive large neighborhood search heuristic algorithm to solve it. Numerical experiments demonstrate that our methodology performs well in terms of effectiveness and efficiency. Additionally, we discuss the resulting schedules and include a sensitivity analysis of the transfer prices to provide information that can be used in strategic and tactical decision making in a subway-assisted delivery system.

Privacy-preserving correlation of cross-organizational cyber threat intelligence with private graph intersections

Sharing cyber threat intelligence is important because it allows organizations to stay ahead of new and emerging threats, prevent downtime and improve their overall security posture. Information about known vulnerabilities and post-mortem analyses of successful attacks is instrumental to make tactical decisions and implement adequate countermeasures. However, organizations are hesitant or cautious to share their locally collected cyber threat intelligence with third parties because of possible damage to the organization's reputation, legal or liability concerns, or the risk that the information is used against them.In order to promote a collaborative cybersecurity environment that accommodates the varying confidentiality requirements of both threat intelligence producers and consumers, we introduce and assess a viable solution for preserving privacy while sharing and analyzing sensitive or confidential data. This solution is designed to work seamlessly with modern cyber threat intelligence platforms. Furthermore, we examine the security implications and computational impact associated with these techniques, enabling the analysis of correlations between threat events in a manner that respects confidentiality and extends across multiple organizations involved in information sharing.

Teaching GP triage decision-making using Tactical Decision Games

Teaching GP triage decision-making using Tactical Decision Games

Identifying firefighters' situation awareness requirements for fire and non-fire emergencies using a goal-directed task analysis

A firefighter's situation awareness (SA) is considered crucial to making effective tactical decisions and actions at the scene. Despite the importance of the firefighter's SA, there have been limited research efforts to understand what cues and information firefighters use to assess ongoing situations and predict future conditions. In addition to fire events, contemporary firefighters respond to an increasing volume of non-fire incidents. Thus, this study aims to identify firefighters' SA during three fire incidents (single house fire, vehicle fire, and passenger aircraft fire) and three non-fire incidents (medical emergency, hazardous materials, and urban search and rescue). A goal-directed task analysis was conducted via focus group discussions with eight career firefighters. Findings indicate that firefighters build their SA by processing various cues from hazards (e.g., fire, ignition source), humans (e.g., occupants, bystanders, drivers, passengers), spatial elements (e.g., building structure, location of hazards), and surrounding conditions (e.g., traffic, weather). Our findings provide insights into SA measurement, SA-oriented work processes, training for SA, and designing technologies to support firefighters' SA during all-hazard responses.

Profiling Professional Rugby Union Activity After Peak Match Periods.

The aim of this investigation was to quantify professional rugby union player activity profiles after the most intense (peak) passages of matches. Movement data were collected from 30 elite and 30 subelite professional rugby union athletes across respective competitive seasons. Accelerometer-derived PlayerLoad and global navigation satellite system-derived measures of mean speed and metabolic power were analyzed using a rolling-average method to identify the most intense 5- to 600-second passages (ie,worst-case scenarios) within matches. Player activity profiles immediately post their peak 5- to 600-second match intensity were identified using 5 epoch duration-matched intervals. Mean speed, metabolic power, and PlayerLoad declined sharply (∼29%-86%) after the most intense 5 to 600seconds of matches. Following the most intense periods of rugby matches, exercise intensity declined below the average match-half intensity 81% of the time and seldom returned to or exceeded it, likely due to a host of individual physical and physiological characteristics, transient and/or accumulative fatigue, contextual factors, and pacing strategies. Typically, player exercise intensities after the most intense passages of matches were similar between match halves, positional groups, and levels of rugby competition. Accurate identification of the peak exercise intensities of matches and movement thereafter using novel methodologies has improved the limited understanding of professional rugby union player activity profiles following the worst-case scenarios of matches. Findings of the present study may inform match-representative training prescription, monitoring, and tactical match decisions (eg,substitutions and positional changes).

Dynamics of crop category choices reveal strategies and tactics used by smallholder farmers in India to cope with unreliable water availability

CONTEXTChanging cropping pattern is a potentially effective lever to cope with unreliable water resources, but given the multiple factors driving crop choices, assessing if farmers actually use it specifically for this objective remains difficult. OBJECTIVEWe aimed at analyzing whether and how farmers choose crop categories with different water requirements to cope with limited water resources in peninsular India. METHODSWe monitored over a 10 year period crop choices, weather, and groundwater level for the three cropping seasons in 205 irrigable farms in the Berambadi watershed, in southern India. We categorized crops according to their seasonal water requirement. We built farm types based of Sequence Analysis and Agglomerative Hierarchical Clustering of crop category sequences over 10 years for each cropping season. For each type, we correlated the variation in crop category choices to variations in rainfall and groundwater availability, to identify tactical adaptations. Finally, we grouped the crop category choices of the three seasons to identify the main strategic pathways followed by farmers. RESULTS AND CONCLUSIONSSequence analysis of crop category choices revealed different types of crop category sequences, reflecting farmers' different strategies, which were not significantly linked with groundwater availability. We identified five main pathways across the three cropping seasons, including combining long-cycle irrigated crop and other crop categories, specializing in short-cycle irrigated crops over two or three seasons, specializing in rainfed crops or abandoning agriculture. Within each type, correlations between variation in water availability and crop categories highlighted specific tactical adaptations. SIGNIFICANCEThe opportunity for farmers to choose their crops among a variety of species encompassing a large range of water requirements allows them to base their system resilience on a large diversity of strategies and tactics. This suggests that some farmers empirically estimate the water balance of their cropping systems at seasonal scale to take tactical decisions. Providing them with science-based tools to refine this estimation could therefore improve their decision-making. This also implies that modelling farmer decisions must account for their diversity. Maintaining or increasing the capacity of farmers to cultivate a broad range of crops with different seasonal water requirements is important for farming system resilience, and should therefore be part of the agenda of policy makers for agricultural or environmental regulations.

Situational Analysis and Tactical Decision-Making in Elite Handball Players

Situational analysis and decision-making represent key elements of elite sports performances, but few studies have investigated which player’s skills related to these aspects are relevant in elite handballers. The aim of this study was to address differences among handballers belonging to two tiers in processing situational probabilities information related to offensive and defensive situations. A total of 38 handballers (male = 22, female = 16, age: 25.6 ± 6.5 years, first-tier = 11, second-tier = 27) saw videos about different offensive and defensive actions. According to the temporal occlusion paradigm, each handballer provided a response about the best action a selected player had to perform according to the game’s context. The time, accuracy, and technical correctness of each player’s response were assessed. MANOVA revealed moderate-to-high skills differences between first- and second-tier players. First-tier players provided higher scores in response time and accuracy; they also obtained higher technical correctness scores in the most complex situation. The members of the first tier seemed to mainly depend on the accuracy of responses, even if the technical correctness also resulted in a predictor in the most complex situation. Playing in the best tier seems to require the development of very good skills related to processing situational probability information; therefore, training these elements seems to be necessary for determining the differences among elite handballers.

The role of team collaboration and communication in volleyball matches

This paper explores the crucial roles of team collaboration and communication in volleyball matches. Volleyball is a sport highly reliant on teamwork, where success in a match depends not only on the individual skills of players but also on seamless teamwork and effective communication among team members. By analyzing team dynamics, communication methods, and tactical decisions in volleyball matches, this study aims to uncover the impact of these factors on match outcomes.

Anthropometric, Power, and Configuration of The Volleyball Game Between Sarawak and Penang Players

This ex post facto research design was conducted to investigate the anthropometric aspects of power and small-sided volleyball game play configuration between Sarawak and Penang volleyball players. The performance of both teams was evaluated through the differences of height, power of leg muscles and skills execution (serve, digging and spiking) in 4 vs 4 volleyball game play. The sample of this research consists of volleyball player from both teams with 15 to 21 years old. The result indicated there was no significant differences between both teams players in term of height, t (30) = 1.696, p= 0.100. However, there was a significant difference in leg power (vertical jump) between the players from the two states, t (30) = 2.916, p = 0.007. Regarding skills execution, no significant differences were found in service skill in the 4 on 4 game play between both states t (30) = 0.808, p = 0.426. The same applied to digging skill in volleyball game play, t (30) = -0.486, p = 0.630 and spiking skill in volleyball game, t (30) = 1.623, p = 0.115. Moreover, tactical decision-making for opening and closing the space also showed no significant differences between the players from Sarawak and Penang, t (30) = 0.877, p = 0.387; t (30) = 0.939, p = 0.355. In conclusion, this finding proved that the development of volleyball game training between the two states are almost similar. It is suggested that volleyball player should focus on technical and tactical concurrently development in game play.

Анализ ресурсного потенциала объектов системы переработки нефтесодержащих отходов с учетом переменного эффекта масштаба

The article proposes a new approach developed according to the Data Envelopment Analysis (DEA) method for calculating the estimates of the resource potential of the schemes of oil-contaminated waste (OCW) storage - recycling technology as part of the OCW recycling system. A two-stage calculation algorithm has been developed, at the first stage of which the estimate of the resource value of the OCW in storages is calculated in a known way, and at the second stage, using the BCC and Super-efficiency models of the DEA method, estimates of the resource potential of system objects with a constant, decreasing or increasing effect of scale are determined. Depending on the ranking of the obtained estimates of the resource potential of the objects of comparison in the system and the effect of scale, the order of processing of the OCW in storages by the appropriate technologies is determined. The developed procedure for control waste recycling in the system allows making sound operational and tactical decisions based on the results of solving two optimization problems according to the criteria: increasing the resource potential of the system objects and reducing the processing time. Approbation of the developed approach was carried out on the example of the OCW recycling system, which includes 20 storage facilities and 10 technologies located on the territory of the Samara region. The proposed approach can be extended to other regions of the Russian Federation to make informed management decisions in the OCW recycling system.

Clear vision: a step towards unravelling student recruitment in English universities?

Purpose The recruitment of undergraduate students within English universities is of vital importance to both the academic success and the financial stability of the organisation. Despite the primacy of the task, there has been a dearth of research looking at related performance and how to ensure that the process is optimised. The purpose of this study was to investigate the degree of variation both within a university and between different universities. The reliance that individual programmes and/or universities place on the Clearing process is key; given its uncertainty, resource demands and timing shortly before students take up their places.Design/methodology/approach The Nomogramma di Gandy diagrammatical approach utilises readily available data to analyse universities’ performance in recruiting students to different programmes, and the degree to which they each rely of the Clearing process. Inter-university performance was investigated on a whole-student intake basis for a sample of English universities, representative of type and region.Findings The study found that there were disparate patterns for the many programmes within the pilot university and also disparate patterns between different types of universities across England. Accordingly, universities should internally benchmark their programmes to inform both strategic and tactical decision-making. Similarly, Universities and Colleges Admissions Service benchmarking inter-university patterns could inform the overall sector.Originality/value The approach and findings provide lessons for analysing student recruitment which could be critical to universities’ academic and financial health, in an increasingly competitive environment.

The Influence of Guardian and Warrior Police Orientations on Australian Officers’ Use of Force Attitudes and Tactical Decision-Making

Concerns about excessive use of force by U.S. police have led to calls for agencies to move from ‘warrior’ to ‘guardian’ policing. ‘Warrior’ policing embodies an aggressive or coercive approach to law enforcement, while ‘guardian’ policing prioritises communication, procedural justice and citizen safety. Associations between guardian and warrior policing orientations and use of force attitudes in the U.S. have been found, however the influence of these orientations on police use of force in Australia has not been examined. This study examined the association of guardian and warrior policing orientations with use of force attitudes, threat perceptions and tactical decision-making among Australian officers, through a survey of 183 police officers in Queensland. Regression analyses indicated that warrior policing was associated with greater support for use of force and greater perceived threat in an ambiguous threat scenario, while guardian policing was associated with more restraint in tactical decision-making among Australian police officers.

Tactical Features of Operation of the Specialized Anti-Epidemic Team of the Rospotrebnadzor on the Territory of the Republic of Crimea under Conditions Characteristic of a Combined Emergency

The tactics of activities of the specialized anti-epidemic team (SAET) of the Rospotrebnadzor on the territory of the Republic of Crimea has been determined by the conditions of emergency situation of sanitary-epidemiological and natural character. The aim of the work was to analyze the features and effectiveness of the functional response of the Rospotrebnadzor SAET to the dynamics of epidemiological risks caused by emergency of combined nature in the Republic of Crimea in 2020–2021. Materials and methods. We used report materials of the Rospotrebnadzor SAET; information materials of the Interregional Rospotrebnadzor Administration in the Republic of Crimea and the Federal city of Sevastopol; “Coronavirus Monitor” service data. Results and discussion. Tactical decisions on the work of the SAET on the territory of the Republic of Crimea had the stage-by-stage nature. In the event of a complication of the epidemiological situation on the new coronavirus infection, a mobile group of the SAET was involved. Together with specialists from the Plague Control Station of the Republic of Crimea, it conducted 211 148 studies of clinical material to detect SARS-CoV-2 RNA using PCR during the period of 2020–2021. In response to the emergence of additional risks caused by the consequences of a dangerous meteorological phenomenon, the group of SAET specialists was reinforced and mobile complex (MС) of the SAET was deployed. During the entire course of work, a prolonged target rotation of personnel was implemented in order to provide for adequate laboratory support for monitoring upon epidemiological indications in accordance with the nature of emerging risks. That tactics of operation made it possible to conduct 18 591 screening studies of clinical material for acute respiratory viral infections (ARVI), natural-focal and acute intestinal infections (AII), as well as the study of 280 water samples for cholera. Introduction of the sequence of operational procedures adapted for work in emergency situations resulted in isolation of 10 Vibrio cholerae O1 ctxA–</sup tcpA–/em> strains from water bodies. The phased involvement of the mobile group of SAET specialists, and later the MC of the SAET, in combination with the consistent operational target rotation of personnel in order to provide adequate laboratory support for monitoring studies, determined the tactical features of the SAET functioning. Prompt investigation, substantiation of potential and response to realized (actual) epidemiological risks associated with the extraordinary situation made it possible to prevent complications of the epidemiological situation in the territory of the tourist cluster of the Russian Federation.

A comparison of the learning effects between TGfU-SE and TGfU on learning motivation, sport enjoyment, responsibility, and game performance in physical education.

Both the Sport Education (SE) model and Teaching Games for Understanding (TGfU) have been connected to the theory of situated learning, which is a game-centered curricular model. TGfU emphasizes tactical awareness, decision making, and skill execution. The SE model provides a complete season during physical education (PE) lessons. Therefore, it is worth exploring the integration of TGfU with SE (TGfU-SE) model in PE courses, and whether the hybrid TGfU-SE model can achieve better learning effects for students than the TGfU model alone. The purpose of the study was to compare the difference in learning effects between the TGfU-SE model and the TGfU model on students' learning motivation, sport enjoyment, responsibility, and game performance. This study used a quasi-experimental design to compare different learning effects between the experimental group (TGfU-SE) and the control group (TGfU). The participants lived in Taiwan, including two junior high school PE teachers and four PE classes with a total of 90 students (TGfU-SE group, n = 46; TGfU group, n = 44). Each teacher taught two PE classes, one with an experimental group and one with a control group. This study used four research instruments, including the Responsibility Scale in Physical Education (RSPE), Learning Motivation Scale in Physical Education (LMSPE), Sport Enjoyment Scale in Physical Education (SESPE), and Game Performance assessment instrument (GPAI). Analysis of covariance (ANCOVA) and the independent t-test were used to analyze the data. The results of this study showed that the TGfU-SE model had more positive learning effects on students' learning motivation, sport enjoyment, responsibility, and game performance than the TGfU model. we concluded that the TGfU-SE model had a more positive influence on students' learning performance than the TGfU model. It is suggested that the hybrid TGfU-SE model could be implemented effectively in the PE curriculum.