For signalized locations, delay is one of the key parameters in assessing the level of service and redesigning the traffic signals. Around the world, Highway Capacity Manual (HCM) and Webster delay ...models are commonly used in calculating the vehicle delay at signalized intersections, notwithstanding that these models assume homogeneous traffic conditions and lane discipline. Furthermore, it is worth noting that previous studies have mostly focused on developing delay models for signalized intersections, whereas signalized midblock crosswalks were overlooked by past researchers. In view of this, the current study presents a modified vehicle delay model for signalized midblock crosswalks (SMCs) under mixed traffic conditions. Mixed traffic conditions refers to diverse vehicles, complex interactions, and no lane discipline on the road—conditions which are usually noticed in developing nations. The HCM vehicle delay model is modified in the current study by incorporating factors related to mixed traffic conditions and SMCs. To test the accuracy of the proposed model, it was validated with the field delay using data collected at other SMCs in Hyderabad, India. Field delay was calculated by plotting the measured queue length against the signal cycle length. The performance metrics of root mean square error (RMSE), mean absolute percentage error, Nash–Sutcliffe efficiency, RMSE-observations standard deviation ratio, and percent bias were used to test the accuracy of the proposed model. Results revealed that the proposed model yielded the lowest error rates and the highest correlation coefficients between modeled and actual vehicle delay. The maximum error between the field delay and the modeled delay was found to be less than 5%.
Regional perimeter control based on the existence of macroscopic fundamental diagrams has been widely studied as an effective tool to regulate traffic and prevent oversaturation in dense urban areas. ...Significant research efforts have been performed concerning the modeling aspects of perimeter control. More recently, data-driven techniques for perimeter control have shown remarkable promise; however, few studies have examined the transferability of these techniques. While it is surely of the highest priority to devise effective perimeter control methods, the ability of such methods to transfer the learned knowledge and quickly adapt control policies to a new setting is critical, particularly in real-life situations where training a method from scratch is intractable. This work seeks to bridge this research gap by comprehensively examining the effectiveness and transferability of a reinforcement-learning-based perimeter control method for a two-region urban network in a microsimulation setting. The results suggest: 1) the presented data-driven method demonstrates promising control effectiveness in comparison with no perimeter control and an extended greedy controller and 2) the method can readily transfer its learned knowledge and adapt its control policy with newly collected data to simulation settings with different traffic demands, driving behaviors, or both.
In recent years, with the introduction of national, provincial and municipal policies, rules and regulations, and the introduction of big data technology, drug control personnel have further ...increased their awareness of data. However, in practice, how to carefully control drugs and make full use of big data technology to improve the level of control has become a new confusion for drug control personnel. Therefore, the purpose of this paper is to study the platform of auxiliary drug control based on big data. Based on the actual situation of drug use, this paper analyzes the main problems in the process of drug control, and designs an auxiliary drug control platform based on big data. The auxiliary drug management and control platform based on big data proposed in this paper can collect data in real time, comprehensively analyze all kinds of information, and realize intelligent management and improve the efficiency of each specific application scenario. In this paper, through the research of drug use management and control platform, doctors can get scientific guidance in formulating drug use plan, and the efficiency of drug query is improved by about 80% compared with the traditional plan. At the same time, the drug use plan can be improved in time according to the patient's illness development in the process of drug use, which promotes the rational and standardized clinical application of drugs.
Design methods to transform actual aircraft propulsion systems into hybrid, and to analyze the performance must be developed. Present work details the first approach of a preliminary design method ...and evaluation of a hybrid-electric power-train for a conventional airplane. High fidelity models of the components are developed based on the physical relations of the involved variables. The main characteristics of the chosen aircraft with conventional propulsion on a typical mission are the inputs of an application developed in SUAVE, which renders aerodynamic variables for the design process. The turboprop engines of the conventional and hybrid (in parallel architecture) systems are modeled in GasTurb. The propeller is modeled using blade element momentum theory (BEMT) on the software JBlade. The first simulation results are used to calculate the initial power-train electrical components characteristics. Modeling results in steady state conditions are inputs of a code developed in MatLab, a design optimization algorithm that calculates the base characteristics of the optimal hybrid motor components. The method was tested employing the gas turbine TR5000 on turbo-prop configuration as the engine of the hybrid set. The aircraft EMB–120 ‘Brasilia’ was the airplane of this application, aiming to characterize the most important outcomes from this multidisciplinary approach.
Purpose
Since the introduction of balanced scorecard by Kaplan and Norton in 1992, it garnered considerable research and practice attention across disciplines. Using bibliometric analysis, this study ...examines trends in balanced scorecard research in last 20 years and identifies future areas of research.
Design/methodology/approach
The Web of Science database was used to extract research papers from the 2003 to 2023 period with “Balanced Scorecard” as topic. The final sample consisted of 445 articles. Trends and patterns were analyzed using bibliometric analysis through research profiling and thematic analysis.
Findings
The findings reveal that BSC, spanning across disciplines, including business and operations, has enriched the theory and practice of BSC research. Analytical and survey methods were more prevalent than primary studies. Scholars from the USA and the UK have made noteworthy contributions to balanced scorecard research. Emerging themes include integrating human resources, sustainability, subjectivity in performance evaluation and non-financial performance indicators in BSC for better strategic decision-making.
Practical implications
The study would inspire researchers to generate new research questions and hypotheses and help in identifying gaps in the current knowledge base and areas where further investigation is needed. Managers would gain useful insights into performance management by studying the BSC research evolution to find a fit for modern-day industry needs.
Originality/value
The authors’ contribution fills the void by providing useful account of extent research over last 20 years using bibliometric analysis and motivate future research directions.
To solve the problems of strong uncertainty, dynamics, and high complexity during the operation process in a discrete manufacturing shop floor that produces a variety of variable-volume products, a ...data-driven smart management and control framework of a digital twin shop floor (DTS) is proposed. Its implementation process is analyzed. Five key tasks are illustrated in detail: (1) the construction of a shop floor digital twin (DT) model from the multi-dimensional multi-scale perspective; (2) data acquisition and management technology in a DTS; (3) the real-time data-driven synchronous modeling of the shop floor operating status; (4) the model- and data-driven online prediction of the shop floor operation status; and (5) the multi-agent-based operation decision of a DTS. In addition, for products that are complex to produce on the assembly shop floor, a DT-based smart management and control system named the DT-VPPC is developed. The effectiveness of the proposed method is verified by a specific application example on an assembly shop floor.
Buildings are responsible for over 30% of global final energy consumption and nearly 40% of total CO2 emissions. Thus, rapid penetration of renewable energy technologies (RETs) in this sector is ...required. Integration of renewable energy sources (RESs) into residential buildings should not only guarantee an overall neutral energy balance over long term horizon (nZEB concept), but also provide a higher flexibility, a real-time monitoring and a real time interaction with end-users (smart-building concept). Thus, increasing interest is being given to the concepts of Hybrid Renewable Energy Systems (HRES) and Multi-Energy Buildings, in which several renewable and nonrenewable energy systems, the energy networks and the energy demand optimally interact with each other at various levels, exploring all possible interactions between systems and vectors (electricity, heat, cooling, fuels, transport) without them being treated separately. In this context, the present paper gives an overview of functional integration of HRES in Multi-Energy Buildings evidencing the numerous problems and potentialities related to the application of HRESs in the residential building sector. Building-integrated HRESs with at least two RESs (i.e., wind–solar, solar–geothermal and solar–biomass) are considered. The most applied HRES solutions in the residential sector are presented, and integration of HRES with thermal and electrical loads in residential buildings connected to external multiple energy grids is investigated. Attention is focused on the potentialities that functional integration can offer in terms of flexibility services to the energy grids. New holistic approaches to the management problems and more complex architectures for the optimal control are described.
In recent years, variable speed limit (VSL) strategies have proven to be an efficient control measure to mitigate traffic congestion at freeway bottlenecks. In general, the VSL change time is a ...constant value. However, there are certain limitations in traffic situations handled by a constant cycle VSL. Therefore, in this paper, we develop a dynamic cycle strategy of VSL based on predictive control. We first analyze the applicable situation of the dynamic control cycle and establish a probability model to determine the range of cycle selection. Then, the cell transmission model predicts the parameters of macroscopic traffic flow. Finally, an optimization algorithm is designed that is suitable for this strategy, which optimizes the cycle and speed limit options. An objective optimization function is formulated to minimize the total travel time. A sensitivity analysis is applied to compare different control strategies under a variety of road bottleneck structures by both the numerical analysis and simulation experiments. The simulation results show that the strategies and algorithms proposed in this paper can effectively reduce traffic congestion duration and enhance the service level of a freeway network.
Dedicated lanes for autonomous vehicles (AV) are introduced as an effective strategy to improve mobility in mixed traffic of AVs and heterogeneous drivers. However, adding a new lane is costly, and ...dedicating an existing lane may increase traffic congestion in other lanes. Previous studies investigated the impacts of AV dedicated lanes on throughput at the segment level and/or assumed a fixed route choice. However, AV dedicated lanes change route choice behavior, which affects traffic distribution over the network. Therefore, this study explores the impacts of AV dedicated lanes on the traffic performance of large-scale networks by conducting a network-level cost–benefit analysis on the implementation of AV dedicated lanes under different demand and AV market penetration rate (MPR) scenarios. This study examines the impacts of implementing AV dedicated lanes to freeway links on traffic congestion at corridor and network levels. Various factors are explored: changes in aggregate flow–density relationships, throughput, and average travel times. To this end, DYNASMART-P software is updated to consider AV dedicated lanes and is used to simulate the mixed traffic. Traffic simulation analyses on the large-scale network of Chicago indicate that these impacts depend on the AV MPR, demand level, and AV dedicated lane implementation approach. Dedicated lanes for AVs are beneficial for a high demand level scenario at all AV MPRs. However, for the base demand scenario, (760,000 vehicles during a.m. peak), deploying such lanes is only justified for low AV MPRs. Furthermore, the impacts of AV dedicated lanes on traffic at the network level are different from those on single segments.
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