Modeling Queue Service System in Pedestrian Simulation

2011 ◽  
Vol 187 ◽  
pp. 1-6 ◽  
Author(s):  
De Wei Li ◽  
Bao Ming Han
Keyword(s):  
Large Scale ◽  
Service System ◽  
Safety Control ◽  
Large Scale Systems ◽  
Queue System ◽  
Proposed Model ◽  
Machine Layout ◽  
Pedestrian Simulation ◽  
Grid Based

Pedestrian simulation is widely used on the assessment of facility design and crowd safety control. It proposed a grid-based model of queue simulation system considering human physiology and psychology. Both logic queue system and animation queue system are modeled separately. Deadlock deal mechanism is designed. The proposed model established a good interface between the pedestrian behavior, queue system and animation. It can reproduce phenomenon like traffic shock wave effectively. A case study is shown by simulation of ticket vendor machine layout assessment in Beijing South Railway Station. It concluded that the model is effective and adapted to large scale systems.

scholarly journals Sustainable Ship Loading Planning for Prefabricated Products in the Construction Industry

2020 ◽  
Vol 12 (21) ◽  
pp. 8905
Author(s):  
Wen Yi ◽  
Robyn Phipps ◽  
Hans Wang
Keyword(s):  
Construction Industry ◽  
Large Scale ◽  
Transportation Cost ◽  
Sustainable Transportation ◽  
Construction Site ◽  
Integer Optimization ◽  
Construction Sites ◽  
Capacity Limits ◽  
Proposed Model

This paper focuses on sustainable transportation of prefab products from factories to construction sites by ship. Since the transportation cost for all the prefab products of a construction site is mainly dependent on the number of cargo holds used on ships, a loading plan for prefab products that minimizes the number of holds required is highly desirable. This paper is therefore devoted to the development of an optimal loading plan that decides which prefab products are loaded into each cargo hold and how to pack these prefab products into the holds so that as few holds as possible are used. We formulate the problem as a large-scale integer optimization model whose objective function is to minimize the total number of cargo holds used and whose constraints represent the cargo hold capacity limits. We develop a heuristic to solve the problem and obtain a high-quality solution. We have tested the model and algorithm on a case study that includes 20 prefab products. We find that different cargo holds carry prefab products that have quite different densities. Moreover, the orientations of many prefab products are different from their default orientations. The results demonstrate the applicability of the proposed model and algorithm.

scholarly journals Impact of Prioritization on the Outpatient Queuing System in the Emergency Department with Limited Medical Resources

Symmetry ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 796 ◽  
Author(s):  
Ao Zhang ◽  
Xiaomin Zhu ◽  
Qian Lu ◽  
Runtong Zhang
Keyword(s):  
Emergency Department ◽  
Emergency Services ◽  
Service System ◽  
Queuing System ◽  
Hospital Service ◽  
Key Factors ◽  
Queuing Model ◽  
Medical Resources ◽  
Proposed Model

The emergency department has an irreplaceable role in the hospital service system because of the characteristics of its emergency services. In this paper, a new patient queuing model with priority weight is proposed to optimize the management of emergency department services. Compared with classical queuing rules, the proposed model takes into consideration the key factors of service and the first-come-first-served queuing rule in emergency services. According to some related queuing indicators, the optimization of emergency services is discussed. Finally, a case study and some compared analysis are conducted to illustrate the practicability of the proposed model.

Dynamic Meta-Learning for Failure Prediction in Large-Scale Systems: A Case Study

2008 ◽  
Author(s):  
Jiexing Gu ◽  
Ziming Zheng ◽  
Zhiling Lan ◽  
John White ◽  
Eva Hocks ◽  
...  
Keyword(s):  
Large Scale ◽  
Failure Prediction ◽  
Large Scale Systems ◽  
Meta Learning

Applying RCM in large scale systems: a case study with railway networks

2003 ◽  
Vol 82 (3) ◽  
pp. 257-273 ◽  
Author(s):  
Jesús Carretero ◽  
José M. Pérez ◽  
Félix Garcı́a-Carballeira ◽  
Alejandro Calderón ◽  
Javier Fernández ◽  
...  
Keyword(s):  
Large Scale ◽  
Large Scale Systems ◽  
Railway Networks

scholarly journals Container Slot Co-Allocation Planning with Joint Fleet Agreement in a Round Voyage for Liner Shipping

2013 ◽  
Vol 66 (4) ◽  
pp. 589-603 ◽  
Author(s):  
Jihong Chen ◽  
Shmuel Yahalom
Keyword(s):  
Large Scale ◽  
Economies Of Scale ◽  
Programming Model ◽  
Liner Shipping ◽  
Shipping Industry ◽  
Round Trip ◽  
Factors Affecting ◽  
Proposed Model ◽  
Allocation Planning

In the liner shipping market carriers share container slots to offer better service and realize economies of scale. This paper studies slot co-allocation planning for a joint fleet in a round trip for a shipping alliance in the liner shipping industry. In particular, a conceptual model is developed based on joint fleet and slot co-allocation management. The factors affecting slot co-allocation planning are explored in detail. A large-scale integer programming model is formulated to guide carriers in an alliance in pursuing an optimal slot co-allocation strategy. In contrast to the existing research, this approach leads to a more accurate representation of the situation for cooperative services in the liner shipping market. Extensive numerical experiments based on a true Asia-Europe cooperative route of COSCO and HANJIN show that the proposed model can be efficiently solved by LINGO11.0 for the case study. The computational results suggest that the mechanism and model can be used to benefit carriers in making better decisions in shipping cooperation services.

scholarly journals False Sequential Command Attack of Large-Scale Cyber-Physical Systems

Electronics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 176 ◽  
Author(s):  
Yinqiao Xiong ◽  
Ziyu Yang ◽  
Baoyao Wang ◽  
Peng Xun ◽  
Tiantian Deng
Keyword(s):  
Physical Process ◽  
Large Scale ◽  
Cyber Physical Systems ◽  
Physical Systems ◽  
Attack Model ◽  
Command Sequence ◽  
Proposed Model ◽  
Feedback Data ◽  
Bad Data

Previous studies have demonstrated that false commands can cause severe damage to large-scale cyber-physical systems (CPSs). We focus on a kind of threat called false sequential command attack, with which attackers can generate false sequential commands, resulting in the illegal control of the physical process. We present a feasible attack model. Attackers delay the disaggregation of former commands by manipulating maliciously sub-controllers. Simultaneously, bad feedback data is injected to defeat the controller to issue latter commands. Thus, false command sequence is executed and the disruption of physical process can be obtained. It is also difficult for the detector to identify such attacks as injecting bad data. We also discuss other possible attack paths and analyze the corresponding disadvantages. Compared with other paths, the proposed model is more feasible and has more difficulties to be detected. A case study is given to validate the feasibility and effectiveness of proposed false sequential command attack model. Finally, we discuss the possible countermeasure.

Social movements thinking for managing change in large-scale systems

2020 ◽  
Vol 33 (5) ◽  
pp. 697-714
Author(s):  
Judith A. Holton
Keyword(s):  
Social Movements ◽  
Conceptual Framework ◽  
Large Scale ◽  
System Change ◽  
Status Quo ◽  
Content Type ◽  
Large Scale Systems ◽  
Large Scale System ◽  
The Status

PurposeThis study explores the efficacy of social movements thinking for mobilizing resources toward sustainable change in large-scale systems such as health and social services.Design/methodology/approachThe study proceeds from a critical realist perspective employing a qualitative multi-case study approach. Drawing on the tenets of grounded theory (i.e. constant comparative analysis and theoretical sampling), data from semi-structured interviews and field notes were analyzed to facilitate theoretical integration and elaboration.FindingsOne case study explores the emergence of social movements thinking in mobilizing a community to engage in sustainable system change. Data analysis revealed a three-stage conceptual framework whereby building momentum for change requires a fundamental shift in culture through openness and engagement to challenge the status quo by acknowledging not only the apparent problems to be addressed but also the residual apathy and cynicism holding the system captive to entrenched ideas and behaviors. By challenging the status quo, energy shifts and momentum builds as the community discovers shared values and goals. Achieving a culture shift of this magnitude requires leadership that is embedded within the community, with a personal commitment to that community and with the deep listening skills necessary to understand and engage the community and the wider system in moving forward into change. This emergent conceptual framework is then used to compare and discuss more intentional applications of social movements thinking for mobilizing resources for large-scale system change.Originality/valueThis study offers a three-stage conceptual framework for mobilizing community/system resources toward sustainable large-scale system change. The comparative application of this framework to more intentional applications of social movements thinking to planned change initiatives offers insights and lessons to be learned when large-scale systems attempt to apply such principles in redesigning health and social service systems.

scholarly journals Typical Daily Profiles, a novel approach for photovoltaics performance assessment: Case study on large-scale systems in Chile

Solar Energy ◽  
2021 ◽  
Vol 225 ◽  
pp. 357-374
Author(s):  
Julián Ascencio-Vásquez ◽  
Juan Carlos Osorio-Aravena ◽  
Kristijan Brecl ◽  
Emilio Muñoz-Cerón ◽  
Marko Topič
Keyword(s):  
Performance Assessment ◽  
Large Scale ◽  
Large Scale Systems ◽  
Novel Approach
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