• Title, Summary, Keyword: Turnaround time

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Study on Relationship between Turn-back Time and Assignment of Trainsets (철도 차량의 반복시간과 소요량 사이의 관계 고찰)

  • Ki, Hyung-seo;Oh, Suk-mun;Park, Dongjoo
    • Journal of the Korean Society for Railway
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    • v.19 no.6
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    • pp.802-814
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    • 2016
  • This study examines the relationship between the operational turnaround time and the rolling stock requirements. In this study, the operational turnaround time of rolling stock is divided into physical turnback time and waiting time. This paper presents a variety of models and estimation results of the existing studies on operational turnaround time. The proposed estimation model of the operational turnaround time in this study is designed to minimize the operational turnaround time in terminus stations, while the rolling stock requirement is reduced. The developed estimation model was applied in a real-world example, and it was found that the operational turnaround time and the required rolling stocks were lessened compared with the current condition. The method presented in this paper is expected to be utilized in train operational planning and rolling stock routing plans, thereby minimizing the rolling stock requirements of existing railway operating authorities.

RFID-Based RTLS for Improvement of Loading Productivity in Container Terminals

  • Park, Doo-Jin;Nam, Ki-Chan
    • Journal of Navigation and Port Research
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    • v.30 no.4
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    • pp.285-290
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    • 2006
  • Shipping companies consider most of the ship turnaround time as a critical factor when selecting a rolling port for reducing costs. So, many researchers have been studying for the optimization of preplanning and high~performance of the Gantry Cranes (GCs) in container terminals for faster loading and unloading. Therefore, in this paper, we propose an RFID (Radio Frequency Identification) based RTLS (Real-Time Location System) for reducing the ship turnaround time in ubiquitous port environment. In addition, pre-planning based on ubiquitous computing environment will support the GC and Yard Tractors (YTs), and reduce ship turnaround time more effectively. Especially, the proposed method enormously enhances the productivity of loading for the twin-lift system It will reduce the whole lead-time in the process of port logistics.

A Sensitivity Risk Analysis for Additional Truck Turnaround Time (ATTT) by Container Inspection Stations Derived from C-TPAT and CSI.

  • Yoon, Dae-Gwun
    • Journal of Navigation and Port Research
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    • v.31 no.2
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    • pp.151-157
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    • 2007
  • After World Trade Center's Terror in 2001 and promulgating Maritime Transportation Security Act (MTSA, 2002) and Security and Accountability For Every Port Act (SAFE Port Act, 2006) in the United States, most of the attention on security of international transportation including marine carrier and facility has focused increasingly. Inspection stations in foreign seaport terminal including Busan, South Korea, have been installed by Container Security Initiative (CSI) and Customs Trade Partnership against Terrorism (C-TPAT). The inspection station, however, may directly and indirectly affect delay of truck turnaround time in the seaport, especially high and severe level of security. This paper was analysed a risk for the additional average delay of truck turnaround time incurring by the inspection station under the all level of security, C-TPAT and CSI. As a result of this risk analysis, the higher weighted inspection time based on raising security level, the less number of trucks to be inspected, which will derive high delay in the inspection station.

Analysis of Average Waiting Time and Average Turnaround Time in Web Environment (웹 환경에서의 평균 대기 시간 및 평균 반환 시간의 분석)

  • Lee, Yong-Jin
    • The KIPS Transactions:PartC
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    • v.9C no.6
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    • pp.865-874
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    • 2002
  • HTTP (HyperText Transfer Protocol) is a transfer protocol used by the World Wide Web distributed hypermedia system to retrieve the objects. Because HTTP is a connection oriented protocol, it uses TCP (Transmission control Protocol) as a transport layer. But it is known that HTTP interacts with TCP badly. it is discussed about factors affecting the performance or HTTP over TCP, the transaction time obtained by the per-transaction TCP connections for HTTP access and the TCP slow-start overheads, and the transaction time for T-TCP (Transaction TCP) which is one or methods improving the performance or HTTP over TCP. Average waiting time and average turnaround time are important parameters to satisfy QoS (Quality of Service) of end users. Formulas for calculating two parameters are derived. Such formulas can be used for the environment in which each TCP or T-TCP transaction time is same or different. Some experiments and computational experiences indicate that the proposed formulas are well acted, can be applied to the environment which the extension of bandwidth is necessary, and time characteristics of T-TCP are superior to that of TCP. Also, the load distribution method of web server based on the combination of bandwidths is discussed to reduce average waiting time and average turnaround time.

A Prediction Model of Timely Processing on Medical Service using Classification and Regression Tree (분류회귀나무를 이용한 의료서비스 적기처리 예측모형)

  • Lee, Jong-Chan;Jeong, Seung-Woo;Lee, Won-Young
    • Journal of IKEEE
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    • v.20 no.1
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    • pp.16-25
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    • 2016
  • Turnaround time (called, TAT) for imaging test, which is necessary for making a medical diagnosis, is directly related to the patient's waiting time and it is one of the important performance criteria for medical services. In this paper, we measured the TAT from major imaging tests to see it met the reference point set by the medical institutions. Prediction results from the algorithm of classification regression tree (called, CART) showed "clinics", "diagnosis", "modality", "test month" were identified as main factors for timely processing. This study had a contribution in providing means of prevention of the delay on medical services in advance.

CPU Scheduling with a Round Robin Algorithm Based on an Effective Time Slice

  • Tajwar, Mohammad M.;Pathan, Md. Nuruddin;Hussaini, Latifa;Abubakar, Adamu
    • Journal of Information Processing Systems
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    • v.13 no.4
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    • pp.941-950
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    • 2017
  • The round robin algorithm is regarded as one of the most efficient and effective CPU scheduling techniques in computing. It centres on the processing time required for a CPU to execute available jobs. Although there are other CPU scheduling algorithms based on processing time which use different criteria, the round robin algorithm has gained much popularity due to its optimal time-shared environment. The effectiveness of this algorithm depends strongly on the choice of time quantum. This paper presents a new effective round robin CPU scheduling algorithm. The effectiveness here lies in the fact that the proposed algorithm depends on a dynamically allocated time quantum in each round. Its performance is compared with both traditional and enhanced round robin algorithms, and the findings demonstrate an improved performance in terms of average waiting time, average turnaround time and context switching.

Efficient Task Distribution Method for Load Balancing on Clusters of Heterogeneous Workstations (이기종 워크스테이션 클러스터 상에서 부하 균형을 위한 효과적 작업 분배 방법)

  • 지병준;이광모
    • Journal of Internet Computing and Services
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    • v.2 no.3
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    • pp.81-92
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    • 2001
  • The clustering environment with heterogeneous workstations provides the cost effectiveness and usability for executing applications in parallel. The load balancing is considered as a necessary feature for the clustering of heterogeneous workstations to minimize the turnaround time. Since each workstation may have different users, groups. requests for different tasks, and different processing power, the capability of each processing unit is relative to the others' unit in the clustering environment Previous works is a static approach which assign a predetermined weight for the processing capability of each workstation or a dynamic approach which executes a benchmark program to get relative processing capability of each workstation. The execution of the benchmark program, which has nothing to do with the application being executed, consumes the computation time and the overall turnaround time is delayed. In this paper, we present an efficient task distribution method and implementation of load balancing system for the clustering environment with heterogeneous workstations. Turnaround time of the methods presented in this paper is compared with the method without load balancing as well as with the method load balancing with performance evaluation program. The experimental results show that our methods outperform all the other methods that we compared.

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Batch Resizing Policies and Techniques for Fine-Grain Grid Tasks: The Nuts and Bolts

  • Muthuvelu, Nithiapidary;Chai, Ian;Chikkannan, Eswaran;Buyya, Rajkumar
    • Journal of Information Processing Systems
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    • v.7 no.2
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    • pp.299-320
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    • 2011
  • The overhead of processing fine-grain tasks on a grid induces the need for batch processing or task group deployment in order to minimise overall application turnaround time. When deciding the granularity of a batch, the processing requirements of each task should be considered as well as the utilisation constraints of the interconnecting network and the designated resources. However, the dynamic nature of a grid requires the batch size to be adaptable to the latest grid status. In this paper, we describe the policies and the specific techniques involved in the batch resizing process. We explain the nuts and bolts of these techniques in order to maximise the resulting benefits of batch processing. We conduct experiments to determine the nature of the policies and techniques in response to a real grid environment. The techniques are further investigated to highlight the important parameters for obtaining the appropriate task granularity for a grid resource.

Efficient Simulation Acceleration by FPGA Compilation Avoidance (FPGA 컴파일 회피에 의한 효과적인 시뮬레이션 가속)

  • Shim, Kyu-Ho;Park, Chang-Ho;Yang, Sei-Yang
    • The KIPS Transactions:PartA
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    • v.14A no.3
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    • pp.141-146
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    • 2007
  • In this paper, we proposed an efficient FPGA-based simulation acceleration method based on FPGA compilation avoidance, which can effectively decrease the long debugging turnaround time incurred from the every debugging process in the functional verification. The proposed method had been experimentally applied to the functional verification for a microcontroller design. It had clearly shown that the debugging turnaround time was greatly reduced while the high simulation speed of the simulation acceleration was still maintained.

Load Balancing of Heterogeneous Workstation Cluster based on Relative Load Index (상대적 부하 색인을 기반으로 한 이기종 워크스테이션 클러스터의 부하 균형)

  • Ji, Byoung-Jun;Lee, Kwang-Mo
    • Journal of KIISE:Computing Practices and Letters
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    • v.8 no.2
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    • pp.183-194
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    • 2002
  • The clustering environment with heterogeneous workstations provides the cost effectiveness and usability for executing applications in parallel. Load balancing is considered a necessary feature for a cluster of heterogeneous workstations to minimize the turnaround time. Previously, static load balancing that assigns a predetermined weight for the processing capability of each workstation, or dynamic approaches which execute a benchmark program to get relative processing capability of each workstation were proposed. The execution of the benchmark program, which has nothing to do with the application being executed, consumes the computation time and the overall turnaround time is delayed. In this paper, we present efficient methods for task distribution and task migration, based on the relative load index. We designed and implemented a load balancing system for the clustering environment with heterogeneous workstations. Turnaround times of our methods and the round-robin approach, as well as the load balancing method using a benchmark program, were compared. The experimental results show that our methods outperform all the other methods that we compared.