• Title/Summary/Keyword: Timetable

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A Template-based Interactive University Timetabling Support System (템플릿 기반의 상호대화형 전공강의시간표 작성지원시스템)

  • Chang, Yong-Sik;Jeong, Ye-Won
    • Journal of Intelligence and Information Systems
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    • v.16 no.3
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    • pp.121-145
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    • 2010
  • University timetabling depending on the educational environments of universities is an NP-hard problem that the amount of computation required to find solutions increases exponentially with the problem size. For many years, there have been lots of studies on university timetabling from the necessity of automatic timetable generation for students' convenience and effective lesson, and for the effective allocation of subjects, lecturers, and classrooms. Timetables are classified into a course timetable and an examination timetable. This study focuses on the former. In general, a course timetable for liberal arts is scheduled by the office of academic affairs and a course timetable for major subjects is scheduled by each department of a university. We found several problems from the analysis of current course timetabling in departments. First, it is time-consuming and inefficient for each department to do the routine and repetitive timetabling work manually. Second, many classes are concentrated into several time slots in a timetable. This tendency decreases the effectiveness of students' classes. Third, several major subjects might overlap some required subjects in liberal arts at the same time slots in the timetable. In this case, it is required that students should choose only one from the overlapped subjects. Fourth, many subjects are lectured by same lecturers every year and most of lecturers prefer the same time slots for the subjects compared with last year. This means that it will be helpful if departments reuse the previous timetables. To solve such problems and support the effective course timetabling in each department, this study proposes a university timetabling support system based on two phases. In the first phase, each department generates a timetable template from the most similar timetable case, which is based on case-based reasoning. In the second phase, the department schedules a timetable with the help of interactive user interface under the timetabling criteria, which is based on rule-based approach. This study provides the illustrations of Hanshin University. We classified timetabling criteria into intrinsic and extrinsic criteria. In intrinsic criteria, there are three criteria related to lecturer, class, and classroom which are all hard constraints. In extrinsic criteria, there are four criteria related to 'the numbers of lesson hours' by the lecturer, 'prohibition of lecture allocation to specific day-hours' for committee members, 'the number of subjects in the same day-hour,' and 'the use of common classrooms.' In 'the numbers of lesson hours' by the lecturer, there are three kinds of criteria : 'minimum number of lesson hours per week,' 'maximum number of lesson hours per week,' 'maximum number of lesson hours per day.' Extrinsic criteria are also all hard constraints except for 'minimum number of lesson hours per week' considered as a soft constraint. In addition, we proposed two indices for measuring similarities between subjects of current semester and subjects of the previous timetables, and for evaluating distribution degrees of a scheduled timetable. Similarity is measured by comparison of two attributes-subject name and its lecturer-between current semester and a previous semester. The index of distribution degree, based on information entropy, indicates a distribution of subjects in the timetable. To show this study's viability, we implemented a prototype system and performed experiments with the real data of Hanshin University. Average similarity from the most similar cases of all departments was estimated as 41.72%. It means that a timetable template generated from the most similar case will be helpful. Through sensitivity analysis, the result shows that distribution degree will increase if we set 'the number of subjects in the same day-hour' to more than 90%.

Calibration of Timetable Parameters for Rail-Guided Systems

  • Zhao, Weiting;Martin, Ullrich;Cui, Yong;Kosters, Maureen
    • International Journal of Railway
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    • v.9 no.1
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    • pp.1-9
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    • 2016
  • In order to achieve a comprehensive utilization of railway networks, it is necessary to accurately assess the timetable indicators that effect the train operation. This paper describes the parameter calibration for two timetable indicators: scheduled running time and scheduled dwell time. For the scheduled running time, an existing model is employed and the single timetable parameter (percentage of minimum running time) in that model is optimized. For the scheduled dwell time, two intrinsic characteristics: the significance of stations and the average headway at each station are proposed firstly to form a new model, and the corresponding timetable parameters (the weight of the significance and the weight of the average headway) are calibrated subsequently. The Floyd Algorithm is used to obtain the connectivity among stations, which represents the significance of the stations. A case study is conducted in a light rail transportation system with 17 underground stations. The results of this research show that the optimal value of the scheduled running time parameter can be automatically determined, and the proposed model for the scheduled dwell time works well with a high coefficient of determination and low relative root mean square error through the leave-one-out validation.

Flexibility and Controllability of Symmetric Timetable Modules with Potential Blocks (잠재적 블록을 가지는 대칭적 시간표 모듈의 유연성과 제어성)

  • Ha, Jong-Sung;Yoo, Kwan-Hee
    • The Journal of the Korea Contents Association
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    • v.18 no.12
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    • pp.229-237
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    • 2018
  • This paper considers effective timetable modules in order to easily satisfy various user requirements during scheduling timetables in universities. Noticing that the methods for allocating time blocks change according to the timetable modules, we suggest six models of symmetric timetable modules composed of 4 blocks, and show that our models have more benefits without any loss from the viewpoint of customers, if the suppliers consider the decreasing upper bound of ratio utilizing space resources. By adapting a concept of potentially determined blocks and suggesting their management strategies, finally, we accomplish a method for supporting flexibility and controllability when the universities timetables are scheduled.

A Study on Time-Expanded Network Approach for Finding Maximal Capacity of Extra Freight on Railway Network (시간전개형 네트워크 접근법을 이용한 기존 열차시각표를 고려한 추가적 철도화물 최대수송량 결정에 관한 연구)

  • Ahn, Jae-Geun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.8
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    • pp.3706-3714
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    • 2011
  • This study deals with the algorithm to finding the maximum capacity and their schedule of extra freight while honoring planned timetable of trains on railway network. Time-expanded network, a kind of space-time graph, can be shown both planned train timetable and dynamic features of given problem. Pre-processing procedure is a series of infeasible arcs removal from time-expanded network honoring planned timetable. In the result, this preprocessing transforms dynamic features of given problem into static maximal flow problem which can be easily solved.

An Exploratory Development of Railway-timetable Rescheduling Model Considering Transferring Service between KTX and Conventional Train on a Double Line Track (KTX열차와 일반열차 간 접속대기를 고려한 복선구간 열차시각표 재수립 모형의 기본설계)

  • Kim, Jae-Hee;Oh, Seok-Moon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.6
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    • pp.1337-1345
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    • 2009
  • In the railway, the delay of a train may affect the schedule of other trains. Hence, the timetable management activity involving overtaking and transferring becomes an important issue. The timetable rescheduling is the conflict resolution of the disrupted schedule and a matter of deciding the sequence of moves among trains and the place for meeting. In Korea, there are few cases where operations research models were applied to railway timetable rescheduling problem in consideration of the transfer between Korea Train eXpress (KTX) trains and conventional trains. Hence, we present a mathematical approach that can minimize the total delay of the whole trains secondly. We applied the model to the exemplary section of a double-line track, the Gyung-Boo Line, and it is confirmed that the mathematical model could effectively address the transfer service as well as the complicated railway conflicts of Gyung-Boo Line.

A Study on School Timetabling (강의시간표 작성기법에 관한 연구)

  • 신영수
    • Journal of the Korean Operations Research and Management Science Society
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    • v.8 no.2
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    • pp.67-71
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    • 1983
  • The purpose of this paper is to propose a method of constructing a school timetable under consideration of subjects, teachers, classes, rooms, activity types and so on. The method gives an acceptable timetable which satisfies all dispensable requirements and different timetables also are obtained by changing the order of assignments. The resulting timetables are evaluated and compared by scoring scheme which can be modified by users. The results achieved using real data have been encouraging.

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An Enumeration Algorithm for the Rolling Stock Requirement Plan (철도차량소요계획을 위한 열거알고리듬)

  • Kim Seongho;Kim Dong-Hee;Choi Tae-Sung
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.514-521
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    • 2004
  • A routing is the path that an actual train set follows as it moves from one train to another train in a timetable. The number of routings is equivalent to the number of trainsets required to cover the timetable. The primary factors of rolling stock requirement plan include evaluating the minimum number of routings. This can be formulated as a set partitioning problem and solved using enumeration method or column generation method. In this paper we presents an enumeration algorithm which is useful to implement the enumeration method for the rolling stock requirement plan.

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An Optimization Model for Minimizing Transfer Time (도시철도 환승시간 최소화를 위한 최적화 모형)

  • Sohn, Moo-Sung;Kim, Kwang-Tae;Kim, Se-Won;Oh, Suk-Mun
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1722-1729
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    • 2011
  • This paper presents an optimization model for revising train timetable based on an existing timetable to improve transfer time at each station. The transfer time consists of walking and waiting time. The model is formulated as a mixed integer programming. The objective function is to minimize the transfer time from one train to another train at each station. To reflect real situations, range of revising departure time is considered as major condition in the model. To validate the effectiveness of the model, rudimentary computational results are included, and the results are analyzed in terms of transfer time.

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Design A Timetable System Using A Genetic Algorithm (유전알고리즘을 이용한 강의시간표 작성 시스템 설계)

  • Kang, Myung-Ju
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2011.01a
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    • pp.289-292
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    • 2011
  • 본 논문에서는 유전 알고리즘을 이용한 강의시간표 작성 시스템 설계 방법을 제안한다. 강의시간표는 교과목의 강의시간, 강의실, 교수자 등의 정보를 시간표 테이블에 할당하는 문제이면서 스케줄링 문제이다. 강의시간표로써의 의미를 가지기 위해서는 강의실 중복 회피, 교수의 강의시간 중복회피와 같은 필수 제약조건(Hard Constraint)을 만족해야 한다. 또한, 강의시간표 문제는 NP-Complete 문제로 알려져 있으며 기존의 Exact 알고리즘으로는 최적 해를 구하는 것이 힘들다. 따라서 본 논문에서는 휴리스틱 알고리즘 중의 하나인 유전 알고리즘을 교과목의 강의시간 배정 부분과 강의실 배정 부분을 각각 별도의 부시스템 (Sub-system)으로 나누어 적용하는 방법을 제안한다. 실험 결과 강의시간표로써의 의미를 가질 수 있는 필수 제약 조건을 만족시킬 수 있음을 알 수 있었다.

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