• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.11
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• pp.973-980
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• 2016

An air traffic management (ATM) has been studied in a variety of fields to utilize an air traffic capacity efficiently and solve a congested air traffic situation due to an increment of an air traffic demand. In this paper, an air traffic management, which is related with controlling and determining the sequencing of an aircraft approaching to an airport, in terminal control area is studied. This paper focuses on scheduling algorithms with a given problem for the air traffic management with operational constraints, such as a space separation, an overtaking on the same air-route, and a route merge point (a scheduling point). For a real-time calculation, the presented algorithms focus on dispatching heuristic rules which are able to assign tasks in a fast time period with an adequate performance, which can be demonstrated as a proper and realistic scheduling algorithm. A simulation result is presented to illustrate the validity and applicability of the proposed algorithm. Each scheduling rule is analyzed on the same static and dynamic air traffic flow scenario with the ATM Monte-Carlo simulation.

• Korean Management Science Review
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• v.13 no.2
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• pp.147-161
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• 1996

Due-date is an important factor in Flexible Manufacturing System scheduling. Even though most of researchers have focused part selection and loading problem using fixed due-date assignment rules, FMSs consist of multi-function machines which facilitate alternative processes. This research investigates interactions of three dispatching mechanisms, three NSS (Next Station Selection) rules and four due-date assignment rules using simulation. Both cost-based and time-based performance measures are considered in this research.

• IE interfaces
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• v.17 no.2
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• pp.233-241
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• 2004

The main subject to become a hub port is automation. The automated container terminal has already operated in advanced ports and it has been planned for the basic planning and operation design in domestic case. The key of automated container terminal is effective operation of both ATC(automated transfer crane) and AGV(automated guided vehicle) which is automated handling equipments. This is essential to productivity of automated container terminal. This study suggests the most optimal method of equipment operation in order to minimize loading time using each three types of effective ATC operation methods and AGV dispatching rules in automated container terminals. As the automated equipment operation causes unexpected deadlocks or interferences, it should be proceeded on event-based real time. Therefore we propose the most effective ATC operation methods and AGV dispatching rules in this paper. The various states occurred in real automated container terminals are simulated to evaluate these methods. This experiment will show the most robust automated equipment operation method on various parameters(the degree of yard re-marshaling, the number of containers and AGV)

• Journal of the military operations research society of Korea
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• v.17 no.2
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• pp.90-99
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• 1991

In this paper a dispatching rule, $D^{*}$, for AGV operations in automated manufacturing system is proposed to improve the performance measures. And the algorithm is compared with existing heuristic rules via simulation to evaluate its capabilities. It is shown that the proposed rule enhances mean flow time, makespan and throughput, and avoids the locking phenominon which can be fatal to the operation of automated manufacturing systems.

• Journal of the Korea Safety Management & Science
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• v.2 no.2
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• pp.85-94
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• 2000

This paper deals with the selection of a proper dispatching rule for an one-process Job scheduling that follows a particular distribution of an order production. That is, it makes a distribution on an order per unit period and applies to simulation model that uses it. This study consists of two purposes either seeks adequately production scheduling using priority rule or seeks extension of the facilities that increase current production efficiency through computer simulation in scheduling.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.25-29
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• 2001

There are so many researches about the search method for the most compatible dispatching rule to a manufacturing system state. Most of researches select the dispatching rule using simulation results. This paper touches upon two research topics: the clustering method for manufacturing system states using simulation, and the search method for the most compatible dispatching rule to a manufacturing system state. The manufacturing system state variables are given to ART II neural network as input. The ART II neural network is trained to cluster the system state. After being trained, the ART II neural network classifies any system state as one state of some clustered states. The simulation results using clustered system state information and those of various dispatching rules are compared and the most compatible dispatching rule to the system state is defined. Finally there are made two knowledge bases. The simulation experiments are given to compare the proposed methods with other scheduling methods. The result shows the superiority of the proposed knowledge base.

• International Journal of Quality Innovation
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• v.8 no.2
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• pp.132-146
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• 2007

Constructing an effective production control policy is the most important issue in wafer fabrication factories. Most of researches focus on the input regulations of wafer fabrication. Although many of these policies have been proven to be effective for wafer fabrication manufacturing, in practical, there is a need to help operators decide which lots should be pulled in the right time and to develop a systematic way to alleviate the long queues at the bottleneck workstation. The purpose of this study is to construct a photolithography workstation dispatching rule (PADR). This dispatching rule considers several characteristics of wafer fabrication and influential factors. Then utilize the weights and threshold values to design a hierarchical priority rule. A simulation model is also constructed to demonstrate the effect of the PADR dispatching rule. The PADR performs better in throughput, yield rate, and mean cycle time than FIFO (First-In-First-Out) and SPT (Shortest Process Time).

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1111-1116
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• 1993

In this study, we discuss the design of the expert system for the scheduling of the FMC(Flexible Manufacturing Cell) consisting of the several versatile machines. Due to the NP property, the scheduling problem of several machine FMC is very complex task. Thus we proposed the two heuritstic shceduling algorithms for solving the problem and constituted the algorithm based of solving the problem and constituted the algorithm base of ISS(Intelligent Scheduling System) using them. By the rules in the rule base, the best alternative among various algorithms in algorithm base is selected and applied in controlling the FMC. To show the efficiency of ISS, the scheduling output of ISS and the existent dynamic dispatching rule were tested and compared. The results indicate that the ISS is superior to the existent dynamic dispatching rules in various performance indexes.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.131-134
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• 1996

Application of machine learning to scheduling problems has focused on improving system performance based on opportunistic selection among multitudes of simple rules. This study proposes a new method of learning scheduling rules, which first establishes qualitatively meaningful criteria and quantitatively optimizes the use of them, a similar way as human scheduler accumulate their expertise. The weighting of these criteria is trained in response to the system states through simulation. To mimic human quantitative feelings, distributed fuzzy sets are used for assessing the system state. The proposed method was applied to job dispatching in a simulated FMS environment. The job-dispatching criteria used were the length of the processing time of a job and the situation of the next workstation. The results show that the proposed method can develop efficient and robust scheduling strategies, which can also provide understandable and usable know-hows to the human scheduler.

• Journal of Navigation and Port Research
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• v.36 no.8
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• pp.665-671
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• 2012

A remarshalling is studied as an important operational strategy in an automated container terminal to enhance the productivity of container handling. This means the rearrangements of the containers scattered at a vertical yard block. The dispatching problem for remarshalling is selecting the remarshalling operation considering the available operation time and deciding the operation sequencing to maximize the effectiveness of remarshalling. This study develops the optimal mathematical model for yard crane dispatching problem with mixed integer program and explains dispatching problem using an example. However it is difficult to apply this model to a field problem because of its computational time. Therefore, we compare the representative 5 dispatching rules for real world adaption. In a numerical experiment, maximum weight ratio(MR) rule shows an overall outstanding performance.