• Management Science and Financial Engineering
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• v.15 no.2
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• pp.23-52
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• 2009

This study compares the cycle times of handling operations of yard cranes under different sequencing rules. An operation cycle was divided into several elementary movements and formulas for the expectation and the variance of each elementary movement were analytically derived. The expected waiting time of trucks was estimated based on the given arrival rate of trucks. The previous studies focused on developing a method to make an efficient schedule of operations for yard cranes. This paper introduces several sequencing rules, such as first-come-first-served, unidirectional travel, and Z pick travel rules. In addition, a formula for estimating the cycle times of yard cranes under each sequencing rule is derived, and the performance under the different sequencing rules are compared with each other.

• Industrial Engineering and Management Systems
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• v.15 no.1
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• pp.11-18
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• 2016

This paper considers a scheduling problem in a flexible job shop with a reconfigurable manufacturing cell. The flexible job shop has both operation and routing flexibilities, which can be represented in the form of a multiple process plan, i.e. each part can be processed through alternative operations, each of which can be processed on alternative machines. The scheduling problem has three decision variables: (a) selecting operation/machine pairs for each part; (b) sequencing of parts to be fed into the reconfigurable manufacturing cell; and (c) sequencing of the parts assigned to each machine. Due to the reconfigurable manufacturing cell's ability of adjusting the capacity, functionality and flexibility to the desired levels, the priority scheduling approach is proposed in which the three decisions are made at the same time by combining operation/machine selection rules, input sequencing rules and part sequencing rules. To show the performances of various rule combinations, simulation experiments were done on various instances generated randomly using the experiences of the manufacturing experts, and the results are reported for the objectives of minimizing makespan, mean flow time and mean tardiness, respectively.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.1
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• pp.119-135
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• 1995

We consider problems of tool loading and scheduling in a flexible manufacturing system (FMS) in which tool transportation constitutes the major portion of material flows. In this type of FMSs, parts are initially assigned to machines and released to the machines according to input sequencing rules. Operations for the parts released to the machines are performed by tools initially loaded onto the machines or provided by an automatic tool transport robot when needed. For an efficient operation of such systems, therefore, we may have to consider loading and scheduling problems for tools in addition to those for parts. In this paper, we consider three problems, part loading, tool loading, and tool scheduling problems with the overall objective of minimizing the makespan. The part loading problem is solved by a method similar to that for the bin packing problem and then a heuristic based on the frequency of tool usage is applied for tool loading. Also suggested are part input sequencing and tool scheduling rules. To show the effectiveness of the overall algorithm suggested here, we compare it with an existing algorithm through a series of computational tests on randomly generated test problems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10a
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• pp.309-313
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• 1998

Delay time of receiving and delivery is one of important factors that should be considered in the evaluation of the customer service level of a container terminal. In this study, dispatching rules are tested with the objective of minimizing the service delay time for arriving outside trucks. A dynamic programming model is suggested for a static dispatching problem in which all the truck arrivals are known in advance. In order to overcome the excessive computational time of the dynamic programming technique, several heuristic rules are suggested that can be applied in practices. A simulation study is carried out to test the performances of the heuristic rules.

• The KIPS Transactions:PartA
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• v.11A no.2
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• pp.207-212
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• 2004

In this paper, based on SCORM Sequencing Model, we propose the learning content structure which has structure informations of learning object and decision rules how to transfer learning object to learner. It is intended to provide the technical means for learning content objects to be easily shared and reused across multiple learning delivery environment. We develop the generation tool of learning object sequencing, for processing the learning with variable teaching methodologies. The teaming objects also are automatically packaged the PIE(Package Interchange File) to transmit with SCORM RTE(Run-Time Environment) and attached SCO(Sharable Content Object) function for tracking learner information.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.252-256
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• 2003

This paper deals with a case study on the development of computerized scheduling system for core products. We propose a heuristic algorithm which is based on the sequencing rules and the allocation rules to satisfy the due date for each product, and develop a scheduling system for the manufacturer of core products. The system operates under a client/server circumstance. The important information constitutes a database, and it can be retrieved whenever it is needed. The benefits of the scheduling system are the exclusion of hand operations of data, the reduction of execution time for production planning and the reduction of average inventories.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.2
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• pp.190-194
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• 2004

This paper shows the application of fuzzy system for a modeling of nonlinear biochemical process. A wastewater treatment process for nitrogen removal in a sequencing batch reactor (SBR) is presented and fuzzy systems with different consequent polynomials in the fuzzy rules to model and identify the oxidation reduction potential (ORP) of the process are introduced. The paper compares, analyzes the results of fuzzy modeling, and shows the nonlinear process can be modeled reasonably well by the present scheme.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.3
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• pp.24-31
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• 2012

Priority rules or sequencing heuristics conventionally used to determine resource allocation is to maximize the earned value on time and cost. This study provides a effective strategy-oriented approach for the program resource management problem with limited same resource, which systematically connects individual project objectives to the overall organizational goal, by introducing financial values as well as priority rules in a broader context. It deals with the resource allocation problem as the decision making problem in the strategic management paradigm to meet business objective and solves it using the analytic hierarchy process, and explains the method of application and usefulness through some simulation cases.

• Journal of Korean Institute of Industrial Engineers
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• v.17 no.2
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• pp.1-16
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• 1991

This paper deals with some critical activities of CAPP system such as generation of part description database, part feature recognition, process and operation selection, and sequencing method for turning operation of symmetric rotational parts. The part description database is generated by data conversion module from CAD data, and the part feature is recognized by using both pattern primitives and feature recognition rules. Machining processes and operations are selected based on machining surface features and its sequence is determined by rules acquired from process planning expert. AutoCAD is employed as CAD system and computer program is developed by using Turbo-C on IBM PC/AT compatible system.

• Journal of Mechanical Science and Technology
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• v.18 no.12
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• pp.2095-2103
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• 2004

A macro-level CAPP system is proposed to plan the complicated mechanical prismatic parts efficiently. The system creates the efficient machining sequence of the features in a part by analyzing the feature information. Because the planning with the individual features is very complicated, feature groups are formed for effective planning using the nested relations of the features of a part, and special feature groups are determined for sequencing. The process plan is generated based on the sequences of the feature groups and features. When multiple machines are required, efficient machine assignment is performed. A series of heuristic rules are developed to accomplish it.