• Management Science and Financial Engineering
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• v.11 no.2
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• pp.45-60
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• 2005

This paper investigates the application of the computer method COMSOAL (Computer Method of Sequencing Operations for Assembly Lines) to the process routing (PR) problem with multiple objectives. In any computer aided process planning (CAPP) system, one of the most critical activities for manufacturing a part could be to generate the sequence that optimizes production time, production cost, machine utilization or with multiple these criteria. The COMSOAL has been adopted to find the optimum sequence of operations that optimizes two major conflicting criteria : production cost and production quality. The COMSOAL is here slightly modified to simultaneously generate and evaluate a set of possible solutions (called as population) instead of processing a solution stepwise in each iteration. The significant features of the COMSOAL include : no parameters settings needed, and a guarantee of feasible solutions. Experimental results show that COMSOAL is a simple but powerful method to quickly generate multiple feasible solutions which are as good as the ones obtained from several other well-known process routing algorithms.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.617-620
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• 2000

In this paper, we show an application of constraint logic programming to the operation scheduling on machines in a job shop. Constraint logic programming is a new genre of programming technique combining the declarative aspect of logic programming with the efficiency of constraint manipulation and solving mechanisms. Due to the latter feature, combinatorial search problems like scheduling may be resolved efficiently. In this study, the jobs that consist of a set of related operations are supposed to be constrained by precedence and resource availability. We also explore how the constraint solving mechanisms can be defined over a scheduling domain. Thus the scheduling approach presented here has two benefits: the flexibility that can be expected from an artificial intelligence tool by simplifying greatly the problem; and the efficiency that stems from the capability of constraint logic programming to manipulate constraints to prune the search space in an a priori manner.

• 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.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.05a
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• pp.145-153
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• 1999

We consider a Direct Input Output Manufacturing System(DIOMS) which has a munber of machine centers placed along a built-in Automated Storage/Retrieval System(AS/RS). The Storage/Retrieval (S/R) machine handles parts placed on pallets for the machine centers located at either one or both sides of the As/Rs. This report studies the operational aspect of DIOMS and determines the optimal operating policy by combining computer simulation and genetic algorithm. The operational problem includes: input sequencing control, dispatching rule of the S/R machine, machine center-based part type selection rule, and storage assignment policy. For each operating policy, several different policies are considered based on the known research results. In this report, using the computer simulation and genetic algorithm we suggest a method which gives the optimal configuration of operating policies within reasonable computation time.

• Korean Management Science Review
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• v.13 no.3
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• pp.187-198
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• 1996

The traveling salesman problem has been studied for many years since the model can be used for various applications such as vehicle routing, job sequencing, clustering a data array, and so on. In this paper one of the typical exact algorithms for TSP, Minty's, will be modified to improve the performance of the algorithm on the applications without losing simplicity. The Little's algorithm gives good results, however, the simple and plain Minty's algorithm for solving shortest-route problems has the most intuitive appeal. The suggested Minty's modification is based on the creation of penalty-values on the matrix of a TSP. Computer experiments are made to verify the effectiveness of the modification.

• IE interfaces
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• v.14 no.4
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• pp.385-393
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• 2001

In this paper, a scheme of scheduling a bottleneck operation is presented for production planning of make-to-order. We focus on the problem of capacity-dependent processing time in which processing time of the bottleneck operation is not fixed, but varies with job sequence or equipment capacity. For this, a genetic algorithm is applied for job sequencing with an objective function of mean square of weighted deviation. An experimental study is implemented in power transformer plant and results are compared with those of the EDD rule. It shows that the genetic algorithm is relatively good for most cases.

• Journal of Computational Design and Engineering
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• v.3 no.2
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• pp.102-111
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• 2016

In this paper, we study the problem of computing smooth feature curves from CAD type point clouds models. The proposed method reconstructs feature curves from the intersections of developable strip pairs which approximate the regions along both sides of the features. The generation of developable surfaces is based on a linear approximation of the given point cloud through a variational shape approximation approach. A line segment sequencing algorithm is proposed for collecting feature line segments into different feature sequences as well as sequential groups of data points. A developable surface approximation procedure is employed to refine incident approximation planes of data points into developable strips. Some experimental results are included to demonstrate the performance of the proposed method.

• Journal of Korean Institute of Industrial Engineers
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• v.1 no.2
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• pp.73-81
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• 1975

In an earlier paper ('Scheduling Jobs on a Number of Identical Machines' by Elmaghraby and Park, March 1974, AIIE Transactions) a branch-and-bound algorithm was developed for the sequencing problem when all jobs are available to process at time zero and are independet (i.e., there are not a priori precedence relationships among jobs.). However, the amount of computation required by the algorithm was not considered to be short if more than 50 jobs were processed. As an effort to improve the algorithm, the present paper modifies the implicit enumeration procedure in the algorithm so that moderately large problems can be treated with what appears to be a short computational time. Mainly this paper is concerned with improving the lower bound in the implicit enumeration procedure. The computational experiences with this new branch-and-bound algorithm are given.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.275-284
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• 1996

It can be made a definition that scheduling is a imposition of machinery and equipment to perform a collection of tasks. Ultimately scheduling is an assessment of taking order for which would be perform. So it is called "sequencing" in other words. In a job shop scheduling, the main object is to making delivery in accordance with the due date and order form customer, not to producing lots of quantity with minimizing mean flow time in a given time. Actually, in a company, they concentrate more in the delivery than minimizing the mean flow time. Therefore this paper suggest a new priority dispatching rule under consideration as below in a n/m job shop scheduling problem with due date. 1. handling/transportation time, 2. the size of customer order With this algorithm, we can make a scheduling for minimizing the tardiness of delivery which satisfy a goal of production.roduction.

• Design & Manufacturing
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• v.16 no.3
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• pp.34-38
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• 2022

Regular expression pattern matching is widely used in applications such as computer virus vaccine, NIDS and DNA sequencing analysis. Hardware-based pattern matching is used when high-performance processing is required due to time constraints. ReCPU, SMPU, and REMP, which are processor-based regular expression matching processors, have been proposed to solve the problem of the hardware-based method that requires resynthesis whenever a pattern is updated. However, these processor-based regular expression matching processors inefficiently handle repetitive operations of regular expressions. In this paper, we propose a new instruction set to improve the inefficient repetitive operations of ReCPU and SMPU. We propose REMPi, a regular expression matching processor that enables efficient iterative operations based on the REMP instruction set. REMPi improves the inefficient method of processing a particularly short sub-pattern as a repeat operation OR, and enables processing with a single instruction. In addition, by using a down counter and a counter stack, nested iterative operations are also efficiently processed. REMPi was described with Verilog and synthesized on Intel Stratix IV FPGA.