• Management Science and Financial Engineering
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• v.18 no.2
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• pp.5-11
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• 2012

In this paper, stochastic scheduling problems are considered when processing times and due dates follow arbitrary distributions and due dates are either common or exchangeable. For maximizing the expected number of early jobs, two policies, one, based on pairwise comparisons of the processing times, and the other, based on survivabilities, are introduced. In addition, it is shown that the former guarantees optimal solutions when the processing times and due dates are deterministic and that the latter guarantees optimal solutions when the due dates follow exponential distributions. Then a new approach, exploiting the two policies, is proposed and analyzed which turns out to give better job sequences in many situations. In fact, the new approach guarantees optimal solutions both when the processing times and due dates are deterministic and when the due dates follow exponential distributions.

• Korean Management Science Review
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• v.30 no.2
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• pp.133-141
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• 2013

In this paper, we considers the outsourcing decision problem in a single machine scheduling problem. The decision problem is to determine for each job whether to be processed on an in-house manufacturing or external facilities(outsourcing). Moreover, this paper considers a situation where each job has a due date. The objective of the problem is to minimize the outsourcing cost, subject to the due date constraints. The considered problem is proved to be NP-hard. Some solution properties and valid inequalities are derived, and an effective lower bound is derived based on the LP-relaxation. The results of experimental tests are presented to evaluate the performance of the suggested lower bound.

• Journal of the Korea Safety Management & Science
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• v.4 no.1
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• pp.131-139
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• 2002

Since introducing the "Theory of Constraints" by Goldratt, its effect was verified by lots of scholars, men of enterprise. These days it is also introducing and studying in this country with good results. The objective of this study is to show how to determine the constraint resources on DBR scheduling. Actually, previous studies based on the line which just think a load/capacity rate on doing scheduling. This study will show a scheduling method which reflects multi-parameters. It could be a standard to reflect real manufacturing surroundings. On calculating a priority of each resources, we classified factors with subjective and objective factors. And we propose a decision model to incorporate values assigned by a group of experts on different factors to select a critical resource. On deploying this model, SN ratio of Taguchi method for each of subjective and objective factors will be used. And we propose a procedure which is organized with 7 steps. To understand the logic, a numerical manufacturing simulation will be presented. This method is a incorporating decision model on determining the constraint on multi parameters with experts.h experts.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.1
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• pp.135-139
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• 2014

In a connection-oriented packet switching network, the data communication starts after a virtual circuit is established between source and destination. The virtual circuit establishment time includes the queue waiting times in the direction from source to destination and the other way around. We use this two-way queueing delay to evaluate scheduling policies of a packet switching processor through simulation studies. In this letter, we also suggest user testing functions for the packet switching processor to manage virtual circuits. By detecting error causes, the user testing helps the packet switching processor provide reliable connection-oriented services.

• IEMEK Journal of Embedded Systems and Applications
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• v.16 no.5
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• pp.201-207
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• 2021

Edge Computing enables image-based inference in close proximity to end users and real-world objects. However, since edge servers have limited computational and accelerator resources, efficient resource management is essential. In this paper, we present HeteroAccel system that performs optimal scheduling in Kubernetes platform based on available node and accelerator information for various inference requests. Our experiments showed 25.3% improvement in overall inference performance over the default scheduling scheme in edge computing environment in which four types of inference services are requested.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.643-648
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• 2005

The planning process for roadway construction involves a large amount of information on design, construction methods, quantities, unit costs, production rates, and site conditions. Therefore, it is very important to acquire, manage, and process the necessary information efficiently to produce a rigorous construction plan. GIS (Geographic Information System) is a very effective tool for integrating and managing various types of information including spatial and non-spatial data required for roadway construction planning. This paper proposes a GIS-based system for improving roadway construction planning with its 'Interactive Space Scheduling' and 'Operation Level Planning' functions. The proposed system can assist construction planners in a unique way by integrating design and construction information and creating modularized design elements for space scheduling in real time. It is expected that the proposed system could improve the efficiency of roadway construction planning.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.468-473
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• 2011

The goal of a project manager is generally to minimize the cost of the project and also to cope with uncertainty. This paper deals with the problem of project scheduling a set of activities satisfying precedence constraints in order to minimize the sum of the costs associated with the starting times of the activities in the network with imprecise activity durations, represented by means of interval or fuzzy numbers. So far this problem has been completely solved by several authors when the activities durations have crisp values. However, they do not consider the imprecision in activity durations in their models. Here the framework of possibility theory is proposed to solve this problem. In fuzzy arithmetic, usually, the interval calculations are used for the aim of complexity reduction and simplification. Thus the case of interval-valued durations is first addressed, and then extended to fuzzy intervals. A numerical example is used to illustrate the developed concept.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.422-425
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• 2003

The purpose of this study is using a TACT planning and scheduling for apartment houses construction that have many of same units. Because using a TACT planning and scheduling is concluded time reduction at same units as apartment plan. The main contents of this study are 1) window and door work through the field study, 2) adjust worker assignment to minimize work time variation, and 3) an effect of working time through a case study. As a result, the total working time can be improved $21.2\%$ by using the TACT planning and scheduling. The stu요 recommends that 1) establish an accurate data between work period and resource, and 2) preparation to measures minimization of waiting time before using a TACT planning and scheduling.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.153-161
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• 2016

Semiconductor manufacturing has suffered from the complex process behavior of the technology oriented control in the production line. While the technological processes are in charge of the quality and the yield of the product, the operational management is also critical for the productivity of the manufacturing line. The fabrication line in the semiconductor manufacturing is considered as the most complex part because of various kinds of the equipment, re-entrant process routing and various product devices. The efficiency and the productivity of the fabrication line may give a significant impact on the subsequent processes such as the probe line, the assembly line and final test line. In the management of the re-entrant process such as semiconductor fabrication, it is important to keep balanced fabrication line. The Performance measures in the fabrication line are throughput, cycle time, inventory, shortage, etc. In the fabrication, throughput and cycle time are the conflicting performance measures. It is very difficult to achieve two conflicting goal simultaneously in the manufacturing line. The capacity of equipment is important factor in the production planning and scheduling. The production planning consideration of capacity can make the scheduling more realistic. In this paper, an input and scheduling rule are to achieve the balanced operation in semiconductor fabrication line through equipment capacity and workload are proposed and evaluated. New backward projection and scheduling rule consideration of facility capacity are suggested. Scheduling wafers on the appropriate facilities are controlled by available capacity, which are determined by the workload in terms of the meet the production target.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.135-142
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• 2004

This paper proposes the CPM bar chart (CBC), a hybrid of the bar chart and the critical pad method (CPM). The CBC overcomes shortages of the fenced bar chart, while still keeping advantages. The fence with direction is applied instead of the broken fence, which triggers considerable problems to identify and apply in the fenced bar chart. In addition, the notorious task to find dummy activities is no longer required. Upon the benefits of simplicity in the bar chart and logical work sequence in the CPM network. the CBC provides a relatively easy way to create and understand a schedule, thus improving communication quality between project participants. With the advantages, the CBC can also be effectively applied to various scheduling techniques such as resource constrained scheduling, resource leveling, scheduling with activity split, delay impact analysis, etc.