• IE interfaces
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• v.7 no.3
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• pp.125-135
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• 1994

This thesis reports the development of a Computer-Aided Process Planning system for rotational parts. The developed system ultimately generates process plans for rotational parts through a knowledge-base. The knowledge-base and decision-making algorithms are represented by Pascal computer programming language. We have developed a process planning system which adjusts the sequence of processes by itself to ensure the quality of the parts. This system generates more detailed job sequence and descriptions than other well-known process planning systems. We present realistic and efficient process plans through the integration of process planning and scheduling. This system optimizes flow time of parts by decreasing the number of machine set-ups.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.1095-1100
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• 2010

Customer satisfaction is a main issue in the modern competitive industrial environment. So quality and productivity are the most important requisites. This paper presents a method for effective real time dispatching for parallel machines with multi product that minimizes mean tardiness and maximizes the quality of the product. In this paper, the effectiveness of the method has been examined in the simulation and compared with other dispatching methods. Using this method presented in this paper, companies can improve customer satisfaction.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.134-136
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• 2012

클라우드 컴퓨팅 서비스 시장이 성장하면서, 서비스 제공자들은 전력 사용량 감소와 서비스 수준을 보장하는 등의 여러 가지 문제와 맞딱드리게 되었다. 이런 문제에 대한 원인 중 하나는 자원 효율성을 높이기 위해 도입한 가상머신 기반의 서버 통합 정책이다. 현재의 가상머신 기술들은 아직까지 완벽한 격리수준을 제공하지 못하기 때문에, 같은 노드에 배치된 가상머신들은 자원을 공유하면서 서로 간에 간섭을 일으키게 된다. 본 연구에서는 가상머신끼리 공유하는 자원 중 프로세서의 말단 캐시(Last-level Cache, LLC)에서의 간섭을 최대한 줄여서 성능을 극대화하기 위한 방법을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.830-833
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• 2020

콜센터에서 인력 스케줄링은 매우 중요하다. 모든 콜센터에서 인건비는 고정비 성격이 강하여 차지하는 비중이 매우 높아 콜센터의 이익을 좌지우지한다. 그렇기 때문에 콜센터의 적정 인력의 고용과 배치는 인건비 뿐만 아니라 콜 성공률 또한 직결되어 있어 콜센터 운영에서 중요한 사안이라고 할 수 있다. 대부분의 콜센터가 현재까지도 관리자의 경험에 의해 인력배치를 수립하는데, 이러한 방법은 과학적이지 않으며 인원수에 영향을 미치는 모든 변수들을 고려할 수 없다. 과거 수학적 모델을 수립하는 것이었다면, 지금은 모델을 학습시키고, 학습된 모델을 기반으로 미래의 고객과 인원수를 예측해야 한다. 본 논문에서는 수리제약식을 통해 다양한 변수들을 고려하고 비선형 정수 계획법과 딥러닝 기반의 예측 값을 이용하여 비선형 정수계획법을 통해 최적의 인력배치 스케줄링을 수립하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.369-372
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• 2021

Scheduling the movements of trains in the modern railway system is becoming essential and important. Swiss Federal Railway Company (SBB) and machine learning researchers began collaborating to make a simulation environment and held a Flatland challenge. In this paper, the methodologies of the winners of this competition are analyzed to achieve insight and research trends. This problem is similar to the Multi-Agent Path Finding (MAPF) and Vehicle Rescheduling Problem (VRSP). The potential of the attempted methods from the Flatland challenge to be applied to various transportation systems as well as railways is discussed.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.177-179
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• 2002

We have developed a scheduling system for heavy ion radiotherapy considering the condition of three treatment rooms and treatment planning for each patient. This system consists of a database (patient information, treatment method and machine schedule), a schedule for radiotherapy and WEB server. All operation of this system, such as data input, to change and to view the schedule, are performed by using a WEB browser. In order to protect personal information for the patients, access privilege to each information are limited by according to the occupational category. This system is connected with a hospital central information management system (AMIDAS) and an irradiation-managing computer for the heavy ion radiotherapy. A basic information for the patient is got from AMIDAS and the daily schedule sends to the treatment control computer at each treatment room through the irradiation-managing computer every morning. The daily, weekly, monthly schedules in the treatment room and the treatment condition of each patient are shared on the WEB browser with the all participants of the heavy ion therapy. This system could be useful to save a time to generate a treatment schedule and to inform us the most up-to-date treatment schedule and the related information at the same time.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.1
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• pp.41-41
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• 1992

In the real world situations that some jobs need be processed only on certain limited machines frequently occur due to the capacity restrictions of machines such as tools fixtures or material handling equipment. In this paper we consider n-job non-preemptive and m parallel machines scheduling problem having two machines group. The objective function is to minimize the sum of earliness and tardiness with different release times and due dates. The problem is formulated as a mixed integer programming problem. The problem is proved to be Np-complete. Thus a heuristic is developed to solve this problem. To illustrate its suitability and efficiency a proposed heuristic is compared with a genetic algorithm and tabu search for a large number of randomly generated test problems in ship engine assembly shop. Through the experimental results it is showed that the proposed algorithm yields good solutions efficiently.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.449-455
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• 2002

This paper considers that advanced planning and scheduling (APS) in manufacturing and the efficient purchasing where each customer order has its due date and multi-suppliers exit We present a Make-To­Order Supply Chan (MTOSC) model of efficient purchasing process from multi-suppliers and APS with outsourcing in a supply chain, which requires the absolute due date and minimized total cost. Our research has included two states. One is for efficient purchasing from suppliers: (a) selection of suppliers for required parts; (b) optimum part lead­time of selected suppliers. Supplier selection process has received considerable attention in the business­management literature. Determining suitable suppliers in the supply chain has become a key strategic consideration. However, the nature of these decisions usually is complex and unstructured. These influence factors can be divided into quantitative and qualitative factors. In the first level, linguistic values are used to assess the ratings for the qualitative factors such as profitability, relationship closeness and quality. In the second level a MTOSC model determines the solutions (supplier selection and order quantity) by considering quantitative factors such as part unit price, supplier's lead-time, and storage cost, etc. The other is for APS: (a) selection of the best machine for each operation; (b) deciding sequence of operations; (c) picking out the operations to be outsourcing; and (d) minimizing makespan under the due date of each customer's order. To solve the model, a genetic algorithm (GA)-based heuristic approach is developed. From the numerical experiments, GA­based approach could efficiently solve the proposed model, and show the best process plan and schedule for all customers' orders.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.57-66
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• 2010

In this paper, we propose the reliability constrained resource allocation scheduling algorithm in cellular network for uplink transmission, where uplink transmission is supported via packet switching schemes without the dedicated uplink circuit links. We evaluate the performance of the proposed algorithm, and compared with the conventional works to identify the pros and cons. The proposed uplink scheduling algorithm is to satisfy the constraints requirements of the MTC services which is considered as the core technology for future mobile wireless networks. It is different to conventional works which target to maximize the link capacity. The proposed algorithm provides reliable uplink transmission independent to the location and the quality of the wireless link of the mobile terminal. Based on the performance evaluation results, we conclude that the proposed method provides enhanced reliability performance than conventional works.

• Journal of the Korea Society for Simulation
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• v.19 no.1
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• pp.1-11
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• 2010

K company produces semiconductor package products under the make-to-order policy to supply for domestic and foreign semiconductor manufacturing companies. Its production process is a machine-paced assembly line type, which consists of die sawing, assembly, and test. This paper suggests three plans to increase process throughput based on the process analysis of K company and evaluates them via a simulation model using a real data collected. The three plans are line balancing by adding machines to the bottleneck process, product group scheduling, and reallocation of the operators in non-bottleneck processes. The evaluation result shows the highest daily throughput increase of 17.3% with an effect of 2.8% reduction of due date violation when the three plans are applied together. Payback period for the mixed application of the three plans is obtained as 1.37 years.