• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.104-111
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• 2023

The semiconductor industry, which relies on global supply chains, has recently been facing longer lead time for material procurement due to supply chain uncertainties. Moreover, since increasing customer satisfaction and reducing inventory costs are in a trade-off relationship, it is challenging to determine the appropriate safety stock level under demand and lead time uncertainties. In this paper, we propose a framework for determining safety stock levels by utilizing the optimization method to determine the optimal safety stock level. Additionally, we employ a linear regression method to analyze customer satisfaction scores and inventory costs based on variations in lead time and demand. To verify the effectiveness of the proposed framework, we compared safety stock levels obtained by the regression equations with those of the conventional method. The numerical experiments demonstrated that the proposed method successfully reduces inventory costs while maintaining the same level of customer satisfaction when lead time increases.

• Korean Journal of Hazardous Materials
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• v.3 no.1
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• pp.28-36
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• 2015

In early 2011, the Fukushima nuclear power plant had greater damage due to earthquake in Japan, and the awareness of safety has increased. In particular, special response systems should be required to handle disaster situations in plant sites which are likely to occur for large disasters. In this study, a program is designed to set up optimum escape routes, by a smart phone application, when a disaster situation occurs. This program could get information of the cumulative damage from sensors and display the escape route of the smallest damage in real-time on the screen. Utilizing our application in real-time evacuation has advantage in reducing cumulative damage. The optimal evacuation route, focusing on horizontal path, is calculated based on getting the data of fire, detected radioactivity and hazardous gas. Thus, using our application provides information of optimal evacuation to people who even can not hear sensor alarms or do not know geography, without requiring additional costs except fixed sensors or server network deployment cost. As a result, being informed of real-time escape route, the user could behave rapidly with suitable response to individual situation resulting in improved evacuation than simply reacting to existing warning alarms.

• Journal of the Semiconductor & Display Technology
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• v.23 no.2
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• pp.107-113
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• 2024

Scheduling of semiconductor test facilities has been crucial since effective scheduling contributes to the profits of semiconductor enterprises and enhances the quality of semiconductor products. This study aims to solve the scheduling problems for the wafer burn-in test facilities of the semiconductor back-end process by utilizing simulation and deep reinforcement learning-based methods. To solve the scheduling problem considered in this study. we propose novel state, action, and reward designs based on the Markov decision process. Furthermore, a neural network is trained by employing the recent RL-based method, named proximal policy optimization. Experimental results showed that the proposed method outperformed traditional heuristic-based scheduling techniques, achieving a higher due date compliance rate of jobs in terms of total job completion time.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.249-252
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• 2004

컴포넌트 기반 개발은 소프트웨어의 생산성을 높이며 유연성, 확장성, 호환성, 상호운영성 높은 정보시스템을 구축한다. 하지만, 이러한 특성이 성능을 저하시키는 요인이 되기도 한다. J2EE 환경에서 3-tier 컴포넌트 조립방식의 웹 어플리케이션 개발 시 성능 향상을 가져오는 아키텍처 패턴을 제시한다. 또한 그 제시한 아키텍처 패턴을 기반으로 한 구현을 통한 응답시간을 측정해 성능 향상 결과를 제시한다

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.472-474
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• 2022

본 논문에서는 기존 음악 거래 플랫폼의 문제점을 보완하기 위해 블록체인 기술을 기반으로 한 새로운 음악 거래 플랫폼을 제안한다. 기존 음악 거래 플랫폼은 높은 중개 수수료와 생산자에 대한 불공정한 보수 그리고 불투명한 거래가 이루어진다는 단점이 있다. 이러한 단점을 블록체인 기술의 탈중앙성, 보안성, 투명성, 안전성 등의 특징을 이용하여 보완하고자 한다. 또한, 블록체인 기반 플랫폼 구축을 위해 IPFS, signature file, bloomfilter 등 다양한 기술을 사용한다. 최종적으로 생산자와 소비자 모두가 공정하고 투명한 음악 거래를 할 수 있는 음악 거래 플랫폼을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1035-1038
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• 2008

가상 메모리의 스왑 저장 장치로서 플래시 메모리를 사용하는 경우, 시스템을 기동할 때 스왑 영역의 초기화를 위한 삭제 연산이 요구되어 기동 시간이 오래 걸리는 문제점이 있다. 본 논문에서는 스왑 영역의 플래시 메모리 내용을 모두 삭제하지 않고 일부만을 삭제함으로서 기동 시간을 줄일 수 있는 방법을 연구하였다.

• Bulletin of the Korean Chemical Society
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• v.20 no.12
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• pp.1475-1478
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• 1999

Ligand field calculations have been performed based on the data from the absorption and low temperature sharp-line excitation spectra of fac-Cr(gly)₃, fac-Cr(L-serine)₃ · 2H₂O and fac-Cr(L-leucine)₃·2H₂O. The optimized ligand field parameters for all complexes show that the carboxylate and the amino groups are moderate σ-donor. The values of $e_{{\pi}O}$ are typical of other complexes with carboxylate ligands. However, the π-interaction of carboxylic oxygen to the chromium in serinato complex is much weaker than that of other complexes. The inclusion of π-anisotropy is necessary to adequately explain the large doublet splittings.

• Journal of KIBIM
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• v.10 no.4
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• pp.60-69
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• 2020

Allowing on-site workers to access information of the construction process can enable task control, data integration, material and resource control. However, in the current practice of the construction industry, the existing methods and scope is quite limited, leading to inefficient management during the construction process. In this research, by adopting cutting edge technologies such as Augmented Reality(AR), digital twins, deep learning and computer vision with wearable AR devices, the authors proposed an AR visualization framework made of virtual components to help on-site workers to obtain information of the construction process with ease of use. Also, this paper investigates wearable AR devices and object detection algorithms, which are critical factors in the proposed framework, to test their suitability.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2021.06a
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• pp.36-38
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• 2021

본 논문은 물체 검출(Object Detection)과 물체영역분할(Object Segmentation)의 CNN 추론 결과를 MPEG-7 서술자 이진화를 통해 표현함으로써 원본과의 용량을 비교한다. 영상의 사용 목적에 따라 CNN 추론 결과를 압축하여 활용할 시 원본 영상 대비 용량을 측정하여 그 효율성을 판단하는 것이 목표이다. 물체 검출과 물체영역분할에 대한 추론 결과를 MPEG-7 서술자를 이용해 압축하였으며, 비교를 위해 원본 영상, CNN 추론 결과 파일, MPEG-7 서술자, MPEG-7 서술자 이진화 파일의 크기를 측정하였다. 실험 결과, MPEG-7 서술자를 이진화를 통한 표현 방식이 원본 영상 및 추론 결과 파일에 비해 효율적임을 알 수 있었다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.305-306
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• 2021

Breakdown structure (BS) is a tool used to allocate information packages for various management functions and drive computerized information systems. Although several BS exists, work breakdown structures (WBS) and cost breakdown structures (CBS) are the most widely studied and used in previous literature. Nevertheless, heterogeneity of BS and respective management capabilities in current practices are not adequately addressed. In this context, this paper compared the management capabilities of various BS in both building and plant industries through systematic literature. Management requirements and applications scope, in terms of life cycle and stakeholder, were analyzed, respectively. Finally, finding and lesson-learned are outlined.