• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제9권8호
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• pp.229-234
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• 2020

본 논문은 임베디드 소프트웨어에 대한 Concolic 테스팅을 효과적이고 효율적으로 지원하기 위해 임베디드 타겟(target) 시스템과 호스트(host) 시스템의 분산적이고 동시적으로 테스트 생성을 위한 작업을 수행하는 Concolic 테스팅 도구의 설계와 구현 사례를 소개한다. 소개하는 테스트 케이스 생성 도구는 Concolic 테스팅 과정 중 (1) 임베디드에 종속적인 특성을 갖는 테스트검증 대상 프로그램의 실행 부분은 임베디드 타겟 시스템에서 수행하고, (2) 시스템에 비종속적인 실행 부분인 탐색 전략, 제약식 해법기 실행 과정은 계산성능이 좋은 호스트 시스템에 분산하고, 독립적인 단계를 동시적으로 실행하도록 기존 Concolic 도구를 개선하였다. Arm Cortex A54 아키텍쳐의 임베디드 타겟 시스템과 x86-64 아키텍쳐의 호스트 시스템을 대상으로 본 기법을 구현하여 오픈소스 C 프로그램의 Grep, Busybox Awk, Busybox Ed를 대상으로 실험한 결과, 기존 도구 보다 1.59~2.64배 테스트케이스 생성속도가 향상됨을 확인할 수 있었다.

• 전기학회논문지
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• 제57권1호
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• pp.65-72
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• 2008

This paper describes the development of a novel islanding detection method, which uses the signal cross-corelation scheme between the injected reactive current and the power frequency deviation. The existing method, which injects the reactive current of 2.5-5% to the rated current and detects the frequency deviation directly, brings about lowing the power quality due to the harmonic pollution. The proposed method eliminates the weak point of the existing method, because it injects the reactive current less than 1% to the rated current. The operational feasibility was verified through computer simulations with PSCAD/EMTDC software, and experimental works with a 10kVA hardware prototype. The proposed method can detect the islanding status effectively without lowing the power quality of interconnected distributed generation system.

• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.2099-2104
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• 2015

The paper presents a monitoring system for the cooling of distribution transformers. The suggested system is controlled by a microcontroller scheme. The system is designed to control the oil temperature. It gives a solution to improve the cooling system by adding a number of fans especially for indoor transformers that are placed in badly-ventilated rooms. Also, the paper includes an alarm system with the possibility of tripping the transformer if it is necessary. The monitoring system consists of acquisition temperature sensor, and on-site unit. The hardware and software of the on-site unit are demonstrated with sufficient illustrations. Small prototype is constructed in the laboratory. Some laboratory experiments are carried out for examining the designed circuit by using Proteus Virtual System Modeling as well as for testing the prototype monitoring system. Concerning this research point, a study is carried out to evaluate the economic feasibility. The results are recorded and associated with many recommendations that may be valuable to electrical distribution (utility) companies.

• 한국환경보건학회지
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• 제38권6호
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• pp.550-560
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• 2012

Objectives: QSAR methodology was applied to explain two different sets of acceptable daily intake (ADI) data of 74 pesticides proposed by both the USEPA and WHO in terms of setting guidelines for food and drinking water. Methods: A subset of calculated descriptors was selected from Dragon$^{(R)}$ software. QSARs were then developed utilizing a statistical technique, genetic algorithm-multiple linear regression (GA-MLR). The differences in each specific model in the prediction of the ADI of the pesticides were discussed. Results: The stepwise multiple linear regression analysis resulted in a statistically significant QSAR model with five descriptors. Resultant QSAR models were robust, showing good utility across multiple classes of pesticide compounds. The applicability domain was also defined. The proposed models were robust and satisfactory. Conclusions: The QSAR model could be a feasible and effective tool for predicting ADI and for the comparison of logADIEPA to logADIWHO. The statistical results agree with the fact that USEPA focuses on more subtle endpoints than does WHO.

• 한국통신학회논문지
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• 제14권6호
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• pp.621-632
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• 1989

기존망이 ISDN으로 가는 과도기적 단계에서 발생할 수 있는 다양한 망 접속 및 가입자/망간 접속에 대처하기 위해서는 각종 정합 장치 및 이에 적용될 실현 기준과 알고리즘의 개발이 필수적이다. 본 논문에서는 ISDN신호 방식과 기준망의 신호 방식을 정합 시킬 수 있는 방안을 연구, 검토한 후 ISDN 가입자 단말 장치를 기존망이 효과적으로 수용 가능한 신호 정합 방안을 제안하였다. 또한 이에 기초한 신호 정합 장치를 구현하여 본 연구의 타당성과 그 효용성을 검증하였다.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2004년도 품질경영모델을 통한 가치 창출
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• pp.248-252
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• 2004

본 논문에서는 신상품개발 활동의 효율적인 수행을 위하여 개발된 CUPID(Creative Utility for Product planning and Intelligent DFSS:이하 CUPID로 약칭)라는 소프트웨어를 가지고 짧은 시간에 효율적으로 개발이 이루어 질 수 있는 방안을 제시해 보고자 한다. 현재 개발부문의 6시그마 경영혁신 활동인 DFSS 추진을 위하여 많은 기업이 시간과 자원을 투입하고 있으나, 그 내용이 너무 방대하여 개발부문에 부담으로 작용하고 있는 상황으로 CUPID를 이용하여 간단히 핵심품질인 CTQ의 품질목표 달성을 이루어 가는 과정을 제시하고자 한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.235-238
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• 2016

With the vision of Internet of Things (IoT), physical world itself is becoming a connected information system on the Internet and cyber world is computing as a physical act to sense and respond to real-world events collaboratively. The systems that tightly interlink the cyber and physical worlds are often referred to as Smart Systems or Cyber-Physical Systems. Smart IoT Clouds aim to provide a cyber-physical infrastructure for utility (pay-as-you-go) computing to easily and rapidly build, modify and provision auto-scale smart systems that continuously monitor and collect data about real-world events and automatically control their environment. Developing specifications for service interoperability is critical to enable to achieve this vision. In this paper, we bring an issue to extend Open Cloud Computing Interface for uniform, interoperable interfaces for Smart IoT Cloud Services to access services and build a smart system through orchestrating the cloud services.

• International journal of advanced smart convergence
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• 제7권1호
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• pp.15-23
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• 2018

Spectrum allocation is a key operation in cognitive radio networks (CRNs), where secondary users (SUs) are usually selfish - to achieve itself utility maximization. In view of this context, much prior lit literature proposed spectrum allocation base on non-cooperative game models. However, the most of them proposed non-cooperative game models based on complete information of CRNs. In practical, primary users (PUs) in a dynamic wireless environment with noise uncertainty, shadowing, and fading is difficult to attain a complete information about them. In this paper, we propose a non-cooperative game joint hidden markov model scheme for spectrum allocation in CRNs. Firstly, we propose a new hidden markov model for SUs to predict the sensing results of competitors. Then, we introduce the proposed hidden markov model into the non-cooperative game. That is, it predicts the sensing results of competitors before the non-cooperative game. The simulation results show that the proposed scheme improves the energy efficiency of networks and utilization of SUs.

• 한국의류학회지
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• 제26권8호
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• pp.1205-1215
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• 2002

The purpose of this study was to develop a production line using simulation method, which could improve work allocation, labor utility and productivity. Using simulation software AIM, a simulation model of functional sports wear assembly line was developed. A functional sports wear production factory were analysed to gather data necessary for this research. Factory layouts, production facilities, work time of each unit jobs were investigated. The data obtained were used as to build a base simulation model. Then, the base simulation model was verified using the obtained data, such as daily productivity. Using simulation method, low alternative production plans were suggested, which were to enhance productivity, and work efficiency and to reduce queue length and throughput time.

• Journal of Power Electronics
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• 제8권2호
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• pp.156-162
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• 2008

This paper proposes a low-cost power converter for micro wind turbine systems using permanent magnet synchronous generators (PMSG). The proposed converter consists of a two-leg three-phase PWM inverter for the generator control and a single-phase half-bridge PWM converter which is connected to the utility grid. For the two separate DC-link voltages, a balancing control is added and the adverse effect of the DC-link voltage ripples on the inverter output voltage is compensated. The control performance of the proposed converter topology for the micro wind turbine system is shown by the simulation results using PSIM software.