• 한국멀티미디어학회논문지
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• 제23권8호
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• pp.1030-1039
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• 2020

The biggest feature of the online environment is anonymity. So it is difficult to identify the sender accurately in Email. So we use PGP to enhance the security of email. PGP is an e-mail encryption program that has become the standard for email security worldwide. But PGP has a weak point in security. PGP can identify users, but it is difficult to verify reliability. In PGP, the more reliable other users guarantee that user are, the more reliable they are. In the previous study, the PGP structure was implemented by utilizing the block chain to lay the foundation, and in this paper, the structure of the previous article is applied to the e-mail environment to measure up the sender's reliability, and a system is proposed that allows users to distinguish the reliability of the message.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.762-766
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• 1998

Mechanical valve is one of the most widely used implantable artificial organs, Since its failure (mechanical failures and thrombosis to name two representative example) means the death of patient, its reliability is very important and early noninvasive detection is essential requirement . This paper will explain the method to detect the thrombosis formation by spectral analysis and neural network. In order quantitatively to distinguish peak of a normal valve from that of a thrombotic valve, a 3 layer backpropagation neural network, which contains 7,000 input nodes, 20 hidden layer and 1output , was employed. The trained neural network can distinguish normal and thrombotic valve with a probability that is higher than 90% . In conclusion, the acoustical spectrum analysis coupled with a neural network algorithm lent itself to the noninvasive monitoring of implanted mechanical valves. This method will be applied to be applied to the performance evaluation of other implantable rtificial organs.

• 품질경영학회지
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• 제45권3호
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• pp.447-462
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• 2017

Purpose: This study aims to develop distributable samples that can be used for proficiency testing to verify the ability of the testing laboratory to perform high temperature and low temperature tests. Method: In this study, the temperature-resistance characteristics of the NTC thermistor were used to develop samples. The homogeneity and stability of samples were examined according to the proficiency testing requirements. Results: Thirty samples with homogeneity and stability were developed and used for the proficiency testing. Thus, it was possible to distinguish between the test laboratories that showed satisfactory results and those that did not. Conclusion: It was the first time to develop samples that can be used for proficiency testing in high temperature and low temperature tests. and it was proved that the proficiency test program can be operated using the characteristics of NTC thermistor.

• 한국정보전자통신기술학회논문지
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• 제9권5호
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• pp.472-477
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• 2016

영상 감시 시스템에서 핵심적인 기술은 얼마나 정확하게 검출을 할 수 있는가 하는 것이다. 객체를 정확하게 추적하기 위해서는 영상에서 배경과 객체를 정확히 분리 할 수 있어야 한다. 하지만 사람의 시각이 아닌 시스템 스스로가 배경과 객체를 정확히 구분하고, 상황을 판단하는 것은 쉽지 않다. 영상처리 시스템의 신뢰도를 높이기 위해서는 배경과 객체를 정확히 검출해 내야 객체를 정확하게 추적할 수 있게 되며 이는 시스템 제작의 성공 여부에 큰 영향을 끼친다. 본 논문은 시시각각으로 변하는 배경 환경을 정확히 파악하기 위해 배경의 변화를 관찰하여 배경과 객체를 보다 정확하게 구분할 수 있는 방안을 제안하였다.

• 한국기계가공학회지
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• 제18권10호
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• pp.68-74
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• 2019

In the case of a partition panel for a vehicle, it is used as a vehicle chassis component that serves to distinguish the indoor and outdoor spaces of a vehicle and is mounted on a backrest portion of the vehicle's back seat to ensure the convenience of passengers by connecting the floor and the side of the vehicle. Because it is a relatively large-sized plate material among automobile chassis parts except the moving parts and non-ferrous materials can be applied, it is considered as a part having a large light-weight effect. However, the partition panel is one of the vehicle parts that must satisfy the light-weight effect as well as various structural reliability, such as torsional rigidity, vibration, and impact characteristics, for securing the running stability of the vehicle when driving at the same time. So, In this study, the possibility of replacing the aluminum partition panel as CFRP(Carbon Fiber Reinforced Plastic) partition panel is evaluated through comparing the two partition panels by using the structural reliability(stiffness/strength analysis), vibration analysis, impact analysis.

• 한국전문물리치료학회지
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• 제30권4호
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• pp.306-313
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• 2023

Background: As social problems due to the acceleration of the aging era and the increase in the elderly population are becoming serious, virtual reality (VR)-based healthcare is emerging as an approach for preventing and managing health issues. Objects: This study used validity and reliability analyses to examine the clinical efficacy that is, the clinical value and usability of a novel VR cognitive evaluation system index that we developed. Methods: We developed a VR cognitive evaluation system based on motion recognition analysis evaluation for individuals aged 65 to 85. After conducting the Korean version of the Mini-Mental State Exam (K-MMSE) cognitive evaluation, the evaluation score was verified through correlation analysis in the VR cognitive evaluation system. To verify the construct validity of the two groups, the Global Deterioration Scale (GDS) grades were categorized into a normal cognitive group (GDS grade 1) and a cognitive impairment group (GDS grades 2 and 3). The data were measured twice to determine the reliability between the two measurements and assess the stability and clinical value of the evaluation system. Results: Our evaluation system had a high correlation of 0.85 with the widely used K-MMSE cognitive evaluation. The system had strong criterion-related validity at the 95% confidence interval. Compared to the average score of GDS grade 1 in the VR cognitive evaluation system, the average score of GDS grades 2 and 3 in the VR cognitive evaluation system was statistically significantly lower while also having strong construct validity at the 95% confidence interval. To measure the reliability of the VR cognitive evaluation system, tests-retests were conducted using the intraclass correlation coefficient (3,1), which equaled 0.923 and was statistically significant. Conclusion: The VR cognitive evaluation system we developed is a valid and reliable clinical tool to distinguish between normal cognitive status and mild cognitive impairment.

• 재활치료과학
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• 제8권4호
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• pp.65-76
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• 2019

목적 : 본 연구는 문화적 차이를 보이는 Upper extremity performance test for elderly (TEMPA)를 한국판으로 수정 및 번역하고 그 타당도 및 신뢰도를 검증하는 것이다. 연구방법 : 연구대상자는 40세이상의 손 기능에 장애가 없는 성인 171명과 손 기능에 장애가 있는 성인 41명 이었다. 내용 타당도와 분별 타당도를 검증하였고, 검사-재검사 신뢰도와 검사자 간 신뢰도를 검증하였다. 결과 : 내용 타당도를 통해 문화적 차이를 보이는 2개의 항목 ('자물쇠 열고 약통 열기', '편지 봉투 작성하고 우표 붙이기')을 수정하였다. 분별 타당도를 통해 TEMPA는 손 기능에 장애가 있는 성인과 없는 성인을 구별할 수 있는 평가 도구임을 확인 하였다 (p<.001). 신뢰도 검증 결과 수행 속도는 급간 내 상관계수(ICC)= .71-.92, 기능 정도는 카파계수 (kappa) = 1.0, 수행 분석은 ICC = 1.0로 중간수준에서 높은 수준의검사-재검사 신뢰도를 보였다. 검사자 간 신뢰도는 실행 속도 ICC = 1.0, 기능 정도 kappa = .79-1.0, 수행 분석 ICC = .94-1.0으로 상당한 수준에서 높은 수준의 신뢰도를 보였다. 결론 : TEMPA는 손 기능의 장애가 있는 성인을 구별해 낼 수 있고, 높은 수준의 신뢰도를 보이는 평가 도구로 임상적 평가 및 근거 기반의 연구에 있어 많이 사용되기를 기대한다.

• 제어로봇시스템학회논문지
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• 제21권12호
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• pp.1185-1192
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• 2015

In this paper, a study of advanced sound source localization is conducted by eliminating the noise of the sound source using the discrete wavelet transform. And experiments are conducted to evaluate the performance of the proposed system that the mobile robot follows sound source stably. In addition, we compare the position estimation performance by applying a discrete wavelet transform to improve the reliability of the sound signal. The experimental results reveal that the de-nosing filter which removes the noise component in sound source can make the performance of position estimation more precisely and help the mobile robot distinguish the objective sound source clearly.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.95-96
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• 2008

We constructed an on-line PD monitoring system for the 380kV U/G Cable project at the Riyad 9012 substation in Saudi-arabia. The system will be monitoring the termination of the two 380kV XLPE Cables to prevent unexpected failure of the cable insulation. The system had been tested in the laboratory and on-site for detection of various PD signals and reliability of operation. The system distinguish the existence and nonexistence of the partial discharge and then judge the source of partial discharge using automatic PD pattern recognition software.

• 조명전기설비학회논문지
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• 제28권10호
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• pp.49-55
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• 2014

This paper is basic study for development of an advanced photoelectric type smoke detector that has high reliability by reducing the occurrence of nuisance alarms. This paper was attempted to distinguish optical characteristics of the typical fire smoke particle and non-fire smoke particle. According to UL 268 standards, three types of test fires (the paper, the wood and the flammable liquid) were used in this paper for measurement of the fire smoke particles, and the water vapor and the cigarette smoke that were known as the main cause of the nuisance alarms were also used for the non-fire smoke particles. A smoke detection chamber was created, which was equipped with one light source and several light sensors for enabling simultaneous detection of light extinction and scattering, respectively. This paper analyzes the optical characteristics of each smoke particle using this chamber.