• 한국광학회지
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• 제16권1호
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• pp.50-55
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• 2005

기준광과 탐사광의 경로길이가 매우 크게 차이가 나는 경로길이 불일치 간섭계(unequal path interferometer)를 이용한 직경 300mm 카세그레인 형태의 인공위성 망원경과 같은 대구경 광학계의 변조전달함수(modulation transfer function : MTF)와 파면오차를 동시에 측정하는 방법을 제안하고 이를 실험적으로 확인하였다. 이러한 경로불일치 간섭계를 이용한 측정시스템에서 필요한 평행한 시준광을 만들기 위해서 쌍방향 층밀리기 간섭계를 사용하였으며, 파면오차를 측정하기 위해서 직경 400 mm인 비축 포물경을 사용하는 긴 광경로차의 대구경 피조우 간섭계를 사용하였다. 또한 회전하는 확산판을 이용하여 레이저 광을 부분가간섭광으로 바꿈으로써 피조우 간섭계의 파장으로부터 쉽게 MTF를 측정할 수 있었다.

• 한국시뮬레이션학회논문지
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• 제27권2호
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• pp.101-114
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• 2018

무인 비행체의 실시간 경로계획 생성 시 최적의 경로를 찾기 위한 다양한 연구가 진행되어 왔다. 본 논문에서는 진화알고리즘을 통한 무인비행체의 경로계획 생성을 수행하고, 이를 에이전트 기반 시뮬레이션 환경에서 구현 및 테스트가 가능함을 검증하였다. 이를 위해, Repast toolkit에 JGAP 패키지를 탑재하여 Java 기반의 유전 알고리즘 프로그래밍을 통한 무인 비행체의 경로 계획을 생성하였고, 해당 결과를 에이전트 기반으로 시뮬레이션을 수행하였다. 본 논문에서는 에이전트 기반 시뮬레이션 소프트웨어를 소프트웨어 공학 개발 생명주기에 맞춰 문서화하여 설계 및 구현되었으며, 에이전트 모델링 설계는 자동화, 적응성 및 에이전트 간의 상호 작용에 초점을 맞추었다. 또한, 시뮬레이션을 통해 에이전트 기반 환경에서 설계한 모델 및 시나리오를 검증하여 다수의 비행 에이전트에 내재된 동적 경로계획 알고리즘이 실시간으로 자율적인 경로 생성이 가능함을 증명하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.314-317
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• 2007

Automotive rear subframe of aluminum tube was developed by using hydroforming process, based on the numerical analysis and physical tryouts. In the previous study, the effect of prebending was evaluated on the basis of forming limit diagram which had been obtained from free bulging, T-shape forming and cross-shape forming, using the developed tube hydroformability testing system. In order to get the sound products, appropriate internal pressure is to be imposed corresponding to the axial feeding. In this study, the loading path, the combination of internal pressure and axial feeding during the process, was optimized to ensure minimum thickness variation and dimensional accuracy, by using response surface method.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2002년도 춘계학술발표논문집 (하)
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• pp.1611-1614
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• 2002

하나의 보드에 대한 소자들의 테스팅을 위해서 IEEE 1149.1이 제안되었고 완전한 테스팅을 지원한다. 하지만 여러 보드에 대해서는 불가능하여 IEEE 1149.1을 확장한 시스템 레벨의 테스팅 방법이 제안되었다. 기존의 IEEE 1149.1을 확장한 방법은 보드 레벨의 테스팅과 시스템 레벨의 테스팅이 하나의 데이터 패스에 의해서 테스트 시간이 길고 비효율적이다. 본 논문에서는 보드 레벨 테스팅과 시스템 레벨 테스팅을 구분하여 불필요한 테스트 데이터 이동을 줄여 테스트 시간을 줄이고 효율적인 방법을 제시한다. 그리고 이를 지원하기 위한 Path Select Unit을 설계한다. 구현된 PSU는 작은 게이트 사이즈로 적은 테스트 비용으로도 효율적으로 시스템 레벨 테스팅이 가능해진다.

• 한국재료학회지
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• 제15권1호
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• pp.6-13
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• 2005

Copper based leadframe sheets were immersed in two kinds of hot alkaline solutions to form brown-oxide or blackoxide layer on the surface. The oxide-coated leadframe sheets were molded with epoxy molding compound (EMC). After post mold curing, the oxide-coated EMC-leadframe joints were machined to form sandwiched double-cantilever beam (SDCB) specimens. The SDCB specimens were used to measure the fracture toughness of the EMC/leadframe interfaces under quasi-Mode I loading conditions. After fracture toughness testing, the fracture surface were analyzed by various equipment to investigate failure path. An adhesion model was suggested to explain the failure path formation. The adhesion model is based on the strengthening mechanism of fiber-reinforced composite. The present paper deals with the introduction of the adhesion model. The explanation of the failure path with the proposed adhesion model was introduced in the companion paper.

• Restorative Dentistry and Endodontics
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• 제44권2호
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• pp.22.1-22.8
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• 2019

Objectives: The aim of this study was to investigate the effect of glide path preparation with PathFile and ProGlider nickel-titanium (NiTi) files on the cyclic fatigue resistance of WaveOne NiTi files. Materials and Methods: Forty-four WaveOne Primary files were used and divided into four groups (n = 11). In the first group (0 WaveOne), the WaveOne Primary files served as a control group and were not used on acrylic blocks. In the 1 WaveOne Group, acrylic blocks were prepared using only WaveOne Primary files, and in the PF+WaveOne group and PG+WaveOne groups, acrylic blocks were first prepared with PathFile or ProGlider NiTi files, respectively, followed by the use of WaveOne Primary files. All the WaveOne Primary files were then subjected to cyclic fatigue testing. The number of cycles to failure was calculated and the data were statistically analyzed using one-way analysis of variance (ANOVA) and the Tukey honest significant difference multiple-comparison test at a 5% significance level. Results: The highest number of cycles to failure was found in the control group, and the lowest numbers were found in the 1 WaveOne group and the PF+WaveOne group. Significant differences were found among the 1 WaveOne, PF+WaveOne, and control groups (p < 0.05). No statistically significant differences were found between the PG+WaveOne group and the other three groups (p > 0.05). Conclusion: Glide path preparation with NiTi rotary files did not affect the cyclic fatigue resistance of WaveOne Primary files used on acrylic blocks.

• ETRI Journal
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• 제25권3호
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• pp.187-194
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• 2003

Delay testing has become an area of focus in the field of digital circuits as the speed and density of circuits have greatly improved. This paper proposes a new scan flip-flop and test algorithm to overcome some of the problems in delay testing. In the proposed test algorithm, the second test pattern is generated by scan justification, and the first test pattern is processed by functional justification. In the conventional functional justification, it is hard to generate the proper second test pattern because it uses a combinational circuit for the pattern. The proposed scan justification has the advantage of easily generating the second test pattern by direct justification from the scan. To implement our scheme, we devised a new scan in which the slave latch is bypassed by an additional latch to allow the slave to hold its state while a new pattern is scanned in. Experimental results on ISCAS'89 benchmark circuits show that the number of testable paths can be increased by about 45 % over the conventional functional justification.

• 비파괴검사학회지
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• 제9권1호
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• pp.8-21
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• 1989

This paper presents the ultrasonic characteristics of weldment and detectability of defects of weldment in Austenitic Stainless Steel Type 304 that is composed of mostly coolant piping system in nuclear power plants. The results of this experient show as follows: 1. When the ultrasonic beam detects the defects on the side of base metal and on the opposite side of weldment, the indications which was detected on the screen show different amplitude and different metal path each. 2. The ultrasonically estimated notch depth is generally oversized than actual notch depth. 3. It is easy for the false indication to show up on the screen because of columnar structure of weldment in austenitic stainless steel. 4. The higher frequencies of transducer have more difficulties to detect the defects of the opposite side of weldment because of ultrasonic attenuation in weldment and the longitudinal transmitter-receiver transducer is the most effective in detecting the opposite side defects of weldment.

• Journal of the Optical Society of Korea
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• 제20권1호
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• pp.174-179
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• 2016

In this paper, a novel full-aperture reflective null measuring method is proposed to detect the transmission wavefront of a conformal dome surface. An aspheric compensator is designed and placed behind the dome to reflect the aspheric testing wave back to the same path. To ensure the feasibility of this method, tolerance analysis is conducted, and guidance to assembly is given accordingly. The accuracy of this method is verified to be λ/30 (λ =3.39 μm) by Monte Carlo algorithm. In addition, the influence of different error factors, including the thickness error and decenter error of the dome, on the testing wavefront is analyzed. Simulation and experiment indicate that this method is practical and simple, and can measure the conformal domes precisely and comprehensively.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.492-496
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• 1987

The testing philosophy and control schemes are investigated and applied to construct the Automatic Microwave Leakage Inspection System (AMLIS) . AMLIS is consists of three major parts such as Material Handling Mechanism, Fine Positioning Mechanism and Scanning Mechanism. The material Handling unit is designed to perform loading and unloading microwave oven onto the testing point by pneumatic cylinder and vacuum pump. The Fine positioning part includes X-Y-.THETA. table and distance sensing equipment. The scanning part is composed of five SCARA robots, which traverse X-Y-Z catesian coordinates respectively. The leakage testing probes are placed at the end of this each robot then the path and speed are both controlled via microprocessors. A performance test of this system combined with electric parts and software is done and the basic major function of system are accomplished.