• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1309-1313
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• 2008

This paper suggests an example of modification of the durability test specifications of electronic control unit for an automotive system in phase of design validation. The basic concept to redefine the specifications of durability test is based on the Arrhenius relationship for accelerated temperature test and the modified Coffin-Manson model for temperature cycle test. The ambient temperature of the powered-event durability test is increased to reduce the required test time of the current specification. Furthermore, the holding time between the events to cool down the temperature of the components is shortened and the resultant temperature rise affects the durability of the components. Thus, the acceleration factor due to the increased temperature range of temperature cycle is also estimated by the modified Coffin-Manson model.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.937-946
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• 2021

The floating crane is used to lift the heavyweight on the ocean. The floating crane has a winch system for lifting the heavyweight and the system is controlled by the winch control system. The heavyweight is lifted safely by control of the winch control system. Before the make the control system and controller, there are many restricted conditions to test and validate at design and development steps. In order to solve the problems, commonly use the HILS (Hardware-In-the-Loop-Simulation). HILS is the method of test and validation for the hardware control system. It can be composed of the control system in hardware with surrounding environments which is a virtual model. In this study, we developed the winch system model for HILS of the 150t winch control system in a floating crane. Through this simulation and winch model, it can be applied to HILS for the winch control system.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 춘계학술대회 논문집
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• pp.69-74
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• 2000

Linear and nonlinear motion responses of a Tension Leg Platform(TLP) was investigated by model tests. The model tests were carried out at KRISO's Ocean Engineering Basin which has a deep pit of which diameter and depth are 5 meters and 12.5 meters, respectively. Optical sensors were used for measuring drift motions, and a set of accelerometers were employed for analyzing wave frequency motions. ISSC TLP was chosen as the model for the present study. Scale ratio was 1/65 and elastic modelling of tether system were conducted. Very good agreement was obtained between experimental results and theoretical calculations not only in linear motion responses but tension responses, nonlinear wave drift force and double frequency excitations.

• 한국신뢰성학회지:신뢰성응용연구
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• 제18권3호
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• pp.229-239
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• 2018

Purpose: There is a difficulty in Environmental Stress Screening (ESS) test design for weapon system's electrical/electronic components/products in small and medium-sized enterprises. To overcome this difficulty, I propose an easy ESS test design approach algorithm that is optimized with only one environment tolerance design information parameter (${\Delta}T$). Methods: To propose the mass production weapon system ESS test design for cost-effective optimization, I define an optimum cost-effective mathematical model ESS test algorithm model based on modified MIL-HDBK-344, MIL-HDBK-2164 and DTIC Technical Report 2477. Results: I clearly confirmed and obtained the quantitative data of ESS effectiveness and cost optimization along our ESS test design algorithm through the practical case. I will expect that proposed ESS test method is used for ESS process improvement activity and cost cutting of mass production weapon system manufacturing cost in small and medium-sized enterprises. Conclusion: In order to compare the effectiveness of the proposed algorithm, I compared the effectiveness of the existing ESS test and the proposed algorithm ESS test based on the existing weapon system circuit card assembly for signal processing. As a result of the comparison, it was confirmed that the test time was reduced from 573.0 minutes to 517.2minutes (9.74% less than existing test time).

• 한국해양환경ㆍ에너지학회지
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• 제19권4호
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• pp.259-265
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• 2016

본 연구에서는 대형 케이슨의 단독 예인 조건에서의 예인 안정성을 해석하기 위한 모형시험 시스템을 개발하였다. 그리고 이를 이용해 9,300톤급 케이슨의 단독 예인 중 안정성을 추정하는데 활용하였다. 케이슨이나 다른 부유체의 예인 안정성 평가를 위한 일반적인 모형시험 시스템에서는 일정한 예인 속도로 모형을 예인하는데 반해, 제안된 예인 시스템은 예인삭에 일정한 예인력을 제공하도록 설계되었다. 실제 예인 조건에서는 예인선에 의해 대상 물체가 일정한 동력으로 예인되기 때문에, 일정한 장력이 가해지는 새 모형 시험 시스템을 이용하여 예인 조건을 실제와 더 유사하게 모사할 수 있을 것으로 기대된다. 실험은 예인수조 시설에서 수행되었고, 9,300톤급 대형 케이슨의 1/30 축척비의 모형을 사용하였다. 모형 시험을 통해 케이슨 모형의 6자유도 운동과 예인삭의 장력 변동을 계측하고 해석하였다. 새 시스템을 이용하였을 경우 기존의 실험 시스템의 사용 결과에 비해 모형의 운동과 예인삭 장력이 감소하였다. 흘수와 초기 트림의 변화가 모형 시험에 적용되었으며, 초기 트림의 경우 예인 안정성에 도움이 되는 것으로 나타났다.

• 한국추진공학회지
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• 제6권4호
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• pp.47-58
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• 2002

압력조절 레귤레이터는 KSR-III 추진제 탱크의 압력 조절용으로 개발하였다. KSR-III 가압 시스템은 가압 탱크, 압력조절용 레귤레이터, 추진제 탱크로 구성된 가장 기본적인 시스템이며 레귤레이터는 헬륨 탱크, 파이로밸브, 헬륨주입밸브와 더불어 가장 핵심적인 부품이다. 1차 시제품으로 기밀, 강도, 기본 성능을 만족하는 상세 설계를 완성하였고 2차 시제품으로 추진기관 종합수류시험을 수행하였다. 2차시험을 통해서 밸브의 용량(Cv)을 늘려야 할 필요성이 나타났다. 3차 시제품에 이를 개선하였으며 추진기관 종합 실추진제 시험과 연소시험을 통해 최종 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.131-134
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• 2001

The three-dimensional precision measurement technology for industry product of middle and/or large scale has been developed. Theodolite measurement system which is one of the technology is widely used in aerospace industry. This paper describes measurement method and results for spacecraft structure test model by using the measurement system. And structural stability for STM is desribed through the comparison between design values and measured values.

• 컴퓨터교육학회논문지
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• 제11권1호
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• pp.1-10
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• 2008

정보 교육에서 수업과 평가를 통합하는 과정지향적인 평가가 수시로 이루어지기 위해서는 평가자인 교사가 보다 편리한 방법으로 평가를 할 수 있게 지원해 주는 사용성(Usability)이 고려된 웹기반평가시스템이 필요하다. 본 연구에서는 기존의 웹기반평가시스템의 사용성 요소를 분석한 후, 오프라인 지필평가과정에 내재한 사용성 요소를 추출하여 사용성이 제고된 PBA(Paper-Based Assessment) 평가 모델을 제안하였다. PBA 모델에 의한 웹기반 평가시스템은 교사주도하에 평가전, 평가중, 평가후의 모든 과정이 제어된다. 특히 평가 대상을 손쉽게 바꿀 수 있고, 평가지에 대한 접근을 평가 단계마다 철저히 차단시켜 평가 결과에 대한 신뢰성을 높일 수 있다. 또한 학생들은 자신들의 학년, 반, 번호, 이름을 사용하여 손쉽게 평가지에 로그인할 수 있다. 본 논문에서는 이와같은 PBA 모델에 기초하여 정보교육용 웹기반평가시스템 PAS(PBA-based Assessment System)를 설계 및 구현하였다.

• 조명전기설비학회논문지
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• 제25권7호
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• pp.63-71
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• 2011

Due to the rapid development of digital technnology and informantion communication, in the IEC 61850 based substation automation system, the innovative paradigm shift is expected and also required in many substation-related jobs, especially in the device function test area Accordingly a common testing model which can simplify the complex contents of the SAS performance test performed by test engineers has been identified, that can overcome limitations of engineers' own testing knowledge and experience. Testing models and its design system for the comprehensive performance test of the Substation Automation System is developed and the result of the study is reported in this paper.

• 한국정보시스템학회지:정보시스템연구
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• 제28권4호
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• pp.377-401
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• 2019

Purpose The purpose of this study is to investigate the effects of learning expectation and perceived knowledge sharing on user satisfaction and IS continuance in the Korean Army which is currently using the Regiments' Information System to help their Integrated Administration Management. Based on both the Information System(IS) Continuance Model and IS Success Model, this study also examine the role of system quality on user satisfaction. We develop a research model(structural equation model) and its hypotheses that learning expectation, perceived knowledge sharing, and system quality increase users' satisfaction, which leads to IS continuance. The effect of learning expectation on perceived knowledge sharing is also hypothesized. Design/methodology/approach Online Survey using e-mails was administered to test our research model and associated hypotheses. Among the 360 e-mail letters including our survey questionnaire, 285 responses were collected via e-mails. Meaningful 225 cases were analyzed for our study. SPSS Statistics 24.0 and SmartPLS 3.0 were used to analyze both measuremant test and hyotheses test by using the data set. Findings Survey results show that learning expectation(confirmation variable), learning expectation, perceived knowledge sharing(a perceived usefulness variable), and system quality(a system characteristic) each increases user satisfaction, which leads to IS continuance, under the control of the effect of habit to use information systems. Learning expectation also has a positive influence on perceived knowledge sharing. Theoretical and practical implications are presented.