• Structural Engineering and Mechanics
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• 제9권6호
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• pp.601-613
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• 2000

Existing models for the shear strength degradation of reinforced concrete members present varied conceptual approaches to interpreting test data. The relative superiority of one approach over the others is difficult to determine, particularly given the sparseness of ideal test data. Nevertheless, existing models are compared using a suite of test data that were used for the development of one such model, and significant differences emerge. Rather than relying purely on column test data, the body of knowledge concerning degradation of concrete as a material is considered. Confined concrete relations are examined to infer details of the degradation process, and to establish a framework for developing phenomenologically-based models for shear strength degradation in reinforced concrete members. The possibility of linking column shear strength degradation with material degradation phenomena is explored with a simple model. The model is applied to the results of 7 column tests, and it is found that such a link is sustainable. It is expected that models founded on material degradation phenomena will be more reliable and more broadly applicable than the current generation of empirical shear strength degradation models.

• 소성∙가공
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• 제13권3호
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• pp.242-247
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• 2004

Literature review on reliability test method for developing high performance optical/thermofluidic components. Since the miniaturization by the conventional mechanical process is limited to milli-structure, i.e. $10^{-3}m$, new technology for fabricating of mechanical components is needed to match cost, reliability, and integrability criteria of micro-structure. Although numbers of various researches on MEMS/MOEMS devices and components, including material characterization, design and optimization, system validation, etc., the lack of standards and specifications make the researches and developments difficult. For that reason, this paper is intended to propose the methods of reliability test for measuring the mechanical property of optical/ thermofluidic components.

• 항공우주시스템공학회지
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• 제4권1호
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• pp.23-26
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• 2010

In this study, it was performed damage assesment of small scale composite aircraft developing. This aircraft adopted the sandwich structure to skin of wing. This study aims to investigate the residual strength of sandwich composites with Nomex honeycomb core and carbon fiber face sheets after the open hole damage by the experimental investigation. The 4-point bending tests were used to find the bending strength, and the open hole was applied to introduce the simulated damage on the specimen. The bending strength test results after open hole was compared with the results of no damaged specimen test. The FEM analysis is assessed via an experimental 4-point bending test.

• 항공우주시스템공학회지
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• 제12권2호
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• pp.59-65
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• 2018

항공기 구성품인 착륙장치 핸들은 항공기 이 착륙 시 착륙장치 작동을 위한 핵심적인 장비이다. 착륙장치 핸들의 개발을 위한 진동시험 중 착륙장치 핸들 내부의 브라켓 파손 현상이 발생하였다. 따라서 본 논문에서는 착륙장치 핸들 개발 시 수행한 진동시험 절차와 진동시험 중 발생한 결함사항에 대한 원인 분석, 설계 개선사항 그리고 검증 결과를 함께 기술하였다.

• 한국건축시공학회지
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• 제15권3호
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• pp.339-349
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• 2015

A large-scale research project to develop a robot-based automated building construction system for steel structures was successfully conducted in South Korea. This paper discusses the results of the real-scale test and the key lessons gained from the testing process. The system was assessed in terms of system productivity, construction cost, quality control, and safety improvements. While the productivity of the automated system showed an improvement of about 9.5%, the construction cost was about six times higher than that of the conventional method. The field test also indicated that the automated system requires more on-site quality control measures. However, because the system can eliminate the causes of various safety accidents, safety levels might be expected to be improved significantly. It is expected that this paper will provide knowledge and insight for developing new systems, and the results of the real-scale test might be useful for other researchers and similar research projects in the future.

• 한국신뢰성학회지:신뢰성응용연구
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• 제18권2호
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• pp.122-129
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• 2018

Purpose: This article develops an optimal reliability acceptance sampling plan for the case where the degradation quantity of the performance characteristic follows Weibull distribution. Method: For developing reliability acceptance sampling plans, the sample size and the acceptance constant are determined based on the accelerated characteristic of the test condition and the product. Results: The sample size and the acceptance constant are provided such that the constraints of the producer and the consumer risks are satisfied. Conclusion: Reliability acceptance sampling plans based on the accelerated degradation test method can be used for the quality control within a resonable amount of cost and time. In this article. an optimal reliability sampling plans are newly developed for this purpose.

• 한국군사과학기술학회지
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• 제15권1호
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• pp.28-35
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• 2012

We propose the live fire test process model based on systems engineering which consists of 4 phases i.e., review, setup, conduct and result. We also suggest the 4 phases acquisition model consisting of planning, execution, evaluation and disposal for test infrastructure. CMMI, TMMi and PMBOK are referred and hierarchial analysis method are adopted in developing the models. Thus, the detailed sub-processes are designed after defining higher level processes first. The higher level processes are defined by extracting common areas of all the test types. The low level processes for each specific test are designed by tailoring the higher level processes. By applying the proposed test process models into collaboration tool and information system, effective and systematic test processes for weapon systems are established.

• 한국군사과학기술학회지
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• 제17권3호
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• pp.318-326
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• 2014

The Shipyard Test of Naval Combat System depends on external factors, such as weather conditions and availability of its sensor-weapon, due to the need of on-board sensor-weapon during the test. This paper suggests the Supportive Equipment using virtual simulator for Shipward Test, in case of the unavailability of the on-board sensor-weapon or the test support force(aircraft, surface ship etc.), to pre-check the functions of the combat system as well as to prepare the Shipyard Test. To mock the real sensor-weapon functions as similar as possible, the Supportive Equipment for Shipyard Test was verified by the Verification and Validation process, which is usually performed while developing models in the Modeling & Simulation field.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1157-1162
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• 2016

Background: Cervical cancer is known as one of the most prevalent types of cancers and a major public health problem in developing countries which can be detected by Pap test, prevented, and treated. Despite the effective role of Pap test in decreasing the incidence and mortality due to cervical cancer, it is still one the most common causes of cancer-related deaths among women, especially in developing countries. Thus, this study aimed to examine the effect of educational interventions implemented by health volunteers based on protection motivation theory (PMT) on promoting Pap test use among women. Materials and Methods: This quasi-experimental study was conducted on 60 health volunteers and 420 women. The study participants were divided into an intervention and a control group. Data were collected using a valid self-reported questionnaire including demographic variables and PMT constructs which was completed by both groups before and 2 months after the intervention. Then, the data were entered into the SPSS statistical software, version 19 and were analyzed using Chi-square test, independent T-test, and descriptive statistical methods. P<0.05 was considered as statistically significant. Results: The findings of this study showed that the mean scores of PMT constructs (i.e. perceived vulnerability, perceived severity, fear, response-costs, self-efficacy, and intention) increased in the intervention group after the intervention (P<0.001). However, no significant difference was found between the two groups regarding response efficacy after the intervention (P=0.06). The rate of Pap test use also increased by about 62.9% among the study women. Conclusions: This study showed a significant positive relationship between PMT-based training and Pap test use. The results also revealed the successful contribution of health volunteers to training cervical cancer screening. Thus, training interventions based on PMT are suggested to be designed and implemented and health volunteers are recommended to be employed for educational purposes and promoting the community's, especially women's, health.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 전문대학교육위원 P
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• pp.1-3
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• 1999

EM (ElectroMagnetic) pump is used for the purpose of transporting liquid sodium coolant with electrical conductivity in the LMR(Liquid Metal Reactor). (In the present study, pilot EM pump has been designed by using of equivalent circuit method which is commonly employed to analyze linear induction machines for the test of removal of residual heat. The length and diameter of the pump have fixed values of 840 mm and 101.6 mm each by taking account of geometrical size of circulation loop for the installation of EM pump. Flowrate versus developing pressure is related from Laithwaite's standard design formula and the characteristic analyses of developing force and efficiency are carried out according to change of input frequency. From the characteristic curve, input frequency of 13 Hz is determined as the design frequency. On the other hand, The annular air gap size of 6.05 mm is selected not to bring about too much hydraulic loss. Resultantly design analysis makes pump have the electrical input of 604 VA and the hydrodynamical capacity of 1.3 bars and 40 l/min.