• 한국응용과학기술학회지
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• 제31권2호
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• pp.197-202
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• 2014

Positive plate was composed of lead hydroxide via reaction between lead oxide and $H_2O$ and lead sulfate was formed of the reaction of lead hydroxide with sulfuric acid. And its density is $3.8g/cm^3$, $4.0g/cm^3$, $4.2g/cm^3$ and $4.4g/cm^3$ by controlling volume of refined water. Curing of positive plate is done for low ($45^{\circ}C$, 40hr, over 95% of relative humidity) & high ($80^{\circ}C$, 40hr, over 95% of relative humidity) temperature, which created 3BS & 4BS active materials. Experimental result of DOD with 100% life cycle test shows that it was not related to the density of active materials but to the low & high temperature aging of active materials. The test makes us to understand that the crystallization which is made by curing of active materials is a more of a main factor than density of active materials under the deep cycle using circumstances. The active materials which were from the high temperature curing are better for deep cycle performance.

• 대한기계학회논문집
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• 제13권2호
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• pp.307-315
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• 1989

본 연구에서는 단조과정을 거친후 노멀라이징(normalizing) 처리된 SF45A강종과 압연후 자연 냉각시킨 SM41B강종의 두 국산 강종에 대해 저사이클 피로시험을 행하여 저사이클 피로특성을 밝히고, 강재의 가공공정과 부하변형율변화에 따른 피로과정중의 연화 및 경화 거동을 관찰하였다. 그리고 저사이클 피로파면의 미시적 고찰을 통해서 부하변형율 크기에 따른 미시적 파면 양상의 변화를 밝혀 파괴 해석의 기초자료로 제공하였다.

• 한국군사과학기술학회지
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• 제27권2호
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• pp.203-212
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• 2024

This paper describes the establishment of defense systems test works architecture model for the efficient operation of an expanded test organization and the provision of standardized test services after the integration of proving grounds in ADD. The system engineering vee model is applied to the defense system test works to define the project management model and the unit-test management model. In order to establish the defense systems test works architecture model, the process flow of test works, artifacts by life cycle, and interrelations between regulations and test works are explained, and Integrated Test Information System for implementation of architecture model is discussed. Through the defense systems test works architecture model presented in this study, it will contribute to quickly responding to the test requirements of complex and diverse defense systems, efficiently managing projects, and providing standardized test services.

• 한국국방경영분석학회지
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• 제30권1호
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• pp.168-188
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• 2004

Integrated Logistic Support (ILS) is a management and technical process whereby all the diverse elements needed to fully operate, maintain, and totally support a materiel system in the field are identified, developed, and deployed simultaneously and on an equal priority with the item of materiel being supported. The test and evaluation (T＆E)of ILS act the important role of reduction of life-cycle cost and keeping of good performance for weapon system. In this article, we suggest the alternatives for improvement in the test and evaluation of ILS during weapon system acquisition. It is hoped that this research is valuable and beneficial to persons related weapon system acquisition, in order to maximize the efficiency of defense acquisition management by reducing the life-cycle cost and enhancing the quality of weapon system.

• 대한기계학회논문집A
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• 제32권2호
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• pp.177-185
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• 2008

Low-cycle environmental fatigue tests of cast austenitic stainless steel CF8M at the condition of fatigue strain rate 0.04%/sec were conducted at the pressure and temperature, 15MPa, $315^{\circ}C$ of a operating pressurized water reactor (PWR). The used test rig was limited to install an extensometer at the gauge length of the cylindrical fatigue specimen inside a small autoclave. So the magnet type LVDT#s were used to measure the fatigue displacement at the specimen shoulders inside the high temperature and high pressure water autoclave. However, the displacement and strain measured at the specimen shoulders is different from the one at the gauge length for the geometry and the cyclic strain hardening effect. Displacement of the fatigue specimen gauge length calculated by FEM (finite element method) used to modify the measured displacement and fatigue life at the shoulders. A series of low cycle fatigue life tests in air and PWR conditions simulating the cyclic strain hardening effect verified that the FEM modified fatigue life was well agreed with the simulating test results. The process and method developed in this study for the environmental fatigue test inside the small sized autoclave would be so useful to produce reliable environmental fatigue curves of CF8M stainless steel in pressurized water reactors.

• 국제강구조저널
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• 제18권4호
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• pp.1384-1396
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• 2018

One of the failure modes observed in steel yield energy dissipating devices (SYEDs) excited by a strong earthquake would be the low-cycle fatigue failure. Fatigue cracks of a SYED are prone to initiate at the notch areas where stress concentration is usually occurred, which is demonstrated by the cyclic tests and analyses carried out for this study. Since the fatigue failure of SYEDs dramatically deteriorates their structural capacities, the thorough investigation on their fatigue life is usually required. To do this, sophisticated modeling with considering a time-consuming and complicate fracture mechanism is generally needed. This study makes an effort to investigate the low-cycle fatigue life of SYEDs predicted by a simplified method utilizing damage indices and fatigue prediction equations that are based on the plastic strain amplitudes obtained from typical finite element analyses. This study shows that the low-cycle fatigue failure of SYEDs predicted by the simplified method can be conservatively in good agreement with the test results of SYED specimens prepared for experimental validation.

• 한국자동차공학회논문집
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• 제12권3호
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• pp.122-129
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• 2004

In plastic working, as working becomes speedy, automatic and working condition deteriorates, the increase of forging working has been remarkable. Therefore, we need the estimation of mold lift in detail, in order to counterplan of effective mold life extension. In this study, on the SKH51, mold steel which is forged by cold working and the KCW1, tool steel of low alloy, we estimated mold life on the base of FEM analysis and investigated mold lift by low cycle fatigue test. Also, this paper suggested a new method of estimation of mold lift.

• 시스템엔지니어링워크숍
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• 통권4호
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• pp.17-22
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• 2004

This paper present the brief generation process of system requirements or mart UAV from a development obejective. The current Snart UAV requirements deal with the restricted life cycle from development to test and verification exclusive of full life cycle beacuse of the new technology demonstration research program funded by goverments. The Smart UAV system consists of flight vechicle, avionics, communication link, payload, ground control stationand ground supporting system. In thus paper, top-down flown requirememts are intoduced how to allocate to each sub-system.

• 산업경영시스템학회지
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• 제17권30호
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• pp.177-184
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• 1994

The importance of usability evaluation is increasing in developing the system(or product). Many usability measures and test methods have been developed in the fields of ergonomics and cognitive engineering. A systematic usability effort using established methods may be qualify as usability engineering. In this paper, general aspects of the usability engineering are introduced, and application methods of usability engineering model based on product's life cycle are presented.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.757-758
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• 2010