검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 129

        42.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The live fire test has been playing a critical role in evaluating the goals-to-meet of the weapon systems which utilize the power of explosives. As such, the successful development of the test systems therein is quite important. The test systems development covers that of ranges and facilities including system-level key components such as mission control, instrumentation or observation, safety control, electric power, launch pad, and so on. In addition, proper operational guidelines are needed with well-trained test and operation personnel. The emerging weapon systems to be deployed in future battle field would thus have to be more precise and dynamic, smarter, thereby requiring more elaboration. Furthermore, the safety consideration is becoming more serious due to the ever-increasing power of explosives. In such a situation, development of live fire test systems seems to be challenging. The objective of the paper is on how to incorporate the safety and other requirements in the development. To achieve the goal, an architectural approach is adopted by utilizing both the system components relationship and safety requirement when advanced instrumentation technology needs to be developed and deteriorated components of the range are replaced. As an evaluation method, it is studied how the level of maturity of the test systems development can be assessed particularly with the safety requirement considered. Based on the concepts of both systems engineering and SoS (System-of-Systems) engineering process, an enhanced model for the system readiness level is proposed by incorporating safety. The maturity model proposed would be helpful in assessing the maturity of safety-critical systems development whereas the costing model would provide a guide on how the reasonable test resource allocation plan can be made, which is based on the live fire test scenario of future complex weapon systems such as SoS.
        4,000원
        43.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To precisely assemble the fuel test rod, an orbital TIG welding system was designed and developed to accurately conduct orbital TIG welding for the nuclear fuel test rod. Using this system, a welding process needs to confirm the welding properties for orbital TIG welding. Therefore, preliminary weld tests were performed on the cladding tubes under various conditions, and the results show that the width and depth of HAZ of the cladding specimen welded using identical power during an orbital TIG welding cycle was continuously increased from a welded start-point to a welded end-point because of heat accumulation. The performance tests were conducted under the welding conditions considered through preliminary welding tests, and the properties of the specimens were conformed through surface and microstructure analyses.
        4,000원
        44.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The weapon systems development has some distinct characteristics in that a big size of government budget (derived from national tax) has been expended frequently and the completion of the development projects seems to take long. Thus, the impact of the potential changes in the required operational capability on the development activities can induce some type of project risks. As such, proper management of project risk has been one of crucial subjects in the weapon systems development. Although a variety of methods can be considered, an approach based on the test and evaluation (T&E) process has been selected in this paper in order to appropriately handle those potential risks. In the study of the underlying T&E process, the safety consideration (for instance, explosiveness) of weapon systems is also included. To achieve the objective of the paper, a step-by-step procedure is first presented in the analysis of the T&E process. Then, to pursue some enhancement on the process, a set of necessary and useful activities are added in terms of risk and safety management. The resultant process is further analyzed and tailored based on a design structure matrix method. The case study of a tank development is also discusse
        4,000원
        45.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 보호자의 인터뷰 없이 환자의 평가를 통해 다양한 인지영역을 빠르게 평가할 수 있고, 경도 인지장애의 치료적 중재 제공을 결정하는 노인 경도 인지장애 선별 검사 항목 개발하고자 한다. 연구방법 : 2014년 10월 23일부터 2014년 12월 16일까지 총 3회에 걸쳐 전문가 패널로 선정된 30명의 참여자에게 전자우편을 통해 델파이 조사를 실시하였다. 이후 경도 인지장애 환자 28명을 포함하여 총 81명의 환자에게 한국판 간이 정신상태 검사(Korean version of Mini-Mnetal State Examination; MMSE-K)와 본 평가도구를 평가하여 타당도를 검증하였다. 결과 : 최종 델파이 조사결과 평균 적합도 4.24와 중요도 4.30으로 분석되어 경도인지장애 선별평가 항목 으로 적절한 것으로 분석되었다. 적합도의 내용타당도 비율 0.84, 중요도의 내용타당도 비율 0.93으로, 적합도와 중요도 모두 내용타당도 비율이 높게 나타났다. 최종적으로 델파이 조사를 통해 노인 경도 인 지장애 선별검사 항목 개발에 관한 24개의 항목이 최종적으로 도출 되었다. MMSE-K와 높은 상관성을 보이고, Cronbach’s α는 .80으로 높은 타당도를 보였다. 결론 : 전문가의 의견을 수렴한 델파이방법을 통해 만들어진 본 평가도구는 기존의 평가도구와 높은 상관 성을 보이고 타당도가 높은 것으로 나타났다. 이에 본 도구는 경도 인지장애를 평가함에 있어 효과적이 라고 사료된다. 주제어 : 경도 인지장애, 노인, 델파이 조사, 선별평가, 항목개발
        4,800원
        46.
        2015.03 구독 인증기관 무료, 개인회원 유료
        This study is reduction to measuring error rate which checked or evaluated of overspeed euipment in the local roadway, national roadway and highway for overspeed driving vehicle. Especially, reliability of overspeed equipment is very important according to speed measurement devices between roof sensing method and radar, etc. So, this study is to measuring method and measuring devices for high reliability.
        4,000원
        47.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To conduct a nuclear fuel irradiation test, the inside of the nuclear fuel rod must be assembled along with the test fuel, several different parts, and sensors, and then filled with high-pressure and high-purityhelium gas. Therefore, it is necessary to develop helium gas filling techniques that can achieve exact TIG (Tungsten Inert Gas) spot welding at a pin-hole of the nuclear fuel rod to fill helium gas into the nuclear fuel test rod. However, previous apparatuses do not have repeatability for TIG spot welding as they lack an electrode position control jig to exactly fix a TIG electrode in a high-pressure chamber, and they consume a large amount of helium gas. Therefore, a TIG spot welding apparatus was developed to easily and accurately conduct TIG spot welding and significantly reduce the gas consumption. In addition, the optimum welding conditions of this welding apparatus were established through various weld tests.
        4,000원
        48.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The author introduces a test platform system that has been developed for variable-speed control moment gyroscopes(VCMGs). VCMGs are important actuators for spacecraft attitude control. The test platform consists of two VCMGs driven by servo motors and sensor modules. The control program has been coded by the NI LabVIEW. Accelerometers and gyros have been used to measure the attitude angle and angular speed of the platform. The 2nd order low pass filters have effectively filtered out noises from measurements. Wheel speeds and gimbal angles have been controlled satisfactory by PI control. Through some tests, moment generation has been verified. The moment has been generated as commanded. However, friction effect by a ball bearing, that supports the platform’s rotation, has been not negligible. As further studies, friction reduction will be studied. In conclusion, this test platform will be used for engineering education and research.
        4,000원
        49.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This study aims to develop a strength test method for irregularly shaped concrete block paver. METHODS : Ten (10) different types of concrete block pavers including porous and dense blocks were tested for strength capacities. Destructive and non-destructive methods were used to develop a strength test method for irregularly shaped concrete block paver. The flexural strength evaluation was conducted in accordance to KS F 4419, while compressive strength was conducted with a 45.7mm-diameter core specimen. The impact echo test method was used to evaluate the elastic modulus. Finally, regression analysis was used to investigate the relationship between flexural strength, compressive strength and elastic modulus based on their corresponding test results. RESULTS : The flexural strength of the tested block pavers ranged from 4MPa to 10MPa. At 95% confidence level, the coefficients of determination between compressive-flexural strength relationship and compressive strength-elastic modulus relationship were 0.94 and 0.84, respectively. These coefficients signified high correlation. CONCLUSIONS : Using the test method proposed in this study, it will be easier to evaluate the strength of irregularly shaped concrete block pavers through impact echo test and compressive test, instead of the flexural test. Relative to the flexural strength requirement of 5MPa, the minimum values of compressive strength and elastic modulus, as proposed, are 13.0MPa and 25.0GPa, respectively.
        4,000원
        51.
        2014.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The Notched Ring Test(NRT) has proven to be very useful in determining the slow crack growth behavior of polyethylene pressure pipes. In particular, the test is simple and an order of magnitude shorter in experimental times as compared to the currently used Notched Pipe Test(NPT), which makes this method attractive for use as the accelerated slow crack growth test. In addition, since the NRT specimen is taken directly from the pipe, having maintained the cross-section, processing induced artifacts that would affect the slow crack growth behavior are not altered. This makes the direct comparison to the slow crack growth specimen in pipe from more meaningful. In this study, for comparison with other available slow crack growth methods, including the NPT, the stress intensity factor equation for NRT specimen was developed and demonstrated of its accuracy within 3% of that obtained from the finite element analysis. The equation was derived using a flexure formula of curved beam bending along with numerically determined geometric factors. The accuracy of the equation was successfully tested on 63, 110, 140, 160, 250, and 400 mm nominal pipe diameters, with crack depth ranging from 15 % to 45 % of the pipe wall thickness, and for standard dimensional ratio(SDR) of 9, 11, and 13.6. Using this equation the slow crack results from 110SDR11 NRT specimen were compared to that from the NPT specimen, which demonstrated that the NRT specimen was equivalent to the NPT specimen in creating the slow crack, however in much shorter experimental times.
        4,000원
        52.
        2014.02 구독 인증기관·개인회원 무료
        Since 2003, policies and practices related to the reduction of CO2 gas emission from ships has been discussing by the International Maritime Organization. The representative emission index and indicator are the EEDI (Energy Efficiency Design Index) for the new ships and EEOI (Energy Efficiency Operational Indicator) during the voyage. In this paper a water tank test and procedure development are introduced for the purpose of improving EEDI. The results showed good agreement explaining the characteristics properly.
        53.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Many automotive components for power generation such as motors and alternators have been widely using ferrite magnets. To ensure a high level of efficiency could be achieved in an alternator, the assembled magnets must be in good enough durability. Recently, some hairline cracks have been found on the magnet produced by manufacturers in Korea. Thus, there is an increasing concern that some of the magnets produced could cause further problems after being assembled in the alternator. Based on the standard alternator test (RS0008 : 2006), this paper has developed an accelerated failure-free test for magnets in alternator to demonstrate that assembled magnets will meet durability objective specified by the manufacturer. This guarantees the target life of the magnet with 90 percent reliability and 90 percent confidence level (R90C90). Temperature and rotation speed were selected as accelerated stress factors.
        4,000원
        54.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recent trends in rail industry can be characterized by the multifunctionality and very high-speed modes of operations. In particular, the adoption of the unmaned or operatorless operations has been getting increased attention in which case ensuring systems safety is crucial. On the other hand, according to the result of analyzing rail accidents, the human/operator errors have turned out to be one of the key causes of the accidents. Therefore, the effort of improving the work environment of locomotive cabs is quite necessary in order to decrease the accidents. The objective of this paper is studying on how to incorporate the factors related to the train operators in the design of the locomotive cabs and also on how to evaluate the design results obtained, which is subsequently reflected in the generation of the test and evaluation procedure. The approach taken is based on systems engineering, yielding the procedure document as a result. The results obtained in the paper can be useful in confirming the design of locomotive cabs utilizing the domestic human/operator measure. Also, the way of achieving the objectives can be utilized to cover the expanded rail systems development with appropriate design activities added.
        4,000원
        55.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 문항반응이론에 근거한 라쉬분석을 적용하여 뇌졸중 환자의 연하기능 검사를 개발하는 것이다. 연구방법 : 뇌졸중으로 인한 연하장애 환자 153명을 대상으로 5개 영역에 24개 항목으로 구성된 예비 연하기능 검사를 수집하였다. 수집된 자료는 라쉬분석을 적용하여 대상자 및 항목의 적합도와 항목 난이도, 분리신뢰도, 평정척도 분석 을 실시하였다. 최종적으로 요인분석을 통해 항목의 영역을 분류하였다. 결과 : 153명의 대상자 중 11명이 부적합한 대상자로 판정되었으며, 23개 항목 중 6개 항목이 부적합 판정을 받았다. 부 적합한 항목은 1)폐렴과거력, 2)구강감각, 3)구역반사, 4)비강/구강 역류, 5)삼킴지연, 6)삼킴 후 천명이었다. 항목의 난이도에서 가장 어려운 항목은‘후두거상’으로 나타났으며, 가장 쉬운 항목은‘각성도’로 분석되었다. 연하기능 검사 의 평정척도(0~4점)는 적합한 척도 범주로 분석되었으며, 항목에 대한 분리신뢰도는 .98, 대상자에 대한 분리신뢰도 는 .95로 분석되었다. 최종적으로 요인분석을 통해 4개 영역에 17개 항목으로 구성된 연하기능 검사를 개발하였다. 결론 : 라쉬분석을 적용하여 뇌졸중 환자를 대상으로 한 연하기능 검사의 신뢰도와 타당도를 입증하였다. 연하기능 검사 의 각 항목들은 임상적으로 환자의 기능과 회복 수준을 세부적으로 파악할 수 있으며, 항목들의 난이도 수준을 고려하 여 중재 가이드라인을 제시할 수 있을 것으로 기대한다.
        5,400원
        56.
        2013.11 구독 인증기관 무료, 개인회원 유료
        최근 현대 무기체계는 최첨단 기술로 인한 무기체계 개발 속도 증가와 획득환경의 다변화와 더불어 이에 대한 위험도 동시에 증가하고 있다. 이에 따라 미국방부는 무기체계의 수명주기를 고려하여 시험평가를 지속 적용토록 강조하고 있다. 따라서 기존의 무기체계 시험평가 프로세스에서 다루는 시스템 설계에 대한 위험 관리 활동의 강화의 필요성 역시 강조되고 있다. 그 중에서도 무기체계 개발의 탐색개발 및 체계개발 단계는 양산에 들어가기 전의 최종 활동으로서 제대로 수행되어야만 초기에 의도한 무기체계 개발의 목적을 달성할 수 있을 것이다. 본 논문에서는 위험 관리 활동을 고려한 시험평가 프로세스의 개선사항 도출과 모델링을 통해 무기체계 시스템인 무기체계를 대상으로 적용 및 조정 구축에 대한 내용을 기술하고 있다. 본 연구의 결과를 토대로 향후 시험평가 시 위험관리에 대한 투자를 통해 전체 프로젝트의 기간 단축 및 비용 절감과 안전성 확보를 개선시킬 수 있을 것으로 기대된다.
        4,200원
        57.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With the recent changes in the environment of weapon systems acquisition, the systems development is becoming more susceptible to a variety of risks. To cope with this situation, US DoD has been emphasizing the importance of constantly applying the test and evaluation (T&E) process throughout the whole life cycle of the weapon systems. In particular, the safety requirements are called for attention while dealing with system risks. To this end, the present paper is aimed at studying the T&E process which incorporates the systems safety in weapon systems development. Analyzing and modeling the relevant processes has made it possible to achieve the objective. As a case study, the model results were applied to the development of unmanned aerial vehicles.
        4,000원
        58.
        2013.04 구독 인증기관 무료, 개인회원 유료
        최근 현대 무기체계는 최첨단 기술로 인한 무기체계 개발 속도 증가와 획득환경의 다변화와 더불어 이에 대한 위험도 동시에 증가하고 있다. 이에 따라 미국방부는 무기체계의 수명주기를 고려하여 시험평가를 지속 적용토록 강조하고 있다. 따라서 기존의 무기체계 시험평가 프로세스에서 다루는 시스템 설계에 대한 단계별 안전 활동의 강화의 필요성 역시 강조되고 있다. 그 중에서도 무기체계 개발의 핵심 활동에 해당하는 체계개발 단계는 양산에 들어가기 전의 최종 활동으로서 제대로 수행되어야만 초기에 의도한 무기체계 개발의 목적을 달성할 수 있을 것이다. 본 논문에서는 시스템 안전성 요소를 고려한 시험평가 프로세스의 개선사항 도출과 모델링을 통해 무기체계 시스템인 무기체계를 대상으로 적용 및 조정 구축에 대한 내용을 기술하고 있다. 본 연구의 결과를 토대로 향후 시험평가 기간의 단축 및 비용 절감과 데이터의 관리 및 추적 기능을 개선함으로써 무기체계 개발 후의 안전사고 발생 가능성을 줄일 수 있을 것으로 기대된다.
        4,600원
        59.
        2012.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 소형선박 국제표준규격(ISO-12215)이 제정되면서 소형선박-선체구조 및 치수-제5장 부속서 B에 의하여 길이 2.5미터 이상 6미터 미만 소형선박의 낙하시험에 의한 강도시험 기준을 적용할 수 있게 되었으나, 육안검사로 실시되는 현재의 방법으로는 선체 강도 평가의 객관적인 평가가 어려운 문제점이 있다. 본 연구에서는 레저선박의 낙하시험의 정량적 평가가 가능한 평가시스템을 개발하기 위하여 레저선박의 낙하시험에 대한 국내 외 규정을 기반으로 한 낙하시험 평가시스템을 설계하였으며, 5미터급 알루미늄선박의 낙하시험을 통하여 시스템의 적용가능성을 검토하고 낙하 시 선박의 상태 및 낙하자세에 따라 발생되는 문제점을 확인하였다.
        4,000원
        60.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recent technological advances in the domestic railway industry have turned out to deliver a profound impact on the forefront of other industries as well. Furthermore, the introduction of the high-speed railway systems has made it possible to travel around our country in a day, thereby changing our life styles a lot. However, it has been well recognized that many factors can cause unanticipated accidents during the operation. One of the causes is known to be the human errors made by the train operators in locomotive cabs. The problem is getting more serious as the trains run at high speed. As such, the objective of this paper is on how to improve the work environment of the locomotive cabs. Our approach is based on the systems engineering methodology. Specifically, we first identify the context and scope of the problem to be solved. We then continue our effort in deriving the requirements set to accomplish the improvement. These results are utilized in constructing a computer-aided management system for test and evaluation intended for the improvement. The approach taken and the results obtained in this paper is expected to make a contribution on the route to keeping our nation's technologies on the competitive edges in the high-speed railway systems industry.
        4,200원
        1 2 3 4 5