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        검색결과 54

        1.
        2023.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A transfer cask serves as the container for transporting and handling canisters loaded with spent nuclear fuels from light water reactors. This study focuses on a cylindrical transfer cask, standing at 5,300 mm with an external diameter of 2,170 mm, featuring impact limiters on the top and bottom sides. The base of the cask body has an openable/closable lid for loading canisters with storage modules. The transfer cask houses a canister containing spent nuclear fuels from lightweight reactors, serving as the confinement boundary while the cask itself lacks the confinement structure. The objective of this study was to conduct a structural analysis evaluation of the transfer cask, currently under development in Korea, ensuring its safety. This evaluation encompasses analyses of loads under normal, off-normal, and accident conditions, adhering to NUREG-2215. Structural integrity was assessed by comparing combined results for each load against stress limits. The results confirm that the transfer cask meets stress limits across normal, off-normal, and accident conditions, establishing its structural safety.
        4,600원
        4.
        2022.05 구독 인증기관·개인회원 무료
        The License on Technology Export of Nuclear Plant is a system that permits the export of strategic technologies for large-scale NPP projects collectively during the project period. So, an issuance of the export license could be omitted for each transfer of technology, but Post Strategic Items Confirmation must be performed before the transfer as a follow-up obligation. Sometimes, transfers of technology have been urgently required during the project. As Post Strategic Items Confirmation process takes up to 15 working days, it may be difficult to respond to urgent situations timely, which may cause setbacks on the project. Therefore, Urgent Technology Transfer System, which allows to transfer technology without prior Post Strategic Items Confirmation, was established to reduce a burden on licensee and improve the efficiency of regulation. This system applies only to the License on Technology Export of Nuclear Plant. In other words, the technology transferred through Urgent Technology Transfer System (hereinafter referred as Urgent Transfer Technology) does not pose any problem with regard to export control because it is already licensed. In addition, the Urgent Transfer Technology should be considered as a strategic technology until Post Strategic Items Confirmation, which means that the Urgent Transfer Technology is more strictly controlled than the generally transferred technology. Also, the Urgent Technology Transfer System does not apply to intangible technology transfers such as technical support through personnel dispatch. The system could be only used in specific conditions which are stipulated for each licensed project in advance in order to prevent indiscriminate abuse of the system by licensee. Licensees are required to report quarterly the stipulated condition corresponding to each Urgent Technology Transfer case, and it would be checked through post-site inspection whether the actual reason for the transfer meets the consulted condition. Moreover, the deadline of application on Post Strategic Items Confirmation after the Urgent Technology Transfer is stipulated for licensee so as not to omit the classification procedure. This Urgent Technology Transfer System does not apply to dual-use items. If the Urgent Transfer Technology is classified as a non-Trigger List Item through the Post Strategic Items Confirmation, it is outside the scope of the NSSC’s export license. In this case, the technology may be subject to an export license of the Ministry of Trade, Industry and Energy (MOTIE). However, if the technology is classified to be a dual-use item after Urgent Technology Transfer, it may result in unauthorized transfer because it has already been transferred. Licensee must apply to classification of MOTIE before Urgent Technology Transfer if the technology being transferred may be related with Dual-use Items. It is easy for licensee to overlook due to the low awareness about this system. Therefore, outreach activities are necessary to raise licensee’s awareness by explaining the Urgent Technology Transfer System and current issues in detail. Consultation with MOTIE may be needed for the improvement on issues.
        5.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, a heat exchange system using cooling dehumidification and mixing process was proposed as an experimental study for a white smoke reduction heat exchanger system under winter condition. The white smoke reduction heat exchange system is divided into an EA part, SA part, W part and mixing zone. For the operating conditions, three types (Cases 1, 2, and 3) were selected depending on whether EA fan, SA fan, and A-W heat exchanger were operated. In addition, in order to visualize the white smoke exhausted from the mixing zone, it was photographed using CCTV. In order to investigate the performance of the white smoke reduction heat exchange system, the temperature reduction rate and absolute humidity reduction rate of EA and the heat recovery rate of W were calculated. The temperature change of EA and SA according to operating conditions was most effective in Case 3, and the temperature and absolute humidity at the outlet of the mixing zone were greatly reduced. From the results of the white smoke visualization, it was confirmed that the white smoke generation mechanism was different depending on the operating conditions, and the amount of white smoke generation was greatly reduced.
        4,000원
        6.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The enhancement of heat transfer in cooling system of cylindrical lithium-ion battery pack is numerically investigated by installing fins on the cooling plate. Battery Design StudioⓇ software is used for modeling electro-chemical heat generation in the battery and the conjugated heat transfer is analyzed with the commercial package STAR-CCM+. The result shows that installing fins on the cooling plate increases the convective heat transfer on the surface and thus lowers the maximum temperature of the battery pack. As the length and thickness of the fins increase, heat transfer in the battery pack improves. Considering the geometry and airflow of the battery pack, the optimal values for the length and thickness of the fin are both 2mm. As the convective heat transfer coefficient of the surface increases, the maximum temperature of the battery pack is greatly reduced and the temperature gradient is greatly improved.
        4,000원
        7.
        2021.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        급변하는 환경에서 지속 가능한 경쟁우위를 확보하기 위해 기업들은 끊임없이 새로운 지식을 획득해야 한다. 인수합병이나, 지식재산권의 구매 등이 이를 위한 대표적인 수단이나, 합작회사의 설립도 보완자산을 내재화하기 위한 효과적인 지식 획득 방법으로 주 목받고 있다. 그러나 모든 합작회사가 새로운 지식을 성공적으로 획득하는 것은 아닌데, 이는 기업들이 획득하고자 하는 지식의 특성에 맞는 적절한 학습전략 및 조직 구조를 갖추지 못했기 때문인 경우가 많다. 본 연구는 이 같은 문제의식 하에 상황이론 관점에서 지식의 특성을 다차원 적으로 구분하고 지식 특성에 맞는 학습전략과 조직구조의 필요성을 자동차 부품분야의 국제 합작회사 사례를 통해 살펴보았다. 하드웨어 기술에 최적화된 사례 회사(국제 합작회사)는 다른 성격의 지식인 소프트웨어 기술을 습득하기 위해 차별화된 학습 전략과 조직구조를 갖추지 못했고, 이러한 미스매치로 인해 합작회사를 통한 새로운 지식(엔진제어시 스템 기술)의 흡수에 실패하였다. 본 연구는 기업이 성공적 지식흡수를 위해 고려해야 할 요소들을 이론적 프레임워크를 통해 제시하고 실증분석을 통해 이를 검증함으로써 합작회사 설립, 인수합병 등 조직 변화를 통해 동태적 역량을 확보하고자 하는 기업들에게 실무적 시사점을 제공하고 있다.
        7,000원
        9.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although somatic cell nuclear transfer (SCNT)-derived embryonic stem cells (ESCs) in pigs have great potential, their use is limited because the establishment efficiency of ESCs is extremely low. Accordingly, we tried to develop in-vitro culture system stimulating production of SCNT blastocysts with high performance in the colony formation and formation of colonies derived from SCNT blastocysts for enhancing production efficiency of porcine ESCs. For these, SCNT blastocysts produced in various types of embryo culture medium were cultured in different ESC culture medium and optimal culture medium was determined by comparing colony formation efficiency. As the results, ICM of porcine SCNT blastocysts produced through sequential culture of porcine SCNT embryos in the modified porcine zygote medium (PZM)-5 and the PZM-5F showed the best formation efficiency of colonies in α-MEM-based medium. In conclusion, appropriate combination of the embryo culture medium and ESC culture medium will greatly contribute to successful establishment of ESCs derived from SCNT embryos.
        4,000원
        11.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, effects of reducing white smoke at a heat exchange system for white smoke reduction were studied in the winter season. For this purpose, the heat transfer processes on the exhaust air were investigated by Solidworks. Five wave heat exchangers of air-to-air and air-to-water type were applied for the exhaust air heat recovery. The analytical condition of the exhaust air was fixed and the computational analysis was performed according to the change of SA(supply air) inlet velocities. In order to evaluate the performance of the heat exchange system for white smoke reduction, W(water)/SA recovered capacities and the temperature/ absolute humidity reduction rate were calculated. As SA inlet velocity increased, the exit temperature and absolute humidity of the mixing zone were reduced by up to about 40℃ and 0.12kg/kg respectively. Also, W/SA recovered capacities increased linearly up to about 35%.
        4,000원
        12.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the present study, the white reduction system was designed and manufactured to evaluate the performance of a heat exchange system using a wave heat exchanger. The reducing effect of white smoke and the amount of heat recovered from cooling water were investigated experimentally using the cooling and dehumidifying method. The white smoke reduction system consists of two parts; the generating part and the reducing part of white smoke. Experimental conditions on EA(exhaust air) and SW(supply water) were fixed. And the outlet temperature and absolute humidity of EA were measured according to inlet velocity of SA(supply air). The outlet temperatures and absolute humidities of EA gradually decreased as inlet velocities of SA increased. From the experimental results, we can see that the absolute humidity reduction rate of EA was max. 84%, and the heat recovery rate of SW was max. 42%.
        4,000원
        14.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to review the relationship between managerial system and incremental innovation, and the mediating effect of knowledge transfer in small business. In order to verify and achieve the purposes mentioned above, questionnaire data were gathered and analysed from 255 enterprise managers in western Kangwon-do province. Empirical survey's findings are as follows; First, CEO's support and education/training appeared to be positively related with knowledge transfer. Second, managerial system and knowledge transfer appeared to be positively related with incremental innovation. Third, knowledge transfer had mediating effect on the relationships of CEO's support-incremental innovation and education/training-incremental innovation.
        4,300원
        15.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we investigated to the heat transfer performance of coating nano-structure with various shapes and patterns on the heat transfer surface. As a result of the measurement of the 3D nano shape, it was confirmed that the roughness generally increases when the adhesive is sprayed on the coating surface and finished durability experiment. In the case of TEOS adhesive, the roughness increased by 0.074 ㎛, 0.012 ㎛ and 0.015 ㎛, and the contact angle decreased 12.64°, 1.31°, 9.84° at the coating time of 120 seconds, 180 seconds and 240 seconds, respectively. In the case of PVA adhesive, the roughness increased by 0.069 ㎛, 0.056 ㎛ and 0.03 ㎛, and the contact angle decreased 2.85°, 4.82°, 6.96° at the coating time of 120 seconds, 180 seconds and 240 seconds, respectively. In the case of DGEBF adhesive, the roughness increased by 0.042 ㎛, 0.053 ㎛ and 0 ㎛, and the contact angle decreased 0.81° at the coating time of 120 seconds, increased 4.82°, 6.96° at the coating time of 180 seconds and 240 seconds, respectively. As a result, the durability tends to decrease as more nano-structures are deposited, and 3D nano shapes, contact angles and SEM photographs showed that the performance of the PVA adhesive was superior among the three adhesives.
        4,000원
        16.
        2017.03 KCI 등재 구독 인증기관·개인회원 무료
        현행 여신전문금융업법 제19조 제1항 및 제4항은, 신용카드가맹점으 로 하여금 ‘신용카드 결제를 거절하는 행위’, ‘신용카드회원을 불리하게 대우하는 행위’, ‘가맹점수수료를 신용카드회원에게 부담시키는 행위’를 금지하고 있다. 동 조항은, 국민의 금융편의를 도모하고, 거래의 투명화 및 이를 통한 탈세방지를 위하여 도입된 것으로 그간 충분한 효과를 보 여주었으나, 동 조항의 남용을 통한 가맹점 피해, 신용카드를 발급받지 못하는 저신용자에게 비용이 전가되는 등 경제적 정의에 반한다는 점, 사회전체의 거래비용이 증가한다는 점 등의 부작용이 발생하고 있다. 이 러한 부작용을 최소화하며 입법목적을 달성할 수 있도록 입법적 보완작 업이 필요하다. 예를 들어, 거액 결제와 같은 경우에는 동 조항의 적용을 배제하는 방안, 가맹점수수료 정도의 합리적인 범위내의 차별을 허용하 는 방안, 현금결제와의 차별만 금지하고 다른 전자지급결제수단과의 차 별은 허용하는 방안 등을 논의해 볼 필요가 있다. IT산업의 발달과 더불어, 과거 전통적 결제수단이었던, 현금, 어음, 수 표, 계좌이체, 신용카드 외에, 계좌이체지급결제대행, 신용카드지급결제대 행, 직불카드(직불전자지급수단), 선불카드(선불전자지급수단), 전자화폐 의 방법이 등장하였다. 이들 결제수단 중 최근 서민을 위한 결제방식으 로 부상하고 있는 계좌이체지급결제대행의 경우, 신용카드를 발급받을 수 없는 저신용자도 이용이 가능할 뿐 아니라, 탈세방지 목적에도 부합 하고, 간편결제 방식의 적용에 따라 그 이용도 매우 편리하게 되었다. 그 러나 계좌이체지급결제대행의 경우에도 제19조 제1항 및 제4항을 적용 하게 되면, 신용카드(혹은 신용카드지급결제대행 방식)에 비하여 회원 유치 경쟁력이 떨어지게 되어, 그 확산에 어려움이 있다. 현금결제 고객 과는 달리 지급결제대행업체에 의한 별도의 용역제공 행위가 있음을 감 안하여 현행 여신전문금융업법 하에서도 제19조 제1항 및 제4항의 형식 적 적용을 배제하는 적극적 해석이 필요하다.
        17.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Numerical models of composite floor systems with various thickness of phase change material and sizes of circular spacers were developed based on finite element analysis. In order to perform a heat transfer analysis, thermal properties of steels were determined and those of phase change material were estimated from experiment results. In addition, the thermal insulation performance of composite floor systems with respect to different thickness of phase change material and sizes of circular spacers was predicted. To verify the validity of analysis, analysis results were compared with vertical furnace fire test results of equivalent conditions. As a result, available thicknesses of phase change material and sizes of circular spacers were proposed to satisfy the thermal insulation criteria of Korean Standards.
        4,000원
        18.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        단동 이중비닐하우스에서 수막에 의한 열전달 특성 및 가온효과를 구명하기 위하여 작물이 재배되는 수막온실의 실내외 기온과 수막의 수온 등을 계측하였고, 단위 피복면적당 수막에 의한 총 공급열량, 열관류율, 관류열량, 온실 내부로 전달되는 열량비율 변화를 비교·분석하였다. 1중과 2중사이의 기온은 외부기온보다는 수막유량과 공급수온에 따라 결정되는 것으로 나타났다. 수막유량이 증가할수록, 공급수온이 높을수록 수막과 2중 하우스 내부와의 열관류율(UW-IN)은 유의하게 증가하는 경향을 보였다. 그러나 수막유량과 공급수온이 일정조건(수 막유량 0.00266L·m-2·s-1, 공급수온 19.8oC) 이상에서는 UW-IN 값이 10W·m-2·oC-1 정도로 수렴되는 것으로 나타났다. 수막과 1·2중 공기 사이의 열관류율(UW-B)의 경우에도 수막유량 및 공급수온에 따라 증가하는 경향을 보였으나, 경향성은 상대적으로 작은 것으로 분석되었다. UW-B는 연구자에 따라 전체적으로 큰 차이를 보이고 있으며, 본 연구에서는 3.27~4.44W·m-2·oC-1의 범위를 보였다. 수막에 의한 총 공급열량(QW)과 온실 내외부로 전달 되는 관류열량(QW-IN, QW-B)의 경우, QW 값이 QW-IN과 QW-B의 합과 매우 유사하게 일치하고 있어 본 연구에서 제시한 결과가 신뢰성이 있음을 확인할 수 있었다. 수막에 의해 내부공기를 가열하는데 사용되는 열량은 최대 57% 수준으로 분석되었고, 우리나라 수막재배온실의 경우 약 22~28% 수준으로 판단된다. 본 연구는 농업인이 실제 사용하는 수막온실과 가장 유사한 조건에서 수막에 의한 온도변화, 열관류율과 관류열량을 계량화함으로써 향후 경제적인 수막온실 설계 시 활용할 수 있을 것으로 기대된다.
        4,000원
        19.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The efficiencies of thermal power system using fossil fuel depend on heat exchangers which extract energy from the exhaust gas before it is expelled to the atmosphere. To increase heat transfer efficiency it is very important to maintain the surface of heat exchanger as clean condition. The accepted skill of cleaning of fouled surface of heat exchanger is soot blowing. A high pressure jet of air is forced through the flat surface of plate to remove the deposit of fouling. There is, however, little knowledge of the fundamental principles of how the jet behave on the surface and how the jet actually removes the deposit. Therefore, the study focuses on the measuring of cleaning area and cleaning dwell time after accumulating the simulated deposit on the flat surface. The deposit test rig was built for the study and simulated deposit material is used after measuring the physical property of the each material by shearing stress test. Much data was obtained for the analysis by the parameters change such as the different jet speed, different inner pressure and variable distance of the jet from the test rig surface. The experimental data was compared with the theoretical equation and most of the data matches well except some extreme cases.
        4,000원
        20.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the last 10 years, porcine somatic cell nuclear transfer to generate transgenic pig has been performed tremendous development with introduction and knockout of many genes. However, efficiency of porcine somatic cell nuclear transfer is still low and embryo transfer (ET) is one of important step for production efficiency. In porcine ET for production of transgenic cloned pig, we can consider many of points to increase production rates. In respect of seasonality and weather, porcine ET usually is not performed in summer and winter. Cloned transgenic embryos must be transferred into reproductive tracts of recipients where embryos are located after natural fertilization with similar estrous cycle. If cloned embryos with 2∼4 cell stage are transferred, they must be transferred into oviducts in periovulatory stage. Number and deposition sites of transferred cloned embryos are important. And we must compare the methods of ET between surgical and non-surgical ones in respect of production efficiency. Sow recipients after natural estrus is most preferred recipients however its cost is must be considered. Here we will review many of current studies about porcine embryo transfer to increase production efficiency of transgenic pigs and strategies for further studies.
        4,000원
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