• 한국초전도ㆍ저온공학회논문지
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• 제18권1호
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• pp.64-68
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• 2016

High Temperature Superconductor power cable systems are being developed actively to solve the problem of increasing power demand. With increases in the unit length of the High Temperature Superconductor power cable, it is necessary to develop highly efficient and reliable cryogenic pumps to transport the coolant over long distances. Generally, to obtain a high degree of efficiency, the cryogenic pump requires a high pressure rise with a low flow rate, and a partial emission type pump is appropriate considering its low specific speed, which is different from the conventional centrifugal type, full emission type. This paper describes the design of a partial emission pump to circulate subcooled liquid nitrogen. It consists of an impeller, a circular case and a diffuser. The conventional pump and the partial emission pump have different features in the impeller and the discharge flow passage. The partial emission pump uses an impeller with straight radial blades. The emission of working fluid does not occur continuously from all of the impeller channels, and the diffuser allows the flow only from a part of the impeller channels. As the area of the diffuser increases gradually, it converts the dynamic pressure into static pressure while minimizing the loss of total pressure. We used the known numerical method for the optimum design process and made a CFD analysis to verify the theoretical performance.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.851-856
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• 2003

A cross-flow fan consists of an impeller, a stabilizer and a rearguider. When it applied for an air conditioner, an evaporator should be added. It relatively makes high dynamic pressure at low speed because a working fluid passes through an impeller blade twice and blades have a forward curved shape. Therefore, the performance of a cross-flow fan is influenced 25% by the impeller, 60% by the rearguider and the stabilizer, 15% by the heat exchanger. At the low flow rate, there are a rapid pressure head reduction, a noise increase and an unsteady flow against a stabilizer and a rearguider. Moreover, the reciprocal relation between the impeller and the flow passage is the important factor for performance improvement of the cross-flow tan because each parameter is independent. The performance characteristics in the cross-flow fan are graphically depicted with various impeller outlet angles and rearguiders.

• 한국산업융합학회 논문집
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• 제16권3호
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• pp.95-102
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• 2013

It is indispensable to modern society metal processing since the industrialized rapidly, but it is a metalworking cutting fluid immediately. In addition, this means selecting a emulsion on the basis of quality criteria processing method, the material of the material, cutting depth, cutting speed, Djourou fence Liang, and surface roughness, cutting oil, the shape of the device based on the emulsion, I will be the structure of the tank, filtration equipment also changes. In particular, acting bacteria is now breeding in response to the passage of time due to metal ion degradation due to heat generated hydraulic fluid leakage, humidity tung, during processing, seep from processing material at the time of processing the water-soluble cutting oil for generating the malodor by dropping significantly the performance of the cutting oil to corruption from, sometimes by introducing various additives to suppress spoilage in advance. In this study, we expect the effect of the cost reduction in the extension of fluid replacement cycle through the application of the management apparatus and deep understanding in the management of cutting fluid, the working environment through the understanding and interest of workers in the production site more than anything I try to become useful for the improvement.

• 한국직업건강간호학회지
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• 제25권3호
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• pp.238-248
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• 2016

Purpose: The purpose of this empirical research was to describe the contents what had happened to nurses experiencing taeoom. Methods: This study explored the phenomenological ways to understand lived experiences in nurses' 'Taeoom' and investigated the 'Taeoom' through the deductive content analysis. For the this study, the data was collected through individual interviews with 11 nurses who worked over 12months in 1 hospital, lived in 5 areas, working 7 nursing unit of 10 hospitals. The interviews conducted by semi structured questions about participants' lived experiences in 'Taeoom'. Results: Inductive contents analysis identified 5 categories and 15 subcategories. Main themes in this study included a failed membership, difficult of practical field adaptation, feared with nursing unit life, self-centered peer relationships and rite of passage. Conclusion: This study results have been illuminated with edged sword which has a dark side and a light side to experienced in 'Taeoom'. Newly employed nurses have suffering from 'Taeoom' as well as retained nurse. Therefore, policy and practice programs for a diminution of suffering and management for nurses 'Taeoom' should be developed and implemented.

• 한국주거학회논문집
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• 제18권6호
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• pp.103-113
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• 2007

In Korea, open spaces of urban housing do not serve residents as "regular living areas". We carried out research on the "streets" of urban housings in that the meaning of traditional "streets", playing roles which are not only means of passage but also boundary of life, cannot include present meaning of "streets" of the urban housing. This research is to propose the direction of planning Community Streets for the recovery of the public- and communal urban housing's streets, researching the present employment condition of Community Streets that were prepared recently. Working with 3 complexes which have been completed since 2000, We studied the present employment condition and planned signification, according to the conditions of their surroundings, the physical conditions of Community Streets, and the relationship among main apartment buildings, open spaces, and facilities. From this study, We came up with several suggestions that can present the planning line of Community Streets. Therefore this research is to create the Community Streets for the activity of the streets, the recovery of the community, and improvement of ambulatory environment.

• Nuclear Engineering and Technology
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• 제40권2호
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• pp.155-162
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• 2008

Heat transfer experiments in an annulus passage were performed using SPHINX(Supercritical Pressure Heat Transfer Investigation for NeXt Generation), which was constructed at KAERI(Korea Atomic Energy Research Institute), to investigate the heat transfer behaviors of supercritical $CO_{2}$. $CO_{2}$ was selected as the working fluid to utilize its low critical pressure and temperature when compared with water. The mass flux was in the range of 400 to 1200 $kg/m^{2}s$ and the heat flux was chosen at rates up to 150 $kW/m^{2}$. The selected pressures were 7.75 and 8.12 MPa. At lower mass fluxes, heat transfer deterioration occurs if the heat flux increases beyond a certain value. Comparison with the tube test results showed that the degree of heat transfer deterioration in the heat flux was smaller than that in the tube. In addition, the Nusselt number correlation for a normal heat transfer mode is presented.

• 문화기술의 융합
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• 제5권4호
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• pp.157-169
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• 2019

본 연구의 목적은 간호사 태움에 대한 개념분석을 통해 그 개념을 명확히 하고, 유사개념인 직장 내 괴롭힘(workplace bullying)과의 차이를 규명하여 간호이론과 지식개발을 위한 기초자료를 마련하고자 함이다. 본 연구는 Rodgers의 진화론적 방법에 따라 태움에 대한 개념분석을 실시하였으며, 검색된 총 125편의 논문 중 본 연구에 필요한 15의 논문을 정독한 후 분석하였다. 연구결과로 나타난 태움의 속성은 통과의례, 고통스러운 인간관계, 언어적 공격, 업무관계였다. 본 연구결과 태움과 집단 내 괴롭힘은 다른 개념으로 추후 간호연구와 실무에서 구분되어 사용되어야 하며, 태움의 속성이 시대와 사회 환경에 따라 점차 더 확대되고, 부정적으로 변화하고 있는 것으로 확인되었다.

• 대한조선학회논문집
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• 제56권3호
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• pp.187-199
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• 2019

In the case of gas carriers and oil tankers, pipes are installed on the upper deck as a moving passage to load LPG, LNG, crude oil, etc. Pipes used for loading or unloading liquid cargo in cargo holds are connected to the hull through support structures. However, many cases of hull damage have been reported where the various equipment and support structures are installed on the upper deck. It is assumed that not only the structural discontinuity where the hull and the pipe support structure meet, but also action due to the pipe loads and the hull girder bending moment are simultaneously affected. This paper deals with the design and strength evaluation of the support structure of pipes and cables installed on the upper deck of commercial ships and offshore structures. For these supporting structures, design conditions and working loads were defined. The design procedure was established through the structure analysis on the method of determining the member dimensions. A series of finite element analysis was performed on the factors to be considered in the design and the effects were discussed. The accuracy and design periods of the strength evaluation was improved and reduced by application of the automation program in the finite element analysis. It is also expected that the design reliability of the shipyard is improved.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2013년도 춘계학술발표대회
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• pp.507-510
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• 2013

Cloud computing is an emerging technology, which allows the user to fulfill his needs by outsourcing the resources. With the passage of time, cloud computing has become an essential part of our lives. But it still requires some sort of standardization, specially in terms of user's trust, privacy, and security related things. This study presents different types of cloud computing services and their working domains along with some key virtualization related issues that are encountered by the cloud service provider as well as the user. Those key issues, related with virtual network are discussed in this paper. This study provides a basis to work further on those issues, so that the key concerns are addressed as soon as possible and cloud computing could become standardized and more prevalent.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.86-86
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• 2003

Research has been in progress for more than a decade to production of useful proteins by genetic modification in cattle. However, the levels of protein production in transgenic cattle have been reported very low. To enhance protein production in transgenic animal, we tried homologous recombination to donor cells for production of transgenic clone cattle through nuclear transfer procedure. Thus, we constructed the two targeting vectors of human thrombopoietin (TPO) at bovine $\beta$-casein locus using homologous recombination with 13.6 kb and 9.6 kb homology. In two targeting vectors, positive selection was through the neomycin resistance gene and negative selection was by the diphtheria toxin (DT). Gene targeting was attempted in bovine embryonic fibroblasts (bEF) and bovine ear skin fibroblasts (bESF). To determine the most appropriate concentration of neomycin for bEF and bESF, G4l8 resistance was confirmed by culturing the cells in various concentrations of the drug and both of the cells were optimally selected at $900 \mu g/ml$ of neomycin. The transfected bEF and bESF by the targeting vectors were colonized efficiently at the ratio of DNA to transfection reagent such as $4 \mu g$:2 ${mu}ell$ and $1 \mu g$:$2 \mu l$. Comparing number of healthy clones from passage 4 to passage 8, bESF (17%) persist in culture for much longer than bEF (6%). The two gene-targeted bESF clones of 30 random-integrated clones with 9.6 kb homology length were confirmed, however, nothing was out of 72 random integration clones with 13.6 kb homology length, The DT also worked more efficiently in clones transfected with the vector of 9.6 kb homology length. Our data suggests that the choice of donor cell for long culture period should be considered to obtain targeted cell clone, and the gene-targeting frequency and the DT working efficiency are dependent on the length of target homology.