• 제목/요약/키워드: Transfer efficiency

검색결과 2,708건 처리시간 0.032초

자기유도방식 무선전력전송 시스템 송수신 코일 Layer 구조에 따른 특성 분석 (Analysis of Inductive Power Transfer System According to Layer Structure of Transceiver Coil)

  • 김철민;유재곤;김종수
    • 전력전자학회논문지
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    • 제24권2호
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    • pp.78-83
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    • 2019
  • In this study, we analyze the structure of the transceiver coil in the inductive power transfer (IPT) system. In the IPT system, the transceiver coil design needs to have the highest magnetic coupling possible because of the relatively low magnetic coupling due to the large gap of distance without the core. The transmitting coil may be formed as a multi-layer type according to the distance between the transmitting and receiving coils if the receiving coil is configured as a multi-layer type on the inner structure of the receiving apparatus, thereby improving the magnetic coupling and system efficiency. We compare and analyze the coil magnetic coupling, and system efficiency according to the layer structure of the transmitting and receiving coils and verify the analysis by JMAG simulation. Experimental results show that the layer structure of the transceiver should be considered according to the inner space of the receiving device and the spacing distance.

Cloning Livestock from Cultured Cells Creates New Opportunities for Agriculture

  • Wells, D.N.
    • 한국수정란이식학회:학술대회논문집
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    • 한국수정란이식학회 2003년도 제3회 발생공학 국제심포지움 및 학술대회
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    • pp.29-48
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    • 2003
  • It is remarkable that nuclear transfer using differentiated donor cells can produce physiologically normal cloned animals, but the process is inefficient and highly prone to epigenetic errors. Aberrant patterns of gene expression in clones contribute to the cumulative losses and abnormal phenotypes observed throughout development. Any long lasting effects from cloning, as revealed in some mouse studies, need to be comprehensively evaluated in cloned livestock. These issues raise animal welfare concerns that currently limit the acceptability and applicability of the technology. It is expected that improved reprogramming of the donor genome will increase cloning efficiencies realising a wide range of new agricultural and medical opportunities. Efficient cloning potentially enables rapid dissemination of elite genotypes from nucleus herds to commercial producers. Initial commercialisation will, however, focus on producing small numbers of high value animals for natural breeding especially clones of progeny-tested sires. The continual advances in animal genomics towards the identification of genes that influence livestock production traits and human health increase the ability to genetically modify animals to enhance agricultural efficiency and produce superior quality food and biomedical products for niche markets. The potential opportunities inanimal agriculture are more challenging than those in biomedicine as they require greater biological efficiency at reduced cost to be economically viable and because of the more difficult consumer acceptance issues. Nevertheless, cloning and transgenesis are being used together to increase the genetic merit of livestock; however, the integration of this technology into farming systems remains some distance in the future.

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가상 설계 환경을 활용한 지로터 펌프의 배제용적 증량 설계 사례 (Design for Increasing Displacement Volume of Gerotor Pumps using Virtual Design Environment)

  • 노대경;이동원;전정배;장주섭
    • 드라이브 ㆍ 컨트롤
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    • 제21권2호
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    • pp.15-22
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    • 2024
  • The objective of this study was to examine whether a gerotor pump used in a transmission could be converted into an electric vehicle thermal management system pump using a virtual design environment. To achieve this objective, we first built an environment that could analyze the performance of a gerotor pump in heat transfer fluid. Flow rate, pressure, and volumetric efficiency were then analyzed when using heat transfer fluid in a gerotor pump. Finally, how large the displacement volume of the pump should be designed when using a heat transfer fluid other than oil was determined. Based on results of this study, it is expected that gerotor pumps will be applied to new business fields such as electric vehicle cooling systems.

기술이전 및 사업화 활성화를 위한 전략 도출 프레임워크 - R&BD 효율성 평가를 기반으로 - (The Framework for the Strategy of Research & Business Development)

  • 김준영;성시일;박재훈
    • 품질경영학회지
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    • 제44권4호
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    • pp.785-798
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    • 2016
  • Purpose: This paper developed the framework for extracting strategies of research and business development (R&BD) based on the data envelopment analysis(DEA). Methods: DEA has been widely utilized in evaluating R&D efficiency. Even though, technology transfer and commercialization has been regarded as the important factors for practical R&D efficiency evaluation, most research have evaluated R&D efficiency by just using the DEA outputs such as the number of patents and papers. The technology transfer, commercialization and relations among costs and generated technology and commercialization are needed to be considered for more practical R&D efficiency evaluation. Thus, this research addressed a method on how to incorporate the commercialization factors into the R&DB efficiency evaluation, and improve the efficiency strategically in terms of R&D and B&D. To achieve this, this research utilized a two-stage network DEA model for R&BD efficiency evaluation. Results: The proposed framework was applied to the 15 public research institutes and the 34 universities for validation. R&BD efficiency for the 15 public research institutes and the 34 universities was evaluated, and the differentiated improvement strategies for the inefficient DMUs to improve their efficient were proposed. Conclusion: The R&BD efficiency would be effectively analyzed based on two-stage network DEA. It would be utilized for the effective strategy planning for cultivating R&BD.

창호에 SHGC를 반영한 공동주택의 방위각별 에너지 효율성 평가를 통한 합리적인 창호 계획 방안 연구 (A Study on the optimized Performance Designing of the Window of the Apartment based on the Annual Energy Demand Analysis according to the Azimuth Angle applying the Solar Heat Gain Coefficient of the Window)

  • 이장범
    • 대한건축학회논문집:계획계
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    • 제35권11호
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    • pp.25-34
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    • 2019
  • It is important to design windows in a reasonable way considering the performance characteristics of the elements of the window rather than just to increase the thermal energy performance of the window. In this study, the Heat-transfer Coefficient as insulation performance of the windows and together with the grade of the glass's SHGC (Solar Heat Gain Coefficient) were analyzed to relate to the energy efficiency performance of the building by azimuth angle. Based on this basic study, the Heat-transfer Coefficient of windows and the SHGC rating of glass were applied to the unit plan of apartment building, and the Heating and Cooling Demand were analyzed by azimuth angle. Apartment plan types were divided into 2 types of Non-extension and extension of balcony. The designPH analysis data derived from the variant of the Heat-transfer Coefficient and SHGC, were put into PHPP(Passive House Planning Package) to analyze precisely the energy efficiency(Heating and Cooling Demands) of the building by azimuth angle. In addition, assuming the 'ㅁ' shape layout, energy efficiency performance and potential of PV Panel installation also were analyzed by floors and azimuth angle, reflecting the shading effects by surrounding buildings. As the results of the study, the effect of Heat Gain by SHGC was greater than Heat Loss due to the Heat-transfer Coefficient. So it is more effective to increase SHGC to satisfy the same Heating Demand, and increasing SHGC made possible to design windows with low Heat-transfer Coefficient. It was also revealed that the difference in annual Heating and Cooling Demands between the low, mid and high floor households is significantly high. In addition to it, the installation of PV Panel in the form of a shading canopy over the window reduces the Cooling Load while at the same time producing electricity, and also confirmed that absolute thermal energy efficiency could not be maximized without controlling the thermal bridge and ventilation problems as important heat loss factors.

삼차원 조도관의 압력손실 및 열전달 성능에 대한 실험적 연구 (An Experimental Study on the Pressure Drop and Heat Transfer Performance in Tubes with Three Dimensional Roughness)

  • 김내현
    • 설비공학논문집
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    • 제7권2호
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    • pp.276-286
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    • 1995
  • In this study, pressure drop and heat transfer coefficients were measured in tubes with three dimensional roughness. Dimples were made by rotating the saw-tooth shaped finning disc on the outer tube surface. Resultant dimple shape was oval. Friction and heat transfer tests were performed with a range of roughness variables-roughness height 'e', axial roughness pitch 'p', circumferential roughness pitch 'z'. Within the test range, tube with e=0.5mm, z=5mm, p=3mm performed best. The efficiency ratio(rati of the heat transfer improvement and the pressure drop increase) of the tube approached 1.0 at low Reynolds number, and it was higher than that of the two-dimensional roughess tube of the same roughness height. Test data were predicted by 'discrete element method'. Results show that discrete element method underpredicts the friction data by 2% to 32%, and overpredicts the heat transfer data by-12% to 113%.

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정적혼합기술 응용 열교환기의 압력손실 및 열전달 특성 (Pressure Loss and Heat Transfer Characteristics of Heat Exchanger Using Static Mixing Technology)

  • 박상규;양희천;전준철
    • Journal of Advanced Marine Engineering and Technology
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    • 제30권1호
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    • pp.65-72
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    • 2006
  • Heat transfer augmentation in heat exchangers has received much attention in recent years, mainly due to energy efficiency and environmental considerations. Many active and Passive techniques are currently being employed in heat exchangers, with some inserts providing a cost-effective and efficient means of augmenting heat transfer. The Purpose of this paper is to determine the pressure loss and heat transfer characteristics of a heat exchanger using static mixing technology. Experimental measurements were taken on two set-ups: a single tube heat exchanger and a shell-tube heat exchanger with two static mixing inserts. It was concluded that the static mixing inserts resulted in an increase in the pressure loss and heat transfer characteristics as can be expected.

양측벽면에 반복돌출형 거칠기가 있는 이중관통로내의 난류운동과 열전달 (Turbulent Flow and Heat Transfer in an Annular Passage with Repeated-Ribbed Roughness on Both Walls)

  • 안수환;이윤표
    • 한국자동차공학회논문집
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    • 제4권5호
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    • pp.26-36
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    • 1996
  • The fully developed turbulent momentum and heat transfer induced by the square-ribbed roughness elements on both the inner and outer wall surfaces in concentric annuli are studied analytically based on a modified turbulence model. The analytical results of the fuid flow are verified by experiment. The experiment is done with a pitot tube and a X-type hot wire anemometer to measure the time mean velocity profiles, zero shear stress positions, maximum velocity positions and friction factors, and etc. shown in Fig.1. The resulting momentum and heat transfer are discussed in terms of various parameters, such as the radius ratio, the relative roughness, the roughness density, Reynolds number, Nusselt bumber and Prand시 number. The study demonstrates that certain artificial roughness elements may be used to enhance heat transfer rates with advantage from the overall efficiency point of view by investigating turbulent flows and heat transfer in Fig.1.

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특허기술의 성공적인 거래 촉진을 위한 컨조인트 분석 (Conjoint Analysis for Contract Strategy for Promoting Successful Transfer of Patented Technology in Korean University)

  • 구민정;손소영
    • 대한산업공학회지
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    • 제34권3호
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    • pp.355-361
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    • 2008
  • Technology developers in academia tend to be short of professional knowledge and recognition of technology transfer strategies. It is even severe in Korea where the concept of employee's invention has just started to effect in academia. Wasteful contract negotiation disputes cannot only be painful but also can hamper better invention. The main purpose of this paper is to design guidelines for an optimal contract strategy for technology transfer from the perspective of the technology developer in academia, the intermediary and the receiver. Applying conjoint analysis, this study shows not only the relative importance of the attributes related to the technology transfer contract but also the most important conditions of the contract. It is expected that this study may improve the efficiency of technology transfer activities in academia in Korea.

The Impacts of Technology Transfer on Productivity Growth of Firms based on Malmquist Productivity Index

  • Han, Jaeseung;Kwon, Youngkwan;Lee, Sang-Yong Tom
    • Asia pacific journal of information systems
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    • 제26권4호
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    • pp.542-560
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    • 2016
  • This study determines whether or not firms can achieve high productivity growth through external technology acquisition. It also identifies the key factors affecting adopting firms' productivity growth by employing the Malmquist productivity index (MPI) methodology, which features computational ease, low data dependency, and decomposition of productivity growth into technical efficiency change and technical change. Results showed that the effects of productivity growth arising from technology transfer became stronger over time. Moreover, patent transfer guaranteed firms' productivity growth, but no evidence was found that factors such as age and size could increase productivity. Finally, cultural similarity could be another factor conditioning the effectiveness of technology transfer in the productivity of adopting firms.