• 제목/요약/키워드: cut-cell method

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PWR 핵연료 봉 커팅 및 펠렛 압출장치에 대한 연계 시스템 구축 (Interface System Construction for PWR Spent Fuel Rod Cutting and Pellet Pressing Device)

  • 정재후;윤지섭;흥동희;김영환;진재현;박기용
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.684-687
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    • 2002
  • The authors have developed two devices which cuts the spend fuel rod to an optimal size and extracts fuel pellet from the pieces of cut fuel rods. These devices are so important to reduce radioactive wastes that some advanced countries developed their own methods and devices. The authors have benchmarked from these methods and devices. For spent fuel rod cutting, the tube cutting method has been chosen. some mechanical properties of the fuel tube and pellet has been carefully considered for an optimal cutting size. For fuel pellet extraction, a mechanically extracting method has been adopted. The existing chemical method have turned out to be inappropriate because it produced large amount of radioactive wastes, in spite of its high fuel recovery characteristics. The developed method has an advantage that it can be applied to other fuel rods that have different shapes and sizes. The two devices are set up and operated in the hot cell where people can not go in, so that the devices have been designed to be controlled remotely and modulated for easy maintenance. And the performance of the devices has been tested by using simulated fuel rod. From the experimental results, the devices are supposed to be useful for reducing radioactive wastes.

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Comparison of Efficacy in Abnormal Cervical Cell Detection between Liquid-based Cytology and Conventional Cytology

  • Tanabodee, Jitraporn;Thepsuwan, Kitisak;Karalak, Anant;Laoaree, Orawan;Krachang, Anong;Manmatt, Kittipong;Anontwatanawong, Nualpan
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권16호
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    • pp.7381-7384
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    • 2015
  • This study was conducted to 1206 women who had cervical cancer screening at Chonburi Cancer Hospital. The spilt-sample study aimed to compare the efficacy of abnormal cervical cells detection between liquid-based cytology (LBC) and conventional cytology (CC). The collection of cervical cells was performed by broom and directly smeared on a glass slide for CC then the rest of specimen was prepared for LBC. All slides were evaluated and classified by The Bethesda System. The results of the two cytological tests were compared to the gold standard. The LBC smear significantly decreased inflammatory cell and thick smear on slides. These two techniques were not difference in detection rate of abnormal cytology and had high cytological diagnostic agreement of 95.7%. The histologic diagnosis of cervical tissue was used as the gold standard in 103 cases. Sensitivity, specificity, positive predictive value, negative predictive value, false positive, false negative and accuracy of LBC at ASC-US cut off were 81.4, 75.0, 70.0, 84.9, 25.0, 18.6 and 77.7%, respectively. CC had higher false positive and false negative than LBC. LBC had shown higher sensitivity, specificity, PPV, NPV and accuracy than CC but no statistical significance. In conclusion, LBC method can improve specimen quality, more sensitive, specific and accurate at ASC-US cut off and as effective as CC in detecting cervical epithelial cell abnormalities.

얇은 연료극 구조가 용융탄산염 연료전지 성능에 미치는 영향 (Influence of the Thin Anode Geometry on the Performance of Molten Carbonate Fuel Cells)

  • 서동호;박동녘;윤성필;한종희;오인환
    • 한국수소및신에너지학회논문집
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    • 제22권5호
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    • pp.599-608
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    • 2011
  • The Ni-Al anodes of the molten carbonate fuel cell (MCFC) with three different structures were successfully fabricated in order to reduce the thickness of the anode down to 0.3 mm; one was the non-supported anode made by a conventional tape casting method, and others were the supported anodes made by lamination or direct casting on the nickel screen. It was seen from the physical analyses and cell operation that the supported thin anodes made by direct casting showed good mechanical strength and cell performance because of a good contact between the anode materials and the support. The single cell using the above anode showed the cell voltage of 0.858 V at the current density of 150$mA/cm^2$ with the nitrogen cross-over of only 0.6% at the operation time of 1,000 h, which was similar to the performance of the conventional thick (0.7 mm) anode. The ability to utilize a thin configuration of anode should cut down the amount of nickel alloy and consequently reduce its manufacturing cost.

비정상 Euler 방정식을 이용한 Chimera 기법의 병렬처리에 관한 연구 (A Study of Parallel Implementations of the Chimera Method using Unsteady Euler Equations)

  • 조금원;권장혁;이승수
    • 한국전산유체공학회지
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    • 제4권3호
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    • pp.52-62
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    • 1999
  • The development of a parallelized aerodynamic simulation process involving moving bodies is presented. The implementation of this process is demonstrated using a fully systemized Chimera methodology for steady and unsteady problems. This methodology consists of a Chimera hole-cutting, a new cut-paste algorithm for optimal mesh interface generation and a two-step search method for donor cell identification. It is fully automated and requires minimal user input. All procedures of the Chimera technique are parallelized on the Cray T3E using the MPI library. Two and three-dimensional examples are chosen to demonstrate the effectiveness and parallel performance of this procedure.

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Cast Poly-Si을 이용한 태양전지 제작 및 특성 (Fabrication and Characterization of Solar Cells Using Cast Polycrystalline Silicon)

  • 구경완;소원욱;문상진;김희영;홍봉식
    • 전자공학회논문지A
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    • 제29A권2호
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    • pp.55-62
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    • 1992
  • Polycrystalline silicon ingots were manufactured using the casting method for polycrystalline silicon solar cells. These ingots were cut into wafers and ten n$^{+}$p type solar cells were made through the following simple process` surface etching, n$^{+}$p junction formation, metalization and annealing. For the grain boundary passivation, the samples were oxidized in O$_2$ for 5 min. at 80$0^{\circ}C$ prior to diffusion in Ar for 100 min. at 95$0^{\circ}C$. The conversion efficiency of polycrystalline silicon solar cells made from these wafers showed about 70-80% of those of the single crystalline silicon solar cell and superior conversion efficiency, compared to those of commercial polycrystalline wafers of Wacker Chemie. The maximum conversion efficiency of our wafers was indicated about 8%(without AR coating) in spite of such a simple fabrication method.

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가스차단기의 소전류 차단성능 향상을 위한 유동해석 (Flow Analysis of Gas Circuit Breakers for Developing the Small Current Interruption Performance)

  • 이종철;최종웅;강성모;김윤제
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1961-1965
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    • 2003
  • The flow analysis is needed to verify the physical phenomena through interruption processes for improving the capacity and the reliability of gas circuit breakers. Moreover the small current interruption performance of GCBs could be predicted by coupling the flow characteristics with the electric field one. In this paper, the unsteady flow characteristics and the traveling trajectory are depicted with a commercial CFD code, PHOENICS, programmed for moving motion of objects. In order to validate computational results, the measured pressure data in cylinder and in front of arcing contact are compared with the test results of small current interruption.

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부분공진기법을 이용한 태양광발전 제어시스템 (The Photovoltaic generation control system using partial resonant method)

  • 고강훈;이현우;김영철;최광주
    • 조명전기설비학회논문지
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    • 제14권4호
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    • pp.16-22
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    • 2000
  • 본 논문은 트렌스포머를 제거하고 부분공짚 스위칭 기법올 적용한 승.강압초퍼와 고효율의 PWM 인버터를 결합한 트렌스포머리스형 계통연계 시스템을 구성하게 되므로 소형경량화가 가능하며, 비용저지감과 신뢰성 향상을 도모할 수 있다. 이러한 시스템의 장점으로서는 태양잔지의 발전전압의 크기에 관계없이 임의의 전력올 부하와 계통에 송전할 수 있으며, 계통과 동상의 신호로 제어함으로서 상 고역률올 얻을 수 있다.

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Chimera 기법의 병렬처리에 관한 연구 (A Study of Parallel Implementations of the Chimera Method)

  • 조금원;권장혁;이승수
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 1999년도 춘계 학술대회논문집
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    • pp.35-47
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    • 1999
  • The development of a parallelized aerodynamic simulation process involving moving bodies is presented. The implementation of this process is demonstrated using a fully systemized Chimera methodology for steady and unsteady problems. This methodology consist of a Chimera hole-cutting, a new cut-paste algorithm for optimal mesh. interface generation and a two-step search method for donor cell identification. It is fully automated and requires minimal user input. All procedures of the Chimera technique are parallelized on the Cray T3E using the MPI library. Two and three-dimensional examples are chosen to demonstate the effectiveness and parallel performance of this procedure.

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야생등줄쥐(Apodemus agrarius) 후각망울의 neuropeptide Y 면역반응세포의 분포 (Distribution of the neuropeptide Y immunoreactive neurons in the olfactory bulb of striped field mouse(Apodemus agrarius))

  • 정영길;김길수;정주영;이남섭;이경렬;김무강
    • 대한수의학회지
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    • 제39권3호
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    • pp.407-416
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    • 1999
  • This study was carried out to investigate the NPY-immunohistochemical characteristics of the olfactory bulb in the striped field mouse(Apodemus agrarius). The animals were anesthesized with thiopental sodium and perfused with 4% paraformaldehyde through left ventricle and aorta. Brains were removed and tranfered 10%, 20% and 30% sucrose. Sections were then cut on a cryostat into $40{\mu}m$-thick. The tissue immunostained with avidin-biotinylated complex method. The main olfactory bulb consisted of seven circumferential laminae : an olfactory nerve fiber layer, a glomerular layer with glomeruli surrounding by periglomerular cells, an external plexiform layer having granule and tufted cells, a mitral cell layer, a narrow internal plexiform layer, a granule cell layer forming several cell rows and a layer of white matter. The accessory olfactory bulb had four layers : an olfactory or vomeronasal nerve fiber layer, a glomerular layer consisting of small glomeruli, a mixed layer not distinguishing the external plexiform/mitral cell/granule cell layers and a granule cell layer. Most of NPY-immunoreactive(NPY-IR) neurons in main olfactory bulb were localized in the deeper portion of granule cell layer, white matter and anterior olfactory nucleus. In addition, some NPY-IR neurons were identified in the external plexiform layer. The shape of NPY-IR neurons of all olfactory bulb were predominant round or oval, sometime multipolar in shape. And most NPY-IR processes were parallel to long axis of white matter. In accessory olfactory bulb, NPY-IR neurons were not found in all region.

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Quantum Packet for the Next Generation Network/ISDN3

  • Lam, Ray Y. W.;Chan, Henry C. B.;Chen, Hui;Dillon, Tharam S.;Li, Victor O. K.;Leung, Victor C. M.
    • Journal of Communications and Networks
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    • 제10권3호
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    • pp.316-330
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    • 2008
  • This paper proposes a novel method for transporting various types of user traffic effectively over the next generation network called integrated services digital network 3 (ISDN3) (or quantum network) using quantum packets. Basically, a quantum packet comprises one or more 53-byte quanta as generated by a "quantumization" process. While connection-oriented traffic is supported by fixed-size quantum packets each with one quantum to emulate circuit switching, connectionless traffic (e.g., IP packets and active packets) is carried by variable-size quantum packets with multiple quanta to support store-and-forward switching/routing. Our aim is to provide frame-like or datagram-like services while enabling cell-based multiplexing. The quantum packet method also establishes a flexible and extensible framework that caters for future packetization needs while maintaining backward compatibility with ATM. In this paper, we discuss the design of the quantum packet method, including its format, the "quantumization" process, and support for different types of user traffic. We also present an analytical model to evaluate the consumption of network resources (or network costs) when quantum packets are employed to transfer loss-sensitive data using three different approaches: cut-through, store-and-forward and ideal. Close form mathematical expressions are obtained for some situations. In particular, in terms of network cost, we discover two interesting equivalence phenomena for the cut-through and store-and-forward approaches under certain conditions and assumptions. Furthermore, analytical and simulation results are presented to study the system behavior. Our analysis provides valuable insights into the. design of the ISDN3/quantum network.