• Title/Summary/Keyword: multiple S/H

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Design of Voltage Balancing Circuit applied to Multiple Cells (다중셀에 적용된 전압안정화회로 설계)

  • Hwang H. S.;Nam J. H.;Jang D. K.;Choi J. H.;Sin I. S.
    • Proceedings of the KIPE Conference
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    • 2003.11a
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    • pp.193-196
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    • 2003
  • For a power source of usual electronic devices such as PDA, smart phone, UPS and electric vehicle, the battery made of serially connected multiple cells is generally used. In this case, if there are some unbalanced among cell voltages, the total lifetime and the total capacity of the battery are limited to a lower value. To maintain a balanced condition in cells, an effective method of regulating the cell voltage in indispensable. In this paper introduced a method for battery balancing system using dissipation in the resistance.

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Comparison of Output Characteristics of Pulsed Nd:YAG Laser using PFN Method with Multiple-Mesh (다단메쉬 PFN방식 펄스형 Nd:YAG 레이저의 출력특성 비교)

  • Joung, J.H.;Kwak, B.G.;Kim, D.H.;Moon, J.K.;Kim, H.J.;Cho, J.S.
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1900-1902
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    • 1997
  • In order to obtain various waveforms of current pulse applied at the flashlamp, we have fabricated a Pulsed Nd:YAG laser by PFN with multiple-mesh formed LC network. we have obtained various waveforms of current pulse by adjusting the values of L and C, compared these waveforms of current pulse with laser beam, and then analyzed the laser output energy. We have got relations for $E_{TH}$ and $E_L$ at each mesh which supplies energy with flashlamp and found that output of Pulsed Nd:YAG Laser for 2-mesh, 5-mesh coincided with computer's simulation, PSPICE.

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Analysis of Thermal Distribution and Compensation of Error for Spindle of Machining Center (공작기계 스핀들 부위의 열분포 분석 및 오차 보정)

  • Ko, H.S.;Park, K.H.;Seo, H.R.;Ha, J.S.
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1352-1357
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    • 2004
  • Thermal error compensation has been developed for CNC (Computer Numerical Control) machining center with moving heat sources. The thermal error in CNC machining center has an effect on machining accuracy more than the geometric error does. Thus, temperature distributions of a spindle unit have been analyzed numerically by a Finite Differential Method and experimentally by an infrared (IR) camera in this study. A multiple variable method has been derived to estimate the thermal deformation of the machine origin stably and effectively after measuring deformation and temperature data. The experimental results for a vertical machining center have shown that the thermal errors of the machine origins were reduced more than 30% by the developed method.

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Microsatellite Instability Is Associated with the Clinicopathologic Features of Gastric Cancer in Sporadic Gastric Cancer Patients

  • Kim, Shin-Hyuk;Ahn, Byung-Kyu;Nam, Young-Su;Pyo, Joo-Youn;Oh, Young-Ha;Lee, Kang-Hong
    • Journal of Gastric Cancer
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    • v.10 no.4
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    • pp.149-154
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    • 2010
  • Purpose: Replication error is an important mechanism in carcinogenesis. The microsatellite instability (MSI-H) of colorectal cancers is associated with the development of multiple cancers. The influence of MSI-H on the development of multiple gastric cancers in sporadic gastric cancer patients has not been defined. This study was performed to reveal the association between the clinicopathologic features and MSI in sporadic gastric cancers. Materials and Methods: Between July 2004 and March 2009, the clinicopathologic characteristics, including MSI status, were evaluated in 128 consecutive patients with sporadic gastric cancers. None of the patients had hereditary non-polyposis colorectal cancer of familial gastric cancer. The markers that were recommended by the NCI to determine the MSI status for colorectal cancers were used Results: MSI-H cancers were found in 10.9% of the patients (14/128). Synchronous gastric cancers were shown in 4 patients (3.1%). Synchronous cancers were found in 2 of 14 patients with MSI-H gastric cancer (14.3%) and 2 of 114 patients with MSS gastric cancer (1.8%; P=0.059, Fisher's exact test). Among the patients with synchronous cancer 50% (2/4) had MSI-H cancer, but 9.7% of the patients (12/124) without synchronous cancer had MSI-H cancer. MSI-H (RR, 24.7; 95% CI, 1.5~398.9; P=0.024) was related with to synchronous gastric cancer, but age, gender, family history, histologic type, location, gross morphology, size, and stage were not related to synchronous gastric cancer. Conclusions: MSI is associated with the intestinal-type gastric cancer and the presence of multiple gastric cancers in patients with sporadic gastric cancer. Special attention to the presence of synchronous and the development of metachronous multiple cancer in patients with MSI-H gastric cancer is needed.

Fabrication and Test Results of an HTS Magnet with Pancake Windings Excited by Multiple Power Sources (별도전원으로 여자되는 팬케이크 권선형 고온초전도 마그넷의 제작과 특성 시험)

  • Lee, K.Y.;Hun, K.M.;Lee, Y.S.;Lee, H.J.;Cha, G.S.
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.3
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    • pp.384-389
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    • 2008
  • The cental magnetic field of an HTS magnet consisting of pancake windings can be increased if the magnet is excited by multiple power sources. Multiple power sources enable all pancake windings to conduct their critical currents. The HTS magnet consisting of pancake windings was excited by separate power sources in this paper. Critical currents of each pancake winding were determined by using optimization technique. Fabrication of the BSCCO magnet consisting of 10 pancake windings is described and test results of the BSCCO magnet are given. Central magnetic field and perpendicular magnetic field of the magnet excited by multiple power sources were compared with those of the magnet excited by a single power source.

Identification of multiple sources in a plate structure using pre-filtering process for reduction of interference wave

  • Lee, S.K.;Moon, Y.S.;Park, J.H.
    • Smart Structures and Systems
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    • v.8 no.2
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    • pp.219-237
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    • 2011
  • This paper presents novel research into the source localization of multiple impacts. Source localization technology for single impact loads in a plate structure has been used for health monitoring. Most of research on source localization has been focused only on the localization of single impacts. Overlapping of dispersive waves induced by multiple impacts and reflection of those waves from the edge of the plate make it difficult to localize the sources of multiple impacts using traditional source localization technology. The method solving the overlapping problem and the reflection problem is presented in the paper. The suggested method is based on pre-signal processing technology using band pass filter and optimal filter. Results from numerical simulation and from experimentation are presented, and these verify the capability of the proposed method.

Aerodynamic method of H-Darrieus wind turbines (H-다리우스형 풍력터빈의 공력설계 방법의 구축)

  • Jeong, Suyun;Chang, Semyeong;Lee, Jangho
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.179.2-179.2
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    • 2010
  • In this study, we have constructed the method of design about H-Darrieus wind turbine, a kind of VAWT(vertical axis wind turbine). The NACA 0012 airfoil is chosen for the blade, and DMS(double multiple streamtube) theory is used for the analysis. The flow field is computed with numerical solution of rotating Navier-Stokes equations. From the result of experimental data of power coefficient curves, the validity of the present research is checked. Through the non-dimensional parameter analysis for the wind turbine design, we estimated the efficiency of wind turbine with the resultant Cp's, with which an efficient design of VAWT is achieved, and aerodynamic characteristics are presented systematically.

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Heat transfer characteristics of impinging flat plate of multiple slot jets by changing of jet-to-jet distance (배열 슬롯제트의 노즐간격 변화에 따른 충돌면에서의 열전달 특성)

  • Chung, In-Kee;Park, Si-Woo;Hong, Sung-Ho;Ko, Wan-Wook
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.534-539
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    • 2001
  • An experimental investigation of heat transfer characteristics on confined jet impinging plate using multiple slot jets has been performed. The effects of jet Reynolds numbers(Re=2000, 3950, 5900, 7900), dimensionlesss slot-to-plate distances(H/B=2, 4, 6, 8) and jet-to-jet distances(S=16B, 20B, 24B, 30B) on the local and average heat transfer coefficients have been examined. To clarify local heat transfer characteristics, naphthalene sublimation technique were used. From the experimental results, it was found that the local and average heat transfer rates increase with increasing jet Reynolds number. Measurements of local heat transfer coefficients produced by multiple of slot jets have given an indication of the nature of the interaction between jets and of the uniformity of heat transfer obtainable with various arrangements. At S/B=20, Re=7900 and H/B=6, maximum average Nusselt number is obtained.

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