• 제목/요약/키워드: Branch flow

검색결과 448건 처리시간 0.027초

자기 펄스 발생기의 연결 도체 설계에 관한 연구 (A Study on the Design of Branch Conductor in the Magnetic Pulse Generator)

  • 서주하
    • 산업기술연구
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    • 제9권
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    • pp.101-107
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    • 1989
  • The magnetic forming system must be able to store very important electric energy, several tens kilojoules, and flow this energy through the forming coil within some hundreds microseconds. So several hundreds kiloamperes of current can flow through the branch conductor. For the good performance of this type of machine, internal impedance must be minimized. By the computation of distribution of current inside the conductors using integral equation method, we can obtain the inductance and resistance of some dispositions of branch conductors and by comparison obtain some principles for the design of branch conductors in the high power magnetic pulse generator.

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소양호 지류하천의 비점오염원 유출특성에 관한 연구 (A Study on the Out Flow Characteristics of Non-Point Source Pollution in the Branch River of So-yang Lake)

  • 최한규;최창호;박수진
    • 산업기술연구
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    • 제29권B호
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    • pp.199-205
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    • 2009
  • This study selected Naerin Stream, Inbuk Stream and Buk Stream, branch rivers of Soyang Dam, also area of highland agriculture as test sites and measured flow and water quality, particularly eutrophication factors (BOD, COD, T-N, and T-P) in precipitation season and non precipitation season for a year, 2008. Based on the result, the study examined the change in water quality in relation to flow, and created flow discharged - pollution loads regression line by estimating pollution loads flowed from each branch river. And the study calculated annual pollution discharge loads for unit area and proposed regression equation on it by using regression analysis.

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마이크로 PIV를 이용한 마이크로 분지관에서의 유동해석 (Analysis of Flow in a Microchannel Branch by Using Micro-PIV Method)

  • 윤상열;김경천
    • 대한기계학회논문집B
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    • 제28권9호
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    • pp.1015-1021
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    • 2004
  • Micro-resolution Particle Image Velocimetry(Micro-PIV) was used to measure the flow in a micro-branch(Micro-Bypass). In this paper, effects of particle lump at the tip of a Micro-branch and difficulties of Micro-PIV measurements for microfluidics with branch passage were described. Micro-bypass was composed of a straight channel(200(100)${\mu}$m width ${\times}$ 80${\mu}$m height) and two branches which has 100(50)${\mu}$m width ${\times}$ 80${\mu}$m height. One of branches was straight and the other was curved. Experiments were performed at three regions along streamwise direction(entrance, middle and exit of branch) and five planes along vertical direction (0, ${\pm}$10, ${\pm}$20 ${\mu}$m) for the range of Re=0.24, 1.2, 2.4. Numerical simulation was done to compare with the measurements and understand the effects of particle lump at the tip of branch. And another fluid(3% poly vinyl Alcohol aqueous solution) were adapted for this study, so there were no particle sticking. In this case, we could get velocity difference between straight and curved branches.

수직(垂直)컬럼형(形) 풍력선별기(風力選別機)의 분리효율향상(分離效率向上)을 위한 bypass유로(流路)의 적용(適用) (Application of Bypass Flow for Improving Performance of the Vertical Column Pneumatic Separator)

  • 이계승;송영준;요츠모토 히로키
    • 자원리싸이클링
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    • 제22권3호
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    • pp.65-72
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    • 2013
  • 수직컬럼형 풍력선별기의 선별능력을 향상시키기 위해 일시적인 중광(middling)의 흐름을 형성할 수 있는 측로(bypass)를 선별컬럼의 중앙에 설치하였다. 측로를 흐름을 조절하여 주선별컬럼에서 상부흐름의 속도는 가벼운 물질만이 상부로 회수하도록 설정하고 하부흐름의 속도는 무거운 물질만이 하부로 회수되도록 설정하였다. 측로로 이동하는 흐름은 사이클론을 통과시켜 중광이 피더로 회수되도록 하였다. 일반 수직컬럼형 풍력선별기와 개조된 선별기에서 유리와 지르코니아 비드(bead)의 혼합물을 사용하여 성능향상의 효과를 실험하였다.

A Study on the Method of the Vulnerable Area Investigation In Severe Contingencies Using Branch Parameter Continuation Power Flow (BCPF)

  • Seo Sangsoo;Lee Byongjun;Kim Tae-Kyun;Song Hwachang
    • KIEE International Transactions on Power Engineering
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    • 제5A권4호
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    • pp.390-395
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    • 2005
  • The most widely used index for the vulnerable area investigation has been the reactive power margin or sensitivity analysis. But we can only obtain the results of these analyses if the results of load flow are convergent in severe contingencies. Otherwise these methods are not adoptable. This paper presents a good index for overcoming severe contingencies, though the power flow equation is unsolvable using the branch parameter continuation power flow. In simulation, the Korea Electric Power Corporation (KEPCO) Systems are applied.

Design and Analysis of Spider Bionic Flow Field for Proton Exchange Membrane Fuel Cell

  • Jian Yao;Fayi Ya;Xuejian Pei
    • Journal of Electrochemical Science and Technology
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    • 제14권1호
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    • pp.38-50
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    • 2023
  • Proton exchange membrane fuel cell (PEMFC) is a portable and clean power generation device. The structural arrangement of the flow field has a significant influence on the delivery efficiency of PEMFC. In this article, a new bionic flow channel is designed based on the inspiration of a spider shape. The branch channel width and branch corner are studied as the focus, and its simulation is carried out by the method of computational fluid dynamics (CFD). The results show that when channel width/rib width and corner of the branch are 1.5 and 130° , respectively, it is the best numerical combination and the cell comprehensive performance is excellent. The final model using this numerical combination is compared with the traditional flow channel model to verify the advancement of this scheme.

≪영추(靈樞)·경근(經筋)≫의 서술 방법과 공통 용어에 대한 연구 (A Study on the Descriptive Method and Common Terminology of 『Yeongchu·Gyeonggeun(靈樞·經筋)』)

  • 김민식;김창건;김소림;이은용
    • 대한한의학회지
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    • 제44권1호
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    • pp.56-64
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    • 2023
  • Objectives & Methods: The entire ≪Lingshu·Jingjin≫ content was analyzed to find repetitive patterns, as well as to analyze commonly used terms. Through this, the guidelines for interpretation were presented. Results & Conclusions: ≪Lingshu·Jingjin≫ is not a question-and-answer format, but a simple enumerated narrative format. There is no part corresponding to the introduction, only the descriptions of 12 individual Meridian-muscle exist. Each Meridian-muscle is divided into 'Flow of Muscle Mechanics(流走)' part and 'Diseases' part, and 'Flow of Muscle Mechanics' of each Meridian-muscle can be divided into 'Main Flow' and 'Branch'. 'Main Flow' is the most central 'Flow' in each 'Meridian-muscle', and 'Branch' is the part where 'Main Flow' ends and the description of another 'Flow' begins. 'Branch' has different expressions according to the importance. The expression also varies depending on the dynamics. 'Meridian-muscle' should be interpreted based on this.

UPFC Control based on New IP Type Controller

  • Shirvani, Mojtaba;Keyvani, Babak;Abdollahi, Mostafa;Memaripour, Ahmad
    • Journal of Electrical Engineering and Technology
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    • 제7권5호
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    • pp.664-671
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    • 2012
  • This paper presents the application of Unified Power Flow Controller (UPFC) in order to simultaneous control of power flow and voltage and also damping of Low Frequency Oscillations (LFO) at a Single-Machine Infinite-Bus (SMIB) power system installed with UPFC. PI type controllers are commonly used controllers for UPFC control. But for the sake of some drawbacks of PI type controllers, the scope for finding a better control scheme still remains. In this regard, in this paper the new IP type controllers are considered as UPFC controllers. The parameters of these IP type controllers are tuned using Genetic Algorithms (GA). Also a stabilizer supplementary controller based UPFC is considered for increasing power system damping. To show the ability of IP controllers, this controller is compared with classical PI type controllers. Simulation results emphasis on the better performance of IP controller in comparison with PI controller.

A Study on Transmission System Expansion Planning using Fuzzy Branch and Bound Method

  • Park, Jaeseok;Sungrok Kang;Kim, Hongsik;Seungpil Moon;Lee, Soonyoung;Roy Billinton
    • KIEE International Transactions on Power Engineering
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    • 제2A권3호
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    • pp.121-128
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    • 2002
  • This study proposes a new method for transmission system expansion planning using fuzzy integer programming. It presents stepwise cost characteristics analysis which is a practical condition of an actual system. A branch and bound method which includes the network flow method and the maximum flow - minimum cut set theorem has been used in order to carry out the stepwise cost characteristics analysis. Uncertainties of the permissibility of the construction cost and the lenient reserve rate and load forecasting of expansion planning have been included and also processed using the fuzzy set theory in this study. In order to carry out the latter analysis, the solving procedure is illustrated in detail by the branch and bound method which includes the network flow method and maximum flow-minimum cut set theorem. Finally, case studies on the 21- bus test system show that the algorithm proposed is efficiently applicable to the practical expansion planning of transmission systems in the future.

비골 동맥 천공지 피판의 혈관 해부학 (Vascular Anatomy of Peroneal Perforator Flap)

  • 정덕환;한정수;황준성
    • Archives of Reconstructive Microsurgery
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    • 제13권1호
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    • pp.36-42
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    • 2004
  • Materials and Methods: We studied 50 cases of peroneal perforating branch about branching pattern, course, length of vascular pedicle, and perforating level of the perforating cutaneous branches from Oct. 1985 to November 2003 by doppler flow meter and intraoperative findings. Results: 1) The perforating cutaneous branches were classified into four types, the Straight Branch (27cases), the Proximal Oblique Branch (11cases), the Branch from Muscular Artery (10cases), the Distal Oblique Branch(2 cases) respectively. The most common patten was Straight Branch, that was 54%. 2) There were 3 pathways of these branches, the most common one passed between the Soleus and Peroneus muscles(34 cases, 68%) 3) The length of vascular pedicle in Buoy Flap was variable from from 3 cm to 15 cm, but 32 cases(64%) were distributed between 5 cm and 6 cm. 4) The perforating level of branches were 5.9 cm in average from fibular neck to subcutaneous perforator artery 5) Peroneal Buoy Flap in possible to reconstruct both seperated bone and skin defect in some distance by One-Stage Operation and we can harvest maximal $8{\times}16cm$ sized flap in one perforating artery. If we include more two perforating artery, we get more wide flap which can cover large defect.

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