• 제목/요약/키워드: internal flows

검색결과 267건 처리시간 0.03초

유방질환(乳房疾患)에 관한 침구치료(鍼灸治療)와 외치법(外治法)에 대한 문헌적(文獻的) 고찰(考察) (A literatual study on Acupunctural and External therapy about the breast disease)

  • 권일혜;정진홍
    • 혜화의학회지
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    • 제10권1호
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    • pp.67-78
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    • 2001
  • From the study of acupuncture and external diseases on mammary diseases, the following conclusions are obtained. 1. Point Shanzhong, Shaoze and Rugen are often used for galactostasis in acupuncture. 2. Often used vessels for galactostasis in acupuncture are Stomach Meridian, Conception Vessel, Small Intestine Meridian, Bladder Meridian, Liver Meridian and Large Intestine Meridian in order. 3. The direct stimulations are used in external treatment for galactostasis, often accompanied by internal medical treatment, to promote the circulation of Qi and Blood. 4. Point Zuimup, Guangming of Gall bladder Meridian and Zusanli of Stomach Meridian is used for lactation pain in acupuncture. 5. Point Jianjing, Zusanli and Shanzhong are most often used for acuremastitis and breast cancer in acupuncture. 6. Often used vessels for acuremastitis and breast cancer in acupuncture are Stomach Meridian, Gall bladder Meridian, Conception Vessel, Small Intestine Meridian, Bladder Meridian, Pericardium Meridian in order. 7. The external treatment used for acuremastitis and breast cancer can be classed into its pathological period. When lactation is interrupted, Kumhwang Powder, Okro Powder, Robongbang, Allii Radix, Pinelliae Rhizoma, garlic moxibustion and Arusaenatus Rgizoma powder are used. When pus is piled up, Chunghwa Extracts, Dioscoreae Rhizoma, Leonuri Herba, Typa Latifolia, Taraxacum platycarpum, Phaseolus angularis, Manchong, Crvi Cornus latex, and Aucklandiae Radix are used. When pus flows down, Salviae Miltiorrhizae Radix Extract, nine-one pellet, Yongboo extract, eight-dampness extract, Tissue-regeneration Powder, Toad-net treatment, Kitten-hair, Hongseung pellet are used. 8. Stomach Meridian, Conception Vessel, Small Intestine Meridian, Gall Bladder Meridian, Bladder Meridian are most often used vessels for mammary diseases. From the conclusions above, It appears that the medical effect could be maximized by further studying and developing of the acupuncture and external treatment for mammary diseases according to the its nature, while accompanying internal medicine appropriately at the same time.

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IC 내부 온도측정이 가능한 MOS 온도센싱 회로에 관한 연구 (A Study on the temperature sensing circuit using MOS applicable for the IC internal temperature measurement)

  • 강병준;이민우;김한슬;한정우;손상희;정원섭
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2013년도 추계학술대회
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    • pp.695-697
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    • 2013
  • 본 논문에서는 MOSFET을 사용하여 IC내부의 온도를 측정해 전압을 출력으로 나타내는 온도감지회로를 제안하였다. 제안한 온도감지회로는 CMOS공정에서 구현하기 위해 MOSFET을 이용한 두 개의 전류미러 회로를 이용하여 설계하였고, 다양한 어플리케이션에 적용 가능하도록 하였다. 온도감지회로는 온도감지모드, 절전모드 두 가지 동작을 하며 각각의 모드 시뮬레이션 결과 온도감지모드에서는 $0^{\circ}C{\sim}125^{\circ}C$까지 스윕했을 때 출력전압이 0V에서 1.2V까지 측정되었고, 절전모드에서는 출력전류가 100pA 이하로 흐르는 것을 확인 할 수 있었다.

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전철 탑재형 피뢰기의 모듈설계 및 성능평가기술 (Module Design and Performance Evaluation of Surge Arrester for Loading In Railway Rolling Stock)

  • 조한구;김석수;한세원;이운응
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.2038-2040
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    • 2000
  • The main objective of this paper is to design and test a new type of polymer ZnO surge arrester for AC power system of railroad vehicles. Metal oxide surge arrester for most electric power system applications, electric train and subway are now being used extensively to protect overvoltage due to lightning. Surge arresters with porcelain housing must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of ZnO elements in a surge arrester occurs due to flashover, fault short current flows through the arrestor and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock, pressure rise. etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion. The main research works are focused on the structure design by finite element method, pressure relief of module, and studies of performance of surge arrester for electric railway vehicle.

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전철 탑재용 피뢰기의 설계 및 성능평가 (Design and Performance Evaluation of Surge Arrester for Loading in Railway Rolling Stock)

  • 조한구;한세원;이운용;김석수;장태봉
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마
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    • pp.74-77
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    • 2000
  • The main objective of this paper is to design and test a new type of polymer ZnO surge arrester for AC power system of railroad vehicles. Metal oxide surge arrester for most electric power system applications, electric train and must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of ZnO elements in a surge arrester occurs due to flashover, fault short current flows through the arrester and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock. pressure rise, etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion. The main research works are focused on the structure design by finite element method, pressure relief of module, and studies of performance of surge arrester for electric railway vehicle.

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The Effect of the Buffer Size in QoS for Multimedia and bursty Traffic: When an Upgrade Becomes a Downgrade

  • Sequeira, Luis;Fernandez-Navajas, Julian;Saldana, Jose
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권9호
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    • pp.3159-3176
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    • 2014
  • This work presents an analysis of the buffer features of an access router, especially the size, the impact on delay and the packet loss rate. In particular, we study how these features can affect the Quality of Service (QoS) of multimedia applications when generating traffic bursts in local networks. First, we show how in a typical SME (Small and Medium Enterprise) network in which several multimedia flows (VoIP, videoconferencing and video surveillance) share access, the upgrade of the bandwidth of the internal network may cause the appearance of a significant amount of packet loss caused by buffer overflow. Secondly, the study shows that the bursty nature of the traffic in some applications traffic (video surveillance) may impair their QoS and that of other services (VoIP and videoconferencing), especially when a certain number of bursts overlap. Various tests have been developed with the aim of characterizing the problems that may appear when network capacity is increased in these scenarios. In some cases, especially when applications generating bursty traffic are present, increasing the network speed may lead to a deterioration in the quality. It has been found that the cause of this quality degradation is buffer overflow, which depends on the bandwidth relationship between the access and the internal networks. Besides, it has been necessary to describe the packet loss distribution by means of a histogram since, although most of the communications present good QoS results, a few of them have worse outcomes. Finally, in order to complete the study we present the MOS results for VoIP calculated from the delay and packet loss rate.

Passive Control of the Condensation Shock Wave Using Bleed Slots

  • 김희동;이권희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집E
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    • pp.299-304
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    • 2001
  • The current study describes experimental and computational work on the passive control of the steady and unsteady condensation shock waves, which are generated in a transonic nozzle. The bleed slots are installed on the contoured wall of the transonic nozzle in order to control the magnitude of the condensation shock wave and its oscillations. For computations, a droplet growth equation is incorporated into the two-dimensional Navier-Stokes equation systems. Computations are carried out using a third-order MUSCL type TVD finite-difference scheme with a second-order tractional time step. Baldwin-Lomax turbulence model is employed to close the governing equations. An experiment using an indraft transonic wind tunnel is made to validate the computational results. The current computations represented well the experimental flows. From both the experimental and computational results it is found that the magnitude of the condensation shock wave in the bleed slotted nozzle is significantly reduced, compared with no passive control of solid wall. The oscillations of the condensation shock wave are successfully suppressed by a bleed slot system.

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기체유동에서 발생하는 복합초킹 현상에 관한 연구 (A Study of the Compound Choking Phenomenon in Gas Flows)

  • 이준희;백승철;최보규;김희동
    • 대한기계학회논문집B
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    • 제27권1호
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    • pp.54-60
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    • 2003
  • Compound choking frequently occurs at a minimum area of the flow passage, where two or more streams which have different stagnation properties are merged. This phenomenon is especially important in that the flow choking may not be given by Mach number, M=1 at the nozzle throat. In order to obtain a detailed understanding of the flow characteristics involved in the compound flow choking, the two-dimensional, compressible, Wavier-Stokes equations are solved using a fully implicit finite volume method and the predicted solutions are compared with the results of the one-dimensional theoretical analysis. Stagnation pressure and temperature of each stream are changed to investigate the effects on the compound choking. The results show that stagnation pressures of each stream affect Mach number and static pressure distributions downstream of the exit of the convergent nozzle. However, the flow characteristics of the compound choking are not significantly dependent on the total temperature ratio.

터빈 익렬내부의 3차원 압축성 점성유동장의 수치해석 (Numerical Analysis of Three-Dimensional Compressible Viscous Flow Field in Turbine Cascade)

  • 정희택;백제현
    • 대한기계학회논문집
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    • 제16권10호
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    • pp.1915-1927
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    • 1992
  • 본 연구에서는 3차원 압축성 내부유동해석 코드를 개발하여 터어빈 정익이나 동익 내부의 차원 익렬 유동을 수치적으로 해석하고자 한다. 여기에서 사용된 코드 는 Obyashi의 LU-ADI기법을 이용한 기존의 2차원 익렬 유동해석 코드를 3차원 유동장 으로 학장한 것이고, 난류유동해석에는, Baldwin-Lomax의 박층 대수모델을 3차원으로 확장한 알고리즘을 적용하였다.Kiock등이 실험한 선형 터어빈 익렬 내부의 천음속 유동장에 적용하여 양끝 벽면에 의한 3차원 유동장 특성을 분석하고, 3차원 익렬 유동 코드의 적합성을 검토하였다.

열원이 바뀌는 고온용 히트파이프의 천이 과정 동작에 관한 수치적 연구 (A numerical study on the transient operation of high temperature heat pipe with a switching heat source)

  • 박종흥;이재헌
    • 대한기계학회논문집B
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    • 제21권1호
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    • pp.68-78
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    • 1997
  • A numerical study on the transient vapor flow and heat transfer is performed to investigate the ideal switching operation of heat source in a high temperature heat pipe. The cylindrical 2-dimensional compressible laminar vapor flow is assumed for the vapor space and the conjugate heat transfer for the heat pipe wall, wick and vapor space is calculated. The different boundary conditions such as constant heat flux, convective or radiative boundary at the outer wall are used respectively to compare the influence of boundary conditions on the transient operation. The transient temperature profile and the internal flow of the entire pipe for the switching operation are described as a result. The results show that the transient time is not significantly affected by the boundary conditions at the outer wall in present study. During the transition, two independent flows are observed temporarily on the right side and left side of the heat pipe. It is also found that the trend of temperature variation in the vapor region is different from the variation in the wick and wall region.

고분자 전해질 연료전지의 매니폴드 설계 및 해석 (NUMERICAL STUDY ON THE FLOW CHARACTERISTICS OF MANIFOLD FEED-STREAM IN POLYMER ELECTROLYTE FUEL CELL)

  • 정혜미;엄석기;박정선;이원용;김창수
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.260-263
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    • 2005
  • The effects of internal manifold designs the reactant feed-stream in Polymer Electrolyte Fuel Cells (PEFCs) is studied to figure out mass flow-distribution patterns over an entire fuel cell stack domain. Reactants flows are modeled either laminar or turbulent depending on regions and the open channels in the bipolar plates are simulated by porous media where permeability should be pre-determined for computational analysis. In this work, numerical models for reactant feed-stream in the PEFC manifolds are classified into two major flow patterns: Z-shape and U-shape. Several types of manifold geometries are analyzed to find the optimal manifold configurations. The effect of heat generation in PEFC on the flow distribution is also investigated applying a simplified heat transfer model in the stack level (i.e. multi-cell electrochemical power-generation unit). This modeling technique is well suited for many large scale problems and this scheme can be used not only to account for the manifold flow pattern but also to obtain information on the optimal design and operation of a PEMC system.

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