• Title/Summary/Keyword: Flow Control System

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Development of Microprocessor-based Automatic Storage Controller and Temperature Auto-measurement System for Horticultural Crops (마이크로프로쎄서를 이용한 과채류 자동 저장 제어장치의 제작과 온도 자동계측 관리 시스템)

  • Park, Je-Kyun;Chun, Jae-Kun;Lee, Seung-Koo;Kim, Kong-Hwan
    • Korean Journal of Food Science and Technology
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    • v.20 no.6
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    • pp.845-849
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    • 1988
  • A laboratory scale storage facility consisting of a cold room, sample jars and a ventilation device was designed and built. Storaging sample jars (1.7 l) for fruit were fabricated with transparent acryl and provided with a constant air flow. For the supplying of air to sample jars, the air distributing system was built with solenoid valves, an air precooling coil and a pressure equalizing tank. To provide the programmable storaging environment of the facility a microprocessor-based controller was designed and installed. The controller was built with the 8 bit microprocessor (Z-80), EPROM, RAM, programmable peripheral interface(8255 PPI), and A/D converter. Softwares for the auto-temperature measurement and control of the storage system were developed and systemized in ROM. The automated storage system was applied to citrus storage, and the temperature of the storage facilities was successfully acquisited to the computer and controlled.

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Development of a New Simulation Method of Casting Process Based on a Cylindrical Coordinate System (원통좌표를 이용한 주조공정의 수치해석모델 개발)

  • Mok, Jin-Ho;Park, Seong-Joon;Lee, Jin-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.4
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    • pp.433-440
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    • 2004
  • Since the numerical analysis was adopted in the mold design, lots of computational methods have been proposed for the simulations of casting processes for the various shaped molds. Today, it is possible to simulate the filling and solidification processes of most casts using the VOF technique. Though the three-dimensional numerical model based on the Cartesian coordinate system can be applied to any shape of cast, it becomes very inefficient when the three-dimensional model is applied to the cast of axi-symmetrical shape since the control volume includes at least 11 of the physical model. In addition, the more meshes should be distributed along the circumferential boundaries of curved shape in the Cartesian coordinate system fur the better results, while such curved circumferential boundary does not need to be considered in the two-dimensional cylindrical coordinate system. This motivates the present study i.e. developing a two-dimensional numerical model for the axi-symmetrically shaped casts. The SIMPLER algorithm, the VOF method, and the equivalent specific heat method have been adopted in the combined algorithm for the flow calculation, the free surface tracking, and the phase change heat transfer, respectively. The numerical model has been applied to the casting process of a pulley, and it was proven that the mesh and time effective calculation was accomplished comparing to the calculation using three-dimensional model.

A Design and Implementation of Service Provider Initiated Multicast Middleware for Reliable Multimedia Data Communication (멀티미디어 데이터 통신의 신뢰성 보장을 위한 서비스 제공자 중심의 멀티캐스트 미들웨어 설계 및 구현)

  • Kim, Moon-Hwa;Hwang, Jun
    • Journal of Internet Computing and Services
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    • v.3 no.4
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    • pp.11-18
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    • 2002
  • The IP multicasting service system based on IGMP(Internet Group Management Protocol) is the receiver initiated multicasting system that all receivers must join to and leave from the server of multicasting service. The IGMP is less effective and reliable to apply the education system that all computers of students ore synchronized a teacher's computer. A proposed middle-ware in this paper provides the reliable data transferring and the server initiated multicasting system that client as student's PC is controled by a multicasting server as teacher's PC, This middle-ware is consisted with two major component, The one is the group manager that handle the status informations of members in each group. Another is the reliable sender/receiver that has The transmission protocol based on NAK message and flow control. As the results of the test that 22khz digital voice data and 1024$\times$768 24bit color image data were tested for 30 PCs connected with 100baseT, the voice data was completely without error transferred and the image data was successfully transferred with 0.004% retransmit rate under 2 frames/sec load.

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Design and Implementation of a Realtime Video Player on Tiled-Display System (타일드-디스플레이 시스템에서 실시간 동영상 상영기의 설계 및 구현)

  • Choe, Gi-Seok;Yu, Jeong-Soo;Choi, Jeong-Hooni;Nang, Jong-Ho
    • Journal of KIISE:Computer Systems and Theory
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    • v.35 no.4
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    • pp.150-157
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    • 2008
  • This paper presents a design and implementation of realtime video player that operates on a tiled-display system consisting of multiple PCs to provide a very large and high resolution display. In the proposed system, the master process transmits a compressed video stream to multiple PCs using UDP multicast. All slaves(PC) receive the same video stream, decompress, clip their designated areas from the decompressed video frame, and display it to their displays while being synchronized with each other. A simple synchronization mechanism based on the H/W clock of each slave is proposed to avoid the skew between the tiles of the display, and a flow-control mechanism based on the bit-rate of the video stream and a pre-buffering scheme are proposed to prevent the jitter The proposed system is implemented with Microsoft DirectX filter technology in order to decouple the video/audio codec from the player.

A Study on the Optimization of Fuel Metering for the Lean Combustion System in a Gasoline Engine (I) (가솔린 자동차의 희박연소시스템 적용을 위한 연료공급 최적화에 관한 연구 (I) - 가솔린 인젝터의 연료분열특성에 관한 연구 -)

  • Yoon, S.J.;Cho, D.J.;Pang, D.Y.
    • Journal of ILASS-Korea
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    • v.3 no.3
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    • pp.33-41
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    • 1998
  • In recently, a study on the lean combustion is investigated intensively, because it is expected that this method may decrease the harmful exhaust gas and improve fuel economy in gasoline engine. The problems of lean combustion system in gasoline engine are ignition difficulty, misfire and instability of combustion. The investigation on the optimization of fuel metering and the control of mixing gas flow may be critical to improve the performance of lean combustion. In the fuel injection gasoline engine, the formation of mixture influences strongly on the engine performance such that the importance of fuel metering system becomes apparent. First of all, a study on the fuel breakup characteristics of gasoline fuel injector was carried out in this paper. Fuel injectors are pintle and 4hole-2spray type. The purpose of this study is to clarify the atomization mechanism of spray injected into atomosphere field through electronic controlled-fuel injectors, and to analyze spray characteristics such as drop size distribution and mean drop diameter produced at fuel injector. In this paper, the spray development is observed by taking photograps using 80mm still-camera system, and drop sizes are measured by PMAS. From these experiment, spray pattern injected from gasoline fuel injectors was investigated clearly. Also, it was found that SMD and drop size distribution of injected fuel spray from gasoline fuel injectors.

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Information Engineering and Workflow Design in a Clinical Decision Support System for Colorectal Cancer Screening in Iran

  • Maserat, Elham;Farajollah, Seiede Sedigheh Seied;Safdari, Reza;Ghazisaeedi, Marjan;Aghdaei, Hamid Asadzadeh;Zali, Mohammad Reza
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6605-6608
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    • 2015
  • Background: Colorectal cancer is a major cause of morbidity and mortality throughout the world. Colorectal cancer screening is an optimal way for reducing of morbidity and mortality and a clinical decision support system (CDSS) plays an important role in predicting success of screening processes. DSS is a computer-based information system that improves the delivery of preventive care services. The aim of this article was to detail engineering of information requirements and work flow design of CDSS for a colorectal cancer screening program. Materials and Methods: In the first stage a screening minimum data set was determined. Developed and developing countries were analyzed for identifying this data set. Then information deficiencies and gaps were determined by check list. The second stage was a qualitative survey with a semi-structured interview as the study tool. A total of 15 users and stakeholders' perspectives about workflow of CDSS were studied. Finally workflow of DSS of control program was designed by standard clinical practice guidelines and perspectives. Results: Screening minimum data set of national colorectal cancer screening program was defined in five sections, including colonoscopy data set, surgery, pathology, genetics and pedigree data set. Deficiencies and information gaps were analyzed. Then we designed a work process standard of screening. Finally workflow of DSS and entry stage were determined. Conclusions: A CDSS facilitates complex decision making for screening and has key roles in designing optimal interactions between colonoscopy, pathology and laboratory departments. Also workflow analysis is useful to identify data reconciliation strategies to address documentation gaps. Following recommendations of CDSS should improve quality of colorectal cancer screening.

Analysis of Storm Water Run-off Characteristics to Evaluate the Intercepted Volume of CSOs during Wet Weather (강우시 합류식 하수관거의 월류수 차집용량 산정을 위한 유출특성 분석)

  • Choi, Sung-Hyun;Choi, Seung-Chol;Kim, Byoung-Ug;Rim, Jay-Myoung
    • Journal of Korean Society of Water and Wastewater
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    • v.18 no.3
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    • pp.320-330
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    • 2004
  • Most of domestic city is served combined sewer system among various sewer system like as separate sanitary, combined sewer system and storm sewers. During the wet weather, sewer and rainfall have been overflowed because it is over capacity of the combined sewer system; that is called combined sewer overflows(CSOs) This research was carried out to investigate runoff characteristics of combined sewer and to evaluate the effective CSOs volume in Hong-Chun gun. During wet weather, SS load of first rainfall at H-1, H-2, and H-3 were 600kg/event, 370kg/event, and 289kg/event, respectively. 55 load of second rainfall were 216kg/event, 113kg/event, and 37.2kg/event. When the first rainfall, event mean concentrations(EMCs) at each site were 702mg/L, 816mgjL and 861.5mg/L. The second rainfall's event mean concentrations(EMCs) were 99.9gm/L, 161.9mg/L, 103.6mg/L. Rrst flush coefficient b at each site were 0.237,0.166, and 0.151. When the first rainfall, the flow containing 80% of pollutant mass of CSOs at each site were 0.55, 0.23, 0.48 in first rainfall, respectively. The case of second rainfall were 0.79, 0.83, 0.81. Most of all, characteristics of rainfall like as analysis of first-flush, CSOs volume, pollutant loadings is investigated to decide intercepted volume for control of CSOs.

Effects of Manual Lymph Drainage on Patients with Secondary Lymphedema of Legs After Gynecologic Cancer (부인과 암 이후 이차적인 다리 림프 부종 환자에게 적용한 림프흡수 마사지의 효과)

  • Jeong, Seong-gwan;Lee, Seung-byung
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.22 no.2
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    • pp.35-39
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    • 2016
  • Background: The superficial lymphatic system is divided into areas called lymphatic territories which are separated by watersheds. When the lymphatic system fails to remove its load either due to surgery, radiotherapy or some congenital malformation of it then the fluid and the proteins and wastes contained within it accumulates in that territory. Anastomotic connections exist across the watersheds and while they can work unaided manual lymph drainage (MLD) can significantly help drainage across them into unaffected lymphatic territories. The purpose of the study is to examine the effectiveness of a manual technique in moving fluids and softening hardened tissues using a tape measure and Patient-Specific Functional Scale. Methods: We examined the movement of fluids from the affected limbs of lymphedema patients who underwent a standardized 30-min treatment using the Dr. Vodder method of MLD. We chose a typical cross section of patients with secondary leg or secondary arm lymphedema. The lymphedema patient was also measured after the conclusion of treatment and underwent a follow-up control measurement, within 8 weeks. Both evaluation tools indicated a movement of fluid to different and unblocked lymphatic territories as well as a softening of tissues in some of the affected limbs. Results: MLD is an effective means of fluid clearance when it accumulates as a consequence of a failure of the lymphatic system. It seems likely that MLD has a systemic effect on the lymphatic system and that it can improve flow from otherwise normal tissues. Conclusions: It is hypothesized that a series of treatments would result in even more significant improvements.

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Dynamic modeling of the hydraulic-thermal behavior of the buried pipe network for district heating (지역난방용 지중매설 배관망 네트워크 열-유체 동적 거동 모델링)

  • Lee, Jeongbin;Yi, Jun Young;Kim, Lae-Hyun;Shin, Chee Burm
    • Journal of Energy Engineering
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    • v.21 no.2
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    • pp.144-151
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    • 2012
  • A district heating system produces thermal energy and supplies it to a large region. District heating systems can provide higher efficiencies and better pollution control than localized boilers. The heat generated by a district heating system is distributed to the customer via a network of insulated pipes. For the optimal operation of a district heating system, it is important to predict the distributions of pressure, flow rate and temperature of heating fluid within the network of pipes at various operating conditions. In this work, a mathematical modeling was performed to predict the dynamic hydraulic-thermal behaviors of heating fluid in the network of pipes for a district heating system. The mathematical model accounts for the conservations of mass, momentum and energy. In order to verify the validity of modeling, the modeling results were compared with the monitoring data of Gang-nam Branch of District Heating.

Establishment of Ultrahigh Vacuum Standard down to $10^{-10}$ torr Range ($10^{-10}$ torr까지의 초고진공 표준 확립)

  • Hong, Seung-Su;Im, Jae-Yeong;Park, Jae-Hong;Sin, Yong-Hyeon;Lee, Cheol-Ro;Jeong, Gwang-Hwa
    • Journal of the Korean Vacuum Society
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    • v.2 no.2
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    • pp.139-144
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    • 1993
  • The dynamic calibration system which can calibrate the ultrahigh vacuum pressure down to $10^{-10}$torr has been fabricated. The production and control of minute flow of $10^{-6}~10^{-9}$torr L/s range is done by a porous plug connected to the high vacuum standards system. The base pressure of the UHV standards system down to $10^{-11}$torr range was obtained by refrigerator type cryopump, whose pumping speed is known to be constant. By using the UHV standards system, 2 extractor gauges and 1 nude ion gauge were calibrated and their linearities and scatterings were studied.

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