• Title/Summary/Keyword: Channel Distribution

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A study on the uncertainty of setpoint for reactor trip system of NPPs considering rectangular distributions

  • Youngho Jin;Jae-Yong Lee;Oon-Pyo Zhu
    • Nuclear Engineering and Technology
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    • v.56 no.5
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    • pp.1845-1853
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    • 2024
  • The setpoint of the reactor trip system shall be set to consider the measurement uncertainty of the instrument channel and provide a reasonable and sufficient margin between the analytical limit and the trip setpoint. A comparative analysis was conducted to find out an appropriate uncertainty combination method through an example problem. The four methods were evaluated; 1) ISA-67.04.01 method, 2) the GUM95 method, 3) the modified GUM method developed by Fotowicz, and 4) the modified IEC61888 method proposed by authors for the pressure instrument channel presented in ISA-RP67.04.02 example. The appropriateness of each method was validated by comparing it with the result of Monte Carlo simulation. As a result of the evaluation, all methods are appropriate when all measurement uncertainty elements are normally distributed as expected. But ISA-67.04 method and GUM95 method overestimated the channel uncertainty if there is a dominant input element with rectangular distribution among the uncertainty input elements. Modified GUM95 methods developed by Fotowicz and modified IEC61888 method by authors are able to produce almost the same level of channel uncertainty as the Monte Carlo method, even when there is a dominant rectangular distribution among the uncertainty components, without computer-assisted simulations.

A Study on Cooperation in the Franchise Channel of Garment Goods (패션 프랜차이즈 경로에서의 협력에 관한 연구)

  • 황호종
    • Proceedings of the Korean DIstribution Association Conference
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    • 1999.11a
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    • pp.161-177
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    • 1999
  • Marketing channels have been characterized as social systems by the recent channel literatures. Under this assumption, many channel behavioral theories were developed by examining hypothetical relationships among several channel variables. Among them, interrelationship of channel cooperation with other variables has been one of major concerns to channel managers. From this point of view, the objective of this paper is to examine the role of cooperation in the franchise system of garments goods. In order to achieve our goal, data was collected from garment retailers and a simple random sample of 150 dealers was drawn and tested. Major findings through the data analysis are as follows : 1. Higher levels of dependence lead to higher levels of cooperation. 2. Noncoercive sources of power tends to increase intrachannel cooperation. However, the hypothesis that higher levels of coercive sources of power will lead to lower levels of cooperation was not statistically supported. 3. Another hypothesis that higher levels of conflict will lead to lower levels of cooperation was partially supported. 4. Higher levels of cooperation lead to higher levels of cooperation. In this study, data was gathered from the retail side of the franchise channel dyad for garments goods. Therefore, future research are suggested to investigate respondents of both sides(franchiser and franchisee) of the channel dyad.

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Movement and evolution of macromolecules in a grooved micro-channel

  • Zhou, L.W.;Liu, M.B.;Chang, J.Z.
    • Interaction and multiscale mechanics
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    • v.6 no.2
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    • pp.157-172
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    • 2013
  • This paper presented an investigation of macromolecular suspension in a grooved channel by using the dissipative particle dynamics (DPD) with finitely extensible non-linear elastic (FENE) bead spring chains model. Before studying the movement and evolution of macromolecules, the DPD method was first validated by modeling the simple fluid flow in the grooved channel. For both simple fluid flow and macromolecular suspension, the flow fields were analyzed in detail. It is found that the structure of the grooved channel with sudden contraction and expansion strongly affects the velocity distribution. As the width of the channel reduces, the horizontal velocity increases simultaneously. Vortices can also be found at the top and bottom corners behind the contraction section. For macromolecular suspension, the macromolecular chains influence velocity and density distribution rather than the temperature and pressure. Macromolecules tend to drag simple fluid particles, reducing the velocity with density and velocity fluctuations. Particle trajectories and evolution of macromolecular conformation were investigated. The structure of the grooved channel with sudden contraction and expansion significantly influence the evolution of macromolecular conformation, while macromolecules display adaptivity to adjust their own conformation and angle to suit the structure so as to pass the channel smoothly.

Performance and Thermal-Flow Characteristics in a Planar Type Solid oxide Fuel Cell with Single Channel and Multi-Channel (단일채널 및 다채널을 포함한 평판형 고체산화물연료전지의 열유동 해석 및 성능평가)

  • Ahn, Hyo-Jung;Cha, Suk-Won
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.12
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    • pp.1033-1041
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    • 2007
  • This paper studied the characteristics of performance and temperature in a unit cell of a planar type SOFC under various conditions by employing computational fluid dynamics (CFD). In order to derive thermal stress distribution and performance characteristics, the 3-D model simulation for a single channel was performed in various conditions which include interconnect materials $(LaCrO_3/AISI430)$, gas flow direction (co-flow/counter-flow) and inlet temperature (923 K/1173 K). From these results of a single channel, the most effective conditions were applied to the unit stack with multi-channel and the temperature distribution is displayed. Considering both thermal stress and performance, the best combination is 923 K inlet temperature, counter-flow and interconnector of stainless steel. As the end results, flow, thermal and current density distributions were found in the model with multi-channel applied to the best combination and were concentrated in the middle of channels than in the edge.

Effects of Consumer Self-Determination Motivation and Service Quality on Purchase Intention of Omni-Channel Service in Omni-Channel Environment (옴니채널 환경에서 소비자의 자기결정 동기와 서비스품질이 옴니채널 서비스 구매의도에 미치는 영향)

  • Park, Joonyong;Kim, Ji Su;Kim, Renee B.
    • Journal of Information Technology Services
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    • v.18 no.4
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    • pp.23-38
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    • 2019
  • With the development of information and communication technology, logistics distribution systems and services have been improved, new types of services have been provided, and consumption patterns in consumer markets have also changed. In the domestic distribution market, the development of ICT technology, the spread of smart devices, and the growth of the e-commerce market have led to Omni-channel, a service that integrates offline channels and online channels. Omni-channel service aims to provide consumers with consistent and convenient service by integrating offline and online domain into one. Consumers can get integrated service on and offline. In this study, consumers' intention to use Omni-channel was examined by Self Determination Theory and SERVQUAL. The survey was conducted on Omni-channel user and the research model was composed of 2nd order factor model considering the characteristics of Omni-channel which provides integrated service based on the prior literature and PLS-SEM (partial least squares structural equation modeling).

CALCULATION OF FLOW FIFLD IN A CHANNEL SUBJECTED TO PRESSURE-BASED BOUNDARY CONDITION

  • Park, Jong-Hyeong;Lee, Jae-Hyeon
    • ETRI Journal
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    • v.10 no.4
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    • pp.118-126
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    • 1988
  • A numerical analysis was performed for the flow field in the vertical channels consist of dummy cards and active cards to define the hydrodynamic role of dummy card which is often installed in electronic equipment between active cards to control the cooling air distribution. For a given velocity profile at the inlet and a pressure-based boundary condition at the outlet of the computation domain, the percentage of the flow rate distribution through active channel and dummy channel formed by an active card and dummy card, respectively, were investigated. As a result of present analysis, the pecentage of flow rate through active channel increases quadraticaly with the increase of the ratio of the height of barrier to the width of the dummy channel.

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CFD Analysis on a Flow Channel of a Bipolar Plate with Varying Cross-sectional Area in a PEM Fuel Cell (PEM 연료전지용 Bipolar Plate의 변화단면 유로에 대한 CFD 해석)

  • Yang, Dong-Jin;Park, Woon-Jean
    • New & Renewable Energy
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    • v.3 no.3
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    • pp.14-19
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    • 2007
  • A flow channel model of a bipolar plate with varying cross-sectional area was newly designed for improving performance and efficiency of a PEM fuel cell stack. As a result, the varying cross-sectional area model showed poor uniformity in velocity distribution, however, maximum velocity in the flow path is about 30% faster than that of the uniform cross-sectional area model. The proposed varying cross-sectional area model is expected to diffuse operating fluids more easily into diffusion layer because it has relatively higher values in pressure distribution compared with other flow channel models. It is expected that the implementation of the varying cross-sectional area model can reduce not only the mass transport loss but also the activation loss in a PEM fuel cell, and open circuit voltage of a fuel cell can thus be increased slightly.

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A Fluid Flow Numerical Study on the Design Factor of Inlet Distribution Channel for Flocculation/Sedimentation Basin (유동(流動) 수치해석(數値解析)을 이용한 응집·침전지 유입 분배수로 설계인자 연구)

  • Yoon, Jang-Ken;Kim, Jeong-Hyun;Oh, Jung-Woo;Ha, Eun-Jung
    • Journal of Korean Society of Water and Wastewater
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    • v.14 no.4
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    • pp.337-342
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    • 2000
  • In water treatment plants, open channel is used to distribute incoming flow to parallel treatment unit, such as flocculation basin and sedimentation basin. These control devices must be designed so that the incoming flow evenly distributed to the process unit. this is important in the view of optimizing process unit. In the recent past. significant insights into the sedimentation process have been developed. In this study, the 2-D computer program is developed to investigate fluid flow field and velocity vectors in flocculation sedimentation inlet distribution weir and calculate flow rates in each inlet weir. The specific purpose of this study is to analyze physical design factors, such as now rates, shape of channel, tapered angle in tapered type channel and main channel width.

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Dose Distribution of 3-Channel Ovoid Applicator (3-Channel Vaginal Ovoids의 선량분포 특성)

  • Kim Chang Hee;Yun Sang Mo;Kim Sung Kyu;Shin Sei One
    • Progress in Medical Physics
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    • v.15 no.3
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    • pp.134-139
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    • 2004
  • This study was aimed to develop a new ovoid applicator for vaginal high-dose rate intracavitary radiation therapy, evaluate uniformity of dose distribution, and assess clinical applicability. The authors evaluated dose uniformity of vaginal mucosa according to 5-different ovoid-separation using 2-channel and modified 3-channel ovoid applicator. There were no significant differences in the dose distribution along the vaginal mucosa with 2 and 2.5 cm separations, but there were between the 2-channel and 3-channel ovoid applicator with a separation of 3 cm or more. Although a low dose area was shown between two ovoid applicators with the 2-channel ovoid applicator, the dose distribution along the vaginal mucosa with the 3-channel ovoid applicator was very uniform.

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산업용품 유통합리화를 위한 유통단지조성에 관한 연구

  • Seol, Bong-Sik;Lee, Gyeong-Won;Kim, Ung-Jin
    • Journal of Distribution Research
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    • v.1 no.2
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    • pp.199-220
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    • 1996
  • Our courtry's distribrtion business is on the luring point by opening the market to foreign countries from this year. It can be said that industrial goods are intermediated goods for the production of other goods or service So it requires quality and specialty than any other things. But the lack of understanding, small scale and classification by non-productive industry by government bring about difficulty to the distribution itself and other fields. Industrial goods have a long distribution channel. This distribution stracture can be reduce the channel by establishment of distribution complex. Establishment of distribution complex will strengthen the role of quality management and go far toward quality improvement. This study examine the distribution status of industrial goods, problems and study the extablishment of complex and expected affect.

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