• Title/Summary/Keyword: Supply hole

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Agent Based Modeling and Simulation of Structural Hole Based Order Allocation Strategy (구조적 공백 기반 주문 분배 전략의 에이전트 기반 모델링 및 시뮬레이션)

  • Kim, Dae-Young;Kang, Bok-Young;Kang, Suk-Ho
    • Korean Management Science Review
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    • v.29 no.1
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    • pp.153-168
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    • 2012
  • Order allocation is one of the most important decision-making problems of firms having significant influences on performances of themselves and the whole supply chain. Existing researches about order allocation have mainly focused on evaluating capabilities of directly connected suppliers so that it is hard to consider effects and interactions from undirected connections over multiple lower-layers. To alleviate the limitation, this paper proposed a novel approach to order allocation using structural hole. By applying the concept of structural hole to the supply network, we could evaluate the structural supplying powers of firms with respect to both of direct and indirect connections. In the proposed approach, we derived a methodology to measure the potential supplying power of each firm by modifying the effective size as one of the measurements of structural hole and then, proposed its application, the structural hole based order allocation strategy. Furthermore, we conducted the agent based modeling of supply chain to perform the decision-making process of order allocation and simulated the proposed strategy. As a results, by coping with the variance of demand more stably, it could improve the performance of supply chain from the aspects of fill rate, inventory level and demand-supply balance.

Study on the Spray Characteristics of a Port Fuel Injector for a Gasoline Engine (가솔린엔진용 포트분사식 인젝터의 분무특성에 관한 연구)

  • Lee, Sang-In;Lee, Sung-Won;Park, Sung-Young
    • Journal of ILASS-Korea
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    • v.15 no.2
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    • pp.61-66
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    • 2010
  • Fuel spray characteristics of the gasoline engine injector has been studied experimentally. To provide fundamental performance data of 4-hole and 12-hole injectors, spray fuel-mass distribution, wall wetting fuel amount and visualization of injectors have been tested and measured with various fuel supply pressure conditions. Spray visualization has been performed to analyze spray formation, spray angle, stream width and penetration length. Test result shows that wall wetting is greatly influenced by the induction air amount and spray atomization. Spray visualization shows that the 12-hole injector has robust performance characteristics with various fuel supply pressure conditions compared with the 4-hole injector. 4-hole injector generates relatively less wall-wetting fuel amount than 12-hole injector does.

Numerical analysis on effect of hole size on Emergency Evacuation Support System (수치해석을 통한 비상피난지원 시스템의 급기구 크기에 따른 유동분석)

  • Kim, Ji Tae;Park, Won Hee;Lee, Duck Hee;Ro, Kyoung-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.4
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    • pp.324-329
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    • 2020
  • The emergency evacuation support system provides a safe means of evacuation by preventing the inflow of smoke through the formation of a smoke shield curtain in fire situations and pressurizing fresh air to the inside of the smoke shield curtain. In this study, numerical analysis was performed to examine the effects of the hole size on the flow inside the smoke curtain. As the air supply size decreased, the flow rate through the air supply was formed relatively uniformly from the inlet to the outlet length of the emergency support system. In addition, the size of the air supply hole was more than 20 mm, the flow rate was very low near the outlet, so the air supply hole size should be smaller than 20 mm. In addition, the minor loss of the air supply hole was calculated to be K = 1.5 from the numerical results. Therefore, the proper design of an emergency evacuation support system is possible using the flow characteristics according to the size and minor loss of the air supply hole.

Microscopic hole fabrication of glass using electro-chemical discharge method (전해 방전법에 의한 유리의 미세 구멍 가공)

  • Lee, Wang-Hoon;Lee, Young-Tae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.89-92
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    • 2001
  • In this paper, we studied on drilling a microscopic hole of glass using electro-chemical discharge methode. In this research, we fabricated a electro-chemical discharge machine for drilling glass hole. The used parameters to get a fine microscopic hole are the concentration of NaOH solution from 5wt% to 50wt%, the supply voltage from 10V to 40V and the fabricating time from 5 second to 50 second. Also, we used a 0.16mm glass plate. We learned from our experiment that, the fabrication most efficient when supply voltage is 25V-30V and concentration of NaOH solution 35wt% or less.

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Microscopic hole fabrication of glass using electro-chemical discharge method (전해 방전법에 의한 유리의 미세 구멍 가공)

  • 이왕훈;이영태
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.89-92
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    • 2001
  • In this paper, we studied on drilling a microscopic hole of glass using electro-chemical discharge methode. In this research, we fabricated a electro-chemical discharge machine for drilling glass hole. The used parameters to get a fine microscopic hole are the concentration of NaOH solution from 5wt% to 50wt%, the supply voltage from 10V to 40V and the fabricating time from 5 second to 50 second. Also, we used a 0.16mm glass plate. We learned from our experiment that, the fabrication most efficient when supply voltage is 25V-30V and concentration of NaOH solution 35wt% or less.

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A Study on the Ventilation Effect by Establishment Location of Supply Opening and Exhaust Fan of Bathroom in Apartment House (공동주택 화장실의 급기구 및 배기팬 설치 위치에 따른 환기효과에 관한 연구)

  • 함진식
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2002.11a
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    • pp.321-326
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    • 2002
  • To design mechanical ventilation for bathroom of apartment houses where air supply and exhaust are taken Into consideration, mock-ups of ventilation systems, widely used in bathroom of apartment houses with an area of 100$m^2$, were made and installed in a laboratory, These ventilation mock-ups were available for control of air supply and exhaust, and the size of supply openings were 40cm$\times$1cm, 40cm$\times$3cm, 40cm$\times$5cm. They were installed at five positions, spaced 40cm at a height of 25cm from the floor. and the position of exhaust fans were four corners and center Exhaust fan established each one on corner of the ceiling and one in center. As result that measure ventilation effect by each condition, size of hole that supply air is big, and ventilation effect took effect to be good establishment location is low, Also, distance of exhaust fan is far with hole that supply air, ventilation effect took effect by superior thing.

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Application of Micro Cross-Flow Turbine to Water Supply System (마이크로 관류수차의 상수도 관로시스템 적용에 관한 연구)

  • Choi Young-Do;Kurokawa Junichi
    • The KSFM Journal of Fluid Machinery
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    • v.9 no.3 s.36
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    • pp.36-43
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    • 2006
  • Recently, micro hydropower and it's useful utilization are taking a growing interest as a countermeasure of global worming by carbon dioxide and exhaustion of fossil fuel. The purpose of this study is to investigate the possibility of extracting micro hydropower wasted by a valve in water supply system using micro cross-flow hydraulic turbine. In order to fulfill the functions of controlling flow rate and pressure in substitute for the valve, air and water are supplied into an air suction hole which is installed on the side wall of micro cross-flow hydraulic turbine. The results show that in case of supplying a lot of air into the air suction hole, about 50% of flow rate and relatively high value of loss coefficient are controlled by the turbine. Moreover, including high possibility of applying the micro cross-flow turbine to water supply system, extended application of the turbine to the water discharge system of drainage and irrigation canal.

Analytical Study on the Optimized Design of Engine Bearings for a Passenger Car (자동차용 엔진베어링의 최적설계에 관한 해석적 연구)

  • Kim, Chung-Kyun;Kim, Han-Goo
    • Tribology and Lubricants
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    • v.25 no.1
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    • pp.1-6
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    • 2009
  • In this paper, the minimum oil film thickness and the maximum oil film pressure of engine bearings have been analyzed by using the elastohydrodynamic theory and Taguchi's design method as functions of the oil groove width, oil hole diameter, oil hole position, and oil supply pressure. The optimized design of the engine bearing f3r an automotive Diesel engine is very important for supporting a load-carrying capacity due to gas pres-sures from the engine combustion chamber and inertia forces of the piston. The optimized design data of engine bearings indicated that the optimized oil groove width and an oil diameter of a engine bearing are 8mm at the speed of 2,000 rpm for a given 4-cylinder Diesel engine. Thus, the oil groove oil groove and an oil hole for high performances of an engine bearing may be considered as major design parameters compared to other design factors, which are strongly related to the minimum oil film thickness and the maximum oil pressure distribution of the engine oil.

Development of Venturi System for Microbubble Generation (미세기포 생성을 위한 벤츄리 시스템 개발)

  • Yun, Jeong Eui;Kim, Joo Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.10
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    • pp.865-871
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    • 2014
  • This study was conducted with the aim of developing a venturi-type air supply system for a microbubble generator. In order to determine the influence of the varying geometry of the venturi tube on the flow characteristics, a computational fluid dynamics (CFD) simulation was performed using the commercial CFD software ANSYS CFX-15. Furthermore, in order to elucidate the effects of variation in major design dimensions such as the air supply hole size, position of holes, and number of holes on the air supply characteristics, two-phase multiflow CFD analysis was performed. The analysis results showed that the starting point of expansion on the venturi tube with 0.75 is the best hole position and that the air supply hole size and the number of holes are linearly proportional to the amount of air.

Predictions of Load Support Performance of a Pressurized Gas Foil Thrust Bearing with Sloped and Stepped Recesses (경사형과 계단형 리세스를 갖는 가압형 가스 포일 스러스트 베어링의 하중지지 성능 예측)

  • Nam Kyu Kim;YongBum Kwon;Chan Sol Park;Tea Ho Kim
    • Tribology and Lubricants
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    • v.40 no.5
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    • pp.151-156
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    • 2024
  • Gas foil thrust bearings (GFTBs) support axial loads in oil-free, high speed rotating machinery using gas as a lubricant. However, under low-speed and high-load conditions, such a bearing experiences friction, leading to wear and a reduced lifespan. Therefore, a pressurized GFTB (PGFTB) that combines hydrostatic and hydrodynamic lubrication by supplying pressurized gas through the supply hole of the top foil has been developed, and various studies have been conducted. In this study, we develop mathematical models of PGFTBs with sloped and stepped recesses and predict its load support performance. The PGFTB maintains a minimum film thickness of approximately 20 ㎛ at rest (0 rpm), regardless of the type of recess, indicating a sufficient hydrostatic pressure to lift the runner at a low rotor speed. Furthermore, the minimum film thickness increases slightly as the numbers of feed holes in the in- and outward radial directions relative to the centerline of the PGFTB pad increase. These findings highlight the importance of supply hole placement in enhancing load support performance. As the rotor speed increases, the minimum film thickness increases rapidly, regardless of the number of supply holes, and without pressurization, sufficient hydrodynamic pressure is generated to lift the runner upon exceeding a certain rotor speed. When comparing the sloped and stepped recesses, the PGFTB with the sloped groove exhibits a superior overall load support performance.