• Title/Summary/Keyword: 유로 가이드 장치

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Thermal Optimization of a Straight Fin Heat Sink with Bypass Flow (바이패스가 있는 히트 싱크의 열성능 최적화)

  • Kim, Jin-Wook;Kim, Sang-Hoon;Kim, Joong-Nyon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.2
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    • pp.179-184
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    • 2010
  • This experimental study investigated the effect of tip clearance and bypass flow on the cooling performance of a straight fin heat sink. Both the horizontal and vertical directions of the bypass flow were studied by using a mass flow controller and test sections. The thermal resistance of a heat sink was obtained to elucidate the response of the cooling performance to tip clearance and bypass flow. The thermal resistance of a straight fin heat sink gradually increases with increasing tip clearance. A flow guide unit was employed to reduce the bypass flow. An optimal distance from the leading edge of the heat sink to the flow guide unit was found for the fixed volume flow rate. The contribution of the flow guide unit to the thermal performance of a heat sink increases with increasing volume flow rate.

Design of SCR Reactor for NOx Reduction (질소산화물 제거를 위한 SCR 반응기 설계)

  • 이인영;김동화;이정빈;김우영
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2001.11a
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    • pp.425-426
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    • 2001
  • 선택적촉매환원(Selective Catalytic Reduciton: SCR)공정은 배기가스 중 질소산화물을 암모니아와 촉매상에서 반응시켜 무해한 질소와 물로 전환하는 기술이다(Bosch, 1988). SCR 공정에서 우수한 촉매가 확보되었을 경우, 설비의 성능은 촉매층로 유입되는 유동의 조건에 따라 좌우되므로 최적의 유동조건을 갖도록 반응기의 구조와 가이드 베인등 유로변경장치를 설계하는 것은 매우 중요하다(Cho, 1994). (중략)

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Development of the Small Scale Testbed for Running Dynamic Characteristics Analysis of the Capsule Train (캡슐트레인 주행 동특성 분석을 위한 축소 시험장치의 개발)

  • Lee, Jin-Ho;You, Won-Hee;Lee, Kwansup
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.643-651
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    • 2020
  • A capsule train runs inside a sub-vacuum tube and can reach very high speed due to the low air resistance. A capsule train uses a superconducting electrodynamic suspension (SC-EDS) method for levitation, which allows for a large levitation gap and does not require gap control. However, SC-EDS has inherent characteristics such as the large gap variation and a small damping effect in the levitation force, which can degrade the running stability and ride comfort. To overcome this, a stability improvement device should be designed and applied based on dynamic analysis. In this study, a 1/10 small-scale testbed was developed to replicate the dynamic characteristics of a capsule train and investigate the performance of stability improvement devices. The testbed is composed of a 6-degree-of-freedom Stewart platform for the realization of bogie motion, a secondary suspension with a running stabilization device, and a carbody. Based on the dynamic similarity law proposed by Jaschinski, the small-scale testbed was manufactured, and a bogie motion algorithm was applied with the consideration of guideway irregularity and levitation stiffness. The experimental results from the testbed were compared with simulation results to investigate the performance of the testbed.

Characteristics of Inclusive Playground Guidelines (통합놀이터 가이드라인의 특성)

  • Kim, Yun-Geum;Kim, Hana;Maeng, Soo-hyun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.6
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    • pp.75-84
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    • 2018
  • The inclusive playground is a playground where disabled children and non-disabled children can play together, not a playground for the disabled. It started with the change of social awareness of the citizenship rights of disabled people in the 1960s and the resulting playgrounds. Since then, inclusive playgrounds have been developed in many countries, and these are organized in the form by guidelines. In Korea, social interest in inclusive playgrounds is increasing, but there are no systematic guidelines in Korea, and the application of overseas cases or guidelines is limited. The purpose of this study is to classify the concept of inclusive playgrounds and design guidelines, that were previously presented in inclusive playground design guideline of various countries and analyze the characteristics of, design scope, and design principles, and provide a basic framework for creating guidelines. The purpose of the design guideline was to present specific numerical values to the inclusive playground design guidelines, to link with academic research and industrial products, to present pursuit values, and to expand the value of pursuing design methods. The contents were covered by scope, conceptualization, principles of design and design process, design guidelines, and checklists. Most of the guideline covers specific autonomous governments or countries that can apply the related systems or laws, but the composition of the detailed contents is different. The guiding value of inclusive playgrounds presented in each guideline is not a playground for the disabled but a playground for all, and some guidelines refer to the difficulty in playgrounds considering non-disabled children. Based on these concepts, design guidelines are presented in each guideline. Improving the accessibility in design principles is a common theme and adds to the principles of safety, independence, convenience, and playability. None of the guidelines do not provide design guidelines. Although there is a difference in the degree and method of specificity provided by each of the guidelines, the design guidelines can be generally summarized as space, copper line, and unit facilities. As mentioned in many guidelines, an inclusive playground is not only a playground for children with disabilities. Therefore, in the design guidelines, it is also important to the support play of children with disabilities and to induce inclusive play. The design guidelines presented in the guideline can be rearranged into three stages of 'supporting the play of children with disabilities', 'securing the dimensions and materials of spaces and facilities', 'adding auxiliary devices' and 'designing new facilities'. There are three design guidelines for inducing inclusive play. First, by creating various difficulty levels and intersecting spaces, children with various abilities can play with each other, and at the same time, they can interact witheach other. Second, all children can cooperate and play without distinction between children with disabilities and non-disabled children. Finally, the guardian provides the conditions for efficient support so that the disabled child can fully enjoy the inclusive playground.

Section Analysis of EMS Rail by Finite Element Analysis (유한요소해석을 통한 EMS 레일 단면 해석)

  • Yu, Byoung Kwon
    • Transactions of the KSME C: Technology and Education
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    • v.3 no.1
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    • pp.63-69
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    • 2015
  • Among the material handling system, EMS (Electric Monorail System), which is the facility of transferring the material hanging on truss, has the strength point of the maximum utilization of working space and the improvement of working environment including low-level noise generation. This paper will introduce the variable method of EMS rail analysis, which has the main role of supporting the whole material weight and guiding them with high-speed transportation, and, based on the analysis, the direction of optimization of the rail design be described. The rail with light-weight and high-strength contributes the reduction of the load of truss, the cost-down of rail production and the easy-installation on site.

Evaluation of Data-based Expansion Joint-gap for Digital Maintenance (디지털 유지관리를 위한 데이터 기반 교량 신축이음 유간 평가 )

  • Jongho Park;Yooseong Shin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.2
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    • pp.1-8
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    • 2024
  • The expansion joint is installed to offset the expansion of the superstructure and must ensure sufficient gap during its service life. In detailed guideline of safety inspection and precise safety diagnosis for bridge, damage due to lack or excessive gap is specified, but there are insufficient standards for determining the abnormal behavior of superstructures. In this study, a data-based maintenance was proposed by continuously monitoring the expansion-gap data of the same expansion joint. A total of 2,756 data were collected from 689 expansion joint, taking into account the effects of season. We have developed a method to evaluate changes in the expansion joint-gap that can analyze the thermal movement through four or more data at the same location, and classified the factors that affect the superstructure behavior and analyze the influence of each factor through deep learning and explainable artificial intelligence(AI). Abnormal behavior of the superstructure was classified into narrowing and functional failure through the expansion joint-gap evaluation graph. The influence factor analysis using deep learning and explainable AI is considered to be reliable because the results can be explained by the existing expansion gap calculation formula and bridge design.

A Study on Integrating Wire & Wireless Communication Networks for Reducing Communication Costs in the National ITS Physical Architecture (통신비 절감을 위한 국가 ITS 물리 아키텍쳐 상의 유.무선통신망 통합에 관한 연구)

  • Lee, Bong-Gyou;Hong, In-Gi;Ryu, Seung-Ki;Moon, Hak-Yong
    • Journal of Korea Spatial Information System Society
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    • v.6 no.2 s.12
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    • pp.77-84
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    • 2004
  • The purpose of this study is to suggest an effective guideline for reducing communication costs and improving qualities of Intelligent Transport Systems (ITS) by totally or partially integrating wireless communication networks between equipments of ITS Centers and Roadside in the National ITS Physical Architecture. We analyzed wire and wireless communication networks such as wireless LAN and satellite communications in the National Highway Traffic Management System (NHTMS) for receiving and transmitting transportation data. Also, we analyzed operation and communication costs to find out right communication networks for ITS. The results of this study will be used to build and operate many other ITS systems including Korea Highway Corporation.

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Multilevel Modulation Codes for Holographic Data Storage (홀로그래픽 데이터 저장장치에서의 멀티레벨 변조부호)

  • Jeong, Seongkwon;Lee, Jaejin
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.9
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    • pp.13-18
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    • 2015
  • The mutilevel holographic data storage offers considerable advantage for capacity, since it can store more than one bit per pixel. In this paper, we search the number of codewords for each code depending on three conditions: (1) the number of levels, (2) the number of pixels in a codeword, and (3) the minimum Euclidean distance of a code. Increasing the number of levels per pixel creates more capacity, while causing more errors, by reducing the noise margin. Increasing the number of pixels in a codeword can increase the code rate, which means more capacity, but increases the complexity of the encoder/decoder of the code. Increasing the minimum distance of a code reduces the detection error, while reducing the code rate of the code. In such a fashion, a system design will always have pros and cons, but our task is to find out an effective one under the given conditions for the system requirements. Therefore, the numbers we searched can provide some guidelines for effective code design.

Analytical Study of Railroad Bridge for Maglev Propulsion Train with Dynamical Influence Variable (동적영향변수를 통한 자기부상열차용 철도교의 해석적 연구)

  • Yoo, Yi-Seul;Park, Won-Chan;Yhim, Sung-Soon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.532-542
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    • 2018
  • Because maglev trains have a propulsion and absorption force without contact with the rails, they can drive safely at high-speed with little oscillation. Recently, test model of a maglev propulsion train was produced and operated, and has since been chosen as a national growth industry in South Korea; there have been many studies and considerable investment in these fields. This study examined the dynamic responses due to bridge-maglev train interaction and basic material to design bridges for maglev trains travelling at high-speed. Depending on the major factors affecting the dynamic effects, the scope of this study was restricted to the relationship between dynamic responses. A concrete box girder was chosen as a bridge model and injured train and rail types in domestic production were selected as the moving train load and guideway analysis model, respectively. From the analysis results, the natural frequency of a bridge for a maglev train, which has a deflection limit L/2000, was higher than those of bridges for general trains. The dynamic responses of the girder of the bridge for a maglev train showed a substantial increase in proportion to the velocities of the moving train like other general bridge cases. Maximum dynamic response of the girder is shown at a moving velocity of 240km/h and increased with increasing moving velocity of train. These results can be used to design a bridge for maglev propulsion trains and provide the basic data to confirm the validity and verification of the design code.