• Title/Summary/Keyword: Traveling standard

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Numerical Analysis on Effects of Radius Ratio in a Concentric Annulus with a Rotating Inner Cylinder (내부회전실린더를 가진 동심환형관에서 반경비의 영향에 관한 수치해석적 연구)

  • Bae, Kang-Youl;Kim, Hyoung-Bum;Lee, Sang-Hyuk
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.327-330
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    • 2006
  • This paper represents the numerical analysis on effects of radius ratio in a concentric annulus with a rotating inner cylinder. The numerical model consisted of two cylinder which inner cylinder is rotating and outer cylinder is fix, and the axial direction is used the cyclic condition because of the length for axial direction is assumed infinite. The diameter of inner cylinder is assumed 86.8mm, the numerical parameters are angular velocity and radius ratio. Also, the whole walls of numerical model have no-slip and the working fluid is used water at $20^{\circ}C$. The numerical analysis is assumed the transient state to observe the flow variations by time and the 3-D cylindrical coordinate system. The calculation grid adopted a non-constant grid for dense arrangement near the wall side of cylinder, the standard $k-{\omega}$ high Reynolds number model to consider the effect of turbulence flow and wall, the fully implicit method for time term and the quick scheme for momentum equation. The numerical method is compared with the experimental results by Wereley and Lueptow, and the results are very good agreement. As the results, TVF isn't appeared when Re is small because of the initial flow instability is disappear by effect of the centrifugal force and viscosity. The vortex size is from 0.8 to 1.1 for TVF at various $\eta$, and the traveling distance for wavy vortex have the critical traveling distance for each case.

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A Study on standard Model of Tourist Sign Board in Korea (한국 관광안내표지판의 발전모델)

  • 양영종;김제중
    • Archives of design research
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    • v.13 no.1
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    • pp.247-256
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    • 2000
  • Recently, foreign tourists and car owners or motorists are increasing, so tourist sign boards are necessary to inform them. Unfortunately, tourist sign boards are difficult to understand because they are often written incorrectly. This paper has a thorough grasp of this problem and will present an ideal standard model which is precise and detailed. This paper includes research of tourist boards sign Seoul, Kyongju, Pusan, Kwangju, Yosu, Kwang reung in Korea. Also tourist sign boards in the U.K, France, Switzerland, Italy and Austria will be discussed. A survey was conducted of eight hundred people to determine tourist information is obtained. In conclusion, tourist sign board should convey accurate and useful information to people of all ages. Tourist information should be systematic and logical. An ideal standard model of tourist signs will render traveling easier for tourists all over the world. It will be more convenient for both kinds of tourist; domestic and foreign. Futhermore good tourist sign board will give an excellent and bright image.

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Results of Key Comparison on LS1P Microphones (LS1P 마이크로폰 핵심측정표준 국제비교 결과)

  • Suh Jae Gap;Jho Moon Jae;Kwon Hyu-Sang;Suh Sang Joon
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.4
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    • pp.194-201
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    • 2005
  • Since the necessity for the accurate measurement in the field of acoustics, vibration, and ultrasound was internationally increased, CCAUV (Consultative Committee for Acoustics , Ultrasound and Vibration) was created by the CIPM (International Committee for Weights and Measures) in 1998. One of the first activities of CCAUV is the key comparison on 1' standard microphones. The key comparison was done from April. 1999 to April. 2001 and 12 NMIs(National Metrology Institutes) including KRISS (Korea Research Institute of Standards and Science) were participated. The pilot laboratory was the National Physical Laboratory(NPL). The traveling standards were two LSIP(Laboratory Standard 1' Pressure Type) microphones specified in IEC 61094-1 and the calibration frequency ranges covers from 63Hz to 8kHz. In this paper, the analyzed results in the final report were summarized.

Bicycle road arrangement standard of bicycle user center that use GIS (GIS기반의 자전거 도로관리시스템 도입의 필요성 고찰)

  • Kang, Ho-Yun;Kang, In-Joon;Kang, Ki-Suk;Choi, Hyun
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.345-348
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    • 2007
  • People's income level is being ehanced, utilization of a car is increasing. Utilization of a car is increasing by peoples' income level elevation along with growth of economy. Economical loss and environmental pollution by vehicles stagnation of downtown are increasing. Specially, in case of downtown it is trend that the city traveling speed is decreasing every year. Lately, transfer bicycle-user to use public traffic is increasing. And they is using much on leisure because of physical strength improvement and the 5 day work week. In this study, we introduce examples of overseas designing and managing bicycle-user road based on GIS(a target of America and Canada). And we purpose construction-necessity of Bicycle Road Management System(BRMS) using GIS technique in domestic.

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Influences on the Droplet Dynamics and Evaporation due to Closely Spaced Droplet Interaction (입자간의 상호작용으로 인한 입자의 운동 및 증발에 미치는 영향)

  • 이효진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.9
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    • pp.1770-1779
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    • 1992
  • The present study investigated dynamically and thermally interacting droplets in a closely spaced tandem array. By measuring the velocity and diameter of the droplet traveling along the isothermal vertical plate drag coefficients and vaporization rates of droplets at certain location were obtained. During the experiment initial droplet spacings were less than 5, and initial droplet diameters were ranged between 280 .mu.m and 700 .mu.m Drag coefficients on closely spaced droplets were placed far below the standard drag coefficient, for which it was caused turbulence induced from aforelocating droplets also narrow spaces among droplets restricted heat transfer to droplets from hot gas flow. In addition evaporated vapor entrapted between droplets was major factor in delaying droplet vaporization. With the experimental results the drag coefficient was correlated with respect to Reynolds number for the droplet as follows : $c_{D}$ =2.4/Red.$^{0.37}$

Economic valuation for Recreation Roles of Tourist Farms (관광농원의 레크리에이션 기능에 대한 경제가치 평가)

  • Shin, Yong-Kwang;Rhee, Sang-Young;Cho, Soon-Jae;Kang, Kyeong-Ha
    • Journal of Korean Society of Rural Planning
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    • v.10 no.1 s.22
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    • pp.35-40
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    • 2004
  • The expansion of demand associated with leisure, which has resulted from the elevated standard of living, has made the domestic tourist demand diversified. Recently, people, especially urban population, show the higher interest and need for environmentally friendly rural tourism. This study aims to grasp the utilization of recreation roles of tourist farms and then to evaluate the economic value for recreation roles of tourist farm using Traveling Cost Method. Data were collected from a survey in 2003. The results show that its value is 62,037 won per head annually and so the tourist farms play their role of connecting the urban population with rural amenity.

The plan of rational span decision to track beam of monorail (모노레일 시스템 궤도빔의 합리적인 경간장 결정방안)

  • Ahn, Yong-Mo;Baek, Cha-Seung
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.199-205
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    • 2008
  • The monorail system as new transportation system mostly has being constructed as an elevated construction and the track beam as mostly main work type occupy the important parts. The structure of monorail system, the track beam support directly vehicle's load and comprised of the track beam structure to be traveling side and understructure to be transmitted from their load to the ground. In particular, in case of construction to elevated structure in the center of a city, it is important to decision plan for span to be considered the economic, execution and maintenance according to transport, installation, and the structure problem, scene and civil appeals to be decided the beam elevation and span. Therefore the standard span of monorail track beam shall be considered the efficient execution, economic and transportation. And propose to reasonable decision plan incorporated the minimizing the road occupied width due to openness to center of a city and bridge pole, minimize to basis size.

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A Route-Splitting Approach to the Vehicle Routing Problem

  • Kang Sungmin;Thomas L. Joseph
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.10a
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    • pp.389-392
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    • 2004
  • The column generation process for the set-partitioning model of the vehicle routing problem requires repeated solutions of column generation subproblems which has a combinatorial structure similar to that of the traveling salesman problem. This limits the size of the problem that can be addressed. We introduce a new modeling approach, termed route-splitting, which splits each vehicle route into segments, and results in more tractable subproblems. A lower bounding scheme that yields an updated bound at each iteration of the column generation process is developed. Implementation issues, including a technique of controlling columns in the master problem, are explored. Lower bounds are computed on standard benchmark problems with up to 199 customers.

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Analysis of transmission delay of timecode over SpaceWire network using OMNeT++ (OMNeT++을 이용한 스페이스와이어 네트워크의 타임코드 전송 지연 분석)

  • Ryu, Sang-Moon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.9
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    • pp.2022-2028
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    • 2015
  • SpaceWire is a standard for high-speed links and networks between spacecraft components, which was invented for better, cheaper and faster on-board data handling in spacecraft. The standard defines timecode and its distribution which can be used for time synchronization among the nodes in a SpaceWire network. A timecode output from the time master which provides standard time over a SpaceWire network travels through links and routers to reach every nodes. While traveling, a timecode suffers from transmission delay and jitter which cause some difference in time synchronization among nodes. In this work, a simulator was developed using OMNeT++ to simulate the operation of a SpaceWire network and some analyses were performed on the transmission delay and jitter accompanied with a transmission of a timecode. The result will be used in the near future for the research of a precise time synchronization technique over a SpaceWire network.

Fast and Scalable Path Re-routing Algorithm Using A Genetic Algorithm (유전자 알고리즘을 이용한 확장성 있고 빠른 경로 재탐색 알고리즘)

  • Lee, Jung-Kyu;Kim, Seon-Ho;Yang, Ji-Hoon
    • The KIPS Transactions:PartB
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    • v.18B no.3
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    • pp.157-164
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    • 2011
  • This paper presents a fast and scalable re-routing algorithm that adapts to dynamically changing networks. The proposed algorithm integrates Dijkstra's shortest path algorithm with the genetic algorithm. Dijkstra's algorithm is used to define the predecessor array that facilitates the initialization process of the genetic algorithm. After that, the genetic algorithm re-searches the optimal path through appropriate genetic operators under dynamic traffic situations. Experimental results demonstrate that the proposed algorithm produces routes with less traveling time and computational overhead than pure genetic algorithm-based approaches as well as the standard Dijkstra's algorithm for large-scale networks.