• 제목/요약/키워드: part master

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Perceptions and Use of Open Access Journals by Nigerian Postgraduate Students

  • Ayeni, Philips Oluwaseun
    • Journal of Information Science Theory and Practice
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    • 제5권1호
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    • pp.26-46
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    • 2017
  • This article investigates perceptions and use of Open Access journals (OAJs) by master's degree students in two universities in the southwestern part of Nigeria. A descriptive survey design was used in the study and the study population was comprised of 7,423 master's degree students in the University of Ibadan and 1,867 from Obafemi Awolowo University. A multistage random sampling technique was used to select a sample size of 249 and the data collection instrument was a structured questionnaire. Data were analyzed using frequency counts, percentages, mean, standard deviation, correlation, and regression analyses. The findings revealed that OAJs were used for learning, dissertation writing, personal research, and development. OAJs were not frequently used because of download delays, unavailability of Internet facilities, and limited access to computers terminals, among other issues. OAJs were found to be of relative advantage, positively perceived, and found to be compatible with existing values and quality assurance in scholarly publications, hence their use for academic activities. The regression analyses showed that there was a significant positive relationship between positive perception, perception of relative advantage, perception of compatibility, perception complexity, and master's degree students' use of OAJs. Negative perception was found to have a significant negative correlation with the use of OAJs. This article recommends that quality assurance of OAJs should be ensured in order to boost users' positive perceptions to increase their patronage and usage of these scholarly outlets for various academic activities, which will in turn encourage research and development across the various institutions of higher learning in Nigeria.

프록시를 이용한 NoC의 병목현상 해소 방법 (Method for NoC Bottleneck Relaxation Using Proxy)

  • 김규철;권태환
    • 정보처리학회논문지A
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    • 제18A권1호
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    • pp.25-32
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    • 2011
  • 최근, 공유버스 구조의 한계를 극복하기 위하여 NoC가 활발하게 연구되고 있다. 본 논문에서는 NoC 구조의 통신 효율을 향상시키기 위해, 컴퓨터 네트워크의 프록시 서버와 유사한 역할을 하는 버퍼를 사용한 NoC 구조를 제안한다. 제안된 NoC 구조에서 매스터가 슬레이브와 직접 통신하기 어려울 때마다 매스터를 대신하여 슬레이브와 통신할 수 있는 프록시 서버와 통신한다. NoC에서 제안된 방식을 사용하면 통신 채널의 속도를 높이고 대역폭을 늘릴 수 있다. 실험 결과로부터, 패킷을 스위치 버퍼에 머무르게 하지 않고 프록시 서버에 보냄으로써 전반적인 통신효율이 크게 향상됨을 확인하였다.

ThermoJet 3D 프린터로 직접 제작한 패턴과 세라믹쉘 주조법을 이용한 기능성 시제품의 쾌속제작 (Rapid Tooling Technology for Producing Functional Prototypes using Ceramic Shell Investment Casting and Patterns Produced Directly from ThermoJet 3D Printer)

  • 김호찬;이석;이석희
    • 한국정밀공학회지
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    • 제23권8호
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    • pp.203-210
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    • 2006
  • This paper focuses on the development of RT technology suitable for manufacturing a small quantity of metal prototype of a precise part from an RP master. Dimensional accuracy and surface roughness are evaluated from Thermojet part of a 3D printer, and effective post-processing method is introduced. Investment casting is done using a prototype built from 3D printer as a wax pattern. Ceramic shell investment casting technique is developed to build a prototype with materials mostly wanted. Also, experimental result shows this research is very useful in manufacturing of a small quantity of functional part or a test part of a specific material.

급속광조형 마스터 모델을 이용한 제품 및 간이 금형 제작 (Fabrication of Mold and Part by Using SLA Master Models)

  • 박문선;김대환;강범수
    • 한국정밀공학회지
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    • 제16권12호
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    • pp.7-13
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    • 1999
  • The potential for growth and the future impact of Rapid Prototyping that it will have on the product development cycle are enormous. Since making tools, precedes making parts, Rapid Tooling becomes widely used in automobile, aerospace, electronic, and other industries. In this study, master models formed by Rapid Prototyping of Stereolithography have been applied for vacuum casting to obtain silicone patterns which have transformed into epoxy models. The epoxy models have been measured to check dimension errors, and tested their functions. These checking and measurement have provided information on plastic injection possibilities and data for die design, Temporary die making with the materials of Aluminum/Epoxy and powder injection metal (PIM) has also been discussed in terms of hardness, surface roughness, and SEM microstructures.

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철도운행선의 생활소음 저감방안 연구 (A Study for the Reduction of Railway Noise)

  • 한두섭;김희만;이상배;이진호;강성해
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 춘계학술대회논문집
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    • pp.673-676
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    • 2007
  • These days, the damage of noise has increased seriously by rapid change of life style because of the centralization of urban population, and the rapid increase of traffic. The Ministry of Environment has emphasis on the systematic management about the noise of daily life and the close connection of daily noise management policy with relevant ministries, and put into practice "the master plan of lessening the noise of daily life" from year 2006. This study tried to find out the reduction methods and the effective management of railway noise in the action plan of railway part of "the master plan of lessening the noise of daily life". According to this study, railway noise can be reduced greatly by taking action of railway detail plans. The cause of railway noise varies by rolling stock, track and more, so the reduction methods of railway noise can be studied specially, scientifically and constantly in every field.

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미얀마 장기 계통계획 수립 결과 및 전망 (Master Plan for Long-term Transmission System in Myanmar)

  • 허연;김종화;한경남;최영성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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    • pp.9-11
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    • 2005
  • kEPCO is now conducting a project called the "Feasibility Study & Basic Designs for the 500kV Transmission System in Myanmar" as its second overseas project following the "Development Study on the rover System Network Analysis in Myanmar" performed from 2001 to 2002. As a part of this project, this paper deals with the analysis process and results of the demand forecasts, master plan for transmission system expansion, and the major factors for the new 500kV transmission facilities.

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Development of Force Reflecting Joystick for Field Robot

  • Song, In-Sung;Ahn, Kyung-Kwan;Yang, Soon-Yong;Lee, Byung-Ryong
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.132.5-132
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    • 2001
  • In teleoperation field robotic system such as hydraulically actuated robotic excavator, the maneuverability and convenience is the most important part in the operation of robotic excavator. Particularly the force information is important in dealing with digging and leveling operation in the teleoperated excavator. Excavators are also subject to a wide variation of soil-tool interaction forces. This paper presents a new force reflecting joystick in a velocity-force type bilateral teleoperation system. The master system is electrical joystick and the slave system is hydraulically actuated cylinder with linear position sensor. Particularly Pneumatic motor is used newly in the master joystick for force reflection and the information of the pressure of salve cylinder is measured and utilized as the force feedback signal. Also force-reflection gain greatly affects the ...

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분자계의 Overlap Integral의 계산의 Spherical Harmonics 전개방법의 응용 (Application of the Expansion Method for Spherical Harmonics for Computation of Overlap Integrals in Molecular System)

  • 안상운
    • 대한화학회지
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    • 제22권3호
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    • pp.117-127
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    • 1978
  • 두점 A와 B에 위치한 Slater원자궤도함수의 spherical harmonics부와 지름부를 기준점 A를 중심으로 전개하여 공통좌표상에 기술하였다. 이 Slater 원자궤도함수의 전개식을 사용하여 two center overlap integral의 기본식을 유도하였으며 이 기본식을 이용하여 $CH_4,\;H_2O,\;NH_3,\;C_2H_6$$PH_3$ 분자의 two center overlap integral을 계산하였을 때 이 값이 Mulliken의 값과 일치하였다.

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공장 자동화 응용을 위한 Satellite Processor System 연구 (A Study on Satellite Processor System for Factory Automation)

  • 김종진;박찬익
    • 대한전자공학회논문지
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    • 제22권5호
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    • pp.39-44
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    • 1985
  • 본 논문에서는 공장 자동화 분야에 견합한 컴퓨터 시스템에 관하여 연구하였구 기초적인 satellite pro-cessor 시스템을 구성하였다. 전체 시스템은 하나의 운영체제에 의하여 제어되어 계층적 구조를 가진다. 기존의 UN상 시스템과 완전 호환성을 가지도록 하기 위하여 UNIX 운영체제를 수정 보완한 SPUNIX 운영체제를 구성하였다. 또한 응용 동작에 근접하는 동작을 하게 하기 위하여 특별한 프로그램 이것을 co-process라 부르기로 한다-과 이 co-process와 상호 협력하여 전체 동작을 형성하는 satellite pro-cessor kernel 등이 구성되었다. 많은 수의 satellite Processor가 대재하기 때문에 신뢰도, 확장성, 동시성(concurrence) 등의 특성이 나타난다.

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조립지향적 제품설계지원 전문가시스템의 개발 (Development of Expert System for Supporting Assembly-Oriented Product Design)

  • 조규갑;하재우;차동균
    • 산업공학
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    • 제6권2호
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    • pp.19-35
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    • 1993
  • This paper presents the development of a knowledge-based expert system to assist for designer in the process of designing products for easier assembly. The developed expert system for supporting assembly-oriented product design, which is named as DFA-MASTER, consists of two subsystems such as "Assembly Method Selection System" which provides feasible assembly methods to designer and "DFA-Analysis System" which provides guidelines to improve assemblability of products in the early stage of product design. The developed system is interfaced with AutoCAD system and can be run under PC environments. By using DFA-MASTER, designer can obtain feasible assembly methods which have high assemblability under the given asssembly conditions and also evaluate the assemblability of part feature or product structure.

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