• 제목/요약/키워드: end

검색결과 26,957건 처리시간 0.076초

필렛 엔드밀을 이용한 자유곡면 황삭가공 시간단축 (Machining Time Reduction in Rough Machining of Sculptured Surface using Filleted End Mill)

  • 신동혁;김종일;김병희;주종남
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.15-19
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    • 1996
  • The cusp height in ball end milling, flat end milling and filleted end milling according to various surface inclination angle was calculated. The calculation result shows that, for each kind of tools, there exists certain range of inclination angle in which cusp height characteristics favorable. From machining time calculation, filleted end mill found to be superior to flat end mill in rough machining of sculptured surface.

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최종이용자 온라인 탐색 (End User Online Searching)

  • 장우권
    • 한국정보관리학회:학술대회논문집
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    • 한국정보관리학회 1995년도 제2회 학술대회 논문집
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    • pp.45-48
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    • 1995
  • Since the early 1970s online searching has provided end-users with commercial and governmental bibliographic databases by trained intermediaries through the developed Vendor/Agency Systems. Recently, the situation has begun to change. The era of end-user searching is coming. End Users are the “information consumers” as the final user of an IT product or set of information. This study on end-user online searching is presented with the following aspects: development, characterization, training, end user online search services in university libraries, role of the intermediaries and librarians, the future.

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대면적 고분자전해질 연료전지의 데드엔드 운전 (Dead-end Mode Operation of a Large Scale PEM Fuel Cell Stack)

  • 정지훈;신현길;한인수;서하규;김민성;조성백;허태욱
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 추계학술대회 초록집
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    • pp.83.1-83.1
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    • 2010
  • A Dead-end mode operation is one of the best way to maximize the gas usage rate. But, some components of fuel cell stack like gas diffusion layer(GDL) or membrane can be damaged in dead-end mode operation. In this study, a Large Scale Polymer electrolyte membrane fuel cell(PEMFC) for a dead-end operation has been developed. The stack is composed with 4 cells which has over 400cm2 of active area. Hydrogen is used as a fuel, and oxygen is used as a oxidant. The dead-end operation performance was evaluated by a long-term dead-end mode operation. The fuel cell stack is operated over 1,500 hours in dead-end mode operating fuel cell test station. And the performance change of the fuel cell stack was investigated.

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Distributed Routing Based on Minimum End-to-End Delay for OFDMA Backhaul Mobile Mesh Networks

  • Chung, Jong-Moon;Lee, Daeyoung;Park, Jong-Hong;Lim, Kwangjae;Kim, HyunJae;Kwon, Dong-Seung
    • ETRI Journal
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    • 제35권3호
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    • pp.406-413
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    • 2013
  • In this paper, an orthogonal frequency division multiple access (OFDMA)-based minimum end-to-end delay (MED) distributed routing scheme for mobile backhaul wireless mesh networks is proposed. The proposed scheme selects routing paths based on OFDMA subcarrier synchronization control, subcarrier availability, and delay. In the proposed scheme, OFDMA is used to transmit frames between mesh routers using type-I hybrid automatic repeat request over multipath Rayleigh fading channels. Compared with other distributed routing algorithms, such as most forward within radius R, farthest neighbor routing, nearest neighbor routing, and nearest with forwarding progress, simulation results show that the proposed MED routing can reduce end-to-end delay and support highly reliable routing using only local information of neighbor nodes.

Hybrid Code Network를 이용한 한국어 식당 예약 시스템 모델 (Korean Restaurant Reservation System Model Using Hybrid Code Network)

  • 이동엽;허윤아;임희석
    • 한국컴퓨터교육학회 학술대회
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    • 한국컴퓨터교육학회 2017년도 하계학술대회
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    • pp.57-59
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    • 2017
  • 대화 시스템(dialogue system)은 텍스트나 음성을 통해 다양한 분야에서 특정한 목적을 수행할 수 있는 시스템이다. 대화 시스템을 구현하기 위한 방법으로 인공 신경망(neural network)을 기반으로한 end-to-end learning 방식이 제안되었다. End-to-end learning 방식을 이용한 식당 예약 시스템 모델의 학습을 위해 페이스북은 영어로 이루어진 식당 예약에 관련된 학습 대화 데이터셋(The 6 dialog bAbI tasks)을 구축하였다. 하지만 end-to-end learning 방식의 학습은 많은 학습 데이터가 필요하다는 단점이 존재하는데, 액션 템플릿(action template)의 정의를 통해 도메인 지식을 표현함으로써 일반적인 end-to-end learning 방식보다 적은 학습량으로 좋은 성능의 모델을 학습할 수 있는 Hybrid Code Network 구조를 제안한 연구가 있다. 본 논문에서는 Hybrid Code Network 구조를 이용하여 한국어 식당 예약 시스템을 구축할 수 있는 방법을 제안하고, 한국어로 이루어진 식당 예약에 관련한 학습 대화 데이터를 구축하는 방법을 제안한다.

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End-Fire 방사특성을 가지는 2.4GHz ISM 밴드용 Open End 슬롯 안테나의 설계

  • 조윤기;권기환;윤정호;임성균;이영순
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2010년도 춘계학술대회
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    • pp.154-155
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    • 2010
  • 본 논문에서는 end-fire 방사패턴 특성을 가지는 2.4GHz ISM 밴드용 소형 open-end slot 안테나를 설계하였다. 안테나 설계 공간은 $23mm{\times}15mm$의 좁은 영역으로 한정된 공간 내에 안테나를 설계하기 위하여 한번의 Bent된 slot을 도입하였고, End-Fire 방사특성을 내기위해 안테나 수평면상의 위쪽 방향으로 slot을 open시킨 구조이다. Bent된 slot을 이용해 전체 slot의 길이를 변화시키지 않고 주파수의 조절이 가능하고, Feeding Line의 길이와 폭을 조절하여 보다 광대역의 특성을 얻을 수 있었다. 제작된 안테나의 공진 주파수는 2.46GHz이고 대역폭은 2.4GHz~2.61GHz 까지 약 210MHz(VSWR<2) 이다. 방사패턴은 동작 주파수 내에서 slot이 open된 방향으로 end-fire특성을 가지고, 안테나의 이득과 효율은 각 각 1dBi, 70% 이상의 성능을 가진다. 설계 결과의 검증을 위해 모의실험 결과와 측정 결과를 비교하여 제시하였다.

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과업의 불확실성이 최종사용자컴퓨팅 특성과 최종사용자의 만족도에 미치는 영향

  • 김창기;이진주
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 1993년도 춘계공동학술대회 발표논문 및 초록집; 계명대학교, 대구; 30 Apr.-1 May 1993
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    • pp.329-338
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    • 1993
  • The main objective of this paper is analyzing the effects of task uncertainty on EUC characteristics and end user satisfaction. Task uncertainty were identified as an important determinant of EUC characteristics. And the moderating effect of task uncertainty on the relationship between EUC characteristics and end user satisfaction was suggested. A field study was undertaken to test the hypothesized relationships among task uncertainty, EUC characteristics, and end user satisfaction Data were collected from 138 end-user of 19 Korean business organizations. The empirical results indicated that task uncertainty was significantly related to EUC characteristics and that task uncertainty had significant effect on the relationship between EUC characteristics and end user satisfaction. Implications and future research directions are drawn for the management of EUC and for further research on EUC.

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Development of 3D CAM system for End mills manufacturing

  • Trung-Thanh Pham;Ko, Sung-Lim;Kim, Yong-Hyun
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.850-853
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    • 2004
  • The development of 3D CAM system for the manufacturing of end mills becomes a key approach to save the time and reduce cost for end mills manufacturing. This paper presents the calculation and simulation of end mill tools CNC machining bases on 5-axes CNC grinding machine tool. In this study describes the process of generation and simulation of grinding point data between the tool and the grinding wheels through the machined time. Depend on input data of end mill geometry, wheels geometry, wheel setting, machine setting the end mill configuration and NC code for machining will be generated and visualized in 3 dimension before machining. The 3D visualizations of end mill manufacturing was generated by using OpenGL in C++. The development software was designed by using Microsoft Visual C++, which has many advantages for users, saving time and reducing manufacturing cost.

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상수 서비스 시간을 갖는 개방형 대기행렬의 종대종 지연과 윈도우 구조의 영향 분석 (An Impact Analysis of Window Mechanism and End to End Delay of Tandem Queueing Network with Constant Service Times)

  • 이영
    • 한국경영과학회지
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    • 제29권3호
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    • pp.99-109
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    • 2004
  • In this paper, we investigate the impact of window mechanisms on end to end delay in a series of nodes with constant service times. It is shown that arbitrary combinations of window mechanisms, each applying to an arbitrary subset of data, can be embedded on the nodes without affecting the departure instants from the system if the windows are at least as large as the number of nodes spanned. The window mechanisms are shown to have no impact on the average end to end delay of data. As the condition on the windows is a minimal necessary requirement for full parallelism, the results show that the transparent operation from viewpoint of data transmission can be achieved with minimal resources.

Flow Dynamics Near End-to-End Anastomoses Part II. Computer Flow Simulation

  • Kim, Y.H.
    • 대한의용생체공학회:의공학회지
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    • 제13권4호
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    • pp.313-322
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    • 1992
  • A finite analytic(FA) numerical study was performed to determin'e flow dynamics in the vicinity of an end-to-end anastomosis. Experimental data of instantaneous lumen cross-section were used to simulate steady flow through an end-to-end anastomosis In order to solve the governing axisymmetric Wavier-Stokes equations. Wall shear stresses increased proximal to the anastomosis In flow from the Penrose tubing to the PTFE graft. In flow the PTFE graft to the Penrose tubing, low wall shear stresses were observed distal to the anastomosis. The present study suggests a correlation betweerl regions of low wall shear stress and the do velopment of pnastomotic neointimal fibrous hyperplasia(ANFH ) in end-to-end anastomoses.

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