• 제목/요약/키워드: point-contact

검색결과 1,218건 처리시간 0.21초

치과용 다이아몬드 버의 연삭 가공 특성 (Grinding Characteristic of Diamond Burs in Dentistry)

  • 이근상
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 춘계학술대회 논문집
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    • pp.414-418
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    • 1996
  • This paper aims at reviewing the possibility application over normal or abnormal, detection used by AE and the characteristics of grinding process. In this study, when diamond bur in dentistry with chosen grinding conditions were tuned at grinding. The variation of grinding resistance and AE signal is detected by the use of AE measuring system. The tests are carried out in accordance with diamond burs and workpiece: arcyl and cowteeth. According to the experiment results, the following can be expected; AE has the possibility to detect the state normality and abnormality. However, the grinding resistance measuring can find it difficult to detect it. It can be accurately excepted from AE occurrence pattern in contact start point of diamond but and cowteeth, grinding condition and derailment point. It is known that AErms is well compatible with grinding resistance.

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한국형 고속전철(KTX) 방사패턴에 관한 연구 (A study on patterns of propagation for high speed train(KTX))

  • 구동회;김재철;박태원;문경호
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 춘계학술대회논문집
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    • pp.836-842
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    • 2001
  • The more sophisticated patterns of propagation model is presented in this paper, which includes three different source characteristics. The spherical, cosine and dipole radiation characteristics compared and sound event level and the maximum sound level are calculated by experiment and calculation. It is shown that patterns of propagation has dipole characteristics for low speed range(below about 150km/h) at electric multiple system. We know that push-pull high speed system(maximum speed: 300km/h) has cosine characteristics of noise propagation. For this purpose, We conduct the experiment of noise and know the empirical formula of noise level and radiation coefficient K. This model of simulation is conducted through point source array model at wheel/rail contact point by using program and experimental formula. We can guess prediction of profile, flat and wear of wheel by above modeling in near field.

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한복 변천에 관한 연구 - 1950년대 이후 여자 한복 중심(中心)으로 - (A Study on the Transition of Korean Clothes Since the 1950's)

  • 진미희
    • 복식
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    • 제15권
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    • pp.149-166
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    • 1990
  • Korean clothes is traditional folk costume native to Korea, Which is in Korea clothes. The past Korean costume was developed in the native costume, together influenced by chinese costume. But in the late Yi dynasty the contact with western countries brought about a turning point in Korean costume history, with rapid growth of economy since Korean war in the 1950's, the magnification of industrial structure, the development of productive technique, transformation of consumption pattern and the development of communication have been increased concerns for the western costume. In 1953 the introduction of nylon which was imported from Japanese brought about a fuming point in clothing habits. In 1967 the development of the fiber industry got a firm stand in ready-made clothes. Consequently our traditional Korean clothes was regarded as nonfunctional, nonproductive and it was pushed out of daily life little by little and it was deprived of the function of ordinary costume by the influence of western costume. But in these days the Korean clothes appears as the desire of pursuing traditional style in addition to mordern style of Korean clothes.

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서비스 사이언스를 위한 서비스의 식별 (Service Identification for Service Science)

  • 이상준
    • 한국IT서비스학회지
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    • 제6권3호
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    • pp.209-224
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    • 2007
  • Currently, the world has experienced a mass exodus of workforce from the manufacturing industry to service related industry. In addition, the changes of industry structure toward service industry have been gradually accelerated. We have felt that it is time to conduct researches about IT service systematizing and discovering the essence of service itself with scientific and synthetic ways based on Service Science. For Service Science researchers, service identification is regarded as a difficult activity when they contact it for the first time and they want to apply it real environment. In reality, there exist mismatches between business and IT service to identify service since service is identified from the business point of view in Service Science area and it is identified from the technical point of view in IT service area. In this paper, we have conducted researches about service identification placed on the first priority and regarded as difficult area in service-oriented business area. To lessen aforementioned difficulties, we propose procedures and methods for extracting and identifying service in the viewpoint of business process. We conducted case study and comparison with existing researches to verify the applicability and the excellence of our proposal.

포텐셜 에너지를 이용한 5축 NC 밀링의 공구방향 결정 (Determination of Tool Orientation in 5-Axis Milling Using Potential Energy Method)

  • 조인행;이건우
    • 한국정밀공학회지
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    • 제13권6호
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    • pp.161-167
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    • 1996
  • In five-axis milling, optimal CL-data (cutter location data) should be generated to have advantages over three-axis milling in terms of accuracy and efficiency. This paper presents an algorithm for generating collision-free CL-data for five-axis milling using potential energy method. By virtually charging the cutter and part surfaces with static electricity, global collision as wells as local interference is eliminated. Additionally, machining efficiency is improved by minimizing the curvature difference between the part surface and tool swept surface at a CC-point (cutter contact point) simultaneously.

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PREDICTION OF SOUND RADIATION FROM TIRE TREADBAND VIBRATION

  • Kim, B.S.
    • International Journal of Automotive Technology
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    • 제2권1호
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    • pp.33-38
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    • 2001
  • The noise generated from a treadband mechanism of a tire has been the subject of this research. In particular, the treadband has been treated as an infinite tensioned beam resting on an elastic foundation which includes damping. The main objective is here to predict the sound power generated from a system mentioned above by locating harmonic point forces representing the excitation of treadband at the contact patch. It is possible to predict the sound power radiated from this structure by wavenumber transformation techniques. To find out the minimum radiated sound power, All parameters were varied. Thus this model can be used as a tire design guide for selecting parameters which produce the minimum noise radiation.

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무인선박의 항해시스템을 위한 항로계획 기법 (An Route Planning for the Navigation System of Autonomous vessel)

  • 조재희;지민수;김용기
    • 한국지능시스템학회논문지
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    • 제15권4호
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    • pp.418-424
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    • 2005
  • 선박의 안전 운항과 운항 경비의 절감을 위해 선박의 운항 자동화 및 지능화 기술이 요구된다. 선박의 자동화를 위해서는 GPS와 전자해도에 기반한 항해시스템의 항로 계획이 선행되어야 한다. 본 논문에서는 항해시스템의 자동화된 항로 계획을 위해 장애물의 접점 산출 기법과 이를 이용한 트리 생성 기법, 그리고 생성된 트리 구조를 기반으로 한 항로 산출 기법을 제안한다. 제안한 항로 산출 기법의 효율성 검증을 위해 최적화 관점에서 대표적 항로 계획 기법인 A*기법과 비교$\cdot$분석한다.

이동식 플래시 버트 용접의 효과 (The effect of Mobile Flash Butt Welding)

  • 김준식;이종수;이학규;이중권;이지하
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.793-799
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    • 2004
  • In track a third weakness point is joint part, turnout part, curve part. One of them joint part of rail have been known to the most weak point by loosen of joint bar and fish bolt due to impulse and vibration by wheel contact at times. In addition happen to deformation and failure at end of rail, failure and miniature of ballast gravel. Finally impact between wheel and rail become origin cause of a welded rail, noise and vibration. riding condition deterioration, besides track failure. In the present domestic, Thermite and Gas pressure weldings have been used to continuous welded rail(CWR), however stiffness and confidence in quality is lower than Flash butt welding method. FRW have the excellent capacity, however have a shortcoming large scale of machine and power equipment. Therefore we will introduce Mobile Flash Butt Welder can weld in track.

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평면형 차륜 형상을 가진 탈선계수 측정용 윤축의 하중시험 (Load test of wheel-set for derailment coefficient measurement that have plane style wheel plate)

  • 함영삼;홍재성
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.228-233
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    • 2004
  • A derailment coefficient of railway vehicle is as one of important element that estimate running safety. Derailment coefficient is ratio of lateral load/vertical load happens in contact point between wheel and rail. Lateral load increases, dangerous of derailment can rise. There are ground and vehicle to measurement method of these derailment coefficient. Method of ground is simple, but when vehicles passes data of a point, there is shortcoming that acquire locally. Curved surface style wheel shape that use so far among vehicle method in this research wishes to be not but describe about static load test of wheel-set for derailment coefficient measurement that have plane plate shape that manufacture separate way and correction result etc. to test.

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C-space 및 유효반경-맵을 이용한 5축 페이스 밀링의 공구자세 최적화에 관한 연구 (CL-data Optimization of 5-axis Face-milling Via C-space and Effective-radius Map)

  • 박정환;이정근
    • 한국CDE학회논문집
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    • 제7권1호
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    • pp.34-41
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    • 2002
  • Five-axis NC machining, in general, is utilized in fabricating impellers, turbine blades, marine propellers that can be machined more effectively rather than three-axis machining. There have been many researches concerning tool interference avoidance, optimization of tool orientation. The C-space or Configuration-space was originated from the robotics area, which depicts interference-free joint-values in motion planning. In the paper we propose an optimizing scheme by which the maximum effective-radius of a face-milling cutter can be achieved for each CC(cutter-contact) point. Also the concept of a C-space for a CC point, the effective-radius map for 5-axis face-milling, and some illustrative examples of marine propeller machining, are presented.