• Title/Summary/Keyword: PART

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미세성형품의 정밀 냉간단조시 치수변화 분석 (Dimensional change of micro forged part on precision cold forging)

  • 이명원;이영선;이정환
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2008년도 추계학술대회 논문집
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    • pp.254-258
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    • 2008
  • Dimensional accuracy is very important quality in micro forged part, especially on forged part. Dimension of forged part is changed continuously during forging process. Loading, unloading and ejecting stage affects dimensional of the forged tool. The elasto-plastic material model for billet and elastic model for die were used to analyze these changes. At same time, the calculated results were compared and analyzed by the experiment on same conditions. From the experimental and analytical studies, we can calculated the amount of difference between die and forged part, that is 0.49% based on the die dimension. The dimensional change is smaller than that of general sized-forged part,0.6%.

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하천수 열원 2단 압축 열펌프시스템의 부분부하 운전특성에 관한 실험적 연구 (An Experimental Study on the Part-Load Performance of a River Water Source 2-Stage Heat Pump)

  • 김지영;백영진;이영수;나호상
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.1964-1968
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    • 2007
  • The river water heat source heat pump has the advantage in the performance compared to air source heat pump. Although its better performance, the large temperature difference between load and source makes system performance worse by nature. In this study, 2-stage compression is considered as the solution of this problem. Generally, heat pump is designed for maximum capacity rate, but it actually operates at part load condition in many cases. Therefore, an information on the part-load character is very important in view of the system overall performance. In this study, part-load performance tests of a R134a 2-stage compression heat pump were carried out over the river water and supply heating water temperature changes. The experimental results show that the system performance is influenced by the part load rates, river water temperature, load temperature, etc.

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Insert Tip용 End Mill Body의 5-축 가공에 관한 연구. (A Study on the 5-Axis Machining of End Mill Body with Insert Tip)

  • 조현덕;박영원
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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    • pp.399-406
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    • 2001
  • This study describes the geometric characteristic and the 5-axis machining method of end mill body with insert tip. The geometry of end mill body is consisted of the flute part and the insert tip part. Thus, this study defines the flute part as ruled surface with constant helix angle and the insert tip part as rectangular plane on general direction. The geometric algorithm and the 5-axis NC part program were calculated by our programmed software and a sampled end mill body was machined on 5-axis machining center equipped with two index tables. The machined end mill body with insert tip was very agreeable to the designed end mill body with insert tip. Thus, the method proposed in this study may be very useful for the machining of end mill body with insert tip.

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푸드 코디네이터의 직무에 관한 기초 연구 (A Study on Job Characteristics of Foodcoordinator)

  • 황재선;주나미;한영실
    • 한국식생활문화학회지
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    • 제19권6호
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    • pp.611-619
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    • 2004
  • This study was conducted to investigate the job characteristics of foodcoordinator. 34.56% of subjects have the part of food as a speciality in college or University. 50.67% of subjects don't have any licence which is related with food. 30.67% of subjects have 1-3year or under career in the food part. Upon investigation the educational period by the period of career in food part, Subjects who had 5 year over career in the food part have 60.34month educational period. Upon investigation the speciality in college or University by the period of career in food part, 58.33% of 5 year over career in the food part respondents have food speciality in college or University. As the period of career in food was increased, the importance of cooking was increased.

한국어에 적합한 효율적인 품사 태깅 (An Efficient Korean Part-of-Speech Tagging)

  • 김영훈
    • 한국콘텐츠학회논문지
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    • 제2권2호
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    • pp.98-102
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    • 2002
  • 본 논문에서는 형태소 분석 단계에서 발생하는 형태소 모호성을 줄이기 위해서 말뭉치를 이용한 형태소 태깅을 구현한 시스템이다. 형태소 태깅을 위한 말뭉치가 대량의 것이 아니라도 효율적인 품사 분류와 태깅 알고리즘을 가지고 올바르고 효율적인 태깅을 할 수 있도록 하였다. 어절의 올바른 품사 태깅을 위해서 어절들 간의 인접도가 아니라 품사들 간의 인접도, 그리고 품사간의 제약 정보를 추가한 품사의 태깅에 이용을 하였다. 이와 같이 함으로 효율적인 시스템을 구현할 수 있었다.

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자금제약하에서 동류전용이 허용될 때 수리가능한 동시조달부품의 적정소요량 결정 (Provisioning Quantity Determination of Repairable Concurrent Spare Part under Budget Constraint and Cannibalization Allowed)

  • 오근태;나윤균
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제12권3호
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    • pp.225-238
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    • 2012
  • In this paper determined is the quantity of repairable concurrent spare parts(CSP) of a new equipment system to maximize the operational availability under budget constraint and cannibalization allowed. When a part fails, the part is replaced and the failed part is repaired for later use while cannibalization is allowed. The failure of a part is assumed to follow a Poisson process and the availability in CSP is defined. The solution procedure consists of two parts. Firstly, a mathematical model is developed under the assumption that the failure rate is constant during the CSP period and cannibalization is not allowed. Secondly, proposed is a simulation search procedure which improves the heuristic solution to the near optimal solution in a reasonable amount of time under the assumption that the cannibalization is allowed.

Study molded part quality of plastic injection process by melt viscosity evaluation

  • Lin, Chung-Chih;Wu, Chieh-Liang
    • Advances in materials Research
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    • 제3권2호
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    • pp.91-103
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    • 2014
  • A study that demonstrates how to investigate the molded part quality and the consistency of injection process based on the rheological concept is proposed. It is important for plastic material whose melt viscosity is variable with respect to the processing condition. The formulations to couple the melt viscosity with injection pressure and fill time are derived first. Taking calculations of the measured pressure and the time by using these formulations, the melt viscosity in injection process can be determined on machine. As the relation between the injection speed and the melt viscosity is constructed, the influences of the setting parameter of injection machine on the molded part quality can be investigated through evaluating the state of the melt viscosity. In addition, a pressure sensor bushing (PSB) designed with a quick installation feature is also provided and validated. The results show that a higher injection speed improves the tensile strength of the molded part but also the consistency of the molded part quality. This work provides an alternative to evaluate the molding quality scientifically.

신경망 기반의 코골이 검출 알고리즘 개발에 관한 연구 (A Study for Snoring Detection Based Artificial Neural Network)

  • 장원규;조성필;이경중
    • 대한전기학회논문지:시스템및제어부문D
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    • 제51권7호
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    • pp.327-333
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    • 2002
  • In this study, we developed a snoring detection algorithm that detects snores automatically. It consists of preprocessing and snoring detection part. The preprocessing part is composed of a noise removal part using spectrum subtraction, and segmentation part, and computation part of temporal and spectral features. And the snoring detection part decides whether detected blocks are snores with BPNN(Back-Propagation Neural Network). BPNN with one hidden layer and one output layer, is trained with data of 7 subjects and tested with data of 11 subjects of total 18 subjects. The proposed algorithm showed a Sensitivity of 90.41% and a Predictive Positive Value of 84.95%.

Technology and Standardization in Telematics: Telematics Reference Model

  • Kim K. H.;Jang J. A.;Han E. Y.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.87-90
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    • 2004
  • Telematics is an emerging industrial field made up of the convergence of technologies. The key technologies for Telematics are server-side technology, terminal-side technology, communication-related technology, and positioning technology. Standardization in Telematics is now getting more notice these days. Domestic situation is explained for several related facilities such as ETRI, TTA, and Telematics Standardization Forum. In this paper, we will focus especially on the standard reference model that is the most fundamental framework of Telematics technology standardization. In the reference model, the Telematics system is composed of Telematics client part, communication part, and Telematics server part. The Telematics client part consists of terminal, positioning device, and car electronic devices. Communication part can be composed of various telecommunication channels such as CDMA, WLAN, DMB, WiBro, etc. which can guarantee the seamless two-way communication. Telematics server part is composed of TSP(Telematics Service Provider) server and CP(Contents Provider) servers gathering and managing the various Telematics services. This Telematics reference model is expected to be utilized as the base architecture in developing the technology and standards from now on.

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