• Title/Summary/Keyword: essential component

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FTA(Falut tree Analysis)기법을 이용한 이송용 로울러베어링 고장 진단

  • 배용환;이석희;이형국;최진원
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1992.10a
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    • pp.325-329
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    • 1992
  • The development of automatic production system have required intelligent diagnostic and monitoring function to repair system failure and reduce production loss by the failure. In order to perform accurate functions of intelligent system, inference about total system failure and fault analysis due to each mechanical component failures are required. Also the solution about repair and maintenance can be suggested from these analysis results. Generally, bearing is a essential mechanical component in the machinery. The bearing failure is caused by lubricant system failure, metallurgical defficiency, mechanical condition(vibration overloading misalignment), environmental effect. This study described roller bearing fault train due to stress variation and metallurgical defficiency from lubricant failure by using FTA.

Hand Region Segmentation and Tracking Based on Hue Image (Hue 영상을 기반한 손 영역 검출 및 추적)

  • 권화중;이준호
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.1003-1006
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    • 1999
  • Hand segmentation and tracking is essential to the development of a hand gesture recognition system. This research features segementation and tracking of hand regions based the hue component of color. We propose a method that employs HSI color model, and segments and tracks hand regions using the hue component of color alone. In order to track the segmented hand regions, we only apply Kalman filter to a region of interest represented by a rectangle region. Initial experimental results show that the system accurately segments and tracks hand regions although it only uses the hue compoent of color. The system yields near real time throghput of 8 frames per second on a Pentium II 233MHz PC.

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A Numerical Study on the Effectiveness Factor of Ni Catalyst Pellets for Steam-Methane Reforming (수증기-메탄개질용 Ni 촉매의 유용도에 관한 수치적 연구)

  • Choi, Chong-Gun;Nam, Jin-Hyun;Shin, Dong-Hoon;Jung, Tae-Yong;Kim, Young-Gyu
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.11a
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    • pp.63-66
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    • 2007
  • Reformers which produce hydrogen from natural gas are essential for the operation of residential PEM fuel cells. For this purpose, steam-methane reforming reactions with Ni catalysts is primarily utilized. Commercial Ni catalysts are generally made to have porous pellet shapes in which Ni catalyst particles are uniformly dispersed over Alumina support structures. This study numerically investigates the reduction of catalyst effectiveness due to the mass transport resistances posed by porous structures of spherical catalyst pellets. The multi-component diffusion through porous media and the accurate kinetics of reforming reaction is fully considered in the numerical model. The preliminary results on the variation of the effectiveness factor according to different operation conditions are presented, which is planned to be used to develop correlations in future studies.

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Fault diagnosis of walking beam roller bearing by FTA (FTA(Fault Tree Analysis)기법을 이용한 이송용 대부하 베어링 고장 진단)

  • Bae, Y.H.;Lee, H.K.;Lee, S.J.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.5
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    • pp.110-123
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    • 1994
  • The development of automatic production systems have required inteligent diagnostic and monitoring function to repair system failure and reduce production loss by the failure. In order to perform accurate functions of intelligent system, inferencing about total system failure and fault analysis due to each mechanical component failures are required. Also the solution about repair and maintenance can be suggested from these analysis results. As an essential component of mechanical system, a bearing system is investigated to define the failure behavior. The bearing failure is caused by lubricant system failure, metallurgical defficiency, mechanical condition(vibration, overloading, misalignment) and environmental effect. This study described roller bearing fault train due to stress variation and metallurgical defficiency from lubricant failure by using FTA.

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Apoptosis in Cancer - An Update

  • Sankari, S. Leena;Masthan, K.M.K.;Babu, N. Aravindha;Bhattacharjee, Tathagata;Elumalai, M.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.10
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    • pp.4873-4878
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    • 2012
  • Apoptosis is programmed cell death which is essential for development and survival of living organisms. It is a sequentially regulated suicidal programme where cells activate certain enzymes which dissolute their own nuclear component and various protein component of nucleus and cytoplasm. Disturbance of this regulatory pathway may lead to various diseases like autoimmune diseases, neurodegenerative diseases and cancers. The potential mechanisms of apoptosis and its role in cancer are discussed. The ability of apoptosis to modulate the life or death of a cell is also recognized for its immense therapeutic potential. Understanding the mechanisms from this review will give us better insight to the pathogenesis of various diseases including cancer and will open new horizons to therapeutic approaches.

FBW System and Operational Flight Program Development for Small Aircraft (소형항공기를 위한 FBW 시스템과 비행운영 프로그램 개발)

  • Lee, Seung-Hyun;Kim, Eung Tai;Seong, Kiejeong
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.21 no.1
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    • pp.1-7
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    • 2013
  • To have the competitiveness in the future worldwide small aircraft market, we should be able to develop the aircraft which is highly safe, easy to fly, and having excellent flight characteristics. FBW(Fly-By Wire) system is essential for the enhancement of flight safety and control easiness. FBW system that has been applied only to the modern fighter and transport aircraft is recently applied to smaller aircraft such as regional aircraft, business aircraft and even small aircraft. The purpose of this research includes the development of flight control computer, the definition of FBW system component, the design concept of each component for redundant management, OFP(Operational Flight Program) development, FBW system integration and HILS(Hardware In-the Loop Simulation) verification environment to test this FBW system.

Reliability Analysis of Slab Transfer Equipment in Hot Rolling Furnace (열간압연 가열로 슬라브 이송장치 신뢰도 해석)

  • Bae, Young-Hwan
    • Journal of the Korean Society of Safety
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    • v.21 no.1 s.73
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    • pp.6-14
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    • 2006
  • The development of automatic production systems have required intelligent diagnostic and monitoring functions to overcome system failure and reduce production loss by the failure. In order to perform accurate operations of the intelligent system, implication about total system failure and fault analysis due to each mechanical component failures are required. Also solutions for repair and maintenance can be suggested from these analysis results. As an essential component of a mechanical system, a bearing system is investigated to define the failure behavior. The bearing failure is caused by lubricant system failure, metallurgical deficiency, mechanical condition(vibration, overloading, misalignment) and environmental effects. This study described slab transfer equipment fault train due to stress variation and metallurgical deficiency from lubricant failure by using FTA.

Comparative Chemical Composition of Domestic and Imported Chrysanthemum indicum L. Flower Oils

  • Chang, Kyung-Mi;Kim, Gun-Hee
    • Food Science and Biotechnology
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    • v.18 no.5
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    • pp.1288-1292
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    • 2009
  • Volatile flavor compounds were isolated from the flowers of Chrysanthemum indicum L. (gamguk) produced in Korea and China by the hydro distillation, and were analyzed by gas chromatography-mass spectrometry (GC/MS). The yield of oils from Korean and Chinese gamguk were 2.0 and 0.5%(v/w), respectively. Sixty-three volatile compounds of Korean gamguk representing 89.28% of the total peak area were tentatively identified, including 35 hydrocarbons, 12 alcohols, 6 ketones, 3 esters, 5 aldehydes, 1 oxide, and 1 miscellaneous component. Thirty-six volatile components of Chinese gamguk constituted 58.15% of the total volatile composition were tentatively characterized, consisting of 19 hydrocarbons, 7 alcohols, 2 ketones, 2 esters, 4 aldehydes, 1 oxide, and 1 miscellaneous component. The predominant components of Korean oil were ${\alpha}$-pinene, 1,8-cineol, and chrysanthenone. Whereas, camphor, ${\alpha}$-curcumene, and ${\beta}$-sesquiphellandrene were the main aroma compounds of Chinese gamguk.

A custom building deterioration model

  • Hosny, O.A.;Elhakeem, A.A.;Hegazy, T.
    • Structural Engineering and Mechanics
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    • v.37 no.6
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    • pp.685-691
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    • 2011
  • Developing accurate prediction models for deterioration behavior represents a challenging but essential task in comprehensive Infrastructure Management Systems. The challenge may be a result of the lack of historical data, impact of unforeseen parameters, and/or the past repair/maintenance practices. These realities contribute heavily to the noticeable variability in deterioration behavior even among similar components. This paper introduces a novel approach to predict the deterioration of any infrastructure component. The approach is general as it fits any component, however the prediction is custom for a specific item to consider the inherent impacts of expected and unexpected parameters that affect its unique deterioration behavior.

Delays and its Analysis: Indian Residential Construction Projects

  • Metha, Rakesh L.;Gaikwad, Suraj V.
    • Journal of Construction Engineering and Project Management
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    • v.7 no.4
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    • pp.20-28
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    • 2017
  • In almost every construction project, delay is an inevitable yet controllable phenomenon. The Indian construction industry encounters an enormous amount of delays in projects. Delay affects both time and money in the forms of schedule and cost overruns, respectively. Due to impressive and dynamic growth in the Indian construction sector, planned efforts are essential to limit these undesirable delays. On account of the surge in the rate of residential building construction, the task of identification and analysis of the delays in residential projects in India has been attempted by the authors. A questionnaire survey was conducted involving 100 stakeholders. Further analysis included an Importance Index to rank the identified delays, Principle Component Analysis for advanced statistical analysis, and Correlation Analysis to check the extent of agreement amongst stakeholders. Conclusions drawn with reference to the analysed data eventually reflected finance-related issues, as well as labour related problems as the dominating causes of delays. The aim of the research is to provide insight to the construction stakeholders and researchers, on an international scale, with the obtained results.