• Title/Summary/Keyword: Operating Limitations

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Establishment of Rotor Speed Operating Limitation for Medium Class Utility Rotorcraft (중형 기동 회전익기 로터회전수 제한 수립)

  • Park, Jonghoo
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.21 no.2
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    • pp.26-32
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    • 2013
  • The rotorcraft makes lift and control forces by the rotor thrust. At the development phase of the rotorcraft, the operational limitations have to be established. And it shall be demonstrated to operate the rotorcraft safely within the limitations. This paper introduces establishment and evaluation results of operational rotor speed limitations for the medium class utility rotorcraft. And it shows the follow-up activities after design changes of rotor speed indicators and aural warning systems for implementing the rotor speed limitations.

A Study on Optimal Electric Load Distribution and Generator Operating Mode Using Dynamic Programming (동적계획법을 이용한 발전기의 운전모드 및 최적부하 배분에 관한 연구)

  • H-H Yoo
    • Journal of Advanced Marine Engineering and Technology
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    • v.26 no.3
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    • pp.313-319
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    • 2002
  • Since the oil crisis in 1970, a great deal of effort has been made to develop automatic electric load sharing systems as a part of the efforts to save energy. A large scale electric generating system composes more than two generators whose characteristics may be different. When such a system is operated individually or in parallel, the lagrange multiplier's method has difficulty in achieving optimal load distribution because generators usually have the limitations of the operating range with inequality constraints. Therefore, a suitable operating mode of generators has to be decided according to the selection of the generators to meet electric power requirements at the minimum cost. In this study, a method which solves the optimal electric load distribution problem using the dynamic programming technique is proposed. This study also shows that the dynamic programming method has an advantage in dealing with the optimal load distribution problem under the limitations of the operating range with inequality constraints including generator operation mode. In this study, generator operating cost curve of second order equation by shop trial test results of diesel generators are used. The results indicate that the proposed method can be applied to the ship's electric generating system.

Characteristics of Performance Parameters of Dual Mode(Ramjet-Scramjet Combined) Engine Based on the Analysis of The Operating limitations (작동한계 관점에서의 이중모드(램제트-스크램제트 연합 작동)엔진의 성능 인자 특성)

  • Sung, Hong-Gye;Byun, Jong-Ryul
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2006.11a
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    • pp.393-396
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    • 2006
  • This paper presents the characteristics of the performance parameters of dual mode(ramjet-scramjet combined) engine, inlet and combustor for wide range of flight Mach number, resulted from the analysis of its operating limitations. The transitional-critical flight Mach number from ramjet to scramjet and the performance of two types of combustors, such as constant pressure- and constant area- combustor, are conceptually evaluated.

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Comparison of the Heat transport Limitations for Screen Mesh Wick and Sintered Metal Wick Heat Pipes by Theoretical Analysis (이론적 해석에 의한 스크린 메쉬윅과 소결윅 히트파이프의 열수송 한계 비교)

  • Kim Keun-Bae;Kim Yoo
    • Journal of Energy Engineering
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    • v.13 no.4
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    • pp.267-274
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    • 2004
  • Theoretical analysis for predicting the heat transport limitations of screen mesh wick and sintered wick heat pipes was performed. The heat pipe diameter was 8mm and water was used for working fluid. For the 250 mesh, each capillary pressures and heat transport limitations, thermal resistances were analyzed according to the operating temperatures, wick thicknesses and inclination angles, based on the effective capillary radius (r$\_$c/), porosity ($\varepsilon$) and permeability (K). The wick capillary limitation was increased as the operating temperature and the wick thickness were increased, and generally the sintered wick showed higher heat transport limitations than that of the screen wick. The thermal resistance of the screen wick was higher than that of the sintered wick and both thermal resistances were linearly increased as the wick thickness was increased.

Practical Limitations of Theoretical Acceptance Sampling (이론 샘플링 검사의 실무적 한계)

  • Choe, Seong-Un
    • Proceedings of the Safety Management and Science Conference
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    • 2011.11a
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    • pp.205-211
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    • 2011
  • The papaer reviews four theoretical acceptance sampling plans as OC(Operating Characteristics) curve based inspection, rectifying inspection, switching inspection, and continuous inspection. In addition, the study presents practical limitations of theoretical acceptance sampling by attribute and by variable. Finally, following research also recommends the sampling inspection based on production technology. However, the inspection method requires quality expertise with various experience and implicit knowledge of the field.

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INTERNATIONAL PROJECT MANAGEMENT OF SUZHOU SCIENCE AND CULTURAL ART CENTRE AND SUZHOU INTERNATIONAL EXPO CENTRE

  • Tan Wei Szu Jackson
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.19-29
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    • 2007
  • This paper shares our project management experience in the 2 large-scale projects in managing a diverse international project team of consultants and managing in a foreign land. The first part introduces the two projects, second part addresses management of the projects and the last portion presents some of the challenges we experienced and highlights the importance of understanding the peculiarities of the operating environment, their norms, cultures, effectiveness and limitations of conventional project management tools while operating in a foreign country.

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Efficient Implementing of DNA Computing-inspired Pattern Classifier Using GPU (GPU를 이용한 DNA 컴퓨팅 기반 패턴 분류기의 효율적 구현)

  • Choi, Sun-Wook;Lee, Chong-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.7
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    • pp.1424-1434
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    • 2009
  • DNA computing-inspired pattern classification based on the hypernetwork model is a novel approach to pattern classification problems. The hypernetwork model has been shown to be a powerful tool for multi-class data analysis. However, the ordinary hypernetwork model has limitations, such as operating sequentially only. In this paper, we propose a efficient implementing method of DNA computing-inspired pattern classifier using GPU. We show simulation results of multi-class pattern classification from hand-written digit data, DNA microarray data and 8 category scene data for performance evaluation. and we also compare of operation time of the proposed DNA computing-inspired pattern classifier on each operating environments such as CPU and GPU. Experiment results show competitive diagnosis results over other conventional machine learning algorithms. We could confirm the proposed DNA computing-inspired pattern classifier, designed on GPU using CUDA platform, which is suitable for multi-class data classification. And its operating speed is fast enough to comply point-of-care diagnostic purpose and real-time scene categorization and hand-written digit data classification.

Load spectra growth modelling and extrapolation with REBMIX

  • Volk, Matej;Fajdiga, Matija;Nagode, Marko
    • Structural Engineering and Mechanics
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    • v.33 no.5
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    • pp.589-604
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    • 2009
  • In the field of predicting structural safety and reliability the operating conditions play an essential role. Since the time and cost limitations are a significant factors in engineering it is important to predict the future operating conditions as close to the actual state as possible from small amount of available data. Because of the randomness of the environment the shape of measured load spectra can vary considerably and therefore simple distribution functions are frequently not sufficient for their modelling. Thus mixed distribution functions have to be used. In general their major weakness is the complicated calculation of unknown parameters. The scope of the paper is to investigate the load spectra growth for actual operating conditions and to investigate the modelling and extrapolation of load spectra with algorithm for mixed distribution estimation, REBMIX. The data obtained from the measurements of wheel forces and the braking moment on proving ground is used to generate load spectra.

On the Possibilities and Limitations of Arbitration Punishment

  • Zhu, Fuyong
    • Journal of Arbitration Studies
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    • v.28 no.3
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    • pp.3-20
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    • 2018
  • Independence and impartiality are the operating core of an arbitration disciplinary mechanism. Due to many factors, illegalities and improper acts in arbitration cases are facts of life in our country, and have greatly damaged the credibility of arbitration. It is necessary for us to perfect the operating mechanism of arbitration discipline from the four pluralistic progressive aspects of disciplining the cause externalization, disciplining the subject duality, the quasi-judicature of disciplinary procedures and the disciplining measures so that the populace can experience fairness and justice in every case. We should perfect the supporting measures such as the strict selection conditions and procedures of arbitrators, improving the quality of the arbitrator team, exploring the management mechanisms and strengthening the evaluation dynamic. An examination is a general investigation and evaluation so as to provide encouragement for being continually engaged as arbitrators, but it does not provide an objective basis of arbitration discipline. It is urgent to perfect the arbitration guarantee system on the basis of meeting the material needs of the arbitrators so as to enhance the sense of professional rank and honour of arbitration.

Estimation of Operating Cost and Efficiency of the Introduction of Urban Subway (대중교통 운영비용계수 추정 및 도시철도 도입 효율성 검토)

  • Park, Jun-Sik;Oh, Dong-Kyu;Kho, Seung-Young
    • Journal of Korean Society of Transportation
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    • v.26 no.6
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    • pp.113-122
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    • 2008
  • This study extended Park et al.(2007c), which analyzed the efficiency of a hierarchical transit network, showed the result of a real data, and analyzed its applicability. Operating cost was estimated using a model which was established in this study, and minimum transit demand was derived from the operating cost. The minimum transit demand value is just a sample calculation, thus it varies by many inside and outside factors of the model. Looking at the inside of the model, operating cost and travel speed are major factors, and the possibility of introducing urban subway becomes high when the operating cost of the transit system is low and its travel speed is high. As far as the outside factors are concerned, according to the analysis on the network structure, transit demand, and transit mode share, the minimum transit demand value which was derived in this study will be the maximum value among the possible values. In the feasibility study, the benefit is likely to be overestimated and the cost is likely to be underestimated than those of this study. It could be concluded that the methodology of a feasibility study is appropriate in the field standard. This study analyzed the efficiency of introduction of urban subway using analytical approach, thus has many shortcomings and limitations. However the practical approach, like feasibility study, has some limitations as well. This study could be a basis on establishing an analysis framework that is more accurate and reasonable by comparing analytical approach and practical approach.