• 제목/요약/키워드: alternative set

검색결과 824건 처리시간 0.022초

HFC152a 대체냉매를 이용한 자동차 냉방장치의 성능 최적화에 관한 연구 (Study of Performance Optimization as an Alternative Refrigerant HFC152a in a Mobile Air Conditioning System)

  • 이대웅
    • 설비공학논문집
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    • 제27권6호
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    • pp.321-327
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    • 2015
  • This study presents an HFC152a refrigerant air conditioner as an alternative to HFC134a, which is currently used in mobile air conditioning systems. Cool-down performance tests of an HFC152a air conditioning system were conducted and compared to a baseline HFC134a air conditioner. The experimental set-up consisted of a belt-driven compressor, a sub-cooled type condenser, an evaporator, and a block-type thermal expansion valve (TXV). A drop-in test was carried out on the mobile air conditioning system under various vehicle running speeds in a climate-controlled wind tunnel (CWT). Additionally, to optimize the HFC152a air conditioning system, the effects of the TXVs on the performance were studied. The results show that compared to the HFC134a air conditioning system, the refrigerant charge quantity was reduced by approximately 20%, the discharge pressure was reduced by about 350~430 kPa, and the air discharge temperature at vehicle running conditions was $0.5{\sim}1.5^{\circ}C$ lower. In addition, good compressor durability was expected due to the lower compression ratio.

Merging the old with the new: a cybermedicine marriage for oncology interactions with traditional herbal therapies and complementary medicines

  • Yap, Kevin Yi-Lwern;Lim, Ken Juin
    • 셀메드
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    • 제2권2호
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    • pp.18.1-18.16
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    • 2012
  • An oncology-specific database called OncoRx (http://bit.ly/cancerRx) was previously set up in cyberspace to aid clinicians in identifying interactions of anticancer drugs (ACDs) and chemotherapy regimens with traditional Chinese medicines (TCMs) and complementary and alternative medicines (CAMs). Since then, users have requested the drug-CAM interactions (DCIs) of 5 specific CAMs (cranberry, melatonin, co-enzyme Q10, huachansu, reishi mushroom) to be updated in the database. Pharmacokinetic properties (metabolism, enzyme induction/inhibition, elimination), TCM properties and DCIs of each CAM were collated with 117 ACDs using 9 hardcopy compendia and online databases as resources. Additionally, individual ACDs and CAMs were used as keywords for PubMed searches in combination with the terms 'anticancer drugs', 'drug interactions', 'herb-drug/drug-herb interactions', 'pharmacokinetic interactions' and 'pharmacodynamic interactions'. DCI parameters consisted of interaction effects, evidence summaries, proposed management plans and alternative non-interacting CAMs, together with relevant citations and update dates of the DCIs. OncoRx is also used as a case to introduce the "Four Pharmaco-cybernetic Maxims" of quality, quantity, relationship and manner to developers of digital healthcare tools. Its role in Hayne's "5S" hierarchy of research evidence is also presented. OncoRx is meant to complement existing DCI resources for clinicians and alternative medicine practitioners as an additional drug information resource that provides evidence-based DCI information for ACD-CAM interactions.

공영방송의 대안적 재원과 재원산정구조의 모색 (Alternative Financial Resource and Option for the Funding of Public Broadcasting)

  • 심영섭
    • 한국언론정보학보
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    • 제72권
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    • pp.121-145
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    • 2015
  • 한국에서 공영방송의 재원은 주로 라디오와 텔레비전을 보유한 가구의 수신료와 광고수입으로 충당해 왔다. 이 논문은 수신료뿐만 아니라 공영방송의 대안적 재원을 모색하는 데 있다. 이를 위해 공영방송에 적절한 인센티브를 줄 수 있도록, 자치(정부로부터의 독립)와 균형(재원의 효율성과 지속가능성), 통합(이원방송체제에서의 재원 분배의 형평성)의 관점에서 기존의 방송재원의 특징을 분석하고, 이를 바탕으로 대안적인 방송재원을 탐색해 보았다. 그 결과 공영방송의 재원은 효율성과 지속가능성, 형평성 측면에서 세금이나 특별 부담금이 수신료보다 더 안정적이라고 할 수 있지만, 추가적인 가계 부담과 국가권력으로부터의 영향력으로부터 자유로울 수 없다는 측면에서 한계가 있었다. 이러한 이유로 향후 공영방송의 재원은 수신료와 보조금을 기본재원으로 하고, 광고와 후원금, 부대수익을 보조재원으로 제도화하는 구조개편이 필요하다.

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초기계획단계에서 열원시스템 선정을 위한 경제성 간이 평가법에 관한 연구 (A Study on the Simplified Economics Evaluation Method for Selecting a Heat Source System at the Pre-design Phase)

  • 박률;박종일
    • 설비공학논문집
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    • 제16권11호
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    • pp.1060-1067
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    • 2004
  • To apply an analysis method of life cycle cost when assessing economics of equipment system, we should basically set up preconditions such as useful life, price escalation rate, interest rate, etc. as well as consider a calculation algorism of source energy and heat source system, which is a complex process for life cycle costing. For this reason, equipment designers tend to plan heat source systems, without a thorough investigation on economics of alternative systems at the pre-design phase. In this process, architectural designers should adopt a proper heat source system, which is one of the most important factors for planning an appropriate architectural design, through a discussion with equipment designers in a short time. In order to offer an evaluation method for equipment designers to analyze economics of an alternative heat source system easily at the pre-design phase, this research would define the simplified economics, evaluation method through analysis of existing papers for economics evaluation, and examine validity through comparison of simplified method values ($LCC_{EC}$) and life cycle costing values ($LCC_{15}$) for six alternative heat source systems.

Robust Unit Root Tests with an Innovation Variance Break

  • Oh, Yu-Jin
    • Communications for Statistical Applications and Methods
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    • 제19권1호
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    • pp.177-182
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    • 2012
  • A structural break in the level as well as in the innovation variance has often been exhibited in economic time series. In this paper we propose robust unit root tests based on a sign-type test statistic when a time series has a shift in its level and the corresponding volatility. The proposed tests are robust to a wide class of partially stationary processes with heavy-tailed errors, and have an exact binomial null distribution. Our tests are not affected by the size or location of the break. We set the structural break under the null and the alternative hypotheses to relieve a possible vagueness in interpreting test results in empirical work. The null hypothesis implies a unit root process with level shifts and the alternative connotes a stationary process with level shifts. The Monte Carlo simulation shows that our tests have stable size than the OLSE based tests.

분해 가능한 테이블 디자인 연구 (A Study on Table Design for Disassembly)

  • 한정엽
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2007년도 춘계학술대회 논문집
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    • pp.110-113
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    • 2007
  • Modernity which is superficial phenomenon set off the mass scale for mass consumption and provide uniformly artificial environment. But natural destruction, environment pollution, resources exhaustion and so on has been caused by this and now ecology is threatened by destruction and damage beyond the limitation and human beings survival is even threatened. Accordingly furniture development for environment preservation considered environment problem is the urgent real situation. Recent paradigm is the concept of Eco-design which is the green design possible to live together in symbiosis, and new types of alternative furniture are needed in Korea as well. 'Furniture for disassembly' is presented as new method for alternative furniture.

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A PETRI NET-BASED CELL CONTROLLER FOR A FLEXIBLE MANUFACTURING SYSTEM

  • Janssens, Gerrit-K.;Tabucanon, Mario-T.
    • Management Science and Financial Engineering
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    • 제3권1호
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    • pp.15-38
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    • 1997
  • In a flexible manufacturing system, a cell controller is able to identify and evaluate a number of alternative decisions to meet the objectives set by the factory level controller. In this paper, a Petri net-based cell controller is presented to accomplish this task. A static model is developed by using the Integrated Computer Aided Definition(IDEF0) method to represent clear functional relationships among the objects of the system. Based on the static model, two Petri net models are developed for the physical part flow and for the information flow. Multiple decision alternatives are generated from the physical part flow model and are synchronized with the information flow model for execution of the selected alternative.

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Neural network based model for seismic assessment of existing RC buildings

  • Caglar, Naci;Garip, Zehra Sule
    • Computers and Concrete
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    • 제12권2호
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    • pp.229-241
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    • 2013
  • The objective of this study is to reveal the sufficiency of neural networks (NN) as a securer, quicker, more robust and reliable method to be used in seismic assessment of existing reinforced concrete buildings. The NN based approach is applied as an alternative method to determine the seismic performance of each existing RC buildings, in terms of damage level. In the application of the NN, a multilayer perceptron (MLP) with a back-propagation (BP) algorithm is employed using a scaled conjugate gradient. NN based model wasd eveloped, trained and tested through a based MATLAB program. The database of this model was developed by using a statistical procedure called P25 method. The NN based model was also proved by verification set constituting of real existing RC buildings exposed to 2003 Bingol earthquake. It is demonstrated that the NN based approach is highly successful and can be used as an alternative method to determine the seismic performance of each existing RC buildings.

대체냉매 R-407C의 모세관 선정에 관한 연구 (Investigation on the selection of capillary tube for the alternative refrigerant R-407C)

  • 김용환;김창년;박영무
    • 설비공학논문집
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    • 제10권1호
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    • pp.56-65
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    • 1998
  • In this paper, experimental investigation of capillary tube performance for R-407C is performed. The experimental setup is made of real vapor-compression refrigerating system. In this study, mass flow rate is measured for capillary tubes of various diameter and length as inlet pressure and degree of subcooling are changed. These data are compared with the results of a numerical model. The mass flow rates of the numerical model are less than by 14% compared with the measured mass flow rates. It is found that mass flow rate and length for R-407c are less than those of R-22 under the same condition. Also based on this experimental study and the numerical model, a set of capillary tube selection charts for R-407C is constructed.

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Impostor Detection in Speaker Recognition Using Confusion-Based Confidence Measures

  • Kim, Kyu-Hong;Kim, Hoi-Rin;Hahn, Min-Soo
    • ETRI Journal
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    • 제28권6호
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    • pp.811-814
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    • 2006
  • In this letter, we introduce confusion-based confidence measures for detecting an impostor in speaker recognition, which does not require an alternative hypothesis. Most traditional speaker verification methods are based on a hypothesis test, and their performance depends on the robustness of an alternative hypothesis. Compared with the conventional Gaussian mixture model-universal background model (GMM-UBM) scheme, our confusion-based measures show better performance in noise-corrupted speech. The additional computational requirements for our methods are negligible when used to detect or reject impostors.

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