• Title/Summary/Keyword: Trade-off

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연료 막냉각을 적용한 액체로켓 연소기의 연소/냉각 성능 간 trade-off 해석 (A Trade-off Analysis between Combustion and Cooling Performance of a Liquid Rocket Combustor with Fuel Film Cooling Scheme)

  • 조미옥;김성구;최환석
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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    • pp.35-41
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    • 2012
  • 액체로켓 추력실의 성능 예측 및 초음속 노즐부 형상 설계에 활용 중인 in-house 해석 도구를 이용하여 재생냉각 연소기에 대한 성능/냉각 통합해석을 수행하였으며, 막냉각 유량 및 외곽 분사기열의 혼합비 변화에 따른 연소 성능과 냉각 성능 간 trade-off 경향을 고찰하였다. 향후 막냉각 및 주요 설계인자의 최적화 도구로 활용될 수 있도록 개발 연소기에 대한 시험 결과와의 비교 등을 통하여 수치해석 도구를 검증/개선해나갈 계획이다.

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복합공종 MEP 천정 선조립 공법 사례조사를 통한 단계별 중점관리사항 도출 (Deriving Critical Management Factors based on Case Studies of Multi-trade MEP Ceiling Rack Prefabrication)

  • 이동민;장세준
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 추계 학술논문 발표대회
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    • pp.76-77
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    • 2015
  • In construction industry, management of construction factors such as cost, schedule, quality and safety is the most important key for delivering successful projects. According to the Smart Market Report, a magazine specialized in construction industry, recently said 'Off-site Prefabrication' is a significant trend related with construction productivity in global construction industry. It is a kind of practice shift from On-site to Off-site. A lot of general contractors in oversea have been using 'Multi-trade MEP Ceiling Rack Prefabrication' method for getting benefits such as decreased cost & schedule and increased labor productivity. Thus, in this paper, critical management factors at each phase from design to installation was derived by researching case studies. Forwardly, it can be a basic guideline for applying Multi-trade MEP Ceiling Rack Prefabrication in Korea construction industry.

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발화길이와 유창성 간의 교환효과: 언어 발달시기에 있는 36-48 개월의 정상아동을 대상으로 (The Trade-off Effects between MLU and Fluency in Normal Preschool-age Children)

  • 이수진;황민아
    • 음성과학
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    • 제8권4호
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    • pp.157-168
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    • 2001
  • The limited capacity model has been used to explain linguistic interactions and trade-offs that occur in children's speech. The purpose of the present investigation is to explore the interrelationship of MLU (as an index of syntactic development) and fluency in the spontaneous speech of normal children. Twenty normal children's (ten girls and ten boys, aged 36-48 months) spontaneous speech samples were obtained during free-play interactions with their mothers or other adults. The results indicated that the MLU of disfluent utterances were significantly longer than that of fluent utterances. Also, disfluencies occurred more frequently in longer utterances than in shorter utterances. In addition, the utterances where disfluencies occurred more than 2 times were longer than those where disfluencies occurred once. These results imply that the increase of MLU appear to affect not only the occurrence of disfluent utterances, but also the number of disfluencies within the utterances. In other' words, these findings show that there are trade-off effects between MLU and fluency. This is discussed within a limited capacity framework.

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Time-Profit Trade-Off of Construction Projects Under Extreme Weather Conditions

  • Senouci, Ahmed;Mubarak, Saleh
    • Journal of Construction Engineering and Project Management
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    • 제4권4호
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    • pp.33-40
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    • 2014
  • Maximizing the profitability and minimizing the duration of construction projects in extreme weather regions is a challenging objective that is essential for project success. An optimization model is presented herein for the time-profit trade-off analysis of construction projects under extreme weather conditions. The model generates optimal/near optimal schedules that maximize profit and minimize the duration of construction projects in extreme weather regions. The computations in the model are organized into: (1) a scheduling module that develops practical schedules for construction projects, (2) a profit module that computes project costs (direct, indirect, and total) and project profit, and (3) a multi-objective module that determines optimal/near optimal trade-offs between project duration and profit. One example is used to show the impact of extreme weather on construction time and profit. Another example is used to show the model's ability to generate optimal trade-offs between the time and profit of construction projects under extreme weather conditions.

QoS-Guaranteed Multiuser Scheduling in MIMO Broadcast Channels

  • Lee, Seung-Hwan;Thompson, John S.;Kim, Jin-Up
    • ETRI Journal
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    • 제31권5호
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    • pp.481-488
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    • 2009
  • This paper proposes a new multiuser scheduling algorithm that can simultaneously support a variety of different quality-of-service (QoS) user groups while satisfying fairness among users in the same QoS group in MIMO broadcast channels. Toward this goal, the proposed algorithm consists of two parts: a QoS-aware fair (QF) scheduling within a QoS group and an antenna trade-off scheme between different QoS groups. The proposed QF scheduling algorithm finds a user set from a certain QoS group which can satisfy the fairness among users in terms of throughput or delay. The antenna trade-off scheme can minimize the QoS violations of a higher priority user group by trading off the number of transmit antennas allocated to different QoS groups. Numerical results demonstrate that the proposed QF scheduling method satisfies different types of fairness among users and can adjust the degree of fairness among them. The antenna trade-off scheme combined with QF scheduling can improve the probability of QoS-guaranteed transmission when supporting different QoS groups.

적응 윈도윙을 기반으로한 적응 필터 (Adaptive Filter Based on Adaptive Windowing)

  • 우종진;신현출;송우진
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
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    • pp.81-84
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    • 2001
  • We propose a novel noise littering method based on adaptive windowing. To restore a noisy signal adaptive filtering methods have been widely researched and used. However, conventional adaptive filtering methods have a trade-off between noise suppression and edge preservation since they adopt fixed size filters. In this paper applying the adaptive windowing concept to adaptive filtering, we overcome the trade-off, The filter size is adaptively selected depending on signal statistics. The visual results of the signal and image restorations convincingly show the superior preservation of edge and detail and suppression of noise for the proposed adaptive windowed adaptive filter compared with conventional methods.

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보안성 향상을 위한 RFID 태그 구현시의 Trade off 분석 (Analyse of Trade-off for Implementing RFID Tag to Enhance Security)

  • 김정태
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2011년도 춘계학술대회
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    • pp.754-756
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    • 2011
  • Most of the sources of security and privacy issues in RFID technology arise from the violation of the air interface between a tag and its reader. This paper will approach the security risk analysis is process from the perspective of the RFID tag life cycle, identify the tag usage processes, identify the associated vulnerability and threat to the confidentiality, integrity and availability of the information assets and its implications for privacy, and then mitigate the risks.

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국내 태양광산업의 해외진출을 위한 시장 선택 요인에 대한 분석 (Development of International Market Selection Models for Solar Power System Industry of Korea)

  • 전진효;오근엽;유진만
    • 무역학회지
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    • 제44권1호
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    • pp.269-283
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    • 2019
  • Due to environmental issues such as global warming, the importance of renewable energy is growing. Solar Power System is one of the most growing eco-friendly energy industries in the world, but Korea's solar energy industry faces fierce competition due to the trade regulations and changes in energy related laws in the major markets such as the U.S., EU and China. Therefore, Korea needs to diversify its export markets towards emerging markets. This paper analyzed 162 countries in the world and developed a model to measure how promising the countries are. GSMI(Grid connected Solar Market Index) and OSMI(Off-grid Solar Market Index) are invented based on the models. By using the developed model and the data of 162 countries over the 15-year period from 2000 to 2014, the foreign markets are ranked for searching the export market. According to the analysis, China, Japan, U.S, India and Taiwan ranked first to fifth in GSMI and OSMI ranking, which were followed by China, India, Bangladesh, Philippines and Afghanistan. The model developed through this research is expected to provide a more reasonable and scientific approach to the advancement of the Korean solar energy industry into overseas markets.

e-무역상사의 발전과제에 관한 연구 (A Study on the Issues for Developing e-Trade Service Provider)

  • 이봉수
    • 무역상무연구
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    • 제20권
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    • pp.423-440
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    • 2003
  • The trial business of e-trade service providers for supporting small enterprises to find their markets abroad is about to begin from the end of March, 2003. The department of Industrial Resources held the "Committee of e-trade service provider selection" with professors of e-trade field, and selected three companies: ECplaza, EC21 and Tpage Global. The e-trade service providers combine the various technologies of on-line trades and off-line trades to support small enterprises with lack of marketing skills by intermediation of overseas buyers and production, registration of e-catalogs and offers, administration of inquiries, trade negotiations, and contract settlement. Prospective small enterprises with exports under US$ 5 million will be selected by 2005. The selected companies will be supported fully by the government, and will be provided with the services by the e-trade service providers. e-Trade service will be the most potential and successful ones in the future, which helps traders and organizations preparing for globalization.

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