• Title/Summary/Keyword: 안정성 한계

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An Energy-efficient Power-aware Routing Protocol based on Load-balancing for Ad hoc Networks (Ad hoc 네트워크 환경에서 부하 균등 기반의 power-aware 라우팅 프로토콜)

  • Kim Dong-hyun;Ha Rhan
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.11a
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    • pp.379-381
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    • 2005
  • Ad hoc 네트워크에서 노드의 한정된 에너지 용량은 개설 경로의 수명과 안정성에 많은 영향을 미치는 요소이다. 따라서 이러한 에너지 한계를 극복하기 위한 다양한 power-aware 라우팅 프로토콜들이 네트워크 계층에서 제안되고 있으며, 이들 라우팅 프로토콜들은 기본적으로 노드의 배터리 잔량 에너지와 전송 전력량을 경로 탐색 과정에서 반영한다. 본 논문에서는 기존의 power-aware 라우팅 프로토콜보다 개설 경로의 동작시간을 높이고 전체 네트워크의 부하균등을 이를 수 있도록 하는 새로운 라우팅 프로토콜을 제안하며 TPR(Traffic load based power-aware routing protocol)로 명명한다. TPR은 NS-2를 이용한 성능 평가를 통해 전체 네트워크의 부하 균등과 개설 경로의 수면, 안정성 측면에서의 개선점을 확인한다.

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A Stability Study of Three Open-Ended Coaxial Probe Conversion Models under the Error Situations (오차에 대한 3가지 개방단말 동축선 프로브의 환산모델들간 안정성 연구)

  • 조유선;현승엽;김상욱;김세윤
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2001.11a
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    • pp.300-303
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    • 2001
  • 개방단말 동축선 프로브는 임의의 매질에 접촉하여 복소 유전율을 구하므로 사용이 용이한 측정법이다. 복소 유전율의 측정 과정은 두 단계로 구성된다. 먼저 프로브의 개구면을 미지의 매질에 접촉시켜서 반사계수를 측정한다. 다음에는 반사계수를 환산모델에 대입하여 복소 유전율을 구한다. 그러나 실제 측정시 발생하는 오차들에 대해 취약하다는 단점을 가지고 있다. 정확성을 떨어뜨리는 주요 오차 요인으로는 프로브의 개구면과 측정매질 사이의 공극으로 인한 불완전 접촉오타와 프로브의 제작 한계로 인한 오차를 들 수 있다. 본 논문에서는 이런 오차상황에서 유한 차분 시간영역법으로 반사계수를 계산하고나서 환산모델에 의해 복소 유전율로 환산함으로써 오차에 대한 환산모델들간의 안정성을 살펴보고자 한다.

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Numerical Investigation on the Stability of Reinforced Earth Wall during Rainfall (강우시 보강토 옹벽의 안정성에 관한 수치 해석 연구)

  • Yoo, Chung-Sik;Kim, Sun-Bin;Han, Joon-Yeon
    • Journal of the Korean Geotechnical Society
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    • v.24 no.12
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    • pp.23-32
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    • 2008
  • This paper presents the results of numerical investigation on the stability of reinforced earth wall during rainfall. A series of limit-equilibrium based slope stability analyses within the framework of unsaturated shear strength, coupled with transient seepage analyses, were conducted with due consideration of rainfall characteristics in Korea. It is shown that the factor of safety of the reinforced wall during rainfall decreases with time due to decreases in the suction in the reinforced as well as retained zones. Also revealed is that the decrease in the factor of safety depends not only on the backfill soil type but also on the rainfall characteristics. Practical implications of the findings were discussed.

Comparison and Analysis of Small Gas Turbine Performance Deck and Experimental Result (소형 가스터빈엔진의 천이상태 모사와 시험결과 비교분석)

  • 전용민;양인영;남삼식;김춘택;양수석;이대성
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2002.04a
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    • pp.28-28
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    • 2002
  • 가스터빈 엔진을 운용하는 데 있어서 가/감속율을 크게 하면 엔진성능 천이 시간은 짧으나 압축기에서의 서지나 터빈 입구온도의 급격한 상승이 발생할 수 있으며 가/감속율을 작게 하면 엔진은 안정적이나 천이시간이 길어지게 되어 결과적으로 엔진의 동적 응답성이 나빠지게 된다. 또한 압축기에서 발생할 수 있는 서지를 방지하기 위하여 압축기 서지 마진이 l0%∼20%인 서지 한계선(조정선)을 설정하여 엔진이 서지 한계선을 넘지 않도록 제어한다.

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The Methods for Improving Revenue in the Webcasting Business (웹캐스팅 비즈니스의 수익성제고 방안)

  • 전춘화;한계섭
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.05b
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    • pp.699-702
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    • 2003
  • 버블론 이후 인터넷 기업은 안정적인 수익창출을 위한 다양한 시도와 역량을 집중하고 있으나 대부분의 기업 뿐만 아니라 웹캐스팅 업체도 여전히 적자 상태이다. 본 연구에서는 컨텐츠 비즈니스의 구체적인 신조류를 분석하며, 기존의 웹캐스팅 비즈니스의 수익모델을 분석하여 그 한계요소를 도출하고 이들의 해결안을 광고, 컨텐츠 유료화, 컨텐츠 개발 및 확보, 전자상거래, 컨텐츠 전달방식, 전자결제방식, 매체 확장 등 인터넷 비즈니스 요소 측면에서 제시함으로써 수익성 제고를 모색해 보았다.

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A theoretical review on the limitations of applying copyright law in the arts (예술창작에서 저작권법 적용의 한계에 대한 이론적 고찰)

  • Hong, Kiwon
    • Korean Association of Arts Management
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    • no.51
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    • pp.167-190
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    • 2019
  • Copyright law has functioned to certify the authorship and artistic identity of an artist as well as to remunerate the artist's labor in monetary terms. However, the legal stability of copyright law may be questioned and even challenged because it shares the ground with unfixed notions of the concept of art. This study is an attempt to find theoretical argument where such instability of copyright law stems from, by looking into the theories of Aesthetics and history of arts. The first argument builds up on the ambiguity of discriminating between the Aesthetic concept of expression and idea. The second argument illuminates how new conventions of creating art work and emerging ideals of making art prevents to accommodate copyright law in the fields of art. New art forms such as conceptual art and place specific art are such examples. Increasing role of public arts projects also questions the conventional adoptions of copyright law. Arts management is closely related with this phenomena since their job is to administer the complex situation of introducing artists to the knowledge of copyright law.

Stability Evaluation Methods of Agricultural Reservoir by Field Monitoring (현장계측에 의한 농업용저수지 제체의 안정관리기법)

  • Lee, Dal-Won;Oh, Beom-Hwan
    • Korean Journal of Agricultural Science
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    • v.30 no.2
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    • pp.164-174
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    • 2003
  • This study was performed to suggest a rational method for the stability evaluation of agricultural reservoir in the very soft ground. The stability methods for agricultural reservoir was used to compare and analyze with various condition by limit equilibrium method. The behavior of settlement-displacement obtained by field monitoring system was used to compare and analyze with various stability methods, and to investigate the applicability of the methods for stability evaluation of agricultural reservoir. The horizontal displacement was abruptly increased when physical properties of soft clay reached its maximum values and therefore, the values of these properties could be used to the fundamental data for stability evaluation. The evaluation of the stability of agricultural reservoir was suggested to use the inclination of curve rather than critical line.

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The Study on the Simple Measurement by Using the Strain Gauge at Dam Dynamic Behavior Analysis (댐 거동 분석에서의 Strain Gauge를 이용한 단일 계측에 관한 연구)

  • Lee, Seungho
    • Journal of the Korean GEO-environmental Society
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    • v.8 no.1
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    • pp.5-11
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    • 2007
  • Internal stress variation in the face slab concrete induced by reservoir water pressure may affect on the stability of the dam so that the reclamation type of strain gauge is applied for measuring internal stress variation. In this study, internal as well as external stress variation of dam was measured by using strain gauge that was reclaimed to the ${\circ}{\circ}$ dam. In the result, it was confirmed that other measurements by relevant gauges need to be supplemented as the use of strain gauge only is insufficient to evaluate the stability analysis and global behavior of the dam.

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Geosynthetic-Reinforced Segmental Retaining Walls in Tiered Arrangement - Case Study and Field Trial Wall Instrumentation (다단식 보강토 옹벽의 설계 - 사례연구 및 시험시공)

  • Yoo, Chung-Sik;Jung, Hyuk-Sang
    • Journal of the Korean Geosynthetics Society
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    • v.3 no.1
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    • pp.27-36
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    • 2004
  • This paper presents the results of stability analyses on soil-reinforced segmental retaining walls in a tiered arrangement. Four different walls were examined to investigate the appropriateness of their designs within the context of the current design guidelines based on limit equilibrium. Slope stability analysis against the compound failure mode, which is frequently ignored during design, was also performed based on the method recommended by FHWA design guidelines. Also presented are the results of instrumentation on a full-scale field trial wall constructed as part of this study. The implications of the findings from this study are discussed.

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Effects of Pressure Variation on the Combustion Characteristics of a Gaseous CH4/O2 Bipropellant in a Model Combustor (모델연소실 내 압력 변화가 메탄/산소 이원추진제의 연소특성에 미치는 영향)

  • Choi, Sun;Kim, Tae Young;Kim, Hee Kyung;Koo, Jaye;Kwon, Oh Chae
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.1
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    • pp.63-71
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    • 2017
  • Liquid methane ($CH_4$)/oxygen ($O_2$) bipropellants have been recently considered as a next-generation propellant due to eco-friendly and non-toxic properties, low cost and high performance. In this study, the combustion characteristics of gaseous $CH_4/O_2$ nonpremixed coflow flames in a model combustor with variation of internal pressure are investigated through measuring the combustion stability limits and visualizing flames. Results show that the combustion stability limits are extended and the reaction region is widened with increasing internal pressure of the combustion chamber for fuel-rich condition.