10 research outputs found
CHARACTERIZATION OF COURNOT EQUILIBRIA IN A MARKET WITH NETWORK EFFECTS
No full textMarket equilibria are difficult to describe in markets with network effects because they often involve an upward sloping demand curve and/or multiple equilibria. In the framework of symmetric Cournot oligopoly, I investigate for a minimal set of conditions and thus extend the standard equilibrium analysis by , pp. 132-148) and , pp. 235-254) to these kinds of markets. Copyright � 2007 The Author; Journal compilation � 2007 Blackwell Publishing Ltd and The University of Manchester.
Characterization of the Screened Soil from a Closed Landfill to Evaluate the Stabilization
No full text사용종료매립지 정비사업 시행시 다량으로 발생하는 선별토사의 재활용 타당성을 평가하기 위하여 선별토사에 대한 기본 물성치 실험, 회분식 실험, 모형매립조 실험을 실시하였다. 실험에 사용된 선별토사는 공주에 위치한 사용종료매립지에서 매립연한 별로 1, 5, 10, 15, 20년이 경과한 토사를 25mm체로 선별하여 채취하였다. 체분석 실험결과 선별토사는 매립연한에 관계없이 입도분포가 양호하여 지반공학적인 면에서는 성토재 등으로의 재이용이 가능할 것으로 사료된다. 그러나, 이물질부피비의 경우 20년 선별토사를 제외하고 모두 재활용을 위한 법적 기준인 1%를 넘어 재이용을 위해서는 보다 정밀한 선별이 필요할 것으로 판단되었다. 선별토사의 VS는 매립연한에 따라 특별한 경향을 보이지 않아서 안정화 판단 기준으로 적절치 않음을 보였다. 혐기조건, 호기조건에서의 미생물 활성도 실험은 혐기분해를 모사한 모형매립조 실험과 호기조건을 모사한 soil respiration test와 동일한 양상을 보여, 생물학적 분해가능성에 대한 좋은 판단 근거가 될 수 있음을 알 수 있었다. 생물학적으로 분해가 쉬운 non-humic substances의 경우 매립연한이 증가함에 따라 토사 내 전체 유기물에 대한 비율이 감소하였다. Soil respiration test, biochemical methane potential test등을 실시해 본 결과, 매립연한이 짧은 선별토사의 경우 토사 내 유기물이 아직 안정화되지 못한 것을 알 수 있었고, 모형매립조 실험을 통해 10년 이상의 선별토사 또한 장기적으로는 지반침하, 가스, 악취, 침출수 등의 문제점이 발생할 수 있는 것으로 판단되었다. 따라서, 사용종료매립지 선별토사의 재활용을 위해서는 쓰레기에서 유래한 토사 내 유기물의 안정화를 위한 복원공법 적용이 선행되어야 할 것이다.이 연구는 (주)선진엔지니어링과 2001년도 두뇌한국21 사업에 의해 지원되었습니다. 이 연구의 수행을 지원해 준 서울대학교 공학연구소에도 감사드립니다
An Architecture for Interoperability of Service Discovery Protocols Using Dynamic Service Proxies
No full textAlthough all existing service discovery middlewares provide
similar functionality, they are incompatible with one another due to differences
in approach and architecture. We believe that co-existence of
various service discovery middlewares will be indispensable since their
target services and network environments are quite different to each
other. Considering the future pervasive computing environment, the interoperability
between them must be essential toward minimum user distraction
under the heterogeneous systems. As the requirements of this
interoperability system under these environment, complete translation,
accommodation of changes of legacy middlewares, and simplicity of managing
available services must be very important aspects. We propose a
novel architecture which satisfies these requirements, using dynamic service
proxy concept. While this concept provides various advantages, it
has a notable drawback such that it needs to prepare many proxy codes
per each service. To alleviate the load, we design and implement a Service
Code Development Toolkit. We implemented a sample application
and proposed architecture, and the results show that this architecture
fully satisfies targeted design objectives
An Architecture for Interoperability of Service Discovery Protocols Using Dynamic Service Proxies
No full text
Compressed Passive Macromodeling
Get PDFThis paper presents an approach for the extraction of passive macromodels of large-scale interconnects from their frequency-domain scattering responses. Here, large scale is intended both in terms of number of electrical ports and required dynamic model order. For such structures, standard approaches based on rational approximation via vector fitting and passivity enforcement via model perturbation may fail because of excessive computational requirements, both in terms of memory size and runtime. Our approach addresses this complexity by first reducing the redundancy in the raw scattering responses through a projection and approximation process based on a truncated singular value decomposition. Then we formulate a compressed rational fitting and passivity enforcement framework which is able to obtain speedup factors up to 2 and 3 orders of magnitude with respect to standard approaches, with full control over the approximation errors. Numerical results on a large set of benchmark cases demonstrate the effectiveness of the proposed techniqu
Clinical and Radiologic Outcomes after Arthroscopic Rotator Cuff Repair : Single-row versus Speed-Bridge Technique
No full textPurpose We compared clinical outcome between the Speed-Bridge technique and single-row techniques in patients with full-thickness rotator cuff tears and figured out the patterns of retear by computed tomography (CT) arthrogram and ultrasonography follow-up. Methods 209 patients with full-thickness rotator cuff tears who underwent arthroscopic rotator cuff repair and were followed up for at least 2-year were enrolled retrospectively (group 1: single-row repair, group 2: Speed-Bridge repair). Pre- and postoperative data were reviewed to assess clinical and radiologic outcomes. Results There were no significant differences in clinical outcome between the 2 groups. The retear rates of medium and large-sized rotator cuff tear groups were higher in group 1 than in group 2 (p<0.05). There was no significant difference in the medial row failure rate between the 2 groups. Conclusions Present study showed that the knotless suture Bridge technique may be a considerable alternative method for treating full-thickness rotator cuff-tears
