• Title/Summary/Keyword: adaptive capacity

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Seismic Assessment of Plan-irregular Wall Structures using Adaptive Modal Analysis (수정 모드해석방법을 이용한 비대칭 벽식 구조물의 내진성능평가)

  • Ha, Tae-Hyu;Hong, Sung-Gul
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.589-596
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    • 2006
  • Torsional behavior of eccentric structures under seismic loading may cause stress and/or strain concentration, which result in the failure of the structures in an unexpected manner. This study propose how to assess the seismic capacity of plan-irregular RC wall structures. The seismic capacities ate expressed in terms of lateral displacement capacity of each wall. The seismic demands for displacement are assessed by so called displacement-based design approach. Those seismic capacity and demands are combined D-R coordinate, which is made up of lateral displacement and rotation angle. To expand these concepts to the inelastic region the adaptive modal analysis method is used. In addition, the failure mechanisms including torsional failure are defined on D-R coordinate. Finally, seismic assessments of two 3-story plan-irregular wall structures ate presented.

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Technological Innovation System for Energy Transition in Small Island Developing States: Adaptive Capacity, Market Formation and Policy Direction in the Maldives

  • Mohamed, Shumais
    • Asian Journal of Innovation and Policy
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    • v.11 no.3
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    • pp.293-319
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    • 2022
  • By analyzing the adaptive capacity, market formation and policy direction as functional areas of Technological Innovation System (TIS), the article evaluates the progress of renewable energy transition in the Maldives, with the inclusion of ideas from Mauritius and Cabo Verde. On the policy direction in the Maldives, technology roadmaps produced with assistance from International Renewable Energy Agency (IRENA) and Asian Development Bank (ADB) are evaluated. Although there are inducing factors such as the Solar Risk Management Initiative, the progress of energy transition is hindered by the lack of technical capacity and local value chain. The findings indicate the importance of facilitating and establishing industry and knowledge networks, incorporating innovation policies, greater involvement of the local private sector along with international investors, and taking water-energy nexus to achieve complementary targets. The study adds value to knowledge by offering a simplified TIS framework, with a current insight of the energy transition in Small Island Developing States with a focus on the Maldives.

Performance Improvement on Adaptive OFDM System with a Multi-Step Channel Predictor over Mobile Fading Channels (이동 페이딩 채널하의 멀티 스텝 채널 예측기를 이용한 적응 OFDM 시스템의 성능개선)

  • Ahn, Hyun-Jun;Kim, Hyun-Dong;Choe, Sang-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.12A
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    • pp.1182-1188
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    • 2006
  • Adaptive OFDM(Orthogonal Frequency Division Multiplexing) improves data capacity and system performance over multipath fading by adaptively changing modulation schemes according to channel state information(CSI). To achieve a good performance in adaptive OFDM systems, CSI should be transmitted from receiver to transmitter in real time through feedback channel. However, practically, the CSI feedback delay d which is the sum of the data processing delay and the propagation delay is not negligible and damages to the reliability of CSI such that the performance of adaptive OFDM is degraded. This paper presents an adaptive OFDM system with a multistep predictor on the frequency axis to effectively compensate the multiple feedback delays $d(\geq2)$. Via computer simulation we compare the proposed scheme and existing adaptive OFDM schemes with respect to data capacity and system performance.

Adaptive Modulation Techniques for COFDM-CDMA Based Wireless Networks

  • Wasantha, M.K.;Fernando, W.A.C.
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.381-384
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    • 2002
  • Orthogonal Frequency Division Multiplexing (OFDM), which employs orthogonal overlapping subcarriers to modulate the signals, has been attracted much attention in recent time as a favorable option for future generation wireless networks due to its ability to overcome many impairments in wireless channels. Since OFDM is a multi-carrier system adaptive modulation techniques can be effectively and efficiently used to enhance the system performance in terms of both BER and overall system capacity. This paper discusses a COFDM-CDMA system with adaptive modulation schemes for future generation wireless networks.

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AN ADAPTIVE DISPATCHING ALGORITHM FOR AUTOMATED GUIDED VEHICLES BASED ON AN EVOLUTIONARY PROCESS

  • Hark Hwnag;Kim, Sang-Hwi;Park, Tae-Eun
    • Proceedings of the Korea Society for Simulation Conference
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    • 1997.04a
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    • pp.124-127
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    • 1997
  • A key element in the control of Automated Guided Vehicle Systems (AGVS) is dispatching policy. This paper proposes a new dispatching algorithm for an efficient operation of AGVS. Based on an evolutionary operation, it has an adaptive control capability responding to changes of the system environment. The performance of the algorithm is compared with some well-known dispatching rules in terms of the system throughput through simulation. Sensitivity analysis is carried out varying the buffer capacity and the number of AGVS.

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Performance Analysis of MIMO-OFDM System Applying AMC and SFC Schemes (AMC와 SFC기법을 적용한 MIMO-OFDM 시스템의 성능 분석)

  • Lee, Yun-Ho;Kim, Hyung-Jung;Jo, G.D.;Kim, Kyung-Seok
    • The Journal of the Korea Contents Association
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    • v.8 no.4
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    • pp.55-62
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    • 2008
  • Adaptive modulation and Coding(AMC) scheme is promising technique to support the demands for high data rates and wideband proposed for 4G mobile communication system standards. In this paper, adaptive modulation and coding(AMC) based on OFDM system is analyzed through simulation for single user case and compared with SISO-OFDM and SFBC(Space frequency block coding)-OFDM. The performance analysis in terms of capacity for downlink system environments with different values of constellation size under multipath fading channel is done. The adaptive modulation and coding technique is based on perfect estimation channel. It has been observed that SFBC(Space-frequency block coding)-OFDM system gives better performance in terms of capacity.

Evaluation of Pullout Capacity of Embedded Suction Anchors in Uniform Clay using Numerical Analysis with ALE(Arbitrary Lagrangian Eulerian) Technique (ALE 기법이 적용된 수치해석을 통한 점토지반에서 석션 매입 앵커의 인발 저항력 평가)

  • Na, SeonHong;Jang, In-Sung;Kwon, OSoon;Lee, Seung-Hyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2428-2435
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    • 2014
  • Numerical analysis with ALE (Arbitrary Lagrangian Eulerian) Adaptive Meshing technique was performed to evaluate the pullout capacity of the embedded suction anchors (ESA) in uniform clay. The numerical method was verified by the previous study, analytical results based on limit-equilibrium theory and centrifuge tests. The pullout capacity of the ESA under horizontal, vertical, and inclined loading were evaluated, and the effect of initial rotation of the ESA on pullout capacity was also investigated. The analysis results showed that the maximum horizontal capacity was obtained at the mid-point, and the each vertical capacity gave the similar value regardless of the loading points. Furthermore, the inclined capacity was decreased as the load inclination angle increased at the mid-point of the anchor, and almost the same pullout capacity was obtained when the initial rotation angles were below 30 degrees.

UNDP's Adaptation Policy Framework for Climate Change (국제연합개발계획의 기후변화 적응 정책 체계 소개)

  • Shm, Im-Chul;Lee, Eun-Jeong;Kwon, Won-Tae;Lim, Jaekyu
    • Atmosphere
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    • v.15 no.1
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    • pp.59-68
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    • 2005
  • United Nations Development Programme (UNDP) introduced the Adaptation Policy Framework (APF) to support the developing countries in order to help to make adaptation policy and strategy to climate change. This study provides the summary of the APF and will help for preparing policy regarding the impact of climate change and its adaptation. APF consists of five basic and two cross-cutting steps. Five basic steps are made of (a) defining project scope and design, (b) assessing current vulnerability and adaptation, (c) assessing future climate-related risks, (d) developing an adaptation strategy, and (e) continuing the adaptation process. Cross-cutting steps consist of engaging stakeholder and enhancing adaptive capacity. The project scope and design process includes four major tasks: scope the project and define its objectives, establish the project team, review and synthesize existing information on vulnerability and adaptation, and design the APF project. The main purpose of assessing current vulnerability and adaptation is to understand the characteristics of current climate-related vulnerability in priority systems and the scope of adaptive responses. Future climate-related risks are assessed in order to characterize future climate-related risks, so that adaptation policies and measures can be designed to reduce the system's exposure to future climate hazard. In developing an adaptation strategy, all of the preceding APF-related work is synthesized into a well-considered strategy that can direct real adaptation action. Continuing the adaptation process is in order to implement and sustain the APF-strategy, polices, and measure. The purpose of involvement of stakeholders is to communicate between individuals and groups about projects. Finally, enhancing adaptive capacity provides guidance on how adaptive capacity can be assessed and enhanced.

Design of Smart OTT Platform based on the Analysis of Adaptive Buffering (적응 버퍼링 성능분석 기반의 스마트 OTT 플랫폼 설계☆)

  • Kim, Inki;Kang, Mingoo
    • Journal of Internet Computing and Services
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    • v.17 no.4
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    • pp.19-26
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    • 2016
  • In this paper, the dynamic buffering based smart OTT platform was proposed, and analyzed for adaptive bit-rate video delivery with the optimization of HLS (HTTP Live Streaming). This platform consists of the software platform between sever and client which detects the bandwidth capacity, and adjusts the quality of the streaming for multiple bit-rates resolutions. In order to apply adaptive buffering, two buffers are added to the basic HLS player, and each buffer is responsible for constantly buffering a previous and the next channels relative to the current channel. This adaptive transmitting with smart OTT platform is superior to delivering a static video file at a single buffering, because the video stream of adaptive double buffers can be switched streaming according to client's available network speed. As a result, this proposed smart OTT can be cooperated to the application of HLS server with segmented H.265 MPEG-2 TS video & m3u8 files with its information based on the optimized transmission channel state of live and VOD, and applied to PLC transmission, too.

A Novel Resource Allocation Scheme for QoS guarantee of Assured Service in Differentiated Services (DiffServ 방식의 Assured Service에서 QoS 보장을 위한 효율적인 자원 할당 방안)

  • Hur, Kyeong;Cho, Seong-Dae;Eom, Doo-Seop;Tchah, Kyun-Hyon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.8C
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    • pp.758-770
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    • 2002
  • In this paper, we propose a novel resource allocation scheme which can maximize capacity for QoS guarantee of Assured Service in Differentiated Services. Performance of the proposed resource allocation scheme is analyzed with each buffer management scheme such as RIO and Adaptive RIO. To prevent an early random drop of the admitted In-profile packet, Adaptive RIO scheme updates parameters of RIO scheme every time interval according to the estimated numbers of maximum packet arrivals of In-profile traffic and Out-of-profile traffic during the next time interval. The numbers of maximum packet arrivals during the next time interval are estimated based on the buffer size determined by the network topology and the ratio of bandwidth allocated to each subclass. We can find from simulation results that proposed resource allocation scheme with Adaptive RIO can guarantee QoS and can maximize capacity for Assured Service.