• Title/Summary/Keyword: 동적 주기

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Cache Replacement Policy Based on Dynamic Counter for High Performance Processor (고성능 프로세서를 위한 카운터 기반의 캐시 교체 알고리즘)

  • Jung, Do Young;Lee, Yong Surk
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.4
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    • pp.52-58
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    • 2013
  • Replacement policy is one of the key factors determining the effectiveness of a cache. The LRU replacement policy has remained the standard for caches for many years. However, the traditional LRU has ineffective performance in zero-reuse line intensive workloads, although it performs well in high temporal locality workloads. To address this problem, We propose a new replacement policy; DCR(Dynamic Counter based Replacement) policy. A temporal locality of workload dynamically changes across time and DCR policy is based on the detection of these changing. DCR policy improves cache miss rate over a traditional LRU policy, by as much as 2.7% at maximum and 0.47% at average.

Mechanical Evaluation of Posterior Dynamic Omega-wire Stabilization System (후방 요추 극돌기간 유동적 오메가형 스프링 고정재의 역학적 평가)

  • Lee, Yeon-Soo;Song, Geun-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.11
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    • pp.1099-1104
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    • 2012
  • The study investigates the mechanical deformation of a newly developed screwless omega-wire dynamic system for stabilization of the spine. The omega-wire spring stabilization system was tested under tension, compression, and dynamic compressive fatigue loads. In addition, its bending deformation was compared to that of a spiral-wire spring system using FEA. A model whose hanger inter-center distance is 60 mm showed an ultimate tensile stress of 3981.7 N at a displacement of 3.61 mm and an ultimate compressive load of 535.6 N at a displacement of 2.16 mm. Under fatigue loading of 5 Hz with 10 N/1 N, it did not show any failure over 5 million cycles, and the displacement was restricted to 8-9 mm. In the FEA, the omega-wire spring system showed more flexible bending features than did the spiral-wire spring system.

Air Passenger Demand Forecasting and Baggage Carousel Expansion: Application to Incheon International Airport (항공 수요예측 및 고객 수하물 컨베이어 확장 모형 연구 : 인천공항을 중심으로)

  • Yoon, Sung Wook;Jeong, Suk Jae
    • Journal of Korean Society of Transportation
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    • v.32 no.4
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    • pp.401-409
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    • 2014
  • This study deals with capacity expansion planning of airport infrastructure in view of economic validation that reflect construction costs and social benefits according to the reduction of passengers' delay time. We first forecast the airport peak-demand which has a seasonal and cyclical feature with ARIMA model that has been one of the most widely used linear models in time series forecasting. A discrete event simulation model is built for estimating actual delay time of passengers that consider the passenger's dynamic flow within airport infrastructure after arriving at the airport. With the trade-off relationship between cost and benefit, we determine an economic quantity of conveyor that will be expanded. Through the experiment performed with the case study of Incheon international airport, we demonstrate that our approach can be an effective method to solve the airport expansion problem with seasonal passenger arrival and dynamic operational aspects in airport infrastructure.

Desirable Strategy of Dam Operation consider to Downstream Ecosystem (하류 하천환경을 고려한 바람직한 댐 운영방향)

  • Lee, Yo-Sang;Lee, Gwang-Man;Lee, Eul-Lae;Park, Jin-Hyuk
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.1989-1993
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    • 2009
  • 댐의 조절방류가 하류 하천생태에 미는 영향은 매우 복잡하다. 하류생물상에 미치는 영향은 댐에서의 거리, 유황의 변화크기에 따라 달라진다. 흐르는 물에 서식하는 물고기는 좋아하는 수심, 유속 및 하상재질 등을 이용하여 살아간다. 다만 생물상은 주변환경에 적응하거나 변화하는 능력이 있어 댐의 조절방류에 의한 수생태계 변화구조를 명확히 해석하기는 불가능하다(Power et al., 1988). 댐에 의한 일정방류는 생물다양성을 감소시키며, 보다 변동성이 큰 방류하천은 하천, 연안 및 생물상 변화 유도에 긍정적인 것은 사실이다. 또한 큰 규모의 홍수파는 하천지형의 동적활동을 촉진시키며, 이는 하천을 터전으로 서식하는 동물상을 위한 생태학적 여건을 개선시켜 주게 된다. 이는 주변 식생의 생태적 조건 변화에 도움을 주기 때문에 적어도 1년에 2번 정도의 홍수파방류는 하천주변 서식처의 다양성 변화에 필요한 것으로 보고되고 있다(Kondolf and Wilcock, 1996). 최근들어 댐 하류하천의 생태복원을 위해 연속적인 홍수파 방류의 중요성이 강조되고 있는데(Stanford et al, 1996) 자연하도에서 댐과 같은 구조물에 의한 유량조절은 하중도나 사주 등을 발달시키고 사주에서는 두꺼운 식생층이 형성될 뿐만아니라 수목군의 현저한 출현을 보여준다. 이렇게 사주나 식생이 고착됨에 따라 이의 저항을 피해가는 수로가 형성되고 저수로 구간외에서는 식생의 발달이 더욱 왕성해져 그 면적이 확대되고 있다. 결국 사주와 사주가 식생으로 연결되고 여기에 수목이 자라면서 웬만한 홍수에도 파괴되지 않는 거대한 식생대가 출현하게 되는데 우리나라에서도 많은 하천에서 볼 수 있는 현상이다. 또한 댐에 의한 퇴사의 차단은 하천지형의 불균형을 초래하고 식생의 발달과 함께 저수도부는 좁아지고 세굴에 의해 깊어지는 현상을 보인다. 이와같은 현상들은 수문특성의 변화에 의하여 결국 댐의 조절방류에 의한 수문 변화는 하천지형의 변화를 유발하고 하천지형의 변화는 하천환경에 변화를 미치게 된다. 본 연구에서는 실제적으로 댐이 건설된 지역에서 조사된 몇몇의 자료를 분석하여 댐건설후에 나타나는 부정적 영향을 최소화하기 위한 바람직한 댐운영방안을 제시하고자 한다.

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Progressive Collapse Resisting Capacity of Moment Frames with Viscous Dampers (점성감쇠기가 설치된 모멘트골조의 연쇄붕괴 저항성능)

  • Kim, Jin-Koo;Lee, Seung-Jun;Choi, Hyun-Hoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.23 no.5
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    • pp.517-524
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    • 2010
  • In this paper the progressive collapse resisting capacity of steel moment frames with viscous dampers was evaluated by nonlinear dynamic analysis. The effects of dampers installed in steel beam-column sub-assemblages with varying natural period and yield strength were evaluated after sudden removal of a column. According to the parametric study the vertical displacement general decreased as the damping ratio of the system increased, and the dampers were effective both in elastic and elasto-plastic systems. The nonlinear dynamic analysis results of the 15-story analysis models showed that the decrease in vertical deflection of the structure with 9m span length, which showed larger deflection, was more predominant than that of the structure with 6m span length.

3D Image Mergence using Weighted Bipartite Matching Method based on Minimum Distance (최소 거리 기반 가중치 이분 분할 매칭 방법을 이용한 3차원 영상 정합)

  • Jang, Taek-Jun;Joo, Ki-See;Jang, Bog-Ju;Kang, Kyeang-Yeong
    • Journal of Advanced Navigation Technology
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    • v.12 no.5
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    • pp.494-501
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    • 2008
  • In this paper, to merge whole 3D information of an occluded body from view point, the new image merging algorithm is introduced after obtaining images of body on the turn table from 4 directions. The two images represented by polygon meshes are merged using weight bipartite matching method with different weights according to coordinates and axes based on minimum distance since two images merged don't present abrupt variation of 3D coordinates and scan direction is one direction. To obtain entire 3D information of body, these steps are repeated 3 times since the obtained images are 4. This proposed method has advantage 200 - 300% searching time reduction rather than conventional branch and bound, dynamic programming, and hungarian method though the matching accuracy rate is a little bit less than these methods.

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A Fair Scheduling of Heterogeneous Multi-Server Systems by Cumulative Extra Capacity Sharing (누적적 잉여용량 공유를 통한 이질적 다중 서버 시스템의 공정 스케줄링)

  • Park, Kyeong-Ho;Hwang, Ho-Young
    • The KIPS Transactions:PartA
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    • v.14A no.7
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    • pp.451-456
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    • 2007
  • In this paper, we regard computer systems as heterogeneous multi-server systems and propose a cumulative fair scheduling scheme that pursues long-term fairness. GPS(generalized processor sharing)-based scheduling algorithms, which are usually employed in single-server systems, distribute available capacity in an instantaneous manner. However, applying them to heterogeneous multi-server systems may cause unfairness, since they may not prevent the accumulation of scheduling delays and the extra capacities are distributed in an instantaneous manner. In our scheme, long-term fairness is pursued by proper distribution of extra capacities while guaranteeing reserved capacities. A reference capacity model to determine the ideal progresses of applications is derived from long-term observations, and the scheduler makes the applications gradually follow the ideal progresses while guaranteeing their reserved capacities. A heuristic scheduling algorithm is proposed and the scheme is examined by simulation.

Parametric Design of Contact-Free Transportation System Using The Repulsive Electrodynamic Wheels (반발식 동전기 휠을 이용한 비접촉 반송 시스템의 변수 설계)

  • Jung, Kwang Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.3
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    • pp.310-316
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    • 2016
  • We propose a novel contact-free transportation system in which an axial electrodynamic wheel is applied as an actuator. When the electrodynamic wheel is partially overlapped by a fixed conductive plate and rotates over it, three-axis magnetic forces are generated on the wheel. Among these forces, those in the gravitational direction and the lateral direction are inherently stable. Therefore, only the force in the longitudinal direction needs to be controlled to guarantee spatial stability of the wheel. The electrodynamic wheel consists of permanent magnets that are repeated and polarized periodically along the circumferential direction. The basic geometric configuration and the pole number of the wheel influence the stability margin of a transportation system, which would include several wheels. The overlap region between the wheel and the conductive plate is a dominant factor affecting the stiffness in the lateral direction. Therefore, sensitivity analysis for the major parameters of the wheel mechanism was performed using a finite element tool. The system was manufactured based on the obtained design values, and the passive stability of a moving object with the wheels was verified experimentally.

A Study on the Flow Control Mechanism based on RTP/RTCP for Real-Time Traffic Transmission (실시간 트래픽 전송을 위한 RTP/RTCP의 흐름제어 기법 연구)

  • Choi, Hyun-Ah;Song, Buk-Sub;Kim, Jeong-Ho
    • Proceedings of the Korea Contents Association Conference
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    • 2007.11a
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    • pp.60-64
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    • 2007
  • Increasing using multimedia services as VoIP, Video conference, DMB, IPTV, etc, it is necessary to increase network traffics and develop the mechanism about a flow control for real time traffic transmission. In order to transfer realtime multimedia data, the transfer rate can be control on network state data measuring packet losses of a receiver and delay time of packets through getting periodical feedback RTP/RTCP packet. This paper describes using efficiant flow control on multicast that can reduce errors according to getting feedback tranfer delay and proposes the mechanism that can adapt dynamic change of network. In simulation, the transfer rate can efficiently be control on dynamic change of network and it makes the maximum of the use of a bandwidth and the minimum of packet losses.

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An Adaptive Neighbor Discovery for Tactical Airborne Networks with Directional Antenna (지향성 안테나 기반 공중전술네트워크를 위한 적응적 이웃노드 탐색기법)

  • Lee, Sung-Won;Yoon, Sun-Joong;Ko, Young-Bae
    • Journal of KIISE:Information Networking
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    • v.37 no.1
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    • pp.1-7
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    • 2010
  • Network Centric Warfare(NCW) is becoming a prominent concept in the current trend of warfare. To support high quality communication between strategic/tactical units in the concept of NCW, Tactical Airborne Networks are likely to be constructed in the near future to take part in the NCW. In these Tactical Airborne Networks with dynamic topology variations due to very high mobility of participants nodes, more efficient and reliable neighbor discovery protocols are needed. This paper presents the adaptive HELLO message scheduling algorithm for Tactical Airborne Network using directional antennas. The purposed algorithm can reduce the overhead of periodic HELLO message transfer, while guaranteeing successful data transmission. We concluded a mathematical analysis and simulation studies using Qualnet 4.5 for evaluation the performance and efficiency of the proposed scheme.