• 제목/요약/키워드: cluster method

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Vehicle Instrument Cluster Layout Differentiation for Elderly Drivers

  • Kim, Sang-Hwan
    • 대한인간공학회지
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    • 제35권5호
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    • pp.449-464
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    • 2016
  • Objective: The objective of this study is to identify essential requirements of the instrument cluster's features and layout for elderly drivers through interview and paper prototyping. Background: Recent updates implemented in passenger vehicles require more complex information to be processed by drivers. Concurrently, a large portion of the US population, the baby boomer generation has aged, causing their physical and cognitive abilities to deter. Thus it is crucial that new methods be implemented into vehicle design in order to accommodate for the deterioration of mental and physical abilities. Method: Forty elderly drivers and twenty young drivers participated in this study. The test included three sessions including: 1) location value assessment to identify the priority of areas within the instrument cluster; 2) component value assessment to capture rankings of the degree of importance and frequency of use for possible instrument cluster components; and 3) paper prototyping to collect self-designed cluster with selection of designs for each component and location of features from each participant. Results: Results revealed differences in the area priority of the instrument cluster as well as the shape and location of component features for age and gender groups. Conclusion: The study provided insights on instrument cluster layout guidelines by proving elderly driver's mental model and preferred cluster design configurations to improve driving safety. Application: LCD-based vehicle instrument cluster design, with an adaptable feature configuration for cluster components and layouts.

항공기 요동보상을 위한 SAR시스템의 타이밍 제어 기법 (A Novel Timing Control Method for Airborne SAR Motion Compensation)

  • 이현익
    • 한국군사과학기술학회지
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    • 제13권3호
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    • pp.453-460
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    • 2010
  • For high quality image acquisition, compensating air-vehicle motion is essential for airborne SAR system. This paper describes a timing control based motion compensation method for airborne SAR system. Efficient timing control is critical for SAR system since it maintains many timing signals and timing setting for the signals should be updated frequently. This paper proposes Timing Cluster method as an efficient means for timing control of SAR system. Moreover, this paper suggests a simple and efficient method to compensate air-vehicle motion based on the Timing Cluster method. Timing Cluster method enables SAR system to control the timing in a timing noncritical way just maintaining little amount of information.

Web Server Cluster Load Balancing

  • Kyung Sung;Kim, Seok-Soo
    • Journal of information and communication convergence engineering
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    • 제2권2호
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    • pp.106-109
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    • 2004
  • This study designs a load balancer via direct routing that share a virtual service on a single IP address in the Linux system and suggests an efficient load balancing method to improve transmission speed in the web server cluster environment. It will increase performance and scalability with fast packet transfer and removing bottleneck problem by using TCP Splicing and Content-Aware Distributor method. This method is expected to be the noticeable technology that provides an important interface, which make application services for e-commerce effectively be applied to high-speed network infrastructure. At this time, it is required to study further on the optimum balancing method in the web server cluster environment so as to apply the hybrid (optimum load balancing method by software and hardware) method and improve the reuse of security cession based on high-speed TCP connections.

무선 센서 네트워크에서 에너지 효율적 클러스터 헤드 선정 기법 (Energy-Efficient Cluster Head Selection Method in Wireless Sensor Networks)

  • 남춘성;장경수;신호진;신동렬
    • 한국인터넷방송통신학회논문지
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    • 제10권2호
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    • pp.25-30
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    • 2010
  • 무선 센서 네트워크는 제한된 자원을 가지고 특정한 지역에 임의로 뿌려진 센서 노드가 자가 구성적으로 형성하는 네트워크를 말한다. 센서 네트워크의 확장성(scalability), 로드 밸런싱(load balancing) 그리고 네트워크 라이프타임(network lifetime)을 보장하기 위해서 네트워크를 지역적으로 관리하는 클러스터링 알고리즘이 필요하다. 이전의 클러스터링 알고리즘에서 클러스터 헤드를 선정할 때 노드의 위치 및 에너지를 알아내기 위해 추가적인 통신비용이 발생하고, 클러스터 간 불균형이 클러스터 헤드에게 과부하를 유발한다. 따라서 본 논문은 이러한 문제점들을 해결하기 위해 추가적인 통신비용과 클러스터 불균형을 고려하는 새로운 클러스터 헤드 선정 알고리즘을 제안한다. 제안된 알고리즘은 실험결과를 통해 기존의 방법보다 에너지 측면에서 효율적임을 보여준다.

Adaptive method for selecting Cluster Head according to the energy of the sensor node

  • Kim, Yong Min;LEE, WooSuk;Kwon, Oh Seok;Jung, Kyedong;Lee, Jong-Yong
    • International Journal of Advanced Culture Technology
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    • 제4권2호
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    • pp.19-26
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    • 2016
  • The most important factor in the wireless sensor network is the use of effective energy and increase in lifetime of the individual nodes in order to operate the wireless network more efficiently. For this purpose, various routing protocols have been developed. The LEACH such a protocol, well known among typical cluster routing protocols. However, when a cluster head is selected, the energy consumption may not be equal because it does not take into account the energy of the nodes. In this paper, we seek to improve the cluster head selection method according to residual energy of each sensor node. This method then adaptively applies the LEACH algorithm and the cluster head section algorithm with consideration of node energy in accordance with the energy of the whole sensor field. Through the simulation, it was found that this proposed algorithm was effective.

센서 네트워크에서 클러스터 응집도를 이용한 에너지 절약 방안 (An Energy Saying Method using Cluster Cohesion in Sensor Networks)

  • 김진수
    • 한국산학기술학회논문지
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    • 제8권3호
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    • pp.569-575
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    • 2007
  • 본 논문에서는 에너지 소비를 줄여 네트워크의 수명을 길게 하는 연구에 주안점을 두고 있고, 센서 네트워크의 수명을 길게 하기 위해 각 센서 및 클러스터 헤드에서의 데이터 전송량을 줄이기 위한 방법을 제안한다. 센서의 에너지 소모를 줄이는 가장 중요한 요소는 전송되는 메시지 수를 줄이는 것이다. 본 연구에서는 그러한 목적을 달성하기 위해 클러스터 응집도를 제안한다. 그 방법은 네트워크 토폴로지 측면에서 클러스터 응집도를 이용하여 클러스터 수를 적응적으로 조정하여 메시지 전송량을 줄이는 것이다. 이 기법은 네트워크 소통량을 크게 줄이고 네트워크의 수명을 연장시키는데 있어서 더 효율적이고 또한 효과적인 방법이다.

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이동 에드-혹 네트워크에서 조합 가중치 클러스터링 알고리즘에 의한 클러스터 그룹 멀티캐스트 (Cluster Group Multicast by Weighted Clustering Algorithm in Mobile Ad-hoc Networks)

  • 박양재;이정현
    • 전자공학회논문지CI
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    • 제41권3호
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    • pp.37-45
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    • 2004
  • 본 논문에서는 이동 에드-혹 네트워크에서 조합가중치 클러스터링 알고리즘을 적용하여 강건하고 신뢰성 있는 클러스터 기반의 그룹 멀티캐스트 방식을 제안한다. 에드-혹 네트워크는 고정된 통신 하부 구조의 도움 없이 이동 단말기로만 구성된 무선 네트워크이다. 제한된 대역폭과 높은 이동성으로 인하여 에드-혹 네트워크에서의 라우팅 프로토콜은 강건하고, 간단하면서 에너지 소비를 최소화하여야 한다. WCGM(Weighted Cluster Group Multicast)방식은 조합 가중치 다중 클러스터 기반 구조를 이용하고 기존의 FGMP(Forwarding Group Multicast Protocol)방식의 장점인 제한적인 플러딩에 의한 데이터 전달방식은 유지하면서 클러스터 헤드 선출 시 조합가중치를 적용한다. 이것은 안정적이며 강건한 데이터 전달 구조를 가지기 때문에 데이터 전달 구조를 유지하기 위한 오버헤드(Overhead)와 데이터 전달을 위한 오버헤드를 모두 줄이는 효과를 시뮬레이션을 통하여 검증하였다.

Bonded-cluster simulation of tool-rock interaction using advanced discrete element method

  • Liu, Weiji;Zhu, Xiaohua;Zhou, Yunlai;Li, Tao;Zhang, Xiangning
    • Structural Engineering and Mechanics
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    • 제72권4호
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    • pp.469-477
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    • 2019
  • The understanding of tool-rock interaction mechanism is of high essence for improving the rock breaking efficiency and optimizing the drilling parameters in mechanical rock breaking. In this study, the tool-rock interaction models of indentation and cutting are carried out by employing the discrete element method (DEM) to examine the rock failure modes of various brittleness rocks and critical indentation and cutting depths of the ductile to brittle failure mode transition. The results show that the cluster size and inter-cluster to intra-cluster bond strength ratio are the key factors which influence the UCS magnitude and the UCS to BTS ratio. The UCS to BTS strength ratio can be increased to a more realistic value using clustered rock model so that the characteristics of real rocks can be better represented. The critical indentation and cutting depth decrease with the brittleness of rock increases and the decreasing rate reduces dramatically against the brittleness value. This effort may lead to a better understanding of rock breaking mechanisms in mechanical excavation, and may contribute to the improvement in the design of rock excavation machines and the related parameters determination.

한국의 나노기술 분야에서 핵심 연구영역 도출에 관한 연구 -국가 연구개발사업 수준에서 기술군집분석의 적용- (A Study on Selecting the Key Research Areas in Nano-technology Field in Korea: An Application of Technology Cluster Analysis in National R&D Program)

  • 이용길;이세준;이재영
    • 기술혁신학회지
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    • 제6권2호
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    • pp.175-190
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    • 2003
  • This paper deals with the methods for selecting the key research areas, which fit for the large, multi-disciplinary, and long-term programs by making use of Technology Cluster Analysis. This method is applied to mano-technology field at the level of national R&D program. 56 nano-technologies are analyzed and grouped into three main clusters based on the survey data from 180 experts. Three main clusters are \circled1 naro-materials related cluster, \circled2 naro-device related cluster, and \circled3 naro-bio related cluster. These three clusters are coincided with the focused areas of nano-technology in Korea. Each cluster is analyzed in view of its competence position.

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