• 한국소음진동공학회논문집
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• 제26권7호
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• pp.865-874
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• 2016

This research is concerned with the experimental investigation on the vibrations of a flexible two-link system for verifying the theoretical result from simplified equations of motion for the system along with the kinematical synthesis are proposed to simulate the elastic vibrations of a previous study. The structure consists of flexible two-links; The link 2 is attached to the end of the link 1. The link 1 is made of composite fiber reinforced polymer and the link 2 is an aluminum beam. In order to verify the theoretical result, a flexible two-link system operated by the AC and RC servo motors was constructed. Experimental results show that the dynamic modeling approach and the kinematical synthesis proposed in this paper are effective.

• 한국경영과학회지
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• 제30권2호
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• pp.1-11
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• 2005

The network structures of a hyperlinked environment can be a rich source of information about the contents of the environment and it provides effective means for understanding it. Recently, there have been a number of algorithms proposed analyzing hypertext link structure so as to determine the best authorities for a given topic or query. In this paper, we review the algorithm of mutual reinforcement relationship for finding hubs and authorities from World Wide Web, and suggest SHA, a new approach for link-structure analysis, which uses the relationships among a set of relative authoritative pages, a set of hub pages, and a set of super hub pages.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권2호
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• pp.143-149
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• 2017

Purpose: In recent years, weight reduction for improving fuel efficiency of the vehicle and cost reduction have been developed. The structure of suspension link is widely used as a single plate press structure which can reduce process and weight compared to existing pipe welding method. However, it was found that the lifetime of a single plate press structure is determined by initial defects that occurred during initial manufacturing rather than fatigue damage caused by driving. Methods: I research the mechanism of failure phenomenon of the single plate press assist arm of rear wheel. In addition, I investigate durability effect parameters to determine the link lifetime in inserting bush into single plate press process through durability test. Conclusion: I discover significant durability effect parameter in inserting bush into single plate press process. It is expected that the durability can be improved by suggesting a bush inserting process inspection guide for similar suspension link like single plate press structure.

• 한국정밀공학회지
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• 제15권1호
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• pp.60-68
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• 1998

Parallel link manipulators have an ability of more precise positioning than serial open-loop manipulators. However. general parallel link manipulators have been restricted to the real applications since they have limited workspace due to interference among actuators. In this study, we suggest a closed-loop manipulator with 6 degrees-of-freedom and with enlarged workspace. It consists of two parts for minimizing the interference among actuators. One part is lower structure with planar 3 degrees-of-freedom and the other is upper one with spatial 3 degrees-of-freedom. Forward kinematics and inverse kinematics are solved, research about singularity points are carried out and workspace is evaluated. The comparison of workspace between Stewart platform, which is the typical parallel link manipulator, and the suggested manipulator shows that the workspace of the latter is wider than that of the former. Especially, simulation results also show that the suggested manipulator is more suitable when there needs rotation in the end-effector.

• 한국전자통신학회논문지
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• 제12권6호
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• pp.1115-1120
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• 2017

본 논문에서는 다중경로 페이딩의 무인기 채널환경에서 무인기 속도에 따른 도플러 영향을 극복하기 위해 LMMSE(: Linear Minimum Mean Square Error) 알고리즘을 적용하였고, 파일럿 배치 및 패턴에 따른 영향성을 분석하였다. 모의 실험결과 파일럿 배치 및 패턴에 따라 성능 차이를 확인할 수 있었고, 본 논문에서 제시한 프레임 구조를 통해 실제 운용 환경에서도 고속의 무인기에 대해 안정적인 보조링크를 제공할 수 있음을 확인하였다.

• 디지털콘텐츠학회 논문지
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• 제12권1호
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• pp.133-139
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• 2011

구조화된 P2P (Structured Peer-to-peer) 네트워크는 지금까지 많은 관심을 받아왔다. 중앙 서버가 없는 분산 환경에서 구조화된 P2P 네트워크를 사용하면 원하는 자료를 로그 스케일의 검색 시간 안에 찾을 수 있다. 구조화된 P2P 네트워크의 이러한 특성을 유지하려면 그것의 링크 구조를 유지해야 한다. 네트워크에 노드가 빈번하게 참여, 이탈하는 상황에서 구조화된 P2P 네트워크를 운용하면 유효하지 않은 (unavailable) 링크가 발생하게 되고, 이러한 링크가 많아지면 검색 성능이 점차 떨어지게 된다. 구조화된 P2P 네트워크의 특성을 유지하기 위해 주로 사용 되어온 방법은 주기적으로 링크를 복구하는 것이다. 그러나 이 방법은 노드의 참여, 이탈 속도가 빈번하게 변하는 환경에서 충분히 링크를 복구하지 못하거나, 필요 이상의 메시지를 사용할 수 있는 단점을 가지고 있다. 본 논문은 노드의 참여, 이탈 속도에 대응하여 링크 복구 주기를 결정함으로써 노드가 참여, 이탈하는 속도가 동적으로 변화하는 환경에서 구조화된 P2P 네트워크의 특성을 유지할 수 있는 알고리듬을 제시한다. 시뮬레이션 결과 제시한 알고리듬은 다양한 노드의 이탈 속도에 대해 적절한 QoS를 유지함을 확인할 수 있었다.

• 한국전자통신학회논문지
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• 제15권3호
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• pp.457-464
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• 2020

한국군은 Link-11, Link-16 과 Link-K를 적용한 한국형 전술 데이터링크 체계 JTDLS(: Joint Tactical Data Link System)를 운용하고 있다. Link-11에서 Link-22로의 교체 시점이 도래함에 따라 JTDLS 완성형 사업에서는 기존의 전술 데이터링크 외에 Link-22 등의 전술 데이터링크 처리가 추가될 예정이다. 다양한 전술 데이터링크 메시지 처리를 위해 본 논문에서는 Link-K, Link-16, KVMF 등 다중 전술 데이터링크의 데이터를 처리 할 수 있는 데이터 관리 구조를 제안하고, DLP 측면에서 많은 데이터를 빠르게 처리하는 방안을 찾기 위한 Shared Memory, In-Memory DB, 자체개발 DB를 이용하여 모의시험을 진행하고, 그 결과를 확인해 보고자 한다.

• Steel and Composite Structures
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• 제20권1호
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• pp.107-125
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• 2016

Steel shear wall system has been used in recent years in tall buildings due to its appropriate behavior advantages such as stiffness, high strength, economic feasibility and high energy absorption capability. Coupled steel plate shear walls consist of two steel shear walls that are connected to each other by steel link beam at each floor level. In this article the frames of 3, 10, and 15 of (C-SPSW) floor with rigid connection were considered in three different lengths of 1.25, 2.5 and 3.75 meters and link beams with plastic section modulus of 100% to the panel beam at each floor level and analyzed using three pairs of accelerograms based on nonlinear dynamic analysis through ABAQUS software and then the performance of walls and link beams at base shear, drift, the period of structure, degree of coupling (DC) and dissipated energy evaluated. The results show that the (C-SPSW) system base shear increases with a decrease in the link beam length, and the drift, main period and dissipated energy of structure decreases. Also the link beam length has different effects on parameters of coupling degrees.

• 디지털융복합연구
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• 제5권2호
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• pp.91-98
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• 2007

Destination marketing organizations (DMO) have been building up the cyber city in the WWW. Website for DMO is a core channel to promote regional attractions. This research suggests the issue of criteria for evaluating DMO's performance in the Internet. The method of evaluation focuses on the structure in perspective of linkage based on small world theory and direct network. Convention & Visitors & Bureau (CVB) in tourism and travel industry playa role to promote and held the international meeting and exhibitions. CVB's websites evaluated according to web link structure and performance.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2005년도 춘계 학술대회
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• pp.67-72
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• 2005

The bonding structure of organic materials such as fluorinated amorphous carbon films was classified into two types due to the chemical shifts. The electrical properties of fluorinated amorphous carbon films also showed very different effect of two types notwithstanding a very little difference. Fluorinated amorphous carbon films with the cross-link breakage structure existed large leakage current resulting from effect of the electron tunneling. Increasing the cation due to the electron-deficient group increased the barrier height of the films with the cross-link amorphous structure, therefore the electric characteristic of the final materials with low dielectric constant was also improved. The lowest dielectric constant is 2.3 at the sample with the cross-link amorphous structure.