• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권5호
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• pp.1303-1315
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• 2012

In the draft of the IEEE 802.11s standard, a tree topology is established by the proactive tree-building mode of the Hybrid Wireless Mesh Protocol (HWMP). It is used for cases in which the root station (e.g., gateway) is an end point of the majority of the data connections. In the tree topology, the root or central stations (e.g., parent stations) are connected to the other stations (e.g., leaves) that are one level lower than the central station. Such mesh stations are likely to suffer heavily from contention in bottleneck links when the network has a high traffic load. Moreover, the dependence of the network on such stations is a point of vulnerability. A failure of the central station (e.g., a crash or simply going into sleep mode to save energy) can cripple the whole network in the tree topology. This causes performance degradation for end-to-end transmissions. In a connected mesh topology where the stations having two or more radio links between them are connected in such a way that if a failure subsists in any of the links, the other link could provide the redundancy to the network. We propose a scheme to utilize this characteristic by organizing the network into concentric tiers around the root mesh station. The tier structure facilitates path recovery and congestion control. The resulting mode is referred to as Tier-based Proactive Path Selection Mode (TPPSM). The performance of TPPSM is compared with the proactive tree mode of HWMP. Simulation results show that TPPSM has better performance.

• 국제초고층학회논문집
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• 제5권1호
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• pp.21-30
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• 2016

The structural efficiency of tall buildings heavily depends on the lateral stiffness and resistance capacity. Among those structural systems for tall buildings, outrigger system is one of the most common and efficient systems especially for those with relatively regular floor plan. The use of outriggers in building structures can be traced back from early 50 from the concept of deep beams. With the rise of building height, deep beams become concrete walls or now in a form of at least one story high steel truss type of outriggers. Because of the widened choice in material to be adopted in outriggers, the form and even the objective of using outrigger system is also changing. In the past, outrigger systems is only used to provide additional stiffness to reduce drift and deflection. New applications for outrigger systems now move to provide additional damping to reduce wind load and acceleration, and also could be used as structural fuse to protect the building under a severe earthquake condition. Besides analysis and member design, construction issue of outrigger systems is somehow cannot be separated. Axial shortening effect between core and perimeter structure is unavoidable. This paper presents a state-of-the-art review on the outrigger system in tall buildings including development history and applications of outrigger systems in tall buildings. The concept of outrigger system, optimum topology, and design and construction consideration will also be discussed and presented.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.463-467
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• 2006

Several segmentation algorithms have been proposed for DTM generation or building modeling from airborne LiDAR data. Three components are important for accurate segmentation: (i) the adjacent relationship of n-nearest points or mesh, etc. (ii) the effective decision parameters of height, slope, curvature, and plane condition, (iii) grouping methods. In this paper, we created the topology of point cloud data using the contour tree and implemented the region-growing Terrain and non-terrain points were classified correctly in the segmented data, which can be used also for feature classification.

• 한국전산구조공학회논문집
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• 제13권1호
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• pp.115-127
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• 2000

본 논문에서는 건물 구조 통합 구조설계 시스템의 구현을 위한 설계모델인 설계 객체 모델을 제안하였다. 건물 구조에 대한 구조 설계 정보를 단계(초기구조설계, 해석, 상세설계) / 계층(시스템, 서브시스템, 콤퍼넌트)별로 분류 모델링한 후, 제시된 요구조건에 대한 세부관점별 해결방법을 고려하여 설계 객체 모델을 개발하였다. 이와 같은 방법론을 통하여 시스템 구현을 고려한 설계 객체 모델의 체계적 분석과 모델링이 가능하였다. 제시된 설계 객체 모델은 계획 설계 측면의 설계정보 표현을 통하여 효율적인 설계정보의 관리가 가능하며, 위상 설계 객체에 의한 공간상 구조부재의 인식이 용이하고, 해석 관련 설계정보를 이해하기 용이한 표현으로 관리할 수 있게 한다.

• 한국농촌건축학회논문집
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• 제21권3호
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• pp.41-48
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• 2019

The purpose of this study is to understand whether the architecture of the mountain village conforms to the geography and local landscape, and become a unique scenic element. Also, the study is to grasp the status of the village landscape design elements. The methods and contents of the study were surveyed by field research with references in Biederbach community, an isolated mountain village in Southwestern Germany. The time frame for the survey research is July 2015. The contents of the study include the analysis of the village's landscape structure, architecture, and landscape design patterns. The following conclusions were reached through the above research process. First, the village landscape structure seen in the mid-distance view is the hilly scene of the alpine region, which houses the sloping terrain of Black Forest and surrounds the residential area with the grassland covered by the Black Forest. Second, the main elements of the town's landscape building are historical culture, traditional architecture, topology and nature, and artificial environmental design. Third, the landscape design utilizing the village's resources creates a sustainable community's residential environment.

• 대한공간정보학회지
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• 제9권1호
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• pp.27-38
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• 2001

1995년 국가GIS사업이 추진된 이래 수치지형도를 활용한 GIS 구축사업이 활발하게 진행되고 있으나, 수치지형도의 기하학적 결점 및 위상관계가 정립되어 있지 않아서 GIS 구축 시 바로 활용할 수 없는 실정이다. GIS 선진국에서는 속성 자료와 공간 자료간의 위상이 정립된 자료를 GIS 사용자들에게 제공해주고 있는데, 이 자료를 프레임워크 자료(Framework Data) 즉, 기본지리정보라 하며 공간정보의 가장 핵심적이고 기본이 되는 자료로 활용하고 있다. 본 연구에서는 국가 공간정보의 기본도가 되는 국가기본지리정보의 범위와 정의를 설정하였으며, 기본지리정보 중 도시기반정보구축에 있어 가장 핵심이 되고 기준이 되는 교통/도로 기본지리정보 구축과 품질관리 방안에 관한 연구를 수행하였다.

• 한국통신학회논문지
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• 제24권6B호
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• pp.1080-1087
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• 1999

VOD 서비스를 제공하기 위해서는 대용량의 저장매체와 전송 대역이 필요하며 이를 위해서는 막대한 네트워크 구축비용이 필요하다. 이러한 VOD 서비스 구축비용을 줄이기 위한 방법으로 분산 서버 구조를 바탕으로 한 망 계위 설계, topology에 따른 서버 위치 최적화, 프로그램 caching 등에 관한 연구가 현재 활발히 진행되고 있다. 본 논문에서는 분산 트리 구조의 망에서 하위 준위와 링크간의 물리적인 전송 대역의 차이에 따른 전체 준위의 변화와 비용의 관계를 분석하여 전체 준위 크기의 제한 조건을 도출하였으며, 각 노드에서의 가지수와 비용의 관계를 분석하여 물리적으로 주어진 링크간의 전송 대역의 차에 적합한 망 구조를 설계하였다. 따라서 본 연구 결과는 VOD 서비스 제공에 적합한 경제적인 망 구조 설계와 노드 설계에 활용될 수 있을 것으로 기대된다.

• Advances in Computational Design
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• 제1권1호
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• pp.1-25
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• 2016

Domes are architectural and elegant structures which cover a vast area with no interrupting columns in the middle, and with suitable shapes can be also economical. Domes are built in a wide variety of forms and specialized terms are available to describe them. According to their form, domes are given special names such as network, lamella, Schwedler, ribbed, and geodesic domes. In this paper, an optimum topology design algorithm is performed using the enhanced colliding bodies optimization (ECBO) method. The network, lamella, ribbed and Schwedler domes are studied to determine the optimum number of rings, the optimum height of crown and tubular sections of these domes. The minimum volume of each dome is taken as the objective function. A simple procedure is defined to determine the dome structures configurations. This procedure includes calculating the joint coordinates and element constructions. The design constraints are implemented according to the provision of LRFD-AISC (Load and Resistance Factor Design-American Institute of Steel Constitution). The wind loading act on domes according to ASCE 7-05 (American Society of Civil Engineers). This paper will explore the efficiency of various type of domes and compare them at the first stage to investigate the performance of these domes under different kind of loading. At the second stage the wind load on optimum design of domes are investigated for Schwedler dome. Optimization process is performed via ECBO algorithm to demonstrate the effectiveness and robustness of the ECBO in creating optimal design for domes.

• Steel and Composite Structures
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• 제15권5호
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• pp.519-538
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• 2013

The design optimization of a cold-formed steel portal frame building is considered in this paper. The proposed genetic algorithm (GA) optimizer considers both topology (i.e., frame spacing and pitch) and cross-sectional sizes of the main structural members as the decision variables. Previous GAs in the literature were characterized by poor convergence, including slow progress, that usually results in excessive computation times and/or frequent failure to achieve an optimal or near-optimal solution. This is the main issue addressed in this paper. In an effort to improve the performance of the conventional GA, a niching strategy is presented that is shown to be an effective means of enhancing the dissimilarity of the solutions in each generation of the GA. Thus, population diversity is maintained and premature convergence is reduced significantly. Through benchmark examples, it is shown that the efficient GA proposed generates optimal solutions more consistently. A parametric study was carried out, and the results included. They show significant variation in the optimal topology in terms of pitch and frame spacing for a range of typical column heights. They also show that the optimized design achieved large savings based on the cost of the main structural elements; the inclusion of knee braces at the eaves yield further savings in cost, that are significant.

• 한국컴퓨터정보학회논문지
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• 제13권6호
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• pp.233-241
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• 2008

최근 IP 멀티캐스팅 대신에 각광을 받고 있는 오버레이 멀티캐스팅은 다수의 사용자를 위하여 서버의 자원과 네트워크의 대역폭을 효율적으로 활용할 수 있는 스케줄링 기법이 필요하다. 따라서 본 논문에서는 효율적인 멀티미디어 서비스를 위하여 오버레이 멀티캐스팅 환경에서의 복합스트림 토폴로지 정책을 제안한다. 본 논문의 성능 평가를 위하여 본 논문과 유사성을 가진 Overcast[5]와 비교하여 멀티캐스트에 참여한 노드들의 RTT(Round Trip Time) 수치, 트리 구축시간에 따른 대역폭 소모량 측정, 그리고 수행시간에 따른 MOR 영향 실험을 하였다. 그 결과 약 $8{\sim}20%$의 성능의 향상을 보여 주었다.