• Title/Summary/Keyword: topological information

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High-rate growth $YBa_2$$Cu_3$$O_{7-x}$ thick films and thickness dependence of critical current density (Y$Ba_2$$Cu_3$$O_{7-x}$ 후막의 고속 증착과 임계 전류 밀도의 두께 의존성)

  • Jo W.
    • Progress in Superconductivity
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    • v.6 no.1
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    • pp.13-18
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    • 2004
  • High-.ate in-situ$ YBa_2$Cu$Cu_3$$O_{7-x}$ (YBCO) film growth was demonstrated by means of the electron beam co-evaporation. Even though our oxygen pressure is low, ∼$5 ${\times}$10^{-5}$ Torr, we can synthesize as-grown superconducting YBCO films at a deposition rate of around 10 nm/s. Relatively high temperatures of around 90$0^{\circ}C$ was necessary in this process so far, and it suggests that this temperature at a given oxygen activity allows a Ba-Cu-O liquid formation along with an YBCO epitaxy. Local critical current density shows a clear correlation with local resistivity. Homogeneous transport properties with a large critical current density ($4 ∼ 5 MA/\textrm{cm}^2$ at 77K, 0T) are observed in top faulted region while it is found that the bottom part carries little supercurrent with a large local resistivity. Therefore, it is possible that thickness dependence of critical current density is closely related with a topological variation of good superconducting paths and/or grains in the film bodies. The information derived from it may be useful in the characterization and optimization of superconducting films for electrical power and other applications.

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A graph-based method for fitting planar B-spline curves with intersections

  • Bon, Pengbo;Luo, Gongning;Wang, Kuanquan
    • Journal of Computational Design and Engineering
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    • v.3 no.1
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    • pp.14-23
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    • 2016
  • The problem of fitting B-spline curves to planar point clouds is studied in this paper. A novel method is proposed to deal with the most challenging case where multiple intersecting curves or curves with self-intersection are necessary for shape representation. A method based on Delauney Triangulation of data points is developed to identify connected components which is also capable of removing outliers. A skeleton representation is utilized to represent the topological structure which is further used to create a weighted graph for deciding the merging of curve segments. Different to existing approaches which utilize local shape information near intersections, our method considers shape characteristics of curve segments in a larger scope and is thus capable of giving more satisfactory results. By fitting each group of data points with a B-spline curve, we solve the problems of curve structure reconstruction from point clouds, as well as the vectorization of simple line drawing images by drawing lines reconstruction.

Architectural Theories and Planning Concepts of Korean Residence, Soengyo-jang (전통주택(傳統住宅) 선교장(船橋莊)의 건축이론(建築理論)과 계획개념(計劃槪念) 연구 - 집합론적(集合論的) 해석(解釋)을 중심으로 -)

  • Kim, Bong-Ryol
    • Journal of architectural history
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    • v.7 no.1 s.14
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    • pp.31-48
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    • 1998
  • Soengyo-jang has some characteristics as the most great house, the special functions, and the non-regional type of house form. And it has constructed continuously for two centuries by many owners in the different generations, It needs a special research method ; which are consist of a) comprehension of background information from documents and oral instructed materials, b) pursuit of design process through the building survey, and c) theoretical interpretation about 'collectivism'. From the results of this research, it is revealed that the architectural purpose of this house was constructing 'a great manor'. At first phase, it had been a single ordinary house, at second, it had expanded to a complex including many housing clusters, and finally became to expand its dwelling territory into whole village. Its expansion was progressed by the four collecting phases of which were building, building cluster, group of clusters, and topological setting. Main design elements operated in each of collecting phases ; they were partial element of , exterior spaces of , a linear building of , and a pavilion of . The last two elements were also powerful datum.

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Group Key Management Scheme for Survelliance and Reconnaissance Sensor Networks based on Probabilistic Key Sharing (확률론적 키 공유를 통한 감시정찰 센서네트워크에서의 그룹 키 관리 기법)

  • Bae, Si-Hyun;Lee, Soo-Jin
    • Convergence Security Journal
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    • v.10 no.3
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    • pp.29-41
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    • 2010
  • Survelliance and Reconnaissance Sensor Network(SRSN) which can collect various tactical information within battlefield in real time plays an important role in NCW environment, of sensor to shooter architecture. However, due to the resource-limited characteristics of sensor nodes and the intrinsic attributes of sensor network such as wireless communication, the SRSN may be vulnerable to various attacks compared to traditional networks. Therefore, in this paper, we propose a new group key management scheme to guarantee confidentiality, integrity, availability, and authentication during the operation of the SRSN. Proposed scheme generates and distributes the group key based on the topological characteristic of the SRSN and the probabilistic key sharing. The communication cost for distributing the group key is O(logn).

On a Distributed Routing Control Scheme in Multistage Baseline Networks (다단계 베이스라인 네트워크에서의 분산 라우팅 제어 방법에 관한 연구)

  • Son, Yoo-Ek;Ahn, Gwang-Seon
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.6
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    • pp.15-22
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    • 1989
  • This paper presents a distributed routing scheme for allowing network control to be distributed through the switching elements of a multistage baseline network. The routing technique we use here is the destination tag scheme which uses the binary representation of a destination address as the reuting tag. With the topological properties of the network, we introduce a distributed algorithm which allows any connection from a source to arbitrary number of destinations. Also, the performance of the proposed method is evaluated by computer simulation, and the results of the method is compared to other schemes in terms of time complexity.

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$L_2$-Norm Pyramid--Based Search Algorithm for Fast VQ Encoding (고속 벡터 양자 부호화를 위한 $L_2$-평균 피라미드 기반 탐색 기법)

  • Song, Byeong-Cheol;Ra, Jong-Beom
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.1
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    • pp.32-39
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    • 2002
  • Vector quantization for image compression needs expensive encoding time to find the closest codeword to the input vector. This paper proposes a search algorithm for fast vector quantization encoding. Firstly, we derive a robust condition based on the efficient topological structure of the codebook to dramatically eliminate unnecessary matching operations from the search procedure. Then, we Propose a fast search algorithm using the elimination condition. Simulation results show that with little preprocessing and memory cost, the encoding time of the proposed algorithm is reduced significantly while the encoding quality remains the same with respect to the full search algorithm. It is also found that the Proposed algorithm outperforms the existing search algorithms.

Estimation of Branch Topology Errors in Power Networks by WLAN State Estimation (최소절대값 상태추정에 의한 전력계통 선로 토폴로지 에러의 추정)

  • Kim, Hong-Rae;Song, Gyeong-Bin
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.49 no.6
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    • pp.259-265
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    • 2000
  • The purpose of this paper is to detect and identify topological errors in order to maintain a reliable database for the state estimator. In this paper, a two stage estimation procedure is used to identify the topology errors. At the first stage, the WSAV state estimator which has characteristics to remove bad data during the estimation procedure is run for finding out the suspected branches at which topology errors take place. The resulting residuals are normalized and the measurements with significant normalized residuals are selected. A set of suspected branches is formed based on these selected measurements; if the selected measurement is a line flow, the corresponding branch is suspected; if it is an injection, then all the branches connecting the injection bus to its immediate neighbors are suspected. A new WLAV state estimator adding the branch flow errors in the state vector is developed to identify the branch topology errors. Sample cases of single topology error and topology error with a measurement error are applied to IEEE 14 bus test system.

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A Error Analysis of Scanning for Topological Data Construction in Geographic Information Systems (GIS의 지형자료 구축을 위한 SCANNING 방법의 오차분석)

  • Yoo, Hwan-Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.10 no.2
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    • pp.37-44
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    • 1992
  • Although scanners are much more expensive than other input devices expect for some low quality devices, raster scanner and vectorizing softwares have been used and will be used as a means for the data entry in GIS. In this study, the accuracy of raster data and vectorizing in data entry by scanning technology, the coverage generation are investigated. As a result, the deterioration of spatial resolution can be improved by using the histogram analysis and the line enhancement when we scan a map at a lower dpi. It is to be desired that a raster scanner dpi is selected 150 dpi or 200 dpi among five densities (75 dpi, 150, dpi, 200 dpi, 300 dpi, 400 dpi) in view of the storage of raster data and the RMSE of coverage generation. Also, it was very important role of the choice of trace parameters to trace raster data in the vectorizing procedure.

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Management Scheme of Urbanization Runoff Using XP-SWMM (XP-SWMM을 이용한 도시화 유역에서의 유출 관리 방안 연구)

  • Lee, Beum-hee;Chai, Jun-young
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.1167-1172
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    • 2004
  • Recently, runoff characteristics of urban area are changing because of the increase of impervious area by rapid increasing of population and industrialization, urbanization. It needs to extract the accurate topological and hydrological parameters of watersheds in order to manage water resource efficiently. In this paper, rainfall-runoff analysis in An-Yang stream basin was made using GIS(Geographic Information System) and XP-SWMM(Export Stormwater and Wastewater Management Model). The basin was divided into 13 sub-basins using GIS. The area, slope, width of each subcatchment and length, slop of each stream reach were acquired from topographic maps, and imperviousness rate, land use types, infiltration capacities of each subcatchment from land use maps and soil maps using GIS. We gave th runoff management method of urbanization area us ing XP-SWMM.

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Effect of watershed characteristics on the criteria of Flash Flood warning (유역인자의 특성이 경계경보발령 기준에 미치는 영향분석)

  • 양인태;김재철;김태환
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.11a
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    • pp.389-392
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    • 2004
  • A recent unusual change in the weather is formed as a localized heavy rain in a short time. This phenomenon has caused a flash flood, and flash floods extensively have damaged human lives many times. In large river's case, the extent of loss of lives and properties has been decreased through the flood warning system by flood control stations of each stream. However, the extent of damage in other small rivers has increased reversely. Therefore, it is necessary to establish a new flood warning system against flash floods instead of the existing flood warning system. It is a specific character that the damage from flash floods in mountain streams brings much more loss of lives than large river's flood. The purpose of this study is calculating the characteristic of flash floods in streams, analyzing topographical characteristics of water basin through applying GIS techniques with the calculation as mentioned above and researching what topographical conditions have influence on hydrological flash floods in water basin. The flash flood prediction model we used is made by GIUH (geomorphoclimatic instantaneous unit hydrograph) with hydrologic-topographical technology. As applying the flash flood prediction model, this is a procedure for calculating topographical information in basin: we made a topological data up out of database with utilizing GIS, and we also produced a DEM (digital elevation model) and used it as a topographical data for determining amount of flash floods.

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