• Title/Summary/Keyword: Map Size

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Performance Analysis of MAP Algorithm by Robust Equalization Techniques in Nongaussian Noise Channel (비가우시안 잡음 채널에서 Robust 등화기법을 이용한 터보 부호의 MAP 알고리즘 성능분석)

  • 소성열
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.9A
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    • pp.1290-1298
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    • 2000
  • Turbo Code decoder is an iterate decoding technology, which extracts extrinsic information from the bit to be decoded by calculating both forward and backward metrics, and uses the information to the next decoding step Turbo Code shows excellent performance, approaching Shannon Limit at the view of BER, when the size of Interleaver is big and iterate decoding is run enough. But it has the problems which are increased complexity and delay and difficulty of real-time processing due to Interleaver and iterate decoding. In this paper, it is analyzed that MAP(maximum a posteriori) algorithm which is used as one of Turbo Code decoding, and the factor which determines its performance. MAP algorithm proceeds iterate decoding by determining soft decision value through the environment and transition probability between all adjacent bits and received symbols. Therefore, to improve the performance of MAP algorithm, the trust between adjacent received symbols must be ensured. However, MAP algorithm itself, can not do any action for ensuring so the conclusion is that it is needed more algorithm, so to decrease iterate decoding. Consequently, MAP algorithm and Turbo Code performance are analyzed in the nongaussian channel applying Robust equalization technique in order to input more trusted information into MAP algorithm for the received symbols.

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Crack Prevention of Very-Early Strength Latex-Modified Concrete (초속경 라텍스개질 콘크리트의 균열 억제방안)

  • Lee, Bong-Hak;Choi, Pan-Gil
    • Journal of Industrial Technology
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    • v.28 no.A
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    • pp.89-96
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    • 2008
  • An increase in the amount of cracking in repaired concrete bridge decks using VES-LMC(Very Early Strength - Latex Modified Concrete ; below VES-LMC) has been noticed by Yun et al(1). Literature indicates that indeed many concrete bridge decks develop transverse cracking, most developing at early ages(3~7 days), many right after construction. The purpose of this study was to establish prevention of map, transverse and longitudinal cracking in VES-LMC and to provide a control methods for minimizing the occurrence of cracks. The proposed prevention against map and transverse cracking was verified by field applications. VES cement was modified, the unit cement contents was reduced into $360kg/m^3$ from $390kg/m^3$, the maximum size of coarse aggregate was increase into 19mm from 13mm, wire mesh and steel fibers were incorporated in concrete mixture. A series of variable combinations were attempted. As a results, the proposed prevention against map and transverse cracking was verified because no crack were occurred until 90 days after overlay.

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Modified Delaunay Mesh generation adapted to the mesh density map (격자밀도에 적응하는 드로우니 격자 생성방법)

  • 홍진태;이석렬;양동열
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10a
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    • pp.159-162
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    • 2003
  • The remeshing algorithm using the constrained Delaunay method adapted to the mesh density map is developed. In the finite element simulation of forging process, the numerical error increases as the process goes on. However, it is not desirable to use a uniformly fine mesh in the whole domain. Therefore, it is necessary to reduce the analysis error by constructing locally fine mesh at the region where the error is concentrated such as die corner. In this paper, the point insertion algorithm is used and mesh size is controlled by using a mesh density map constructed with a posteriori error estimation. And an optimized smoothing technique is adapted to have smooth distribution and improve the quality of the mesh.

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An Enhancement of Ultrasonic Based Map-building Using Newton Interpolation (뉴턴 보간법을 이용한 초음파센서 기반의 맵빌딩 개선)

  • Choi, Kyung-Sik;Choi, Jung-Won;Lee, Suk-Gyu
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.8
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    • pp.62-71
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    • 2009
  • In mobile robotics, ultrasonic sensors became one of the most popular devices for collision avoidance and navigation primarily due to data robustness, the easy availability of low-cost systems, their compact size, simple circuits, and their ease in interfacing with computers. However, ultrasonic sonic sensors are subject to noise which results in inaccuracy of mapping and localization of the robot. This paper introduces a new approach to enhance environmental maps based on ultrasonic range data using linear interpolation and Newton interpolation. The simulation and experimental results show that the proposed method improves of the accuracy of the map through better distance estimation between the mobile robot and obstacles.

Adaptive Delaunay Mesh Generation Technique Based on a Posteriori Error Estimation and a Node Density Map (오차 예측과 격자밀도 지도를 이용한 적응 Delaunay 격자생성방법)

  • 홍진태;이석렬;박철현;양동열
    • Transactions of Materials Processing
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    • v.13 no.4
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    • pp.334-341
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    • 2004
  • In this study, a remeshing algorithm adapted to the mesh density map using the Delaunay mesh generation method is developed. In the finite element simulation of forging process, the numerical error increases as the process goes on because of discrete property of the finite elements and distortion of elements. Especially, in the region where stresses and strains are concentrated, the numerical error will be highly increased. However, it is not desirable to use a uniformly fine mesh in the whole domain. Therefore, it is necessary to reduce the analysis error by constructing locally refined mesh at the region where the error is concentrated such as at the die corner. In this paper, the point insertion algorithm is used and the mesh size is controlled by using a mesh density map constructed with a posteriori error estimation. An optimized smoothing technique is adopted to have smooth distribution of the mesh and improve the mesh element quality.

A Study on the Site Information of Urban (도시의 지형적 입지정보에 관한 연구)

  • Youn, In-Hyeok
    • The Journal of Information Technology
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    • v.10 no.2
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    • pp.1-9
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    • 2007
  • This study analyzed major cities of Chung-cheong area in Korea, -Daejeon($36^{\circ}11'{\sim}36^{\circ}30'\;N$, $127^{\circ}15'{\sim}127{\circ}34'\;E$), Chungju($36^{\circ}54'{\sim}37{\circ}02'\;N$, $127^{\circ}52'{\sim}128^{\circ}02'\;E$), and Cheongju($36^{\circ}34'{\sim}36^{\circ}44'\;N$, $127^{\circ}22'{\sim}127^{\circ}34'\;E$)- their characteristics as a Information Site. The geology map, a summit level map, and a drainage network map are created and analyzed the Site. The results are as follows : First, the geology of these cities are related with the shapes and the characteristics of the inner basins. The relief of inner basin determines by the characteristics of the bedrocks. Second, the major cities are close to rivers and the size of the granite & alluvium area influences the relief energy of the urban areas. Finally, the drainage networks explains the process involved in forming the basin and development of urban area.

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Improved Super-Resolution Algorithm using MAP based on Bayesian Approach

  • Jang, Jae-Lyong;Cho, Hyo-Moon;Cho, Sang-Bock
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.35-37
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    • 2007
  • Super resolution using stochastic approach which based on the Bayesian approach is to easy modeling for a priori knowledge. Generally, the Bayesian estimation is used when the posterior probability density function of the original image can be established. In this paper, we introduced the improved MAP algorithm based on Bayesian which is stochastic approach in spatial domain. And we presented the observation model between the HR images and LR images applied with MAP reconstruction method which is one of the major in the SR grid construction. Its test results, which are operation speed, chip size and output high resolution image Quality. are significantly improved.

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Hierarchical stereo matching using feature extraction of an image

  • Kim, Tae-June;Yoo, Ji-Sang
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.99-102
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    • 2009
  • In this paper a hierarchical stereo matching algorithm based on feature extraction is proposed. The boundary (edge) as feature point in an image is first obtained by segmenting an image into red, green, blue and white regions. With the obtained boundary information, disparities are extracted by matching window on the image boundary, and the initial disparity map is generated when assigned the same disparity to neighbor pixels. The final disparity map is created with the initial disparity. The regions with the same initial disparity are classified into the regions with the same color and we search the disparity again in each region with the same color by changing block size and search range. The experiment results are evaluated on the Middlebury data set and it show that the proposed algorithm performed better than a phase based algorithm in the sense that only about 14% of the disparities for the entire image are inaccurate in the final disparity map. Furthermore, it was verified that the boundary of each region with the same disparity was clearly distinguished.

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The Design and Prototype Presentation of Web-based Geographic Information System for Irrigation Facilities (농업수리시설물의 웹 기반 지리정보시스템 설계 및 프로토타입 구현)

  • 고홍석;최진규;이정문;박순철;오동석;백영기
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.40 no.3
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    • pp.54-62
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    • 1998
  • This study is the part of development of information management system for irrigation facilities. It describes the design and prototype presentation of WISIF(Web-based geographic Information System for Irrigation Facilities). WISIF manages the IFDB(Irrigation Facilities DataBase) and offers geographic information of irrigation facilities from IFSDB(Irrigation Facilities Spatial DataBase) through World Wide Web. GeoMedia Web Map software of Intergraph is used to offer geographic information to users. GeoMedia Web Map generates vector format, so called ActivCGM. The file generated in ActiveCGM format can be downloaded fast since its size is so small and generated as an interactive map file since its format supports hyperlink.

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Landscape Structure and Ecological Restoration of Mt. Hwangryung in Pusan, korea (부산시 황령산의 경관구조와 생태적 복원)

  • 이창석;조현제
    • The Korean Journal of Ecology
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    • v.21 no.6
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    • pp.791-797
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    • 1998
  • An attempt to clarify the landscape structure of urban areas was carried out on Mt. Hwangryung located in the center of Pusan, southern Korea. By means of aerial photographs and field survey, a vegetation map including land-use pattern was made. Landscape structure was described by analyzing the vegetation map. Landscape element types were classified into secondary forest, introduced plantation, and other elements including urbanized area. almus firma and Pinus thunbergii communities, introduced plantation elements, formed matrix and some secondary forest elements and the other artificial plantations of small scale tended to distribute as small patches in such matrix. The number of patches per unit area in secondary forest elements was more than that in introduced plantation element. The result on patech size was vice versa. As the results of landscape ecological analyses, it was estimated that differentiation of patches recognized in community level would be related to artificial interference and those in sub-communities levels to natural process such as progression of succession. On the other hand, restoration plans in viewpoints of restoration and landscape ecology were suggested to improve ecological quality of Mt. hwangryung.

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