• Title/Summary/Keyword: spatial moment

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Conditional Moment-based Classification of Patterns Using Spatial Information Based on Gibbs Random Fields (깁스확률장의 공간정보를 갖는 조건부 모멘트에 의한 패턴분류)

  • Kim, Ju-Sung;Yoon, Myoung-Young
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.6
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    • pp.1636-1645
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    • 1996
  • In this paper we proposed a new scheme for conditional two dimensional (2-D)moment-based classification of patterns on the basis of Gibbs random fields which are will suited for representing spatial continuity that is the characteristic of the most images. This implementation contains two parts: feature extraction and pattern classification. First of all, we extract feature vector which consists of conditional 2-D moments on the basis of estimated Gibbs parameter. Note that the extracted feature vectors are invariant under translation, rotation, size of patterns the corresponding template pattern. In order to evaluate the performance of the proposed scheme, classification experiments with training document sets of characters have been carried out on 486 66Mhz PC. Experiments reveal that the proposed scheme has high classification rate over 94%.

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Evaluation of Structural Performance of Joints Between Modules With Non-Symmetric Section (비대칭 단면으로 구성된 모듈 간 접합부의 구조 성능 평가)

  • Park, Keum-Sung;Lee, Sang-Sup;Moon, Ji-Ho
    • Journal of Korean Association for Spatial Structures
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    • v.19 no.2
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    • pp.35-42
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    • 2019
  • The purpose of this paper is to evaluate the structural performance of joints between modules with steel plate press forming type non-symmetric cross section. The main experimental variables are direction of load, whether vertical bolts are fastened, and whether the concrete inside the column is filled. A total of three experiments were performed for each variable. Experimental results show that the behavior of the joints dominated by the local buckling deformation of the upper and lower beam flanges of the module joints, and the final failure was the fracture of the column-beam welds. In case of short side direction, it is possible to secure the performance of intermediate moment frame (0.02 rad). In case of long side direction, it is evaluated that the performance of special moment frame (0.04 rad) is secured regardless of whether or not concrete is infilled in the column.

Experimental and Application Examples of Composite Beams Strengthened by Lower End Compression Member and Upper Tension Reinforcement (단부 하부 압축재와 상부 인장 철근으로 보강한 합성보의 실험 및 적용 사례 연구)

  • Oh, Jung-Keun;Shim, Nam-Ju
    • Journal of Korean Association for Spatial Structures
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    • v.19 no.1
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    • pp.83-91
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    • 2019
  • The BX composite beam is designed to have the same cross-section regardless of the size of the momentum, which is a disadvantage of the existing steel structure. Combination of the H-beam end compressive material and the H-section steel tensile reinforcement according to the moment size in a single span, It is possible to say that it is an excellent synthesis which increases the performance. When underground and overhead structures are constructed, it is possible to reduce the bending, increase lateral stiffness, reduce construction cost, and simplify joints. The seamability of the joining part is a simple steel composite beam because of the decrease of the beam damping at the center of the beam and the use of the end plate of the new end compressing material. In the case of structures with long span structure and high load, it is advantageous to reduce the material cost by designing large steel which is high in price at less than medium steel.

Experimental Evaluation of FREE NODE with Axial Load and Moment for Single Layer Free-Form Structures (축력과 모멘트를 동시에 받는 FREE NODE의 실험적 평가)

  • Oh, Jin-Tak;Chung, Kwang-Ryang;Kim, Do-Hyun
    • Journal of Korean Association for Spatial Structures
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    • v.14 no.1
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    • pp.51-59
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    • 2014
  • Single layer free-form structures are being highlighted in the field of architecture due to its attractive shape. In these structures, node connecting system is very important because the node must resist bending and axial stress simultaneously. So the local and global stabilities of entire structure can be determined by the stiffness of node system. In this study, therefore, various types of bending test with axial force were performed. As a result, bending capacity with axial force of a new spherical node for free-form structure could be performed and structural capacities were checked to use in real structure.

Singularity-Circumvented Computation of Green's Functions for 2D Periodic Structures in Homogeneous Medium

  • Kahng, Sung-Tek
    • Journal of electromagnetic engineering and science
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    • v.7 no.2
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    • pp.59-63
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    • 2007
  • This paper suggests a novel method to efficiently calculate the spatial-domain Green's functions of 2D electromagnetic problems Briefly speaking, this method combines spectral and spatial domain calculation schemes and prevents the Green's functions from poor convergence due to the singularities that complicate the process of the Method of Moment(MoM) applications For the validation of this proposed method, fields will be evaluated along the spatial distance including zero distance for 2D free-space and periodic homogeneous geometry The numerical results show the validity of the prosed method and correspondng physics.

Proposal of Singularity-Circumvented Green's Functions for 2D Periodic Structures in Homogeneous Medium (특이점이 제거된 2 차원 단일매질 주기구조에 대한 그린함수의 제안)

  • Kahng, Sung-Tek;Kim, Hyeong-Seok
    • Proceedings of the KIEE Conference
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    • 2006.10a
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    • pp.133-134
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    • 2006
  • In this paper, a novel method is presented for efficient calculation of the spatial-domain Green's functions of 2D electromagnetic problems. This method combines spectral and spatial domain calculation schemes and prevents the Green's functions from diverging at the singularities that complicate the process of the Method of Moment(MoM) application. For the validation of this proposed method, fields will be evaluated along the spatial distance including zero distance for 2D free-space and periodic homogeneous geometry. The numerical results show the validity of the prosed method and correspondng physics.

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Building DSMs Generation Integrating Three Line Scanner (TLS) and LiDAR

  • Suh, Yong-Cheol;Nakagawa , Masafumi
    • Korean Journal of Remote Sensing
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    • v.21 no.3
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    • pp.229-242
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    • 2005
  • Photogrammetry is a current method of GIS data acquisition. However, as a matter of fact, a large manpower and expenditure for making detailed 3D spatial information is required especially in urban areas where various buildings exist. There are no photogrammetric systems which can automate a process of spatial information acquisition completely. On the other hand, LiDAR has high potential of automating 3D spatial data acquisition because it can directly measure 3D coordinates of objects, but it is rather difficult to recognize the object with only LiDAR data, for its low resolution at this moment. With this background, we believe that it is very advantageous to integrate LiDAR data and stereo CCD images for more efficient and automated acquisition of the 3D spatial data with higher resolution. In this research, the automatic urban object recognition methodology was proposed by integrating ultra highresolution stereo images and LiDAR data. Moreover, a method to enable more reliable and detailed stereo matching method for CCD images was examined by using LiDAR data as an initial 3D data to determine the search range and to detect possibility of occlusions. Finally, intellectual DSMs, which were identified urban features with high resolution, were generated with high speed processing.

Designing Augmented Spatial Experiences of Architectural Heritage - Information Modeling for Intelligent Content Service Platform - (건축문화유산의 공간경험 디자인 - 지능형 콘텐츠 서비스 플랫폼과 정보표현체계 -)

  • Jang, Sun-Young;Kim, Seongjun;Kim, Sung-Ah
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.4
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    • pp.15-24
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    • 2019
  • Currently, museums and architectural heritage provide augmented user experiences by incorporating various media technologies. They still, however, suffer from the limitation of entertainment-based and the provision of location-based simple and repetitive contents. In addition, while acting as a key medium of experience for architectural heritage, the concept of space is not properly reflected in current services. The purpose of this study is to design user space experience considering such characteristics of architectural heritage. The spatial experience content and content production platform are defined. This software platform creates content that enhances the experience of the place by giving a context-based digital data associated with space and objects. The spatial experience content is designed as a series of experience sequences. The composition of the sequence borrows the method of film and narrative which segment and connect consecutive experiences on a scene basis considering user's detailed spatial experience. Therefore, content components can be combined and reproduced in various types. Augmented contents were extracted by using rule-based reasoning function of ontology at the moment. As a practical example of architectural heritage, the Seokjojeon Hall is used to reveal a spatial experience scenario.

Exclusion zones for GNSS signals when reconfiguring receiver hardware in the presence of narrowband RFI

  • Balaei, Asghar T.;Dempster, Andrew G.;Barnes, Joel
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.347-352
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    • 2006
  • Narrowband interference can severely degrade the performance of GPS receivers. Detecting the presence of interference and then characterizing it can lead to its removal. Receivers can be reconfigured to focus on other signals or satellites that are less vulnerable to that interference at that moment. Using hardware reconfigurability of FPGA receivers and characterizing the effect of narrowband interference on the GNSS signal quality lead us to a new RFI mitigation technique in which the highest quality and less vulnerable signal can be chosen at each moment. In the previous work [1], the post processing capability of a software GPS receiver, has been used to detect and characterize the CW interference. This is achieved by passing the GPS signal and the interference through the correlator. Then, using the conventional definition of C/No as the squared mean of the correlator output divided by its variance, the actual C/No for each satellite is calculated. In this work, first the 'Exclusion zone' for each satellite signal has been defined and then by using some experiments the effects of different parameters like signal power, jamming power and the environmental noise power on the Exclusion zone have been analyzed. By monitoring the Doppler frequency of each satellite and using the actual C/No of each satellite using the traditional definition of C/No and actual data from a software GPS receiver, the decision to reconfigure the receiver to other signal can be made.

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