• Title/Summary/Keyword: Corner Processing

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A Voronoi Distance Based Searching Technique for Fast Image Registration (고속 영상 정합을 위한 보르노이 거리 기반 분할 검색 기법)

  • Bae Ki-Tae;Chong Min-Yeong;Lee Chil-Woo
    • The KIPS Transactions:PartB
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    • v.12B no.3 s.99
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    • pp.265-272
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    • 2005
  • In this paper, we propose a technique which is speedily searching for correspondent points of two images using Voronoi-Distance, as an image registration method for feature based image mosaics. It extracts feature points in two images by the SUSAN corner detector, and then create not only the Voronoi Surface which has distance information among the feature points in the base image using a priority based Voronoi distance algorithm but also select the model area which has the maximum variance value of coordinates of the feature points in the model image. We propose a method for searching for the correspondent points in the Voronoi surface of the base image overlapped with the model area by use of the partitive search algorithm using queues. The feature of the method is that we can rapidly search for the correspondent points between adjacent images using the new Voronoi distance algorithm which has $O(width{\times}height{\times}logN)$ time complexity and the the partitive search algerian using queues which reduces the search range by a fourth at a time.

A Study on Gaze Tracking Based on Pupil Movement, Corneal Specular Reflections and Kalman Filter (동공 움직임, 각막 반사광 및 Kalman Filter 기반 시선 추적에 관한 연구)

  • Park, Kang-Ryoung;Ko, You-Jin;Lee, Eui-Chul
    • The KIPS Transactions:PartB
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    • v.16B no.3
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    • pp.203-214
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    • 2009
  • In this paper, we could simply compute the user's gaze position based on 2D relations between the pupil center and four corneal specular reflections formed by four IR-illuminators attached on each corner of a monitor, without considering the complex 3D relations among the camera, the monitor, and the pupil coordinates. Therefore, the objectives of our paper are to detect the pupil center and four corneal specular reflections exactly and to compensate for error factors which affect the gaze accuracy. In our method, we compensated for the kappa error between the calculated gaze position through the pupil center and actual gaze vector. We performed one time user calibration to compensate when the system started. Also, we robustly detected four corneal specular reflections that were important to calculate gaze position based on Kalman filter irrespective of the abrupt change of eye movement. Experimental results showed that the gaze detection error was about 1.0 degrees though there was the abrupt change of eye movement.

Detection of Red Tide Distribution in the Southern Coast of the Korea Waters using Landsat Image and Euclidian Distance (Landsat 영상과 유클리디언 거리측정 방법을 이용한 한반도 남부해역 적조영역 검출)

  • Sur, Hyung-Soo;Kim, Seok-Gyu;Lee, Chil-Woo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.4
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    • pp.1-13
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    • 2007
  • We make image that accumulate two principal component after change picture to use GLCM(Gray Level Co-Occurrence Matrix)'s texture feature information. And then these images use preprocess to achieved corner detection and area detection. Experiment results, two principle component conversion accumulation images had most informations about six kind textures by Eigen value 94.6%. When compared with red tide area that uses sea color and red tide area of image that have all principle component, displayed the most superior result. Also, we creates Euclidian space using Euclidian distance measurement about red tide area and clear sea. We identify of red tide area by red tide area and clear sea about random sea area through Euclidian distance and spatial distribution.

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Next-generation Sequencing for Environmental Biology - Full-fledged Environmental Genomics around the Corner (차세대 유전체 기술과 환경생물학 - 환경유전체학 시대를 맞이하여)

  • Song, Ju Yeon;Kim, Byung Kwon;Kwon, Soon-Kyeong;Kwak, Min-Jung;Kim, Jihyun F.
    • Korean Journal of Environmental Biology
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    • v.30 no.2
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    • pp.77-89
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    • 2012
  • With the advent of the genomics era powered by DNA sequencing technologies, life science is being transformed significantly and biological research and development have been accelerated. Environmental biology concerns the relationships among living organisms and their natural environment, which constitute the global biogeochemical cycle. As sustainability of the ecosystems depends on biodiversity, examining the structure and dynamics of the biotic constituents and fully grasping their genetic and metabolic capabilities are pivotal. The high-speed high-throughput next-generation sequencing can be applied to barcoding organisms either thriving or endangered and to decoding the whole genome information. Furthermore, diversity and the full gene complement of a microbial community can be elucidated and monitored through metagenomic approaches. With regard to human welfare, microbiomes of various human habitats such as gut, skin, mouth, stomach, and vagina, have been and are being scrutinized. To keep pace with the rapid increase of the sequencing capacity, various bioinformatic algorithms and software tools that even utilize supercomputers and cloud computing are being developed for processing and storage of massive data sets. Environmental genomics will be the major force in understanding the structure and function of ecosystems in nature as well as preserving, remediating, and bioprospecting them.

A Study on the Forming Characteristics of Clinching Joint Process (크린칭 접합의 성형특성에 관한 연구)

  • Jayasekara, V.R.;Noh, J.H.;Hwang, B.B.;Ham, K.C.;Jang, D.H.
    • Transactions of Materials Processing
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    • v.16 no.8
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    • pp.603-613
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    • 2007
  • This paper is concerned with joining of thin metal sheets by single stroke clinching process. This method has been used in sheet metal work as it is a simple process and offers the possibility of joining similar-dissimilar thin sheet metals. Clinching generates a joint by overlapping metal sheets deforming plastically by punching and squeezing sequence. AA 5754 aluminum alloy of 0.5 mm thick sheets have been selected as a modal material and the process has been simulated under different process conditions and the results have been analyzed in terms of the quality of clinch joints which are influenced mainly by tool geometries. The rigid-plastic finite element method is applied to analyses in this paper. Analysis is focused mainly on investigation of deformation and material flow patterns influenced by major geometrical parameters such as die diameter, die depth, groove width, and groove corner radius, respectively. To evaluate the quality of clinch joints, four controlling or evaluation parameters have been chosen and they are bottom, neck thickness of bottom and top sheets, and undercut thickness, respectively. It has been concluded from the simulation results that the die geometries such as die depth and diameters are the most decisive process parameters influencing on the quality of clinch joints, and the bottom thickness is the most important evaluation parameter to determine if the quality of clinch joints satisfies the demand for industrial application.

Numerical Study for the Improvement of Tapered-hole Clinching Joint Strength of Fiber Metal Laminates and Aluminum 5052 using the Taguchi Method (다구찌 기법을 이용한 섬유금속적층판과 Al 5052 합금의 경사 홀 클린칭 접합력 향상을 위한 수치적 연구)

  • Kang, D.S.;Lee, B.E.;Park, E.T.;Kim, J.;Kang, B.S.;Song, W.J.
    • Transactions of Materials Processing
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    • v.24 no.1
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    • pp.37-43
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    • 2015
  • The purpose of the current study is to improve the clinching joint strength of aluminum and fiber metal laminates (FMLs) comprised of three layers. The joining of FML and Al 5052 by a conventional clinching joint has some disadvantages such as necking of the upper sheet, lack of interlocking, defects caused by the vertical load, and especially loss of strength of the composite material due to the low ductility. In the current study, a tapered-hole clinching method is proposed as an alternative for the joining of Al 5052 and FMLs. A hole with a tapered shape is formed before the joining process. The design parameters were evaluated using the Taguchi method for the geometry of the tapered hole in order to determine the maximum separation load. The diameter of the punch corner, clearance, punch stroke and the tapered length were used as the main variables in the Taguchi method. In conclusion, the contribution ratio for each of the fours variable examined was 35.07%, 22.44%, 21.32% and 14.11%, respectively. In addition, the appropriate combination of the design parameters can make a 5% improvement in the vertical direction joint strength.

Experimental and FE Analyses of Hot Curvature-Forming for Aluminum Thick Plate Using Grid-Typed Hybrid Die (격자형 하이브리드 금형에 의한 열간 알루미늄후판 곡면성형공정해석 및 실험)

  • Lee, I.K.;Lee, J.M.;Son, Y.K.;Lee, C.J.;Kim, B.M.
    • Transactions of Materials Processing
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    • v.20 no.4
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    • pp.316-323
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    • 2011
  • The hot curvature-forming of large aluminum thick plate using a grid-typed hybrid die is a process for the production of a spherical LNG tank. Many variables such as the initial die surface quality, grid size, grid thickness, size of blank plate and cooling line design, control the success of the process. In addition, the plate used in this process is generally larger than $10{\times}10m$ in size. Thus, it is very difficult to predict the surface characteristics of the plate during forming and to measure the different parameters due to the high cost of the experiments. In order to optimize the process design for the grid-type die, the development of an analytical method to predict the surface characteristics of the final product in hot curvature-forming is needed. This paper described the development of the method and procedures for FE simulations of the hot curvature-forming process, including hot forming, air flow, cooling, and thermal deformation analyses. An experiment for a small scale model of the process was conducted to check the validity of the numerical method. The results showed that the curvature of the plate in the analysis agrees well with that of the experiment within 0.037 and 0.016% tolerance margins for its side and corner, respectively.

Decipherment of the Wooden Tablet Prescription Excavated at Anapji (안압지 출토 목간(木簡) 처방전의 석독(釋讀)에 대한 연구)

  • Lee, Deok-Ho;Lee, Sun-A;Kim, Nam-Il
    • Korean Journal of Oriental Medicine
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    • v.15 no.2
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    • pp.85-91
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    • 2009
  • The manufacture date of the number 198 wooden tablet excavated at Anapji is estimated to be between year 751 and 774. As medical artifacts around this period of time is scarce, the discovery of an artifact with distinct medical information such as names of medicinal drugs recorded in hand writing holds great value in the history of medicine. This wooden tablet was presumably a prescription for a medicinal formula. That the '灸' character which is a method of processing drugs is found after '甘草' indicates the possibility of this wooden tablet to be a practical form of prescription. On this slip, a certain sign can be found at the upper right corner of the names of drugs. This is thought to be an additional sign added to the original text. It seems to have been originated from the letter '了', based on the composition and finishing touches of the strokes, presumably to confirm the end of a work by adding the letter '了' which means 'to finish'. The base material of 靑黛 and 藍淀 are the same, and the two often took each other's place in a prescription. It is difficult to find an example of a formula where both drugs are included. Therefore, the prescription on the front with 靑黛, and the one on the back with 藍淀 of tablet 198 can be understood as separate formulas.

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Texture Classification Algorithm for Patch-based Image Processing (패치 기반 영상처리를 위한 텍스쳐 분류 알고리즘)

  • Yu, Seung Wan;Song, Byung Cheol
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.11
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    • pp.146-154
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    • 2014
  • The local binary pattern (LBP) scheme that is one of the texture classification methods normally uses the distribution of flat, edge and corner patterns. However, it cannot examine the edge direction and the pixel difference because it is a sort of binary pattern caused by thresholding. Furthermore, since it cannot consider the pixel distribution, it shows lower performance as the image size becomes larger. In order to solve this problem, we propose a sub-classification method using the edge direction distribution and eigen-matrix. The proposed sub-classification is applied to the particular texture patches which cannot be classified by LBP. First, we quantize the edge direction and compute its distribution. Second, we calculate the distribution of the largest value among eigenvalues derived from structure matrix. Simulation results show that the proposed method provides a higher classification performance of about 8 % than the existing method.

Key Point Extraction from LiDAR Data for 3D Modeling (3차원 모델링을 위한 라이다 데이터로부터 특징점 추출 방법)

  • Lee, Dae Geon;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.5
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    • pp.479-493
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    • 2016
  • LiDAR(Light Detection and Ranging) data acquired from ALS(Airborne Laser Scanner) has been intensively utilized to reconstruct object models. Especially, researches for 3D modeling from LiDAR data have been performed to establish high quality spatial information such as precise 3D city models and true orthoimages efficiently. To reconstruct object models from irregularly distributed LiDAR point clouds, sensor calibration, noise removal, filtering to separate objects from ground surfaces are required as pre-processing. Classification and segmentation based on geometric homogeneity of the features, grouping and representation of the segmented surfaces, topological analysis of the surface patches for modeling, and accuracy assessment are accompanied by modeling procedure. While many modeling methods are based on the segmentation process, this paper proposed to extract key points directly for building modeling without segmentation. The method was applied to simulated and real data sets with various roof shapes. The results demonstrate feasibility of the proposed method through the accuracy analysis.