• Title/Summary/Keyword: Merging point

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Spherical-Coordinate-Based Guiding System for Automatic 3D Shape Scanning (3D 형상정보 자동 수집을 위한 구면좌표계식 스캐닝 시스템)

  • Park, Sang Wook;Maeng, Hee-Young;Lee, Myoung Sang;Kwon, Kil Sun;Na, Mi-Sun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.9
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    • pp.1029-1036
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    • 2014
  • Several types of automatic 3D scanners are available for use in the 3D scanning industry, e.g., an automatic 3D scanner that uses a robot arm and one that uses an automatic rotary table. Specifically, these scanners are used to obtain a 3D shape using automatic assisting devices. Most of these scanners are required to perform numerous operations, such as merging, aligning, trimming, and filling holes. We are interested in developing an automatic 3D shape collection device using a spherical-coordinate-based guiding system. Then, the aim of the present study is to design an automatic guiding system that can automatically collect 3D shape data. We develop a 3D model of this system and measuring data which are collected by a personal computer. An optimal design of this system and the geometrical accuracy of the measured data are both evaluated using 3D modeling software. The developed system is then applied to an object having a highly complex shape and manifold sections. Our simulation results demonstrate that the developed system collects higher-quality 3D data than the conventional method.

Investigation on the Contamination of the Vicinity of Abandoned Coal Mines Located Near the Obong Darn and Preventive Measures (오봉댐 유역의 폐탄광에 의한 오염특성과 감소방안 연구)

  • Park, Sun Hwan;Chang, Yoon Young;Jeong, Jeong Ho;Son, Jeong Ho;Park, Seok Hyo
    • Journal of Environmental Impact Assessment
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    • v.16 no.2
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    • pp.143-156
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    • 2007
  • This study has researched the management status and the pollution level of water, soil, stream sediments of 11 abandoned coal mines out of a total of 12 within Obong-Dam area except Bukyung mine, which was submerged when constructing Obong-Dam, and selected areas which are in needs to have pollution control facilities in the first place. From the results of examination on the runoff at the waste rock pile and mineheads, the runoff from Sueun mine (pH, Fe, Al), Samwon mine (pH, Al), Wangdo mine (pH, Al), Mose mine (pH, Fe, Al) and Daeryeong mine (pH) exceeded the permissible discharge standards of the water quality, but the water at merging point with Obong-Dam after joined with Doma branch satisfied both Water Quality Standards and Drinking Water Quality Standards. In regard to groundwater contamination, it is found that areas where exceeded the Drinking Water Quality Standards are Wangdo mine (pH), Jangjae mine (pH, Zn), Daeryeong mine (pH) whereas all areas satisfied Soil Contamination Warning Standards of Soil Environmental Conservation Law. When comparing a research result on underwater sediments of branches of abandoned mines to the EPA Guidelines for classification of great lakes harbor sediments, Dongguk Gaerim (Fe), Jungwon mine (Fe), Daebo mine (Mn), Samwon mine (Mn) and Daeryeong mine (Mn) showed mid-level of contamination, whereas Sueun (Fe, Mn), Daebo mine (Fe), Woosung mine (Fe, Mn), Wangdo mine (Fe, Mn), Mose mine (Fe) and Daeryeong mine (Fe) showed high-level of contamination. In addition, contamination levels of underwater sediments in Wangsan and Doma branch where abandoned mine's branches merge together, Wangsan branch showed no contamination at all whereas Doma branch shows mid-level of contamination which reflect the Doma branch is affected by waste rock pile and minehead runoff of the abandoned mines in the Doma branch area. It is concluded that Mose mine and Sueun mine required treatment of acid mine drainage. and Wangdo, Jungwon, and Samwon mines were in need of mine tailing and erosion control work. The Samwon mine additionally required a control system for closed minehead runoff. Although the Samwon mine reached a high concentration of Al, Mn $Ca^{2+}$, $SO{_4}^{2-}$ in the runoff, the levels decreased after it was combined with a tributary. It has been concluded that after further monitoring of the cause of pollution, a preventive measure system may be needed to be built.

Abstracted Partitioned-Layer Index: A Top-k Query Processing Method Reducing the Number of Random Accesses of the Partitioned-Layer Index (요약된 Partitioned-Layer Index: Partitioned-Layer Index의 임의 접근 횟수를 줄이는 Top-k 질의 처리 방법)

  • Heo, Jun-Seok
    • Journal of Korea Multimedia Society
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    • v.13 no.9
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    • pp.1299-1313
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    • 2010
  • Top-k queries return k objects that users most want in the database. The Partitioned-Layer Index (simply, the PL -index) is a representative method for processing the top-k queries efficiently. The PL-index partitions the database into a number of smaller databases, and then, for each partitioned database, constructs a list of sublayers over the partitioned database. Here, the $i^{th}$ sublayer in the partitioned database has the objects that can be the top-i object in the partitioned one. To retrieve top k results, the PL-index merges the sublayer lists depending on the user's query. The PL-index has the advantage of reading a very small number of objects from the database when processing the queries. However, since many random accesses occur in merging the sublayer lists, query performance of the PL-index is not good in environments like disk-based databases. In this paper, we propose the Abstracted Partitioned-Layer Index (simply, the APL-index) that significantly improves the query performance of the PL-index in disk-based environments by reducing the number of random accesses. First, by abstracting each sublayer of the PL -index into a virtual (point) object, we transform the lists of sublayers into those of virtual objects (ie., the APL-index). Then, we virtually process the given query by using the APL-index and, accordingly, predict sublayers that are to be read when actually processing the query. Next, we read the sublayers predicted from each sublayer list at a time. Accordingly, we reduce the number of random accesses that occur in the PL-index. Experimental results using synthetic and real data sets show that our APL-index proposed can significantly reduce the number of random accesses occurring in the PL-index.

A New Clock Routing Algorithm for High Performance ICs (고성능 집적회로 설계를 위한 새로운 클락 배선)

  • 유광기;정정화
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.36C no.11
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    • pp.64-74
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    • 1999
  • A new clock skew optimization for clock routing using link-edge insertion is proposed in this paper. It satisfies the given skew bound and prevent the total wire length from increasing. As the clock skew is the major constraint for high speed synchronous ICs, it must be minimized in order to obtain high performance. But clock skew minimization can increase total wire length, therefore clock routing is performed within the given skew bound which can not induce the malfunction. Clock routing under the specified skew bound can decrease total wire length Not only total wire length and delay time minimization algorithm using merging point relocation method but also clock skew reduction algorithm using link-edge insertion technique between two nodes whose delay difference is large is proposed. The proposed algorithm construct a new clock routing topology which is generalized graph model while previous methods uses only tree-structured routing topology. A new cost function is designed in order to select two nodes which constitute link-edge. Using this cost function, delay difference or clock skew is reduced by connecting two nodes whose delay difference is large and distance difference is short. Furthermore, routing topology construction and wire sizing algorithm is developed to reduce clock delay. The proposed algorithm is implemented in C programming language. From the experimental results, we can get the delay reduction under the given skew bound.

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Torso Pattern Design for Korean Middle-Aged Women using 3D Human Body Scan Data (차원 인체 스캔 데이터를 활용한 한국 중년여성 토르소 원형 설계)

  • Kim, Hye-Jin;Park, Soon-Jee
    • Fashion & Textile Research Journal
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    • v.13 no.4
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    • pp.600-613
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    • 2011
  • The purpose of this study is to provide Torso pattern for Korean middle-aged women using 3D human body scan data. 155 women in their 40's or 50's were measured by Martin's anthropometry. Merging the data of 914 middle aged women provided by Korean agency for technology and standards, total of 1,069 subjects' data were analyzed. For data analysis, ANOVA, factor analysis and cluster analysis were done using SPSS PC+. And representative subject of each cluster was selected and they participated in 3D scanning and Torso pattern suggested for middle-aged women Torso pattern which investing the amount of ease according to each group for diffuse front interscye 30%, armscye circumference 30%, back interscye 40% using 3D human body scan data. The results of this study are as follows. Firstly, as a result of the factor analysis, the first factor was 'obesity index of body', The second factor was 'verticality size of body', The third factor was 'verticality length of upper bodice', The fourth factor was 'drop value to represent silhouette', and the fifth factor was 'physique of upper bodice'. And, middle-aged women type were classified 3 types according to the cluster analysis. Type 1(Y-type) was the long upper Torso with wide shoulder. Type 2(H-type) was flat-body type with comparatively thin upper bodice and thin lower bodice. And type 3(A-type) was the obese type with comparatively thin upper bodice and fat lower bodice. Secondly, using CAD program, point filtering was performed and approximated surface model was made. It used that generated surface smoothing corrected for abnormally extruded points and scattered points based on the curvature information. And 3D surfaces were flatted onto the plane by the internal tools of CAD program. Difference ratios of outline length and area between 3D curves and 2D plane were 0.42% and 0.54%, respectively. Third, wearing test by the sensory evaluation showed that distinct difference almost every category. The movement functionality test shows that, in all the tests which reveal significant differences, especially, 'comparison pattern A' experienced inconvenience to neck width and neck depth.

A Study on the Hyperspectral Image Classification with the Iterative Self-Organizing Unsupervised Spectral Angle Classification (반복최적화 무감독 분광각 분류 기법을 이용한 하이퍼스펙트럴 영상 분류에 관한 연구)

  • Jo Hyun-Gee;Kim Dae-Sung;Yu Ki-Yun;Kim Yong-Il
    • Korean Journal of Remote Sensing
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    • v.22 no.2
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    • pp.111-121
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    • 2006
  • The classification using spectral angle is a new approach based on the fact that the spectra of the same type of surface objects in RS data are approximately linearly scaled variations of one another due to atmospheric and topographic effects. There are many researches on the unsupervised classification using spectral angle recently. Nevertheless, there are only a few which consider the characteristics of Hyperspectral data. On this study, we propose the ISOMUSAC(Iterative Self-Organizing Modified Unsupervised Spectral Angle Classification) which can supplement the defects of previous unsupervised spectral angle classification. ISOMUSAC uses the Angle Division for the selection of seed points and calculates the center of clusters using spectral angle. In addition, ISOMUSAC perform the iterative merging and splitting clusters. As a result, the proposed algorithm can reduce the time of processing and generate better classification result than previous unsupervised classification algorithms by visual and quantitative analysis. For the comparison with previous unsupervised spectral angle classification by quantitative analysis, we propose Validity Index using spectral angle.

Development of Registration Post-Processing Technology to Homogenize the Density of the Scan Data of Earthwork Sites (토공현장 스캔데이터 밀도 균일화를 위한 정합 후처리 기술 개발)

  • Kim, Yonggun;Park, Suyeul;Kim, Seok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.5
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    • pp.689-699
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    • 2022
  • Recently, high productivity capabilities have been improved due to the application of advanced technologies in various industries, but in the construction industry, productivity improvements have been relatively low. Research on advanced technology for the construction industry is being conducted quickly to overcome the current low productivity. Among advanced technologies, 3D scan technology is widely used for creating 3D digital terrain models at construction sites. In particular, the 3D digital terrain model provides basic data for construction automation processes, such as earthwork machine guidance and control. The quality of the 3D digital terrain model has a lot of influence not only on the performance and acquisition environment of the 3D scanner, but also on the denoising, registration and merging process, which is a preprocessing process for creating a 3D digital terrain model after acquiring terrain scan data. Therefore, it is necessary to improve the terrain scan data processing performance. This study seeks to solve the problem of density inhomogeneity in terrain scan data that arises during the pre-processing step. The study suggests a 'pixel-based point cloud comparison algorithm' and verifies the performance of the algorithm using terrain scan data obtained at an actual earthwork site.

Survey of coastal topography using images from a single UAV (단일 UAV를 이용한 해안 지형 측량)

  • Noh, Hyoseob;Kim, Byunguk;Lee, Minjae;Park, Yong Sung;Bang, Ki Young;Yoo, Hojun
    • Journal of Korea Water Resources Association
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    • v.56 no.spc1
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    • pp.1027-1036
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    • 2023
  • Coastal topographic information is crucial in coastal management, but point measurment based approeaches, which are labor intensive, are generally applied to land and underwater, separately. This study introduces an efficient method enabling land and undetwater surveys using an unmanned aerial vehicle (UAV). This method involves applying two different algorithms to measure the topography on land and water depth, respectively, using UAV imagery and merge them to reconstruct whole coastal digital elevation model. Acquisition of the landside terrain is achieved using the Structure-from-Motion Multi-View Stereo technique with spatial scan imagery. Independently, underwater bathymetry is retrieved by employing a depth inversion technique with a drone-acquired wave field video. After merging the two digital elevation models into a local coordinate, interpolation is performed for areas where terrain measurement is not feasible, ultimately obtaining a continuous nearshore terrain. We applied the proposed survey technique to Jangsa Beach, South Korea, and verified that detailed terrain characteristics, such as berm, can be measured. The proposed UAV-based survey method has significant efficiency in terms of time, cost, and safety compared to existing methods.

Improving Performance of Recommendation Systems Using Topic Modeling (사용자 관심 이슈 분석을 통한 추천시스템 성능 향상 방안)

  • Choi, Seongi;Hyun, Yoonjin;Kim, Namgyu
    • Journal of Intelligence and Information Systems
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    • v.21 no.3
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    • pp.101-116
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    • 2015
  • Recently, due to the development of smart devices and social media, vast amounts of information with the various forms were accumulated. Particularly, considerable research efforts are being directed towards analyzing unstructured big data to resolve various social problems. Accordingly, focus of data-driven decision-making is being moved from structured data analysis to unstructured one. Also, in the field of recommendation system, which is the typical area of data-driven decision-making, the need of using unstructured data has been steadily increased to improve system performance. Approaches to improve the performance of recommendation systems can be found in two aspects- improving algorithms and acquiring useful data with high quality. Traditionally, most efforts to improve the performance of recommendation system were made by the former approach, while the latter approach has not attracted much attention relatively. In this sense, efforts to utilize unstructured data from variable sources are very timely and necessary. Particularly, as the interests of users are directly connected with their needs, identifying the interests of the user through unstructured big data analysis can be a crew for improving performance of recommendation systems. In this sense, this study proposes the methodology of improving recommendation system by measuring interests of the user. Specially, this study proposes the method to quantify interests of the user by analyzing user's internet usage patterns, and to predict user's repurchase based upon the discovered preferences. There are two important modules in this study. The first module predicts repurchase probability of each category through analyzing users' purchase history. We include the first module to our research scope for comparing the accuracy of traditional purchase-based prediction model to our new model presented in the second module. This procedure extracts purchase history of users. The core part of our methodology is in the second module. This module extracts users' interests by analyzing news articles the users have read. The second module constructs a correspondence matrix between topics and news articles by performing topic modeling on real world news articles. And then, the module analyzes users' news access patterns and then constructs a correspondence matrix between articles and users. After that, by merging the results of the previous processes in the second module, we can obtain a correspondence matrix between users and topics. This matrix describes users' interests in a structured manner. Finally, by using the matrix, the second module builds a model for predicting repurchase probability of each category. In this paper, we also provide experimental results of our performance evaluation. The outline of data used our experiments is as follows. We acquired web transaction data of 5,000 panels from a company that is specialized to analyzing ranks of internet sites. At first we extracted 15,000 URLs of news articles published from July 2012 to June 2013 from the original data and we crawled main contents of the news articles. After that we selected 2,615 users who have read at least one of the extracted news articles. Among the 2,615 users, we discovered that the number of target users who purchase at least one items from our target shopping mall 'G' is 359. In the experiments, we analyzed purchase history and news access records of the 359 internet users. From the performance evaluation, we found that our prediction model using both users' interests and purchase history outperforms a prediction model using only users' purchase history from a view point of misclassification ratio. In detail, our model outperformed the traditional one in appliance, beauty, computer, culture, digital, fashion, and sports categories when artificial neural network based models were used. Similarly, our model outperformed the traditional one in beauty, computer, digital, fashion, food, and furniture categories when decision tree based models were used although the improvement is very small.

A Study on changes in Hitting-pressing forms of flat plate in Gyeongju area -Short beating, Medium beating plate, long beating plate and Stamped-roof tile- (경주지역 평기와의 타날형태 변화에 대한 검토 -단판·중판·인장 그리고 장판으로-)

  • Cha, Soon-chul
    • Korean Journal of Heritage: History & Science
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    • v.40
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    • pp.73-104
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    • 2007
  • Centering around ruins recognized of being relatively early stage related to flat tile and brick, excavated in Silla capital area, the study attempted elementary approach to seek the appearance time of every remain through comparing them from the excavated cases and production methods of Short beating, Medium beating plate, Long beating plate and Stamped-roof tile. Gyeongju began to use the short beating plate made of tile-less plates or tile plate and increased its quantity. That is deemed to be due to efficiency of beating plate making methods, and moreover to be limited only for use in the palace castle and offices. That is, making short beating plates is presumed to be made merely under some definite objectives. Medium beating plate has been spread to the whole country since Silla and Baekje united. Differently from Koguryo and Baekje, Silla had its unique Beating-plates making technology available for mass-production, which was spread to the whole country and resulted in disappearing of Koguryo and Baekje technology. Long beating plate was not nearly founded in Gyeongju area, but flat tile and common tile excavated in Sachunwang Temple site and Samrang Temple 3rd remains are known. In the outskirts of Gyeongju, long beating plate appeared between the latter half of 8C and the beginning of 9C. Until now, different views have raised to appearance of long beating plate of Unified Silla, which is expected to be clarified under the situation excavated by position relations. Stamped-roof title in Gyeongju is estimated as used after the datum point year 679. While in Baekje area, five stems and branches were involved, in Silla area, code or sign was shown much. The difference between two areas would be due to each other factory, and especially the marked contents werenot letters, which means it had been changed from Baekje s existing-methods. That is, it says the production environment changed owing to Silla's merging. And stamped-roof tile was temporarily used in Gyeongju but soon disappeared, which was because Silla beating plates made under cylinder-shaped tile barrel(圓筒瓦桶) and hitting-pressing of Medium beating plate had beenspread to the whole country, so the production technology of Koguryo and Baekje was naturally dismissed. In consequence, the mergence by Silla brought about unification of each nation's special technology.