• Journal of Information Processing Systems
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• v.16 no.2
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• pp.406-420
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• 2020

In order to make up the deficiencies of the existing research results which cannot effectively deal with the nearest neighbor query based on the line segments in obstacle space, the k nearest neighbor query method of line segment in obstacle space is proposed and the STA_OLkNN algorithm under the circumstance of static obstacle data set is put forward. The query process is divided into two stages, including the filtering process and refining process. In the filtration process, according to the properties of the line segment Voronoi diagram, the corresponding pruning rules are proposed and the filtering algorithm is presented. In the refining process, according to the relationship of the position between the line segments, the corresponding distance expression method is put forward and the final result is obtained by comparing the distance. Theoretical research and experimental results show that the proposed algorithm can effectively deal with the problem of k nearest neighbor query of the line segment in the obstacle environment.

• The Transactions of the Korea Information Processing Society
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• v.6 no.8
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• pp.2213-2221
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• 1999

A line segment has a symmetrical property about its midpoint. With this symmetrical property for a line segment we have proposed a variant of Bresenham's line drawing algorithm that selects two pixels at the same time. It implies that bi-directional line drawing toward the midpoint of line segment from each-end be possible. Besiders, it can select two pixels using only one decision parameter, instead of two different parameters for each pixel. We also present a theoretical proof for the correctness of such a selection. Thus, we can reduce the time of generating line segment by approximately less than 5% compared to the Bresenham's method. Also, our experimental results show that the shape of line segment generated by the proposed approach is the exactly same as that of Bresenham's method.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.141-143
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• 2004

This paper represents 3D line segment extraction method, which can be used in generating 3D rooftop model. The core of our method is that 3D line segment is extracted by using line fitting of elevation data on 2D line coordinates of ortho-image. In order to use elevations in line fitting, the elevations should be reliable. To measure the reliability of elevation, in this paper, we employed the concept of self-consistency. We carry out the experiment of 3D line extraction using synthetic images generated from Avenches data set of Ascona aerial images.

• Journal of Korea Multimedia Society
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• v.11 no.3
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• pp.292-300
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• 2008

An algorithm for detecting a line segment in an image is presented using incremental pixel extension. We use a different approach from conventional algorithms, such as the Hough transform approach and the line segment grouping approach. The Canny edge is calculated and an arbitrary point is selected among the edge elements. After the arbitrary point is selected, a base line approximating the line segment is calculated and edge pixels within an arbitrary radius are selected. A weighted value is assigned to each edge pixel, which is selected by using the error of the distance and the direction between the pixel and the base line. A line segment is extracted by Jilting a line using the weighted least square method after determining whether selected pixels are linked or delinked using the sum comparison of the weights. The proposed algorithm is compared with two other methods and results show that our algorithm is faster and can detect the real line segment.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.4
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• pp.608-621
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• 1993

The Purposes of this study were 1)to find the body surface total line and segment line significantly(${\alpha}$=0.05) changed by the leg movement including all movement direction of hip joint, knee joint and ankle joint for the more functional clothing. 2)to classify them into 3 types-expansion type, contraction type, expansion & contraction type, and 3)to identify the characteristics of the body surface length changes. 10 Crosswise and 5 lengthwise body surface total lines and 48 crosswise & 39 lengthwise body surface segment lines of 26 female college students aged from 18 to 24 years were measured directly on the body surface and were analyzed by ANOVA & Multiple Comparison Test (Tukey). The results were as following : Body surface total lines significantly changed were all the body surface total lines except abdoman girth, 1/2thigh girth of lower leg and ankle girth, and these were classified into 3 types : Center front leg line belonged to expansion & contraction type, whereas lateral leg line, legscye girth, and total crotch length belonged to contraction type. The rest belonged to expansion type. Knee girth showed maximum expansion, whereas center front leg line showed maximum contraction. Body surface total lines have shown large expansion crosswise whereas lengthwise they have mainly shown contraction. At least more than one component segment line of each body surface total lines except abdoman girth and ankle girth have shown significant change. Top segment of inner leg line showed maximum expansion. whereas just below top segment of center front leg line showed maximum contraction. Crosswise all the body surface segment lines have shown expansion except inner back segments of thigh girth and 1/2thigh girth of upper leg which have shown contraction. Lengthwise they have shown both expansion and contraction according to the location of front or back, and below or upper 1/2thigh girth line except the component segment lines of lateral leg line, which has shown contraction only.(cf. figure 2. figure 3. and table 2-2).

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.177-181
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• 1999

This paper presents an algorithm for building detection from aerial image using segment measure function and line relation. In the detection algorithm proposed, edge detection, linear approximation and line linking are used and then line measure function is applied to each line segment in order to improve the accuracy of linear approximation. Parallelisms, orthogonalities are applied to the extracted liner segments to extract building. The algorithm was applied to aerial image and the buildings were accurately detected.

• International Journal of Advanced Culture Technology
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• v.6 no.4
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• pp.317-322
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• 2018

We use edge detection technique for the input image to extract the entire edges of the object in the image and then select only the edges that construct the outline of the object. By examining the positional relation between these pixels composing the outline, a simplified version of the outline of the object in the input image is generated by removing unnecessary pixels while maintaining the condition of connection of the outline. For each pixel constituting the outline, its direction is calculated by examining the positional relation with the next pixel. Then, we group the consecutive pixels with same direction into one and then change them to a line segment instead of a point. Among those line segments composing the outline of the object, a line segment whose length is smaller than a predefined minimum length of acceptable line segment is removed by merging it into one of the adjacent line segments. As a result, an outline composed of line segments of over a certain length is obtained through this process.

• Journal of the Korean Society of Costume
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• v.58 no.2
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• pp.162-180
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• 2008

The purpose of this study is to find the basic design factors that affect the changes in body surface lines caused by lower limb movements, thereby resulting in slacks that fit well regardless of whether the human form is static or in motion. Using unmarried female university students aged 18-24 as subjects, a total of 32 body surface lines (15 body surface total lines and 17 body surface segment lines) were measured in one static and 9 movement poses, The analysis first involved the calculation of the expansion and contraction rates per body part in body surface line in 9 lower limb movements, Second, a factor analysis was conducted using the expansion and contraction rates of these changes in body surface line. The results of this study are as follows, According to the factor analysis, basic design factors that affect changes in body surface lines comprised 8 types of factors as illustrated in fig, 2-fig, 9, which explained 79.2% of total variate for the variables studied, Factor 1, comprising the lower segment of center back leg line, center front leg line and inner leg line, and lower limb girth except midway thigh girth and ankle girth below hip girth, accounted for 30.3% of total variance, Factor 2, comprising waist girth, the total and upper segment of center back leg line and center tront leg line, and front and back segment of crotch length, explained 17.4% of total variance, Factor 3, the total and upper segment of lateral leg line at the center, accounted for 56.5% of total variance in accordance with Factors 1, 2, and 3, Factor 4 was the contracting upper part of lower leg between legscye girth and midway thigh girth, Factor 5 comprised the total and upper segment of inner leg line and posterior knee girth, Factor 6 was the total crotch length, Factor 7 was the ankle girth, Factor 8 was the abdomen girth.

• Journal of the Korean Society for Railway
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• v.16 no.2
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• pp.117-121
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• 2013

Railway line segment deterioration can be affected by rail tracks, subgrades, bridges, tunnels, and line shapes. In this paper, an evaluation method is presented for the railway line segment deterioration using the analytic hierarchy process (AHP) and data envelopment analysis (DEA). The importance weights can be assessed systematically for component facilities from numerous experts using AHP. The importance weights provided by experts may differ according to each expert; however, the DEA enables the evaluation of railway line segment deterioration that reflects the variety of expert opinions using these importance weights.

• Geophysics and Geophysical Exploration
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• v.25 no.1
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• pp.44-49
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• 2022

Closed-form expressions of vector gravity and gravity gradient tensor based on a line segment are derived. If a cylindrical object with axial symmetry is observed from a distance, it is possible to approximate it as a line segment; therefore, it is necessary to compute the gravity and the gravity gradient tensor due to a line source by using closed-form expressions. The gravitational potential for a line segment is defined as a one-dimensional integral, and this integral is differentiated with respect to the Cartesian coordinate system to derive the vector gravity. The expressions of the gravity gradient tensor are derived by differentiating the vector gravity once more in the same coordinate system.