• Title/Summary/Keyword: Line-based

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Adaptable Center Detection of a Laser Line with a Normalization Approach using Hessian-matrix Eigenvalues

  • Xu, Guan;Sun, Lina;Li, Xiaotao;Su, Jian;Hao, Zhaobing;Lu, Xue
    • Journal of the Optical Society of Korea
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    • v.18 no.4
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    • pp.317-329
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    • 2014
  • In vision measurement systems based on structured light, the key point of detection precision is to determine accurately the central position of the projected laser line in the image. The purpose of this research is to extract laser line centers based on a decision function generated to distinguish the real centers from candidate points with a high recognition rate. First, preprocessing of an image adopting a difference image method is conducted to realize image segmentation of the laser line. Second, the feature points in an integral pixel level are selected as the initiating light line centers by the eigenvalues of the Hessian matrix. Third, according to the light intensity distribution of a laser line obeying a Gaussian distribution in transverse section and a constant distribution in longitudinal section, a normalized model of Hessian matrix eigenvalues for the candidate centers of the laser line is presented to balance reasonably the two eigenvalues that indicate the variation tendencies of the second-order partial derivatives of the Gaussian function and constant function, respectively. The proposed model integrates a Gaussian recognition function and a sinusoidal recognition function. The Gaussian recognition function estimates the characteristic that one eigenvalue approaches zero, and enhances the sensitivity of the decision function to that characteristic, which corresponds to the longitudinal direction of the laser line. The sinusoidal recognition function evaluates the feature that the other eigenvalue is negative with a large absolute value, making the decision function more sensitive to that feature, which is related to the transverse direction of the laser line. In the proposed model the decision function is weighted for higher values to the real centers synthetically, considering the properties in the longitudinal and transverse directions of the laser line. Moreover, this method provides a decision value from 0 to 1 for arbitrary candidate centers, which yields a normalized measure for different laser lines in different images. The normalized results of pixels close to 1 are determined to be the real centers by progressive scanning of the image columns. Finally, the zero point of a second-order Taylor expansion in the eigenvector's direction is employed to refine further the extraction results of the central points at the subpixel level. The experimental results show that the method based on this normalization model accurately extracts the coordinates of laser line centers and obtains a higher recognition rate in two group experiments.

A New line Matching Technique for Solving Correspondence Problem in Stereo Method (스테레오 방식에서 일치성 문제를 해결하기 위한 새로운 선소 정합법)

  • Kang, Dae-Kap;Kwon, Jung-Jang;Kim, Seong-Dae
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.3
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    • pp.116-123
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    • 1990
  • Most algorithms utilized the horizontal epipolar lines for solving the correspondence problem in 3-D computer vision. However, the requirement is very difficult to be satisfied in real situations. In this paper, we propose a binocular-stereo matching algorithm, based on line matching method, which does not require the horizontal epipolar lines of the extreme pixels of a given line segment and two circles whose radius is equal to the maximum disparity. And we use the features including the direction of line segments, edge strength and cross-correlation for line matching. The experimental results show that the proposed algorithm can be a useful tool for solving the correspondence problem in 3-D computer vision.

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Informativeness and Consumer Misleading Potentialities on the Internet Shopping Mall Sites -The Study of Comparison between On-line Market Place and Integrated Internet Stores- (인터넷 쇼핑몰 사이트에서의 정보성과 소비자 오도가능성 - 온라인 마켓 플레이스와 인터넷 종합쇼핑몰의 비교 -)

  • Kim, So-Ra
    • Journal of Families and Better Life
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    • v.26 no.1
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    • pp.15-29
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    • 2008
  • The study examined the characteristics of internet shopping mall sites including on-line market places and integrated internet stores from a perspective of consumer protection. Specifically, the study investigated 1) whether sufficient information is provided on the internet shopping mall sites, 2) whether shopping mall sites abide by internet advertising principles, and 3) specific examples of consumer misleading potentialities from internet shopping sites. Further, on-line market places and integrated internet stores were compared based on their informativeness and potential consumer misleading factors. Total 50 shopping mall sites were analyzed for examining the types of information provided and consumer misleading factors. To verify study questions, descriptive statistics were used. For comparison between on-line market places and integrated internet stores, Chi-square test and independent-sample t-test were employed. The results of this study were as the following: First, not a few of the internet shopping mall sites did not provided important information such as safety and warrantees. Second, important disclosures were not noticeable on the web pages and distracting factors were frequently used. Third, integrated internet stores were desirable compared to on-line marketplaces based on informativeness and consumer misleading potentialities. As the result of this study, internet shopping malls need to advised to provide sufficient information and reduce potential misleading factors.

A Study on Consumer's Response Depending on Congruent . Incongruent Shopping Situation -Focusing on the comparison of online shopping mall and off-line department store- (조화ㆍ부조화 쇼핑상황에서의 소비자 반응에 관한 연구 -온라인 인터넷쇼핑몰과 오프라인 백화점의 비교를 중심으로-)

  • 김원겸;김형순;박주영
    • Journal of Distribution Research
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    • v.8 no.2
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    • pp.1-18
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    • 2003
  • This study has tried an integrated approach toward consumer response difference between the online internet shopping mall and the off-line department store focusing on the moderating role of shopping value according to shopping situation. This study has analyzed consumer behavior differences between online and off-line channel formats in one framework and identified differences in consumer behaviors between the two channel formats. Managerial implications of this paper include measuring the effects of the integration of online and off-line channel and developing multichannel strategy. This paper suggests marketers to develop channel strategies based on customer segmentation criteria reflecting different consumer shopping value between online and off-line channel formats rather than developing strategies based only on the conventional marketing mix.

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Analysis of Line of Sight Stabilization Performance based on Direct vs. Indirect of a 2-axis Gimbaled Servo System for Millimeter Wave Seeker (밀리미터파 탐색기 2축 직구동 김발 서보 시스템의 직접 및 간접 시선안정화 성능 분석)

  • Shin, Seungchul;Lee, Sung-Yong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.11
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    • pp.1555-1561
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    • 2018
  • Tracking and detecting targets by the millimeter wave seeker is affected by movement of platform. Stabilization equipments use an inertial sensor to compensate for disturbance of stabilizing gimbal or platform. In the direct line of sight stabilization system, an inertial sensor is mounted on inner gimbal to compensate the disturbance directly, so the performance is excellent and the implementation method is simple. However gimbal design requires somewhat larger volume. Since an inertial sensor is mounted on gimbal base in the indirect line of sight stabilization system, additional space of gimbal is not required for the gimbal design. However, this method does not directly compensate for the disturbance of the line of sight stabilization axis, which can degrade performance. In order to perform the tracking performance, two methods are analyzed for line of sight stabilization performance based on direct and indirect of a 2-axis gimbaled servo system for millimeter wave seeker in this study. The simulation and experimental results validate the performance comparison of two methods.

Development of a Camera-based Position Measurement System for the RTGC with Environment Conditions (실외 주행환경을 고려한 카메라 기반의 RTGC 위치계측시스템 개발)

  • Kawai, Hideki;Kim, Young-Bok;Choi, Yong-Woon
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.9
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    • pp.892-896
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    • 2011
  • This paper describes a camera-based position measurement system for automatic tracking control of a rubber Tired Gantry Crane (RTGC). An automatic tracking control of RTGC depends on the ability to measure its displacement and angle from a guide line that the RTGC has to follow. The measurement system proposed in this paper is composed of a camera and a PC that are mounted on the right upper between front and rear tires of the RTGC's side. The measurement accuracy of the system is affected by disturbances such as cracks and stains of the guide line, shadows, and halation from the light fluctuation. To overcome the disturbances, both side edges of the guide line are detected as two straight lines from an input image taken by the camera, and parameters of the straight lines are determined by using Hough transform. The displacement and angle of the RTGC from the guide line can be obtained from these parameters with the robustness against the disturbances. From the experiments with the disturbances, we found the accurate displacement and the angle from the guide line that have the standard deviations of 0.95 pixels and 0.22 degrees, respectively.

Static and Dynamic Behavior of Tunable DFB Laser based on Modal Transmission-Line Theory (전송선로 이론에 기초한 파장 변환 DFB 레이저의 정적 및 동적 작용)

  • Ho, Kwang-Chun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.2
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    • pp.147-152
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    • 2014
  • A longitudinal modal transmission-line theory(L-MTLT) to analyze the static and dynamic behavior of two-section distributed feedback (DFB) lasers is used. The characteristic impedance and equivalent propagation constant of DFB structure with active layer are derived from L-MTLT. A two-section DFB laser is analogous to a transmission-line network, in which each section is described by transmission-line block corresponding to the equivalent factors. The longitudinal resonant condition of DFB laser based on equivalent transmission-line network is used to reformulate the rate equations so that static and dynamic behavior of two-section DFB lasers with active layer is demonstrated and analyzed accurately.

A Study on the semantic network system of the line of flow appearing on the residential space of super high-rise apartments (초고층아파트 주거공간에 나타난 동선의 의미적 네트워크 체계에 관한 연구)

  • Yoon, Jae-Eun;Kim, Joo-Hee
    • Korean Institute of Interior Design Journal
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    • v.16 no.3 s.62
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    • pp.58-65
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    • 2007
  • The residential space of super high-rise buildings, having a form of a huge three-dimensional vertical city, affect the residents psychologically and qualitatively according to the line of flow. Because of these affects, the system of the line of flows is a very important factor. In this study, we recognize the super high-rise apartment's line of flow as a semantic network system based on case studies. And we also understand the mutual relationship by analyzing each space to recognize what effect it does on the residential environment. Furthermore, to bring up a better semantic network system for super high-rise apartment's line of flows is our goal. According to the case studies, the semantic network of the line of flow consists of 3 parts: the functional network, economical network and unit network. The functional network is composed of the 'need' and 'has', while the economical network includes variable walls that can be changed following the user's taste and eccentric positioned living rooms that protect personal privacy. Therefore the economical network started to appear while the personal value changed according to the improvement of the social condition. Finally, the unit network is a network that effects each unit that has ambiguous boundaries due to the appropriate arrangement between transitional spaces. And the unit network is based on the functional network.

Vision-Based Camber and Optimal Cutting Line Detection Algorithm for Hot-Rolling Process (열연 공정에서의 영상을 이용한 캠버 및 최적 절단선 검출 알고리즘)

  • Kong, Nam-Wong;Moon, Jung-Hye;Park, Poo-Gyeon
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.155-156
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    • 2007
  • This paper presents the vision-based camber and optimal cutting line detection algorithm for hot-rolling process. It is important to measure the camber of head and tail part of strips because many problems are caused by the camber in the hot-rolling process. The hot-rolling process has time constraints. The camber detection algorithm of head and tail parts requires fast and less complex for satisfying time constraints. The proposed algorithm consists of two parts: measurement of the camber in the head and tail part of strips and decision part of the optimal cutting line of hot-rolled strip. First, we obtain the camber value of the strip from the difference between the real center line and the center line of head, tail part. Second, the head and tail part of strips isn't suitable for strips connections. Therefore, the cutting process is needed in the hot-rolling process. The optimal cutting line is determined by the head and tail images obtained from cameras. The algorithm is applied into the vision system with two area cameras, Matrox image processing board and host PC for verification.

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Efficient Signal Detection Based on Artificial Intelligence for Power Line Communication Systems (전력선통신 시스템을 위한 인공지능 기반 효율적 신호 검출)

  • Kim, Do Kyun;Hwang, Yu Min;Sim, Issac;Kim, Jin Young
    • Journal of Satellite, Information and Communications
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    • v.12 no.2
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    • pp.42-45
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    • 2017
  • It is known that power line communication systems have more noise than general wired communication systems due to the high voltage that flows in power line cables, and the noise causes a serious performance degradation. In order to mitigate performance degradation due to such noise, this paper proposes an artificial intelligence algorithm based on polynomial regression, which detects signals in the impulse noise environment in the power line communication system. The polynomial regression method is used to predict the original transmitted signal from the impulse noise signal. Simulation results show that the signal detection performance in the impulse noise environment of the power line communication is improved through the artificial intelligence algorithm proposed in this paper.