• Title/Summary/Keyword: point matching

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Robust PCB Image Alignment using SIFT (잡음과 회전에 강인한 SIFT 기반 PCB 영상 정렬 알고리즘 개발)

  • Kim, Jun-Chul;Cui, Xue-Nan;Park, Eun-Soo;Choi, Hyo-Hoon;Kim, Hak-Il
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.7
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    • pp.695-702
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    • 2010
  • This paper presents an image alignment algorithm for application of AOI (Automatic Optical Inspection) based on SIFT. Since the correspondences result using SIFT descriptor have many wrong points for aligning, this paper modified and classified those points by five measures called the CCFMR (Cascade Classifier for False Matching Reduction) After reduced the false matching, rotation and translation are estimated by point selection method. Experimental results show that the proposed method has fewer fail matching in comparison to commercial software MIL 8.0, and specially, less than twice with the well-controlled environment’s data sets (such as AOI system). The rotation and translation accuracy is robust than MIL in the noise data sets, but the errors are higher than in a rotation variation data sets although that also meaningful result in the practical system. In addition to, the computational time consumed by the proposed method is four times shorter than that by MIL which increases linearly according to noise.

Time-Matching Poisson Multi-Bernoulli Mixture Filter For Multi-Target Tracking In Sensor Scanning Mode

  • Xingchen Lu;Dahai Jing;Defu Jiang;Ming Liu;Yiyue Gao;Chenyong Tian
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.6
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    • pp.1635-1656
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    • 2023
  • In Bayesian multi-target tracking, the Poisson multi-Bernoulli mixture (PMBM) filter is a state-of-the-art filter based on the methodology of random finite set which is a conjugate prior composed of Poisson point process (PPP) and multi-Bernoulli mixture (MBM). In order to improve the random finite set-based filter utilized in multi-target tracking of sensor scanning, this paper introduces the Poisson multi-Bernoulli mixture filter into time-matching Bayesian filtering framework and derive a tractable and principled method, namely: the time-matching Poisson multi-Bernoulli mixture (TM-PMBM) filter. We also provide the Gaussian mixture implementation of the TM-PMBM filter for linear-Gaussian dynamic and measurement models. Subsequently, we compare the performance of the TM-PMBM filter with other RFS filters based on time-matching method with different birth models under directional continuous scanning and out-of-order discontinuous scanning. The results of simulation demonstrate that the proposed filter not only can effectively reduce the influence of sampling time diversity, but also improve the estimated accuracy of target state along with cardinality.

A Robust Real-Time Lane Detection for Sloping Roads (경사진 도로 환경에서도 강인한 실시간 차선 검출방법)

  • Heo, Hwan;Han, Gi-Tae
    • KIPS Transactions on Software and Data Engineering
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    • v.2 no.6
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    • pp.413-422
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    • 2013
  • In this paper, we propose a novel method for real-time lane detection that is robust for inclined roads and not require a camera parameter, the Inverse Perspective Transform of the image, and the proposed lane filter. After finding the vanishing point from the start frame of the image and storing the region surrounding the vanishing point as the Template Area(TA), our method predict the lanes by scanning toward the lower part from the vanishing point of the image and obtain the image removed the perspective effect using the Inverse Perspective Transform coefficients extracted based on the predicted lanes. To robustly determine lanes on inclined roads, the region surrounding the vanishing point is set up as the template area (TA), and, by recalculating the vanishing point by tracing the area similar to the TA (SA) in the input image through template matching, it responds to the changes on the road conditions. The proposed method for a more robust lane detection method for inclined roads is a lane detection method by applying a lane detection filter on an image removed of the perspective effect. Through this method, the processing region is reduced and the processing procedure is simplified to produce a satisfactory lane detection result of about 40 frames per second.

Semi-Automatic Registration of Brain M Images Based On Talairach Reference System (Talairach 좌표계를 이용한 뇌자기공명영상의 반자동 정합법)

  • Han Yeji;Park Hyun Wook
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.41 no.1
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    • pp.55-62
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    • 2004
  • A semi-automatic registration process of determining specified points is presented, which is required to register brain MR images based on Talairach atlas. Generally, ten specified points that define Talairach coordinates are anterior commissure(AC), posterior commissure (PC), anterior feint (AP), posterior point (PP), superior point (SP), inferior point (IP), left point (LP), right point (RP) and two points for the midline of the brain. The suggested method reduces user interaction for S points, and finds the necessary points for registration in a more stable manner by finding AC and PC using two-level shape matching of the corpus callosum (CC) in an edge-enhanced brain M image. Remaining points are found using the intensity information of cutview.

Scientific Study of Magnetic Acu-point Therapy on Eight Extraordinary Meridian for Lowering Blood Pressure (기경팔맥 자석침의 혈압 강하 효과에 대한 과학적 검증 연구)

  • Yoo, Ho-Rhyong;Lee, Jae-Hwi;Kang, Ji-Sun;Moon, Seung-Hee;Kang, Byung-Gab;Lim, Seung-Min;An, Joung-Jo;Jo, Hyun-Kyung;Kim, Yoon-Sik;Seol, In-Chan
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.1
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    • pp.165-170
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    • 2010
  • This study assessed effects of magnetic acu-point therapy as an add-on to conventional antihypertensive managements such as medication or lifestyle modification for hypertensive or pre-hypertensive subjects. This study was conducted with the purpose to evaluate the decreasing effect of the blood pressure on the hypertensive patients who were given to magnetic acu-point therapy. A single-blind, placebo-controlled trial by cross matching was conducted at Daejeon University Oriental Hospital. The washout periods of cross matching are 10 days. 22 hypertensive (systolic BP>140 mmHg or diastolic BP>90 mmHg) volunteers were recruited and treatments were donemagnetic acu-points on Oegwan(TE 5), Jogimeup(GB 41), Naegwan(PC 6), Gongson(SP 4), Hugye(SI 3), Sinmaek(BL 62). The treated group was statistically significant decrease of the blood pressure, while control group show no statistically significant difference of BP. From the results, magnetic acu-point therapy seems to offer a benefit to the treatment of hypertensive patients.

Improved LTE Fingerprint Positioning Through Clustering-based Repeater Detection and Outlier Removal

  • Kwon, Jae Uk;Chae, Myeong Seok;Cho, Seong Yun
    • Journal of Positioning, Navigation, and Timing
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    • v.11 no.4
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    • pp.369-379
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    • 2022
  • In weighted k-nearest neighbor (WkNN)-based Fingerprinting positioning step, a process of comparing the requested positioning signal with signal information for each reference point stored in the fingerprint DB is performed. At this time, the higher the number of matched base station identifiers, the higher the possibility that the terminal exists in the corresponding location, and in fact, an additional weight is added to the location in proportion to the number of matching base stations. On the other hand, if the matching number of base stations is small, the selected candidate reference point has high dependence on the similarity value of the signal. But one problem arises here. The positioning signal can be compared with the repeater signal in the signal information stored on the DB, and the corresponding reference point can be selected as a candidate location. The selected reference point is likely to be an outlier, and if a certain weight is applied to the corresponding location, the error of the estimated location information increases. In order to solve this problem, this paper proposes a WkNN technique including an outlier removal function. To this end, it is first determined whether the repeater signal is included in the DB information of the matched base station. If the reference point for the repeater signal is selected as the candidate position, the reference position corresponding to the outlier is removed based on the clustering technique. The performance of the proposed technique is verified through data acquired in Seocho 1 and 2 dongs in Seoul.

Compensation of Discrete-Time Saturating Systems Trough Equilibrium Point Matching Method (평형점 근접 방법을 통한 이산 포화 시스템의 보상)

  • 박종구;최종호
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.189-194
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    • 1993
  • This paper presents an ARW(Anti-Reset Windup) method for discrete-time control systems with saturation nonlinearites. The method is motivated by the concept of the equilibrium point. The design parameters of the ARW scheme is explicitly derived by minimizing a reasonable performance index. The proposed method is closely related with the singular perturbed theory. The proposed method is applicable to any open-loop stable plants with saturation nonlinearities whose controllers are determined a priori by some design technique.

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Belief propagation stereo matching technique using 2D laser range finder (2차원 레이저 거리측정기를 활용한 신뢰도 전파 스테레오 정합 기법)

  • Kim, Jin-Hyung;Ko, Yun-Ho
    • Journal of Korea Multimedia Society
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    • v.17 no.2
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    • pp.132-142
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    • 2014
  • Stereo camera is drawing attention as an essential sensor for future intelligence robot system since it has the advantage of acquiring not only distance but also other additive information for an object. However, it cannot match correlated point on target image for low textured region or periodic patterned region such as wall of building or room. In this paper, we propose a stereo matching technique that increase the matching performance by fusing belief propagation stereo matching algorithm and local distance measurements of 2D-laser range finder in order to overcome this kind of limitation. The proposed technique adds laser measurements by referring quad-tree based segment information on to the local-evidence of belief propagation stereo matching algorithm, and calculates compatibility function by reflecting over-segmented information. Experimental results of the proposed method using simulation and real test images show that the distance information for some low textured region can be acquired and the discontinuity of depth information is preserved by using segmentation information.

Correspondence Matching of Stereo Images by Sampling of Planar Region in the Scene Based on RANSAC (RANSAC에 기초한 화면내 평면 영역 샘플링에 의한 스테레오 화상의 대응 매칭)

  • Jung, Nam-Chae
    • Journal of the Institute of Convergence Signal Processing
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    • v.12 no.4
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    • pp.242-249
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    • 2011
  • In this paper, the correspondence matching method of stereo images was proposed by means of sampling projective transformation matrix in planar region of scene. Though this study is based on RANSAC, it does not use uniform distribution by random sampling in RANSAC, but use multi non-uniform computed from difference in positions of feature point of image or templates matching. The existing matching method sampled that the correspondence is presumed to correct by use of the condition which the correct correspondence is almost satisfying, and applied RANSAC by matching the correspondence into one to one, but by sampling in stages in multi probability distribution computed for image in the proposed method, the correct correspondence of high probability can be sampled among multi correspondence candidates effectively. In the result, we could obtain many correct correspondence and verify effectiveness of the proposed method in the simulation and experiment of real images.

An Experimental Study of Comfortable Pitch and Loudness with Target Matching: Effects on Electroglottographic and Acoustic Measures

  • Choi, Seong Hee
    • Phonetics and Speech Sciences
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    • v.4 no.4
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    • pp.139-146
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    • 2012
  • This study was designed to examine comfort levels of pitch and loudness with target matching and their effects on electroglottographic (EGG) and acoustic measures. Twelve speakers, six males and six females, were instructed to produce /a/ sustained vowel for three seconds at a comfortable pitch and loudness level without any instruction and with a target matching procedure of either a certain f0 or SPL separately with visual and auditory feedback. The range of pitch for females and males were presented by progressing up and down randomly at intervals of 5Hz from 150 Hz to 310 Hz (total 33 frequency targets) and from 85 Hz to 190 Hz (total 22 frequency targets), respectively. The loudness levels were 65, 75, 85, 95 dB (total of four intensity targets) for both males and females. Subjective estimations of comfortable levels were obtained using a 10-point equal-appearing interval rating scale following each phonation. The results showed that males and females demonstrated similar trends in loudness levels with greatest comfort at 75 dB, whereas pitch comfort ratings showed a greater variability with females having a wider range with target matching. In the comfort levels of individuals, most male and female speakers rated higher comfort at soft, rather than loud phonations. On the other hand, most male speakers perceived highest comfort levels below the comfort pitch levels they phonated under natural conditions. Higher frequency ranges, however, were perceived to be more comfortable than those of natural condition in most female speakers, although the comfortable pitch levels in spontaneous phonations were within the comfort level ranges determined by targeted phonations. When comparing acoustic (%jitter, %shimmer, SNR) and EGG measures (CQ%) between spontaneous comfortable phonations and targeted phonations produced by the same subject at similar f0 and intensity, no significant differences were observed (p>0.05). Thus, target matching procedures may be considered a compatible and alternative method to reduce the variability of comfortable pitch and loudness levels by eliciting consistent comfortable phonations.