• Title/Summary/Keyword: symmetry region

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A Study on Frontal Face Detection Using Wavelet Transform (Wavelet 변환을 이용한 정면 얼굴 검출에 관한 연구)

  • Rhee Sang-Brum;Choi Young-Kyoo
    • Journal of Internet Computing and Services
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    • v.5 no.1
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    • pp.59-66
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    • 2004
  • Symmetry region searching can extract face region without a prior information in an image by using symmetric. However, this method requires a plenty of the computation time because the mask size to process symmetry region searching must be larger than the size of object such as eye, nose and mouth in face. in this paper, it proposed symmetric by using symmetry region searching and Wavelet Transform to reduce computation time of symmetry region searching, and It was applied to this method in an original image. To extract exact face region, we also experimented face region searching by using domain division in extraction region.

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A Study on Face Region Extraction Using Domain Division (영역 분할을 이용한 얼굴 영역 추출방법에 관한 연구)

  • 김규식;채덕재;이상범
    • Journal of the Korea Computer Industry Society
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    • v.3 no.12
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    • pp.1669-1678
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    • 2002
  • Symmetry region searching can extract face region without a prior information in an image by using symmetric. However, this method requires a plenty of the computation time because the mask size to process symmetry region searching must be larger than the size of object such as eye, nose and mouth in face. In this paper, we proposed symmetric by using symmetry region searching in the reduced image to reduce computation time of symmetry region searching. It was applied to this method in an original image. To extract exact face region, we also experimented face region searching by using domain division in extraction legion.

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Site-Directed Mutation Effect of the Symmetry Region at the mRNA 5'-end of Escherichia coli aeg-46.5 Gene

  • Ahn, Ju-Hyuk;Choe, Mu-Hyeon
    • BMB Reports
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    • v.29 no.1
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    • pp.92-97
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    • 1996
  • The age-46.5 gene of Escherichia coli is induced by nitrate ion and regulated by Fnr, NarL, and NarP during anaerobic growth. aeg-46.5::lacZ fusion gene shows its maximum expression in narL host after two hours of aerobic to anaerobic switch in M9-Glc-nitrate medium. Fnr and NarP act as positive regulators, and NarL acts as a negative regulator. The control region of the aeg-46.5 was identified and the binding sites of regulator proteins have been predicted (Reznikoff and Choe (1993)). It has two symmetry regions. One is located at -52~-37 bp from the anaerobic mRNA 5'-end, which is the binding site of NarL and NarP. The other is located at +37~+56 bp from the 5'-end of mRNA. In this study, the downstream symmetry region from the mRNA 5'-end was investigated by site-directed mutagenesis. The destruction of the symmetry region increases the expression level of aeg-46.5. We propose that the symmetry region interferes with the expression of aeg-46.5 possibly by forming a stem-and-loop structure.

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Postbuckling strength of an axially compressed elastic circular cylinder with all symmetry broken

  • Fujii, Fumio;Noguchi, Hirohisa
    • Structural Engineering and Mechanics
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    • v.11 no.2
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    • pp.199-210
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    • 2001
  • Axially compressed circular cylinders repeat symmetry-breaking bifurcation in the postbuckling region. There exist stable equilibria with all symmetry broken in the buckled configuration, and the minimum postbuckling strength is attained at the deep bottom of closely spaced equilibrium branches. The load level corresponding to such postbuckling stable solutions is usually much lower than the initial buckling load and may serve as a strength limit in shell stability design. The primary concern in the present paper is to compute these possible postbuckling stable solutions at the deep bottom of the postbuckling region. Two computational approaches are used for this purpose. One is the application of individual procedures in computational bifurcation theory. Path-tracing, pinpointing bifurcation points and (local) branch-switching are all applied to follow carefully the postbuckling branches with the decreasing load in order to attain the target at the bottom of the postbuckling region. The buckled shell configuration loses its symmetry stepwise after each (local) branch-switching procedure. The other is to introduce the idea of path jumping (namely, generalized global branch-switching) with static imperfection. The static response of the cylinder under two-parameter loading is computed to enable a direct access to postbuckling equilibria from the prebuckling state. In the numerical example of an elastic perfect circular cylinder, stable postbuckling solutions are computed in these two approaches. It is demonstrated that a direct path jump from the undeformed state to postbuckling stable equilibria is possible for an appropriate choice of static perturbations.

Method of Human Detection using Edge Symmetry and Feature Vector (에지 대칭과 특징 벡터를 이용한 사람 검출 방법)

  • Byun, Oh-Sung
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.8
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    • pp.57-66
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    • 2011
  • In this paper, it is proposed for algorithm to detect human efficiently using a edge symmetry and gradient directional characteristics in realtime by the feature extraction in a single input image. Proposed algorithm is composed of three stages, preprocessing, region partition of human candidates, verification of candidate regions. Here, preprocessing stage is strong the image regardless of the intensity and brightness of surrounding environment, also detects a contour with characteristics of human as considering the shape features size and the condition of human for characteristic of human. And stage for region partition of human candidates has separated the region with edge symmetry for human and size in the detected contour, also divided 1st candidates region with applying the adaboost algorithm. Finally, the candidate region verification stage makes excellent the performance for the false detection by verifying the candidate region using feature vector of a gradient for divided local area and classifier. The results of the simulations, which is applying the proposed algorithm, the processing speed of the proposed algorithms is improved approximately 1.7 times, also, the FNR(False Negative Rate) is confirmed to be better 3% than the conventional algorithm which is a single structure algorithm.

Conservative neural symmetry of the caprine mandible

  • Pares-Casanova, Pere M.
    • Korean Journal of Veterinary Research
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    • v.53 no.4
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    • pp.207-210
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    • 2013
  • Fifteen dry dentate and complete mandible samples from the White Rasquera goat breed were studied for symmetry. Thirty-one landmarks were digitally located on the images of the lateral and medial aspects of each hemimandible. Distances between these landmarks allowed the evaluation of the whole hemimandible and also the neural mandible. In the studied samples, the mandible was rather symmetrical, especially in the medial neural part, and in general, there was no side dominance. Only the diastema differed significantly between the sides, and this was related to the rostral part (incisive arch). The incisive region was the least symmetrical region of the caprine mandible, indicating a modular structure more conservative for the neural part. If unsigned asymmetry is interpreted as a measure of developmental stability, then the studied breed presented a marked ability to develop in good fitness despite the harsh environment. The measurements presented here can also be used as a reference for researchers designing experimental studies, especially on mandibular catch-up growth, and as an aid for zooarchaeologists comparing results from dead animals with those from living goat populations.

Symmetry Region at Beginning of Transcript Inhibits Expression of Escherichia coli aeg-46.5 Operon

  • Lee, Seung-Hwa;Lee, Sang-Ho;Sung, Ha-Chin;Kim, Joon;Choe, Mu-Hyeon
    • Journal of Microbiology and Biotechnology
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    • v.9 no.4
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    • pp.436-442
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    • 1999
  • The aeg-46.5 operon of Escherichia coli is induced by nitrate and anaerobic conditions. Positive regulators Fnr and NarP, and a negative regulator NarL control the expression of the aeg-46.5. It has two symmetry regions [6], one of which is located between +37 and +56 bp from the 5'end of the anaerobic transcription initiation site. In this study, mutagenized symmetry regions were transferred from plasmid to chromosome by homologous recombination to evaluate the mutation as a single copy in the fnr, narL, narP, and narL-narP double mutant background. The expressions of the aeg-46.5 operon with these mutations indicated that the control was not through the possible stem-loop structure. Whether there is a protein that mediates this control remains to be seen. The results from the narL-narP double mutant indicated that the anaerobic Fill induction was independent of NarL repression.

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On-Road Succeeding Vehicle Detection using Characteristic Visual Features (시각적 특징들을 이용한 도로 상의 후방 추종 차량 인식)

  • Adhikari, Shyam Prasad;Cho, Hi-Tek;Yoo, Hyeon-Joong;Yang, Chang-Ju;Kim, Hyong-Suk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.3
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    • pp.636-644
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    • 2010
  • A method for the detection of on-road succeeding vehicles using visual characteristic features like horizontal edges, shadow, symmetry and intensity is proposed. The proposed method uses the prominent horizontal edges along with the shadow under the vehicle to generate an initial estimate of the vehicle-road surface contact. Fast symmetry detection, utilizing the edge pixels, is then performed to detect the presence of vertically symmetric object, possibly vehicle, in the region above the initially estimated vehicle-road surface contact. A window defined by the horizontal and the vertical line obtained from above along with local perspective information provides a narrow region for the final search of the vehicle. A bounding box around the vehicle is extracted from the horizontal edges, symmetry histogram and a proposed squared difference of intensity measure. Experiments have been performed on natural traffic scenes obtained from a camera mounted on the side view mirror of a host vehicle demonstrate good and reliable performance of the proposed method.

CAD for Detection of Brain Tumor Using the Symmetry Contribution From MR Image Applying Unsharp Mask Filter

  • Kim, Dong-Hyun;Ye, Soo-Young
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.4
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    • pp.230-234
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    • 2014
  • Automatic detection of disease helps medical institutions that are introducing digital images to read images rapidly and accurately, and is thus applicable to lesion diagnosis and treatment. The aim of this study was to apply a symmetry contribution algorithm to unsharp mask filter-applied MR images and propose an analysis technique to automatically recognize brain tumor and edema. We extracted the skull region and drawed outline of the skull in database of images obtained at P University Hospital and detected an axis of symmetry with cerebral characteristics. A symmetry contribution algorithm was then applied to the images around the axis of symmetry to observe intensity changes in pixels and detect disease areas. When we did not use the unsharp mask filter, a brain tumor was detected in 60 of a total of 95 MR images. The disease detection rate for the brain was 63.16%. However, when we used the unsharp mask filter, the tumor was detected in 87 of a total of 95 MR images, with a disease detection rate of 91.58%. When the unsharp mask filter was used in the pre-process stage, the disease detection rate for the brain was higher than when it was not used. We confirmed that unsharp mask filter can be used to rapidly and accurately to read many MR images stored in a database.

Pupil Detection using PCA and Hough Transform

  • Jang, Kyung-Shik
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.2
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    • pp.21-27
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    • 2017
  • In this paper, we propose a pupil detection method using PCA(principal component analysis) and Hough transform. To reduce error to detect eyebrows as pupil, eyebrows are detected using projection function in eye region and eye region is set to not include the eyebrows. In the eye region, pupil candidates are detected using rank order filter. False candidates are removed by using symmetry. The pupil candidates are grouped into pairs based on geometric constraints. A similarity measure is obtained for two eye of each pair using PCA and hough transform, we select a pair with the smallest similarity measure as final two pupils. The experiments have been performed for 1000 images of the BioID face database. The results show that it achieves the higher detection rate than existing method.