• 제목/요약/키워드: extracting methods

검색결과 957건 처리시간 0.023초

임의 형상 음향 공동의 효율적인 고유치 및 고유모드 추출을 위한 개선된 NDIF법 개발 (Development of an Improved NDIF Method for Efficiently Extracting Eigenvalues and Eigenmodes of Arbitrarily Shaped Acoustic Cavities)

  • 강상욱;윤주일
    • 한국소음진동공학회논문집
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    • 제21권10호
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    • pp.960-966
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    • 2011
  • An improved NDIF method is introduced to efficiently extract eigenvalues and eigenmodes of two-dimensional, arbitrarily shaped acoustic cavities. The NDIF method, which was developed by the authors for the eigen-mode analysis of arbitrarily shaped acoustic cavities, membranes, and plates, has the feature that it yields highly accurate eigenvalues compared with other analytical methods or numerical methods(FEM and BEM). However, the NDIF method has the weak point that the system matrix of the NDIF method depends on the frequency parameter and, as a result, a final system equation doesn's take the form of an algebra eigenvalue problem. The system matrix of the improved NDIF method developed in the paper is independent of the frequency parameter and eigenvalues and mode shapes can be efficiently obtained by solving a typical algebraic eigenvalue problem. Finally, the validity and accuracy of the proposed method is verified in two case studies, which indicate that eigenvalues and mode shapes obtained by the proposed method are very accurate compared to the exact method, the NDIF method or FEM(ANSYS).

Pan-sharpening Effect in Spatial Feature Extraction

  • Han, Dong-Yeob;Lee, Hyo-Seong
    • 대한원격탐사학회지
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    • 제27권3호
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    • pp.359-367
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    • 2011
  • A suitable pan-sharpening method has to be chosen with respect to the used spectral characteristic of the multispectral bands and the intended application. The research on pan-sharpening algorithm in improving the accuracy of image classification has been reported. For a classification, preserving the spectral information is important. Other applications such as road detection depend on a sharp and detailed display of the scene. Various criteria applied to scenes with different characteristics should be used to compare the pan-sharpening methods. The pan-sharpening methods in our research comprise rather common techniques like Brovey, IHS(Intensity Hue Saturation) transform, and PCA(Principal Component Analysis), and more complex approaches, including wavelet transformation. The extraction of matching pairs was performed through SIFT descriptor and Canny edge detector. The experiments showed that pan-sharpening techniques for spatial enhancement were effective for extracting point and linear features. As a result of the validation it clearly emphasized that a suitable pan-sharpening method has to be chosen with respect to the used spectral characteristic of the multispectral bands and the intended application. In future it is necessary to design hybrid pan-sharpening for the updating of features and land-use class of a map.

Feature Selection to Mine Joint Features from High-dimension Space for Android Malware Detection

  • Xu, Yanping;Wu, Chunhua;Zheng, Kangfeng;Niu, Xinxin;Lu, Tianling
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권9호
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    • pp.4658-4679
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    • 2017
  • Android is now the most popular smartphone platform and remains rapid growth. There are huge number of sensitive privacy information stored in Android devices. Kinds of methods have been proposed to detect Android malicious applications and protect the privacy information. In this work, we focus on extracting the fine-grained features to maximize the information of Android malware detection, and selecting the least joint features to minimize the number of features. Firstly, permissions and APIs, not only from Android permissions and SDK APIs but also from the developer-defined permissions and third-party library APIs, are extracted as features from the decompiled source codes. Secondly, feature selection methods, including information gain (IG), regularization and particle swarm optimization (PSO) algorithms, are used to analyze and utilize the correlation between the features to eliminate the redundant data, reduce the feature dimension and mine the useful joint features. Furthermore, regularization and PSO are integrated to create a new joint feature mining method. Experiment results show that the joint feature mining method can utilize the advantages of regularization and PSO, and ensure good performance and efficiency for Android malware detection.

스마트공장 공급기업 설문조사를 바탕으로 한 스마트공장 정책 제언 (Policy Suggestions on the Smart Factory Based on the Survey Results from Smart Factory Suppliers)

  • 윤영호;이진;이은빈;문보명;서지형;이정철;장태우;성시일
    • 품질경영학회지
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    • 제48권1호
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    • pp.1-11
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    • 2020
  • Purpose: This paper treats the survey result from the suppliers of smart factories. Based on the survey results, it is provided suggestions about government policies of the smart factory. Methods: For providing political suggestions, the survey of smart factory is conducted. The survey results are analyzed by the correlation and association methods based on the stratification. Results: The survey results are analyzed for extracting policy-level suggestions. Multiple policy-level suggestions are identified and presented in the conclusion. Conclusion: Six policy-level suggestions are presented for enhancing the management efficiency of suppliers of smart factory.

한글 문서의 효과적인 검색을 위한 n-gram 기반의 색인 방법 (An n-gram-based Indexing Method for Effective Retrieval of Hangul Texts)

  • 이준호;안정수;박현주;김명호
    • 정보관리학회지
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    • 제13권1호
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    • pp.47-63
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    • 1996
  • 기존의 한글 자동 색인 방법들은 어절 단위 색인법과 형태소 단위 색인법으로 분류될 수 있다. 전자는 문서내의 어절에서 비색인 분절을 절단함으로써 색인어를 추출하는 방법으로, 문서들이 많은 복합 명사들을 포함할 경우 검색 효과가 저하된다. 후자는 형태소 해석이나 구문 해석을 이용하여 중요한 의미를 갖는 명사나 명사구를 추출하는 방법으로 단일 명사를 추출함으로써 복합 명사의 띄어쓰기 문제를 극복할 수 있다. 그러나 색인 과정에서 요구되는 많은 언어 정보를 개발하고 유지 보수해야 하는 부담을 지니고 있다. 본 논문에서는 기존의 색인 방법들의 문제점들을 완화할 수 있는 새로운 색인 방법을 제안한다. 그리고 실험을 통하여 제안하는 방법의 성능을 평가한다.

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지형/지물 이미지 데이타베이스를 위한 형태 특징 추출 방법 (A Shape Feature Extraction Method for Topographical Image Databases)

  • 권용일;박호현;이석룡;정진완
    • 한국정보과학회논문지:데이타베이스
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    • 제33권4호
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    • pp.384-395
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    • 2006
  • 항공 및 위성 사진과 같은 지형 / 지물 이미지는 대부분 비슷한 색상과 질감을 갖는다. 따라서 지형 / 지물 이미지 데이타베이스에서 질의 이미지를 정확하게 검색하기 위해서는 이미지의 형태 특정을 추출하는 것이 매우 중요하다. 본 논문에서는 지형 / 지물 이미지 검색을 위한 형태 특정 추출 방법을 제안한다. 이 방법은 이미지내 홀(hole) 이 있거나 이미지가 연결되지 않은 영역들로 구성되어 있을 경우에도 형태 특징들을 효과적으로 추출할 수 있다. 그리고 세그멘테이션 (segmentation)과 같은 특정 추출의 전처리 과정 (pre-processing) 에서 발생할 수 있는 오류에 강인하다. 본 논문에서 제안하는 방법이 기존의 방법들 보다 우수함을 다양한 이미지 검색 실험을 통해 보인다.

스프레드 스펙트럼 워터마킹 기법의 연구 (A Study on the Spread Spectrum Watermarking Method)

  • 강환일;김갑일;한승수
    • 한국지능시스템학회논문지
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    • 제11권8호
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    • pp.731-735
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    • 2001
  • 본 논문은 새로운 워터마킹기법을 제안하고 이 기법은 실시간 처리에 이용될 수 있다. 웨이브릿변환 대신에 계산량을 줄이기 위해 정수 웨이브릿변환을 이용한다. 본 논문에서 정수 웨이브릿 공간에서 카이자승분포와 관련한 워터마크를 삽입한다. 워터마크를 추출할 때 확산스펙트럼 기법을 이용하고 유사도는 공분산 수열에서 결정하낟. 실험을 통하여 카이 자승분포를 이용한 워터마크를 이용하는 것이 소음에 강인함을 보인다. 이 워터마킹 기법은 동시에 은닉된 정보에 제어되고 오디오 신호에 따라 움직일 수 있는 전기 기기의 제작에 쓰일 수 있다.

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Extracting The Prostate Boundary Using Direction Features of Prostate Boundary On Ultrasound Prostate Image

  • Park, Jae Heung;Seo, Yeong Geon
    • 한국컴퓨터정보학회논문지
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    • 제21권11호
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    • pp.103-111
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    • 2016
  • Traditionally, in the hospital the doctors saw the TRUS images by their eyes and manually segmented the boundary between the prostate and nonprostate. But the manually segmenting process not only needed too much time but also had different boundaries according to the doctor. To cope the problems, some automatic segmentations of the prostate have been studied to generate the constant segmentation results and get the belief from patients. Besides, on detecting the boundary, the ones in the middle of all images are easy to find the boundary but the base and apex of the images are hard to do it since there are lots of uncertain boundary. Accurate detection of prostate boundaries is a challenging and difficult task due to weak prostate boundaries, speckle noises and the short range of gray levels. In this paper, we propose the method that extracts a prostate boundary using features of its directions on prostate image. As a result of our experiments, it shows that the boundary never falls short of the existing methods or human expert's segmentation. And also, its searching speed is too fast because the method searches a smaller area that other methods.

신호처리 기법을 응용한 차량번호판 추출방법 (A Method to Extract Vehicle Number Plates by Applying Signal Processing Techniques)

  • 전병태;윤호섭
    • 전자공학회논문지B
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    • 제30B권7호
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    • pp.92-101
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    • 1993
  • This paper describes algorithms to extract license plates in vehicle images. Conventional methods perform preprocessing on the entire vehicle image to produce the edge image and binarize it. Hough transform is applied to the binary image to find horizontal and vertical lines, and the license plate area is extracted using the charateristics of license plates (the boundary information of license plates). Problems with this approach are that real-time processing is not feasible due to long processing time and that the license plate area is not extracted when lighting is irregular such as at night or when the plate boundary does not show up in the image. This research uses the gray level transition characteristics of license plates to verify the digit area by examining the digit width and the gray level difference between the background area the digit area, and then extracts the plate area by testing the distance between the verified digits. This research solves the probelm of failure in extracting the license plates due to degraded plate boundary as in the conventional methods and resolves the provlem of the time requirement by processing in real time such that practical application is possible.

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피부 현미경 영상을 통한 피부 특징 추출 및 피부 나이 도출 기법 (A scheme of extracting age-related wrinkle feature and skin age based on dermoscopic images)

  • 최영환;황인준
    • 전기전자학회논문지
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    • 제14권4호
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    • pp.332-338
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    • 2010
  • 영상 처리를 통한 특징 추출은 영상 검색, 객체 인식, 영상 인덱싱을 포함하는 다양한 분야에서 전처리 과정으로 사용되어 왔다. 특히, 영상 질감 분석에서는 질감 특성 추출을 더 용이하게 하기 위해 질감의 대비를 증가시키는 방법을 사용한다. 생체 현미경 영상에서 두드러진 질감중의 하나는 주름이며 주름의 특징은 노화 관련 응용에 유용한 정보를 다양하게 제공한다. 본 논문에서는 피부 영상에서 나이 관련 특징을 추출하는 기존 방법을 개선하여 피부 나이 측정의 정확도를 높이는 방법을 제안한다.