• International Journal of Control, Automation, and Systems
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• 제6권4호
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• pp.515-525
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• 2008

In this paper, the problem of delay-dependent stabilization for singular systems with multiple internal and external incommensurate constant point delays is investigated. The condition when a singular system subject to point delays is regular independent of time delays is given and it can be easily test with numerical or algebraic methods. Based on Lyapunov-Krasovskii functional approach and the descriptor integral-inequality lemma, a sufficient condition for delay-dependent stability is obtained. The main idea is to design multiple memoryless state feedback control laws such that the resulting closed-loop system is regular independent of time delays, impulse free, and asymptotically stable via solving a strict linear matrix inequality (LMI) problem. An explicit expression for the desired memoryless state feedback control laws is also given. Finally, a numerical example illustrates the effectiveness and the availability for the proposed method.

• 반도체디스플레이기술학회지
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• 제7권2호
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• pp.69-76
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• 2008

Recently, as the multimedia processing application increases rapidly by going on increasing multimedia data, the efficient retrieval method of image information is required in many fields of application and becoming the matter of major concern. Furthermore, in the last few years rapid improvements in hardware technology have made it possible to process, store and retrieve huge amounts of data in a multimedia format. As a result, Content-Based Image Retrieval (CBIR) has been receiving widespread interest during the last decade. This paper propose the content-based retrieval system as a method for performing image retrieval through the effective feature analysis of the object of significant meaning by using YCbCr channel merging on the basis of the characteristics of man's visual system.

• 반도체디스플레이기술학회지
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• 제17권3호
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• pp.113-116
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• 2018

This paper proposes a mobile image search system which uses a sensor information of smart phone, and enables running in a variety of environments, which is implemented on Android platform. The implemented system deals with a new image descriptor using combination of the visual feature (CEDD) with EXIF attributes in the target of JPEG image, and image matching scheme, which is optimized to the mobile platform. Experimental result shows that the proposed method exhibited a significant improved searching results of around 80% in precision in the large image database. Considering the performance such as processing time and precision, we think that the proposed method can be used in other application field.

• 반도체디스플레이기술학회지
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• 제16권4호
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• pp.97-102
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• 2017

Object detection and tracking have become one of the most active research areas in the past few years, and play an important role in computer vision applications over our daily life. Many tracking techniques are proposed, and Camshift is an effective algorithm for real time dynamic object tracking, which uses only color features, so that the algorithm is sensitive to illumination and some other environmental elements. This paper presents and implements an effective moving object detection and tracking to reduce the influence of illumination interference, which improve the performance of tracking under similar color background. The implemented prototype system recognizes object using invariant features, and reduces the dimension of feature descriptor to rectify the problems. The experimental result shows that that the system is superior to the existing methods in processing time, and maintains better problem ratios in various environments.

• International Journal of Control, Automation, and Systems
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• 제4권3호
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• pp.271-280
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• 2006

This paper proposes a new approach to solve robust $H{\infty}$ control problems for uncertain continuous-time descriptor systems. Necessary and sufficient conditions for robust $H{\infty}$ control analysis and design are derived and expressed in terms of a set of LMIs. In the proposed approach, the uncertainties are allowed to appear in all system matrices. Furthermore, a couple of assumptions that are required in earlier design methods are not needed anymore in the present one. The derived conditions also include several interesting results existing in the literature as special cases.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권1호
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• pp.347-370
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• 2019

In the computer-aided detection (CAD) system of pulmonary nodules, a high false positive rate is common because the density and the computed tomography (CT) values of the vessel and the nodule in the CT images are similar, which affects the detection accuracy of pulmonary nodules. In this paper, a method of automatic detection of pulmonary nodules based on multi-scale enhancement filters and 3D shape features is proposed. The method uses an iterative threshold and a region growing algorithm to segment lung parenchyma. Two types of multi-scale enhancement filters are constructed to enhance the images of nodules and blood vessels in 3D lung images, and most of the blood vessel images in the nodular images are removed to obtain a suspected nodule image. An 18 neighborhood region growing algorithm is then used to extract the lung nodules. A new pulmonary nodules feature descriptor is proposed, and the features of the suspected nodules are extracted. A support vector machine (SVM) classifier is used to classify the pulmonary nodules. The experimental results show that our method can effectively detect pulmonary nodules and reduce false positive rates, and the feature descriptor proposed in this paper is valid which can be used to distinguish between nodules and blood vessels.

• 전기전자학회논문지
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• 제23권4호
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• pp.1423-1429
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• 2019

최근에, 효율적인 상호작용을 지원하는 시스템 인 휴먼 머신 인터페이스(HMI)가 인기를 끌고있다. 본 논문에서는 차량 상호작용방법 중 하나로 새로운 실시간 저비용 손동작 제어 시스템을 제안한다. 계산 시간을 줄이기 위해 RGB 카메라를 사용하여 손 영역을 감지할 때 많은 계산이 필요하므로 TOF (Time-of-Flight) 카메라를 사용하여 깊이 정보를 취득한다. 또한, 푸리에 기술자를 사용하여 학습 모델을 줄였다. 푸리에 디스크립터는 전체 이미지에서 적은 수의 포인트만 사용하므로 학습 모델을 소형화 할 수 있다. 제안 된 기법의 성능을 평가하기 위해 데스크탑과 라즈베리 pi 2의 속도를 비교했다. 실험 결과에 따르면 소형 임베디드와 데스크탑의 성능 차이는 크지 않다. 제스처 인식 실험에서 95.16 %의 인식률이 확인되었다.

• 정보처리학회논문지B
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• 제10B권2호
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• pp.179-188
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• 2003

내용기반 영상검색에서 질의는 영상 그 자체이며 질의와 유사한 영상을 찾는 방식으로 검색이 진행된다. 즉 사용자가 검색을 원하는 영상의 색, 형태, 질감 또는 이들의 공간적인 배치 등의 내용을 염두에 두고 있어야 검색이 가능하다. 이러한 검색방법은 사용자가 검색대상의 내용을 상당 부분 파악하고 있어야 검색이 가능하다는 제약을 수반한다. 본 논문에서는 사용자가 영상이 제공하는 감성을 이용하여 칼라영상을 검색하는 방법을 제안한다. 제안된 방법은 검색과 감성평가가 relevance feedback을 통하여 동시에 진행됨으로 기존의 내용기반 영상검색과 통합이 용이하며, 사용자의 주관적인 평가가 이루어질 수 있다는 점에서 과거의 감성기반 칼라영상 검색과 차이가 있다. 본 논문에서 제안한 검색기의 평가를 위해 영상속성으로 MPEG-7의 칼라 기술자(descriptor)를 사용하였으며 "깨끗한" "밝은" "재미있는", "포근한" 등의 감성형용사를 적용한 결과 1500개의 벽지영상을 대상으로 만족할 만한 결과를 얻을 수 있었다.과 1500개의 벽지영상을 대상으로 만족할 만한 결과를 얻을 수 있었다.

• 한국정보전자통신기술학회논문지
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• 제12권3호
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• pp.251-256
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• 2019

본 연구에서는 손동작을 인식하기 위하여 밀리미터파 기반 레이더에서 얻어진 손동작의 주파수 반향 특성을 이용하는 알고리즘 및 시스템을 제안하였다. 제안된 시스템은 밀리미터파 아날로그 송수신부, ADC부 및 신호 처리부가 원칩으로 구현된 시스템을 이용하여 데이터를 수집하도록 구성하였고, 제안한 알고리즘은 반사된 주파수 영상의 제르니케모멘트로부터 얻어진 전역 및 지역 디스크립터로 구성된 BoF에서 K-means 클러스터링을 이용하여 코드 워드를 생성하고 SVM을 이용한 손동작 분류를 수행하였다. 수행 결과는 혼동행렬에서 얻어진 정밀도, 민감도 및 정확도를 이용하여 평가였다. 정확도 평가에서는 제안한 방법은 GZM방법 및 LZM방법과 비교하여 성능 평가를 위한 인덱스에서 제안한 방법이 95.6%의 성능을 보였고 비교한 나머지 두 방법은 88.4% 및 84%을 나타내어 제안한 방법이 기존의 두 방법에 비하여 7~8% 성능이 향상되었으며 정밀도 및 민감도에서도 나머지 두 방법에 대하여 향상된 성능을 나타내었다. 제안한 방법은 소형화된 밀리미터파 기반 레이더를 이용하여 동작 인식을 할 수 있는 임베디드 시스템의 응용가능성을 보여준다.

• Journal of Mechanical Science and Technology
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• 제16권1호
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• pp.75-82
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• 2002

A simultaneous optimal design problem of structural and control systems is discussed by taking a 3-D truss structure as an object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these forms. We consider a minimum weight design problem for structural system and disturbance suppression problem for the control system. The structural objective function is the structural weight and the control objective function is $H_{\infty}$ norm from the disturbance input to the controlled output in the closed-loop system. The design variables are cross sectional areas of the truss members. The conditions for the existence of controller are expressed in terms of linear matrix inequalities (LMI) By minimizing the linear sum of the normalized structural objective function and control objective function, it is possible to make optimal design by which the balance of the structural weight and the control performance is taken. We showed in this paper the validity of simultaneous optimal design of structural and control systems.