• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.3
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• pp.1-10
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• 2010

As various interfacing devices for computational machines are being developed, a new HCI method using hand motion input is introduced. This interface method is a vision-based approach using a single camera for detecting and tracking hand movements. In the previous researches, only a skin color is used for detecting and tracking hand location. However, in our design, skin color and shape information are collectively considered. Consequently, detection ability of a hand increased. we proposed primary orientation edge descriptor for getting an edge information. This method uses only one hand model. Therefore, we do not need training processing time. This system consists of a detecting part and a tracking part for efficient processing. In tracking part, the system is quite robust on the orientation of the hand. The system is applied to recognize a hand written number in script style using DNAC algorithm. Performance of the proposed algorithm reaches 82% recognition ratio in detecting hand region and 90% in recognizing a written number in script style.

• 전자공학회논문지 IE
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• v.48 no.2
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• pp.32-39
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• 2011

The output image of the uncooled thermal infrared camera is difficult the identification of target because of the limited dynamic range and the various noises. Retinex algorithm based on the theory of the human visual perception is known to be effective contrast enhancement technique. However, the image quality is insufficient when it is adopted to the narrow dynamic range image as the infrared image. In this paper, we propose the revised retinex algorithm to enhance the contrast of the infrared image. To improve the contrast enhancement performance, we designed the new dynamic range compression function instead of log function. To reduce the noise and compensate the loss of edge, we added the contrast compensation procedure in the MSR image generation process. According to the output picture comparing and numerical analysis, the proposed algorithm shows the better contrast enhancement performance and the more suitable method for the infrared image enhancement.

• 한국HCI학회:학술대회논문집
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• 2007.02c
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• pp.194-198
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• 2007

본 연구의 주제는 텍스트를 어떻게 회화적이미지로 전환시킬 수 있을까?에 대한 것이다. 오늘날 디지털 환경 속에 있는 우리는 이미지 중심의 세계 속에 살고 있다. 과거 텍스트가 해왔던 정보의 생산과 전달 그리고 저장의 역할을 오늘날은 상당부분 이미지가 하게 되었다. 하지만 그럼에도 불구하고 아날로그 방식과 정서는 여전히 우리 곁에 남아있는 것도 사실이다. "Yesterday to Today"는 문자의 최소 단위인 알파벳을 통하여 이미지를 재현하려는 작품이다. 이 작품은 크게 두 가지 Idea로 이루어지는데 하나는 복수개의 실시간 영상 소스를 이용하여 이미지를 구성해내는 것과, 다른 하나는 텍스트에 의한 이미지의 변환이다. 복수개의 실시간 영상 소스는 프로그램이 작동하는 컴퓨터와 직/간접적으로 연결되어 전달되는데, 직접적으로 연결되어 근거리의 특정한 지점으로부터 영상 소스를 받을 수 있고, 또 하나의 방법은 인터넷을 통한하나 이상의 원거리 지점으로부터 보내어지는 영상을 조합하여 받을 수 있다. 프로그램 구현 개념은 픽셀 소스 카메라에서 캡쳐된 최초 이미지를 명도, 색상, 채도로 분류하고, 이것의 각각을 26개의 구간-자판의 개수에 의하여 정해짐-으로 나누고, 다시 그 각각의 구간을 26단계로 나눈다. 이렇게 나누어진 구간들은 알파벳과 1:1로 대응시켜 결과이미지의 해당 부분을 수치대로 재현하도록 프로그램 시킨다. 이미지의 부분들을 지정하기 위하여 특정한 텍스트로부터 알파벳의 빈도수를 조사했는데, 이 조사를 바탕으로 빈도수의 많고 적음에 따라 이미지부분들이 26개 구간으로 정해졌다. 이미지 재현 방법은 사용자가 모니터 위의 Result Image Cam을 통하여 얻고자 하는 이미지를 캡쳐한 후, 특정한 텍스트를 타이핑하면 이미지를 재현할 수 있는데, -입력된 텍스트의 알파벳은 프로그램이 지정한 HSI 컬러 모델의 영역과 1:1로 대응하게 하였다-이 이미지는 특정 장소에 실시간으로 받아진 영상을 데이터화 한 소스에 의하여 만들어진다. 이미지를 재현할 때 텍스트에 따라 알파벳 빈도수는 달라질 수 있으므로 비록 최초 이미지가 동일할지라도 얻고자하는 결과 이미지가 달라진다. 그러므로 사용자는다양한 창조적 경험을 할 수 있다.

• Journal of the Korea Society of Computer and Information
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• v.16 no.7
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• pp.49-58
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• 2011

Augmented Reality(AR) assists human's cognitive ability through the information visualization by substantiating information about virtual situation. This technology is studied in a variety of ways including education, design, industry, and so on, by various supply of information devices equipped with cameras and display monitors. Since the most of the AR system depends on limited interaction that responds to the order from user, it can not reflect diverse real world situation. In this study, we suggest a knowledge based augmented reality system, which is composed of context awareness agent that provides recognized context information, along with knowledge based component that provides intelligent capability by utilizing domain knowledges. With this capability, the augmented object can generate dynamic model intelligently by reflecting context information, and can make the interaction possible among the multiple objects. We developed rule based context awareness system along with 3D model generation, and tested interaction among the augmented objects. And we suggest a framework that can provide a convenient way of developing augmented reality system for user.

• Journal of Digital Convergence
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• v.9 no.4
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• pp.1-8
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• 2011

A mobile device is a handheld device, typically having a display screen with touch input and/or a miniature keyboard and accessible to the Internet. Because mobile devices are innovative and rapidly changing products, consumers are confronted with a decision-making problem to select the best device. This paper proposes an Analytic Hierarchy Process method to assess mobile devices and shows a method to select best mobile devices when purchasing. For this paper, the mobile devices considered as in the AHP model included net-book, tablet PC, smart phone, and camera phone. We derived 6 main criteria and 15 sub-criteria to synthesize the overall priority of criteria and mobile devices. The criterion of convenience in carrying showed the highest rank in the criteria. Although smart phones had the highest priority, the four mobile devices did not show significant differences in consumer preference.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.1
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• pp.1-6
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• 2010

The lens distortion in the machine vision system is inevitable phenomenon. Distortion is getting worse, due to the selection of lens in the trend of reducing prices and size of the system. In this trend, the distortion correction becomes more important. But, the traditional correction methods has problems, such as complexity and requiring more operations. Effective distorted digital image correction is the precondition of target detection and recognition based on vision inspection. To overcome the disadvantage of traditional distortion correction algorithms, such as complex modeling, massive computation and marginal information loss, an image distortion correction algorithm based on photogrammetry method is proposed in this paper. In our method, we use the lattice image as the measurement target. Through the experimental results, we could find that we can reduce the processing time by 4ms. And also the inspection failure rate of our method was reduced by 2.3% than human-eyes inspection method.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.4
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• pp.23-35
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• 2012

This paper presents a 3-D pose (position and orientation) estimation method for an elliptic object in 3-D space. It is difficult to resolve the problem of determining 3-D pose parameters with respect to an elliptic feature in 3-D space by interpretation of its projected feature onto an image plane. As an alternative, we propose a two points-based pose estimation algorithm to seek the 3-D information of an elliptic feature. The proposed algorithm determines a homogeneous transformation uniquely for a given correspondence set of an ellipse and two coplanar points that are defined on model and image plane, respectively. For each plane, two triangular features are extracted from an ellipse and two points based on the polarity in 2-D projection space. A planar homography is first estimated by the triangular feature correspondences, then decomposed into 3-D pose parameters. The proposed method is evaluated through a series of experiments for analyzing the errors of 3-D pose estimation and the sensitivity with respect to point locations.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.787-790
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• 2017

This study is a preliminary research on characterization of methane - oxygen combustion used in bipropellant thruster. The limit of combustion stability and flame shape of methane - oxygen non-premixed flame injected by shear coaxial injector in the model combustion chamber Experimental studies have been carried out. A direct image of the flame was photographed using a DSLR camera, and combustion characteristics and flame length were quantified through image post-processing. As a result, it was confirmed that the stabilized flame was generated at the stoichiometric ratio as the oxidizer Reynolds number ($Re_o$) was increased, and the length of the turbulent flame was increased under the same injector diameter condition.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.3
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• pp.60-68
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• 2007

In this paper, we propose an automatic facial expressions recognition system to analyze facial expressions (happiness, disgust, surprise and neutral) using tree structures based on heuristic rules. The facial region is first obtained using skin-color model and connected-component analysis (CCs). Thereafter the origins of user's eyes are localized using neural network (NN)-based texture classifier, then the facial features using some heuristics are localized. After detection of facial features, the facial expression recognition are performed using decision tree. To assess the validity of the proposed system, we tested the proposed system using 180 facial image in the MMI, JAFFE, VAK DB. The results show that our system have the accuracy of 93%.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.177-186
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• 2009

Nowadays, as going to information society based knowledge, the informations are acquired, processed, serviced based digital environment. In surveying field, the trend have been changed from the analog foundation to the digital foundation. Also, aerial photogrammetry is being changed from analog aerial photogrammetry to digital aerial photogrammetry. In this paper, the analysis of accuracy is performed for the comparison of traditional aerial photogrammetry with digital aerial photogrammetry usign UltracamX in AT and Block Adjustment. As the results, Bundle adjustment in digital aerial photogrammetry with GPS/INS have more advantages than traditional independent adjustment in analog aerial photogrammetry. Digital aerial photogrammetry contributes the higher accuracy in AT and block adjustment more than analog aerial photogrammetry.