• 한국통신학회논문지
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• 제24권8B호
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• pp.1438-1443
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• 1999

In this paper, we propose detection methods for gradual scene changes such as dissolve, pan, and zoom. The proposal method to detect a dissolve region uses scene features based on spatial statistics of the image. The spatial statistics to define shot boundaries are derived from squared means within each local area. We also propose a method of the camera motion detection using four representative motion vectors in the background. Representative motion vectors are derived from macroblock motion vectors which are directly extracted from MPEG streams. To reduce the implementation time, we use DC sequences rather than fully decoded MPEG video. In addition, to detect the gradual scene change region precisely, we use all types of the MPEG frames(I, P, B frame). Simulation results show that the proposed detection methods perform better than existing methods.

• Earthquakes and Structures
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• 제16권2호
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• pp.129-139
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• 2019

This paper develops a new method for estimating the elastic-plastic buckling strength of the truss structures under the static and seismic loads. Firstly, a new method for estimating the buckling strength of the truss structures was derived based on the buckling strength of the representative member considering the parameters, such as the structure configurations, boundary conditions, etc. Secondly, the new method was verified through the buckling strength estimation and the finite element method (FEM) analysis of the single member models, portal frame models and simple truss models. Finally, the method was applied to evaluate the buckling strength of a simple truss structure under seismic load, and the failure loads between the proposed method and the FEM were analyzed reasonably. The results show that the new method is feasible and reliable for structure engineers to estimate the buckling strengths of the truss structures under the static loads and seismic loads.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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• pp.213-216
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• 2001

Key frame extraction is an important method of summarizing a long video. This paper propose a technique to automatically extract several key frames representative of its content from video. We use the color layout descriptor to select key frames from video. For selection of key frames, we calculate similarity of color layout features extracted from video, and extract key frames using similarity. An important aspect of our algorithm is that does not assume a fixed number of key frames per video; instead, it selects the number of appropriate key frames of summarizing a long video Experimental results show that our method using color layout descriptor can successfully select several key frames from a video, and we confirmed that the processing speed for extracting key frames from video is considerably fast.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 춘계 종합학술대회 논문집
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• pp.167-171
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• 2006

시론적인 엠엠오알피지에 대한 분석틀을 제시하고, 이 분석틀을 이용하여 대표적인 3개의 게임에 대하여 분석하여 보았다. 분석틀은 커뮤니티성, 피케이용이성, 아이템 이용 용이성, 캐릭터 다양성, 밸런스, 편의성, 심미성의 7개 항목을 가지는 것으로 그 안에서 세부적으로 다시 구체적인 조사항목이 정해진다. 이러한 분석틀을 이용한 직접 분석 결과는 경험적이며 일반적으로 알려진 사항과 일치하는 것으로 나타났다. 즉, 국내게임에 비해 외국게임이 다양한 게임성과 높은 심미성을 제공하는 반면에 편의성과 밸런스 등의 측면에서 취약한 것으로 나타났다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.58-61
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• 2000

In this paper, we describe an effective method to enhance the color night images with spatio-temporal multi-scale retinex focused to the Intelligent Transportation System (ITS) applications such as in the single CCD based Electronic Toll Collection System (ETCS). The basic spatial retinex is known to provide color constancy while effectively removing local shades. However, it is relatively ineffective in night vision enhancement. Our proposed method, STMSR, exploits the iterative time averaging of image sequences to suppress the noise in consideration of the moving vehicles in image frame. In the STMSR method, the spatial term makes the dark images distinguishable and preserves the color information day and night while the temporal term reduces the noise effect for sharper and clearer reconstruction of the contents in each image frame. We show through representative simulations that incorporating both terms in the modeling produces the output sequential images visually more pleasing than the original dim images.

• 대한전자공학회논문지SP
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• 제46권4호
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• pp.58-66
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• 2009

최근 경량화 비디오 부호화를 위함 분산 비디오 부호화 기술 (DVC: Distributed Video Coding)에 대한 연구가 활발히 이루어지고 있으며, Wyner-Ziv 부호화 기술은 이의 대표적인 기술로써 각광받고 있다. Wyner-Ziv (WZ) 부호화기는, 영상을, 기존의 인트라 부호화기를 이용하는 키 (Key) 프레임과 WZ 부호화를 하는 WZ 프레임으로 나누어 독립적으로 부호화 한다. WZ 복호화기로 전송된 키 프레임은 복원된 뒤 키 프레임 사이의 WZ 프레임을 추정하는데 사용되며 추정된 WZ 프레임을 보조정보 (Side Information)라고 한다. 보조정보는 WZ 프레임에 대한 정보가 없는 상태에서 추정되므로 필연적으로 WZ 프레임과 다르며 WZ 복호화기에서는 보조정보와 WZ 프레임과의 차이를 가상의 채널 잡음으로 간주한다. WZ 복호화 과정은 가상의 채널잡음을 WZ 복호화기 내에 존재하는 채널코드를 이용하여 제거함으로써 이루어지므로 채널 정보를 정확히 아는 것은 채널코드의 에러정정능력에 큰 영향을 미친다. WZ 복호화기에서는 추정된 WZ 영상만이 존재하므로 정확한 잡음의 양을 알 수 없으며, 일반적으로 선형 움직임에 근거한 키 프레임 간의 차를 하나의 예측 수단으로 사용한다. 또한 이와 같이 예측이 갖는 불확실성으로 채널코드의 효율이 저하되는 것을 막기 위하여 주변의 잡음과 비교를 통한 잘못된 잡음을 정정하는 방법도 제안되었다. 하지만 이런 방법들이 모든 프레임이나 비트 플레인에 존재하는 잡음을 제대로 측정한다고 할 수는 없다. 따라서 본 논문에서는 여러 개의 후보 잡음 모델을 생성한 후, 복호화 과정에서 가장 효율적인 모델을 선택하는 방법을 제안한다. 제안 방법에 대한 실험결과는 최대 0.8 dB의 PSNR이득을 보여준다.

• 한국공간구조학회논문집
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• 제13권1호
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• pp.69-77
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• 2013

This study is the research appling the representative Displacement-Based Design which is the basic concept of Direct Displacement Based Design proposed by Chopra and Goel to original Reinforced Concrete moment frame and determining the thickness of retrofit Steel Jacket about the Maximum design ground acceleration, and developing the more improved Algorithm as well as program by the Retrofit Design method and Nonlinear analysis by the Performance design method before and after reinforcement appling the determined retrofit thickness. It also shows the result of the seismic performance improvement which is the ratio of seismic performance appreciation result yield displacement 19%, yield strength ratio 24%, displace ductility ratio the maximum 27% comparing Multi degree of freedom, column member of Reinforced Concrete with the performance improvement column member considering the thickness of the determined Steel Jacket. The developed Algorithm and program are easy to apply seismic design and application to the original Reinforced Concrete building, at the same time, it applicate to display well the design result of Target displacement performance level about nonlinear behavior.

• Earthquakes and Structures
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• 제3권5호
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• pp.749-766
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• 2012

Structural control through integration of passive damping devices within the building structure has been increasingly implemented internationally in the last years and has proven to be a most promising strategy for earthquake safety. In the present paper an alternative configuration of an innovative energy dissipation mechanism that consists of slender tension only bracing members with closed loop and a hysteretic damper is investigated in its dynamic behavior. The implementation of the adaptable dual control system, ADCS, in frame structures enables a dual function of the component members, leading to two practically uncoupled systems, i.e., the primary frame, responsible for the normal vertical and horizontal forces and the closed bracing-damper mechanism, for the earthquake forces and the necessary energy dissipation. Three representative international earthquake motions of differing frequency contents, duration and peak ground acceleration have been considered for the numerical verification of the effectiveness and properties of the SDOF systems with the proposed ADCS-configuration. The control mechanism may result in significant energy dissipation, when the geometrical and mechanical properties, i.e., stiffness and yield force of the integrated damper, are predefined. An optimum damper ratio, DR, defined as the ratio of the stiffness to the yield force of the hysteretic damper, is proposed to be used along with the stiffness factor of the damper's- to the primary frame's stiffness, in order for the control mechanism to achieve high energy dissipation and at the same time to prevent any increase of the system's maximum base shear and relative displacements. The results are summarized in a preliminary design methodology for ADCS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1689-1701
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• 2019

In recent years, personal videos have been shared online due to the popular uses of portable devices, such as smartphones and action cameras. A recent report predicted that 80% of the Internet traffic will be video content by the year 2021. Several studies have been conducted on the detection of main video events to manage a large scale of videos. These studies show fairly good performance in certain genres. However, the methods used in previous studies have difficulty in detecting events of personal video. This is because the characteristics and genres of personal videos vary widely. In a research, we found that adding a dataset with the right perspective in the study improved performance. It has also been shown that performance improves depending on how you extract keyframes from the video. we selected frame segments that can represent video considering the characteristics of this personal video. In each frame segment, object, location, food and audio features were extracted, and representative vectors were generated through a CNN-based recurrent model and a fusion module. The proposed method showed mAP 78.4% performance through experiments using LSVC data.

• 산업융합연구
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• 제21권3호
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• pp.181-188
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• 2023

전자정부 표준 프레임워크는 국내 정부/공공기관 등 웹 환경 개발을 위한 공통 컴포넌트 재사용, 표준 모듈의 연계와 종속성 해소 등 전반적인 기술을 제공하고 있다. 그러나, 획일화된 개발 환경은 코어 버전에 따른 구버전 업데이트 문제와 해킹이나 컴퓨터 바이러스 등에 의한 개인정보와 기밀정보 유출 가능성이 존재한다. 본 연구는 국내 eGovFrame을 운영하는 웹사이트 중심으로 보안 취약성을 직접 분석한다. 내부 프로그래밍 언어 소스 코드 수준에서 취약점을 분석/분류한 결과, 대표 보안 취약성과 연계되는 5개 항목을 다시 추출할 수 있었다. 이에 대한 대응책으로, 2단계(1, 2차)를 통한 보안 설정과 기능 그리고 보안 정책을 설명한다. 본 연구는 향후 전자정부 프레임워크 보안 기능 개선하고 서비스 활성화에 이바지하고자 한다.