• 산업융합연구
• /
• 제21권3호
• /
• pp.181-188
• /
• 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.

• 대한수학회보
• /
• 제58권2호
• /
• pp.461-479
• /
• 2021

This paper includes a general version of Bessel multipliers in Hilbert C∗-modules. In fact, by combining analysis, an operator on the standard Hilbert C∗-module and synthesis, we reach so-called generalized Bessel multipliers. Because of their importance for applications, we are interested to determine cases when generalized multipliers are invertible. We investigate some necessary or sufficient conditions for the invertibility of such operators and also we look at which perturbation of parameters preserve the invertibility of them. Subsequently, our attention is on how to express the inverse of an invertible generalized frame multiplier as a multiplier. In fact, we show that for all frames, the inverse of any invertible frame multiplier with an invertible symbol can always be represented as a multiplier with an invertible symbol and appropriate dual frames of the given ones.

• 전기전자학회논문지
• /
• 제15권2호
• /
• pp.122-128
• /
• 2011

최근 들어 공장자동화의 프레임 그래버 분야에서 전통적인 아날로그 인터페이스 대신 고속, 고해상도의 디지털 인터페이스 방식의 카메라로의 전환이 이루어지고 있으며 이들은 카메라링크를 표준으로 채택하고 있다. 본 논문에서는 PC를 사용하지 않는 임베디드 프레임 그래버 테스트베드를 개발하여 영상처리 응용 솔루션을 제공하고자 한다. 따라서 카메라링크 표준의 라인스캔 CCD 카메라와의 접속을 위하여 하드웨어 회로를 설계하였고 VHDL 코드를 이용하여 FPGA를 프로그래밍하였다. 향후 광학영상기 등의 의료영상, 머신비젼, 산업전자 등의 다양한 영상처리에 본 칩을 이용할 수 있을 것이다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 춘계학술대회 논문집
• /
• pp.1523-1526
• /
• 2007

This study introduces the testing results of the carbody. The load test was performed to evaluate the structural characteristic and stability of the stainless carbody. The carbody is made of stainless steel. The body structure consisted of side frame, under frame, roof frame, and end frame. Of these components, the side frame and under frame were the most important components considering the vehicle and passenger loads. Loading test were performed under the condition based on "Performance Test Standard for Electrical Multiple Unit". The test results showed that the body structure is safe and stable under the condition of designed load.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
• /
• pp.163-168
• /
• 2000

In this paper, a 3-D computer-aided die design process was developed for automobile rear frame with drawing, trimming, flanging, cam-piercing and piercing for tool design. The tool design has been done using Pro/Engineer on a personal computer. It is composed of four stations. The goal of this research is to apply each of stations for the standard tool specification to each station.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 추계학술대회 논문집
• /
• pp.628-633
• /
• 2004

we studied the structural weak areas of an electric car bogie frame by finite element analysis. The bogie frame under consideration is a part of the standard electric car with aluminium car body. Vertical, torsional. lateral and longitudinal loadings were applied. Numerical results were compared with the experimental results. The two results are in a good agreement.

• 한국운동역학회지
• /
• 제16권4호
• /
• pp.147-152
• /
• 2006

The purpose of this study was to develop the experimental machine for the putting strokes. This experimental machine is called Pendulum Putting Machine(PPM). The height of PPM is 75cm and the mass is 10kg. To make the frame of this machine, 24 and 20 diameters of iron pipes were used. Bottom of the frame(bottom girdle) was made with circle shape and top of the frame(top girdle) was made with rectangular shape. Above the top girdle, iron plate($12{\times}17{\times}0.5cm$) was placed to connect the ball bearing. At the top of the frame two ball bearings with axis were placed for the diverse lies of putters and irons. To verify usefulness of this machine, experiments were executed with the PPM. Two major experimental conditions were hitting points(sweet spot, toe side, heel side) and hitting places(bottom, 3cm before bottom, 3cm after bottom). Eleven different cases were tested. The results showed that the diversity of the ball placement(distance and direction) was acceptable(distance range, 2.70-5.87 standard deviation; direction range, 1.71-4.65 standard deviation). Overall the Pendulum Putting Machine is very useful for the study of putting and driving strokes.

• 한국정보통신학회논문지
• /
• 제10권11호
• /
• pp.2020-2025
• /
• 2006

H.264/AVC는 ITU-T 비디오 코딩 전문가 그룹과 ISO/IEC MPEG 그룹에 의해 제안된 최신 비디오 코딩 표준안이다. 최근 DMB와 멀티미디어 장비들이 비디오 압축 표준으로 H.264/AVC를 채택하고 있다. 본 논문에서는 메모리 사용을 최소화하고, 칩 면적을 최소화할 수 있는 H.264/AVC의 인트라 프레임 디코더를 제안한다. 제안한 인트라 프레임 디코더는 하드웨어 설계 언어인 VHDL로 기술하여 model_sim을 사용하여 시뮬레이션을 수행하였다. 그리고 FPGA칩인 XCV1000E에 다운로드하여 칩 레벨에서 설계된 H.264/AVC의 인트라 프레임 디코더를 검증하였다.

• 한국정보시스템학회지:정보시스템연구
• /
• 제14권3호
• /
• pp.117-122
• /
• 2005

This paper presents a method for detecting scene changes in video sequences, in which the $chi^{2}$-test is modified by imposing weights according to NTSC standard. To automatically determine threshold values for scene change detection, the proposed method utilizes the frame differences that are obtained by the weighted $chi^{2}$-test. In the first step, the mean and the standard deviation of the difference values are calculated, and then, we subtract the mean difference value from each difference value. In the next step, the same process is performed on the remained difference values, mean-subtracted frame differences, until the stopping criterion is satisfied. Finally, the threshold value for scene change detection is determined by the proposed automatic threshold estimation algorithm. The proposed method is tested on various video sources and, in the experimental results, it is shown that the proposed method is reliably estimates the thresholds and detects scene changes.

• Journal of Communications and Networks
• /
• 제10권4호
• /
• pp.412-421
• /
• 2008

We observe simultaneous transmission of relay stations (RSs) allowed in current IEEE 802.16j draft standard for multi-hop relay networks may involve severe interference among the RSs, hence leading to throughput degradation. Allowing only 1/3 of the RSs to simultaneously transmit instead of 1/2 RSs as in the current draft standard reduces the interference but results in reduced throughput. To remedy this problem, we devise schemes to incorporate network coding at link-layer level (decode-and-forward) into the simultaneous transmission of RSs. Data movement is rearranged to maximize coding gain. Formula is derived to dictate exact movement of packets traveling between base station (BS) and mobile stations (MSs) via intermediate RSs. The frame structure in the current IEEE 802.16j draft standard does not allow broadcast needed for network coding. We devise a new frame structure which supports the broadcast. A new R-MAP (pointers to the burst data) is introduced to implement the broadcast. Since our new frame structure is used only for BS to RS or RS to RS communication, our schemes retain backward compatibility with legacy MSs based on IEEE 802.16e standard. Simulation based on simple configuration of RSs shows considerable improvement in terms of system throughput and round trip delay. For a 4-hop relay network with 1 BS and 4 RSs with symmetric traffic in uplink (UL) and downlink (DL), throughput is improved by 49% in DL and by 84% in UL traffic compared with IEEE 802.16j draft standard under the assumption that omni-directional antennae are used in BS and RSs.