• 한국ITS학회 논문지
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• 제22권6호
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• pp.114-123
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• 2023

컴퓨터 비전(Computer Vision: CV) 기술 발전으로 폐쇄회로 TV(Closed-Circuit television: CCTV)와 같은 영상 센서로 돌발상황을 검지하고 있다. 그러나 현재 이러한 기술은 대부분 고정식 영상 센서를 기반으로 한다. 따라서 고정식 장비의 영상 범위가 닿지 않는 음영지역의 돌발상황 검지에는 한계가 존재해왔다. 최근 엣지 컴퓨팅(Edge-computing) 기술의 발전으로 이동식 영상정보의 실시간 분석이 가능해졌다. 본 연구는 차량 내 설치된 이동식 영상 센서(dashboard camera 혹은 dash cam)에 컴퓨터 비전 기술을 도입하여 고속도로에서 실시간으로 돌발상황 검지 가능성에 대해 평가하는 것이 목적이다. 이를 위해 한국도로공사 순찰차량에 장착된 dash cam에서 수집된 4,388건의 스틸 프레임 데이터 기반으로 학습데이터를 구축하였으며, YOLO(You Only Look Once) 알고리즘을 활용하여 분석하였다. 분석 결과 객체 모두 예측 정밀도가 70% 이상으로 나타났고, 교통사고는 약 85%의 정밀도를 보였다. 또한 mAP(mean Average Precision)의 경우 0.769로 나타났고, 객체별 AP(Average Precision)를 보면 교통사고가 0.904로 가장 높게 나타났고, 낙하물이 0.629로 가장 낮게 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.583-585
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• 2004

In this paper we will deal with a calibration method for low cost motion capture system using psd(position sensitive detection) optical sensor. To measure the incident direction of the light from LED emitted marker, the PSD is used the output current ratio on the electrode of PSD is proportional with the incident position of the light focused by lens. In order to defect the direction of the light, the current output is converted into digital voltage value by opamp circuits peak detector and AD converter with the digital value the incident position is measured. Unfortunately, due to the non-linearly problem of the circuit poor position accuracy is shown. To overcome such problems, we compensated the non-linearly by using least-square fitting method. After compensated the non-linearly in the circuit, the system showed more enhanced position accuracy.

• 대한전기학회논문지
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• 제33권5호
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• pp.173-180
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• 1984

The spectra of scattering light fromlaser-produced plasma near its fundamental and second harmonic wavelength were observed respectively by means of spectroscopic technique. The experimental results and the generation mechanism of nonlinear effects such as the second garmonics and the brillouin scattering were analysed theoretically. The spectra of reflected laser light became wider than that of incident laser light. And the peak of spectrum of reflected light shifted to red-side from that of incident light. The second harmonic light is generated from the nonlinear interaction of the incident laser light and the electron plasma wave excited in resonance region by the oblique incidence of laser light to the plasma. The Brillouin backscattering from laser-produced plasmas of hydrogen and deuterium has shown an isotope effect in the red-side region of the generated second harmonic light. This isotope shift is explained by the parametric instability at the cutoff (resonance) region using frequency-and phase-matching conditions of the waves.

• Journal of information and communication convergence engineering
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• 제9권4호
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• pp.353-357
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• 2011

U.S. Obama government is submit a motion to consider cyber attacks on State as a war. 7.7DDoS attack in Korea in 2009 and 3.4 DDoS attacks 2011, the country can be considered about cyber attacks. China hackers access a third country, bypassing South Korea IP by hacking the e-commerce sites with fake account, that incident was damaging finance. In this paper, for WiBro service, DDoS attacks, hackers, security incidents and vulnerabilities to the analysis. From hacker's attack, WiBro service's prognostic relevance by analyzing symptoms and attacks, in real time, Divide Red, Orange, Yellow, Green belonging to the risk rating. For hackers to create a blacklist, to defend against attacks in real-time air-conditioning system is the study of security. WiBro networks for incident tracking and detection after the packets through the national incident response should contribute to the development of technology.

• Journal of the Optical Society of Korea
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• 제13권4호
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• pp.472-477
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• 2009

A Stokes polarimetry imaging (SPI) system was developed and utilized to detect tendon tears by constructing the degree of linear polarization (DOLP) image maps after linearly polarized light illumination. The micro and partial-thickness tears of turkey tendons were made and imaged by the SPI system at different incident polarization angles (IPA) with different mechanical loads on the tendon. The micro and partial-thickness tendon tears were detected by the DOLP images due to weak birefringence around the tears. The tendon tears were detected by a highest DOLP contrast at longest visible wavelength (Red, 650 ${\pm}$ 50 nm). All polarized images showed modulated DOLP as the incident polarization angle (IPA) was varied. The varying DOLP allowed the optimal detection of the micro and partial-thickness tendon tears at a certain IPA. The SPI system with variable IPA and spectral information can improve the detection of the tendon tears by higher visibility of fiber orientations, and thereby improve diagnosis and treatment of the tendon related injuries.

• 한국ITS학회 논문지
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• 제15권2호
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• pp.13-23
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• 2016

기존의 많은 돌발상황 자동감지 알고리즘은 복잡한 구조와 계산 과정, 수많은 매개변수, 그리고 필터링/평활화 같은 선 작업 때문에 지속적인 유지관리가 사실상 중단된 상태이고 오보율 또한 높아 많은 교통관리센터로부터 기피 대상이 되고 있는 등 돌발상황감지의 주력 수단으로서 자동 알고리즘의 지위가 위태해진 현실은 매우 우려할만하다. 본 연구에서는 상대 점유율과 속도 항을 활용하여 적체 교통량이라는 신 개념을 도입, 구조가 아주 간단하면서도 검측 원시자료의 보정이 거의 필요 없는 DiFI(Displaced Flow Index) 기반의 돌발상황 자동감지알고리즘을 개발하였다. DiFI 알고리즘의 성능평가는 2003년도 내부순환로 검지기자료를 활용하여 검증을 수행하였으며, 2011년도 경부고속도로 검지기 자료를 수집 정리하여 이식성 검사를 이행하였다. 성능평가는 검지율, 오보율, 평균검지시간, 기타 CR, CI, PI를 사용하였는데 100%의 검지율과 2.99%의 낮은 오보율, 1분을 약간 초과하는 평균검지시간을 보였다. 이는 SAO는 물론 국내 현장에 가장 많이 접목된 APID 및 DELOS 등과 비교해서도 모든 면에서 우월한 성능을 보이는 것이었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권5호
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• pp.1953-1958
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• 2015

Background: In India, cancer accounts for 7.3% of DALY's, 14.3% of mortality with an age-standardized incident rate of 92.4/100,000 in men and 97.4/100,000 in women and yet there are no nationwide screening programs. Materials and Methods: We calculated age-standardized and age-truncated (30-69 years) detection rates for men and women who attended the Indian Cancer Society detection centre, New Delhi from 2011-12. All participants were registered with socio-demographic, medical, family and risk factors history questionnaires, administered clinical examinations to screen for breast, oral, gynecological and other cancers through a comprehensive physical examination and complete blood count. Patients with an abnormal clinical exam or blood result were referred to collaborating institutes for further investigations and follow-up. Results: A total of n=3503 were screened during 2011-12 (47.8% men, 51.6% women and 0.6% children <15 years) with a mean age of 47.8 yrs (${\pm}15.1yrs$); 80.5% were aged 30-69 years and 77.1% had at least a secondary education. Tobacco use was reported by 15.8%, alcohol consumption by 11.9% and family history of cancer by 9.9% of participants. Follow-up of suspicious cases yielded 45 incident cancers (51.1% in men, 48.9% in women), consisting of 55.5% head and neck (72.0% oral), 28.9% breast, 6.7% gynecological and 8.9% other cancer sites. The age-standardized detection rate for all cancer sites was 340.8/100,000 men and 329.8/100,000 women. Conclusions: Cancer screening centres are an effective means of attracting high-risk persons in low-resource settings. Opportunistic screening is one feasible pathway to address the rising cancer burden in urban India through early detection.

• 한국안전학회지
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• 제33권6호
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• pp.85-92
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• 2018

This study aimed to reduce of traps incident of metro train door by suggesting preventive actions throughout analyzing why railway drivers and passengers commit unsafe behaviors which are human factors making occurrence of the incidents. The incident cases were analyzed and Incident Tree was structured by brainstorming with safety experts. In addition, the questionnaire survey was conducted for comparison with the analysis results. As the result, this study suggested driver's factors, passenger's factors, and public relation plan for safe use of metro in order to reduce the frequency of the incidents. For driver's factors, implementing job-rotation systems between railway and non-railway drivers, installing Object Detection Sensors between the metro doors and PSD, and flexible operation of dwell time were suggested. For passenger's factors, placing a platform safety person, installing a safety fence in front of the stairs and the elevators, and country wide public relations through mass media were suggested.

• The Journal of the Acoustical Society of Korea
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• 제25권3E호
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• pp.115-122
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• 2006

The bistatic scattering of an incident wave by a hemi-spherically capped cylinder is of particular interest because it has rarely been studied until the present day. The configuration of a hemi-spherically capped cylinder is similar to naval underwater weapons (submarines, mines, torpedos, etc.), but which is not exactly the same. This paper describes a novel laboratory experiment aimed at direct measurement of bistatic scattering by a hemi-spherically capped cylinder. Bistatic scattering by a hemi-spherically capped cylinder was measured in an acoustic water tank (5m long, 5m wide, 5m deep) using a high frequency projector (120kHz) and hydrophone. Measurements of monostatic scattering were also made under the same conditions. The bistatic scattering pattern by a hemi-spherically capped cylinder was measured against the incident angles $(0^{\circ},\;15^{\circ},\;20^{\circ},\;30^{\circ},\;45^{\circ},\;60^{\circ},\;90^{\circ})$ in order to verify various scattering pattern characteristics by the change of incident angle. The results indicate that the bistatic scattering TS at a wide scattering angle is much stronger than the mono static scattering TS. In bistatic scattering, the forward scattering TS is significantly stronger than the backward scattering TS, and the forward scattering pattern is also broader. In case of seven incident angles, the maximum value of forward scattering TS is about 14dB stronger than that of backward scattering TS. It is also found that forward scattering varies with the incident angle of sound to a much less extent than backscattering, and it is not seriously affected by the incident angle. These features could be the advantages of using forward scattering for detecting underwater targets at long range and increasing detection area and probability.

• 한국ITS학회 논문지
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• 제11권2호
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• pp.29-38
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• 2012

검지기 자료의 품질은 동일한 교통 조건이라도 검지기의 종류, 보정 및 유지 보수의 노력, 도로의 기하구조 등에 의해 내재적으로 10% 이상 변수 값 차이를 보일 수 있다. 이러한 내재적인 변수 값 차이로 인해 성능이 검증된 돌발상황 자동감지알고리즘을 사용하더라도 검지율(DR)이 낮아지고 오보율(FAR)이 높아지는 문제가 야기될 수 있다. 본 연구는 교통특성 변수의 간단한 산술계산기법(SAO)를 활용하여 새로운 AIDA를 개발하는데 목적이 있다. SAO는 내재적으로 존재하는 변수 값 차이를 보정하여 AIDA의 성능 저하를 극복하기 위해 개발되었다. AIDA 모형의 개발 및 검증을 위해 내부순환도로와 경부고속도로에서 수집된 30초 단위의 점유율을 사용하였다. SAO 기반 알고리즘 분석 결과 100% 돌발상황을 검지하는 높은 검지율을 보였고, 검지시간(MTTD)은 1분 이내로 나타났다. 오보율의 경우 본 연구에서 개발된 SAO 기반 AIDA의 오보율이 기개발된 AIDA의 오보율보다 3.5%~31.0% 감소하는 것을 확인하였다. SAO 기반의 알고리즘은 돌발상황의 지속성 분석에서도 탁월한 능력을 보였다.