• Current Optics and Photonics
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• 제8권4호
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• pp.355-365
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• 2024

Wavefront coding (WFC) imaging systems can redistribute the energy of an interference laser spot on an image plane sensor by wavefront phase modulation and reduce the peak intensity, realizing laser protection while maintaining imaging functionality by leveraging algorithmic post-processing. In this paper, a spiral axicon WFC imaging system is proposed, and the performance for laser protection is investigated by constructing a laser transmission model. An Airy disk on an image plane sensor is refactored into a symmetrical hollow ring by a spiral axicon phase mask, and the maximum intensity can be reduced to lower than 1% and single-pixel power to 1.2%. The spiral axicon phase mask exhibits strong robustness to the position of the interference laser source and can effectively reduce the risk of sensor damage for an almost arbitrary lase propagation distance. Moreover, we revealed that there is a sensor hazard distance for both conventional and WFC imaging systems where the maximum single-pixel power reaches a peak value under irradiation of a power-fixed laser source. Our findings can offer guidance for the anti-laser reinforcement design of photoelectric imaging systems, thereby enhancing the adaptability of imaging systems in a complex laser environment. The laser blinding-resistant imaging system has potential applications in security monitoring, autonomous driving, and intense-laser-pulse experiments.

• 한국정보통신학회논문지
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• 제15권7호
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• pp.1423-1432
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• 2011

해양에서의 선박의 사고는 교통량의 증가와 더불어 끊임없이 증가하는 추세에 있으며, 해상에서의 안전운항을 확보하기 위하여 사고 발생 후의 대처도 중요하지만 해양사고를 미연에 방지하는 운항 안전을 위한 사전 감시기술이 부각되고 있는 실정이다. 따라서, 본 논문에서는 안전운항을 위한 통합적인 안전관리 플랫폼 기반의 시스템을 제안하였고, 항해 근무상태 감시 및 항해/추진/기관/발전 등 이상상태 및 오동작 상태 감시를 위한 선교운용 단말장치 및 경보시스템을 구현하였으며, 선박 탑재를 위하여 선급 표준에 근거한 성능 평가를 수행하여 실증화를 위한 기반을 갖추었다.

• Journal of Multimedia Information System
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• 제7권3호
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• pp.231-238
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• 2020

This work presents a fully analog baseline wander tracking and removal circuitry using high-pass filter (HPF) based R-peak detection and quadratic interpolation that does not require digital post processing, thus suitable for compact and low power long-term ECG monitoring devices. The proposed method can effectively track and remove baseline wander in ECG waveforms corrupted by various motion artifacts, whereas minimizing the loss of essential features including the QRS-Complex. The key component for tracking the baseline wander is down sampling the moving average of the corrupted ECG waveform followed by quadratic interpolation, where the R-peak samples that distort the baseline tracking are excluded from the moving average by using a HPF based approach. The proposed circuit is designed using CMOS 0.18-㎛ technology (1.8V supply) with power consumption of 19.1 ㎼ and estimated area of 15.5 ㎟ using a 4^th order HPF and quadratic interpolation. Results show SNR improvement of 10 dB after removing the baseline wander from the corrupted ECG waveform.

• 한국측량학회지
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• 제34권4호
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• pp.357-372
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• 2016

Augustine volcano, located along the Aleutian Arc, is one of the most active volcanoes in Alaska and nearby islands, with seven eruptions occurring between 1812 and 2006. This study monitored the surface displacement before and after the most recent 2006 eruption. For analysis, we conducted a time-series analysis on data observed at the permanent GPS(Global Positioning System) observation stations in Augustine Island between 2005 and 2011. According to the surface displacement analysis results based on GPS data, the movement of the surface inflation at the average speed of 2.3 cm/year three months prior to the eruption has been clearly observed, with the post-eruption surface deflation at the speed of 1.6 cm/year. To compare surface displacements measurement by GPS observation, ENVISAT(Environmental satellite) radar satellite data were collected between 2003 and 2010 and processed the SBAS(Small Baseline Subset) method, one of the time-series analysis techniques using multiple InSAR(Interferometric Synthetic Aperture Radar) data sets. This result represents 0.97 correlation value between GPS and InSAR time-series surface displacements. This research has been completed precise surface deformation using GPS and time-series InSAR methods for a detection of precursor symptom on Augustine volcano.

• 한국식품조리과학회지
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• 제8권2호
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• pp.123-135
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• 1992

Time and temperature conditions, and microbiological qualities of six categories of menu items were assessed according to the process of food product Row in a 500 bed general hospital. The Harzard Analysis Critical Control Point (HACCP) system was applied to determine harzards, to assess their severity and risks, and to identity CCPs and memos for monitoring mem. The Critical Control Points identified for each category of menu items were: Meat Soup (Kyung Sang Do Gogi Guk): Pre-preparation, holding after pre-preration, and holding after cooking; Pot Stewed Stuffed Cabbage (Soe Yangbaechu Mali Chim): pre-preparation, holding after Pre-preparation, stuffing, cooking and holding after cooking; Boned Pork Sour Salad (Doeji Suyuk Muchim): Pre-preparation, holding after pre-preparation, and post-preparation after cooking; Sauteed Pork Ball (Jeyuk Wanja Jon): pre-preparation, holding after pre-preparation, shaping, and holding after cooking; Stir-fried Fragrant Mushroom (Pyogo Bosot Bokkum): basic ingredients, Pre-preparation, holding after pre-preparation, and holding after cooking; and Fried Corn with Vegetables (Oksusu Yachae Tuigim): pre-preparation, holding after pre-preparation, mixing, and holding after cooking.

• 제어로봇시스템학회논문지
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• 제16권1호
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• pp.69-76
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• 2010

The segmentation of moving object in video sequence is a core technique of intelligent image processing system such as video surveillance, traffic monitoring and human tracking. A typical method to segment a moving region from the background is the background subtraction. The steps of background subtraction involve calculating a reference image, subtracting new frame from reference image and then thresholding the subtracted result. One of famous background modeling is Gaussian mixture model (GMM). Even though the method is known efficient and exact, GMM suffers from a problem that includes false pixels in ROI (region of interest), specifically shadow pixels. These false pixels cause fail of the post-processing tasks such as tracking and object recognition. This paper presents a method for removing false pixels included in ROT. First, we subdivide a ROI by using shape characteristics of detected objects. Then, a method is proposed to classify pixels from using histogram characteristic and comparing difference of energy that converts the color value of pixel into grayscale value, in order to estimate whether the pixels belong to moving object area or shadow area. The method is applied to real video sequence and the performance is verified.

• 한국산학기술학회논문지
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• 제19권10호
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• pp.8-15
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• 2018

본 논문은 실시간 범죄대응 및 예방적 방범을 위한 지능형 방범 통합 플랫폼 개발 연구를 진행하였다. 방범 시스템 및 플랫폼 연구, 지능형 방범 관련 연구 등의 선행연구와 지자체 통합운영센터 방범시스템 사례를 분석하여 지능형 방범 플랫폼 요소를 설정하였다. 이를 통해 실질적인 지능형 방범 플랫폼을 개발하고, 확장성을 고려한 기존 지자체 및 스마트시티 통합플랫폼 시스템과의 연계방안을 제시하였다. 이를 통해 기존 지자체 통합관제센터에서 사후처리로만 활용되는 CCTV 모니터링을 실시간 범죄에도 대응 가능하게 하고, 실외 뿐 아니라 실내에서도 신고자의 정밀한 위치를 파악하여 골든타임 내 사건 사고를 해결할 수 있을 것으로 기대된다. 또한 관제효율 향상 뿐 아니라 시민참여를 강화하여 시민 중심의 범죄 예방형 사회안전망 정보공유서비스 제공이 가능하다. 지능형 방범 플랫폼은 기존 지자체 시스템 및 스마트시티 통합플랫폼을 비롯한 타 방범서비스와의 연계 확장성을 고려하여 개발하였으므로 지자체 확산 보급되기 용이한 장점을 가진다. 향후 지능형 방범 플랫폼의 실질적 적용 및 운영, 지자체 확산을 위한 정책적 지원 등의 후속연구가 진행되어 국민들이 안전한 생활을 영위하는데 도움이 되길 기대한다.

• 한국지반신소재학회논문집
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• 제10권2호
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• pp.13-19
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• 2011

PC 암거는 터파기, 하부지반 처리, 암거 거치, 상호접합면에 누수방지용 패킹재 부착, PS 강선의 긴장을 통한 상호박스 접합, 되메우기 등의 일련의 과정으로 시공되어진다. 이 때 부적절한 하부지반 처리는 박스간 상호 부등침하를 야기할 수 있으며 결과적으로 지하수의 와류 및 내부유수의 누수를 발생시키게 된다. 본 연구에서는 하부지반이 연약한 경우 PC 암거 접합부의 부등침하를 저감하기 위하여 개발된 PC 기초판과 일체화된 암거의 거동을 현장 시험시공을 통해 분석하였다. 암거의 거동은 접합부에서 암거간의 벌어짐, 하부지반에 작용하는 토압 증가량, 암거 상부의 침하량 계측을 통해 분석되었으며, 분석결과로부터 PC 기초판과 일체화된 암거가 일반적인 시공방법인 PS 강선의 인장으로 체결된 암거에 비하여 침하 및 접합부에서 벌어짐이 적게 발생하는 것으로 나타났다.

• 한국콘텐츠학회논문지
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• 제10권11호
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• pp.262-274
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• 2010

장애인복지관에는 정부의 정보화 촉진 계획에 따라 2001년부터 업무표준화를 시작으로 개발된 전산시스템이 사용되고 있다. 그러나 기술적 측면과 사용자 편의 추구에만 치중되었을 뿐 정보화의 역기능에 대한 논의와 대비는 전혀 이루어지지 못하였다. 이에 본 논문은 업무 전산시스템의 활용현황과 개인정보 보호에 대한 법을 살펴봄으로서 개인정보보호의 필요성과 법적인 근거를 확인 하였다. 또한 장애인복지관의 개인정보보호 정책과 실태를 파악하고 분석함으로써 개인보호 정책 방향과 대안을 찾고자 하였다. 장애인복지관에 적용 가능한 개인정보보호 대안으로는 개인정보보호에 대한 인식을 강화시키는 교육과 개인정보의 생명주기를 반영한 제도적 보호 장치 마련과 업무전산시스템과 개인정보 사용에 대한 수시 모니터링이 필요하다. 개인정보의 유출로 인한 침해는 발생 이후 사후 조치를 취하더라도 그 피해를 막기 어렵다. 이번 논문을 계기로 장애인복지관과 사회복지 기관 전반적으로 개인정보보호에 대한 인식을 새롭게 하고, 기술적 제도적 대응 방안을 마련하는 것이 필요하다.

• 한국농공학회지
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• 제39권5호
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• pp.86-96
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• 1997

The arrangement of small streams in rural area, in the past times, attached importance to the prevention of flood damage through the straightening and lining of streams. Recently, the way of small stream arrangement is introducing the idea of water friendly environment or friendly space. As a result, there has been much concern with water favorable river management model which may lead to control flood. However, it is very difficult to develop a model applicable to all types of rivers, since each river has different flow velocity, flow amount and unique ecological characteristics. In this study, photo processing technique, one of landscape simulation methods, has been adopted because it helps to visually express and comprehensively evaluate pre and post scenery and easily applicable. Some important guideline and technique for the planning of small stream landscape arrangement are mentioned in this study. The simulation system for acquiring water favorable space and arranging landscapes needs to develop database which can forecast various types of landscape. It may also be used for the bases of planning and designing river environment arrangement. Computer aided image processing system enables to make selective planning in river environment arrangement. It may also enables to develop the methods for river environment development, ecology conservation, and multipurpose space utilization. Moreover, it makes economic river arrangement by applying river environment arrangement methods relevant to geographical characteristics. There are some limitations in this study, such as shortage of exact investigation on the stream direction and velocity in landscape arrangement. Continuous monitoring and research may be required to develop techniques through the application of computer graphics and digital image processing.