• 한국인터넷방송통신학회논문지
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• 제20권4호
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• pp.93-99
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• 2020

드론 기술의 발전으로 감시, 재난사고 예방 및 구호 등 공공임무 수행에도 지능화된 드론 활용이 급속히 늘어날 것으로 본다. 드론이 스마트 안전도시 플랫폼에 구축에 사용되기 위해서는 목표물 탐지 및 추적기술, 드론비행 시에 비행 조정 및 장애물 회피기능, 착륙지점 탐지 및 제어 기능 등의 주요 기술 구현이 필요하다. 드론 시스템 은 기술적 파급효과가 크고 신기술 분야의 산업화를 촉진한다. 본 논문에서는 이와 같은 드론 개발을 위하여 객체지향 분석/설계 방법을 이용한 요구사항 분석 및 플로우차트, 화면 설계 등을 보여여줌으로 효과적인 드론 시스템의 소프트웨어 분석 및 설계 방법을 제시하고자 한다.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3547-3552
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• 2014

Laser Raman spectroscopy is one of the most powerful technologies for standoff detection of hazardous materials including explosives. Supported by recent development of laser and sensitive ICCD camera, the technology can identify trace amount of unknown substances in a distance. Using this concept, we built a standoff detection system, in which nanosecond pulse laser and nanosecond gating ICCD technique were delicately devised to avoid the large background noise which suppressed weak Raman signals from the target sample. In standoff detection of explosives which have large kill radius, one of the most important technical issues is the detection distance from the target. Hence, we focused to increase the detection distance up to 54 m by careful optimization of optics and laser settings. The Raman spectra of hazardous materials observed at the distance of 54 m were fully identifiable. We succeeded to detect and identify eleven hazardous materials of liquid or solid particles, which were either explosives or chemical substances used frequently in chemical plants. We also performed experiments to establish the limit of detection (LOD) of HMX at 10 m, which was estimated to be 6 mg.

• Ocean and Polar Research
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• 제24권4호
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• pp.391-398
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• 2002

Trace organic contaminants in deep-sea sediments near Dokdo were analyzed. Total PAMs concentration ranged 14.8-314 ng/g dry weight and high molecular weight PAHs were dominant. The highest PAHs concentration was detected at A19 which located at Ulleung Basin. Most of organochlorines were under detection limit. Among the detected organochlorines, DDT compounds were dominant and followed by HCHs and HCB. Butyltin compounds and most of organophosphorus pesticides were not detected. Vertical distribution of PAHs showed typical sub-surface maximum and decreasing trends depending on depth. The highest PAHs concentration reached 454ng/g. Some organochlorines, DDT, HCH was detected and also showed decreasing trends. Other target organic pollutants were not detected in core sediments. Abnormally high level of PAHs concentration in A19 was discussed and the input sources were inferred to be the transport of sludge derived pollutant dumped at dumping site 'Byung' by deep current.

• Geomechanics and Engineering
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• 제36권3호
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• pp.205-215
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• 2024

Manually mapping fractures in construction stone mines is challenging, time-consuming, and hazardous. In this method, there is no physical access to all points. In contrast, digital image processing offers a safe, cost-effective, and fast alternative, with the capability to map all joints. In this study, two methods of detecting the trace of discontinuities using image processing in construction stone mines are presented. To achieve this, we employ two modified Hough transform algorithms and the degree of neighborhood technique. Initially, we introduced a method for selecting the best edge detector and smoothing algorithms. Subsequently, the Canny detector and median smoother were identified as the most efficient tools. To trace discontinuities using the mentioned methods, common preprocessing steps were initially applied to the image. Following this, each of the two algorithms followed a distinct approach. The Hough transform algorithm was first applied to the image, and the traces were represented through line drawings. Subsequently, the Hough transform results were refined using fuzzy clustering and reduced clustering algorithms, along with a novel algorithm known as the farthest points' algorithm. Additionally, we developed another algorithm, the degree of neighborhood, tailored for detecting discontinuity traces in construction stones. After completing the common preprocessing steps, the thinning operation was performed on the target image, and the degree of neighborhood for lineament pixels was determined. Subsequently, short lines were removed, and the discontinuities were determined based on the degree of neighborhood. In the final step, we connected lines that were previously separated using the method to be described. The comparison of results demonstrates that image processing is a suitable tool for identifying rock mass discontinuity traces. Finally, a comparison of two images from different construction stone mines presented at the end of this study reveals that in images with fewer traces of discontinuities and a softer texture, both algorithms effectively detect the discontinuity traces.

• 공업화학
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• 제31권3호
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• pp.237-257
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• 2020

The role of nano bio-composites precursor to chitosan are innumerable and are known for having different applications in various branches of physical sciences. The application to the sensor development is relatively new, where only few literature works are available to address the specific and critical analysis of nanocomposites in the subject area. The bio-composites are potential and having greater affinity towards the heavy metals and several micro-pollutants hence, perhaps are having wider implications in the low or even trace level detection of the pollutants. The nano-composites could show good selectivity and suitability for the detection of the pollutants as they are found in the complex matrix. However, the greater challenges are associated using the bio-composites, since the biomaterials are prone to be oxidized or reduced at an applied potential and found to be a hinderance for the detection of target pollutants. In addition, the materials could proceed with a series of electrochemical reactions, which could produce different by-products in analytical applications, resulting in several complex phenomena in electrochemical processes. Therefore, this review addresses critically various aspects of an evaluation of nano bio-composite materials in the electrochemical detection of heavy metals and micro-pollutants from aqueous solutions.

• 융합보안논문지
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• 제18권5_1호
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• pp.113-120
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• 2018

오늘날 정보 통신 기술의 발전은 네트워크 기반의 서비스 사용자 수를 빠르게 증가시키고 있으며, 인터넷 상에서 사용자 상호간 실시간 정보 공유를 가능하도록 한다. 정보의 공유 과정에는 다양한 방법들이 존재하지만 일반적으로 포털서비스 기반의 정보 공유가 대중화 되어있다. 그렇지만 이러한 정보 공유 과정은 특정 이해 당사자 상호간 해당 정보의 사회적 관심도 증폭을 위한 불법 행위를 유발시키는 원인이 되고 있다. 그 중 매크로 기능을 이용한 여론 조작 공격은 정상적인 여론의 방향을 왜곡시키기 때문에 이에 대한 보안 대책이 시급한 실정이다. 일반적으로 매크로 공격이란 불법적인 사용자들이 다수의 IP나 아이디를 확보한 후 특정 웹 페이지의 내용에 대하여 여론을 조작하는 공격으로 정의한다. 본 논문은 특정 사용자의 매크로 공격에 대하여 트레이스 백 기반의 네트워크 경로 정보를 분석한 후 해당 사용자의 다중 접속을 탐지할 수 있도록 하였다. 즉, 특정 웹 페이지에 대한 전체적인 접근 경로 정보와 사용자 정보가 일치하는 접근이 2회 이상 발생하면 이를 매크로 공격으로 판정하였다. 또한 동일한 지역에서 특정 웹 페이지에 대하여 다수의 아이디를 이용한 접근이 발생하는 경우, 이에 대한 임계 카운트 값 분석을 통하여 특정 웹 페이지에 대한 전체적인 여론 결과를 왜곡 할 수 없도록 하였다.