• 한국환경복원기술학회지
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• 제20권1호
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• pp.55-75
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• 2017

The purpose of this study is to present the basic data for restoration of physical stream environment by analyzing habitat variables because habitat environment is changed due to the construction of waterfront space in urban streams. Assessment results of 10 habitat variables(three divisions) were almost same as optimal condition, in the reach of reference stream where there are no stream crossing structures and channel alteration. Assessment results of reaches in urban rivers, where streams were improved on water-friendly recreation activities, appeared to be marginal condition. Because habitat environment got worse due to stream improvement works such as construction of weir for water landscape, stepping stones for walking, low water revetment and high water revetment, and high water channel. In addition, in the case of mid gradient stream, the frequency of riffles was small or not existed because the intervals of the river crossing structures was short. In the case of mild stream types, the diversity of the pool was damaged due to the deposition of sludge in the upstream pool of weir and the installation of low water revetment.

• 한국식생활문화학회지
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• 제13권3호
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• pp.159-168
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• 1998

This survey was carried out to obtain the information concerning nutritional status, including factors of food intake and health condition of elderly living in Ulsan area. Main results were as follows. 1) Average height of subjects was close to Korean reference, while weight was below Korean reference, average obesity rate and body mass index were +6.93% and 21.9. 2) In health related factors, 41% of subjects exercised regularly, 31.6% of subjects drank alcoholic beverage, and 41.4% of subjects smoked currently. 3) Mean food habits score was 32.1(ranging from 10 to 50) and milk and lipid food intake were decreased. 4) Dietary intake data showed the average daily intake of all nutrients except phosphorus, were lower than RDA, especially vitamin A, calcium and zinc were lower than other nutrients. According to the percentage of RDA, vitamin A was the nutrient found to be least sufficient. 5) Among the various influential factors resident type, pocket money, exercise and smoking influenced on nutrient intake considerably

• 한국통신학회논문지
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• 제19권4호
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• pp.685-690
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• 1994

벡터 양자화의 부호화에서 입력벡터에 가장 잘 정합되는 코드벡터를 탐색하는 과정에서 발생하는 계산의 복잡도는 코드북의 크기에 비례하여 지수직으로 증가하고 실질적으로 응용을 제한한다. 본 논문에서는 정합 가능성이 없는 코드벡터에 대한 왜곡의 계산을 제거하기 위한 조건의 시작 벡터로서 참조 벡터를 사용하는 단순, 고속의 효율적인 벡터 양자화의 부호화 알고리즘을 제안하였다. 이는 입력벡터에 정합 기능성을 갖는 참조 벡터를 선택하고 코드 벡터에 대한 왜곡의 계산을 제거하기 위한 조건을 결합하는 것이다. 제한된 방법은 전탐색 벡터 양자화에 비하여 단지 10~15%의 수학적 연산을 필요로 한다. 그리고 덧셈과 비교 연산의 수는 크게 줄어들지 않지만 곱셈은 벡터 양자화의 여러 고속부호화 방법의 70~80%까지 들었다.

• 제어로봇시스템학회논문지
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• 제22권3호
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• pp.233-240
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• 2016

This paper describes a three-dimensional reference trajectory generation method for giving commands to an unmanned air vehicle (UAV). The trajectory is a set of consecutive curves with constant acceleration during each interval and passing through via-points at specified times or speeds. The functional inputs are three-dimensional positions and times (or speeds) at via-points, and velocities at both boundaries. Its output is the time series of position values satisfying the piecewise constant acceleration condition. To be specific, the shape of the trajectory, known as the path, is first represented by splines using third degree polynomials. A numeric algorithm is then suggested, which can overcome the demerits of cubic spline method and promptly generate a piecewise constant acceleration trajectory from the given path. To show the effectiveness of the present scheme, trajectory generation cases were treated, and their speed calculation errors were evaluated.

• 한국공작기계학회논문집
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• 제16권1호
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• pp.60-68
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• 2007

It has been conducted by laser vision sensor for weldability estimation of front-bead after doing high speed butt laser welding of any condition. It has been developed a real time GUI(Graphic User Interface) system for weldability application in the basis of texts and field qualify levels. In the reference of bead imperfections, defects absolute position and defects intensity index of front-bead in the basis of formability reference, it has been produced a weldability estimation and defects intensity index of back-bead by back propagation neural network. In the result of by comparing measuring data by laser vision sensor of back-bead and data by back propagation neural network of one, it has been shown the similar results. Finally, under knowledge of welding condition in production line, it has been conducted a weldability estimation of back-bead only in knowledge of informations of front-bead data without using laser vision sensor or welding inspection experts and furthermore it can be used data for final inspection results of back-bead.

• 한국멀티미디어학회논문지
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• 제3권6호
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• pp.586-591
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• 2000

알반적으로 CPT에 재현되는 칼라영상은 수상기의 특성이나 외부광원에 의하여 영향을 받으며 CPT에 재현되는 부정확한 칼라의 조정은 주어진 영상의 색 왜곡을 발생시킨다. 본 논문에서는 일상적인 광원 환경아래 시청자들의 측면에서 CPT에 재현되는 색의 모델링을 위한 색 조정 방법을 기술하였다. 이를 위하여 본 논문에서는 광원의 세기에 따른 감마 보정 상태에서의 휘도 보상 방법, 광원의 종류에 따른 색상 및 색농도 보상 방법 및 기준색 설정을 위한 특정색 조정 방법을 제안하였다. 제안한 방법에 근거하여 광원의 반사성분의 영향과 CPT의 감마변환 및 최적의 색 설정을 위한 기준 장면 조정시 발생될 수 있는 색 오차를 감소시키는 색 보상 시스템 구현 방법을 제안하였다.

• 방송공학회논문지
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• 제20권4호
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• pp.606-618
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• 2015

컴퓨터 그래픽스(CG: computer graphics) 기술은 영화나 TV와 같은 미디어 컨텐츠에서 중요한 요소 기술로 자리매김하고 있다. 영상 속 특정 인물의 얼굴을 다른 사람의 얼굴로 교체하는 얼굴 교체 기술은 대표적인 CG 기술 중의 하나로써 오래전부터 많이 연구되어 왔다. 본 논문에서는 3D 모델을 사용하지 않고 특정 조명 환경을 갖고 있는 목표 동영상 속의 얼굴을 다른 조명 환경을 갖고 있는 참조 정지 영상 속의 얼굴로 자연스럽게 교체할 수 있는 기술을 제안한다. 실험 결과, 제안하는 방법이 서로 다른 조명을 갖고 있는 두 얼굴 간의 얼굴 교체를 자연스럽게 수행할 수 있는 것을 확인할 수 있었다.

• 제어로봇시스템학회논문지
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• 제17권4호
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• pp.289-294
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• 2011

Digital redesign is yet another efficient tool to convert a pre-designed analog controller into a sampled-data one to maintain the analog closed-loop performance in the sense of state matching. A rising difficulty in developing a digital redesign technique for trackers with time-varying references is the unavailability of a closed-form discrete-time model of a system, even if it is linear time-invariant. A way to resolve this is to approximate the time-varying reference as a piecewise constant one, which deteriorates the state matching performance. Another remedy may be to decrease a sampling period, which however could numerically destabilize the optimization-based digital redesign condition. In this paper, we develop a digital redesign condition for time-varying trackers by approximating the time-varying reference through a triangular hold and by introducing delta-operated discrete-time models. It is shown that the digitally redesigned sampled-data tracker recovers the performance of the pre-designed analog tracker under a fast sampling limit. Simulation results on the formation flying of satellites convincingly show the effectiveness of the development.

• 한국산학기술학회논문지
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• 제7권6호
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• pp.1219-1223
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• 2006

혀는 전통 한의학(중의학)에서 환자 진단의 가장 중요한 부분의 하나이다. 본 논문은 사람의 혀 영상을 이용한 건강 모니터링 방법을 제안한다. 제안한 방법은 사용자의 혀의 절대적 특징을 사용하지 않고 병원에서 진단된 기준 건강 상태(RHC)와 특징차를 이용하는 방법이다. 건강 모니터링 시스템은 사용자로부터 매일 혀 영상을 획득하고, 혀의 관심영역을 추출하여 기준 건강 상태의 특징값과 비교한다. 실험에서 제안한 혀 영상 분석 방법이 건강 모니터링에 사용 가능성을 보였다.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.907-914
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• 2018

In this article, we conducted molecular dynamics simulations to investigate the effect of applied strain and temperature on irradiation-induced damage in alpha-zirconium. Cascade simulations were performed with primary knock-on atom energies ranging between 1 and 20 KeV, hydrostatic and uniaxial strain values ranging from -2% (compression) to 2% (tensile), and temperatures ranging from 100 to 1000 K. Results demonstrated that the number of defects increased when the displacement cascade proceeded under tensile uniaxial hydrostatic strain. In contrast, compressive strain states tended to decrease the defect production rate as compared with the reference no-strain condition. The proportions of vacancy and interstitial clustering increased by approximately 45% and 55% and 25% and 32% for 2% hydrostatic and uniaxial strain systems, respectively, as compared with the unstrained system, whereas both strain fields resulted in a 15-30% decrease in vacancy and interstitial clustering under compressive conditions. Tensile strains, specifically hydrostatic strain, tended to produce larger sized vacancy and interstitial clusters, whereas compressive strain systems did not significantly affect the size of defect clusters as compared with the reference no-strain condition. The influence of the strain system on radiation damage became more significant at lower temperatures because of less annealing than in higher temperature systems.