• Journal of The Korean Association of Information Education
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• 제11권4호
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• pp.471-482
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• 2007

These days UCC(User-created content) is being made and shared increasingly in entertainment and sports area, but its life cycle seems to be very short and the cases that it is used for an education or a learning purposes are not common yet. In this study a new methodology is suggested for adapting a UCC to a distance education. A teacher upload the movie that he or she made for the distance education system, so the students can carry out the self-centered learning procedure. After that, the students send their own movie files to the teacher, and get a feedback from the teacher as a evaluation of the course. In this study a distance education system was established as a prototype, and a short bamboo flute class was chosen for this study from the specialty developmental education program of the elementary school. According to the result of the questionnaire the students thought that their performance skill was improved a lot and they were satisfied with the learning program and the method of evaluation. They also answered that their skills dealing with a camera, a camcorder and a computer got much better. Moreover, most of the students thought that the relationships with their friends and their parents got better also because they spent lots of time together making and watching the movie files for this education program.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2007년도 학술발표회 논문집
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• pp.911-915
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• 2007

영상측정기법을 적용하여 경제적이고 효율적인 유속 측정 방법에 대하여 많은 연구들이 진행되어 왔다. 현재 이동식 LSPIV 시스템은 실험실의 수리모형실험과 현장의 국부적인 유속측정에 효율적으로 이용되고 있지만, 고정식 LSPIV 시스템의 적용에는 많은 문제점들이 있어서 현장 적용이 미루어져왔다. 고정식 LSPIV 시스템은 수문분석에 많이 의존하고 있는 현재의 홍수량 산정에 좀 더 정확한 유속과 수위를 동시에 고려할 수 있는 하천유량측정 시스템이다. 이는 과거 하천유량측정 시 많은 비용과 인력 그리고 위험성들을 대폭 줄일 수 있는 현장 모니터링 시스템의 구축을 가능하게 해줄 수 있다. 본 연구에서는 LSPIV (Large Scale Particle Image Velocimetry) 시스템을 탄천(대곡교)에 설치하여 연속적으로 유량 측정을 하였다. 탄천(대곡교)에 적용된 고정식 LSPIV 시스템은 유속측정을 위한 디지털 카메라 2대와 컴퓨터 그리고 수위 측정을 위한 DCU1104 초음파 수위계로 구성된다. 위의 현장 장비들에서 들어온 실시간 영상과 수위자료는 CDMA 무선통신을 이용하여 서버컴퓨터로 들어와서 인터넷에서 손쉽게 받아 볼 수 있다. 이와 같이 실시간으로 들어온 입력 자료는 LSPIV 프로그램을 이용하여 언제 어디에서나 비교적 정확한 유량을 산정할 수 있다. 또한 실시간으로 들어오는 하천 영상을 통해 실시간 현장 모니터링도 가능하게 되고 시간적으로 연속적인 영상을 얻을 수 있기 때문에 하천 유량 변화를 쉽게 알 수 있다. 따라서 과거 현장에서 어렵게 측정하여 얻을 수 있던 유속자료를 간단한 실시간 영상 분석만으로 구할 수 있으므로 앞으로 유량조사에 유용하게 활용될 수 있을 것이다. 입체 영상) 입체영상은 영화에서 시작되었으나, 20c후반기에 들어서면서 애니메이션 분야와 모바일, 광고 패널, 텔레비전등의 매체를 이용한 입체 영상의 개발로 인하여 특정 분야에 한정 시킬 수 없으므로 영상으로 칭한다. 입체 영상은 21c에 들어서면서 영상매체의 한 분야로 급부상하고 있다. 1900년 무렵부터 연구된 입체영화(3-Dimensional motion Picture)는 In여 년이 지난 지금 대중화를 눈앞에 두고 있다. 국내에서는 놀이 동산이나 박물관등에서 흔히 볼 수 있다. 하지만 앞으로는 HDW등의 대중화로 화질의 발전을 이룬 텔레비전 분야 등에서 실용화 될 전망이다. 국제적인 흐름과 함께 국내에서도 입체 영화에 대한 연구가 활성화 되어 영상산업의 한 주류로서 대두되고 있다. 이러한 상황에서 입체영상에 대한 이해와 콘텐츠(Contents)의 개발은 기술적인 진보에 발맞추어 준비되어야 한다. 본 논문은 이러한 기술적인 계보에 발맞춘 영상 콘텐츠 개발에 박차를 가하고자 앞으로의 발전분야에 대한 기술적인 면과 기법적인 면을 제시하여 기술만 앞서고 내용은 수입하는 수입국이기 보다는 미리 준비하여 비전문가나 타국의 기술에 선점 당하지 않는 분야로 성장할 수 있는 진보적인 영상 인들의 관심과 지속적인 연구를 독려하고자 한다.시민의 휴식 및 여가선용 공간으로 활용하기 위한 사업의 기초자료로 활용되며 이미 설계검토가 시작되었다. 본 연구결과는 유수지 및 저수지의 환경개선 사업의 선두적인 성공사례로 국내 타 지역의 유사한 사업에 있어 벤치마킹을 할 수 있는 훌륭한 사례가 될 것이다.요 생산이 증가하자 군신의 변별(辨別)과 사치를 이유로 강력하게 규제하여 백자의 확대와 발전에 걸림돌이 되었다. 둘째, 동

• Journal of the Earthquake Engineering Society of Korea
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• 제13권3호
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• pp.11-19
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• 2009

Recently, concerns relating to the maintenance of large structures have been increased. In addition, the number of large structures that need to be evaluated for their structural safety due to natural disasters and structural deterioration has been rapidly increasing. It is common for the structural characteristics of an older large structure to differ from the characteristics in the initial design stage, and changes in dynamic characteristics may result from a reduction in stiffness due to cracks on the materials. The process of deterioration of such structures enables the detection of damaged locations, as well as a quantitative evaluation. One of the typical measuring instruments used for the monitoring of bridges and buildings is the dynamic measurement system. Conventional dynamic measurement systems require considerable cabling to facilitate a direct connection between sensor and DAQ logger. For this reason, a method of measuring structural responses from a remote distance without the mounted sensors is needed. In terms of non-contact methods that are applicable to dynamic response measurement, the methods using the doppler effect of a laser or a GPS are commonly used. However, such methods could not be generally applied to bridge structures because of their costs and inaccuracies. Alternatively, a method using a visual image can be economical as well as feasible for measuring vibration signals of inaccessible bridge structures and extracting their dynamic characteristics. Many studies have been conducted using camera visual signals instead of conventional mounted sensors. However, these studies have been focused on measuring displacement response by an image processing technique after recording a position of the target mounted on the structure, in which the number of measurement targets may be limited. Therefore, in this study, a model experiment was carried out to verify the measurement algorithm for measuring multi-point displacement responses by using a DIC (Digital Image Correlation) technique.

• Journal of Biomedical Engineering Research
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• 제19권2호
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• pp.119-128
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• 1998

This paper describes a filtering algorithm which employs apriori information of SPECT lesion detectability potential for the filtering of degraded projection images prior to the backprojection reconstruction. In this algorithm, we determined m minimum detectable lesion sized(MDLSs) by assuming m object contrasts uniformly-chosen in the range of 0.0-1.0, based on a signal/noise model which provides the capability potential of SPECT in terms of physical factors. A best estimate of given projection image is attempted as a weighted combination of the subimages from m optimal filters whose design is focused on maximizing the local S/N ratios for the MDLS-lesions. These subimages show relatively larger resolution recovery effect and relatively smaller noise reduction effect with the decreased MDLS, and the weighting on each subimage was controlled by the difference between the subimage and the maximum-resolution-recovered projection image. The proposed filtering algoritym was tested on SPECT image reconstruction problems, and produced good results. Especially, this algorithm showed the adaptive effect that approximately averages the filter outputs in homogeneous areas and sensitively depends on each filter strength on contrast preserving/enhancing in textured lesion areas of the reconstructed image.

• Journal of Korea Water Resources Association
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• 제49권10호
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• pp.887-901
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• 2016

Cohesive sediments form flocs through the flocculation process. The size and density of floc are variable whereas those of a fine sediment are always assumed to be constant. The settling velocity, one of main factors of sediment transport, is determined by size and density of particle. Therefore, the flocculation process plays an important role in transport of cohesive sediment. It is of great difficulty to directly measure the density of floc in the field due to technical limitation at present. It is a popular approach to estimate the density of floc by applying the fractal theory. The main assumption of fractal theory is the self-similarity. This study aims to examine the applicability of fractal theory to cohesive sediment in small rivers of Korea. Sampling sediment has been conducted in two different basins of Geum river and Yeongsan river. The results of settling experiments using commercial camera show that the sediment in Geum river basin follows the main concept of fractal theory whereas the sediment in Yeongsan river basin does not have a clear relationship between floc size and fractal dimension. It is known from this finding that the fractal theory is not easily applicable under the condition that the cohesive sediment includes the high content of organic matter.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2017년도 학술발표회
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• pp.100-100
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• 2017

하천에 유입된 오염물질의 2차원 혼합거동은 하천 주흐름에 의한 이송현상과 유속 성분의 수심평균 값에 대한 공간적 편차로부터 야기되는 분산현상으로 설명 할 수 있다. 이는 3차원 이송확산 방정식으로부터 수심 적분된 2차원 이송-분산 방정식으로 수학적 유도가 가능하며, 수심방향으로 적분하는 과정에서 발생되는 농도의 분산항은 Taylor Dispersion 개념에 기초하여 종방향 및 횡방향의 2차원 분산계수로 표현된다. Fischer(1978)는 연직방향 유속분포로부터 2차원 분산계수를 추정하는 해석해를 수학적으로 유도하였으나, 실제 하천에서 정밀한 연직방향 유속분포를 계측하는 것은 많은 비용 및 노동력을 초래한다. 따라서 선행 연구자들은 2차원 혼합모형의 분산계수를 산정하고자 실험적 방법으로써 추적자실험을 수행하였다. 추적자실험은 추적자 물질을 수체에 주입한 후 농도의 변화를 관측함으로써 추적자물질이 하천에서 이송 및 분산되는 과정을 이해하는데 유용하다. 기존의 추적자실험은 고정된 위치에서 농도를 계측하여 시계열적인 농도의 변화를 관측한 후, 오염운 동결가정을 통해 종,횡방향 분산계수의 산정이 가능하지만, 오염물질 농도의 공간적 분포를 얻기에는 한계가 있다. 본 연구에서는 기존의 추적자실험법의 한계를 극복하고자 형광물질을 이용한 추적자실험을 수행함과 동시에 드론에 장착된 디지털카메라를 이용하여 항공영상을 취득 및 분석하여, 하천에 주입된 형광물질의 농도분포를 시공간적으로 추출하는 기법을 개발하고, 이를 바탕으로 오염물질의 2차원 혼합거동을 분석하였다. 본 실험은 한국건설기술연구원의 안동하천실험센터의 A3실험수로에서 수행되었으며, 실험수로는 평균 하폭 5 m, 평균 수심 0.44 m, 유량 $0.96m^3/s$의 실제 소규모 하천과 유사한 축척을 가지고 있다. 추적자물질은 Rhodamine WT 용액이 사용되었으며, 실험수로 내 설치된 15개의 형광광도계(YSI-600OMS)를 이용하여 농도를 측정하였다. 항공영상의 취득을 위해 이용된 드론은 DJI-Phantom 3 Professional 이며, 3840x2160의 해상도로 초당 30 frame의 동영상으로 취득되었다. 영상의 정합 및 좌표화를 위해 RTK-GPS를 이용하여 12개의 지상 기준점의 좌표를 취득한 후, 사영변환을 통해 영상좌표를 지상좌표로 변환하였다. 영상의 픽셀값을 농도장으로 변환하기 위해 각 RGB 밴드의 픽셀값을 통계적으로 분석하여 농도장으로 변환하였으며, 영상으로부터 얻은 농도장은 형광광도계에 의해 실측된 농도와 결정계수 0.9이상의 수준으로 정확도를 나타냈다.

• Journal of Practical Agriculture & Fisheries Research
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• 제18권1호
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• pp.101-112
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• 2016

Monitoring and control of the greenhouse environment play a decisive role in greenhouse crop production processes. The network system for greenhouse control was developed by using recent technologies of networking and wireless communications. In this paper, a remote monitoring and control system for greenhouse using a smartphone and a computer with internet has been developed. The system provides real-time remote greenhouse integrated management service which collects greenhouse environment information and controls greenhouse facilities based on sensors and equipments network. Graphical user interface for an integrated management system was designed with bases on the HMI and the experimental results showed that a sensor data and device status were collected by integrated management in real-time. Because the sensor data and device status can be displayed on a web page, transmitted using the server program to remote computer and mobile smartphone at the same time. The monitored-data can be downloaded, analyzed and saved from server program in real-time via mobile phone or internet at a remote place. Performance test results of the greenhouse control system has confirmed that all work successfully in accordance with the operating conditions. And data collections and display conditions, event actions, crops and equipments monitoring showed reliable results.

• Journal of the Society of Disaster Information
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• 제19권4호
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• pp.770-778
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• 2023

Purpose: In order to reduce forklift industrial accidents, it is necessary to classify them into institutional, technical, and educational factors and conduct research on whether each factor affects disaster reduction. Method: Descriptive statistical analysis, validity analysis, reliability analysis, and multiple regression analysis were conducted using SPSS 18 program based on an offline questionnaire based on a 5-point Likert scale. Result: As a result of multiple regression analysis, it was found that institutional, technical, and educational factors, which are independent variables for disaster reduction, explain about 62.5% of the variance in disaster prevention, which is the dependent variable. The regression model verification was found to be statistically significant with F=118.775 and significance probability p<0.01. Conclusion: First, there is a need to prevent disasters by including electric forklifts weighing less than 3 tons in the inspection system. Second, there is a need to make it mandatory to install front and rear cameras and forklift line beams to prevent forklift collision disasters. Third, there is a need to conduct special training related to forklifts every year, and drivers and nearby workers need to be included in the special training for forklifts.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2004년도 정기총회 및 제6최 특별 심포지움
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• pp.104-117
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• 2004

Dmitri Donskoi, which went down during the Russo-Japanese War occurred 100 years ago, was found by using geophysical exploration techniques at the 400 m water depth of submarine valley off Jeodong of Ulleung Island. In the submarine area with the rugged seabed topography and volcanic seamounts, in particular, the reliable seabed images were acquired by using the mid-to-shallow Multibeam exploration technique The strength of corrosion (causticity) of the sunken Donskoi, measured by the electrochemical method, decreased to 2/5 compared with the original strength.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• 제35권2호
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• pp.93-101
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• 1999

A simple experimental method was used in an attempt to realize the elevation of the fishing ability of purse seine in the sea area of Cheju Island, the changes of seine volume and tension in the purseline during pursing. Experiments carried out on the six types simplified reduced model seines which were made of knotless nettings. The nettings were woven in different leg length 4.3, 5.0, 5.5, 6.0, 6.6 and 7.7mm of polyester 28 tex two threads two-ply twine, and each of the seines were named I, II, III, IV, V and Ⅵ seine. Dimension of seine models were 450cm for corkline and 85cmfor seine depth, each seines rigged up 160g of float for a floatline and 50g (underwater weight) of lead for a leadline. These model purse seines were made of the scale of 1/200 of its full scale, a 120 ton in the near sea of Cheju Island. Designing and testing for the model purse seines were based on the Tauti's law. Experiments were measured in the observation channel of a flume tank at the static conditions set up shooting and pursing equipments. Motion of purse seine during purse line was recorded by the two sets video camera for VTR which were placed in top and front of the model seine. The reading coordinate of seine volume carried out by the video digitization system, disk data for the purseline tension. An analysis were performed on the changes seine volume and tension in the purseline during pursing. The results obtained were as follows: 1. The seine volume during pursing was largest for Ⅵ seine with smallest d/l followed by V, IV, III, II and I seines, and tension in the purseline was small. 2. Seine volume during pursing can be expressed by the following equation; CVt=l-EXP[｛2.79 (d/l）＋0.35｝t-33.37 (d/l) ＋ 0.57] Where CVt is volume ratio, d is twine diameter, l is leg length and t is pursing time (sec). 3. Tension in the purse line during pursing can be expressed by the following equation; T= 1- EXP ｛0.57t ＋ 13.36 (d/l)+2.97｝ Where T is tension (kg) in the purseline during pursing.