• 한국정밀공학회지
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• 제11권1호
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• pp.166-176
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• 1994

The problem of reducing the vibration level of elastic plates driven by multiple random point forces is analyzed in this study. First, the analytical solution for the vibration level of finite thin plates with four simply supported edges under the action of multiple random point force is derived. By assuming the plates to be lightly damped, an approximate solution for the vibration level of the plate is obtained. A numerical study is carried out to determine an optimal spacing distance between the multiple point forces in order to produce a relative minimum in the plate's vibration level. The optimal spacing distance is shown to depend on the given excitation band. The effects of wave cancellation in the near field of the multiple point forces are discussed by using the equivalence of certain stationary random responses and deterministic pulse responese.

• 환경영향평가
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• 제7권1호
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• pp.63-70
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• 1998

TCM has been used for many environmental impact assessments in Korea. But there was reported that an error was found in area source calculation of original TCM and modified. In this study, TUM(TCM-urban mode) and TRM(TCM-rural mode) were developed for urban and rural area by modification of original TCM. McElroy-Pooler dispersion parameter was used for area and point source in TUM, Pasquill-Gifford parameter was used for area and point source in TRM. And Irwin's vertical wind speed profile exponents were used for TUM and TRM. Then predicted value by TUM, TRM and a value from the same area and point data by CDM2, ISCLT3 were compared. And it was found that predicted value from point source by TUM, TRM was very similar to a value by CDM2, ISCLT3, and predicted value from area source by TRM was similar to a value by CDM2, ISCLT3. But predicted value from area: source by TUM was an half lower than a value by CDM2, ISCLT3.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.229-233
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• 2007

This study is to test the applicability of QuickBird image for non-point source pollution assessment. SWAT (Soil and Water Assessment Tool) model was adopted and the model was calibrated for a stream watershed of 255.4 $km^2$ Landsat land use data. For model application with QuickBird image, a precise agricultural land use map of 1.16 $km^2$ area located in the upstream watershed was produced by field investigation. The model was run with the combination of land use and soil map scales (1:5,000, 1:25,000 and 1:50,000). The results were compared and analyzed for the contribution of non-point source pollution by the land use scale and contents.

• 한국광학회지
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• 제22권1호
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• pp.58-63
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• 2011

외선 점광원 탐지장비의 탐지성능 예측을 위한 최소탐지조도(MDI)를 측정하고 실험결과를 제시하였다. 최소탐지조도 측정은 시준기를 이용하여 실험실 환경에서 수행할 수 있는 방법으로 구현하였으며 측정에 따르는 시험조건 및 절차를 상세히 기술하였다. 또한 최소탐지조도 측정 결과를 이용하여 분석한 적외선 탐지장비의 최대탐지거리 예측결과를 제시하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1354-1356
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• 2009

In this paper, we explained characteristics of integral imaging microscope using point light source. To display the bio-medical information, which is captured as a form of the elemental images, using autostereoscopic displays, the characteristics analysis of three-dimensional information is required. For integral imaging microscope using point light source array, the elemental image capturing configuration has to satisfy a specific condition. We explain the condition to capture the elemental images and show the experimental results.

• 방사선산업학회지
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• 제17권3호
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• pp.275-282
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• 2023

Workers in nuclear power plants are likely to be exposed to radiation from various geometrical sources. In order to evaluate the exposure level, the point-kernel method can be utilized. In order to perform a dose assessment based on this method, the radiation source should be divided into point sources, and the number of divisions should be set by the evaluator. However, for the general public, there may be difficulties in selecting the appropriate number of divisions and performing an evaluation. Therefore, the purpose of this study is to develop an algorithm for dose assessment for arbitrary shaped sources based on the point-kernel method. For this purpose, the point-kernel method was analyzed and the main factors for the dose assessment were selected. Subsequently, based on the analyzed methodology, a dose assessment algorithm for arbitrary shaped sources was developed. Lastly, the developed algorithm was verified using Microshield. The dose assessment procedure of the developed algorithm consisted of 1) boundary space setting step, 2) source grid division step, 3) the set of point sources generation step, and 4) dose assessment step. In the boundary space setting step, the boundaries of the space occupied by the sources are set. In the grid division step, the boundary space is divided into several grids. In the set of point sources generation step, the coordinates of the point sources are set by considering the proportion of sources occupying each grid. Finally, in the dose assessment step, the results of the dose assessments for each point source are summed up to derive the dose rate. In order to verify the developed algorithm, the exposure scenario was established based on the standard exposure scenario presented by the American National Standards Institute. The results of the evaluation with the developed algorithm and Microshield were compare. The results of the evaluation with the developed algorithm showed a range of 1.99×10^-1~9.74×10^-1 μSv hr^-1, depending on the distance and the error between the results of the developed algorithm and Microshield was about 0.48~6.93%. The error was attributed to the difference in the number of point sources and point source distribution between the developed algorithm and the Microshield. The results of this study can be utilized for external exposure radiation dose assessments based on the point-kernel method.

• 기술혁신연구
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• 제13권3호
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• pp.27-49
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• 2005

In this Paper, we analyzed the relative importance of multiple sources and their effects on innovative activities. Through factor analysis, we found 5 sources of innovative activities; university/laboratory source, within firm source, general information source, vertical/competitive relation source, and horizontal relation source. Through regression analysis, we found that (1) 'within firm source' is the most important source on innovative activities, (2) from inputs' point of view, the more 'vertical/competitive relation source' is, the less innovative activities we, (3) from outputs' point of view, innovations are more activated when 'university/laboratory source' is abundant. but, they are less activated when 'general information source' and 'vertical/competitive relation source' is abundant, and (4) according to firm size and innovation stages(newproduct innovation, upgraded product innovation, and process innovation), the effect of sources on innovative activities is different.

• Journal of the Optical Society of Korea
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• 제16권3호
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• pp.256-262
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• 2012

We derive the point-spread function of the reconstructed image from a point-source complex hologram, which includes phase error caused by polarization components, in the longitudinal direction of the point-spread function and analyze the effect of the error sources of polarization components having influence on image reconstruction of a point-source complex hologram in incoherent triangular holography.

• 한국위성정보통신학회논문지
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• 제11권3호
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• pp.80-85
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• 2016

본 연구는 선음원과 점음원의 이론에 근거하여 개발된 혼타입 스피커와 라인어레이 타입 스피커에 대해 비교분석하여 실제에서 이론대로 적용되는지에 대해 연구하였다. 이론적으로 점음원은 거리가 2배 됨에 따라 6dB 감쇄하며, 선음원은 거리가 2배 됨에 따라 3dB 감쇄한다. 선음원 이론에 근거하여 개발된 라인어레이 스피커 시스템이 선음원의 이론대로 작은 음압감쇄가 일어나는지에 대하여 분석하여 사용 목적과 환경에 따른 올바른 스피커의 배열 구성이 선택되도록 하는 것이 본 연구의 목적이다. 이를 위해 점음원과 선음원의 이론을 분석하였으며, 이론을 바탕으로 설계된 혼타입 스피커와 라인어레이 스피커를 시뮬레이션으로 파라메터 값들을 분석하였다.

• 한국물환경학회지
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• 제33권1호
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• pp.78-89
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• 2017

Water quality monitoring network data is being affected continuously due to non-point source pollution arising from agricultural land located on the Gwangsancheon outlet in the Nakdong River basin. In this study, we have performed analysis of water quality monitoring system, water quality pattern using SOM and water quality in the Gwangsancheon for sub-basin located at Gisan-myeon in the Nakdong River basin. We have developed and applied the model to estimate the runoff and non-point source loading. As a result of SOM pattern, the effect of non-point source pollution was the largest in the paddy fields and fields. As a result of the developed model, we found contribution rate and reduction rate for non-point source loading according to change of landuse because the reduction effect of nonpoint pollutants was 20.9% of SS, 9.9% of TN, 21.2% of TP and 8.9% of TOC depending on the landuse change.