• 환경영향평가
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• 제19권3호
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• pp.297-305
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• 2010

This study has intended to analyze the nature of the errors that occur as a result of shadows during the process of NDVI calculation using high-resolution satellite images of Cheongju City, in order to calibrate such errors, and to verify the results. This study has calibrated the shadow errors by utilizing the relationship between the Greenness above Bare Soil (GRABS) calculated through Tasseled-Cap transformation and the original NDVI. To verify the accuracy of the results, this study has compared the shadow area extracted by the difference between before and after calibration of NDVI, with the original shadow area. The NDVI value converged on the value of -1.0, representing water, because shadow areas could not accept the reflection value from each band. However, after performing Tasseled-Cap transformation, the NDVI of shadow areas that had converged on -1.0 prior to calibration had increased to a level similar to the NDVI of neighboring areas. In addition, the average NDVI in general had increased from -0.08 to -0.01. Finally, the shadow area drawn out was almost matched to the original one, meaning that the NDVI calibration method employed turned out to be highly accurate in extracting shadow areas.

• 산업경영시스템학회지
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• 제35권1호
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• pp.57-65
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• 2012

The relationship between product quality/function and customer satisfaction has been considered an important point for the new product development. The seminal paper by Kano was the first to thoroughly address the non-linear relationship between product performance/function and customer satisfaction. In the analysis framework of the original Kano model, five factors are assumed, among which indifference factor occupies 40% in the classification scheme. When we analyze survey response using Kano model, many quality attributes can be resulted in indifference factor. This implies that some attributes which are meaningful tend to be classified as indifferent attributes for the customer satisfaction. In order to tackle this problem, a modified Kano model is proposed by reducing the indifference factor. The modified Kano model can be robust for the survey response. A survey is performed for the quality attributes of the smart phone. The response is analyzed and compared based on the original and modified Kano model. The surveyed quality characteristics of the smart phone are performance related attributes, application programs, functional attributes and subjective emotional quality attributes. Many quality attributes classified as indifference factor in the original model are classified as attractive, must-be, and expected factors, respectively.

• 간호행정학회지
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• 제19권1호
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• pp.146-154
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• 2013

Purpose: To do nursing research effectively requires an understanding of fundamental principles of statistical methods. In this article, some key statistical methods which are commonly used in nursing research are identified and summarized. Methods: Ninety-two original articles from the Journal of Korean Academy of Nursing Administration were reviewed. Statistical methods were classified and summarized for usage in research and occurrence of common errors. Results: Among the original articles reviewed, 58 statistical usages contained errors. Most errors were found in linear regression analysis, Pearson correlation analysis, and chi-square test. From the detection of statistical errors in usage, suggestions for appropriate statistical methods were made. Conclusion: In order to improve validity of original articles in the Journal of Korean Academy of Nursing Administration, clearly stated statistical usage and close editorial attention to statistical methods are needed. Understanding statistical methods is part of the process that researchers must use to determine both quality and usefulness of the research. Research findings will be used to guide nursing practice and reduce uncertainty in decision making. However, to understand how to interpret research results, it is important to be able to understand basic statistical concepts. Researchers should also choose statistical methods that match their purposes.

• 한국정보컨버전스학회논문지
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• 제1권1호
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• pp.17-24
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• 2008

영상 감시 카메라는 각종 범죄를 예방하고 범죄사건을 해결하는데 중요한 정보를 제공해 준다. 2차원 얼굴 영상을 확대 복원하기 위해서는 사용하는 보간법은 비트맵 이미지를 사용하기 때문에 높은 품질의 영상으로 복원하기에는 많은 문제점이 있다. 따라서 이러한 문제점을 보완하면서 좀 더 높은 품질의 영상을 복원하고자 벡터 이미지 방식을 도입하여 영상을 복원하고자 한다.

• 한국음향학회지
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• 제19권3호
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• pp.86-91
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• 2000

본 논문에서는 피아노 음을 FFT(Fast Fourier Transform)를 이용하여 주파수 영역으로 변환한 후, 크기(magnitude)와 위상(phase)에 대한 특성들을 분석한다. 이 분석한 결과로 크기와 위상을 모델링하여 파라미터를 생성한다. 크기의 특성에서 기본주파수와 고조파 부분은 다른 부분에 비해 크기가 매우 크다. 그래서 이 부분의 모델링은 오차를 줄이기 위해 곡선의 적합성(Curve Fitting) 방법을 이용하였고, 노이즈 부분의 모델링은 기본주파수 전후의 노이즈가 피아노 음색 특성에 중요한 역할을 하고 불규칙하므로 선분 근사법을 이용하였으며, 크기가 작고 완만하게 변하는 나머지 노이즈 부분은 곡선의 적합성을 이용하였다. 위상은 크기에 적응한 방법과 동일하게 적용하였다. 생성된 파라미터로 크기와 위상을 만들어 역변환 FFT를 하면 피아노 원음에 매우 근접한 음을 얻을 수 있다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.59-62
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• 2009

In general, as a dynamic range of digital still camera is narrower than a real scene‘s, it is hard to represent the shadow region of scene. Thus, multi-scaled retinex algorithm is used to improve detail and local contrast of the shadow region in an image by dividing the image by its local average images through Gaussian filtering. However, if the chromatic distribution of the original image is not uniform and dominated by a certain chromaticity, the chromaticity of the local average image depends on the dominant chromaticity of original image, thereby the colors of the resulting image are shifted to a complement color to the dominant chromaticity. In this paper, a modified multi-scaled retinex method to reduce the influence of the dominant chromaticity is proposed. In multi-scaled retinex process, the local average images obtained by Gaussian filtering are divided by the average chromaticity values of the original image in order to reduce the influence of dominant chromaticity. Next, the chromaticity of illuminant is estimated in highlight region and the local average images are corrected by the estimated chromaticity of illuminant. In experiment, results show that the proposed method improved the local contrast and detail without color distortion.

• 한국정밀공학회지
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• 제26권12호
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• pp.131-137
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• 2009

Recent technological advances made a vehicle more intelligent to increase safety and comfort. An intelligent vehicle provides drivers with safety warning information through audible sounds, visual displays, and tactile devices. However, elderly drivers have been known to decrease the physical and cognitive abilities such as muscular strength, hearing, eyesight, short term memory, and spatial perception. Therefore, possible age-related deficits should be considered to design an effective warning system. This paper aims to evaluate the impact of advancing age on response performance on audible safety warnings which are widely used for alerting driving hazards. In order to understand the effect of age-related hearing loss and movement slowing, three sound characteristics (frequency, intensity, and period) and three age groups (younger, middle, and older) are considered. Data was drawn from 38 drivers who drove a simulated rural road in a driving simulator. Experimental results show that age influences driver's response performance. In conclusion, the appropriate range of a warning sound is suggested.

• 한국농촌건축학회논문집
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• 제12권4호
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• pp.1-11
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• 2010

This study is a research examining reshaped pattern in the perspective of repairing parts and materials through repairing renovation of registered cultural properties constructed in modern times and results are as followings. Repairing construction of registered cultural properties of Jollanamdo according to parts is shown numerously in the order of roof, walls and windows, and mostly outworn as time passes on and leakage were the main cause of repair. Also when original shape was damaged by previous repair in the past, and this was another reason of repairing. It was surveyed that among the repairing job repair of damage occurred on the part of roofing area including water leakage, corrosion and damage of roofing material, and damage of groove channel were the most main cause of repair. Especially when roof leakage is occurred by outworn of roofing materials, this cause corrosion and damage of materials due to the damage of leakage parts and this cause repeating cycles of worse leakage again and again. Main repairing materials which deform the original shape of registered cultural properties were confirmed as copper plate used on the roof. Copper plate showing high frequency of application which replaces groove slate or cement roofing tile used on the roof before has high durability and anti-corrosion but it is considered improper material to recover original shape.

• 대한조선학회논문집
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• 제45권2호
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• pp.124-131
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• 2008

This paper presents the analysis of resistance performance and bow waves for the resistance-minimized hull form of small fishing boat by using numerical simulations and model tests. The resistance-minimized hull form is developed from an original hull form which is selected from existing small fisher boats in our country. In order to estimate the resistance performance for the original and the developed hull form, several numerical simulations and model tests are carried out. Marker and Cell(MAC) method and Marker-Density method are adopted to simulate the free-surface bow waves around advancing hull surface. The results of numerical simulations are compared with the model tests in towing tank. The results show that the resistance performance of the resistance-minimized hull form is improved than that of the original hull form. The results of this study will be a good guide to the hull form development of small fishing boats in future.

• 조명전기설비학회논문지
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• 제29권10호
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• pp.89-96
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• 2015

Explicit numerical integration methods for power system transient stability simulation require very small time steps to avoid numerical instability. The EXST1 exciter model is a primary source of fast dynamics in power system transients. In case of the EXST1, the required small integration time step for entire system simulation increases the computational demands in terms of running time and storage. This paper presents a practical exciter model reduction approach which allows the increase of the required step size and thus the method can decrease the computational demands. The fast dynamics in the original EXST1 are eliminated in the reduced exciter model. The use of a larger time step improves the computational efficiency. This paper describes the way to eliminate the fast dynamics from the original exciter model based on linear system theory. In order to validate the performance of the proposed method, case studies with the GSO-37 bus system are provided. Comparisons between the original and reduced models are made in simulation accuracy and critical clearing time.