• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.347-355
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• 2005

We investigate the distribution of central spot and the encircled energy in order to assess the performance of central obstructed optical system having central obstruction, when the central obstruction and the degree of truncated Gaussian amplitude of incident beam change. When the radius of central obstruction increases the radius of central spot on the image plane decreases, and when the degree of truncated Gaussian amplitude of incident beam increases the radius of central spot on the image plane increases. As the central obstruction and the degree of truncated Gaussian amplitude of incident beam increase, the depth of focus increases and the encircled energy of central spot decreases. We know from theses results that the effect of Gaussian factor is small as the central obstruction increases. These results was applied to develope the large optical reflection system.

• Korean Journal of Optics and Photonics
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• v.32 no.6
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• pp.286-295
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• 2021

A modified catadioptric omnidirectional optical system (MCOOS) using an RGB/NIR CMOS sensor is optically designed for a capsule endoscope with the front field of view (FOV) in visible light (RGB) and side FOV in visible and near-infrared (NIR) light. The front image is captured by the front imaging lens system of the MCOOS, which consists of an additional three lenses arranged behind the secondary mirror of the catadioptric omnidirectional optical system (COOS) and the imaging lens system of the COOS. The side image is properly formed by the COOS. The Nyquist frequencies of the sensor in the RGB and NIR spectra are 90 lp/mm and 180 lp/mm, respectively. The overall length of 12 mm, F-number of 3.5, and two half-angles of front and side half FOV of 70° and 50°-120° of the MCOOS are determined by the design specifications. As a result, a spatial frequency of 154 lp/mm at a modulation transfer function (MTF) of 0.3, a depth of focus (DOF) of -0.051-+0.052 mm, and a cumulative probability of tolerance (CPT) of 99% are obtained from the COOS. Also, the spatial frequency at MTF of 170 lp/mm, DOF of -0.035-0.051 mm, and CPT of 99.9% are attained from the front-imaging lens system of the optimized MCOOS.

• Journal of Korean Society of Steel Construction
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• v.10 no.3 s.36
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• pp.339-353
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• 1998

In this paper, the previous damage models for structures and their components under seismic repeated loading were reviewed systematically. A failure criterion for steel members under severe cyclic excitations as in strong earthquakes was described. A new approach to seismic damage assessment for steel members was proposed. This method was based on a series of the experimental and numerical investigations for steel members under very low cyclic loading. In this study, very low cyclic loading means repetitive loading, 5 to 20 loading cycles, within the large plastic range. The proposed damage assessment method was focused on the local strain history at the cross-section of the most severe concentration of deformation.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.986-994
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• 2013

With reviewing major advertising effect models, this research aimed to describe the accepted view of how advertising works, to discover the limits of current advertising effects research paradigm and to suggest the solutions. The results show that current advertising research has been mainly focused on brand attitude but other advertising effects have been neglected. Due to radically changing advertising media, the author proposes that new perspectives on the advertising effect are needed such as brand perception, brand familiarity and brand salience.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.284-291
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• 2012

This study is to present development plan for next study on applying the method of case study by applying scientific inference focusing on analysis and generalization of case study or study question about the tendency of thesis for case study of the field of crisis management released since 2004. As the result of analysis, the study on crisis management of Korea is almost individual technical case study and it is rarely to get proper study which can contribute theoretical formation for development of individual course of crisis management. Furthermore researchers are required to study in-depth about study plan that presents organization of study or logic of case selection and formality for data analysis.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.164-175
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• 2014

The purpose of this study is to confirm violence regulation of television. Television programs that infringed the standards of violence and were sanctioned, were analyzed in terms of broadcasting violence standards and the level of sanction imposed, according to network and cable television. The results show that both network and cable television were mainly imposed on sanction of caution and recommendation. And violation of article 36 was most. But there were differences in violation of articles 36, 39, 51 between network and cable television.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.2
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• pp.74-85
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• 2012

As competition increases, ski resort managers need to search for ways to attract previous visitors or to gain new visitors through word-of-mouth. This study examined the impact of skiers' perceived value, satisfaction and self-congruity on the revisit intention and the positive word-af-mouth intention. Total respondents were also segmented into a promotion-focus and prevention-focus individuals then later examined the differences in the effect of independent variables between groups in order to suggest a managerial direction that will enhance business competency of ski resorts. Results from regression analysis showed that all independent variables utilized in this study were good predictors of two dependent variables. Specially, satisfaction was a highly significant predictor. Promotion and prevention-focused individuals were also differed in evaluating the importance of independent variables for their revisit and word-of-mouth intention. It means that self-regulatory focus is an effective variable for segmentation. More specifically, satisfaction was the only variable influencing the revisit intention for promotion-focused individuals; whereas both satisfaction and self-congruity had significant effects on the revisit intention for prevention-focused individuals. All independent variables had significant effects on the word-of-mouth intention, except self-congruity for promotion-focused individuals. This research suggests several managerial implications on the findings based on the analysis and the characteristics of the visitors.

• Korean Journal of Optics and Photonics
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• v.19 no.6
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• pp.389-393
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• 2008

Enhanced reconstruction of heavy occluded objects was represented using estimation of variance in computational integral imaging. The system is analyzed to extract information of enhanced reconstruction from an elemental images set. To obtain elemental images with enhanced resolution, low focus error, and large depth of focus, synthetic aperture integral imaging (SAII) utilizing a digital camera has been adopted. The focused areas of the reconstructed image are varied with the distance of the reconstruction plane. When an occluded object is occluded heavily, an occluded object can not be reconstructed by removing the occluding object. To obtain reconstruction of the occluded object by remedying the effect of heavy occlusion, the statistical technique has been adopted.

• Journal of Korea Water Resources Association
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• v.42 no.9
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• pp.725-736
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• 2009

A flood event can be defined by three characteristics; peak discharge, total flood volume, and flood duration, which are correlated each other. However, a conventional flood frequency analysis for the hydrological plan, design, and operation has focused on evaluating only the amount of peak discharge. The interpretation of this univariate flood frequency analysis has a limitation in describing the complex probability behavior of flood events. This study proposed a bivariate flood frequency analysis using a Gumbel mixed model for the flood evaluation. A time series of annual flood events was extracted from observations of inflow to the Soyang River Dam and the Daechung Dam, respectively. The joint probability distribution and return period were derived from the relationship between the amount of peak discharge and the total volume of flood runoff. The applicability of the Gumbel mixed model was tested by comparing the return periods acquired from the proposed bivariate analysis and the conventional univariate analysis.

• Journal of Digital Contents Society
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• v.19 no.2
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• pp.221-228
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• 2018

This study mainly focused on horror movies and horror games. Camera angles of horror movies and compositions of horror games are main factors that can cause fear in people's minds. Through analyzing four kinds of factors, including sensual, expectant, restrictive and executive fear elements, in horror games, and combining with the patterns of camera angles and film techniques that Alfred Hitchcock applied in his horror movies, this research investigated certain types of compositions and concluded ones that were more effective on growing fear in players' minds and enhancing their involvement. In conclusion, only the combination of factors in horror-game compositions, like diagonal composition, dual-diagonal composition and inverse triangle-line composition, with visual elements enables player's growing sense of fear and the increase in involvement. Therefore, future works should apply more of these fear-inducing compositions.