• 방송공학회논문지
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• 제15권3호
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• pp.368-379
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• 2010

고선명 영상에 대한 수요가 증가하면서 다양한 방면에서 좀 더 선명하고 큰 영상을 보고 촬영하려는 요구가 늘어나고 있다. 이에 따라 고선명 동영상의 화질을 향상시키기 위한 적절한 화질 향상 방법이 필요하다. 본 논문에서는 고선명 동영상의 색상과 명암 대비를 개선하기 위한 방법을 제안한다. 고선명 동영상에서 처리 속도를 높이면서 효과적으로 화질 향상 방법을 적용하기 위해 고선명 동영상을 축소시킨 동영상에서 화질 향상 방법에 필요한 변수를 추출해낸다. 고선명 동영상의 색상을 향상시키기 위해 색채 항상성 방법을 사용하였는데 장면별로 동일한 변환값이 적용되도록 동영상을 컷 탐지 방법을 이용하여 분리한 후 장면마다 동일한 변환값을 계산하여 적용한다. 고선명 동영상의 명암대비를 향상시키기 위해 원본 영상과 히스토그램 평활화 영상의 조합을 사용하였고 가중치를 결정하기 위해 히스토그램 순위 기반 방식을 사용하였다. 마지막으로 고선명 동영상을 촬영할 수 있는 디지털 캠코더를 이용하여 촬영한 실험 영상으로 제안하는 방법의 성능을 분석하였다.

• 대한인간공학회지
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• 제32권2호
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• pp.207-215
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• 2013

Objective: This study aimed to investigate important human factors that should be considered when developing ultra-high definition TVs by reviewing measurement methods and main characteristics of ultra-high definition displays. Background: Although much attention has been paid to high-definition displays, there have been few studies for systematically evaluating human factors. Method: In order to determine human factors to be considered in developing human-friendly displays, we reviewed subjective and objective measurement methods to figure out the current limitations and establish a guideline for developing human-centered ultra-high definition TVs. In doing so, pros and cons of both subjective and objective measurement methods for assessing humans factors were discussed and specific aspects of ultra-high definition displays were also investigated in the literature. Results: Hazardous effects such as visually-induced motion sickness, visual fatigue, and mental fatigue in the brain caused by undesirable TV viewing are induced by not only temporal decay of visual function but also cognitive load in processing sophisticated external information. There has been a growing evidence that individual differences in visual and cognitive ability to process external information can make contrary responses after exposing to the same viewing situation. A wide vision, ultra-high definition TVs provide, can has positive and negative influences on viewers depending on their individual characteristics. Conclusion: Integrated measurement methods capable of considering individual differences in human visual system are required to clearly determine potential effects of super-high vision displays with a wide view on humans. All of brainwaves, autonomic responses, eye functions, and psychological responses should be simultaneously examined and correlated. Application: The results obtained in this review are expected to be a guideline for determining optimized viewing factors of ultra-high definition displays and accelerating successful penetration of the next-generation displays into our daily life.

• 디지털융복합연구
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• 제16권4호
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• pp.149-155
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• 2018

FHD(Full High Definition Television)의 시대를 지나 UHD(Ultra High Definition Television) 시대를 맞이하였다. 두 TV에서 화소(Pixel)수의 차이에 따라 발생하는 문제에 대하여 이야기하고 이를 개선할 수 있는 방법을 도입하고자 한다. 이 방법은 WENO(Weighted Essential Non-Oscillation)으로 주어진 영상(Image)에 적합한 보간법을 시행하는 방법이다. 이를 통하여 영상의 왜곡현상을 줄이고 보다 나은 화질을 보장할 수 있다. 따라서 예전에 만들어진 영상물을 UHD TV로 시청하려고 할 때 WENO 방법론을 활용하면 화소수에 따른 화질의 저하 없이 UHD TV의 고화질을 누릴 수 있다.

• 한국지리정보학회지
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• 제22권3호
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• pp.133-145
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• 2019

우리나라 미래 핵심과제 중 하나인 자율주행자동차를 지원하는 정밀도로지도에 대한 구축과 연구가 민간, 국가 차원에서 빠른 실용화를 목표로 적극적으로 추진되고 있다. 이러한 상황에서 정밀도로지도의 변화정보의 최신성 확보 및 갱신에 대한 방법이 핵심과제로 부각되고 있다. 따라서 이 연구에서는 정밀도로지도의 효율적인 갱신체계 정립 방안을 마련하기 위하여 도로의 종류, 도로변화의 원인과 연간 변화율 등의 현황과 정밀도로지도 관련 시스템과 정밀도로지도 갱신체계 구축을 위한 고려사항을 분석하였다. 이러한 현황분석을 토대로 정밀도로지도의 전각문자, 내용, 지역 등을 고려하여 도로변화 정보의 수집 탐지 방법과 정밀도로지도의 갱신체계를 단기적 방안과 중장기적 방안으로 제시하였다. 현재는 기술적, 시스템적 제한으로 인해 단기적 갱신체계를 적용해야 할 것으로 판단되었으며 향후에는 기술개발과 업무협조 체계 구축 등 시스템적 개선을 통해 중장기 갱신체계 방안을 조속히 도입해 효율적이고 실시간적인 정밀도로지도 갱신체계를 구축해야 할 것으로 판단된다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.269-276
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• 2009

The local preconditioning method has both robust convergence and accurate solutions by using local flow properties for parameters in the preconditioning matrix. Preconditioning methods have been very effective to low speed inviscid flows. In the viscous and turbulent flows, deterioration of convergence should be overcame on the high aspect ratio grids to get better convergence and accuracy. In the present study, the local time stepping and min-CFL/max-VNN definitions are applied to compare the results and we propose the method that switches between two methods. The min-CFL definition is applied for inviscid flow problems and the min-CFL/max-VNN definition is implemented to viscous and turbulent flow problems.

• 방송공학회논문지
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• 제10권2호
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• pp.131-138
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• 2005

High-quality digital broadcasting contents are susceptible to illegal copy and unauthorized redistribution, which makes broadcasters difficult to protect valuable media assets. So, broadcasters and content providers need the technology for copyright protection of professional digital content. Digital watermarking technology is one of the most actively developed solutions for the copyright protection. This paper suggests the requirements of watermarking technology in DTV(Digital TV) environment for copyright protection and shows the developed real-time watermark embedding/detecting system for HD(High Definition)/SD(Standard Definition) video and experimental results of the system against watermark attack tests. Our watermarking system meets the watermarking requirements of invisibility, robustness and security of DTV environment.

• 한국지능시스템학회논문지
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• 제17권6호
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• pp.813-818
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• 2007

This paper is concerned with the problem of recognizing definition sentences. Given a definition question like "Who is the person X?", we are to retrieve the definition sentences which capture descriptive information correspond variously to a person's age, occupation, of some role a person played in an event from the collection of news articles. In order to retrieve as many relevant sentences for the definition question as possible, we adopt a centroid based statistical approach which has been applied in summarization of multiple documents. To improve the precision and recall performance, the weight measure of centroid words is supplemented by using external knowledge resource such as Wikipedia and redundant candidate sentences are removed from candidate definitions. We see some improvements obtained by our approach over the baseline for 20 IT persons who have high document frequency.

• 한국학교수학회논문집
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• 제15권3호
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• pp.453-465
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• 2012

본 연구에서는 연속함수에 대한 오개념 이미지의 원인을 찾기 위하여 고등학교 수학II 교과서와 수학과 고등학교 교육과정해설서를 조사 분석하고 고등학교 학생들을 대상으로 설문조사를 실시하였다. 그 결과, 고등학교 교과서에서 도입하고 있는 함수의 연속성에 대한 정의 방법이 교과서별로 동일하지 않고, 대학의 공식적인 정의와도 큰 차이가 있기 때문에 연속함수에 대한 학생들의 오개념 이미지가 나타나는 것으로 분석되었다. 따라서 이러한 오개념 이미지를 바로잡기 위해서는 함수의 연속성과 불연속성에 대한 대학의 공식적인 정의를 학교수학에서 적극적으로 수용하여 학생들의 수준에 맞는 방법으로 함수의 연속과 불연속에 대한 정의를 명확하게 제시하여 한다.

• 재활간호학회지
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• 제1권1호
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• pp.1-14
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• 1998

The purpose of this study was to identify the factors affecting family functioning of stroke patients. A descriptive survey research was conducted in which 65 stroke patients and their primary caregivers were conveniently sampled. Data were collected from July to September, 1998 through interviewing using a structured questionnare. The measuring instruments used were Barthel Index by Mahoney and Barthel(15 items), Quality of Relationship Scale by Archbold and Stewart(15 Items), Role Stress of Caregiver Scale by Yang(14 items), Situational Definition Scale by Lee(9 items), Family Hardiness Index by McCubbin, McCubbin. and Thompson(20 items), and Family Adaptability Cohesion Evaluation Scale(FACES-III) by Olson, Portner, and Lavee(20 items). The obtained data were analyzed using percentage, t-test, ANOVA, Duncan test, and Pearson coefficients correlation by SAS/PC program. The results were as follows; 1. Role Stress of Caregiver was not severe and Quality of Relationship was moderate. The level of Situational Definition of primary caregivers was not high but Family Hardiness and Family Functioning were rather high. 2. The following relationships between research variables and demographic characteristics of the primary caregivers of stroke patients were significantly different; occupation of caregiver between Quality of Relationship, occupation of caregiver between Situational Definition, family type between Role Stress, caregiving duration between Family Hardiness, caregiving duration between Family Functioning, and hospitalization days between Family Functioning. 3. The correlations between research variables were as follows; There was positively correlated between patient's ADL and Quality of Relationship. The relationship of the patient's ADL between Role Stress was negatively correlated. Quality of Relationship between Situational Definition, Family Hardiness, and Family Functioning were significantly correlated. The correlation of Situational Definition between Family Hardiness, and Situational Definition between Family Functioning were very high. As a result of these findings, Quality of Relationship, Role Stress, Situational Definition. and Family Hardiness were useful variables for identifying Family Functioning of stroke patients. It is important for the rehabilitation nurse to be knowledgeable about family functioning of stroke patients to promote rehabilitation process.

• Korean Journal of Mathematics
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• 제22권1호
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• pp.169-180
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• 2014

In this study, we consider the informal and formal definition of limit on the basis of middle and high school curriculum, and then analyze the reason of difficulties experienced when sophomores learn the formal definition(${\epsilon}-{\delta}$ procedure) of limit. We conducted teaching of the formal definition of limit with sophomores and analyzed their errors which were appeared when they applied to limits problems. In addition, we try to improve the understanding of ${\epsilon}-{\delta}$ procedure of the limit taught in analysis.