• 대한원격탐사학회지
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• 제39권6_3호
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• pp.1791-1799
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• 2023

한국항공우주연구원은 위성정보활용협의체 소속기관을 대상으로 아리랑위성 시리즈 영상자료 보급 및 활용지원을 담당하고 있다. 협의체 소속기관 사용자들은 대부분 광학 영상 중심으로 위성영상을 활용하고 있으며, 상대적으로 Synthetic Aperture Radar (SAR) 영상에 대한 활용 방안은 미흡한 실정이다. 본 논문에서는 SAR 영상자료 활용을 지원하기 위한 일환으로 향후 개발할 SAR 강도 기반 변화탐지 기술의 결정을 위해 현재까지 연구되어진 SAR 강도 기반 변화탐지 기술과 그 활용사례들을 조사했다. 조사 결과 많은 연구자로부터 강도 차분, 상관계수, 히스토그램(Histogram) 또는 편파 정보를 활용하여 변화 픽셀을 탐지하고 분석하기 위한 다양한 알고리즘들과 도시, 홍수, 산불, 식생과 같은 다양한 분야에서 변화탐지 알고리즘의 활용방안이 연구되었음을 확인할 수 있었다. 본 연구는 위성정보활용협의체에 활용할 SAR 변화탐지 기술 개발에 활용할 예정이다.

• 대한의용생체공학회:의공학회지
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• 제28권2호
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• pp.212-217
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• 2007

As a preliminary study for the development of electrical stimulation strategy of artificial retina, we set up a method fur the reconstruction of input intensity variation from retinal ganglion cell(RGC) responses. In order to estimate light intensity variation, we used an optimal linear filter trained from given stimulus intensity variation and multiple single unit spike trains from RGCs. By applying ON/OFF stimulation(ON duration: 2 sec, OFF duration: 5 sec) repetitively, we identified three functional types of ganglion cells according to when they respond to the ON/OFF stimulus actively: ON cell, OFF cell, and ON-OFF cell. Experiments were also performed using a Gaussian random stimulus and a binary random stimulus. The input intensity was updated once every 90 msec(i. e. 11 Hz) to present the stimulus. The result of reconstructing 11 Hz Gaussian and binary random stimulus was not satisfactory and showed low correlation between the original and reconstructed stimulus. In the case of ON/OFF stimulus in which temporal variation is slow, successful reconstruction was achieved and the correlation coefficient was as high as 0.8.

• 한국콘텐츠학회논문지
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• 제17권5호
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• pp.624-632
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• 2017

영상을 이용한 나비 종 자동 인식 기법은 생물종 다양성 연구 및 종의 진화, 발달 과정의 연구를 위한 기초 작업을 돕는 것으로 연구자들의 관심이 높다. 기계학습 기반의 나비 종 인식 시스템은 사용하는 특징 추출 방법에 성능이 크게 좌우되는 성질을 가지고 있다. 본 논문은 나비 영상이 가진 색채 강도의 분포를 이용하는 색채 강도 (Color Intensity) 엔트로피를 제안하고 기존에 제시된 가지 길이 유사성 (Branch Length Similarity) 엔트로피와 함께 사용할 경우 10% 이상의 인식률 향상을 얻을 수 있음을 보인다. 제안한 방법의 신뢰성 있는 성능 평가를 위해 영상 인식에 자주 사용되는 대표적인 특징 추출 방법인 아이겐 이미지, 2D 푸리에 변환, 2D 웨이블릿 변환 방법들을 비교 대상으로 다양한 기계학습을 이용해 성능을 평가한다.

• 산경연구논집
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• 제9권1호
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• pp.89-97
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• 2018

Purpose - The Regional Comprehensive Economic Partnership (RCEP) among 16 countries including South Korea, the largest free trade agreement in the Asia-Pacific region, will be concluded next year. The participating countries decided to pursue a comprehensive and high -quality agreement, while ensuring flexibility considering development level of each country. In this study, trade structures between nations from 2005 through 2016 were examined to see the impact that this agreement will have on Korea and to come up with effective countermeasures. Research design, data, and methodology - The method of analysis includes the analysis of the trade matrix, which is useful for identifying the dependency of the individual countries on the market in the region and the reciprocal dependency of the member countries on the market, and the index of intensity of trade, which is useful for figuring out the share of trade between the parties in total trade. Results - The results showed that first, the international trade coefficients of Vietnam and Philippines are higher than those of China and Japan. Secondly, the international inducement coefficients between China and Japan were high, and that between Indonesia and Burma were low, indicating that Korea's exports did not have much effect on export increase of these countries. Third, as a result of analyzing Korea's trade intensity, it was found that export intensity and import intensity were greater than 1 in Vietnam and Philippines, which shows that there is a high degree of relational bond with these countries. India and Laos countries still have a low level of relational bond, which indicates that there is room for improvement in economic relations when the agreement is concluded. After the signing of the agreement in the future, more diverse industrial structures should be continuously studied. Conclusions - The analysis of trade matrix, trade structure, trade inducement coefficient and trade intensity between Korea and RCEP participating countries shows that the majority of the countries have the high level of economic relationship with Korea. Korea should drive a harder bargain when negotiating the terms of the RCEP, in comparison with the level of the existing FTA agreement excluding Japan.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.962-965
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• 2005

A high intensity progressive wave tube is installed at Korea Aerospace Research Institute (KARI) for acoustic environmental tests. The test facility has 700 mm x 800 mm cross-sectional area, and provides acoustic environment of 165 dB over the frequency range of $25Hz{\sim}10,000Hz$. The facility consists of a 6 m long acoustic wave tube, acoustic power generation systems, gases nitrogen supply systems, and acoustic control systems. This paper describes how the basic parameters of the facility and power generation systems are controlled to meet the requirement of the test. The shape and length of the tube has been designed by using the size of test objects and the wave propagation characteristics of the tube. The capacity of acoustic power generation systems is determined by the energy conversion of acoustic wave and the efficiency of acoustic modulators. Moreover, the paper introduces test run results of the tube. Overall of 163dB has been generated by using the test facility.

• 근관절건강학회지
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• 제8권1호
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• pp.51-64
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• 2001

The purposes of this study were to examine and to predict the affecting factors on exercise participation of Rheumatoid arthritis Patients. The subjects were 161 adult out-patients who visited the hospital for rheumatic disease in H-university. Data were composed of self-reported questionnaire. The conceptual model of this study consisted of that personal characters(age, marriage, education, income), situational characters(pain intensity, fatigue, IADL, depression), behavioral characters(formerly exercise behavior, life-style), and cognitive-perceptional characters(perceived health status, perceived benefit, perceived barrier, perceived self-efficacy) affected directly to exercise participation. Logistic regression analysis was applied for testing model of this study. The results were as follows : 1. Personal characters(education), situational characters(pain intensity), behavioral characters(formerly exercise behavior, life-style), and cognitive characters(perceived barrier, perceived self-efficacy) were significant difference between current exercise participants(127subjects) and non-exercise participants(34). 2. Personal characters(income), situational characters(pain intensity), behavioral characters(life-style), and cognitive-perceptional characters(perceived barrier, perceived self-efficacy) were correlated to exercise participation. 3. Formerly exercise behavior, perceived barrier, and perceived self-efficacy were significant predictor of exercise participation. The logistic equation predicted overall 81.94% of this study subjects 161.

• 대한임베디드공학회논문지
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• 제11권5호
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• pp.313-323
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• 2016

With the development of autonomous vehicle, there has been active research on advanced driver assistance system for road marking detection using vision sensor and 3D Laser scanner. However, vision sensor has the weak points that detection is difficult in situations involving severe illumination variance, such as at night, inside a tunnel or in a shaded area; and that processing time is long because of a large amount of data from both vision sensor and 3D Laser scanner. Accordingly, this paper proposes a road marking detection and classification method using single 2D Laser scanner. This method road marking detection and classification based on accumulation distance data and intensity data acquired through 2D Laser scanner. Experiments using a real autonomous vehicle in a real environment showed that calculation time decreased in comparison with 3D Laser scanner-based method, thus demonstrating the possibility of road marking type classification using single 2D Laser scanner.

• Nuclear Engineering and Technology
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• 제51권4호
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• pp.1154-1162
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• 2019

China is undertaking an energy reform from fossil fuels to clean energy to accomplish $CO_2$ intensity (CI) reduction commitments. After hydropower, nuclear energy is potential based on breadthwise comparison with the world and analysis of government energy consumption (EC) plan. This paper establishes a CI energy policy response forecasting model based on national and provincial EC plans. This model is then applied in Fujian Province to predict its CI from 2016 to 2020. The result shows that CI declines at a range of 43%-53% compared to that in 2005 considering five conditions of economic growth in 2020. Furthermore, Fujian will achieve the national goals in advance because EC is controlled and nuclear energy ratio increased to 16.4% (the proportion of non-fossil in primary energy is 26.7%). Finally, the development of nuclear energy in China and the world are analyzed, and several policies for energy optimization and CI reduction are proposed.

• Restorative Dentistry and Endodontics
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• 제48권1호
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• pp.5.1-5.22
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• 2023

This systematic review and network meta-analysis aimed to answer the following focused research question: "Does the type of endodontic sealer affect the postoperative pain in patients who received endodontic treatment?" Different databases and grey literature were surveyed. Only one randomized controlled trial were included. The risk of bias in the studies was evaluated by using the Cochrane Collaboration's tool. A random-effects meta-analysis was conducted to compare the risk and intensity of postoperative pain. The quality of the body of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. Out of 11,601 studies, 15 remained for qualitative analyses and 12 for meta-analysis. Seven studies were classified at high risk of bias, and 8 studies raised some concerns. No significant differences between the endodontic materials were observed in the direct comparisons, both in risk and in intensity of postoperative pain (pairwise comparisons with 2 studies: I² = 0%; p > 0.05 and 8 studies: I² = 23%; p > 0.05, respectively). The certainty of the evidence was graded as low or moderate. There was no difference in the risk and intensity of postoperative pain after filling with different endodontic sealers. Further systematic reviews should be conducted.

• 응용화학
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• 제15권1호
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• pp.33-36
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• 2011

A chemiluminescent method with gold nanoparticles for determination of vitamin C has been presented. Gold nanoparticles highly increased chemiluminescence intensity of lumimol-H₂O₂ system by its catalytic effect. The gold nanoparticles enhanced chemiluminescent method is applicable for the determination of an antioxidant such as vitamin C. When vitamin C was introduced to the lumimol system with gold nanoparticles, chemiluminescence intensity was reduced with the concentration of the added vitamin C. Low concentrated vitamin C solutions in the range of 1×10^-3-1×10^-9 M were produced reduced chemiluminescence intensity of lumimol-H₂O₂ with gold nanoparticles system.