• 한국재료학회지
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• 제28권5호
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• pp.301-307
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• 2018

A boron-doped diamond(BDD) electrode is attractive for many electrochemical applications due to its distinctive properties: an extremely wide potential window in aqueous and non-aqueous electrolytes, a very low and stable background current and a high resistance to surface fouling. An Ar gas mixture of $H_2$, $CH_4$ and trimethylboron (TMB, 0.1 % $C_3H_9B$ in $H_2$) is used in a hot filament chemical vapor deposition(HFCVD) reactor. The effect of argon addition on quality, structure and electrochemical property is investigated by scanning electron microscope(SEM), X-ray diffraction(XRD) and cyclic voltammetry(CV). In this study, BDD electrodes are manufactured using different $Ar/CH_4$ ratios ($Ar/CH_4$ = 0, 1, 2 and 4). The results of this study show that the diamond grain size decreases with increasing $Ar/CH_4$ ratios. On the other hand, the samples with an $Ar/CH_4$ ratio above 5 fail to produce a BDD electrode. In addition, the BDD electrodes manufactured by introducing different $Ar/CH_4$ ratios result in the most inclined to (111) preferential growth when the $Ar/CH_4$ ratio is 2. It is also noted that the electrochemical properties of the BDD electrode improve with the process of adding argon.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.109-112
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• 1995

This paper is a study on the detection of the significant point in ECG signal. ECG signal consists of two components; one is high frequency component to be detected and the other is low frequency component to be removed. AR model is appropriate for modelling and removing the low frequency component. AR model coefficients are updated by artificial neural network algorithm. We can remove the background noise(low frequency) by passing through the AR filter. The remaining signals which include high frequency noise are sent to the matched filter to pass only the signal which we want to extract. The template used in matched filter is updated adaptively.

• 한국멀티미디어학회논문지
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• 제21권1호
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• pp.69-76
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• 2018

Augmented Reality (AR) technology has rapidly been applied to various application areas including e-learning and e-education. Focusing on the design and development of android tablet application, this study targeted to develop infant music education using AR technology. We used a tablet instead of personal computer because it is more easily accessible and more convenient. Our system allows infant users to play with teaching aids like blocks or puzzles to mimic musical play like game. The user sets the puzzle piece on the playground in front of the tablet and presses the play button. Then, the system extracts a region of interest among the images acquired by internal camera and separates the foreground image from the background image. The block recognition software analyzes, recognizes and shows the result using AR technology. In order to have reasonably working recognition ratio, we did experiments with more than 5,000 frames of actual playing scenarios. We found that the recognition rate can be secured up to 95%, when the threshold values are selected well using various condition parameters.

• 한국통신학회논문지
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• 제28권10C호
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• pp.1013-1022
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• 2003

본 논문은 연속적인 영상에 대해 비모수적 영상 처리 기법과 칼만 필터 기반의 동적 AR(2) 프로세스 기법을 적용하여 객체의 움직임을 적응적으로 추적하는 실시간 객체 추적 알고리즘을 구현하였다. 다양한 환경 조건에서 입력되는 영상에 대해 비모수적 영상 처리 기법을 이용하여 처리함으로써 효과적으로 움직임 객체를 추출하였으며, 객체의 움직임을 동적 AR(2) 프로세스 모형으로 모델링하고 동적으로 변하는 AR(2) 프로세스의 파라미터를 칼만 필터를 통해 추정함으로써 객체의 다변적인 움직임을 적응적으로 예측하여 추적할 수 있었다. 구현된 객체 추적 시스템을 실험한 결과, 기존의 선형 칼만 필터 기법을 이용한 추적 기법과 비교하여 추정 오차가 약 1/2.5∼1/50 만큼 더 적게 나와 객체의 움직임을 더 근사적으로 추적함을 알 수 있었다.

• 한국게임학회 논문지
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• 제18권4호
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• pp.53-64
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• 2018

시대적 변화에 따라 디지털 시대가 열리며 생활 속 많은 부분이 편리해졌다. 이러한 편리한 삶에 의해 사람들의 비만율이 점차 증가하고 있으며, 운동의 필요성이 대두되고 있다. 하지만 많은 사람들이 운동을 하지 않거나 운동을 하더라도 3~6개월 사이에 중단한다는 사실이 여러 연구사례를 통해 증명되었다. 본 논문에서는 이러한 사실들을 검증하기 위해 운동에 대한 이론적 배경과 선행연구사례를 바탕으로 헬스케어 체감형 AR게임인 "Walking Pet" Prototype을 설계하고 개발하였다. 개발한 "Walking Pet"은 운동에 대한 동기부여를 위해 운동 데이터를 제공하며, 운동을 자발적으로 즐겁게 할 수 있도록 펫 시스템을 적용하였다. 본 논문에서 개발한 "Walking Pet" Prototype의 효율성을 검증하기 위해 헬스케어 어플리케이션을 필요로 하는 남녀 100명을 대상으로 순기능적인면의 만족도에 대한 설문통계를 하였다.

• Journal of Chest Surgery
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• 제52권1호
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• pp.9-15
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• 2019

Background: Although aortic valve repair can reduce prosthesis-related complications, rheumatic aortic regurgitation (AR) caused by leaflet restriction is a significant risk factor for recurrent AR. In this study, we evaluated the long-term results of the leaflet extension technique for rheumatic AR. Methods: Between 1995 and 2016, 33 patients underwent aortic valve repair using the leaflet extension technique with autologous pericardium for rheumatic pure AR. Twenty patients had severe AR and 9 had combined moderate or greater mitral regurgitation. Their mean age was $32.2{\pm}13.9$ years. The mean follow-up duration was $18.3{\pm}5.8$ years. Results: There were no cases of operative mortality, but postoperative complications occurred in 5 patients. Overall survival at 10 and 20 years was 93.5% and 87.1%, respectively. There were no thromboembolic cerebrovascular events, but 4 late deaths occurred, as well as a bleeding event in 1 patient who was taking warfarin. Twelve patients underwent aortic valve reoperation. The mean interval to reoperation was $13.1{\pm}6.1$ years. Freedom from reoperation at 10 and 20 years was 96.7% and 66.6%, respectively. Conclusion: The long-term results of the leaflet extension technique showed acceptable durability and a low incidence of thromboembolic events and bleeding. The leaflet extension technique may be a good option for young patients with rheumatic AR.

• Nutrition Research and Practice
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• 제17권5호
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• pp.997-1006
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• 2023

BACKGROUND/OBJECTIVES: Asthma and allergic rhinitis (AR) are closely related and considered as allergic respiratory diseases (ARD), and their prevalence has recently increased. Data on the association of dietary antioxidant vitamin intake with asthma and AR in adults are limited. The present study aimed to investigate the associations of vitamin A and C intake with asthma, AR, and all cases of both diseases in young adults who participated in a cross-sectional national survey, with the use of high-sensitivity C-reactive protein (hs-CRP) level as an effect modifier. SUBJECTS/METHODS: This study included 6,293 male and female adults aged 20-49 years from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted between 2016 and 2018. The questionnaire-based reports on asthma and AR diagnosis were used to determine outcome variables. Further, 24-h recall data on dietary vitamin A and C, carotene, and retinol intake were acquired. Logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence interval (CI). RESULTS: Dietary vitamin C intake was inversely associated with asthma prevalence among participants with hs-CRP levels (≥ 1 mg/L); the OR of asthma prevalence was 0.27 (95% CI, 0.08-0.84) for participants with vitamin C consumption ≥ 75 mg/day compared with those consuming < 20 mg/day. Similar association analyses limiting to non-users of dietary supplements were performed to rule out the potential effects of supplement intake on the outcomes; results showed a stronger association. However, the association between vitamin C and asthma was not significant in participants with hs-CRP levels < 1 mg/L; the OR of asthma was 1.44 (95% CI, 0.66-3.16) for participants with vitamin C consumption ≥ 75 mg/day compared with those consuming < 20 mg/day. Vitamin C intake was not associated with AR. Moreover, there was no association between vitamin A intake and neither asthma nor AR. CONCLUSIONS: These findings suggest that higher vitamin C intake may play a potential role in reducing asthma prevalence. Nevertheless, further studies should be conducted to evaluate whether this association is causal.

• 한국초등과학교육학회지:초등과학교육
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• 제41권4호
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• pp.725-739
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• 2022

본 연구는 AR 기술을 활용하여 안내된 과학탐구 프로그램을 개발함에 있어서 초등 예비교사들이 무엇에 중점을 두었으며, 어떠한 어려움을 겪었는지 분석하고, 이를 토대로 예비교사의 역량 함양 및 양성교육을 위한 시사점을 제공하는 데 목적이 있다. 이를 위하여 AR 기반 안내된 탐구 프로그램을 개발하는 강의에 참여한 초등 예비교사들의 사례를 수집하고 그들이 중점을 둔 부분과 겪은 어려움을 프로그램 '설계 단계'와 '제작 단계'로 범주화하여 분석하였다. 분석 결과, 프로그램 설계 단계에서 예비교사들은 능동적인 탐구과정을 촉진하는 시나리오를 구성하고, 동시에 AR 기술이 지닌 고유의 행위유도성으로서 3D 환경의 생생한 시각 자료를 구성하여 가상세계와 실세계에서의 탐구 경험을 의미 있게 연결짓는 데에 중점을 두었다. 또한 예비교사들은 시나리오의 설계, 탐구 프로그램 개발을 위한 정보 수집, 초등학생의 능동적 관찰을 이끄는 방법구현에 어려움을 경험하였으며, 탐구에 대한 근본적 의문으로 어려움을 겪었다. 또한 예비교사들은 AR 기술의 장점을 살리는 것을 어려워하였으며, 컨텐츠 제작 프로그램인 CoSpaces에 대한 배경지식이 부족하여 탐구 프로그램을 구상하는 데에 어려움을 겪었다. 프로그램 제작 단계에서는 초등학생들이 탐구에 집중할 수 있는 환경을 조성하기 위해, 예비교사들은 프로그램 조작을 쉽고 단순하게 구성하고자 했으며, 게임적 요소나 쌍방향적 상호작용 요소를 추가하여 학습자의 흥미를 높일 방법에 중점을 두었다. 또한 CoSpaces를 이용한 프로그래밍 과정에서 어려움을 겪었다. 이러한 결과를 바탕으로 예비교사 역량 함양 및 교사양성교육 방안 모색을 위한 시사점에 대해 논의하였다.

• Journal of Chest Surgery
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• 제50권3호
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• pp.144-152
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• 2017

Background: The ubiquitin-proteasome system (UPS) is an important pathway of proteolysis in pathologic hypertrophic cardiomyocytes. We hypothesize that MG132, a proteasome inhibitor, might prevent hypertrophic cardiomyopathy (CMP) by blocking the UPS. Nuclear factor kappa-light-chain-enhancer of activated B cells ($NF-{\kappa}B$) and androgen receptor (AR) have been reported to be mediators of CMP and heart failure. This study drew upon pathophysiologic studies and the analysis of $NF-{\kappa}B$ and AR to assess the cardioprotective effects of MG132 in a left ventricular hypertrophy (LVH) rat model. Methods: We constructed a transverse aortic constriction (TAC)-induced LVH rat model with 3 groups: sham (TAC-sham, n=10), control (TAC-cont, n=10), and MG132 administration (TAC-MG132, n=10). MG-132 (0.1 mg/kg) was injected for 4 weeks in the TAC-MG132 group. Pathophysiologic evaluations were performed and the expression of AR and $NF-{\kappa}B$ was measured in the left ventricle. Results: Fibrosis was prevalent in the pathologic examination of the TAC-cont model, and it was reduced in the TAC-MG132 group, although not significantly. Less expression of AR, but not $NF-{\kappa}B$, was found in the TAC-MG132 group than in the TAC-cont group (p<0.05). Conclusion: MG-132 was found to suppress AR in the TAC-CMP model by blocking the UPS, which reduced fibrosis. However, $NF-{\kappa}B$ expression levels were not related to UPS function.

• 디지털융복합연구
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• 제17권7호
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• pp.311-316
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• 2019

모바일 게임 환경은 인공지능과 더불어 AR( 증강현실) 기술의 발전과 함께 그 범위가 급속하게 확대되고 있다. 특히, AR(증강현실) 기술이란 VR(가상현실)의 한 분야로 실제 환경에 가상의 정보나 이미지를 혼합하여 보여주는 기술이다. 최근 콘텐츠의 이해를 기반으로 다양한 활용방안이 제시되는 시점에서 증강현실 기술을 활용하는 인터랙션 기반의 모바일 UI 디자인에 대한 연구도 중요하게 대두 되고 있다. 어느 정도 형성된 공급체계와는 달리 소비자가 다각도로 활용할 수 있는가에 대한 측면에서는 몇 가지 이슈들이 여전히 남아있으며, 이 중 접근성이 떨어지는 UI로 인한 이슈들도 분명히 존재한다. 본 연구에서는 배경이론을 바탕으로 문제가 되는 UI이슈들을 해소하기 위하여 스마트 증강현실의 선행연구와 문헌연구를 통해 스마트 미디어 증강현실을 활용하는 인터랙션 기반의 모바일 UI 디자인 사례를 제시한다.