• The Journal of Advanced Prosthodontics
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• 제14권3호
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• pp.150-161
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• 2022

PURPOSE. The purpose of the study was to assess the influence of build orientations and density of support structures on the trueness of the 3D printed removable partial denture (RPD) frameworks. MATERIALS AND METHODS. A maxillary Kennedy class III and mandibular class I casts were 3D scanned and used to design and produce two 3D virtual models of RPD frameworks. Using digital light processing (DLP) 3D printing, 47 RPD frameworks were fabricated at 3 different build orientations (100, 135 and 150-degree angles) and 2 support structure densities. All frameworks were scanned and 3D compared to the original virtual RPD models by metrology software to check 3D deviations quantitatively and qualitatively. The accuracy data were statistically analyzed using one-way ANOVA for build orientation comparison and independent sample t-test for structure density comparison at (α = .05). Points study analysis targeting RPD components and representative color maps were also studied. RESULTS. The build orientation of 135-degree angle of the maxillary frameworks showed the lowest deviation at the clasp arms of tooth 26 of the 135-degree angle group. The mandibular frameworks with 150-degree angle build orientation showed the least deviation at the rest on tooth 44 and the arm of the I-bar clasp of tooth 45. No significant difference was seen between different support structure densities. CONCLUSION. Build orientation had an influence on the accuracy of the frameworks, especially at a 135-degree angle of maxillary design and 150-degree of mandibular design. The difference in the support's density structure revealed no considerable effect on the accuracy.

• 한국염색가공학회지
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• 제33권4호
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• pp.210-219
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• 2021

It was intended to conduct basic research to reduce development lead time and cost consumed in DTP process technology development. For the simulation of HTPE fabric, virtual engineering software was used to generate fiber model, yarn model, fabric model, and finite element model of HTPE fiber. The purpose of this study is to analyze the correlation and error rate between the stiffness numerical analysis results according to the direct DTP process parameters using reactive dyes in the generated finite element model and the stiffness measurements of the actual sample ac- cording to ASTM D1388. And, after dyeing the HTPE plain fabric according to the direct DTP process parameters, we want to analyze the dyeability of the HTPE fabric fabrics according to the direct DTP process parameters through the color fastness analysis. When looking at the results of the analysis of the finite element model, a higher value was shown when the distance between the nozzle and the fabric was 3mm than when the distance was 10mm. When the distance between the nozzle and the fabric was 10mm and 7mm, the reactive dye did not penetrate sufficiently, resulting in poor clarity when viewed with the naked eye.

• 한국멀티미디어학회논문지
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• 제25권8호
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• pp.1167-1174
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• 2022

With the sustainable development and transformation of the city, public art as a business card of the famous city of culture has become a hot topic of research. The intervention of public art in public space not only brings users a sense of space experience, but also becomes a unique carrier of urban and rural image making. Although there is much research on the classification, aesthetics and function of public art, there is few quantitative research on user satisfaction. This paper takes the basic features of airport public art as a research object and the basic features of airport public art as the theoretical basis to study the impact of the basic characteristics of airport public art on user satisfaction. Research methods were based on questionnaire data of 247 people, in which models and hypotheses were tested using SPSS 21.0 software, based on the induction and extraction of nine influential factors in the basic characteristics of public art. The study found that public interpretation, media patterns, color perception, modeling form, place perception, city image and memory have significant positive effects on user satisfaction. The sharedness of public art, cognition and communication in public culture and spatial relations do not affect satisfaction. Conclusion, inspiration and prospect provide suggestions for designers and reference data and theoretical support for public art evaluation.

• 방송공학회논문지
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• 제28권2호
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• pp.194-212
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• 2023

다수의 색상 및 거리 순서쌍으로 구성된 몰입형 영상 압축을 위한 MPEG immersive video (MIV) 표준은 시점 간 중복 영역 제거 후 잔여 영상을 병합하여 높은 압축률을 확보하였다. 비슷한 영역을 표현하는 시점 간 그룹화를 통해 품질 향상 및 선택적 스트리밍 구현이 가능하나, 최근 그룹 기반 MIV 부호화 기술은 활발히 논의되고 있지 않다. 본 논문은 최신 MIV 참조 소프트웨어에서 그룹 기반 부호화 기술을 이식하고, 최적의 그룹 별 시점 및 영상 개수 산출을 위한 실험을 진행하였으며, 출력 영상 내 잔여 영상의 비율을 기반으로 전역적 영상 표현을 위한 최적의 출력 영상 수를 결정하는 기법을 제안한다.

• 한국축산식품학회지
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• 제43권1호
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• pp.61-72
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• 2023

The practical use of Korean native black goat skin as a source of gelatin extraction is limited. The objective of this study was to optimize the extraction temperature and time of gelatin from Korean native black goat skin, and to compare the quality characteristics of goat skin gelatin and other commercial gelatin products. Response surface methodology was applied to optimize the extraction temperature and time of gelatin obtained from native Korean black goat skin. The effects of temperature (50℃-70℃) and time (2-4 h) on extraction yield and gel strength were investigated using a face-centered central composite design with 13 experiments. Gelatin extraction from Korean native black goat skin was prepared through the serial processes of alkali pre-treatment, bleaching, neutralization, hot-water extraction, and freeze-drying. Using the optimization plot of Minitab software, the optimized conditions for extracting temperature and time of goat skin gelatin were 59.49℃ and 3.03 h, and the optimized values of extraction yield and gel strength were 12.52% and 263.37 g, respectively. Based on a quality comparison of goat skin gelatin with commercial gelatin, the pH value of gelatin extracted from Korean native black goat skin was 5.57. The color of gelatin extracted from Korean native black goat skin was darker than that of commercial gelatin (p<0.05). Higher emulsifying properties and gel strength of goat skin gelatin were observed when compared to those of commercial gelatin (p<0.05). Therefore, the results of this study indicate that Korean native black goat skin may be a valuable source for gelatin extraction.

• 한국컴퓨터정보학회논문지
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• 제28권8호
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• pp.87-93
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• 2023

본 논문에서는 사용자의 골격 자세를 분석하여 네트워크 학습 기반으로 거북목 자세를 정확하고 효율적으로 판별하는 시스템을 제안한다. 거북목 증후군이란 목이 구부정하게 앞으로 나오는 자세를 오래 유지함으로써 목의 자세가 바뀌고 뒷목, 어깨, 허리 등에 통증이 생기는 증상을 말하며, 수술이나 약물치료보다 평소의 자세 습관이 효과적이라고 알려져 있다. 기존의 방법들은 웹캠을 이용한 합성곱 신경망을 이용하였고, 이러한 접근법은 영상의 명도와 조명, 피부 색 등에 영향을 받기 때문에 특정 인물에 대해서만 수행되는 문제가 있다. 본 논문에서는 이 문제를 완화하고 자 영상으로부터 골격을 추출하고, 정면보다는 측면에 해당하는 데이터를 학습하여 이전 기법보다 효율적이고 정확하게 거북목 자세를 찾아낸다. 결과적으로 이전 기법에 비해 다양한 실험 장면에서 정확도가 되었음을 보여준다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제11권12호
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• pp.509-516
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• 2022

3차원 공간에서 물체들의 정확한 자세 예측은 실내외 환경에서 장면 이해, 로봇의 물체 조작, 자율 주행, 증강 현실 등과 같은 많은 응용 분야들에서 폭넓게 활용되는 중요한 시각 인식 기술이다. 물체들의 자세 예측을 위한 과거 연구들은 대부분 각 인식 대상 물체마다 정확한 3차원 CAD 모델을 요구한다는 한계점이 있었다. 이러한 과거 연구들과는 달리, 본 논문에서는 3차원 CAD 모델이 없어도 RGB 컬러 영상들만 이용해서 미지 물체들의 자세를 예측해낼 수 있는 새로운 신경망 모델을 제안한다. 제안 모델은 적응형 깊이 추정기인 AdaBins를 이용하여 스스로 미지 물체 자세 예측에 필요한 각 물체의 깊이 지도를 효과적으로 추정해낼 수 있다. 벤치마크 데이터 집합들을 이용한 다양한 실험들을 통해, 본 논문에서 제안한 모델의 유용성과 성능을 평가한다.

• 대한치과기공학회지
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• 제45권3호
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• pp.67-73
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• 2023

Purpose: This in vitro study aimed to evaluate the clinical acceptability of precision of fit of the support thickness of Co-Cr alloy copings fabricated using selective laser melting (SLM). Methods: Thirty dental stone models of maxillary left molar abutments were manufactured, images were taken using a scanner, and a computer-aided design program was used to design the form of a conventional metal ceramic crown coping. Overall, 30 single copings were made from Co-Cr alloy using SLM and divided into three support radius groups (0.1, 0.25, and 0.35 mm) of 10 for each. Digitized data were superimposed with three-dimensional inspection software to quantitatively obtain the machinability of a ceramic crown coping, and visual differences were confirmed using a color map. The root mean square values of the ceramic crown coping group were statistically analyzed using one-way analysis of variance (α=0.05). Results: The precision of fit was superior with 0.25 mm compared with 0.1 mm and 0.35 mm, and the results exhibited significant differences (p<0.05). All specimens showed that various support thicknesses did not exceed the clinically permitted value of 120 ㎛, which mean that more than 0.1 mm and 0.35 mm of support radius for SLM was adequate. Conclusion: The support thickness of Co-Cr alloy restoration fabricated using SLM is shown to affect the adaptation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권1호
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• pp.126-146
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• 2024

Caladium bicolor is one of the most popular plants in Thailand. The original species of Caladium bicolor was found a hundred years ago. Until now, there are more than 500 species through multiplication. The classification of Caladium bicolor can be done by using its color and shape. This study aims to develop a model to classify Caladium bicolor using a transfer learning technique. This work also presents a proof of concept, GUI design, and web application deployment using the user-design-center method. We also evaluated the performance of the following pre-trained models in this work, and the results are as follow: 87.29% for AlexNet, 90.68% for GoogleNet, 93.59% for XceptionNet, 93.22% for MobileNetV2, 89.83% for RestNet18, 88.98% for RestNet50, 97.46% for RestNet101, and 94.92% for InceptionResNetV2. This work was implemented using MATLAB R2023a.

• 한국컴퓨터정보학회논문지
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• 제29권2호
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• pp.101-108
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• 2024

AI-OCR은 광학 문자 인식(OCR) 기술과 Artificial intelligence(AI)의 결합으로 사람의 인식이 필요하던 OCR의 단점을 보완하는 기술 향상을 이뤄내고 있다. AI-OCR의 성능을 높이기 위해서는 다양한 학습데이터의 훈련이 필요하다. 하지만 이미지 색상이 비슷한 밝기를 가진 경우에는 인식률이 떨어지기 때문에, Homomorphic filtering(HF)을 이용한 전처리 과정으로 색상 차이를 분명하게 하여 텍스트 인식률을 높이게 된다. HF은 감마값을 이용해 이미지의 고주파와 저주파를 각각 조절한다는 점에서 텍스트 추출에 적합하지만 감마값의 조절이 수동적으로 이뤄지는 단점이 존재한다. 본 연구는 시험적 과정을 거쳐 이미지의 대비, 밝기 및 엔트로피를 근거하는 감마의 임계값 범위를 제안한다. 제안된 감마값 범위를 적용한 HF의 실험 결과는 효율적인 AI-OCR의 높은 등장 가능성을 시사한다.