냉간성형 각형강관 가새부재의 연성능력 확보를 위한 제안

김욱태,여승민,한상환 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

The Purpose of this study is to suggest formula to improve the ductility of cold-formed Hollow Structural section(HSS) brace members with a small width-thickness ratio(w/t ratio). For this purpose, experimental tests with eight full-scale test specimens were carried out using quasi static reversed cyclic loading with a symmetric shape in compression and tension From the experiment results, it is shown that HSS bracing members with a small wit ratio can not guarantee the large amount of energy dissipation due to the early fracture of slotted end connection in the members having a small wit ratio This is because brace members designed in compliance with LPFD manual satisfied the design strength but decreased the ductility due to net-section fracture caused by the strain concentration of slotted end connection in spite of the small wit ratio. Thus, this study suggests formula to improve the ductility by controlling the fracture mode in order to have the fracture occur in the mid-section. Moreover, this study verified the validity of the formula by testing the specimen with the smallest wit ratio(8) designed according to the proposed formula.

임플란트 지지 고정성 치과 보철물 유지방식에 따른 고정체의 직경과 길이 분포 비교 연구

김욱태 대한치과기공학회 2006 대한치과기공학회지 Vol.28 No.2

도재 소성 횟수가 색조변화에 미치는 영향

김욱태,박창근 대한치과기공학회 2008 대한치과기공학회지 Vol.30 No.1

Recently natural characteristics and esthetics have been interested increasing in clinical dentistry. Thus the evaluation of the shade of dental porcelain has become an important part in dental research. Noritake Super Porcelain EX-3 Vita shade A2 (Noritake, Japan) Vintage HaLo Vita shade A2 (Shofu, Japan), Vita omega 900 Vitapan 3D-master shade 2M2 (Vita, Germany) were conducted for six times for repeated firing in a way to observe the change of color with respect to the number of firing. The repeated firing was implemented with the vacuum firing and air firing, and by using Shade Eye-EX Chroma meter (Shofu, U.S.A.), the changes in values of shade, value and chroma were compared. With the above results, the change of color was not noticed only in Vita when repeated firing was applied.

수학과 ‘확률과 통계’ 영역에서 ChatGPT를 활용한 서답형 평가 피드백이 학생들의 피드백 리터러시에 미치는 영향

김욱태,김영식 한국컴퓨터교육학회 2024 컴퓨터교육학회 논문지 Vol.27 No.3

본 논문은 수학과 ‘확률과 통계’ 영역의 서답형 평가에서 인간 교사가 제공하던 형성적 피드백을 ChatGPT가 보완 또는 대체할 수 있는지에 대한 탐구를 수행하였다. 연구 방법으로 학생들을 두 집단으로 나누어 서답형 평가를 시행하고, 이에 대한 피드백을 ChatGPT 및 인간 교사가 각각 제공하도록 실험을 진행하였다. 실험 데이터는 독립표본 t-검정을 이용하여 해석하였으며, 실험 결과 피드백 제공자가 인공지능이든 인간 교사든 피드백 리터러시의 하위 구성 요소인 피드업, 피드백, 피드포워드, 인지, 정서조절 및 피드백 구하기에서 통계적으로 유의미한 차이가 없음이 밝혀졌다. 이와 같은 연구 결과는 ChatGPT가 교육 분야에서 피드백을 제공하는 도구로 활용될 가능성을 시사한다. This thesis investigates how artificial intelligence, represented by ChatGPT, can replace the formative feedback traditionally provided by human educators in the field of mathematics, specifically in the realm of probability and statistics education. To conduct this study, students were divided into two groups and subjected to formative assessments, with feedback provided by both artificial intelligence, specifically ChatGPT, and human educators. The experimental results did not reveal statistically significant differences in students' feedback literacy, encompassing their ability to comprehend and utilize feedback, between the feedback providers, be it artificial intelligence or human educators. These research findings suggest the potential utility of artificial intelligence, ChatGPT in particular, as a tool for delivering feedback in the field of education.

무치악 환자에서 디지털 가이드를 이용한 임플란트 수복증례

김욱태 대한치과기공학회 2021 대한치과기공학회지 Vol.43 No.4

By classifying temporary denture production for surgical guides, digital guide-based surgery, and final prosthesis production, the problems of each process were assessed in advance and the factors that could be improved were confirmed in this study. The manufacturing process of fusion dental prosthesis uses virtual programs and computed tomography images to manufacture devices using the latest technologies of computer-aided design/computer- aided manufacturing and three-dimensional printing, which enables implants to be placed in the desired location in advance. Moreover, implant placement is not dependent on the skill and condition of the dentist, and because it uses a computer system, it can always be performed at a constant and optimal position. This can reduce the remanufacturing rate compared with the general method, shorten the treatment period, and eliminate patient discomfort. Unlike the traditional method of using impression materials and plaster models, digital fusion dental prostheses would be evaluated as a technology for producing prosthesis through professional design technology and communication.

두 종의 밀링 시스템으로 제작된 3본 고정성 치과보철물의 내면 정확도 비교

김욱태 한국산학기술학회 2023 한국산학기술학회논문지 Vol.24 No.1

연구의 목적은 두 가지 밀링 시스템으로 제작된 3본 고정성 보철물의 내면 정확도를 평가하는 것이다. 제작 방법은 부분적 디지털 워크플로인 Ray 시스템, 완전 디지털 워크플로인 CEREC 시스템을 적용하였다. 두 가지 밀링 시스템으로 제작된 3본 고정성 치과보철물의 정확도 평가는 3본 브리지 보철물의 디자인 파일인 CAD 기준 모형과 실제 제작된 3본 브리지 보철물의 내면이 스캔된 파일인 CAD 실험 모형을 검사 소프트웨어에서 중첩하여 삼차원 분석되었다(N=15). 통계분석은 Independent t-test를 사용하여 두 그룹을 비교하였다 (α =.05). CEREC 시스템과 Ray 시스템의 내면 정확도 측정 결과를 보면, 모든 지대치에서 CEREC 시스템의 내면 정확도가 유의하게 낮은 값을 보였다 (P<.001). 그리고 Ray 시스템 그룹이 CEREC 시스템 그룹보다 유의하게 높은 값을 보였다 (P<.001). 결과적으로 구강 스캐너를 사용하여 구강 디지털 데이터를 획득하는 CEREC 시스템 디지털 워크플로가 모형 스캐너를 사용하여 디지털 데이터를 획득하는 Ray 시스템보다 나은 3본 고정성 치과보철물 제작을 가능하게 한다.

마모가 심한 환자의 전악 고정성보철물 제작 증례

김욱태 대한치과기공학회 2020 대한치과기공학회지 Vol.42 No.4

This case study is aimed at introducing a full-mouth rehabilitation of a patient with severe tooth wear using fixed prosthesis. This is a case report of a patient with severe wear dentition with changing vertical dimension. In line with using prosthetic treatment, patient adaptation was verified with provisional restorations followed by diagnostic wax-up. Function, esthetics, and occlusal stability were verified during a 4-week follow up period. Prosthodontic reconstruction based on systemic analysis, diagnosis, and treatment plan led to satisfactory results after delivery of definitive prosthesis. Prosthetic treatment of severe wear dentition was functionally and esthetically successful. Dentists and dental technicians would be able to develop better treatment approaches using fixed dental prosthesis.

다양한 석고제품으로 제작한 석고 모형의 정확성의 평가: 3차원 이미지의 컴퓨터 지원 분석

김욱태 대한치과기공학회 2020 대한치과기공학회지 Vol.42 No.4

Purpose: This study is to evaluate the accuracy of gypsum replica models made from various gypsum products. Methods: One main model was made of stainless steel by CNC milling process. Molds were formed from the main model, and the gypsum replica models were made using 8 types of type IV gypsum, 10 pieces each. The main model was digitized by a contact scanner (Incise; Renishaw) and the gypsum replicas were digitized by an optical scanner (E4; 3Shape A/S). The difference between the main model and the gypsum replicas were measured by inspection software (3D Systems). One-way ANOVA was performed to evaluate the statistical significance of differences between groups. In addition, the independent sample T test was performed to determine the difference between the conventional and scannable stone group (n=10, α=0.05). Results: The root mean square of the stone models were 7.24 μm to 10.78 μm, and statistical significance was found between the two groups (SR, FR) and the other 6 groups (IS, SG, CA, CS, ER, EBG) (p<0.05). The accuracy of the gypsum replicas was 9.04 μm and 7.62 μm in the conventional and scannable stone group, respectively. There was statistical significance between the two groups (p<0.01). Conclusion: In the limited results of this study, the product with low setting expansion and the scannable showed high accuracy. Therefore, in order to obtain a stable and accurate scan model, it is more effective in terms of accuracy to use a scannable stone with a low setting expansion.

노인의 구강위생행태와 주관적 구강건강 형태에 대한 분석

김욱태 대한치과기공학회 2012 대한치과기공학회지 Vol.34 No.2

사회심리적 건강측정도구를 이용한 치과기공사의 스트레스 평가

김욱태,한태영 대한치과기공학회 2009 대한치과기공학회지 Vol.31 No.3