• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.327-327
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• 1995

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.55.6-55
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• 2002

Huafei Liao is a graduate student of the Automation department in Tsinghua University, China. His research involves computer-aided process planning, 3D CAD/CAM, virtual reality, and feature recognition.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.1
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• pp.44-54
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• 2023

In order to manufacture functional and esthetic prostheses, it is essential to accurately transmit information about the patient's occlusal plane. In particular, in the case of a completely edentulous patient, the occlusal plane is very important to correctly support the soft tissue, to achieve aesthetic harmony with the facial appearance, and to properly pronounce it, and to form a balanced occlusal relationship for stable mastication. In the conventional method, various facebow systems were used to transmit patient's information from the clinic to the laboratory, but there were several limitations in the process of transferring them to CAD. To simplify this process, a prefabricated POP (PNUD Occlusal Plane) Bow system was recently developed. In this case, a CAD-CAM (Computer-aided design-computer-aided manufacturing) treatment dentures reflecting the patient's occlusal plane information was manufactured using the POP Bow system during the treatment of a completely edentulous patient, and aesthetic and functional satisfaction was obtained.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.179-184
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• 2009

Recent evolution of computer technology enhances the effectiveness of CFD(Computational Fluid Dynamics) analysis for the 3-dimensional complex transport phenomena including turbulent flows. Cheaper and easier than laser and ultra-sonic methods, the windows simulator name by CAMSI(Computer-Aided Management of Stereo Images) has been developed in order to implement the 3-dimensional image using a disparity histogram extracted from left and right stereo images. In our program using the area-based method, the matching pixel finding methods consist of SSD(Sum of Squared Distance), SAD(Sum of Absolute Distance), NCC(Normalized Correlation Coefficient) and MPC(Matching Pixel Count). On performing the program, stereo images on different window sizes for various matching pixel finding methods are compared reasonably. When the image has a small noise, SSD on small window size is more effective. Whereas there is much noise, NCC or MPC is more effective than SSD. CAMSI from the present study will be much helpful to implement the complex objects and to analyze 3-dimensional CFD around them.

• Restorative Dentistry and Endodontics
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• v.37 no.3
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• pp.136-141
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• 2012

Objectives: The maintenance of the healthy periodontal ligament cells of the root surface of donor tooth and intimate surface contact between the donor tooth and the recipient bone are the key factors for successful tooth transplantation. In order to achieve these purposes, a duplicated donor tooth model can be utilized to reduce the extra-oral time using the computer-aided rapid prototyping (CARP) technique. Materials and Methods: Briefly, a three-dimensional digital imaging and communication in medicine (DICOM) image with the real dimensions of the donor tooth was obtained from a computed tomography (CT), and a life-sized resin tooth model was fabricated. Dimensional errors between real tooth, 3D CT image model and CARP model were calculated. And extra-oral time was recorded during the autotransplantation of the teeth. Results: The average extra-oral time was 7 min 25 sec with the range of immediate to 25 min in cases which extra-oral root canal treatments were not performed while it was 9 min 15 sec when extra-oral root canal treatments were performed. The average radiographic distance between the root surface and the alveolar bone was 1.17 mm and 1.35 mm at mesial cervix and apex; they were 0.98 mm and 1.26 mm at the distal cervix and apex. When the dimensional errors between real tooth, 3D CT image model and CARP model were measured in cadavers, the average of absolute error was 0.291 mm between real teeth and CARP model. Conclusions: These data indicate that CARP may be of value in minimizing the extra-oral time and the gap between the donor tooth and the recipient alveolar bone in tooth transplantation.

• Journal of the Korea Institute of Building Construction
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• v.16 no.2
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• pp.169-175
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• 2016

A survey of small-size contractors in Jeju was conducted to investigate college graduate's CAD (computer aided design) competence. Most of small-size contractors use CAD softwares to review and update drawings submitted from an architect. This research analyzed the curriculum of the architectural engineering in several national universities. The CAD classes have 4 or 6 hours per week and use AutoCAD primarily. This research proposes that a CAD class needs at least 6 hours per week, 2D drawing is the main theme in the curriculum, and exercises to make 3D models are also included in the CAD class. The improved methods, Internet cafe and real time feedbacks using a smartphone, to evaluate the reports and exercise results are necessary.

• Journal of Mechanical Science and Technology
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• v.18 no.8
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• pp.1358-1367
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• 2004

As a part II of theis research, new local inspection planning strategy is proposed in this paper based on the proposed inspection feature extraction method. In the local inspection planning stage, each feature is decomposed into its constituent geometric elements for more effective inspection planning. The local inspection planning for the decomposed features are performed to determine: (1) the suitable number of measuring points, (2) their locations, and (3) the optimum probing paths to minimize measuring errors and times. The fuzzy set theory, the Hammersley's algorithm and the TSP method are applied for the local inspection planning. Also, a new collision checking algorithm is proposed for the probe and/or probe holder based on the Z-map concept. Finally, the results are simulated and analyzed to verify the effectiveness of the proposed methods.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.475-481
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• 2005

현재 국내외에서는 유비쿼터스에 대한 연구 및 의료도메인에 대한 많은 연구가 진행되고 있다. 그러나 기존의 연구들은 전체적인 시스템에 대한 연구가 대부분이어서 실제 환경을 구축하는데 상당한 어려움이 따르고 있다. 본 연구에서는 위와 같은 문제점을 해결하기 위하여 고위험군 환자를 대상으로 다음과 같은 시나리오를 작성하였다. 시나리오는 Home -medical 서비스, Emergency call center 서비스 그리고 응급차량 서비스로 구성하였다. 본 연구에서는 위와 같은 시나리오를 기반으로 고위험군 환자의 생체 신호를 획득한 후 신경망을 이용하여 생체 신호 데이터를 학습한 후 환자의 이상 징후를 진단하는 CAD시스템의 프레임웍과 환자의 위험 수위를 단계별로 분류하는 알고리즘을 제시한다. 또한 과거의 데이터를 이용하여 미래의 환자상태를 예측하는 CAP시스템의 프레임웍을 제시하고 프레임웍에 대한 타당성을 검증하고자 한다.

• Journal of Biomedical Engineering Research
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• v.26 no.5
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• pp.283-294
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• 2005

The Center for Imaging Human Structures (CIH) was established in December 2002 to develop new diagnostic imaging techniques and to make them available to the greater community of biomedical and clinical researchers at Sungkyunkwan University. CIH has been involved in 5 specific activities to provide solutions for early diagnosis and improved treatment of human diseases. The five area goals include: 1) development of a digital mammography system with computer aided diagnosis (CAD); 2) development of digital radiological imaging techniques; 3) development of unified medical solutions using 3D image fusion; 4) development of multi-purpose digital endoscopy; and, 5) evaluation of new imaging systems for clinical application

• Advances in materials Research
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• v.3 no.2
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• pp.91-103
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• 2014

A study that demonstrates how to investigate the molded part quality and the consistency of injection process based on the rheological concept is proposed. It is important for plastic material whose melt viscosity is variable with respect to the processing condition. The formulations to couple the melt viscosity with injection pressure and fill time are derived first. Taking calculations of the measured pressure and the time by using these formulations, the melt viscosity in injection process can be determined on machine. As the relation between the injection speed and the melt viscosity is constructed, the influences of the setting parameter of injection machine on the molded part quality can be investigated through evaluating the state of the melt viscosity. In addition, a pressure sensor bushing (PSB) designed with a quick installation feature is also provided and validated. The results show that a higher injection speed improves the tensile strength of the molded part but also the consistency of the molded part quality. This work provides an alternative to evaluate the molding quality scientifically.