• Korean Journal of Radiology
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• v.24 no.11
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• pp.1081-1092
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• 2023

Objective: To investigate the incidence of microvascular myocardial ischemia in diabetic patients without obstructive coronary artery disease (CAD) and its relationship with angina. Materials and Methods: Diabetic patients and an intermediate-to-high pretest probability of CAD were prospectively enrolled. Non-diabetic patients but with an intermediate-to-high pretest probability of CAD were retrospectively included as controls. The patients underwent dynamic computed tomography-myocardial perfusion imaging (CT-MPI) and coronary computed tomography angiography (CCTA) to quantify coronary stenosis, myocardial blood flow (MBF), and extracellular volume (ECV). The proportion of patients with microvascular myocardial ischemia, defined as any myocardial segment with a mean MBF ≤ of 100 mL/min/100 mL, in patients without obstructive CAD (Coronary Artery Disease-Reporting and Data System [CAD-RADS] grade 0-2 on CCTA) was determined. Various quantitative parameters of the patients with and without diabetes without obstructive CAD were compared. Multivariable analysis was used to determine the association between microvascular myocardial ischemia and angina symptoms in diabetic patients without obstructive CAD. Results: One hundred and fifty-two diabetic patients (mean age: 59.7 ± 10.7; 77 males) and 266 non-diabetic patients (62.0 ± 12.3; 167 males) were enrolled; CCTA revealed 113 and 155 patients without obstructive CAD, respectively. For patients without obstructive CAD, the mean global MBF was significantly lower for those with diabetes than for those without (152.8 mL/min/100 mL vs. 170.4 mL/min/100 mL, P < 0.001). The mean ECV was significantly higher for diabetic patients (27.2% vs. 25.8%, P = 0.009). Among the patients without obstructive CAD, the incidence of microvascular myocardial ischemia (36.3% [41/113] vs. 10.3% [16/155], P < 0.001) and interstitial fibrosis (69.9% [79/113] vs. 33.3% [8/24], P = 0.001) were significantly higher in diabetic patients than in the controls. The presence of microvascular myocardial ischemia was independently associated with angina symptoms (adjusted odds ratio = 3.439, P = 0.037) in diabetic patients but without obstructive CAD. Conclusion: Dynamic CT-MPI + CCTA revealed a high incidence of microvascular myocardial ischemia in diabetic patients without obstructive CAD. Microvascular myocardial ischemia is strongly associated with angina.

• Journal of The Korean Digital Architecture Interior Association
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• v.2 no.1
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• pp.9-15
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• 2002

As architectural forms tend to be large-scaled, high-storied and complicated, use of computer for processing design information has been generalized. However, CAD use in the process of developing architectural design has been neglected greatly in the educational field of architectural field due to the surging of recognition that it may limit the essential property of architectural design. It may be resulted from the limitation of CAD system, that is, it is because of tardy speed of application development for the related areas with the lack of simplicity and clarity of flexibility to be secured on the drawing and user interface. Recent CAD systems, however, overcome such a limitation, convert into object-based design from entity-based drawing, drafting and modeling for implementing design concept of architects and it connects with internet linked to superspeed information communication network and changes process and stream of architectural design. Therefore, this study deals with utility of object based CAD system with products of Autodesk Co. and consequently obtain the following conclusions. First, it expands architect's design areas by supporting cooperative design system based on model-based architectural design and internet. Second, it reduces consumption of personal and material resources and time in the process of drawing production for improving architectural design works. Third, it can reduce the frequent design changes by improving understanding of architectural space with visualization of immediate 3D information, escaping from traditional methods to deliver design information to building owner through 2D drawing or model and perspective drawing requiring much cost and time. Fourth, it keeps exactness without omission or duplication of design information and generate and renew information of all related drawings on a drawing. Fifth, it is possible to change difficult and boring architectural design work into a pleasure owing to immediate modeling and drawing of design idea. In addition, digital drawing generated by using object-based CAD system can playa role of establishing Urban Information System to be used for protecting from building in disaster and urban disasters in connection with GIS numerical map and be used for reference of all kinds of information required fro post-management of buildings. However, what is more important is that surplus time from introduction of object-based CAD system should be used for consideration to be recognized as a good space and building built as a product of this project for comfort to urban people.

• Science of Emotion and Sensibility
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• v.8 no.2
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• pp.95-101
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• 2005

This study is based on previous information regarding reduced cardiac vagal activity in patients with coronary artery disease(CAD), on reduced variance(SDNN : standard deviation of all normal RR intervals), low-frequency power(LF), and the complexity of heart rate variability(HRV) in patients with chronic heart failure(CHF), and on the normalized high-frequency power of HRV is the highest in the right lateral decubitus position among 3 recumbent postures in patients with CAD, However, nothing is known about the nonlinear dynamics of HRV for the 3 recumbent postures in patients with CAD. To investigate the linear and non-linear characteristics of HRV in patients with CAD, 29 patients as CAD group and 23 patients as control group were studied. Electrocardiogram(ECG) with lead II channel was measured on these patients for 3 recumbent postures in random order. The HRV from ECG was analyzed with linear method(for time and frequency domains) and nonlinear method. The lower the high-frequency power in normalized unit(nHF) in the supine or left lateral decubitous position, the higher the increase in nHF when the position was changed from supine or left lateral decubitous to right lateral decubitous. Among the 3 recumbent postures in patients with severe CAD, the right lateral decubitus position was observed to induce the highest vagal modulation, the lowest sympathetic modulation, and the highest complexity of human physiology system.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.225-236
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• 1996

Computer simulation methods for three area of textile design, wearing, and design were developed by using CAD system, and its results were applied to pattern design simulation. Textile design created by using the CAD system was applied to T-shirt schematization. Created wearing, printing, and knitting design respectively were applied to women clothing, children's wear, and men sweater. In this rearch, several equipped since various color working, materials, pattern development and swift intention decision of goods direction are possible on the moniter. Third, many goods order are rushed within short time because spot direction are possible on the moniter. Third, many goods order are rushed within short time because intention decision of buyer could be induced and embodied design almost reflection the buyer's will on the spot before production of goods and samples. Forth, time and expense were saved to get the information in terms of design information systematically and could be managed annually. Fifth, creative design development can be not only availed but saved the service expense of outside orders and the traffic expense.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1187-1197
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• 1996

In this work, two-dimensional FIR digital filter is designed and simulated using research and educational CAD tools. The two-dimensional digital filter consists mainly of one-dimensional digital filter and line memory. To speed up one-dimensional digital filter, multiplications are carried out on the basis of hardwired-shifting methods by the digital filter coefficients represented in CSD formats, while carry-save adder and Manchester adder are used in addition. It is found that the designed digital filter operates up to 30 Mhz in VHDL simulation and operates normally in IRSIM simulation for the layout made by Berkeley CAD tools.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.173-181
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• 2006

In this paper, an integration framework of Geometric Constraint Solving Engine and AutoCAD is presented, and a dynamic geometric constraint system is introduced. According to inherent orientation features of geometric entities and various Object Snap results of AutoCAD, the' proposed system can automatically construct an under-constrained geometric constraint model during interactive drawing. And then the directed constraint graph in a geometric constraint model is realtime modified in order to produce an optimal constraint solving sequence. Due to the open object-oriented characteristics of AutoCAD, a set of user-defined entities including basic geometric elements and graphics constraint relations are defined through derivation. And the custom-made Object Reactor and Command Reactor are also constructed. Several powerful characteristics are achieved based on these user-defined entities and reactors, including synchronously processing geometric constraint information while saving and opening DWG files, visual constraint relations, and full adaptability to Undo/Redo operations. These characteristics of the proposed system can help the designers more easily manage geometric entities and constraint relations between them.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.227-230
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• 2000

건설 도면정보의 공유 및 교환은 건설 CALS/EC(Continuous Acquisition & Lifecycle Support /Electronic commerce) 환경의 필수적인 요소이다. 그러나 CAD 시스템의 버전변화와 별도의 한글처리로 인하여 도면정보의 관리 렌 활용에 많은 문제점이 발생하고, 상이한 CAD 시스템간의 파일 교환이 제대로 이루어지지 못하는 등 도면정보 교환을 위한 정보모델의 구축이 절실히 요구되고 있다. 이러한 환경에서 STEP(Standard for the Exchange of Product model data)은 건설 도면정보의 교환 및 공유를 위한 정보모델을 구축함에 있어서 그 활용 가능성이 높다. 본 연구에서는 STEP을 이용하여 건설분야에서 활용 가능한 2차원 도면정보 모델을 개발하고자 한다. 이를 위하여 STEP내의 AP 202를 기반으로, AP 214와 독일의 2차원 도면정보 표준화 프로젝트인 STEP-CDS를 참조하도록 한다. 그리고 실제 개발된 도면정보모델이 기존 CAD 도면 데이터를 제대로 표현할 수 있는지 검증하기 위하여 상용 CAD시스템인 AutoCAD Rl4의 DXF 데이터를 개발된 정보모델로 변환하여 그 결과를 검토하고자 한다. 세부적으로는 DXF 데이터의 도면정보모델로의 변환을 위하여 DXF 구조의 STEP 스키마를 정의한다. 이때 이 스키마와 도면정보모델의 스키마간의 매핑을 위하여 STEP내의 EXPRESS-X를 이용하기로 한다. 또한 도면정보 모델의 데이터의 뷰잉과 브라우징을 위하여 도면정보 뷰어를 개발한다.

• Journal of Technologic Dentistry
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• v.35 no.2
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• pp.89-95
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• 2013

Purpose: The purpose of this study was to evaluate bond strength of Metal Disk alloy and casting alloy. Methods: Metal specimens were divided into 4 groups for each alloy. Three point flexural test were used to measure the bond strength of CAD/CAM metal alloy and casting alloy. Statistical analysis was done using the Statistical Package for Social Sciences version 19.0 for Windows. As for the analysis methods, the study used Kruskal-Wallis test. Results: The average bonding strengths of Group 1 to porcelain was $36.7{\pm}9.90$ MPa, Group 2 to porcelain was $37.68{\pm}4.51$ MPa, Group 3 to porcelain was $36.43{\pm}6.57$ MPa, Group 4 to porcelain was $42.88{\pm}6.81$ MPa, Each group was not significantly different. Conclusion: Bond strength of Casting alloy is equal to or higher than bond strength of CAD/CAM Metal Disk alloy. Alloy clinical bond strength is 25 MPa, So CAD/CAM Metal Disk alloy can be used as dental material.

• Korean Journal of Computational Design and Engineering
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• v.13 no.2
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• pp.131-138
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• 2008

With the advancements of the Internet and CAD data translation techniques, more CAD models are transferred from a CAD system to another through the network and interoperability is getting a common word in the CAD industry. However, when a CAD model is translated for an incompatible system into a neutral format such as STEP or IGES, its precious feature information is lost. When this feature information is lost, the advantage of feature based modeling is not valid any longer, and modification for the model is purely dependent on geometric and topological manipulations. However, the capabilities of the existing methods to modify these feature-independent models are limited as the modification involves a topological change in the model. To address this issue, we present a volumetric method to modify the solid models in neutral format. First, this method selectively decomposes the solid model to separate the portion of interest called feature volume. Next, the designer modifies the feature volume without concerning a topological change. Finally, the feature volume is united with the original solid model to complete the modification process. The results of test cases are presented to attest the usefulness of the proposed method.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.1
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• pp.4-14
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• 2016

Although CAD/CAM technology has been used in dentistry for more than decades, the present CAD/CAM dentistry is still quite inefficient or unesthetic. Zirconia restoration has faced with two contradictory words, 'Efficiency' and 'Esthetics'. One can consider monolithic zirconia restoration to be efficient with CAD/CAM. The monolithic zirconia restoration, however, is rarely esthetic due to the current limitations with zirconia. On the contrary, porcelain build-up is almost indispensible in fabricating esthetic restoration, especially in anterior region. In this article, the current status of monolithic zirconia restoration and clinical cases will be presented.