• Korean Architects
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• s.560
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• pp.82-87
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• 2015

지난 회에서는 형태와 형태이면에 있는 구현의 논리를 모두 다룰 수밖에 없는 파라메트릭 툴의 성격에 대하여 간략하게 이야기 해보았고 이를 반증할수 있는 곡면상의 패널링의 예를 살펴 보았습니다. 삼차원 곡면으로 인해 발생하는 패널들의 시각적 왜곡 및 구축상의 어려움을 해결하고자 왜곡이 발생하는 물리적인 이유를 이해하고 이를 미적분의 개념을 빌어 해결해 보았습니다. 오늘 살펴볼 예도 이와 비슷한 미적분의 개념을 빌리게 되지만 문제의 해결을 위함이 아닌 자연 현상을 시뮬레이션 하고 시뮬레이션의 결과로 얻어진 데이터를 설계에 반영하기 위함이라는데에 차이가 있다고 할 수 있겠습니다. 오늘 살펴볼 내용은 Harvard GSD에서 대학원 설계 수업의 일환으로 제가 진행하였던 파라메트릭 디자인 워크샵의 결과물이며 추후에 이를 실무에 이용하게 됩니다.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.9
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• pp.54-61
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• 1999

Three dimensional CAD data viewer helps a user to view and use many different types of CAD data without having costly programs that produced them loaded on their computers. A viewer for standard data formats such as STEP and IGES is more useful since most of the CAD systems provide translators for them. We developed a 3D CAD viewer for STEP AP203 solid and assembly data. In addition to the standard shading and assembly tree display, functions for 3D markups and measurement of distance and angles were implemented.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.130-132
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• 2005

다차원 온라인 분석처리 시스템(MOLAP)에서 집계 연산은 중요한 기본 연산이다. 기존의 MOLAP 집계 연산은 다차원 배열구조를 기반으로 한 파일구조에 대해서 연구되어 왔다. 다차원 배열구조는 편중된 분포를 갖는 데이터에서는 잘 동작하지 못한다는 단점이 있다. 본 논문에서는 편중된 분포에도 잘 동작하는 다차원 파일구조를 사용한 MOLAP 저장구조의 물리적 설계기법을 제안한다. 실험결과에 의하면 이차원 파일구조의 경우 집계 연산처리를 위한 저장구조의 성능이 일곱 배 이상까지 향상됨을 확인하였다. 삼차원 이상의 파일구조에 대해서는 더욱더 큰 성능향상이 예상된다. 이러한 성능의 향상은 제안된 MOLAP 저장구조의 물리적 설계기법이 매우 유용함을 나타내는 것이다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.1081-1089
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• 1999

Volume data modeling is concerned with finding a mathematical function which represents the relationship implied by the 3D data. Modeling a volume data geometrically can visualize a volume data using surface graphics without voxelization. It has many merits in that it is fast and requires little memory. We proposes, a method based on wavelet transformation and tetrahedrization. we implement a prototype system based on the proposed method. Last, we evaluated the proposed method comparing it with marching cube algorithm. the evaluation results show that though the proposed method uses only 13% of the volume data, the images generated is as good as the images generated by the marching cubes algorithm.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.597-610
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• 2022

Knowledge of the failure behavior of friction materials considering their intermediate principal stress is related to an understanding of situations where these materials might be used: for example, the stability of deep-seated boreholes and fault slip analysis. This study designed equipment for physically implementing true triaxial compression and used it to assess specimens of plaster, a friction material. The material's mechanical behaviors are discussed based on the results. The applicability of the 3D failure criteria are also reviewed. The tested specimens were molded cuboids of width, length, and height 52, 52, and 104 mm, respectively. A total of 24 true triaxial compression tests were performed under various combinations of 𝜎₃ and 𝜎₂ conditions. Conventional uniaxial and triaxial compression tests were employed to estimate the mechanical properties of the plaster for use as parameters for 3D failure criteria. Examining the stress-strain relations of the plaster materials showed that a large difference between the intermediate principal stress and the minimum principal stress indicated strong brittle behavior. The mechanical behavior of the plaster used here reflects the change of intermediate principal stress. Nonlinear multiple regression analysis on the test data in the principal space showed that the modified Wiebols-Cook failure criterion and the modified Lade failure criterion were the most suitable 3D failure criteria for the tested plaster.

• The Journal of the Korea Contents Association
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• v.11 no.8
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• pp.1-13
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• 2011

In order to create an intelligent autonomous agent in virtual world, we need a sophisticated design for perception, recognition, judgement and behavior. We develop the perception and recognition functions for such an autonomous agent. Our perception mechanism identifies lines based on differences in color, the primitive visible data, and exploits those lines to grasp shapes and regions in the scene. We develop an inferencing algorithm that can infer the original shape from a damaged or partially hidden shape using its characteristics from the ontology in order to intelligently recognize the perceived shape. Several individually recognized 2D shapes and their spatial relations form 3D shapes and those 3D shapes in turn constitute a scene. Each 3D shape occupies its respective region, and an agent analyzes the associated objects and relevant scenes to recognize things and phenomena. We also develop a mechanism by which an agent uses this recognition function to accumulate and use her knowledge on the scene in the historical context. We implement these functions presented above against an example situation to demonstrate their sophistication and realism.

• Archives of design research
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• v.17 no.1
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• pp.299-308
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• 2004

The methods of presenting information are more variable with advanced computer media technology. However, when we visualize information of database, it is more difficult to understand data meaning by complex date, which is not required by user. To compose new information, user needs to combine own his memory and new information presenting result. To be quickly explored new information and be exactly understood relationship of data structure, the data presenting of visualized information is more structured and presented with meaning form. It is possible to make information visualization system, which users can explore database by oneself, with supporting interaction to be able to control and combine relationship of three-dimensional scene graphic structure, presenting factors of animation and data structure of database. There are several diagrams, such as VR diagram, Form structure diagram and simulated diagram as the case study.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.309-315
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• 2009

Image reconstruction of Inverse Fourier Transform after Frequency Domain Data is filtered applies to Image signal acquired from MR. There are various kinds of image processing techniques; image preprocessing, image reconstruction, image compression, image restoration image mixture, noise and artifact elimination, and image quality improvement. In this paper, optimum filter applicable to diagnosis in clinic by comparing and analyzing the characteristics of the filter will be explained. Fermi-Dirac filter will improve the image quality better than the previous MR image.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5169-5175
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• 2013

We present a framework for 3D hand gesture design and modeling. We adapted two different pattern matching techniques, Dynamic Time Warping (DTW) and Hidden Markov Models (HMMs), to support the registration and evaluation of 3D hand gestures as well as their recognition. One key ingredient of our framework is a concept for the convenient gesture design and registration using HMMs. DTW is used to recognize hand gestures with a limited training data, and evaluate how the performed gesture is similar to its template gesture. We facilitate the use of visual sensors and body sensors for capturing both locative and inertial gesture information. In our experimental evaluation, we designed 18 example hand gestures and analyzed the performance of recognition methods and gesture features under various conditions. We discuss the variability between users in gesture performance.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1291-1300
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• 2017

In the high-dimensional data, the number of variables is very larger than the number of observations. In this case, the impact of influential observations on regression coefficient estimates can be very large. Jang and Anderson-Cook (2017) suggested the LASSO influence plot. In this paper, we propose the LASSO influence plot, LASSO variable selection ranking plot, and three-dimensional LASSO influence plot as graphical methods for evaluating the impact of influential observations in high-dimensional data. With real two high-dimensional data examples, we apply these graphical methods as the regression diagnostics tools for finding influential observations. It has been found that we can obtain influential observations with by these graphical methods.