• Title/Summary/Keyword: Geometric Representation

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Key Point Extraction from LiDAR Data for 3D Modeling (3차원 모델링을 위한 라이다 데이터로부터 특징점 추출 방법)

  • Lee, Dae Geon;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.5
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    • pp.479-493
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    • 2016
  • LiDAR(Light Detection and Ranging) data acquired from ALS(Airborne Laser Scanner) has been intensively utilized to reconstruct object models. Especially, researches for 3D modeling from LiDAR data have been performed to establish high quality spatial information such as precise 3D city models and true orthoimages efficiently. To reconstruct object models from irregularly distributed LiDAR point clouds, sensor calibration, noise removal, filtering to separate objects from ground surfaces are required as pre-processing. Classification and segmentation based on geometric homogeneity of the features, grouping and representation of the segmented surfaces, topological analysis of the surface patches for modeling, and accuracy assessment are accompanied by modeling procedure. While many modeling methods are based on the segmentation process, this paper proposed to extract key points directly for building modeling without segmentation. The method was applied to simulated and real data sets with various roof shapes. The results demonstrate feasibility of the proposed method through the accuracy analysis.

The Study on the Silver Fashion Icon Iris Apfel's Fashion Style (실버 패션 아이콘 Iris Apfel의 패션 스타일에 관한 연구)

  • Kim, Janghyeon;Kim, Youngsam
    • Journal of Fashion Business
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    • v.24 no.3
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    • pp.101-113
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    • 2020
  • This study considers aesthetic characteristics by examining the fashion style of the silver fashion icon Iris Apfel. The research methods were a quantitative and qualitative analysis of Iris Apfel's images that were collected from 2015 to 2019 on various web-sites according to four criterions following advanced research analysis of fashion style. The results of the study are as follows. The analysis results on the fashion style of Iris Apfel, an icon of silver style, showed that cocoon, barrel and A-line silhouettes appeared most in terms of silhouettes. Second, in terms of colors, achromatic colors dominated among solid colors while one particular vivid color appeared most it came to mixed color. In terms of multi colors, these appeared according to the patterns applied to her clothing, in particular, colorful colors were used to emphasize splendor. Third, flower, bird and geometric patterns appeared most in terms of material patterns. Lastly, it was found that white short cut hair, large necklaces or bangle bracelets, over-sized black glasses and fur mufflers or canes were used in terms of hair and accessories. The features derived through analysis of the fashion style of Iris Apfel, an icon of silver style, are as follows. The first feature is exaggeration through splendid primary colors and over-sized silhouettes. The second feature is the hybrid of modern composition methods using natural images and exotic preferences. The third feature is her representation of identity using fixed items.

A Review of Computational Phantoms for Quality Assurance in Radiology and Radiotherapy in the Deep-Learning Era

  • Peng, Zhao;Gao, Ning;Wu, Bingzhi;Chen, Zhi;Xu, X. George
    • Journal of Radiation Protection and Research
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    • v.47 no.3
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    • pp.111-133
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    • 2022
  • The exciting advancement related to the "modeling of digital human" in terms of a computational phantom for radiation dose calculations has to do with the latest hype related to deep learning. The advent of deep learning or artificial intelligence (AI) technology involving convolutional neural networks has brought an unprecedented level of innovation to the field of organ segmentation. In addition, graphics processing units (GPUs) are utilized as boosters for both real-time Monte Carlo simulations and AI-based image segmentation applications. These advancements provide the feasibility of creating three-dimensional (3D) geometric details of the human anatomy from tomographic imaging and performing Monte Carlo radiation transport simulations using increasingly fast and inexpensive computers. This review first introduces the history of three types of computational human phantoms: stylized medical internal radiation dosimetry (MIRD) phantoms, voxelized tomographic phantoms, and boundary representation (BREP) deformable phantoms. Then, the development of a person-specific phantom is demonstrated by introducing AI-based organ autosegmentation technology. Next, a new development in GPU-based Monte Carlo radiation dose calculations is introduced. Examples of applying computational phantoms and a new Monte Carlo code named ARCHER (Accelerated Radiation-transport Computations in Heterogeneous EnviRonments) to problems in radiation protection, imaging, and radiotherapy are presented from research projects performed by students at the Rensselaer Polytechnic Institute (RPI) and University of Science and Technology of China (USTC). Finally, this review discusses challenges and future research opportunities. We found that, owing to the latest computer hardware and AI technology, computational human body models are moving closer to real human anatomy structures for accurate radiation dose calculations.

Research on BGP dataset analysis and CyCOP visualization methods (BGP 데이터셋 분석 및 CyCOP 가시화 방안 연구)

  • Jae-yeong Jeong;Kook-jin Kim;Han-sol Park;Ji-soo Jang;Dong-il Shin;Dong-kyoo Shin
    • Journal of Internet Computing and Services
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    • v.25 no.1
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    • pp.177-188
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    • 2024
  • As technology evolves, Internet usage continues to grow, resulting in a geometric increase in network traffic and communication volumes. The network path selection process, which is one of the core elements of the Internet, is becoming more complex and advanced as a result, and it is important to effectively manage and analyze it, and there is a need for a representation and visualization method that can be intuitively understood. To this end, this study designs a framework that analyzes network data using BGP, a network path selection method, and applies it to the cyber common operating picture for situational awareness. After that, we analyze the visualization elements required to visualize the information and conduct an experiment to implement a simple visualization. Based on the data collected and preprocessed in the experiment, the visualization screens implemented help commanders or security personnel to effectively understand the network situation and take command and control.

A Study on Fashion Design Using Shape Grammar (형상문법(Shape Grammar)을 활용한 패션디자인 연구)

  • Soo Kyung Ko;Chul Yong Choi
    • Journal of the Korea Fashion and Costume Design Association
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    • v.25 no.4
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    • pp.123-132
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    • 2023
  • The term 'module' is an architectural term. It refers to the components or systems that make up a finished product. As industries develop, modules have become one of the methods that can create diverse and creative designs. Traditional modular fashion design mainly focused on structural methods, such as the combination, assembly, overlap, and arrangement of modules, as well as the tessellation of geometric shapes. However, in this paper, significance lies in exploring the application of shape grammar, a design method in architecture, to fashion design. It aims to search for ways to express three-dimensional designs, derive designs that can be worn and produced, and propose fashion design by applying the rules of shape grammar to the design process. Through this analysis, the paper aims to examine the methods and characteristics of shape grammar. The research method of this paper is as follows. First, by utilizing optimized programs for implementing the modules of shape grammar, it was possible to propose a method for producing modules of shape grammar and suggest module designs. Additionally, effective methods of representation using the Clo 3D program were explored in the design development process. Second, by applying shape grammar to the fashion design process, five-dimensional modular fashion designs were proposed, including a bolero, dress 1, dress 2, setup, and coat. The proposed modular fashion design using shape grammar in this paper provides a rational design process that differentiates itself from traditional modular fashion design. By formalizing the shapes between modules and creating rules, it overcomes the limitations of design that rely on the designer's intuition or sensibility and enables the development of more diverse modular fashion designs. This application of shape grammar in fashion design can provide an important direction in exploring a sustainable fashion industry.

Caricaturing using Local Warping and Edge Detection (로컬 와핑 및 윤곽선 추출을 이용한 캐리커처 제작)

  • Choi, Sung-Jin;Bae, Hyeon;Kim, Sung-Shin;Woo, Kwang-Bang
    • Journal of the Korean Institute of Intelligent Systems
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    • v.13 no.4
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    • pp.403-408
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    • 2003
  • A general meaning of caricaturing is that a representation, especially pictorial or literary, in which the subject's distinctive features or peculiarities are deliberately exaggerated to produce a comic or grotesque effect. In other words, a caricature is defined as a rough sketch(dessin) which is made by detecting features from human face and exaggerating or warping those. There have been developed many methods which can make a caricature image from human face using computer. In this paper, we propose a new caricaturing system. The system uses a real-time image or supplied image as an input image and deals with it on four processing steps and then creates a caricatured image finally. The four Processing steps are like that. The first step is detecting a face from input image. The second step is extracting special coordinate values as facial geometric information. The third step is deforming the face image using local warping method and the coordinate values acquired in the second step. In fourth step, the system transforms the deformed image into the better improved edge image using a fuzzy Sobel method and then creates a caricatured image finally. In this paper , we can realize a caricaturing system which is simpler than any other exiting systems in ways that create a caricatured image and does not need complex algorithms using many image processing methods like image recognition, transformation and edge detection.

A Study on the Characteristics and Utility of Oriental Calligraphy Technique (동양적 캘리그라피 기법의 특성과 활용에 관한 연구)

  • 김병옥
    • Archives of design research
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    • v.16 no.4
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    • pp.163-172
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    • 2003
  • Nowadays calligraphy technique is widely utilized in diverse areas throughout the world. It is adopted in the visual environment of modern people comprehending from graphic design areas such as advertisement, package, symbol marks, logotypes, and movie posters to modern abstract paintings. It is because its dynamic and suggestive power of expression as symbolic and kinetic representation has been appreciated anew. In response to modern people's aversion from the mechanical and artificial digital environment as well as from the uniform, official, and modernistic trend, calligraphy technique is attracting people's attention as a new expressive style with oriental mysticism and emotional intimacy. Therefore, this study aims at illuminating the history of calligraphy, understanding its characteristics, searching for the expanded value of modern paintings and graphic designs, and ultimately contributing to the propagation of visual languages and expressive styles. In addition, this study attempted to establish the concept of Calli-Illust, which combines oriental painting techniques and materials and calligraphy techniques, and to explore for its potential uses in order to expand the area of illustration. According to the results of this study, calligraphy technique is a painting style of abstract expressionism, contributing to the expansion of the territory of a new formative area. Furthermore, this study proved that it is necessary to develop new expressive styles to overcome the limitation of design styles based on western rational, logical, and geometric functionalism, which have been received uncritically in the design environment of diversity. What is more, the concept and definition of calli-illust, which has been understood as a part of the concept of calligraphy so far, were clarified Research on calli-illust is just in its beginning stage. The present researcher expects that deeper and more extensive studies will be carried out in the future, so that calli-illust can be applied to communication design in various ways.

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A Hand Gesture Recognition System using 3D Tracking Volume Restriction Technique (3차원 추적영역 제한 기법을 이용한 손 동작 인식 시스템)

  • Kim, Kyung-Ho;Jung, Da-Un;Lee, Seok-Han;Choi, Jong-Soo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.6
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    • pp.201-211
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    • 2013
  • In this paper, we propose a hand tracking and gesture recognition system. Our system employs a depth capture device to obtain 3D geometric information of user's bare hand. In particular, we build a flexible tracking volume and restrict the hand tracking area, so that we can avoid diverse problems caused by conventional object detection/tracking systems. The proposed system computes running average of the hand position, and tracking volume is actively adjusted according to the statistical information that is computed on the basis of uncertainty of the user's hand motion in the 3D space. Once the position of user's hand is obtained, then the system attempts to detect stretched fingers to recognize finger gesture of the user's hand. In order to test the proposed framework, we built a NUI system using the proposed technique, and verified that our system presents very stable performance even in the case that multiple objects exist simultaneously in the crowded environment, as well as in the situation that the scene is occluded temporarily. We also verified that our system ensures running speed of 24-30 frames per second throughout the experiments.

A Linkage between IndoorGML and CityGML using External Reference (외부참조를 통한 IndoorGML과 CityGML의 결합)

  • Kim, Joon-Seok;Yoo, Sung-Jae;Li, Ki-Joune
    • Spatial Information Research
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    • v.22 no.1
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    • pp.65-73
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    • 2014
  • Recently indoor navigation with indoor map such as Indoor Google Maps is served. For the services, constructing indoor data are required. CityGML and IFC are widely used as standards for representing indoor data. The data models contains spatial information for the indoor visualization and analysis, but indoor navigation requires semantic and topological information like graph as well as geometry. For this reason, IndoorGML, which is a GML3 application schema and data model for representation, storage and exchange of indoor geoinformation, is under standardization of OGC. IndoorGML can directly describe geometric property and refer elements in external documents. Because a lot of data in CityGML or IFC have been constructed, a huge amount of construction time and cost for IndoorGML data will be reduced if CityGML can help generate data in IndoorGML. Thus, this paper suggest practical use of CityGML including deriving from and link to CityGML. We analyze relationships between IndoorGML and CityGML. In this paper, issues and solutions for linkage of IndoorGML and CityGML are addressed.

Interface Capturing for Immiscible Two-phase Fluid Flows by THINC Method (THINC법을 이용한 비혼합 혼상류의 경계면 추적)

  • Lee, Kwang-Ho;Kim, Kyu-Han;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.24 no.4
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    • pp.277-286
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    • 2012
  • In the numerical simulation of wave fields using a multi-phase flow model that considers simultaneous flows of materials with different states such as gas, liquid and solid, there is need of an accurate representation of the interface separating the fluids. We adopted an algebraic interface capturing method called tangent of hyperbola for interface-capturing(THINC) method for the capture of the free-surface in computations of multi-phase flow simulations instead of geometrical-type methods such a volume of fluid(VOF) method. The THINC method uses a hyperbolic tangent functions to represent the surface, and compute the numerical flux for the fluid fraction functions. One of the remarkable advantages of THINC method is its easy applicability to incorporate various numerical codes based on Navier-Stokes solver because it does not require the extra geometric reconstruction needed in most of VOF-type methods. Several tests were carried out in order to investigate the advection of interfaces and to verify the applicability of the THINC method to wave fields based on the one-field model for immiscible two-phase flows (TWOPM). The numerical results revealed that the THINC method is able to track the interface between air and water separating the fluids although its algorithm is fairly simple.