• Title/Summary/Keyword: Virtual methods

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Upper Body Surface Change Analysis using 3-D Body Scanner (3차원 인체 측정기를 이용한 체표변화 분석)

  • Lee Jeongran;Ashdoon Susan P.
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.12 s.148
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    • pp.1595-1607
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    • 2005
  • Three-dimensional(3-D) body scanners used to capture anthropometric measurements are now becoming a common research tool far apparel. This study had two goals, to test the accuracy and reliability of 3-D measurements of dynamic postures, and !o analyze the change in upper body surface measurements between the standard anthropometric position and various dynamic positions. A comparison of body surface measurements using two different measuring methods, 3-D scan measurements using virtual tools on the computer screen and traditional manual measurements for a standard anthropometric posture and for a posture with shoulder flexion were $-2\~20mm$. Girth items showed some disagreement of values between the two methods. None of the measurements were significantly different except f3r the neckbase girth for any of the measuring methods or postures. Scan measurements of the upper body items showed significant linear surface change in the dynamic postures. Shoulder length, interscye front and back, and biacromion length were the items most affected in the dynamic postures. Changes of linear body surface were very similar for the two measuring methods within the same posture. The repeatability of data taken from the 3-D scans using virtual tools showed satisfactory results. Three times repeated scan measurements f3r the scapula protraction and scapula elevation posture were proven to be statistically the same for all measurement items. Measurements from automatic measuring software that measured the 3-D scan with no manual intervention were compared with the measurements using virtual tools. Many measurements from the automatic program were larger and showed quite different values.

Digital Restoration of Traditional Architectural Buildings Using Multimedia and Augmented Reality Technologies (멀티미디어 및 증강현실 기술을 이용한 전통목조건축물 디지털 복원)

  • Lee, Kang-Hun;Cho, Sae-Hong
    • Journal of Korea Multimedia Society
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    • v.16 no.2
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    • pp.206-212
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    • 2013
  • Information and Communications Technologies(ICT) represented by Multimedia, Virtual Reality and Network could be used as the better ways to preserve and restore the original shape of cultural contents. This paper presents the detailed methods of Multimedia and Virtual Reality technologies to digitally implement the traditional wooden buildings which are called as a typical 'Korean Cultural Content." We implemented a 3D modeling of architectural parts, realized a roof curve, and texture-mapped the material qualities of traditional wooden buildings by using Graphic techniques. In addition, the information, which is implemented by marker-based Augment Reality, for the traditional wooden buildings can be obtained through the mobile appliances such as a smart phone. We, also, presented how to practically use the implemented digital Korea traditional wooden buildings.

Design and Implementation of Java Crypto Provider for Android Platform (안드로이드 플랫폼을 위한 자바 보안 프로바이더 설계 및 구현)

  • Son, Mikyung;Kang, Namhi
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.9
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    • pp.851-858
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    • 2012
  • Java crypto library such as SUN JCA/JCE or BC JCE is generally used to implement secure applications for smart devices using Android platform. Programming functions written by Java language are launched and executed inside Java Virtual Machine (JVM), thereby difficult to use system hardware specific functionalities and degrading performance as well. In case of crypto primitive, few secure applications can use crypto primitive executing in JVM because both amount of computing and complexity of such primitives are very high. From the aspect of performance, in particular, time sensitive real time applications such as streaming services or secure application frequently applying public key based crypto algorithm cannot use Java crypto library. To solve the problem, we design and implement crypto library which employ JNI and NDK methods to directly access functions that implemented by native language such as C or C++. The proposed Java Crypto provider supports faster execution. Also developer can use our provider in the same way by writing traditional Java crypto library.

Quantitative Analysis of Enlarged Cervical Lymph Nodes with Ultrasound Elastography

  • Zhang, Jun-Peng;Liu, Hua-Yan;Ning, Chun-Ping;Chong, Jing;Sun, Yong-Mei
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.16
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    • pp.7291-7294
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    • 2015
  • Purpsoe: To investigate the diagnostic value of quantitative analysis of a tissue diffusion and virtual touch tissue imaging quantification (VTIQ) technique with acoustic radiation force impulse (ARFI) elastography for assessing enlarged cervical lymph nodes. Materials and Methods: Fifty-six enlarged cervical lymph nodes confirmed by pathologic diagnoses were covered in the study. According to the results of pathologic diagnosis, patients were classified into benign and malignant groups. All the patients were examined by both conventional ultrasonography and elastography. AREA% and shear wave velocity (SWV) in ROI of different groups were calculated and compared using ROC curves. Cut-off points of AREA% and SWV were determined with receiver operating characteristic curves. Results: Final histopathological results revealed 21 cases of benign and 35 cases of malignant lymph nodes. The mean values of AREA% and SWV in benign and malignant groups were $45.0{\pm}17.9%$ and $2.32{\pm}0.57m/s$, and $61.3{\pm}21.29%$ and $4.36{\pm}1.25$)m/s, respectively. For the parameters of elastography, "AREA%" and SWV demonstrated significant differences between groups (p=0.002). AREA% was positively correlated with SWV with a correlation coefficient of 0.809 (P<0.001). Conclusions: Stiffness of different lymph node diseases in patients may differ. Elastography can evaluate changes sensitively and provide valuable information to doctors. The study proved that the VTIQ elastography technique can play an important role in differential diagnosis of lymph nodes.

Research on Design Methods about Game Contents based on Head Mounted Device(HMD) (HMD 기반 게임 콘텐츠의 기획 방법론 제안)

  • Kim, Do Hyung;Woo, Tack
    • Journal of Korea Game Society
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    • v.16 no.5
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    • pp.23-36
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    • 2016
  • The industry of virtual reality has received huge attention again after releasing the advanced Head Mounted display Devices, such as, the Oculus Rift VR, Samsung Gear VR, and PlayStation VR. However, almost VR contents studios concentrating on the only visual stimulus, before getting the diversity of genre. We found that the reasons of this phenomenon were lacking of enough time for profound studies, developments, and seeking resources. Therefore, this research suggests that the designing method about VR contents through the game resource, as a structure of story, which can handle the visual flow and the psychological commitments, to improves VR industry. Also we established the theoretical base of various VR contents planning and producing for game designers.

GEOMETRY OF SATELLITE IMAGES - CALIBRATION AND MATHEMATICAL MODELS

  • JACOBSEN KARSTEN
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.182-185
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    • 2005
  • Satellite cameras are calibrated before launch in detail and in general, but it cannot be guaranteed that the geometry is not changing during launch and caused by thermal influence of the sun in the orbit. Modem satellite imaging systems are based on CCD-line sensors. Because of the required high sampling rate the length of used CCD-lines is limited. For reaching a sufficient swath width, some CCD-lines are combined to a longer virtual CCD-line. The images generated by the individual CCD-lines do overlap slightly and so they can be shifted in x- and y-direction in relation to a chosen reference image just based on tie points. For the alignment and difference in scale, control points are required. The resulting virtual image has only negligible errors in areas with very large difference in height caused by the difference in the location of the projection centers. Color images can be related to the joint panchromatic scenes just based on tie points. Pan-sharpened images may show only small color shifts in very mountainous areas and for moving objects. The direct sensor orientation has to be calibrated based on control points. Discrepancies in horizontal shift can only be separated from attitude discrepancies with a good three-dimensional control point distribution. For such a calibration a program based on geometric reconstruction of the sensor orientation is required. The approximations by 3D-affine transformation or direct linear transformation (DL n cannot be used. These methods do have also disadvantages for standard sensor orientation. The image orientation by geometric reconstruction can be improved by self calibration with additional parameters for the analysis and compensation of remaining systematic effects for example caused by a not linear CCD-line. The determined sensor geometry can be used for the generation? of rational polynomial coefficients, describing the sensor geometry by relations of polynomials of the ground coordinates X, Y and Z.

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IMAGE FUSION ACCURACY FOR THE INTEGRATION OF DIGITAL DENTAL MODEL AND 3D CT IMAGES BY THE POINT-BASED SURFACE BEST FIT ALGORITHM (Point-based surface best fit 알고리즘을 이용한 디지털 치아 모형과 3차원 CT 영상의 중첩 정확도)

  • Kim, Bong-Chul;Lee, Chae-Eun;Park, Won-Se;Kang, Jeong-Wan;Yi, Choong-Kook;Lee, Sang-Hwy
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.5
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    • pp.555-561
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    • 2008
  • Purpose: The goal of this study was to develop a technique for creating a computerized composite maxillofacial-dental model, based on point-based surface best fit algorithm and to test its accuracy. The computerized composite maxillofacial-dental model was made by the three dimensional combination of a 3-dimensional (3D) computed tomography (CT) bone model with digital dental model. Materials and Methods: This integration procedure mainly consists of following steps : 1) a reconstruction of a virtual skull and digital dental model from CT and laser scanned dental model ; 2) an incorporation of dental model into virtual maxillofacial-dental model by point-based surface best fit algorithm; 3) an assessment of the accuracy of incorporation. To test this system, CTs and dental models from 3 volunteers with cranio-maxillofacial deformities were obtained. And the registration accuracy was determined by the root mean squared distance between the corresponding reference points in a set of 2 images. Results and Conclusions: Fusion error for the maxillofacial 3D CT model with the digital dental model ranged between 0.1 and 0.3 mm with mean of 0.2 mm. The range of errors were similar to those reported elsewhere with the fiducial markers. So this study confirmed the feasibility and accuracy of combining digital dental model and 3D CT maxillofacial model. And this technique seemed to be easier for us that its clinical applicability can good in the field of digital cranio-maxillofacial surgery.

A Novel Fast Open-loop Phase Locking Scheme Based on Synchronous Reference Frame for Three-phase Non-ideal Power Grids

  • Xiong, Liansong;Zhuo, Fang;Wang, Feng;Liu, Xiaokang;Zhu, Minghua;Yi, Hao
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1513-1525
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    • 2016
  • Rapid and accurate phase synchronization is critical for the reliable control of grid-tied inverters. However, the commonly used software phase-locked loop methods do not always satisfy the need for high-speed and accurate phase synchronization under severe grid imbalance conditions. To address this problem, this study develops a novel open-loop phase locking scheme based on a synchronous reference frame. The proposed scheme is characterized by remarkable response speed, high accuracy, and easy implementation. It comprises three functional cascaded blocks: fast orthogonal signal generation block, fast fundamental-frequency positive sequence component construction block, and fast phase calculation block. The developed virtual orthogonal signal generation method in the first block, which is characterized by noise immunity and high accuracy, can effectively avoid approximation errors and noise amplification in a wide range of sampling frequencies. In the second block, which is the foundation for achieving fast phase synchronization within 3 ms, the fundamental-frequency positive sequence components of unsymmetrical grid voltages can be achieved with the developed orthogonal signal construction strategy and the symmetrical component method. The real-time grid phase can be consequently obtained in the third block, which is free from self-tuning closed-loop control and thus improves the dynamic performance of the proposed scheme. The proposed scheme is adaptive to severe unsymmetrical grid voltages with sudden changes in magnitude, phase, and/or frequency. Moreover, this scheme is able to eliminate phase errors induced by harmonics and random noise. The validity and utility of the proposed scheme are verified by the experimental results.

An XML Schema Manager based on the User-defined XML View (사용자 정의 XML 뷰 기반의 XML 스키마 관리 시스템)

  • Jung, Chai-Young;Kim, Young-Ok;Lee, Mi-Young;Kang, Hyun-Syug;Bae, Jong-Min
    • The KIPS Transactions:PartD
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    • v.10D no.3
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    • pp.367-374
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    • 2003
  • A mediator-wrapper system, which is one of integration methods of heterogeneous databases, preserves a virtual integrated view rather than physical movement of the contents of each database. In order for a mediator to preserve a virtual integrated view, it requires the schema manager of the wrapper which communicates with local databases. This paper presents a schema manager of a wrapper that provides a mediator with XML schema which is generated from relational database schema. The XML schema manager supports a user-defined XML view. We present the view tree model which is used for materializing the use-defined XML view to generate XML schema, and the conversion algorithm based on the proposed view tree model. This model is can be uniformly applied to all schema managers of heterogeneous information sources.

Privacy Data Protection Methods on Smartphone Using A Virtual Disk Platform (스마트폰에서 가상 디스크 플랫폼을 사용한 프라이버시 데이터 보호 방안)

  • Shin, Suk-Jo;Kim, Seon-Joo;Jo, In-June
    • The Journal of the Korea Contents Association
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    • v.13 no.12
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    • pp.560-567
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    • 2013
  • The release of iPhone by Apple in 2009 has changed the life pattern of an individual tremendously. That is, with the emergence of a smart phone, various services including voice/video call, camera, receiving and sending of e-mail, and web browsing have been realized. However, the broader the scope of the use of a smart phone has become, the greater the need for companies to introduce an MDM solution for protecting important documents has become. However the MDM solution may have a problem in that all data such as contacts, pictures, and memos saved in the smart phone can be accessed unlimitedly. For this reason, there is a risk that unwanted violation of privacy may happen to smart phone users. This paper proposed a plan to protect a personal privacy file of smart phone users, which disables access by others except for related smart phone users by enabling a person in charge of security or an MDM manager in a company to have access only to the file which was allowed by smart phone users to be disclosed and by saving non-disclosed files in a virtual disk.