• 제목/요약/키워드: Parallel Integration

검색결과 160건 처리시간 0.024초

Crack-contact problem for an elastic layer with rigid stamps

  • Birinci, Ahmet
    • Structural Engineering and Mechanics
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    • 제37권3호
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    • pp.285-296
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    • 2011
  • The plane crack-contact problem for an infinite elastic layer with two symmetric rectangular rigid stamps on its upper and lower surfaces is considered. The elastic layer having an internal crack parallel to its surfaces is subjected to two concentrated loads p on its upper and lower surfaces trough the rigid rectangular stamps and a pair of uniform compressive stress $p_0$ along the crack surface. It is assumed that the contact between the elastic layer and the rigid stamps is frictionless and the effect of the gravity force is neglected. The problem is reduced to a system of singular integral equations in which the derivative of the crack surface displacement and the contact pressures are unknown functions. The system of singular integral equations is solved numerically by making use of an appropriate Gauss-Chebyshev integration formula. Numerical results for stress-intensity factor, critical load factor, $\mathcal{Q}_c$, causing initial closure of the crack tip, the crack surface displacements and the contact stress distribution are presented and shown graphically for various dimensionless quantities.

동시공학적인 도면정보관리시스템 개발 (The Development of the Drawing Information Management System Based on Concurrent Engineering)

  • 문희석;김선호;신용하
    • 산업공학
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    • 제9권1호
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    • pp.41-52
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    • 1996
  • As part of effort to reduce the process time from design to manufacture and delivery, the concept of CE(concurrent engineering) has been applied to design process. In this research, the drawing information management system (DIMS) was developed based on CE. The system can distribute electronic documents of drawing or work instruction parallel to all reviewers simultaneously and collect their annotations through network. Mark-up functions are used for annotations on the electronic documents. DIMS is a system which integrates drawing management, engineering BOM, CAD and raster drawings, etc. In this system, a SUN workstation is interfaced with PCs by LAN. CIMCAD-2D, Image Hunter, and ORACLE RDBMS are used for CAD drawings, raster drawings, and drawing information management, respectively. As an integration tool for all the information, LINKAGE is adopted.

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FPGA를 이용한 레이더 신호처리 설계 (Radar Signal Processor Design Using FPGA)

  • 하창훈;권보준;이만규
    • 한국군사과학기술학회지
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    • 제20권4호
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    • pp.482-490
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    • 2017
  • The radar signal processing procedure is divided into the pre-processing such as frequency down converting, down sampling, pulse compression, and etc, and the post-processing such as doppler filtering, extracting target information, detecting, tracking, and etc. The former is generally designed using FPGA because the procedure is relatively simple even though there are large amounts of ADC data to organize very quickly. On the other hand, in general, the latter is parallel processed by multiple DSPs because of complexity, flexibility and real-time processing. This paper presents the radar signal processor design using FPGA which includes not only the pre-processing but also the post-processing such as doppler filtering, bore-sight error, NCI(Non-Coherent Integration), CFAR(Constant False Alarm Rate) and etc.

Dynamic Model of PEM Fuel Cell Using Real-time Simulation Techniques

  • Jung, Jee-Hoon;Ahmed, Shehab
    • Journal of Power Electronics
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    • 제10권6호
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    • pp.739-748
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    • 2010
  • The increased integration of fuel cells with power electronics, critical loads, and control systems has prompted recent interest in accurate electrical terminal models of the polymer electrolyte membrane (PEM) fuel cell. Advancement in computing technologies, particularly parallel computation techniques and various real-time simulation tools have allowed the prototyping of novel apparatus to be investigated in a virtual system under a wide range of realistic conditions repeatedly, safely, and economically. This paper builds upon both advancements and provides a means of optimized model construction boosting computation speeds for a fuel cell model on a real-time simulator which can be used in a power hardware-in-the-loop (PHIL) application. Significant improvement in computation time has been achieved. The effectiveness of the proposed model developed on Opal RT's RT-Lab Matlab/Simulink based real-time engineering simulator is verified using experimental results from a Ballard Nexa fuel cell system.

CFD/CSD 정밀 연계해석기법을 이용한 3차원 곡면날개의 가상 플러터 시험 (Virtual Flutter Test of Spanwise Curved Wings Using CFD/CSD Coupled Dynamic Method)

  • 김동현;오세원;김현정
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.457-464
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    • 2005
  • The coupled time-integration method with a staggered algorithm based on computational structural dynamics (CSD), finite element method (FEM) and computational fluid dynamics (CFD) has been developed in order to demonstrate physical vibration phenomena due to dynamic aeroelastic excitations. Virtual flutter tests for the spanwise curved wing model have been effectively conducted using the present advanced computational methods with high speed parallel processing technique. In addition, the present system can simultaneously give a recorded data fie to generate virtual animation for the flutter safety test. The results for virtual flutter test are compared with the experimental data of wind tunnel test. It is shown from the results that the effect of spanwise curvature have a tendency to decrease the flutter dynamic pressure for the same flight condition.

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개념적 시간관계 기반의 멀티미디어 프레젠테이션 저작 시스템 (A Multimedia Presentation Authoring System based on Conceptual Temporal Relations)

  • 노승진;장진희;성미영
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제9권3호
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    • pp.266-277
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    • 2003
  • 모든 개념적 시간관계는 7가지의 관계(‘before’,‘meets’,‘starts’,‘finishes’,‘overlaps’, ‘during’,‘equals') 중 하나로 표현될 수 있다. 개념적 표현은 멀티미디어’저작 시스템의 자동 생성에 필요한 세부적 시간에 대해 효과적인 수단을 제공한다. 본 연구에서는 서로 다른 미디어들 간의 시간관계를 개념적으로 표현하는 사용하기 쉽고 효과적인 멀티미디어 프레젠테이션 저작 시스템을 개발하였다. 본 시스템을 구성하는 시간관계 편집기는 사용자에게 다른 편집기들로부터의 시간 정보를 간단하고 직접적인 그래픽 조작을 이용하여 프레젠테이션의 개념적 흐름을 직관적으로 표현할 수 있는 메커니즘을 제공한다. 본 시스템은 SMIL(Synchronized Multimedia Integration Language)에 기반한다. 본 시스템의 편집기들은 SMIL 객체 관리자를 통해 실시간으로 정보를 서로 교환하여 SMIL 코드를 자동 생성한다. 그리고, 본 시스템에서는 멀티미디어 프레젠테이션의 내부표현 구조로 TRN(Temporal Relation Network) 을 제안한다. TRN은 프레젠테이션의 흐름을 방향 그래프 구조로 표현한 것이다. TRN의 모든 병렬관계는 하나의 동기화된 블록으로 간소화될 수 있다. 이것은 컴포넌트들 간의 재생시간을 결정하는데 유용하며, 이미 구성되어 있는 프레젠테이션 문서를 재사용 할 때 그 기본단위로 이용될 수 있다. 또한, 멀티미디어 프레젠테이션 플레이어의 스케줄러로의 응용에도 적합하다.

저속 WPAN용 비동기 OOK 방식 UWB 송수신기 성능 분석 (Performance Analysis of Noncoherent OOK UWB Transceiver for LR-WPAN)

  • 기명오;최성수;오휘명;김관호
    • 한국통신학회논문지
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    • 제30권11A호
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    • pp.1027-1034
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    • 2005
  • 수십 센터미터 이내의 오차를 만족시키는 거리/위치인식 기능 및 저속 데이터 송수신 기능 구현을 주목적으로 발족된 저속 WPAN(LR-WPAN: Low Rate Wireless Personal Area Network)의 표준화 그룹인 IEEE802.15.4a에서는 간단하고 경제적이며 전력 소모가 적은 송수신기 구조를 요구한다. 이에 본 논문에서는 PEWB(Parallel Energy Window Banks)를 이용한 독창적인 비동기 OOK(On-Off Keying) 방식 UWB(Ultra-Wide Band) 송수신기 구조를 제안한다. 또한 무선 다중경로 페이딩 채널 상황을 다소 극복할 수 있게 유연성 있는 운영이 가능한 송수신기 구조를 위해 펄스 및 비트 반복 기법을 사용한다. 제안된 송수신기 구조의 잡음 특성 분석을 위해 chi-square 분포가 적용되며, 반복적 계산을 통해 얻어진 최적임계값을 적용하며 비트오율 성능을 분석한다. 모의실험 결과, 10-5의 비트오율을 얻기 위한 신호대잡음비 및 수신에너지 적분시간은, LOS(Line-Of-Sight) 주거 환경의 경우 15.3dB, 32ns이고, NLOS(Non-Line-Of-Sight) 실외 환경의 경우 16.2dB, 72ns이다. 최소의 비트오율을 얻기 위한 적분에너지 대 전체 수신에너지 비는 약 $86\%$이다.

현대 미술에 표현된 예술의상의 상징성 연구 (Symbolism of Fashion Art in Contemporary Art)

  • 허정선;금기숙
    • 복식
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    • 제55권7호
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    • pp.156-170
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    • 2005
  • As contemporary art tends to diverge from its fixed genres and intends to appeal to the public, fashion comes to contribute to the contemporary art area, by playing an important part in the creation of artistic value of art work. Nowadays, it is not unusual to see fashion work shown in an art exhibition parallel with art work, since some artists adopt costumes as the medium of their work in order to explore various means of expression. The occurrence of philosophical, sociological theories concerning human body parallelled with the prevalence of the post-structuralist ideas and occurrence of various styles of artistic expressions of body encouraged active research and attracted social attention to body. With such background, fashion art was formed by a means of the integration of body and fashion in order to create extreme artistic expression. 1 intend to investigate a variety of trends in fashion art from the viewpoint of body space. This study developed criteria for fashion image in contemporary art. Those criteria are based on the dichotomy that divides body into inner aspects and outer aspects. According to the criteria, Firstly, the extension type of body shape includes enlargement and reduction as its sub-types. Secondly, the opening-closure type includes opening type and closure type as its sub-types. Thirdly, the intensity type categorizes clothes into uniqueness and hybridity. Dynamism type classifies fashion art into fixation and moving. The various expressions of clothes type are interpreted as a means by which we can criticize many phenomena of modern society, such as loss of humanity, isolation of individuals, loss of identity, commercialism, and materialism. In the latter period of modern society, the integration of the double-faced nature of body and spirit was attempted and popular fashion was introduced into art in order to express desire, death, gender, identity, and sexual pleasure.

Displacements, damage measures and response spectra obtained from a synthetic accelerogram processed by causal and acausal Butterworth filters

  • Gundes Bakir, Pelin;Richard, J. Vaccaro
    • Structural Engineering and Mechanics
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    • 제23권4호
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    • pp.409-430
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    • 2006
  • The aim of this study is to investigate the reliability of strong motion records processed by causal and acausal Butterworth filters in comparison to the results obtained from a synthetic accelerogram. For this purpose, the fault parallel component of the Bolu record of the Duzce earthquake is modeled with a sum of exponentially damped sinusoidal components. Noise-free velocities and displacements are then obtained by analytically integrating the synthetic acceleration model. The analytical velocity and displacement signals are used as a standard with which to judge the validity of the signals obtained by filtering with causal and acausal filters and numerically integrating the acceleration model. The results show that the acausal filters are clearly preferable to the causal filters due to the fact that the response spectra obtained from the acausal filters match the spectra obtained from the simulated accelerogram better than that obtained by causal filters. The response spectra are independent from the order of the filters and from the method of integration (whether analytical integration after a spline fit to the synthetic accelerogram or the trapezoidal rule). The response spectra are sensitive to the chosen corner frequency of both the causal and the acausal filters and also to the inclusion of the pads. Accurate prediction of the static residual displacement (SRD) is very important for structures traversing faults in the near-fault regions. The greatest adverse effect of the high pass filters is their removal of the SRD. However, the noise-free displacements obtained by double integrating the synthetic accelerogram analytically preserve the SRD. It is thus apparent that conventional high pass filters should not be used for processing near-fault strong-motion records although they can be reliably used for far-fault records if applied acausally. The ground motion parameters such as ARIAS intensity, HUSID plots, Housner spectral intensity and the duration of strong-motion are found to be insensitive to the causality of filters.

Enhanced Production of Itaconic Acid through Development of Transformed Fungal Strains of Aspergillus terreus

  • Shin, Woo-Shik;Park, Boonyoung;Lee, Dohoon;Oh, Min-Kyu;Chun, Gie-Taek;Kim, Sangyong
    • Journal of Microbiology and Biotechnology
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    • 제27권2호
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    • pp.306-315
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    • 2017
  • Metabolic engineering with a high-yielding mutant, A. terreus AN37, was performed to enhance the production of itaconic acid (IA). Reportedly, the gene cluster for IA biosynthesis is composed of four genes: reg (regulator), mtt (mitochondrial transporter), cad (cis-aconitate decarboxylase), and mfs (membrane transporter). By overexpressing each gene of the IA gene cluster in A. terreus AN37 transformed by the restriction enzyme-mediated integration method, several transformants showing high productivity of IA were successfully obtained. One of the AN37/cad transformants could produce a very high amount of IA (75 g/l) in shake-flask cultivations, showing an average of 5% higher IA titer compared with the high-yielding control strain. Notably, in the case of the mfs transformants, a maximal increase of 18.3% in IA production was observed relative to the control strain under the identical fermentation conditions. Meanwhile, the overexpression of reg and mtt genes showed no significant improvements in IA production. In summary, the overexpressed cis-aconitate decarboxylase (CAD) and putative membrane transporter (MFS) appeared to have positive influences on the enhanced IA productivity of the respective transformant. The maximal increases of 13.6~18.3% in IA productivity of the transformed strains should be noted, since the parallel mother strain used in this study is indeed a very high-performance mutant that has been obtained through intensive rational screening programs in our laboratory.