• Title/Summary/Keyword: Dynamic US

검색결과 453건 처리시간 0.028초

Effects of the geometrical parameters of the core on the mechanical behavior of sandwich honeycomb panel

  • Ahmed, Settet T.;Aguib, Salah;Toufik, Djedid;Noureddine, Chikh;Ahmed, Chellil
    • Coupled systems mechanics
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    • 제8권6호
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    • pp.473-488
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    • 2019
  • The present work is the study of mechanical behavior due to variation of the geometrical parameters in the core of the sandwich honeycomb panel. This study has allowed us to increase or decrease the strains and stresses of the panel, in changing the angle of alveolus, as explained and described below. In taking into consideration the results obtained previously to improve the mechanical properties and increase the adhesion of different parts of the panel, without changing the adhesive, we have conceived two new models, in increasing the contact surfaces in boundary of each part of the panel and giving a conical hexagonal shape in his corp.

동적 형상조정 프레임워크의 모델링 및 구현 (Modeling and Implementation of A Dynamic Reconfiguration Framework)

  • 윤태웅;민덕기
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 2003년도 춘계학술대회논문집
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    • pp.115-119
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    • 2003
  • It requires a great deal of efforts to maintain a distributed system. What is important here is that we should be able to upgrade/maintain a distributed system without stopping the system in operation. For this, what we need is a dynamic reconfigurable framework for highly available distributed systems. In this paper, we propose objects-hot-swapping methods as a solution to our problem. These methods permit us to dynamically upgrade/expand a system without stopping the system in operation. In addition, we analyze these methods and show that an approach based on proxy is the most efficient. Furthermore, we propose two proxy-based approaches: the first one based on the static proxy provides for a fast execution time but it is difficult to implement. The second one based on the dynamic proxy provides for a slow execution time but it is easier to implement. Finally, we propose a hot swapping framework for these static and dynamic proxy.

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상시 계측결과를 이용한 경부고속철도 교량의 동적거동 분석 (A analysis on dyanmic movements of Bridge status using High Rail monitoring systems)

  • 정재민;한상철;최일윤;이준석;서형렬
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.934-939
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    • 2004
  • The Korea high-speed rail, based on the French design. It also implements new concept to increase the strength of bridge deck by adding an impact factor (dynamic intensity factor) in static load. In order to assure the dynamic stability, SYSTRA and Jeseph Penzien, a professor in CEC (the US) conducted a dynamic stability review on design phase. Analyzing the review results, they developed design criteria for dynamic behavior. This study deal with operating PSC box GIRDER equipped with measurement equipment or measured data of Seoul $\∼$ Taejeon, P.S.C BOX GIRDER bridge and steel comsition bridge equipped with measurement equipment based on structual knowledge about configuration of measuring sensor, response analysis of structure when train runs was performed by using measured data of PSC box girder to directly compare with design criteria. moreover, the dynamic stability with comparison of high-speed rail construction criteria was reviewed and analyzed based on historical records.

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의사 결정 구조에 의한 오존 농도예측 (Forecasting Ozone Concentration with Decision Support System)

  • 김재용;김태헌;김성신;이종범;김신도;김용국
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.368-368
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    • 2000
  • In this paper, we present forecasting ozone concentration with decision support system. Since the mechanism of ozone concentration is highly complex, nonlinear, and nonstationary, modeling of ozone prediction system has many problems and results of prediction are not good performance so far. Forecasting ozone concentration with decision support system is acquired to information from human knowledge and experiment data. Fuzzy clustering method uses the acquisition and dynamic polynomial neural network gives us a good performance for ozone prediction with ability of superior data approximation and self-organization.

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능동적 점성감쇠를 이용한 차량용 동적 흡진기의 모델링과 제어에 관한 연구 (A Study about Modeling and Control of Dynamic Absorber for Vehicle by Using Active Viscous Damping)

  • 김대원;배준영
    • 소음진동
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    • 제9권1호
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    • pp.121-130
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    • 1999
  • Generally, A Dynamic Absorber by using Active viscous Damping is highlighted for effective suspension system, such as improved ride comfort and handling in the market. Lately, this system based on the Sky-Hook damper theory is introduced by the name of "Active Dynamic Absorber" to us. This system has an excellent performance in contrast to Passive. Adaptive Dynamic Absorber, besides having low cost components of system, low energy consumption. light weight of system. In this viewpoint. most of car-maker will adopt this system in the near future. For this reason, we developed Dynamic Absorber by using Active viscous Damping which is equipped with continuously variable Dynamic Absorber and Control logic consisting Filter and Estimator. control apparatus of Dynamic Absorber operated by 16-bit microprocessor of high performance. variable device of viscous Damping. G-sensor so on. In this paper. several important points of development procedure for realizing this system will be described with results in which is obtained from experiment by simulation and Full car test in Proving ground. respectively.pectively.

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Practical and Verifiable C++ Dynamic Cast for Hard Real-Time Systems

  • Dechev, Damian;Mahapatra, Rabi;Stroustrup, Bjarne
    • Journal of Computing Science and Engineering
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    • 제2권4호
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    • pp.375-393
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    • 2008
  • The dynamic cast operation allows flexibility in the design and use of data management facilities in object-oriented programs. Dynamic cast has an important role in the implementation of the Data Management Services (DMS) of the Mission Data System Project (MDS), the Jet Propulsion Laboratory's experimental work for providing a state-based and goal-oriented unified architecture for testing and development of mission software. DMS is responsible for the storage and transport of control and scientific data in a remote autonomous spacecraft. Like similar operators in other languages, the C++ dynamic cast operator does not provide the timing guarantees needed for hard real-time embedded systems. In a recent study, Gibbs and Stroustrup (G&S) devised a dynamic cast implementation strategy that guarantees fast constant-time performance. This paper presents the definition and application of a cosimulation framework to formally verify and evaluate the G&S fast dynamic casting scheme and its applicability in the Mission Data System DMS application. We describe the systematic process of model-based simulation and analysis that has led to performance improvement of the G&S algorithm's heuristics by about a factor of 2. In this work we introduce and apply a library for extracting semantic information from C++ source code that helps us deliver a practical and verifiable implementation of the fast dynamic casting algorithm.

Study of Dynamic Polling in the IEEE 802.11 PCF

  • Kim, Che-Soong;Lyakhov, Andrey
    • 대한산업공학회지
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    • 제34권2호
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    • pp.140-150
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    • 2008
  • Point Coordination Function (PCF) of the IEEE 802.11 protocol providing a centrally-controlled polling-based multiple access to a wireless channel is very efficient in high load conditions. However, its performance degrades with increasing the number of terminals and decreasing the load, because of wastes related to unsuccessful polling attempts. To solve the problem, we propose and study analytically the generic dynamic polling policy using backoff concept. For this aim, we develop Markov models describing the network queues changes, what allows us to estimate such performance measures as the average MAC service time and the average MAC sojourn time, to show the dynamic polling efficiency and to tune optimally the backoff rule.

공작기계 구조물의 System Identification에 관한 연구

  • 하병한;노승훈;정성환;김교형
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1992년도 춘계학술대회 논문집
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    • pp.323-328
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    • 1992
  • The vibrations of the main spindles of the M/C tools is the most important in the con- sideration of the dynamic performance of the M/C tools. In order to analyze and predict the dynamic behaviour of the machine tool structure it is necessary to have the mathematical model of the system. The system identification is the procedure to provide us with the mathematical model of the system of which we want to know the dynamic characteristics. This study illustrates a procedure of the system identification of the structure of the M/C tools to predict the dynamic behaviour of the machine and further to have the basis for the design of M/C tools.

전산모델을 이용한 에스컬레이터의 동특성 해석 (Dynamic Characteristics Analysis of an Escalator Using a Computer Model)

  • 박찬종;권이석;박태원
    • 한국정밀공학회지
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    • 제16권4호통권97호
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    • pp.95-101
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    • 1999
  • In this paper, we propose a dynamic model of an escalator which can be used to build a design database. The model permits to estimate the forces applied to the structure by calculating three primary types of forces; the torque required to operate the escalator, the reaction forces at part interconnection points, and contact forces between parts. These forces can then be used to calculate dynamic stresses in the structure which is required to estimate the durability of the structure. Result of the computer model are compared with testing results. This simulation model is used to construct a design database. So when we design a new escalator, this design database can be used to make a new simulation model which makes it possible for us to do a Knowledge-Based-Design.

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발전소 시뮬레이터의 다이나믹 모델과 디스플레이 모델간 데이터전송 (Data Transporting between Dynamic Model and Display Model of Power Plant Simulator)

  • 김동욱
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 1998년도 The Korea Society for Simulation 98 춘계학술대회 논문집
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    • pp.86-90
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    • 1998
  • The safety and reliability of nuclear power plant operations relies heavily on the plant operators ability to respond to various emergency situations. It has become standard industry practice to utilize simulators to improve the safety and reliability of nuclear power plants operations. The simulators built for Younggwang#3,4, which is the basic model of the Korean Nuclear Power Plant design, has been developed precisely for this purpose. Dynamic Model and Display Model are developed under US3(UNIX Simulation Software Support System) environment in simulator for Younggwang#3,4. Since these two models are developed under each own operating system, it is necessary to develop a method for transporting data between these two systems. This paper descirves communication environment between Dynamic Model and Display Model, and addresses a file generation method for the Display Model, which will be necessary for designing MMI of MCR(Main Control Room) in the furture.

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