• 제목/요약/키워드: Critical collision

검색결과 119건 처리시간 0.022초

An Adaptive Fast Expansion, Loading Statistics with Dynamic Swapping Algorithm to Support Real Time Services over CATV Networks

  • Lo Chih-Chen, g;Lai Hung-Chang;Chen, Wen-Shyen E.
    • Journal of Communications and Networks
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    • 제8권4호
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    • pp.432-441
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    • 2006
  • As the community antenna television (CATV) networks becomes ubiquitous, instead of constructing an entirely new broadband network infrastructure, it has emerged as one of the rapid and economic technologies to interconnecting heterogeneous network to provide broadband access to subscribers. How to support ubiquitous real-time multimedia applications, especially in a heavy traffic environment, becomes a critical issue in modern CATV networks. In this paper, we propose a time guaranteed and efficient upstream minislots allocation algorithm for supporting quality-of-service (QoS) traffic over data over cable service interface specification (DOCSIS) CATV networks to fulfill the needs of realtime interactive services, such as video telephony, video on demand (VOD), distance learning, and so on. The proposed adaptive fast expansion algorithm and the loading statistics with dynamic swapping algorithm have been shown to perform better than that of the multimedia cable network system (MCNS) DOCSIS.

실시간 산업용 네트워크를 위한 가상 폴링 기반 이더넷 구현 (Ethernet with Virtual Polling Algorithm for real-Time Industrial Communication Network)

  • 김태준;이경창;이석
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.602-605
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    • 2001
  • This paper focus on a method to use Ethernet Network for Industrial Communication Network. Ethernet use the CSMA/CD MAC(Medium Access Control) Protocol at the Data-Link Layer, Which isn't suit for Industrial Communication Network requiring Real-Time Communication, periodic data processing, critical data processing characteristics. In this paper we proposed the Virtual Polling Algorithm at the Application Layer will be solution of using the Ethernet Network for the Industrial Communication Network, Proposed Algorithm terminate the Collision in the network thus Delay Time is reduced and Real-Time Communication will be implemented.

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크레인 구동부의 Lateral Motion에 관한 연구 (The Study on Lateral Motion of Crane Driving Mechanism)

  • 이형우;이성섭;박찬훈;박경택;이만형
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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    • pp.703-707
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    • 2000
  • This paper studied on the lateral motion of the gantry crane which is used for the automated container terminal. Though several problems are occurred in driving of gantry crane, they are solved by the motion by the operator. But, if the gantry crane is unmanned, it is automatically controlled without any human operation. Especially, the collision between wheel-flange and rail is a very critical problem in driving of unmanned gantry crane. To bring a solution to these problems, the lateral and yaw dynamic equations of the driving mechanism of gantry crane are derived. And this study used PD(Proportional-Derivative) Controller to control the lateral displacement and the yaw angle. The simulation result of the driving mechanism using the Runge-Kutta method is presented in this paper.

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천공 다층 복합 바닥재의 모델링 및 성능 평가 (Modeling and Performance Evaluation of Muti-layered Composite Floor Plates with Holes)

  • Yoo, Hong-Hee;Lee, Chang-Guen;Yoo, Hong-Geol;Ju, Young-Jun;Cho, Jung-Eun
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.367.1-367
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    • 2002
  • Recently, the noise environmental issue in compound residential areas like apartments becomes a very critical factor fer the building designers. In order to satisfy the customer need to live in a quiet environment, several interior structures for buildings are being introduced. The multi-layered composite floor plate is one of them. This structure is designed to prevent the noise generated by an object collision. (omitted)

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자유곡면 5축 NC가공에 있어서의 최적 CL data산출

  • 최병규;박정환;김화영
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 1991년도 춘계공동학술대회 발표논문 및 초록집; 전북대학교, 전주; 26-27 Apr. 1991
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    • pp.124-130
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    • 1991
  • 5-axis NC machining of sculptured surface using non-ballendmill cutters (eg. facemilling cutters) is widely used in the machining of turbine blades and marine propellers. Since there are more degrees of freedom in 5-axis machining than in 3-axis machining, generating "optimum" cutter paths and finding desirable cutter positions become very important in order for an efficient use of 5-axis NC machines. Also critical in 5-axis NC machining are collision avoidance, gouging checking, and efficient kinematic solutions. In this paper we discuss the above issues in generating 5-axis CL data. They are : kinematics modeling of NC machine; inverse kinematics solution; interference between machine component and surface; cutter gouging. A unique search method for obtaining optimal CL data is proposed. The proposed method has been successfully implemented in the machining of marine propellers on a dual 5-axis (ie, 9-axis) NC machine.C machine.

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철도 건널목사고 위험도 평가 모델 개발 (Development of Risk Assessment Models for the Level-Crossing Accidents)

  • 왕종배;박찬우;최돈범;김민수
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.1524-1530
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    • 2008
  • Generally a road vehicle's wrong entry into level crossing gives rise to hazardous events, the eventual collision with a approaching train depends on the effective operation of safety barriers such a abnormal condition detecting or emergency braking. In this paper, the risk assessment models developed for the level-crossing accidents will be introduced. The definition of hazardous events and the related hazardous factors are identified by the review of the accident history and engineering interpretation of the accident behavior. A probability of the hazardous events will be evaluated by the FTA, which is based on the accident scenario. For the severity estimation, the critical factors which can effect on the consequence will be reviewed during the ETA. Finally, the number of casualty for the public(vehicle drivers) and the train passengers are converted into an equivalent fatality.

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$CF_4$ 기체의 MCS-BEq 알고리즘에 의한 전자에너지 분포함수 (Electron Energy Distribution Function in $CF_4$ Gas used by MCS-BE Algorithm)

  • 박재세;김상남;김일남
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 학술대회 논문집 전문대학교육위원
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    • pp.102-105
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    • 2002
  • In this paper, the electron transport characteristics in $CF_4$ has been analysed over the E/N range 1${\sim}$300 [Td] by a two-term approximation Boltzmann equation method and by a Monte Carlo simulation. The motion has been calculated to give swarm parameters for the electron drift velocity, longitudinal diffusion coefficient, the ratio of the diffusion coefficient to the mobility, electron ionization and attachment coefficients, effective ionization coefficient, mean energy, collision frequency and the electron energy distribution function. The swarm parameter from the swarm study are expected to serve as a critical test of current theories of low energy electron scattering by atoms and molecules, in particular, as well as crucial information for quantitative simulations of weakly ionized plasmas.

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시뮬레이션에 의한 $CF_4$ 기체의 전자수송특성 (A Study of the Insulation Characteristic in $CF_4$ Gas)

  • 김상남;황청호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.468-469
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    • 2007
  • In this paper, the electron transport characteristics in $CF_4$ has been analysed over the E/N range 1~300[Td] by a two-tenn approximation Boltzmann equation method and by a Monte Carlo simulation. The motion has been calculated to give swarm parameters for the electron drift velocity, longitudinal diffusion coefficient, the ratio of the diffusion coefficient to the mobility, electron ionization and attachment coefficients, effective ionization coefficient, mean energy, collision frequency and the electron energy distribution function. The swarm parameter from the swarm study are expected to serve as a critical test of current theories of low energy electron scattering by atoms and molecules, in particular, as well as crucial information for quantitative simulations of weakly ionized plasmas.

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용존공기부상법(容存空氣浮上法)(DAF)에서 미세기포(微細氣泡)의 제타전위측정(電位測定) (Measuring Zetapotential of Microbubbles in DAF)

  • 독고석;한무영;박중현
    • 상하수도학회지
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    • 제12권4호
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    • pp.53-58
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    • 1998
  • Dissolved Air flotation (DAF) has become increasingly important in the field of drinking water treatment, however, the research to investigate the mechanism of collision between bubble and particle has been limited. The electrostatic repulsion forces between them are critical to collide with each other. Zetapotential of bubble and particle show their electrostatic condition. In this research, a setup to measure the zetapotential of rising microbubble is made using electrophoresis method and measured ZP of bubble in our Lab. The results show the effect of pH on zetapotential of bubble. The findings from this research are compared with other results. It will he helpful to understand and explain the mechanism of collisions between bubble and particle on different conditions of bubble charge in DAF process.

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Structural Analysis of [Cu(II)-amyloidogenic peptide] Complexes

  • Cha, Eugene;Seo, Jae-Hong;Kim, Ho-Tae
    • Mass Spectrometry Letters
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    • 제9권1호
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    • pp.17-23
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    • 2018
  • Studies on the interactions of amyloidogenic proteins with trace metals, such as copper, have indicated that the metal ions perform a critical function in the early oligomerization process. Herein, we investigate the effects of Cu(II) ions on the active sequence regions of amyloidogenic proteins using electrospray ionization mass spectrometry (ESI-MS) and collision induced dissociation tandem MS (CID-MS/MS). We chose three amyloidogenic peptides NNQQNY, LYQLEN, and VQIVYK from yeast prion like protein Sup35, insulin chain A, and tau protein, respectively. [Cu-peptide] complexes for all three peptides were observed in the mass spectra. The mass spectra also show that increasing Cu(II) concentrations decrease the population of existing peptide oligomers. The tandem mass spectrum of NNQQNY shows preferential binding for the N-terminal region. All three peptides are likely to appear to be in a Cu-monomer-monomer (Cu-M-M) structure instead of a monomer-Cu-monomer (M-Cu-M) structure.