• Title/Summary/Keyword: state-dependent delay

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Performance Analysis of a Dynamic Priority Control Scheme for Delay-Sensitive Traffic (음성 트래픽을 위한 동적우선권제어방식의 성능분석)

  • 김도규;김용규;조석팔
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.8
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    • pp.3-11
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    • 2000
  • This paper considers the performance of a dynamic priority control function (DPCF) of a threshold-based Bernoulli priority jump (TBPJ) scheme. Loss-sensitive and delay-sensitive traffics are applied to a system with a TBPJ scheme that is a general state-dependent Bernoulli scheduling scheme. Loss-sensitive and delay-sensitive traffics represent sound and data, respectively. Under the TBPJ scheme, the first packet of the loss-sensitive traffic buffer goes into the delay-sensitive traffic buffer with Bernoulli probability p according to system states which represent the buffer thresholds and the number of packets waiting for scheduling. Performance analysis shows that TBPJ scheme obtains large performance build-up for the delay-sensitive traffic without performance degradation for the loss-sensitive traffic. TBPJ scheme shows also better performance than that of HOL scheme.

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A generalized disturbance observer theory and application to control of the GoldStar DD robot arm

  • Koh, Kwang-Ill;Lim, Kye-Young;Kang, Sung-Soo;Chae, Ho-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10b
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    • pp.878-883
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    • 1990
  • There have been many approaches to solve the disturbance rejection problem in the control of LTI systems with state independent disturbances or possibly nonlinear state dependent disturbances. From the view point of each actuator, robot manipulators can be modeled as the second class of systems. With this model, M.Nakao et al. [1] introduced a decentralized control scheme based on interference estimation which is simple in its implementation and robust to the coupled dynamics and parameter variations. This paper systematically generalizes the control scheme to arbitrary finite dimensional LTI systems with disturbances. In doing so, we develop a disturbance observer theory for solving the disturbance rejection problem. We also present a discrete version of the theory with discussion of sampling and time-delay effects.

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Cognitive Function in Non-Insulin Dependent Diabetic Patients (인슐린 비의존성 당뇨병 환자의 인지기능)

  • Jung, Mi-Ha;So, Hee-Young
    • The Korean Journal of Rehabilitation Nursing
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    • v.8 no.1
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    • pp.38-49
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    • 2005
  • Purpose: The purpose of this study was to examine the cognitive function in NIDDM patients. Method: The data were collected at MI OPD in C University hospital. with Digit Span Forward & Backward, Trail Making Test-A, Trail Making Test-B, and MMSE. Result: There were significant differences in DF, DB, TMT-A, and TMT-B according to gender, and in TMT-A according to living with spouse and comorbidity. There were significant differences in DF, DB, TMT-A, TMT-B, and MMSE according to monthly income, and in DF, TMT-A, and TMT-B according to hypertensive state. But, there was no difference in cognitive function score according to diabetes-related complication and diabetes treatment modality. There was a significant positive correlation between duration of NIDDM and TMT-A(r=.215, p=.025). The global cognition score was explained 42.1% of varient by age, duration of education, monthly income, and hypertensive state. Conclusion: As above results showed, among age, duration of education, monthly income, and hypertensive state, prevented and managed hypertensive state which is modifiable factor may reduce or delay cognitive function impairment in NIDDM patients. And DF & DB, TMT-A & B could be more utilized as useful cognitive function measurements because those tests reflected cognitive function in NIDDM patients better than MMSE.

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Real-time hybrid simulation of a multi-story wood shear wall with first-story experimental substructure incorporating a rate-dependent seismic energy dissipation device

  • Shao, Xiaoyun;van de Lindt, John;Bahmani, Pouria;Pang, Weichiang;Ziaei, Ershad;Symans, Michael;Tian, Jingjing;Dao, Thang
    • Smart Structures and Systems
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    • v.14 no.6
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    • pp.1031-1054
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    • 2014
  • Real-time hybrid simulation (RTHS) of a stacked wood shear wall retrofitted with a rate-dependent seismic energy dissipation device (viscous damper) was conducted at the newly constructed Structural Engineering Laboratory at the University of Alabama. This paper describes the implementation process of the RTHS focusing on the controller scheme development. An incremental approach was adopted starting from a controller for the conventional slow pseudodynamic hybrid simulation and evolving to the one applicable for RTHS. Both benchmark-scale and full-scale tests are discussed to provide a roadmap for future RTHS implementation at different laboratories and/or on different structural systems. The developed RTHS controller was applied to study the effect of a rate-dependent energy dissipation device on the seismic performance of a multi-story wood shear wall system. The test specimen, setup, program and results are presented with emphasis given to inter-story drift response. At 100% DBE the RTHS showed that the multi-story shear wall with the damper had 32% less inter-story drift and was noticeably less damaged than its un-damped specimen counterpart.

Performance Analysis of Threshold-based Bernoulli Priority Jump Traffic Control Scheme (동적우선권제어함수 기반 TBPJ 트래픽 제어방식의 성능분석)

  • Kim, Do-Kyu
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.11S
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    • pp.3684-3693
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    • 2000
  • In this paper, performance of a nonblocking high speed packet switch with switching capacity m which adopts a dynamic priority control function (DPCF) of a threshold- based Bernoulli priority jump (TBPJ) scheme is considered. Each input queue has two separate buffers with different sizes for two classes of traffics, delay-sensitive and loss-sensitive traffics, and adopts a TBPJ scheme that is a general state-dependent Bernoulli scheduling scheme. Under the TBP] scheme, a head packet of the delay-sensitive traffic buffer goes into the loss -sensitive traffic buffer with Hernoulli probability p according to systems states that represent the buffer thresholds and the number of packets waiting for scheduling. Performance analysis shows that TBPJ scheme obtains large performance build-up for the delay-sensitive traffic without performance degradation for the loss-sensitive traffic. In addition to, TBP] scheme shows better performance than that of HOL scheme.

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A Study on the Bandwidth Assignment Scheme for Video Data Using Dynamic Parameters in the Wireless ATM Networks (무선 ATM망에서 동적 변수를 이용한 비디오 데이터의 대역폭 할당방식에 대한 연구)

  • Jang, Dong-Hyeok;Kim, Seung-Hwan;Lee, Sun-Sook;Kwon, Oh-Seok
    • The KIPS Transactions:PartC
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    • v.9C no.1
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    • pp.73-78
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    • 2002
  • In WATM networks, in order to perform dynamic slot allocation required slots of mobile terminals are estimated based on DP (Dynamic Parameter) reflecting characteristics of traffic. In VBR (Variable Bit Rate) traffic, slot allocation is done at MT considering both time-dependent characteristics and QoS (Quality of Service) requirements. In this paper, DPs-buffer state information and buffer state change-are transmitted through in-band signaling. BS (Base Station) performs dynamic slot allocation considering traffic characteristics of each MT (Mobile Terminal), in other words, buffer state information informs the potentiality of 'buffer full state'to BS if MT buffer is over the specific threshold value and buffer state change notifies change in buffer state of incoming cells to MT. If buffer state information is equal to 'low (more than threshold)' and 'abrupt increase' it generates 'buffer full' state cell transmission delay or cell loss might occur. At this time BS should assign additional slots to MT, and then MT consumes cells in its buffer. In simulation, the proposed scheme shows better performance in cell delay and loss than EPSA (Estimation-Prorated Slot Assignment) in-band scheme.

Fuzzy Controller for Intelligent Networked Control System with Neutral Type of Time-delay (뉴트럴 타입 시간 지연을 갖는 지능형 네트워크 제어 시스템의 퍼지 제어기 설계)

  • Joo, Young-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.2
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    • pp.174-179
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    • 2009
  • We consider the stabilization problem for a class of networked control systems with neutral type of time delays. The neutral type of time-delays occur in controller-to-actuator and sensor-to-controller. The Takagi-Sugeno (T-S) fuzzy model is employed to represent a nonlinear system with neutral type of time-delays. The stabilization via state-feedback is first addressed, and delay-range-dependent stabilization conditions are proposed in terms of linear matrix inequalities (LMIs). Finally, an application example will be given to show the merits and design a procedure of the proposed approach.

Topology Graph Generation Based on Link Lifetime in OLSR (링크 유효시간에 따른 OLSR 토폴로지 그래프 생성 방법)

  • Kim, Beom-Su;Roh, BongSoo;Kim, Ki-Il
    • IEMEK Journal of Embedded Systems and Applications
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    • v.14 no.4
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    • pp.219-226
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    • 2019
  • One of the most widely studied protocols for tactical ad-hoc networks is Optimized Link State Routing Protocol (OLSR). As for OLSR research, most research work focus on reducing control traffic overhead and choosing relay point. In addition, because OLSR is mostly dependent on link detection and propagation, dynamic Hello timer become research challenges. However, different timer interval causes imbalance of link validity time by affecting link lifetime. To solve this problem, we propose a weighted topology graph model for constructing a robust network topology based on the link validity time. In order to calculate the link validity time, we use control message timer, which is set for each node. The simulation results show that the proposed mechanism is able to achieve high end-to-end reliability and low end-to-end delay in small networks.

The Regulation of LexA on UV-Induced SOS Response in Myxococcus xanthus Based on Transcriptome Analysis

  • Sheng, Duo-hong;Wang, Ye;Wu, Shu-ge;Duan, Rui-qin;Li, Yue-zhong
    • Journal of Microbiology and Biotechnology
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    • v.31 no.7
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    • pp.912-920
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    • 2021
  • SOS response is a conserved response to DNA damage in prokaryotes and is negatively regulated by LexA protein, which recognizes specifically an "SOS-box" motif present in the promoter region of SOS genes. Myxococcus xanthus DK1622 possesses a lexA gene, and while the deletion of lexA had no significant effect on either bacterial morphology, UV-C resistance, or sporulation, it did delay growth. UV-C radiation resulted in 651 upregulated genes in M. xanthus, including the typical SOS genes lexA, recA, uvrA, recN and so on, mostly enriched in the pathways of DNA replication and repair, secondary metabolism, and signal transduction. The UV-irradiated lexA mutant also showed the induced expression of SOS genes and these SOS genes enriched into a similar pathway profile to that of wild-type strain. Without irradiation treatment, the absence of LexA enhanced the expression of 122 genes that were not enriched in any pathway. Further analysis of the promoter sequence revealed that in the 122 genes, only the promoters of recA2, lexA and an operon composed of three genes (pafB, pafC and cyaA) had SOS box sequence to which the LexA protein is bound directly. These results update our current understanding of SOS response in M. xanthus and show that UV induces more genes involved in secondary metabolism and signal transduction in addition to DNA replication and repair; and while the canonical LexA-dependent regulation on SOS response has shrunk, only 5 SOS genes are directly repressed by LexA.

Nonlinear fluid-structure interaction of bridge deck: CFD analysis and semi-analytical modeling

  • Grinderslev, Christian;Lubek, Mikkel;Zhang, Zili
    • Wind and Structures
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    • v.27 no.6
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    • pp.381-397
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    • 2018
  • Nonlinear behavior in fluid-structure interaction (FSI) of bridge decks becomes increasingly significant for modern bridges with increasing spans, larger flexibility and new aerodynamic deck configurations. Better understanding of the nonlinear aeroelasticity of bridge decks and further development of reduced-order nonlinear models for the aeroelastic forces become necessary. In this paper, the amplitude-dependent and neutral angle dependent nonlinearities of the motion-induced loads are further highlighted by series of computational fluid dynamics (CFD) simulations. An effort has been made to investigate a semi-analytical time-domain model of the nonlinear motion induced loads on the deck, which enables nonlinear time domain simulations of the aeroelastic responses of the bridge deck. First, the computational schemes used here are validated through theoretically well-known cases. Then, static aerodynamic coefficients of the Great Belt East Bridge (GBEB) cross section are evaluated at various angles of attack, leading to the so-called nonlinear backbone curves. Flutter derivatives of the bridge are identified by CFD simulations using forced harmonic motion of the cross-section with various frequencies. By varying the amplitude of the forced motion, it is observed that the identified flutter derivatives are amplitude-dependent, especially for $A^*_2$ and $H^*_2$ parameters. Another nonlinear feature is observed from the change of hysteresis loop (between angle of attack and lift/moment) when the neutral angles of the cross-section are changed. Based on the CFD results, a semi-analytical time-domain model for describing the nonlinear motion-induced loads is proposed and calibrated. This model is based on accounting for the delay effect with respect to the nonlinear backbone curve and is established in the state-space form. Reasonable agreement between the results from the semi-analytical model and CFD demonstrates the potential application of the proposed model for nonlinear aeroelastic analysis of bridge decks.