• Title/Summary/Keyword: Performance state

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Performance-based remaining life assessment of reinforced concrete bridge girders

  • Anoop, M.B.;Rao, K. Balaji;Raghuprasad, B.K.
    • Computers and Concrete
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    • v.18 no.1
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    • pp.69-97
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    • 2016
  • Performance-based remaining life assessment of reinforced concrete bridge girders, subject to chloride-induced corrosion of reinforcement, is addressed in this paper. Towards this, a methodology that takes into consideration the human judgmental aspects in expert decision making regarding condition state assessment is proposed. The condition of the bridge girder is specified by the assignment of a condition state from a set of predefined condition states, considering both serviceability- and ultimate- limit states, and, the performance of the bridge girder is described using performability measure. A non-homogeneous Markov chain is used for modelling the stochastic evolution of condition state of the bridge girder with time. The thinking process of the expert in condition state assessment is modelled within a probabilistic framework using Brunswikian theory and probabilistic mental models. The remaining life is determined as the time over which the performance of the girder is above the required performance level. The usefulness of the methodology is illustrated through the remaining life assessment of a reinforced concrete T-beam bridge girder.

The Effect of Green Innovation on Corporate ESG Performance: Evidence from Chinese Listed Enterprises

  • Xu, Jingshi;Li, Xue;Choe, Soonkyoo
    • Asia-Pacific Journal of Business
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    • v.13 no.1
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    • pp.1-17
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    • 2022
  • Purpose - This study was aimed to investigate whether the outcomes of green innovation brought positive effects to Chinese firms' ESG performance. Design/methodology/approach - Green innovation patents and ESG performance data of Chinese listed firms were empirically analyzed using panel data fix-effect linear estimations. Findings - The study found that green innovation performance enhanced Chinese firms' ESG performance. Also, the results showed that corporate social responsibility decoupling weakened this relationship and state ownership positively moderated this relationship, whereas corporate philanthropic giving did not have significant impact. Research implications or Originality - The findings indicated that green innovation was beneficial to enhancing corporate sustainability performance. In addition, the study highlighted the role of CSR communications and state ownership in interacting the positive effect that green innovation performance brings to corporate ESG performance.

Performance Analysis of the state model based optimal FIR filter (STATE MODEL BASED OPTIMAL FIR 필터의 성능분석)

  • Lee, Kyu-Seung;Kwon, Wook-Hyun
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.917-920
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    • 1988
  • The effects of the errors due to incorrect a priori informations on the noise model as well as the system model in the continuous state model based optimal FIR filter is considered. When the optimal filter is perturbed, the error covariance is derived. From this equation, the performance of the state model based optimal FIR filter is analyzed for the given modeling error. Also the state model based optimal FIR filter is compared to the standard Kalman filter by an example.

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Crosstalk evaluation in multiview autostereoscopic three-dimensional displays with an optimized diaphragm applied

  • Peng, Yi-Fan;Li, Hai-Feng;Zheng, Zhen-Rong;Xia, Xin-Xing;Yao, Zhi;Liu, Xu
    • Journal of Information Display
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    • v.13 no.2
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    • pp.83-89
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    • 2012
  • The crosstalk evaluation of multiview autostereoscopic three-dimensional (3D) displays is discussed, with both the human and technical factors investigated via image quality assessment. In the imaging performance measurements and analysis for a multiview autostereoscopic display prototype equipment, it was inferred that crosstalk would have both a positive and a negative effect on the imaging performance of the equipment. The importance of the attached diaphragm in the crosstalk evaluation was proposed and then experimentally verified, using the developed prototype equipment. The luminance distribution and crosstalk situation were given, with two different diaphragm arrays applied. The analysis results showed that the imaging performance of this 3D display system can be improved with minimum changes to the system structure.

A study on the Performance Improvement of Position Controller in DC Servo Motor System (직류서보전동기 위치제어기의 성능향상에 관한 연구)

  • Yoo, Jong-Gul;Lee, Kee-Sang;Hong, Soon-Chan
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.555-558
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    • 1991
  • The IESF(Integral Error and State Feedback) controller, which incorporates state feedback as a modern control scheme and integral action as a classical control scheme, has better performance than that of the conventional PID controller in linear time-invariant systems. The IESF controller requires the measurement of all the state variables. But, unfortunately, it may be difficult or impossible to measure all state variables in many applications. And the IESF controller is applicable only to pole-assignable linear time-invariant system without time delay. In this paper, new IESF controller structure was proposed which performs feedback with only measurable state variables. In order to estimate the unmeasurable state variables. It was adopted the filter mode by full-order obserber. The good performance and effectiveness of the proposed controller was confirmed by computer simulation.

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Gain Scheduled State Feedback and Disturbance Feedforward Control for Systems with Bounded Control Input (제어입력 크기제한을 갖는 시스템에서 이득 스케쥴 상태되먹임-외란앞먹임 제어)

  • Kang, Min-Sig
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.915-920
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    • 2007
  • A new optimal state feedback and disturbance feedforward control design in the sense of minimizing $L_{2}-gain$ from disturbance to control output is proposed for disturbance attenuation of systems with bounded control input and measurable disturbance. The controller is derived in the framework of linear matrix inequality(LMI) optimization. A gain scheduled state feedback and disturbance feedforward control design is also suggested to improve disturbance attenuation performance. The control gains are scheduled according to the proximity to the origin of the state of the plant and the magnitude of disturbance. This procedure yields a stable linear time varying control structure that allows higher gain and hence higher performance controller as the state and the disturbance move closer to the origin. The main results give sufficient conditions for the satisfaction of a parameter-dependent performance measure, without violating the bounded control input condition.

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Gain Scheduled State Feedback and Disturbance Feedforward Control for Systems with Bounded Control Input - Theory (제어입력 크기제한을 갖는 시스템에서 이득 스케줄 상태되먹임-외란앞먹임 제어 - 이론)

  • Kang, Min-Sig
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.11
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    • pp.59-65
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    • 2007
  • A new optimal state feedback and disturbance feedforward control design in the sense of minimizing $L_2$-gain from disturbance to control output is proposed for disturbance attenuation of systems with bounded control input and measurable disturbance. The controller is derived in the framework of linear matrix inequality(LMI) optimization. A gain scheduled state feedback and disturbance feedforward control design is also suggested to improve disturbance attenuation performance. The control gains are scheduled according to the proximity to the origin of the state of the plant and the magnitude of disturbance. This procedure yields a stable linear time varying control structure that allows higher gain and hence higher performance controller as the state and the disturbance move closer to the origin. The main results give sufficient conditions for the satisfaction of a parameter-dependent performance measure, without violating the bounded control input condition.

A study on the steady-state and dynamic performance of polymer electrolyte fuel cells under various external humidification conditions (고분자 전해질 연료전지의 외부가습 조건에 따른 정상상태 및 비정상상태 성능특성 연구)

  • Lee, Yong-Taek;Kim, Bo-Sung;Kim, Yong-Chan;Choi, Jong-Min;Ko, Jang-Myoun
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.3407-3412
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    • 2007
  • The performance characteristics of the polymer electrolyte fuel cells (PEFCs) were investigated under various humidification conditions at steady-state and transient conditions. The PEFC studied in this study was characterized by I-V curves in potentiostatic mode. The I-V curves representing steady-state performance were obtained from OCV to 0.25V, and the dynamic performance responses were obtained at some points of voltages. The anodic external humidification was applied and the humidity was controlled from 20% to 100%. The effects of relative humidity of hydrogen were measured with the dry air at the cathode. At high voltage region, the performance at high temperature was higher, but at low voltage region, low temperature condition showed the higher performance. The dynamic responses were observed at the instant when the voltage of the PEFC was changed. It was observed that the performance reached steady-state earlier with the increase of temperature.

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Listed Local State-Owned Enterprises and Environmental Performance: Evidence from China

  • TANG, Kai;BAE, Khee Su
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.255-262
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    • 2021
  • The paper examines the influence of ownership type on environmental performance of Chinese listed enterprises. China's environmental problems are attributed to the collusion between enterprises and economy-oriented local governments, which has allowed many companies to skirt environmental regulations. Especially, local state-owned enterprises (SOEs) tend to have worse environmental performance than private firms, under the wing of local governments, with whom they have a closer political connection. According to the report of the Environmental Protection Agency, currently the unacceptably poor environmental performance of local SOEs has severely hampered the realization of green economy in China. After examining the dataset of 15,996 firm-year observations from 2,688 listed firms, this paper found that, in the presence of central government supervision and personnel intervention, listed local SOEs will be forced to improve their environmental performance in accordance with standards set by the central government, which leads to better environmental performance than that of listed private firms (private firms). The result of two-stage regression also supports the conclusion. This shows increased supervision and personnel intervention from the central government can significantly improve the environmental performance of local SOEs. The research in this paper expects to make a contribution to attaining the goal of green economy in China.

Enhanced deep soft interference cancellation for multiuser symbol detection

  • Jihyung Kim;Junghyun Kim;Moon-Sik Lee
    • ETRI Journal
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    • v.45 no.6
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    • pp.929-938
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    • 2023
  • The detection of all the symbols transmitted simultaneously in multiuser systems using limited wireless resources is challenging. Traditional model-based methods show high performance with perfect channel state information (CSI); however, severe performance degradation will occur if perfect CSI cannot be acquired. In contrast, data-driven methods perform slightly worse than model-based methods in terms of symbol error ratio performance in perfect CSI states; however, they are also able to overcome extreme performance degradation in imperfect CSI states. This study proposes a novel deep learning-based method by improving a state-of-the-art data-driven technique called deep soft interference cancellation (DSIC). The enhanced DSIC (EDSIC) method detects multiuser symbols in a fully sequential manner and uses an efficient neural network structure to ensure high performance. Additionally, error-propagation mitigation techniques are used to ensure robustness against channel uncertainty. The EDSIC guarantees a performance that is very close to the optimal performance of the existing model-based methods in perfect CSI environments and the best performance in imperfect CSI environments.