• 한국자동차공학회논문집
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• 제12권3호
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• pp.170-176
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• 2004

MR dampers show highly nonlinear and histeretic dynamic behavior. Therefore, for a vehicle dynamic simulation with MR dampers, this dynamic characteristics should be accurately reflected in the damper model. In this paper, an artificial neural network technique was developed for modeling MR dampers. This MR damper model was successfully verified through a random input forcing test. This MR damper model can be used for semi-active suspension vehicle dynamics and control simulations with practical accuracy.

• 전자공학회논문지A
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• 제33A권4호
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• pp.11-17
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• 1996

In the case of redundancy control performed by a netowrk management system, it can not be ignored some delay of control time and break of control by failure of the system. This paper proposed a new method to improve the performacne of a redundancy control system interfaced to the network management system. At first, it produced the modelling of the total system and analyzed the functional relation of reliability and failure rate for a transmission system having an one-to-one active redundancy structure controlled by itself. After describing the loss rate of transmission data and the time required for the redundancy control process of the network management system when a failure is occurred, it proposed the new redundancy method of complex system control mode as an effective redundancy control method to improve reliability of a redundancy control system. Finally, it proved the effect by comparing the new result to the previous result.

• Structural Engineering and Mechanics
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• 제31권2호
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• pp.153-162
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• 2009

The reduction of the dynamic response of an offshore structure subjected to wind-generated random ocean waves is of extreme significance in the aspects of serviceability, fatigue life and safety of the structure. In this study, a new neuro-control scheme is applied to the vibration control of a fixed offshore platform under random wave loads to examine the applicability of the proposed method. It is called the Lattice Probabilistic Neural Network (LPNN), as it utilizes lattice pattern of state vectors as the training data of PNN. When control results of the LPNN are compared with those of the NN and PNN, LPNN showed better performance in effectively suppressing the structural responses in a shorter computational time.

• 비파괴검사학회지
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• 제27권6호
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• pp.509-519
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• 2007

This paper presents new techniques under development for monitoring the health and vibration of the active components in nuclear power plants, The purpose of this study is to develop an automated system for condition classification of a check valve one of the components being used extensively in a safety system of a nuclear power plant. Acoustic emission testing for a check valve under controlled flow loop conditions was performed to detect and evaluate disc movement for valve failure such as wear and leakage due to foreign object interference in a check valve, It is clearly demonstrated that the evaluation of different types of failure types such as disc wear and check valve leakage were successful by systematically analyzing the characteristics of various AE parameters, It is also shown that the leak size can be determined with an artificial neural network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권1호
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• pp.123-140
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• 2011

In this paper, we propose an Energy Efficient Media Access Control (EE-MAC) protocol for wireless sensor networks. The proposed scheme is designed to save power consumption and guarantee quality-of-service for real-time traffic. EE-MAC uses the superframe structure which is bounded by the transmission of a beacon frame and can have an active and an inactive portion. The active period is divided into the contention free period (CFP) for real-time traffic transmission and the contention access period (CAP) for non-real-time traffic transmission. We propose the exclusively allocated backoff scheme which assigns a unique backoff time value to each real-time node based on bandwidth allocation and admission control. This scheme can avoid collision between real-time nodes by controlling distributed fashion and take effect a statistical time division multiple access. We also propose the algorithm to change the duty cycle adaptively according to channel utilization of media depending on network traffic load. This algorithm can prolong network lifetime by reducing the amount of energy wasted on idle listening.

• 전자통신동향분석
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• 제37권3호
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• pp.23-32
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• 2022

This paper provides an overview of optical transport technology for 5G mobile fronthaul. The configuration of fronthaul network is classified with dedicated fiber, passive WDM(Wavelength Division Multiplexing), active WDM, and semi-active WDM, which has its own advantages and drawbacks. Various WDM technology is applied for fronthaul transport, depending on the wavelength bands, required number of wavelength channels, configuration of fronthaul network, etc. In order to meet the increasing transport capacity, a 50/100 Gbps optical transceiver will be used in place of the present 10/25 Gbps technology. Trends will be continued to enhance the flexibility and reliability of the fronthaul optical network supporting highly advanced 5G mobile services.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1060-1068
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• 2018

Droop control schemes have been widely employed in the control strategies for Multi-Terminal Direct Current (MTDC) system for its high reliability. Under the conventional DC voltage-active power droop control, the droop slope applies a proportional relationship between DC voltage error and active power error for power sharing. Due to the existence of DC network impedance and renewable resource fluctuation, there is inevitably a DC voltage deviation from the droop characteristic, which in turn results in inaccurate control of converter's power. To tackle this issue, a piecewise droop control with DC voltage dead band or active power dead band is implemented into controller design. Besides, an advanced droop control scheme with versatile function is proposed, which enables the converter to regulate DC voltage and AC voltage, control active and reactive power, get participated into frequency control, and feed passive network. The effectiveness of the proposed control method has been verified by simulation results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.227-231
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• 2004

In this paper, a robust Sliding Mode Variable Structure (SMVS) controller is designed for Active Queue Management (AQM). This type of controller is insensitive to noise and variance of the parameters, thus it is suitable to time varying network systems. Simulation results conform the robust performance of SMVS controller against the disturbance. At the same time, a complete comparison between SMVS and PI controllers is made. The conclusion is that both transient and steady state performance of SMVS controller is better than that of PI one.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2004년도 International Conference on Digital Policy & Management
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• pp.173-184
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• 2004

E-Government security is crucial to the development of e-government. Due to the complexity and characteristics of e-government security, the viable current approaches for security focus on preventing the network intrusion or misusing in advanced and seldom concern of the forensics data attaining for the investigation after the network attack or fraud. We discuss the method for resolving the problem of the e-government security from the different side of view - network forensics approaches? from the thinking of the active protection or defense for the e-government security, which can also improve the ability of emergence response and incident investigation for e-government security.

• 한방안이비인후피부과학회지
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• 제35권4호
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• pp.75-94
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• 2022

Objectives : To identify the active ingredient of Poncirus Trifoliata Immaturus and to explore the mechanism expected to potentially act on dermatitis accompanied by pruritus. Methods : We conducted the network pharmacological analysis. We selected effective ingredients among the active compounds of Poinciri Fructus Immaturus. We found the target protein of the selected active ingredient, disease(dermatitis accompanied by pruritus) and fexofenadine. Then we established the network between the proteins which Poinciri Fructus Immaturus and fexofenadine intersected with disease respectively, and the coregene was also extracted. After that, the active pathways in the human body involving the groups and coregenes were searched. Results : Total of 7 active ingredients were selected, and 202 target proteins were collected. There were 756 proteins related to inflammatory skin disease accompanied by pruritus, and 75 proteins were related to fexofenadine. 42 proteins crossed by Poinciri Fructus Immaturus with a disease, and 31 proteins crossed by fexofenadine with a disease. 12 proteins were found as a coregene from the proteins that cross Poinciri Fructus Immaturus and disease. Coregenes are involved in 'Nitric-oxide synthase regulator activity', 'Epidermal growth factor receptor signaling pathway'. 2 groups that extracted are invloved in 'Fc receptor signaling pathway', 'Central carbon metabolism in cancer', 'Phosphatidylinositol 3-kinase complex, class IB', and 'omega-hydroxylase P450 pathway'. Conclusion : It is expected that Poinciri Fructus Immaturus will be able to show direct or indirect anti-pruritus and anti-inflammatory effects on skin inflammation accompanied by pruritus in the future. And it is also expected to have a synergy effect with fexofenadine on skin disease.