• Title/Summary/Keyword: time coordination

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Effect of Transcranial Direct Current Stimulation on Visuomotor Coordination Task in Healthy Subjects

  • Kwon, Yong Hyun;Cho, Jeong Sun
    • The Journal of Korean Physical Therapy
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    • v.26 no.6
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    • pp.386-390
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    • 2014
  • Purpose: We aimed to investigate whether visuomotor function would be modulated, when healthy subjects performed tracking task after tDCS application over the primary sensorimotor cortex (SM1) in the non-dominant hemisphere. Methods: Thirty four right-handed healthy participants were enrolled, who randomly and evenly divided into two groups, real tDCS group and sham control group. Direct current with intensity of 1 mA was delivered over SM1 for 15 minutes. After tDCS, tracking task was measured, and their performance was calculated by an accuracy index (AI). Results: No significant difference in AI at the baseline between the two groups was observed. The AI of the real tDCS group was significantly increased after electrical stimulation, compared to the sham control group. Two way ANOVA with repeated measurement showed a significant finding in a large main effects of time and group-by-repeated test interaction. Conclusion: This study indicated that application of the anodal tDCS over the SM1 could facilitate higher visuomotor coordination, compared to sham tDCS group. These findings suggest possibility that tDCS can be used as adjuvant brain modulator for improvement of motor accuracy in healthy individuals as well as patients with brain injury.

The Evolution of Korea's Basic Acts on Science and Technology and their Characteristics

  • Lee, Changyul;Lee, Elly Hyanghee;Kim, Seongsoo
    • Asian Journal of Innovation and Policy
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    • v.10 no.3
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    • pp.355-379
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    • 2021
  • This study examined the evolution of S&T Basic Acts in Korea from the Science and Technology Promotion Act (1967) through the Special Act on STI (1997) to the Framework Act on Science and Technology (2001) in the following aspects: 1) comprehensive plans, 2) coordination mechanisms for S&T policies, 3) enforcement of R&D programs and performance diffusion, 4) promotion of human resources, 5) and S&T investment and budgeting. Before the Framework Act on S&T was enacted in 2001, critical issues were found in establishing S&T master plans, promotion of R&D programs, comprehensive coordination mechanisms, and R&D budgeting. The three Basic Acts have expanded the scope of regulation over time to cover the entire cycle of the S&T process. They concern a wide range of issues, including creating a basis for scientific and technological development, S&T promotion, disseminating and commercializing research outcomes, and preventing adverse effects from science and technology. The content of the Basic Acts has evolved in response to changes in the political, economic, and social environment of Korean industry during the past five decades.

Application of Multi-Agent System to Over Current Protective Relaying System (과전류 보호계전 시스템에의 Multi-Agent System 응용)

  • Chang, Choong-Koo;Min, Byung-Un;Lee, Seung-Jae
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.209-211
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    • 2000
  • This paper presents a Multi-Agent system for setting and coordination of overcurrent protective devices in the distribution system. The simulation model shows its feasibility in which KQML is used for communication among agents. The proposed system could make it possible to keep the protection system in the optimal state all the time.

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Multi-robot simulator for collision avoidance (충돌 회피를 위한 다중 로봇 시뮬레이터)

  • 이재용;이범희
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.417-422
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    • 1993
  • Robots working in the multiple robot system can perform the variety of tasks compared to the single robot system, while they are subject to the various tight constraints such as the precise coordination and the mutual collision avoidance during the task execution. In this paper, we provide an algorithm and graphical verification for collision avoidance between two robots working together. The algorithm calculates the minimum time delay for collision avoidance and the graphical verification is performed through the 3-D graphic simulator.

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A Study of the Interference Varying from a NGSO network to a GSO Network according to NGSO Satellite Tracking Strategies (비정지궤도 위성망의 위성 선정 방식에 따른 정지궤도 위성망으로의 간섭량 변화에 대한 연구)

  • 강병수;권태곤;박세경
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.841-844
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    • 1999
  • The interference situation from NGSO/FSS network to GSO/FSS network is more complicated than the situation between GSO networks because of the time varying orbital characteristics of NGSO systems. In this paper, the interference characteristics for several types of hand-over strategies are simulated and it is shown that the results should be useful in practical coordination of inter-network interference.

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Genetic Algorithm-based Coordination of Multiagent Systems with Fuzzy Processing Time (퍼지 처리시간을 갖는 다중 에이전트 시스템의 유전자 알고리즘 기반 작업 조정)

  • 이건명
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.05a
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    • pp.59-62
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    • 2003
  • 에이전트에서 수행할 수 있는 작업들에 대한 처리시간이 실제 작업 전에는 퍼지값으로만 주어지고, 실제 작업이 수행될 때야 작업 시간이 결정되는 다중 에이전트 시스템에 대해서 작업을 조정하는 방법을 제안한다. 제안한 방법은 두 단계의 유전자 알고리즘으로 구성되는데, 상위 단계의 유전자 알고리즘에서는 작업들을 적합한 에이전트에 할당하는 역할을 하고, 하위 단계의 유전자 알고리즘은 첫 번째 유전자 알고리즘의 제시하는 작업 할당 방법에 가장 적합한 작업 스케줄을 탐색하는 역할을 한다. 이 논문에서는 제안한 유전자 알고리즘 기반 작업 조정 방법을 소개하고, 제안한 방법을 구현하여 실험한 결과를 보인다.

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Antochini crane flies (Diptera: Limoniidae: Limoniinae) of Korea

  • Podenas, Sigitas;Byun, Hye-Woo
    • Journal of Species Research
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    • v.2 no.2
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    • pp.167-184
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    • 2013
  • Korean species of Antochini crane flies (Diptera: Limoniidae) are taxonomically revised. Identification keys, redescriptions and illustrations of all species and both sexes are presented. Antocha (Antocha) dentifera Alexander, 1924, Antocha (Antocha) dilatata Alexander, 1924 and Elliptera zipanguensis zipanguensis Alexander, 1924 are listed as new records for the Korean peninsula; Limnorimarga limonioides (Alexander, 1945) as new for South Korea. Females of A. (A.) dentifera, A. (A.) integra Alexander, 1940 and L. limonioides are described for the first time.

Voltage Time characteristic of electrical breakdown in $SF_6$ ($SF_6$ 가스중 V-t절연파괴특성)

  • Seo, Kil-Soo;Kim, Ik-Soo
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1770-1772
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    • 1997
  • In this paper, Voltage-time characteristics of lightning impulse and switching surge breakdown in SF6 is studied on the gap and various pressure. The characteristics is categorized into three pattern depending on the configuration of the gap and gas pressure. The properties of the voltage-time characteristics in these patterns are generalized as semi-empirical formula which will be useful in the quantitation voltage evaluation of insulation coordination and the abnormal voltage protection of SF6 insulated power equipment.

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Dynamic Resource Adjustment for Coexistence of LAA and Wi-Fi in 5 GHz Unlicensed Bands

  • Choi, Jihoon;Kim, Eunkyung;Chang, Sungcheol
    • ETRI Journal
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    • v.37 no.5
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    • pp.845-855
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    • 2015
  • To enable the coexistence of Licensed Assisted Access (LAA) and Wi-Fi in 5 GHz unlicensed bands, a new channel access mechanism is proposed. Accounting for the fairness between LAA and Wi-Fi, the proposed mechanism finds the optimal transmission time ratio by adaptively adjusting the transmission durations for LAA and Wi-Fi. In addition, we propose a new analytical model for the distributed coordination function of IEEE 802.11 through some modifications of conventional analytical models for saturation and non-saturation loads. By computing the activity ratio of Wi-Fi, the proposed analytical model is able to control the time ratio between LAA and Wi-Fi, which is required for practical implementation of the proposed access mechanism. Through numerical simulations, the proposed channel access mechanism is compared with conventional methods in terms of throughput and utility.

Steady-State Harmonic Domain Matrix-Based Modeling of Four-Quadrant EMU Line Converter

  • Wang, Hui;Wu, Mingli;Agelidis, Vassilios G.;Song, Kejian
    • Journal of Power Electronics
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    • v.14 no.3
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    • pp.572-579
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    • 2014
  • As a non-linear time variant system, the four-quadrant line converter of an electric multiple unit (EMU) was expressed by linear time periodic functions near an operating point and modeled by a steady-state harmonic domain matrix. The components were then combined according to the circuit connection and relations of the feedback control loops to form a complete converter model. The proposed modeling method allows the study of the amplitude of harmonic impedances to explore harmonic coupling. Moreover, the proposed method helps provide a better design for the converter controllers, as well as solves the problem in coordination operation between the EMUs and the AC supply. On-site data from an actual $CRH_2$ high-speed train were used to validate the modeling principles presented in the paper.