• Title/Summary/Keyword: 진자

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Analysis of Coronavirus Response Policy Effiectiveness According to the Strigency Index (엄격성 지수 분석에 따른 감염병 대응 정책 효과성 분석)

  • Jeon, Eun-Goo
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2022.10a
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    • pp.143-144
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    • 2022
  • 본 연구에서는 엄격성 지수(Strigency Index)분석에 따른 OECD 가입국들의 코로나19 대응 정책 엄격성의 효과성을 분석하였다. 코로나바이러스감염증-19(이하, 코로나19)발생 이후 전 세계 대다수 국가들은 점진적 일상회복 단계로 접어들어 'with corona' 시대로 가고 있다. 코로나19의 완전 방역을 이루며 이전과 같은 일상으로 돌아가고 있지만, 또다시 대규모 감염병이 발생할 수 있다는 가능성을 가지고 있다. 그리하여 본 연구에서는 옥스퍼드 코로나바이러스 정부대응추적 프로젝트(OxCGRT)에서 제시된 21개 지표 중 OurWorldinData서 엄격성 지수 분석에 활용되는 9개 지표를 분석하여 정책의 엄격성을 분석하여 추후 발생하는 대규모 감염병에 효과적으로 대응하기 위한 기초 자료가 되고자 한다. 엄격성 지수 분석 결과, 9개 지표 중 6개 지표에서 정책의 도입한 시점부터 확진자가 감소하는 추세를 보이는 유사한 변화를 찾을 수 있었다. 하지만, 엄격성 지수 분석을 통해 국가 대응의 적절성·효과성을 입증하기에는 판단 기준이 0~4점 사이의 임의의 기준으로 분류되고 있었으며, 변수설정 또한 제시되어 있지 않아 대응 정책의 엄격성을 평가하는 기준으로 활용하기에는 한계점이 있어 보인다. 본 연구에서 엄격성 지수 분석을 통한 감염병 대응 정책의 효과성을 찾고자 하였다. 지수와 확진자 추세 간 유사한 변화는 찾았지만, 엄격성 지수의 한계점이 존재하는 연구이다. 그러나 본 연구의 결과를 통해 추후 확진자 증감 대비 엄격성 지수 분석을 통한 상관관계 분석, 지표별 평균치와 확진자 추세 분석을 통한 공통적인 효과성 분석 등 다른 연구의 기초 자료가 될 수 있을 것이라 판단된다.

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A Study on Complement of the Design and Analysis Procedures of Friction Pendulum System (마찰진자형 면진받침의 설계 및 해석절차 보완에 관한 연구)

  • Kim, Hyun-Uk;Joo, Kwang-Ho;Noh, Sang-Hoon;Song, Jong-Keol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.1
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    • pp.488-494
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    • 2014
  • Although friction pendulum system has various advantages it is difficult to estimate the behavior because of velocity, bearing pressure, and temperature dependent characteristics of coefficient of friction. This research focuses on evaluating the conservatism of each method used and the effects of bearing pressure on the behavior of the system by conducting comprehensive examination on design and analytic procedure of friction pendulum system, as is proposed in standard, code and literature. In addition, this study provides comparative analysis on general behavior characteristics of friction pendulum system by comparing the result with that of the analysis on lead rubber bearing which possesses the same dynamic properties.

A Proof of Concept Investigation on a Pendular Power Take-Off System of Horizontal Wave Power Generator (수평파력 발전장치의 진자형 1차 에너지 추출 시스템에 대한 기초 모형실험 및 시뮬레이션)

  • Park, Yong-Kun;Lim, Chae Gyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.9
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    • pp.68-75
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    • 2017
  • This paper presents the experimental and theoretical results of the dynamic responses of a pendular energy extractor in a two-dimensional wave channel. By adopting a wave maker with varying wave height and period, the dynamic responses of the pendular buoy were experimentally obtained. Furthermore, with the aid of the co-simulation of moving particle analysis and rigid dynamic analysis, the dynamic responses of the pendular system were evaluated. In order to validate the feasibility of the proposed wave power generator, the force tuning of the pendular system with restoring energy was carried out. The results provide proof of concept data for the development and design of a commercial model for horizontal wave power generators in the shoreline area.

A Controlled Trial of Placebo Versus Real Venesection (위자락과 진자락 요법에 관한 대조 시험)

  • Kim, Woo-Young;Baek, Seung-Tae;Byun, Hyuk;Lee, A-Ram;Jeong, Yong-Rae;Kim, Kap-Sung;Lee, Seung-Deok
    • Journal of Acupuncture Research
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    • v.22 no.6
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    • pp.125-134
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    • 2005
  • 목적 : 이 연구의 목적은 플라시보 자락요법을 계발하기 위함이다. 방법 : 이 연구에서 우리는 자락요법을 잘 알고 있는 특정 피시험군에 진자락요법과 위자락요법을 시행하고, 피시험자에게 본인이 받은 치료가 무엇이었는지 설문조사하였다. 위자락요법은 피부를 뚫어 혈관을 자파시키지 않고 피부 겉에서 느낌만 나도록 자극을 주고 흡입하는 것이다. 결과 : 총 53명의 피시험자가 모든 시험과정에 적절하게 참가하였으므로 모든 데이터를 신뢰할 수 있었다. 결과는 두 그룹간에 유의한 차이를 발견할 수 없었다. 위자락요법을 받은 피시험자중 44.4%는 그들이 받은 치료가 진자락요법이라고 생각했고, 55.6%는 위자락요법이라고 생각했다. 진자락요법을 받은 피시험자중 53.8%는 그들이 받은 치료가 진자락요법이라고 생각했고, 46.2%는 위자락요법이라고 생각했다. 결론 : 각 군간의 민감도와 특이도 간에 유의한 차이가 나타나지 않으므로, 자락요법에 있어 플라시보가 성공했다고 볼 수 있다. 이 연구는 자락요법을 적응증으로 하는 다양한 질환의 임상연구에 있어서 대조군 처치시 좋은 모델을 제시하였다.

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Relationship Between Pendulum Test Measurements of Post-Stroke Spasticity (뇌졸중 후 강직 평가를 위한 진자검사 측정값의 상관관계)

  • Kim, Yong-Wook
    • The Journal of the Korea Contents Association
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    • v.10 no.5
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    • pp.325-332
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    • 2010
  • The purpose of this study was to investigate the relationship between three quantitative measures of the pendulum test for spasticity in strokes: The relaxation index, the number of oscillations, and the duration of oscillations. Twenty-six stroke subjects participated in the study. Correlations among these measures of spasticity used Pearson's correlation coefficient. There was a statistically significant positive correlation between the relaxation index and number of oscillations in strokes (r=.881, p<.01). In addition there was significant positive correlation between the relaxation index and duration of oscillations (r=.896, p<.01), and between the number of oscillations and duration of oscillations (r=.938, p<.01). Thus, it is possible to use the number of oscillations and duration of oscillations as quantitative measures of spasticity, rather than the relaxation index, which is more complicated to obtain. According to the result of this study, the use of the simple and objective measurements of the number of oscillations and the duration of oscillations are required clinically in the quantitative measures of spasticity in the future.

Design of Optimized Fuzzy PD Cascade Controller Based on Parallel Genetic Algorithms (병렬유전자 알고리즘 기반 최적 Fuzzy PD Cascade 제어기의 설계)

  • Jung, Seung-Hyun;Choi, Jeoung-Nae;Oh, Sung-Kwun;Kim, Hyun-Ki
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.3
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    • pp.329-336
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    • 2009
  • In this paper, we propose the design of an optimized fuzzy cascade controller for rotary inverted pendulum system by means of Hierarchical Fair Competition-based Genetic Algorithms (HFCGA) which is a kind of parallel genetic algorithms. The rotary inverted pendulum system is the system for controlling the inclination of pendulum axis through the adjustment of rotating arm. The control objective of the system is to control the position of rotating arm and to make the pendulum maintain the unstable equilibrium point of vertical position. To control rotary inverted pendulum system, we designs the fuzzy cascade controller scheme consisted of two fuzzy controllers and optimizes the parameters of the designed controller by means of HFCGA. A comparative analysis between the simulation and the practical experiment demonstrates that the proposed HFCGA based fuzzy cascade controller leads to superb performance in comparison with the conventional LQR controller as well as HFCGA based PD cascade controller.

Seismic Fragility Analysis of a LNG Tank with Friction Pendulum System of Various Friction Coefficient (마찰재 물성변화에 따른 마찰진자시스템을 적용한 LNG 탱크의 지진취약도 분석)

  • Moon, Ji-Hoon;Kim, Ji-Su;Lee, Tae-Hyung;Han, Tong-Seok
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.2
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    • pp.95-102
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    • 2017
  • The friction pendulum system(FPS) is a kind of seismic isolation devices for isolating structures from an earthquake. To analyze the effect of friction materials used in the friction pendulum system, fragility analysis of LNG tank with seismic isolation system was conducted. In this study, titanium dioxide($TiO_2$) nanoparticles were incorporated into polyvinylidene fluoride(PVDF) matrix to produce friction materials attached to the FPS. The base moment of the concrete outer tank and the acceleration of the structure were evaluated from different mixing ratios of constituents for the friction materials. The seismic fragility curves were developed based on two types of limit state. It is confirmed that evaluation of combined fragility curves with several limit states can be applied to select the optimum friction material satisfying the required performance of the FPS for various infrastructure.

The effect of ambiguity of information on Covid-19 patients' contact trace on intention to visit the commercial district: Comparison of residents in Gangnam-gu and Seocho-gu (코로나19 확진자 동선정보의 모호성 차이가 유관 상권 방문의도에 미치는 영향 연구: 강남구민과 서초구민의 비교)

  • Min, Dongwon
    • Journal of Digital Convergence
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    • v.18 no.8
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    • pp.179-184
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    • 2020
  • This study aims to investigate the effect that local government's information release range on Covid-19 patients' contact trace on consumer sentiment in the region. One hundred twenty-eight residents of Gangnam-gu and Seocho-gu participated in the study. The results showed that when ambiguity of information increased perceived anxiety on Covid-19 patients' contact trace, which in turn led lower intention to visit the commercial district near the Covid-19 patients' contact trace. Based on the findings, several suggestions was proposed for future research, including longitudinal studies covering even the "long-term" changes in consumer sentiment, the effect of implicit anxiety, and the behavioral difference between residence and non-residence.

Position Control and Stabilization of Inverted Pendulum using the Evolution Strategies (진화전략을 이용한 도립진자의 안정화 및 위치제어)

  • 이동욱;심귀보
    • Journal of the Korean Institute of Intelligent Systems
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    • v.6 no.4
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    • pp.71-80
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    • 1996
  • This paper presents stabilization and position control of the Inverted-Pendulum system with cart by using Evolution Strategies that is one of the Evolutionary Computation and is effective in searching real number. The control input of the Inverted-Pendulum is the element of chromosome corresponding to the divided space of Inverted-Pendulum state variable x, x, 0, 0 . In general, the larger the length of the chromosome is, the longer the time of evolution to search optimal solution is. So in this paper, we propose a scheme that reduce the state space by half by taking the method, that is, converting only the sign of the control input without obtaining separately for the symmetrical sections of the Inverted-Pendulum to improve the speed of Evolution, and improved the efficiency of the entire system in addition to the improvement of the chromosome's evolution time by carrying out the chromosome's evolutional process by two steps one of which is that cart is positioned near the control point and the other cart is positioned far from that point. We propose another method that is Neural Network-Evolution StrategiedNN-ES) Controller. We verify the effectiveness of the proposed control scheme by computer simulations.

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The LMI mixed ${H_2}/H_{\infty}$ control of inverted pendulum system using LFR (도립진자 시스템의 LFR에 의한 LMI 혼합 ${H_2}/H_{\infty}$ 제어)

  • 박종우;이상철;이상효
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.7A
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    • pp.967-977
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    • 2000
  • In this paper, we apply a mixed $H_2/H_{\infty}$ control to a generalized plant of inverted pendulum system represented by an LFR(Linear Fractional Representation). First, in order to obtain the generalized plant, the linear model of the inverted pendulum represented by an LFR(Linear fractional Representation) is derived. In LFR, we consider system uncertainties as three nonlinear components and a pendulum mass uncertainty. Augmenting the LFR model by adding weighting functions, we get a generalized plant. And then, we design a mixed $H_2/H_{\infty}$ controller for the generalized plant. In order to design the mixed $H_2/H_{\infty}$ controller, we use the LMI technique. To evaluate control performances and robust stability of the mixed $H_2/H_{\infty}$ controller designed, we compare it with the $H_{\infty}$ controller through the simulation and experiment. In the result, with the fewer feedback information, the mixed $H_2/H_{\infty}$ controller shows the better control performances and robust stability than the $H_{\infty}$ controller in the sense of pendulum angle.

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