• 대한물리의학회지
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• 제12권1호
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• pp.67-74
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• 2017

PURPOSE: The purpose of this study was to determine the effect of action observation with observation type on the limits of stability and dynamic gait ability in stroke patients. METHODS: The 20 stroke patients who participated in this study were randomly divided into two experimental groups who underwent training three times a week for 4 weeks. Their balance was tested as the limit of stability with Biorescue. Their Dynamic gait ability was tested with the Dynamic Gait Index (DGI) before the intervention, and after 4 weeks. Independent and paired t-tests were used to analyze the results. RESULTS: The results confirmed the limit of stability on the moving areas of the paralyzed and non-paralyzed sides. The limit of stability and dynamic gait index measurements confirmed that the moving area showed a significant difference after the intervention in the whole movement observation group (p<.05), but the partial movement observation group showed no significant difference (p>.05). A significant difference was also noted for the comparison between the both groups after the interventions (p<.05). The functional walking ability showed a significant difference when compared to the ability before the intervention, as determined by the changes in scores obtained for the dynamic gait index (p<.05). CONCLUSION: Interventions utilizing whole movement confirm that training improves stability and functional walking ability in stroke patients with disabilities in balance and walking ability.

• PNF and Movement
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• 제17권2호
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• pp.245-252
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• 2019

Purpose: The purpose of this study was to determine the effects of action observation training on lower limb muscle activity and dynamic balance in chronic stroke patients. Methods: This study evaluated 20 chronic stroke patients who were divided randomly into a control and an experimental group comprising 10 patients each. Both the experimental group and the control group performed the general exercise therapy provided by the hospital, but the experimental group also performed action observation training. Lower limb muscle activity was measured with a surface electromyograph, and dynamic balance was measured with the Timed Up and Go test and the 10-meter walk test. The paired t-test was used to compare the groups before and after the experiment. Furthermore, the independent t-test was used to assess differences in the degree of change between the two groups before and after the experiment. Results: The within-group comparisons for both the experimental group and the control group showed significant differences in muscle activity and dynamic balance (p<0.05). In a comparison between the groups, the differences in the muscle activity and dynamic balance of the experimental group appeared significant compared with those of the control group (p<0.05). Conclusion: The study results indicate that action observation training is effective in improving the muscle activity and dynamic balance of chronic stroke patients.

• 한국정밀공학회지
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• 제33권8호
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• pp.617-622
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• 2016

The article describes the determination of the dynamic stability for an observation antenna, considering the rotational speed by the payload driving motor. A finite element model of the observation antenna was made using the solid and beam elements. The connecting parts between the solid and the beam was adequately coupled. The boundary conditions were made by restriction of the degree of freedoms in the supporting points. With the comparison between the modal analysis results and the rotating speed of the payload driving motor, no resonance for the structure of antenna was identified and first natural frequency was determined under 33 Hz (Seismic Cut-Off Frequency). Therefore, the dynamic stability of the antenna was confirmed by the comparism between the seismic safety criterion and the stress results of the dynamic analysis applied the loading conditions and required response spectrum (RRS).

• 한국자기학회지
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• 제5권5호
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• pp.885-891
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• 1995

로렌트 SEM을 이용하여 동적자구 모양의 관찰에 대한 검토가 50 Hz ~ 10 kHz의 주파수 범위에서 수행되었다. 동적자구 모양의 관찰은 여자주파수와 SEM의 주사주파수의 정수 배와의 사이에 미소한 차를 두고 관찰하는 방법이며, 이 관찰 방법에 따라서 시뮬레이션하여 시뮬레이션한 모양과 관찰모양을 비교 검토하였다. 또한 더욱 높은 주파수에서 동적자구 모양을 관찰하기 위해서는 SEM의 주사주파수의 안정화에 대한 필요한 것을 알았다.

• 한국산학기술학회논문지
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• 제9권4호
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• pp.964-969
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• 2008

본 논문은 화자 독립의 음성인식을 위한 연구로서, DMS(Dynamic Multi-Section) 모델에 의한 DMSVQ(Dynamic Multi-Section Vector Quantization) 코드북과 퍼지 개념을 이용한 HMM(Hidden Markov Model) 음성인식 방법을 제안한다. 제안된 인식 방법에서는 학습 데이터를 동적으로 몇 개의 구간(section)으로 분할한 후, 각 구간마다 DMSVQ 코드북(codebook)으로 부터 거리값이 작은 순으로 퍼지 법칙을 적용함으로써 적당한 확률값을 준 다중 관측열(multi-observation sequences)을 구한다. 그런 다음, 이 다중 관측열을 이용하여 HMM을 작성하고, 인식시에는 관측 확률값이 가장 높은 것을 인식된 것으로 선택한다. 제안된 방법에 의한 인식 실험은 기존의 다양한 인식 실험들과 비교를 위해 동일한 조건하에서 같은 데이터로 수행 하였다. 실험 결과로서, 본 연구에서 제안한 방법이 기존의 방법들보다 우수한 방법임을 입증하였다.

• 대한임베디드공학회논문지
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• 제3권2호
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• pp.109-118
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• 2008

We present a robust localization algorithm using particle filter for mobile robots in a dynamic environment. It is difficult to describe moving obstacles like people or other robots on the map and the environment is changed after mapping. A mobile robot cannot estimate its pose robustly with this incomplete map because sensor observations are corrupted by un-modeled obstacles. The proposed algorithms provide robustness in such a dynamic environment by suppressing the effect of corrupted sensor observations with a selective update or a sampling from non-corrupted window. A selective update method makes some particles keep track of the robot, not affected by the corrupted observation. In a sampling from non-corrupted window method, particles are always sampled from several particle sets which use only non-corrupted observation. The robustness of proposed algorithm is validated with experiments and simulations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.523-528
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• 1990

This paper discusses the problem of designing an observation function as coarsest as possible in supervisory control of discrete event dynamic systems. Some algebraic properties of two sets consisting of observation functions for which the given desirable behavior is realizable are investigated:these sets with a partial ordering turn out not to possess largest elements. Two natural methods of obtaining an observation function, which is frequently coarser than the identity mapping, are also presented. An example illustrates the use of these methods.

• 전기학회논문지P
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• 제58권2호
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• pp.164-171
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• 2009

This paper presents new learning algorithm of dynamic Bayesian networks (DBN) by means of constrained least square (LS) estimation algorithm and gradient descent method. First, we propose constrained LS based parameter estimation for a Markov chain (MC) model given observation data sets. Next, a gradient descent optimization is utilized for online estimation of a hidden Markov model (HMM), which is bi-linearly constructed by adding an observation variable to a MC model. We achieve numerical simulations to prove its reliability and superiority in which a series of non stationary random signal is applied for the DBN models respectively.

• Communications for Statistical Applications and Methods
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• 제10권3호
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• pp.795-804
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• 2003

In this article, a tomography for the estimation of the origin-destination(OD) traffic intensities in dynamic routing network is considered. Vardi(1996)'s approach based on fixed route is not directly applicable to dynamic routing protocols, which arises from the fact that we cannot access the route at every observation time. While it uses link-wise traffics as the observations, the proposed method considers the triple of ingress/outgress/relayed traffics data at each node so that we can transform the problem into a routing-independent tomography. An EM algorithm for implementation and some simulated experiments are provided.

• 품질경영학회지
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• 제19권2호
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• pp.1-16
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• 1991

Recently, Cook and Weisberg(l989) presented dynamic graphics for regression diagnostics. They suggested animating graphics which could aid to understanding the effects of adding a variable to a model. In this paper, using the Cook and Weisberg's idea of animation, we propose a dynamic graphical method for residuals to display the effects of removing an observation from a model. Based on the information obtained from these animating graphics, it is possible to see the influence of outliers on influencial observations for regression diagnostics.