• Title/Summary/Keyword: time-distance function

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Effects of Visual Cue Deprivation During Sideways Treadmill Training on Balance and Walking in Stroke Patients (트레드밀 측방보행 훈련 동안 시각차단이 뇌졸중 환자의 균형 및 보행에 미치는 영향)

  • Kim, Tae-Woo;Kim, Yong-Wook
    • Physical Therapy Korea
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    • v.21 no.1
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    • pp.20-28
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    • 2014
  • The purpose of this study was to investigate the effects of visual cue deprivation during sideways treadmill training in individuals with stroke. Twenty-eight stroke patients were divided into two groups, and each group participated in a sideways treadmill training session for 20 minutes, three times per week for 4 weeks. The eyes close group (15 subjects) performed this treadmill training with visual cue deprivation, while the eyes open group (13 subjects) performed it without visual cue deprivation. Gait function was measured in both groups before and after the training sessions with the Biodex Gait Trainer 2, which determined walking speed, distance, step length, and time on each foot. Balance was measured before and after each training period in both groups using the Five-Times Sit-to-Stand Test (FTSST), the Timed Up and Go test (TUG), and the seven-item Berg Balance Scale-3P (7-item BBS-3P). The eyes close group showed significantly improved gait function, walking speed, distance, step length, and time on each foot after training (p<.05). The eyes close group showed improved balance ability, FTSST, TUG, and 7-item BBS-3P test after training (p<.05). The findings indicated that sideways treadmill training with visual cue deprivation positively affects gait ability of stroke patients. Therefore, sideways treadmill training with visual cue deprivation may be useful for the recovery of gait ability of stroke patients.

Quantitative Evaluation of Escape Safety Considering Extension of Escape Time by Escape Distance and Escape Barrier (피난거리와 장해에 의한 피난시간 연장의 정량화를 통한 피난안전성의 정량적인 평가수법개발)

  • Jeong, Gun-Sik
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.5
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    • pp.1-7
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    • 2009
  • Escape distance and escape barrier are critical elements for the quantitative evaluation of escape safety. Through theoretical demonstration and modeling in precedent studies, they have been analyzed for their generality and applicability. To make more practical evaluation method, we should quantitatively analyze the influence of each barrier and escape condition on escape safety considering various barriers in escaping routes. In this study, to develop more accurate and applicable escape analysis model, we have focused on three research methods as below: First, we derived quantified function to predict various escape barriers in escaping routes by theoretical analyses of the escape barriers and conditions. Second, we substituted the derived quantified function for an evaluation tool of escape safety suggested by precedent studies. Third, we examined applicability and feasibility of the developed method by modeling with the consideration of the escape conditions and barriers.

A Study on Real-time Data Preprocessing Technique for Small Millimeter Wave Radar (소형 밀리미터파 레이더를 위한 실시간 데이터 전처리 방법 연구)

  • Choi, Jinkyu;Shin, Youngcheol;Hong, Soonil;Park, Changhyun;Kim, Younjin;Kim, Hongrak;Kwon, Junbeom
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.6
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    • pp.79-85
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    • 2019
  • Recently, small radar require the development of small millimeter wave radar with high distance resolution to disable the target's system with a single strike. Small millimeter wave radar with high distance resolution need to process large amounts of data in real time to acquire and track target. In this paper, we summarized the real-time data preprocessing method to process the large amount of data required for small millimeter wave radar. In addition, the digital IF(Intermediate Frequency) receiver, Window processing, and, DFT(Discrete Fourier Transform) functions presented by real-time data preprocessing are implemented using FPGA(Field Programmable Gate Array). Finally the implemented real-time data preprocessing module was applied to the signal processor for small millimeter wave radar and verified by performance test related to the real-time preprocessing function.

Trajectory Planning of Articulated Robots with Minimum-Time Criterion (최소시간을 고려한 다관절 로봇의 궤적계획)

  • Choi, J.S.;Yang, S.M.;Kang, H.Y.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.6
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    • pp.122-127
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    • 1996
  • The achievement of the optimal condition for the task of an industrial articulated robot used in many fields is an important problem to improve productivity. In this paper, a minimum-time trajectory for an articulated robot along the specified path is studied and simulated with a proper example. A general dynamic model of manipulator is represented as a function of path distance. Using this model, the velocity is produced as fast as possible at each point along the path. This minimum-time trajectory planning module together with the existing collision-free path planning modules is utilized to design the optimal path planning of robot in cases where obstacles present.

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Location Estimation Enhancement Using Space-time Signal Processing in Wireless Sensor Networks: Non-coherent Detection

  • Oh, Chang-Heon
    • Journal of information and communication convergence engineering
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    • v.10 no.3
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    • pp.269-275
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    • 2012
  • In this paper, we proposed a novel location estimation algorithm based on the concept of space-time signature matching in a moving target environment. In contrast to previous fingerprint-based approaches that rely on received signal strength (RSS) information only, the proposed algorithm uses angle, delay, and RSS information from the received signal to form a signature, which in turn is utilized for location estimation. We evaluated the performance of the proposed algorithm in terms of the average probability of error and the average error distance as a function of target movement. Simulation results confirmed the effectiveness of the proposed algorithm for location estimation even in moving target environment.

Congestion Control Scheme for Wide Area and High-Speed Networks (초고속-장거리 네트워크에서 혼잡 제어 방안)

  • Yang Eun Ho;Ham Sung Il;Cho Seongho;Kim Chongkwon
    • The KIPS Transactions:PartC
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    • v.12C no.4 s.100
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    • pp.571-580
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    • 2005
  • In fast long-distance networks, TCP's congestion control algorithm has the problem of utilizing bandwidth effectively. Several window-based congestion control protocols for high-speed and large delay networks have been proposed to solve this problem. These protocols deliberate mainly three properties : scalability, TCP-friendliness, and RTT-fairness. These protocols, however, cannot satisfy above three properties at the same time because of the trade-off among them This paper presents a new window-based congestion control algorithm, called EM (Exponential Increase/ Multiplicative Decrease), that simultaneously supports all four properties including fast convergence, which is another important constraint for fast long-distance networks; it can support scalability by increasing congestion window exponentially proportional to the time elapsed since a packet loss; it can support RTT-fairness and TCP-friendliness by considering RTT in its response function; it can support last fair-share convergence by increasing congestion window inversely proportional to the congestion window just before packet loss. We evaluate the performance of EIMD and other algorithms by extensive computer simulations.

Derivation of the Basin Instantaneous Unit Hydrograph Considering the Network Geometry and Hillslope of Small Basin (소유역의 수로기하학적특성과 사면을 고려한 유역순간단위도의 유도)

  • Kim, Jae Han;Yoon, Seok Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.2
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    • pp.161-171
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    • 1993
  • The basin instantaneous unit hydrograph was derived by considering the network geometry and hillslope. The network geometry is quantified in a function, termed the width function, that reflects the distribution of runoff with flow distance from the outlet. The model using the derivation of the basin IUH consists of two components: the routing component of the initial distribution through the network by means of a simplified diffusion approximation and the hillslope component by means of a exponential distribution that is the probability density function of the travel time in the hillslope. The application of this method was tested on four observed flood data of Bocheong stream and Wi stream. The results show that the proposed method can be used for the analysis of the basin IUH.

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A Study on the Threshold of Avoidance Sector in the New Evaluation of Collision Risk (신 충돌위험도평가에서 피항구역의 문턱값 결정에 관한 연구)

  • Jeong Tae-Gweon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.11a
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    • pp.57-60
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    • 2004
  • Evaluating the risk of collision quantitatively plays a key role in developing the expert system of navigation and collision avoidance. This study analysed thoroughly how to determine the thresholds as described in the new evaluation of collision risk using sech function, and developed the appropriate equation as applicable.

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Effects of atmospheric turbulence on the laser cross-beam velocimeter (레이저 크로스빔 속도계에 대한 대기교란 효과)

  • sung pyung-shik
    • Journal of the Korea Computer Industry Society
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    • v.6 no.2
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    • pp.259-264
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    • 2005
  • This paper have derived an expression(the fringe modle is used) for the photocurrelation-correlation function for a cross-beam laser velocimeter, taking into account the effects of atmospheric turbulence on the amplitude and phase of the incident beams. the result, as long as the atmospheric disturbances do not greatly damp out sinusoidal variations of the photocurrent-correlation function in the time it takes a particle to travel the fringe-separation distance, the disturbances do not hinder the determination of the velocity of the partides from the correlation funtion.(the scattering particles are assumed to have a well-defined V).

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A Study on Determination of Gradient Coefficients in the New Evaluation of Collision Risk (신 충돌위험도평가의 기울기계수 결정에 관한 연구)

  • Jeong, Tae-Gweon
    • Journal of Navigation and Port Research
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    • v.27 no.4
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    • pp.351-357
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    • 2003
  • Evaluating the risk of collision quantitatively plays a key role in developing the expert system of navigation and collision avoidance. This study analysed theoretically and thoroughly how to determine the gradient coefficients as described in the new evaluation of collision risk using sech function, and suggested the appropriate values as applicable.