• Journal of The Korean Society of Integrative Medicine
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• v.6 no.2
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• pp.45-57
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• 2018

Purpose : This study was conducted to evaluate the effects of an task oriented training program combined with action-observation on balance and gait ability of patients with chronic stroke. Method : The subjects of this study were 30 patients with hemiplegia who agreed to participate and were picked up. Participants were randomly divided into equal groups; namely, an experimental group that underwent task oriented training combined with action-observation for at least 30 minutes/day for 6 weeks and a control group that underwent general task-oriented training. Patients' balance was assessed using the Sway Length, Sway Area and Limit of Stability test. In addition, gait ability was assessed using the 10 Meter Walking Test to measure the taken to walk 10 meters. Gait time and speed taken to walk 10 meters were used to examine gait ability. Results : There were significant improvements in the subscales of the balance and gait ability test of those who participated in the action-observational training program, while the control group showed only significant changes in the evaluation items of the sway length in eyes opened condition and gait time. Conclusion : Therefore, Action-observational training program effectively improved the balance and gait ability in patients with stroke.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1241-1251
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• 2016

We consider a correlated discrete-time random walk in which the current jump size depends on the previous jump size and a noncorrelated discrete-time random walk where the jump size is determined independently. By using the strong law of large numbers of Markov chains we derive the formula for the asymptotic means of the random mixture and the periodic pattern of these two random walks and then we show that there exists Parrondo's paradox where each random walk has mean 0 but their random mixture and periodic pattern have negative or positive means. We describe the parameter sets at which Parrondo's paradox holds in each case.

• Journal of Korean Physical Therapy Science
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• v.13 no.2
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• pp.37-45
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• 2006

The purpose of this study was to determine the effect of treadmill training on gait, balance, and trunk control in a patient with hemiparesis. A female subject who had suffered a left hemiparesis 12 months previously was selected for this study. A single subject ABA design was used. Eight data-collection sessions were conducted during each of three phases (baseline-intervention-withdrawal). During baseline and withdrawal phases, the treatment based on Bobath approach was performed for the subject, and during the intervention phase, treadmill walking training was added. Assessment tools were made using the 10 m walk test, Rivermead Visual Gait Assessment(RVGA), Berg Balance Scale(BBS), and a seated Lateral Reach Test(LRT). During the intervention phase, the time measured in 10 m walk test and the scores of RVGA and BBS were significantly improved, and the number of steps in 10 m walk test and LRT showed a small improvement. During withdrawal phase, the time measured in 10 m walk test and the scores of RVGA and BBS were shown the carry-over effect. This findings indicate that treadmill training has significant effect to gait function and balance in a patient with chronic hemiparesis.

• Journal of the Korean Operations Research and Management Science Society
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• v.12 no.1
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• pp.19-26
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• 1987

In analyzing time series, estimating the level or the current mean of the process plays an important role in understanding its structure and in being able to make forecasts. The studies the class of time series models where the level of the process is assumed to follow a random walk and the deviation from the level follow an ARMA process. The estimation and forecasting problem in a Bayesian framework and uses the Kalman filter to obtain forecasts based on estimates of level. In the analysis of time series, we usually make the assumption that the time series is generated by one model. However, in many situations the time series undergoes a structural change at one point in time. For example there may be a change in the distribution of random variables or in parameter values. Another example occurs when the level of the process changes abruptly at one period. In order to study such problems, the assumption that level follows a random walk process is relaxed to include a major level change at a particular point in time. The major level change is detected by examining the likelihood raio under a null hypothesis of no change and an alternative hypothesis of a major level change. The author proposes a method for estimation the size of the level change by adding one state variable to the state space model of the original Kalman filter. Detailed theoretical and numerical results are obtained for th first order autoregressive process wirth level changes.

• KDI Journal of Economic Policy
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• v.38 no.2
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• pp.1-20
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• 2016

In this paper, we conduct uniform inference of two widely used versions of the Phillips curve, specifically the random-walk Phillips curve and the New-Keynesian Phillips curve (NKPC). For both specifications, we propose a potentially time-varying natural unemployment (NAIRU) to address the uncertainty surrounding the inflation-unemployment trade-off. The inference is conducted through the construction of what is known as the uniform confidence band (UCB). The proposed methodology is then applied to point-ahead inflation forecasting for the Korean economy. This paper finds that the forecasts can benefit from conducting UCB-based inference and that the inference results have important policy implications.

• Journal of the Korea Society for Simulation
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• v.13 no.1
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• pp.1-9
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• 2004

In this paper some models for obtaining the distribution of a sojourn time in CDMA cellular systems are proposed. Knowledge on this is essential for reliable modeling of the soft handoff and for solving other related problems in the analysis of cellular system. The proposed model is based on random walk and can be adopted to different conditions. Analytical results can be obtained that lead to a quite complicated numerical scheme so simulation models are used for Monte Carlo experiments. Main assumptions include different kinds of mobile carriers (pedestrians and transport passengers) and round shape of a cell. The scheme for simulation experiments is presented along with the discussion of simulation results.

• Quality Improvement in Health Care
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• v.20 no.1
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• pp.12-24
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• 2014

Objectives: The aim of this study was to explore whether emergency bell could shorten door to electrocardiograms (ECG) time in chest pain patients presenting to emergency department (ED) by self-transport. Methods: This was a planned 6-month before-and-after interventional study design. We set up the emergency bell in walk-in patients' waiting room. Prior to the change, patients were triaged before an ECG was obtained. In new process, as soon as patient with chest pain push the emergency bell, emergency physicians examined patient and prioritized performing ECG. We analyzed door to electrocardiograms (DTE) times for patients with chest pain and ST segment elevation myocardial infarction (STEMI) patients between two periods. Results: During the enrollment period, a total of 63 patients called emergency bell. The median DTE time was 6 min (interquartile range: 3.0 - 9.0) and 82.5% received an ECG within 10 minutes, and only three patients were STEMI. DTE time in patient with chest pain was not different between two periods (p=0.980). Before intervention period, 15 walk-in patients admitted in ED for STEMI and 53.8% of STEMI patients received an ECG within 10 minutes. After intervention period, total 19 walk-in patients admitted in ED for STEMI. Of these, 89.5% met the time requirement. Conclusion: Because a small portion of patients with chest pain activated the emergency bell, new strategy for promotion of emergency bell must be needed.

• The Korean Journal of Emergency Medical Services
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• v.24 no.2
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• pp.51-66
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• 2020

Purpose: The purpose of this study was to determine whether, in patients with acute coronary syndrome (ACS), according to the mode of arrival affect the emergency medical process. Methods: The participants of this study were 118 adult patients (46 patients admitted by emergency medical services (EMS), 48 walk-in patients, and 24 transferred from other hospitals) admitted to the emergency departments at one regional-level medical center who underwent coronary angiography between January 1, 2016 and December 31, 2017. To compare treatment courses, the median values of the following variables were compared among groups: symptom to door time; door to triage time; and door to ECG time. All data were analyzed using SPSS program. Results: Based on the initial assessment at triage, there was a significantly greater proportion of Korean Triage and Acuity Stage (KTAS) Level 1 or 2 among patients admitted by EMS than among walk-in patients. All three analyzed variables were lower in patients admitted by EMS than in the other two groups. Conclusion: Our results show that ACS patients who accessed EMS reached the emergency center faster after symptom onset, received initial triage assessment at earlier stages, and underwent sooner important examinations (i.e., the 12-lead ECG).

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.4
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• pp.295-303
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• 2012

Based on the data observed and analyzed on a groundwater flow system in the KURT (KAERI Underground Research Tunnel) site, the transport of radionuclides, which were assumed to be released at the supposed position, was calculated on the time-domain. A groundwater pathway from the release position to the surface was identified by simulating the groundwater flow model with the hydrogeological characteristics measured from the field tests in the KURT site. The elapsed time when the radionuclides moved through the pathway is evaluated using TDRW (Time Domain Random Walk) method for simulating the transport on the time-domain. Some retention mechanisms, such as radioactive decay, equilibrium sorption, and matrix diffusion, as well as the advection-dispersion were selected as the factors to influence on the elapsed time. From the simulation results, the effects of the sorption and matrix diffusion, determined by the properties of the radionuclides and underground media, on the transport of the radionuclides were analyzed and a decay chain of the radionuclides was also examined. The radionuclide ratio of the mass discharge into the surface environment to the mass released from the supposed repository did not exceed $10^{-3}$, and it decreased when the matrix diffusion were considered. The method used in this study could be used in preparing the data on radionuclide transport for a safety assessment of a geological disposal facility because the method could evaluate the travel time of the radionuclides considering the transport retention mechanism.

• Journal of Korea Game Society
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• v.7 no.4
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• pp.71-80
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• 2007

In this paper, we introduce an efficient GPU-based real-time rendering technique applicable to every kind of game. Our method, without an extra geometry, can represent terrain just with a height map. It makes it possible to freely go around in the air or on the surface, so we can directly apply it to any computer games as well as a virtual reality. Since our method is not based on any geometrical structure, it doesn't need special LOD policy and the precision of geometrical representation and visual quality absolutely depend on the resolution of height map and color map. Moreover, GPU-only technique allows the general CPU to be dedicated to more general work, and as a result, enhances the overall performance of the computer. To date, there have been many researches related to the terrain representation, but most of them rely on CPU or confmed its applications to flight simulation, Improving existing displacement mapping techniques and applying it to our terrain rendering, we completely ruled out the problems, such as cracking, poping etc, which cause in polygon-based techniques, The most important contributions are to efficiently deal with arbitrary LOS(Line Of Sight) and dramatically improve visual quality during walk-through by reconstructing a height field with curved patches. We suggest a simple and useful method for calculating ray-patch intersections. We implemented all these on GPU 100%, and got tens to hundreds of framerates with height maps a variety of resolutions$(256{\times}256\;to\;4096{\times}4096)$.