• Journal of Korean Academy of Nursing
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• v.46 no.6
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• pp.804-812
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• 2016

Purpose: This research was done to identify the hospital arrival rate and factors related to prehospital delay in arriving at an emergency medical center within the golden time after symptom onset in patients with acute myocardial infarction (AMI). Methods: Data used in the research was from the National Emergency Department Information System of the National Emergency Medical Center which reported that in 2014, 9,611 patients went to emergency medical centers for acute myocardial infarction. Prehospital time is the time from onset to arrival at an emergency medical center and is analyzed by subdividing arrival and delay based on golden time of 2 hour. Results: After onset of acute myocardial infarction, arrival rate to emergency medical centers within the golden time was 44.0%(4,233), and factors related to prehospital delay were gender, age, region of residence, symptoms, path to hospital visit, and method of transportation. Conclusion: Results of this study show that in 2014 more than half of AMI patients arrive at emergency medical centers after the golden time for proper treatment of AMI. In order to reduce prehospital delay, new policy that reflects factors influencing prehospital delay should be developed. Especially, public campaigns and education to provide information on AMI initial symptoms and to enhance utilizing EMS to get to the emergency medical center directly should be implemented for patients and/or caregivers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.95-98
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• 1997

Theoritical predictions are given of the time dependence of charged particle densities and electric field in a pseudospark discharge. Our medel is based on a numerical solution of the continuity equation for electrons and positive ions and coupled with Poisson's equation for the electric field. From numerical results, we can identify phisical mechanisms that lead to the rapid rise in current in the onset of a pseudospark discharge.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.243-248
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• 2004

The timings of two successive events of interest may not be measurable, instead it may be right censored or interval censored; this data structure is called doubly censored data. In the study of HIV, two such events are the infection with HIV and the onset of AIDS. These data have been analyzed by authors under the assumption that infection time and induction time are independent. This paper investigates the regression problem when two events arc modeled to allow the presence of a possible relation between two events as well as a subject-specific effect. We derive the estimation procedure based on Goetghebeur and Ryan's (2000) piecewise exponential model and Gauss-Hermite integration is applied in the EM algorithm. Simulation studies are performed to investigate the small-sample properties and the method is applied to a set of doubly censored data from an AIDS cohort study.

• Journal of Veterinary Clinics
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• v.36 no.6
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• pp.364-367
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• 2019

The aim of this study was to compare the plasma progesterone concentrations during gestation in 4 breeds of companion bitches. When Day 0 was timed the first male acceptance, plasma progesterone were 1.8 ± 0.4 ng/ml (Mean ± SD) at Day 0 and increased constantly with 58.5 ± 8.9 ng/ml a peak at Day 20. Thereafter plasma progesterone concentrations was decreased below 1.0 ng/ml with 0.7 ± 0.2 g/ml at Day 65. There were no statistically significant differences of plasma progesterone concentrations in the each day of gestation and in litter size among the companion bitches (p < 0.01). These results indicated that the plasma progesterone concentrations was useful method for estimating optimal breeding time, ovulation time, the time of onset of parturition, properly planned elective cesarean section and abortion time in companion bitches.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5789-5796
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• 2011

This study examined the effect of VT(Vibration Training) on the symptoms of DOMS (Delayed-Onset Muscle Soreness) before induced by eccentric exercise of the left leg triceps surae. Twenty one healthy adult men and women who had not participated in a regular exercise program for the lower extremities were assigned to one of two experimental groups: vibration training group, Control group. We measured the VAS(Visual Analogue Scale), ankle plantar flexor strength, triceps surae circumference, CK(Creatine Kinase) before and after exercise and 24, 48 and 72 hours after eccentric exercise. After inducing DOMS, VAS showed significant differences between groups at a point of time 48 hours, and showed significant differences within groups in accordance with the time of measurement(p<.05). Plantar flexor strength of groups with VT did not show significant difference between groups but, showed significant differences within groups in accordance with the time of measurement(p<.05). Triceps surae circumference of groups with VT did not show significant difference between groups but, showed significant differences within groups in accordance with the time of measurement(p<.05). CK of groups with VT did not show significant difference between groups but, showed significant differences within groups in accordance with the time of measurement(p<.05). As a result of the study, VT prior to eccentric exercise is effective to inhibit pain. So, this method can be suggested to prevent DOMS in doing an unfamiliar activites.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.3
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• pp.433-444
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• 2020

This study proposes a method to improve the sleep stage and efficiency estimation of sleep apnea patients using a UWB (Ultra-Wideband) radar. Motion and respiration extracted from the radar signal were used. Respiratory signal disturbances by motion artifacts and irregular respiration patterns of sleep apnea patients are compensated for in the preprocessing stage. Preprocessing calculates the standard deviation of the respiration signal for a shift window of 15 seconds to estimate thresholds for compensation and applies it to the breathing signal. The method for estimating the sleep stage is based on the difference in amplitude of two kinds of smoothed respirations signals. In smoothing, the window size is set to 10 seconds and 34 seconds, respectively. The estimated feature was processed by the k-nearest neighbor classifier and the feature filtering model to discriminate between the sleep periods of the rapid eye movement (REM) and non-rapid eye movement (NREM). The feature filtering model reflects the characteristics of the REM sleep that occur continuously and the characteristics that mainly occur in the latter part of this stage. The sleep efficiency is estimated by using the sleep onset time and motion events. Sleep onset time uses estimated features from the gradient changes of the breathing signal. A motion event was applied based on the estimated energy change in the UWB signal. Sleep efficiency and sleep stage accuracy were assessed with polysomnography. The average sleep efficiency and sleep stage accuracy were estimated respectively to be about 96.3% and 88.8% in 18 sleep apnea subjects.

• Physical Therapy Korea
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• v.27 no.3
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• pp.191-198
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• 2020

Background: Stroke patients experience multiple dysfunctions that include motor and sensory impairments. Therefore, new intervention methods require a gradational approach depending on functional levels of a stroke patient's activity and should include cognition treatment to allow for a patient's active participation in rehabilitation. Objects: This study investigates the effect of integrated revision of electrical sensory stimulation, which stimulates somatosensory and action observation training, which is synchronized cognition intervention method on stroke patients' functions. Methods: Twenty-one stroke patients were randomized into two groups. The two groups underwent twenty minutes of intervention five times a week for three weeks. This study used an electromyogram to evaluate symmetric muscle activation of lower extremities and muscle onset time when performing sit to stand before and after intervention. A weight-bearing ratio was used to evaluate the weight-bearing of the affected side in a sit to standing. To evaluate sit to stand performance ability, this study performed five timed sit to stand tests. Results: The two groups both showed statistically significant improvement in muscle onset time of lower extremity, static balance ability in a standing position, and sit to stand performance after the intervention (p < 0.05). In addition, the action observation and synchronized electrical sensory stimulation group showed significant improvement in symmetric muscle activation of lower extremities and weight-bearing ratio of the affected side (p < 0.05). Conclusion: action observation and synchronized electrical sensory stimulation (AOT with ESS) can have positive effects on a stroke patient's sit to stand performance, and the intervention method that provides integrated AOT with ESS can be used as new nervous system intervention program.

• Genomics & Informatics
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• v.21 no.3
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• pp.28.1-28.13
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• 2023

Mild cognitive impairment (MCI) is a clinical syndrome characterized by the onset and evolution of cognitive impairments, often considered a transitional stage to Alzheimer's disease (AD). The genetic traits of MCI patients who experience a rapid progression to AD can enhance early diagnosis capabilities and facilitate drug discovery for AD. While a genome-wide association study (GWAS) is a standard tool for identifying single nucleotide polymorphisms (SNPs) related to a disease, it fails to detect SNPs with small effect sizes due to stringent control for multiple testing. Additionally, the method does not consider the group structures of SNPs, such as genes or linkage disequilibrium blocks, which can provide valuable insights into the genetic architecture. To address the limitations, we propose a Bayesian bi-level variable selection method that detects SNPs associated with time of conversion from MCI to AD. Our approach integrates group inclusion indicators into an accelerated failure time model to identify important SNP groups. Additionally, we employ data augmentation techniques to impute censored time values using a predictive posterior. We adapt Dirichlet-Laplace shrinkage priors to incorporate the group structure for SNP-level variable selection. In the simulation study, our method outperformed other competing methods regarding variable selection. The analysis of Alzheimer's Disease Neuroimaging Initiative (ADNI) data revealed several genes directly or indirectly related to AD, whereas a classical GWAS did not identify any significant SNPs.

• International Journal of Automotive Technology
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• v.8 no.1
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• pp.33-38
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• 2007

Since it is difficult to analytically express the Melnikov function when a dynamic system possesses multiple saddle fixed points with homoclinic and/or heteroclinic orbits, this paper investigates a vehicle model with nonlinear suspension spring and hysteretic damping element, which exhibits multiple heteroclinic orbits in the unperturbed system. First, an algorithm for Melnikov integrals is developed based on the Melnikov method. And then the amplitude threshold of road excitation at the onset of chaos is determined. By numerical simulation, the existence of chaos in the present system is verified via time history curves, phase portrait plots and $Poincar{\acute{e}}$ maps. Finally, in order to further identify the chaotic motion of the nonlinear system, the maximal Lyapunov exponent is also adopted. The results indicate that the numerical method of estimating chaotic threshold is an effective one to complicated vehicle systems.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3039-3044
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• 2007

A few fluid structure interaction analyses have been developed for turbomachinery blades in comparison with aircraft wings. Also, the existing aeroelastic analyses for turbomachinery blades have been mostly limited to cases with a steady freestream. In reality, however, the inflowing freestream is often pulsating. Therefore, this paper presents stability and forced response analyses of an isolated three-dimensional blade under pulsating freestream conditions. A new three-dimensional unsteady vortex lattice model under a pulsating freestream has been developed in discrete time domain to examine unsteady aerodynamic forces acting on a vibrating blade. The blade's structural behaviors have been analyzed by using a three-dimensional plate model. In the aeroelastic analysis, the flutter onset of a blade under pulsating freestream is predicted by the Floquet analysis. The new time domain method can predict aeroelastic stability as well as time history.