• The Korean Journal of Applied Statistics
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• v.23 no.5
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• pp.871-882
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• 2010

In animal tumorigenicity data, the occurrence time of tumor is not observed because the existence of a tumor is examined only at either time of natural death or time of sacrifice for the animal. A three-state model (Health-Tumor onset-Death) is widely used to model the incomplete data. In this paper, we employed a frailty effect into the three-state model to incorporate the dependency of death on tumor occurrence when the time of natural death works as an informative censoring against the tumor onset time. For the inference of parameters, then the EM algorithm is considered in order to deal with missing quantities of tumor onset time and random frailty. The proposed method is applied to the bladder tumor data taken from Lindsey and Ryan (1993, 1994) and a simulation study is performed to show the behavior of the proposed estimators.

• Journal of Biomedical Engineering Research
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• v.6 no.2
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• pp.53-62
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• 1985

The position and time interval of wave components of the electrocardiogram are used as important data for physician's diagnosis. In case of using the existing definition of the onset of the wave component of the electrocardiogram, they have some problems of defining the precise position of the isoelectric line, of defining the limit of the gradient accepted as the onset, and of the gradient being changed by noise. Therefore, in this paper all time intervals and positions of wave components needed for data of diagnosis were obtained correctly by turning point data reduction algorithm and linear regression intersection algorithm, and the viability of the method of intersecting lines was established in comparison to the four methods of calculating the PR interval.

• PNF and Movement
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• v.21 no.1
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• pp.107-117
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• 2023

Purpose: The aim of this study is to compare the immediate effects of weight-assisting methods on vastus medialis oblique (VMO) and vastus lateralis (VL) muscle activation, on the VMO/VL muscle activation ratio, and on muscle onset time in healthy subjects when ascending stairs. Methods: Healthy participants were randomly assigned to the belt group (n = 11), hand group (n = 11), and control group (n = 11). In the belt group, a belt was wrapped around the sacrum and pulled forward with both hands, moving the center of weight forward, while ascending stairs. The hand group grasped the hips with both hands and climbed stairs, assisting their weight from the rear and moving the center of weight backward, and the control group climbed the stairs without any intervention. Results: Muscle activation of the VMO decreased significantly after the intervention in the belt and hand groups, and activation of the VL muscle in both groups showed a greater decrease than that of the VMO muscle. Further, the VMO/VL muscle activation ratio increased significantly, with an improvement shown in the order of the belt group, hand group, and control group, while muscle onset time also improved in the order of the belt group, hand group, and control group. Conclusion: The belt group demonstrated the greatest effect across all dependent variables, confirming that in clinical practice, these two weight-assisting methods are more effective interventions during stair ascent for patients with knee joint instability, pain, and imbalance than no assistance.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.3
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• pp.105-110
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• 2016

PURPOSE: The aim of this study was to investigate the influence of hip abduction velocity and position change on the relative onset times of the gluteus medius, the tensor fascia latae, and the quadratus lumborum in healthy subjects. METHODS: For this study, 15 healthy young adults were recruited. The subjects were asked to move their hip joints up to 35 degrees of abduction at a speed of $70^{\circ}/sec$ and $17.5^{\circ}/sec$ in the supine and side-lying positions. Electromyography data was collected for the gluteus medius, tensor fascia latae, and quadratus lumborum to determine the onset times. RESULTS: There were significant differences between the fast speed ($70^{\circ}/sec$) and the slow speed ($17.5^{\circ}/sec$) in hip abduction in a supine position and in a side-lying position, relatively. The onset time of the gluteus medius was faster than that of the tensor fascia latae and the quadratus lumborum in the side-lying position at the speed of $70^{\circ}/sec$ and $17.5^{\circ}/sec$. CONCLUSION: The findings of this study indicated that hip abduction in a side-lying position is an effective method to recruit the gluteus medius earlier than the tensor fascia latae and the quadratus lumborum. Thus, the exercise position is considered necessory in the purpose of rehabilitation for gluteus medius muscle strengthening program.

• Korean Journal of Adult Nursing
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• v.19 no.2
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• pp.167-177
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• 2007

Purpose: This cross-sectional survey research was undertaken to identify the factors influencing time from onset to hospital arrival of stroke patients and to provide basic information for the development of intervention programs for stroke patients. Methods: The data were collected using a convenient sampling method from three hospitals in Inchon. The subjects were 78 patients who were diagnosed as stroke by doctor and they voluntarily participated in the study. Results: On the average, subjects arrived at the hospitals by 16.72 hours after the onset of stroke events with the range from 0.17 hours to 72 hours. Thirty-four(43.6%) subjects arrived within 3 hours which can maximize treatment effects. There was significant difference in hospital presentation time according to the level of knowledge(${\chi}^2=18.629$, p=.0003). A negative correlation was found between the hospital presentation time and self-efficacy (r= -.320, p=.004). Stepwise multiple regression analysis revealed that the most powerful predictor was self-efficacy. Self-efficacy, the level of knowledge and physical symptoms were significant factors and accounted for 21.7% of the variance of hospital presentation time in stroke patients. Conclusion: According to the results, self-efficacy is a useful concept for reducing the hospital presentation time from onset of attack in stroke patients. Therefore, nurses should consider educational programs which include not only a knowledge of stroke and recurrence prevention but also the concept of self-efficacy.

• Journal of Biosystems Engineering
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• v.29 no.6 s.107
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• pp.515-520
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• 2004

A device far estimating the optimal artificial insemination time consisted of a computer, RS module, and six direct-reflex photo-sensors. Program was written in LabWindows CVI. In order to establish references for estimating optimal artificial insemination time, lying rate of the thirty three $Berkshire{\times}Hampshire crossbred sows (parity 5 to 6) was recorded from 2 days after moving into stalls to artificial insemination using a time lapse VCR and was measured every hour with one minute interval using the scan point sampling method. Twenty low hours in a day were divided into three comparing periods : 21:00 to 06:59, 07:00 to 13:59, and 14:00 to 20:59. If sum of the percentages of tying during a comparing period was less than the reference value, the starting hour of the comparing period was considered as onset of estrus and the optimal artificial insemination time was estimated at 20 to 24 hours after onset of estrus. The experimental device was evaluated with twenty five $Berkshire{\times}Hampshire$ crossbred sows (parity 2 to 7) and 23 of 25 sows $(92\%)$ were pregnant. This result suggests that the experimental device is excellent in performance for estimating optimal artificial insemination time.

• Speech Sciences
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• v.10 no.4
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• pp.255-261
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• 2003

The purpose of this study was to investigate correlation of auditory development and language development of children with hearing impairment Eighteen subjects with severe or profound hearing loss participated in this study. They were 22-to 55-month-olds who had hearing parents with no additional disabling conditions. The test material was the Meaningful Auditory Integration Scale (MAIS) and MacArthur Communicative Development Inventory-Korea (MCDI-K). A Pearson Correlation Coefficient was determined through a statistical analysis. The results followed as; firstly there was a strong correlation between auditory development and receptive language development. Secondly, there was a strong correlation between receptive language development and expressive language development. Finally, there was a strong correlation between auditory development and education onset time. Therefore, auditory training is important method for auditory rehabilitation and education onset time is important variation for auditory development.

• Journal of Korean Biological Nursing Science
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• v.11 no.1
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• pp.23-31
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• 2009

Purpose: The purpose of the present study was to investigate the prevalence and related factors of sleep-wake disturbance (SWD) in Korean post-stroke patients. This study was the first to address post-stroke SWD in Korea using a structured questionnaire. Method: We investigated the prevalence of SWD and related factors including lesion location, stroke severity, presence of depression and fatigue. We assessed sleep-wake pattern including quality of sleep, sleep latency, wake episodes, wake time after sleep onset, daytime sleep episode and sleep time at daytime. Ninety stroke patients admitted to a university affiliated hospital in Seoul between the period September 2008 and January 2009 were included in the study. Result: Thirty five patients (38.9%) complained insomnia and 32 (35.6%) complained excessive daytime sleepiness (EDS). Quality of sleep (p=.000), sleep latency (p=.000) and total sleep time (p=.001) were significantly poorer in 16 patients with both insomnia and EDS than in the others. The related factors to insomnia were level of education (p=.030), depression (p=.007) and fatigue (p=.034), though related factors to EDS were stroke onset time (p=.049), stroke severity (p=.005), motor dysfunction (p=.035), dysphasia (p=.018), fatigue (p=.001) and lesion location (p=.019). Conclusion: Sleep-wake disturbance is a common problem in Korean stroke patients. Strategies to improve quality of sleep are urgently needed in the post-stroke patients.

• Journal of IKEEE
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• v.17 no.4
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• pp.505-510
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• 2013

In this paper, a method of estimating hand and elbow movements using electrocorticogram (ECoG) signals is proposed. Using multiple channels, surface electromyogram (EMG) signals and ECoG signals were obtained from patients simultaneously. The estimated movements were those to close and then open the hand and those to bend the elbow inward. The patients were encouraged to perform the movements in accordance with their free will instead of after being induced by external stimuli. Surface EMG signals were used to find movement time points, and ECoG signals were used to estimate the movements. To extract the characteristics of the individual movements, the ECoG signals were divided into a total of six bands (the entire band and the ${\delta}$, ${\Theta}$, ${\alpha}$, ${\beta}$, and ${\gamma}$ bands) to obtain the information entropy, and the maximum likelihood estimation method was used to estimate the movements. The results of the experiment showed the performance averaged 74% when the ECoG of the gamma band was used, which was higher than that when other bands were used, and higher estimation success rates were shown in the gamma band than in other bands. The time of the movements was divided into three time sections based on movement time points, and the "before" section, which included the readiness potential, was compared with the "onset" section. In the "before" section and the "onset" section, estimation success rates were 66% and 65%, respectively, and thus it was determined that the readiness potential could be used.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.1
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• pp.139-145
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• 1996

The input estimation method estimates maneuvering input acceleration in order to track a maneuvering target. In this paper, the optimal input estimator is derived by choosing the MAP hypothesis among maneuvering input transition hypotheses under the assumption that a maneuvering input acceleration is a semi-Markov process. The optimal input estimation method cannot be realized because the optimal filter should consider every maneuver onset time hypothesis from filter starting time to current time which increase rapidly. Hence the suboptimal filter using a sliding window is proposed. Since the proposed method can consider all hypotheses of input transitions inside the window, it is general enough to include Bogler's input estimation method. Simulation results show, however, that we can obtain a good performance even when the filter considering just one input transition in the window is used. (author). 9 refs., 3 figs., 1 tab.