• Phonetics and Speech Sciences
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• v.3 no.3
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• pp.91-98
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• 2011

In this paper, a multi-channel speech enhancement method using the linearly constrained minimum variance (LCMV) algorithm and a variable learning rate control is proposed. To control the learning rate for adaptive filters of the LCMV algorithm, the direction of arrival (DOA) is measured for each short-time input signal and the likelihood function of the target speech presence is estimated to control the filter learning rate. Using the likelihood measure, the learning rate is increased during the pure noise interval and decreased during the target speech interval. To optimize the parameter of the mapping function between the likelihood value and the corresponding learning rate, an exhaustive search is performed using the Bark's scale distortion (BSD) as the performance index. Experimental results show that the proposed algorithm outperforms the conventional LCMV with fixed learning rate in the BSD by around 1.5 dB.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.34
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• pp.139-146
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• 1995

This study is concerned with cost analysis in periodic maintenance policy. Generally periodic maintenance policy in which item is repaired periodic interval times. And in the article minimal repair is considered. Minimal repair means that if a unit fails, unit is instantaneously restored to same hazard rate curve as before failure. In the paper periodic maintenance policy with minimal repair is as follows; Operating unit is periodically replaced in periodic maintenance time, if a failure occurs between minimal repair and periodic maintenance time, unit is replaced by a spate until the periodic time comes. Also unit undergoes minimal repair at failures in minimal-repair-for-failure interval. Then total expected cost per unit time is calculated according to maintenance period and scale parameter of failure distribution. Total cost factors ate included operating, fixed, minimal repair, periodic maintenance and replacement cost Numerical example is shown in which failure time of system has erlang distribution.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.36
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• pp.287-295
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• 1995

This paper is concerned with cost analysis model in periodic maintenance policy. Generally periodic maintenance policy in which item is repaired periodic interval times. And in the article minimal repair is considered. Mimimal repair means that if a unit fails, unit is instantaneously restored to same hazard rate curve as before failure. In the paper periodic maintenance policy with minimal repair is as follows; Operating unit is periodically replaced in periodic maintenance time, if a failure occurs between minimal repair and periodic maintenance time, unit is replaced by a new item until tile periodic maintenance time comes. Also unit undergoes minimal repair at failures in minimal-repair-for-failure interval. Then total expected cost per unit time is calculated according to scale parameter of failure distribution. Maintenance cost factors are included operating, fixed, minimal repair, periodic maintenance and new item replacement cost. Numerical example is shown in which failure time of system has weibull distribution.

• Archives of Plastic Surgery
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• v.46 no.4
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• pp.359-364
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• 2019

Background Few scales are currently available to evaluate changes in hand volume. We aimed to develop a hand grading scale for quantitative assessments of dorsal hand volume with additional consideration of changes in skin texture; to validate and prove the precision and reproducibility of the new scale; and to demonstrate the presence of clinically significant differences between grades on the scale. Methods Five experienced plastic surgeons developed the Hand Volume Rating Scale (HVRS) and rated 91 images. Another five plastic surgeons validated the scale using 50 randomly selected images. Intra- and inter-rater agreement was calculated using the weighted kappa statistic and intraclass correlation coefficients (ICCs). Paired images were also evaluated to verify whether the scale reflected clinical differences. Results The intra-rater agreement was 0.95 (95% confidence interval, 0.922-0.974). The interrater ICCs were excellent (first rating, 0.94; second rating, 0.94). Image pairs that differed by 1, 2, and 3 grades were considered to contain clinically relevant differences in 80%, 100%, and 100% of cases, respectively, while 84% of image pairs of the same grade were found not to show clinically relevant differences. This confirmed that the scale of the HVRS corresponded to clinically relevant distinctions. Conclusions The scale was proven to be precise, reproducible, and reflective of clinical differences.

• Phonetics and Speech Sciences
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• v.9 no.4
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• pp.129-136
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• 2017

This study investigates the effect of voice quality on speech intelligibility and the relationship between voice quality and intelligibility for children with spastic CP. We recruited 36 children with spastic CP (mean age 10.43 year, 17 girls, 19 boys, spastic type 34, mixed 2) from a special school and a rehabilitation hospital. Voice samples for the perceptual analysis of voice quality were extracted from a sustained vowel /a/ and were rated on the GRBAS scales by two experienced speech language pathologists. Ten adult subjects with no hearing problems evaluated speech intelligibility for the 37 words listed in the Assessment of Phonology and Articulation for Children on a 7-point interval scale. The children with spastic CP were divided into three groups according to the rated G scores on the GRBAS scales (G1(n)=10, G2(n)=13, G3(n)=13). Analyses of ANCOVA and Pearson correlation showed that there was a significant difference in speech intelligibility among three groups. There was also a significant correlation in G scale (grade), A scale (asthenia), B scale (breathy) score, and speech intelligibility. These findings suggest that poor speech intelligibility of spastic CP might be related to asthenia and breathiness. Vocal intensity should be increased and vocal functioning should be improved for speech therapy to improve speech intelligibility of the children with spastic CP.

• Journal of Korean Neurosurgical Society
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• v.52 no.3
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• pp.172-178
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• 2012

Objective : The aim of this study was to determine the role of intra-arterial (IA) nimodipine injections for cerebral vasospasm secondary to ruptured subarachnoid hemorrhage (SAH) and to investigate the factors that influence vasodilation and clinical outcomes. Methods : We enrolled 29 patients who underwent aneurysm clipping for ruptured cerebral aneurysms between 2009 and 2011, and who received IA nimodipine after subsequently presenting with symptomatic vasospasm. The degree of vasodilation shown in angiography was measured, and the correlation between the degree of vasodilation and both the interval from SAH to cerebral vasospasm and the interval from clipping to cerebral vasospasm was determined. The change in blood flow rate after IA injection was assessed by transcranial Doppler ultrasound. Multiple clinical parameters were completed before and after IA nimodipine injection to evaluate any improvements in clinical symptoms. Results : For eight patients, Glasgow Coma Scale (GCS) scores increased by two or more points. The regression analysis demonstrated a positive correlation between the change in GCS scores after IA nimodipine injection and the change in blood vessel diameter (p=0.025). A positive correlation was also observed between the interval from SAH to vasospasm and the change in diameter (p=0.040); and the interval from clipping to vasospasm and the change in diameter (p=0.022). Conclusion : IA nimodipine injection for SAH-induced vasospasm led to significant vasodilation in angiography and improvement in clinical symptoms without significant complications. Our findings suggest that IA nimodipine injection should be utilized when intractable vasospasm develops despite rigorous conservative management.

• Therapeutic Science for Rehabilitation
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• v.9 no.4
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• pp.107-120
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• 2020

Objective : The purpose of this study was to investigate the effectiveness and basis of rehabilitation intervention in patients with spinal cord injury by systematic review and meta-analysis of randomized controlled studies. Methods : Two researchers independently searched and selected a study published in an academic journal using a search term in an international thesis database. A total of 21 studies met the selection criteria, and qualitative evaluation of the study was conducted using the PEDro Scale. Meta-analysis was performed using Comprehensive Meta-Analysis 3.0 program. Results : A total of 713 subjects were included. The results of the meta-analysis showed a score of 0.406 (95.0% confidence interval: 0.221 ~ 0.591) for intervention using physical activity and 0.505 (95.0% confidence interval: 0.449 ~ 1.528) for electronic stimulation therapy, which showed medium effect; educational intervention had a 0.248 (95.0% confidence interval: 0.033 ~ 0.464), and mixed intervention 0.280 (95.0% confidence interval: 0.122 ~ 0.438). It was shown that the effect of small (small). There was a significant heterogeneity in the statistical heterogeneity test, and thus the random effects model was selected and analyzed. Conclusion : The results showed that rehabilitation interventions were effective for patients with spinal cord injury. During the rehabilitation of spinal cord injury patients, clinicians are expected to contribute to the development of programs to improve their lifestyles.

• 한국체육학회지인문사회과학편
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• v.58 no.4
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• pp.447-459
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• 2019

This study was conducted to investigate the differences between emotional responses and neurotransmitters in moderate-intensity continuous exercise (MICE) and high-intensity interval exercise (HIIE) in 30 low-active women. Both groups performed a designed acute treadmill exercise and repeated the same exercise three times at intervals of one week. MICE performed a 25-minute continuous exercise at 90% VT(ventilation threshold) after a 5-minute warm-up session at 50% VT and then cooled down for 5 minutes at 50% VT level. The HIIE was repeated 6 times for 2 minutes at 115% VT level, and the intermediate active recovery was repeated 4 times for 2 minutes at 85% VT level. The results of the statistical analysis are as follows. MICE was showed positive effect for feeling scale and PACES after exercise in the first experiment, but negative effect in the third experiment. Conversely, HIIE was showed negative effect for feeling scale and PACES after exercise in the first experiment, but positive effect in the third experiment. Neurotransmitters were significantly increased in all three groups after 10 minutes of exercise compared to before exercise. In summary, HIIE exercise may be a strategy to increase exercise compliance for low-active women.

• Physical Therapy Korea
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• v.23 no.1
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• pp.46-54
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• 2016

Background: Rasch analysis estimates the probability that a respondent will endorse an item and select a particular rating for that item. It has the advantage of placing both the items and the person along a single ration scale and calibrates person ability and item difficulty onto an interval scale by logits. In addition, Rasch analysis is a useful tool for exploring the validity of questionnaires that have been developed using traditional methods. Therefore, it has been recommended as a method for developing and evaluating functional outcome measures. Objects: The purpose of this study was to investigate the item fit, item difficulty, and rating scale of the Korean version of the Fullerton Advanced Balance Scale (KFAB) using Rasch analysis. Methods: Total 97 subjects (39 males and 58 females) with dwelling elderly adults were participated, but 3 people were excluded for misfit persons. Rasch analysis was then done by means of the Winsteps program to determine the item fit, item difficulty, rating scale, and reliability of the KFAB. Results: In this study, the 'standing with feet together and eyes closed', 'two-footed jump', 'walk with head turns', and 'stand on foam, eyes closed' items shown misfit statistics. The most difficult item was 'stand on one leg', whereas the easiest item was 'turn in full circle'. The rating scale was acceptable with all criteria. Both item and person separation indices and reliability showed acceptable values. This would indicated that each domain covers a useful range of item difficulty that is appropriate for measuring a person with a wide range of functional ability. Conclusion: The KFAB has been proven reliable, valid and an appropriate tool with which to evaluate the balance of the elderly people.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.281-288
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• 2015

In this paper, the maximum likelihood estimators and confidence intervals for parameters of Weibull distribution are derived under three level constant stress accelerated life tests and the assumption that a log quadratic relationship exits between stress and the scale parameter ${\theta}$. The compound linear plan proposed by Kim (2006) is used to allocate the test units at each stress level, which performed nearly as good as the optimum quadratic plan and had the advantage of simplicity. Some simulation studies are given.