• Physical Therapy Korea
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• v.28 no.2
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• pp.123-131
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• 2021

Background: Only 2% of falls in older adults result in serious injuries (i.e., hip fracture). Therefore, it is important to differentiate injurious versus non-injurious falls, which is critical to develop effective interventions for injury prevention. Objects: The purpose of this study was to a. extract the best features of surface electromyography (sEMG) for classification of injurious falls, and b. find a best model provided by data mining techniques using the extracted features. Methods: Twenty young adults self-initiated falls and landed sideways. Falling trials were consisted of three initial fall directions (forward, sideways, or backward) and three knee positions at the time of hip impact (the impacting-side knee contacted the other knee ("knee together") or the mat ("knee on mat"), or neither the other knee nor the mat was contacted by the impacting-side knee ("free knee"). Falls involved "backward initial fall direction" or "free knee" were defined as "injurious falls" as suggested from previous studies. Nine features were extracted from sEMG signals of four hip muscles during a fall, including integral of absolute value (IAV), Wilson amplitude (WAMP), zero crossing (ZC), number of turns (NT), mean of amplitude (MA), root mean square (RMS), average amplitude change (AAC), difference absolute standard deviation value (DASDV). The decision tree and support vector machine (SVM) were used to classify the injurious falls. Results: For the initial fall direction, accuracy of the best model (SVM with a DASDV) was 48%. For the knee position, accuracy of the best model (SVM with an AAC) was 49%. Furthermore, there was no model that has sensitivity and specificity of 80% or greater. Conclusion: Our results suggest that the classification model built upon the sEMG features of the four hip muscles are not effective to classify injurious falls. Future studies should consider other data mining techniques with different muscles.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.25-26
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• 2021

Due to COVID-19, the spread of non-face-to-face culture is increasing the time spent indoors. Accordingly, it is necessary to reduce indoor air pollutants. Also, among building materials, there are paints. As the number of coatings increases, the coating film becomes thick, and there is a risk of cracking and falling off. Therefore, this study is to examine the adsorption properties of indoor air pollutants according to the number of coatings of a paint mixed with powdered activated carbon. In the experimental plan, the addition ratio of powdered activated carbon was selected as 30%, and the number of coatings was selected as primcoating, second coat, and finishing coat, and the concentration of formaldehyde and volatile organic compounds were measured. As a result, as the number of coatings increased, the concentration of formaldehyde and volatile organic compounds tended to decrease. This is considered to be due to the fact that not only the physical adsorption acted by the internal pores of the powdered activated carbon, but also because a lot of powdered activated carbon was present on the painted surface as the coating film was formed. However, since it is judged that there is an error in the concentration due to the inflow of external air as the chamber cover is opened to put the test object in the adsorption test process, it is considered that the experimental method needs to be supplemented.

• Safety and Health at Work
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• v.15 no.1
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• pp.53-58
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• 2024

Background: As social distancing persists and interest in work-life balance grows, more companies are adopting flexible work policies. While there have been studies on sleep disorders associated with different types of work, such as shift work, research exploring the relationship between flexible work schedules and sleep disorders is still limited, particularly among Korean workers. Methods: We performed a secondary analysis of the 6th Korean Working Conditions Survey, focusing on 31,243 paid workers out of a total of 50,538 participants. We defined flexible workers as those who set their own working hours. Sleep disorders were divided into three categories: 'difficulty falling asleep,' 'frequent waking during sleep,' and 'waking up feeling exhausted and fatigued.' Using scores derived from three specific symptoms, the Minimal Insomnia Symptoms Scale (MISS) was calculated to assess the prevalence of insomnia. We used chi-square tests to analyze demographic and job-related differences. A multivariate logistic regression analysis was employed to identify any relationship between flexible work schedules and sleep disorders. Results: Significant differences were found between flexible and non-flexible workers regarding age, income level, education level, and job type. Flexible workers reported sleep-related symptoms significantly more often. The odds ratio for insomnia was 1.40 (95% CI 1.21-1.61). For males, the odds ratio was 1.68 (1.36-2.08). Conclusion: This study establishes a correlation between flexible work schedules and sleep disorders among Korean salaried workers. Potential causes could include changes in circadian rhythm, increased work demands, and extended working hours. To precisely determine causality and associated diseases, further research is required.

• The Journal of Korean Physical Therapy
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• v.4 no.1
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• pp.27-42
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• 1992

The purpose of this study is to investigate the occurence properties of the complications in spinal cord injured patients. Clinical observation were for 116 cases in and out wards, were carried out during one year from july, 1990 to June, 1991 at 4 general hospitals in Taegu, Korea. The results of this study is summarized as follows : 1. Among the 116 cases, $67.7\%$ was male and $35.3\%$ was female. The largest groups were noted in $60.7\%$, of the forties by age, in $34.5\%$ of the middle school by educational career, in $27.6\%$ of the administer by professional division. 2. The number of complications in a patient in the largest group was two-type. The next groups were three-type, $23.3\%$ and five-type, $20.7\%$. Of each factors, the largest numbers of two-type recorded tuberculosis of spine$(71.4\%)$, thoracic cord injury$(63.4\%)$, incomplete paraplegia$(48.4\%)$, and inwards during 1-2 months $(47.4\%)$. 3. Total number of the complications were counted to 367 cases. The largest group of complications was pain, $24.8\%$. The next groups were pressure sores, $19.9\%$. spasticity, $12.5\%$, and urinary tract infection, $9.3\%$. 4. The number of the 4 major complications(pain, pressure sores, joint contracture, spasticity) was counted to 280 cases. The largest group of the major complications was pain, $32.5\%$. The next groups were pressure sores, $26.1\%$, joint contracture, $25.9\%$ and spasticity, $16.4\%$. Of each factors, the largest numbers of the pain recorded female$(40.5\%)$, thirties$(49.2\%)$, non-educate $(53.8\%)$, labor$(38.2\%)$, traffic accidents$(32.8\%)$, thoracic cord injury$(34.4\%)$, complete paraplegia$(58.1\%)$, and inwards during above 13 months$(37.5\%)$. 5. The largest group of the pain portion was shoulder. $49.4\%$. The non groups were lower extremity, $25.2\%$, hip, $11.0\%$, and all bodies, $4.3\%$. The largest numbers of the shoulder pain recorded thirties$(59.4\%)$, traffic accidents $(52.7\%)$, cervical cord injury$(67.2\%)$. complete quadriplegia$(81.8\%)$, and inwards during above 13 months$(100.0\%)$. 6. The largest group of the pressure sores sites was sacral portion, $83.6\%$. The next groups were hip, $6.8\%$, maleollus, $4.1\%$. The largest numbers of pressure sores formation in the sacral portion recorded below 19 and above $60(100.0\%)$, falling objects$(100.0\%)$, lumbar cord injury$(100.0\%)$, incomplete paraplegia$(100.0\%)$, and in wards during 3-4 months$(95.9\%)$. 7. The largest group of the joint contracture portion was lower extremity, $61.4\%$, follows was upper extremity, $38.6\%$. The largest numbers of the joint contrcture portions recorded thirties$(100.0\%)$, traffic accidents$(86.1\%)$, cervical cord injury$(80.4\%)$, complete quadriplegia$(86.7\%)$, and inwards during 3-4 months $(82.2\%)$ 8. The largest group of spasticity portion was lower extremity, $53.0\%$. The next groups were hip. 23.9, 23.9, ankle, $8.7\%$, and elbow, $4.3\%$. The largest numbers of the spasticity portions recorded above $60(100.0\%)$, falling $(100.0\%)$, cervical cord injury$(71.4\%)$, incomplete quadriplegia$(71.4\%)$, and inwards during 1-2 months $(100.0\%)$.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.2
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• pp.102-107
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• 2003

At orthodontic treatment, we have made every effort to get rigid anchorage which is not stirred when teeth move. As a result, the miniscrew that is rigid anchorage was invented recently, and now it is used widely. Concerning the advantage of miniscrew, it is reduced dependence of extraoral anchorage and it shortens treatment time for rapid tooth movement. In contrast, the defect of miniscrew is falling off it resulted from increasing of the mobility. So the purpose of this research is to be of help to prognose clinical use of miniscrew, which is inserted for intraoral anchorage, by investigating and comparing the failure rate of miniscrew for loading time. This study researches the failure rate of miniscrew for teeth movement at the orthodontic treatment. The failure rate of miniscrew in mid course, after inserting 147 miniscrews in 51 patients, is 13%(20/147). It showed no statistically significant differences as compared man with woman, maxilla with mandible, double-head with uni-head miniscrew, and drilling and non-drilling before inserting the miniscrew. In comparison below twenties with over twenties and the times that we give load to miniscrew, it produced that the failure rate of miniscrew is 9.7% higher in the case of below the twenties than over the twenties. Also, the failure rate of loading immediately is 10.8% higher than loading after 7 days. According to using driver for the insertion of miniscrew, the failure rate of miniscrew is higher in the case of using machined driver than in the case of using hand driver when the level of significance is 95%. According to the research, we can suppose that the failure rate has no concern with using miniscrew on man or woman, maxilla or mandible, the shape of head, and drilling or non-drilling before insertion of miniscrew. Therefore, we can choose eclectic miniscrew as demands. In addition, we must notify the patient, below twenties, to be possibility of high failure rate. And It is strongly recommended to give load after $1{\sim}2$ weeks for healing of the insertion area.

• Research in Plant Disease
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• v.13 no.3
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• pp.131-136
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• 2007

Occurrence of popcorn disease on mulberry fruits was surveyed in several locations in Korea from 2005 to 2007. The diseased fruits turned grayish white and changed to hard and black sclerotia during overwintering after falling onto the ground. Apothecia produced from overwintered sclerotia in the fields of mulberry trees were observed in early May. Two types of apothecia were produced from the sclerotia, which were cup-shaped or club-shaped. The fungus with cup-shaped apothecia was identified as Ciboria shiraiana, and that with club-shaped apothecia as Scleromitrula shiraiana. C. shiraiana occurred at the ratio of about 6 vs. 4 in the fields. Occurrence of the disease differed remarkably depending on years, locations, and varieties of mulberry trees investigated. Field survey of the disease incidence showed that Baekhahyeongsang, Dahojosaeng, Hasusang, a native variety and Sawonppong 22 were resistant to the disease, Cheongilppong, Daeseongppong, Guksang 20 and Turkey-D were moderately susceptible, and Cateneo, Moreji and Sanggwa were highly susceptible. Disease incidence in the fields mulched with nonwoven fabrics or plastic films was much lower than that in the non-mulched fields. Disease incidence in the fields mulched with rice straws was similar to that in the non-mulched fields.

• Korean Journal of Plant Taxonomy
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• v.44 no.1
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• pp.22-32
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• 2014

The petal and sepal micromorphology of five species of Glechoma (Lamiaceae) was investigated to evaluate their taxonomic significance, and a molecular phylogeny using the sequences of internal transcribed spacers (ITS) regions of nuclear ribosomal DNA was carried out to resolve their phylogenetic relationships. Stomatal complexes were mostly found in the inner and outer part of the sepal from all investigated taxa, and the size length of the guard cell was variable among the taxa. Five types of trichomes (uni-cellular non-glandular trichome, multi-cellular non-glandular trichome, short-stalked capitate glandular trichome, long-stalked capitate glandular trichome, and peltate glandular trichome) were variable among the taxa as well as their distribution and density. In molecular phylogenetic studies, the genus Glechoma was composed of three geographically distinct major monophyletic groups (Europe-U.S.A., China-Korea, Japan). G. longituba in Korea and China formed well-supported monophyletic group. G. hederacea in Europe and U.S.A. formed a monophyletic and well-supported clade with G. sardoa, which are endemic species in Italy, with G. hirsuta falling as a sister to this clade. However, G. grandis did not form any phylogenetic relationships with the remaining taxa. The ITS analyses provided taxonomic boundaries of taxa in Glechoma although the petal and sepal micromorphological characters provided weak evidences of the systematic value. As further studies, incorporating more DNA regions to the matrix including other additional morphological analysis will be significant to provide clearer taxonomic structure in Glechoma.

• Journal of Oriental Neuropsychiatry
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• v.11 no.1
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• pp.145-167
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• 2000

Jiu Qi(九氣) was shown at Ju Tong Lun(擧痛論) in Shao Wen(素問) Huang Ti Nei Ching(黃帝內經), and is nine important factors that affect the function of human body. Jiu Qi concludes endogenous, exogenous, non-endo-exogenous factors. I do the bibliographical study on the Jiu Qi, the results were as follows; 1. The Qi of Jiu Qi has two opposite meanings. one is genuine vital energy(正氣), and the other is the factors causing abnormal state in vital energy. Jiu Qi is nine factors concluding coldness-heat(exogenous factors). six emotional factors(endogenous factor), overworking(non -endo-exogenous factor). 2. Anger may lead to abnormal rising of vital energy. Anger causes Qi of the liver to go perversely upward, and perverted flow of exuberant Qi of the liver lead to dysfunction of the spleen, so resulted in hematemesis, diarrhea, indigestion. 3. Joy can promote the harmony of vital energy and blood, so do the circulation of nutrient and defensive energy in physiological state. But an excessive joy may lead to the sluggishness of vital energy. 4. The lung keeps the pathway of air unconstructed, disseminates vital energy, cleanses the inspired air and keeps vital energy flowing downward. Sorrow affects on the function of the lung and the heart, so could result in obstruction of the circulation of nutrient and defensive energy. An excessive sorrow after stagnation may lead to the consumption of vital energy. 5. Fear makes vital energy and essence of the kidney sink to inward and downside, makes Yang-Qi can't go upward, so causes obstruction of triple wanner. An excessive fear can obstructs the ascending of Yang-Qi, so may lead to the abnormal falling of vital energy. 6. Coldness makes the sweat pore be contracted, so obstructs the circulation of triple warmer, causes sluggishness of defensive energy or Qi of the internal organ. 7. Heat makes the sweat pore be open, much amount of sweat is excreted with Yang-Qi, defensive energy, vital energy. Heat may consume vital energy. 8. Sudden fright affects on spirits of the heart and liver, causes disorder of the mental faculties and separation of blood and vital energy. Fright may lead to disorder of Qi. 9. Overwork concludes overfatigue and exhaustion caused by intemperance in sexual life. Overwork renders vital energy consumed, and hence results in lassitude and listlessness. 10. Thinking affects on the function of the heart and the spleen. Over thinking may lead to depression of vital energy. Through the bibliographical study on Jiu Qi, I got smallest amount of it, and this must be more investigated correlating with clinical study.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.4
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• pp.550-561
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• 2019

Objectives: The purpose of this study is to provide basic data for the improvement of the working environment for health prevention and related countermeasures for shift workers. This study was conducted based on the Fifth Korean Working Conditions Survey (KWCS), which analyzed the health effects of shift work forces and compared them with preceding studies. Methods: By analyzing secondary rates using raw data from the 5th KWCS, 4,870 (9.7%) of the 50,184 total study subjects were divided into shift work and 45,314 (90.3%) non-shift work groups based on the response to shift status. Variables that could affect work health issues were identified and corrected. A cross-analysis was conducted to examine demographic characteristics (gender, age, and education level) of the workers and occupation characteristics (monthly net earnings, employment type, occupation, working period up to now, workplace scale, type of work system, and weekly working hours). In order to find the work health issue ratio between the shift and non-shift work groups, logistic regression was analyzed and the association with health problems according to shift type by gender was looked at through cross-analysis. Results: According to the surveys conducted from the 1st KWCS (2006) to the 5th KWCS (2017), the proportion of shift workers continued to increase. Also, muscular pains in the lower limbs (hips, legs, knees, feet, etc.) (OR=1.135, 95%CI 1.031-1.251), headaches, eyestrain (OR=1.580, 95% CI 1.428-1.748), anxiety (OR=1.715, 95% CI 1.402-2.099), difficulty falling asleep (OR=1.391), and other problems (OR=7.392) were reported. In addition, back pain, muscular pains in shoulders, neck and/or upper limbs, muscular pains in lower limbs (hips, legs, knees, feet, etc.), headaches, eyestrain, depression, anxiety, overall fatigue resulted in significant results for both male and female shift workers. Depression and anxiety were higher in female shift/circulation compared to males. Conclusions: The social nets for the health and safety of shift workers should be explored in a variety of ways, including management and supervision of shift sites, attempts to reorganize and improve the shift system, development of workers' health recovery programs, promotion, systematic treatment, and compensation systems.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.3
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• pp.101-109
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• 2021

Wave observations using a marine X-band radar are conducted by analyzing the backscattered radar signal from sea surfaces. Wave parameters are extracted using Modulation Transfer Function obtained from 3D wave number and frequency spectra which are calculated by 3D FFT of time series of sea surface images (42 images per minute). The accuracy of estimation of the significant wave height is, therefore, critically dependent on the quality of radar images. Wave observations during Typhoon Maysak and Haishen in the summer of 2020 show large errors in the estimation of the significant wave heights. It is because of the deteriorated radar images due to raindrops falling on the sea surface. This paper presents the algorithm developed to increase the accuracy of wave heights estimation from radar images by adopting convolution neural network(CNN) which automatically classify radar images into rain and non-rain cases. Then, an algorithm for deriving the Hs is proposed by creating different ANN models and selectively applying them according to the rain or non-rain cases. The developed algorithm applied to heavy rain cases during typhoons and showed critically improved results.