• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.288-289
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• 2005

As high temperature superconductor applications became a reality due to increase in coated conductor performance, it is important to understand their stability behavior to design safe electrical power systems. We have experimentally studied the dependence of quench and recovery characteristics of coated conductors on the amplitude of current and duration time. The sample used in the present study is stabilized with stainless steel. Stability tests of 3 cm long sample were performed in a liquid nitrogen bath cooling condition by applying a short period over current pulses for 50 and 100 ms, with amplitude up to ~ 6 times of the critical current. The transport current that follows before and after the current pulse was fixed about ~85% the critical current. We analyzed the quench recovery using the current voltage characteristic.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.10 no.1
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• pp.1-8
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• 2014

Patients with disabilities are a significant segment of Korea population. However, they encounter more challenges when seeking dental care. So, dentists and students who are future dental providers should have a responsibility to provide oral care services for them. In this study, we hypothesize that the education of special care dentistry may influence positive attitudes of the disabled. The attitudes are influenced by demographic variables such as gender, religion, experience of volunteer activities and marital status. Therefore, the objective of this study was to explore the change of attitudes of students towards people with disabilities between before and after class of special care dentistry. 72 students enrolled at the Kyung Hee University were surveyed. All participants attended class of Special Care dentistry in the third grade. The survey was conducted two times, just before class and after class. The attitudes of students were assessed using the well-documented ATDP (Attitude Toward Disabled Person)-O(Original) scale and MAS (Multidimensional Attitudes Scales Toward Persons with Disabilities) scale through the methodology of questionnaires. The results indicated that gender, experience of volunteer activities and marital status did not affect their ATDP and MAS score. In religious affiliation, only, there were statistically significant difference in student attitudes between before and after class of Special care dentistry. It means that habitual religious activity may offer stronger effects on student's attitude than short-term education. Therefore, long-term and specific educational experiences are needed to promote positive attitudes for people with disability.

• The Journal of Advanced Prosthodontics
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• v.5 no.1
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• pp.21-28
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• 2013

PURPOSE. This study examined the effects of the abutment types and dynamic loading on the stability of implant prostheses with three types of implant abutments prepared using different fabrication methods by measuring removal torque both before and after dynamic loading. MATERIALS AND METHODS. Three groups of abutments were produced using different types of fabrication methods; stock abutment, gold cast abutment, and CAD/CAM custom abutment. A customized jig was fabricated to apply the load at $30^{\circ}$ to the long axis. The implant fixtures were fixed to the jig, and connected to the abutments with a 30 Ncm tightening torque. A sine curved dynamic load was applied for $10^5$ cycles between 25 and 250 N at 14 Hz. Removal torque before loading and after loading were evaluated. The SPSS was used for statistical analysis of the results. A Kruskal-Wallis test was performed to compare screw loosening between the abutment systems. A Wilcoxon signed-rank test was performed to compare screw loosening between before and after loading in each group (${\alpha}$=0.05). RESULTS. Removal torque value before loading and after loading was the highest in stock abutment, which was then followed by gold cast abutment and CAD/CAM custom abutment, but there were no significant differences. CONCLUSION. The abutment types did not have a significant influence on short term screw loosening. On the other hand, after $10^5$ cycles dynamic loading, CAD/CAM custom abutment affected the initial screw loosening, but stock abutment and gold cast abutment did not.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.5
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• pp.43-57
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• 2022

This study aims to classify forest fire-affected areas, identify forest types by the intensity of forest fire damage using multi-time Landsat-satellite images before and after forest fires and to analyze the effects of artificial restoration sites and natural restoration sites. The difference in the values of the Normalized Burned Ratio(NBR) before and after forest fire damage not only maximized the identification of forest fire affected and unaffected areas, but also quantified the intensity of forest fire damage. The index was also used to confirm that the higher the intensity of forest fire damage in all forest fire-affected areas, the higher the proportion of coniferous forests, relatively. Monitoring was conducted after forest fires through Normalized Difference Vegetation Index(NDVI), an index suitable for the analysis of effects by restoration type and the NDVI values for artificial restoration sites were found to no longer be higher after recovering the average NDVI prior to the forest fire. On the other hand, the natural restoration site witnessed that the average NDVI value gradually became higher than before the forest fires. The study result confirms the natural resilience of forests and these results can serve as a basis for decision-making for future restoration plans for the forest fire affected areas. Further analysis with various conditions is required to improve accuracy and utilization for the policies, in particular, spatial analysis through forest maps as well as review through site checks before and immediately after forest fires. More precise analysis on the effects of restoration will be available based on a long term monitoring.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.4
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• pp.109-118
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• 2022

The data of the missing section among the vertex surface sea temperature observation data was imputed using the Bidirectional Recurrent Neural Network(BiRNN). Among artificial intelligence techniques, Recurrent Neural Networks (RNNs), which are commonly used for time series data, only estimate in the direction of time flow or in the reverse direction to the missing estimation position, so the estimation performance is poor in the long-term missing section. On the other hand, in this study, estimation performance can be improved even for long-term missing data by estimating in both directions before and after the missing section. Also, by using all available data around the observation point (sea surface temperature, temperature, wind field, atmospheric pressure, humidity), the imputation performance was further improved by estimating the imputation data from these correlations together. For performance verification, a statistical model, Multivariate Imputation by Chained Equations (MICE), a machine learning-based Random Forest model, and an RNN model using Long Short-Term Memory (LSTM) were compared. For imputation of long-term missing for 7 days, the average accuracy of the BiRNN/statistical models is 70.8%/61.2%, respectively, and the average error is 0.28 degrees/0.44 degrees, respectively, so the BiRNN model performs better than other models. By applying a temporal decay factor representing the missing pattern, it is judged that the BiRNN technique has better imputation performance than the existing method as the missing section becomes longer.

• Korea journal of population studies
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• v.34 no.1
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• pp.53-72
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• 2011

This study analyzes the effects of life course events and labor market conditions on the duration of career interruption among Korean women. The data were drawn from 'A Survey on the Women's Employment Interruption in Korea' conducted by the Korean Ministry of Gender Equality in 2009(currently the Korean Ministry of Gender Equality and Family). This study categorizes the duration of career interruption into three categories: (1) short term interruption(less than 12months), (2) short-medium term interruptio(12-35 months), (3) intermediate term interruption(36-59 months), (4) long term interruption(longer than 36 months), and then analyzes how demographic factors, labor market condition, and life events shape the timing of re-entry into the labor market among women. According to the findings, the jobs that are conducive to combining market work and mother's role expedite women's return to the labor market. Further, the younger, higher the level of human capital, and higher monthly wages that women earned before leaving the labor market, women are likely to experience short-term interruption(less than 12 months) rather than long-term interruption(longer than 60 months). Women who left from the labor market to care for kids are also likely to return to the labor market. However, women who have preschoolers are likely to experience long-term career interruption. These findings highlight the role of family supportive culture at the workplace in order for women to continue their employment while intensive family formation period. Furthermore, the finding that the discriminatory practices against women, in particular mother workers at the workplace lead women to exit from the market work calls for attention to establish family friendly workplace.

• Quality Improvement in Health Care
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• v.2 no.2
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• pp.112-129
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• 1996

Background : A small number of high cost patients usually spend a larger proportion of scarce health resources. Aged, long-term care and readmitted patients usually belong to these high cost patient group. Among others, long length of stay and readmission can be reduced by checking its cause, and these are the areas needed most of quality improvement activity. Characteristics of high cost medical users between health insurance program and medical assistance program were reviewed. Methods : The inpatient claims of health insurance and medical assistance program were analyzed. Patients were divided by 6 groups; long-term, mid-term, short-term, readmitted, cancer and aged. We defined high cost patients as those who had spent one and half million won and over per 6 months. Characteristics of high cost patients for each group were reviewed. Results : medical assistance patients used much more resources than the insured members in the average hospital cost per case but less in daily hospital cost. The former had a longer length of stay and had much heavier diseases. Major diseases of both group were cancer, diseases of circulatory system and chronic degenerative diseases. Gallstone and schizophrenia were more in the insured program. However, pulmonary tuberculosis, asthma were more common among the medical assistance patients. Early readmission before 2 weeks were 28-30% of the total readmission. Readmission rate in the malignat neoplasm and renal failure were 80% and more. Q.A program should be installed to prevent unnecessary readmissions. Conclusion : Almost 30% of early readmissions and admissions due to complications and long length of stay should be reviewed carefully to keep cost down and to enhance the quality of hospital care.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.6
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• pp.299-306
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• 2008

Sometimes, spinal cord injury (SCI) results in various chronic neuropathic pain syndromes that occur diffusely below the level of the injury. It has been reported that behavioral signs of neuropathic pain are expressed in the animal models of contusive SCI. However, the observation period is relatively short considering the natural course of pain in human SCI patients. Therefore, this study was undertaken to examine the time course of mechanical and cold allodynia in the hindpaw after a spinal cord contusion in rats for a long period of time (30 weeks). The hindpaw withdrawal threshold to mechanical stimulation was applied to the plantar surface of the hindpaw, and the withdrawal frequency to the application of acetone was measured before and after a spinal contusion. The spinal cord contusion was produced by dropping a 10 g weight from a 6.25 and 12.5 mm height using a NYU impactor. After the injury, rats showed a decreased withdrawal threshold to von Frey stimulation, indicating the development of mechanical allodynia which persisted for 30 weeks. The withdrawal threshold between the two experimental groups was similar. The response frequencies to acetone increased after the SCI, but they were developed slowly. Cold allodynia persisted for 30 weeks in 12.5 mm group. The sham animals did not show any significant behavioral changes. These results provide behavioral evidence to indicate that the below-level pain was well developed and maintained in the contusion model for a long time, suggesting a model suitable for pain research, especially in the late stage of SCI or for long term effects of analgesic intervention.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.129-142
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• 1986

Fifty-five local collections of buck wheat, Fagopyrum esculentum, were investigated their ratios of long-styled (LS) and short-styled (SS) flowers, fertility, meiosis of megaspore and microspore mother cell, female and male gametogenesis, and egg apparatus in accordance with the sowing seasons (spring, summer), altitudes (20m, 50-100m, 300m), and parent style types (L, S). Also they were embryologically investigated the fertility, fertilizing phenomenon and proembryogenesis by the legitimate and illegitimate pollination. There were no differences in the ratios of long-styled and short-5tyled flowers along with altitudes, but more irregularness was observed in plain area than that in the mountaineous or coastal area. LS versus SS ratios by sowing seasons were significantly separated into 1 : 1 in the summer sowing (P 0.1), but they were irregularly separated in the spring sowing. The segregating ratios by parent style types showed more number of short-styled flower in the spring sowing, and were statistically seperated into 1 : 1 in the summer sowing (P 0.25), regardless to parent style types. In the artificial legitimate union, the seed setting rates of the summer sowing (59-61%) were much higher than those of the spring sowing (about 30%), but in the artificial illegitimate union the seed setting rates were only fructified about 0.8-1.8% in the spring sowing. The seed setting rates in accordance with flowering stages were larger in turn early, middle, late, in the summer sowing. The grain number and grain weight per plant of short-styled flower were more than those of long-styled one regardless to style types. The 1,000 grain weight of long-styled flower was heavier than that of short-styled one in large grain, but it was lighter than that of short-styled flower in small or medium grain. The percentage of normal female and male gametogenesis in the summer sowing were higher than those in the spring sowing. The ovule was atropous and two polar nuclei were a synkarion before flowering. The pollens germinated at 30 minuts after pollination and the pollen tube grew continually and penetrated into micropyle at 1.5-2 hours and the two male nuclei fertilized with egg nucleus at 3 -5 hours after pollination. Flertilizing times in summer were shorter than in autumn. The fertilized egg was divided in a small apical cell toward the interior of the embryo sac and a large basal cell toward the micropyle cell at 15-24 hours after pollination, and division times in summer were shorter than in autumn. The proembryo began the embryogenesis at 7-8 days and formed itself into the perfect embryo at 15 days after pollination.

• The Journal of Korean Medicine
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• v.45 no.1
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• pp.251-256
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• 2024

Objectives: The purpose of this study was to report the short-term blood pressure-lowering effects observed in a patient with malignant hypertension through slow breathing maneuver with heart rate variability(HRV) biofeedback. Methods: Biofeedback sessions, totaling 13, each lasting 10 minutes, were administered. Blood pressure was measured pre and post-treatment, as well as thrice daily at 10 am, 4 pm, and 8 pm. Systolic blood pressure(SBP), diastolic blood pressure(DBP), and pulse rate were recorded for comparative analysis. Results: Before biofeedback, the average SBP, DBP, and pulse rate were 227.2±18.3, 135.2±11.0, and 104.4±5.3, respectively. Immediately post-biofeedback, these values changed to 213.7±15.2, 126.9±8.5, and 99.2±3.6. However, sustained long-term blood pressure reduction was not observed. Conclusions: The findings suggest that biofeedback therapy induces a short-term reduction in blood pressure in cases of malignant hypertension, potentially associated with autonomic nervous system regulation. Integrating biofeedback with other Korean medicine treatments, such as acupuncture or moxibustion, may offer a comprehensive approach for managing malignant hypertension.