• Elastomers and Composites
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• v.39 no.2
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• pp.131-141
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• 2004

The recycling of waste XLPE(crosslinked polyethylene), which is a major source of scraps from high voltage power transmission cables, has been discussed. The waste XLPE scraps were ground into fine powder with various sizes from less than $100{\mu}m$ up to about $1000{\mu}m$ using two types of tailor-made pulverizers. The compounds were prepared in a modular intermeshing co-rotating twin screw extruder at various conditions such as different compositions, types and powder sizes of waste XLPE, screw configurations and various polymer matrices (LDPE, HDPE, PP, PS). The mechanical and rheological properties and the fracture surface or the compounds were investigated. It was found that an improved impact strength was obtained from the compound with white XLPE powder pulverized from the scraps without outer/inner semi-conductive layers. Generally, the impact strength increases with the content of XLPE but decreases with the size of XLPE. Especially for LDPE, the extrusion was possible up to 80 wt% loading of XLPE. Also, the impact strength increases with the number of kneading disc blocks in the given screw configurations. The melt viscosity of the compounds increases with increasing XLPE loading. However, the higher shear thinning behavior of the compounds at common shear rates implies proper processibility of the compounds. In addition, the impact strength for other polymer matrices used increases with XLPE and it is noticeable that the impact strength of PS/XLPE (80/20 wt%) compound was improved twice that of pure PS.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.367-373
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• 2015

The purpose of this study was to examine the effect of backward walking training on the balance capability(Functional Gait Assessment; FGA, Timed Up & Go Test; TUG) and gait performance(10 meter Walking Test; 10 mWT) of stroke patients. Eighteen with stroke patients were randomly allocated to an experimental and contral group of nine patients each. both groups received general neurorehabilitative physical therapy for 45 minutes per day 5 times per week during 4 weeks. The experimental group also performed additional backward walking training for 20 minutes per day 3 times per week during 4 weeks. There were signicantly increase by backward walking training in outcome of the balance capability from the FGA was increase from $17.67{\pm}1.00scores$ to $19.22{\pm}1.00scores$(p<.05), TUG was decrease from $26.45{\pm}1.37sec$ to $23.28{\pm}1.35sec$(p<.05) and 10 mWT was decreased from $21.74{\pm}1.35sec$ to $18.33{\pm}1.10sec$ (p<.05). These result suggest that backward walking training for stroke patients is effective in improving balance capability(FGA, TUG) and gait performance(10 mWT).

• Journal of Digital Convergence
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• v.15 no.4
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• pp.537-547
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• 2017

This study attempted to determine differences between the perceived empowerment level and job satisfaction depending on hairdressers' demographic characteristics and analyze the effects of their empowerment on job satisfaction. For this, a total of 310 hairdressers in Gwangju-Jeonnam and Seoul-Gyeonggi-do were chosen through convenience sampling, and then a questionnaire survey was conducted. The valid 277 copies were used for final analysis. For data analysis, descriptive statistics, factor analysis, reliability analysis, t-test, ANOVA, Duncan's test, and multiple regression analysis were conducted using SPSS 15.0. The study results found the following: First, in terms of the subordinate factors of empowerment, the following four factors were found: meaningfulness, self-determination, competence, and impact. Second, depending on demographic characteristics (e.g., age, career, type of beauty salon, job title, punch-in time, monthly pay), a statistically significant difference was found between empowerment and job satisfaction (p<.01). Third, hairdressers' perceived empowerment level had a positive impact on job satisfaction (p<.01). In terms of the empowerment on job satisfaction by sub-factor, 'self-determination' was largest, followed by 'meaningfulness' and 'competence.' Therefore, beauty salon owners need to manage their business more efficiently by converging cosmetology and business management by expanding empowerment among hairdressers properly after recognizing the importance of hairdresser empowerment.

• Korean Journal of Social Welfare
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• v.57 no.4
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• pp.35-65
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• 2005

The purpose of this study is to examine the Korean social workers' level of social work values and advocacy(attitudes and strategies) and to verify the relations among social work education, social work advocacy and social work values by examining whether social work education influences social work advocacy and social work values, and whether social work values affect social work advocacy. Further, this study wishes to confirm not only the direct effect that social work education has on social work advocacy, but also how social work education indirectly influences social work advocacy through social work values as a mediator. The research of this study was conducted on 242 social workers who have obtained social worker licenses and are currently working in the community centers. As survey tools, this study utilized social work advocacy attitudes, social work advocacy strategies, outcomes of social work education, social work values, self-esteem and locus of control. Collected data were analyzed by using SPSS/PC+ 12.0 for descriptive analysis, Pearson's correlation, reliability analysis, exploratory factor analysis and multiple regression. The research hypothesis was established according to the analysis method of the testing mediation of Baron & Kenny (1986) in order to examine whether social work values intervene between social work education and social work advocacy. The results of the hypothesis test confirm that social work values on the social level serve as a mediator variable.

• Korean Journal of Social Welfare
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• v.63 no.1
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• pp.291-316
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• 2011

The purpose of this study is to find out the right strategies for social welfare education and the efficient human resource management of public social workers. Not to make any flaws when looking for the appropriate strategies, this report studies how outcomes of social welfare education influences the performances of public social workers and how the empowerment is connected to the relationship between the social welfare education and the performances of public social workers. For clearer study, a survey was conducted for 396 public social workers and the Structural Equation Model by AMOS was used to analyze the outcome. According to the result, the Fitness Index of the Casual Model, proposed by this study, was similarly matched with that of theological model. The Casual Model proved that it explains the connection between social welfare education, job performance and empowerment. Hence, to improve performance of public social workers, various education and training policies for human resources management are needed and basically associates related social welfare education should do their effort. Also to enhance empowerment of public social workers, various measures are needed.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.649-659
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• 2005

The purpose of this study was to quantify and compare the level of MMP-1 in the healthy or inflamed gingival tissue of patients with or without type 2 diabetic mellitus. We investigated whether mean amount of MMP-1 was changed by chronic periodontitis and type 2 DM. Gingival tissue samples were obtained during periodontal surgery or tooth extraction. According to the patient's systemic condition & clinical criteria of gingiva, each gingival sample was divided into the three group. Group 1(n=8) was clinically healthy gingiva without bleeding and no evidence of bone resorption or periodontal pockets, obtained from systemically healthy 8 patients. Group 2(n=8) was inflamed gingiva from patients with chronic periodontitis. Group 3(n=8) was inflamed gingiva from patients with chronic periodontitis and type 2 diabetes. Tissue samples were prepared and analyzed by Western blotting. The quantitative analysis of MMP-1 was performed using a densitometer and statistically analyzed by ANOVA. MMP-1 was expressed in all samples and an increased MMP-1 level was observed in group 2 compared to group 1 and decreased MMP-1 level was found group 3 compared to group 2, but the differences among 3 groups were not statistically significant. In conclusion, this study demonstrated that MMP-1 levels of inflamed gingiva of systemically healthy patient(group 2) were higher than normal gingiva of systemically health patients and although the severity of gingival inflammation in group 2 and 3 were similar, MMP-1 expression was decreased in diabetic patients than systemically healthy periodontal patients.

• Journal of Korea Water Resources Association
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• v.45 no.7
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• pp.631-641
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• 2012

In this study, satellite data (MTSAT-1R), a numerical weather prediction model, RDAPS (Regional Data Assimilation and Prediction System) output, ground weather station data, and artificial neural networks were used to improve the accuracy of summer rainfall forecasts. The developed model was applied to the Seoul station to forecast the rainfall at 3, 6, 9, and 12-hour lead times. Also to reflect the different weather conditions during the summer season which is related to the frontal precipitation and the cyclonic precipitation such as Jangma and Typhoon, the neural network models were formed for two different periods of June-July and August-September respectively. The rainfall forecast model was trained during the summer season of 2006 and 2008 and was verified for that of 2009 based on the data availability. The results demonstrated that the model allows us to get the improved rainfall forecasts until lead time of 6 hour, but there is still a large room to improve the rainfall forecast skill.

• Fire Science and Engineering
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• v.34 no.3
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• pp.43-48
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• 2020

The purpose of this study is to develop an earth leakage alarm circuit breaker, equipped with a leakage alarming function (JER-E2S, ETECKOREA Co., Korea), and to analyze its characteristics. The developed mechanism is exclusively used for single-phase and 220 V circuits, with a rated current of 32 A, 20 A, 20 A (for restrooms), 16 A, etc. It satisfies all characteristics of existing earth leakage circuit breakers (ELB). If a fire current, which is a resistive leakage current (Igr), flows through an electric line, the device detects the leakage current in real time and warns against the leakage through a blinking LED lamp. Since the developed device displays a tolerance to a capacitative leakage current (Igc) that inevitably occurs in LED lamps, communication devices, etc., it ensures a stable power supply. In addition, the earth leakage alarm circuit breaker protects against power failure due to a momentary ground fault. Therefore, it can supply power without the risk of the circuit breaker malfunctioning due to a momentary ground fault caused by water droplets, leaves, etc. Moreover, with a standby power of less than 0.1 W, the developed earth leakage alarm circuit breaker exhibits a power saving performance that is 3~8 times greater than that of other ELBs. Installation of approximately 10 earth leakage alarm circuit breakers in one apartment household, with an area of 120 ㎡, can save 2~5 kWh per month. Therefore, the developed earth leakage alarm breaker not only satisfies the characteristics of existing earth leakage breakers, but also exhibits outstanding power supply quality since it has the functions of electric fire prevention and malfunction prevention. Therefore, this device can innovatively contribute to electric fire prevention.

• Fire Science and Engineering
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• v.34 no.3
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• pp.67-75
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• 2020

In this study, the risk of heat generation due to normal and overload currents that vary with the abnormal loosening angle of wire-connecting bolts were identified. The risks were analyzed based on the thermal characteristics to minimize the carbonization accidents of terminal blocks inside distribution panels typically used in industrial sites. We applied a method for measuring the heating temperature and temperature variations in the terminal blocks in real-time by installing a resistance temperature detector sensor board in the terminal block. The experimental results showed that the terminal block model with a low-rated current exhibited a higher heating temperature, thus, confirming the need to select the terminal block capacity based on load currents. Additionally, the higher the rated current of the terminal block with a high-rated current and the higher the degree of loosening, the faster the carbonization point. Such heating temperature monitoring enabled real-time thermal temperature measurement and a step-by-step risk level setting through thermal analysis. The results of the measurement and analysis of carbonization risks can provide a theoretical basis for further research regarding the risk of fire due to carbonization. Furthermore, the deterioration measurement method using the temperature sensor board developed in this study is widely applicable to prevent fires caused by poor electrical contact as well as risk-level management.

• Journal of Life Science
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• v.22 no.9
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• pp.1207-1213
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• 2012

Onion peels is a natural source of high-value functional ingredients produced in the onion industry without suitable processing. The objective of this study was to evaluate characteristics of onion peel extract (OPE), including its biological activities, obtained from solvent extraction in 3 times pilot scales (Lot A, B, and C). Mineral analysis showed that K was present in the largest amount (13,767.56-15,506.78 ppm), followed by Na and Ca at 8,602.44-9,796.00 ppm and 4,255.78-4,903.33 ppm, respectively. The amounts of total phenol, total flavonoid, and quercetin in the OPE were in the ranges of 598.57~626.73, 211.73~233.64, and 93.78~107.29 mg/g, respectively. The biological activities such as antioxidant and effects of fibrinolysis increased in parallel with the concentration of OPE. The $IC_{50}$ value of DPPH radical scavenging activity was in the range of 517.58~557.32 ppm in the OPE. The $IC_{50}$ value for superoxide dismutase (SOD)-like activity was in the range of 11,900.91~12,690.35 ppm. A clear zone of OPE (20,000 ppm) in fibrinolysis test was three times higher than the plasmin as a reference. In conclusion, OPE could be used as a good source of antioxidants and fibrinolytic activities.