• Tunnel and Underground Space
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• v.9 no.1
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• pp.12-19
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• 1999

In this study, ground vibrations of a surface blasting for golf links and a tunnel blasting for highway construction were measured to investigate the effect of blasting conditions such as total charge and distance from blasting point. In surface blasting, site factor K and n were 74.1 and -1.37, respectively, which were analyzed by means of cube root scaled distance. The more were measuring distance, the higher were absolute value of K and n. Principal frequency was in range of 5~60 Hz in surface blasting, where that of 80 percent was in range of 10~30 Hz. On the other hand it was in range of 25~98 Hz in tunnel blasting, which showed higher than of surface blasting.

• Korean Journal of Childcare and Education
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• v.14 no.4
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• pp.43-62
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• 2018

Objective: The purpose of this study was to examine the effect of child care teachers' happiness and social support on job performance. Methods: The subjects were 380 teachers employed in child care centers and kindergartens in Gyeonggi Province. Self-report questionnaires were used to investigate teachers' happiness, social support and job performance. The data were analyzed by frequency, percent, Pearson's correlation and stepwise regression with the SPSS program. Results: The results of this study were as follow. First, teachers' job performance was positively associated with teachers' happiness. The highest correlation sub-variable was purpose in life. Next were personal growth, self-acceptance, environmental mastery and autonomy. And the last was positive relationships with others. Teachers' job performance was positively associated with teachers' social support. The highest correlation sub-variable was evaluative support. Next were affective support and material support. And the last was informative support. Second, teachers' happiness and social support affected job performance. Evaluative support, which was a sub-variable of social support, affected job satisfaction. And personal growth, purpose in life, and self-acceptance, which were sub-variables of happiness, affected job satisfaction. Conclusion: This study revealed that teacher's happiness and social support were important factors for teachers job performance.

• Composites Research
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• v.31 no.6
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• pp.365-370
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• 2018

One of the critical parameters to improve the output power for triboelectric nanogenerators (TENGs) is the surface charge density. In this work, we modify the tribo-material of TENG by introducing the $TiO_x$ embedded Polydimethylsiloxane (PDMS) in anatase and rutile phase. The effect of dielectric constant and electronic structure of the $TiO_x$ on the capacitance of TENG and the output power as well are discussed. The surface charge density is increased as the control of the dielectric constant in difference weight percent of $TiO_x$ and PDMS. As the results of that, the 5% $TiO_x$ rutile phase and 7% $TiO_x$ anatase phase embedded PDMS exhibit the highest TENG output. The peak value of voltage/current obtained from $TiO_x$ rutile and anatase phase are ${\sim}180V/8.2{\mu}A$ and $211.6V/8.7{\mu}A$, respectively, at the external force of 5 N and working frequency of 5 Hz, which gives over 12-fold and 15-fold power enhancement compared with the TENG based on the pristine PDMS film. This study provides a better understanding for TENG performance enhancement from the materials view.

• Korea Trade Review
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• v.44 no.3
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• pp.289-305
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• 2019

Recently, each country has been using non-tariff barriers (Non-Tariff Barriers, NTB) as a new protection trade policy. In particular, TBT lies at the center of NTB. In this context, we examine the impact of Technical Barriers to Trade (TBT) on Korea's exports to ASEAN. Using 10-year statistics from 2007 to 2016 that came into effect with the ASEAN FTA, we analyze the impact of TBT on the Korean exports in the electrical machinery industry (HS85), which accounts for more than 30 percent of Korea's total exports to ASEAN. The results of the empirical analysis using a gravity model showed significant and positive effects in the variables of GDP and real effective exchange rate in each ASEAN country on Korea's exports to ASEAN. As expected, the tariff rate has a negative effect. As for TBT, the key variable of this study, the results are as follows. Although many previous studies reported that TBT has negative impacts on exports, this study could not find any significant impact of TBT and found that Korea's exports of electrical machinery to ASEAN countries are not affected by TBT. Various implications of these results are suggested.

• Journal of the Korean Society of School Health
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• v.14 no.2
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• pp.227-235
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• 2001

Depression is one of the most common psychologic disorder and dealt as a major public health concern. School students have heavy school work loads and stress from various evaluations representing school performance. In this study, to examine the effect of school performance and stress on depressive symptoms, we assessed the frequency of risk factors for depressive symptoms among 2,717 high school students. From April 2001 to May 2001, using a self-reported questionnaire, we collected data on the frequency of occurrence of depressive symptoms and potential risk factors for depressive symptoms. Depressive symptoms were measured using Center Epidemiologlc Studies Depression (DES-D) index. Thirty-seven percent of high school students reported having high depressive symptoms for a week Female students had a higher prevalence of depressive symptoms than males (OR=1.44, 95% CI 1.22-1.70). In a multiple logistic regression model, we found that good perceived school performance (OR=0.43, 95% CI 0.31-0.60) had a negative association with depressive symptoms. On the contrary, we also found that stress from school performance (OR=2.03, 95% CI 1.69-2.44) associated with high depressive symptoms. In conclusion, high school students had a relatively high prevalence of depressive symptoms. Students with stress from school performance had the higher risk for depressive symptoms.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.631-634
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• 2004

The method that exists in Photodynamic Therapy uses Photosensibility drug strongly Influencing tumour accumulation together with photochemical laser effect and makes the structure of tumour be localized and become extinct. The intracavity transformation of the Nd :YAP main radiation 1079 nm was Raman converted in barium nitrate crystal and the Stokes frequency (1216 nm) was doubled using KTP or RTA crystals. The LiF or Cr:YAG crystals are used for the Q-switch. The radiation Parameters were obtained at 100 Hz pump repetition frequency. The average power at 608 nm radiation with LiF and KTP was 700 mW at multi-mode generation. The 3-6 single 10-15 ns pulses were generated during one cycle of pumping. The doubling efficiency with RTA was two times more than with KTP. The cells of Ehrlich adenocarcinoma (0.1 ml) were i.m. implanted in hind thighs of ICR white non-imbred mice. The cells were preliminarily diluted in medium 199 in the ratio of 1 to 5. HpD was intravenous administered in a dose of 10 mg/kg. The left clean-shaven hind leg was irradiated with laser light 21-27 hours after the administration of the preparation. The right non-Irradiated leg of each animal served as a control. The animals with the transplanted tumor that were not injected with HpD sewed as a control to estimate the complex effect (HpD+ irradiation). Before the administration of HpD and on 3 and 4 days after irradiation the tumor size was measured and the percent of the tumor growth inhibition was calculated. The results of animal treatments has shown high efficiency of PDT method for cancer treatment by means 0.608 m high power pulse solid state laser.

• Korean Journal of Acupuncture
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• v.23 no.1
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• pp.111-118
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• 2006

Objectives : To test the therapeutic efficacy of acupuncture applied to PC6 and ST36 for the relief of fullness of epigastrium or epigastric pain. Subjects and Methods : We enrolled fifty patients in a case series study The patients were mainly female (94 %) with an average age of 55 years $({\pm}15.0)$; the average age of the male patients was 51 years $({\pm}20.0)$. Twenty four percent of patients were in acute phase which epigastric pain had lasted below 1 month. Twenty eight percent of patients were in chronic phase which the pain had lasted over 6 month. The rest were in subacute phase. Acupuncture needles were inserted into PC6 and ST36 bilaterally. The acupuncture treatments were performed 2 times a week for 4 weeks. One treat session was lasted for 30 min. At each visit, overall symptomatic improvement, frequency and intensity of symptoms were checked on a 4 scaled questionnaire. Results : After acupuncture treatment, a progressive improvement of pain intensity was reported in 46 of the 50 patients, including 23 of excellent and 23 of good. The progress of symptom was more superior in subacute phase to acute or chronic phase. The symptom of 22 of 24 patients in subacute phase was improved. No patient experienced minor side-effects during acupuncture treatment. Conclusion : These preliminary data suggest the acupuncture treatment provides good pain relief for most patients presenting with epigastric pain. Randomized trials with appropriate control groups are needed to validate the effectiveness of this therapy in the treatment of epigastric pain.

• Journal of the Korean Home Economics Association
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• v.29 no.1
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• pp.59-70
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• 1991

This study was designed to investigate the effects of aerobic and /or Ca supplementation for six months on lipid metabolism and blood pressure in postmenopausal women. The subjects were healthy 29 women aged from 60 to 70 years old. They were divided into four groups: placebo and Ca supplementation group with and without exercise. The amount of Ca supplemented was 500mg a day. The frequency of doing exercise was three times a week and each time, it took 40 minutes to complete all the course of aerobic dancing programmed for old women. During the experimental period, the subjects ate their usual diets and the use of druge as well as additional exercise was prohibited. The results were summarized as follows. 1. Percent body fat and BMI were significantly decreased and the body weight tended to decreased due to aerobic dancing. 2. Serum lipids content tended to show only a slihgt changes due to Ca supplementation: serum triglyceride, total-chol, LDL-chol, FFA content tended to decrease but serum HDL-chol / LDL-chol ratio tended to increase after the experiment in Ca group. On the contrary, serum lipids level was not changed by exercise. 3. Blood pressure did not show any significant changes by Ca supplementation and / or exercise for 6 months in old women. 4. Serum Ca level of Ca group was significantly increased after experiment in Ca group (p<0.05) but not in Ex-Ca group. In summarization, it appeared that the aerobic dancing was a definite way to reduce percent body fat and BMI in postmenopausal women. On the other hand, Ca supplementation seemed to be able to induce favorable changes in serum lipids. However, any synergistic metabolic effects of exercise and Ca supplementation was not seen in this study. Further study is needed to elucidate the relationship between exercise and/or Ca supplementation and the changes in blood lipids profile as well as blood pressure more clearly.

• Korea Journal of Hospital Management
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• v.23 no.1
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• pp.51-64
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• 2018

Purposes : In February 2014, the government said that the National Health Insurance Service (NHIS) will enforce plan for reducing the financial burden from two major non-covered services including physician surcharges and private room charges, the main causes to increase uninsured, by 2017. The purpose of this study is to analyze the policy effect that performed so far by comparing out-of-pocket payment rates of policy process Methodology: This study analyzed admission medical expenses that occurred from January 2013 to March 2016 at a upper grade general hospitals in Daejeon. Number of study subjects were 134,924 and the data were analyzed with SPSS 22.0 program by using frequency, percentage, mean, standard deviation, ANOVA. The effect of two major non-payment improvement plan on out-of-pocket rates was ascertained via generalized estimating equation. Findings: Out-of-pocket payment rates was statistically significantly declined 2.7 percent than enforcement ago. Also, out-of-pocket payment, physician surcharge, the proportion of out-of-pocket payment of hospital room charge to out-of-pocket payment was statistically significantly declined. However, a further analysis of the cause of the decline in total medical costs is needed. Practical Implications: Physician surcharges and private room charges improvement policy had a positive effect on the decline of out-of-pocket payment rate. The policy of physician surcharges was very effective after the first policy enforcement but it was less effective to medical aids and near poor that was a more greater coverage than national health insurance. Since the policy has not been finalized, we have to continue a research for the successful implementation of the policy.

• Clinical and Experimental Pediatrics
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• v.48 no.9
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• pp.986-990
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• 2005

Purpose : Certain strains of lactobacilli are known to accelerate recovery from acute diarrhea. Lactobacillus reuteri is isolated from human breast milk and a commonly occurring Lactobacillus species with therapeutic potential in acute diarrhea. The purpose of the present study was to investigate the therapeutic effect of L. reuteri in acute diarrhea in young children. Methods : Fifty patients between 6 and 36 months of age hospitalized with acute diarrhea (rotavirus in 40 percent) were randomized into two groups to receive either $10^8$ colony-forming units of L. reuteri or a matching placebo, twice a day for their length of hospitalization, or for up to 5 days. Antidiarrheal drugs were not prescribed to either group. The clinical outcome of diarrhea was evaluated. Results : The mean duration of watery diarrhea after initiation of treatment was 2.3 days for the L. leuteri group(n=25) vs. 2.9 days for the placebo group(n=25)(P=0.072). By the second day of treatment, watery diarrhea persisted in 64 percent of patients receiving L. reuteri, compared to 84 percent of those receiving placebo(P=0.006). On the second day, the mean frequency of watery diarrhea was 1.9 in the L. leuteri group and 3.4 in the placebo(P=0.046). Also, vomiting continued to the second day in 16 percent of patients receiving L. reuteri and 40 percent of those recieving placebo(P=0.031). Conclusion : L. reuteri is effective as a therapeutic agent in acute diarrhea in children.