• Structural Engineering and Mechanics
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• v.35 no.5
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• pp.631-643
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• 2010

A numerical procedure for the geometrical and material nonlinear analysis of concrete beams prestressed with external tendons is described, where the effects of external prestressing are treated as the equivalent loads applied on the concrete beams. The geometrical nonlinearity is considered not only the eccentricity variations of external tendons (second-order effects) but also the large displacement effects of the structure. The numerical method can predict the nonlinear response of externally prestressed concrete beams throughout the entire loading history with considerable accuracy. An evaluation of second-order effects of externally prestressed concrete beams is carried out using the proposed analysis. The analysis shows that the second-order effects have significant influence on the response characteristics of externally prestressed concrete beams. They lead to inferior ultimate load and strength capacities and a lower ultimate stress increase in tendons. Based on the current analysis, it is recommended that, for simply-supported externally prestressed beams with straight horizontal tendons, one deviator at midspan instead of two deviators at one-third span be furnished to minimize these effects.

• Korean Journal of Psychosomatic Medicine
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• v.5 no.2
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• pp.195-204
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• 1997

Objectives : The behavioral and physiological effects following low doses and high doses of melatonin have not been fully explored. In this study the authors investigated the nature and extent of the hypnotic effects, oral temperature, blood pressure effects, performance effects and subjective feelings following the acute administration of low pharmacological oral doses of melatonin at mid-day. Methods : Thirty-five healthy young medical students were randomly assigned to receive 6mg of oral melatonin(N=11), 12mg of oral melatonin(N=12) or a placebo(N=12) in a double-blind, placebo controlled trial. Measures of the behavioral and physiological effects used in the study were Stanford Sleepiness Scale, Digit Symbol Substitution Test, Trail test and visual analogue scale for subjective feelings. Oral temperature and blood pressure were measured. The subjects were studied between 10:00 and 16:00 hours. Data were analyzed by using repeated-measures analyses of variance(ANOVA). Results: Melatonin produced statistically significant effects on oral temperature, but there were no significant effects on time and the $dose{\times}time$ interaction. There was a significant difference on oral temperature between the 12mg oral melatonin group and the placebo group at 12:00 and 16:00 hours, but no significant difference between the 12mg and the 6mg oral melatonin groups. Melatonin produced a dose-related increase in subjective sleepiness and had significant effects on time, the $dose{\times}time$ interaction. There was a significant difference on subjective sleepiness among the placebo, 6mg, 12mg oral melatonin groups at 13:00-16:00 hours. Melatonin did not produce statistically significant dose-related effects on subjective fatigue but produced significant effects on time and the $dose{\times}time$ interaction. There was a significant difference on subjective fatigue between the 12mg, the 6mg oral melatonin groups and the placebo group at 13:00 hour. Conclusions : These data indicated that acute administration of melatonin at mid-day increased subjective sleepiness and fatigue but decreased oral temperatures. These effects were shown especially in 12mg oral melatonin group.

• Journal of Global Scholars of Marketing Science
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• v.5
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• pp.171-204
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• 2000

This paper intends to investigate the hierarchical effects of personality variables and values on pro-environmental product purchase and recycling behaviors mediated by 3 factor environmental attitudes. Previous literature review on pro-environmental behaviors has three categories of research trends. The first category generally done during 70's and early 80's is mainly focused on identifying pro-environmental consumer groups. Second stream of studies has focused on the mediating and moderating effects of variables, such as PCE, environmental knowledge, the perceived importance of behavioral consequences etc., on various pro-environmental behaviors. The last and latest trends of literature is focused on hierarchical and interactive effects of variables on behaviors. Following the trends of literature is review of such specific variables as social responsibility, community mindedness, locus of control, values, and environmental attitudes. The result shows that both locus of control and social responsibility have positive effects on two of environmental attitudes, harmony with nature and limits to growth, but community mindedness did not have effects on environmental attitudes. And social belonging value has positive effects on two of environmental attitudes, limits to growth and nature over human, and environmental value has positive effects on the formation of harmony with nature and limits to growth. But self-actualization has negative effects. And it's also suggested the positive effects of environmental attitudes on purchase and recycling behaviors. Specifically, all environmental attitude variables have positive effects on the formation of pro-environmental product purchase and recycling behaviors except in case of the effects of nature over human to recycling. And it's also revealed that pro-environmental product purchase is a preceeding behavior to recycling behavior, which suggest that consumers have to purchase environment friendly and recyclable products in order to engage in effective recycling behavior. Various applications of the results are discussed in the conclusion.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.8
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• pp.1334-1345
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• 1997

The purpose of this study were 1) to identify the effects of age and sex of Korean adolescents on the psychological variables(body attitudes, public/private self-consciousness, self-esteem), weight control practices, and clothing behaviors, and 2) to identify the relation- ships between psychological variables and weight control practices, and the effects of the variables on clothing behaviors in the adolescent' groups classified by sex and age. The results of this study were as follows: 1) Two factors of body attitudes were identified: Body-shape consciousness and Physical attractiveness. Four factors of clothing attitudes were identified: Clothing interest/dressing for others, Clothing exhibition, Dressing for self, and Psychological clothing-dependerlce. 2) There were significant effects of sex on all of the research variables. Age was found to have effects on Physical attractiveness, self-esteem, public/private self-consciousness, Clothing exhibition, and Psychological clothing- dependence. 3) In the relationships between psychological variables and weight control practices, Body-shape consciousness was negatively correlated with Physical attractiveness in all groups. Also, Body-shape consciousness had effects on weight control practice in all subject groups. 4) Public self-consciousness had direct/indirect effects on the Clothing interest/dressing for others in all subject groups. Private self-consciousness had direct/ indirect effects on dressing for self in high school boys and girls. Body-shape consciousness had indirect effects on Preference for up-to date style in male college students group, whereas weight control practices had effects on the Preference for up-to date style in female college students group. Self-esteem was found to have the effects on clothing behavior in college students groups. Among clothing attitude factors, Clothing exhibition had distinct effects on the Preference for up-to date style in all subject groups, and Clothing interest/dressing for others had effects on Clothing exhibition and Psychological clothing-dependence in high school boys and girs.

• The Korean Journal of Financial Management
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• v.24 no.2
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• pp.41-79
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• 2007

This study examines the expiration-day effects of stock index futures and options in the Korean stock market. The so-called 'expiration-day effects', which are the abnormal stock price movements on derivatives expiration days, arise mainly from cash settlement. Index arbitragers have to bear the risk of their positions unless they liquidate their index stocks on the expiration day. If many arbitragers execute large buy or sell orders on the expiration day, abnormal trading volumes are likely to be observed. If a lot of arbitragers unwind positions in the same direction, temporary trading imbalances induce abnormal stock market volatility. By contrast, if some information arrives at market, the abnormal trading activity must be considered a normal process of price discovery. Stoll and Whaley(1987) investigated the aggregate price and volume effects of the S&P 500 index on the expiration day. In a related study, Stoll and Whaley(1990) found a similarity between the price behavior of stocks that are subject to program trading and of the stocks that are not. Thus far, there have been few studies about the expiration-day effects in the Korean stock market. While previous Korean studies use the KOSPI 200 index data, we analyze the price and trading volume behavior of individual stocks as well as the index. Analyzing individual stocks is important for two reasons. First, stock index is a market average. Consequently, it cannot reflect the behavior of many individual stocks. For example, if the expiration-day effects are mainly related to a specific group, it cannot be said that the expiration of derivatives itself destabilizes the stock market. Analyzing individual stocks enables us to investigate the scope of the expiration-day effects. Second, we can find the relationship between the firm characteristics and the expiration-day effects. For example, if the expiration-day effects exist in large stocks not belonging to the KOSPI 200 index, program trading may not be related to the expiration-day effects. The examination of individual stocks has led us to the cause of the expiration-day effects. Using the intraday data during the period May 3, 1996 through December 30, 2003, we first examine the price and volume effects of the KOSPI 200 and NON-KOSPI 200 index following the Stoll and Whaley(1987) methodology. We calculate the NON-KOSPI 200 index by using the returns and market capitalization of the KOSPI and KOSPI 200 index. In individual stocks, we divide KOSPI 200 stocks by size into three groups and match NON-KOSPI 200 stocks with KOSPI 200 stocks having the closest firm characteristics. We compare KOSPI 200 stocks with NON-KOSPI 200 stocks. To test whether the expiration-day effects are related to order imbalances or new information, we check price reversals on the next day. Finally, we perform a cross-sectional regression analysis to elaborate on the impact of the firm characteristics on price reversals. The main results seem to support the expiration-day effects, especially on stock index futures expiration days. The price behavior of stocks that are subject to program trading is shown to have price effects, abnormal return volatility, and large volumes during the last half hour of trading on the expiration day. Return reversals are also found in the KOSPI 200 index and stocks. However, there is no evidence of abnormal trading volume, or price reversals in the NON-KOSPI 200 index and stocks. The expiration-day effects are proportional to the size of stocks and the nearness to the settlement time. Since program trading is often said to be concentrated in high capitalization stocks, these results imply that the expiration-day effects seem to be associated with program trading and the settlement price determination procedure. In summary, the expiration-day effects in the Korean stock market do not exist in all stocks, but in large capitalization stocks belonging to the KOSPI 200 index. Additionally, the expiration-day effects in the Korean stock market are generally due, not to information, but to trading imbalances.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.1
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• pp.26-37
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• 2017

The study is to develop safety performance functions(SPFs) for urban intersections using random effects Tobit regression model and to analyze correlations between crashes and factors. Also fixed effects Tobit regression model was estimated to compare and analyze model validation with random effects model. As a result, AADT, speed limits, number of lanes, land usage, exclusive right turn lanes and front traffic signal were found to be significant. For comparing statistical significance between random and fixed effects model, random effects Tobit regression model of total crash rate could be better statistical significance with $R^2_p$ : 0.418, log-likelihood at convergence: -3210.103, ${\rho}^2$: 0.056, MAD: 19.533, MAPE: 75.725, RMSE: 26.886 comparing with $R^2_p$ : 0.298, log-likelihood at convergence: -3276.138, ${\rho}^2$: 0.037, MAD: 20.725, MAPE: 82.473, RMSE: 27.267 for the fixed model. Also random effects Tobit regression model of injury crash rate has similar results of model statistical significant with random effects Tobit regression model.

• The Journal of Internal Korean Medicine
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• v.19 no.1
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• pp.202-218
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• 1998

In order to evaluate the effects of SIMNETONG, GANGJIYOUNSOODAN and CHUNGSIMJOKITANG(Xinnao-Tong, Jiangzhiyanshou-Dan and Qingxintiaoqi-Tang) on hyperlipidemia, the experimental study was performed in rats without or with hyperlipidemia induced by 2% cholesterol fed-diet or Triton WR-1339. And the levels of serum total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol and phospholipid were measured. The results are summarized as follows : In the model of hyperlipidemia induced by 2% cholesterol Fed-diet 1. Both low & highly concentrated GANGJIYOUNSOODAN showed significantly decreasing effects on the level of serum total cholesterol while SIMNETONG & CHUNGSIMJOKlTANG didn't. 2. GANGJIYOUNSOODAN, SIMINETONG and CHUNGSIMJOKITANG showed decreasing effects on the level of serum triglyceride with no statistical significance. 3. Only highly concentrated GANGJIYOUNSOODAN showed increasing effects on the level of serum HDL-cholesterol while the others had no effects. 4. Only highly concentrated GANGJIYOUNSOODAN had decreasing effects on the level of serum LDL-cholesterol while the others had no effects. 5. Highly concentrated GANGJIYOUNSOODAN and CHUNGSIMJOKITANG showed significantly decreasing effects on the level of serum phospholipid while the other had no effects. In the model of hyperlipidemia induced by Triton WR-1339 6. SIMNETONG, GANGJIYOUNSOODAN and CHUNGSIMJOKITANG showed slightly decreasing effects on the levels of serum total cholesterol and triglyceride with no statistical significance. 7. None of SIMNETONG, GANGJIYOUNSOODAN and CHUNGSIMJOKITANG showed any effects on the level of serum HDL-cholesterol. 8. Highly concentrated GANGJIYOUNSOODAN and CHUNGSIMJOKITANG showed decreasing effects on the level of serum LDL-cholesterol but the other had no effects. 9. All of highly concentrated SIMNETONG, GANGJIYOUNSOODAN and CHUNGSIMJOKITANG showed decreasing effects on the level of serum phospholipid with statistical significance. These results show that GANGJIYOUNSOODAN and CHUNGSIMJOKITANG, in orders, have antihyperlipidemic effects. Further study on the mechanism and on the herb screening of these prescription should be followed.

• The Journal of Internal Korean Medicine
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• v.24 no.1
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• pp.44-54
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• 2003

Objectives : This study was done to investigate the protective effects of Gagaminjakdowha-Tang on liver injury of rats induced by $CCl_4$ and d-galactosamine. Methods : All animals were divided into 5 groups, those were normal group(untreated), control group(treated with 0.9% Saline solution), sample I group(200mg/kg administrated), sample II group(400mg/kg administrated), Silymarin(200mg/kg administrated) group. Liver injury of rats were induced by $CCl_4$ and d-galactosamine, and then the serumtransaminase(ALT & AST) alkaline phosphatase(ALP), lactic dehydrogenase(LDH) for enzyme activities, Liver cytosol malondialdehyde(MDA), catalase, superoxide dismutase(SOD), glutathione S-transferase(GST) and glutathione-peroxidase(GPX) for enzyme activities were measured. Results : The inhibitory effects on the serum ALT activities were noted in both sample I and sample II group. The inhibitory effects on the serum AST activities were noted in only sample II group. The inhibitory effects on the serum ALP activities were noted in both sample I and sample II group. The inhibitory effects on the serum LDH activities were noted in only sample II group. The inhibitory effects on the liver cytosol malondialdehyde were noted in only sample II group. The decresed effects on the liver cytosol catalase activities were inhibited in only sample II group. The decresed effects on the liver cytosol superoxide dismutase activities were inhibited in only sample II group. The decresed effects on the liver cytosol GST activities were inhibited in only sample II group. The decresed effects on the liver cytosol GPX activities were inhibited in only sample II group. The inhibitory effects of the serum ALT activities were noted in both sample I and sample II. The inhibitory effects of the serum AST activities were noted in only sample II group. The inhibitory effects of the serum ALP activities were noted in only sample II group. The inhibitory effects of the serum LDH activities were noted in both sample I and sample II group. Conclusions : Gagaminjakdowha-Tang has protective effects against liver injury in rats induced by $CCl_4$ and d-galactosamine.

• Journal of Oral Medicine and Pain
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• v.23 no.4
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• pp.343-352
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• 1998

This experiment was performed to investigate effects of zinc containing solution on the major normal flora Staphylococccus aureus, Streptococus mutans and Candida albicans and to observe the variation according to anionic change and concentration difference. Zinc chloride, zinc iodide and zinc acetate solution were added to werially diluted broth culture so that each final concentration might be 0.25%, 0.5%. 1%. After that, 100ul of each aliquot was spreaded on each selective media plate( Mannitol Salts Agar plate for Staphylococcus aureus, Mitis Salivarius Agar plate for Streptococcus mutans and Sabouraud Destrose Agar plate for Candida albicans). The % killing was calculated bu CFU count after incubation under the appropriate condition. 1. zinc iodide, zinc chloride, and zinc acetate solutions showed inhibitory effects on Staphylococcus aureus, Streptococcus mutans and Candida albicans. 2. The inhibitory effects on Staphylococcus aureus were ranked in order of ainc iodide, zinc chloride and zinc actate. 3. The inhibitory effects on Streptococcus mutans were ranked in orfer of zinc iodide, zinc chloride and zinc acetate. 4. the inhibitory effects on Candida albicans showed no difference among zinc iodide, zinc chloride and zinc acetate. 5. The inhibitory effects of zinc chloride and zinc acetate on Staphylococcus aureus and Streptococcus mutnas showed increasing pattern as the concentration increase. But the inhibitory effects of zinc iodide on Staphylococcus aureus and Streptococcus mutans showed no apparent difference according to concentrations and it was the case with the inhibitory effects of zinc iodide, zinc chloride and zinc acetate on Candida albicans.

• Korean Journal of Childcare and Education
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• v.14 no.1
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• pp.249-268
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• 2018

Objective: The purpose of this study was to examine the effects of preschooler's temperament on peer play activity, focusing on the mediation of mothers' social interaction parenting behaviors Methods: 1695 mothers of preschoolers completed questionnaires on children's temperament and peer play behaviors, and mothers' parenting behaviors. Data were analyzed by regression analyses by SPSS 18.0. Results: First, preschoolers' sociability exerted positive effects on good peer play behaviors(play interaction) and negative effects on the bad peer play behaviors (disruption, disconnection) and both were partially mediated by mothers' social interaction parenting behaviors. Second, preschoolers' emotionality exerted negative effects on good peer play behaviors and positive effects on the bad peer play behaviors and both were partially mediated by mothers' social interaction parenting behaviors. Preschoolers' activity exerted positive effects on good peer play behaviors and negative effects on the bad peer play behaviors and both were partially mediated by mothers' social interaction parenting behaviors. Conclusion/Implications: These findings provide preliminary evidence that mothers' social interaction parenting behavior partially mediate the effects of preschoolers' temperament on peer play behaviors. Implications for the use of intervention targeting specific temperament have been discussed.