• Journal of Korean Ophthalmic Optics Society
• /
• v.15 no.4
• /
• pp.361-366
• /
• 2010

Purpose: HCD ion plating apparatus by hollow cathod discharge method was fabricated and TiN films were deposited on stainless steel by this apparatus with increasing in $N_2$ gas flow and the fine color changes of TiN films were analyzed. Methods: The spectroradiometer and spectrophotometer were used to observe optically the fine color changes of TiN thin films, and XPS was used to analyze the compositions of TiN thin films with increasing in $N_2$ gas flow. Results: The color coordinate of TiN thin film with $N_2$ 120 sccm gas flow showed (0.382, 0.372) which had the mixed colors of gold and silver, and the color coordinate changed to the increasing value of (x,y) with increasing in $N_2$ gas flow which indicated the deep gold color. It was found that the slopes of the reflectances at 550nm were increased with increasing in $N_2$ gas flow. And from the Ti scans using XPS, it was found that the peak heights of 455 eV derived from TiN composition were increased with increasing in $N_2$ gas flow, while the peak heights of 459 eV from $TiO_2$ composition were decreased. Conclusions: The results obtained above were that the color of TiN film with 120 sccm $N_2$ gas flow had been observed from the mixed color of silver and gold due to TiC, $N_2$, TiN on the surface and TiN, $N_2$ inside film, and the color of TiN films changed a deep gold color with increasing in $N_2$ gas flow due to increasing TiN composition.

• Clinical and Experimental Pediatrics
• /
• v.48 no.10
• /
• pp.1082-1089
• /
• 2005

Purpose : Abdominal obesity is encountered as a risk factor for cardiovascular diseases. However, the anthropometric cut-off value to estimate the cardiovascular risk, has not been suggested. This study was designed to find the relationship between the abdominal fat and various parameters of obesity to find the cardiovascular risk factors related to abdominal obesity and to establish practical methods to measure them. Methods : Twenty seven obese Korean adolescents of moderate to severe degree and 22 healthy adolescents were enrolled. The body mass index(BMI), arm circumference and skinfold thickness were measured. Furthermore, blood lipid, sugar, insulin and four different cytokines' levels were checked and the distribution of body composition was measured by bioelectrical impedance analysis. The subcutaneous and intra-abdominal fat thickness by abdominal ultrasonography(US) and the total and intra-abdominal fat area by abdominal computerized tomography(CT) were measured in the obese group. Results : The most accurate method to measure abdominal fat in children is abdominal CT and the fat mass measured by bioelectrical impedance was strongly correlated with it(r=0.954). It was also correlated with arm circumference, fat thickness measured by abdominal US, BMI, aspartate aminotransferase(AST), alanine aminotransferase(ALT) and triglyceride level. Conclusion : Abdominal CT is the most accurate method to measure intra-abdominal fat, and it can be replaced by abdominal US for cost effectiveness. The screening methods that can be used at school or in outpatient basis include bioelectrical impedance, waist/hip ratio, and arm circumference. The cardiovascular risk factors include leptin, triglyceride and insulin level.

• Clinical and Experimental Pediatrics
• /
• v.49 no.10
• /
• pp.1037-1041
• /
• 2006

Purpose : The prevalence of obesity and nonalcoholic steatohepatitis(NASH) was increased in adolescents. This study was performed to observe the prevalence of elevated aminotransferase levels in adolescents and to assess the correlations between aminotransferase levels and obesity related parameters(body mass index, waist circumference, hip circumference, waist to hip ratio and insulin level). Methods : We obtained weight, height, waist circumference and hip circumference from 2,417 male and 1,219 female adolescents. Mean age was $15.7{\pm}0.7$ years old. We measured fasting insulin, aspartate aminotransferase(AST) and alanine aminotransferase(ALT). Obese and overweight were defined as body mass indices(BMI) of more than the 95th, and 85th-94th percentiles, respectively, for age and sex. Results : The number of adolescents with obesity is 324(8.9 percent). 414(11.4 percent) subjects belonged to the overweight group. The average ALT level of obese, overweight and control groups were significantly different(obese : $32.1{\pm}34.3U/L$, overweight : $19.6{\pm}13.6U/L$, control : $12.7{\pm}6.7U/L$, P<0.001). The average AST level was also different according to group(obese : $27.8{\pm}16.5U/L$, overweight : $22.8{\pm}8.6U/L$, control : $20.8{\pm}8.5U/L$, P<0.001). AST and ALT were correlated with anthropometric parameters and insulin level. After multiple regression analysis, waist circumference was the significant predictive value for AST(r=0.234, P<0.001). Waist circumference, BMI and insulin levels were significant predictive values for ALT(r=0.435, P<0.001). Conclusion : The prevalence of abnormal aminotransferase was higher in the obese and overweight groups than control group. Waist circumference was useful to predict abnormal aminotransferase levels.

• Clinical and Experimental Pediatrics
• /
• v.45 no.4
• /
• pp.482-488
• /
• 2002

Purpose : We performed this study to evaluate the diagnostic usefulness of endoscopic finding of nodular gastritis, CLO and HpKit test for H. pylori infection in children. Methods : Gastroduodenal endoscopy and mucosal biopsy were performed on 212 children who visited our hospital between Jul. 1999 and May 2000 due to abdominal pain. We performed CLO and HpKit test for H. pylori with the time interval of 15, 30 minutes, 1, 2, 3, 24, 48, 72, 96, 120 and 144 hours. Histological examination of H. pylori was made by H-E or Alcian yellow stain with biopsy specimens. Sensitivity, specificity, positive predictive and negative predictive value of nodular gastritis, CLO and HpKit test were calculated from the analysis of above data. Results : Sensitivity and specificity of 3 hour-CLO test was 68.4% and 100% respectively. Sensitivity and specificity of 3 hour-HpKit test was 65.8% and 100% respectively. No significant difference in sensitivity and specificity was found between in 3 hour-CLO and HpKit test(P>0.05). Sensitivity of CLO test increased as time lapsed, but corresponding specificity did not decrease as time lapsed(sensitivity and specificity at 144 hours : 89.5% and 94.8% respectively). However, sensitivity of HpKit test increased as time lapsed, but specificity markedly decreased. Sensitivity and specificity of the nodular gastritis was 78.9% and 93.7% respectively. Conclusion : Both CLO and HpKit test have relatively low sensitivity and specificity for the detection of H. pylori in 3 hours of testing in children. The endoscopic finding of nodular gastritis is another good standard in the diagnosis of H. pylori infection in children.

• Clinical and Experimental Pediatrics
• /
• v.52 no.10
• /
• pp.1161-1166
• /
• 2009

Purpose : Kawasaki disease—the most common cause of acquired heart disease in children—incidence is increasing yearly. Therefore, we evaluated the predictive indicators of coronary complications of Kawasaki disease based on clinical and laboratory data. Methods : Between January 2005 and March 2008, of the 201 children with Kawasaki disease treated at the Gil Hospital of Gachon University of Medicine and Science, 51 had coronary artery lesions (Group II) and 150 had no lesions (Group I). The reasons for coronary artery lesions were deduced from the clinical and laboratory data. Results : Analysis of the 2 groups revealed that fever duration and days of fever after and before initial intravenous gammaglobulin (IVIG) treatment were significantly longer in Group 2 than in Group I. IVIG infusions were statistically higher in Group II than in Group I. As per the laboratory data, C-reactive protein (CRP) value was significantly higher in Group II. Collectively, >10 days of fever duration, >48 h of fever duration after, and >10 days of fever before IVIG treatment increased the risk of coronary artery lesions 6-, 5-, and 3.5-fold, respectively. Furthermore, additional IVIG courses and higher CRP level increased the risk of coronary artery lesions 4-fold and 2-3-fold, respectively. Conclusion : The following 3 factors were responsible for increased risk of coronary artery lesions in children with Kawasaki disease: fever duration and days of fever after and before IVIG treatment. To identifythe predictive indicators of coronary complications, it is necessary to further elucidate the relationship between well-known forecasting factors.

• Journal of Astronomy and Space Sciences
• /
• v.26 no.4
• /
• pp.425-438
• /
• 2009

We reevaluate the Burton equation (Burton et al. 1975) of predicting Dst index using high quality hourly solar wind data supplied by the ACE satellite for the period from 1998 to 2006. Sixty magnetic storms with monotonously decreasing main phase are selected. In order to determine the injection term (Q) and the decay time ($\tau$) of the equation, we examine the relationships between $Dst^*$ and $VS_s$, ${\Delta}Dst^*$ and $VS_s$, and ${\Delta}Dst^*$ and $Dst^*$ during the magnetic storms. For this analysis, we take into account one hour of the propagation time from the ACE satellite to the magnetopause, and a half hour of the response time of the magnetosphere/ring current to he solar wind forcing. The injection term is found to be $Q(nT/h)\;=\;-3.56VS_s$ for $VS_s$ > 0.5mV/m and Q(nT=h) = 0 for $VB_s\;{\leq}\;0.5mV/m$. The $\tau$ (hour) is estimated as $0.060Dst^*\;+\;16.65$ for $Dst^*$ > -175nT and 6.15 hours for $Dst^*\;{\leq}\;-175nT$. Based on these empirical relationships, we predict the 60 magnetic storms and find that the correlation coefficient between the observed and predicted $Dst^*$ is 0.88. To evaluate the performance of our prediction scheme, the 60 magnetic storms are predicted again using the models by Burton et al. (1975) and O'Brien & McPherron (2000a). The correlation coefficients thus obtained are 0.85, the same value for both of the two models. In this respect, our model is slightly improved over the other two models as far as the correlation coefficients is concerned. Particularly our model does a better job than the other two models in predicting intense magnetic storms ($Dst^*\;{< \atop \sim}\;-200nT$).

• Journal of Distribution Science
• /
• v.10 no.2
• /
• pp.53-62
• /
• 2012

Well-being is a reflection of current sociocultural trends that focus on the quality of life based on economic growth. Furthermore, organic food is believed to help people maintain good health and therefore leads to increased consumption of organic foods. Therefore, consumer interest in organic food is increasing, causing its market to grow, and this trend will be maintained in the future. The abuse of agricultural pesticides, gene manipulation, and bovine spongiform encephalopathy has caused consumers to worry about food safety. The well-being trend has also contributed to consumers' growing interest inorganic food and organic agricultural products. A consumer's choice offood is a complex processes affected by various factors. In particular, organic food is considered an individualistic merit good, considering the consumers' preferences related to certification policies. Therefore, various factors such as personal characteristics and sense of value could affect consumers' decisions. This research focused on an analysis of the factors influencing consumers' purchasing intention for organic food on the basis of an increase in organic food consumption. The research method was based on the theory of planned behavior (TPB). Factors such as consumer characteristics regarding food consumption, purchasing frequency, and other factors affecting purchasing intention were presented. The hypothesis was set using advanced research and stated that it is easier to forecast purchasing intentions by combining the theory of planned behavior and personal characteristics of consumer. The results show that two dimensions, attitude and perceived behavioral control, have statistically significant influence on the purchasing intention. It can be said that a positive attitude toward organic foods in particular increases the possibility of purchasing intention. In addition, consumers who consume more organic food products are more likely to have positive attitudes, and, in the past, purchasing frequency has positively influenced purchasing intention of organic foods. Consumers' negative feelings about the non-purchase of organic foods also showed a negative influence on purchasing intentions. In other words, even though consumers feel uncomfortable when not consuming organic food products, they do not try to purchase such products because of this feeling of discomfort. Furthermore, the subjective norm and the behavioral control of food-related involvement do not have a statistically significant influence on the purchasing intention or attitudes. This research verified the influence of factors related to purchasing intention. This study has several limitations: (1) even though consumers' responses can change based on the type of food, the types of food were not classified in this study; (2) future studies are necessary to analyze the attitudes of consumers on the basis of their purchasing experiences with organic foods.

• Cartoon and Animation Studies
• /
• s.6
• /
• pp.152-171
• /
• 2002

This study analyses the avatar service, which is recognized as an alternative strategy of animation industry. The research questions of this study are following: (1) How have the avatar services been developed and what are the present dominant types? (2) Which structural characteristics of e-business environment are needed for the success of avatar services? (3) What is the economic characteristics of avatar business model? To solve these research questions, the basic conditions and the structural characteristics of avatar services have been investigated. In the first place, two forms of avatar service are classified. One is the internet service site whole primary service is to provide chatting service based on avatar service. The other is the portal site in which many kinds of products and services are presented as bundles to meet the needs of internet users. So avatar service is one of bundles which those portal sites are providing with. In this study, the big five internet service sites are selected based on the profits they earned through the sales of avatar service. The result of analysis is that the pricing strategy of those big five sites is very different from those of traditional off-line markets. The pricing mechanism are based on the value which internet users endow with the avatar items, not based on the costs of making the products. Avatar is the representative informative goods. The informative goods have the original cost structures, constant fixed costs and zero marginal costs, so the providers of avatar services make much of the subjective values of consumers. The sayclub, which is the most successful avatar service site and earn the average sales of 3 billing won a month, takes the aggressive strategy of pricing avatar items at highest price in the industry. The avatar service providers which make lots of profits are planning of making differentiate the services, introducing well-known brand items and star-named items. Nevertheless, the fact that the members of the sayclub are not decreasing means that the network effect of the site is so strongly manifest. Moreover, the costs the members have paid for the avatar items are so big not as to switch from one site to the other site, it can be very costly. These switching costs are endemic in high-technology industries and digital contents industries. It can be so large that switching suppliers is virtually unthinkable, a situation known as 'lock-in'. When switching costs are substantial, competition can be intense to attract new customers, since, one they are locked in, they can be a substantial source of profit. The consumers of avatar items have switching costs if they subscribe for the new avatar service site. The switching costs can be subscription costs as well as the costs of giving up the items they already paid for. One common example of switching costs involves specialized supplies, as with inkjet printer cartridges. In this example, the switching cost is the purchase of a new printer. The market is competitive ex ante, but since cartridges are incompatible, it is monopolized dx post. So the providers of printer/cartridges set pricing printer so cheap and cartridges expensive. On the contrary, since the avatar service can be successful with the strong network effect, the providers of avatar services have to compete aggressively for new customers. So they allow the subscription at a low price(almost marginal cost) in the early market. The network effect can be maximized when the members are sufficiently growing. The providers which have the monopoly power with sufficient subscribers. begin to raise the prices over the lifetime of the product and make profits.

• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.10
• /
• pp.739-747
• /
• 2011

The major 81 tributaries in Chungcheongnam-do were monitored for flowrate and water quality in order to understand the characteristics of the watershed and to select the tributary catchment for improving water quality. The value of flowrate in the tributaries at Nonsancheon catchment at the Geum-River watershed and Gokgyocheon, Muhancheon, Sapgyocheon at the Sapgyo-Reservoir watershed, which is located in the southern and northern area in Chungcheongnam-do, was relatively greater than the other watersheds. The concentration of water pollutants regardless of water quality parameters in Nonsancheon catchment at the Geum-River watershed, Gokgyocheon catchment at the Sapgyo-Reservoir watershed and the Anseongcheon watershed, which have a dense source of pollution, were higher than the other watersheds. However, 64 percent of the tributaries at the Geum-River watershed, 45 percent of tributaries at the Sapgyo-Reservoir watershed, 26 percent of tributaries at the Geum-River watershed all satisfied the Class II regulations in the Framework Act on Environment Policy, but all of the tributaries located in the Anseongcheon watershed exceeded the Class II regulations. Therefore, the policy for improving the water quality of the tributary in Chungcheongnam-do should be established in the following order: Anseongcheon, Seohae, Sapgyo-Reservoir watersheds. Consequently, the tributary catchment for improving water quality, which has a large flowrate and a high concentration of water pollutants, was selected at Ganggyeongcheon, Geumcheon, Nonsancheon, Seokseongcheon, Seungcheoncheon, Jeongancheon, Jeungsancheon (so far Geum-River watershed), Gokgyocheon, Namwoncheon, Maegokcheon, Muhancheon, Sapgyocheon Oncheoncheon, Cheonancheon (so far Sapgyo-Reservoir watershed), Gwangcheoncheon, Dangjincheon, Daecheoncheon, Dodangcheon, Waryongcheon, Cheongjicheon, Pangyocheon, Heungincheon (so far Seohae watershed), Dunpocheon, Seonghwancheon, Ipjangcheon (so far Anseongcheon watershed). The plans as installation of environmental facilities to reduce the source of pollution for improving the water quality of these tributary catchments should be urgently established and implemented.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.2
• /
• pp.119-125
• /
• 2012

The tributary water quality and flowrate monitoring result, which is fundamental data for the establishment of the water environmental policy, is used as very important data for the implementation of TMDL. This study introduced how to use the tributary water quality and flowrate monitoring data for the analysis of the watersheds, the satisfactory assessment of water quality standards in the watersheds, the selection of watersheds for the establishment of the implementation plan, and the selection of the tributary catchments for improving the water quality using a stream grouping method. According to the analytical results of tributary catchment using water quality and flowrate monitoring data of thirty-seven tributaries in the Geum-River watershed at Chungcheongnam-do, the value of flowrate in the tributaries, which is located in the middle-lower Geum-River watershed, was greater than the other areas and the concentration of the water pollutants regardless of water quality parameters in the tributaries at Nonsancheon catchment was relatively higher than the other areas. The problems, which have the determination of satisfaction of water quality standards and selection of target watersheds for establishment of the implementation plan regardless of the water quality of tributary in the watershed due to the water quality and flowrate monitoring results of the main river, were improved use of the results of tributary water quality and flowrate monitoring. Also, the tributary catchments for improving the water quality, according to stream grouping method based on the results of tributary water quality and flowrate monitoring, were selected. In the Geum-River watershed at Chungcheongnam-do, the tributary in the Nonsancheon, Byeongcheoncheon, Seokseongcheon, Jocheon catchments, which has a large flow and a high concentration of water pollutants, should be preferentially selected for improving the water quality of the tributary in accordance with the reduction of the source of pollution.