• Journal of the Korean Vacuum Society
• /
• v.21 no.5
• /
• pp.273-278
• /
• 2012

Over the last decade, the hafnium-based gate dielectric materials have been studied for many application fields. Because these materials had excellent behaviors for suppressing the quantum-mechanical tunneling through the thinner dielectric layer with higher dielectric constant (high-K) than $SiO_2$ gate oxides. Although high-K materials compensated the deterioration of electrical properties for decreasing the thickness of dielectric layer in MOSFET structure, their nano-mechanical properties of $HfO_2$ thin film features were hardly known. Thus, we examined nano-mechanical properties of the Hafnium oxide ($HfO_2$) thin film in order to optimize the gate dielectric layer. The $HfO_2$ thin films were deposited by rf magnetron sputter using hafnium (99.99%) target according to various oxygen gas flows. After deposition, the $HfO_2$ thin films were annealed after annealing at $400^{\circ}C$, $600^{\circ}C$ and $800^{\circ}C$ for 20 min in nitrogen ambient. From the results, the current density of $HfO_2$ thin film for 8 sccm oxygen gas flow became better performance with increasing annealing temperature. The nano-indenter and Weibull distribution were measured by a quantitative calculation of the thin film stress. The $HfO_2$ thin film after annealing at $400^{\circ}C$ had tensile stress. However, the $HfO_2$ thin film with increasing the annealing temperature up to $800^{\circ}C$ had changed compressive stress. This could be due to the nanocrystal of the $HfO_2$ thin film. In particular, the $HfO_2$ thin film after annealing at $400^{\circ}C$ had lower tensile stress, such as 5.35 GPa for the oxygen gas flow of 4 sccm and 5.54 GPa for the oxygen gas flow of 8 sccm. While the $HfO_2$ thin film after annealing at $800^{\circ}C$ had increased the stress value, such as 9.09 GPa for the oxygen gas flow of 4 sccm and 8.17 GPa for the oxygen gas flow of 8 sccm. From these results, the temperature dependence of stress state of $HfO_2$ thin films were understood.

• Journal of Korean Home Economics Education Association
• /
• v.29 no.4
• /
• pp.149-159
• /
• 2017

The objective of this study was to investigate the effects of family meals on eating behavior, academic achievement, and quality of life among middle school students. A total of 302 participants were recruited from a middle school at Goyangsi. We asked participants about family meals, eating behavior, academic achievement, and quality of life, using structured questionnaires. Family meal questionnaires were classified according to frequency, rules, and awareness. The findings of this study were as follows. First, there were significant differences between rules(p<0.05) and awareness (p<0.05) of family meals and family type. Second, there were statistically significant differences between frequency and awareness of family meals and eating behavior, academic achievement, and quality of life. On the other hand, there was a significant difference between rules about family meals and eating behaviors and quality of life. Third, we found that factors of family meal were positively related to the eating behavior, academic achievement, and quality of life at the level of statistical significance. Finally, we found that participants with a higher frequency of family meals and more positive eating behavior were more likely to higher academic achievement and quality of life than those in lower frequency of family meals and less positive eating behavior among middle school students. The frequency of family meals has a strong effect on higher academic achievement and better quality of life. In conclusion, engagement in family meals was related to better eating behavior, academic achievement, and quality of life among middle school students. Our findings may warrant further studies to support the benefit of family meals in improving eating behavior, academic achievement, and quality of life among high school students as well as middle school students.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.4
• /
• pp.511-517
• /
• 2010

This study was performed to estimate the prevalence and the risk factors of metabolic syndrome in Andong rural area. A total of 1,431 people (533 males, 898 females) aged over 45 years participated in this study in 2003. The prevalence of metabolic syndrome was 38.2% (male 23.5%, female 46.9%, p<0.001). As age increased, the prevalence of the metabolic syndrome increased in female, but not in male. The major underlying components of metabolic syndrome were high blood pressure (67.1%), low HDL-cholesterol (60.6%), and abdominal obesity (39.9%). The distinctive component for male was high blood pressure (70.1%), and for female, low HDL-cholesterol (73.6%), high blood pressure (65.3%), and abdominal obesity (54.5%). Subjects having more than one component were 94.7%. The risk factors for metabolic syndrome were analyzed using the multiple logistic regression method according to gender and expressed as age-adjusted odds ratio (OR). The results of comparing female to male (OR=2.953), and of comparing obese by % body fat (M: OR=5.786, F: OR=13.498) or BMI (M: OR=3.782, F: OR=13.301) to normal body weight showed significantly higher risk for metabolic syndrome (p<0.001). Health related habits, such as smoking, alcohol drinking, and exercise, didn't show any effect on metabolic syndrome. This study revealed that the prevalence of metabolic syndrome was significantly higher in female subjects compared to both male and female, and high blood pressure was the main cause of metabolic syndrome. We suggest that the strategy for prevention or reducing the prevalence of metabolic syndrome in this area should be concentrated on reducing high blood pressure through lowering obesity and abdominal obesity.

• Journal of Global Scholars of Marketing Science
• /
• v.19 no.2
• /
• pp.27-39
• /
• 2009

Compulsive consumption is regarded as a global phenomenon that can adversely affect consumer well-being. Although the topic has been studied in different cultural settings, we have seen relatively little theory development and explanations of compulsive behavior Nearly all previous empirical studies attempt to explain this behavior by correlating measures of compulsive behavior with independent variables taken within the same time frame. However, recent developments in social sciences suggest that such a phenomenon may best understood in the context of the person's earlier-in-life experiences. Using the life course paradigm as an overarching framework, the present research extends previous work on this topic. Following hypotheses were drawn from literature review: H1: The earlier in childhood and adolescence a person experiences family dislocation, the greater his or her likelihood of exhibiting compulsive behaviors in adulthood. H2: The earlier in life the young person experienced family dislocation, the greater the number of family disruption events the young person experienced prior entering adulthood years. H3: Family dislocation leads to (a) increased frequency of socio.oriented family communications and (b) decreased frequency of concept-oriented family communication. H4: Young adults who were raised in families characterized by a strong socio-oriented communication structure are more likely to exhibit compulsive consumption tendencies than those who were raised in families characterized by a weak socio-oriented family communication structure. H5: Young adults who were raised in families characterized by a strong concept-oriented communication structure are less likely to exhibit compulsive consumption tendencies than those who were raised in families characterized by a week concept-oriented family communication structure. H6: The relationship between family disruption events experienced during adolescence and perceived stressfulness of these events is moderated by (a) global family support, (b) emotional family support, and (c) material family support. Those reporting higher levels of family support as teenagers are less likely to report experiencing stress due to family disruption events. H7: Perceived stressfulness of family disruption events experienced during adolescent years are associated with compulsive consumption tendencies in early adulthood. H8: The greater the number of family disruption events young adults experienced during their adolescent years the more frequent was their communication about consumption with their peers. H9: The more frequent was the young persons' communication with their peers about consumption during their adolescent years, the more likely they are to report compulsive buying tendencies as young adults. We use a sample of 120 Thai undergraduate students attending classes taught in English as part of a four-year international program. Product-moment correlations, hierarchical regression analysis and partial correlation were used to analyze data. Results of testing hypotheses showed that hypothesis 2, 4, 7 and 9 were supported and hypothesis 1, 3, 5, 6 and 8 were not supported. Our study did not find a significant relationship between the age when a person experienced family dislocation and their compulsive behavior tendencies expressed as young adults. We did not find a significant relationship between family dislocation and family communication structures. But we found a significant positive relationship between socio-oriented communication structure and compulsive buying and a significant relationship between our peer communication and compulsive buying measures. Also we found perceived stressfulness due to the disruptive events to have a significant positive relationship between the perceived stressfulness and compulsive buying. Implications from these findings, limitations of this research and future research suggestions were discussed.

• Korean Chemical Engineering Research
• /
• v.52 no.2
• /
• pp.266-271
• /
• 2014

The effects of antioxidants on the properties of Polycarbonate/Acrylonitrile-Butadiene-Styrene(PC/ABS) blends were studied for the functions of the screw speed and loaded duration of high shear rate processing in order to investigate the degradation for PC/ABS blends. Tris-(2,4-di-tert-butyl-phenyl phosphate) (A1) and Bis(2,4-dicumylphenyl) pentaerythritol diphosphite (A3) as phosphite antioxidants and Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (A2) as a phenolic antioxidant are used. The thermal properties were detected by TGA and severely decreased, after the processing. The stress-induced and thermal degradation for PC/ABS blends with the antioxidant A3 was retarded better than the others. By using UTM, the mechanical properties also showed individually decreased according to the antioxidants, after the processing, especially, the elongations showed considerable decline behaviors, while the tensile strengths of PC/ABS blends changed very little. For example, in the operating conditions of 1000rpm of screw speed and 20 seconds of loaded period, the elongations decreased from 148% before the processing, to 91.6% with the A1, to 63% with the A2 and to 131% with the A3 after the processing, respectively. In order to get the morphological properties, the size distributions of the dispersed phases for PC/ABS were investigated by SEM analysis and tended to decrease, as the screw speed and loaded period of the processing increased. Therefore, we confirmed that the antioxidant A3 was the best of all of three to inhibit the stress-induced degradation of PC/ABS blends during the high shear rate processing.

• Korean Journal of Health Education and Promotion
• /
• v.12 no.1
• /
• pp.83-110
• /
• 1995

The purpose of this study was to investigate the status of the problematic behavior for the demented elderly and the stress among family members, and the effects of the problematic behavior upon the stress in order to offer the basic data for the adult and the elderly health education about dementia. For this purpose, 70 families who were resident in Seoul and Inchon were surveyed by quetionnaires. This was carried out from 26 July, 1994 to 11 September, 1994. Datum was analysed by using SPSS\PC+ including percentage, mean, t - test, ANOVA, Pearson correlation. So, the results of this study were as follows: 1. In view of socia-demographic characteristics, female were 82.9%, and of the female daughters-in-law of the demented elderly were 44.9%. 40th years old were 32.9% and 88.6% wase married. The christian were 34.8%, those who graduated university 47.1%, and those who had a job 32.9%. 2. Of the demented elderly, female were 74.3%, 80 years old were 37.1%, and their average age was seventy-seven point one years old. 66.2% of the elderly has been lived alone and the christian were 27.5%. In addition, those who graduated elementary school were 66.5%. 3. Of the behavior problem for the demented elderly, Activities of the Daily Living(ADL) was the most severe problem. The 2nd was cognitive function problem, the 3th, change of personality, the 4th, emotional disturbance, and the last, misconduct behavior. 4. For the status of behavior problems, females were more severe than male, and 80th years elderly ware the most severe groups. The longer disease period was, the severe problematic behaviors were, and in 4-6 years of the disease period the status was the highest(p＜0.05). Those who diagnosed the disease had more severe problems(p＜0.001). 5. The orders of the stress among family members caring for the demented elderly in this study were as follows : 1. The deficiency of supporting network 2. Decrease of elderly's cognitive activities 3. Assistance of BADL(Basic Activities of Daily Living) 6. Elderly's abnormal behavior 5. Assistance of IADL(Instrumental Activities of Daily Living), 6. As for the status of the stress among family members, female respondants were higher than male. On the ages, 20th years' stress score were the highest. Daughters-in-law were stressed more than other family members. The longer the time of caring per day was, the highest the status of the stress(p＜0.05), 7. Those who caring for female elderly and more than 80 years had more stressed. When the elderly was received the diagnosis, the family members were more stressed. On the disease period, 1-2 years was the highest and after 2 years the status of the stress was decreased and more than 6 years was the lowest(p＜0.05). 8. Behavior problems of the demented elderly were closely associated to the stress for family members. Of the problems, change of personality was the most related factor(r = 0.6552). The factors of Basic Activities of the Daily Living(BADL) was most correlated on assistance of Basic Activities of Daily Living (BADL), emotional disturbance the assistance of IADL(Instrumental Activities of Daily Living). Change of personality was most related to the stress of the decrease of cognitive activities and elderly's abnormal behavior. The deficiency of supporting network was most related to misconduct behavior.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.31-31
• /
• 2010

The growth of the high-quality GaN epilayers is of significant technological importance because of their commercializedoptoelectronic applications as high-brightness light-emitting diodes (LEDs) and laser diodes (LDs) in the visible and ultraviolet spectral range. The GaN-based heterostructural epilayers have the polar c-axis of the hexagonal structure perpendicular to the interfaces of the active layers. The Ga and N atoms in the c-GaN are alternatively stacked along the polar [0001] crystallographic direction, which leads to spontaneous polarization. In addition, in the InGaN/GaN MQWs, the stress applied along the same axis contributes topiezoelectric polarization, and thus the total polarization is determined as the sum of spontaneous and piezoelectric polarizations. The total polarization in the c-GaN heterolayers, which can generate internal fields and spatial separation of the electron and hole wave functions and consequently a decrease of efficiency and peak shift. One of the possible solutions to eliminate these undesirable effects is to grow GaN-based epilayers in nonpolar orientations. The polarization effects in the GaN are eliminated by growing the films along the nonpolar [$11\bar{2}0$] ($\alpha$-GaN) or [$1\bar{1}00$] (m-GaN) orientation. Although the use of the nonpolar epilayers in wurtzite structure clearly removes the polarization matters, however, it induces another problem related to the formation of a high density of planar defects. The large lattice mismatch between sapphiresubstrates and GaN layers leads to a high density of defects (dislocations and stacking faults). The dominant defects observed in the GaN epilayers with wurtzite structure are one-dimensional (1D) dislocations and two-dimensional (2D) stacking faults. In particular, the 1D threading dislocations in the c-GaN are generated from the film/substrate interface due to their large lattice and thermal coefficient mismatch. However, because the c-GaN epilayers were grown along the normal direction to the basal slip planes, the generation of basal stacking faults (BSFs) is localized on the c-plane and the generated BSFs did not propagate into the surface during the growth. Thus, the primary defects in the c-GaN epilayers are 1D threading dislocations. Occasionally, the particular planar defects such as prismatic stacking faults (PSFs) and inversion domain boundaries are observed. However, since the basal slip planes in the $\alpha$-GaN are parallel to the growth direction unlike c-GaN, the BSFs with lower formation energy can be easily formed along the growth direction, where the BSFs propagate straightly into the surface. Consequently, the lattice mismatch between film and substrate in $\alpha$-GaN epilayers is mainly relaxed through the formation of BSFs. These 2D planar defects are placed along only one direction in the cross-sectional view. Thus, the nonpolar $\alpha$-GaN films have different atomic arrangements along the two orthogonal directions ($[0001]_{GaN}$ and $[\bar{1}100]_{GaN}$ axes) on the $\alpha$-plane, which are expected to induce anisotropic biaxial strain. In this study, the anisotropic strain relaxation behaviors in the nonpolar $\alpha$-GaN epilayers grown on ($1\bar{1}02$) r-plane sapphire substrates by metalorganic chemical vapor deposition (MOCVO) were investigated, and the formation mechanism of the abnormal zigzag shape PSFs was discussed using high-resolution transmission electron microscope (HRTEM).

• Asia pacific journal of information systems
• /
• v.19 no.1
• /
• pp.113-145
• /
• 2009

Recently, due to the globalization of the IT(Information Technology) market, devices and systems designed in one country are used in other countries as well. This phenomenon is becoming the key factor for increased interest on cross-cultural, or cross-national, research within the IT area. However, as the IT market is becoming bigger and more globalized, a great number of IT practitioners are having difficulty in designing and developing devices or systems which can provide optimal experience. This is because not only tangible factors such as language and a country's economic or industrial power affect the user experience of a certain device or system but also invisible and intangible factors as well. Among such invisible and intangible factors, the cultural characteristics of users from different countries may affect the user experience of certain devices or systems because cultural characteristics affect how they understand and interpret the devices or systems. In other words, when users evaluate the quality of overall user experience, the cultural characteristics of each user act as a perceptual lens that leads the user to focus on a certain elements of experience. Therefore, there is a need within the IT field to consider cultural characteristics when designing or developing certain devices or systems and plan a strategy for localization. In such an environment, existing IS studies identify the culture with the country, emphasize the importance of culture in a national level perspective, and hypothesize that users within the same country have same cultural characteristics. Under such assumptions, these studies focus on the moderating effects of cultural characteristics on a national level within a certain theoretical framework. This has already been suggested by cross-cultural studies conducted by scholars such as Hofstede(1980) in providing numerical research results and measurement items for cultural characteristics and using such results or items as they increase the efficiency of studies. However, such national level culture has its limitations in forecasting and explaining individual-level behaviors such as voluntary device or system usage. This is because individual cultural characteristics are the outcome of not only the national culture but also the culture of a race, company, local area, family, and other groups that are formulated through interaction within the group. Therefore, national or nationally dominant cultural characteristics may have its limitations in forecasting and explaining the cultural characteristics of an individual. Moreover, past studies in psychology suggest a possibility that there exist different cultural characteristics within a single individual depending on the subject being measured or its context. For example, in relation to individual vs. collective characteristics, which is one of the major cultural characteristics, an individual may show collectivistic characteristics when he or she is with family or friends but show individualistic characteristics in his or her workplace. Therefore, this study acknowledged such limitations of past studies and conducted a research within the framework of 'theoretically integrated model of user satisfaction and emotional attachment', which was developed through a former study, on how the effects of different experience elements on emotional attachment or user satisfaction are differentiated depending on the individual cultural characteristics related to a system or device usage. In order to do this, this study hypothesized the moderating effects of four cultural dimensions (uncertainty avoidance, individualism vs, collectivism, masculinity vs. femininity, and power distance) as suggested by Hofstede(1980) within the theoretically integrated model of emotional attachment and user satisfaction. Statistical tests were then implemented on these moderating effects through conducting surveys with users of four digital devices (mobile phone, MP3 player, LCD TV, and refrigerator) in three countries (US, Germany, and Russia). In order to explain and forecast the behavior of personal device or system users, individual cultural characteristics must be measured, and depending on the target device or system, measurements must be measured independently. Through this suggestion, this study hopes to provide new and useful perspectives for future IS research.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.480-493
• /
• 2007

Many railway-advanced countries are using the various types of track to reduce the track maintenance and repair cost according to the improvement of velocity. It spends on much maintenance and repair cost for ballast track due to abrasion of ballast, track irregularity and unisotropical ballast-support stiffness. The ballast track on railway bridge is accelerating the deterioration of ballast according to interaction of railway bridge and track. As continuing the deterioration, it is caused dynamic loads. Due to these effects, it increases negative loads of track and bridge. However, when designing the railway bridge, the effect of ballast track was applicate only dead load, so elastic behavior effect of ballast track is not influenced. Therefore, this paper presumes the stiffness of ballast track on railway bridge considering dynamic behavior of railway bridge, it was evaluated that effect on dynamic behaviors of railway bridge according to ballast track stiffness.

• Journal of agricultural medicine and community health
• /
• v.37 no.3
• /
• pp.131-144
• /
• 2012

Objectives: This study was performed to identify the associations of empowerment and social capital (such as social participation and trust) with self-rated health in Korean communities with poor health. Methods: This study used the data from community health interviews conducted at 29 administrative sections (dong, eup, or myeon) with high mortality from August to October in both 2010 and 2011 as part of the Health Plus Happiness Plus Projects in Gyeongsangnam-do Province. The study subjects comprised 6,383 individuals composed of approximately 220 adults randomly sampled from each administrative section. The empowerment was measured with five-point Likert scale responses to seven perceived control questions (two at the individual level, five at the community level). The social participation was measured with 'participation in formal and/or informal group' and trust using responses to three questions about trust of others. Results: The high empowerment scores at both individual and community levels, social participation in informal groups, and high trust level had independent and significant associations with good self-rated health after adjusting for socio-demographic factors (sex, age, marital status, occupation, and food affordability) and health behaviors (smoking, alcohol drinking, and exercise) in the logistic regressions. There were weak but significant associations among empowerment, social participation, and trust levels. Conclusions: Empowerment, social participation, and trust were weakly inter-related and significantly associated with self-rated health. More studies are warranted for empowerment and other social capital indices in health promotion.