• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.381-382
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• 2006

The mechanical behaviors of multi-layered foam core sandwich composite were investigated through a 3-point bending test. The sandwich specimens were obtained from sandwich panel consisting of aluminum faces and urethane foam core. Three types of sandwich specimens such as a single structure, a double structure and a triple structure were considered. The span of sandwich specimens were varied from 170mm to 350mm. According to the results, the flexural and shear properties of multi-layered sandwich composite were found to be higher than those of single-layered sandwich composite.

• 조명전기설비학회논문지
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• 제22권10호
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• pp.62-68
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• 2008

본 논문은 임펄스전류의 인가위치에 따른 심매설 봉상 접지전극의 과도접지임피던스와 규약접지임피던스 특성에 관하여 기술하였다. 과도접지임피던스는 심매설 접지전극의 길이 및 임펄스전류의 상승시간과 인가위치에 강하게 의존하며, 접지전극의 자체 인덕턴스는 짧은 시간 영역에서 점지시스템의 과도접지임피던스에 크게 영향을 미치는 것으로 나타났다. 심매설 봉상 접지전극의 자체 인덕턴스의 저감은 과도접지임피던스 특성의 개선에 결정적인 역할을 한다. 접지도선의 길이는 최대한 짧게 하여 접지전극의 상단에 접속하는 것이 효과적이다.

• International Journal of Korean Welding Society
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• 제4권1호
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• pp.46-52
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• 2004

To combine the mechanical advantages of ceramics with those of metals, one often uses both materials within one composite component. But, as known, they have different material properties and fracture behaviors. In this study, a four-point bending test is carried out on $Si_3N_4$ joined to ANSI 304L stainless steel with a Ti-Ag-Cu filler and a Cu interlayer at room temperature to evaluate their longitudinal strain behaviors. And, to detect localized strain, a couple of strain gages are pasted near the joint interfaces of the ceramic and metal sides. The normal strain rates are varied from $3.33{\times}10^5$ to $3.33{\times}10^{-1}s^{-1}$ Within this range, the experimental results showed that the four-point bending strength and the deflection of the interlayer increased with increasing the strain rate.

• Structural Engineering and Mechanics
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• 제85권5호
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• pp.665-677
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• 2023

In the present study, the limit point buckling and postbuckling behaviors of sinusoidal, shallow arches with pinned supports subjected to localized sinusoidal loading, based on the Euler-Bernoulli beam theory, are numerically analyzed. There are some studies on the buckling of sinusoidal shallow arches under the effect of sinusoidal loading. However, in these studies, the sinusoidal loading acts along the horizontal projection of the entire shallow arch. No study has been found in the relevant literature pertaining to the stability of the shallow arches subjected to various lengths of sinusoidal loading. Therefore, the purpose of this paper is to contribute to the literature by examining the effect of the length of the localized sinusoidal loading and the initial rise of the shallow arch on the limit point buckling and postbuckling behaviors. Equilibrium paths corresponding to certain values of the length of the localized sinusoidal loading and various values of the initial rise parameter are presented. It has been observed that the length of the sinusoidal loading and the initial rise parameter affects the transition from no buckling to limit point instability remarkably. The deformed configurations of the sinusoidal shallow arch under localized loading regarding buckling and postbuckling states are illustrated, as well. The effects of the length of the localized sinusoidal loading on the internal forces of the shallow arch are investigated during various stages of the loading.

• 한국환경교육학회지:환경교육
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• 제15권1호
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• pp.18-30
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• 2002

So far, the environmentally responsible behavior(ERB) model has been applied successfully to explain environment behaviors. But the ERB model has several limitations such as underestimation of social factors on environment behaviors. This study planned to point out that the emotional aspects should be considered seriously for explaining human's behaviors to conserve the environment in the ERB model. In this study, the effects of emotional aspects, such as perceived severity or perceived danger, on environment behaviors were investigated and the protective motivation theory(Rogers, 1983) and the ERB-based tentative model were compared Results showed that teenagers in urban areas realized clearly the severity and danger of environmental threats and do environmentally responsible behaviors more than ones in rural areas. Two model's goodness of fit to explain observed environment behaviors were analyzed through the regression analysis and the AMOS analysis. In the regression analysis, self-efficacy, confirmity toward social norm, and knowledge were involved in the regression equation as statistically meaningful variables in the ERB-based tentative model and self-efficacy and perceived severity were involved in the protective motivation theory. Especially, the AMOS analysis showed that the protective motivation theory was more valid model lot explaining environment behaviors than the ERB-based tentative model. In conclusion, it is reasonable that emotional aspects should be considered as meaningful variables for explaining environment behaviors.

• 한국산업융합학회 논문집
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• 제12권4호
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• pp.221-228
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• 2009

This study analyzes the behaviors and images of city residents on the six Gyeongsangbuk-do rural theme villages. The results of analysis bring the following conclusions. 1) Behaviors of city residents are related with the images on rural villages. In addition, the better the image is, the higher their behaviors' needs. 2) Behaviors' needs become higher on the village as the image on 'Scale type' becomes better. 3) Especially, in case of Gimcheon and Gyeongju, we find a strong relationship between the images of 'Scale type' and 'Magnificent type' and behaviors; these villages should raise the scale and standard of villages by certain point.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권12호
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• pp.5927-5942
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• 2017

Many real networks exhibit overlapping community structures. Recent studies have been performed that analyze the impact of overlapping community structure on information propagation, but few of them concerned with individual behaviors. From this point of view, we propose a Markov process model to evaluate the performance of information propagation in social networks with overlapping community structures. In addition, many individual social behaviors are combined in the model. For example, individuals may exhibit selfish behaviors, such as individual and social selfishness, and people may discard the information after they have used it. The accuracy of the model is verified by simulation. Furthermore, the numerical results show that both overlapping community structure of the network and individual behaviors have a significant impact on the outbreak size and propagation speed of the information. Additionally, the overlapping community structure of the social network can reduce the impact of selfishness on information propagation.

• Child Studies in Asia-Pacific Contexts
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• 제1권1호
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• pp.51-58
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• 2011

The purpose of this research is to study differences in perceived parental neglectful behaviors between siblings from a child's perspective. The data were collected using the Multidimensional Neglectful Behavior Scales (MNBS) questionnaire from 158 sibling pairs in grades 4, 5, and 6 who attended the same elementary schools. Younger sibling experienced emotional neglect by their parents significantly more than older siblings. Same gender sibling pairs and older brotheryounger sister pairs perceived their parental neglectful behaviors in a similar manner. However older sister-younger brother pairs showed that the younger brother perceived significantly more neglect than his older sister. This study clearly illustrated that siblings' perceptions of their parents' neglectful behaviors exists differently within a family contrary to previous studies which have shown that siblings' perception of parental neglectful behaviors are similar. The results suggest that the younger brother in mixed-gender sibling pairs are far more likely to experience neglect than any other sibling. Thus, even though siblings can be at equal risk in experiencing parental neglect, the effects can vary depending on the birth order.

• 동아시아식생활학회지
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• 제17권5호
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• pp.615-625
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• 2007

This study investigated the overall conditions related to family meals, including perceptions, attitudes, and behaviors, among middle and high school students. The data were collected from 773 male and female students attending middle and high schools in Seoul and Kyunggi-Do from March to May 2006, using pre-tested self-administered questionnaires. The results are as follows: 78.9% of the subjects lived with their parents and siblings, and 75.7% regarded family meals as meals eaten with all family members living together in a household. As for the frequency of family meals, 40.1% of the middle school subjects answered that they ate with their family 'more than once per day' and 20.8% answered '1 or 2 time per a week'. However 21.0% of the high school students had family meals 'more than once per day', and 31.7% had family meals '1 or 2 times per a week', showing a significant difference between the groups(p<0.001). When the degree of satisfaction with life was evaluated using a Likert scale(strongly satisfied 5 point, strongly unsatisfied 1 point), the middle school students showed a significantly higher level of satisfaction than the high school students towards daily life, health, nutritive conditions, and family care. feelings, attitudes, and behaviors toward family meals were also evaluated(strongly agree 5 point, strongly disagree 1 point), and the results showed that the subjects had positive psychological feelings, with significant differences based on the frequency of family meals. Likewise, the groups who ate frequent family meals scored higher on aspects related to having positive attitudes and behaviors toward the family meal, implying that eating family meals is associated with promoting friendship, psychological stability, and positive thinking in adolescents. These findings suggest that attention needs to he directed toward increasing the frequency of family meals and creating a positive family meal environment.

• 보건교육건강증진학회지
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• 제31권5호
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• pp.147-158
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• 2014

Objectives: This study aims to examine the association of depression, suicidal behaviors with smartphone use behaviors among Korean adolescents. Methods: We analyzed data from 'Youth Health and Life Skills Survey' in 2013. The survey was based on self-reported questionnaires distributed to 915 grade 7th and 8th students at four middle schools in Gangdong-gu, Seoul, Korea in 2013 to evaluate the effects of 'Youth Health and Life Skills' program. Depression and suicidal behaviors were measured in terms of the experience rate, and smartphone use behaviors were measured with average hours of smartphone use a day and overindulged behaviors in smartphone use by using 5-point Likert scales. We examined the association of depression and suicidal behaviors with smartphone use behaviors by using t-test and regression analyses. Results: 21.5% of respondents have ever felt depressed or hopeless to lose interest in school life almost everyday for 2 weeks or longer in the past year. The experience rate of suicidal ideation, suicide plan, and suicidal attempt were 21.1%, 6.1%, and 5.7%, respectively. The mean of average hours of smartphone use a day was 3.9 hours, and the mean score of overindulged behaviors in smartphone use was 2.99. The students who have experienced depression and suicidal behaviors were more likely to have more smartphone using time and higher scores of overindulged behaviors in smartphne use than those who have not. Conclusion: We concluded that for preventing addictive or problematic smartphone use behaviors among adolescents we should consider and develop more positive strategies for the moderate use of smartphone than regulatory measures, which include the implementation of skill-based health education program including life skills at schools and the development of smartphone applications useful for resolving mental stress and promoting mental health.