• Structural Engineering and Mechanics
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• v.11 no.1
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• pp.49-70
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• 2001

This paper is concerned with a study on thermo-elastoplastic characteristics of functionally graded composite. Compared to the classical layered composites, it shows a wide range of thermo-elastoplastic characteristics according to the choice of two major parameters, the thickness-wise volume fraction of constituents and the relative thickness ratio of the graded layer. Therefore, by selecting an appropriate combination of the two parameters, one is expected to design the most suitable heat-resisting composite for a given thermal circumstance. Here, we address the parametric investigation on its characteristics together with theoretical study on thermo-elastoplasticity and numerical techniques for its finite element approximations. Through the numerical experiments, we examine the influence of two parameters on the thermo-elastoplastic characteristics.

• Journal of Information Technology Applications and Management
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• v.26 no.3
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• pp.99-120
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• 2019

The purpose of this study is to provide information necessary for establishing a new strategy for customer service improvement by deriving factors affecting user satisfaction and continuous use intention of mobile app service user characteristics, system characteristics, and social characteristics. The results of this study are summarized as follows. First, reliability, innovation, familiarity, convenience, and self-efficacy among the characteristics of mobile app are analyzed as factors that have the greatest influence on user's perceived usefulness. Second, convenience, mobility, and visibility are some of the characteristics of mobile app service. Third, identity, security, and expectation agreement among mobile app service characteristics are analyzed as negative factors that do not affect users' perceived usefulness. Fourth, interactivity, familiarity, and self-efficacy among the characteristics of mobile app service were analyzed as positive factors that have the greatest effect on user's perceived ease of use. Fifth, reliability, mobility, visibility, and convenience among mobile app service characteristics are analyzed as factors that have some positive effects on perceived ease of use of app users. Sixth, identity, innovation, and security among the characteristics of mobile app service are negatively influenced by mobile app users' perceived ease of use. Seventh, the perceived usefulness of mobile app users is analyzed as a factor that has a very positive effect on user satisfaction. Eighth, the perceived ease of use of mobile app users is analyzed as a factor affecting perceived usefulness positively. Ninth, the perceived ease and expectation of mobile app users are positively influenced on user satisfaction. The tenth, the perceived usefulness of the mobile app users was analyzed as a factor having a very positive influence on the persistent intention to use. For the eleventh, the perceived ease of use of mobile app users was analyzed as a factor having a positive effect on the persistent intention to use. The twelfth, mobile app user satisfaction was analyzed as a factor having a very positive effect on the persistent intention to use.

• Journal of the Korean Institute of Rural Architecture
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• v.16 no.3
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• pp.37-44
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• 2014

This study is to clarify the actual conditions of the floor plan of middle and high schools in the rural area. Recently, many middle school and high school are remodeling the buildings and facilities based on the departmentalized classroom system. This study, through analyzing on 4 remodeling cases of middle and high schools in gyeongnam. This article discuses about the basic characteristics of the plan composition and the education programs of 4 schools. This study is showing the variation before and after remodeling and space organization types. The results of this study are summarized as follows; Home-room and home-base should be more faithfully. Various common space is needed to comfortable school life of students. In case of side corridor type plan, moving path is much needed. Sample schools took much more spaces of home base than before. This article discusses about the basic characteristics of the floor plan and the actual condition of the school facilities.

• Journal of the Korean Chemical Society
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• v.60 no.6
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• pp.415-427
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• 2016

This study analyzed the attributes of the conceptions of $3^{rd}$ to $6^{th}$ grade elementary school students on three states of matter and investigated the characteristics of the classified results of various examples of matter by grades. Through discussion activities, we confirmed the stabilization of conception attributions. For this study, 113 participants from two $3^{rd}$ to $6^{th}$ grade elementary school classes were selected. The concentration analysis (C-factor) and normalized gain (G-factor) of the conceptions for the quantitative analysis of the conception changes were used. The elementary school students retained different percentages of the attributes for states of matter. The characteristic of the grades were different between the 3rd grade and other grades. Based on these results, we pointed out the problems with the present teaching methods in science textbooks and stated the advantages of the effects of the representation of mixtures.

• Korean Institute of Interior Design Journal
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• v.13 no.4
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• pp.118-126
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• 2004

This study started from the premise that the future elementary school should be designed based on ecological approach in order to restore the emotionality of children. This study aimed at providing a guideline for designing the interior of elementary schools based on ecological approach. Through literature review, the characteristics of ecological architecture and the regulations for green buildings were explored. Also 7 elementary schools which were evaluated as good school design through renowned books representing the ecological characteristics were chosen and analyzed. The results revealed that the school design included natural lighting by roof lighting, natural ventilation, greening, and use of natural materials. This study suggested three categories as a the guideline for the interior space of eco-school design; energy efficiency, greening and sustainability, which included natural lighting, natural ventilation, heating and cooling, planting, materials and water recycling.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1327-1330
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• 2002

In this paper examines theoretical analysis of passive intermodulation and its methods of measurement and procedure. And based on the results of field measurement, it defines the reasons of passive intermodulation of base stations, suggests characteristics by device and methods of improvement to minimize the influence of a base station on passive intermodulation, and compares and analyzes the results of field measurement before and after the reasons are improved to secure the characteristics by device and the utility and adequacy of methods of improvement.

• Korean Journal of Health Education and Promotion
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• v.30 no.2
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• pp.11-21
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• 2013

Objectives: The objective of this paper is to study influence of self esteem, family support and adaptation to school life on adolscents' suicidal ideation adjsuted for general characteristics effect. Methods: Using cluster sampling, 318 high school freshmen from T city were extracted as survey subjects. Independent t-test, ANOVA, Duncan test, Pearson's correlation coefficients and multiple regression analysis were applied for statistical analysis. Results: Among general characteristics, religion, family income, single-parentedness, health status and school grades were statistically significant with suicidal ideation. Controlling the above variables, increase in self-esteem (${\beta}$=-.300) and family support (${\beta}$=-.267) showed statistically significant decrease in suicidal ideation but adaptation to school life did not. Conclusions: Therefore, it is proposed that measures for enhancement of self esteem and family support to be included in development of suicide prevention programs.

• Steel and Composite Structures
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• v.52 no.6
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• pp.663-672
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• 2024

This paper researched on the bending vibration characteristics of composite drive shaft with internal damping. To analyze the unbalanced excitation response in full speed range, a transfer matrix model was built based on the improved Layer-wise theory and the numerical damping, and compared with the metal drive shaft. The results show that the effect of internal damping of the composite shaft tube on bending vibration response was different in the subcritical, critical and supercritical speed ranges. Then, the finite element analysis and vibration tests were carried out to verify the analysis results of transfer matrix model.

• Journal of The Korean Society of Clinical Toxicology
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• v.2 no.2
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• pp.90-95
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• 2004

Purpose: The purpose of this study is to compare the toxicologic characteristics of two groups of patients with acute intoxication for two different time periods and to make recommendations based on the results of this study. Methods: We reviewed retrospectively the medical records of patients with acute intoxication in our emergency center from June 1997 to May 1998 (group A) and from June 2000 to May 2003 (group B), and we evaluated differences in the epidemiologic and the toxicologic characteristics between the two groups. Results: The ratios of the number of patients with acute intoxication to the total numbers of patients who visited our emergency department were $0.49\%$ and $0.52\%$ for groups A and B, respectively. In both groups many poisoned patients visited our emergency center from 4:00 pm to midnight. The interval between the time of intoxication and arrival at the hospital was significantly shorter in group B. The number of patients transferred to our emergency center was larger in group B. Attempted suicide was the major cause of acute intoxication in both groups. Major toxic substances in both groups were centrally active drugs and insecticides. The number of comatose and mechanically ventilated patients was larger in group B. However, there was no statistically significant difference in the mortality rates. Conclusion: Emergency physicians who manage intoxicated patients should recognize regional characteristics and differences in the toxicologic characteristics of poisoning. In addition, the establishment of a poisoning control center in the regional emergency center is necessary to integrate data control and to enhance specialized management of intoxicated patients.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.2
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• pp.93-101
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• 2002

We have proposed and fabricated two lateral type field emission diodes, poly-Si emitter by utilizing the local oxidation of silicon (LOCOS) and GaN emitter using metal organic chemical vapor deposition (MOCVD) process. The fabricated poly-Si diode exhibited excellent electrical characteristics such as a very low turn-on voltage of 2 V and a high emission current of $300{\;}\bu\textrm{A}/tip$ at the anode-to-cathode voltage of 25 V. These superior field emission characteristics was speculated as a result of strong surface modification inducing a quasi-negative electron affinity and the increase of emitting sites due to local sharp protrusions by an appropriate activation treatment. In respect, two kinds of procedures were proposed for the fabrication of the lateral type GaN emitter: a selective etching method with electron cyclotron resonance-reactive ion etching (ECR-RIE) or a simple selective growth by utilizing $Si_3N_4$ film as a masking layer. The fabricated device using the ECR-RIE exhibited electrical characteristics such as a turn-on voltage of 35 V for $7\bu\textrm{m}$ gap and an emission current of~580 nA/l0tips at anode-to-cathode voltage of 100 V. These new field emission characteristics of GaN tips are believed to be due to a low electron affinity as well as the shorter inter-electrode distance. Compared to lateral type GaN field emission diode using ECR-RIE, re-grown GaN emitters shows sharper shape tips and shorter inter-electrode distance.