• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.6
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• pp.110-117
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• 2003

The operational characteristics of the landing gear retraction/extension depend on the complexity of design variables operational/environmental conditions. In order to meet the requirements of minimum stow area and performance, the integration of the landing gear system requires operational kinematic and dynamic analysis considering an effect of its related system. This study investigates operational dynamic behaviors of the T-50 landing gear system using ADAMS. Taking into account for various operational/environmental conditions, an analysis of dynamic behavior on the landing gear operational characteristics is performed with experience derived from a wide range of proprietary designs. Analytical results are presented for discussing the effects of temperature, aerodynamic and maneuver load on normal/emergency operation of the landing gears and doors. This analysis leads us to the conclusion that the proposed program is shown to be a better quantitative one that apply to a new development and troubleshooting of the landing gear system.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.4
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• pp.339-356
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• 2012

At this point in time, the importance of cosmeceuticals is being emphasized. This report is about the cosmeceuticals usage analysis of actual condition and purchasing behavior of female undergraduates. I suggest the methods for the sustainable improvement of cosmeceuticals that will satisfy needs of more customers through market segmentation. The subjects of this study were 340 undergraduates of selected 2 women's Universities in Seoul. 300 replies among the total distibuted questionnaires were analyzed with SPSS WIN 15.0 Statistics program. Through the study, it appears that the most female undergraduates use cosmeceuticals and the usage of cosmeceuticals is to resolve their skin problems. The most popular places for the purchase of cosmeceuticals are department stores and the most important consideration on purchases is the effectiveness of products. It is discovered that sunscreens are the most used cosmeceuticals.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.5
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• pp.641-648
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• 2013

A beam is a major load-carrying member in many engineering structures. Beams with properly designed cross sections and stiffeners are required to enhance the structural properties. Such a design may cause various coupling behaviors, and therefore, an accurate analysis is essential for the proper design of beams. In this research, we manufactured box-beams with stiffeners, which mimic the out-of-plane composite bending-shear coupling behavior reported in literature. A modal test is carried out to obtain the dynamic characteristics, such as natural frequencies and mode shapes, of the box-beam. The obtained results are compared with those of 3D FEM, which confirm that the out-of-plane bending-shear coupling behavior reported in literature is possible. The coupling behavior can be controlled by the proper design of the stiffeners.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.6 no.3
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• pp.583-596
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• 1999

The purpose of this study was to examine the effect of self-care of abdominal surgery patients in surgical intensive care unit after offering preoperative nursing information. This study worked out nonequivalant control group post test only design as suspected experimental study. This subjects of the study were 45 patients, 23 in experimental group and 22 in control group. This study was carried at a university hospital in Taegu between January 12, 1999 and March 13, 1999. The experimental group was supplied with preoperative nursing information and the control group received routine care in ICU. The measuring tools of this study were assessment of the self-care role behavior. The data were analyzed by SPSS computer program, $x^2-test$ and t-test and ANOVA were utilized for testing the difference between the experimental and the control group. The hypothesis was examined by t-test. The result of this study are summarized as follows ; 1) The hypothesis, 'The experimental group will show a higher level of self-care than the control group' was accepted(t=-8.958, p=.000). 2) We could not find any meaningful relation about general characteristics and disease associated characteristics between the experimental and the control group. 3) The self-care behavior scores according to the general characteristics and disease associated characteristics show significant statistical difference by economics status (p=.033). 4) The rate of self-care behavior scores of each questionnaire are below average in the questions that request active activity to prevent postoperative complications From the result of this study, the self-care of the experimental group was higher than those of the control group, and the nursing information can be regarded as an effective nursing intervention for preoperative patients.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.2
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• pp.267-279
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• 2017

This study emulated unscheduled phishing e-mails over a long period of time by imitating the manner in which external hackers attacked a group of employees in a company. We then measured and analyzed the recipient's ability to identify and respond to phishing e-mails as training progressed. In addition, we analyzed the changes in participants' response behavior when changing the external control condition between the training. As a result of the analysis, it was confirmed that the training duration had a positive (+) relationship with the employees' ability to identify phishing e-mails and the infection rate, and more employees read emails and infected with phishing attacks using social issues and seasonal events. It was also confirmed that reinforcement of internal control policy on infected persons affects positively (+) on the phishing attack response behavior of employees. Based on these results, we would like to suggest the right training method for each organization to enhance the ability of employees to cope with phishing attacks.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.2
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• pp.156-164
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• 2003

STS316L had been used as the structural material for energy environmental facilities, because austenite stainless steels like 316L have superior mechanical properties of which toughness, ductility, corrosion resistant and etc. However, those welded structures are receiving severe damage due to increasing of the aged degradation. Most studies until now have been carried out against fatigue behaviors of weldments, and were not well studied on nondestructive evaluation methods. In this study, the fatigue crack propagation behavior of STS316L weldment usually used for vessels of the nuclear power plant was investigated. Also, the degradation characteristics of 316L stainless steel weldments were evaluated by the ultrasonic parameter such as ultrasonic velocity, attenuation factor and time-frequency analysis. The results of this study can be used as a basic data for the prediction of the fatigue crack life of weldments structures without disjointing or stopping service of structures in service.

• Bulletin of the Korean Chemical Society
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• v.30 no.4
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• pp.783-786
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• 2009

Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and ion chromatography(IC) were employed to analyze the thermal behavior of $Li_xCoO_2$ cathode material of lithium ion battery. The mass loss peaks appearing between 60 and 125 ${^{\circ}C}$ in TGA and the exothermic peaks with 4.9 and 7.0 J/g in DSC around 75 and 85 ${^{\circ}C}$ for the $Li_xCoO_2$ cathodes of 4.20 and 4.35 V cells are explained based on disruption of solid electrolyte interphase (SEI) film. Low temperature induced HF formation through weak interaction between organic electrolyte and LiF is supposed to cause carbonate film disruption reaction, $Li_2CO_3\;+\;2HF{\rightarrow}\;2LiF\;+\;CO_2\;+\;H_2O$. The different spectral DSC/TGA pattern for the cathode of 4.5 V cell has also been explained. Presence of ionic carbonate in the cathode has been identified by ion chromatography and LiF reported by early researchers has been used for explaining the film SEI disruption process. The absence of mass loss peak for the cathode washed with dimethyl carbonate (DMC) implies ionic nature of the film. The thermal behavior above 150 ${^{\circ}C}$ has also been analyzed and presented.

• Journal of Digital Convergence
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• v.19 no.3
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• pp.437-444
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• 2021

The purpose of this study is to investigate the relationship between consciousness of marine safety, re-participation behavior of marine safety virtual reality experience education. For the study, participants in marine safety virtual reality experience education were surveyed from July to August 2020. Specifically, all participants were NakDanbo Water leisure center and Song-do Marine leisure center. A total of 300 participants were sampled using convenience sampling method, but 253 were finally used in the data analysis excepting incomplete or faithless questionnaires. the data analysis was conducted through frequency analysis, Cronbach's alpha, Exploratory Factor Analysis (EFA), correlation analysis, simple and Multiple regression analysis using SPSS 20.0. The results are as follows. Firstly, participants in marine safety virtual reality experience education positive impact on had a significant effect on consciousness of marine safety. Secondly, participants in marine safety virtual reality experience education positive impact on had a significant effect on re-participation behavior intention. Lastly, consciousness of marine safety had positive effects on re-participation behavior intention.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.337-341
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• 2004

Engineering ceramics have superior heat resistance, corrosion resistance, and wear resistance. Consequently, these art significant candidates for hot-section structural components of heat engine and the inner containment of nuclear fusion reactor. Besides, some of them have the ability to heal cracks and great benefit can be anticipated with great benefit the structural engineering field. Especially, law fracture toughness of ceramics supplement with self-healing ability. In the present study, we have been noticed some practically important points for the healing behavior of silicon nitride, alumina, mullite with SiC particle and whisker. The presence of silicon carbide (SiC) in ceramic compound is very important for crack-healing behavior. However, self-healing of SiC has not been investigated well in detail yet. In this study, commercial SiC was selected as sample, which can be anticipated in the excellent crack healing ability. The specimens were produced three-point bending specimen with a critical semi-circular crack of which size that is about $50-700{\mu}m$. Three-point bending test and static fatigue test were performed cracked and healed SiC specimens. A monotonic bending load was applied to cracked specimens by three-point loading at different temperature. The purpose of this paper is to report Strength Properties and Elastic Waves Characteristics of Silicon Carbide with Crack Healing Ability.

• Journal of environmental and Sanitary engineering
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• v.22 no.4
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• pp.105-117
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• 2007

The research was conducted based on the 1012 cases questionnaire for the purpose of to evaluate the change effect of university student's consciousness and behavior before and after lecture on environmental problems. And this questionnaires were performed with self-administered by the university student who made a application for liberal arts related to environmental subjects. The results were as follows. According to the analysis results the most students responded that the most serious problem of environmental pollution before the lecture on environmental education was a genetic modified organism(3.64/4.00), but the most serious problem of environmental pollution was changed to the topic of water pollution(3.96/4.00) after the lecture on environmental problem. And also according to the analysis results dributed by gender were that boy students show a higher concerning(170%) than that of girl students(150%). The most good results obtained after lecture on environmental problem were water pollution(23.0%), air pollution(11.5%), waste material pollution(10.9%), food additives (10.0%), genetic modified organism(8.0%), endocrine disrupter(7.5%), respectively. And according to the analysis results distributed by a grade were that the concerning of a low grade(freshman, sophomore)were higher than that of a high grade(junior, senior) in the topic of water pollution, air pollution, waste material pollution. But there were high level of awareness on the topic of food additives, genetic modified organism, endocrine disrupter to the all students(freshman to senior). And according to the analysis results distributed by a major field of study were that students who major in art & athletics, liberal art and etc(public health) were show a deep concerning than that of science & engineering. Finally, the environmental education during the university class were effectively contribute to increase the awareness of the seriousness of environmental pollution problem(8.2%) and also contribute to the practical life after class also increase their consciousness of environmental problem(59.8%).