• Journal of Digital Convergence
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• v.13 no.12
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• pp.291-301
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• 2015

It was conducted to investigate effects of the group art-therapy for abused children with depressed, anxiety, negative self image. The subjects were 4 children at OOcity OOgroup home. They lived at group home for 4years 5months with any treatment. Group art therapy had been conducted once a week from Sept. 2013 through Aug. 2014. There were 48sessions and each session lasted 60 minute. To verify the effects of Group art therapy(art activity, works & contents), researchers recorded the subjects' emotional reactions, attitudes, behaviors with the therapeutic purpose in each session and measured CDI, STAIC(TAIC, SAIC), Self-IQYA Korean version Inventory for validity. Pre test(Aug. 2013) & post-test(Aug. 2014) were executed. To do a sum of test reliability, the SPSS 21.0 program is used. The results were: firstly, abused children expressed their emotional state in the works, they changed behaviors and improved relations with friends. Secondly, the score of depression & anxiety in the post_test was lower than in pre_test. Thirdly, the score of self-image in the post_test was higher than in pre_test. Depression & anxiety were reduced and self image changed positively. Exactly, they reduced impulsive act and maintained friendly relationships. Fosterer understood well the children so she would reduce difficulty.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.8
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• pp.621-630
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• 2018

In the case of launch vehicles using liquid fuel, natural frequency changes due to fuel consumption after launch, and a modal test is essential to investigate its effect. However, when relying on modal test to characterize the free vibration characteristics, the testing time is excessively increased and accuracy is reduced. Therefore, this paper suggests a modal test method with finite element analysis to overcome these drawbacks. A cylindrical structure filled with liquid are considered as a study model, and modal tests and finite element analyses are performed. The modal tests are conducted by an impulsive method using an impact hammer and accelerometers. Through the comparison of the modal test and the finite element analysis results, the validity of the proposed modal test method is verified. In addition, the free vibration characteristics and the tendency for the cylindrical structure according to the liquid filled ratio were investigated.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.50-57
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• 2007

Shocks are excited by impulsive forces and cause discomfort in vehicles. Current standards define means of evaluating shocks and predicting their discomfort, but the methods are based on research with a restricted range of shocks. This experimental study was designed to investigate the discomfort of seated subjects exposed to a wide range of vertical shocks. Shocks were produced from the responses of one degree-of-freedom models, with 16 natural frequencies (from 0.5 to 16 Hz) and four damping ratios (0.05 0.1, 0.2 and 0.4), to a hanning-windowed half-sine force inputs. Each type of shock was presented at five vibration dose values in the range $0.35\;ms^{-1.75}$ to $2.89\;ms^{-1.75}$. Fifteen subjects used magnitude estimation method to judge the discomfort of all shocks. The exponent in Stevens' power law, indicating the rate of growth in discomfort with shock magnitude, decreased with increasing fundamental frequency of the shocks. At all magnitudes, the equivalent comfort contours showed greatest sensitivity to shocks having fundamental frequencies in the range 4 to 12.5 Hz. At low magnitudes the variations in discomfort with the shock fundamental frequency were similar to the frequency weighting $W_b$ in BS 6841, but low frequency high magnitudes shocks produced greater discomfort than predicted by this weighting. At some frequencies, for the same unweighted vibration dose value, there were small but significant differences in discomfort caused by shocks having different damping ratios. The rate of increase in discomfort with increasing shock magnitude depends on the fundamental frequency of the shock. In consequence, the frequency-dependence of discomfort produced by vertical shocks depends on shock magnitude. For shocks of low and moderate discomfort, the current methods seem reasonable, but the response to higher magnitude shocks needs further investigation.

• Earthquakes and Structures
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• v.14 no.4
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• pp.323-336
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• 2018

Machine foundations with impact loads are common powerful sources of industrial vibrations. These foundations are generally transferring vertical dynamic loads to the soil and generate ground vibrations which may harmfully affect the surrounding structures or buildings. Dynamic effects range from severe trouble of working conditions for some sensitive instruments or devices to visible structural damage. This work includes an experimental study on the behavior of dry dense sand under the action of a single impulsive load. The objective of this research is to predict the dry sand response under impact loads. Emphasis will be made on attenuation of waves induced by impact loads through the soil. The research also includes studying the effect of footing embedment, and footing area on the soil behavior and its dynamic response. Different falling masses from different heights were conducted using the falling weight deflectometer (FWD) to provide the single pulse energy. The responses of different soils were evaluated at different locations (vertically below the impact plate and horizontally away from it). These responses include; displacements, velocities, and accelerations that are developed due to the impact acting at top and different depths within the soil using the falling weight deflectometer (FWD) and accelerometers (ARH-500A Waterproof, and Low capacity Acceleration Transducer) that are embedded in the soil in addition to soil pressure gauges. It was concluded that increasing the footing embedment depth results in increase in the amplitude of the force-time history by about 10-30% due to increase in the degree of confinement. This is accompanied by a decrease in the displacement response of the soil by about 40-50% due to increase in the overburden pressure when the embedment depth increased which leads to increasing the stiffness of sandy soil. There is also increase in the natural frequency of the soil-foundation system by about 20-45%. For surface foundation, the foundation is free to oscillate in vertical, horizontal and rocking modes. But, when embedding a footing, the surrounding soil restricts oscillation due to confinement which leads to increasing the natural frequency. Moreover, the soil density increases with depth because of compaction, which makes the soil behave as a solid medium. Increasing the footing embedment depth results in an increase in the damping ratio by about 50-150% due to the increase of soil density as D/B increases, hence the soil tends to behave as a solid medium which activates both viscous and strain damping.

• Structural Monitoring and Maintenance
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• v.5 no.1
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• pp.151-171
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• 2018

Transmission tower-line systems are commonly slender and generally possess a small stiffness and low structural damping. They are prone to impulsive excitations induced by cable rupture and may experience strong vibration. Excessive deformation and vibration of a transmission tower-line system subjected to cable rupture may induce a local destruction and even failure event. A little work has yet been carried out to evaluate the performance of transmission tower-line systems in mountain areas subjected to cable rupture. In addition, the control for cable rupture induced vibration of a transmission tower-line system has not been systematically conducted. In this regard, the dynamic response analysis of a transmission tower-line system in mountain areas subjected to cable rupture is conducted. Furthermore, the feasibility of using viscous fluid dampers to suppress the cable rupture-induced vibration is also investigated. The three dimensional (3D) finite element (FE) model of a transmission tower-line system is first established and the mathematical model of a mountain is developed to describe the equivalent scale and configuration of a mountain. The model of a tower-line-mountain system is developed by taking a real transmission tower-line system constructed in China as an example. The mechanical model for the dynamic interaction between the ground and transmission lines is proposed and the mechanical model of a viscous fluid damper is also presented. The equations of motion of the transmission tower-line system subjected to cable rupture without/with viscous fluid dampers are established. The field measurement is carried out to verify the analytical FE model and determine the damping ratios of the example transmission tower-line system. The dynamic analysis of the tower-line system is carried out to investigate structural performance under cable rupture and the validity of the proposed control approach based on viscous fluid dampers is examined. The made observations demonstrate that cable rupture may induce strong structural vibration and the implementation of viscous fluid dampers with optimal parameters can effectively suppress structural responses.

• The Journal of the Korea Contents Association
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• v.7 no.5
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• pp.184-192
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• 2007

A social trend can change market trend because it influences on consumer's lifestyle. Therefore the trend has been considered as an important factor for planning and producing new items. If a new trend occurred, its impact on market needs to be examined. Recently, well-being became top global issue and it caused many changes on packaged food products. This study focuses on measuring the impact of well-being trend on package design. The range of products for this research is limited to packaged food product selling in discount stores because it is main category to show well-being trend. Generally, good package design generates impulsive buying at the point of purchase. Colors on packages are critical point for good product design and they are also reflecting social trend to meet their consumers' psychological desires. After gathering basic information from market research, several colors had been selected and classified. For providing specific evidences result from the trend, the role of four major colors have been compared and analyzed. Finally, questionnaire had been handed out to trendy consumers to reach consensus on well-being color.

• The Journal of the Korea Contents Association
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• v.16 no.2
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• pp.686-695
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• 2016

In this thesis, girls' suicidal mentality which appears in some adolescent novels was sought. We can conclude like these: first, in the novel, Elegant Lies written by Ryeo-ryung Kim, the girl named Wha-yun leaves out Cheon-ji not to be left out alone by her companies. Wha-yun has succeeded in giving an ugly impression of Cheon-ji to the peer girls around her by exercising relational aggression. As a result, Cheon-ji sees herself as a meaningless being and after recognizing that she can't change the situation, she shows psychology of escape. Second, in the novel, Goodbye, from Kilimanjaro written by Ok-soo Lee, Sung-min Yoon's girlfriend Soo-hee born and grown in Africa lives with trauma from her mother's death. As her step-mother suppressed her not to keep in touch with the pet animals, Soo-hee got depressed and out of energy. Parental oppression and verbal violence can let the girl activates self-punishment and lead to suicide. Third, in the novel, Thursday, in Cyprus written by Chae-ran Park, girls could use suicide as a negotiation agenda. Adolescents could commit suicide even if their trivial requests are rejected. In these situations above we can read anticipation of compensation, retaliation and self-punishment mentality.

• Journal of Astronomy and Space Sciences
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• v.22 no.3
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• pp.249-262
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• 2005

Optimization problems are formulated to calculate optimal impulses for deflecting Earth-Crossing Objects using a Nonlinear Programming. This formulation allows us to analyze the velocity changes in normal direction to the celestial body's orbital plane, which is neglected in many previous studies. The constrained optimization in the three-dimensional space is based on a patched conic method including the Earth's gravitational effects, and yields impulsive ${\Delta}V$ to deflect the target's orbit. The optimal solution is dependent on relative positions and velocities between the Earth and the Earth-crossing objects, and can be represented by optimal magnitude and angle of ${\Delta}V $ as a functions of a impulse time. The perpendicular component of ${\Delta}V $ to the orbit plane can sometimes play un-negligible role as the impulse time approaches the impact time. The optimal ${\Delta}V $ is increased when the original orbit of Earth-crossing object is more similar to the Earth's orbit, and is also exponentially increased as the impulse time reaches to the impact time. The analyses performed in present paper can be used to the deflection missions in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.7459-7466
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• 2014

This study examined the purchasing behavior of cosmetics among Japanese, Chinese tourists and Koreans, as well as the differences according to nationality. Based on a literature study, a questionnaire was developed and a field survey was performed. A self-administered survey was conducted throughout Myungdong and Suwon. The 251 usable questionnaires were collected. A Reliability test, Factor analysis, Regression test, and ANOVA were used. The purchasing behavior of cosmetics has 5 factors gained by the factor analysis, including the functionality of cosmetics, the newest one of the cosmetics, brand-oriented cosmetics, impulsive purchase, and physical evidence. In addition, the purchasing behavior of cosmetics is becoming complicated, and the attitudes to cosmetics has changed. Finally, there are a few differences among Japanese, Chinese tourists and Koreans. According to this research, cosmetic companies must underline their brand and focus on managing the cosmetic functionality, physical evidence of the store, and the skill and attitudes of point of sales.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.2
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• pp.249-260
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• 2014

When a train enters the tunnel at high speed, the pressure wave occurs. When this pressure wave reaches at the exit of tunnel, some are either emitted to the outside or reflected in tunnel by the form of expansion wave. The wave emitted to the outside forms the impulsive pressure wave. This wave is called 'Micro Pressure Wave'. The micro pressure wave generates noise and vibration around a exit portal of tunnel. When it becomes worse, it causes anxiety for residents and damage to windows. Thus, it requires a counterplan and prediction about the micro pressure wave for high speed railway construction. In this paper, the effects of train head nose and tunnel portal shape were investigated by model test, measurement for the micro pressure wave at the operating tunnel as well as numerical analysis for the gradient of pressure wave in the tunnel. As results, a method for predicting the intensity of the micro pressure wave is suggested and then the intensity of the micro pressure wave is analyzed by the tunnel length and the cross-sectional area.