• Journal of the Korean Society for Railway
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• v.7 no.3
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• pp.232-238
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• 2004

The dynamic characteristics of the current collection process of the high-speed railway are investigated through signals acquired during a test run. The signals are obtained from accelerometers, load cells, and strain gauges attached to various positions of the pantograph, and they are processed in time-and frequency-domains to obtain the dynamic characteristics. The main natural frequency of the pantograph is found to be 8.5Hz. There also are components at low frequencies varying linearly with the train speed. The contact frequency components above 20Hz is attenuated as they pass through the secondary suspension. The main frequency component of the load cell signal is found to be related with the rolling motion of the panhead generated by the stagger in the catenary.

• Journal of Families and Better Life
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• v.24 no.5 s.83
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• pp.53-68
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• 2006

This study examines Korean and American undergraduate students' intimacy toward the grandmother and their attitudes toward the elderly and aging. The study also identifies the variances that influence undergraduate students' attitudes. The subjects were 397 Korean and 364 America undergraduates. Statistical analysis was conducted to examine frequency, percentage, meat standard deviation, Cronbach's ${\alpha}$, t-test, Duncan test, ANOVA, and stepwise multiple regression. The results of this study were as follows; 1) Both Korean and American undergraduates' attitudes were mid-range, but their intimacy level toward their grandmother was high. 2) The Korean undergraduates' intimacy level differed significantly according to sex and religion, and it showed a significant correlation with attitudes toward the elderly and aging traits, when the student had lived with and had frequent contact with the grandmother. The American undergraduates' intimacy level, however, was significantly different according to the presence of the grandmother. There was also had a significant correlation with the undergraduate students' attitudes toward the elderly and aging traits, frequency of contact with the grandmother and year. 3) The variables that affect the Korean undergraduates' intimacy level toward the grandmother were attitude, cohabitation with her, gender, frequency of contact with the grandmother, and religion, which explained about 21% of total variance. Attitudes toward the elderly and aging traits were very important variables for Korean undergraduates' intimacy with their grandmother. The American undergraduates' intimacy was affected by the variables of attitude, frequency of contact with the grandmother, year, and the presence of the grandmother, which explained about 19% of the total variance. Attitude toward the elderly and aging traits were the most important variables for American undergraduates' intimacy with their grandmother.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.4
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• pp.565-579
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• 1993

This study was accomplished to analyse and compare the occlusal contact patterns during eccentric mandibular movements in adult with normal occlusion. 50 subjects(male 27, female 23), who had natural occlusion and no symptom of temporomandibular disorder, were selected. Teeth contact patterns during mandibular eccentric movements were recorded and the distribution of tooth contacts in maximum intercuspation analysed by T-scan system. And then, tooth contact numbers recored by T-scan and silicone bite registration at centric occlusion were analysed and compared. The results obtained were as follows : 1. Antero-posteriorly, the qualitative center of occlusal contacts in centric occlusion were in the first molar areas, but there was a slight deviation in left-right directions. Thus, distribution of occlusal contacts were not bilaterally symmetric. 2. During the mandibular movements from centric occlusal position to right lateral and left lateral directions, the frequency that maxillary canine joined in lateral guidance was relatively high, but pure canine protected occlusion or pure group function occlusion had small frequency. 3. During mandibular protrusive movement, one or more maxillary central incisors frequently joined in protrusive guidance. 4. During mandibular eccentric movements, working and balancing side premature contact was observered in relatively high frequency. 5. In centric occlusal position, the numbers of occlusal contacts recorded on T-scan were relatively smaller than on silicone bite registration.

• Korea journal of population studies
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• v.30 no.3
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• pp.157-178
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• 2007

This study examines the features of Korean kinship relationships from the comparative perspectives. Based on ISSP (international Social survey program) data, it analyzes the degree of kinship contact and the source of instrumental and emotional social supports. The results show that the contact frequency among Korean kin is relatively low, and the instrumental social supports are more active than emotional social supports. Focusing on the fact that the lower contact frequency among Korean kin cannot be easily explained either the degree of Economic development nor the familism tradition, this study suggests that the hierarchical collectivism inhered in confucian tradition is responsible for the sparse kinship contact. Regarding social supports, results confirm the strong instrumental familism among Koreans. The relationship between hierarchical collectivism and lower emotional support from kin is also discussed. In addition, this study notes that lower extent of emotional support among kin cannot be identified with lower social solidarity among them.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.2
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• pp.180-188
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• 1994

The purpose of this study was to evaluate the effect of basic needs and demographic variables of adult woman on the modesty and aethetics In the selection of clothes. The results of the study were as follows: 1. There are factors which have effect on variables of need. School careers have effect on physical need. Age, marriage status and household type have effect on safty need. Native community and household type have effect on self-esteem. School career, native community, household type and frequency of contact with mass media have effects on need of self-actualizing and native community has effect on the aesthetic need. 2. Physical bleed, self-esteem, self-actualization, safety need, fiequency of contact with mass media, age, native community and income have direct effect on the modesty of clothing. 3. Aethetic and self-actualization need, frequency of contact with mass media and income have direct effect on the aethetics of clothing.

• Journal of Sensor Science and Technology
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• v.20 no.2
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• pp.77-81
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• 2011

This paper presents a single-pole eight-throw(SP8T) switch based on proposed a radio-frequency(RF) microelectromechanical systems (MEMS) switches. The proposed switch was driven by a double stop(DS) comb drive, with a lateral resistive contact. Additionally, the proposed switch was designed to have tapered signal line and bi-directionally actuated. A forward actuation connects between signal lines and contact part, and the output becomes on-state. A reverse actuation connects between ground lines and contact part, and the output becomes off-state. The SP8T switch of 3-stage tree topology was developed based on an arrangement of the proposed RF MEMS switches. The developed SP8T switch had an actuation voltage of 12 V, an insertion loss of 1.3 dB, a return loss of 15.1 dB, and an isolation of 31.4 dB at 6 GHz.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.537-542
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• 2010

The goal of this study was to investigate how spectrographic features of ultrasonic vocalizations (USVs) in rats vary among individuals and behaviors. Eighteen pairs of rats were allocated to individual pair cages. Each pair's behaviors and vocalizations were recorded during the 900s a known cage-mate was returning to the cage. The effects of individuals, behaviors, and the interaction between individuals and behaviors ($individuals{\times}behaviors$) were tested on the duration and peak frequencies. There was difference in the duration and peak frequency: i) among individuals (p<0.0001 and p<0.0001, respectively); ii) among behaviors (p = 0.0667 and p<0.0001, respectively); iii) among individuals${\times}$behaviors (p<0.0001 and p<0.0001, respectively). The frequency of ultrasonic vocalizations changed with a frequency ranging from 40 to 71 kHz which were emitted by individuals, whereas the frequency of ultrasonic vocalizations changed with a frequency ranging from 60 to 70 kHz which were emitted by behaviors. The peak frequency of call on 'contact' behavior was lower than that of call on other behaviors, but call duration of call on 'contact' was longer than on other behaviors. Especially, 40 kHz calls were found on 'contact' and 'other' behaviors. We suggest that ultrasonic vocalizations need to be subdivided and the effects of individuals and behaviors must be considered to assess emotional state of rats because these may influence the features of ultrasonic vocalizations.

• Tribology and Lubricants
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• v.39 no.4
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• pp.154-166
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• 2023

This study establishes a numerical analysis model of the finite element overhung rotor supported by a DTRB and describes the stiffness properties of the DTRB. The vibration characteristics and contact pressure of the RBR system are predicted according to the DTRB support characteristics such as the initial axial compression and roller profile. The stiffness of the DTRB significantly varies depending on the initial axial compression and external load owing to the occurrence of rollers under the no-load condition and increase in the Hertz contact force. The increase in the initial axial compression increases the rigidity of the DTRB, thereby reducing the displacement of the RBR system and simultaneously increasing the natural frequency. However, above a certain initial axial compression, the effect becomes insignificant, and an excessive increase in the initial axial compression increases the contact pressure. The roller crowning radius, which gives a curvature in the longitudinal direction of the roller, decreases the displacement of the RBR system and increases the natural frequency as the value increases. However, an increase in the crowning radius increases the edge stress, causing a negative effect in terms of the contact pressure. These results show that the DTRB support characteristics required for reducing the vibration and contact pressure of the RBR system supported by the DTRB can be designed.

• Journal of the Korean Home Economics Association
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• v.33 no.5
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• pp.221-239
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• 1995

Using a nonclinical sample of 566 female students, this study examines the frequency and the severity of child sexual abuse in Taegu area. It also analyzes the factors that determine the probability of experiencing both contact and noncontact forms of the abuse. The results show that children from low socio-economic status tend to experience severe types of contact abuse while children from higher socio-economic status ten to experience severe types of contact abuse while children from higher socio-economic status are likely to be exposed to noncontact abuse. The growing place in the childhood also affects the victimization to noncontact and contact abuse differently. The absence of the biological parents significantly contributes to the occurrence of contact abuse, but have no impact on the noncontact abuse. However, the closeness of the family members and frequent communication reduce the rates of both contact and noncontact abuse substantially.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.389-392
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• 1997

This paper presents the dynamic analysis and experiment for rotor systems supported by angular contact ball bearings subjected to axial displacement preload. A dynamic software, which has been developed by the authors for the analysis of rotor systems supported by angular contact ball bearings, is used to simulate a uniform shaft system supported by two angular contact ball bearings with the axial displacement preload varied. Experiments are also performed to validate the simulation. An experimental system is constructed which consists of a uniform shaft, two bearings and a device for adjusting the axial displacement preload. Through a series of simulation and experiment, the dynamic characteristics of rotor systems with angular contact ball bearings subject to axial displacement preload are investigated.