• Journal of Biosystems Engineering
• /
• v.34 no.3
• /
• pp.140-146
• /
• 2009

The garlic, along with the red pepper, is one of the major seasoning vegetables in Korea. Garlic clove planting is one of the most laborious operations. Labor cost is the main source of high production cost of the garlic. Because of the geometrical uniqueness and irregularity of garlic cloves, mechanization of garlic clove planting is very difficult. To overcome price competition against the imported garlic, however, there has been a need of development of a clove metering device and a planting device for the garlic clove planter. Computer simulation, laboratory tests and field tests were conducted to develop a garlic clove planter. This research was conducted to drop garlic cloves into a soil holes through a drum bucket metering system and a rotary type planting system. Followings are the major achievements from this study. 1. The metering device consisted of a drum, a guide, a bucket and a bucket cover. Opening positions of the metering hopper were evaluated at different positions and trajectories of planting hoppers. The simulation showed that the optimum positions of hopper was -15${\sim}$0 mm in the x direction. 2. When the planter was tested under different soil textures and water contents, the best performances were obtained in a upland field with 29.1% water content and a paddy field with 18.3% water content where single clove metering and missing rate were 88.4% and 1.3%, and 90.7% and 2.0%, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.1
• /
• pp.117-122
• /
• 2016

In this paper, we propose 24-GHz CMOS radio frequency (RF) power amplifier for short-range automotive collision avoidance radars. This circuit contains common source stage with inter-stages conjugate matching circuit as a class-A mode amplifier. The proposed circuit is designed using TSMC $0.13-{\mu}m$ mixed signal/RF CMOS process ($f_T/f_{MAX}=120/140GHz$). It operates at the supply voltage of 2V, and it is designed to have high power gain, low insertion loss and low noise figure in the low supply voltage. To reduce total chip area, the circuit used transmission lines instead of the bulky real inductor. The designed CMOS power amplifier showed the smallest chip size of $0.1mm^2$, the lowest power consumption of 40mW, the highest power gain of 26.5dB, the highest saturated output power of 19.2dBm and the highest maximum power-added efficiency of 17.2% as compared to recently reported results.

• Progress in Superconductivity
• /
• v.9 no.1
• /
• pp.50-55
• /
• 2007

We have installed a 61-channel magnetocardiography (MCG) system inside a magnetically shielded room (MSR) with a size of $2.4\;m\;{\times}2.4\;m\;{\times}2.4\;m$. The MCG system consists of 1st-order axial gradiometers containing double relaxation oscillation SQUIDs (DROSs) with pick-up coils of a base line of 70 mm. The MSR holds a shielding factor of 50 at 0.1 Hz and 10000 at 100 Hz, when its door in the middle on a front wall is closed. On opening the MSR door, we have obtained the characteristics of the MCG system with a 2.9 Hz noise generated from an air conditioning unit at 13 m distance off the MSR. In an open-door MSR ($140^{\circ}$ opening), a noise at the center channel increases up to $700\;fT/Hz^{l/2}$ at 2.9 Hz and $1.7\;pT/Hz^{1/2}$ at 60 Hz. MCG signals for a healthy human do not show distortion until the door opens to $45^{\circ}$, but show the effect of noise when the door opens further at $90^{\circ}$ and $140^{\circ}$. With the door opens to $45^{\circ}$, MCG measurement can be performed with ease of door operation and without creating claustrophobia for the patient.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.3
• /
• pp.587-594
• /
• 2018

The purpose of this study was to evaluate the correlation between hand washing practice and hand washing on the health belief model among dental practitioners. A self-reported questionnaire was completed by each 140 dental practitioners in dental clinics, general and university dental hospitals. The data were analyzed statistically with t-test, 1-way ANOVA, Pearson's correlation coefficient test(${\alpha}=.05$). The hand washing practice showed a quantitative linear relationship(p<0.01) of r=0.285 with the hand washing on health belief. In order to prevent hospital infection of dental practitioners working in dental clinics or general and university dental hospitals, health beliefs about hand washing consisting of perceived susceptibility, perceived seriousness, perceived benefit, perceived barriers, and cues to action in infection control education should be considered.

• The Journal of the Korea Contents Association
• /
• v.17 no.12
• /
• pp.399-407
• /
• 2017

The purpose of this study was to examine relationships among positive psychological capital and academic self-efficacy on academic stress and identify the factors that influence on academic stress in the adolescents. The data were collected from 140 adolescents in the two middle school located J city using self-reported questionnaires and May 9 2017 to May 19 2017. The data were analyzed by descriptive statistics, T-test, ANOVA, Pearson's correlation coefficient, and multiple regression with SPSS 20.0 program. The result of the multiple regression indicates the positive psychological capital, academic self-efficacy and grade predict 27.1%(F=7.68, P<.001) of academic stress. Therefore, In order to prevent and decrease the academic stress, the developing programs to improve positive psychological capital and academic self-efficacy are needed.Therefore, it is necessary to develop positive psychological capital and academic self-efficacy strategy program for decrease academic stress in adolescents.

• Journal of Digital Convergence
• /
• v.15 no.6
• /
• pp.305-314
• /
• 2017

The purpose of this study was to examine relationships among resilience and job Stress, turnover intention and vitality in general hospital nurses and to provide the basic data for the development of resilience intervention programs. The data were collected from 140 nurses working in the four general hospital located S and Y city using self-reported questionnaires and February 1 2017 to February 17 2017. The data were analyzed by descriptive statistics, T-test, ANOVA, Pearson's correlation coefficient, and multiple regression with SPSS 20.0 program. Resilience was found to be in a significant positive correlation with job stress, turnover intention and vitality. The result of the multiple regression indicates that work pattern and vitality predict 31%(F=10.01, p<.001) of resilience. Therefore it is necessary to develop convergence program to strengthen the resilience of clinical nurses'.

• The Journal of Korean Association of Computer Education
• /
• v.7 no.2
• /
• pp.47-56
• /
• 2004

The purpose of this study was to investigate the effect of learner's characteristics on the student's achievement in Information Communication Technology (ICT) teaching-learning environment. The subjects of this study were a total of 140 8th students in middle school in Taejeon province. The methods of teaching were the ICT teaching-learning, Academic achievement test. the learning style inventory. self-concept test and cognitive style test were used as the instruments to determine the effect. Such statistical analyses as the pearson co-relation, multi regression and t-test through SPSS WIN version 11.0 were used to determine the relationship between learner's characteristics and student's achievement. The results of this study were as follows: first, learner's emotional and social factor of learning style influenced positively the student's academic achievement in ICT teaching-learning environment. Second. learner's academic factor of self-concept had an positive influence on the student's academic achievement in ICT teaching-learning environment. Third, there were differences of student's academic achievements according to the student's cognitive style in ICT teaching-learning environment.

• KSBB Journal
• /
• v.16 no.6
• /
• pp.547-553
• /
• 2001

Glycoprotein from the water extract of dried root barks of slippery Elm was investigated for its anticancer immunostimulating activity, The glycoprotein contained molecular weight 15,000 to 500,000 Da, total carbohydrates 55.8 to 72.1%), total uronic acid 30.0 to 30.5%, and total proteins 5.0 to 6.1%. The anticancer immunostimulating activities were examined for both in vitro bioassays such as immune cell proliferation assay, mixed lymphocyte reaction (MLR), direct mitogenicity, T-dependent antibody production, and in vivo bioassays such as septic shock test and anticancer activity test in B16 melanoma transplanted mouse model. In vivo assay, the glycoprotein at the concentration of 3 mg/kg showed the best result that median survival time increased to about 140% in contrast to control groups.

• Journal of Digital Convergence
• /
• v.15 no.8
• /
• pp.267-275
• /
• 2017

The purpose of this study was to examine relationships among BMI, perception of body shape, appearance stress, and self-perceived competence on body image and to identify the factors that influence on body image in the adolescents. The data were collected from 140 adolescents in the three middle school located J city using self-reported questionnaires and March 15 2017 to March 29 2017. The data were analyzed by descriptive statistics, T-test, ANOVA, Pearson's correlation coefficient, and multiple regression with SPSS Statistics 20.0 program. Body image was found to be in a significant positive correlation with perception of body shape, appearance stress, and self-perceived competence. The result of the multiple regression indicates the self-perceived competence and gender predict 21%(F=10.25, p<.001) of body image. Therefore it is necessary to develop convergence self-perceived competence strategy program for establish right body image of adolescents.

• Journal of Digital Convergence
• /
• v.15 no.9
• /
• pp.365-373
• /
• 2017

The purpose of this study was to examine relationships among positive psychological capital and social support on depression and identify the factors that influence on depression in the adolescents. The data were collected from 140 adolescents in the two middle school located J city using self-reported questionnaires and May 9 2017 to May 19 2017. The data were analyzed by descriptive statistics, T-test, ANOVA, Pearson's correlation coefficient, and stepwise multiple regression with SPSS 20.0 program. Depression was found to be in a significant negative correlation with positive psychological capital and social support. The result of the stepwise multiple regression indicates the positive psychological capital, social support and economic status predict 22.4% (F=14.38, p<.001) of depression. Therefore, it is necessary to develop convergence positive psychological capital and social support strategy program for decrease and prevents depression in adolescents.