• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.8
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• pp.126-132
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• 2010

This paper presents dielectric characteristics of $N_2$ gas under impulse voltages in a quasi-uniform electric field gap. The experiments were carried out at the test gap applied by the 1.2/50[${\mu}s$] lightning impulse voltage, 180/2500[${\mu}s$] switching impulse voltage, 500[ns]/1[MHz] very fast transient overvoltage(VFTO). The gap separation of sphere-to-plane electrodes was 14[mm] and the electric field utilization factor was about 71.2[%]. The gas pressure ranges from 0.2 to 0.6[MPa]. As a result, the electrical breakdowns are occurred by streamer discharge. Breakdown voltages are linearly increased with the gas pressure and the highest breakdown voltage is appeared under the VFTOs having fast rising time. Breakdown voltages under the positive impulse voltages were higher than those under the negative ones, and also the time to breakdown in the positive polarity is longer than that in the negative polarity.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.35-41
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• 2004

In computational study on RF(Radio Frequency) plasmas, a 1D fluid models with an advantage of a short computational time are often adopted. However, in order to obtain realistic calculation results under a typical chamber geometry with unequal-sized electrodes, modeling of the plasma space is an issue to be investigated. In this paper, it is focused on that how much a 1D model can approximate a 2D model. 1D fluid models with unequal-sized electrodes, which have spherical and frustum geometry systems, were developed and their results were compared with those of 2D model with Gaseous Electronic Conference cell structure. Behavior of $N_2$ RF plasmas has been simulated using 1D and 2D fluid models and a technique to take account of unequal-sized electrodes in a 1D fluid models has been examined. Features of the plasma density and the electric potential were discussed as characteristic quantities representing the asymmetry of the chamber geometry.

• Korean Journal of Culture and Social Issue
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• v.29 no.3
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• pp.405-427
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• 2023

This study aimed to identify demographic variables(gender, age group, occupation, living arrangement, economic level, respiratory and chronic diseases, previous medical history), COVID-19 variables(COVID-19 prevention behavior, frequent use of media to obtain COVID-19 information), and psychological behavioral variables(depression, anxiety, loneliness, and increased drinking). From February to March 2021, an online survey of adults was conducted, and a total of 1,434 data were used for analysis. 260 out of 1,434 people were confirmed to have suicide ideation, the prevalence of suicide ideation among adults during the COVID-19 was 18.1%. Logistic regression analyses indicated elevated odds of suicidal ideation among individuals in their 20s and 30s, those living alone, exhibiting fewer COVID-19 preventive behaviors, consuming COVID-19 information more frequently through media, and reporting higher levels of loneliness. Furthermore, within the group experiencing depression, anxiety, and increased drinking, greater levels of these factors correlated with higher odds of suicidal ideation. Based on the results, implications and significance of the study were discussed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.4
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• pp.45-50
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• 2004

In this paper, we present the low voltage and high efficiency Q-band MIMIC oscillator using device-level power combined structure. The oscillator was successfully integrated by using 0.1 ${\mu}{\textrm}{m}$ GaAs PHEMTS and the CPW transmission line. We show that the highest efficiency is 19 % with an output power of 2.6 ㏈m at a frequency of 34.56 ㎓. The operating voltage of the oscillator is 2.2 V which is lower voltage than that of previously reported oscillators at Q-band. And the maximum output power of 6.7 ㏈m was obtained at a frequency of 34.56 ㎓.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.367-373
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• 2022

The purpose of this study is to derive the factors for purchasing a meal kit in their 20s and 30s and analyze the purchasing behavior from which factors they want to buy a meal kit in each lifestyle type. The first methodology of this study is inducing 7 factors derived from previous research on purchasing a meal kit. The second is the in-depth interview on 3 male and 3 female participants with clear purchasing criteria. As a result of the study, meal kit buyers in their 20s-30s evaluated the importance of purchasing factors in the order of quality, convenience, and taste on average in the survey. In in-depth interviews, more than half answered that they could be satisfied with the experience of using the meal kit at least freshness met. In conclusion, MZ generation meal kit consumers have a high rate of pursuing rational consumption. This study is valuable in understanding the priorities of the MZ generation's meal kit purchasing attributes and examining lifestyle type's purchasing behaviors.

• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.332-345
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• 2020

This study sought to explore the demand in the social service sector and present policy implications, focusing on the vulnerable in rural villages exposed to worse conditions amid the Covid-19 crisis. To this end, the social service needs of vulnerable groups by household type were analyzed by utilizing the raw data of the 2018 Survey on Rural Well-Being. Analysis showed that the greatest demand social services for all rural villages, the elderly, the disabled, one-person, one elderly and low-income households were income support services, while in household that included children the demand was for childcare and education-related services. The second-highest social services in terms of demand were cultural leisure vacation support services for all rural villages, healthcare-related services for the elderly, the disabled, one elderly and low-income households, cultural leisure vacation support services for households including children and daily life support services for single-person households. Based on these results, a measure was proposed to support social services, tailored to vulnerable groups in rural villages. In addition, the government's lack of a consultation system between urban and rural welfare policies, such as a basic plan for health and welfare in rural villages, led this paper to discuss the need for a feedback function and dedicated formulation of mid- to long-term policies in rural villages. It also proposed the establishment of conditions for providing customized social services for rural villages.

• Journal of the Korean Institute of Telematics and Electronics
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• v.7 no.2
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• pp.33-42
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• 1970

This report is concerned with the fahrication with the falricationof silicon VVC diode by the double diffusion planer technique. At first, some design charts for VVC diode were derived by considering the voltage-capacitance relations, the critical field intensity at the metallurgical junction, and the cut-off frequency of the diode. These charts enables the fabrication engineers to design VVC diode easily without going into the sophisticated design theory. We started with a 2.5 ohm-cm n-type epitaxial silicon wafer. The phosphorous was diffused by POCl3 impurity source. Then boron diffusion followed make hyperabrupt p-n junction by BN source. The maximum to minimum capacitance ratio of the diode as a tuning diode for a TV tuner made in these experiments was 4:1. Measured electrical characteristics of the sample diodes showed in good agreement with the theoretical expectations. Slicing and polishing technique of the silicon wafer and diffusion technique of the impurity atoms, which were employed in our study, are also stated briefly in this report.

• Magazine of the Korean Society of Agricultural Engineers
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• v.11 no.1
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• pp.1598-1603
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• 1969

A field expeperiment has been conducted in order to explore possibilities of efficient and economical irrigation methods for the rice cultivation through which irrigation water may be saved and rice paddies may keep water for longer period of time, resulting in an increased yield of rice. Some of the major findings from the experimentation are summarized in the following. 1. There is slightly significant difference among experimental plots in the weight of rice straw. 2. The 9cm-lined plot proves to be the best in terms of the thickness. In this connection, however, it seems to by 3cm. 3. The wheat straw-lined plot is found superior in yield. However, this may be resulted in by the application of more fertilizer, and how long the plot could be durable may be problematic. Since every two or three years the straw-lining work has to be done, more labour may be required of the plot. 4. It would be inappropriate to expect any meaningful experimental results for the first year, since surface soil and deep soil are mixed up in the course of work. There is not observed any meaningful difference in the number of ears per stalk and in the number of grains per ear. However, in the lined plots, the number of tillers is slightly increased. 5. Irrigation has been applied by means of ordinary method after lining. When irrigation is applied at the interval of five to six days, irrigation water is saved by 44.9 per cent in the case of 9cm-lined plot, 39.7 per cent in the case of 6 cm-lined plot, and 36.3 percent in the case of 3 cm-lined plot. 6. An increased yields arenoted in the wheat straw-lined plot by 23.8 per cent, in the 9 cm-lined plot by 20.1 per cent, in the 3 cm-lined plot by 12 per cent. and in the case of vinyl-lined plot by 12.5 per cent. 7. The rate of maturity of grains is proved better, and the husking rate also found better(75%), that is, the quality of rice grains is improved.

• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.339-349
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• 2019

The purpose of this study is to analyze the influential factors on the change in life satisfaction of elderly households. In this study, single and couple elderly households were defined as elderly households and the 2nd, 3rd, and 4th data of the Korean Longitudinal Survey of Ageing (KLoSA) provided by the Korea Employment Information Service (KEIS) were used. And 677 respondents aged 65 and over who had replied to all 3 sessions were included in the final subjects. multinomial logistic regression analysis was conducted to examine the influential factors on life satisfaction by the type of elderly households according to consumption pattern and the result showed that there were common influential factors such as house owning status and subjective health status and the factors that influence specific types such as expectancy of standard of living. In addition, in the longitudinal analysis of life satisfaction of elderly households, individual satisfaction level was confirmed to reduce with time and the factors that influence the longitudinal change in the level of life satisfaction of elderly households was analyzed through the conditional model of a latent growth model. The analysis results showed that household type, house owning status, and subjective health status influenced the initial value of life satisfaction of elderly households while household type and expectancy of living standard influenced the change rate of life satisfaction of elderly households. Based on the results of this study, the followings are suggested. There is a need to improve the life satisfaction of old age by increasing the opportunity for self-realization of elderly households and also policy approach should be made selectively taking various types into consideration.

• Journal of the Korean Magnetics Society
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• v.19 no.4
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• pp.142-146
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• 2009

The soft magnetic property for the Corning glass/Ta(5 nm)/[Conetic, Permalloy)/Ta(3 nm) prepared by the ion beam deposition sputtering was investigated. The coercivity and saturation magnetic field of conetic (NiFeCuMo) and permalloy (NiFe) layer with easy and hard direction along to the applying magnetic field during deposition was compared with each other. The surface resistance of conetic film with a thickness of 10 nm was 2 times lower than one of permalloy film. The coercivity and the magnetic susceptibility of conetic film decreased and increased 3 times to one of permalloy film, respectively. These results suggest that a highly sensitive GMR-SV or MTJ using conetic film can be possible to develop the bio-device.