• Journal of the Korean Society of School Health
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• v.20 no.1
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• pp.103-111
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• 2007

Purpose : The purpose of this study was to investigate the effects of stresses to female university students and their habits of dealing with stresses through drinking alcohol and smoking. Methods : Subjects, 313 students, were selected through convenience sampling method from the 2 four-year universities in Chonbuk and Chonnam province from May to June, 2005. Data were collected through the structured questionnaires that include general characteristics, Quantity Frequency methods, the number of cigarette per day, campus stress scale, and stress coping style scale, and they were analyzed by Cronbach' alpha, descriptive statistics, ANOVA and t-test by using SPSS/PC⁺ program. Results: In this study, 80% of subjects have drunk alcohol. The mean frequency of drinking alcohol per month was 4.68 times and the mean number of alcohol consumption amount per drinking 6.16 glasses. The rate of smoking was 13.7%, and the mean number smoking cigarette per day in the previous month was 12.4. The mean score of stress was 2.20. Among 8 sub-factors of stress, study related stress scored highest among the sub-factors. The mean score of coping styles was 2.50. Among 4 coping styles, hopeful thought was mostly used. Among stresses, the concern of one's future affected her drinking habits. Faculty relationship, academic problem, and value affected smoking habits. Hopeful thought comes out to affect smoking, while drinking, perceived health status, and practice time showed no relationship with coping style. Conclusion: Based on the results, developing a life stress counseling program and effective coping program for women's university students is imperative, especially for those of who show passive attitude toward stress and solve it emotionally instead of using problem-oriented methods. Also, it will be necessary to study further nursing intervention to curb university females' drinking alcohol and smoking.

• Convergence Security Journal
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• v.18 no.3
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• pp.61-68
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• 2018

As the digital broadcasting era settled in, the TV, which was only used to watch broadcast programs, developed as a medium for operating various data services. This means that an environment, in which the viewers' TV usage behavior can be changed from a passive attitude to an attitude of actively consuming the media, has been established. Since the advertising market is an industry that is heavily influenced by changes in the media, these changes causes changes in the form of advertising and the advertising consumption behavior of viewers. In this environment, the broadcasting industry needs to think about the new growth strategy that links the possibility of data service with the advertisement market. In this study, we designed a data service that provides supplementary information of an ID advertisement, which has the weakness of short exposure time and shortage of information expression space. Specifically, we have designed the usage scenario and user interface of the data service and developed a method, based on the international digital broadcasting standard DV B, that provides the supplementary information defined by the type of ID advertisement to the data service.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.117-125
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• 2022

Until recently, four types of cellobiose-fermenting Saccharomyces cerevisiae strains have been developed by introduction of a cellobiose metabolic pathway based on either intracellular β-glucosidase (GH1-1) or cellobiose phosphorylase (CBP), along with either an energy-consuming active cellodextrin transporter (CDT-1) or a non-energy-consuming passive cellodextrin facilitator (CDT-2). In this study, the ethanol production performance of two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-2 (N306I) with GH1-1 or CBP were compared with two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-1 (F213L) with GH1-1 or CBP in the simultaneous saccharification and fermentation (SSF) of cellulose under various conditions. It was found that, regardless of the SSF conditions, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the best ethanol production among the four strains. In addition, during SSF contaminated by lactic acid bacteria, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the highest ethanol production and the lowest lactate formation compared with those of other strains, such as the hydrolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-1 with GH1-1, and the glucose-fermenting S. cerevisiae with extracellular β-glucosidase. These results suggest that the cellobiose-fermenting yeast strain exhibiting low energy consumption can enhance the efficiency of the SSF of cellulosic biomass.

• Journal of the Korean Society of Food Culture
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• v.38 no.4
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• pp.217-223
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• 2023

There has been an increase in the viewing of YouTube content among children and adolescents. This, coupled with the popularity of live-streamed video content such as mukbang, where viewers watch the host eat, has raised concerns about media addiction and the indiscriminate imitation of eating behavior. Therefore, there is a need for guidance on the appropriate behavior for viewing YouTube food content to promote healthy eating habits among children. In this study, we aimed to compare the patterns of the main caregivers and their children while viewing media and investigate the impact of viewing YouTube food content on the physical and mental health of the children. The findings suggest that active YouTube food content viewing by the main caregivers may reduce imitative behaviors due to passive media consumption by their children. This study provides valuable insights by comparing and analyzing the YouTube content viewing of the main caregivers and their children. The results can be used as a basis for the development of lifestyle-centered guidelines for children. However, it is important to note that this study was conducted during the coronavirus disease (COVID-19) pandemic when there was a significant increase in the use of media, which is limitation of the study.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.1-10
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• 2013

RFID(Radio Frequency Identification) system is non-contact identification technology. A basic RFID system consists of a reader, and a set of tags. RFID tags can be divided into active and passive tags. Active tags with power source allows their own operation execution and passive tags are small and low-cost. So passive tags are more suitable for distribution industry than active tags. A reader processes the information receiving from tags. RFID system achieves a fast identification of multiple tags using radio frequency. RFID systems has been applied into a variety of fields such as distribution, logistics, transportation, inventory management, access control, finance and etc. To encourage the introduction of RFID systems, several problems (price, size, power consumption, security) should be resolved. In this paper, we proposed an algorithm to significantly alleviate the collision problem caused by simultaneous responses of multiple tags. In the RFID systems, in anti-collision schemes, there are three methods: probabilistic, deterministic, and hybrid. In this paper, we introduce ALOHA-based protocol as a probabilistic method, and Tree-based protocol as a deterministic one. In Aloha-based protocols, time is divided into multiple slots. Tags randomly select their own IDs and transmit it. But Aloha-based protocol cannot guarantee that all tags are identified because they are probabilistic methods. In contrast, Tree-based protocols guarantee that a reader identifies all tags within the transmission range of the reader. In Tree-based protocols, a reader sends a query, and tags respond it with their own IDs. When a reader sends a query and two or more tags respond, a collision occurs. Then the reader makes and sends a new query. Frequent collisions make the identification performance degrade. Therefore, to identify tags quickly, it is necessary to reduce collisions efficiently. Each RFID tag has an ID of 96bit EPC(Electronic Product Code). The tags in a company or manufacturer have similar tag IDs with the same prefix. Unnecessary collisions occur while identifying multiple tags using Query Tree protocol. It results in growth of query-responses and idle time, which the identification time significantly increases. To solve this problem, Collision Tree protocol and M-ary Query Tree protocol have been proposed. However, in Collision Tree protocol and Query Tree protocol, only one bit is identified during one query-response. And, when similar tag IDs exist, M-ary Query Tree Protocol generates unnecessary query-responses. In this paper, we propose Adaptive M-ary Query Tree protocol that improves the identification performance using m-bit recognition, collision information of tag IDs, and prediction technique. We compare our proposed scheme with other Tree-based protocols under the same conditions. We show that our proposed scheme outperforms others in terms of identification time and identification efficiency.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.283-295
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• 2011

Many actions against climate change have been taken to reduce greenhouse gases (GHGs) emissions at home and abroad. As of 2007, the GHGs emitted from buildings accounted for about 23 % of Korea's total GHGs emission, which is the second largest GHG reduction potential following industry. In this study, we introduced Carbon Zero Building (CZB), which was constructed by the National Institute of Environmental Research to cut down GHGs from buildings in Korea, and evaluated the main applied technologies, the amount of energy load and reduced energy, and economic values for CZB to provide data that could be a basis in the future construction of this kind of carbon-neutral buildings. A total of 66 technologies were applied for this building in order to achieve carbon zero emissions. Applied technologies include 30 energy consumption reduction technologies, 18 energy efficiency technologies, and 5 eco-friendly technologies. Out of total annual energy load ($123.8kWh/m^2$), about 40% of energy load ($49kWh/m^2$) was reduced by using passive technologies such as super insulation and use of high efficiency equipments and the other 60% ($74.8kWh/m^2$) was reduced by using active technologies such as solar voltaic, solar thermal, and geothermal energy. The construction cost of CZB was 1.4 times higher than ordinary buildings. However, if active technologies are excluded, the construction cost is similar to that of ordinary buildings. It was estimated that we could save annually about 102 million won directly from energy saving and about 2.2 million won indirectly from additional saving by the reduction in GHGs and atmospheric pollutants. In terms of carbon, we could reduce 100 ton of $CO_2$ emissions per year. In our Life Cycle Cost (LCC) analysis, the Break Even Point (BEP) for the additional construction cost was estimated to be around 20.6 years.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.6
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• pp.455-466
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• 2020

In this study, we built a thermal model for SNIPE 6U nano-satellite which has scientific mission for measuring science data in near Earth space environment and described thermal design based on the thermal model. And the validity of the thermal design was verified through the on-orbit thermal analysis. The thermal design was carried out mainly on the passive thermal control techniques such as surface finishes, insulators, and thermal conductors in consideration of the characteristics of the nano-satellite. However, the components with narrow operating temperature range and directly exposed to the orbital thermal environments, such as a battery and thrusters, are accomodated with heaters to satisfy the temperature requirements. On-orbit thermal analysis conditions are based on the basic orbital conditions of the satellite, and thermal analysis was performed for Normal mode, Launch & Early Orbit Phase (LEOP), Safehold mode, and Maneuver mode which are classified by the power consumption and the attitude of the satellite according to the mission scenario. The analysis results for each mode confirmed that every component satisfies the temperature requirement. In addition, the heater capacity and duty cycle of the battery and thruster were calculated through the analysis results of the Safehold mode.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.155-163
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• 2018

This study was conducted to investigate the factors related to smoking and smoking differences among adolescents who have experienced smoking using data from the 11th (2015) Korean Youth Risk Behavior Web-based Survey. The data used in this study were from 5,347 middle and high school students who had cigarette smoking and electronic cigarette smoking experience among 68,043 respondents to the 11th (2015) Korean Youth Risk Behavior Web-based Survey. The data were evaluated by frequency analysis, the ${\chi}^2$ test and logistic regression analysis using weighted composite sample analysis. Overall 20% of the total smoking adolescents were dual users and 85.6% of the users of electronic cigarettes used nicotine. The results from multinomial regressions show that: male students (OR 1.63; 95% CI 1.15-2.31), living in the metropolitan area (OR 1.76; 95% CI 1.32-2.33), an average consumption of fast food of once or twice a day (OR 2.48; 95% CI 1.33-4.64), first started smoking during high school (OR 0.76; 95% CI 0.58-0.98), having experience with passive smoking (OR 1.24; 95% CI 1.07-1.44), experience drinking alcohol (OR 2.03; 95% CI 1.65-2.48) and those with higher weekly allowances were more likely to be at risk than dual users. This study provides basic data regarding the dual use of electronic cigarettes and cigarettes by adolescents. The results presented herein will facilitate development of a smoking cessation program and policy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1419-1426
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• 2012

The heating and cooling energy load of the KNU plant factory was analyzed using the DesignBuilder. Indoor temperature set-point, LED supplemental lighting schedule, LED heat gain, and type of double skin window were selected as simulation parameters. For the cases without LED supplemental lighting, the proper growth temperature of lettuce $20^{\circ}C$ was selected as indoor temperature set-point together with $15^{\circ}C$ and $25^{\circ}C$. The annual heating and cooling loads which are required to maintain a constant indoor temperature were calculated for all the given temperatures. The cooling load was highest for $15^{\circ}C$ and heating load was highest for $25^{\circ}C$. For the cases with LED supplemental lighting, the heating load was decreased and the cooling load was 6 times higher than the case without LED. In addition, night time lighting schedule gave better result as compared to day time lighting schedule. To investigate the effect of window type on annual energy load, 5 different double skin window types were selected. As the U-value of double skin window decreases, the heating load decreases and the cooling load increases. To optimize the total energy consumption in the plant factory, it is required to set a proper indoor temperature for the selected plantation crop, to select a suitable window type depending on LED heat gain, and to apply passive and active energy saving technology.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.87-95
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• 2013

In this paper, 2.5 Gb/s burst-mode clock and data recovery(CDR) is presented. Digital frequency calibration scheme is adopted to eliminate mismatch between the input data rate and the output frequency of the gated voltage controlled oscillator(GVCO) in the clock recovery circuitry. A jitter rejection scheme is also used to reduce jitter caused by input data. The proposed burst-mode CDR is designed using 0.11 ${\mu}m$ CMOS technology. Post-layout simulations show that peak-to-peak jitter of the recovered data is 14 ps with 0.1 UI input referred jitter, and maximum tolerance of consecutive identical digit(CID) is 2976 bits without input data jitter. The active area occupies 0.125 $mm^2$ without loop filter and the total power consumption is 94.5 mW.