• Journal of the Korean Applied Science and Technology
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• v.25 no.3
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• pp.322-331
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• 2008

In order to synthesize high-solid coatings, acrylic resins (HSAs) containing 90% solid content were first synthesized, then the synthesized HSAs were cured with a curing agent, isocyanate, at room temperature to obtain high-solid coatings. In the HSAs synthesis, conversion was in a range of $82{\sim}87%$, and viscosities and number-averaged molecular weight ($M_n$) of the HSAs were in a range of $4380{\sim}8010$ cP and $1540{\sim}1660$, respectively. From the correlation between $T_g$ value, viscosity and $M_n$, it was found that, with increasing $T_g$ value, viscosity increases rapidly and molecular weight increases slowly. From the visco-elasity measured by the pendulum method, it was found that the curing time decreased with increasing $T_g$ values. From the tests of physical properties of the coatings' film, $60^{\circ}$ specular gloss, impact resistance and heat resistance were proved to be good and pencil hardness, drying time and pot-life were proved to be poor.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.359-365
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• 2017

Biochar has the ability to mitigate climate change, improve crop productivity, and adsorb various contaminants. The aim of this work was to confirm the effect of biochar as a soil amendment on growth of Chinese cabbage (Brassica chinensis) using a pot experiment. Biochar was produced from residual-wood burnt at a pyrolytic temperature of $400^{\circ}C$ and consisted of 51.6 % carbon (C) by mass. The biochar was added to the soil at 0, 1, 3, and 5% by weight, which represent about 0, 18, 54, and $90t\;ha^{-1}$, respectively. The treatments were arranged in a randomized complete block design with 3 replications. The Chinese cabbage was grown for 49 days in a glasshouse in pots filled with sandy loam soil. Experimental results showed that the residual-wood biochar used for the experiment was slightly alkaline (pH 7.5). The fresh weights of Chinese cabbage were 86.22 g, 84.1 g, 63.23 g and 70.87 g, respectively, for biochar applications at 0, 18, 54, and $90t\;ha^{-1}$. Compared with the control (i.e., no biochar), biochar application increased soil pH and electrical conductivity (EC). Addition of biochar (54 and $90t\;ha^{-1}$) to sandy loam soil had no effect on growth of Chinese cabbage. This might be due to excessive increase of soil pH from the biochar application, leading to reduced availability of plant nutrients. Based on these results, the authors conclude that an excessive addition of biochar may have negative effects on the healthy growth of Chinese cabbage.

• The Journal of Korean Society for School & Community Health Education
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• v.21 no.2
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• pp.73-86
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• 2020

Objectives: The purpose of this study was to effects of education program of smoking prevention and cessation through the linkages between subjects on smoking knowledge, grit, health promoting behaviors of college students in some area. Methods: A non-equivalent control group pre-post test design was used. The intervention group received the education program for 6 weeks from October 1 to November 15, 2019. The control group lived only usual daily life. Results: t-test showed that Smoking Knowledge (t=3.78, p<.001) and grit (t=3.75, p<.001) were significant differences between the two groups. In terms of health promotion behaviors, total(t=2.89, p=.002) and physical activity(t=3.20, p=.002), health responsibility(t=3.90, p<.001), spiritual growth(t=1.99, p=.049), interpersonal relations(t=2.61, p=.010) were significant difference between the two groups, in other hands nutrition(t=0.89, p=.372) and stress management(t=1.69, p=.092) were no significant difference between two groups. Conclusions: the education program of smoking prevention and cessation through the linkages between subjects was founded to be an effective education program in improving smoking Knowledge, grit, health promoting behaviors of college students in some area.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.90-95
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• 2006

For single engine application like T-50, advanced supersonic jet trainer, airstart capability is very important. This paper presents the results of airstart tests performed to verify T-50 airstart capability for various flight condition. The tests include spooldown, APU assisted and auto-relight airstart tests. Except for the auto-relight tests T-50 engine was successfully restarted for all airstart tests. After modifying FADEC flameout detection schedule, auto-relight tests also were successfully demonstrated. Through T-50 engine airstart tests excellent T-50 airstart capability was validated.

• Child Health Nursing Research
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• v.27 no.3
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• pp.243-255
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• 2021

Purpose: This study aimed to develop and examine the effects of a psychosocial adaptation program for North Korean adolescent defectors. Methods: This quasi-experimental study was conducted with 28 North Korean adolescent defectors who were recruited through alternative schools. The experimental and control groups consisted of 14 participants each. A program was conducted across eight sessions, each lasting about 90-120 minutes. The data were analyzed using the x² test, t-test, paired t-test, and analysis of covariance. Results: No significant differences were observed in the score changes for psychosocial adaptation (t=0.25, p=.808), post-traumatic stress symptoms (t=0.32, p=.749), cultural adaptation stress (t=0.05, p=.957), and self-efficacy (t=0.35, p=.726) in either group before and after the intervention. No intergroup differences were observed for psychosocial adaptation (t=0.12, p=.902), post-traumatic stress symptoms (t=0.07, p=.946), cultural adaptation stress (t=0.01, p=.994), and self-efficacy (t=0.58, p=.570). Conclusion: These findings suggest that psychosocial adaptation, stress, and self-efficacy cannot be improved by a short-term intervention program alone. It was also determined that the cultural characteristics of the North Korean adolescent defectors were not sufficiently considered before implementing the program. Therefore, it is essential to provide an in-depth orientation for the participants before implementing the program.

• Journal of the Korea Society of Computer and Information
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• v.25 no.7
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• pp.9-16
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• 2020

In this paper, we propose a prototype design and implementation of a fire detection algorithm using multiple sensors. The proposed topic detection system determines fire by applying rules based on data from multiple sensors. The fire takes about 3 to 5 minutes, which is the optimal time for fire detection. This means that timely identification of potential fires is important for fire management. However, current fire detection devices are very vulnerable to false alarms because they rely on a single sensor to detect smoke or heat. Recently, with the development of IoT technology, it is possible to integrate multiple sensors into a fire detector. In addition, the fire detector has been developed with a smart technology that can communicate with other objects and perform programmed tasks. The prototype was produced with a success rate of 90% and a false alarm rate of 10% based on 10 actual experiments.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.221-226
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• 2002

To provide reliable data for drift prediction models, field experiments were carried out in the coastal region off Busan port. Four different size of vessels(10, 30, 50, 90G/T ton) were deployed for the experiment. Among them G/T 50ton class vessel was equipped with instruments measuring the currents, winds, headings and trajectory data. In the rest of vessels only the position data were recorded for the purpose of target divergence study. The trajectories of each vessel were measured by DGPS(Differential Global Positioning System) and collected by APRS(Automatic Position Reporting System). The experiment was done in wind of 2~10m/s and current of 0.5~1.5m/s. The leeway was derived by subtracting surface current velocity from target drifting velocity. The leeway rate of G/T 50ton vessel was found to be about 3.6% and the computed leeway speed equation was $U_L$=0.042 W - 0.034. The processed leeway angle data were deflected by $-30^{\circ}$~$40^{\circ}$ from the direction of ship drift.

• Korean Journal of Food Science and Technology
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• v.12 no.2
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• pp.133-139
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• 1980

The extraction mechanism and extraction conditions of cellular lipid of freeze-dried cells of Rhodotorula rubra YUFE 1526, which was reported as coenzyme Q producing microorganism, were studied. 1. Methyl alcohol was the most appropriate solvent for extraction of cellular lipids and the resulting total lipid was 19.17 weight %. 2. When 1 % (w/v) of freeze-dried cell was extracted by methyl alcohol, the extraction yield was 90.49 % at $50^{\circ}C$ for 2 hr. 3. The diffusivity varied with extraction temperature and the empirical equation was derived as follows : $2.2e^{0-02907T}{\times}10^{-9}\;mm^2/min.$ 4. The diffusivity of cellular lipid of Rhodotorula rubra YUFE 1526 was $9.4{\times}10^{-9}\;mm^{2}/min.$ 5. The extraction model was well fitted on the extraction of cellular lipid.

• Journal of Pharmaceutical Investigation
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• v.35 no.1
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• pp.39-44
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• 2005

The purpose of the present study was to evaluate the bioequivalence of two cefaclor capsules, Ceclor (Lilly Korea Co., Ltd.) and Kyongbocefaclor (Kyongbo Pharm. Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of cefaclor from the two cefaclor formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four healthy male subjects, $22.96{\pm}1.52$ years in age and $67.03{\pm}7.90$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ crossover study was employed. After one capsule containing 250 mg of cefaclor was orally administered, blood was taken at predetermined time intervals and the concentrations of cefaclor in serum were determined using HPLC method with UV detector. The dissolution profiles of two formulations were similar at all dissolution media. In addition, the pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, Ceclor, were -1.90%, 2.68% and -7.60% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 $(e.g.,\;log0.91{\sim}log\;1.06\;and\;log0.92{\sim}log\;1.18\;for\;AUC_t\;and\;C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Kyongbocefaclor capsule was bioequivalent to Ceclor capsule.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.1
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• pp.17-26
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• 2018

This study aimed to investigate the effects of vacuum packaging on the quality characteristics of frozen Tteokgalbi made from spent laying hen meat and mechanically deboned chicken meat (MDCM). The samples were prepared with different levels of added MDCM; C (0%), T1 (20%), T2 (40%), and T3 (60%). The samples were allocated for microbiological and physico-chemical analyses after 0, 45, and 90 days at $-18^{\circ}C$, with or without vacuum packaging. After 90 days of storage, the values of volatile basic nitrogen were significantly lower in the vacuum packaged samples compared to the non-vacuum samples, irrespective of the added levels of MDCM (p<0.05). Sensory results at day 0 of storage showed that the texture scores of C and T1 samples were significantly higher than those of T2 and T3, while the flavor scores were the lowest for the T3 samples (p<0.05). In addition, with increased storage duration, the texture and flavor attributes of the vacuum-packaged samples were found to be higher than those of non-vacuum samples. In general, the vacuum-packaged samples tended to show superior physico-chemical quality characteristics compared to the non-vacuum samples, when the storage time was extended up to 90 days.