• Journal of the Korean Society of Food Culture
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• v.28 no.1
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• pp.48-56
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• 2013

The purpose of this study was to examine the dietary habits of boarding high school students in Gangwon based on gender and stress levels. Questionnaires were distributed to 571 boarding high school students and collected from 491 students from June 28 to July 20, 2011. The statistical data analyses were completed using SPSS (ver. 19.0) for the descriptive analysis, independent sample t-test and $X^2$-test. The mean stress score was 23.7 out of 40, and male's stress was significantly higher than female's (p<0.05). The rates of having daily breakfast and dinner were significantly influenced by gender (p<0.01), and the regularity of lunch was significantly different depending on the stress level (p<0.05). Female students consumed less flour based foods (p<0.01), carbonated drinks (p<0.01), juices (p<0.05) and functional drinks (p<0.01) than male students, but male students consumed less cookies and breads (p<0.01). Dietary habits that boarding high school students should improve were an unbalanced diet (38%), too much intake at once (17%) and prejudice against foods (11%), and their primary value in dietary life was preference (33%), followed by staving off hunger (18%) and pleasure (18%). The average level of interest in dietary life was 2.46 (on a Likert-type 3-point scale) and it was significantly higher for female students (2.53) than male (2.40) (p<0.05). About 54% of students washed their hands before a meal when they thought of it, but only 25% of students always scrubbed up. The regularity of breakfast and dinner, frequency of snack intake, dietary habits that need to improve, intrest in dietary life, and washing hands before meals showed significant difference by gender but not by stress levels.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.1
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• pp.126-133
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• 2017

This paper presents the shear capacities of hollow slab with plate and octagonal pillar type hollow sphere. Recently, the interest in precast hollow slab system for buildings is growing up according to the demand for high quality control and the increase in slab thickness. A hollow slab system is widely known as one of the effective slab system which can reduce self-weight of slab. However, hollow slabs are vulnerable to the deterioration in the shear strength due to the decrease of concrete at slab web which resists shear. Especially, in case of precast hollow slabs, it has joint surface between precast concrete slab modules along transverse axis of slab, and shear failure, that is caused by cracks at joints, has to be prevented. Therefore, in this study, shear capacity of the I-slab system is evaluated by 3-points-supported shear test along the longitudinal and transverse axis of slab specimen. Test results showed that I-slab had enough shear strength compared to theoretical shear strength even if it included the joint surfaces.

• Child Health Nursing Research
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• v.9 no.1
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• pp.57-65
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• 2003

Purpose: This study was intended to present basic data of a more effective drug free education program by examining and analyzing the needs of drug and health education in the adolescent. Method: The study subjects were 480 students from six high schools in Pusan. The data were collected by a self-administered questionnaire between June 1 and June 10, 1999. Descriptive statistics, t-test, one-way ANOVA, Scheffe test in SPSS program were used for data analysis. Result: The scoring rate of knowledge for drug abuse of the subjects was 26.8％. For the scores of knowledge according to the type of drug, cigarettes were the highest at 38.4％, and for the scores of knowledge according to items, the abuse part was 59％, also the highest. The needs of drugs and drug education for the subjects had an average of 19.59. For the score of needs according to the items, plans to maintain and improve health was 1.72, the highest, methods to control anger and stress was 1.66, toxicity of drugs was 1.51, and medicinal use of drugs was 1.44. For the characteristics of the subject and characteristics relating to drugs, and the comparison of needs of drug education, consisted of students who said they liked or disliked their school life, those who have had drug education at school, who having received drug education by various kinds of materials, all had high needs for the education. Conclusion: It is necessary that drug free education plans including plans to maintain and improve health on the basis of the needs of drug education for the adolescent and other contents such as the methods to control anger and stress are established. Development of various kinds of audio-visual materials, publicity booklets and educational programs for parents etc. are needed in order to make the adolescent have an interest in drug free education, and recognize its importance.

• Journal of Korea Technology Innovation Society
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• v.14 no.2
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• pp.205-222
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• 2011

The Korean government continuously increases the R&D investment in order to pursue an economic growth through technological innovation. Hence, the intensity of governmental R&D has increased rapidly. However, the whole amount of the R&D investment is still small compared to developed countries. And the type of R&D policies is more and more changing from the catch-up model to the technology-driven model. Therefore, there is a growing interest in the efficiency of public R&D investment. Hence, many studies on the efficiency of R&D investment have been researched. This study estimated the efficiency of governmental R&D programs considering the technological outcomes, e.g. theses, patents and so on, using DEA(Data Envelopment Analysis) with data of S&T investment and outcomes from NTIS(National S&D Information Service). In addition, we used the Mann-Whitney Test to investigate the characteristics of governmental R&D investment.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.43-53
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• 2014

Shock tunnels are known to be capable of simulating flow-field environments of supersonic and hypersonic flights. They have been operated successfully world-wide for almost half a century. As a consequence of the strong interest in hypersonic vehicles in Korea, attention has been given on this type of facility and so an intermediate-sized shock tunnel has lately been built at KAIST. In the light of this, this paper presents our tunnel performance and some of the model scramjet test data. The freestream flow used in this work replicates a supersonic combustor environment for a Mach 5.7 flight speed.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.89-95
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• 2021

As the influence of fine dust on society spreads gradually, the public's interest in indoor air is increasingly rising. Air-purifying plants are drawing keen attention due to their natural purifying function enabled by plant physiology. However, as their fine dust reduction mechanism is limited to adsorption only, vegetation bio-filters that optimize purification effects through integration with air-conditioning systems is rising as an alternative. In accordance with the relevant standard test methods, this study looked into the fine dust reduction assessment method by air-conditioning airflow volume that can be used for the industrial spread of vegetation bio-filters. In the case of PM₁₀ at 300 ㎍/m³, it was in the order of EG-B(3,500CMH, 29 min.) < EG-A (2,500CMH, 37 min.) < CG(0CMH, 64 min.) for reaching the maintenance level (100 ㎍/m³) of publicly used facilities. For reaching the WHO Guideline(50 ㎍/m³) requirement, it was in the order of EG-B (51 min.) < EG-A (160 min.) < CG (170 min.). In the case of PM_2.5, it was in the order of EG-B (26 min.) < EG-A (33 min.) < CG (57 min.) for reaching the maintenance level (50 ㎍/m³) of publicly used facilities. It was in the order of EG-B (48 min) < EG-A (140 min) < CG (158 min) for reaching the WHO Guideline (25 ㎍/m³) requirement. The findings from the analysis showed that fine dust can be reduced most efficiently when the system is operated at 3,500CMH level. The limitation of this study is that due to the absence of a way of assessing the stress of plants in vegetation bio-filters, generating optimal air-conditioning air flow of the relevant system and economics analysis against the existing facility-type air purification system have been clarified, which should be explored further though follow-up studies.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2334-2340
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• 2021

Radioactive particle tracking (RPT) is a minimally invasive nuclear technique that tracks a radioactive particle inside a volume of interest by means of a mathematical location algorithm. During the past decades, many algorithms have been developed including ones based on artificial intelligence techniques. In this study, RPT technique is applied in a simulated test section that employs a simplified mixer filled with concrete, six scintillator detectors and a¹³⁷Cs radioactive particle emitting gamma rays of 662 keV. The test section was developed using MCNPX code, which is a mathematical code based on Monte Carlo simulation, and 3516 different radioactive particle positions (x,y,z) were simulated. Novelty of this paper is the use of a location algorithm based on a deep learning model, more specifically a 6-layers deep rectifier neural network (DRNN), in which hyperparameters were defined using a Bayesian optimization method. DRNN is a type of deep feedforward neural network that substitutes the usual sigmoid based activation functions, traditionally used in vanilla Multilayer Perceptron Networks, for rectified activation functions. Results show the great accuracy of the DRNN in a RPT tracking system. Root mean squared error for x, y and coordinates of the radioactive particle is, respectively, 0.03064, 0.02523 and 0.07653.

• Smart Structures and Systems
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• v.33 no.1
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• pp.55-64
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• 2024

This paper proposes a fusion imaging-based coating-defect classification method for steel structures that uses zero-shot learning. In the proposed method, a halogen lamp generates heat energy on the coating surface of a steel structure, and the resulting heat responses are measured by an infrared (IR) camera, while photos of the coating surface are captured by a charge-coupled device (CCD) camera. The measured heat responses and visual images are then analyzed using zero-shot learning to classify the coating defects, and the estimated coating defects are visualized throughout the inspection surface of the steel structure. In contrast to older approaches to coating-defect classification that relied on visual inspection and were limited to surface defects, and older artificial neural network (ANN)-based methods that required large amounts of data for training and validation, the proposed method accurately classifies both internal and external defects and can classify coating defects for unobserved classes that are not included in the training. Additionally, the proposed model easily learns about additional classifying conditions, making it simple to add classes for problems of interest and field application. Based on the results of validation via field testing, the defect-type classification performance is improved 22.7% of accuracy by fusing visual and thermal imaging compared to using only a visual dataset. Furthermore, the classification accuracy of the proposed method on a test dataset with only trained classes is validated to be 100%. With word-embedding vectors for the labels of untrained classes, the classification accuracy of the proposed method is 86.4%.

• Journal of Food Hygiene and Safety
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• v.38 no.1
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• pp.1-11
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• 2023

Skin sanitizers are effective in killing or removing pathogenic microbial contaminants from the skin of food handlers, and the progressive growth of consumer interest in personal hygiene tends to drive product diversification. This review covers the advances in the application of efficacy tests for hand sanitizers to suggest future perspectives to establish an assessment system that is optimized to each product type (gel, liquid, and wipes). Previous research on the in vivo simulative test of actual consumer use has adopted diverse experimental conditions regardless of the product type. This highlights the importance of establishing optimal test protocols specialized for the compositional characteristics of sanitizers through the comparative analysis of test methods. Although the operational conditions of the mechanical actions associated with wiping can affect the efficacy of the removal and/or the inactivation of target microorganisms from the skin's surface, currently there is a lack of standardized use patterns for the exposure of hand sanitizing wipes to skin. Thus, major determinants affecting the results from each step of the overall assessment procedures [pre-treatment - exposure of sanitizers - microbial recovery] should be identified to modify current protocols and develop novel test methods. The ex vivo test, designed to overcome the limited reproducibility of in vivo human trials, is also expected to replicate the environment for the contact of sanitizers targeting skin microorganisms. Recent progress in the area of skin microbiome research revealed distinct microbial characteristics and distribution patterns after the application of sanitizers on hands to establish the test methods with the perspectives on the antimicrobial effects at the community level. The future perspectives presented in this study on the improvement of efficacy test methods for hand sanitizers can also contribute to public health and food safety through the commercialization of effective sanitizer products.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.117-124
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• 2018

Recently, the interest and consumption of mini watermelon (Citrullus lunatus Thunb.) are increasing due to nuclear family and one person household. However, there's no research for mini watermelon. Therefore, the purpose of the study is to develop standard cultivation method of mini watermelon. The test cultivar is 'Minimi', which is a small-sized fruit, the rootstock is 'Bullojangsaeng', which is a cucurbit line. Grafted plants were transplanted on April 5, 2017, and harvested in early July. Cultivated types were 3 methods, which are ${\cap}-form$, arched, and runner type, and plant spacing were 40, 60, and 80 cm, respectively. The rowth and yield in ${\cap}-form$ was higher than that of the arched and runner types, and the sugar content was higher a bit. The yield per unit area was about 50% higher than ${\cap}-form$, which can be plant density cultivation than that of the runner type. The number of seeds per fruit of 'Minimi' was similar to that of 'Sambokggul', but seed weight was one third lower than that of 'Sambokggul'. The content of lycopene was 30% higher than that of 'Sambokggul' watermelon, and the main sugar content is similar to or slightly less. In conclusion, the ${\cap}-form$ staking cultivation was superior to the runner type or arched cultivation in terms of fruit setting ratio, yield and quality.