• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.603-622
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• 2023

Human error (HE) is an important concern in safety-critical systems such as nuclear power plants (NPPs). HE has played a role in many accidents and outage incidents in NPPs. Despite the increased automation in NPPs, HE remains unavoidable. Hence, the need for HE detection is as important as HE prevention efforts. In NPPs, HE is rather rare. Hence, anomaly detection, a widely used machine learning technique for detecting rare anomalous instances, can be repurposed to detect potential HE. In this study, we develop an unsupervised anomaly detection technique based on generative adversarial networks (GANs) to detect anomalies in manually collected surveillance data in NPPs. More specifically, our GAN is trained to detect mismatches between automatically recorded sensor data and manually collected surveillance data, and hence, identify anomalous instances that can be attributed to HE. We test our GAN on both a real-world dataset and an external dataset obtained from a testbed, and we benchmark our results against state-of-the-art unsupervised anomaly detection algorithms, including one-class support vector machine and isolation forest. Our results show that the proposed GAN provides improved anomaly detection performance. Our study is promising for the future development of artificial intelligence based HE detection systems.

• Food Science and Industry
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• v.51 no.3
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• pp.209-217
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• 2018

Delphi technique is widely used to develop consensus on group opinion. It is important to identify the strategic technologies and evaluate technology level for the establishment of national R&D policy to upgrade technology level. The aim of this article was to reflect on Food Safety technology level by using Delphi methodology. And, competitiveness of patents and journal articles is evaluated for Korea, USA, Japan, China and EU. As a result, USA is the most competitive country for all technology categories. The average technology level of Korea was 79.5% of world-top coungry and average technological gap was 6.1 years. Korea is grouped in middle-lower class for overall food safety technology level. However, there are some variances among the level of technologies. As a result of this study, food safety research management needs to expand R&D investment and training of food safety specialist. The results of this research can be utilized to establish a road map for transportation R&D and plans.

• Analytical Science and Technology
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• v.24 no.6
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• pp.435-442
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• 2011

Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants (BFRs) which have taken much interest recently due to their potential hazardous effects to human body and ecosystem. Many countries and European community prohibits the usage of certain BFRs in electronics and electronic devices (e.g. RoHS). In this perspectives, Korea Research Institute of Standards and Science (KRISS) has designed and practiced proficiency testing programs based on the ISO/IEC 17043 in order to assist laboratory accreditation activities. The programs for interlaboratory comparisons include congeners of PBDE (PBDE-154, 183, 206, 209) in high impact polystyrene (HIPS). A sample bottle that contains 10 g granular HIPS was distributed to 35 participating laboratories and the test results were calculated by the statistical procedure using z-scores to evaluate performance of each laboratory. The results and the laboratory's performance were discussed.

• Journal of the Korean School Mathematics Society
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• v.9 no.4
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• pp.557-573
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• 2006

The purpose of this study is to examine the usefulness of teaching Maple in College Mathematics Education. The subject are 60 students of college of science in H university and C university located in Daejeon. They were divided into two parts; an experimental group (group I, group II, each of 20 students) and a control group (group III of 20 students). The group I and II are provided calculus lecture in class as well as Maple lab, while group III are lectured only in class. In order to know the effectiveness of using Maple, a test is designed in the way that group I is allowed to use both pencil and Maple, while group II and III are restricted to use only pencil. The result of this study is as follows. i) According to the performance of testing exam, there is no significant difference between three groups (p>.05) when they are allowed to use only pencil. ii) The achievement of group I is much higher than that of group II and III (p<.05) when they were provided both pencil and Maple. iii) Lot of students in group I who fail to solve with pencil can succeed in solving problems using Maple.

• Journal of the Korean earth science society
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• v.37 no.7
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• pp.476-488
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• 2016

The purposes of this study were to develop a scientific inquiry-based STEAM education program and to investigate its effect on changing middle school students' self-efficacy in science, job awareness, and attitudes toward STEM. A scientific inquiry-based STEAM program was developed with the theme of 'earthquakes', using the ADBA model, which was taking up the total of six class periods. The final program, which had been revised and completed after being pre-tested with middle school students, was implemented to 105 third-graders of middle school in a metropolitan city. One sample pre-post paired t-test before and after applying the program to the same group was conducted, and its effectiveness was analyzed in terms of self-efficacy in science, job awareness, attitudes toward science, technology, engineering and mathematics. Results showed that the STEAM program on the theme of 'earthquakes' demonstrated its effect on improving the students' of self-efficacy in science subject and their awareness of science-related jobs. Furthermore, this program indicated a statistical significance in improving middle school students' attitudes, awareness, and abilities, values, and continuing interest towards science, technology, engineering, and mathematics. Therefore, we suggest that this scientific inquiry based STEAM program be used to help students to improve their scientific investigation skills as well as their creative and integrated thinking abilities in schools.

• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.183-195
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• 2020

In this study, the objective of this study is to verify the effects between lecturer's capability, education program, education service, and physical educational environment factors, and university students' interest in and attitude toward mathematics. A survey was conducted on 228 male and female students in science and engineering majors attending universities in the Pusan metropolitan area, and empirical analysis was conducted using the SPSS 26.0 program. The research results are as follows. First, among the characteristics of college mathematics maker classes, instructor competency (β=.349, t=6.380, p<.001), educational program (β=.361, t=5.650, p<.001), and physical educational environment (β=.196, t=3.281, p<.01) had a significant positive (+) effect on college students' interest in mathematics. Second, the factors of interest (β=.349, t=6.380, p<.001) in college mathematics maker classes were found to have a significant positive (+) effect on college students' attitudes toward mathematics. Third, among the characteristics of college mathematics maker classes, instructor competency (β=.340, t=6.365, p<.001), educational program (β=.352, t=5.559, p<.001), physical educational environment (β=.226, t=3.537, p<.01) was found to have a significant positive (+) effect on college students' attitudes toward mathematics. Through the results of this study, it was concluded that when the level of education program and teaching ability of the university mathematics maker class are high and the physical educational environment is excellent, it can have a positive effect not only on the university student's attitude towards mathematics but ultimately on the attitude of mathematics.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.821-827
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• 2013

The purpose of this study was to investigate the effects of three kinds of horticultural activities (HAs) on attention concentration of elementary students. We selected 20 students using a Wee Class counseling office at J elementary school in Yeongcheon, and divided them into experimental and control groups composed of ten students each. The experimental group participated in three HAs including flower arrangement, planting, and pressed flower. Each HA was composed of three sessions and a session proceeded for a week. For the examinations of attention concentration, two groups responded the questionnaires before a week of the first session and at the end of the 9th session, only the experimental group participated in the measurement using grid by Harris before a week of the first session and at the end of each HA every week. The results of questionnaire survey showed that the scores of problem in emotion and problem in controlling, and the total score decreased 9.2, 7.8, and 19.0 points, respectively (P < 0.05), indicating that the attention concentration of the experimental group improved compared with the control. In the measurements using grid by Harris, the flower arrangement, planting, and pressed flower activities increased the scores by 2.22, 2.49, and 2.41 points compared with the pre-HA of 6.00, respectively (P < 0.05), that means the improvements of attention concentration. At the post-HAs, the flower arrangement, planting, and pressed flower activities increased the scores by 1.12, 1.39 and 1.31 points compared with the control group of 7.10, respectively (P < 0.05). In conclusion, the indoor HAs improved the attention and concentration of elementary students irrespective of kind of activities.

• Journal of Forest and Environmental Science
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• v.30 no.2
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• pp.218-225
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• 2014

Studies were carried out to standardize and develop a suitable macro-propagation technology for large scale production of superior clonal stock through stem cuttings in Commiphora wightii Arnott (Bhandari), a data deficient medicinal plant of arid region. For the purpose, three experiments were conducted. The first experiment was tried to elucidate the impact of various cutting diameters (0.50-0.75 cm, 0.75-1.00 cm, 1.00-1.50 cm, and >1.50 cm) in combination with varying growing conditions (sunlight, shade house and mist chamber) on shoot sprouting and rooting without using exogenous plant growth regulators. Cutting diameter (size 0.75-1.00 cm) in mist chamber has shown maximum sprouting (90.00%) and rooting (73.33%), primary root (6.67) and secondary root (16.67) followed by 1.00-1.51 cm in mist chamber. Minimum sprouting (40.00%), rooting (33.33%), number of shoot (1.33), primary root (1.00) and number of secondary root (1.00) was recorded in cutting diameter (size >1.50 cm) in sunlight. Second experiment was performed to find out optimum growth regulator concentration of rooting hormone (100, 200, 500 and 1000 ppm) of Indole-3-acetic acid (IAA) and Indole-3-butyric Acid (IBA) on adventitious root formation on cuttings diameter (size 0.25-0.50 cm) in comparison to control. Maximum rooting percentage (93.33%) was recorded in 200 ppm followed by 500 ppm (86.66%) of IBA as compared to control, which showed only 60 per cent sprouting. Third experiment was performed with newly formed juvenile micro-cuttings treated with varying concentrations of IAA and IBA. The juvenile cuttings (size 6-10 cm, basal dia <0.25 cm) were selected as micro-cuttings. The cuttings treated with IBA (500 ppm) showed 64.30% rooting as compared to other treatments. Results of above experiments indicate that cuttings (size 0.75-1.00 cm dia) may be developed in mist chamber for better performance. While using heavier cuttings, no growth promoting hormones is required however; growth regulator 200 ppm concentration of IBA rooting hormone was observed optimum for promoting macro-propagation in stem cuttings of lower diameter class (0.25-0.50 cm).

• Forest Science and Technology
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• v.14 no.4
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• pp.160-168
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• 2018

The seeds of Elaeocarpus serratus, a tropical underutilized fruit tree are characterized by hard seed coat and consequent poor water uptake and low germination. To improve the regeneration through seeds, various parameters such as viability of seeds, water uptake, and effect of seed mass on germination and pretreatments were performed using a completely randomized design (CRD). Tetrazolium (TZ) test was conducted using fresh, mature seeds revealed $50{\pm}2.56%$ mean viability. Seeds of different weight classes showed similar pattern of water uptake and the saturation level was achieved at 60 hrs of soaking. Seeds belong to weight class 2.6-3.5g were germinated ($12.5{\pm}1.26%$) with $175{\pm}1.75days$ (d) of mean time taken for germination (MTG). Germination capacity of seeds varied significantly among different populations and Varkala population gave $12.5{\pm}1.1%$ germination with $174.6{\pm}2.5d$ MTG. Among various seed treatments, mechanical scarification was superior in germination and significant reduction in MTG ($p{\leq}0.05$). The mechanical scarification by complete removal of seed coat resulted in $49.2{\pm}1.52%$ germination within a short period of time ($9.52{\pm}0.89d$ MTG). However, the complete removal of seed coat without damaging to embryo is a difficult task. An alternate treatment (Mechanical scarification II) by making cracks on nut faces vertically followed by soaking in distilled water for 24 hrs gave $48.4{\pm}1.73%$ germination with significantly reduced MTG ($12.14{\pm}0.56d$) over unsoaked, untreated control ($6.5{\pm}1.84%$ germination and $197.18{\pm}1.79d$ MTG; $p{\leq}0.05$). This treatment (Mechanical scarification II) is therefore recommended for E. serratus seeds as it can adopt easily and can achieve 7 fold increases in germination over control. The recorded germination through mechanical scarification is in tune with realized viability percentage of the seeds.

• Science of Emotion and Sensibility
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• v.16 no.3
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• pp.363-372
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• 2013

When retrieving music with folksonomy tags, internal use of numeric tags (AV tags: tags consisting of Arousal and Valence values ) instead of word tags can partially solve the problem posed by synonyms. However, the two predecessor tasks should be done correctly; the first task is to map word tags to their numeric tags; the second is to get numeric tags of the music pieces to be retrieved. The first task is verified through our prior study and thus, in this paper, its significance is seen for the second task. To this end, we propose the music mapping table defining the relation between AV values and music and ANOVA tests are performed for analysis. The result shows that the arousal values and valence values of music have different distributions for 12 mood tags with or without synonymy and that their type I error values are P<0.001. Consequently, it is checked that the distribution of AV values is different according to music mood.