• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.369-376
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• 2021

The International Maritime Organization has developed the Energy Efficiency Design Index, an index related to carbon dioxide emissions, to enforce regulations on newly built ships. In this study, a new type of energy-saving device called the ring stator was used for 158k crude oil carriers, whose hull form was developed as a very thin after-body hull to reduce the resistance by delaying separation. The Energy-Saving Device (ESD) particularly involving the duct, is not adapted to the thin-after body hull form-like container ship. This new ring stator was developed considering these characteristics. A parametric study was conducted through Computational Fluid Dynamics (CFD) analysis using the Star-CCM+ program, and approximately 3.4 % improvement in propulsion efficiency was achieved. Further optimization investigations and experimental studies should be conducted in the future.

• Journal of The Korean Association of Information Education
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• v.25 no.3
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• pp.483-490
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• 2021

In the era of the fourth industrial revolution, the importance of artificial intelligence(AI) is growing day by day, and there is no disagreement that AI education will bring great innovation in the future. Various attempts are being made to educate the topic of AI, but students who have no experience in AI education recognize AI only as a difficult target. Therefore, in this study, we analyze the changes in students' perception of AI by teaching them using AI. AI convergence education were conducted for 6th grade elementary school students, and pre and post tests were conducted in the form of AI awareness survey questionnaires which included questions such as interest in AI, changes brought by AI, and AI education. As a result, we confirm significant results that suggest the level of awareness of AI has improved through AI education in all factors. AI convergence education requires various AI convergence education programs as a form of education for social needs and future students, and hopefully a design based on this will help realize student centered education.

• Journal of The Korean Association of Information Education
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• v.25 no.3
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• pp.571-578
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• 2021

This study compares Online SW-based maker education in terms of self-efficacy, learning motivation, and interest after applying differently according to blended learning strategies. First, a SW maker program for blended learning was developed and applied as a live seminar-type class including real-time interactive and a support-providing class consisting of online content and Q&A. As a result of comparing the differences between students according to the two strategies divided into pre- and post- survey, in the self-efficacy part, there was a significant difference in the positive efficacy and the overall part, and in the learning motivation part, the live seminar form was significantly higher in the confidence part. In the interest part, the support-providing form showed a significantly higher average in the instrumental interest and nervous part. In order to maintain the effect of maker activities like existing face-to-face situations in Online learning, it is necessary to increase sharing time between students, an integrated learning environment, and sufficient provision of exploration time and learning materials.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.335-343
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• 2021

The study aimed to elucidate how to design a learning environment on the premise of micro-learning (ML) and investigate its impact on website designing skills and achievement motivation among secondary school students. Adopting the experimental approach, data were collected through an achievement test, a product evaluation form, and a test to gauge motivation for achievement. The sample was divided into two experimental groups. Results revealed statistically significant differences at 0.05≥α between the mean scores of the two groups that experienced ML, irrespective of the two modes of presenting the video in the pre-test and post-test, as for the test of websites design skills, product evaluation form, and achievement motivation test. Besides, there have been statistically significant differences at 0.05≥α between the mean scores of the first experimental group that had exposure to ML using the split-video presentation style and the scores of the second experimental group that underwent ML using continuous video presentation style in the post cognitive test of website design and management skills in favor of the group that had segmented-video-presentation ML. Another salient finding is the nonexistence of significant differences at 0.05≥α between the mean scores of the first experimental group that underwent segmented-video-presentation ML and the grades of the second experimental group that received ML with continuous video presentation style in the post-application of the product scorecard of websites designing skills and the motivation test. In light of these salient findings, the study recommended using ML in teaching computer courses at different educational stages in Saudi Arabia, training computer and information technology teachers to harness ML in their teaching and using ML in designing courses at all levels of education.

• Education of Primary School Mathematics
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• v.19 no.3
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• pp.211-222
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• 2016

This article examines K-8 pre-service teachers' (PSTs) engagement in lesson plan modification using the eight Mathematics Teaching Practices (MTPs) in Principles to Actions, the most recent landmark publication of framework by National Council of Teachers of Mathematics (NCTM) in the U.S. The activity consisted of four phases that involved the analysis and modification of an existing lesson plan. Fifty-seven PSTs participated in the activity throughout the semester, and data from each phase was analyzed using the inductive content analysis approach. PSTs' initial conceptions of lesson planning reflected little on teaching practices (i.e., the MTPs) with more emphasis placed on the form - rather than function - of lesson elements. With the opportunity to interpret MTPs and analyze lesson plans using MTPs as an analytical lens, PSTs demonstrated various interpretations of MTPs, made efforts to incorporate MTPs into lessons, and attended to the interwoven nature of MTPs. This article also shares the challenges, conflicts, and tensions reported by PSTs during their participation of lesson plan modification; as such, the results from this study will inform the research examining the pedagogical (im)possibilities for utilizing MTPs in mathematics teacher training programs.

• Journal of Pharmacopuncture
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• v.4 no.3
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• pp.7-14
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• 2001

Objective: This study was done to observe the effects on the thermal changes and side effects of Bee Venom acupuncture. The objectives are as follows; If there are remarkable local thermal changes between pre and post Bee Venom acupuncture therapy on D.I.T.I. or not. If there are those, we examine how long it' s changes are maintained, what is the adequate interval on Bee Venom acupuncture therapy, and what the reactions in a local or whole body are on that therapy. Methods: To study the local thermal changes in Bee Venom acupuncture therapy, D.I.T.I. was used. Determination of this analysis periods are pre and post-therapy(5 minutes, 1 hour, 1day,2days, 3days, 5days and 7days later). The study group was divided into two groups. One was BV group(N=19), another was NS(Normal Saline) group. The Bee Venom acupuncture was injected by 0.2ml divided into 0.05ml at the Fengmen(風門:12), Feishu(肺兪:B13), Fufen(附分:B41), Pohu(魄戶: B42) 4 points. Then, in order to analyze the clinical form, we have observed responses of 23 students whenever we checked the thermal changes of their after performing. Results: The following results were obtained. 1. In BV group, there was a significant dermatothermal difference between pre and post therapy. That difference was most remarkable in post-therapy 1 hour to lday, and was not remarkable in post-therapy 5-7days later. 2. There was no significant dermatothermal changes at NS group, but BV group had remarkable changes between operated and non operated area in post-therapy 1hour, 1day, 2days. But there was none 7 days later. 3. Among the physical reactions after Bee Venom acupuncture therapy, operated-area pain, itching, pain on moving and fatigue sign most appeared until post-therapy 3days. Itching and fatigue sign appeared until post-therapy 7days. 4. In comparison the dermatothermal changes with the physical reactions, the decrease of { CT = (Rt Temperature -Lt. Temperature) / Rt. $Temperature{\times}100$} and the disappearance of physical reactions were about the same.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.1
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• pp.21-28
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• 2017

The steel-plate concrete(SC) is used in a form of module assembly construction in the outer wall of nuclear-power plant and LNG containment. Since the steel-plate concrete modules are generally manufactured from the plant, the weight of SC has significantly effect on the total construction cost in the aspect of shipment. Therefore, the use of lightweight aggregates concrete(LWAC), which fill the inside of SC module can be a solution. However, the amount of used lightweight aggregates(LWA) is limited in the use of current concrete mixing process due to the concrete quality problems and it also determines the allowable minimum density of LWAC. In this research, the preplaced casting method is applied because of increasing the volume fraction of LWA significantly, which results from the producing process of pre-packing the LWA in the formwork and filling the interstitial voids between LWA using cement paste grout. The density and compressive strength of selected preplaced LWAC were $1,600kg/m^3$ and 30MPa and it was applied for the mock-up specimens of SC panel. It was used for the 3-point bending test for evaluating its structural performance. The results show that the preplaced LWAC can reduce the density of concrete with the adequate mechanical and structural performance.

• Environmental and Resource Economics Review
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• v.15 no.4
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• pp.693-712
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• 2006

A pre-feasibility test is done for renewable energy hybrid power systems at off~grid islands in which the current power supply is provided only by diesel generation. We apply Homer (Hybrid Optimization Model for Electric Renewables) which was developed by the National Renewable Energy Laboratory (NREL) for the analysis to identify the cost-minimizing combination of power generating facilities for the given load profiles. Chuja-Do, Geomun-Do and Youngsan-Do have been selected for our analysis considering the wind resources data of the Korea Institute of Energy Research (KIER). Information on wind speed, solar radiation and temperature is also used for the analysis. System component cost information from overseas market has been used due to the lack of domestic information. Site specific Load profile for electricity demand for those islands are reconstructed based on the partial survey results obtained form other sources. The LCOE of the least cost hybrid power systems for Chuja-Do, Geomun-Do and Youngsan-Do are $0.278/kWh, $0.234/kWh and $0.353/kWh, respectively Considering the fact that diesel generation is being subsidized at the price of $0.300/kWh by the government, first 2 cases are economically feasible for the introduction of renewable energy hybrid systems to those islands. But the third case of Youngsan-Do does not meet the criteria. The basic differences of these pre-feasibility test results are from the differences of the site specific renewable energy conditions, especially wind resources. In summary, promoting hybrid systems in the off-grid remote island should be based on the economic feasibility test results. Not all the off-grid islands are feasible for introducing this renewable energy hybrid system.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.171-176
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• 2007

A total of 4,627 records on pre-weaning growth traits, birth weight(BW), weaning weight(WW) and pre-weaning daily gain(ADG) of Hanwoo’s born form 1970 to 2005 were collected from Hanwoo Experiment Station, National Livestock Research Institute. Variance components and heritabilities of BW, WW and ADG were estimated with two models; Model 1 included only direct genetic effect while Mode1 2 included direct genetic, maternal genetic and permanent environmental effects. Direct herit- ability estimates of BW, WW and ADG estimated by model 1 were 0.34, 0.26 and 0.20, respectively. In model 2, direct heritability and maternal genetic heritability estimates were 0.14 and 0.06 for BW, 0.07 and 0.04 for WW and 0.05 and 0.04 for ADG. Estimates of genetic correlation between direct and maternal effect for BW, WW and ADG were 0.58, 0.75 and 0.61, respectively. Genetic correlation coefficients between BW and WW, between BW and ADG, and between WW and ADG were 0.76, 0.62 and 0.99, respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.11
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• pp.4999-5003
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• 2016

The testicular cancer (TCa) incidence is increasing in many countries, with age-standardized incidence rates up to 7.8/100,000 men in the Western world, although reductions in mortality and increasingly high cure rates are being witnessed at the same time. In Africa, where rates are lower, presentation is often late and morbidity and mortality high. Given this scenario, awareness of testicular cancer and practice of testicular self-examination among future first response doctors is very important. This study was conducted to determine knowledge and attitude to testicular cancer, and practice of testicular self-examination (TSE) among final (6th) year medical students. In addition, the effect of an intervention in the form of a single PowerPoint(R) lecture, lasting 40 minutes with image content on testicular cancer and testicular self examination was assessed. Pre and post intervention administration of a self-administered structured pre tested questionnaire was performed on 151 medical students, 101 of whom returned answers (response rate of 66.8%). In the TC domain, there was a high level of awareness of testicular cancer, but poor knowledge of the age group most affected, with significant improvement post intervention (p<0.001). Notable also was the poor awareness of the potential curability of TC, this also being improved following the intervention (p<0.001). A poor level of awareness and practice of testicular self-examination pre-intervention was found considering the nature of the study group..Respondents had surprisingly weak/poor responses to the question "How important to men's health is regular testicular self-examination?" Answers to the questions "Do you think it is worthwhile to examine your testis regularly?" and "Would you be interested in more information on testicular cancer and testicular self-examination?" were also suboptimal, but improved post intervention p<0.001, p<0.001 and p=0.037. Age, gender and marital status were without specific influence. In conclusion, this study showed poor levels of knowledge regarding epidemiology of TCa and its potential curability when detected early. There was also a poor awareness of, practice of, and poor attitudes to TSE. The significant improvement in these parameters post intervention indicates value in educational intervention. We recommend inclusion of TCa coverage and TSE teaching in the secondary school curriculum (targeting adolescents). Greater emphasis should also be given to testicular cancer in the curricula of medical schools and other training institutions for health care personnel.