• Steel and Composite Structures
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• v.48 no.2
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• pp.163-177
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• 2023

Complex and intricate preparation techniques, the imperative for utmost precision and sensitivity in instrumentation, premature sample failure, and fragile specimens collectively contribute to the arduous task of measuring the fracture toughness of concrete in the laboratory. The objective of this research is to introduce and refine an equation based on the gene expression programming (GEP) method to calculate the fracture toughness of reinforced concrete, thereby minimizing the need for costly and time-consuming laboratory experiments. To accomplish this, various types of reinforced concrete, each incorporating distinct ratios of fibers and additives, were subjected to diverse loading angles relative to the initial crack (α) in order to ascertain the effective fracture toughness (Keff) of 660 samples utilizing the central straight notched Brazilian disc (CSNBD) test. Within the datasets, six pivotal input factors influencing the Keff of concrete, namely sample type (ST), diameter (D), thickness (t), length (L), force (F), and α, were taken into account. The ST and α parameters represent crucial inputs in the model presented in this study, marking the first instance that their influence has been examined via the CSNBD test. Of the 660 datasets, 460 were utilized for training purposes, while 100 each were allotted for testing and validation of the model. The GEP model was fine-tuned based on the training datasets, and its efficacy was evaluated using the separate test and validation datasets. In subsequent stages, the GEP model was optimized, yielding the most robust models. Ultimately, an equation was derived by averaging the most exemplary models, providing a means to predict the Keff parameter. This averaged equation exhibited exceptional proficiency in predicting the Keff of concrete. The significance of this work lies in the possibility of obtaining the Keff parameter without investing copious amounts of time and resources into the CSNBD test, simply by inputting the relevant parameters into the equation derived for diverse samples of reinforced concrete subject to varied loading angles.

• The Korean Journal of Nuclear Medicine Technology
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• v.26 no.2
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• pp.43-47
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• 2022

Purpose Radioimmunoassay implement quality control by systematizing the internal quality control system for quality assurance of test results. This study aims to contribute to the quality assurance of radioimmunoassay results and to implement systematic quality control by measuring the average CV of internal quality control and external quality control by plenty of institutions for reference when setting the laboratory's own acceptable range. Materials and Methods We measured the average CV of internal quality control and the bounce rate of more than 10.0% for a total of 42 items from October 2020 to December 2021. According to the CV result, we classified and compared the upper group (5.0% or less), the middle group (5.0~10.0%) and the lower group (10.0% or more). The bounce rate of 10.0% or more was compared by classifying the item of five or more institutions into tumor markers, thyroid hormones and other hormones. The average CV was measured by the overall average and standard deviation of the external quality control results for 28 items from the first quarter to the fourth quarter of 2021. In addition, the average CV was measured by the overall average and standard deviation of the proficiency results between institutions for 13 items in the first half and the second half of 2021. The average CV of internal quality control and external quality control was compared by item so we compared and analyzed the items that implement well to quality control and the items that require attention to quality control. Results As a result of measuring the precision average of internal quality control for 42 items of six institutions, the top group (5.0% or less) are Ferritin, HGH, SHBG, and 25-OH-VitD, while the bottom group (≤10.0%) are cortisol, ATA, AMA, renin, and estradiol. When comparing more than 10.0% bounce rate of CV for tumor markers, CA-125 (6.7%), CA-19-9 (9.8%) implemented well, while SCC-Ag (24.3%), CA-15-3 (26.7%) were among the items that require attention to control. As a result of comparing the bounce rate of more than 10.0% of CV for thyroid hormones examination, free T4 (2.1%), T3 (9.3%) showed excellent performance and AMA (39.6%), ATA (51.6%) required attention to control. When comparing the bounce rate of 10.0% or more of CV for other hormones, IGF-1 (8.8%), FSH (9.1%), prolactin (9.2%) showed excellent performance, however estradiol (37.3%), testosterone (37.7%), cortisol (44.4%) required attention to control. As a result of measuring the average CV of the whole institutions participating at external quality control for 28 items, HGH and SCC-Ag were included in the top group (≤10.0%), however ATA, estradiol, TSI, and thyroglobulin included in bottom group (≥30.0%). Conclusion As a result of evaluating 42 items of six institutions, the average CV was 3.7~12.2% showing a 3.3 times difference between the upper group and the lower group. Cortisol, ATA, AMA, Renin and estradiol tests with high CV will require continuous improvement activities to improve precision. In addition, we measured and compared the overall average CV of the internal quality control, the external quality control and the proficiency between institutions participating of six institutions for 41 items excluding HBs-Ab. As a result, ATA, AMA, Renin and estradiol belong to the same subgroup so we require attention to control and consider setting a higher acceptable range. It is recommended to set and control the acceptable range standard of internal quality control CV in consideration of many things in the laboratory due to the different reagents and instruments, and the results vary depending on the test's proficiency and quality control materials. It is thought that the accuracy and reliability of radioimmunoassay results can be improved if systematic quality control is implemented based on the set acceptable range.

• Journal of Digital Contents Society
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• v.18 no.6
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• pp.1067-1078
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• 2017

Previous research on university life of Chinese students studying in Korea has been conducted on students in Korea, but Chinese students have a sense of belonging and university prejudice against Korean universities, so the objectivity of research is not clear. This paper conducted a survey of the Chinese people in China and conducted a media search for attracting foreign students. Not all foreign students are proficient in Korean language. Even students who have completed more than one year of education in the Korean language institutes or passed advanced level of Test of Proficiency in Korean(TOPIK) have difficulties in everyday life and acquiring a degree. According to the results of this study, until foreign students who lack sufficient Korean language skills are able to adapt to culture and acquire information in Korea, it is desirable to prepare multilingual content services so that they can obtain academic information or daily information necessary for studying in their native language.

• Journal of Digital Convergence
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• v.16 no.8
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• pp.19-26
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• 2018

In an effort to investigate the effects of chatbots on English listening and reading skills, 46 college students participated in the current study. Participants consisted of first-year students who enrolled in an English class at a university in South Korea. They were randomly divided into two groups: one experimental group (n=24) and one control group (n=22). During 16 weeks, the experimental group engaged in chats with a chatbot, named Elbot, while the control group did not. There were pre- and post-tests to confirm the effects of the chatbot usage. Major findings are as follows: First, participants in both groups significantly improved listening and reading skills. On the post-listening test, however, the experimental group showed more improvements. Their listening proficiency level improved from intermediate to advanced level after engaging in chat with the chatbot. Limitations and implications for theory and practice are discussed at the end.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.657-662
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• 2005

Extractions fro fertilizer and soil samples were performed to yield the operationally defined fractions 'soluble' chromate (extractable with $NH_4NO_3$), 'exchangeable' chromate (extractable with phosphate buffer pH 7.2), and these results were compared with the data obtained by extractions with ammonium sulfate, borate buffer pH 7.2, saturated borax pH 9.6, and polyphosphate (Graham's salt). In order to maintain the pH of extractant solution about constant, the concentration of extractant buffer had to be raised to at least 0.5 M. The results strongly depended on the kind of extractant, and the solid: liquid ratio. For most of the samples investigated, the extraction efficiency increased in the order borate-sulfate-nitrate-phosphate. Whereas the recovery of $K_2CrO_4\;and\;CaCrO_4$ added to the samples of basic slags prior to the extraction was about complete, the recovery of added $PbCrO_4$ was highly variable. In soil extracts, the color reaction was interfered from co-extracted humics, which react with the chromate in weak acid solution during the time period necessary for color reaction (1 hour). However, this problem can be overcome by standard addition and subtraction of the color of the extractant solution. In soil extract of about pH < 7, organic material reduced chromate during the extraction period also, and standard addition of soluble chromate is recommended to prove recovery and the stability of chromate in the samples. In admixtures of soils and basic slags, results for hexavalent chromium were lower than from the mere basic slags. This effect was more pronounced in phosphate than in nitrate extracts. As a proficiency test, samples low in organic carbon from contaminated sites in Hungary were tested. The results from $NH_4NO_3$ extracts satisfactorily matched the results of the Hungarian labs obtained from $CalCl_2$ extractants.

• The Korean Journal of Emergency Medical Services
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• v.7 no.1
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• pp.5-28
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• 2003

The purpose of this study which was conducted by framing of standardized advanced emergency care instructor qualification course outline and training competent instructor Course development based on following educational principle and it would be expected more improved aspect. Advanced Emergency care Instructor Qualification Course Development (1) based on advanced emergency care instructor job analysis and paramedic job description. (2) Learning of emergency care instructor qualification course is continuous. It is important to begin at the learner's level of knowledge and to relate new learning to information the learner needs. (3) Learning of emergency care instructor qualification course is purposeful and must make sense to the learner. Progress in learning must make sense to the learner. Progress in learning must be constantly appraised through feedback. The purpose of learning BLS information and skills must be kept in sharp focus. (4) Learning involves as many senses as possible. The more stimulating a learner activity is to the senses, the longer the information will be retained. Conservative figures indicate that 75% of what is heard is for-gotten after 2 days. It has been said that learners remember (5) Learning activities must be appropriate for the emergency situation through the PBL educational method. In BLS lecture skill learning, the greatest proportion of class time should be spent in manikin practice, using performance sheets as a learning tool or guide. (6) Learning must be stimulating. Instructors can motivate learners by helping them achieve higher levels of proficiency and encouraging other levels of course completion, such as instructor and instructor trainer. (7) Learning is affected by the physical and social environment. The physical environment should be conducive to both the kind of learning taking place and the activities used for learning. Advanced emergency care instructor qualification course organized educational psychology, educational methodology I,II,III, educational material making skill, lecture & conversational skill, BLS theory & pratice lecture skill, minic lecture designed PBL module. test of minic lecture & pratice lecture skill. Advanced emergency care instructor qualification course continued to active instructor training and motivated to active EMS system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.2038-2044
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• 2011

Serious games are selected by users according to the original goals such as education, treatment, training and so on. Therefore, those type of games are evaluated inside and outside the game about whether the goals are archived or not. Among quality test elements of serious game, assessment is about whether, in games, ability to verify goal achievement is included or not. In this paper, we examined the achievement-assessing function of serious game through several cases. Furthermore, to utilize for developing serious games for English learning, we designed a level system which achievement-assessing function is applied to. In this level system, we used 'competition and reward' as the core elements of game, and designed the system through simulation of which grades are level-designed along the user's English proficiency level based on notice of MEST(Ministry of Education, Science and Technology). This paper is expected to be useful reference for designing English learning game containing achievement assessing function.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.477-484
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• 2011

The purpose of this study is to research middle school student's reading problem and to suggest how to improve their reading competence through the use of the NIE. For this research, we proposed three research questions of study as below. First, what difference is there in English reading competence between experimental and control group? Second, what difference is there in the English reading competence according to English proficiency? Third, what are the effects of interest and satisfaction through NIE? The subject of a sample was 34 experimental group and 36 control group, total 70 eighth graders in Kwangju. The experimental group had been taught through NIE for 10 weeks. Grammar Translation Method was applied while teaching English to the control group. The data analyzing method was t-test through the statistics program SPSS12.0. Based on the result of this study, NIE approach was effective in improving the students' reading competence. Most of the students who were taught reading by NIE responded that they had more interest and satisfaction in the reading lesson.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.5
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• pp.453-467
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• 2000

The aim of this research is to collect and characterize fine particles (FPM:$\leq$2.5${\mu}{\textrm}{m}$) and coarse particles (CPM: 2.5~10${\mu}{\textrm}{m}$) using a low volume air sampler provided by the IAEA, at urban (Taejon) and rural area(Wonju) for a period of about two years(April 1996 to May 1998) and to promote a use of nuclear analytical techniques for air pollution studies. For the collection of airborne particulate matter (PM(sub)10), the Gent stacked filter unit sampler and polycarbonate membrane filters were employed. The concentration of trace elements in collected APM samples were determined byu instrumental Neutron Activation Analysis. For validation of the analytical data, internal quality control were implemented by using both the comparison of the analytical results of standard reference materials(NIST SRM 1648) and interlaboratory comparison for proficiency test (NAT-3). The standard uncertainty was less than 15% and Z-score of two samples were within $\pm$1. The monitoring of (PM(sub)10) mass concentration and elemental concentrations were carried out weekly. The average mass concentration of (PM(sub)10) in urban and rural areas were 59.2$\pm$36.5$\mu\textrm{g}$/㎥ and 41.4$\pm$23.7$\mu\textrm{g}$/㎥, respectively. To investigate the emission source, the enrichment factors were calculated for the fine and coarse particle fractions at two sites, respectively and these values were classified for anthropogenic and soil origin elements.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.203-213
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• 2017

This study is to find the effectiveness of the invitational training in healthcare field of developing countries through grasping the change of the national image of Korea. To this end, we collected data on the satisfaction on the invitational training from 192 participants of short-term and long-term training programs conducted by the Korea Foundation for International Healthcare(KOFIH). T-test, ANOVA analysis and hierarchical regression analysis were conducted. The results of the analysis are as follows. First, the national image was enhanced after the invitational training. Second, satisfaction on contents of the training programs had a significant positive (+) effect on the national image. Third, English proficiency and nationality influenced national image significantly. According to this study, it was confirmed that the invitational training in healthcare was influential for enhancing the national image. To enhance the effectiveness of the invitational training, it is necessary to study the contents of the training program and the process of selecting the participants.