• Journal of Educational Research in Mathematics
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• v.21 no.4
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• pp.327-344
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• 2011

This study is the first step for us toward improving high school students' capability of statistical inferences, such as obtaining and interpreting the confidence interval on the population mean that is currently learned in high school. We suggest 5 underlying concepts of 'discretion of contingency and inevitability', 'discretion of induction and deduction', 'likelihood principle', 'variability of a statistic' and 'statistical model', those are necessary to appreciate statistical inferences as a reliable arguing tools in spite of its occasional erroneous conclusions. We assume those 5 concepts above are to be gradually developing in their school periods and Korean mathematics textbooks of grades 1-12 were analyzed. Followings were found. For the right choice of solving methodology of the given problem, no elementary textbook but a few high school textbooks describe its difference between the contingent circumstance and the inevitable one. Formal definitions of population and sample are not introduced until high school grades, so that the developments of critical thoughts on the reliability of inductive reasoning could not be observed. On the contrary of it, strong emphasis lies on the calculation stuff of the sample data without any inference on the population prospective based upon the sample. Instead of the representative properties of a random sample, more emphasis lies on how to get a random sample. As a result of it, the fact that 'the random variability of the value of a statistic which is calculated from the sample ought to be inherited from the randomness of the sample' could neither be noticed nor be explained as well. No comparative descriptions on the statistical inferences against the mathematical(deductive) reasoning were found. Few explanations on the likelihood principle and its probabilistic applications in accordance with students' cognitive developmental growth were found. It was hard to find the explanation of a random variability of statistics and on the existence of its sampling distribution. It is worthwhile to explain it because, nevertheless obtaining the sampling distribution of a particular statistic, like a sample mean, is a very difficult job, mere noticing its existence may cause a drastic change of understanding in a statistical inference.

• Journal of Food Hygiene and Safety
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• v.25 no.1
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• pp.16-23
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• 2010

Although concerns about Arsenic (As) contamination in agricultural foods have currently increased, there in on adequate international risk management standards for As particularly on agricultural commodities and processed agricultural products. This scenario holds true also in Korea. Australia, and New Zealand has determined the As maximum level (ML) but only on cereals grains which is based on total As contents. ln addition, Japan has regulated the ML based on trivalent As contents in agricultural commodities, which do not have legal restrictions. On the other hand, China has developed a systemic risk management to restrict the As contamination above MLs in agricultural commodities and processed agricultural products based on inorganic and total As contents. The establishment of an adequate analytical method for As specification in agricultural foods is essential to determine the acceptable level of As in agricultural food. Probabilistic approach may remove some uncertainties in calculating human risk assessment from As. It should be reviewed in terms of maximum levels to set the best scenario based on a realiability and availability to achieve effective As management on agricultural foods in Korea.

• Korean Journal of Forensic Psychology
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• v.13 no.1
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• pp.1-22
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• 2022

This study tested the effect of the verdict category of lay-participation trial in Korea on the legal decision of layperson and the role of representation of 'innocent' in the process. Representation of 'innocent' refers to a psychological threshold for deciding someone's innocence (no fault or sin) in a general sense. The functions as a threshold for a legal decision of 'beyond a reasonable doubt (BRD)' and the individual threshold (IT), regarded as a standard for judgment of guilt established by law and an estimate of an individual's threshold, respectively, were compared. This study used a 2×2 complete factorial design in which the verdict category (guilty/innocent vs. guilty/not guilty) and the defendant's likelihood of guilt (low vs. high) were manipulated. Data from 137 lay-people who voluntarily participated in the online experiment was analyzed. The experiment's procedure was in the order of measuring 'representation of innocent' and the likelihood of guilt of an accused, presenting one of four trial vignettes, and obtaining legal decisions (verdict confidence and estimation of the likelihood of guilt for the defendant). As a result, it was found that the verdict category did not significantly affect the legal decision of layperson. However, the guilty verdict rate of the 'guilty/innocent' condition tended to be higher than those of the 'guilty/not guilty' condition. The layperson's representation of 'innocent' and the verdict category had an interaction effect on the difference between BRD and IT (threshold change) at the significance level of .1. In the 'guilty/innocent' condition, the threshold change varying with layperson's representation of 'innocent' was larger than in the 'guilty/not guilty' condition. In comparing the function of BRD and IT, IT significantly predicted the lay person's legal decision at the significance level of .1 by interacting with the likelihood of guilt for the defendant. Therefore, it could be said that IT was a better threshold estimator than BRD. The implication of this study is that it provided experimental evidence for the effect of the verdict category of lay-participation trial in Korea, which is a problem often raised among lawyers, and suggested logical reasoning and empirical grounds for the psychological mechanism of the possible effect.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.237-245
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• 2020

The development of information and communication technology (ICT) provides many opportunities for businesses to increase productivity, to have better relationships with customers and suppliers, and to develop new products more efficiently and effectively. However, recently, there have been claims that ICT development in a country would increase income inequality of the country. In this debate, we examine the impact of ICT development on the income inequality at the country level. Data of 28 OECD countries were used for our study. According to results of the analysis, a country with a higher level of ICT development is likely to have a lower the level of income inequality. There have been many concerns that development of ICTs may result in a higher level of income inequality mainly because wealthy companies or individuals can more affordable to utilize advanced ICT and ICTs have replaced labor. However, there has been no such identified impact, at least in recent OECD countries. Rather, we can expect ICT development to play a role in lowering income inequality of a country.

• Korean journal of applied entomology
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• v.29 no.3
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• pp.209-215
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• 1990

Some preliminary studies were conducted to find out whether the levee-burning could justifiable for the suppression of insect pests, particularly the smaller brown planthopper (Laodelphax striatellus F.). Density surveys on pests and their enemies (mostly spiders) were carried out upto the mid May at an experimental paddy field located in Suwon after of it's levee $(72\times1m)$ was burned on Feb. 20, 1987. Results were discussed in relation to density recovering of both pests and their possible enemies (spiders) and summarized as below. Not a single individual of any pest or enemy was found from the levee upto sometime after the levee-burning. Grasses started to grow more vigorously in burned ares than in unburned upto about 60 days after the burning. And densities of both pest and enemies grew higher in burned areas than in unburned from about 75 days after the burning (in Early may). It is suspected that all individuals of pests and enemies fond from the burned areas could have immigrated from the surrounding areas. If levee-burning was carried out in much wider areas, much longer time would be needed to recover the density of both pests and enemies to the center region of the burning. Wingless spiders would require even longer time than winged pest species to re-establish in the center region of the widely burned field. Pirata subpiraticus, the most abundant spider species in Korean paddy fields, starts to move about and searches for food at above $9^{\circ}C$ which is somewhat lower than the critical temperature for the pest species. Thus P. subpiraticus would require more food than other pest species early in the spring, and therefore, it would have lower probability to survive than pest species particularly in burned areas. Experiments for pest suppression with levee-burning would better be carried on in much wider areas, and its justification seems to be discussed after man other disciplines related to both pests and their natural enemies were throughly studied together with their density surveys. However, according to the present point of vie, the opinion that levee-burning is helpful for controlling pests which over winter on levee areas could not be justifiable.

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.2
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• pp.321-350
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• 2013

The purpose of this study to analysis of problem posing in 5th and 6th grade mathematics textbooks and to comprehend errors in the problem posing activity of 6th graders in elementary school. For solving the research problems, problem posing contents were extracted from mathematics textbooks and practice books for the 5th and 6th grade of elementary school in the 2007 revised national curriculum, and they were analyzed, according to each grade, domain and type. Based on the analysis results, 10 problem posing questions which were extracted and developed, were modified and supplemented through a pre-examination, and a questionnaire that problem posing questions are evenly distributed, according to each grade, domain and type, was produced. This examination was conducted with 129 6th graders, and types of error in problem posing were analyzed using collected data. The implications from the research results are as follows. First, it was found that there was a big numerical difference of problem posing questions in the 5th and 6th grade, and problem posing questions weren't properly suggested in even some domains and types, because the serious concentration in each grade, type and domain. Therefore, textbooks to be developed in the future would need to suggest more various and systematic of problem posing teaching learning activity for each domain and type. Second, the 'error resulting from the lack of information' occurred the most in the problems that 6th graders posed, followed by the 'error in the understanding of problems', 'technical errors', 'logical errors' and 'others'. This implies that a majority of students missed conditions necessary for problem solving, because they have been used to finding answers to given questions only. For such reason, there should be an environment in which students can pose problems by themselves, breaking from the way of learning to only solve given problems.