• Journal of Intelligence and Information Systems
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• v.25 no.1
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• pp.127-137
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• 2019

Recidivism prediction has been a subject of constant research by experts since the early 1970s. But it has become more important as committed crimes by recidivist steadily increase. Especially, in the 1990s, after the US and Canada adopted the 'Recidivism Risk Assessment Report' as a decisive criterion during trial and parole screening, research on recidivism prediction became more active. And in the same period, empirical studies on 'Recidivism Factors' were started even at Korea. Even though most recidivism prediction studies have so far focused on factors of recidivism or the accuracy of recidivism prediction, it is important to minimize the prediction misclassification cost, because recidivism prediction has an asymmetric error cost structure. In general, the cost of misrecognizing people who do not cause recidivism to cause recidivism is lower than the cost of incorrectly classifying people who would cause recidivism. Because the former increases only the additional monitoring costs, while the latter increases the amount of social, and economic costs. Therefore, in this paper, we propose an XGBoost(eXtream Gradient Boosting; XGB) based recidivism prediction model considering asymmetric error cost. In the first step of the model, XGB, being recognized as high performance ensemble method in the field of data mining, was applied. And the results of XGB were compared with various prediction models such as LOGIT(logistic regression analysis), DT(decision trees), ANN(artificial neural networks), and SVM(support vector machines). In the next step, the threshold is optimized to minimize the total misclassification cost, which is the weighted average of FNE(False Negative Error) and FPE(False Positive Error). To verify the usefulness of the model, the model was applied to a real recidivism prediction dataset. As a result, it was confirmed that the XGB model not only showed better prediction accuracy than other prediction models but also reduced the cost of misclassification most effectively.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.13 no.1
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• pp.93-103
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• 2002

The aim of this study is to examine the diagnostic profiles and related clinical variables of children with attention and hyperactivity in psychiatric outpatient clinic. Seventy one children with age range of 5 to 14 were diagnosed by DSM-IV, and assessment battery including KEDI-WISC, KPI-C, ADS(ADHD Diagnostic System) were completed. The subjects were divided into 3 diagnostic groups：ADHD only(n=17), ADHD comorbid(n=27), Other diagnosis(n=27). The results were as follows：In ADHD comorbid group, tic disorder, developmental language disorder, borderline intellectual function, oppositional defiant/conduct disorder, and learning disorder were combined in descending order. Other diagnosis group consisted of tic disorder, borderline intellectual function, depression/anxiety, oppositional defiant/conduct disorder, and others. There were significant differences in IQ, PIQ, and VIQ among the three groups, and ADHD only group showed higher scores of IQ and VIQ than ADHD comorbid group. On the KPI-C, there were no significant differences in all subscales among the three groups. On the visual ADS, omission error and sensitivity showed significant differences among the three groups, and ADHD comorbid group represented higher omission error and lower sensitivity than other diagnostic group. The findings indicated that the inattention and hyperactivity symptoms could be diagnosed into diverse psychiatric disorders in child psychiatry, and ADHD children with comorbidity will show more problems in academic performance and school adjustment.

• Journal of Korea Society of Industrial Information Systems
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• v.9 no.4
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• pp.56-67
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• 2004

This study analyzes human error of workers performing simple repetitive tasks, and in order to prepare preventative measures, 486 people were used as subjects. The results of the study are like the following. First, the biggest cause of human error showed to be the worker himself in $77.8\%$ of the cases, machinery showed to be the cause in $16.3\%$ of the cases and management showed to be the cause in $6.0\%$ of the cases. The results show that most of the human error occurred due to the worker performing simple repetitive tasks and the human errors showed to be caused more by bad ergonomics and long hours rather than by problems with machinery. In addition, the area with the highest rate of human error showed to be the Human Information Processing System with Task Input Error being the highest with $46.9\%$, followed by Judgement and Memory Error with $36.4\%$ and Recognition Verification Error with $16.7\%$. Although fully automated tasks may reduce the rate of human error we must focus on lowering the rate of problems arising from spontaneous errors caused by workers performing simple repetitive tasks by continuously renewing plans and budgets in order to standardize tasks by incorporating cyclic positioning according to experience and positional exchange and by inspecting the workplace to increase efficiency of the workers.

• The Journal of the Korea Contents Association
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• v.14 no.2
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• pp.527-534
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• 2014

Motivated by the fact that English grapheme is realized as 5 different English vowels [ɑ, eɪ, æ, ɔ, ə], the present study aims to investigate how Korean students perceive and produce English grapheme in words. To this end, 31 university students participated in the perception and production tests on 28 English words containing grapheme . Overall, the participants performed better on production than perception both in the pretest and posttest. Also, the accuracy of perception and production was improved in the posttest. While the accuracy rates of [ɑ] and [eɪ] were among highest in the perception test, those of [ɑ] and [ɔ] were in the production test. By contrast, the accuracy of unstressed [ə] was worst both in perception and production. As for the training effect, [eɪ] and [æ] showed significant improvement both in perception and production. In addition, the perception and the production of [ɔ] were improved at the .051-4 significance level. However, the accuracies of [ɑ] improved significantly neither in perception nor in production. In the case of [ə], the production ability was improved significantly whereas the perception ability was not. The prominent error patterns of were the replacement of the target vowels with [æ], [ɑ], or [eɪ]. The influence of orthography was attested through the persistent occurrence of [ɑ]. Finally, pedagogical implications were discussed.

• Korean Journal of Cognitive Science
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• v.22 no.1
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• pp.57-78
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• 2011

Paraphrasing is the act of writing a text using other words without altering the meaning. Paraphrases can be used in many fields of natural language processing. In particular, paraphrases can be incorporated in machine translation in order to improve the coverage and the quality of translation. Recently, the approaches on paraphrase extraction utilize bilingual parallel corpora, which consist of aligned sentence pairs. In these approaches, paraphrases are identified, from the word alignment result, by pivot phrases which are the phrases in one language to which two or more phrases are connected in the other language. However, the word alignment is itself a very difficult task, so there can be many alignment errors. Moreover, the alignment errors can lead to the problem of selecting incorrect pivot phrases. In this study, we propose a method in paraphrase extraction that discriminates good pivot phrases from bad pivot phrases. Each pivot phrase is weighted according to its reliability, which is scored by considering the lexical and part-of-speech information. The experimental result shows that the proposed method achieves higher precision and recall of the paraphrase extraction than the baseline. Also, we show that the extracted paraphrases can increase the coverage of the Korean-English machine translation.

• Journal of Korean Home Economics Education Association
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• v.30 no.3
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• pp.151-173
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• 2018

The purposes of this study was to identify the magnitude and direction of the effects of Practical Reasoning Instruction (PRI) on students' achievements in Home Economics classes using the meta-analysis method and to examine whether the effects of PRI vary across publication status, study design, year of the studies, school level, gender of students, type of students' achievements, content area, location where the interventions of PRI were conducted, and duration. Thirty-four primary studies with 44 effect sizes were analyzed with calculation method of Becker(1988). A funnel plot method result revealed no publication bias. The results of this meta-analysis are as follows. First, PRI was more effective than traditional instruction on students' achievements. A summary statistic was 0.60 with a standard error of .074, which means that an increase of about two-third of a standard deviation beyond what would be expected from traditional instruction was gained from PRI intervention. Second, categorical and regression analyses were employed to find the sources of variance and moderators that predict the effects of PRI. The moderator analyses revealed no statistically significant effects of publication status, study design, school level, gender of students, type of students' achievements, and duration. Content area, location where the interventions of PRI were revealed to be moderators. It was concluded that PRI was effective in improving students' achievements regardless of publication status, study design, year of the studies, school level, gender of students, type of student achievement, and duration.

• Journal of The Korean Association For Science Education
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• v.18 no.1
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• pp.1-17
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• 1998

What does mean the statement that scientific reasoning is logical? In this study, we clarify the logical structure of the scientific explanation, prediction and the process of hypothesis testing. To simplify and identify the structure of scientific explanations and prediction more clearly, we used syllogism and presented various concrete examples. Especially, we showed that the logical structure of scientific explanation was well reflected in dynamics. Based on this analysis, it can be said that the deficit of students' understanding of dynamics is because that many scientific activities are focused on prediction rather than explanation. To explain the process of hypothesis testing, we reinterpreted the Wason's selection task as two stages: the process of prediction of experimental phenomena based on the presented hypothesis, and the process of the hypothesis testing based on the predicted experimental phenomena. And we suggested the reason of the logical fallacy of 'affirming the consequent' in science was because that many scientific relationships between the variables is one-to-one relationship, and compared this suggestion with the Lawon's multiple hypothesis theory. To check out the effect of content on the deductive reasoning, we reviewed some researches about psychology and psychology of science. And to understand the role of deductive reasoning in student's scientific activities, we reviewed researches about the analysis of students' responses in the task of conceptual change or evaluation of evidence and so on.

• Journal of Preventive Medicine and Public Health
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• v.34 no.2
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• pp.103-108
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• 2001

Recently, numerous studies have focused on the health effects of ambient particulate pollutants. Compared to earlier studios that focused on severe air pollution episodes, recent studies are more relevant to understanding the health effects of air pollution at levels common to contemporary cities. We reviewed recent epidemiologic studies that evaluated health effects of particulate air pollution and concluded that respirable particulate air pollution is an important contributing factor to acute mortality and morbidity. We observed increased respiratory and cardiovascular deaths, increased hospital admissions and visits, and decreased lung function. We also observed increased mortality and morbidity in a Korean population. Theses health effects were observed at levels below the current Ambient Air Quality Standard for particulate air pollution.

• Communications of Mathematical Education
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• v.36 no.3
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• pp.335-353
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• 2022

The purpose of this study is to identify the characteristics and types of errors in the conceptual image of Korean language learners according to the types of terms in mathematics that are the basis for solving mathematical word problems, and to prepare basic data for effective teaching and learning methods in solving the word problems of Korean language learners. To do this, a case study was conducted targeting four Korean language learners to analyze the specific conceptual images of terms registered in curriculum and terms that were not registered in curriculum but used in textbooks. As a result of this study, first, it is necessary to guide Korean language learners by using sufficient visualization material so that they can form appropriate conceptual definitions for terms in school mathematics. Second, it is necessary to understand the specific relationship between the language used in the home of Korean language learners and the conceptual image of terms in school mathematics. Third, it is necessary to pay attention to the passive term, which has difficulty in understanding the meaning rather than the active term. Fourth, even for Korean language learners who do not have difficulties in daily communication, it is necessary to instruct them on everyday language that are not registered in the curriculum but used in math textbooks. Fifth, terms in school mathematics should be taught in consideration of the types of errors that reflect the linguistic characteristics of Korean language learners shown in the explanation of terms. This recognition is expected to be helpful in teaching word problem solving for Korean language learners with different linguistic backgrounds.

• Journal of Satellite, Information and Communications
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• v.9 no.3
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• pp.33-40
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• 2014

One of the most important requirements for the Ethernet-based automobile is the reliability. In order to achieve this goal, we propose using the High-availability Seamless Redundancy (HSR) protocol (IEC 62439-3 clause 5) in these networks. The HSR protocol provides duplicated frame copies for each sent frame, which means that the destination node will receive at least one copy in case the second copy is lost due to a failure. In other words, there will be no network stoppage even if failure occurs. Moreover, the destination node will receive at least one frame copy with zero-recovery time (seamless) and it will not need to wait to receive the other copy if the first one is lost, which occurs it in the Ethernet standard, as a result of reconfiguration of the network paths. However, the main drawback of the HSR protocol is the unnecessary redundant traffic that is caused by the duplicated frames. Several solutions, including QR, VRing, RURT, and DVP, have already been proposed to improve the traffic performance of the HSR protocol. In this paper, we propose three automobile network topologies. each of which has pros and cons depending on the automobile requirements. Then we applied the HSR protocol with and without the QR and VRing approaches to each scenario. The comparison among these topologies depend on the traffic performance result for each of them. The QR and VRing approaches give a better traffic reduction percentage, ranging from 48% to 75% compared to the standard HSR protocol. Therefore they could limit the redundant traffic in automobile networks when the HSR protocol is used instead of the Ethernet network, which does not provide any seamless recovery if a failure occurs.