• Journal of the Korean School Mathematics Society
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• v.10 no.1
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• pp.113-127
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• 2007

This study explored the possibility of building a statistical model predicting difficulty of mathematics test items through the analysis of nation-wide scholastic ability test results for the past 5 years. Multiple linear regression analysis was conducted in predicting difficulty of mathematics test items. We adopted three major areas for independent variables: the content area, the behavior area, and the test item format area, each of which was categorized into more detailed sub-areas. For the dependent variable, the proportion of correct answer was used to represent the item difficulty. Statistically significant independent variables were included in the regression model based on the stepwise selection method. Several important factors affecting difficulty of mathematics test items for each area were identified. R-squares for the final regression model were fairly high, implying that the regression equation can be used to predict difficulty of test items at an acceptable level. Lastly, the regression model was cross-validated using independently collected data. We believe that this study will provide basic but very critical information for predicting the proportion of correct answer by showing the factors that should be considered for developing mathematics test items for the college entrance examination or high school classroom test.

• Journal of Educational Research in Mathematics
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• v.14 no.1
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• pp.71-88
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• 2004

The purpose of this study was to examine particular variables that play a significant role in the difficulty of math test items in College Scholastic Ability Test (CSAT). The study also aimed to develop a model of measuring the item difficulty. Variables correlated to item difficulty were drawn from the review of the related literature and the analysis of the content and difficulty of the past test items of CSAT. The first instrument was designed by using the correlated variables. According to the results of correlation analysis, the second instrument was made by deleting the variables which showed relatively low correlation with item difficulty and by refining some variables. Several models were proposed by using the revised instrument. The comparison of the R square and cross validity of each model reveals that integrated regression model was the most stable and accurate among the proposed models. The study also showed that statistically significant predictors were choice format, content domain, behavior domain, and the degree of item familiarity in the order of proportion of variance accounted by the predictors. Despite the limited scope of the present research, it can be suggested that its findings provide useful insights into predicting math test item difficulty.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.594-603
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• 2021

This study explored the moderating effects of task difficulty for flow, learning motivation, and interesting in distant PBL classes of pre-service teachers. For this, the research model was constructed by analyzing previous studies. The research model verification was conducted by 105 students of taking courses in the curriculum. The distant PBL used a real-time video conference system. Cooperative activities were carried out in real time. After the end of the distant PBL activity, the level of learning motivation, interesting, flow, and task difficulty perception were measured. The collected data were analyzed using a test of the structural model invariance across the groups using a structural equation model. This analysis verifies the difference in path coefficients between measurement models. The control effect of task difficulty was verified through the difference in path coefficient. As a result, it was verified that interesting mediates the influence of learning motivation on flow. And the moderating effect of the perceived task difficulty appeared on the path from learning motivation to interesting.

• Proceedings of KOSOMES biannual meeting
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• 2004.11a
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• pp.57-62
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• 2004

A mariner feels the ship-handling difficulty when the vessel onboard passes through breakwater. Until now, there is no a layout design of breakwater to take into account the ship-handling difficulty for the mariner. 11Us paper reproduced this situation which ship-handling is difficult by using marine traffic flow simulation, and it applied to Environmental Stress Model as the assessment model which is a quantitative model for evaluating the difficulty of ship-handling arising from restriction in maneuvering water areas and arising from traffic congestion The results are as follows. (1) The layout change of breakwater has little influence for reduction of ship-handling difficulty in the areas of vessel traffic volume. (2) In the situation of same breakwater width, difference of ship speed has an effect on decrease of ship-handling difficulty. (3) Expansion of breakwater width decreases ship-handling difficulty quantitatively.

• The Journal of the Korean dental association
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• v.51 no.9
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• pp.511-517
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• 2013

To assess the association between oral health and general health, this study examined the relationship between chewing difficulty and twelve chronic health conditions such as hypertension, hyperlipidemia, diabetes, cerebro- and cardiovascular disease, musculoskeletal disease, respiratory disease, eye/nose/throat disease, stomach/intestinal ulcer, renal dysfunction, thyroid disease, depression, and cancer in Korea. The study population was 3,066 elders aged 65 years old and more from the fourth Korean National Health and Nutrition Examination Survey. Chewing difficulty was measured on a 5-point Likert scale. Chronic conditions were assessed by self-reported questionnaire. Confounders were age, gender, education, income, smoking, drinking, and obesity. Chi-square test, general linear model, and multiple logistic regression model were done with complex sampling design. Musculoskeletal disease (adjusted odds ratio=1.33), respiratory disease (adjusted odds ratio=1.52), and cancer (adjusted odds ratio=1.58) were independently associated with chewing difficulty. Multiple chronic conditions with more than 4 chronic disease showed significant association with chewing difficulty (adjusted odds ratio=1.37).

• Research in Mathematical Education
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• v.10 no.1 s.25
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• pp.13-31
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• 2006

This paper uses a composite difficulties model developed by the author (Bao 2002a, 2002b) to compare the characteristics of two sample mathematics tests in China and UK. The initial findings were described through five difficulty factors on several difficulty levels. According the initial findings, the author then tries to analyze the styles of mathematics problem-solving and the curriculum backgrounds in these two countries.

• Journal of Navigation and Port Research
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• v.29 no.3 s.99
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• pp.175-180
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• 2005

A mariner feels the shiphandling difficulty when the vessel onboard passes through breakwater. Until now, the shiphandling difficulty of the mariner has not been taken into account in the layout of a pair of breakwater. This paper reproduced such a situation that shiphandling is difficult enough by using marine traffic flow simulation, it is assessed by using ES Model which is a quantitative model for evaluating the difficulty of shiphandling arising from maneuvering a ship in the restricted or congested waters. The results are as follows. (1) The change in the layout of a pair of breakwaters has little influence on the shiphandling difficulty. (2) If the width between breakwaters is the same. the speed of a ship affects the shiphandling difficulty. (3) The increase of the width decreases the shiphandling difficulty.

• Journal of the Korean Society of Marine Environment & Safety
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• v.9 no.1
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• pp.57-63
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• 2003

Marine traffic system is composed of ship, ship's operators and traffic environment The navigation channel is a part of traffic environment and the design of channel is a crucial factor for safe navigation This paper aims to evaluate ship-handling difficulty in straight and bend channels with an Environmental Stress model(ES-model). The ES-model is used to evaluate ship handling difficulty quantitatively on the basis of the ship operator's subjective judgement for safety in navigation The calculation of ES value was made on the basis of three factors such as channel width, ship's length and speed in straight and channels for safe navigation. The interrelation between factors was analyzed and reasonable design standards of channel width, ship's length and speed were proposed for safe navigation of ship in bend channel.

• Korean Security Journal
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• no.42
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• pp.37-57
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• 2015

The purpose of this study was to verify goodness-of-fit by Many-Facets Rasch model for applying martial arts training satisfaction scale to security martial arts trainees. To achieve the purpose, 255 security martial arts trainees' data were used in the analysis. In addition, In addition, the AMOS 20.0 program was used for unidimensionality validation, and take advantage of the Facets 3.61 program for goodness-of-fit verification. Specific results are as follows: First, Unidimensionali test results showed that model fit, reliability and standardized ${\beta}$ value are suitable. Second, the analysis results of goodness-of-fit, items 1, 2, 3 are inadequate, 4, 8, 11, 13, 14 items once found to be over-fit questions. Also, analysis of item difficulty, item 1 has highest difficulty and item 7 was lowest. Third, According Facets item difficulty and response difference verification result, female group exhibited a high level of item difficulty compared to the male group, goodness-of-fit was all accurate. As the result of item difficulty and response difference verification based on Martial arts training flow, there is no response difference according to the training experience. On the other hands, less than 4 years to 5 years and less than 5 years to 6 years trainees represented over-fit features. Results of item difficulty and response difference verification by grade level, first grade was the most highly recognized the item difficulty and fourth grade was also recognized the lowest of item difficulty Fourth, the response category analysis showed that the six points response categories are not appreciate.

• Journal of the Korean Operations Research and Management Science Society
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• v.42 no.2
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• pp.35-48
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• 2017

As the technology convergence paradigm emerges, the need for "CIA techniques" to analyze the mutual effects of technology is increasing. However, since the CIA input parameter estimation is difficult, the present study suggests a "CIA input parameter setting model" to alleviate the difficulty of CIA input parameter estimation. This paper is focused on the difference of measurement difficulty by each scale which expert's estimation behavior was defined as measurement activity quantifying the judgment of future technology. Therefore, this model is designed to estimate the input variable as a sequence or isometric scale that is relatively easy to measure, and then converts it into a probability value. The input parameter setting model of the CIA technique consists of three sub-models : 'probability value derivation model', 'influence estimation model', and 'impact value calculation model', in order to develop a series of models the Thurstone V model, Regression Analysis, etc has been used.