• Journal of the Korean School Mathematics Society
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• v.19 no.4
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• pp.357-371
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• 2016

The purpose of this study was to decide the task space and Rating Scheme of task difficulty in complicated mathematical modelling situations. One of main objective was also to conform the validation of Rating Scheme to determine the degree of difficulty by comparing the student performance with the statement of the theoretical model. In spring 2014, the experimental setting was in Modelling Course for 38 in-service teachers in mathematics education. In conclusions, we developed the Model of Task Space based on their solution paths in mathematical modelling tasks and Rating Scheme for task difficulty. The Validity of Rating Scheme to determine the degree of task difficulty based on comparing the student performance gave us the meaningful results. Within a modelling task the student performance verifies the degree of difficulty in terms of scoring higher using solution approaches determined as easier and vice versa. Another finding was some relations among three research topics, that is, degree of task difficulty on rating scheme, levels of students performance and numbers of specific heuristic. Those three topics showed the impressive consistence pattern.

• Preventive Nutrition and Food Science
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• v.21 no.1
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• pp.73-77
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• 2016

Flow and dynamic rheological properties of thickened waters prepared with commercial food thickeners were investigated at different pH levels (3, 4, 5, 6, and 7). The commercial xanthan gum (XG)-based thickener (thickener A) and starch-based thickener (thickener B), which have been commonly used in a domestic hospital and nursing home for patients with swallowing difficulty (dysphagia) in Korea, were selected in this study. Thickened samples with both thickeners at different pH levels showed high shear-thinning flow behaviors (n=0.08~0.22). Thickened samples at pH 3 showed higher n values and lower consistency index (K) values when compared to those at other pH levels. The K values of thickener A increased with an increase in pH level, while the n values decreased, showing that the flow properties greatly depended on pH. There were no noticeable changes in the K values of thickener B between pH 4 and 7. At pH 3, the thickened water with thickener A showed a higher storage modulus (G') value, while that with thickener B showed a lower G'. These rheological parameters exhibited differences in rheological behaviors between XG-based and starch-based thickeners, indicating that the rheological properties of thickened waters appear to be greatly influenced by the acidic condition and the type of food thickener. Appropriately selecting a commercial food thickener seems to be greatly important for the preparation of thickened acidic fluids with desirable rheological properties for safe swallowing.

• Journal of Korea Game Society
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• v.19 no.3
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• pp.25-32
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• 2019

This paper proposes a automatic generation method of Match-3 game levels through genetic algorithm. It takes a lot of time and effort if persons have to control the level in the game. In this paper, the genetic algorithm is applied to create an appropriate block combination. We create block combination from integer DNA. Fitness is high if success probability played by computer is closer to given probability. Experiments have shown that computer-determined levels of difficulty have a significant impact on the results of game played persons.

• The Journal of the Korean dental association
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• v.58 no.11
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• pp.670-682
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• 2020

This research examined the difference in cognitive load and the virtual presence depending on auditory feedback and task difficulty in haptic-based dental simulation. In the field of dental education, practice-centered training using handpiece has been crucial because a practitioner's psychomotor experience has a significant impact on the mastery of treatment skills. For the novice, it is necessary to reduce errors in dental treatment to enhancing skill acquisition in the haptic practice. In the training process, the force-feedback is crucial to elaborate subtle movement to guide what to do and how it should be hard or soft. However, It is not easy to add force-feedback to generate kinetic experience training. As an alternative method, we examined that auditory feedback can help learners' skill training. In this study, we analyzed how the presence/absence of auditory feedback at the different levels of task difficulty impacts learners' psychological demand and virtual presence in the virtual reality simulation. For this study, 29 dental college students participated in a dental simulation. The participants were grouped into two conditions that are with and without auditory feedback. Additionally, two consecutive tooth preparation tasks with different levels of difficulty were used in the simulation. The auditory feedback condition gives alarms to a learner when he treats a non-targeted tooth with a virtual handpiece. The user's cognitive load and virtual presence were measured to examine the effects of auditory feedback. The results revealed that the main effect was found in cognitive loads. Also, a significant interaction effect was shown in the virtual presence. We discussed the effective design methods for the virtual reality-based dental simulation through the result of this study.

• School Mathematics
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• v.9 no.2
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• pp.223-240
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• 2007

The purpose of this study was to investigate the degree to which the middle school mathematics curriculum matched the item difficulty levels of representative mathematics items. The items used in this study were developed for the National Assessment of Educational Achievement. Ranks for difficulty values of the 60 multiple-choice item were calculated via both Classical Test Theory and Item Response Theory and correlated with the rank order of the mathematics content and cognitive domains sequence. There are six content domains; number and operation, algebra, measurement, figure, pattern and function, and probability and statistics. The cognitive domains include computation, understanding, reasoning and problem-solving. Results suggest a congruence between cognitive domain's sequence and item difficulty levels of items based on that sequence. This finding indicates that the linear or hierarchical assumptions concerning the sequence appears to be reasonable. The characteristics of items that were exceptions to this trend were addressed.

• English Language & Literature Teaching
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• v.15 no.4
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• pp.75-94
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• 2009

This study was designed to assess demotivation factors and compare the factor between two secondary school student groups. It furthermore examined how the factors related to students' L2 proficiency. A 31-item questionnaire was completed by 407 junior (JH) and senior high school (SH) students. Five factors were extracted through the principal axis factoring: Teachers' competence and teaching styles, Dissatisfaction with English classes and grading system, Difficulty of learning English, Lack of motivation and interest in learning English, and Inadequate learning contents. Although both JH and SH students did not perceive their English teacher as a strong attribution of demotivation, Difficulty of learning English and Dissatisfaction with English classes and grading system were the two strongest demotivating factors. When compared the overall mean scores of each factor between JH and SH groups, significant differences were found in all factors except Factor 4, with SH students reporting stronger demotivation. JH students attributed their demotivation to Difficulty of learning English, while SH students attributed that to Dissatisfaction with English classes and grading system. Both groups tended to attribute their demotivation to external forces. The study also showed that several demotivation factors related negatively to L2 proficiency.

• Korean Journal of Cognitive Science
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• v.34 no.1
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• pp.21-38
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• 2023

The present study was designed to investigate the effect of the difficulty level of retrieval practice and the association strength of categories and stimuli within categories on memory inhibition. Most of the studies have investigated whether inhibition was occurred by manipulating the degree of association strength, emotion value or physical characteristics of non-retrieval practice words within the retrieval practice category. Therefore, it was necessary to study how inhibition occurs according to the degree of difficulty of retrieval stimuli during retrieval practice. The difficulty of retrieval was manipulated into three levels: difficult condition, normal condition, and easy condition through the degree of presentation of consonants and vowels of words during retrieval learning. Additionally, the strength of association between categories and words within categories was manipulated. In previous studies, retrieval-induced forgetting occurred under conditions where the association strength between categories and words within the categories was strong. On the other hand, retrieval-induced forgetting did not occur under conditions where the association strength between categories and words within the categories was weak. The present study, if the inhibition process differs according to the difficulty of retrieval, the possibility of different results from previous studies was explored according to the difference in the strength of association with the category. As a result of the study, in the condition of strong association strength, retrieval-induced forgetting was observed under normal and difficult retrieval difficulty conditions. Whereas retrieval-induced forgetting was not observed under conditions of easy retrieval difficulty condition. In the condition of weak association strength, retrieval-induced forgetting tended to occur under difficult retrieval difficulty conditions. Whereas retrieval-induced forgetting was not observed under conditions of normal and easy retrieval difficulty condition. These results suggest that memory inhibition may appear differently depending on the difficulty of retrieval.

• Journal of the Korea Convergence Society
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• v.11 no.3
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• pp.67-75
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• 2020

The 'level of difficulty' is one of the major factors for learners when selecting learning contents. However, the criteria for the difficulty level is mostly defined by the contents providers. This approach does not support the personalized education which should consider the abilities and environments of various learners. In this research, the knowledge of the learners and contents were formalized and generalized to resolve the issue, and object models, including a metric for personalized difficulty level, were designed in order to be applied for experiments. And then, based on 100 contents for music education and 20 learners, we performed simulations with an implemented tool to validate our approach. The experimental results showed that our method can calculate the personalized difficulty levels considering the similarities between the knowledges from the learning state and the contents. Our approach can be effectively applied to the on-line learning management system which contains easy access to the learning state and contents data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.240-247
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• 2021

The purpose of this study was to identify the professional identity levels and characteristics of occupational therapists through Rasch analysis and to use this as the basis for further assessment and research on the same subject. An online survey was conducted, and the response of 88 people working as occupational therapists between May and June 2020 was analyzed. The collected data included the frequency, analyzed by SPSS 22.0 and technical statistics, Winsteps 3.8.0 target and item suitability, item difficulty, level scale, and separation reliability. According to the analysis, 17 (16.3%) of the subjects and 5 (20%) out of 25 items were unsuitable. Item difficulty was the highest in the category "I systematically read professional publications on occupational therapy", and the lowest level of difficulty in "I make my own decisions about what to do." The three-point scale was suitable for the equilibrium scale, and the separation reliability was between .86 and .95. Thus, identity levels and characteristics of occupational therapists, the suitability of items and subjects, and difficulty levels can be identified through Rasch analysis. In the future, research should be conducted on various sample groups, to develop identity measurement tools specifically for occupational therapists, and to present items appropriate to the characteristics of their work.

• The Journal of Korean Society for School & Community Health Education
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• v.19 no.1
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• pp.85-98
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• 2018

The purpose of this study was to examine the levels of the subjective oral health awareness of local residents in the city of Changwon and Haman county in an effort to lay the foundation for the development of customized local oral health education programs. The 2015 community health survey data were used, and the data from 864 residents in Changwon and from 719 dwellers in Haman county were analyzed. The Changwon residents brushed their teeth after lunch more, received more oral checkups over the past year and had more scaling experience. The Haman residents had more experience of not receiving dental treatment. The subjective health awareness, subjective oral health awareness, chewing difficulty and periodontal health of the Haman dwellers were all worse, and all the levels of awareness were lower among the respondents who were older and who were diagnosed with hypertension and/or diabetes. The respondents who made use of dentures and who didn't brush their teeth after lunch had experience of not receiving dental treatment, and all the levels of health-related awareness were lower among the respondents who didn't receive dental checkups nor had scaling experience. To remedy the situation, efforts should be made to prevent and manage chronic diseases, and the establishment of a system that guarantees regular dental checkups and scaling is required. And the kind of environments that everybody can receive dental treatment when they want should be prepared. In order to change negative awareness, necessary measures should be taken to provide oral health education that is not temporary but sustainable and tailored to local characteristics and different life stages.