• The Mathematical Education
• /
• v.57 no.2
• /
• pp.111-136
• /
• 2018

This study suggests a framework for analyzing items based on the characteristics, and shows the relationship among the characteristics, difficulty, percentage of correct answers, academic achievement and the actual mathematical problem solving competency. Three mathematics educators' classification of 30 items of Mathematics 'Ga' type, on 2017 College Scholastic Ability Test, and the responses given by 148 high school students on the survey examining mathematical problem solving competency were statistically analyzed. The results show that there are only few items satisfying the characteristics for mathematical problem solving competency, and students feel ill-defined and non-routine items difficult, but in actual percentage of correct answers, routineness alone has an effect. For the items satisfying the characteristics, low-achieving group has difficulty in understanding problem, and low and intermediate-achieving group have difficulty in mathematical modelling. The findings can suggest criteria for mathematics teachers to use when developing mathematics questions evaluating problem solving competency.

• Communications for Statistical Applications and Methods
• /
• v.17 no.3
• /
• pp.327-335
• /
• 2010

Item response theory provides a fixed results about students, regardless of the item difficulty and discrimina-tion and it is also a kind of item analysis methods which provides the same proper competence scores to students in spite of them taking different test repeatedly. In this paper, we researched item difficulty and item discrimina-tion and analyzed items in the national academic aptitude test which were given from 2000 to 2009 in the past 10 years through item response theory, especially, in connection with given items about statistical unit. As a result, we found that about 60 percents of the items were too difficult for high school students to solve, however, item discrimination proved to be great.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.2352-2355
• /
• 2003

In recent yeas, studies on computer aided diagnosis (CAD) using image analysis on CT images have been conducted with respect to various diseases. Extracting ground-glass opacities (GGO) on lung CT images is one of such subjects, though it has not found an established method yet. If the region of ground-glass opacities is large on CT images, it can be detected without much difficulty. On the other hand, if the region is small, it is still difficult to find it exactly. In the latter case, increasing overlooking possibility cannot be avoided according to smaller size of the region. To solve this difficulty, this paper proposes an automatic technique for extracting ground-glass opacities on lung CT images employing some statistical parameters of a gray level histogram and a differential histogram. The proposed technique is applied to some lung CT images in the performed experiment. The results are shown with discussion on future work.

• Journal of Korean Society for Geospatial Information Science
• /
• v.17 no.2
• /
• pp.81-90
• /
• 2009

Mountain trails play an important role in the daily life and health of the citizens, and also are major areas for recreation operators strive to balance the needs of pedestrian with the needs of wildlife and health improvement. In this view point, this research aims at analyzing the slope of mountain trails using mobile GPS and suggesting the suitable path to citizens for improving health. The result shows that the trail slope analysis by using mobile GPS could be effectively evaluated the degree of walk difficulty.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.39 no.4
• /
• pp.51-69
• /
• 2014

Times to multiple events (TMEs) are a major data type in large-scale business and medical data. Despite its importance, the analysis of TME data has not been well studied because of the analysis difficulty from censoring of observation. To address this difficulty, we have developed a Bayesian-based multivariate survival analysis method, which can successfully estimate the joint probability density of survival times. In this work, we extended this method for the analysis of precedence, dependency and causality among multiple events. We applied this method to the electronic health records of 2,111 patients in a children's hospital in the US and the proposed analysis successfully shows the relation between times to two types of hospital visits for different medical issues. The overall result implies the usefulness of the multivariate survival analysis method in large-scale big data in a variety of areas including marketing, human resources, and e-commerce. Lastly, we suggest our future research directions based multivariate survival analysis method.

• Journal of Distribution Science
• /
• v.17 no.2
• /
• pp.101-107
• /
• 2019

Purpose - The purpose of this study is to analyze the user requirements and developer requirements in virtual reality(VR), and suggest ways to increase the satisfaction of users who experience virtual reality. Specifically, focused on experience store of VR as a distribution retailer, user requirements were analyzed according to the results of previous research that the characteristics of Affordance, Presence, and Head Mounted Display (HMD) affect user satisfaction. Research, design, data, and methodology - Based on previous studies, in this study, we analyzed the importance of immerse, interaction, perception, and presence for the satisfaction of the user through the questionnaire, and the user experiences virtual reality (VR) The importance of HMD, Presence, Affordance, and experience satisfaction were analyzed. Based on this, we analyzed the user requirements and the developer requirements based on the questionnaires and interviews of the experts, starting from the user's desire or preference using QFD technique. Results - As a result of the analysis, the development factors that occupied a big part in the virtual reality field appeared to be visual. In detail, this showed that there was a lack of sense of presence for users. This should be improved. This paper shows that the requirements for visual, auditory, and tactile development are necessary. For the satisfaction of the users of virtual reality (VR) users, it is necessary to develop them according to their priority in consideration of importance and difficulty in the future. Conclusions - In this study, it was suggested that development according to priority should be considered, considering the difficulty level. Based on the results of this study, the following suggestions are made. First, we tried to search the list of user requirements as much as possible, but it is likely to change due to the development of VR technology. Therefore, it is necessary for developers to continually supplement user requirements with recent research literature. Second, development priorities according to difficulty level should be considered. This aspect should be considered in the actual VR development process, so if the numerical value of the difficulty is calculated, it should be presented in the research.

• Quality Improvement in Health Care
• /
• v.21 no.2
• /
• pp.40-56
• /
• 2015

Objectives: To outline overall duties of quality improvement (QI) performers within a health care organization, thus describing their key tasks, including task element-related frequency, importance and difficulty in enough detail. Methods: A DACUM (Developing A CurriculUM) workshop took place to outline overall job activities of QI performers. To examine the scope of their duty and task, we performed a questionnaire survey of 338 QI performers from 111 hospitals. Results: The results of our survey showed that for the task assigned to each QI performer, there were 10 duties, 31 tasks and 119 task elements. Respondents cited a project planning as the most frequent/important duty, and a research was the highest level of difficulty in their duty. They also said that the most frequent task was index management, the most important task was a business plan, and the highest level of difficulty was a practical application of QI research. QI performers added that the most frequent task element was receipt of patient safety reporting in patient safety system, the most important task element was an analysis for patient safety and its improvement, and the highest level of difficulty was a regional influence analysis related to the patient safety and its improvement. Conclusion: To ensure that QI performers play a pivotal role as a manager to better improve patient safety and the quality of health care services, proper training program for them should be developed by reflecting the results of our study.

• Journal of Korean Elementary Science Education
• /
• v.27 no.4
• /
• pp.420-436
• /
• 2008

The purpose of this study was to investigate and analysis the elementary teachers' and students' views about the difficulties in teaching and learning in geology units of elementary school science. For the purpose of this study, semi-structured interviews were conducted individually with seventeen elementary teachers who have serviced more than three years, and with sixteen elementary students located in Cheongju City. The interview questions were developed through Seidman's step to acquire a reliability in the interview data with triangulation, then in-depth interview questions were modified and completed through pre-interview after constructing the trustworthiness of interviewees. In-depth interviews were performed in applying the analytic induction method and the interviews were recorded. From the interviews, we found that elementary teachers' views about the difficulties in teaching geology units; teachers' inner difficulties, the difficulty of lab activities, the problems of rock samples, the problems of curriculum in geology units, the difficulty of the geological feature, the problems of the cramming education, the lack of the opportunity for the speciality, and so on. And the students have the views about the difficulties in learning geology units; the difficulty of the unit contents understanding, the problems of learning by heart, the lack of the interest, the lack of materials, the problems of rock samples, the difficulty of the field learning, and so on. Based on the results, the study suggested that an interesting lab activities should be included in the geology units and taught in the geological field trip to help elementary school students more fully comprehend contents of the geology units.

• The Korean Journal of Rehabilitation Nursing
• /
• v.10 no.2
• /
• pp.108-115
• /
• 2007

Purpose: This study was to investigate the effects of respiratory rehabilitation training on the respiratory functions of hospitalized cervical spinal cord injury patients. Methods: One group pre and post test design was used. Subjects were 20 cervical spinal cord injury inpatients of the national rehabilitation center. Training program consisted of air cumulation training, manual assisted coughing training, and abdominal breathing. Trained rehabilitation nurse implemented 20 minutes program twice a day for 4 weeks. Respiratory function was measured as peak coughing flow rate, and perceived respiratory difficulty after activity on wheel chair for 30 minutes and during speaking and singing. Perceived respiratory difficulty was measured with modified Borg scale. Also content analysis was done with the result of open ended question about subjective feeling about training. All variables were measured 3 times before, 2weeks and 4 weeks after the program. Results: Peak coughing flow rate significantly improved after compared to before training. Also all three perceived respiratory difficulty variables decreased significantly after training. In the content analysis, 'it's easier to cough up phlegm' was the most frequent answered subjective feeling. 'Sound at speaking and coughing became louder', 'respiratory volume increased', and 'comfortable chest feeling' were frequent answered subjective feeling, in order. Conclusion: Although it is preliminary since no control group, respiratory rehabilitation training was found to be effective to improve respiratory function in terms of peak coughing flow rate, perceived respiratory difficulty, and subjective feeling. It is necessary further systemic research to investigate the effects of respiratory rehabilitation training.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.11
• /
• pp.1700-1713
• /
• 2018

Objective: The aim of this study was to verify the usefulness of artificial neural networks (ANN), multivariate adaptive regression splines (MARS), naïve Bayes classifier (NBC), general discriminant analysis (GDA), and logistic regression (LR) for dystocia detection in Polish Holstein-Friesian Black-and-White heifers and cows and to indicate the most influential predictors of calving difficulty. Methods: A total of 1,342 and 1,699 calving records including six categorical and four continuous predictors were used. Calving category (difficult vs easy or difficult, moderate and easy) was the dependent variable. Results: The maximum sensitivity, specificity and accuracy achieved for heifers on the independent test set were 0.855 (for ANN), 0.969 (for NBC), and 0.813 (for GDA), respectively, whereas the values for cows were 0.600 (for ANN), 1.000 and 0.965 (for NBC, GDA, and LR), respectively. With the three categories of calving difficulty, the maximum overall accuracy for heifers and cows was 0.589 (for MARS) and 0.649 (for ANN), respectively. The most influential predictors for heifers were an average calving difficulty score for the dam's sire, calving age and the mean yield of the farm, where the heifer was kept, whereas for cows, these additionally included: calf sex, the difficulty of the preceding calving, and the mean daily milk yield for the preceding lactation. Conclusion: The potential application of the investigated models in dairy cattle farming requires, however, their further improvement in order to reduce the rate of dystocia misdiagnosis and to increase detection reliability.