• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.288-307
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• 2016

Image distortions are typically characterized by degradations of structures. Dictionaries learned from natural images can capture the underlying structures in images, which are important for image quality assessment (IQA). This paper presents a general-purpose no-reference image quality metric using a GRadient-Induced Dictionary (GRID). A dictionary is first constructed based on gradients of natural images using K-means clustering. Then image features are extracted using the dictionary based on Euclidean-norm coding and max-pooling. A distortion classification model and several distortion-specific quality regression models are trained using the support vector machine (SVM) by combining image features with distortion types and subjective scores, respectively. To evaluate the quality of a test image, the distortion classification model is used to determine the probabilities that the image belongs to different kinds of distortions, while the regression models are used to predict the corresponding distortion-specific quality scores. Finally, an overall quality score is computed as the probability-weighted distortion-specific quality scores. The proposed metric can evaluate image quality accurately and efficiently using a small dictionary. The performance of the proposed method is verified on public image quality databases. Experimental results demonstrate that the proposed metric can generate quality scores highly consistent with human perception, and it outperforms the state-of-the-arts.

• Korean Medical Education Review
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• v.15 no.2
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• pp.87-92
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• 2013

The purpose of this study was to assess third-year medical students' competency for development or revision of the undergraduate curriculum and assessments. One hundred and twenty-seven third-year medical students at the Pusan National University were included in the study. After third- and fourth-year students took a common written examination, clinical performance examination (CPX), and objective structured clinical examination (OSCE) with common items as a summative assessment, the third-year students' competency was compared with 132 forth-year students' results. The correlation of the written examination and CPX/OSCE was analysed, and the summative results were compared with the grade point average (GPA) through the second year, CPX/ OSCE in the second year, and GPA in the clerkship. On the written examination, the third-year students' mean score was lower than the fourth-year students' by over 11 points, whereas the gap in the CPX/OSCE was 4 points and there was no difference in the OSCE. There was a moderate correlation between the written examination and the CPX/OSCE scores (R=0.371, p<0.01). The written examination was highly correlated with GPA through the second year, which mainly evaluated medical knowledge (R=0.771, p<0.01). A relatively high correlation was observed between CPX/OSCE scores and GPA in the clerkship (R=0.641, p<0.01). The summative CPX/ OSCE scores showed a moderate correlation with formative CPX/OSCE scores in the second year (R=0.464, p< 0.01). The third-year students' score was quite low on the written examination and slightly low on the CPX/OSCE compared to that of the fourth-year students. The written examination and CPX/OSCE cannot replace each other and should be combined with other methods of evaluation to measure competency. Early OSCE and workplacebased assessment should be useful in the early assessment of clinical skills competency.

• Journal of Korean Clinical Nursing Research
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• v.18 no.1
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• pp.136-148
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• 2012

Purpose: The purpose of this study was to develop a reliable and valid pain assessment tool suitable for critically ill patients with communication problem in Korean intensive care unit. Methods: This pain assessment tool, Critical Care Non-verbal Pain Scale (CNPS), was developed based on review of national and international researches. Data were collected from ten intensive care units at five major general hospitals in Seoul. Reliability and validity were tested during performance of position change and endotracheal suctioning. Pain was measured before, during, and 20 minutes after the two procedures. Results: Interrater reliability of the CNPS was analyzed by ICC (Intraclass correlation coefficients). ICC values were significant from .833 to .883. Significant correlation between the FPS (Face Pain Scale) scores and the CNPS scores verified concurrent validity of the CNPS. For position change, CNPS scores increased significantly between before and during (t=-23.399, p<.001) and decreased significantly between during and 20 minutes after (t=22.760, p<.001). For endotracheal suctioning, CNPS scores increased significantly between before and during (t=-29.064, p<.001) and significantly decreased between during and 20 minutes after (t=28.194, p<.001), verifying construct validity of the CNPS. Conclusion: Results indicate that the CNPS can be used to assess pain of critically ill patients who have communication problem.

• Journal of Broadcast Engineering
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• v.21 no.2
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• pp.157-168
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• 2016

In image processing and computer vision fields, mean squared error (MSE) has popularly been used as an objective metric in image quality optimization problems due to its desirable mathematical properties such as metricability, differentiability and convexity. However, as known that MSE is not highly correlated with perceived visual quality, much effort has been made to develop new image quality assessment (IQA) metrics having both the desirable mathematical properties aforementioned and high prediction performances for subjective visual quality scores. Although recent IQA metrics having the desirable mathematical properties have shown to give some promising results in prediction performance for visual quality scores, they also have high computation complexities. In order to alleviate this problem, we propose a new fast IQA metric using a simple Laplace operator. Since the Laplace operator used in our IQA metric can not only effectively mimic operations of receptive fields in retina for luminance stimulus but also be simply computed, our IQA metric can yield both very fast processing speed and high prediction performance. In order to verify the effectiveness of the proposed IQA metric, our method is compared to some state-of-the-art IQA metrics. The experimental results showed that the proposed IQA metric has the fastest running speed compared the IQA methods except MSE under comparison. Moreover, our IQA metric achieves the best prediction performance for subjective image quality scores among the state-of-the-art IQA metrics under test.

• Imaging Science in Dentistry
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• v.46 no.3
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• pp.211-216
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• 2016

Purpose: The use of electronic tools in teaching is growing rapidly in all fields, and there are many options to choose from. We present one such platform, Learning Catalytics$^{TM}$ (LC) (Pearson, New York, NY, USA), which we utilized in our oral and maxillofacial radiology course for second-year dental students. Materials and Methods: The aim of our study was to assess the correlation between students' performance on course exams and self-assessment LC quizzes. The performance of 354 predoctoral dental students from 2 consecutive classes on the course exams and LC quizzes was assessed to identify correlations using the Spearman rank correlation test. The first class was given in-class LC quizzes that were graded for accuracy. The second class was given out-of-class quizzes that were treated as online self-assessment exercises. The grading in the self-assessment exercises was for participation only and not accuracy. All quizzes were scheduled 1-2 weeks before the course examinations. Results: A positive but weak correlation was found between the overall quiz scores and exam scores when the two classes were combined (P<0.0001). A positive but weak correlation was likewise found between students' performance on exams and on in-class LC quizzes (class of 2016) (P<0.0001) as well as on exams and online LC quizzes (class of 2017) (P<0.0001). Conclusion: It is not just the introduction of technological tools that impacts learning, but also their use in enabling an interactive learning environment. The LC platform provides an excellent technological tool for enhancing learning by improving bidirectional communication in a learning environment.

• International Commerce and Information Review
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• v.12 no.4
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• pp.279-302
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• 2010

A better selection model on management innovative enterprises is needed since the Korean government provides multi benefits to those selected enterprises. However, the selection model's propriety is suspicious because of the shortage of consideration of assessment items. In particular, the most important two assessment items, strategy and performance are suspected of multicollinearity because of high correlation scores. No consideration on multicollinearity among those items leads to erroneous selection which doubly counts the same components with different item names. The principle component analysis is applied to factor out the uncorrelated items. Using the resulted principle components, the new estimations are carried out. The comparison between estimated results from using principle components and non principle components shows that the present selection model overly considers the performance items compared to the real effect of items, which is a result of multicollinearity between performance and strategy.

• Journal of Korean Home Economics Education Association
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• v.21 no.1
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• pp.71-88
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• 2009

This study was a quasi-experimental study to test a research question: Is the school library-assisted instruction effective in enhancing students' academic achievement? To solve the research question, 14 hours of school library-assisted instruction and traditional lecture were carried out to 164 9th grade middle school female students(82 of experimental group, 82 of control group). SPSS 12.0 was used for statistical analysis of frequency analysis, $x^2$-test, and t-test. The results showed that there was a statistically significant difference between the pre-test and the post-test in the total academic achievement scores of both experiment group and comparison group. There was a statistically significant difference between the pre-test and the post-test in paper and pencil test scores for comparison group. There were statistically significant differences between the pre-test and the post-test both in paper and pencil test scores and performance assessment for two groups. But there were no statistically significant differences between the experiment group and the comparison group in post-test pre-test gap of total academic achievement, paper and pencil test, and performance assessment scores.

• Journal of Labour Economics
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• v.32 no.3
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• pp.61-89
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• 2009

This paper undertakes an international study on impacts of private education spending on student academic performance, using the OECD's PISA 2006 data. To circumvent endogeneity of the education spending, it relies on a propensity-score matching method. The empirical results suggest thai the effect of private education spending remains only modest for all the countries examined in the PISA 2006 data. A 10 percent increase in spending leads to no more than a 0.6 percent average improvement in test scores.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.211-219
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• 2016

The current study was conducted to make pre-post comparisons of education done for 119 emergency medical technicians (EMT) on the patient assessment performance. The data are expected to offer applicable training methods and educational resources for emergency medical services. Twenty six EMT from four cities and provinces participated in the study, which was carried out from 14 to 17 December, 2015. The technicians performed a patient assessment and marked reports on simulated patients. In the course of the assessment, a pre-post evaluation of education was done using a checklist regarding the respective symptoms, such as headache, chest pain, and dyspnea. The median value (quartile value) was used as the descriptive analysis. While patient assessment scores marked 66 points (54.00-80.25) out of 100 (p<0.01) before education, there was a significant increase in the after-education scores, which reached 88.5 points (80.00-93.00). The patient assessment performances revealed a significant increase (p<.0.01) in 5 chest pain, 7 headache, and 9 dyspnea items after education. Similarly, there was an increase in wanting to meet the EMT again scale in regards to categories involved in developing positive relations with patients. Moreover, the adequacy in the patient condition reports all marked a significant increase (p<0.01) in assessment categories. The present study shows that education based on simulation practices are necessary for improvements in patient assessment performance of 119 EMT. Therefore, practical and systematic patient assessment educations may serve as a prerequisite. Further opportunities should be provided for the EMT consistently.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.8
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• pp.653-660
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• 2020

The paper examines the impact of proctoring environments on student performance in two different exam proctoring environments: online versus offline proctored exams. This study employs a set of aggregated data from 1,762 students over the eight-year period from 2009 to 2016 in a university. Although there were nine courses offered, they could have been counted more than once as students may appear several times to take exams for different courses. This study employs independent samples t-test and regression analysis to compare the means of two independent groups and to test the hypothesis. The results of the independent samples t-test and the regression analysis indicate that there is no difference in the mean scores of exams and, therefore, the findings suggest that the exam proctoring environment is unlikely related to student performance even when students take their exams either in online proctoring or offline proctoring environments. This study concludes that the proctoring environment unlikely results in a statistically significant difference of exam scores and, thus, the exam proctoring environment does not appear to cause any change in student performance. The findings suggest that the exam proctoring environments does not appear to impact on student academic achievements and assessments.