• 한국수학교육학회지시리즈A:수학교육
• /
• 제44권3호
• /
• pp.375-396
• /
• 2005

This paper reports on the main results of 3 study that compared students' beliefs, skills, and understandings in an innovative approach to differential equations to more conventional approaches. The innovative approach, referred to as the Realistic Mathematics Education Based Differential Equations (IODE) project, capitalizes on advances within the discipline of mathematics and on advances within the discipline of mathematics education, both at the K-12 and tertiary levels. Given the integrated leveraging of developments both within mathematics and mathematics education, the IODE project is paradigmatic of an approach to innovation in undergraduate mathematics, potentially sewing as a model for other undergraduate course reforms. The effect of the IODE projection maintaining desirable mathematical views and in developing students' skills and relational understandings as judged by the three assessment instruments was largely positive. These findings support our conjecture that, when coupled with careful attention to developments within mathematics itself, theoretical advances that initially grew out research in elementary school classrooms can be profitably leveraged and adapted to the university setting. As such, our work in differential equations may serve as a model for others interested in exploring the prospects and possibilities of improving undergraduate mathematics education in ways that connect with innovations at the K-12 level

• 한국정보시스템학회지:정보시스템연구
• /
• 제26권1호
• /
• pp.75-91
• /
• 2017

Purpose Fintech has been recently drawing extensive attention all over the world as the innovative trend that will change the future of the global financial industry. However, fintech has been mostly focusing on the payment service in the embryonic stage in Korea. This paper will investigate the approach to increase the intention to use for those who do not use fintech at present. Design/methodology/approach This paper empirically analyzes the impact of innovation of users and the perceived ease-of-use and security on the intention to use through the perceived usefulness and confidence. The 255 survey responses were used to verify research hypotheses through covariate structural equation model. Findings According to the analysis results, it was found that innovation had a significant impact on the perceived usefulness, but had no significant impact on confidence. The perceived usefulness had a significant impact on perceived usefulness and confidence. Moreover, the perceived usefulness and confidence had a significant impact on the intention to use. Meanwhile, it was identified that the security perceived by those who do not use fintech had a negative impact on perceived usefulness, confidence, and intention to use related to fintech. Accordingly, fintech service providers need to determine an approach to help customers to have a positive perception on the security of fintech.

• Journal of Korean Neurosurgical Society
• /
• 제59권6호
• /
• pp.643-646
• /
• 2016

Chordoid glioma of the third ventricle is a rare and challenging tumor to surgery because of its unique anatomical location and its close juxtaposition to the neurovascular structures and hypothalamus. The authors report a case of chordoid glioma of the third ventricle in a 43-year-old woman, who presented with headache and somnolence. The tumor was approached by endoscopic transnasal technique with a favorable result. Histopathologic examination disclosed a neoplastic tissue composed of eosinophilic epithelioid cells, mucinous, periodic acid Schiff-diastase positive, extracellular matrix, and scattered lymphoplasmacytic infiltrates. The best treatment option remains controversial. Customarily, the surgical route to remove chordoid glioma is transcranial; however, the undersurface of the optic chiasm and optic nerves preclude an adequate surgical visualization. In contrast, an expanded endoscopic transnasal approach provides a direct midline corridor to this region without any brain retraction.

• 품질경영학회지
• /
• 제44권4호
• /
• pp.965-981
• /
• 2016

Purpose: This study aims to propose Kano-SERVQUAL integrated approach as an effective tool for evaluating auto service quality attributes to enhance the use of SERVQUAL. Methods: The Kano-SERVQUAL survey was conducted to evaluate customer perception for 28 auto service quality attributes which were obtained from auto service expert in 'H' company. The correlation analysis of SI(Satisfaction Index), DI(Dissatisfaction Index) and expectation values are conducted in this study. Results: The 28 auto service quality attributes are classified into attractive attributes and one-dimensional attributes. The results of this study show that the correlations between the customers' expectation values and DI is strongly positive correlation with 1% significance level, expectation values and SI is negative correlation with 10% significance level. Conclusion: The results show that the purposed Kano-SERVQUAL integrated approach provides a deeper understanding of service quality attributes in that it distinguishes the customers' expectation values between highly expected attributes(e.g. must-be attribute) and less expected attributes(e.g. attractive attribute).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제11권2호
• /
• pp.959-981
• /
• 2017

Existing Android malware detection approaches mostly have concentrated on superficial features such as requested or used permissions, which can't reflect the essential differences between benign apps and malware. In this paper, we propose a quantitative calculation model of application risks based on the key observation that the essential differences between benign apps and malware actually lie in the way how permissions are used, or rather the way how their corresponding permission methods are used. Specifically, we employ a fine-grained analysis on Android application risks. We firstly classify application risks into five specific categories and then introduce comprehensive risk, which is computed based on the former five, to describe the overall risk of an application. Given that users' risk preference and risk-bearing ability are naturally fuzzy, we design and implement a fuzzy logic system to calculate the comprehensive risk. On the basis of the quantitative calculation model, we propose a risk classification based approach for Android malware detection. The experiments show that our approach can achieve high accuracy with a low false positive rate using the RandomForest algorithm.

• Communications for Statistical Applications and Methods
• /
• 제24권6호
• /
• pp.627-640
• /
• 2017

A common interest in gene expression data analysis is to identify genes that present significant changes in expression levels among biological experimental conditions. In this paper, we develop a Bayesian approach to make a gene-by-gene comparison in the case with a control and more than one treatment experimental condition. The proposed approach is within a Bayesian framework with a Dirichlet process prior. The comparison procedure is based on a model selection procedure developed using the discreteness of the Dirichlet process and its representation via Polya urn scheme. The posterior probabilities for models considered are calculated using a Gibbs sampling algorithm. A numerical simulation study is conducted to understand and compare the performance of the proposed method in relation to usual methods based on analysis of variance (ANOVA) followed by a Tukey test. The comparison among methods is made in terms of a true positive rate and false discovery rate. We find that proposed method outperforms the other methods based on ANOVA followed by a Tukey test. We also apply the methodologies to a publicly available data set on Plasmodium falciparum protein.

• Environmental Engineering Research
• /
• 제25권3호
• /
• pp.366-373
• /
• 2020

The autonomous vehicles (AVs) could make a positive or negative impact on reducing mobile emissions. This study investigated the changes of mobile emissions that could be caused by large-scale adoption of AVs. The factors of road capacity increase and speed limit increase impacts were simulated using a conceptual modeling approach that combines a hypothetical speed-emission function and a traffic demand model using a virtual transportation network. The simulation results show that road capacity increase impact is significant in decreasing mobile emissions until the market share of AVs is less than 80%. If the road capacity increases by 100%, the mobile emissions will decrease by about 30%. On the other hand, driving speed limit increase impact is significant in increasing mobile emissions, and the environmentally desirable speed limit was found at around 95 km/h. If the speed limit increases to 140 km/h, the mobile emissions will increase by about 25%. This is because some vehicles begin to bypass the congested routes at high speeds as speed limit increases. Based on the simulation results, it is clear that the vehicle platooning technology implemented at reasonable speed limit is one of the AV technologies that are encouraging from the environmental point of view.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권2호
• /
• pp.89-97
• /
• 2020

This study was conducted to examine how independent audit firms in Vietnam understand and use risk based audit approach (RBAA) in audit practice. To answer the research questions, the researchers used primary and secondary data collected from 2018 to 2019. The results from the interview survey showed that audit firms were aware of the advantages of adopting RBAA. However, RBAA is practiced to a moderate extent by audit firms in Vietnam. Big 4 audit firms use RBAA more popularly than Non-Big 4 audit firms. The causes of the difference are the disadvantages of adopting RBAA and client's characteristics such as relevant guideline, audit fees, auditors' knowledge and experience. Besides, the study investigated factors impacting on the RBAA adoption by distributing a questionnaire to 246 auditors of 126 audit firms in Vietnam. A set of statistical appropriate methods where used through SPSS software version 22.0. The results indicated that there were six factors influencing RBAA adoption including: Auditor's ability, Technological development, Audit fees, auditors' motivation, Audit time and client's risk. Of which, auditor's ability and technological development are factors that have the most significant and positive impacts on the adoption of RBAA. Additional implications were argued in the final section of this study.

• Journal of Power Electronics
• /
• 제17권3호
• /
• pp.695-703
• /
• 2017

In order to satisfy the urgent requirements for the overheating protection of induction motors, an approach that can be used to identify motor temperature has been proposed based on the rotor slots harmonic (RSH) in this paper. One method to accomplish this is to improve the calculation efficiency of the RSH by predicting the stator winding distribution harmonic order by analyzing the harmonics spectrum. Another approach is to increase the identification accuracy of the RSH by suppressing the influence of voltage flashes or current surges during temperature estimation based on model predictive control (MPC). First, an analytical expression of the stator inductance is extracted from a steady-state positive sequence motor equivalent circuit model developed from the rotor flux field orientation. Then a procedure that applies MPC for reducing the identification error of the rotor temperature caused by voltage sag or swell of the power system is given. Due to this work, the efficiency and accuracy of the RSH have been significantly improved and validated our experiments. This work can serves as a reference for the on-line temperature monitoring and overheating protection of an induction motor.

• Journal of Information Processing Systems
• /
• 제10권2호
• /
• pp.314-333
• /
• 2014

When analyzing default predictions in real estate companies, the number of non-defaulted cases always greatly exceeds the defaulted ones, which creates the two-class imbalance problem. This lowers the ability of prediction models to distinguish the default sample. In order to avoid this sample selection bias and to improve the prediction model, this paper applies a minority sample generation approach to create new minority samples. The logistic regression, support vector machine (SVM) classification, and neural network (NN) classification use an imbalanced dataset. They were used as benchmarks with a single prediction model that used a balanced dataset corrected by the minority samples generation approach. Instead of using prediction-oriented tests and the overall accuracy, the true positive rate (TPR), the true negative rate (TNR), G-mean, and F-score are used to measure the performance of default prediction models for imbalanced dataset. In this paper, we describe an empirical experiment that used a sampling of 14 default and 315 non-default listed real estate companies in China and report that most results using single prediction models with a balanced dataset generated better results than an imbalanced dataset.