• Tribology and Lubricants
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• v.32 no.3
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• pp.101-105
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• 2016

Trap effect of groove is evaluated in a lubricating system using computational fluid dynamics (CFD) analysis. The simulation is based on the standard k-ε turbulence model and the discrete phase model (DPM) using a commercial CFD code FLUENT. The simulation results are also capable of showing the particle trajectories in flow field. Computational domain is meshed using the GAMBIT pre-processor. The various grooves are applied in order to improve lubrication characteristics such as reduction of friction loss, increase in load carrying capacity, and trapping of the wear particles. Trap effect of groove is investigated with variations in cross-sectional shape and Reynolds number in this research. Various cross-sectional shapes of groove (rectangular, triangle, U shaped, trapezoid, elliptical shapes) are considered to evaluate the trap effect in simplified two-dimensional sliding bearing. The particles are assumed to steel, and defined a single particle injection condition in various positions. The “reflect” boundary condition for discrete phase is applied to the wall boundary, and the “escape” boundary condition to “pressure inlet” and “pressure outlet” conditions. The streamlines are compared with particles trajectories in the groove. From the results of numerical analysis in the study, it is found that the cross-sectional shapes favorable to the creation of vortex and small eddy current are effective in terms of particle trapping effect. Moreover, it is found that the Reynolds number has a strong influence on the pattern of vortex or small eddy current in the groove, and that the pattern of the vortex or small eddy current affects the trap effect of the groove.

• Communications of Mathematical Education
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• v.31 no.2
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• pp.203-221
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• 2017

The purpose of this study is to suggest didactical principles for using mathematical teaching aids and to applicate didactical principles in a relation with curriculum. First, we meta-analyzed related literature to suggest didactical principles for using mathematical teaching aids. And we suggested didactical principles as follows: principle of activities, principle of instruments, principle of learning. Using mathematical teaching aids with didactical principles in mind would help avoiding situations in which mathematical teaching aids are only used as interesting tools. Second, we concretized the meaning to applicate didactical principles and use mathematical teaching aids in a relation with curriculum. We considered domain, key concept, function, achievement standard, which were presented in the curriculum of mathematics, and suggested concrete activities. Third, we produced two designs for lessons on incenter and circumcenter of triangle and linear function's graph using mathematical teaching aids.

• Journal of the Korean Society for Library and Information Science
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• v.32 no.3
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• pp.143-156
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• 1998

This paper reports the GEM (Gateway to Educational Materials) project whose goal is to develop an operational framework to provide the K-12 teachers in the world with 'one-stop/any-stop' access to thousands of lesson plans, curriculum units and other Internet-based educational resources. To the IS-element Dublin Core base package, the GEM project added an 8-element, domain-specific GEM package. The GEM project employed the conceptual data modeling approach to designing the GEM database, used the Sybase relational database management system (RDBMS) to construct the backend database for storing the metadata of educational resources, and also employed the active server page (ASP) technology to provide Web interfaces to that database. The consortium members catalog lesson plans and other Internet-based educational resources using a cataloging module program that produces HTML meta tags. A harvest program collects these meta tags across the Internet and outputs an ASCII file that conforms to the standard agreed by the consortium members. A parser program processes this file to enter meta tags automatically into appropriate relational tables in the Sybase database. The conceptual/logical schemas of Dublin Core and GEM profile are presented. The advantages of conceptual modeling approach to manage metadata are discussed. A prototype system that provides access to the GEM metadata is available at http://lis.skku.ac.kr/gem/.

• Journal of KIISE:Software and Applications
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• v.32 no.9
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• pp.835-846
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• 2005

A Product Line (PL) is a set of products (applications) that share common assets in a domain. Product Line Engineering (PLE) is a set of principles, techniques, mechanisms, and processes that enables the instantiation of produce lines. Core assets, the common assets, are created and instantiated to make products in PLE. Model Driven Architecture (MDA) is a new software development paradigm that emphasizes its feasibility with automatically developing product. Therefore, we can get advantages of both of the two paradigms, PLE and MDA, if core assets are represented as PIM in MDA with predefined automatic mechanism. PLE framework in the PIM level has to be interpreted by MDA tools. However, we do not have a standard UML profile for representing core assets. The research about representing PLE framework is not enough to make automatically core assets and products. We represent core asset in PIM level in terms of structural view and semantic view. We also suggest a method for representing architecture, component, workflow, algorithm, and decision model. The method of representing framework with PLE and MDA is used to improve productivity, applicability, maintainability and qualify of product.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.345-352
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• 2004

This paper deals a method to deliver more realistic sound by cancelling the cross-talk which is inherent to the 5.1 channel speaker system. The acoustical model for cross-talk cancellation is the free field model. This model minimizes distortion of sound. 1 used the bark scale sound quality compensation which based on psycho-acoustic. For the surround channels, band-limited sound quality compensation is performed in the frequency domain. I also performed the sound qualify assessment test on the traditional 2 channel stereo and 5.1 channel system. This test is performed in the tort chamber which satisfies the ITU-R specifications. 1 uses the IACC(Inter-Aural Cross-Correlation) to determine the preferences of the amateur and the golden ear experts to asses the trans-aural filter. According to the result from the proposed method, I got more the 38dB separation rates with the Dolby standard speaker array. The results on the diffusion by the subjective test with the experts shows 0.4∼0.5 point Increased then before.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.8
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• pp.566-575
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• 2009

Clinical Data Interchange Standards Consortium (CDISC) developed global and platform-independent data standards to improve ineffective processes of clinical trial studies. Regardless of its objective toward global cooperation, the current version of the CDISC standard cannot describe clinical trial data in various languages for multi-national investigators or reviewers. This problem applies not only to tabulated datasets in Study Data Tabulation Model (SDTM) but also to extensible markup language representation of the datasets in Operational Data Model (ODM) instances. In order to address this issue, we propose to extend the current version of SDTM and ODM to collect clinical data for multi-national clinical trials. SDTM needs to have new special-purpose domain for multi-language representation purpose. Additionally, ODM is recommended to extend its XML schema using subtyping or type inheritance mechanism respectively. Our extension of SDTM and ODM enable to represent any granule of study data tabulation model or XML data entities to describe in efficient languages. This result will contribute to collect multi-language data easily for multi-national clinical trials.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.13 no.1
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• pp.15-23
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• 2006

Purpose: This study was dont: to identify the differences nursing needs and satisfaction with medications in patients admitted to hospital. Method: The participants were 258 patients admitted for 3days or more to D hospital. The data were analyzed using frequencies, percentages, means, standard deviations, t-test and ANOVA. SPSS-WIN 11.0 was used to assist analysis. Results: The results are as follow: 1. Variables effecting nursing needs were education and economic level. All scores of nursing needs were higher in the group with less than middle school education compared to those with high school education or higher. 2. The scores for nursing needs were higher than the score for satisfaction in common item and injection domains. The scores for nursing satisfaction were higher than nursing needs in the oral medication domain. 3. The item with the highest difference between the scores for nursing needs and satisfaction was 'I want to know the side effect of the drugs'. Conclusion: Patients admitted to hospital want to know the therapeutic effect, side effect and reason for their drugs. However satisfaction with medication was not equal to needs. It is necessary to emphasize clinical pharmacology in nursing education programs.

• Gut and Liver
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• v.12 no.6
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• pp.641-647
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• 2018

Background/Aims: Helicobacter pylori eradication rates are decreasing because of increases in clarithromycin resistance. Thus, finding an easy and accurate method of detecting clarithromycin resistance is important. Methods: We evaluated 70 H. pylori isolates from Korean patients. Dual-labeled peptide nucleic acid (PNA) probes were designed to detect resistance associated with point mutations in 23S ribosomal ribonucleic acid gene domain V (A2142G, A2143G, and T2182C). Data were analyzed by probe-based fluorescence melting curve analysis based on probe-target dissociation temperatures and compared with Sanger sequencing. Results: Among 70 H. pylori isolates, 0, 16, and 58 isolates contained A2142G, A2143G, and T2182C mutations, respectively. PNA probe-based analysis exhibited 100.0% positive predictive values for A2142G and A2143G and a 98.3% positive predictive value for T2182C. PNA probe-based analysis results correlated with 98.6% of Sanger sequencing results (${\kappa}$-value=0.990; standard error, 0.010). Conclusions: H. pylori clarithromycin resistance can be easily and accurately assessed by dual-labeled PNA probe-based melting curve analysis if probes are used based on the appropriate resistance-related mutations. This method is fast, simple, accurate, and adaptable for clinical samples. It may help clinicians choose a precise eradication regimen.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.293-302
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• 2019

The purpose of this study was to examine the reliability and validity of Stroke Impact Scale 3.0 (SIS 3.0). Here, the SIS 3.0 was completed by 154 stroke patients (mean = 62.7; standard deviation [SD] = 9.43). Construct validity was verified by analyzing the correlation between SIS 3.0 sub-domains, and convergent validity was investigated by analyzing the correlation between the Modified Barthel Index (MBI) and the Mini-Mental State Examination-Korean (K-MMSE) version. The characteristics of each item were analyzed by internal consistency and item discrimination based on the classical item theory. Construct and convergent validity were verified through this study. Although the item i included in the emotion domain showed low item discrimination, all but this item showed high discrimination. Internal consistency was also high in all sub-domains.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.962-977
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• 2019

The human voice is a convenient method of information transfer between different objects such as between men, men and machine, between machines. The development of information and communication technology, the voice has been able to transfer farther than before. The way to communicate, it is to convert the voice to another form, transmit it, and then reconvert it back to sound. In such a communication process, a vocoder is a method of converting and re-converting a voice and sound. The CELP (Code-Excited Linear Prediction) type vocoder, one of the voice codecs, is adapted as a standard codec since it provides high quality sound even though its transmission speed is relatively low. The EVRC (Enhanced Variable Rate CODEC) and QCELP (Qualcomm Code-Excited Linear Prediction), variable bit rate vocoders, are used for mobile phones in 3G environment. For the real-time implementation of a vocoder, the reduction of sound quality is a typical problem. To improve the sound quality, that is important to know the size and shape of noise. In the existing sound quality improvement method, the voice activated is detected or used, or statistical methods are used by the large mount of data. However, there is a disadvantage in that no noise can be detected, when there is a continuous signal or when a change in noise is large.This paper focused on finding a better way to decrease the reduction of sound quality in lower bit transmission environments. Based on simulation results, this study proposed a preprocessor application that estimates the SNR (Signal to Noise Ratio) using the spectral SNR estimation method. The SNR estimation method adopted the IMBE (Improved Multi-Band Excitation) instead of using the SNR, which is a continuous speech signal. Finally, this application improves the quality of the vocoder by enhancing sound quality adaptively.