• East Asian mathematical journal
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• v.19 no.2
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• pp.207-212
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• 2003

Some new characterization of best approximants from level sets of convex functions in normed linear spaces in terms of norm derivatives are given.

• The Journal of Information Systems
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• v.15 no.4
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• pp.1-22
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• 2006

Nowadays, IS projects are getting more complicated and large-scaled. Therefore, many researchers and practitioners have been interested in the IS development methodologies, automated tools, techniques, and TQM to improve IS performance. Latest Standish Group's research reported that after the PMO introduction, project scale became bulkier than 1 or 2 year ago, and that IS development project success probability was increased sharply by 62 percents from 37. The previous researches listed just various PMO functions. This research is to seize the core functions and management level of the PMO affecting on the IS project performance with banks which are the leading industry to accept the PMO in Korea. The activities in the categories of implementation management technology support management infrastructure management are the core functions of the PMO to affect the IS performance including schedule management quality management user and stakeholders' satisfaction. Also, the PMO management level is important for IS project success. Among the 5 levels PMI suggested, PMO can implement the project effectively at least at the third level. Korean companies which are about to introduce the PMO have to consider the PMO core functions and management level to increase the IS maturity.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.391-396
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• 2008

A level set based topological shape optimization using extended B-spline basis functions is developed for steady state heat conduction problems. The only inside of complicated domain is identified by the level set functions and taken into account in computation. The solution of Hamilton-Jacobi equation leads to an optimal shape according to the normal velocity field determined from the sensitivity analysis, minimizing a thermal compliance while satisfying a volume constraint. To obtain exact shape sensitivity, the precise normal and curvature of geometry need to be determined using the level set and B-spline basis functions. The nucleation of holes is possible whenever and wherever necessary during the optimization using a topological derivative concept.

• The Journal of Korean Physical Therapy
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• v.21 no.2
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• pp.47-54
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• 2009

Purpose: The physical deficits after stroke have been well documented, but there is little information on the sexual functions of stroke patients. This study examined the associations of the general characteristics with the poststroke changes in sexual functions. Methods: A survey was conducted on 200 stroke patients from November 2008 to February 2009. Among the 200 submitted questionnaires, 147 responded, and the results were analyzed by SPSS for windows version 14.0. Results: A majority of the stroke patients reported a marked decline in all the measured sexual functions, i.e., frequency of sexual intercourse, frequency of kissing and romantic touching, thinking about sex with interest or desire, ability to become sexually aroused and the overall level of sexual satisfaction. Significant differences were observed in age (p<0.01), years since diagnosis (p<0.05), and educational level (p<0.01). There were no significant gender differences (p>0.05). Conclusion: Decreased sexual function is a common problem after stroke. These finding demonstrate a need to develop sexual adaptation programs that can be effective in improving the sexual functions reported by stroke patients.

• ETRI Journal
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• v.38 no.6
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• pp.1135-1144
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• 2016

Fractal antenna arrays are geometry-based thinned arrays having multiband applications. The major challenge of these arrays is their large number of elements at higher expansion factors. This article presents the thinning of fractal antenna arrays while maintaining an appropriate balance between the side lobe level and beam width by using various quantized fractal distribution functions. A 2D square fractal antenna array and 3DSierpinski gasket antenna array are considered in this article to validate the proposed distribution functions. Nearly one third of the antenna elements are thinned in each successive iteration except in the case of a one-count distribution function. The proposed technique can simplify practical implementation and exhibits better performance for various parameters such as the side lobe level, side lobe angle, and half power beam width than fully populated fractal antenna arrays.

• Nuclear Engineering and Technology
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• v.42 no.4
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• pp.460-467
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• 2010

In this study, the parameters of the feedwater control system (FWCS) of the OPR1000 type nuclear power plant (NPP) are optimized by response surface methodology (RSM) in order to acquire better level control performance from the FWCS. The objective of the optimization is to minimize the steam generator (SG) water level deviation from the reference level during transients. The objective functions for this optimization are relationships between the SG level deviation and the parameters of the FWCS. However, in this case of FWCS parameter optimization, the objective functions are not available in the form of analytic equations and the responses (the SG level at plant transients) to inputs (FWCS parameters) can be evaluated by computer simulations only. Classical optimization methods cannot be used because the objective function value cannot be calculated directely. Therefore, the simulation optimization methodology is used and the RSM is adopted as the simulation optimization algorithm. Objective functions are evaluated with several typical transients in NPPs using a system simulation computer code that has been utilized for the system performance analysis of actual NPPs. The results show that the optimized parameters have better SG level control performance. The degree of the SG level deviation from the reference level during transients is minimized and consequently the control performance of the FWCS is remarkably improved.

• Communications of the Korean Mathematical Society
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• v.35 no.1
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• pp.63-81
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• 2020

In this paper we consider certain classes of generalized level 2 Eisenstein series by simple differential calculations of trigonometric functions. In particular, we give four new transformation formulas for some level 2 Eisenstein series. We can find that these level 2 Eisenstein series are reducible to infinite series involving hyperbolic functions. Moreover, some interesting new examples are given.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1465-1476
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• 2008

In recent years wavelet methods have been focused on block shrinkage or thresholding approaches to accounting for the sparseness of the wavelet representation for an unknown function. The block shrinkage or thresholding methods have been developed in both of classical methods and Bayesian methods. In this paper, we propose a Bayesian approach to selecting wavelet basis functions at each resolution level without MCMC procedure. Simulation study and an application are shown.

• Journal of Families and Better Life
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• v.17 no.2
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• pp.43-54
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• 1999

This study examined the impact of attachment styles on the size and the level of functions of social networks. 270 mothers of school children responded to the questionnaire and were classified into secure avoidant and anxious attachment groups. Findings indicated that three continuous attachment indexes security avoidance anxiousness and the size and the level of functions of social networks were not affected by mother's age educational level and employment status. However singnificant attachment style effects were obtained for the size and the level of functions of social networks. Secure subjects perceived their husbands closer and more important and listed more nonkin members in their netoworks than anxious subjects. important and listed more nonkin members in their networks than anxious subjects Also secure people perceived receiving more assistance from network members including household tasks money information and advice Secure and anxious subjects reported more emotio al support from networks than avoidant people.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.133-138
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• 2009

Purpose: This study was designed to investigate the changes of vision and ocular functions induced by increase of blood alcohol level. Methods: Blood alcohol level, vision, refractive errors, near point convergence, heterophoria, and relative convergence were measured at 1 h, 4 h, and 24 h after acute alcohol ingestion of 0.7 g per kg body weight. Results: At 1 h after alcohol ingestion, myopization and ocular functions which measured near point convergence, positive and negative convergences, and degree of heterophoria remarkedly worked a changes accompanied with the maximum value of blood alcohol level. But at 24 h after that, all of ocular functions were recovered to degree of 90~99% compared with non-alcoholic normal conditions. Conclusions: As the increase of blood alcohol level is able to induce the significant changes of visual acuity and ocular functions, opticians have to understand thoroughly the patient's conditions by alcohol ingestion before refractive test and ocular examinations.