• Kyungpook Mathematical Journal
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• v.49 no.4
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• pp.651-666
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• 2009

With the aid of weakly weighted sharing and a recently introduced sharing notion in [3] known as relaxed weighted sharing we investigate the uniqueness of meromorphic functions sharing a small function with its differential polynomials. Our results will improve and supplement all the results obtained by Zhang and Yang [17] as well as a substantial part of the results recently obtained by the present author [2] and thus provide a better answer to the questions posed by Yu [14] in this regard.

• Environmental and Resource Economics Review
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• v.9 no.4
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• pp.701-725
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• 2000

Environmental taxes tend to compound the welfare cost of pre-existing tax distortions, the tax-interaction effect, however they also raise government revenues, tax revenue-recycling effect. By incorporating these two opposite tax effects, this paper examines a second- best environmental taxation for a polluting monopolist with distortionary taxes. The analysis suggests that the complications posed by pre-existing tax distortions as well as market structure can be key considerations in designing environmental taxes. In the tax setting game between regulator and regulated firm, we also derive the equilibrium tax rate and examine its relationship with distortionary taxes.

• Bulletin of the Korean Mathematical Society
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• v.61 no.3
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• pp.837-848
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• 2024

It is shown in [1] that the Cauchy problem for the Fornberg-Whitham equation is well-posed in C¹(ℝ) and the data-to-solution map is Hölder continuous from C^α to C([0, T]; C^α) with α ∈ [0, 1). In this short paper, we further show that the data-to-solution map of the Fornberg-Whitham equation is not uniformly continuous on the initial data in C¹(ℝ).

• Journal of applied mathematics & informatics
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• v.7 no.2
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• pp.493-506
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• 2000

Recently the first author and his coworker report a new finite element method for the Poisson equations with homogeneous Dirichlet boundary conditions on a polygonal domain with one re-entrant angle [7], They use the well-known fact that the solution of such problem has a singular representation, deduced a well-posed new variational problem for a regular part of solution and an extraction formula for the so-called stress intensity factor using tow cut-off functions. They use Fredholm alternative an Garding's inequality to establish the well-posedness of the variational problem and finite element approximation, so there is a maximum bound for mesh h theoretically. although the numerical experiments shows the convergence for every reasonable h with reasonable size y imposing a restriction to the support of the extra cut-off function without using Garding's inequality. We also give error analysis with similar results.

• International Journal of Contents
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• v.18 no.1
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• pp.27-39
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• 2022

Short videos are becoming more popular in mobile Internet age. Not only people's media consumption patterns have been changed by the rise of this new media form, but also it has posed challenges to public psychological well-being. For many netizens, their entertainment needs have been met by watching short videos. However, many side effects, such as addiction and anxiety, reduce users' subjective well-being instead of satisfying the entertainment motivation after watching short videos. Therefore, it has become a significant research problem in short videos to figure out how to get audiences to watch short videos on a regular basis while avoiding side effects like anxiety and addiction and improving audiences' subjective well-being. Based on the theory of Internet addiction, this study analyzed short video users using the 2×2×2 research method and explored the relationship between the length of use, addiction, anxiety, and subjective well-being of short video users. The results showed that short video users with different usage lengths showed significant differences in addiction, anxiety, subjective well-being, and online social support; innovative different short video users showed significant differences in addiction and anxiety, as well as a triadic relational interaction of short video users' anxiety under the interaction with self-efficacy and online social support. This study contributes to the advancement of internet addiction theory research and application, assisting short video users in avoiding addiction and anxiety, and improving the subjective well-being of short video users, thereby promoting the growth of the short video industry.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.4
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• pp.41-45
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• 2013

Modern electronic devices such as tablets and smartphones are getting more powerful and efficient. The demand in feature sets, functionality and usability increase exponentially and this has posed a great challenge to the design of a power distribution network (PDN). Power rails merging is a popular option used today in a PDN design as numerous power rails are no longer feasible due to form factor limitation and cost constraint. In this paper, the criteria and limitations for power rails merging are discussed. Despite having all the advantages such as pin count reduction, decoupling capacitors sharing, lower impedance and cost saving, power rails merging can however, introduce coupling noise to the system. In view of this, a PDN design with power rails merging that fulfills design recommendations and specifications such as noise target, power well placement, voltage supply values as well as power supply quadrant assignment is extremely important.

• Magazine of korean Tunnelling and Underground Space Association
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• v.21 no.2
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• pp.103-116
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• 2019

Permanent sprayed concrete tunnel linings waterproofed with bonded membranes have been used at a number of important traffic projects over the last decade. Research has been carried out in several teams in order to increase the understanding of the function, properties and behavior of such linings under different loading and boundary conditions. The basic layout of this lining gives fundamental different system properties compared to the traditional lining systems. The main differences pertain to the groundwater exposure and the resulting hydraulic loading, the response of the concrete and membrane materials to this loading, as well as the geomechanically induced loading of the lining structure. The current understanding of the function and properties of such lining structures is presented in the paper based on review of recent research carried out in Norway, as well as field observations and monitoring carried over a several years. The influence of the water exposure on the final condition of the concrete and membrane materials has proven to be of vital importance for proper material testing and acceptance, assessments of the mechanical contribution of the bonded membrane, as well as assessments of the longterm durability of such linings. Obtaining realistic material parameters for the concrete and membrane materials subject to the boundary conditions posed by the groundwater exposure in an undrained structure is emphasized. Finally, some recent results from currently ongoing research on such linings, particularly the hydraulic response of the rock mass and the long term behavior of the concrete and membrane materials are presented.

• East Asian mathematical journal
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• v.32 no.4
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• pp.565-587
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• 2016

The purpose of this study was to analyze the understanding of the meaning of fraction division and fraction division algorithm of elementary mathematical gifted students through the process of problem posing and solving activities. For this goal, students were asked to pose more than two real-world problems with respect to the fraction division of ${\frac{3}{4}}{\div}{\frac{2}{3}}$, and to explain the validity of the operation ${\frac{3}{4}}{\div}{\frac{2}{3}}={\frac{3}{4}}{\times}{\frac{3}{2}}$ in the process of solving the posed problems. As the results, although the gifted students posed more word problems in the 'inverse of multiplication' and 'inverse of a cartesian product' situations compared to the general students and pre-service elementary teachers in the previous researches, most of them also preferred to understanding the meaning of fractional division in the 'measurement division' situation. Handling the fractional division by converting it into the division of natural numbers through reduction to a common denominator in the 'measurement division', they showed the poor understanding of the meaning of multiplication by the reciprocal of divisor in the fraction division algorithm. So we suggest following: First, instruction on fraction division based on various problem situations is necessary. Second, eliciting fractional division algorithm in partitive division situation is strongly recommended for helping students understand the meaning of the reciprocal of divisor. Third, it is necessary to incorporate real-world problem posing tasks into elementary mathematics classroom for fostering mathematical creativity as well as problem solving ability.

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.3
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• pp.503-522
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• 2013

In the 2009 new curriculum reform, where creativity is the key point, assessment methods for mathematical creativity is recommended. However, lessons for creativity are not carried out well in mathematics classes. One of the reasons for this is the lack of assessment methods for student's creativity and specific instructions on how teachers should evaluate their students using a written test. Therefore, in this paper, we propose a simple way to evaluate student's creativity by differentiating the student's solutions of the posed problems. For validation of the proposed method, we identified the properties of excellent problem solutions cited by both the students group and teachers group. A chi-square test was then carried out to compare any differences in frequency that each of the groups chose as an excellent solution as a result of the student's problem solving

• Kyungpook Mathematical Journal
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• v.45 no.2
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• pp.199-209
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• 2005

An ideal space is ${\cal{I}}-resolvable$ if it has two disjoint ${\cal{I}}-dense$ subsets. We answer the question: If X is ${\cal{I}}-resolvable$, then is X (${\cal{I}}\;{\cup}\;{\cal{N}$)-resolvable?, posed by Dontchev, Ganster and Rose. We give three generalizations of the well known Banach Category Theorem and deduce the Banach category Theorem as a corollary. Characterizations of completely codense ideals and ${\cal{I}-locally$ closed sets are given and their properties are discussed.