• Kyungpook Mathematical Journal
• /
• 제49권4호
• /
• pp.651-666
• /
• 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.

• 자원ㆍ환경경제연구
• /
• 제9권4호
• /
• pp.701-725
• /
• 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.

• 대한수학회보
• /
• 제61권3호
• /
• pp.837-848
• /
• 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
• /
• 제7권2호
• /
• pp.493-506
• /
• 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
• /
• 제18권1호
• /
• pp.27-39
• /
• 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.

• 마이크로전자및패키징학회지
• /
• 제20권4호
• /
• pp.41-45
• /
• 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.

• 자연, 터널 그리고 지하공간
• /
• 제21권2호
• /
• pp.103-116
• /
• 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
• /
• 제32권4호
• /
• pp.565-587
• /
• 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.

• 한국초등수학교육학회지
• /
• 제17권3호
• /
• pp.503-522
• /
• 2013

2009개정 교육과정부터 현장에서 창의성 교육에 대한 관심이 상당히 높아지고 있고, 평가에서도 '수학적 지식과 기능을 바탕으로 창의적으로 사고하는 능력'을 강조하고 있다. 이에 본 연구에서는 문제해결로서 수학창의성을 평가하는 비교적 간단한 방안을 제안한다. 수학적 창의성을 확산적 사고에 초점을 맞추어 유창성, 융통성 및 독창성 요인으로 측정하는 것은 수학이라는 본연의 특징을 반영하지 못한다는 비판도 있지만 지필고사로서는 창의적 산물의 두 가지 기준인 신기성(새로움)과 적절성(가치) 중에서 후자를 반영하기 힘들었다. 본 연구에서 수학적 문제해결에서 학생들이 제출한 해에 서로 다른 가중치를 부여하여 창의성의 적절성을 측정하는 방안에 대한 고려들을 연구하였다. 첫째, 학생과 교사가 생각하는 우수한 해의 특성은 무엇인가? 둘째, 두 집단 간 우수한 해의 판단은 일치하는가? 두 가지 의문에 대해 두 집단 모두 우수한 해는 '풀이과정이 간단하고 이해하기 쉽다.'로 요약되었으며, 반면 나쁜 풀이는 그 반대로 '풀이가 복잡하고 이해하기 힘었다.'로 약될 수 있었다. 그리고 본 연구에서 제시한 두 가지 문제해결에서 두 집단 모두 우수한 해의 순서는 일치하였다. 아울러 두 집단이 평가한 우수 해의 일치가 의미하는 바와 해의 차등화 방안에 대한 논의를 통해 수학창의성 평가 방안을 제안하였다.

• Kyungpook Mathematical Journal
• /
• 제45권2호
• /
• pp.199-209
• /
• 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.