• Kyungpook Mathematical Journal
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• v.61 no.3
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• pp.513-522
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• 2021

In this paper we investigate a subclass 𝓜(α) of the class of starlike functions in the unit disk |z| < 1. 𝓜(α), π/2 ≤ α < π, is the set of all analytic functions f in the unit disk |z| < 1 with the normalization f(0) = f'(0) - 1 = 0 that satisfy the condition $$1+\frac{{\alpha}-{\pi}}{2\;sin\;{\alpha}}. The class 𝓜(α) was introduced by Kargar et al. [Complex Anal. Oper. Theory 11: 1639-1649, 2017]. In this paper some basic geometric properties of the class 𝓜(α) are investigated. Among others things, coefficients estimates and bound are given for the Fekete-Szegö functional associated with the k-th root transform [f(z^k)]^1/k. Also a certain subclass of bi-starlike functions is introduced and the bounds for the initial coefficients are obtained.

• Nonlinear Functional Analysis and Applications
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• v.26 no.4
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• pp.855-868
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• 2021

If p(z) is a polynomial of degree n having all its zeros in |z| ≤ k, k ≤ 1, then for 𝜌R ≥ k² and 𝜌 ≤ R, Aziz and Zargar [4] proved that $${\max_{{\mid}z{\mid}=1}}{\mid}p^{\prime}(z){\mid}{\geq}n{\frac{(R+k)^{n-1}}{({\rho}+k)^n}}\{{\max_{{\mid}z{\mid}=1}}{\mid}p(z){\mid}+{\min_{{\mid}z{\mid}=k}}{\mid}p(z){\mid}\}$$. We prove a generalized L^r extension of the above result for a more general class of polynomials $p(z)=a_nz^n+\sum\limits_{{\nu}={\mu}}^{n}a_n-_{\nu}z^{n-\nu}$, $1{\leq}{\mu}{\leq}n$. We also obtain another L^r analogue of a result for the above general class of polynomials proved by Chanam and Dewan [6].

• Nonlinear Functional Analysis and Applications
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• v.27 no.3
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• pp.569-585
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• 2022

A brief comparative survey of some generalizations of a metric space with three dimensional metric structures and different forms of the triangle inequality is done along with their topological properties. Then a common fixed point is obtained for reciprocally continuous and compatible self-maps in a G-metric space. Further, a common fixed point theorem is proved for a pair of weakly compatible self-maps on a G-metric space with the common limit range property.

• Nonlinear Functional Analysis and Applications
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• v.28 no.3
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• pp.613-622
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• 2023

In this paper, finite element method is applied to solve boundary control problem governed by elliptic variational inequality with an infinite number of variables. First, we introduce some important features of the finite element method, boundary control problem governed by elliptic variational inequalities with an infinite number of variables in the case of the control and observation are on the boundary is introduced. We prove the existence of the solution by using the augmented Lagrangian multipliers method. A triangular type finite element method is used.

• Nonlinear Functional Analysis and Applications
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• v.27 no.2
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• pp.381-403
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• 2022

The main goal of this research is to solve variational inequalities involving quasimonotone operators in infinite-dimensional real Hilbert spaces numerically. The main advantage of these iterative schemes is the ease with which step size rules can be designed based on an operator explanation rather than the Lipschitz constant or another line search method. The proposed iterative schemes use a monotone and non-monotone step size strategy based on mapping (operator) knowledge as a replacement for the Lipschitz constant or another line search method. The strong convergences have been demonstrated to correspond well to the proposed methods and to settle certain control specification conditions. Finally, we propose some numerical experiments to assess the effectiveness and influence of iterative methods.

• Nonlinear Functional Analysis and Applications
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• v.29 no.2
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• pp.451-460
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• 2024

If a₀ + Σⁿ_ν=μ a_νz^ν, 1 ≤ µ ≤ n, is a polynomial of degree n having no zeroin |z| < k, k ≥ 1 and p'(z) its derivative, then Qazi [19] proved $$\max_{{\left|z\right|=1}}\left|p\prime(z)\right|\leq{n}\frac{1+\frac{{\mu}}{n}\left|\frac{a_{\mu}}{a_0} \right|k^{{\mu}+1}}{1+k^{{\mu}+1}+\frac{{\mu}}{n}\left|\frac{a_{\mu}}{a_0} \right|(k^{{\mu}+1}+k^{2{\mu}})}\max_{{\left|z\right|=1}}\left|p(z)\right|$$ In this paper, we not only obtain the L^r version of the polar derivative of the above inequality for r > 0, but also obtain an improved L^r extension in polar derivative.

• 한국노년학
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• v.36 no.3
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• pp.611-632
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• 2016

Solutions for elderly health issues need to be found that take into account not only a medical perspective, but also interactions with social conditions such as socioeconomic status. With this in mind, this study aims to understand how socioeconomic status leads to health inequalities for the elderly. Specifically, this study investigates the mediating effects of socioeconomic status(income and education levels), health activities as an intermediary of the three dimensions of physical health(medical health, functional health, subjective health), accessibility of medical facilities, social participation, and social network. To test the research model, a secondary data analysis was conducted on the 2014 National Survey of Senior Citizens. The participants of the study were 10,451 elderly men and women aged 65 and above. To test the mediated model, hierarchical multiple regression analysis was conducted following the procedures suggested by Baron and Kenny(1986). In addition, a Sobel test was conducted to test the mediated model's significance. According to the analysis, the effects of income and educational levels on the health of the elderly were not the same. Additionally, different results were found depending on health dimensions. However, the overall direction of the results showed that the socioeconomic status of the elderly creates health disparities, and health behaviors, accessibility of medical facilities, social participation, and social network had significant mediation effects between socioeconomic status and physical health. Study findings especially worth noting are as follows: education was shown to have a stronger effect on health than income; effects of social integration factors such as social participation were highlighted; and significant mediating effects on the accessibility of medical facilities remained even after taking residential area into account. Results of this study shed light on health inequality mechanisms due to socioeconomic conditions and the need to find alternatives to alleviate these problems.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.7
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• pp.976-986
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• 2014

In this paper, the problem of reliable control of linear systems with time-varying delays, randomly occurring disturbances, and actuator failures is investigated. It is assumed that actuator failures occur when disturbances affect to the systems. Firstly, by using a suitable Lyapunov-Krasovskii functional and some recent techniques such as Wirtinger-based integral inequality and reciprocally convex approach, stabilization criterion for nominal systems with time-varying delays is derived. Secondly, the proposed method is extended to the reliable $H_{\infty}$ controller design for linear dynamic systems with time-varying delays, randomly occurring disturbances, and actuator failures. Since nonlinear matrix inequalities (NLMIs) are involved in proposed results, the cone complementarity algorithm will be introduced. Finally, two numerical examples are included to show the effectiveness of the proposed criteria.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.12
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• pp.1330-1337
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• 2004

In this study, the equations of motion of a rigid rotor supported by magnetic bearings are derived via Hamilton's principle, and transformed to a state-space form for control purpose. The optimal motion control of rotor magnetic bearing system based on the LQR(linear quadratic regulator) theory is addressed. New schemes related to the selection of the state weighting matrix Q and the control weighting matrix R involved in the quadratic functional to be minimized are proposed. And the robust control of the system with an LMI(linear matrix inequality) based H$_{\infty}$ theory is dealt with in this paper. Loop shapings of TFM (transfer function matrix) are used to increase the performance of control capability of the system. The control abilities of LQR and H$_{\infty}$ controller are compared by simulation and experimental tests and show that the capability of H$_{\infty}$ controller is superior to that of LQR.

• Journal of Preventive Medicine and Public Health
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• v.26 no.1 s.41
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• pp.1-19
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• 1993

Mail questionnaire was administrated to 370 practising physicians and 388 pharmacists in Taegu city selected by systematic sampling to examine utilization states and opinion of pharmacy under medical care insurance programme and the attitude to the functional division between physicians and pharmacists from April to May 1992. Regarding the opinion on the outcome of drug-store under medical insurance, 71.2 percent of practicing physician answered faliure but 13.4 percent of practicing pharmacists answered failure in contrast. Fifty percent of practicing physician asserted introducing functional division between physician and pharmacist while 66.9 percent of practicing pharmacist answered drug-store under medical insurance itself is sucessful programme. Average daily numbers of preparation of medicine was 32.2 case. Percentage of utilization of drug-store under medical issurance to average daily cases of preparing of medicine was 20 percent, percentage of utilization with physician's prescription was 0.7 percent. And 58.7 percent of practicing physician experienced outside the institute prescription. Regarding the opinion on the pros and cons of enforcing functional division between physician and pharmacist, 59.2 percent of practicing physician prefered pros and 17.7 percent cons, but 38 percent of practicing pharmacist prefered pros and 45.5 percent cons. And pharmacist knew better the content of functional division between physician and pharmacist than physician. As a reason for pros of enforcing functional division between physician and pharmacist, practicing physician emphasized to prevent misuse or abuse of medicine but practicing pharmacist emphasized to display physician and pharmacist's professional ability. And as an opinion on implementation style of functional division between physician and pharmacist in pros respondents, practicing physician favored mandatory enforcement (52.3%), while practicing pharmacist favored partial incomplete functional division (81.7%). As the method of prescription if functional division between physician and pharmacist will be enforced, both practicing physician and pharmacist prefered generic name (44.0%, 89%) mostly, but physician prefered brand name (35.3%) secondly. Regarding the reason for not implementing functional division between physician and pharmacist up to date, both physician and pharmacist answered problem of business right between physician and pharmacist, followed by lack of recognition, and interest of people and lack of the govermental willness. Regarding the opinion on prior decision of condition for enforcing functional division between physician and pharmacist, practicing physician and pharmacist named uneven distribution of medical facilities and drug-store between rural and urban, inequality of physician and pharmacist manpower and the problem of manpower demand and supply mostly, and practicing physician pointed out establishing attitude of acceptance on the part of pharmacist and practicing pharmacist favored establishing attitude of acceptance on the part of physician, which was different attitudes between physician and pharmacist. Following conclusion was reached ; 1. Current drug-store under medical insurance program yield insufficient outcome, so we should consider program conversion from drug-store under medical insurance program to functional division between physician and pharmacist. 2. There were problem of business right and conflicts between physician and pharmacist at enforcing functional division between physician and pharmacist, so the goverment should search for formulating plan to resolve the problem and have neutral willness for the protection of the national health.