• Journal of the Korean Mathematical Society
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• v.37 no.6
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• pp.1043-1057
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• 2000

This paper is devoted to the investigation of mixed Fourier-Bessel transformation (※Equations, See Full-text) We apply the method of [6] which provides the estimate for weighted L(sub)$\infty$-norm of the spherical mean of │f│$^2$ via its weighted L$_1$-norm (generally it is wrong without the requirement of the non-negativity of f). We prove that in the case of Fourier-Bessel transformatin the mentioned method provides (in dependence on the relation between the dimension of the space of non-special variables n and the length of multiindex ν) similar estimates for weighted spherical means of │f│$^2$, the allowed powers of weights are also defined by multiindex ν. Further those estimates are applied to partial differential equations with singular Bessel operators with respect to y$_1$, …, y(sub)m and we obtain the corresponding estimates for solutions of the mentioned equations.

• Proceedings of the Korean Statistical Society Conference
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• 2000.11a
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• pp.105-108
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• 2000

We consider a Markovian retrial queue with waiting space in which the service rates and retrial rates depend on the number of customers in the service facility and in the orbit, respectively. Each arriving customer from outside or orbit decide either to enter the facility or to join the orbit in Bernoulli manner whose entering probability depend on the number of customers in the service facility. In this paper, a stochastic order relation between two bivariate processes (C(t), N(t)) representing the number of customers C(t) in the service facility and N(t) one in the orbit is deduced in terms of corresponding parameters by constructing the equivalent processes on a common probability space. Some applications of the results to the stochastic bounds of the multi-server retrial model are presented.

• Journal of the Korean Statistical Society
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• v.29 no.4
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• pp.473-488
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• 2000

We consider a Markovian retrial queue with waiting space in which the service rates and retrial rates depend on the number of customers in the service facility and in the orbit, respectively. Each arriving customer from outside or orbit decide either to enter the facility or to join the orbit in Bernoulli manner whose entering probability depend on the number of customers in the service facility. In this paper, a stochastic order relation between two bivariate processes(C(t), N(t)) representing the number of customers C(t) in the service facility and one N(t) in the orbit is deduced in terms of corresponding parameters by constructing the equivalent processes on a common probability space. some applications of the results to the stochastic bounds of the multi-server retrial model are presented.

• Structural Engineering and Mechanics
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• v.12 no.1
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• pp.85-100
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• 2001

In this paper, an analytical procedure for solving several static and dynamic problems of non-uniform beams is proposed. It is shown that the governing differential equations for several stability, free vibration and static problems of non-uniform beams can be written in the from of a unified self-conjugate differential equation of the second-order. There are two functions in the unified equation, unlike most previous researches dealing with this problem, one of the functions is selected as an arbitrary expression in this paper, while the other one is expressed as a functional relation with the arbitrary function. Using appropriate functional transformation, the self-conjugate equation is reduced to Bessel's equation or to other solvable ordinary differential equations for several cases that are important in engineering practice. Thus, classes of exact solutions of the self-conjugate equation for several static and dynamic problems are derived. Numerical examples demonstrate that the results calculated by the proposed method and solutions are in good agreement with the corresponding experimental data, and the proposed procedure is a simple, efficient and exact method.

• Structural Engineering and Mechanics
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• v.61 no.2
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• pp.275-282
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• 2017

The Fleck-Hutchinson theory on strain gradient plasticity (SGP), proposed in Adv. Appl Mech 33 (1997) 295, has recently been reformulated by adopting the strategy of decomposing the second order strain presented by Lam et al. in J Mech Pays Solids 51 (2003) 1477. The newly built SGP satisfies the non negativity of plastic dissipation, which is still an outstanding issue in other SGP theories. Furthermore, it explicitly shows how elastic strain gradients and corresponding elastic characteristic length scales come into play in general elastic-plastic loading histories. In this study, the relation between elastic length scales and plastic length scales is investigated by taking wire torsion as an example. It is concluded that the size effects arising when two sets of length scales are of the same order are essentially elastic instead of plastic.

• The Korean Journal of Physiology
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• v.28 no.1
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• pp.19-25
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• 1994

On the basis of morphological and functional studies, it is now established that there exist multiple motor representation areas in the frontal lobe of subhuman primates. Recent development of analysis on cerebral critical organization in human subjects, utilizing novel techniques of PET and MRI, provides evidence of corresponding motor areas. Each area has its unique sources of inputs from the thalamus and from other parts of the cerebral cortex. To understand functional roles of these multiple motor areas, it is necessary to study neural activity while subjects are performing a variety of motor tasks. In view of high accuracy in spatial and temporal resolution, the analysis of single cells in relation to specific aspects of motor behavior remains to be a powerful research technique. It is with this technique that a number of novel concepts on functional roles of multiple motor areas have been proposed.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.620-627
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• 2007

In this study a general analysis method for watersheds with the entire runoff conditions and corresponding water quality is proposed and its applicability based on the currently available information is investigated. Using the 8-day-interval data set of runoff and water quality observed by Nakdong River Environment Research Center, the flow duration curve and discharge-load relation curve for each unit watershed are established, then the load duration curve is finally constructed. This paper discusses how the load duration curve can be used in the assessment of TMDL. The entire Nakdong river watershed is also divided into prior managing areas of point sources or non-point sources in a way of general management. It is thought that LDC can be a great tool for visualizing overall probabilities of current water quality and thus for the TMDL management.

• Fisheries and Aquatic Sciences
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• v.5 no.4
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• pp.271-280
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• 2002

Ovarian cycle, marsupial development and molt cycle of Archaeomysis kokuboi were studied to understand these processes as a whole event. Based on morphological characters the marsupial development is divided into 3 stages, Embryonic stage (duration time of 4 days), Nauplioid stage (5 days) and Postnauplioid stage (4 days). Morphological description was ma de for the 3 stages, and each stage was examined in relation to the corresponding stages of ovarian cycle and molt cycle.

• The Journal of Information Systems
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• v.13 no.1
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• pp.39-57
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• 2004

As a result of the fast development of Information communication technology, the competitive advantage of companies and the service quality of nonprofit organizations has been largely changed. Corresponding to this kind of change, companies have tried to make production improvement, competitive strengthening, and organizational innovation. Meanwhile, the nonprofit organizations directed by the government are pursuing the service innovation from general administration area to the public service for civilians. In relation to this, risk management of the company's information systems outsourcing has largely been studied until now. However, the study of risk management for nonprofit organization information systems outsourcing has rarely been made. In this paper, to provide the theoretical base for further research, we have attempted to develop the evaluation framework for risk management of information systems outsourcing considering the characteristics of nonprofit organizations.

• Convergence Security Journal
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• v.2 no.2
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• pp.67-75
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• 2002

The purpose of this study is to reflect the risk analysis results acquired while building an information system of an organization by applying a risk analysis model capable of analyzing the confronted risk, on the information system build methodology. Risk analysis, a method of utilizing the functional relation between risk, vulnerability and countermeasure of information assets, is used to evaluate the overall information risk level by analyzing the influence range of vulnerability imposed in the information asset of an organization, and the applications of the countermeasures on the frequency and intensity of the corresponding risk.