• East Asian mathematical journal
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• 제24권3호
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• pp.263-274
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• 2008

Let $r\;{\geq}\;q$. We get the stability of the estimates of the $\bar{\partial}$-Neumann problem for (p, r)-forms on a weakly q-convex complex submanifold. As a by-product of the stability of the $\bar{\partial}$-estimates, we get the Mergelyan approximation property for (p, r)-forms on a weakly q-convex complex submanifold which satisfies property (P).

• 약학회지
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• 제25권1호
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• pp.37-42
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• 1981

Penicillin derivatives have a stability problem by hydrolysis of their .betha.-lactam ring. At high temperature, crystal water is released from penicillin derivatives, especially ampicillin trihydrate and concerns itself in hydrolysis. Penicillin derivatives having crystal water show different crystal states and different stability according to the variation of different condition on the process of manufacturing. The stability of ampicillin trihydrate in solid states was determined. Physico-pharmaceutical properties of this compound were determined by using IR spectra, X-ray powder diffraction and differential thermal analysis (DTA).

• 호남수학학술지
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• 제22권1호
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• pp.37-46
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• 2000

We prove the stability of a generalized Cauchy functional equation of the form ; $$f(a_1x+a_2y)=b_1f(x)+b_2f(y)+w.$$ That is, we obtain a partial answer for the open problem which was posed by the Th.M Rassias and J. Tabor on the stability for a generalized functional equation.

• 항공우주시스템공학회지
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• 제7권4호
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• pp.27-35
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• 2013

Identifying the stability of rotor systems is prerequisite for clear determination of the parameter identification and safety, through which operating conditions may be rationally ascertained. For this purpose, the complex modal analysis of periodically time-varying system has been introduced by transforming the relation between periodic eigen-vectors and the corresponding adjoint vectors into the latent value problem. Stability investigation associated with modal features for rotor systems is performed using numerical simulation based upon the analysis model.

• Journal of Electrical Engineering and Technology
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• 제6권5호
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• pp.713-722
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• 2011

In the present paper, the problem of stability analysis for linear systems with interval time-varying delays is considered. By introducing a new Lyapunov-Krasovskii functional, new stability criteria are derived in terms of linear matrix inequalities (LMIs). Two numerical examples are given to show the superiority of the proposed method.

• 전기학회논문지
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• 제58권11호
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• pp.2261-2265
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• 2009

In this paper, the problem of delay-dependent stability of uncertain stochastic systems with time-varying delay is considered. The uncertainties are assumed to be norm-bounded. Based on the Lyapunov stability theory, new delay-dependent stability criteria for the system are derived in terms of LMI(linear matrix inequality). Two numerical examples are given to show the effectiveness of proposed method.

• Structural Engineering and Mechanics
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• 제8권2호
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• pp.193-205
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• 1999

A formulation for the dynamic stability analysis of cylindrical shells resting on elastic foundations is presented. In this previously not studied problem, a normal-mode expansion of the partial differential equations of motion, which includes the effects of the foundation as well as a harmonic axial loading, yields a system of Mathieu-Hill equations the stability of which is analyzed using Bolotin's method. The present study examines the effects of the elastic foundation on the instability regions of the cylindrical shell for the transverse, longitudinal and circumferential modes.

• Nonlinear Functional Analysis and Applications
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• 제29권1호
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• pp.165-177
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• 2024

In this paper, we investigate the suitable conditions for the existence results for a class of 𝔍-Hilfer fractional nonlinear Fredholm-Volterra models with new conditions. The findings are based on Banach contraction principle and Schauder's fixed point theorem. Also, the generalized Hyers-Ulam stability and generalized Hyers-Ulam-Rassias stability for solutions of the given problem are provided.

• 제어로봇시스템학회논문지
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• 제6권9호
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• pp.768-776
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• 2000

A robust high-speed motion controller is proposed. The proposed controller consists of the proximate time optimal servomechai는 (PTOD) for high-speed motion, disturbance observer (DOB) for robustness, friction compensator, and saturation handling element, In the proposed controller, DOB basically provides the chance to apply PTOS to non-double integrator systems by drastically reducing disturbances as well as unwanted signals due to difference between real system and the double integrator model. But, in DOB-based systems, if control input is saturated due to control input PTOS and/or DOB, overall system stability cannot be guaranteed. To solve this problem, ribust stability, when the control input is saturated. Eventually, a simple saturation handling element is inserted to maintain internal stability of overall system. Also, we explain the our two saturation handling methods, Additional Saturation Element (ASE_ and Self Adjusting Saturation (SAS), are the equivalent solutions of the saturation problem to maintain internal stability. The stability and performance of the proposed controller are verified through numerical simulations and experiments using a precision linear motor system.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.651-656
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• 2002

In general, the most important problem in slope stability analysis is that there is no definite way to describe the natural three-dimensional Joint network. Therefore, the many approaches were tried to anlayze the slope stability. Numerical modeling approach is one of the branch to resolve the complexity of natural system. UDEC, FLAC, and SWEDGE are widely used commercial code for the purpose on stability analysis. For the purpose on the more appropriate application of these kind of code, however, three-dimensional distribution of joint network must be identified in more explicit way. Remaining problem is to definitely describe the three dimensional network of joint and bedding, but it is almost impossible in practical sense. Three dimensional joint generation method with random number generation and the results of generation to UDEC have been applied to settle the refered problems in field site. However, this approach also has a important problem, and it is that joint network is generated only once. This problem lead to the limitation on the application to field case, in practical sense. To get rid of this limitation, Monte Carlo Simulation is proposed in this study 1) statistical analysis of input values and definition of the applied system with statistical parameter, 2) instead of the consideration of generated network as a real system, generated system is just taken as one reliable system, 3) present the design parameters, through the statistical analysis of ouput values Results of this study are not only the probability of failure, but also area of failure block, shear strength, normal strength and failure pattern, and all of these results are described in statistical parameters. The results of this study, shear strength, failure area, pattern etc, can provide the direct basement on the design, cutoff angle, support pattern, support strength and etc.