• Journal of applied mathematics & informatics
• /
• 제7권3호
• /
• pp.959-968
• /
• 2000

The existence of the operator-valued Feynman integral was established when a Wiener functional is given by a Fourier transform of complex Borel measure [1]. In this paper, I investigate a stability of the Feynman integral with respect to the potentials.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2013년 춘계학술대회
• /
• pp.263-270
• /
• 2013

• Journal of Electrical Engineering and Technology
• /
• 제10권1호
• /
• pp.83-91
• /
• 2015

This paper presents preventive and emergency control measures for on line transient stability (security) enhancement. For insecure operating state, generation rescheduling based on a real power generation shift factor (RPGSF) is proposed as a preventive control measure to bring the system back to secure operating state. For emergency operating state, two emergency control strategies namely generator shedding and load shedding have been developed. The proposed emergency control strategies are based on voltage magnitudes and rotor trajectories data available through Phasor Measurement Units (PMUs) installed in the systems. The effectiveness of the proposed approach has been investigated on IEEE-39 bus test system under different contingency and fault conditions and application results are presented.

• ETRI Journal
• /
• 제37권2호
• /
• pp.428-437
• /
• 2015

This study was conducted to analyze the effect of information security activities on organizational performance. With this in mind and with the aim of resolving transaction stability in the securities industry, using an organization's security activities as a tool for carrying out information security activities, the effect of security activities on organizational performance was analyzed. Under the assumption that the effectiveness of information security activities can be bolstered to enhance organizational performance, such effects were analyzed based on Herzberg's motivation theory, which is one of the motivation theories that may influence information protection activities. To measure the actual attributes of the theoretical model, an empirical survey of the securities industry was conducted. In this explorative study, the proposed model was verified using partial least squares as a structural equation model consisting of IT service, information security, information sharing, transaction stability, and organizational performance.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.2759-2764
• /
• 2003

Humans usually employ more joints than they actually need, and thus they can be categorized as a kinematically redundant system. Therefore, the behavior of the human body can be analyzed by several redundancy resolution algorithms. Different from typical industrial robots that are fixed to the ground, the COG/ZMP condition should be taken into account in the human body motion in order not to fall down. Thus a COG/ZMP stability index is employed as a measure of stability. Kinematic redundancy inherent in the human body can be exploited to satisfy the COG/ZMP condition. Simulation result shows that the COG/ZMP condition can be satisfied by exploiting the null space motion of the kinematically redundant human body model.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
• /
• pp.360-365
• /
• 1993

In this paper, we propose a new design procedure of the Robust Model Matching(RM) using the Normalized Left Coprime Factorization (NLCF) approach. The RMM aims at reducing the sensitivity of a given control system, but standard design procedures are not for robust stability. Therefore we try applying the robust stability condition based on NLCF to RMM procedure. We first formulate the RMM using the robust stability condition of NLCF approach, then we propose the new procedure of the RMM. The point is that the condition includes the measure of sensitivity of the RMM. In the proposed procedure, a cost function is determined through the condition and solved by H$_{\infty}$ contro technique. Finally we show a design example and check the performance..

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2002년도 제35회 춘계학술대회
• /
• pp.130-134
• /
• 2002

Polyol esters were synthesized by condensation reaction of polyols (PE and DIPE) and linear acids such as valeric acid, caproic acid, heptylic acid and caprylic acid. The structures of polyol esters were confirmed by gas chromatography. Hot tube test was used to measure thermal stability of polyol esters and its thermal properties depended on the structure of acid moiety contained in polyol esters.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1992년도 하계학술대회 논문집 A
• /
• pp.285-287
• /
• 1992

This paper considers the design of robust stabilizing controller of a linear time-invariant digital system subject to variations of parameter vector. For a given controller the radius of the largest stability hypersphere in this parameter space is calculated. This radius is a measure of the stability Margin of the closed-loop system. Based on this calculation a design procedure is proposed to robustify a given stabilizing controller. This algorithm iteratively enlarges the stability hypersphere in parameter space and can be used to design a controller to stabilize a plant subject to given ranges of parameter perturbations. These results are illustrated by an example.

• Journal of Electrical Engineering and Technology
• /
• 제3권4호
• /
• pp.468-475
• /
• 2008

This paper presents a method for estimating the transient stability status of the power system using radial basis function(RBF) neural network with a fast hybrid training approach. A normalized transient energy margin(${\Delta}V_n$) has been obtained by the potential energy boundary surface(PEBS) method along with a time-domain simulation technique, and is used as an output of the RBF neural network. The RBF neural network is then trained to map the operating conditions of the power system to the ${\Delta}V_n$, which provides a measure of the transient stability of the power system. The proposed approach has been successfully applied to the 10-machine 39-bus New England test system, and the results are given.

• 한국안전학회지
• /
• 제12권4호
• /
• pp.134-142
• /
• 1997

The stability of an embankment Impounding a water reservoir is highly depend upon the location of seepage line with the embankment. To evaluate the accurate safety factor of an embankment, it is important to illustrate the seepage phenomenon. Of particular interest is the stability following a rapid change (drawdown) of reservoir level Seepage forces in embankments are easily determined if frictional forces are expressed in relation to hydraulic gradient Ⅰ. If a piezometer is inserted into a body of embankment, the level to which free water rises is a measure of the energy at that point. From model test result, it is possible to calculate safety factors of earth embankment. To assure the validity of this research, tests were conducted with numerical experimental models. And the experiment models were constructed with slopes of 1:1.0, 1:1.5, 1:2.0, 1:2.5. Analysis of experimental results, seepage force was analyzed according to downstream time, internal friction angle and cohesion, respectively.