• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.90-100
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• 2000

The present paper investigates the elasto-plastic buckling of ball-jointed single layer latticed domes considering the connection characteristics. The domes are composed of tubular member elements, ball joints and connectors. To judge yielding of the member, the ends and central part of tubular member elements are assumed as five elasto-plastic springs. Elasto-plastic buckling load can be identified the yielding load of estimated member As a numerical analysis technique, loading incremental method based on the Newton-Raphson method is used. The effects of connection characteristics are investigated by the following points; (1) the length of rigid zone, (2) looseness of screw, (3) diameter of connector Finally, it is emphasized that the connection characteristics as well as the material non-linearity have significant effects upon the buckling toad of domes.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.10
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• pp.335-340
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• 1983

The analysis of static power converter circuit using state-space method is presented. Semiconductors are modeled in two-state resistors depending on their ON or OFF states. Then the modes of circuit are determined according to the conducting states of semiconductors and different describing matrices are given automatically for each mode. Newton-Raphson algorithm is used as an iterative method for obtaining steady-state solution and an adjoint network is introduced for the efficient and accurate evaluation of the Jacobi matrix in the algorithm. Using the porogram exploited from the above algorithm, it is shown through examples that the results are in good agreement with the analytic solutions and computation time is considerably reduced for obtaining the steady-state solutions.

• KIEE International Transactions on Power Engineering
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• v.4A no.4
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• pp.192-200
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• 2004

This paper evaluates FACTS control on the available transfer capability (ATC) enhancement. Technical merits of FACTS technology on boosting ATC are analyzed. More effective control means for line flow and bus voltage require the application of FACTS. In this paper, the power flow calculation method for the power systems with FACTS is based on the current injection model (CIM) and the Newton-Raphson method. An integrated scheme for ATC calculation, which considers the dynamic characteristic of the power system, is suggested. The study is applied to the IEEE 57-bus power system to demonstrate the effectiveness of FACTS control on ATC enhancement.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.151-153
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• 2006

we present a method of sequential speech enhancement, where we infer clean speech signal using a Rao-Blackwellized particle filter (RBPF), given a noise-contaminated observed signal. In contrast to Kalman filtering-based methods, we consider a non-Gaussian speech generative model that is based on the generalized auto-regressive (GAR) model. Model parameters are learned by a sequential Newton-Raphson expectation maximization (SNEM), incorporating the RBPF. Empirical comparison to Kalman filter, confirms the high performance of the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.8
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• pp.446-453
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• 2004

This paper focuses on the evaluation of FACTS control on available transfer capability(ATC) enhancement. Technical merit of FACTS technology on ATC boosting are analyzed. More effective control means for line flow and bus voltage are required for appling FACTS. In this paper, the power flow calculation method for deriving FACTS control parameters based on current injection model(CIM) and newton method. Integrated scheme for ATC calculation considering dynamic characteristic of power system is suggested. Study is based on the IEEE 57-bus system demonstrate the effectiveness of FACTS control on ATC enhancement.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.134-136
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• 1993

This paper presents a novel and efficient method to calculate the critical point of voltage collapse. Conjugate gradient and modified Newton-Raphson methods are employed to calculate two pairs of multiple load flow solutions for two operating conditions, i.e., both +mode and -mode voltages for two loading conditions respectively. Then these four voltage magnitude-load data sets of the bus which is most susceptible to voltage collapse, are fitted to third order polynomial using Lagrangian interpolation in order to represent approximate nose curve (P-V curve). This nose curve locates first estimate of the critical point of voltage collapse. The procedure described above is repeated near the critical point and the new estimate will be very close to the critical point. The proposed method is tested for the eleven bus Klos-Kerner system, with good accuracy and fast computation time.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.324-326
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• 2000

A 3D magnetostatic field is analyzed considering the non-linear characteristics of the material using finite element method. In the finite element formulation, the edge element is adopted since it reduces the required computer memory and the computing time. The modified Newton-Raphson method is also used for non-linear analysis. A numerical example with the TEAM workshop problem 13 is analyzed, and the results are proved to concide well with measured ones.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.24-27
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• 2004

This paper proposes a new algorithm of underground cable fault location based on the analysis of distributed parameter circuit. The proposed method firstly makes voltage and current equations for each of cores and sheathes respectively, and then establishes an equation of the fault distance according to the analysis of the fault conditions. Finally the solution of this equation is calculated by Newton-Raphson iteration method. The effectiveness of this proposed algorithm has been proven through PSCAD/EMTDC simulations.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.569-571
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• 1993

This paper describes a life expectation of electrical insulating materials using a mathematical model. The mathod simultaneously uses the maximum likelihood estimation and the Newton-Raphson method. By using these method, we will reduce time and costs in voltage-life aging test.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.11
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• pp.969-976
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• 2007

In this thesis, an anchoring energy in the upper and lower substrates of TFT-LCD cell has been modeled and applied in the numerical calculation of the molecular orientation of the TN-LCD. The molecular orientation of liquid crystals defined as tilt and twist angles was simulated using the Newton-Raphson method and the Gaussian integration method. From the results, the tilt and twist angles for the strong anchoring energy were proven to be coincide with those of the conventional results. on the other hand, for the weak anchoring energy, azimuth angles of the molecules were changed abruptly from $0^{\circ}\;to\;90^{\circ}$ near the middle area of the cell due to the balance of the anchoring energy and the elastic energy of the liquid crystals.