Efficient Method for Analysis of Gyrodevices With Slotted Cavities

The efficient bounding method for DC contingency analysis is improved using reciprocity properties. Knowing the consequences of the outage of a branch, these properties provide the consequences on that branch of various kinds of outages. This is used in order to reduce computation times and to get rid of some difficulties, such as those occurring when a branch flow is close to its limit before outage. Compensation, sparse vector, sparse inverse and bounding techniques are also used. A program has been implemented for single branch outages and tested on the actual French EHV 650 bus network. Computation times are 60% of the efficient bounding method. The relevant algorithm is described in detail in the first part of this paper. In the second part, reciprocity properties and bounding formulas are extended for multiple branch outages and for multiple generator or load outages. An algorithm is proposed in order to handle all these cases simultaneously.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An efficient contingency evaluation method for power system security analysis

This paper presents an efficient numerical method for the harmonic analysis of viscoelastically damped structural systems characterized by a frequency‐dependent structural damping matrix, making use of the complex mode superposition method. Departing from the undamped eigensolution, the proposed numerical method updates the complex and frequency‐dependent eigenpair avoiding the solution of a complex eigenproblem for each computational frequency. The complex eigenvalues and eigenvectors are updated within the desired tolerance by an adaptive step‐size control scheme using the first‐ and higher order eigenderivatives. The influence on the computation time of the considered number of eigenderivatives and the tolerance is discussed, and the efficiency of the proposed numerical method for the harmonic analysis of viscoelastically damped large‐ordered structural systems is proved. Finally, a practical application is presented where the harmonic response of a constrained layer damping cantilever beam subjected to a base motion is analyzed. The complex and frequency‐dependent eigenvalues and eigenvectors are computed, the modal contributions to the total response are determined, and the total response is approximated by the complex mode superposition method. Finally, the approximated response is validated with the exact one computed by the direct frequency method and with that experimentally measured. Copyright © 2011 John Wiley &amp; Sons, Ltd.

Yield has always been a driving consideration during fabrication of modern semiconductor industry. Statistically, the largest portion of wafer yield loss is defective scan failure. This paper presents efficient failure analysis methods for initial yield ramp up and ongoing product with scan diagnosis. Result of our analysis shows that more than 60% of the scan failure dies fall into the category of shift mode in the very deep submicron (VDSM) devices. However, localization of scan shift mode failure is very difficult in comparison to capture mode failure because it is caused by the malfunction of scan chain. Addressing the biggest challenge, we propose the most suitable analysis method according to scan failure mode (capture / shift) for yield enhancement. In the event of capture failure mode, this paper describes the method that integrates scan diagnosis flow and backside probing technology to obtain more accurate candidates. We also describe several unique techniques, such as bulk back-grinding solution, efficient backside probing and signal analysis method. Lastly, we introduce blocked chain analysis algorithm for efficient analysis of shift failure mode. In this paper, we contribute to enhancement of the yield as a result of the combination of two methods. We confirm the failure candidates with physical failure analysis (PFA) method. The direct feedback of the defective visualization is useful to mass-produce devices in a shorter time. The experimental data on mass products show that our method produces average reduction by 13.7% in defective SCAN & SRAM-BIST failure rates and by 18.2% in wafer yield rates.

In this paper, a simple and efficient numerical method to solve for the dynamic interaction of a high-speed train and railway structure during an earthquake is given. The motion of the train is modeled in multibody dynamics with nonlinear springs and dampers used to connect components. An efficient mechanical model for contact dynamics between the wheel and rail during an earthquake is presented. The railway structure is modeled with various finite elements. A nonlinear spring element based on a trilinear elastic-plastic material model is given for the concrete railway structure during an earthquake. A substructure model where a train runs repeatedly has been devised to obtain an approximated combined motion of the long train with many cars connected and the railway structure during an earthquake. A modal method has been developed to solve large-scale nonlinear equations of motion of the train and railway structure effectively. Based on the present method, a computer program DIASTARS for the dynamic interaction analysis of a Shinkansen train (high-speed train in Japan) and the railway structure during an earthquake has been developed. Numerical examples are demonstrated.

In this paper, a simple and efficient numerical method to solve for the dynamic interaction of a Shinkansen train (high-speed train in Japan) and railway structure during an earthquake is given. The motion of the train is modeled in multibody dynamics with nonlinear springs and dampers used to connect components. An efficient mechanical model for contact dynamics between wheel and rail during an earthquake is presented. The railway structure is modeled with various finite elements. A three-dimensional nonlinear spring element based on a trilinear elastic-plastic material model is given for the concrete railway structure during an earthquake. A loop structure model has been devised to obtain an approximated combined motion of the train and railway structure during an earthquake. A modal method has been developed to solve large-scale nonlinear equations of motion of the train and railway structure effectively. Based on the present method, a computer program DIASTARS for the dynamic interaction of a Shinkansen train and railway structure during an earthquake has been developed. Numerical examples are demonstrated.

Precise simulation of magnetic field in the air gap is necessary to Predict of electromagnetic performance of permanent magnet machines. In this paper an analytical approach is proposed to calculate the magnetic field of slot-less Axial flux permanent magnet machine. Finite element method is the most precise method for magnetic calculation in the air gap although because of its low speed calculation is not appropriate for parametric and optimization studies. In this paper, an efficient analytical method is used to parametric studies on magnetic field in the air gap in case of no-load operation. By applying above mentioned method with high analytical speed, flux density in the middle of air gap is predicted and then induced voltage is calculated. Result of proposed analytical method is compared with 3-D FEM simulations that are reached from Ansys-Electronics software. These results are in the form of Quasi-3D.

While vitamin D3 is recognized as a neuroactive steroid affecting both brain development and function, efficient analytical method in determining vitamin D3 metabolites in the brain tissue is still lacking, and the relationship of vitamin D3 status between serum and brain remains elusive. Therefore, we developed a novel analysis method by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to simultaneously quantify the concentrations of 25-hydroxyvitamin D3 (25(OH)D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) in the serum and brain of rats fed with different dose of vitamin D3. We further investigated whether variations of serum vitamin D3 metabolites could affect vitamin D3 metabolite levels in the brain. Serum and brain tissue were analyzed by HPLC-MS/MS with electrospray ionization following derivatization with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD). The method is highly sensitive, specific, and accurate to quantify 25(OH)D3 and 24,25(OH)2D3 in animal brain tissue. Vitamin D3 metabolites in brain tissue were significantly lower in rats fed with a vitamin D deficiency diet than in rats fed with high vitamin D3 diet. There was also a strong correlation of vitamin D3 metabolites in serum and brain. These results indicate that vitamin D3 status in serum affects bioavailability of vitamin D3 metabolites in the brain.

Plane‐wave scattering by metallic grating with artificial anisotropic substrate is a problem solved in this study for the design of broadband reflectarrays. For determination of the reflection characteristics of such structures, a generalised transmission line modelling is used for evaluating the dyadic Green's function. This function is utilised in a summation equation used for calculating the induced electric currents on the reflectarray's metallic grating. For solving the obtained summation equation, the Periodic Method of Moments with Galerkin procedure is applied. Such an analysis method helps to compute the phase diagram needed to design of reflectarray. The efficiency of this method is assessed by considering its cost‐time and rate of convergence versus space harmonics. In the design step, a new phase realisation approach is implemented for minimising the frequency dispersion's adverse effects. This approach optimises the arrangement of metallic elements on the reflectarray's aperture and decreases the dependency of broadband reflectarray design to the element phase behaviour. As a result, this technique leads to lower side lobe level and better frequency response than traditional approaches. To verify the results of the developed solution, two different broadband reflectarrays for X‐ and Ku‐bands are fabricated and measured.

Sleep Apnea Syndrome (SAS) has attracted considerable attention in recent years because it is known to cause catastrophes when people suffering from it fall asleep while driving. In addition, approximately 70% of SAS patients have other lifestyle-related diseases, which are further complicated owing to SAS; therefore, its early detection is important. Moreover, the detection of pre-SAS, which is likely to turn into SAS in the future, may help in the early detection of SAS. In this study, a method to identify SAS and pre-SAS using only sound data has been proposed. In the proposed method, peculiar breathing sound patterns in SAS are analyzed using the k-means clustering method and perform discriminant analysis using quantification theory based on the results. Because respiratory sound data is extensive and non-uniform during sleep, an efficient analysis method is required. The presented analysis method focuses on the features of SAS sounds, and performs the analysis almost automatically; therefore, the time required for analysis is reduced and the uniformity of the analysis results is guaranteed. Using this method, it is possible to distinguish between non-SAS and SAS symptoms including pre-SAS symptoms, which is difficult to perform using the Apnea-Hypopnea Index, which is a measure of SAS that employs breathing sound data only. Thus, this method, which also analyzes pre-SAS, is convenient for the early detection and treatment of SAS and can also be expected to contribute toward the early detection of preliminary lifestyle-related diseases.

A practical and efficient coupling method for large scale soil–structure interaction problems

An efficient method for ripple analysis of networks with synchronized switching power converters is proposed. While the focus of previous publications is on the operation of a single power converter, the proposed method extends the steady-state and ripple analysis to the area of power converter systems. A network consisting of several converters is modeled as a single piece-wise linear system. The inherent steady-state problem is solved using a new, fast, robust, and accurate steady-state algorithm based on a new set of boundary constraints. The proposed method is efficient in solving problems of practical design such as the determination of voltage ripples and analysis of current distribution in converter common nodes, evaluation of decoupling capacitors, and assessment of various synchronization schemes. Numerical examples are included.

A new unequal-weighted sampling method for efficient reliability analysis

The purpose of the paper is to consider the main provisions of methods of analysis of the effectiveness of public sector projects. A number of issues remain controversial in the methodology of analysing costs and benefits. So, in addition to determining the costs and benefits to be included in the analysis, one should outline the problem of assessing in the monetary equivalent of the social effects that society receives from the project implementation. Methodology. The social nature and scale of tasks that are solved in the public sector deepen the issue of identification of social effects. Discounting costs and benefits and assessing the social effect in the cost-benefit analysis involves the application of the rate of time preference. The parameters of this rate are analysed and substantiated in the study. In addition to the CBA method, an attention is paid to other methods of efficiency analysis, in particular, the method of cost-effectiveness analysis, method of weighted cost-effectiveness analysis, method of cost-utility analysis. Each method has its own specific features and limitations that determine the direction of their application. Results. It is concluded that finding solutions in the direction of studying the relationship between the social rate of intergovernmental preferences and other methods of discounting will allow us to get an idea, in which range may be the value of social discount rate. The ability to determine the range will allow taking into account the specificity of the project being implemented.

A method for the analysis and design of rectangular microstrip antennas coupled through a small aperture to a microstrip feed line in a two-layer configuration is described. The technique is numerically efficient, making it suitable for computer-aided design. The analysis takes into account higher order modes excited underneath the patch. Analysis results were implemented in two computer programs: an analysis program and a design program based on optimization techniques. Experimental results are presented to validate this method.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>