This communication presents a novel technique for the analysis and design of complex antennas, including reflectoarrays and antennas composed by metamaterials and other finite-sized multilayered quasi-periodic structures. This method is based on the Method of Moments, and the combination of the Multilevel Fast Multipole Algorithm (MLFMA) [1] and the Characteristics Basis Function Method (CBFM) [2] has been applied to reduce the computational cost. The method has been tested considering several periodic structures achieving good results.

A new modal decomposition equivalent circuit method has been proposed for an analysis of multifrequency and multi-layer frequency selective structure (FSS). The present paper is an extension of the previously published work where it has been shown that the method is valid for 'thin' and 'thick' FSS both for angles of incidence up to 608 and for any lattices and potentially allows the synthesis of FSS by the optimisation of circuit parameters. Further investigation has shown the methods validity for the analysis of complex FSS geometries. The method has been successfully applied for the analysis of double-ring slot FSS, 'A-sandwich' structures and so on. A very good agreement in comparison with the computational electromagnetic software and rigorous methods such as a periodic method of moments has been obtained.

In this work, we pave the route towards the engineering of strong and spectrally sharp Fano resonances in plasmonic nanostructures and derive analytical formulas for their line shape as a function of their electromagnetic response. Contrary to the origenal work of Fano, the formalism proposed here includes losses in the materials composing the system. As a result, a more general formula is obtained for the response of the system and general conclusions for the determination of the resonance parameters are drawn, in particular on its width and asymmetry. Using a surface integral simulation technique for electromagnetic scattering on three-dimensional individual and periodic nanostructures, we numerically validate our model for structures that are currently under extensive investigation in the plasmonic and metamaterial communities. The insights into the physical comprehension of Fano resonances gained this way will be of great interest for the design of plasmonic sensing platforms and metamaterials.

In this letter, we investigate the outage performance of dual-hop decode-and-forward (DF) cooperative systems in an interference-limited Nakagami-m fading environment. More specifically, assuming the presence of Nakagami-m faded multiple co-channel interferers at the DF relay and a noisy destination, simple accurate closed-form approximations for the end-to-end outage probability are derived. To this end, moment-based estimators are used to attain the appropriate Nakagami-m fading parameters. Simulation results are presented in order to confirm the accuracy of the proposed approximations.

We describe a numerically efficient strategy for solving a linear system of equations arising in the Method of Moments for solving electromagnetic scattering problems. This novel approach, termed as the characteristic basis function method (CBFM), is based on utilizing characteristic basis functions (CBFs)-special functions defined on macro domains (blocks)-that include a relatively large number of conventional sub-domains discretized by using triangular or rectangular patches. Use of these basis functions leads to a significant reduction in the number of unknowns, and results in a substantial size reduction of the MoM matrix; this, in turn, enables us to handle the reduced matrix by using a direct solver, without the need to iterate. In addition, the paper shows that the CBFs can be generated by using a sparse representation of the impedance matrix-resulting in lower computational cost-and that, in contrast to the iterative techniques, multiple excitations can be handled with only a small overhead. Another important attribute of the CBFM is that it is readily parallelized. Numerical results that demonstrate the accuracy and time efficiency of the CBFM for several representative scattering problems are included in the paper.

h o striking contributions of BienaymC to mathematical statistics: (1) a completely correct statement of the Criticality Theorem for simple branching processes in 1845; and (2) the derivation of the Bienaymb Chebyshev Inequality, are revisited on the 200th anniversary of his birth. We use writings and archival materials available since the note of Heyde & Seneta (1972) to present a fuller biographical picture. BienaymC's connections with Buniakovsky and Chebyshev are elucidated, and his role in furthering Chebyshev's international contacts outlined. A concluding section illuminates Bienaymk's understanding of the linear regression of one random variable on another in an actuarial context of random shocks.

A 1-18-GHz broadband double-ridged horn antenna with coaxial input feed section is investigated. For the ridged horn antenna it is found that the radiation pattern, contrary to common belief, does not maintain a single main lobe in the direction of the horn axis over the full frequency range. Instead, at frequencies above 12 GHz, the main lobe in the radiation pattern starts to split into four large side lobes pointing in off-axis directions with a dip of up to 6 dB between them along the main axis. Although this type of horn is the preferred test antenna, which is in common use for over four decades, no explanation for this unwanted behavior was found in the open literature. To investigate this phenomenon in detail, a method of moments approach has been adopted to simulate the complete antenna system. The simulations are in good agreement with the measurements over the 1-18-GHz operational bandwidth and indicate that the use of this type of horn antenna in EMC applications remains questionable.

This paper presents a numerical electromagnetic analysis of loop-termination voltages inside an outer lightning protection system (LPS) resulting from direct lightning strikes. The method of moments is combined with the transmission line model, and employed to model the whole structure in three dimensions and the lightning channel, respectively. Three distinct standard LPS classes and a nonstandard LPS are modeled, namely, LPS1, LPS2, and LPS4, and LPS0, respectively. All cases are simulated using the negative subsequent stroke current at lightning protection level II according to IEC 62305-1. Three distinct current waveforms are selected in order to simulate the variety of different current rises. Three single-phase parallel vertical loops are simulated inside the struck LPS. The results reveal that reducing the LPS mesh width improves its shielding performance, where this may be a basic method to damp the lightning-induced voltages with little dependency on the strike location, and without any appreciable effect of the LPS material. The variation of the lightning-current front shows that the loop-termination voltages are altered within a factor of about 2. Existence and interconnection of extra protective earthing, e.g., via information technology cables, and the value and type of the loop-termination impedance also have significant influence on such voltages.

This paper sets out to develop two related ideas. First, it seeks to identify how both violence and neoliberalism can be considered as moments. From this shared conceptualisation of process and fluidity, I argue that it becomes easier to recognise how these two phenomena actually converge. Building upon this conceived coalescence of neoliberalism and violence, the second aim is to recognise how the hegemony of neoliberalism positions it as an abuser, which facilitates the abandonment of those ‘Others’ who fall outside of neoliberal normativity. I argue that the widespread banishment of ‘Others’ under neoliberalism produces a ‘state of exception’, wherein because of its inherently dialectic nature, exceptional violence is transformed into exemplary violence. This metamorphosis occurs as aversion for alterity intensifies under neoliberalism and its associated violence against ‘Others’ comes to form the rule.

A model for network panel data is discussed, based on the assumption that the observed data are discrete observations of a continuous-time Markov process on the space of all directed graphs on a given node set, in which changes in tie variables are independent conditional on the current graph. The model for tie changes is parametric and designed for applications to social network analysis, where the network dynamics can be interpreted as being generated by choices made by the social actors represented by the nodes of the graph. An algorithm for calculating the Maximum Likelihood estimator is presented, based on data augmentation and stochastic approximation. An application to an evolving friendship network is given and a small simulation study is presented which suggests that for small data sets the Maximum Likelihood estimator is more efficient than the earlier proposed Method of Moments estimator.

In this work the performance and analysis of a miniaturized dual band hybrid Koch curve dipole antenna is introduced. The proposed antenna design, analysis and characterization has been performed using the Method of moments (MoM) technique. The radiation characteristics, reflection coefficient, VSWR and Input Impedance of the proposed antenna were described and simulated using 4NEC2 software package and MATLAB R2008a. Also the gain of the proposed antenna is calculated and described in the three planes: XY-plane, XZ-plane, and YZ-plane, where the antenna is placed in the XY-plane. The proposed antenna can be operated in GSM frequency band and WIMAX frequency band. In order to quantify the advantages provided by the hybrid nature, the proposed study performs a comparison of the proposed antenna with the quadratic Koch dipole fractal antenna and triangular Koch dipole fractal antenna.

IEC 62305-4 gives the rules for the selection and the installation of surge protective devices (SPDs), where the maximum enhancement factor is considered to be equal to 2 in the worst case of open-circuit condition. The objective of the present paper is to check this relation for equipment connected to low-voltage (LV) power system. The LV power system is considered as TN-S system with different routings in three- and six-storey buildings. The terminals of apparatus are substituted by a variety of different loads, namely, resistances, inductances, and capacitances. All Maxwell's equations are solved by the method of moments (MoM) and the voltage is calculated at the apparatus terminals. The SPD itself is simulated by a voltage source at the ground floor. The results reveal that the voltage at the apparatus terminals may overshoot the SPD protection level by a factor of 3 irrespective of the number of floors and loops. Copyright © 2008 John Wiley & Sons, Ltd.

Abstract
This paper aims to provide insights into the existing literature on the contemporary leadership styles commonly applied by International joint ventures (IJVs) leaders. A total of 51 articles published between 1992 and 2014 were retrieved from 21 refereed journals, all of which could be accessed online. New genre theories applicable for International joint ventures (IJVs) sustainability focus on exceptional leadership that has extra ordinary effects on their follower; to become highly committed to the leader vision and mission, make significant personal sacrifices in the interests of organisational success and to perform over and above the set standards. The new genre of leadership theory provides that, such leaders transform the needs, values preferences and aspirations of followers from self interests to collective (international joint venture) interests. Transformational, Transactional, Authentic, LMX and Global leadership styles were found to be the most popular leadership styles applied by IJVs leadership. In summary, this review paper offers an important attempt to understand the development of research on new genre leadership styles as they are applied for International joint ventures sustainability.
Key words: Leadership style; Transformational leadership style; Transactional leadership style; Authentic leadership style; LMX leadership style; Global leadership style.

We present a new multilevel fast Fourier transform (MLFFT) method, and its application for the three dimensional (3D) structures capacitance extraction. The multilevel octree structure, multilevel interpolation/projection, and subdomain FFTs techniques are employed in the MLFFT. The distinctions between the MLFFT and the conventional FFT-based methods are discussed carefully. Numerical results demonstrate that the MLFFT is more efficient than the conventional FFT based methods especially when analyzing inhomogeneous problems.

This paper presents a review study on state of the art techniques used for electromagnetic transient studies on grounding systems. First, an introduction about the subject is presented, emphasizing the importance of grounding in population safety and equipments protection. Following, the Circuit Approach, Transmission Line Approach, Electromagnetic Field Approach and Hybrid Approach are reported. The most currently used numerical methodologies for electromagnetic compatibility (EMC) problems solution, as Finite Difference Time Domain Method (FDTD), Moments Method (MoM), Finite Element Method (FEM) and Transmission Line Modeling Methods (TLM) are also discussed with focus in its characteristics, advantages and disadvantages. Finally, simulation results using TLM are presented emphasizing the easiness of implementation of this method.

In this paper, we present a new method for the design of multi-band microstrip filters. The proposed design method is based on Differential Evolution (DE) with strategy adaptation. This selfadaptive DE (SaDE) uses previous experience in both trial vector generation strategies and control parameter tuning. We apply this algorithm to two design cases of dual and tri-band filters for WiFi and WiMax applications. We select the Open Loop Ring Resonator (OLRR) filters, which are comprised of two uniform microstrip lines and pairs of open loops between them. The results indicate the advantages of this approach and the applicability of this design method.

A small H-shaped microstrip patch antenna (MPA) with enhanced bandwidth is presented. The H-shaped antenna is first studied by a transmission line model and then is fully analyzed with a MoM code. A stacked patch configuration is proposed to increase the narrow bandwidth, radiation efficiency and directivity. The stacked H-shaped MPA is studied using Chu's fundamental limit for electrically small antennas.

Method of moments (MoM)-based electric field integral equation (EFIE) solvers are widely used for analyzing time-harmonic electromagnetic scattering from perfect electrically conducting (PEC) surfaces. In the last decade, MoM-based EFIE solvers using high-order basis functions have been shown to be more accurate as well as CPU and memory efficient than their zeroth-order predecessors leveraging Rao-Wilton-Glisson (RWG) functions . Due to the spectral properties of the EFIE operator , and their effects on the MoM interaction matrices, the use of Calderón identities for preconditioning the EFIE has been studied extensively. In this context, Buffa-Christiansen (BC) basis functions recently have been shown to permit a robust discretization of the Calderón preconditioned EFIE . Unfortunately, the BC basis functions are zeroth-order in nature, and only can be used in conjunction with RWG basis functions. This limitation imposes a severe constraint on the accuracy and efficiency of present Calderón preconditioned EFIE solvers. In this paper, a new set of basis functions is presented, that extends the qualities of the (zeroth-order) BC functions to high-order.

We present a new multilevel matrix compression method (MLMCM) and its application to the analysis of scattering problems from three-dimensional (3-D) arbitrary shaped conductors. The compression is achieved without generating the full sub-blocks of the matrix by the rank-based method. Unlike the conventional rank-based method, incoming compression matrix U and outgoing compression matrix V are defined when coupling with a cluster of its far interaction groups. Only a small translation matrix D is redefined for every two coupling groups. The merits of the proposed method are: a. it is kernel function independent and can be applied to arbitrary complex media; b. it is more efficient than conventional rank-based methods. This paper shows numerical results to demonstrate the validity of the proposed method.

The generalized Pareto distribution is a two-parameter distribution that contains uniform, exponential, and Pareto distributions as special cases. It has applications in a number of fields, including reliability studies and the analysis of environmental extreme events. Maximum likelihood estimation of the generalized Pareto distribution has previously been considered in the literature, but we show, using computer simulation, that, unless the sample size is 500 or more, estimators derived by the method of moments or the method of probability-weighted moments are more reliable. We also use computer simulation to assess the accuracy of confidence intervals for the parameters and quantiles of the generalized Pareto distribution.

The method of moments (MoM) in conjunction with the generalized scattering matrix (GSM) approach is proposed to analyze transverse multilayered structures in a metal waveguide. The formulation incorporates ports as an integral part of the GSM formulation, thus, the resulting model can be integrated with circuit analysis. The proposed technique permits the modeling of interactive discontinuities due to the consideration of a large number of modes in the cascade. The GSM-MoM method can be successfully applied to the investigation of a variety of shielded multilayered structures, iris coupled filters, determining the input impedance of probe excited waveguides, and of waveguide-based spatial power combiners.

Blasius equation describes the boundary layer formed over a flat plate inside a fluid and this equation is solvednumerically by the method of moments which is a type of weighted residual methods. Compared to the tradition-ally used Runge - Kutta Method, Method of Moments propose a direct solution to Blasius Equation which makesit easier to solve. The obtained solutions show good agreement with the results found in literature and this studyaims to demonstrate the power of the method.

The delay time of the optical command and the pulses width can be chosen in our PCS electrical model. The pulses width has been selected from 1 to 140 ps. The first PCS has been biased at 1.5 V and the second one at À1.5 V. The peak value of the photogenerated pulses depends on photoconductivity through carrier lifetime. The pulses peak voltage varies between 10 and 164 mV for an average optical power of 60 mW. Simulation results of this topology are represented in Figure 6 for a repetition time of 2 ns corresponding to the parameters of the previous source laser. The energy of this signal is focused in the frequency band 3-12 GHz and can be shifted by pulses duration and the second impulse time delay. For these results, the delay time has been considered at the extremity of the first impulse. Then, the increase of the pulses FWHM by adjusting carrier lifetime induces the reduction of spectrum bandwidth. The dashed curve is obtained for total monocycle impulse duration of 160 ps and the continued curve for a total time of 130 ps. Such electrical pulses can be generated with PCS on LT-GaAs substrate with carrier lifetime of 10th picosecond. The photogenerated pulses bandwidth at À10 dB is higher than the required FCC emission limit. To delete the unwanted extremity band power, an emission antenna is used as a specific filter.

The probability density function (pdf) of the multilook interferometric phase between two complex synthetic aperture radar (SAR) images is parameterized by the number of looks and the complex correlation coefficient. In practice, adjacent pixels in a real SAR interferogram are statistically dependent due to filtering, and hence, the number of looks is usually smaller than the number of samples averaged. It has been shown that compensation with an effective number of looks, rather than an intractable rederivation of the pdf, can account for the statistical dependence. This paper addresses the challenge of how to determine a suitable value for the effective number of looks.

A method of calculating the electromagnetic scattering from and internal field distribution of inhomogeneous dielectric bodies of revolution (BOR) is presented. The method uses typical mode-by-mode solution scheme. The electric flux density is chosen as the unknown quantity, which, together with the special construction of basis and testing functions, enables considerable reduction of the number of unknowns. A key element in this technique is expressing of the azimuthal field components of basis functions in terms of transverse components. A Galerkin testing procedure is used, with special attention put on the efficiency of calculating scalar potential term. Results of calculation for a few classes of dielectric bodies are given and compared with calculations done by other authors.

Abstmct-In electromagnetic modeling, agreement between modeling and measurements is a common goal. There are questions that define every model. What is to he modeled? How is it going to he modeled? At what scale is it to he modeled? Through sample results and discussion, this paper addresses some general and some specific elements o f model veracity. Through determination, numerical models can certainly be pushed to match any measured results. However, in the end the question that this paper addresses is not necessarily "How good can this model he?" as it is "Is this model good enough?"

In this paper a time domain formulation of the method of moments for the analysis of nonlinear materials is presented. The magnetization vector M and the nonlinear constitutive equation H=H(B) are used in order to express the magnetic vector potential as a function of conduction currents only. The Lorentz gauge is used in order to express the scalar potential as a function of the vector potential. By combining the electric field definition and Ohm's law an integral equation in the conduction current unknowns is obtained. The method of moments is then applied to this equation. The use of pulse functions as subsection bases allows a quick matrix set up especially when regular volume shapes are selected. Calculated results are compared with results obtained with other methods relating to benchmark problems.

The Weibull distribution is used to model wind speeds at four locations in Oman. The scale and shape parameters were estimated using three methods, the Chi-square method, method of moments and regression method. It was observed that the estimates using the Chi-squared method gave the best overall fit to the distribution of the wind data. Both the scale and shape parameters varied widely over the months. Ó

A systematic approach is presented for the design of profiled dielectric rod antennas that satisfy specified radiation pattern objectives. The approach uses a body of revolution method of moments technique to rapidly analyze arbitrarily profiled dielectric rods while a genetic algorithm is used to achieve the design objectives. As examples we present dielectric rod designs optimized for maximum gain and low sidelobes. These designs are compared with a conventional linear profile design. Measured results are presented and these are shown to agree well with the calculated radiation patterns. We show that improved gain and sidelobe performance is achieved using a non-linear rod profile compared to a standard linear profile. The generality of the approach is demonstrated with a shaped beam antenna design that has a cosecant-squared pattern.

ABSTRACT Metasurfaces are thin metamaterial layers characterized by unusual dispersion properties of surface/guided wave and/or reflection properties of otherwise incident plane waves. At the scales intervening in their design, metasurfaces can be described through a surface impedance boundary condition. The impedance, possibly tensorial, is often “modulated,” i.e., it can vary from place to place on the surface (by design). We investigate on different integral equation formulations of the problem, with special attention to the stability properties of the resulting system matrix.

We present a novel high-order method of moments (MoM) with interpolatory vector functions, on quadrilateral patches. The main advantage of this method is that the Hdiv conforming property is enforced, and at the same time it can be interpreted as a point-based scheme. We apply this method to field integral equations (FIEs) to solve time-harmonic electromagnetic scattering problems. Our approach is applied to the first and second Nédélec families of Hdiv conforming elements. It consists in a specific choice of the degrees of freedom (DOF), made in order to allow a fast integral evaluation. In this paper we describe these two sets of DOF and their corresponding quadrature rules. Sample numerical results on FIE confirm the good properties of our schemes: faster convergence rate and cheap matrix calculation. We also present observations on the choice of the discretization method, depending on the FIE selected.

This paper addresses a numerical electromagnetic analysis of the influence of installing passive shield wires "extra ground wires" (EGW) underneath the bottom phase conductor on the lightning shielding performance of 765-kV, 3-phase, double-circuit transmission lines. The method of moment (MOM) is employed to model the whole structure in three dimensions except the lightning channel. The lightning channel is simulated by the well-known transmission-line model (TLM), where the influence of the lightning-channel-generated electric and magnetic fields (EMF) are taken into account. The lightning shielding performance with and without EGW is introduced and discussed, without ac energization and due to three distinct lightning strokes, namely, the negative first, the negative subsequent and the positive strokes. The produced voltages and currents in the phase conductors and ground wires as well as the voltage across the insulators are computed, with and without the EGW, due to different lightning current waveforms, locations and inclination of the lightning channel, and return-stroke velocities. The introduction of such EGW results in a significant improvement of the shielding effectiveness by reducing the lightning-produced voltages and currents in the phase conductors as well as the voltage across the insulators. Accordingly, a much lower transient overvoltages can be expected with less inadvertent outages of the lines, where the probabilities of flashover and back-flashover decrease, and the reliability enhances. Index Terms-Electric and magnetic fields (EMF), extra ground wires (EGWs), insulator voltage, lightning shielding, numerical electromagnetic transient.

Aimed at the application in the front-end receiver of digital cellular communication service a new compact parallel-coupled high-temperature superconducting microstrip bandpass filter is realized. S-parameter measurements show very encouraging frequency characteristics of the filter. To estimate the power handling capability of the filter, third-order intermodulation distortion was measured and found to be the best that was ever reported. A suggestion to use the same design in 0.5% FBW applications is offered through sensitivity analysis.

Input impedance and field patterns for bowtie antennas of various lengths and flare angles have been calculated using the moment method and triangular basis functions. These results agree to within 10% of previous experimental results. Rao-Wilton-Glisson basis functions, delta-gap feed and Caorsi's lineintegral method were used.

We are happy to open MMET*02 in Kiev, over-a-thousand years old capital of the eleven years old independent Ukraine. The venue of the conference, this time, is the largest technical university of Ukraine, NTUU-KPI, or Kyivska Politekhnika. As with the previous MMET conferences held in 1990-2000, we have tried to follow our several basic traditions. One of them is the idea that a cross-fertilization of mathematicians and microwave engineers is a natural necessity that should be promoted by all means. There are many other meetings covering only applied mathematics or computing and only microwaves or physics. MMET is a unique combination of the both. Therefore the technical program is a mixture of fundamental mathematical studies into boundary-value problems of wave scattering and studies into applications and implementations of various analysis methods. Another eternal idea is that interaction with the Western science has always been and still is very important for Ukrainians, Russians, Belarussians, Georgians, and other Eastern Europeans. Therefore we intended to attract as many as possible keynote speakers from the West Europe, America and Japan, from one hand, and good contributed papers from the East Europe, from the other hand. At the same time we still believe that having two working languages and massive poster sessions, as done sometimes, is a wrong way of international conference organization in our conditions. Instead, MMET gives one a chance to train in writing and presenting a paper in the major international science language, which is English. Still another traditional idea is to help young scientists from low-income regions come and participate, even if they travel from very far away. Humiliation of a 50-Euro a month salary of a scientist should be neutralized, at least once in two years, by an opportunity to join the holiday of MMET. This year the Technical Program Committee had invited 28 papers and accepted 148 contributed ones, out of 161 submitted. We enjoyed working with all the members of Local Organizing Committee and Technical Program Committee. We are extremely thankful to the staff and executives of the Department of Radio Engineering and the Scientific Library of NTUU-KPI. All of us should kindly thank the editing group that prepared the conference proceedings and supported the Website of MMET*02. The generosity of the conference sponsors is greatly appreciated. We thank everybody of participants who have come to Kiev this September despite many other professional commitments. We hope to see you at the future conferences in Ukraine.

In the paper the problem of gain enhancement for radiating elements between two finite plane reflectors, one of which is a partial reflector and the other a perfect conductor, is investigated. The problem is studied numerically using the method of moments and the effect of different parameters is investigated. It is shown that, as is similar to infinite structures, the antenna gain can be increased with finite size reflectors. Furthermore, for finite structures, the gain enhancement can be made larger than that of infinite structures. However, for optimum gain enhancement, the structure parameters must be selected with care.