discontinuous galerkin finite element methods for second order hyperbolic problems abstract we prove a priori and a posteriori error estimates for a finite element method for linear second order hyperbolic equations based on a space time finite element discretization with the basis functions being continuous in space and discontinuous in time

fuzzy granular gravitational clustering algorithm for multivariate data abstract a new method for finding fuzzy information granules from multivariate data through a gravitational inspired clustering algorithm is proposed in this paper the proposed algorithm incorporates the theory of granular computing which adapts the cluster size with respect to the context of the given data via an inspiration in newton s law of universal gravitation both conditions of clustering similar data and adapting to the size of each granule are achieved this paper compares the fuzzy granular gravitational clustering algorithm fggca against other clustering techniques on two grounds classification accuracy and clustering validity indices e g rand fm davies bouldin dunn homogeneity and separation the fggca is tested with multiple benchmark classification datasets such as iris wine seeds and glass identification

space time block codes from orthogonal designs we introduce space time block coding a new paradigm for communication over rayleigh fading channels using multiple transmit antennas data is encoded using a space time block code and the encoded data is split into n streams which are simultaneously transmitted using n transmit antennas the received signal at each receive antenna is a linear superposition of the n transmitted signals perturbed by noise maximum likelihood decoding is achieved in a simple way through decoupling of the signals transmitted from different antennas rather than joint detection this uses the orthogonal structure of the space time block code and gives a maximum likelihood decoding algorithm which is based only on linear processing at the receiver space time block codes are designed to achieve the maximum diversity order for a given number of transmit and receive antennas subject to the constraint of having a simple decoding algorithm the classical mathematical framework of orthogonal designs is applied to construct space time block codes it is shown that space time block codes constructed in this way only exist for few sporadic values of n subsequently a generalization of orthogonal designs is shown to provide space time block codes for both real and complex constellations for any number of transmit antennas these codes achieve the maximum possible transmission rate for any number of transmit antennas using any arbitrary real constellation such as pam for an arbitrary complex constellation such as psk and qam space time block codes are designed that achieve 1 2 of the maximum possible transmission rate for any number of transmit antennas for the specific cases of two three and four transmit antennas space time block codes are designed that achieve respectively all 3 4 and 3 4 of maximum possible transmission rate using arbitrary complex constellations the best tradeoff between the decoding delay and the number of transmit antennas is also computed and it is shown that many of the codes presented here are optimal in this sense as well

data driven fuzzy modeling for takagi sugeno kang fuzzy system this paper presents a systematic approach to design first order tagaki sugeno kang tsk fuzzy systems this approach attempts to obtain the fuzzy rules without any assumption about the structure of the data the structure identification and parameter optimization steps in this approach are carried out automatically and are capable of finding the optimal number of the rules with an acceptable accuracy starting with an initial structure the system first tries to improve the structure and then as soon as an improved structure is found it fine tunes its rules parameters then it goes back to improve the structure again to find a better structure and re fine tune the rules parameters this loop continues until a satisfactory solution tsk model is found the proposed approach has successfully been applied to well known benchmark datasets and real world problems the obtained results are compared with those obtained with other methods from the literature experimental studies demonstrate that the predicted properties have a good agreement with the measured data by using the elicited fuzzy model with a small number of rules finally as a case study the proposed approach is applied to the desulfurization process of a real steel industry comparing the proposed approach with some other fuzzy systems and neural networks it is shown that the developed tsk fuzzy system exhibits better results with higher accuracy and smaller size of architecture

a priori estimates for mixed finite element approximations of second order hyperbolic equations with absorbing boundary conditions optimal order l infty in time l 2 in space a priori error estimates are derived for mixed finite element approximations for both displacement and stress for a second order hyperbolic equation with first order absorbing boundary conditions continuous in time explicit in time and implicit in time procedures are formulated and analyzed

a qualified description of extended fuzzy logic abstract the sense of approximate reasoning within fuzzy logic has given rise to speculation as to whether precise reasoning within classical logic can even be considered a feasible way of handling most of the world s problems now another question can be raised can fuzzy logic by itself justify handle the sort of uncertainty found in problems that belong to the class of open world problems this family of problems corresponds to the case of ambiguous mathematical theories mainly due to the fact that there is just imperfect incomplete information about them recently zadeh introduced an extension of fuzzy logic claimed to bridge the gaps in conventional approaches to the open world problems in this paper we present a basic background of extended fuzzy logic fle we address several main concepts such as f transformation and f validity enhance the definition of generalized constraints and propose that fle s rules have two layers one based on the implication model and another based on the conjunction model in addition we explore how fle can handle those conditions described in antonym pairs as well as those occurred without considering rationality in the framework both cases challenge most decision making theories we also suggest fle and second order probability are f complementary rather than f competitive the paper asserts that fle is highly capable of constructing mathematical solutions to problems including computational problems that are stated in natural language

square matrix embeddable space time block codes for complex signal constellations space time block codes for providing transmit diversity in wireless communication systems are considered based on the principles of linearity and unitarity a complete classification of linear codes is given in the case when the symbol constellations are complex and the code is based on a square matrix or restriction of such by deleting columns antennas maximal rate delay optimal codes are constructed within this category the maximal rates allowed by linearity and unitarity fall off exponentially with the number of transmit antennas

a priori and posteriori error analysis for time dependent maxwell s equations abstract we consider time dependent maxwell s equations discretized by variable time steps in time domain and edge elements in spatial domain first the stability and optimal a priori error estimate are proved for both semi and fully discrete schemes then a posteriori error analysis is carried out for both schemes

local stability analysis of continuous time takagi sugeno fuzzy systems a fuzzy lyapunov function approach this paper proposes a strategy to estimate invariant subsets of the domain of attraction da for asymptotically stable zero equilibrium points of continuous time takagi sugeno t s fuzzy systems specifically by using lyapunov s stability theory and the linear matrix inequality lmi technique sufficient conditions for proving the local stability are provided in terms of single parameter minimization problems subject to lmi constraints or eigenvalue problems which are solvable via convex optimizations the fuzzy lyapunov functions flfs expressed by the so called multi dimensional fuzzy summations are employed to characterize invariant subsets of the da as sublevel sets of the flfs to compute a larger inner estimate of the da an iterative lmi algorithm is also developed finally illustrative examples show the efficacy of the approach

multi species pso and fuzzy systems of takagi sugeno kang type we study a method by using the hierarchical cluster based multi species particle swarm optimization hcmspso algorithm to generate a tagaki sugeno kang tsk fuzzy system implemented in a spatial analysis problem precisely we consider an area of study divided in subzones from the data measured in each subzone a tsk fuzzy system is extracted and hence we associate an opportune root means square error rmse if the hth and kth subzones have a defined suitably similarity index s h k greater or equal than a specific threshold s t h r e s h o l d then they are merged in a new subzone and the corresponding datasets are grouped together in a single dataset thus we restart the hcmspso algorithm for generating the tsk fuzzy system of the new subzone this process is iterated until we have that s h k

on maximum likelihood detection and the search for the closest lattice point maximum likelihood ml decoding algorithms for gaussian multiple input multiple output mimo linear channels are considered linearity over the field of real numbers facilitates the design of ml decoders using number theoretic tools for searching the closest lattice point these decoders are collectively referred to as sphere decoders in the literature in this paper a fresh look at this class of decoding algorithms is taken in particular two novel algorithms are developed the first algorithm is inspired by the pohst enumeration strategy and is shown to offer a significant reduction in complexity compared to the viterbo boutros sphere decoder the connection between the proposed algorithm and the stack sequential decoding algorithm is then established this connection is utilized to construct the second algorithm which can also be viewed as an application of the schnorr euchner strategy to ml decoding aided with a detailed study of preprocessing algorithms a variant of the second algorithm is developed and shown to offer significant reductions in the computational complexity compared to all previously proposed sphere decoders with a near ml detection performance this claim is supported by intuitive arguments and simulation results in many relevant scenarios

fuzzy dynamic output feedback control through nonlinear takagi sugeno models we present a convex way to design a fuzzy dynamic output feedback compensator for locally stabilizing a class of nonlinear discrete time systems this class consists of the systems described by takagi sugeno t s models with a sector bounded nonlinear additive term and saturated control signals the local stabilization takes into account the domain of validity of these t s models which is a key issue for practical applications two types of nonlinear fuzzy compensators are considered one having all matrices of the controller depending on fuzzy grade membership functions and the other with only a subset of the matrices with such a dependency the controller design includes a fuzzy anti windup gain that handles saturating actuators besides a time performance index based on the contractivity of the level set of the fuzzy lyapunov function is proposed regarding the closed loop system examples are given to illustrate the effectiveness of this proposal

new stability and stabilization conditions for t s fuzzy systems with time delay this paper is concerned with the problem of the stability analysis and stabilization for takagi sugeno t s fuzzy systems with time delay a new lyapunov krasovskii functional containing the fuzzy line integral lyapunov function and the simple functional is chosen by using a recently developed wirtinger based integral inequality and introducing slack variables less conservative conditions in terms of linear matrix inequalities lmis are derived several examples are given to show the advantages of the proposed results

mutual information analysis on spatial modulation multiple antenna system spatial modulation sm is a recently proposed multiple input multiple output mimo architecture that exploits the space domain for information transmission in this paper sm systems with continuous amplitude phase modulation apm and the corresponding maximum likelihood ml active transmit antenna detector are considered we introduced a method to compute the theoretical transition probability matrix and the mutual information of the ml antenna detector for sm multiple input single output miso system we derive the error probability and the mutual information of the antenna detector in closed form for multiple receive antenna sm system the union bound of error probability and the lower bound of antenna detection mutual information are proposed the analytical results are verified by numerical simulation over rayleigh fading channels we investigate systems with different number of antennas and apm symbol input distributions to evaluate the performance of sm the joint apm and antenna detection mutual information of sm systems is compared to the capacity of vertical bell labs layered space time v blast spatial multiplexing mimo scheme our research gives achievable transmission rates of sm miso mimo systems and can be a guideline for suitable application scenarios

a quasi orthogonal space time block code it has been shown that a complex orthogonal design that provides full diversity and full transmission rate for a space time block code is not possible for more than two antennas previous attempts have been concentrated in generalizing orthogonal designs which provide space time block codes with full diversity and a high transmission rate we design rate one codes which are quasi orthogonal and provide partial diversity the decoder of the proposed codes works with pairs of transmitted symbols instead of single symbols

the extension principle and a decomposition of fuzzy sets we give an algorithm to decompose a fuzzy interval u using this decomposition and the multilinearization of a univariate function f we obtain an approximation of the fuzzy interval where is obtained from f by applying the extension principle we provide approximation bounds some numeric illustration is provided

spatially modulated orthogonal space time block codes with non vanishing determinants this paper proposes a multiple input multiple output mimo transmission scheme for m ary modulations called spatially modulated orthogonal space time block coding sm ostbc based on the concept of spatial constellation sc codewords introduced by le at el in the proposed scheme transmit codeword matrices are generated by multiplying sc matrices with codewords constructed from orthogonal space time block codes o stbc the maximum spectral efficiency of the proposed scheme is equal to n t 2 log 2 m bpcu where n t is the number of transmit antennas and m is the modulation order the sc matrices provide a means of carrying information bits together with the o stbc codewords and allow the sm ostbc scheme to achieve second order transmit diversity by satisfying the non vanishing determinant property a systematic method to design the sc codewords for an even number of transmit antennas greater than 3 is presented a single stream maximum likelihood ml decoder which requires a low computational complexity thanks to the structure of the sm ostbc codewords and to the orthogonality of the o stbcs and a sphere decoder with further reduced signal processing complexity are developed the bit error rate ber performance of the proposed scheme is studied by using both theoretical union bound analysis and computer simulations finally simulation results are presented in order to compare ber performance energy efficiency and decoding complexity of the proposed scheme with those of several existing mimo transmission schemes

a new linguistic computational model based on discrete fuzzy numbers for computing with words in recent years several different linguistic computational models for dealing with linguistic information in processes of computing with words have been proposed however until now all of them rely on the special semantics of the linguistic terms usually fuzzy numbers in the unit interval and the linguistic aggregation operators are based on aggregation operators in 0 1 in this paper a linguistic computational model based on discrete fuzzy numbers whose support is a subset of consecutive natural numbers is presented ensuring the accuracy and consistency of the model in this framework no underlying membership functions are needed and several aggregation operators defined on the set of all discrete fuzzy numbers are presented these aggregation operators are constructed from aggregation operators defined on a finite chain in accordance with the granularity of the linguistic term set finally an example of a multi expert decision making problem in a hierarchical multi granular linguistic context is given to illustrate the applicability of the proposed method and its advantages

space time block codes a maximum snr approach in tarokh et al 1999 space time block codes were introduced to obtain coded diversity for a multiple antenna communication system in this work we cast space time codes in an optimal signal to noise ratio snr framework and show that they achieve the maximum snr and in fact they correspond to a generalized maximal ratio combiner the maximum snr framework also helps in calculating the distribution of the snr and in deriving explicit expressions for bit error rates we bring out the connection between the theory of amicable orthogonal designs and space time codes based on this we give a much simpler proof to one of the main theorems on space time codes for complex symbols we present a rate 1 2 code for complex symbols which has a smaller delay than the code already known we also present another rate 3 4 code which is simpler than the one already known in the sense it does not involve additions or multiplications we also point out the connection between generalized real designs and generalized orthogonal designs

sugeno type controllers are universal controllers abstract we show that given any continuous real valued function on a compact set there is a sugeno type controller that will approximate this function to any degree of accuracy an application of this result to fuzzy control is presented which shows that this type of sugeno controller is a universal controller

structure identification of fuzzy model abstract the problems of structure identification of a fuzzy model are formulated a criterion for the verification of a structure is discussed using the criterion an algorithm for identifying a structure is suggested further a successive identification algorithm of the parameters is suggested the proposed methods are applied to an example

two families of mixed finite elements for second order elliptic problems two families of mixed finite elements one based on triangles and the other on rectangles are introduced as alternatives to the usual raviart thomas nedelec spaces error estimates inl 2 andh 5 are derived for these elements a hybrid version of the mixed method is also considered and some superconvergence phenomena are discussed

coherent and differential space time shift keying a dispersion matrix approach motivated by the recent concept of spatial modulation sm we propose a novel space time shift keying stsk modulation scheme for multiple input multiple output mimo communication systems where the concept of sm is extended to include both the space and time dimensions in order to provide a general shift keying framework more specifically in the proposed stsk scheme one out of q dispersion matrices is activated during each transmitted block which enables us to strike a flexible diversity and multiplexing tradeoff this is achieved by optimizing both the space time block duration as well as the number of the dispersion matrices in addition to the number of transmit and receive antennas we will demonstrate that the resultant equivalent system model does not impose any inter channel interference ici and hence the employment of single stream maximum likelihood ml detection becomes realistic at a low complexity furthermore we propose a differential stsk dstsk scheme assisted by the cayley unitary transform which does not require any channel state information csi at the receiver here the usual error doubling caused by the differential decoding gives rise to 3 db performance penalty in comparison to coherent stsk cstsk additionally we introduce an enhanced cstsk scheme which avoids the requirement of inter antenna synchronization ias between the rf chains associated with the transmit antenna elements aes by imposing a certain constraint on the dispersion matrix design where each column of the dispersion matrices includes only a single non zero component moreover according to the turbo coding principle the proposed cstsk and dstsk schemes are combined with multiple serially concatenated codes and an iterative bit to symbol soft demapper more specifically the associated stsk parameters are optimized with the aid of extrinsic information transfer exit charts for the sake of achieving a near capacity performance

on fast decodable space time block codes we focus on full rate fast decodable space time block codes stbcs for 2 times 2 and 4times2 multiple input multiple output mimo transmission we first derive conditions and design criteria for reduced complexity maximum likelihood ml decodable 2times2 stbcs and we apply them to two families of codes that were recently discovered next we derive a novel reduced complexity 4times2 stbc and show that it outperforms all previously known codes with certain constellations

a priori error estimates for mixed finite element approximations of the acoustic wave equation in this paper we derive optimal a priori l infty l 2 error estimates for mixed finite element displacement formulations of the acoustic wave equation the computational complexity of this approach is equivalent to the traditional mixed finite element formulations of the second order hyperbolic equations in which the primary unknowns are pressure and the gradient of pressure however the displacement formulations with the physical variables of interest displacement and pressure requires less regularity on the displacement

accuracy of finite difference and finite element modeling of the scalar and elastic wave equations numerical solutions of the scalar and elastic wave equations have greatly aided geophysicists in both forward modeling and migration of seismic wave fields in complicated geologic media and they promise to be invaluable in solving the full inverse problem this paper quantitatively compares finite difference and finite element solutions of the scalar and elastic hyperbolic wave equations for the most popular implicit and explicit time domain and frequency domain techniques in addition to versatility and ease of implementation it is imperative that one choose the most cost effective solution technique for a fixed degree of accuracy to be of value a solution technique must be able to minimize 1 numerical attenuation or amplification 2 polarization errors 3 numerical anisotropy 4 errors in phase and group velocities 5 extraneous numerical parasitic modes 6 numerical diffraction and scattering and 7 errors and transmission coefficients this paper shows that in homogeneous media the

stability analysis and design of takagi sugeno fuzzy systems this work presents stable composite control criteria for multivariable takagi sugeno t s fuzzy systems on the basis of the linear matrix inequality lmi control strategy and parametric optimization the composite fuzzy control algorithms are derived unlike earlier studies of fuzzy control systems on an lmi framework this investigation develops a supervisory control approach such that a fuzzy controller can be synthesized more efficiently moreover a robust control scheme is applied to the t s fuzzy model with parametric uncertainties the sufficient conditions are deduced in the form of reduced lmis and adaptive tuning rules finally numeric simulations are given to validate the proposed approach

on high rate full diversity 2 2 space time codes with low complexity optimum detection the 2times2 mimo profiles included in mobile wimax specifications are alamouti s space time code stc for transmit diversity and spatial multiplexing sm the former has full diversity and the latter has full rate but neither of them has both of these desired features an alternative 2times2 stc which is both full rate and full diversity is the golden code it is the best known 2times2 stc but it has a high decoding complexity recently the attention was turned to the decoder complexity this issue was included in the stc design criteria and different stcs were proposed in this paper we first present a full rate full diversity 2times2 stc design leading to substantially lower complexity of the optimum detector compared to the golden code with only a slight performance loss we provide the general optimized form of this stc and show that this scheme achieves the diversity multiplexing frontier for square qam signal constellations then we present a variant of the proposed stc which provides a further decrease in the detection complexity with a rate reduction of 25 and show that this provides an interesting trade off between the alamouti scheme and sm

a fuzzy linear programming method for group decision making with additive reciprocal fuzzy preference relations abstract the existing methods for solving the group decision making gdm problems with preference relations generally include four steps 1 estimation of missing preferences 2 consistency and consensus reaching 3 aggregation and 4 exploitation which make the gdm process complicated relatively very few research results focus on exploring the methods which can simplify this process to improve the efficiency in this paper we develop a new fuzzy linear programming method flpm to deal with the gdm problems with additive reciprocal fuzzy preference relations fprs the flpm can directly produce meaningful results without the four steps an effect index is developed to measure the decision makers dms effects in the gdm problems based on the flpm and the effect index we propose a new method to determine the dms weights a step by step procedure is further proposed to deal with the gdm problems with all the developed methods and its performance is illustrated by examples

a new fuzzy lyapunov function approach for a takagi sugeno fuzzy control system design in this paper a new fuzzy lyapunov function approach is presented for a class of continuous time takagi sugeno fuzzy control system the proposed fuzzy lyapunov function is formulated as a line integral of a fuzzy vector which is a function of the state and it can be regarded as the work done from the origin to the current state in the fuzzy vector field unlike the approaches using a fuzzy blending of multiple quadratic lyapunov functions the time derivatives of membership functions do not appear in the proposed approach the effectiveness of the proposed approach is shown through numerical examples

the construction of left continuous t norms a geometric approach in two dimensions abstract each t norm can be identified with its cayley tomonoid which consists of pairwise commuting order preserving functions from the real unit interval to itself cayley tomonoids provide an easily manageable yet versatile tool for the construction of t norms to give evidence to this claim we review and reformulate several construction methods that are known in the literature we adopt on the one hand a geometric point of view manipulations with t norms have often been inspired by their three dimensional graphs by means of cayley tomonoids the process gains the character of putting together the pieces of a jigsaw puzzle we consider on the other hand construction methods in their algebraic context we show that those constructions that correspond to certain tomonoid extensions can be described on the basis of cayley tomonoids in a particularly transparent way

enhanced spatial modulation with multiple signal constellations in this paper we introduce a new spatial modulation sm technique using one or two active antennas and multiple signal constellations the proposed technique which we refer to as enhanced sm or esm conveys information bits not only by the index es of the active antenna s but also by the constellations transmitted from each of them the main feature of esm is that it uses a primary signal constellation during the single active antenna periods and some other secondary constellations during the periods with two active transmit antennas the secondary signal constellations are derived from the primary constellation by means of geometric interpolation in the signal space we give design examples using two and four transmit antennas and qpsk 16qam and 64qam as primary modulations the proposed technique is compared to conventional sm as well as to spatial multiplexing smx and the results indicate that in most cases esm provides a substantial performance gain over conventional sm and smx while reducing the maximum likelihood ml decoder complexity

upper bounds of rates of complex orthogonal space time block codes we derive some upper bounds of the rates of generalized complex orthogonal space time block codes we first present some new properties of complex orthogonal designs and then show that the rates of complex orthogonal space time block codes for more than two transmit antennas are upper bounded by 3 4 we show that the rates of generalized complex orthogonal space time block codes for more than two transmit antennas are upper bounded by 4 5 where the norms of column vectors may not be necessarily the same we also present another upper bound under a certain condition for a generalized complex orthogonal design its variables are not restricted to any alphabet sets but are on the whole complex plane a generalized complex orthogonal design with variables over some alphabet sets on the complex plane is also considered we obtain a condition on the alphabet sets such that a generalized complex orthogonal design with variables over these alphabet sets is also a conventional generalized complex orthogonal design and therefore the above upper bounds on its rate also hold we show that commonly used quadrature amplitude modulation qam constellations of sizes above 4 satisfy this condition

general type 2 fuzzy logic systems made simple a tutorial the purpose of this tutorial paper is to make general type 2 fuzzy logic systems gt2 flss more accessible to fuzzy logic researchers and practitioners and to expedite their research designs and use to accomplish this the paper 1 explains four different mathematical representations for general type 2 fuzzy sets gt2 fss 2 demonstrates that for the optimal design of a gt2 fls one should use the vertical slice representation of its gt2 fss because it is the only one of the four mathematical representations that is parsimonious 3 shows how to obtain set theoretic and other operations for gt2 fss using type 1 t1 fs mathematics cuts play a central role 4 reviews mamdani and tsk interval type 2 it2 flss so that their mathematical operations can be easily used in a gt2 fls 5 provides all of the formulas that describe both mamdani and tsk gt2 flss 6 explains why center of sets type reduction should be favored for a gt2 fls over centroid type reduction 7 provides three simplified gt2 flss two are for mamdani gt2 flss and one is for a tsk gt2 fls all of which bypass type reduction and are generalizations from their it2 fls counterparts to gt2 flss 8 explains why gradient based optimization should not be used to optimally design a gt2 fls 9 explains how derivative free optimization algorithms can be used to optimally design a gt2 fls and 10 provides a three step approach for optimally designing flss in a progressive manner from t1 to it2 to gt2 each of which uses a quantum particle swarm optimization algorithm by virtue of which the performance for the it2 fls cannot be worse than that of the t1 fls and the performance for the gt2 fls cannot be worse than that of the it2 fls

perfect space time block codes in this paper we introduce the notion of perfect space time block codes stbcs these codes have full rate full diversity nonvanishing constant minimum determinant for increasing spectral efficiency uniform average transmitted energy per antenna and good shaping we present algebraic constructions of perfect stbcs for 2 3 4 and 6 antennas

generalized precoder design formulation and iterative algorithm for spatial modulation in mimo systems with csit in this paper we propose two generalized precoder designs to enhance the bit error rates for the general category of spatial modulation sm in multiple input multiple output mimo systems with channel state information at the transmitter csit we investigate typical sm mimo systems and propose two optimization formulations for designing precoders our design rationale for the first formulation is to maximize the minimum euclidean distance among codewords for the second formulation it is to minimize the total signal power for the lower bounded euclidean distances among codewords since both formulations are non convex and their optimal solutions are generally intractable we propose an algorithm that acquires effective solutions by iteratively solving the alternative convex problem linearized and approximated from the original non convex problem discussions on complexity analysis performance comparisons design challenges and robustness in imperfect csit are then provided by generalizing the design formulations the proposed precoder designs can be extended to generalized sm which completes the investigation for virtually all sm type systems simulation results show that the proposed designs improve the performance of sm gsm mimo systems and outperform existing precoding methods with a potentially higher complexity cost

generalised sphere decoding for spatial modulation in this paper sphere decoding sd algorithms for spatial modulation sm are developed to reduce the computational complexity of maximum likelihood ml detectors two sds specifically designed for sm are proposed and analysed in terms of bit error ratio ber and computational complexity using monte carlo simulations and mathematical analysis it is shown that by carefully choosing the initial radius the proposed sphere decoder algorithms offer the same ber as ml detection with a significant reduction in the computational complexity a tight closed form expression for the ber performance of sm sd is derived in the paper along with an algorithm for choosing the initial radius which provides near to optimum performance also it is shown that none of the proposed sds are always superior to the others but the best sd to use depends on the target spectral efficiency the computational complexity trade off offered by the proposed solutions is studied via analysis and simulation and is shown to validate our findings finally the performance of sm sds are compared to spatial multiplexing smx applying ml decoder and applying sd it is shown that for the same spectral efficiency sm sd offers up to 84 reduction in complexity compared to smx sd with up to 1 db better ber performance than smx ml decoder

method for higher order polynomial sugeno fuzzy inference systems a method for higher order polynomial sugeno fuzzy inference systems formation is presented compared to other existing higher order sugeno implementations it uses fewer parameters and compared to zero and 1st order sugeno fuzzy systems it has overall improved model performance while best models are not always obtained via a higher order representation in our proposed method it is possible to choose the polynomial order which best fits the desired data its input is a previously established model found by a clustering algorithm subtractive algorithm in this case afterward parameters of all higher order polynomials are adjusted using recursive least square algorithm for experimental validation multiple benchmark datasets are tested using hold out and k fold validation as well as data forecasting various performance measures are used although akaike information criterion is used as a primary measure to demonstrate that our proposed higher order polynomials have overall better model performance over zero and 1st order polynomials

unified full implication algorithms of fuzzy reasoning this paper discusses the full implication inference of fuzzy reasoning for all residuated implications induced by left continuous t norms unified a triple i algorithms are constructed to generalize the known results as the corollaries of the main results of this paper some special algorithms can be easily derived based on four important residuated implications these algorithms would be beneficial to applications of fuzzy reasoning based on properties of residuated implications the proofs of the many conclusions are greatly simplified

space time block coded spatial modulation a novel multiple input multiple output mimo transmission scheme called space time block coded spatial modulation stbc sm is proposed it combines spatial modulation sm and space time block coding stbc to take advantage of the benefits of both while avoiding their drawbacks in the stbc sm scheme the transmitted information symbols are expanded not only to the space and time domains but also to the spatial antenna domain which corresponds to the on off status of the transmit antennas available at the space domain and therefore both core stbc and antenna indices carry information a general technique is presented for the design of the stbc sm scheme for any number of transmit antennas besides the high spectral efficiency advantage provided by the antenna domain the proposed scheme is also optimized by deriving its diversity and coding gains to exploit the diversity advantage of stbc a low complexity maximum likelihood ml decoder is given for the new scheme which profits from the orthogonality of the core stbc the performance advantages of the stbc sm over simple sm and over v blast are shown by simulation results for various spectral efficiencies and are supported by the derivation of a closed form expression for the union bound on the bit error probability

genetic programming for model selection of tsk fuzzy systems this paper compares a genetic programming gp approach with a greedy partition algorithm lolimot for structure identification of local linear neuro fuzzy models the crisp linear conclusion part of a takagi sugeno kang tsk fuzzy rule describes the underlying model in the local region specified in the premise the objective of structure identification is to identify an optimal partition of the input space into gaussian axis orthogonal fuzzy sets the linear parameters in the rule consequent are then estimated by means of a local weighted least squares algorithm lolimot is an incremental tree construction algorithm that partitions the input space by axis orthogonal splits in each iteration it greedily adds the new model that minimizes the classification error gp performs a global search for the optimal partition tree and is therefore able to backtrack in case of sub optimal intermediate split decisions we compare the performance of both methods for function approximation of a highly non linear two dimensional test function and an engine characteristic map