The recurrent neural network (RNN) has been used in audio and speech processing, such as language translation and speech recognition. Although RNN-based architecture can be applied to speech synthesis, the long computing time is still the primary concern. This research proposes a fast gated recurrent neural network, a fast RNN-based architecture, for speech synthesis based on the minimal gated unit (MGU). Our architecture removes the unit state history from some equations in MGU. Our MGU-based architecture is about twice faster, with equally good sound quality than the other MGU-based architectures.

With the advantages of higher blocking voltage, higher operation temperature, fast-switching characteristics, and lower switching losses, the silicon carbide (SiC) MOSFET has attracted more attentions and become an available replacement of traditional silicon (Si) power semiconductor in applications. Despite of all the merits above, electromagnetic interference (EMI) issues will be induced consequently by the ultra-fast switching transitions of the SiC MOSFET. To quickly and precisely assess the switching behaviors of the SiC MOSFET for EMI investigation, an analytical model is proposed. This model has comprehensively considered most of the key factors, including parasitic inductances, non-linearity of the junction capacitors, negative feedback effect of Ls and Cgd shared by the power and the gate stage loops, non-linearity of the trans-conductance, and skin effect during voltage and current ringing stages, which will considerably affect the switching performance of the SiC MOSFET. Additionally, a finite-state machine (FSM) is especially utilized so as to analytically and intuitively describe the switching behaviors of the SiC MOSFET via Stateflow. Based on double pulse test (DPT), the effectiveness and correctness of the proposed model are validated through the comparison between the calculated and the measured waveforms during switching transitions. Besides, the model can appropriately depict the spectrum of the drain-source voltage of the MOSFET and is suitable for EMI investigation in applying of SiC devices.

The vast majority of foreground detection methods require heavy hardware optimization to process in real-time standard definition videos. Indeed, those methods process the whole frame for the detection but also for the background modelling part which makes them resource-guzzlers (time, memory, etc.) unable to be applied to Ultra High Definition (UHD) videos. This paper presents a real-time background modelling method called Mixed Block Background Modelling (MBBM). It is a spatio-temporal approach which updates the background model by carefully selecting block by a linear and pseudo-random orders and update the corresponding model's block parts. The two block selection orders make sure that every block will be updated. For foreground detection purposes, the method is combined with a foreground detection designed for UHD videos such as the Adaptive Block-Propagative Background Subtraction method. Experimental results show that the proposed MBBM can process 50min. of 4K UHD videos in less than 6 hours. while other methods are estimated to take from 8 days to more than 21 years. Compared to 10 state-of-the-art foreground detection methods, the proposed MBBM shows the best quality results with an average global quality score of 0.597 (1 being the maximum) on a dataset of 4K UHDTV sequences containing various situation like illumination variation. Finally, the processing time per pixel of the MBBM is the lowest of all compared methods with an average of 3.18×10-8s.

This article describes an approximate model of a group of cells in the wireless 4G network with implemented load balancing mechanism. An appropriately modified model of Erlang's Ideal Grading is used to model this group of cells. The model makes it possible to take into account limited availability of resources of individual cells to multi-rate elastic and adaptive traffic streams generated by Erlang and Engset sources. The developed solution allows the basic traffic characteristics in the considered system to be determined, i.e. the occupancy distribution and the blocking probability. Because of the approximate nature of the proposed model, the results obtained based on the model were compared with the results of a digital simulation. The present study validates the adopted assumptions of the proposed model.

Traffic is a key aspect of everyday life. Its study, as it happens with other complex phenomena, has found in simulation a basic tool. However, the use of simulations faces important limitations. Building them requires considering different aspects of traffic (e.g. urbanism, car features, and individual drivers) with their specific theories, that must be integrated to provide a coherent model. There is also a variety of simulation platforms with different requirements. Many of these problems demand multi-disciplinary teams, where the different backgrounds can hinder the communication and validation of simulations. The Model-Driven Engineering (MDE) of simulations has been proposed in other fields to address these issues. Such approaches develop graphical Modelling Languages (MLs) that researchers use to model their problems, and then semi-automatically generate simulations from those models. Working in this way promotes communication, platform independence, incremental development, and reutilisation. This paper presents the first steps for a MDE framework for traffic simulations. It introduces a tailored extensible ML for domain experts. The ML is focused on human actions, so it adopts an Agent-Based Modelling perspective. Regarding traffic aspects, it includes concepts commonly found in related literature following the Driver-Vehicle-Environment model. The language is also suitable to accommodate additional theories using its extension mechanisms. The approach is supported by an infrastructure developed using Eclipse MDE projects: the ML is specified with Ecore, and a model editor and a code generator tools are provided. A case study illustrates how to develop a simulation based on a driver's behaviour theory for a specific target platform using these elements.

Radio channel modeling is fundamental for designing wireless communication systems. In millimeter or sub-millimeter wave short range communication, shadowing effect by electrically-large objects is one of the most important factors determining the field strength and thus the coverage. Unfortunately, numerical methods like MoM, FDTD, FEM are unable to compute the field scattered by large objects due to their excessive time and memory requirements. Ray theory like geometrical theory of diffraction (GTD) by Keller is an effective and popular solution but suffers various kinds of singularities at geometrical boundaries such as incidence shadow boundary (ISB) or reflection shadow boundary (RSB). Modified edge representation (MER) equivalent edge current (EEC) is an accurate and a fast high frequency diffraction technique which expresses the fields in terms of line integration. It adopts classical Keller-type knife-edge diffraction coefficients and still provides uniform and highly accurate fields everywhere including geometrical boundaries. MER is used here to compute the millimeter-wave field distribution in compact range communication systems where shadowing effects rather than multi-path ones dominate the radio environments. For further simplicity, trigonometric functions in Keller's diffraction coefficients are replaced by the path lengths of source to the observer via the edge point of integration of the scatterers in the form of Fresnel zone number (FZN). Complexity, Computation time and the memory were reduced drastically without degrading the accuracy. The dipole wave scattering from flat rectangular plates is discussed with numerical examples.

In NGN standards, End Host, also referred to as Terminal Equipment (TE), holds an important place in end-to-end path performance. However, most researchers neglect TE performance when considering performance of end-to-end paths. As far as the authors' knowledge goes, no previous study has proposed a model for TE performance. This paper proposes a method for measuring performance of TE and model extraction based on measurement data. The measurement was made possible with the use of a special NPU (Network Processing Unit) implemented as a programmable NIC. Along with the probing itself, a framework for removing the skew between the NPU and OS is developed in this paper. The multidimensional analysis includes method of probing, packet size and background traffic volume, and studies their effect on TE performance. A method for extracting a generic TE model is proposed. The outcome of this research can be used for modelling TE in simulations and in modelling end-to-end performance when considering QoS in NGN.

A simple analytical model to predict the DC MOSFET behavior under electromagnetic interference (EMI) is presented. The model is able to describe the MOSFET performance in the linear and saturation regions under EMI disturbance applied to the gate. The model consists of a unique simple equivalent circuit based on a voltage dependent current source and a reduced number of parameters which can accurately predict the drift on the drain current due to the EMI source. The analytical approach has been validated by means of electric simulation and measurements and can be easily introduced in circuit simulators. The proposed modeling technique combined with the nth-power law model of the MOSFET without EMI, significantly improves its accuracy in comparison with the n-th power law directly applied to a MOSFET under EMI impact.

Software processes and corresponding models are dynamic entities that are often changed and evolved by skillful knowledge workers such as the members of a software development team. Consequently, process flexibility has been identified as one of the most important features that should be supported by both Process Modelling Languages (PMLs) and software tools that manage the processes. However, in the everyday practice, most software team members do not want total flexibility. They rather prefer to have controlled flexibility, i.e., to learn and follow advices previously modelled by a process engineer on which and how they can change the elements that compose a software process. Since process models constitute a preferred vehicle for sharing and communicating knowledge on software processes, the process engineer needs a PML that can express this controlled flexibility, along with other process perspectives. To achieve this enhanced PML, we first need a sound core set of concepts and relationships that defines the knowledge domain associated with the modelling of controlled flexibility. In this paper we capture and represent this domain by using Concept Maps (Cmaps). These include diagrams and descriptions that elicit the relationships between the concepts involved. The proposed Cmaps can then be used as input to extend a PML with modelling constructs to express controlled flexibility within software processes. Process engineers can use these constructs to define, in a process model, advices on changes that can be made to the model itself or to related instances. Software team members can then consult this controlled flexibility information within the process models and perform changes accordingly.

Although the probabilistic model checking tool called PRISM has been applied in many communication systems, such as wireless local area network, Bluetooth, and ZigBee, the technique is not used in a controller area network (CAN). In this paper, we use PRISM to model the mechanism of priority messages for CAN because the mechanism has allowed CAN to become the leader in serial communication for automobile and industry control. Through modeling CAN, it is easy to analyze the characteristic of CAN for further improving the security and efficiency of automobiles. The Markov chain model helps us to model the behaviour of priority messages.

The paper reviews recent advances in on-body antennas and propagation under a joint UK EPSRC research project between Queen Mary College, University of London and University of Birmingham. The study of on-body radio propagation has been extended by using various small antennas. The effect of antenna size, gain and radiation patterns on on-body channel characteristics has been studied. A practical wearable sensor antenna design is presented and it is demonstrated that a global simulation including sensor environment and human body is needed for accurate antenna characterisation. A 3D animation design software, POSER 6 has been used together with XFDTD to predict the on-body path loss variation due to changes in human postures and human motion. Finally, a preliminary study on the feasibility of a diversity scheme in an on-body environment has been carried out.

In this paper, an evolutionary approach is proposed to obtain a discrete-time state-space interval model for uncertain continuous-time systems having interval uncertainties. Based on a worst-case analysis, the problem to derive the discrete interval model is first formulated as multiple mono-objective optimization problems for matrix-value functions associated with the discrete system matrices, and subsequently optimized via a proposed genetic algorithm (GA) to obtain the lower and upper bounds of the entries in the system matrices. To show the effectiveness of the proposed approach, roots clustering of the characteristic equation of the obtained discrete interval model is illustrated for comparison with those obtained via existing methods.

In this letter, an analytic model for real-time flow connections in a Wireless Mobile Internet (WMI) is developed, and then performance measures are derived. Some examples are also presented in order to show the call-blocking ratio and the number of connections admitted into a WMI.

In this paper, routing properties of cube-based optoelectronic OTIS networks are explored. We show emulations of various cubical network topologies on their OTIS augmented variants, including the n-D grid networks, shuffle-exchange, and de Brujin networks. An analytical performance model for OTIS-cube networks is proposed. The model is validated by means of comparison with rigorously obtained simulation results. Using this model, the performance characteristics of the OTIS-hypercube network are evaluated in view of a number of different constraints. Moreover, we compare the performance characteristics of the OTIS-hypercube with that of equivalent fully-electronic networks under various implementation constraints.

Since the interference is quite related to the performance of CDMA cellular systems, it is necessary to estimate Other-Cell-Interference Factor (OCIF). Here, starting from OCIF calculation for an aeronautical communication system, we investigate the forward link performance of data packet transmission in which the capacity, throughput and delay of the system are measured. To the numerical results, one can see that the performance of the aeronautical communication system is worse than that for terrestrial cellular systems and also depends logarithmically on both the cell radius and height.

The comparative analysis of the well known Double Drift Region (DDR) IMPATT diode structure and the n+pvnp+ structure for the avalanche diode has been realized on the basis of the drift-diffusion nonlinear model. The last type of the diode was named as Double Avalanche Region (DAR) IMPATT diode. This structure includes two avalanche regions inside the diode. The phase delay which was produced by means of the two avalanche zones and the drift zone v is sufficient for the negative resistance obtained for the wide frequency region. The numerical model that is used for the analysis of the various diode structures includes all principal features of the physical phenomena inside the semiconductor structure. The admittance characteristics of both types of the diodes were analyzed in very wide frequency region.

A new mesh reconstruction method, called the shrink-wrapped boundary face (SWBF) algorithm, is proposed for approximating a surface from a set of unorganized 3D points. SWBF overcomes the genus-0 spherical topology restriction of previous shrink-wrapping based mesh generation technique. Furthermore, SWBF is much faster since it requires only local nearest-point-search in the shrinking process. Our experimental results demonstrate that SWBF is very robust and efficient, and it is expected to become a general solution for reconstructing a mesh from an unorganized points cloud.

The rapid down-scaling of minimum feature size in CMOS technologies has boosted the RF performance, thereby opening up the RF application area to CMOS. The concurrent reduction of supply voltage pushes the MOSFETs used in circuit design more and more into the moderate-inversion regime of operation. As a consequence, compact MOS models are needed that are accurate in all operating regimes, including the moderate-inversion regime. Advanced analogue applications require accurate modelling of distortion, capacitances and noise. RF application of MOSFETs require the extension of this accurate modelling up to high frequencies and in addition accurate modelling of impedance levels and power gain. The implications for compact MOS models will be discussed, together with the state-of-the-art in compact MOS modelling. Special attention will be paid to some well-known circuit examples, and the compact model requirements needed for a correct description. Where relevant MOS Model 11 will be used to illustrate the discussion.

For more than twenty-five years software inspections have been considered an effective method for defect detection. Inspections have been investigated through controlled experiments in university environment and industry case studies. However, in most cases software inspections have been used for defect detection in documents of conventional structured development process. Therefore, there is a significant lack of information about how inspections should be applied to Object-Oriented artifacts, such as Object-Oriented code and design diagrams. In addition, extensive work is needed to determine whether some inspection techniques can be more beneficial than others. Most inspection experiments include inspection meetings after individual inspection is completed. However, several researchers suggested that inspection meetings may not be necessary since an insignificant number of new defects are found as a result of inspection meeting. Moreover, inspection meetings have been found to suffer from process loss. This paper presents the findings of a controlled experiment that was conducted to investigate the performance of individual inspectors as well as 3-person teams in Object-Oriented design document inspection. Documents were written using the notation of Unified Modelling Language. Two reading techniques, namely Checklist-based reading (CBR) and Perspective-based reading (PBR), were used during experiment. We found that both techniques are similar with respect to defect detection effectiveness during individual inspection as well as during inspection meetings. Investigating the usefulness of inspection meetings, we found out that the teams that used CBR technique exhibited significantly smaller meeting gains (number of new defect first found during team meeting) than meeting losses (number of defects first identified by an individual but never included into defect list by a team); meanwhile the meeting gains were similar to meeting losses of the teams that used PBR technique. Consequently, CBR 3-person team meetings turned out to be less beneficial than PBR 3-person team meetings.

This paper presents a Multi Agent Systems (MAS) approach to crowd modelling, based on the Situated Cellular Agents (SCA) model. This is a special class of Multilayered Multi Agent Situated System (MMASS), providing an explicit representation of spatial structures and different means of agent interaction. Heterogenous agents may be obtained through the definition of different agent types, specifying different behaviors and perceptive capabilities. The model is rooted on some basic principles of Cellular Automata (e.g. the definition of adjacency geometries), but also takes into account the autonomy of modelled entities, with their own internal architecture. A formal definition of the SCA model will be given, with a description of how it can be applied to forward and backward approaches to simulation. Particular attention will be paid to the crowd and pedestrian modelling, and two applications to simulation to crowding will be described.