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This paper summarizes the results of design of new mechanical variable valve actuation (hereafter VVA) systems, developed for high performance motorcycle engines, at University of Napoli Federico II, Department of Industrial Engineering-Section Mechanics and Energy (hereafter DiME). In addition to a first simple (and limited) system used just as a model for the previous analysis, the work has evolved through three basic steps leading to three types of VVA systems, all mechanical systems (as defined in literature and described later). The study has been conducted implementing a numerical procedure specifically designed to determine cam profile and kinematic and dynamic characteristics of the whole system, starting from some data (as described in the paper). The model has been validated against the conventional timing system using kinematic simulations. Results of the numerical procedure verify the validity of the VVA systems and particularly a better performance of the last one, in spite of its higher complexity. [ABSTRACT FROM AUTHOR]

This paper illustrates a methodology for the lap time optimization of a race series hybrid electric vehicle based on the indirect optimal control approach. More specifically, for a vehicle with given characteristics running on a given track, the optimal trajectory and powertrain power flow that minimize the lap time are found. The paper presents a parametric model of a sports series hybrid electric vehicle, illustrates the optimization method and discusses simulation results. [ABSTRACT FROM AUTHOR]

With the increasing need of electric vehicles (EV), necessary development is required to get reliable, efficient and economical drives for electric propulsion. Electric propulsion system using Induction Motor drive (IM) is becoming so popular because of its reliability, technological maturity and low cost. Field Orientation Control (FOC) is so popular in controlling the IM, but it has disadvantages like sensitive to parametric variation, external disturbance, load variation and also algorithm takes more time for execution, hence it requires a very fast microprocessor with high millions of instructions per second (MIPS) for implementation. In this paper, IM is controlled by using Direct Torque Control (DTC) technique because of its simple configuration and gives quick response. The mathematical model takes into account of the inverter, IM dynamics and vehicle aerodynamics. In this paper, the response of the IM with DTC for EV load for driving cycle consists of starting, acceleration, constant speed and deceleration modes are explained and validated using MATLAB/SIMULINK. [ABSTRACT FROM AUTHOR]

This paper proposes a model of a colluding attack in Volunteer Computing (VC), where some of participants are unreliable and may return incorrect results. The colluding attack is one of the most important issues to realize reliable VC because it may ruin the most basic assumption, i.e. "the majority in voting is correct". Especially, check-by-voting archives the largest efficiency by sorting reliable participants based on whether their results are the majority or not. Thus, if some incorrect results become the majority by colluding attack, it may have significant impacts on check-by-voting. In this paper, we perform a Monte Carlo simulation of VC using the proposed colluding model and evaluate the sabotage-tolerance performance of voting methods. Simulation results show that check-by-voting works well if colluding attack happens. [ABSTRACT FROM AUTHOR]

This paper proposes a model of a colluding attack in Volunteer Computing (VC), where some of participants are unreliable and may return incorrect results. The colluding attack is one of the most important issues to realize reliable VC because it may ruin the most basic assumption, i.e. "the majority in voting is correct". Especially, check-by-voting archives the largest efficiency by sorting reliable participants based on whether their results are the majority or not. Thus, if some incorrect results become the majority by colluding attack, it may have significant impacts on check-by-voting. In this paper, we perform a Monte Carlo simulation of VC using the proposed colluding model and evaluate the sabotage-tolerance performance of voting methods. Simulation results show that check-by-voting works well if colluding attack happens. [ABSTRACT FROM AUTHOR]

The design of a microsensor network has to be carried out under several constraints, e.g., limited energy source and dynamic network topology. One practical design scheme in WSNs is clustering. Clustering is an energy efficient and scalable way to organize the WSN. Clustering can stabilize the network topology at the level of sensors and thus cuts on topology maintenance overhead. Recently, a number of clustering algorithms have been specifically designed for WSNs. These proposed clustering techniques widely vary depending on the overall network architectural and operation model and their objectives. In this paper, classification of clustering algorithms is carried out i.e. as energy efficient type, duty cycle control type and third type is the one derived from classic graphic theory. In this paper focus is on the energy efficient type of clustering protocols. Furthermore, classification and analysis of energy efficient protocols viz. LEACH and PEGASIS is presented. Also a hybrid approach Hierarchical Chain-cluster scheme is introduced and the performance of all the three protocols is evaluated and comparison of them is done with the conventional Direct Transmission scheme. [ABSTRACT FROM AUTHOR]

Modeling road accidents using panel data approach recently has gained wide attention and application. As the nature of road crashes are non-negative count, the traditional linear computational approaches is inappropriate giving the nonlinear model of fixed effects (FE) the better choice. This paper examines the road accidents relationship with precipitation factors by estimating the FE Negative Binomial (NB) model. In the FE model two estimation methods were consider in this paper: conditional and unconditional estimation method. Thus, this paper compare the conditional and unconditional FE model for road accidents and discuss the findings obtain. Results showed that the unconditional FE Negative Binomial model gives approximately the same results with conditional models. The effect of monthly rainfall with shorter spell period presents greater risk of accident rate. On the other hand, a negative relationship is found between the monthly rainfalls with longer spell period and accident rate. [ABSTRACT FROM AUTHOR]

In this paper we study optimization of multistage drying process in fluidized bed. The drying of fine particles in fluidized bed is very effective operation because of good contact of phases and a large interfacial surface. Using a relatively high gas velocity improves conditions of mass and heat transfers but a portion of gas begins to flow as bubbles or canals, so an energy carried by this gas is not used efficiently. This is a reason to search for best operating parameters to minimize cost or to maximize efficiency of the process. A method of determining optimal parameters of drying gas (flowrate, temperature and humidity) is described in this paper. As a performance index, i.e. function being optimized, we apply a function describing the exergy input in the drying process. This function consists of three parts, the first two describing the thermal and chemical exergy of gas whereas the third one referring to investment costs expressed in exergy units. The chemical exergy of gas is connected with the difference between gas humidity and ambient humidity. In the optimization calculations we search for a minimum of exergy consumption Any effective method of optimization involves an algorithm of maximum principle for multistage problems. The earliest algorithms of this sort was the Katz' and Fan's algorithm. As it is less suitable for our purposes due to its undefined symplectic structure, we apply a modification of Sieniutycz's and Szwast's algorithm with a constant Hamiltonian (formally similar to the well-know continuous algorithm of Pontryagin). In this paper a modification of the basis algorithm is applied. This modification admits constrained intervals of time. In our calculations we take into consideration the bed hydrodynamics and kinetics of transport processes To describe behavior of fluidized bed we use the well-known two-phase model of Kunii and Levenspiel In this model, the gas excess flows in form of bubbles. The heat and mass transfer between the solid and gas as well between the dense phase (with gas and solid) and bubble phase determines values of optimal gas parameters. We discuss optimal parameters of gas and solid associated with minimum exergy consumption in drying proces. [ABSTRACT FROM AUTHOR]

Plant automation system (technical as well as non-technical ones) can't be designed and made operational without using methods of model building and simulation of the system to be automated. In this paper model equations for closed loop temperature control of heat exchanger used in soda recovery section of Star Paper Mills Ltd., Saharanpur (U.P), India has been developed and mathematically simulated on the basis of available information and knowledge. The mathematical model for transfer function of each elements of control loop developed. Software developed for overall transfer function and simulated using MATLAB. The performance analysis of module is examined with PID controller by varying the controller parameters and set-points. The rise time (tr), peak time (tp), settling time (ts) is calculated at set point 110, 115 & 120. [ABSTRACT FROM AUTHOR]

Energy consumption is one of the most important problems to be solved in wireless sensor networks, since sensor nodes are operated with battery power. Therefore, it is necessary to put the wireless interface of sensor nodes into low power sleep state as much as possible when communication with neighbor sensor nodes is not required, in order to save battery power. In this paper, we analytically derive the steady state probability of sensor node states, sleep, listen, and active states, in Adaptive Fidelity Energy-Conserving Algorithm (AFECA), which belongs to duty cycling scheme for energy conservation in wireless sensor networks. Then, we analyze the energy consumption of AFECA in detail for varying the number of neighboring nodes, sleep timer, listen timer, and active timer values. The performance of AFECA is compared with that of Basic Energy Conservation Algorithm (BECA) in detail via mathematical analysis. The analysis results show that AFECA achieves significant improvement of energy conservation over BECA, even for a small number of neighboring nodes, when the values of sleep timer and active timer are not very large. The result of this paper can provide sensor network operators guideline for selecting appropriate timer values for AFECA. [ABSTRACT FROM AUTHOR]

Energy harvesting has received growing attention over the last decade. The research motivation in this field is due to the reduced power requirement of small electronic components, such as the wireless sensor networks used in structural health monitoring applications. The ultimate goal in this research field is to power such small electronic devices by using the vibration energy available in their environment. If this can be achieved, the requirement of an external power source as well as the maintenance requirement for periodic battery replacement can be minimized. In this paper, the modeling, simulation and experimental results of the piezoelectric energy harvesting using LabVIEW and Matlab are presented. This paper describes a dynamic model to simulate piezoelectric harvester and to identify model parameters with real time measurements and standard laboratory equipment. [ABSTRACT FROM AUTHOR]

Fire detection is an important issue of modern security sensing system. In this paper, we propose a vision-based fire detection algorithm. The proposed approach integrates color, spatial and motion information to locate fire regions in video frames. Potential fire regions are detected by modeling the fire color with Gaussian mixture model. Based on some characteristics of burning flame, we combine spatial and temporal features to remove spurious fire-like regions. Finally, some missing fire regions are located using region growing method. Experimental results indicate that the proposed approach can be applied to a variety of conditions and outperform some existing technique. [ABSTRACT FROM AUTHOR]

A numerical and experimental analysis of a hydraulic actuation system is described in this paper. The approach is based on a combined use of measurements and simulations. The model has been developed adopting a commercial code that allows to take several details into account, differently from a typical mathematical model. The model has been derived taking into account all the components of the hydraulic circuit. The results of numerical simulations are reported and compared with experimental data to show the validation and the performances of the developed model. [ABSTRACT FROM AUTHOR]

Hybrid testing is a technique that combines physical testing and numerical simulation. In this paper, the results of a hybrid test are presented in order to describe the seismic behavior of a steel frame isolated using Fiber Reinforced Bearings (FRBs). FRBs tested in this study are made by recycled rubber and carbon fiber reinforcement. In the hybrid simulations, the seismic bearings constitute the physical models, and the structure is simulated by a numerical model. The test demonstrates the feasibility of an innovative, low cost, seismic isolation technology and the applicability to frame structures. [ABSTRACT FROM AUTHOR]

The use of numerical simulation tools applying the finite element method for the design and analysis of bolted joints involves a series of difficulties providing complexity to the numerical modelling of apparently simple mechanical systems. In order to solve this difficulties and to achieve accurate, effective and fast calculations, it is necessary to take into account several simplifications of the mesh models during the preprocess step. Factors such as the substitution of the bolts and nuts' threads for contact conditions with friction interaction between cylindrical surfaces, the adequate characterization of the preload existing in the different members of the joint, or the correct modelling of contact interactions between the parts suppose a series of problems that will be necessary to overcome so as to successfully face the analysis of a mechanical system with bolted joints subjected to load conditions. The aim of this paper is the development of a numerical technique for the static analysis of preloaded bolted joints by the FEM using the software ABAQUS Standard and a mesh modelling with solid type elements. Parting from a new design with bolted joints for the longitudinal beams of an innovative modular semitrailer, the different problems associated to this type of analysis were stated first. Then, the numerical technique developed has been described and all its considerations have been applied to that specific semitrailer bolted joints. [ABSTRACT FROM AUTHOR]

In this paper, a new viscoelastic model is presented to describe the elastic and viscoelastic behaviors of ligaments and tendons during the preconditioning process. The model is formulated by accounting for the mechanical contribution of the main structures of ligaments and tendons, i. e., the collagen fibers, the proteoglycan-rich matrix and the coupling between the collagen fibers and the matrix. The coupling between the collagen fibers and the matrix is assumed to behave as the links binding the collagen fibers and the matrix together. According to the previous studies, the friction loss in ligaments and tendons plays a significant role on the stress softening and the decreasing of the hysteresis during preconditioning. Therefore, in this work, the links are assumed to gradually break during preconditioning and there will be no links breaking when the preconditioning is completed. Finally, the viscoelastic model can easily describe the stress softening and the decreasing of the hysteresis during preconditioning process. We believe that our model can provide a simple way to interpret the physical mechanism during the preconditioning process in ligaments and tendons. [ABSTRACT FROM AUTHOR]

This paper presents a correlation of Automobile bumper performance with geometry of the Automobile. The study focuses on finding out if there is any existing relationship between the two variables mentioned and to determine the strength of that relationship if there is any. An approach which allows for this- Pearson's Correlation process- developed by Karl Pearson is applied. Varying automobile bumpers resulting from different automobile geometry models were simulated using Solid Work Software. The Correlation analysis carried out with the simulation data, produced Correlation coefficients of 0.990534919 & 0.990658205; showing a very strong positive correlation between the variables. Since the Correlation coefficient obtained is greater than the corresponding critical value of Correlation coefficient, 0.917, (under 0.1 tailed test of type1 error) for the correlation degree of freedom of 4, it follows that this research runs only 1% chance of being wrong in the relationship so determined. Hence, it will be useful in automobile design in general. [ABSTRACT FROM AUTHOR]

The stiffness of the joint is the key part of the whole machine tool stiffness loop. This paper proposes a new orthotropic model and its parameter acquisition method to study the stiffness of the joint. First, the relationship between the stiffness and the parameters of the orthotropic model is established. Then, both static stiffness tests and modal tests are used to obtain the parameters of the model. A finite element model is used to verify the orthotropic model. The results show that the orthotropic model is efficient and precise which can express stiffness of different directions of machine tool joints. [ABSTRACT FROM AUTHOR]

The core of a company is its information system, and the least influential problem leads to major damages, requiring the implementation of a security policy. A logical security policy or, more precisely, the organization of rights is termed Access Control. This latter ensures two fundamental security properties namely: condentiality and integrity. besides, to model a better policy, we must pass through an implementation of organizational security policy. A security model is an access control model. In this paper, we propose a basic study of acces control models by giving a deep description of models, and discussing their reinforcements and weaknesses. This will help us to nd the major security problems that exist in information systems, such as the problem of covert channels. [ABSTRACT FROM AUTHOR]

This work is devoted to create an extension module for a naval manoeuvring simulator (Naval ++), which will allow the training of the crew of deep-water fishing vessels. The Authors were asked to develop the part relating to the "artificial intelligence" of marine biological entities: this should be capable of replicating the movement of a school of fish in a realistic way. This work also foresees an analysis of the main instruments used on-board and the problems inherent in their virtual simulation. Finally the papers outline a possible integration of the proposed model into an IEEE 1516 High Level Architecture Federation. [ABSTRACT FROM AUTHOR]

The paper deals with design and implementation of swing-up algorithm for physical model of inverted pendulum. It presents detail derivation of the full nonlinear mathematical model, formulation of dynamic optimization task and its solution by use of DYNOPT toolbox that finds control signal which causes rising of the pendulum into upright position. The control scheme containing this control signal is implemented in PAC (programmable automation controller) WinPAC-8000 with the use of REX Control System. [ABSTRACT FROM AUTHOR]

In this paper, an efficient multilevel wave form synthesis technique is proposed and applied to a 27-level inverter. The basic principle of the proposed scheme is that the continuous output voltage levels can be synthesized by the addition or subtraction of the instantaneous voltages generated from different voltage levels. This synthesis technique can be realized by an array of switching devices composing full-bridge inverter modules and proper mixing of each transformer terminal voltage. The most different aspect, compared to the conventional approach, in the synthesis of the multilevel output waveform is the utilization of a combination of transformers rather than the accumulation of capacitor voltage sources. A 27-level inverter consists of three full-bridge modules and their corresponding transformers. Quasi-sinusoidal voltage waves can be generated from a suitable selection of the turn's ratio of the transformer. The validity of the proposed scheme is verified by the simulation. [ABSTRACT FROM AUTHOR]

Offshore wind and tidal current are of the most common energy resources for generating electricity in the near future because of the oil problems (crises and pollution). The dynamic model of the offshore wind and tidal current is very important topic for dealing with these renewable energies. This paper describes the overall dynamic models of offshore wind and tidal current turbine using three different types of generators (doubly fed induction generator (DFIG), squirrel cage induction generator (SCIG) and direct drive permanent magnet synchronous generator (DDPMSG)). The state space for all types of the generators are concluded. All models are validated using a common property of the generator for the validation. [ABSTRACT FROM AUTHOR]

In this paper a rational cubic function in the form of cubic/quadratic, with three shape parameters has been developed. Data dependent sufficient constraints are derived for one of these shape parameter to preserve the shape of constrained data that is lying above the straight line. Remaining two of these shape parameters are left free for designer's choice to refine the shape of the curves as desired. The shape preserving interpolating scheme is tested through different numerical examples and showing that the scheme is not only C2, local, computationally economical and visually pleasant but also guarantee the designer to refine the constrained curve as per industrial demand. [ABSTRACT FROM AUTHOR]

In this paper, we have presented some results of undergraduate student retention using machine learning algorithms classifying the student data. We have also made some improvements to the classification algorithms such as Decision tree, Support Vector Machines (SVM), and neural networks supported by Weka software toolkit. The experiments revealed that the main factors that influence student retention in the Historically Black Colleges and Universities (HBCU) are the cumulative grade point average (GPA) and total credit hours (TCH) taken. The target functions derived from the bare minimum decision tree and SVM algorithms were further revised to create a two-layer neural network and a regression to predict the retention. These new models improved the classification accuracy. [ABSTRACT FROM AUTHOR]

This paper proposes using a fuzzy appraisal approach to model the dynamics for the emotion generation process in an individual as a result of events that take place in the environment of the individual. The proposed computational model uses guidelines from OCC emotion theory to formulate a system of fuzzy inferential rules that is capable of tracking the emotional states of the agent. Events are thoroughly analyzed and appraised against the set of goals of the agent and consequently elicited emotions along with their intensities are determined. Results from experiments showed that OCC theory is a suitable and easy to implement framework to be used as a core component in computational models of emotion. [ABSTRACT FROM AUTHOR]

The efficient design of water transmission main involves several optimization processes among which an important place is held by their path optimization. In this paper are developed two deterministic mathematical models for optimization of water transmission main path, based on techniques of sequential operational calculus, implemented in a computer program. Using these optimization models could be obtained an optimal solution for selection of source location and of water transmission main path based on graph theory and dynamic programming. The results of few numerical applications show the effectiveness and efficiency of the proposed optimization models. [ABSTRACT FROM AUTHOR]

This paper considers a Geo/G/1 queue, in which the server operates a single vacation at end of each consecutive service period. After all the customers in the system are served exhaustively, the server immediately leaves for a vacation. Upon returning from the vacation, the server inspects the queue length. If there are customers waiting in the queue, the server either resumes serving the waiting customers (with probability p) or remains idle in the system (with probability 1-p) until the next customer arrives; and if no customer presents in the queue, the server stays dormancy in the system until at least one customer arrives. Using the generating function technique, the system state evolution is analyzed. The probability generating functions of the system size distributions in various states are obtained. The waiting time distribution is also derived. With the vacation of fixed length time (say T), the long run average cost function per unit time is analytically developed to determine the joint optimal values of T and p at a minimum cost. [ABSTRACT FROM AUTHOR]

This study aims at revealing optimal additional relations to a pyramid organization such that the communication of information between every member in the organization becomes the most efficient. This paper proposes a model of adding a relation between two members in the same level of the organization structure in which each member of m-th level below the top has m + 2 subordinates. The total shortening distance which is the sum of shortening lengths of shortest paths between every pair of all nodes is formulated to obtain an optimal pair of two members between which a relation is added. [ABSTRACT FROM AUTHOR]

The problem of the management of water resources is more and more important on a world scale. In particular, there is a requirement for novel concepts helping to solve the water management problem i. e. numerically efficient tools supporting optimal design (redesign) process for water networks. The paper deals with the simulation of network remodeling and demonstrate how virtual distortion generated a chosen branch (e.g. in the branch No.4) can simulate the network modification due to total blocking flow in this branch. To this end, the condition of flow vanishing in the branch under remodelling should be postulated, where the resultant state of flow redistribution is calculated from the formulas superposing linear response of the original network configuration and the component induced by unknown virtual distortion. Then making use of the analytical network model (cf.Refs.3,1) of this installation and using presented below, the so-called Virtual Distortion Method (VDM), simulation of network remodeling can be performed. [ABSTRACT FROM AUTHOR]

The efficient design of water transmission main involves several optimization processes among which an important place is held by their path optimization. In this paper are developed two deterministic mathematical models for optimization of water transmission main path, based on techniques of sequential operational calculus, implemented in a computer program. Using these optimization models could be obtained an optimal solution for selection of source location and of water transmission main path based on graph theory and dynamic programming. The results of few numerical applications show the effectiveness and efficiency of the proposed optimization models. [ABSTRACT FROM AUTHOR]

Software architecture is the process of defining solution that meets all of the technical and operational requirements. It involves a set of related software elements and their relationships to be constructed afterwards in the rest of development phases. A good software architecture design obviously ensures the quality of software product. Typically, the changes of software architecture model during the development phases may effect the expected design rationales, its performance and the complexity of the software product. In this paper, we propose a tool called "xADL: Software Architecture Changes Effect Detection Tools - xSACEDT" in order to detect the effects of the software architecture changes. The original software architecture model, written in xADL, will be compared with the new model. All of the modification issues will be detected and reported. Moreover, the effects on requirement checklists and its design quality attributes are also traced and alerted. [ABSTRACT FROM AUTHOR]

GPBiCG method is an attractive iterative method for the solution of a linear system of equations with nonsymmetric coefficient matrix. However, we meet often with instability of convergence when GPBiCG method is adopted in the solution of realistic problems. In this paper, we consider a new algorithm with minimization of the associate residual and without reverse-ordered recurrence in the algorithm. We refer to a new iterative method as GPBiCG with safety convergence (abbreviated as GPBiCGSafe) method. Moreover we will support that GPBiCGSafe method yields safety convergence through numerical experiments. [ABSTRACT FROM AUTHOR]

Operation research is the representation of real-world systems by mathematical models together with the use of quantitative methods (algorithms) for solving such models, with a view to optimizing. As we know, C++ language is a middle level language and a computer program with this language is executed faster than application softwares of the operation research area. In this paper, a simple template program with simple C++ instructions is presented for simulating many types of optimization problems. This template is very easy to learn and understand for students or anyone who works in the operation research area. They can quickly and easily simulate many types of optimization problems with this template. [ABSTRACT FROM AUTHOR]

Pulse Width Modulation (PWM) inverters play a major role in the field of power electronics. Space Vector Modulation (SVM) is the popular PWM method and possibly the best among all the PWM techniques as it generates higher voltages with low total harmonic distortion and works very well with field oriented (vector control) schemes for motor control. High quality output spectra can be obtained by eliminating several lower order harmonics by adopting a suitable harmonic elimination technique. Selective Harmonic Elimination (SHE) technique offers an apt control for the harmonic spectrum of a given voltage waveform generated by an inverter for induction machine drives. In this paper, a mathematical model of space vector modulated three phase inverter is generated. Further, a method to eliminate the most significant harmonic components of line voltage waveforms of the inverter by SHE is also formulated. The harmonic spectrum analysis of the proposed model shows the effect of eliminating the lower order harmonics in SVM. Simulation results are implemented to confirm the effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

In this paper, the modeling and synthesis of human Insulin Hormone Secretion Mechanism is accomplished using VHDL and FPGAs technologies. A mathematical model is developed and analyzed using Matlab and Least-Square fitting algorithm. C++ is used to model the behavior of Insulin secretion in humans and converted to VHDL. Results are verified then the mechanism is realized on a Xilinx FPGAs chip. This chip is then tested with simulated input and its behavior is deemed consistent with the mathematical model. The chip is therefore an identical replica of the Human Insulin Secretion Mechanism. [ABSTRACT FROM AUTHOR]

Operation research is the representation of realworld systems by mathematical models together with the use of quantitative methods (algorithms) for solving such models, with a view to optimizing. As we know, C++ language is a middle level language and a computer program with this language is executed faster than application softwares of the operation research area. In this paper, a simple template program with simple C++ instructions is presented for simulating many types of optimization problems. This template is very easy to learn and understand for students or anyone who works in the operation research area. They can quickly and easily simulate many types of optimization problems with this template. [ABSTRACT FROM AUTHOR]