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Rectangular concrete-filled steel tubular (RCFST) columns can be designed to have unequal wall thickness to maximize their resistance to combined axial and uniaxial bending loads. However, there is very little published research on their local–global interaction buckling behavior. This paper presents an efficient fiber-based simulation model for analyzing the inelastic interaction buckling of eccentrically loaded RCFST slender columns with unequal wall thickness. The model considers the progressive local–global interaction buckling, distributed plasticity, concrete cracking and crushing, second-order effects, and geometric imperfections. The mathematical model is programmed to compute not only the axial load–displacement responses but also the interaction curves of axial load and moment of slender RCFST columns. The simulation modeling is validated by experimentally measured data. The validated computer model is used to parametrically study the interaction local–global buckling responses of RCFST columns while the range analysis is conducted to identify the relative significance of key parameters. It is demonstrated that the proposed computer model accurately simulates experimentally measured responses. Hence, it can be used with confidence in practice to analyze and design RCFST slender columns fabricated with steel plates of unequal thickness. The existing design standard AS/NZS 2327:2017 provides acceptable strength predictions of RCFST slender columns and beam-columns while the procedure specified in Eurocode 4 overestimates their capacities. [ABSTRACT FROM AUTHOR]

In this paper, we explore the interplay between tumor cells and the human immune system, based on a deterministic mathematical model of minimal interactions by transforming it to stochastic model using a continuous-time Markov chain, where time is continuous but the state space is discrete. Furthermore, we simulate the stochastic basin of attraction to verify the behavior of the three critical points of interest in the deterministic system. Moreover, the stochastic simulations exemplify the cancer immunoediting theory in its three phases of development: elimination, equilibrium and escape. We extend the minimum model proposed in [DeLisi & Rescigno, 1977] to include a term of immunotherapy by lymphocyte injection, and we simulate two treatment regimes, equilibrium and escape, under several schemes. [ABSTRACT FROM AUTHOR]

High reliability against undesirable effects is one of the key objectives in the design for Network-on-Chip (NoC). As a result, designing reliable and efficient routing method is highly desirable. This paper presents a novel turn model called NMad-y using one and two virtual channels along the - and -dimensions, respectively, and Adaptive and Fault-tolerant Routing Method (AFRM) which is designed based on the NMad-y turn model. AFRM can effectively tolerate multiple faulty routers and links in more complicated faulty situations by the link status of neighbor routers within two hops. AFRM is able to impose the reliability of network without losing the performance of network. Simulation results show that AFRM achieves better saturation throughput (0.83% on average) than a state-of-the-art fault-tolerant routing method and maintains high reliability of more than 97.43% on average. [ABSTRACT FROM AUTHOR]

In this paper we present a system which incorporates the features of Fuzzy Qualitative Trigonometry (FQT) with those of the Fuzzy Qualitative Reasoning system, Morven. FQT is designed for modeling and reasoning about robot kinematic systems whereas Morven was designed for simulation and envisionment of straightforward dynamic systems. It has been the case that thus far QR systems have not been designed to reason about the behaviour of dynamic system containing fuzzy trigonometric relations. The resulting tool described in this paper goes some way to addressing this deficit. [ABSTRACT FROM AUTHOR]

This paper extends the particle swarm metaphor into the domain of organization science. A simulator (OrgSwarm) which can be used to model the adaptation of a population of organizations on a strategic landscape is introduced. The simulator embeds a number of features of the process of organizational adaptation, including the resistance of organizations to change (strategic inertia), errorful assessments of the payoffs to proposed strategies, and market competition. These features allow the examination of a wide range of real-life scenarios in organizational adaptation. The paper reports the results of a number of simulation experiments and these suggest that agent (management) uncertainty as to the payoffs to potential strategies has the effect of lowering the average payoffs obtained by a population of organizations. The results also suggest that a degree of strategic inertia can assist rather than hamper adaptive efforts at a populational level. [ABSTRACT FROM AUTHOR]

In this paper the global patterns that result from local interactions between players on a two-dimensional lattice are studied. The assumptions on interaction between players are based on the Prisoner's Dilemma game that has been used extensively in game theory and in the study of biological systems. Each player is located on a square lattice, and is assumed to cooperate or defect, based on mimicking the neighbor with the highest cumulative score from the preceding round of play. The edges of the lattice are glued to form a torus. Computer simulations are conducted for different sized lattices, different payoff values, and different initial conditions. Though the paper is primarily concerned with player behavior without self-interaction, some results with self-interaction are also included. The influence of "ideal" cooperators on the evolution of the system dynamics is also studied. Three generic regimes of behavior are identified. Complex global patterns with complicated dynamics and sometimes unpredictable results occur. Steady-state solutions, simple and complex periodic solutions, and traveling waves are observed depending on the initial conditions and the payoff values. [ABSTRACT FROM AUTHOR]

Multiple clock domain (MCD) systems have different blocks/IP cores operating at different frequencies. These different clocks are generated from a high frequency clock usually by integer division. Fractional-N frequency dividers (FFDs) are needed when the clock required by a block in MCD system is not possible to be derived by simple integer division. In this paper, we present such a FFD with an improved resolution of (1/8). Post layout simulation results after parasitic RC extraction in the 90-nm technology node show that our FFD is able to fractionally divide signals upto 2 GHz frequency with an average error of 0.11% in division ratio even with 2.5° phase error at the input. Our FFD consumes 754 μW when fractionally dividing a 2 GHz signal with a resolution of (1/8). [ABSTRACT FROM AUTHOR]

The Artificial Bee Colony (ABC) algorithm is a recently introduced swarm intelligence algorithm that has been successfully applied on numerous and diverse optimization problems. However, one major problem with ABC is its premature convergence to local optima, which often originates from its insufficient degree of explorative search capability. This paper introduces ABC with Improved Explorations (ABC-IX), a novel algorithm that modifies both the selection and perturbation operations of the basic ABC algorithm in an explorative way. First, an explorative selection scheme based on simulated annealing allows ABC-IX to probabilistically accept both better and worse candidate solutions, whereas the basic ABC can accept better solutions only. Second, a self-adaptive strategy enables ABC-IX to automatically adapt the perturbation rate, separately for each candidate solution, to customize the degree of explorations and exploitations around it. ABC-IX is evaluated on several benchmark numerical optimization problems and results are compared with a number of state-of-the-art evolutionary and swarm intelligence algorithms. Results show that ABC-IX often performs better optimization than most other algorithms in comparison on most of the problems. [ABSTRACT FROM AUTHOR]

According to the terminal relations of the DO-OTA, eight nullor-mirror models for the DO-OTA are presented in this paper, Moreover, the NAME method for two different classes of T-T filters is considered. The class I filters, employing three SISO-OTAs, have 16 different forms, and the class II filters, employing one SISO-OTA and one DISO-OTA or one SIDO-OTA, have eight different forms. Due to use of canonic number of components, the circuits are easy to be integrated and their parameters can be tuned electronically through tuning bias currents of the OTAs. The MULTISIM simulation results have been included to verify the workability of the derived circuit. [ABSTRACT FROM AUTHOR]

With the advent of nanometer age in digital circuits, the overshooting time becomes an important component of gate delay for CMOS logic gates. However, there has been little attention paid to the research of the overshooting effect for multi-input gate in nanometer technologies until now. Therefore, in this paper, an effective model considering the overshooting effect of multi-input gate is presented. The experimental results using 32-nm PTM model reflect that the proposed model is accurate within 3.6% error compared with SPICE simulation results. [ABSTRACT FROM AUTHOR]

This paper contributes to the understanding of memristor operation and its possible application fields through: (a) derivation of a complete mathematical model for the HP memristor which takes into consideration the inter-dependence between memristance, charge and flux along with the boundary and initial conditions of operation; (b) an introduction of detailed charge- and flux-controlled SPICE memristor models realizing the proposed mathematical memristor model; (c) The incorporation of the memristor model in the SPICE realization of a third-order chaotic system where a single HP memristor acts as the nonlinear part of the system. Simulation results are provided to validate the mathematical model and the synthesis and operation of the third-order chaotic system. [ABSTRACT FROM AUTHOR]

The spacecraft attitude control systems are becoming more and more sophisticated with the increasing complex system configurations. This paper investigates the problem of three-axis rigid spacecraft maneuver control. The rigid spacecraft model consisting of the dynamic and kinematics equation is firstly provided. This nonlinear model is converted into a Takagi-Sugeno fuzzy model. Then, based on the parallel distributed compensation scheme, a fuzzy state feedback controller is designed for the obtained T-S fuzzy model with considering the decay rate and input constraints. Next, sufficient conditions for the existence of such a controller are derived in terms of linear matrix inequalities and the controller design is cast into a convex optimization problem subject to linear matrix inequalities constraints, which can be readily solved via Matlab LMI toolbox. At last, a design example shows that the time of spacecraft attitude maneuver is shortened and the input constraint is realized. The simulation results show the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]

Chaotic modeling and simulation is a fast growing field that influences the world around us, and consequently also influences our ways of approaching, analyzing and solving problems. In this paper the rotation-translation case is presented based on the theory analyzed in the book - Chaotic Modeling and Simulation: Analysis of Chaotic Models, Attractors and Forms published by the above authors [Skiadas & Skiadas, 2008]. An overview of the chaotic flows in rotation-translation is given. Special cases and illustrations of chaotic attractors and forms are presented and a method of comparative presentation and analysis of the flows by using both continuous and discrete methods is applied by deriving the appropriate differential and difference equations' analogue. Furthermore, an analysis of chaotic attractors resulting in the models proposed is given along with an exploration of the characteristic or equilibrium points. [ABSTRACT FROM AUTHOR]

Resistance spot welding is a major metal connecting method in vehicle and other domestic electronic domains. Among all the welding techniques, the spot welding inverter is an important direction at the present time. The high nonlinearity and strongly coupled multiple parameters in the resistance spot welding process challenge the classical control theory based on some specific conditions and ideal assumptions, which in real practice obstacle the high-quality welding. This paper put the fuzzy neural network into a constant-current-controlled spot welding inverter, where the welding current peak and its variation are adopted as the input parameters and the duty ratio of the switches is regarded as the output. Eventually a five-layer feed-forward network was constructed, back propagation (BP) algorithm was applied to revise the adjustable parameters in the network, and a mathematical model was established to obtain the training samples serving for the network. The ultimate precision could reach 1.75%, the relative control error is 2.28% with strong external disturbances, the overmodulation is 3.35%, and the total modulating period is seven switching period, which indicated that the proposed algorithm has good performance. [ABSTRACT FROM AUTHOR]

Fuzzy systems properly integrated with Qualitative Reasoning approaches yield a hybrid identification method, called FS-QM, that outperforms traditional data-driven approaches in terms of robustness, interpretability and efficiency in both rich and poor data contexts. This results from the embedment of the entire system dynamics predicted by the simulation of its qualitative model, represented by fuzzy-rules, into the fuzzy system. However, the intrinsic limitation of qualitative simulation to scale up to complex and large systems significantly reduces its efficient applicability to real-world problems. The novelty of this paper deals with a divide-and-conquer approach that aims at making qualitative simulation tractable and the derived behavioural description comprehensible and exhaustive, and consequently usable to perform system identification. The partition of the complete model into smaller ones prevents the generation of a complete temporal ordering of all unrelated events, that is one of the major causes of intractable branching in qualitative simulation. The set of generated behaviours is drastically but beneficially reduced as it still captures the entire range of possible dynamical distinctions. Thus, the properties of the correspondent fuzzy-rule base, that guarantee robustness and interpretability of the identified model, are preserved. The strategy we propose is discussed through a case study from the biological domain. [ABSTRACT FROM AUTHOR]

A recent proposal of q-deformation scheme for the nonlinear maps has stimulated new directions in the studies of various nonlinear dynamical systems. Such studies are advantageous in the analytical modeling of several nonlinear physical phenomena which cannot be perfectly represented by the standard or canonical models. This paper attempts to numerically analyze the behavior of q-deformed version of Henon map, which is one of the prototypical models exhibiting strange chaotic attractor. We particularly investigate the effect of q-deformation on the various kinds of long-term asymptotic dynamics of the canonical Henon map and also characterize the complete deformation parameter space into different regions corresponding to the periodic and strange chaotic motions. We also identify the route to chaos and new structures in the chaotic strange attractor of q-deformed Henon map. [ABSTRACT FROM AUTHOR]

In this paper, we show that the small world and weak ties phenomena can spontaneously emerge in a social network of interacting agents. This dynamics is simulated in the framework of a simplified model of opinion diffusion in an evolving social network where agents are made to interact, possibly update their beliefs and modify the social relationships according to the opinion exchange. [ABSTRACT FROM AUTHOR]

A simple approach for generating (2N + 1)-scroll chaotic attractor from a modified Colpitts oscillator model is proposed in this paper. The key strategy is to increase the number of index-2 equilibrium points by introducing a triangle function to directly replace the nonlinearity term of Colpitts oscillator model. The dynamical characteristics of the new multiscroll chaotic system are studied comprehensively. A circuit realization structure is introduced and the experimental results demonstrate that (2N + 1)-scroll chaotic attractors can be obtained in practical circuit. [ABSTRACT FROM AUTHOR]

In this paper, we consider double zero singularity of a symmetric BAM neural network model with a time delay. Based on the normal form approach and the center manifold theory, we obtain the normal form on the centre manifold with double zero singularity. Some numerical simulations support our analysis results. [ABSTRACT FROM AUTHOR]

In this paper, we present results concerning a natural extension of the class of heterogeneous preferential attachment models, a generalization of the Barabási–Albert model to heterogeneous networks. In this extended class, the network nodes enjoy a nonzero attractiveness even when their connectivity degrees are zero. We analytically show that the degree densities of models in the extended class exhibit a richer scaling behavior than their homogeneous counterparts, and that power-law scaling in their degree distribution is robust in the presence of the offset in the attachment kernel. [ABSTRACT FROM AUTHOR]

This paper reveals the dynamics of a delayed neural network of four neurons, with a short-cut connection through a theoretical analysis and some case studies of both numerical simulations and experiments. It presents a detailed analysis of the stability and the stability switches of the network equilibrium, as well as the Hopf bifurcation and the bifurcating periodic responses on the basis of the normal form and the center manifold reduction. Afterwards, the study focuses on the validation of theoretical results through numerical simulations and circuit experiments. The numerical simulations and the circuit experiments not only show good agreement with theoretical results, but also show abundant effects of the short-cut connection on the network dynamics. [ABSTRACT FROM AUTHOR]

The question how social norms can emerge from microscopic interactions between individuals is a key problem in social sciences to explain collective behavior. In this paper, we propose an agent-based model to show that randomly distributed social behavior by way of local interaction converges to a state with a multimodal distribution of behavior. This can be interpreted as a coexistence of different social norms, a result that goes beyond previous investigations. The model is discrete in time and space, behavior is characterized in a continuous state space. The adaptation of social behavior by each agent is based on attractive and repulsive forces caused by friendly and adversary relations among agents. The model is analyzed both analytically and by means of spatio-temporal computer simulations. It provides conditions under which we find convergence towards a single norm, coexistence of two opposing norms, and coexistence of a multitude of norms. For the latter case, we also show the evolution of the spatio-temporal distribution of behavior. [ABSTRACT FROM AUTHOR]

A new multi-class classifier, decision tree SVM (DTSVM) which is a binary decision tree with a very simple structure is presented in this paper. In DTSVM, a problem of multi-class classification is decomposed into a series of ones of binary classification. Here, the binary decision tree is generated by using kernel clustering algorithm, and each non-leaf node represents one binary classification problem. By compared with the other multi-class classification methods based on the binary classification SVMs, the scale and the complexity of DTSVM are less, smaller number of support vectors are needed, and has faster test speed. The final simulation results confirm the feasibility and the validity of DTSVM. [ABSTRACT FROM AUTHOR]

This paper presents spatio-temporal modeling and analysis methods to fMRI data. Based on the nonlinear autoregressive with exogenous inputs (NARX) model realized by the Bayesian radial basis function (RBF) neural networks, two methods (NARX-1 and NARX-2) are proposed to capture the unknown complex dynamics of the brain activities. Simulation results on both synthetic and real fMRI data clearly show that the proposed schemes outperform the conventional t-test method in detecting the activated regions of the brain. [ABSTRACT FROM AUTHOR]

The objective of this study is to develop a fabric drape mathematical model in order to simulate the dynamic behavior of a textile structure. Simulation of fabric drape is a significant issue in textile research, which contributes to advances within the framework of virtual models and clothing simulation. In the first part of this paper, the existing methods dealing with the fabric simulation are presented. In the following part, a mathematical model that has been selected for simulation is given. The third part is devoted to the identification of unknown parameters. Each parameter corresponds to a predefined test. In order to obtain reliable results, very specific samples were realized, testing the fabric weave method and the influence of the yarn nature. This choice is guided by industrial needs. Moreover, the proposed method enables a sensitivity analysis of the model parameters. Finally, in the fourth part, several simulation results are presented and they are compared with practical results by analyzing textile structural deformation according to parameter variation. [ABSTRACT FROM AUTHOR]

Emergency incidents increase the uncertainty of supply chain environment, and also make the supply chain vulnerability expose. Creating resilient supply chain is an effective way to overcome the supply chain vulnerability. The supply chain characteristics of self-adaptation and self-coordination are consistent with the self-organization feature of ant colony's labor division. In this paper, a generalized ant colony's labor division model with constraints is provided, which is used to construct the ant colony's labor division model with constraints of resilient supply chain to solve task allocation of resilient supply chains. The simulation principle and algorithm of resilient supply chain are provided based on the proposed model and task allocation of the supply chain is analyzed from the five aspects, that is, task allocation status, supply chain coordination, emergency incidents' impact to task allocation, task allocation rate and the influence of different incidents for task allocation. The simulation results show that, with the proposed model, it is effective to allocate resilient supply chain tasks and has excellent performance, such as faster response and robustness. [ABSTRACT FROM AUTHOR]