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In this paper, we consider the identification of matrix state-space models (MSSM) of the following form: \begin{align*} \mathbf {X}(k+1) &= \mathbf {A}_2 \mathbf {X}(k) \mathbf {A}_1^T + \mathbf {B}_2 \mathbf {U}(k) \mathbf {B}_1^T \\ \mathbf {Y}(k) &= \mathbf {C}_2 \mathbf {X}(k) \mathbf {C}_1^T + \mathbf {E}(k) \end{align*} for all time dependent quantities and matrices of appropriate dimensions. Due to the large size of these matrices, vectorization does not allow the use of standard multivariable subspace methods such as N4SID or MOESP. In this paper, the resulting Kronecker structure that appears in the system matrices due to vectorization is exploited for developing a scalable subspace-like identification approach. This approach consists of first estimating the Markov parameters associated to the MSSM via the solution of a regularized bilinear least-squares problem that is solved in a globally convergent manner. Second, a bilinear low-rank minimization problem is tackled which allows to write a three-dimensional low-rank tensor and consequently to estimate the state sequence and the lower-dimensional matrices $\mathbf {A}_1,\mathbf {A}_2,\mathbf {B}_1,\mathbf {B}_2,\mathbf {C}_1,\mathbf {C}_2$. A numerical example on a large-scale adaptive optics system demonstrates the ability of the algorithm to handle the identification of state-space models within the class of Kronecker structured matrices in a scalable manner which results in more compact models. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of identifiability of dynamical networks in the case where the vector of noises on the nodes does not have full rank. In the full-rank noise case, network identifiability is defined as the capability of uniquely identifying the transfer function matrices describing the network from informative data. This includes the noise model, which can be uniquely defined when the noise vector has full rank. When the noise vector has a singular spectrum, it admits an infinite number of different noise models and the definition of network identifiability must be adapted to demand that the correct noise spectrum be identified from informative data rather than a specific noise model. With this new definition, we show that a network with rank reduced noise is identifiable under the same conditions that apply to a network with full-rank noise. [ABSTRACT FROM AUTHOR]

A novel risk-sensitive (RS) control law is proposed for linear systems with stochastic system parameters. RS control laws are efficient means of handling risk in various failures in control caused by stochastic disturbances. However, stochastic parameters invoke problems, resulting controllers may become nonlinear in the state variable and incompatible with linear systems, cannot be obtained in an exact sense, and are defined only on a bounded state region. To solve these problems, this paper presents a risk-sensitive linear (RSL) control method. The important idea is that a standard RS-type cost function is converted to an expectation of a weighted cost function such that the resulting optimal controller is linear in the state. The weight is designed such that the weighted cost function preserves the characteristics of the original RS control. The designed weight allows one to derive the proposed RSL controller whose exact solution is obtained as a linear feedback law for all states. Furthermore, the RSL control law over an infinite horizon guarantees stochastic stability of the feedback system with the control law. The effectiveness of the proposed RSL control law is demonstrated by a numerical simulation. [ABSTRACT FROM AUTHOR]

This paper concerns the nonparametric identification problem for a class of nonlinear discrete-time dynamical systems that is characterized by its cascade structure. This is a Hammerstein system being a series connection of a nonlinear memoryless element followed by a linear dynamic system. The input–output training data generated from the system are dependent and they do not reveal the strong mixing property. The nonlinear part of the system is recovered with the weighted $k$ -nearest neighbor regression estimate. The a priori information is nonparametric, both the nonlinear characteristic and the impulse response of the linear part are completely unknown and can be of any form. Local and global properties of the estimate are examined. Whatever the probability density of the input signal, the estimate converges at every continuity point of the characteristic as well as in the global sense. We derive the formulas for asymptotic bias and the variance and evaluate the corresponding rate of convergence. The convergence rate is independent of the shape of the input density and is proved to be optimal. These results allow us to find a set of optimal nonnegative weights that further improve the accuracy of our estimation algorithm. Our findings are supported by simulation experiments. [ABSTRACT FROM AUTHOR]

This paper studies the stabilization problem via the co-design of controllers and a switching policy for a new class of nonstrict feedback switched nonlinear systems whose subsystems consist of a chain of integrators, feedback paths, and first-order feedforward paths. Designing only smooth feedback controllers cannot deal with the unstabilizable factors caused by feedforward paths. By exploiting the single control Lyapunov function method, an effective switching policy is co-designed to compensate the controllers. In addition, we present a generalized backstepping process, based on which the solvability of virtual controllers is guaranteed, the algebraic condition for stabilizability is identified, and the transient response of the closed-loop systems is improved. Two examples demonstrate the effectiveness. [ABSTRACT FROM AUTHOR]

This paper deals with the consensus tracking problem for a multiagent system with nonholonomic chained-form dynamics. A new distributed observer is first proposed for each follower to estimate the leader state and the leader input in a prescribed finite-time under both undirected and directed communication graphs. Then based on the observer and by adding a power integrator, a novel nonlinear protocol is designed such that the estimated leader state is tracked in a prescribed finite-time. Different from some existing finite-time consensus tracking approaches, an explicit bound without dependence on initial states is derived for the settling time. Therefore, in an unknown environment where initial conditions are unavailable, the proposed strategy is able to meet specific system requirements, e.g., a military target is tracked by a group of field robots in a prescribed time. Finally, numerical examples are provided to demonstrate the effectiveness of the proposed protocol. [ABSTRACT FROM AUTHOR]

This paper presents continuous-time multiagent systems for distributed minimax optimization subject to bounded constraints. All agents in the system are divided into two groups for minimization and maximization. The multiagent system features competitive intergroup interactions and cooperative intragroup interactions, both of which are based on the output information of agents. First, a proportional-integral (PI) intragroup interaction rule is utilized for consensus within each group in the system. With this interaction rule, the system is proved to be convergent to an optimal solution to the problem, under a certain requirement on the intergroup interactions. Second, another discontinuous intragroup interaction rule is introduced. It is proved that the system with such an interaction is still convergent to an optimal solution if the proportional gain exceeds a derived lower bound, without the previous requirement on the intergroup interactions. As a special case, the systems are further applied for distributed optimization. Finally, simulation results are presented to substantiate the theoretical results. [ABSTRACT FROM AUTHOR]

This paper considers the distributed event-triggered consensus problem for general linear multiagent networks. Both the leaderless and leader–follower consensus problems are considered. Based on the local sampled state information, distributed adaptive event-triggered protocols are designed, which can ensure that the consensus of the agents is achieved, and the Zeno behavior is excluded by showing that the interval between any two triggering events is lower-bounded by a strictly positive value. Compared with the previous related works, our main contribution is that the proposed adaptive event-based protocols are fully distributed and scalable, which do not rely on any global information of the network graph and are independent of the network's scale. In these event-based protocols, continuous communications are not required for either control laws updation or triggering functions monitoring. [ABSTRACT FROM AUTHOR]

Abstract The Kagome structure has been shown to be a highly suited micro-architecture for adaptive lattice materials, in which selected lattice members are replaced by actuators aiming to create shape morphing structures. It is the combination of in-plane isotropy, high stiffness and low energy requirement for actuation that makes the planar Kagome structure the best performing micro-architecture known to date. Recently, Pronk et al. (2017) have proposed a set of topological criteria to identify other micro-architectures suitable for actuation. In the present paper, four novel lattice topologies are presented which were contrived in light of these criteria. Matrix analysis is performed to reveal the static and kinematic properties of the pin-jointed versions of these four structures. The finite element method is used to determine their stiffness and actuation characteristics. One of the proposed designs is found to match the optimal elastic properties of the Kagome structure, while it requires less energy for (single member) actuation. However, the displacement field induced by actuation attenuates faster than in a Kagome lattice. The presented results also show that the criteria proposed by Pronk et al. (2017) should be refined in two regards: (i) statically indeterminate lattice materials do not necessarily result in high actuation energy and thus should not be ruled out, and (ii) as shown by counterexample, the criteria are not sufficient. [ABSTRACT FROM AUTHOR]

This paper will investigate the stabilization and optimal linear quadratic (LQ) control problems for infinite horizon discrete-time mean-field systems. Unlike the previous works, for the first time, the necessary and sufficient stabilization conditions are explored under mild conditions, and the optimal LQ controller for infinite horizon is designed with a coupled algebraic Riccati equation (ARE). More specifically, we show that under the exact detectability (exact observability) assumption, the mean-field system is stabilizable in the mean square sense with the optimal controller if and only if a coupled ARE has a unique positive semidefinite (positive definite) solution. The presented results are parallel to the classical results for the standard LQ control. [ABSTRACT FROM AUTHOR]

Abstract Despite numerous theoretical investigations on the mechanical properties of graphene, an accurate identification of its material behavior is still unattained. One hypothesis for this uncertainty is that modeling graphene as a static membrane cannot describe the strong coupling between mechanics and thermodynamics of this structure. Therefore, characterization methods built upon static models could not capture these effects. In this paper, we propose a new method for building a reduced order model for the dynamics of thermalized graphene membranes. We apply the proper orthogonal decomposition algorithm on time responses obtained from molecular dynamics simulations. As a result, a set of orthogonal modes is obtained which are then employed to build a reduced order model. The proposed model can describe the motion of the suspended graphene membrane over the whole spatial domain accurately. Moreover, due to its computational efficiency, it is more versatile for exploring the nonlinear dynamics of the system. This model is then employed for studying the nonlinear dynamics of graphene membranes at large amplitudes to extract Young's modulus. The obtained Young's modulus incorporates the effects of nano-scaled thermally induced dynamic ripples and hence, is temperature and size dependent. Our proposed atomistic modal order reduction method provides a framework for studying the dynamics and extracting the mechanical properties of other nano-structures at the molecular level. [ABSTRACT FROM AUTHOR]

Purpose This paper aims to consider the influence of the temperature and of an external magnetic field on the steady oblique stagnation-point flow for a Boussinesquian nanofluid past a stretching or shrinking sheet.Design/methodology/approach The flow is reduced through similarity transformations to an ordinary boundary value problem, which is solved numerically in MATLAB using the bvp4c function. The behavior of the solution is discussed physically, and some analytical considerations concerning existence of the solution and the occurrence of dual solutions are drawn.Findings The study of the influence of an external magnetic field on the oblique stagnation-point flow of a Buongiorno's Boussinesquian nanofluid is carried out. The fluid clashes on a vertical stretching or shrinking sheet. Dual solutions appear for suitable values of the parameters.Originality/value The present results are new and original. [ABSTRACT FROM AUTHOR]

First-principles calculations in crystalline structures are often performed with a planewave basis set. To make the number of basis functions tractable two approximations are usually introduced: core electrons are frozen and the diverging Coulomb potential near the nucleus is replaced by a smoother expression. The norm-conserving pseudopotential was the first successful method to apply these approximations in a fully ab initio way. Later on, more efficient and more exact approaches were developed based on the ultrasoft and the projector augmented wave formalisms. These formalisms are however more complex and developing new features in these frameworks is usually more difficult than in the norm-conserving framework. Most of the existing tables of norm-conserving pseudopotentials, generated long ago, do not include the latest developments, are not systematically tested or are not designed primarily for high precision. In this paper, we present our PseudoDojo framework for developing and testing full tables of pseudopotentials, and demonstrate it with a new table generated with the ONCVPSP approach. The PseudoDojo is an open source project, building on the AbiPy package, for developing and systematically testing pseudopotentials. At present it contains 7 different batteries of tests executed with ABINIT , which are performed as a function of the energy cutoff. The results of these tests are then used to provide hints for the energy cutoff for actual production calculations. Our final set contains 141 pseudopotentials split into a standard and a stringent accuracy table. In total around 70,000 calculations were performed to test the pseudopotentials. The process of developing the final table led to new insights into the effects of both the core-valence partitioning and the non-linear core corrections on the stability, convergence, and transferability of norm-conserving pseudopotentials. The PseudoDojo hence provides a set of pseudopotentials and general purpose tools for further testing and development, focusing on highly accurate calculations and their use in the development of ab initio packages. The pseudopotential files are available on the PseudoDojo web-interface pseudo-dojo.org under the name NC (ONCVPSP) v0.4 in the psp8, UPF2, and PSML 1.1 formats. The webinterface also provides the inputs, which are compatible with the 3.3.1 and higher versions of ONCVPSP. All tests have been performed with ABINIT 8.4. [ABSTRACT FROM AUTHOR]

Conventional approaches to analyzing the very large coherency strains that can occur during solid-state phase transformations are founded in linear elasticity and rely on infinitesimal strain metrics. Despite this, there are many technologically important examples where misfit strains of multi-phase mixtures are very large during their synthesis and/or application. In this paper, we present a framework for constructing strain-energy expressions and stress-strain relationships beyond the linear-elastic limit for crystalline solids. This approach utilizes group theoretical concepts to minimize both the number of free parameters in the strain-energy expression and amount of first-principles training data required to parameterize strain-energy models that are invariant to all crystal symmetries. Within this framework, the strain-energy and elastic stiffness can be described to high accuracy in terms of a set of conventional symmetry-adapted finite strain metrics that we define independent of crystal symmetry. As an illustration, we use first-principles electronic structure data to parameterize strain energy polynomials and employ them to explore the strain-energy surfaces of HCP Zr and Mg, as well as several important Zr-H and Mg-Nd phases that are known to precipitate coherently within the HCP matrices of Zr and Mg. [ABSTRACT FROM AUTHOR]

This paper derives an analytic expression for the density per unit area of charges confined in a two-dimensional configuration in a Penning trap with an anharmonic applied trap potential that is expressed as a multipole expansion. This expression is used to find the optimum potential, with a given number of multipoles, for trapping a plasma with the most uniform possible density per unit area. Minimum energy states in such an optimized trap potential are evaluated numerically and the resulting crystal structures are shown to be defect-free over the central region of the plasma where the density is most nearly uniform. The paper also briefly considers the possibility of using an ℓ = 3 rotating wall trap potential in order to confine minimum energy states with triangular symmetry and no defects. [ABSTRACT FROM AUTHOR]

In this paper, we consider a phase-field model for dendritic growth in a two-dimensional cavity flow and propose a computationally efficient numerical method for solving the model. The crystal is fixed in the space and cannot be convected in most of the previous studies, instead the supercooled melt flows around the crystal, which is hard to be realized in the real world experimental setting. Applying advection to the crystal equation, we have problems such as deformation of crystal shape and ambiguity of the crystal orientation for the anisotropy. To resolve these difficulties, we present a phase-field method by using a moving overset grid for the dendritic growth in a cavity flow. Numerical results show that the proposed method can predict the crystal growth under flow. [ABSTRACT FROM AUTHOR]

Structural transformations in crystalline solids are increasingly the basis of the functional behavior of materials. Recently, in diverse alloy systems, both low hysteresis and reversibility of phase transformations have been linked to the satisfaction of the nongeneric conditions of compatibility between phases. According to the Cauchy–Born rule, these conditions are expressed as properties of transformation stretch tensor . The transformation stretch tensor is difficult to measure directly due to the lack of knowledge about the exact transforming pathway during the structural change, and the complicating effects of microstructure. In this paper we give a rigorous algorithmic approach for determining the transformation stretch tensor from X-ray measurements of structure and lattice parameters. For some traditional and emerging phase transformations, the results given by the algorithm suggest unexpected transformation mechanisms. [ABSTRACT FROM AUTHOR]

Abstract: When investigating or designing acoustic wave sensors, the behavior of piezoelectric devices is supposed to be linear. However, if the sensors are subjected to a strong elastic field, the amplitude of the elastic strain induced in the piezoelectric material is so large that the nonlinearity, which affects the stability and performance of the piezoelectric sensors, can no longer be ignored. In this paper, we perform a theoretical analysis on nonlinear anti-symmetric thickness vibration of thin-film acoustic wave resonators made from quartz. Using Green’s identity, under the usual approximation of neglecting higher time harmonics, a perturbation analysis is performed from which the resonator frequency–amplitude (A–F) relation is obtained. Numerical calculations are made. Furthermore, the validity of the method is examined. [Copyright &y& Elsevier]

Abstract: Elastic properties play a key role in materials science and technology. The elastic tensors at any order are defined by the Taylor expansion of the elastic energy or stress in terms of the applied strain. In this paper, we present ElaStic, a tool that is able to calculate the full second-order elastic stiffness tensor for any crystal structure from ab initio total-energy and/or stress calculations. This tool also provides the elastic compliances tensor and applies the Voigt and Reuss averaging procedure in order to obtain an evaluation of the bulk, shear, and Young moduli as well as the Poisson ratio of poly-crystalline samples. In a first step, the space-group is determined. Then, a set of deformation matrices is selected, and the corresponding structure files are produced. In a next step, total-energy or stress calculations for each deformed structure are performed by a chosen density-functional theory code. The computed energies/stresses are fitted as polynomial functions of the applied strain in order to get derivatives at zero strain. The knowledge of these derivatives allows for the determination of all independent components of the elastic tensor. In this context, the accuracy of the elastic constants critically depends on the polynomial fit. Therefore, we carefully study how the order of the polynomial fit and the deformation range influence the numerical derivatives, and we propose a new approach to obtain the most reliable results. We have applied ElaStic to representative materials for each crystal system, using total energies and stresses calculated with the full-potential all-electron codes exciting and WIEN2k as well as the pseudo-potential code Quantum ESPRESSO. [Copyright &y& Elsevier]

This paper describes a model for baby Skyrme crystal chunks with arbitrary potential by considering energy contributions from the bulk and surface of a crystal chunk. We focus on two potentials which yield distinct Skyrme lattices: the standard potential V=m²(1-φ³) and the easy plane potential V=12m²(φ¹)². In both models, the static energy functional is minimized over all two-dimensional period lattices, yielding the minimal-energy crystal structure(s). For the standard potential, the Skyrmions form a hexagonal crystal structure, whereas, for the easy plane potential, the minimal-energy crystal structure is a square lattice of half-charge lumps. We find that square crystal chunks are the global minima in the easy plane model for charges B>6, with 2B being a perfect square (m²=1). In contrast, we observe that hexagonal crystal chunks in the standard model become the global minima for surprisingly large charges, B>954 (m²=0.1). [ABSTRACT FROM AUTHOR]

Abstract: We have developed a software package CALYPSO (Crystal structure AnaLYsis by Particle Swarm Optimization) to predict the energetically stable/metastable crystal structures of materials at given chemical compositions and external conditions (e.g., pressure). The CALYPSO method is based on several major techniques (e.g. particle-swarm optimization algorithm, symmetry constraints on structural generation, bond characterization matrix on elimination of similar structures, partial random structures per generation on enhancing structural diversity, and penalty function, etc.) for global structural minimization from scratch. All of these techniques have been demonstrated to be critical to the prediction of global stable structure. We have implemented these techniques into the CALYPSO code. Testing of the code on many known and unknown systems shows high efficiency and the highly successful rate of this CALYPSO method [Y. Wang, J. Lv, L. Zhu, Y. Ma, Phys. Rev. B 82 (2010) 094116] . In this paper, we focus on descriptions of the implementation of CALYPSO code and why it works. [Copyright &y& Elsevier]

In this paper, we present a revised version of BilKristal 3.0 tool. Raycast screenshot functionality is added to provide improved visual analysis. We added atomic distance analysis functionality to assess crystalline defects. We improved visualization capabilities by adding high level cut function definitions. Discovered bugs are fixed and small performance optimizations are made. New version program summary Program title: BilKristal 4.0 Catalogue identifier: ADYU_v4_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADYU_v4_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 370130 No. of bytes in distributed program, including test data, etc.: 8350850 Distribution format: tar.gz Programming language: C, C++, Microsoft .NET Framework 2.0 and OpenGL Libraries. Computer: Personal Computers with Windows operating system. Operating system: Windows XP or higher. RAM: 20–60 Megabytes. Classification: 8. External routines: Microsoft .NET Framework 2.0. For the visualization tool, graphics card driver should also support OpenGL. Catalogue identifier of previous version: ADYU_v3_0 Journal reference of previous version: Comput. Phys. Comm. 187 (2015) 266 Does the new version supersede the previous version?: Yes Nature of problem: Determining the crystal structure parameters of a material is a very important issue in crystallography. Knowing the crystal structure parameters helps the understanding of the physical behavior of material. For complex structures, particularly for materials which also contain local symmetry as well as global symmetry, obtaining crystal parameters can be very hard. Solution method: The tool extracts crystal parameters such as primitive vectors, basis vectors and identifies the space group from atomic coordinates of crystal structures. Reasons for new version: Additional features, Performance optimizations, Minor bug corrections. Summary of revisions: • Raycast screenshot functionality is added to the visualization tool. A raycasting algorithm similar to the one described in [4, 6] is used. The algorithm is multi-core parallelized as described in [5]. • Atomic distance analysis functionality is added. Tool can analyze the crystal structure and give statistical information of atom to atom distances. • In the visualization tool, high level cut function support is added. Users can define cut functions, not just as cut-planes but with more complex functions as well. • Automatic primitive vector and basis vector selection options are added. This way the system selects the simplest primitive and basis vector alternatives and continues without interrupting the user. • In the visualization tool, an unused log file was being created and a redundant configuration file was being used. These issues are corrected. • Dead-codes are removed to improve clarity. Restrictions: Assumptions are explained in [1, 2, 3]. However, none of them can be considered as a restriction to the complexity of the problem. Running time: The tool was able to process input files with more than a million atoms in less than 20 seconds on a PC with an Athlon quad-core CPU at 3.2 GHz using the default parameter values. References: [1] Erhan Okuyan, Ugur Güdükbay, and Oguz Gülseren, Pattern Information Extraction from Crystal Structures, Computer Physics Communications 176 (2007) 486. [2] Erhan Okuyan and Ugur Güdükbay, BilKristal 2.0: A Tool for Pattern Information Extraction from Crystal Structures, Computer Physics Communications 185 (2014) 442. [3] Erhan Okuyan and Erkan Okuyan, A Tool for Pattern Information Extraction and Defect Quantification from Crystal Structures, Computer Physics Communications 187 (2015) 266. [4] Erhan Okuyan, Ugur Güdükbay and Veysi İşler, Dynamic view-dependent visualization of unstructured tetrahedral volumetric meshes, Journal of Visualization 15-2 (2012) 167–178. [5] Erhan Okuyan and Ugur Güdükbay, Direct Volume Rendering of Unstructured Tetrahedral Meshes using CUDA and OpenMP, Journal of Supercomputing 67-2 (2014) 324–344. [6] Erhan Okuyan, Ugur Güdükbay, Ceyhun Bulutay, and Karl-Heinz Heinig, MaterialVis: Material Visualization Tool using Direct Volume and Surface Rendering Techniques, Journal of Molecular Graphics and Modelling 50 (2014) 50–60. [ABSTRACT FROM AUTHOR]

In this paper, we present a revised version of BilKristal 2.0 tool. We added defect quantification functionality to assess crystalline defects. We improved visualization capabilities by adding transparency support and runtime visibility sorting. Discovered bugs are fixed and small performance optimizations are made. New version program summary Program title: BilKristal 3.0 Catalogue identifier: ADYU_v3_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADYU_v3_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1868 923 No. of bytes in distributed program, including test data, etc.: 8854 507 Distribution format: tar.gz Programming language: C, C++, Microsoft .NET Framework 2.0 and OpenGL Libraries. Computer: Personal Computers with Windows operating system. Operating system: Windows XP or higher. RAM: 20–60 Megabytes. Classification: 8. Catalogue identifier of previous version: ADYU_v2_0 Journal reference of previous version: Comput. Phys. Comm. 185 (2014) 442 External routines: Microsoft .NET Framework 2.0. For the visualization tool, graphics card driver should also support OpenGL. Does the new version supersede the previous version?: Yes Nature of problem: Determining the crystal structure parameters of a material is a very important issue in crystallography. Knowing the crystal structure parameters helps the understanding of the physical behavior of material. For complex structures, particularly for materials which also contain local symmetry as well as global symmetry, obtaining crystal parameters can be very hard. Solution method: The tool extracts crystal parameters such as primitive vectors, basis vectors and identifies the space group from atomic coordinates of crystal structures. Reasons for new version: Additional features, Compatibility issues with newer development environments, Performance optimizations, Minor bug corrections. Summary of revisions: • Defect quantification capability is added. The tool can process the imperfect crystal structures, finds and quantifies the crystalline defects. The tool is capable of finding positional defects, vacancy defects, substitutional impurities and interstitial impurities. The algorithms presented in [3] are used for defect quantification implementation. • Transparency support is added to the visualization tool. Users are now allowed to set the transparency of each atom type individually. • Runtime visibility sorting functionality is added to facilitate correct transparency computations. • Visual Studio 2012 support is added. Visual Studio 2012 specific project files are created and the project is tested with this development environment. • In visualization tool, an unused log file was created. This issue is corrected. • In visualization tool, some OpenGL calls which are executed at every draw are changed to be executed only when they are needed, improving the visualization performance. Restrictions: Assumptions are explained in [1,2]. However, none of them can be considered as a restriction onto the complexity of the problem. Running time: The tool was able to process input files with more than a million atoms in less than 20 s on a PC with an Athlon quad-core CPU at 3.2 GHz using the default parameter values. References: [1] Erhan Okuyan, Ugur Güdükbay, Oguz Gülseren, Pattern information extraction from crystal structures, Comput. Phys. Comm. 176 (2007) 486. [2] Erhan Okuyan, Ugur Güdükbay, BilKristal 2.0: A tool for pattern information extraction from crystal structures, Comput. Phys. Comm. 185 (2014) 442. [3] Erhan Okuyan, Ugur Güdükbay, Ceyhun Bulutay, Karl-Heinz Heinig, MaterialVis: material visualization tool using direct volume and surface rendering techniques, J. [ABSTRACT FROM AUTHOR]