Theory Of Large Systems Research Articles

Classical analogue to driven quantum bits based on macroscopic pendula

Quantum mechanics increasingly penetrates modern technologies but, due to its non-deterministic nature seemingly contradicting our classical everyday world, our comprehension often stays elusive. Arguing along the correspondence principle, classical mechanics is often seen as a theory for large systems where quantum coherence is completely averaged out. Surprisingly, it is still possible to reconstruct the coherent dynamics of a quantum bit (qubit) by using a classical model system. This classical-to-quantum analogue is based on wave mechanics, which applies to both, the classical and the quantum world. In this spirit we investigate the dynamics of macroscopic physical pendula with a modulated coupling. As a proof of principle, we demonstrate full control of our one-to-one analogue to a qubit by realizing Rabi oscillations, Landau-Zener transitions and Landau-Zener-Stückelberg-Majorana interferometry. Our classical qubit demonstrator can help comprehending and developing useful quantum technologies.

К вопросу выбора наиболее рационального сочетания землеройной и транспортной техники при производстве земляных работ

Purpose: Analysis of the problem of choosing the optimal set of machines in the building of transport construction facilities. The problem of choosing equipment rational combination choice in earthmoving sets is always relevant. Construction process productivity, construction time, labor costs, production costs and many other indicators of construction efficiency depend on how rationally equipment is chosen in machine construction sets. Methods: The calculation formulas of reliability theory, the theory of large systems and mass service theory are the tool for the research and analysis of the issue of machine optimal set choice at transport facility construction. Since construction processes, being considered by the author, possess all the features of large systems, they are dynamic and can be probabilistically predictable. Results: The article proposes options for rational combination of earth-moving and transport equipment for "excavator - dump trucks" systems in relation to sets of equipment with machines having different technical parameters and for different ranges of soil transportation. The presented variants are obtained by calculation using mathematical apparatus of reliability and mass service theories. Practical significance: The results, presented by the authors, are proposed in easy-to-use tabular form and have practical significance, since if used by construction organizations, they are capable to increase construction process productivity and to reduce facility construction time.

Globalization and integrative factors of the formation of the culture of the post-Soviet space

The purpose of the article is an analysis of the cultural formation of the post-Soviet space in the age of globalization. Methodology. The research methods represent theoretical and interpretative models of analysis of the mechanisms of cultural formation in the context of the post-Soviet space of modern culture, in particular, the use of comparative and systematic approaches. The culture of everyday life is viewed in the context of the historical and cultural transformations of the post-totalitarian regime. The scientific novelty is to reveal the peculiarities of the interpretation and interaction of cultures as reflective attitudes, in particular characterized by holism (the primacy of the system) as a system-consolidating turn and anti-holism (the dominant part, subsystems), which attests to the initiatives of the anti-globalist movements. It has been proved that the globalization of culture cannot be described only as an extensive growth of information technologies. The essence is to homogenize and unify the exchange of cultures. Conclusions. Factors of cultural integration in the context of globalization press are identified as an anti-globalization project to counteract capital expansion and cultural colonization. It is proved that the universalization of communication and information space leads to supra-systemic cultural entities (emergence of planetary information government, communicative ethics, synthesism of reception and production of information on the Internet, etc.). The emphasis is put on the formation of a synthetic cultural discipline - totalology, which makes it possible to understand the processes of globalization and integration in the post-Soviet space on the basis of the application of meta cultural analytical tools within the theory of large systems.

SCC-DFTB Parameters for Fe-C Interactions.

We present an optimized density-functional tight-binding (DFTB) parameterization for iron-based complexes based on the popular trans3d set of parameters. The transferability of the original and optimized parameterizations is assessed using a set of 50 iron complexes, which include carbonyl, cyanide, polypyridine, and cyclometalated ligands. DFTB-optimized structures predicted using the trans3d parameters show a good agreement with both experimental crystal geometries and density functional theory (DFT)-optimized structures for Fe-N bond lengths. Conversely, Fe-C bond lengths are systematically overestimated. We improve the accuracy of Fe-C interactions by truncating the Fe-O repulsive potential and reparameterizing the Fe-C repulsive potential using a training set of six isolated iron complexes. The new trans3d*-LANLFeC parameter set can produce accurate Fe-C bond lengths in both geometry optimizations and molecular dynamics (MD) simulations, without significantly affecting the accuracy of Fe-N bond lengths. Moreover, the potential energy curves of Fe-C interactions are considerably improved. This improved parameterization may open the door to accurate MD simulations at the DFTB level of theory for large systems containing iron complexes, such as sensitizer-semiconductor assemblies in dye-sensitized solar cells, that are not easily accessible with DFT approaches because of the large number of atoms.

Methods of criteria optimization of the choice of means of mechanization of construction works

Subject of research: criteria optimization of technological processes of construction works in solving problems of ter­ritorial innovation in settlements with different building density. Purpose : to substantiate the universality of the criterion approach in terms of cost effectiveness for construction works for various purposes on the example of assessing the technological and energy efficiency of the choice of complex mechanization. Materials and methods: theory of large systems, queueing theory, Wald, savage, Hurwitz, Laplace methods, math­ematical analysis. Results: it is proposed to apply a generalized cost indicator as an optimization criterion. The mechanism of complex mechanization of the choice of technical means of providing is accepted key at technological implementation of con­struction projects. The flexibility of the proposed approach in varying the factors of influence, conventionally represent­ing the energy, resource and other characteristics of mechanization. The efficiency of criterion optimization methods in solving problems under conditions of complete uncertainty is proved. Conclusions: the methods of the coordinated analytical and computational model for the selection of optimal energy and functional efficiency sets of mechanization in the implementation of projects of territorial innovation in settlements with different building density are proposed

Finding optimal multicomponent distillation flowsheets

A general approach to the synthesis of the complete set of distillation flowsheets for multicomponent zeotropic mixtures is considered, which includes construction of generalized separation graphs and an analysis of all intermediate fractions. The approach is applied to the distillation of particular zeotropic four-component mixtures of different compositions. An optimal distillation flowsheet is obtained for each of the 60 cases examined. The dynamic programming conception is inapplicable to mixtures consisting of a few components, because some of the columns of the optimal flowsheet may function in a nonoptimal way, which is in agreement with the optimization theory for large systems.

Key problems faced in high-speed train operation

This paper discusses some key problems faced in high-speed train operation. These problems include: wheel tread concave wear causing the lateral oscillation of the train in operation, wheel roundness higher-order polygonal wear leading to fierce vertical vibration of wheel/rail and abnormal vibration noise of the coach interior of the train thus causing loosening and cracking of the train bogie parts, short pitch rail corrugation generation on the part of the track, fracture of cushion layer and road base fracture of the track, and increased noise inside and outside the train. At present, the mechanism of the occurrence and development of these phenomena is still not fully understood. This paper briefly reviews the related research on these problems in China and abroad, including many important recent papers and the articles published in this special issue. They make outstanding contributions to solving these problems, and include important work on train-track coupling large system theory, the relationship theory and technique of wheel/rail, and the vibration-noise reduction technology of the train.

Quantum mechanical origin of the plasmon: from molecular systems to nanoparticles.

The surface plasmon resonance (SPR) of noble metal nanoparticles is reviewed in terms of both classical and quantum mechanical approaches. The collective oscillation of the free electrons responsible for the plasmon is well described using classical electromagnetic theory for large systems (from about 10 to 100 nm). In cases where quantum effects are important, this theory fails and first principle approaches like time-dependent density functional theory (TDDFT) must be used. In this paper, we give an account of the current understanding of the quantum mechanical origin of plasmon resonances. We provide some insight into how the discrete absorption spectrum of small noble metal clusters evolves into a strong plasmon peak with increasing particle size. The collective character of the plasmon is described in terms of the constructive addition of single-particle excitations. As the system size increases, the number of single-particle excitations increases as well. A configuration interaction (CI) approach can be applied to describe the optical properties of particles of all shapes and sizes, providing a consistent definition of plasmon resonances. Finally, we expand our analysis to thiolate-protected nanoparticles and analyze the effects of ligands on the plasmon.

Equilibrium and disorder-induced behavior in quantum light–matter systems

We analyze equilibrium properties of coupled-doped cavities described by the Jaynes–Cummings–Hubbard Hamiltonian. In particular, we characterize the entanglement of the system in relation to the insulating–superfluid phase transition. We point out the existence of a crossover inside the superfluid phase of the system when the excitations change from polaritonic to purely photonic. Using an ensemble statistical approach for small systems and stochastic mean-field theory for large systems, we analyze static disorder of the characteristic parameters of the system and explore the ground state-induced statistics. We report on a variety of glassy phases deriving from the hybrid statistics of the system. On-site strong disorder induces insulating behavior through two different mechanisms. For disorder in the light–matter detuning, low-energy cavities dominate the statistics, allowing the excitations to localize and bunch in such cavities. In the case of disorder in the light–matter coupling, sites with strong coupling between light and matter become very significant, which enhances the Mott-like insulating behavior. Inter-site (hopping) disorder induces fluidity and the dominant sites are strongly coupled to each other.

Communication: A new approach to dual-basis second-order Møller–Plesset calculations

We describe a hierarchy of approximations (MP2[x]) that allow one to estimate second-order Møller-Plesset (MP2) energies in a large basis set from small-basis calculations. The most cost-effective approximation, MP2[K], is significantly cheaper than full MP2 but numerical tests on small atoms and molecules indicate that it is nonetheless accurate. We conclude that MP2[K] is an attractive level of theory for large systems.

Evaluation models of insurers’ risk management based on large system theory

The financial supply chain is increasingly recognized as an area offering significant potential for generating bottom-line improvements and creating competitive advantage. Insurers’ appraisal is one of the basic decisions for a company, and the choosing course has always many criterions. Considering the stability of the financial supply chain, the coordination evaluation and fuzzy multi-objective evaluation model of insurers’ risk management are firstly studied in this paper by using large system theory and methods. The corresponding coordination evaluation index model is then established to evaluate, forecast and control the actuality and the future of risk coordination management, and to improve the durative development for a combination pension model. The evaluation standards of numerous insurers are established to constitute a set of vectors. By presenting a dimensional point to each insurer, the optimal or the worst insurer is decided. Finally, the distances of each insurer to the optimal or the worst insurer on the basis of the Euclidean distance are counted, and the insurers’ ordering according to the value of distances is sorted out. The financial supply chain and large system theory and methods are combined to contribute new evaluation models that revise the deficiency of intrinsic model and improve the financial stability.

Risk analysis and crisis response

Today’s society is a risk society, filled with challenges as well as opportunities. Frightened by catastrophic events, such as 9.11, SARS, Indian Ocean earthquake and tsunami, South Asia earthquake disaster, and bird flu, people increasingly regard risk and crisis as urgent issues. The term risk analysis has different interpretations among various environments. However, there is a growing acceptance that risk analysis involves the development of the probability distribution for the measure of effectiveness. Furthermore, the risk associated is generally either given as the probability of an unfavorable value for the measure of effectiveness or measured by the variance of measure of effectiveness. This special issue is devoted for the papers presented at the First International Conference on Risk Analysis and Crisis Response September 25–26, 2007, Shanghai, China. About 200 papers were presented at this conference and the extended papers of all were submitted after the conference for possible publication in this special issue of Stochastic Environmental Research and Risk Assessment. After a peer review using at least two referees for each paper, 12 papers included by this issue have been accepted. The financial supply chain is increasingly recognized as an area offering significant potential for generating bottomline improvements and creating competitive advantage. In the first paper, considering the stability of the financial supply chain, the coordination evaluation and fuzzy multiobjective evaluation model of insurers’ risk management are firstly studied by using large system theory and methods. The corresponding coordination evaluation index model is then established to evaluate, forecast and control the actuality and the future of risk coordination management, and to improve the durative development for a combination pension model. The evaluation standards of numerous insurers are established to constitute a set of vectors. By presenting a dimensional point to each insurer, the optimal or the worst insurer is decided. Finally, the distances of each insurer to the optimal or the worst insurer on the basis of the Euclidean distance are counted, and the insurers’ ordering according to the value of distances is sorted out. The second paper presents the morphogenetic system which projects the output samples of fuzzy set to the input samples of the fuzzy sets. In the projection operator the author computes the best rules for the inferential or reasoning process. Modern uncertainty theories (fuzzy logic, Information diffusion) provide a calculus to obtain relationship by observation pattern. With the relationship obtained, the risk in different situation can be estimated. It is known that information structure is essential to forecast the future risk in different situations; the main difficulty in the forecast the risk is to extract rules from a non-coherent set of data. Fuzzy sets and fuzzy rules are essential to detect the uncertainty but are not sufficient to define in an optimal way the rules that describe the relationship among fuzzy variables. Fire is a major risk in the event of large stadium due to fire coincidence with smoke flow and evacuation path. In the next paper, as a part of an effort to improve the life safety in large stadium, the simulation technology combined with fire spread and evacuation is developed. Besides that, in order to decrease the rate of people death in the large stadium fire, the interface between fire and the evacuation people must be designed in the simulation model, based on the influence laws to human behavior by smoke temperature, CO concentration and extinction coefficient in fire condition. Therefore, the investigation of effect of fire spread on life safety is needed. C. Kahraman (&) Department of Industrial Engineering, Istanbul Technical University, 34367 Macka Istanbul, Turkey e-mail: kahramanc@itu.edu.tr

Finite group theory for large systems. 3. Symmetry‐generation of reduced matrix elements for icosahedral C20 and C60 molecules

This paper uses symmetry-generation to simplify the determination of Hamiltonian reduced matrix elements. It is part of a series on using computers to apply finite group theory to quantum mechanical calculations on large systems. Symmetry-generation is an expression of the whole molecule as a sum of symmetry transformations on a smaller reference structure. Then on a suitably-conditioned symmetry-adapted basis, the reduced matrix elements of the Hamiltonian are averages of certain elements of the simpler reference structure matrix. The smaller the reference structure, the greater is the computational savings. Single atom reference structures are used here for the Hückel treatment of icosahedral C(20) and C(60) fullerenes. The analytical power of this approach is illustrated by determining the two bond lengths of C(60) from spectral data.

From a class of kinetic models to the macroscopic equations for multicellular systems in biology

This paper deals with the development of an asymptotic theory for large systems of interacting cells in a vertebrate. Macroscopic diffusion and evolution equations are derived from the microscopic behavior represented by a class of nonlinear kinetic equations obtained as a generalization of the Boltzmann equation in mathematical biology. The analysis shows how the time-scaling plays a crucial role in the derivation of different type of equations. The application, developed in the second part of the paper refers to a model of progressing tumor cells in competition with the immune system. The asymptotic analysis is addressed to derive the mathematical framework of macroscopic equations to describe the evolution of solid tumors in "vivo" or in "vitro" environments.

Finite group theory for large systems. 2. Generating relations and irreducible representations for the icosahedral point group, I(h).

Generating relations and irreducible representations are given for the icosahedral point group, I(h), that are suited to computerized projection of symmetry-adapted bases of arbitrary spaces invariant to the group. With 120 elements I(h ) is a good prototype for symmetry-adaptation to a large finite nonabelian group. The four- and five-dimensional irreducible representations are obtained by coupling direct products of the three-dimensional irreducible representations using the symmetry-adaptation algorithm. The method is applied to the Hückel treatment of icosahedral C(20) fullerene.

Finite group theory for large systems. 1. Symmetry-adaptation.

The challenge of symmetry-adapting large basis sets to finite groups, apart from extensive calculations with large matrices, is obtaining linearly independent bases for frequently repeated irreducible representations, a process that is not determined by the group theory. The usual projection method is modified here to solve this problem efficiently and systematically. The resulting basis is suitably conditioned so that repeated irreducible representations are identical as required by the symmetry-generation theorem.

Modeling electron-electron interactions in reduced-dimensional materials: Bond-charge Coulomb repulsion and dimerization in Peierls-Hubbard models.

To the conventional Peierls-Hubbard model, involving both on-site (U) and nearest-neighbor (V) Coulomb repulsions, we add ``off-diagonal'' terms, not expressible purely in terms of site densities, representing bond-bond (W) and mixed bond-site (X) electron-electron repulsive interactions involving nearest neighbors. We review earlier analyses of these interactions and discuss relative magnitudes of the parameters in applications to real materials. As a specific illustration, we investigate the effects of the off-diagonal W and X terms on dimerization in the one-dimensional, half-filled-band Peierls-Hubbard models, which have been widely applied to conjugated polymers (such as trans-polyacetylene) and to related quasi-one-dimensional charge-density wave (CDW) systems. Using both weak- and strong-coupling perturbation theory for large systems and exact diagonalizations of small systems, we investigate thoroughly the nature of the ground state of the model. For a broad range of the site-diagonal Hubbard parameters (U,V), including the values believed to be relevant to trans-polyacetylene, we find that the off-diagonal terms (W,X) initially enhance dimerization, thereby stabilizing the dimerized [or bond-order-wave (BOW)] ground state. For (unphysically) large values of W relative to U and V, dimerization is destroyed, and the BOW ground state goes over to a ferromagnetic ground state or a CDW ground state, depending on the relative sizes of U, V, and W. We conclude with a general discussion of the applicability of the Peierls-Hubbard models to quasi-one-dimensional materials, including the potential importance of the breaking of charge conjugation (``particle-hole'') symmetry by the X term.

Mathematical significance and application perspectives of medium logic calculus (ML) and medium axiomatic set theory (MS)

In the sense of basic theory of mathematics, ML (Medium Logic) and MS (Medium Set Theory) have widened the foundation of logic and set theory of the precise classical mathematics and extended the research objects of mathematics from precision into fuzziness. Hence ML and MS, in a higher form, contain the whole of precise classical mathematics and its theoretical foundation. ML and MS have also resolved the problems of the revision of the comprehension principle left over historically, i.e. they have not only excluded all the paradoxes in the system, but also preserved all the reasonable content of the comprehension principle. ML and MS have provided a common theoretical foundation for both precise classical mathematics and future uncertain mathematics. The fifth generation of computers must lay its foundation on the acknowledgement of intelligent logic of medium states. Obviously ML will be this logic. ML and MS will also be the theoretical foundation of expert systems and advance the techniques of pattern recognition, graphic analysis, artificial intelligence, intelligent robots, computer vision, etc. to a new stage. In addition to the uncertain quantitative analysis, based on the theoretical foundation of ML and MS, the theory of large systems will present extraordinarily new prospects.

Theoretical Chemistry en route to a Theory of Chemistry

AbstractQuantum mechanical and classical aspects are of equal importance in chemistry, and theoretical chemistry must be able to deal with this situation. Classical quantities with which a chemist has to deal include, for example, the temperature and the chemical potential of a substance, and chirality, knot‐type and tertiary structures of molecules. Classical concepts of this type are no more consequences of traditional quantum chemistry than is the theory of complex chemical processes (for example adsorption, heterogeneous catalysis) and macroscopic systems. Algebraic quantum mechanics affords a general framework for the discussion of classical quantities and large systems. There are other independent approaches for the theoretical treatment of chemical problems; these can be summarized by using the keywords “fractals”, “chaotic motion”, “quasicrystals” and “knot theory”. The relationships between these four research topics and their connection with algebraic quantum mechanics, as well as their importance for theoretical chemistry, were discussed at a NATO Workshop in 1987 (see Ref. [1]). In an extended theoretical chemistry, the notion of “molecules” will not play a role as central as it does in quantum chemistry. In the theory of large systems in particular, the introduction of complementary approaches appears to be appropriate; the term “molecule” as used by the chemist does not appear either in the description of disordered systems by means of fractals or in the thermodynamic limit of algebraic statistical mechanics.

A New Approach to Flexible Automation of Large Systems

The new scheme of flexible automation of large systems — “Multilevel Self-Optimalizing Control” is proposed, and the designs of local self-optimalizing controller and whole optimal coordinator are given. In authors opinion, the combination of artificial intelligence, large system theory and microcomputer network technique is the new approach to flexible automation of large systems.