Arbitrary Components Research Articles

Grid Synchronization With Selective Harmonic Detection Based on Generalized Delayed Signal Superposition

Grid synchronization has always been an important challenge for grid-connected converters under extremely distorted grid conditions. Moreover, how to quickly and accurately extract multiple required harmonics is also essential for control systems. In this paper, two types of generalized delayed signal superposition (GDSS) operators capable of extracting any arbitrary harmonic component out of an input signal are derived. In order to show the benefits of GDSS operators, a new grid information estimation concept based on multiple GDSS operators (referred to as MGDSS-PLL) is proposed to track the fundamental and multiple targeted harmonics under single-phase and three-phase adverse grid conditions. MGDSS-PLL can be flexibly tuned to extract any harmonic components according to specific requirements within one fundamental period, and it also exhibits great robustness to grid disturbances. Simulations and experimental results are presented for verifying the performance of the MGDSS-PLL.

Herbicide resistance costs: what are we actually measuring and why?

Despite the considerable research efforts invested over the years to measure the fitness costs of herbicide resistance, these have rarely been used to inform a predictive theory about the fate of resistance once the herbicide is discontinued. One reason for this may be the reductive focus on relative fitness of two genotypes as a single measure of differential performance. Although the extent of variation in relative fitness between resistant and susceptible plants has not been assessed consistently, we know enough about plant physiology and ecology not to reduce it to a single fixed value. Research must therefore consider carefully the relevance of the experimental environment, the life stage and the choice of metric when measuring fitness-related traits. The reason most often given for measuring the cost of resistance, prediction of the impacts of management options on population dynamics, cannot be addressed using arbitrary components of fitness or a fixed value of relative fitness. To inform management options, the measurement of traits that capture the relevant processes and the main causes of their variation are required. With an emphasis on the benefit of field experiments measured over multiple time points and seasons, we highlight examples of studies that have made significant advances in this direction. © 2017 Society of Chemical Industry.

RConf(PD): Automated resource configuration of complex services in the cloud

Optimal deployment of complex services in a virtualized environment is still an open problem. These services typically consist of a set of connected components, and each component may consist of multiple instances. Each instance can in turn be run in different virtual flavors, while the service constructed by the combination of these instances must satisfy a customer Service Level Objective (SLO).While there have been efforts to answer the questions of when to provision additional resources in a running service, and how many resources are needed, the question of what (i.e., which combination of instances) should be provisioned has not been investigated yet. In this work, we offer to service providers, the first system that automatically deploys component instances for complex services such that the resource utilization at the provider’s premises is maximized in the presence of customer constraints.Our system consists of two key technologies (RConf and RConfPD), both of which build on an analytical model based on robust queueing theory to accurately model arbitrary components. With the help of this model, RConf proposes an algorithm to ultimately find the optimal combination of component instances. Our real-world experiments show that, compared to greedy approaches, RConf provisions 20% less resources in the first place, and can reduce resource wastage on live resources by up to 50%. At the same time, RConfPD trades-off some of the optimality of RConf for a computational expense 1–2 orders of magnitude below that of RConf to provision time-sensitive services. Based on a primal–dual algorithm framework RConfPD relaxes the optimality constraints of RConf and removes dominated combinations to determine an approximation for the optimal solution. Our evaluation shows that RConfPD allows for fast decisions (in many cases <1ms), while maintaining 80%–99% of the solution quality of RConf.

Generating Cognitive Context with Feature-Extracting Bidirectional Associative Memory

Cognitive contexts (CC) have been proposed as a solution to distinguish highly similar patterns during associative learning by using orthogonal contextual information. However, this method relied on the use of arbitrary components, limiting its cognitive plausibility. In this paper, a feature-extracting bidirectional associative memory (FEBAM) was used to generate CC. Results showed these generated CC can be retrieved under noise as effectively as arbitrary orthogonal CC. Furthermore, a network comprised of multiple FEBAMs generated CC of low correlation. These CC can achieve the same improvements in learning and recall performance found with orthogonal components.

Real-time human skin temperature analysis using thermal image recognition for thermal comfort assessment

This paper presents a system for the real-time analysis of human skin temperatures using sensor fusion and thermal image recognition. The aim of this work is to introduce an open and extensible framework that supports multi-modal sensor input with a focus on merging optical data and conventional sensor input for advanced thermal comfort analysis. The goal is to obtain a more complete representation of a person in various indoor climatic conditions. Methods proposed in this paper are important for research and industrial applications with respect to the real-time analysis of thermal comfort and human physiology in indoor climates. Although this paper mainly focuses on the analysis of skin temperatures, the proposed architecture is conceived for being extendable for statistical evaluation and numerical models. Arbitrary software components can be integrated as data sources and sinks by means of a conventional TCP/IP networking interface. Main contributions of this paper are a general architecture for the fusion of multi-modal sensor input using a centralized data server structure, a method for combining depth-map based face and pose tracking with a thermal imaging device and preliminary studies demonstrating the behavior and validity of the system.

Staggered potential and spin polarization effects on RKKY interaction in armchair graphene nanoribbon

Indirect exchange interaction between two magnetic external atoms, named by Ruderman–Kittle–Kasuya–Yosida (RKKY) interaction, has been presented in the staggered armchair graphene nanoribbon. We have studied RKKY interaction as a function of distance between localized moments. It has been shown that a magnetic ordering along the z-axis mediates an anisotropic interaction which corresponds to a XXZ model interaction between two magnetic moments. The static spin susceptibility components of armchair graphene nanoribbon have been calculated to find exchange interaction between arbitrary components of magnetic moments. We have exploited Green’s function approach in order to calculate spin susceptibility components of electronic gas in nanoribbon structure in the context of tight binding model Hamiltonian. The effects of parameter and ribbon width on the dependence of exchange interaction on distance between moments are investigated. Our results show the spin polarization along perpendicular to the plane leads to anisotropic behavior for exchange interaction between the two magnetic moments. In other words the spatial behavior of RKKY interaction between longitudinal components of magnetic moments is different from that of transverse components.

Mean Free Path of Different Segments of the Dislocation Loop in FCC Single Crystals

Numerical value of the shear zone diameter is refined. It is assumed that the shear zone is bounded by long strong dislocation barriers formed in the course of reaction between glissile dislocation segments of the loop and dislocations of non-coplanar sliding systems. Based on the modified model of inter-dislocation contact interactions, the mean free path and the probabilities of occurrence of long strong junctions formed by arbitrary components of the dislocation loop are determined. Results are obtained for different orientations of the crystal deformation axes.

Distortion Measures on Homogeneous Financial Derivatives

This paper extends the evaluation and allocation of distortion risk measures to apply to arbitrary homogeneous components of a portfolio (“financial derivatives,” e.g. reinsurance recovery, of primitive portfolio components, e.g. lines of business). It is argued that the allocation of the portfolio measure to the financial derivative takes the usual form of (distortion-) weighted “co-measure” expectation. Due to homogeneity, the allocation of the derivative’s value to further subcomponents (ultimately, the primitive elements of the portfolio), following Aumann-Shapley, is the exposure gradient. However, the gradient in this case consists of two terms. The first is the familiar distorted expectation of the gradient of the component with respect to the subcomponent. The second term involves the conditional covariance of the component with the subcomponent. Sufficient conditions for this second term to vanish are provided. A method for estimating the second component in a simulation framework is proposed.

Linking polynomials of virtual string links

In this paper, we define two polynomial invariants for virtual string links. One can be defined only on 2-component virtual string links. The other is defined on virtual string links with arbitrary components. Both invariants can distinguish virtual string links from their mirror images. In addition, we also show that these two invariants are link homotopic invariants. In the end, we give some interesting examples to show that the two invariants are different.

Indicators of Financial Vulnerability: A Household Level Study

This paper compares two indicators of household vulnerability using the Bank of Italy’s Survey on Household Income and Wealth (2008-2014). According to the first indicator, a household is considered vulnerable if its debt service-to-income ratio exceeds 30 per cent and its income is below the median of the population. According to the second, a household is defined vulnerable if the sum of its income and liquid financial assets is not sufficient to cover debt payments and basic living costs for four months. While providing similar information on the proportion of households deemed vulnerable, the two indicators capture different aspects of the sector’s financial fragility: vulnerable households according to the first indicator have, on average, higher income, liquid assets and debt than those identified by the second indicator. Moreover, while the first indicator shows a lower correlation with payment arrears, its simplicity, timeliness and less arbitrary components make it better suited for cross-country comparisons.

Conceivability and possibility: some dilemmas for Humeans

The Humean view that conceivability entails possibility can be criticized via input from cognitive psychology. A mainstream view here has it that there are two candidate codings for mental representations (one of them being, according to some, reducible to the other): the linguistic and the pictorial, the difference between the two consisting in the degree of arbitrariness of the representation relation. If the conceivability of P at issue for Humeans involves the having of a linguistic mental representation, then it is easy to show that we can conceive the impossible, for impossibilities can be represented by meaningful bits of language. If the conceivability of P amounts to the pictorial imaginability of a situation verifying P, then the question is whether the imagination at issue works purely qualitatively, that is, only by phenomenological resemblance with the imagined scenario. If so, the range of situations imaginable in this way is too limited to have a significant role in modal epistemology. If not, imagination will involve some arbitrary labeling component, which turns out to be sufficient for imagining the impossible. And if the relevant imagination is neither linguistic nor pictorial, Humeans will appear to resort to some representational magic, until they come up with a theory of a ‘third code’ for mental representations.

Stem taper mismatch has a critical effect on ceramic head fracture risk in modular hip arthroplasty

BackgroundModular total hip prostheses with ceramic heads are well established in orthopedic surgery and widely used. With the variety of different manufacturers and available designs, components are at risk for mismatch. Several case studies show the potentially devastating effects of mismatch. MethodsThe aim of this study was to investigate the outcome of one arbitrary component mismatch with commercially available components that appear to provide a stable fixation during assembly. A biomechanical in-vitro analysis of fracture strength (n=5) was carried out in accordance with ISO 7206-10. “Type1” Bi-Metric®-stems were mismatched with “V40” Al2O3 ceramic heads. FindingsMean fracture strength was reduced to about 50% of the recommended FDA minimum by the mismatch (Mean 23.68kN, SD 2.35kN). A small contact area between head and stem taper was identified as a potential key parameter. InterpretationMixing and matching components can put a patient at greater risk for ceramic head fracture and must be avoided.

Suppressing structure formation at dwarf galaxy scales and below: Late kinetic decoupling as a compelling alternative to warm dark matter

Warm dark matter cosmologies have been widely studied as an alternative to the cold dark matter paradigm, the characteristic feature being a suppression of structure formation on small cosmological scales. A very similar situation occurs if standard cold dark matter particles are kept in local thermal equilibrium with a, possibly dark, relativistic species until the universe has cooled down to keV temperatures. We perform a systematic phenomenological study of this possibility, and classify all minimal models containing dark matter and an arbitrary radiation component that allow such a late kinetic decoupling. We recover explicit cases recently discussed in the literature and identify new classes of examples that are very interesting from a model-building point of view. In some of these models dark matter is inevitably self-interacting, which is remarkable in view of recent observational support for this possibility. Hence, dark matter models featuring late kinetic decoupling have the potential not only to alleviate the missing satellites problem but also to address other problems of the cosmological concordance model on small scales, in particular the cusp-core and too-big-too-fail problems, in some cases without invoking any additional input.

Tools for Predicting the Reliability of Large-Scale Storage Systems

Data-intensive applications require extreme scaling of their underlying storage systems. Such scaling, together with the fact that storage systems must be implemented in actual data centers, increases the risk of data loss from failures of underlying components. Accurate engineering requires quantitatively predicting reliability, but this remains challenging due to the need to account for extreme scale, redundancy scheme type and strength, distribution architecture, and component dependencies. This article introduces CQS im -R, a tool suite for predicting the reliability of large-scale storage system designs and deployments. CQS im -R includes (a) direct calculations based on an only-drives-fail failure model and (b) an event-based simulator for detailed prediction that handles failures of and failure dependencies among arbitrary (drive or nondrive) components. These are based on a common combinatorial framework for modeling placement strategies. The article demonstrates CQS im -R using models of common storage systems, including replicated and erasure coded designs. New results, such as the poor reliability scaling of spread-placed systems and a quantification of the impact of data center distribution and rack-awareness on reliability, demonstrate the usefulness and generality of the tools. Analysis and empirical studies show the tools’ soundness, performance, and scalability.

Fabrication of three-dimensional silicon structure with smooth curved surfaces

A blue-ray laser lithography along with a dry etching process was presented to fabricate a three-dimensional (3-D) silicon structure with smooth surface. Main findings include the reduction of corrugations on photo resist profiles by adjusting the focal depth of grayscale laser lithography, optimization of reactive ion etching process to decrease the surface roughness after dry etching as well as keeping a low etching selectivity, and the introduction of a procedure to design and fabricate arbitrary 3-D silicon structures. Silicon microstructures with a curved surface were fabricated successfully applying this approach and the root-mean-square surface roughness was down to 3.0 nm. This result reduces approximately one order of magnitude than the previously reported surface roughness of arbitrary 3-D silicon microstructures. This approach is promising for fabricating arbitrary shape components in MEMS, optics, and microfluidic applications.

Labelling additively manufactured parts by microstructural gradation – advanced copy-proof design

Purpose As additive manufacturing techniques, such as selective laser melting, allow for straightforward production of parts on basis of simple computer-aided design files only, unauthorized replication can be facilitated. Thus, identification and tracking of individual parts are increasingly vital in light of globalized competition. This paper aims to overcome the susceptibility of additive manufacturing techniques for product piracy by establishing a method for introducing and reading out product identification markers not visible by naked-eye inspection. Design/methodology/approach Lasers of different nominal power were used for altering the solidification mechanisms during processing in distinct areas of the samples. The resulting local microstructural characteristics and mechanical properties, respectively, were determined by scanning electron microscopy and hardness measurements. The applicability of an advanced eddy current technique for reading out local differences in electro-magnetic properties was examined. Findings The findings show that distinct microstructural features are obtained in dependence of the locally applied laser power. These features manifest themselves not only in terms of grain morphology, texture and hardness but also induce changes in the local electro-magnetic properties. The inscribed pattern can be non-destructively visualized by using an advanced eddy current technique. Originality/value Conventional copy protection basically consists in supplementary labelling or surface modification. In the present study, a new method is proposed for additively manufactured parts, overcoming the drawbacks of the former methods through process-induced microstructure manipulation. Slight alterations in the electro-magnetic material properties can be detected by advanced eddy current method allowing for identification of arbitrary and inimitable component information in additively manufactured parts.

Ideology and problems of systems and economic optimization of NPPs

Iterative technique for optimization of components of nuclear fuel and energy complex (NFEC) is described. Nuclear power (NP) is one of such NFEC components. Optimization of nuclear power plant (NPP) is iteratively interconnected with optimization of the structure NP as the component within the NFEC system. Correlation functions between the components describing material flows and their costs as time functions are obtained by sequential optimization of components of the NFEC system. External flows and costs for each iteration step during optimization of specific component are taken from other components of the NFEC system optimized during the same iteration step. Flows and costs obtained during optimization of the component of the NFEC system examined during the consecutive iteration step are transmitted for optimization of other system components during the same iteration step. Specific NPPs are optimized following the same principle. Convergence of plans (solutions) of development and arrangement of all components is achieved by sequential optimization of all components within the NFEC system. Thus, convergence of all time functions including material flows and their costs is achieved allowing finding one or several locally optimal plans of development and arrangement of the fuel and energy complex (FEC) of Russia, as well as power plants (PPs) fueled with coal, gas, NPPs and other PPs. If the number of locally optimal plans is countable, then it is possible to select the best among them by comparing their functionals (values of the objective function). Upon obtaining new information with regard to any of the factors of mathematical models of components of the NFEC system optimization of components of the system must be repeated. In this case optimization must be performed taking into consideration the incurred costs under construction and already commissioned PPs.Problems of systems optimization of components of the NFEC system as the functional of NPP optimization are identified. The task of optimization of complex systems refers to the most complex class of degenerate optimization problems [1]. No theory of degenerate optimization problems exists as of the present moment, although specifically these problems are real. Degenerate optimization problems should not be associated with degenerate matrices. Degenerate optimization problems deal with non-singular matrices having inverse matrices and, consequently, having solutions. However, the nature of these problems is such, that these solutions are degenerate (one or more components of the basis vector of the solution are equal to zero). The problem of convergence in the optimization of arbitrary component of the NFEC system to locally optimal plan coordinated with locally optimal plans for other components of the NFEC system is one of the main problems of degenerate optimization problems. Appearance of iterating loops during internal iterations in the process of optimization of plans for separate component of the NFEC system is not less important for problems of this class. This feature requires including incorporation of additional algorithms for exiting from the loops in the optimization algorithms.

Reliability of systems subject to competing failure propagation and probabilistic failure isolation

ABSTRACTMany real-world systems exhibit probabilistic functional dependence behaviour, where operations of some system components (dependent components) depend on function of another component (trigger component) in a probabilistic manner. A trigger component failure may cause two-fold effects. On one hand, if it occurs first, the corresponding dependent components may be isolated with certain probabilities, and such isolation effects can prevent system function from being compromised by further failures of those dependent components. On the other hand, if any of the dependent components experiences a propagated failure that occurs before the trigger component failure, the entire system can fail due to the propagation effect. This paper models such competitions between probabilistic failure isolation and failure propagation effects in reliability analysis of non-repairable systems through a combinatorial methodology. As demonstrated through examples, the method is applicable to arbitrary component time-to-failure distributions, and can handle diverse statistical relationships between component local and propagated failures.

Does Sleep Improve Your Grammar? Preferential Consolidation of Arbitrary Components of New Linguistic Knowledge.

We examined the role of sleep-related memory consolidation processes in learning new form-meaning mappings. Specifically, we examined a Complementary Learning Systems account, which implies that sleep-related consolidation should be more beneficial for new hippocampally dependent arbitrary mappings (e.g. new vocabulary items) relative to new systematic mappings (e.g. grammatical regularities), which can be better encoded neocortically. The hypothesis was tested using a novel language with an artificial grammatical gender system. Stem-referent mappings implemented arbitrary aspects of the new language, and determiner/suffix+natural gender mappings implemented systematic aspects (e.g. tib scoiffesh + ballerina, tib mofeem + bride; ked jorool + cowboy, ked heefaff + priest). Importantly, the determiner-gender and the suffix-gender mappings varied in complexity and salience, thus providing a range of opportunities to detect beneficial effects of sleep for this type of mapping. Participants were trained on the new language using a word-picture matching task, and were tested after a 2-hour delay which included sleep or wakefulness. Participants in the sleep group outperformed participants in the wake group on tests assessing memory for the arbitrary aspects of the new mappings (individual vocabulary items), whereas we saw no evidence of a sleep benefit in any of the tests assessing memory for the systematic aspects of the new mappings: Participants in both groups extracted the salient determiner-natural gender mapping, but not the more complex suffix-natural gender mapping. The data support the predictions of the complementary systems account and highlight the importance of the arbitrariness/systematicity dimension in the consolidation process for declarative memories.

A Method for Reliability Assessment of Structural Components of Aircraft and Sea-Going Ships with Taking into Account a Given Failure Generation Model

Abstract This paper presents a metod for reliability assessment of structural components on the basis of diagnostic parameters recorded during operation of aircraft and sea going ships. It was assumed that a potential failure may simultaneously concerns surface wear process and fracture of an arbitrary structural component. In order to develop a reliability assessment model some elements of random walk theory were applied. This work covers surface wear density functions of a component. In the case of surface wear the model is based on a difference equation from which, after transformation, a Fokker-Planck partial differential equation was obtained. By solving the equation component’s surface wear density function is achieved. In the second part of the work a generalization of the model was made by introducing to it probability of disastrous fracture of a component. As a result, a generalized Fokkera-Planck’s equation was obtained. By making use of the equation, was obtained a relationship for assessment of reliability of a structural component in case when failure occurs due to surface wear with taking into account possible fracture of the component. In the end a numerical example which shows practical application of the developed method, is attached.