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The crossing number of a graph is a significant measure that indicates the complexity of the graph and the difficulty of visualizing it. In this paper, we examine the crossing numbers of join products involving the complete graph K 5 with discrete graphs, paths, and cycles. We analyze optimal drawings of K 5 , identify all five non-isomorphic drawings, and address previously hypothesized crossing numbers for K 5 + P n , and K 5 + C n . Through a simplified approach, we first establish cr (K 5 + D n) and then extend our method to prove the crossing numbers cr (K 5 + P n) and cr (K 5 + C n) . These results also lead to new hypotheses for cr (W m + S n) and cr (W m + W n) involving wheels and stars. Our findings correct previous inaccuracies in the literature and provide a foundation for future research. [ABSTRACT FROM AUTHOR]

In growth-cycle models, consumption smoothing motivates procyclical household savings and monopolistic competition engenders countercyclical horizontal R&D at fixed costs of capital. However, data in the US and in 15 OECD countries indicate countercyclical household saving, procyclical R&D, and high volatility. This paper explains the observed cyclical properties by realistic income taxes, R&D subsidies, R&D labor, and depreciation. R&D subsidies promote R&D to increase productivity by trading the levels for the varieties of intermediates. R&D-subsidy payments increase consumption and decrease household saving rates by raising taxable income beyond output, thus hindering future R&D and growth. Anticipated R&D-subsidy payments increase household-saving rates by raising returns to saving, thus promoting future R&D and growth. The US taxes yield unstable fluctuations with consecutive periods of R&D, low saving rates, and strong growth as in the technology boom. R&D labor and partial depreciation strengthen the roles of saving and R&D in attaining high volatility. [ABSTRACT FROM AUTHOR]

A vertex-edge perfect Roman dominating function on a graph G = (V; E) (denoted by ve-PRDF) is a function f: V (G) f0; 1; 2g such that for every edge uv 2 E, maxf f (u); f (v)g, 0, or u is adjacent to exactly one neighbor w such that f (w) = 2, or v is adjacent to exactly one neighbor w such that f (w) = 2. The weight of a ve-PRDF on G is the sum w(f) = P v2V f (v). The vertex-edge perfect Roman domination number of G (denoted by p veR(G)) is the minimum weight of a ve-PRDF on G. In this paper, we first show that vertex-edge perfect Roman dominating is NP-complete for bipartite graphs. Also, for a tree T, we give upper and lower bounds for p veR(T) in terms of the order n, l leaves and s support vertices. Lastly, we determine p veR(G) for Petersen, cycle and Flower snark graphs. [ABSTRACT FROM AUTHOR]

Considerable studies have examined the relationship between commodity markets and stock markets. This paper studies the cyclical relationship between commodity markets and stock markets with implications for investing based on index relationships. Stock markets are represented by the U.S. S&P 500 index and aggregate commodity markets by the U.S. producer price index (PPI). Tradeable market indexes readily available to investors, namely the S&P GSCI Index and the Bloomberg Commodity Index (BCOM), are also studied. An optimal bandpass filter is used to estimate the cyclical component using a pricing-performance measure of the S&P 500 relative to the PPI, based on annual data from 1871 to 2022. The S&P GSCI and the BCOM indexes are also used to test the robustness of the findings. The impacts of the financial crisis of 2008 and the coronavirus pandemic are also assessed. The overriding conclusion of the study is that a cyclical relationship exists between stock markets and commodity markets for both aggregate and tradeable indexes which can last, from peak to peak, approximately 31 years. Measuring returns and risks in a manner consistent with these cycles can shed new light on the usefulness of commodity investing via tradeable indexes in seeking efficient portfolios. [ABSTRACT FROM AUTHOR]

Let K = K(a, p; λ1, λ2) be the multigraph with: the number of parts equal to p; the number of vertices in each part equal to a; the number of edges joining any two vertices of the same part equal to λ1; and the number of edges joining any two vertices of different parts equal to λ2. The existence of C4-factorizations of K has been settled when a is even; when a ≡ 1 (mod 4) with one exception; and for very few cases when a ≡ 3 (mod 4). The existence of Cz-factorizations of K has been settled when a ≡ 1 (mod z) and λ1 is even, and when a ≡ 0 (mod z). In this paper, we give a construction for Cz-factorizations of K for z = 2a when a is even. [ABSTRACT FROM AUTHOR]

In this paper, time-invariant spatially coupled low-density parity-check convolutional codes (SC-LDPC-CCs) are considered, and the connections existing between their low-weight codewords and cycles in their Tanner graphs are studied. Using the polynomial representation of these codes, we show that parity-check matrices having columns with weight ≥2 can be analyzed considering a certain number of parity-check sub-matrices having regular columns with weight 2. These sub-matrices are associated to cycles in the code Tanner graph and define as many codes we denote as component codes. Based on this observation, we find that codewords of the main code can be expressed as combinations of codewords of the component codes. The design of codes free of codewords up to a certain weight is also addressed. We show that low-weight codewords in the main code can be avoided by removing some types of cycles in its Tanner graph. Our design approach is applied to some well-known ensembles of SC-LDPC-CCs to prove its effectiveness. [ABSTRACT FROM AUTHOR]

Circuits in a graph are interesting structures and identifying them is of an important relevance for many applications. However, enumerating circuits is known to be a difficult problem, since their number can grow exponentially. In this paper, we propose fast parallel approaches for enumerating elementary circuits of directed graphs based on graphics processing unit (GPU). Our algorithms are based on a massive exploration of the graph in a breadth-first search strategy. Algorithm V-FEC explores the graph starting from different vertices simultaneously. To further reduce the search space, we present T-FEC, another algorithm that uses triplets as an initial set to start exploring. To the best of our knowledge, those are the first parallel GPU-based algorithms for finding all circuits of a given graph. In addition, they find circuits of a given length and circuits with a specific vertex or edge. The evaluation results show that the proposed approaches achieve up to 190x speed-up over Johnson's algorithm, one of the most efficient sequential algorithms for finding circuits. [ABSTRACT FROM AUTHOR]

Let R be a ring with unity. In this paper, we introduce a new graph associated with R called the simple-intersection graph of R, denoted by GS (R). The vertices of GS (R) are the nonzero ideals of R, and two vertices are adjacent if and only if their intersection is a nonzero simple ideal. We study the interplay between the algebraic properties of R, and the graph properties of GS (R) such as connectedness, bipartiteness, girth, dominating sets, etc. Moreover, we determine the precise values of the girth and diameter of GS (R), as well as give a formula to compute the clique and domination numbers of GS (R). [ABSTRACT FROM AUTHOR]

Designs and constructions of quasi-cyclic (QC) LDPC codes for the AWGN channel are presented. The codes are constructed based on the conventional parity-check matrices of Reed–Solomon (RS) codes and are referred to as RS-QC-LDPC codes. Several classes of RS-QC-LDPC codes are given. Cycle structural properties of the Tanner graphs of codes in these classes are analyzed and specific methods for constructing codes with girth at least eight and reducing their short cycles are presented. The designed codes perform well in both waterfall and low error-rate regions. [ABSTRACT FROM AUTHOR]

This is the second in a series of papers on conformal tilings. The overriding themes here are local isomorphisms, hierarchical structures, and the conformal "type" problem. Conformal tilings were introduced by the authors in 1997 with a conformally regular pentagonal tiling of the plane. This and even more intricate hierarchical patterns arise when tilings are repeatedly subdivided. Deploying a notion of expansion complexes, we build two-way infinite combinatorial hierarchies and then study the associated conformal tilings. For certain subdivision rules the combinatorial hierarchical properties are faithfully mirrored in their concrete conformal realizations. Examples illustrate the theory throughout the paper. In particular, we study parabolic conformal hierarchies that display periodicities realized by Mobius transformations, motivating higher level hierarchies that will emerge in the next paper of this series. [ABSTRACT FROM AUTHOR]

This paper introduces a novel solution for building fault aware memory built-in self-test infrastructure based on rules of fault periodicity and regularity in memories and test algorithms. These periodicity and regularity rules are described via special internal structures named fault periodicity table (FPT) and test algorithm template (TAT). Three dimensions of evolution are considered as inputs for forming the mentioned structures: memory cells, multidimensional memory circuits, and memory systems for systems-on-chip where memories are distributed in different subchips. Each column of FPT corresponds to a fault nature which can be associated with a variety of different test mechanisms while each row of FPT corresponds to a fault family determined by the complexity of fault sensitization. FPT allows considering any large number of faults in one table while TAT allows constructing test algorithms without using test algorithm generation tools. Experimental results of the solution applied to both Planar-based (90/65/45/28 nm) and FinFET-based (16/10/7 nm) memory technologies are adduced also in this paper. [ABSTRACT FROM AUTHOR]

Let G be a connected graph and g be a non-negative integer. A vertex set S of graph G is called a g-extra cut if G − S is disconnected and each component of G − S has at least g + 1 vertices. The g-extra connectivity of G is the minimum cardinality of a g-extra cut of G if G has at least one g-extra cut. For two graphs G 1 = (V 1 , E 1) and G 2 = (V 2 , E 2) , the strong product G 1 ⊠ G 2 is defined as follows: its vertex set is V 1 × V 2 and its edge set is { (x 1 , x 2) (y 1 , y 2) | x 1 = x 2 and y 1 y 2 ∈ E 2 ; or y 1 = y 2 and x 1 x 2 ∈ E 1 ; or x 1 x 2 ∈ E 1 and y 1 y 2 ∈ E 2 } , where (x 1 , x 2) , (y 1 , y 2) ∈ V 1 × V 2 . In this paper, we obtain the g-extra connectivity of the strong product of two paths, the strong product of a path and a cycle, and the strong product of two cycles. [ABSTRACT FROM AUTHOR]

In this paper we consider the Glauber dynamics for the one-dimensional Ising model with dissipation, in a mesoscopic regime obtained by letting inverse temperature and volume go to infinity with a suitable scaling. In this limit the magnetization has a periodic behavior. Self-organized collective periodicity has been shown for many mean-field models but, to our knowledge, this is the first example with short-range interaction. This supports the view that self-organized periodicity is not linked with the mean-field assumption but it is a thermodynamic phenomenon compatible with short range interactions. [ABSTRACT FROM AUTHOR]

This paper proposes two heuristic algorithms for finding fixed-length circuits and cycles in undirected edge-weighted graphs. It focusses particularly on a largely unresearched practical application where we are seeking attractive round trips for pedestrians and joggers in urban street networks. Our first method is based on identifying suitable pairs of paths that are combined to form a solution; our second is based on local search techniques. Both algorithms display high levels of accuracy, producing solutions within just a few meters of the target. Run times for the local search algorithm are also short, with solutions in large cities often being found in less than one second. [ABSTRACT FROM AUTHOR]

Purpose -- The purpose of this paper is to investigate two famous postulates of the Schumpeterian doctrine and its implications for the US economy. Design/methodology/approach -- Analytically, the authors investigate whether sector size matters for sectoral: technological change and stability, as expressed through the relevant quantitative measures and variables. To this end, the authors test a number of relevant models that express the various forms of this relationship. More precisely, the authors use panel data for the 14 main sectors of economic activity in the USA over the period 1957-2006, just before the first signs of the US and global recession made their appearance. Findings -- The results seem to be in line with the Schumpeterian postulate that market size matters for technological change and economic stability, for the US economy (1957-2006). Clearly, further research would be of great interest. Originality/value -- This work contributes to the literature in the following ways: first, it provides an extensive review of the literature on the subject and adopts two relevant methodological approaches. Second, based on these quantitative approaches, the paper offers a complete investigation of two famous postulates of the Schumpeterian theory for the US economy, and it is the first, to the best of the authors' knowledge, to do so by sector of economic activity, in a panel data framework. Third, the paper uses a wide data set (1957-2006) to examine the US economy up until the first signs of the US and global economic recession made their appearance. [ABSTRACT FROM AUTHOR]

In this paper, we have studied a practical design of a broadband linear-to-circular polarizer based on a self-complementary metasurface composed of zigzag-shaped metal strips printed on a dielectric substrate. The term self-complementary indicates that the structure is identical to its complement, except for some translation smaller than the periodicity. This property together with the nonresonant response of the unit cells ensures broadband conversion from linear polarization to circular polarization. Although we have experimentally achieved a relative 3-dB-axial-ratio (AR) bandwidth (BW) of 53%, in principle, it could reach up to 70.5%. Moreover, the studied metasurface has a very small periodicity, which avoids any higher order grating lobes and provides angular stability of the phenomenon. In fact, the relative 3-dB-AR BW obtained in experiments stays always above 40% for incidence angles within ±30°. An excellent agreement was achieved among theory, simulations, and experiments. [ABSTRACT FROM PUBLISHER]

This paper proposes a new modeling framework capturing both the long‐run and the cyclical components of a time series. As an illustration, we apply it to four US macro series, namely, annual and quarterly real gross domestic product (GDP) and GDP per capita. The results indicate that the behavior of US GDP can be captured accurately by a model incorporating both stochastic trends and stochastic cycles that allows for some degree of persistence in the data. Both appear to be mean reverting, although the stochastic trend is nonstationary, while the cyclical component is stationary, with cycles repeating themselves every 6–10 years. [ABSTRACT FROM AUTHOR]

The characteristic curve (CC) of a production system is a function describing the behavior of cycle time (CT) versus throughput (TP). In systems with unlimited buffers, this function typically has a knee-type shape. Operating the system below the knee is not efficient, since TP can be increased without an appreciable increase in CT. Operating above the knee is also counterproductive—CT becomes extremely large without a significant increase of TP. Thus, the desirable operating point is at the knee. In order to operate the system at or close to the knee, some knowledge of its CC is necessary. In this paper, an analytical/empirical method for calculating CCs of single-product re-entrant lines is developed using the so-called bottleneck workcenter model of systems at hand. Based on this method, open- and closed-loop raw material release policies, which ensure operating at the desired point of CC, are provided. The development is carried out in terms of the First Buffer First Served (FBFS) and Last Buffer First Served (LBFS) dispatch policies, although CCs for other dispatch policies can be investigated in a similar manner. In addition, it is shown by simulations that the method developed can be used for evaluating CC of a model of a scaled-down wafer fab, which includes multiple workcenters and batching, as long as the severity of the bottleneck workcenter is sufficiently high. [ABSTRACT FROM AUTHOR]

Discovering periodic patterns in a customer transaction database is the task of identifying itemsets (sets of items or values) that periodically appear in a sequence of transactions. Numerous methods can identify patterns exhibiting a periodic behavior. Nonetheless, a problem of these traditional approaches is that the concept of periodic behavior is defined very strictly. Indeed, a pattern is considered to be periodic if the amount of time or number of transactions between all pairs of its consecutive occurrences is less than a fixed maxPer (maximum periodicity) threshold. As a result, a pattern can be eliminated by a traditional algorithm for mining periodic patterns even if all of its periods but one respect the maxPer constraint. Consequently, many patterns that are almost always periodic are not presented to the user. But these patterns could be considered as interesting as they generally appear periodically. To address this issue, this paper suggests to use three measures to identify periodic patterns. These measures are named average, maximum and minimum periodicity, respectively. They are each designed to evaluate a different aspect of the periodic behavior of patterns. By using them together in a novel algorithm called Periodic Frequent Pattern Miner, more flexibility is given to users to select patterns meeting specific periodic requirements. The designed algorithm has been evaluated on several datasets. Results show that the proposed solution is scalable, efficient, and can identify a small sets of patterns compared to the Eclat algorithm for mining all frequent patterns in a database. [ABSTRACT FROM AUTHOR]

The adoption of the virtual synchronous generator (VSG) has attracted wide attention because of the equivalent operating mechanism as a synchronous generator, providing a feasible scheme for the distributed generation connected to utility grid. However, the delivered power and frequency of the VSG may easily oscillate when the dramatic power fluctuation occurred in the distribution generation system. Fortunately, the oscillation can be damped though adjusting the rotating inertia and damping coefficient. Thus, to investigate the influences of parameters perturbation on the active power and frequency for a VSG, the small-signal model is derived and the dynamic performances are analyzed in detail. Then, based on the results of parameters analysis, an adaptive control strategy is proposed in this paper. And an optimal damping ratio can be maintained throughout the whole process of operation to suppress the oscillation of power and frequency. Therefore, the dynamic performances of the VSG are enhanced since the dynamic indexes such as the response time and overshoots are optimized. In the end, a prototype of single-phase VSG has been built and the proposed adaptive control strategy has been verified through experimental results. [ABSTRACT FROM AUTHOR]

Alspach et al. (J. Austral. Math. Soc. 56(3) (1994) 391–402) constructed an infinite family of tetravalent graphs M(a; m, n) and proved that if n ≥ 9 be odd and a 3 ≡ 1 (mod n) , then M(a; 3, n) is half-arc-transitive. In this paper, we show that if a 3 ≡ 1 (mod n) , then M(a; 3, n) is an infinite family of tetravalent half-arc-transitive Cayley graphs for all integers n except 7 and 14. [ABSTRACT FROM AUTHOR]

In this paper, we present some sufficient conditions for the oscillation of all solutions of a second order forced impulsive delay differential equation with damping term. Three factors-impulse, delay and damping that affect the interval qualitative properties of solutions of equations are taken into account together. The results obtained in this paper extend and generalize some of the the known results for forced impulsive differential equations. An example is provided to illustrate the main result. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mechanical Engineering / Strojniški Vestnik is the property of University of Ljubljana, Faculty of Mechanical Engineering, Journal of Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Earlier research work on the dynamics of the brain, disclosing the existence of crucial events, is revisited for the purpose of making the action of crucial events, responsible for the 1/ f −noise in the brain, compatible with the wave-like nature of the brain processes. We review the relevant neurophysiological literature to make clear that crucial events are generated by criticality. We also show that although criticality generates a strong deviation from the regular wave-like behavior, under the form of Rapid Transition Processes, the brain dynamics also host crucial events in regions of nearly coherent oscillations, thereby making many crucial events virtually invisible. Furthermore, the anomalous scaling generated by the crucial events can be established with high accuracy by means of direct analysis of raw data, suggested by a theoretical perspective not requiring the crucial events to yield a visible physical effect. The latter follows from the fact that periodicity, waves and crucial events are the consequences of a spontaneous process of self-organization. We obtain three main results: (a) the important role of crucial events is confirmed and established with greater accuracy than previously; (b) we demonstrate the theoretical tools necessary to understand the joint action of crucial events and periodicity; (c) we argue that the results of this paper can be used to shed light on the nature of this important process of self-organization, thereby contributing to the understanding of cognition. [ABSTRACT FROM AUTHOR]

In this paper, we study the existence of an asymptotically periodic solution of a Volterra integral equation on the time scale ..., which we call a quantum Volterra integral equation. In the process, we study the existence of periodic solutions of an associated equation on the time scale ..., which is an extension of q... We employ Schauder's fixed point theorem in the analysis. [ABSTRACT FROM AUTHOR]

Electrocaloric is a novel emerging not-in-kind cooling technology based on solid-state materials exhibiting the electrocaloric effect, i.e., the property of changing their temperature because of an adiabatic change in the intensity of the electric field applied. This technology has only attracted the interests of the scientific community in the last two decades, even though it has the main feature of being based on eco-friendly materials that, because of their solid-state nature, do not provide a direct contribution in global warming. Even if some steps have already been taken, the research fields connected to electrocaloric cooling are still open: The identification of the most appropriated thermodynamic cycle, electrocaloric refrigerants, as well as the development of efficient cooling systems. To this purpose, this review paper provides a snapshot of the electrocaloric world and compares the progress made by the inherent scientific community in all the connected fields: the thermodynamic cycles, materials, experimental devices, numerical models, energy performances and prospective cooling applications. [ABSTRACT FROM AUTHOR]

The paper promotes the notion of computational experiment supported by a multi-tool digital environment as a means of the development of new mathematical knowledge in the context of education. The main study of the paper deals with the issues of teaching this knowledge to secondary teacher candidates within a graduate capstone mathematics education course. The interplay of mathematics and education is considered through the lens of using technology to enhance one's mathematical background by advancing ideas from mostly known to genuinely unknown. In this paper, the knowns consist of Fibonacci numbers, Pascal's triangle, and continued fractions; among the unknowns are Fibonacci-like polynomials and generalized golden ratios in the form of cycles of various lengths. The paper discusses the interplay of pragmatic and epistemic uses of digital tools by the learners of mathematics. The data for the study were collected over the years through solicited comments by teacher candidates enrolled in the capstone course. The main results indicate the candidates' appreciation of the need for deep mathematical knowledge as an instrument of the modern-day pedagogy aimed at making high schoolers interested in the subject matter. [ABSTRACT FROM AUTHOR]

The problem of finding bipartite (Tanner) graphs with given degree sequences that have large girth and few short cycles is of great interest in many applications including construction of good low-density parity-check (LDPC) codes. In this paper, we prove that for given integers $\alpha $ , $\beta $ , and $\gamma $ , and degree sequences $\pi $ and $\pi '$ , the problem of determining whether there exists a simple bipartite graph with degree sequences $(\pi, \pi ')$ that has at most $\alpha $ ($\beta $ and $\gamma $) cycles of length four (six and eight, respectively) is NP-complete. This is proved by a two-step polynomial-time reduction from the 3-Partition Problem. On the other hand, using connections to linear hypergraphs, we prove that given the degree sequence $\pi $ , a polynomial time algorithm can be devised to determine whether there exists a bipartite graph whose degree sequence on one side of the bipartition is $\pi $ and has a girth of at least six. In addition to these complexity results, we devise a quasi-polynomial time algorithm that can construct a bipartite graph with given (irregular) degree sequences and a girth that increases logarithmically with the size of the graph. Compared to the well-known progressive-edge-growth (PEG) algorithm, the proposed method, in some cases, results in Tanner graphs with larger girth, particularly for scenarios where the degree sequences of the graph are strictly enforced. [ABSTRACT FROM AUTHOR]

Background: This paper addresses the problem of finding attractors in biological regulatory networks. We focus here on non-deterministic synchronous and asynchronous multi-valued networks, modeled using automata networks (AN). AN is a general and well-suited formalism to study complex interactions between different components (genes, proteins,...). An attractor is a minimal trap domain, that is, a part of the state-transition graph that cannot be escaped. Such structures are terminal components of the dynamics and take the form of steady states (singleton) or complex compositions of cycles (non-singleton). Studying the effect of a disease or a mutation on an organism requires finding the attractors in the model to understand the long-term behaviors. Results: We present a computational logical method based on answer set programming (ASP) to identify all attractors. Performed without any network reduction, the method can be applied on any dynamical semantics. In this paper, we present the two most widespread non-deterministic semantics: the asynchronous and the synchronous updating modes. The logical approach goes through a complete enumeration of the states of the network in order to find the attractors without the necessity to construct the whole state-transition graph. We realize extensive computational experiments which show good performance and fit the expected theoretical results in the literature. Conclusion: The originality of our approach lies on the exhaustive enumeration of all possible (sets of ) states verifying the properties of an attractor thanks to the use of ASP. Our method is applied to non-deterministic semantics in two different schemes (asynchronous and synchronous). The merits of our methods are illustrated by applying them to biological examples of various sizes and comparing the results with some existing approaches. It turns out that our approach succeeds to exhaustively enumerate on a desktop computer, in a large model (100 components), all existing attractors up to a given size (20 states). This size is only limited by memory and computation time. [ABSTRACT FROM AUTHOR]

A circulant-permutation-based spatially-coupled (SC) code is constructed by partitioning the circulant permutation matrices (CPMs) in the parity-check matrix of a block code into several components and piecing copies of these components in a diagonal structure. By connecting several SC codes, multi-dimensional SC (MD-SC) codes are constructed. In this paper, we present a systematic framework for constructing MD-SC codes with notably better cycle properties than their one-dimensional counterparts. In our framework, the multi-dimensional coupling is performed via an informed relocation of problematic CPMs. This work is general in the terms of the number of constituent SC codes that are connected together, the number of neighboring SC codes that each constituent SC code is connected to, and the length of the cycles whose populations we aim to reduce. Finally, we present a decoding algorithm that utilizes the structures of the MD-SC code to achieve lower decoding latency. Compared to the conventional SC codes, our MD-SC codes have a notably lower population of small cycles, and a dramatic BER improvement. The results of this work can be particularly beneficial in data storage systems, e.g., 2D magnetic recording and 3D Flash systems, as high-performance MD-SC codes are robust against various channel impairments and non-uniformity. [ABSTRACT FROM AUTHOR]

Since the invention of lithium ion batteries, charging strategies have met great acknowledgment and research over the years. In this paper, a laptop with lithium polymer battery is monitored via three widely used tools, during various operational and charging loads. Several key values are obtained in order to evaluate the correlation between battery cycles, charging percentages and depth of discharge. Ultimately the results show that massive discharges and continuous operation with the device plugged should be avoided, though high load tasks require the AC charger to be connected. Ensuring that battery stays at safe temperature and charging ranges can expand cell life and state, as well as prevent lithium deposits inside the battery. [ABSTRACT FROM AUTHOR]

This paper studies the evolving distribution of prices in a vertical sector in the presence of market cycles. It investigates the dynamic linkages between farm and retail prices with an application to the Chinese pork sector. The econometric approach relies on a quantile autoregressive (QAR) model that provides a flexible representation of the dynamics of price volatility. It investigates the presence and nature of price cycles and their implications for price transmission. We document that the marketing margin is more sensitive to changes in consumer income than in feed cost. In addition, rising feed cost increases the amplitude of the cycle while higher consumer income increases the period of the cycle. [ABSTRACT FROM AUTHOR]

Research has found strong links between past credit booms and adverse outcomes for macroeconomic aggregates like output and investment. However, are price impacts also seen more widely in broad asset classes such as equity and fixed-income markets? We document such a robust and significant connection using a large sample of historical data for many advanced countries since 1870. Credit boom periods with a high "leverage factor" tend to be predictably followed by unusually low returns to risky equities, in absolute terms and relative to a safe fixed-income portfolio. Fixed income is a safe haven at these times and has slightly higher than normal returns. We show these properties hold in-sample and out-of-sample. Return predictability because of the leverage factor is distinct from that because of momentum (lagged return) and value (cashflow relative to price). Trading strategies built on the leverage factor accrue meaningful excess profits out-of-sample. This paper was accepted by Victoria Ivashina, finance. [ABSTRACT FROM AUTHOR]

This article summarizes the main findings on problems related to the measurement and identification of business cycles. The aim of this study is to define and identify the determinants of business cycles. This paper provides an overview of the methodology and its future course. Our investigation suggests that some methodological frameworks are available in the literature, but none is perfect. A new development in the field lies in spectral analysis methods for measuring business cycles, which may have advantages over existing methodologies (nonlinearity, stationarity issues). We feel that fractional integration is important in the proper monitoring and explanation of business cycles. Spectral analysis techniques have also proved to be useful for addressing the problems of stationarity and structural breaks in time series when analyzing business cycles. Another important issue that is excluded when studying business cycles is that the link between cycles and economic growth is presumed to be non-existent, implying money neutrality. [ABSTRACT FROM AUTHOR]

Purpose Credit market models and the microstructure theory of the ratings market suggest that information provided by credit rating agencies becomes more relevant in recessions when agency costs are high and less relevant in expansions when agency costs are low. The purpose of this paper is to empirically test these hypotheses with regard to equity markets.Design/methodology/approach The authors use business cycle identification algorithms to map rating events (credit rating changes and watchlist inclusions) to business cycle phases and apply the event study methodology. The results are backed by cross-sectional regressions using a variety of control variables.Findings The authors find that the relevance of information provided by credit rating agencies for equity prices heavily depends on the level of agency costs. Furthermore, the authors detect a “flight-to-quality” during recessions in the speculative grade segment and a weakened relevance of rating events in expansions in the investment grade segment.Originality/value This paper is the first to empirically analyse how equity investors perceive credit rating changes and watchlist inclusions over the business cycle. In the empirical analysis, the authors use a large sample of about 25,000 rating events in all Organisation for Economic Co-operation and Development markets. The presented results underline that credit ratings address the agency problem in financial markets and can thus be regarded as useful for risk management or regulation. [ABSTRACT FROM AUTHOR]

Due to the recent explosive growth of location-aware services based on mobile devices, predicting the next places of a user is of increasing importance to enable proactive information services. In this paper, we introduce a data-driven framework that aims to predict the user's next places using his/her past visiting patterns analyzed from mobile device logs. Specifically, the notion of the spatiotemporal-periodic (STP) pattern is proposed to capture the visits with spatiotemporal periodicity by focusing on a detail level of location for each individual. Subsequently, we present algorithms that extract the STP patterns from a user's past visiting behaviors and predict the next places based on the patterns. The experiment results obtained by using a real-world dataset show that the proposed methods are more effective in predicting the user's next places than the previous approaches considered in most cases. [ABSTRACT FROM AUTHOR]

Epilepsy is characterized by recurrent, unprovoked seizures. Accurate prediction of seizure occurrence has long been a clinical goal since this would allow to optimize patient treatment, prevent injuries due to seizures, and alleviate the patient burden of unpredictability. Advances in implantable electroencephalographic (EEG) devices, allowing for long-term interictal EEG recordings, have facilitated major progress in this field. Recently, it has been discovered that interictal brain activity demonstrates circadian and multi-dien cycles that are strongly aligned, or phase locked, with seizure risk. Thus, cyclical brain activity patterns have been used to forecast seizures. However, in the effort to develop a clinically useful EEG based seizure forecasting system, challenges remain. Firstly, multiple EEG features demonstrate cyclical patterns, but it remains unclear which feature is best suited for predicting seizures. Secondly, the technology for long-term EEG recording is currently limited in both spatial and temporal sampling resolution. In this study, we compare five established EEG metrics:synchrony, spatial correlation, temporal correlation, signal variance which have been motivated from critical dynamics theory, and interictal epileptiform discharge (IED) which are a traditional marker of seizure propensity. We assess their effectiveness in detecting 24-h and seizure cycles as well as their robustness under spatial and temporal subsampling. Analyzing intracranial EEG data from 23 patients, we report that all examined features exhibit 24-h cycles. Spatial correlation, signal variance, and synchrony showed the highest phase locking with seizures, while IED rates were the lowest. Notably, spatial and temporal correlation were also found to be highly correlated to each other, as were signal variance and IED--suggesting some features may reflect similar aspects of cortical dynamics, whereas others provide complementary information. All features proved robust under subsampling, indicating that the dynamic properties of interictal activity evolve slowly and are not confined to specific brain regions. Our results may aid future translational research by assisting in design and testing of EEG based seizure forecasting systems. [ABSTRACT FROM AUTHOR]

The aim of this paper is to investigate eventual periodicity of the following max-type system of difference equations of higher order with four variables ... [ABSTRACT FROM AUTHOR]

Abstract This paper deals with the classical problem of exploring a ring by a cohort of synchronous robots. We focus on the perpetual version of this problem in which it is required that each node of the ring is visited by a robot infinitely often. The challenge in this paper is twofold. First, we assume that the robots evolve in a highly dynamic ring, i.e., edges may appear and disappear unpredictably without any recurrence, periodicity, or stability assumption. The only assumption we made (known as the temporal connectivity assumption) is that each node is infinitely often reachable from any other node. Second, we aim at providing a self-stabilizing algorithm to the robots, i.e., the algorithm must guarantee an eventual correct behavior regardless of the initial state and positions of the robots. In this harsh environment, our contribution is to fully characterize, for each size of the ring, the necessary and sufficient number of robots to solve deterministically the problem. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the concept of the complete cycle index and discuss a relation with the complete weight enumerator in coding theory. This work was motivated by Cameron's lecture notes "Polynomial aspects of codes, matroids and permutation groups." [ABSTRACT FROM AUTHOR]

This paper initiates the study of shortening universal cycles (u-cycles) and universal words (u-words) for permutations either by using incomparable elements, or by using non-deterministic symbols. The latter approach is similar in nature to the recent relevant studies for the de Bruijn sequences. A particular result we obtain in this paper is that u-words for n -permutations exist of lengths n ! + (1 − k) (n − 1) for k = 0 , 1 , ... , (n − 2) !. [ABSTRACT FROM AUTHOR]

This paper focuses on transactions of edible goods among the Menkü, an indigenous group of the southern Brazilian Amazon. The distribution cycles of killed game are described as a process of sharing by which the relationships of the giver to those around him are created and redefined. In this case sharing is characterized by the co-presence of donor and recipient. Furthermore sharing is conceived as a process which defines and confirms relations of affinity and alterity. It is argued that for the Menkü sharing is a multilateral process that depends on the complementarity of the sexes and the respective life phases of those involved. Transactions are revealed as an ambivalent process, which on the one hand contributes to the creation of good group morality, while on the other hand implying obligations towards the human and non-human worlds. Based on the notion of the high value of social cohesion, the article focuses on how transactions involving consumable goods are incorporated in an egalitarian community. Unlike monetary transactions non-monetary transactions involving edible goods are revealed as allowing multiple interactions to take place with the encompassing environment of the people, ancestors and spirits of the savannah and the forest. It is argued that the distribution and consumption of the components of a 'complete meal' are considered to express successful interactions between different social spheres as a prerequisite for permanent well-being among the Menkü. [ABSTRACT FROM AUTHOR]

Difficulties arise in attempting to discern the effects of nonlinearity in near-field jet-noise measurements due to the complicated source structure of high-velocity jets. This article describes a measure that may be used to help quantify the effects of nonlinearity on waveform propagation. This measure, called the average steepening factor (ASF), is the ratio of the average positive slope in a time waveform to the average negative slope. The ASF is the inverse of the wave steepening factor defined originally by Gallagher [AIAA Paper No. 82-0416 (1982)]. An analytical description of the ASF evolution is given for benchmark cases--initially sinusoidal plane waves propagating through lossless and thermoviscous media. The effects of finite sampling rates and measurement noise on ASF estimation from measured waveforms are discussed. The evolution of initially broadband Gaussian noise and signals propagating in media with realistic absorption are described using numerical and experimental methods. The ASF is found to be relatively sensitive to measurement noise but is a relatively robust measure for limited sampling rates. The ASF is found to increase more slowly for initially Gaussian noise signals than for initially sinusoidal signals of the same level, indicating the average distortion within noise waveforms occur more slowly. [ABSTRACT FROM AUTHOR]

A set S of vertices in a graph G is a dominating set of G if every vertex not in S is adjacent to some vertex in S. The domination number, (G), of G is the minimum cardinality of a dominating set of G. The authors proved in [A new lower bound on the domination number of a graph, J. Comb. Optim. 38 (2019) 721-738] that if G is a connected graph of order n = 2 with k = 0 cycles and l leaves, then (G) = (n - l + 2 - 2k)/3. As a consequence of the above bound, (G) = (n - l + 2(1 - k) + m)/3 for some integer m = 0. In this paper, we characterize the class of cactus graphs achieving equality here, thereby providing a classification of all cactus graphs according to their domination number. [ABSTRACT FROM AUTHOR]

In 2013, Duchene, Kheddouci, Nowakowski and Tahraoui introduced a labeled version of the graph packing problem. It led to the introduction of a new graph parameter, the k-packing label-span k. This parameter corresponds, given a graph H on n vertices, to the maximum number of labels we can assign to the vertices of the graph, such that there exists a packing of k copies of H into the complete graph Kn, coherent with the labels of the vertices. The authors intensively studied the labeled packing of cycles, and, among other results, they conjectured that for every cycle Cn of order n = 2k + x, with k = 2 and 1 = x = 2k 1, the value of k(Cn) was 2 if x is 1 and k is even, and x + 2 otherwise. In this paper, we disprove this conjecture by giving a counterexample. We however prove that it gives a valid lower bound, and we give sufficient conditions for the upper bound to hold. We then give some similar results for the labeled packing of circuits. [ABSTRACT FROM AUTHOR]

This paper is devoted to the role of information context in the dynamics of consumption/savings decisions. The deviations from the traditional model of rational expectations are investigated, and the hypotheses of the «rational inattention» are tested. The basis for the study was a selection of news from the major Russian TV channels for 2006-2016. This news available to ordinary households in Russia was analyzed. News was defined as negative or positive with special program tools of sentiment analysis. It was found that increased uncertainty (the spread of positive and negative news) leads to the choice of consumption to the detriment of savings, which then reduces the investment base of the economy. The authors analyze the connection of the tonality of news and its changes with the real business cycle. The authors found that the information cycle with some lag correlated with the cycle in consumption/savings decisions in the Russian Federation. The authors conclude that the concept of rational inattention is more acceptable for this case. Based on the study, recommendations are offered for adjusting public policy. [ABSTRACT FROM AUTHOR]

Birnbaum (2020) reanalyses the data from Butler and Pogrebna (2018) using his ‘true and error’ test of choice patterns. His results generally support the evidence we presented in that paper. Here we reiterate the reasons for our agnosticism as to the direction any cycles might take, even though the paradox that motivated our study takes a ‘probable winner’ direction. We conclude by returning to the potential significance of predictably intransitive preferences for decision theory generally. [ABSTRACT FROM AUTHOR]