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We present a mathematical model for the slow combustion (smoldering) of a two-dimensional sheet of paper. We describe the evolution of the char region, and we investigate the effects of an orthogonal air flow on the shape of the combustion front. The mathematical formulation consists in a set of two nonlinear PDEs for the temperature and the oxygen concentrations coupled with one ODE for the cellulose concentration. The (dimensionless) problem is solved numerically by means of a spectral collocation scheme based on Chebyshev polynomials. Our results show that the Péclet and the Lewis number strongly influence the shape of the ignition front and that the advancement of the combustion front does not occur if advection and diffusion are neglected (zero Péclet and Lewis numbers). In particular we observe that the burning region and the ignition front are strongly influenced by the velocity of the airflow and by the mass and heat transport phenomena due to diffusion and advection. We shall see that the increasing of the ratio between the convective and diffusive characteristic times (Péclet number) and the decreasing of the ratio between the mass and heat diffusive characteristic times (Lewis number) have a "flattening effect" on the combustion front. [ABSTRACT FROM AUTHOR]

In this article, we present a mathematical model and numerical simulation of the coffee-ring effect on porous papers. The numerical method is based on Monte Carlo simulation. The proposed model is simple but can capture the main mechanism of coffee stain formation on porous papers. Several numerical experiments are presented to demonstrate the performance of the proposed algorithm. We can obtain the coffee-ring effect on porous papers as the computer simulation results. [ABSTRACT FROM AUTHOR]

The quest for cost-effective and thermal efficient structural materials onto beating the high cost of construction is gaining more attention among researchers. This study focused on the blending of cement and sand with waste paper pulp into cost-effective structural materials. The composites were prepared in four mix groups with each containing a fixed amount of sand at 5, 10, 15, and 20 wt.% (by weight of pulp). Cement was varied at 10, 20, 30, and 40 wt.% in each group, and curing was done for 28 days. Properties evaluated are compressive, bending, and splitting strengths. It was observed that increasing cement and sand contents enhanced strengths; howbeit, the blend of 30 wt.% cement/15 wt.% sand resulted in a reduction in bending strength even as 30 wt.% cement/20 wt.% sand engendered a decrease in bending and splitting strength. The microstructural features showed that inherent fibers of the pulp were well bonded with hydration products and sand content yielding good performance in the composites. The optimization procedure carried out depicted a combination of 35.27% cement and 20% sand as the optimum composition. Experimental outcomes were modelled for the purpose of prediction of responses. The models were confirmed statistically fit showing how varying cement content affected strength responses at fixed sand proportion. ANOVA affirmed the significant contribution of cement and sand on the strength responses. Compliance reliability was observed to be dependent on the interactive pattern between cement and sand. Going by the standard prescription for the strength properties, cement and sand content of 35.27 and sand 20 wt.% satisfied all strength requirements for low-cost construction having a compliance reliability of 1.31. [ABSTRACT FROM AUTHOR]

This paper reports the temperature-dependence of methanol generation and the tensile index under ageing conditions for two paper/oil systems: one consisting of a standard wood Kraft paper and the other of a thermally-upgraded Kraft paper (TUK). A linear correlation between methanol and the tensile index for these paper/oil systems was observed in a previous study at 170 °C. In the current study, the correlation was extended to a large range of temperatures (150-190 °C). The experimental data were fitted with a modified Calvini's kinetic model, while the Arrhenius equation was used to model the kinetic of changes of the paper's mechanical properties during ageing. Good agreement with the temperature ( lnk vs. 1/ T) was observed for the rate constants of the chain-end group production, methanol formation, and the decrease of mechanical properties. The Arrhenius equation applied to this data grouping showed activation energy of 130 ± 29 kJ/mol for the decrease in mechanical strength of the standard Kraft paper, while the value was 118 ± 55 kJ/mol for the TUK paper. These values are of the same order of magnitude as those obtained in this study and in the literature for the depolymerization of cellulose and the generation of methanol that was reported. This confirmed the close relationship between cellulose depolymerization, methanol generation and the reduction of the paper's mechanical strength during ageing, dominated by the acid hydrolysis mechanism. The results, which can be seen as a benchmark and pave the way to further research, provide an opportunity for applying the proposed correlations to estimate the insulation condition in operating transformers. [ABSTRACT FROM AUTHOR]

Industrial progress in papermaking in the early nineteenth century led to the technologies that resulted in more acidic papers, which was caused mainly by the exploitation of alum (KAl(SO4)2) and rosin as sizing agents. The papers prepared by such technologies have degraded more quickly. From the 1930s various deacidification and preservation processes with basic agents have been developed. The most widespread deacidification process is with the aerosol (spray system) consisting of microscale particles MgO and perfluoroheptane (PFH) as a carrier (the so-called Bookkeeper process). The shortcomings of this process are the low dissolution of solid MgO particles and the transport to the interior of acidic paper. We have developed a theoretical two-level model of the Bookkeeper process suitable for prediction of deacidification extent. The model involves both the dissolution/reaction of the solid particles and transport of solvated ions and solid particles inside the bulk of paper. The developed model coincides with the results of the performed deacidification experiment. The model is also in good agreement with the Lucas–Washburn equation, which is usually used for the description of the penetration of a deacidifying agent into the paper. [ABSTRACT FROM AUTHOR]

To model advanced 3-D forming strategies for paper materials, the effects of environmental conditions on the mechanical behavior must be quantitatively and qualitatively understood. A tensile test method has been created, verified, and implemented to test paper at various moisture content and temperature levels. Testing results for one type of paper for moisture contents from 6.9 to 13.8 percent and temperatures from 23 to 168 degrees Celsius are presented and discussed. Coupled moisture and temperature effects have been discovered for maximum stress. Uncoupled effects have been discovered for elastic modulus, tangent modulus, hardening modulus, strain at break, tensile energy absorption (TEA), and approximate plastic strain. A hyperbolic tangent function is also utilized which captures the entire one-dimensional stress-strain response of paper. The effects of moisture and temperature on the three coefficients in the hyperbolic tangent function may be assumed to be uncoupled, which may simplify the development of moisture- and temperature-dependent constitutive models. All parameters were affected by both moisture and temperature with the exception of TEA, which was found to only be significantly dependent on temperature. [ABSTRACT FROM AUTHOR]

Abstract  In this paper it is shown that the well known special orthotropy of paper, explained by micromechanical models of complex bodies, actually corresponds to a special case of orthotropy of a plane elastic body. The existence of this special orthotropy was predicted by the author in a previous work. [ABSTRACT FROM AUTHOR]

We prove that the pleated hyperbolic paraboloid, a familiar origami model known since 1927, in fact cannot be folded with the standard crease pattern in the standard mathematical model of zero-thickness paper. In contrast, we show that the model can be folded with additional creases, suggesting that real paper 'folds' into this model via small such creases. We conjecture that the circular version of this model, consisting simply of concentric circular creases, also folds without extra creases. At the heart of our results is a new structural theorem characterizing uncreased intrinsically flat surfaces-the portions of paper between the creases. Differential geometry has much to say about the local behavior of such surfaces when they are sufficiently smooth, e.g., that they are torsal ruled. But this classic result is simply false in the context of the whole surface. Our structural characterization tells the whole story, and even applies to surfaces with discontinuities in the second derivative. We use our theorem to prove fundamental properties about how paper folds, for example, that straight creases on the piece of paper must remain piecewise-straight (polygonal) by folding. [ABSTRACT FROM AUTHOR]

The Buck converter is a commonly used voltage regulator (VR) structure that supplies power to the load devices and responds to load transients. In most of the applications, the VR is controlled by voltage or current mode control, and some nonlinear approaches are used to improve the transient response which brings more complexities to the closed loop design. To achieve a fast transient response without over-regulation under a load step transient, this paper proposes a digital single-cycle regulation (SCCR) controller, which comprised a fast path, a slow path, and a neutralization path. Unlike the conventional PID control, the neutralization path of the SCCR controller is used to offset the excessive energy change in the first cycle after a load step occurs, which makes the inductor current reach its new static condition in a shorter period of time. The mathematical model of the SCCR control is established in this paper and a scanning algorithm is proposed for the design of the compensator parameters. Experimental results are presented to verify the improvement of the transient response when compared to the conventional and nonlinear PID control, the recovery time is decreased by 64.3% and 43% for load step-up and step-down when compared with nonlinear PID control. [ABSTRACT FROM AUTHOR]

In automata networks, it is well known that the way entities update their states over time has a major impact on their dynamics. In particular, depending on the chosen update schedule, the underlying dynamical systems may exhibit more or less asymptotic dynamical behaviours such as fixed points or limit cycles. Since such mathematical models have been used in the framework of biological networks modelling, the question of choosing appropriate update schedules has arised soon. In this note, focusing on Boolean networks, our aim is to emphasise that the adequate way of thinking regulations and genetic expression over time is certainly not to consider a wall segregating synchronicity from asynchronicity because they actually complement rather well. In particular, we highlight that specific update schedules, namely block-parallel update schedules, whose intrinsic features are still not known from a theoretical point of view, admit realistic and pertinent properties in the context of biological modelling and deserve certainly more attention from the community. [ABSTRACT FROM AUTHOR]

The methodology used for analyzing the survival process should keep in mind heterogeneity in empirical data. Cross-sectional data are more heterogeneous in comparison with birth-cohort data. [ABSTRACT FROM AUTHOR]

A series of shredded paper fire experiments were conducted by means of a calorimeter. The mass loss rate and heat release rate were measured. The flame spread process was recorded, which shows that the flame spread process can be divided into four typical stages, and the mean spread rates along different directions were obtained from the observed combustion process. Based on the mean flame spread rate, a mathematical model for predicting the burning surface as a function of time during the four stages is established. Combining this model with the effective heat of combustion calculated from measured mass loss rate and heat release rate, an improved model to predict the heat release rate as a function of time was developed. In this model, the linear relationship between heat release rate and burning surface is found, and the predicted result agrees well with the measured heat release rate. [ABSTRACT FROM AUTHOR]

The Scott bond test method has been used extensively in the paper industry over the years as a means to assess the bond strength of paper. The method has been a subject of some controversy lately since it does not always correlate to the sensitivity of the material to fracture by delamination. To gain some further insight into which parameters govern the fracture process in a Scott bond test a simplified approach has been chosen in order to formulate an analytical mathematical/mechanical model of the test. The model is dynamic in the sense that inertia effects are included. The material model utilised is a simple cohesive theory that assumes a linear behaviour between stress and crack opening when the material has started to degrade. This choice of material model makes the mathematical model very nonlinear. In fact, a system of three coupled nonlinear second order partial differential equations have to be solved and adjusted to the correct initial conditions. The material parameters needed for the model are the elastic modulus in the thickness direction, the transverse shear (elastic) modulus, the tensile strength (in the thickness direction) and the fracture work (per unit area) for a delamination crack. To investigate the ability of the model, a Scott bond testing apparatus have been equipped with a piezoelectric load sensor. The load cell was mounted on the apparatus’ pendulum so that the load acting on the sample holder could be recorded during the whole impact stage. This was done for a number of different initial velocities of the pendulum and it is found that the model gives a fair prediction of the contact load. [ABSTRACT FROM AUTHOR]

We summarize the papers published by Einstein in the Annalen der Physik in the years 1902-1904 on the derivation of the properties of thermal equilibrium on the basis of the mechanical equations of motion and of the calculus of probabilities. We point out the line of thought that led Einstein to an especially economical foundation of the discipline, and to focus on fluctuations of the energy as a possible tool for establishing the validity of this foundation. We also sketch a comparison of Einstein's approach with that of Gibbs, suggesting that although they obtained similar results, they had different motivations and interpreted them in very different ways. [ABSTRACT FROM AUTHOR]

We revisit two old and apparently little known papers by Basuev (Teoret Mat Fiz 37(1):130-134, , Teoret Mat Fiz 39(1):94-105, ) and show that the results contained there yield strong improvements on current lower bounds of the convergence radius of the Mayer series for continuous particle systems interacting via a very large class of stable and tempered potentials, which includes the Lennard-Jones type potentials. In particular we analyze the case of the classical Lennard-Jones gas under the light of the Basuev scheme and, using also some new results (Yuhjtman in J Stat Phys 160(6): 1684-1695, ) on this model recently obtained by one of us, we provide a new lower bound for the Mayer series convergence radius of the classical Lennard-Jones gas, which improves by a factor of the order 10 on the current best lower bound recently obtained in de Lima and Procacci (J Stat Phys 157(3):422-435, ). [ABSTRACT FROM AUTHOR]

One century after the seminal work by Leonor Michaelis and Maud Menten devoted to the theoretical study of the enzymatic reactions, in this paper, we give an overview of the most recent trends concerning the mathematical modeling of several enzymatic mechanisms, focusing on its asymptotic analysis, which needs the use of advanced mathematical tools, such as center manifold theory, normal forms, and bifurcation theory. Moreover, we present some perspectives, linking the models here presented with similar models, arising from different research fields. [ABSTRACT FROM AUTHOR]

The authors comment on the article "Closed-form analytical solutions for assessing the consequences of sea-level rise on groundwater resources in sloping coastal aquifers" published in a previous issue of the journal. They state concerns over the impact of sea-level rise on seawater intrusion, and mention limitations to the article associated with the choice of mathematical model and inland boundary condition. They mention the possibility of employing the Strack single potential approach.

The social identity of a researcher can affect their position in a community, as well as the uptake of their ideas. In many fields, members of underrepresented or minority groups are less likely to be cited, leading to citation gaps. Though this empirical phenomenon has been well-studied, empirical work generally does not provide insight into the causes of citation gaps. I will argue, using mathematical models, that citation gaps are likely due in part to the structure of academic communities. The existence of these 'structural causes' has implications for attempts to lessen citation gaps, and for proposals to make academic communities more efficient (e.g. by eliminating pre-publication peer review). These proposals have the potential to create feedback loops, amplifying current structural inequities. [ABSTRACT FROM AUTHOR]

With this note, we want to open a discussion on the duality theory for Interval Optimization. We begin by showing that some duality results Wu ( J Optim Theory Appl 144:615-628, ) are useless. [ABSTRACT FROM AUTHOR]

The assessment of scientific articles regarding their relevance to a research portfolio is becoming increasingly important. The reason is that scientific works have been growing quantitative and qualitatively. Taking this scenario into account, Methodi Ordinatio was proposed, and its major contribution was the 7th phase of the methodology, the InOrdinatio. It is an equation based on the main criteria for selecting a paper related to a theme: year of publication, number of citation and the impact factor (or journal metrics). However, finding the value of these three factors might not be an easy and quick task. Therefore, in order to improve the use of Methodi Ordinatio, two other tools were developed: FInder and RankIn. Thus, the first purpose of this paper is to present these two new tools. Additionally, considering that the impact factor has been a matter of disputes in the academia, the paper also proposes the use of one single indicator for the impact factor in the equation. To achieve this second purpose, a robust mathematical model was elaborated taking into consideration the other journal metrics in order to estimate the alternative impact factor to be used in InOrdinatio in case one or more papers are not indexed to any metrics. After testing with 48 statistical models and tools, the results show that this indicator is robust and trustworthy to be used. Finally, as the third as last purpose, this paper also proposes an alternative version to calculate the InOrdinatio, which can be flexible regarding the weight of its three criteria used in the equation. [ABSTRACT FROM AUTHOR]

This article is a translation of Michael Sadowsky's original paper 'Ein elementarer Beweis für die Existenz eines abwickelbaren Möbiusschen Bandes und die Zurückführung des geometrischen Problems auf ein Variationsproblem.' which appeared in Sitzungsberichte der Preussischen Akademie der Wissenschaften, physikalisch-mathematische Klasse, 17. Juli 1930.-Mitteilung vom 26. Juni, 412-415. Published on September 12, 1930. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is an important industrial chemical used as a plasticizer in polycarbonate and epoxy resins in the plastic and paper industries. Because of its estrogenic properties, BPA has attracted increasing attention from many researchers. This review focuses primarily on analytical methods for BPA detection that have emerged in recent years. We present and discuss the advantages and disadvantages of sample preparation techniques (e.g., solvent extraction, solid-phase extraction, molecularly imprinted polymer solid-phase extraction, and micro-extraction techniques) and analytical methods (e.g., liquid chromatography, liquid chromatography−mass spectrometry, gas chromatography−mass spectrometry, capillary electrophoresis, immunoassay, and several novel sensors). We also discuss expected future developments for the detection of BPA. [ABSTRACT FROM AUTHOR]

The paper is a response to Antonelli and Quatraro's paper named 'The effects of biased technological change on total factor productivity: empirical evidence from a sample of OECD'. We point out that 'so-called novel method' which is used to identify and disentangle the effects of the direction of technological change on total factor productivity (TFP) in the article is wrongly implemented. Antonelli and Quatraro introduce Solow's methodology as part of his basic model to represent the effect of neutral technical change, ignoring the intrinsic consequence of Solow's calculating which called technical progress productivity is far from neutral. Hence, his methodology has little significance, neither the empirical analysis. Lastly, we give a new method measuring whether the technology is appropriate to the factor endowments' changing. That's the effect of biased technology on TFP. [ABSTRACT FROM AUTHOR]

In this paper, we explore the consequences of a distinction between ‘live' and ‘dead' network nodes; ‘live' nodes are able to acquire new links whereas ‘dead' nodes are static. We develop an analytically soluble growing network model incorporating this distinction and show that it can provide a quantitative description of the empirical network composed of citations and references (in- and out-links) between papers (nodes) in the SPIRES database of scientific papers in high energy physics. We also demonstrate that the death mechanism alone can result in power law degree distributions for the resulting network. [ABSTRACT FROM AUTHOR]

In the paper, "An exact algorithm for the edge coloring by total labeling problem", Borghini, Méndez-Díaz, and Zabala address the edge coloring problem, a classical problem in graph theory. The problem is modeled as a mixed integer nonlinear programming problem considering maximum number of orders, capacity, and budget constraints. In the paper, "A two-level evolutionary algorithm for solving the petrol station replenishment problem with periodicity constraints and service choice", Al-Hinai and Triki address the petrol station replenishment problem with periodicity constraints and introduce the frequency service choice as a decision variable. Arpón, Homem-de-Mello, and Pagnoncelli in their paper, "An ADMM algorithm for two-stage stochastic programming problems", show that the Alternate Direction Method of Multipliers (ADMM) can be applied to solve two-stage stochastic programming problems, and propose an implementation in three blocks, with or without proximal terms, that can be used as an algorithm to solve convex problems with a block structure. [Extracted from the article]

A response by G. Anagnostou and L. Canteini to a discussion on their article "On a Paradox of Elasto-Plastic Tunnel Analysis," is presented. The article focused on the counter-intuitive feature of behaviors exhibited under certain conditions. The authors explain the nature of simplifying assumption of zero gravity and use a simplified model to show that the elasto-plastic tunnel paradox persists in the presence of body forces.

A multiple quantum well (MQW) transistor vertical-cavity surface-emitting laser (T-VCSEL) is designed and numerically modeled. The important physical models and parameters are discussed and validated by modeling a conventional VCSEL and comparing the results with the experiment. The quantum capture/escape process is simulated using the quantum-trap model and shows a significant effect on the electrical output of the T-VCSEL. The parameters extracted from the numerical simulation are imported into the analytic modeling to predict the frequency response and simulate the large-signal modulation up to 40 Gbps. [ABSTRACT FROM AUTHOR]

The developers' physical dispersion in Distributed Software Development (DSD) imposes challenges related to awareness support during collaboration in such scenario. In this paper, we present a systematic literature review and mapping that gathered, analyzed, and classified studies that improve awareness support in DSD, providing an overview of the area. Our initial search returned 1967 papers, of which 91 were identified as reporting some awareness support to DSD. These papers were then analyzed, and classified according to the 3 C collaboration model and to the Gutwin et al. Awareness Framework. Our findings suggest that awareness in DSD is gaining increasingly attention, 71 out of 91 papers were published from 2006 to 2010. Most part of the papers presented tools with some awareness support. The classification showed that the coordination is by far the most supported dimension of the 3C model, while communication is the less explored. It also showed that workspace awareness elements play a central role on DSD collaboration. [ABSTRACT FROM AUTHOR]

A generalized kinetic model resulting from several modifications of the one originally known as the Series Event Model has been applied to describe three different disinfection processes and compare their efficiencies. The work was performed in a well-defined, versatile batch reactor employing Escherichia colias a subrogate bacteria. The following systems were studied: (i) UVC radiation alone, (ii) hydrogen peroxide alone and (iii) UVC radiation combined with hydrogen peroxide. The kinetic parameters of the three models were determined. Within the range of studied operating conditions, the use of UVC alone has shown to produce the best results. [ABSTRACT FROM AUTHOR]

The experimental results obtained for the photocatalytic degradation of a model organic dye in an annular slurry reactor are analyzed with the aid of a mathematical model. The model is used also to study the effects on the performances of many operative conditions: flow rate, photocatalyst concentration, power of the lamp, size of the photocatalytic particles, dimensions of the reactor. The investigation demonstrates that the rate of the process is often limited by the radiant energy transfer and that some simple rules can be followed in order to optimize different yields and the observed rate of reaction. [ABSTRACT FROM AUTHOR]

Wood chipping is a critical component part of many pulp and paper making processes. In order to study the damage mechanisms, when wood chips are created through the wood chipping process, it is crucial to have access to an experimental equipment in which chips can be produced under realistic conditions. In this paper, a laboratory chipper is presented, which has been developed to admit chipping at rates that can be varied in a large interval, i.e. at rates ranging from 0 to 50 m/s. The chipper also makes it possible to study e.g. the influence of different cutting angles on the chip geometry. The knife used to cut the chips is mounted on a knife holder, which is instrumented in such a way that forces in three orthogonal directions can be measured. One reason for measuring the forces acting on the knife during chipping is that the average force in the cutting direction will give information about the wear of the knife over time. Since the actual force and the measured force differ due to inertia effects, a simple mathematical model is developed and used to evaluate the force acting on the knife. The results from the force measurements are presented and it is concluded that the laboratory chipper is a versatile tool in the process of increasing the understanding of the chipping process. [ABSTRACT FROM AUTHOR]

This paper seeks to examine the relationship between competitivenessand environment-friendly behaviour of producers under an economic liberalisation regime. For that purpose, it employs a probit model and estimates the influence of the prime movers of industrial growth suchas technical change and economies of scale on environmental degradation. The empirical results of the study of pulp and paper industry, identified as one of the most polluting industries in India, indicate that these variables, as the key players of competitiveness improvement, have positive influence on environment-friendly behaviour. Such findings, therefore, fail to provide support to a view that articulates ruthless exploitation of the environment under economic liberalisation programme. [ABSTRACT FROM AUTHOR]

In a recent paper, published in Astrophys. Space Sci. (337:107, ) (hereafter paper ZZX) and entitled 'On the triangular libration points in photogravitational restricted three-body problem with variable mass', the authors study the location and stability of the generalized Lagrange libration points L and L. However their study is flawed in two aspects. First they fail to write correctly the equations of motion of the variable mass problem. Second they attribute a variable mass to the third body of the restricted three-body model, a fact that is not compatible with the assumptions used in deriving the mathematical formulation of this model. [ABSTRACT FROM AUTHOR]

It is widely believed that one of the virtues of peer review is that it provides a self-regulating selection mechanism for scientific work, papers and projects. Peer review as a selection mechanism is hard to evaluate in terms of its efficiency. Serious efforts to understand its strengths and weaknesses have not yet lead to conclusive answers. In theory peer review works if the involved parties (editors and referees) conform to a set of requirements, such as love for high quality science, objectiveness, and absence of biases, nepotism, friend and clique networks, selfishness, etc. If these requirements are violated, what is the effect on the selection of high quality work? We study this question with a simple agent based model. In particular we are interested in the effects of rationalreferees, who might not have any incentive to see high quality work other than their own published or promoted. We find that a small fraction of incorrect (selfish or rational) referees is sufficient to drastically lower the quality of the published (accepted) scientific standard. We determine the fraction for which peer review will no longer perform better than pure chance. Decline of quality of accepted scientific work is shown as a function of the fraction of rational and unqualified referees. We show how a simple quality-increasing policy of e.g. a journal can lead to additional loss in overall scientific quality, and how mutual support-networks of authors and referees deteriorate the system. [ABSTRACT FROM AUTHOR]

The article discusses various reports published within the issue, including one by Zhouxuan Teng and Wenliang Du on the problem if building privacy preserving decision trees and another by Kazuko Takahashi, Hiroya Takamura and Manabu Okumura on direct approach fro estimating class membership probability in multiclass classification.

The article presents comments of the author on various semiconductor session papers by Kenneth Flamm, Marie-Therese Flaherty and Edward Steinmueller. The Flamm and Flaherty papers have brought new rigor to an area characterized by bald assertion, flimsy evidence and technobabble. Despite their simple models and limited data, the author thinks both papers have not overstated their claims, but have clearly placed the debate on more solid footing. He especially like how the papers move the debate away from the victimization mode and into trying to present rational scenarios. Most importantly, he believes that the effect Steinmueller is seeking to forecast as a result of cluster tools is currently occurring with gate arrays.

In recent years, path dependence has gained increasing scientific attention in many disciplines, leading to various new concepts and notations, such as path creation or path plasticity. However, if mathematical arguments are used, they are based on the early works by Brian W. Arthur and Paul A. David, usually referring to the mathematical concept of ergodicity. We extend their mathematical framework and develop a graphical representation of systems that allows for a metaphorical discussion of system behaviors beyond the original cases, especially in evolving systems, and the inclusion of the recently developed concepts within path dependence. Visualizations are used to explain the definition and characteristics of seven types of path dependence: lock-in, path-breaking, path-furrowing, path plasticity, path formation, path creation, and path selection. Although these visualizations are explained verbally and can be understood without a mathematical expertise, a mathematical model is used to generate them. The deduction of the metaphorical concept from a mathematical model guarantees the completeness of the identified processes and the rigor in their categorization as well as the identification of respective characteristics for their distinction. However, the aim of the paper is to provide an illustrative concept that allows researchers to classify and structure the various path-dependent processes they observe in their application. While five of the identified processes are in line with concepts from the literature and are defined accordingly, we also detect a sixth process that is new to the literature so far: path-furrowing. Moreover, slightly deviating from the literature, we define path selection as the possibility to choose a path intentionally, thereby focusing on the mindful choice of options. [ABSTRACT FROM AUTHOR]

The electronic, magnetic, mechanical, and other properties of crystalline substances are determined by their structure, i.e., by the periodicity and symmetry of the lattice; therefore, the determination of the structure is an important stage in the study of the characteristics of such materials. This paper considers a number of metals having a crystal lattice of the hexagonal closely packed (HCP) structural type: beryllium, cerium, cobalt, dysprosium, erbium, gadolinium, hafnium, holmium, lanthanum, lutetium, magnesium, neodymium, osmium, praseodymium, rhenium, ruthenium, scandium, terbium, titanium, thallium, thulium, yttrium, and zirconium. The application of the annealing simulation algorithm to find the metric parameters of the materials under consideration is shown using the close packing model, which is widely used in crystallographic calculations. The in-house software implementation of the simulated annealing algorithm presented in this paper allows us to determine the coordinates of the atoms included in the unit cell of the crystal lattice, as well as calculate the lattice constants and the packing density of atoms in the crystal cell of the HCP structural type using the given chemical formula and spatial symmetry group. These structural characteristics can be used as the input parameters in modeling the electronic, magnetic, and other properties of the considered materials. This paper compares the values of the crystal lattice constants obtained as a result of the numerical simulation with the published data. [ABSTRACT FROM AUTHOR]

Francine Shapiro, the founder of Eye Movement Desensitization and Reprocessing (EMDR), reported that the therapeutic use of eye movement patterns was discovered by chance while walking in a park. An alternative accounting for the origins of EMDR comes from research that demonstrates individuals are unable to perceive their own eye movements and from historical sources that document Shapiro's acceptance of Neuro-Linguistic Programming theory on eye movement patterns and super-achievers. The present paper brings together this diverse set of findings to provide a more accurate context within which Shapiro's purported discoveries and subsequent claims can best be viewed. [ABSTRACT FROM AUTHOR]

In the mixed-model assembly line balancing and sequencing problem (MALBSP), workstations are assumed to be constantly available. The failure of any workstation will make the entire assembly line stop working. Preventive maintenance (PM) is a way to maintain the workstation before its failure, reduce unexpected downtime, and prolong its useful life. Previous studies have considered PM scenarios (PMS) in the simple and U-shaped assembly line to improve production efficiency and smoothness effectively, but not in the mixed-model assembly line. This paper fills this research gap, and the MALBSP considering PMS (MALBSP_PMS) is studied in this paper. A mixed-integer linear programming model is proposed to minimize makespan and task alteration. A migrating birds optimization algorithm is improved (IMBO) to obtain well-distributed Pareto frontier solutions. This algorithm designs a restart mechanism and an intra-population crossover operator to avoid falling into the local optimal and enhance its searchability. Experimental results demonstrate the effectiveness of two improvements and the IMBO algorithm. In addition, a real-world case study is introduced to illustrate the importance of considering PM scenarios in MALBSP. [ABSTRACT FROM AUTHOR]

A new mathematical model described by a Volterra integrodifferential equation (VIDE) with constant delay is examined. New agreeable conditions on the uniformly asymptotic stability, boundedness, and square integrability of solutions of the VIDE are obtained by using the Lyapunov–Razumikhin technique. The established conditions improve some former results. They can be also regarded as nonlinear generalizations of these results. Moreover, they are weaker than some available results cited in the bibliography. Two examples are presented to demonstrate possible applications of these results and the introduced concepts. The application of the Lyapunov–Razumikhin technique leads to a significant difference and gives certain advantages over the related methods used in the books and papers cited in the bibliography. [ABSTRACT FROM AUTHOR]

In this paper, we take the four-way shuttle system as the research object and establish the mathematical model of scheduling optimization based on the minimum time for the in/out operation optimization and path optimization scheduling problems of the four-way shuttle system. An improved genetic algorithm is used to solve the task planning, and an improved A* algorithm is used to solve the path optimization within the shelf level. The conflicts generated by the parallel operation of the four-way shuttle system are classified, and the improved A* algorithm based on the time window method is constructed for path optimization through the dynamic graph theory method to seek safe conflict-free paths. Through simulation example analysis, it is verified that the improved A* algorithm proposed in this paper has obvious optimization effect on the model of this paper. [ABSTRACT FROM AUTHOR]

Modern color science finds its birth in the middle of the nineteenth century. Among the chief architects of the new color theory, the name of the polymath Hermann von Helmholtz stands out. A keen experimenter and profound expert of the latest developments of the fields of physiological optics, psychophysics, and geometry, he exploited his transdisciplinary knowledge to define the first non-Euclidean line element in color space, i.e., a three-dimensional mathematical model used to describe color differences in terms of color distances. Considered as the first step toward a metrically significant model of color space, his work inaugurated researches on higher color metrics, which describes how distance in the color space translates into perceptual difference. This paper focuses on the development of Helmholtz's mathematical derivation of the line element. Starting from the first experimental evidence which opened the door to his reflections about the geometry of color space, it will be highlighted the pivotal role played by the studies conducted by his assistants in Berlin, which provided precious material for the elaboration of the final model proposed by Helmholtz in three papers published between 1891 and 1892. Although fallen into oblivion for about three decades, Helmholtz's masterful work was rediscovered by Schrödinger and, since the 1920s, it has provided the basis for all subsequent studies on the geometry of color spaces up to the present time. [ABSTRACT FROM AUTHOR]

A new non-homothetic globally concave flexible cost function is introduced and applied to a panel of firms in the Japanese paper and pulp industry. This cost function is a mixture of the generalized McFadden form and the generalized Ozaki form due to Nakamura (1990). A generalized index of technical change is used in place of the standard quadratic form of time-trend. The estimated cost function satisfied global concavity, and the symmetry condition of the Slutsky matrix was not rejected. Homotheticity was strongly rejected. JEL Classification Numbers: C33, D24. [ABSTRACT FROM AUTHOR]

In this article, the author comments on various semiconductor session papers by the researchers Kenneth Flamm, Marie-Therese Flaherty and Edward Steinmueller. It states that the papers together deliver a forceful blow to an important strand of conventional wisdom. During the early 1970s Texas Instruments, advised by the Boston Consulting Group, openly avowed the practice of learning curve pricing, that is, entering new product markets early and pricing aggressively to gain market share and stimulate demand, thereby racing down learning curves and securing a cost advantage over less aggressive rivals. Flaherty goes on to show that Japan's success in the DRAM market stemmed not from aggressive pricing, but from devising ways to ramp up output more rapidly than their American counterparts.

This paper proposes a novel disturbance observer (DOB) based on the free-chattering sliding-mode control (SMC) to compensate the changing of the disturbance and uncertain values of a micro-electromechanical system (MEMS) gyroscope. First, the mathematical model of the MEMS system is briefly described. Second, the SMC without the sign function was designed to deal with the problem of tracking references of the MEMS system. Due to the chattering occurs from switching control value, this paper used the sliding phase control without the sign function. Third, a DOB was proposed without the information of control inputs. To delete the conjunction of the first derivative disturbance value, a low-pass-filter was applied to drive the feedback disturbance value for compensating the perturbations of the MEMS system. Fourth, the stability of proposed control method was fulfilled the Lyapunov condition. The simulation results are used to verify the correction of the proposed theory. The effectiveness of the novel disturbance observer based on free-chattering control is a good result of tracking control performances for MEMS system. The tested disturbances and uncertainties on x- and y-axis were mostly rejected. The settling time and overshoot values are very small, the maximum settling-time value is 0.3 s. The steady-state are e x ∈ (- 10.09 , 10.03) × 10 - 4 and e x ∈ (- 13.29 , 14.88) × 10 - 4 , for x- and y-axes, respectively. [ABSTRACT FROM AUTHOR]