Search

The article discusses the report conducted by online education organization International Association for K-12 Online Learning (iNACOL) on the early-stage blended learning models for K-12 education. Highlighted are definitions of blended learning models including rotation model, flex model and enriched virtual model. The adoption of the personalized learning in blended learning environment is also explored.

The Latino population in the United States faces significant health disparities compared to their White counterparts. Community-based processes in Gallatin County, Montana, through academic-community partnerships have identified strategies to overcome these barriers. One such strategy includes the utilization of community health workers (CHWs) in the Latino population—in Spanish, "Promotores de Salud." CHWs are often selected to target community health problems because they share the cultural, social, and demographic features of the population they serve. This paper explores the inherent ties between Catholic Social Teaching and the CHW health care model while focusing on a community-academic partnership in Montana that is implementing a CHW program. Catholic health care providers are called to apply CST principles to their health care systems and communities in order to achieve health equity for their patients. This paper proposes that community organizing and advocacy should be taught in medical school curricula across the country in order to promote physician involvement in solving public health disparities. Additionally, the authors suggest that practicing Catholic health care providers immediately incorporate community organizing through the use of CHWs to attain health equity for their patient panels. [ABSTRACT FROM AUTHOR]

The article deals with the mathematical model created by Dirk Brockmann, a physicist at the Max Planck Institute in Germany, and his team to predict the travel patterns of paper money and people as well. Brockmann used the data collected by the Web site Wheresgeorge.com. The site tracks the U.S. paper currency through the serial numbers of the bill that will be supplied by the holder of the bill. It is said that the model might be used to help predict the spread of epidemic diseases.

This paper proposes a universal strategy for correcting limited-accuracy size estimates from a given ultrasonic technique, by using higheraccuracy size information from another technique. The more-accurate size information needed can be developed from destructive techniques, nondestructive techniques or mathematical modeling techniques. The correction can be quantitative or semi-quantitative. As examples of limited-accuracy ultrasonic sizing techniques, this paper uses echodynamic size estimates. For these example techniques, the paper illustrates correcting size estimates both in the general theoretical case and for a specific experimental case involving inclusion-stringer discontinuities. The proposed universal strategy corrections can improve results from a test beyond what would normally be physically possible. The proposed universal strategy corrections can also improve results comparisons when a single part is tested more than once using different ultrasonic setups; examples include round-robin tests as well as periodic piping, weld and vessel maintenance tests. [ABSTRACT FROM AUTHOR]

The image quality of radiographs is determined by reading image quality indicators (IQIs), exposed together with the test object. This has been performed for decades for quality assurance in technical radiography, achieving the present high quality of industrial radiographs. During the last two decades, X-ray film as a detector medium has been increasingly replaced by digital X-ray detectors. Two major technologies are accepted for film replacement: computed radiography and digital radiography with digital detector arrays (DDAs). In 2005, the first set of European Committee for Standardization (CEN) and ASTM International standards was published for computed radiography, and in 2010 the ASTM standards for DDAs were finalized and published. Presently active computed radiography standards and some DDA standards already need a major revision. It was observed by many users that the ¡mage quality for class B of CEN EN 14784-2:2005 is not achievable with most computed radiography systems under the same exposure conditions as used for film exposure following the practice of CEN EN 444:1994 or ISO 5579:1998. A mathematical model was developed and tested, which allows the calculation of the image quality, proven by IQIs, depending on the fixed pattern noise and the efficiency of the imaging plate scanner system for computed radiography. All tested systems provide a fixed correlation between the measured signalto- noise ratio (SNR) and the gray values in the digital images. The maximum achievable SNRmax depends on the fixed pattern noise of the imaging plates (high dose limit). For DDAs, the achievable SNR depends additionally on the calibration procedure and frame integration used for the image acquisition. Depending on the exposure dose, the visibility of IQIs can be predicted using the SNR, the effective attenuation coefficient, ueff, for calculation of the contrast-to-noise ratio (CNR) and the basic spatial resolution of the image for calculation of the normalized CNRN. The diameter of the just visible wire or IQI hole is inversely proportional to the square root of CNRN. This relation is used to evaluate IQI visibility and is presented in this paper. A conversion formula was also derived for calculation of the equivalent penetrameter sensitivity from CNRN. [ABSTRACT FROM AUTHOR]

Over the past decade, the consensus of multiagent systems has received an increasing attention in various fields, such as mathematics, physics, biology, and engineering sciences. There are numerous results reported on the consensus of multiagent systems. Now it is necessary to review the recent advances in consensus of multiagent systems. This paper firstly reviews the main mathematical models of inultiagent systems, including Boids model, Vicsek model, and Couzin-Leviri model. Moreover, this paper reviews the main advances in the consensus of multiagent systems, including the linear local updating rules, nonlinear local updating rules, and leader and asymmetric matrix cases. [ABSTRACT FROM AUTHOR]

This paper discusses the development of an ultrasonic time of flight diffraction-based inspection technique for sizing surface-breaking vertical cracks in complex geometry plant components like a solid steam turbine rotor with integral discs. A simple geometric model was developed. Specimens containing vertical notches simulating cracks in real-life rotors and holding devices for affixing the transmitter and receiver probes in plane and on opposite sides of the disc-like portion of the specimens were designed and fabricated. Experiments were conducted, and the results show that the inspection technique developed here can size such cracks with reasonable accuracy. The technique can be useful for in-situ condition assessment and remaining life assessment of aged, in-service complex geometry plant components. [ABSTRACT FROM AUTHOR]

A long time has passed after receiving many expectations for mathematical theories and applications in real world complex systems. Unfortunately potentiality for theory and modeling of complex systems is not properly advocated. In this paper potentiality of mathematical models in complex systems is discussed in conjunction with real world examples. First, it is described "what mathematical model is" in complex systems. The mathematical model of complex system is not for describing the spatio-temporal features in real world objects, but for idealizing the reality of them. Successful statistical models based on Bayes theorem in complex systems are exemplified, and discussed with the problems of "Big Data". Further, feasibility and availability of mathematical models in complex systems are remarked. [ABSTRACT FROM AUTHOR]

Artificial neural network (ANN) models were developed to evaluate the effect of corrosion on the tensile mechanical properties of reinforcing B500C steel bars in coastal structures. This paper studies the effectiveness of radial basis function neural network models to predict the tensile mechanical properties degradation after several corrosion exposure times for bare reinforcing B500C steel bars of 8,10,12,16 and 18 mm nominal diameter. The input vector consisted of only two parameters, the nominal diameter and mass loss due to corrosion. This investigation shows that the established ANN models are available and effective in simulating the tensile mechanical behavior of corroded reinforcing B500C steel bars. For example, in the case of 16 mm diameter, the maximum prediction accuracy is 99.5% for yield strength and 99.74% for the tensile strength, respectively. [ABSTRACT FROM AUTHOR]

The Japan Sc ience and Technology Agency (JST) renewed J-GLOBAL which had been exhibited as a beta version from 2009, and released the formal vers ion in September, 2012. The service of J-GLOBAL formal version was designed by comparison verification of the concept of J-GLOBAL and a search behavior model. The search engine function and user interface are separated in the system config uration of J-GLOBAL of the forma l version. Such a system configuration serves with the pliability of system extension. The function and the feature of the J-GLOBAL formal version are introduced together with a service design in this paper. [ABSTRACT FROM AUTHOR]

The size, number, morphology and type of inclusion particles are the key factors to estimate the quality of steel product. Although considerable efforts have been made in the mathematical modeling of inclusion growth, few papers were involved in inclusion''s nucleation and collision-growth, and all the existing researches about the behaviors of magnesia inclusion were based on the experiments. Thus, a mathematical model was developed to investigate the nucleation, Ostwald ripening and collision-growth of magnesia inclusion in the molten steel. Numerical results showed that the predicted particle size distributions are consistent with the previous experimental data. For the magnesia inclusions smaller than 100 nm, Brownian collision is the main collision modes. For the inclusions ranging from 0.1 to 10 μm, Brownian collision and turbulent collision are the main collision modes. For the inclusions ranging from 10 to 100 μm, turbulent collision and Stokes collision are the main collision modes. Thus, the strong turbulent flow can decrease the peak-value diameter of the magnesia inclusion effectively. [Copyright &y& Elsevier]

The global stability of SEIRS models with nonlinear incidence rates was conjectured in [15] and has been stated as an outstanding open question for classical bilinear models in [13]. By applying the Poincare-Bendixson property of dynamic systems in space, the authors in [11] have proven the conjecture for the bilinear model with a sufficiently long average immunity period, and in [13] the authors have shown the case with a sufficiently long average infection period. In this paper, we solve the open problem for the bilinear case completely, and furthermore have relaxed the constraint on the general nonlinear transmission function for global stability. [ABSTRACT FROM AUTHOR]

In this paper, we present a time-delayed dengue transmission model. We first introduce the basic reproduction number for this model and then show that the disease persists when Ro > 1. It is also shown that the disease will die out if Ro < 1, provided that the invasion intensity is not strong. We further establish a set of sufficient conditions for the global attractivity of the endemic equilibrium by the method of fluctuations. Numerical simulations are performed to illustrate our analytic results. [ABSTRACT FROM AUTHOR]

This paper deals with a vector-borne disease model containing latency and nonlinear incidence rates. Global dynamics of the model is completely determined by suitable Lyapunov functionals. If the basic reproduction number is less than one, then disease dies out, but if the number is larger than one, we found that one or both of the the strains become endemic. A unique co-endemic equilibrium appears when both the boundary equilibria exist but are unstable, and this in contrast to the situation when mass action incidence is adopted in which co-persistence is impossible and competition exclusion is generic. It is also found that the persistence of a strain not only depends on the respective reproduction number but also depends on the combined parameters and a strain may disappear even though the strain specific reproduction number is larger than one. The higher saturation level of one strain may result in emerge or extinction of the other strain in some situations. [ABSTRACT FROM AUTHOR]

For an HTLV-I infection model, Li and Shu has shown in [6] that delayed CTL response can lead to com-plex bifurcations, and in particular, coexistence of multiple sta-ble periodic solutions. In this paper, we extend results of Li and Shu in [6] and investigate the case when there exist three sequences of Hopf bifurcation points. Through numerical sim-ulations, we show that two of the sequences lead to bounded global Hopf bifurcation branches as observed in [6], and a third sequence gives rise to unbounded Hopf branches that can pro-duce secondary period-doubling bifurcations. Our results show that multiple stable periodic solutions can co-exist in certain parameter regions. [ABSTRACT FROM AUTHOR]

An important question in the study of the evolution of dispersal is what kind of dispersal strategies are evolutionary stable. This work is motivated by recent work of Cosner et al. [9], in which they introduced a class of ideal free dispersal kernels and found conditions suggesting that they determine evolutionarily stable dispersal strategies. The goals of this paper are to introduce a more general class of ideal free dispersal kernels and further to show that such ideal free dispersal strategies are indeed evolutionary stable. Our work also extends some recent work on the evolutionary stability of ideal free dispersal for reaction-diffusion equations and patch models to nonlocal dispersal models. [ABSTRACT FROM AUTHOR]

The article presents the author's comments on the interplay between muscles and ligaments. The author refers to a research paper by osteopath and anatomist Jaap van der Wal, presented at a conference, and the book "The Brain That Changes Itself," by Norman Doidge. The author also discusses his own book "Anatomy Trains," in this context. Diagrams on the traditional view of ligaments, are also given in the article.

Nonlinear delay differential eqnation have been widely used to study the dynamics in biology. but the stability of such equation are challenging. In this paper, new criteria are established for the asymptotic stability of some nonlinear delay differential equations with finite delay via fixed point theory. The techniques involve both the contractive mapping principle and Schauder's fixed point theorem. The criteria are then applied to obtain the stability of some well known models in physiology and ecology. [ABSTRACT FROM AUTHOR]

This paper concerns the detailed modeling of kinesin locomotion along microtubules. Experimentalists have inserted polymers into the neck-linkers of kinesin, extending their lengths and changing their flexibility. Observations of the progression of these mutants along microtubules provide some insight into the mechanisms of locomotion. We formulate a mathematical model of this locomotion that takes into account the rates of various biochemical processes, orientation-dependent binding affinities, and the entropic forces involved in the constrained random walk of a tethered head. Our analysis and simulation of the model with neck-linkers of varying lengths indicate that the processivity of kinesin is obtained through the coordination of the chemical states of two heads, which is regulated by the tension in neck-linkers. We find that both front-gating and rear-gating mechanisms are required for processivity consistent with experimental evidence. [ABSTRACT FROM AUTHOR]

ABSTRACT. This paper concentrates on the study of the propagation of waves in a homogeneous isotropic thermoelastic diffusive plate completely immersed in a viscous fluid on both sides in the context of different theories of thermoclastic diffusion. The secular equations for both symmetric and skew- symmetric modes of wave propagation have been obtained. The dispersion curves, attenuation coefficient and amplitudes of displacement components, temperature change and concentration for the symmetric and skew-symmetric wave modes arc computed analytically and presented graphically. [ABSTRACT FROM AUTHOR]

ABSTRACT. This paper describes a prey predator model with type II functional response where harvesting of each species is taken into consideration. Discrete type gestational delay of predators is incorporated and its effect on the dynamical behaviour of the model system is analyzed. It is shown that harvesting efforts may be used to control the prey predator system considered. We have also studied the Hopf bifurcation of the model system in the neighbourhood of the co-existing equilibrium point considering delay as a variable bifurcation parameter. Numerical simulations are given to verify the analytical results. [ABSTRACT FROM AUTHOR]

This paper analyzes popular time-nonseparable utility functions that describe "habit formation" consumer preferences comparing current consumption with the time averaged past consumption of the same individual and "catching tip with the Joneses" (CuJ) models comparing individual consumption with a cross-sectional average consumption level. Few of these models give reasonable optimum consumption time series. We introduce theoretically justified utility specifications leading to a plausible consumption behavior to show that habit formation preferences must be described by a power CRRA utility function different from the exponential CARA used for CuJ. We also introduce a continuous time formulation for the habit formation problem which yields a nonlinear ordinary differential equation (ODE). The numerical solutions of this ODE are presented and analyzed. [ABSTRACT FROM AUTHOR]

Branching processes are a well-established tool in mathematical biology used to study the dynamics of rarefied populations where agents act independently and small stochastic density-independent changes in population sizes. However, they are often avoided by nonmathematicians because of their reliance on generating functions. Generating functions are powerful computational aids but are often difficult to motivate. In this paper, I review branching process theory using a noncommuting random variable description of multiplication as mnemonic for generating functions. Starting from the elementary definition of multiplication, I show how uncertainty leads to a natural generalization of integer multiplication without the commutative property, and how this in-turn is connected to the well-established study of generating functions. Noncommuting random-variable methods are described in detail and illustrated using examples. [ABSTRACT FROM AUTHOR]

This paper presents a practical technique for finding the most effective setup (probe types and their arrangement) for an ultrasonic testing problem subjected to a limited availability of probes and limited access to the test object's boundary. The technique consists of a preliminary step where candidate setups are quickly found using a simple ray tracing technique, and a second step of selecting the most effective among the candidates based on numerical simulations using a more sophisticated model — the mass spring lattice model. The usefulness of the proposed technique is demonstrated by considering several ultrasonic testing problems of practical interest. The technique proposed in this work may be developed further and packaged into a computer program that can automatically find the most effective ultrasonic testing setup. [ABSTRACT FROM AUTHOR]

Focuses on similarities between human traffic and animal flocking behaviors. Computer simulation of flocking; October 1998 publication of a paper in `Physical Review E' examining similarities with fluid dynamics; The model constructed by University of Oregon physicist John Toner and Yuhai Tu of the IBM Watson Research Lab. INSET: Keeping Flocks Together.

Focuses on similarities between human traffic and animal flocking behaviors. Computer simulation of flocking; October 1998 publication of a paper in `Physical Review E' examining similarities with fluid dynamics; The model constructed by University of Oregon physicist John Toner and Yuhai Tu of the IBM Watson Research Lab. INSET: Keeping Flocks Together.