bluuebunny/crossref_metadata_2025_split huggingface dataset:
Approximate Controllability of Infinite Dimensional Systems of the n-th Order
Authors: Respondek Jerzy 
Published: June 2008

Approximate Controllability of Infinite Dimensional Systems of then-th OrderThe objective of the article is to obtain general conditions for several types of controllability at once for an abstract differential equation of arbitrary order, instead of conditions for a fixed order equation. This innovative approach was possible owing to analyzing then-th order linear system in the Frobenius form which generates a Jordan transition matrix of the Vandermonde form. We extensively used the fact that the knowledge of the inverse of a Jordan transition matrix enables us to directly verify the controllability by Chen's theorem. We used the explicit analytical form of the inverse Vandermonde matrix. This enabled us to obtain more general conditions for different types of controllability for infinite dimensional systems than the conditions existing in the literature so far. The methods introduced can be easily adapted to the analysis of other dynamic properties of the systems considered.
Controllability and Observability of Linear Discrete-Time Fractional-Order Systems
Authors: Guermah Said , Djennoune Said , Bettayeb Maamar 
Published: June 2008

Controllability and Observability of Linear Discrete-Time Fractional-Order SystemsIn this paper we extend some basic results on the controllability and observability of linear discrete-time fractional-order systems. For both of these fundamental structural properties we establish some new concepts inherent to fractional-order systems and we develop new analytical methods for checking these properties. Numerical examples are presented to illustrate the theoretical results.
Extension of First Order Predictive Functional Controllers to Handle Higher Order Internal Models
Authors: Khadir Mohamed , Ringwood John 
Published: June 2008

Extension of First Order Predictive Functional Controllers to Handle Higher Order Internal ModelsPredictive Functional Control (PFC), belonging to the family of predictive control techniques, has been demonstrated as a powerful algorithm for controlling process plants. The input/output PFC formulation has been a particularly attractive paradigm for industrial processes, with a combination of simplicity and effectiveness. Though its use of a lag plus delay ARX/ARMAX model is justified in many applications, there exists a range of process types which may present difficulties, leading to chattering and/or instability. In this paper, instability of first order PFC is addressed, and solutions to handle higher order and difficult systems are proposed. The input/output PFC formulation is extended to cover the cases of internal models with zero and/or higher order pole dynamics in an ARX/ARMAX form, via a parallel and cascaded model decomposition. Finally, a generic form of PFC, based on elementary outputs, is proposed to handle a wider range of higher order oscillatory and non-minimum phase systems. The range of solutions presented are supported by appropriate examples.
Inferring Graph Grammars by Detecting Overlap in Frequent Subgraphs
Authors: Kukluk Jacek , Holder Lawrence , Cook Diane 
Published: June 2008

Inferring Graph Grammars by Detecting Overlap in Frequent SubgraphsIn this paper we study the inference of node and edge replacement graph grammars. We search for frequent subgraphs and then check for an overlap among the instances of the subgraphs in the input graph. If the subgraphs overlap by one node, we propose a node replacement graph grammar production. If the subgraphs overlap by two nodes or two nodes and an edge, we propose an edge replacement graph grammar production. We can also infer a hierarchy of productions by compressing portions of a graph described by a production and then inferring new productions on the compressed graph. We validate the approach in experiments where we generate graphs from known grammars and measure how well the approach infers the original grammar from the generated graph. We show graph grammars found in biological molecules, biological networks, and analyze learning curves of the algorithm.
American Sign Language and Early Intervention
Authors: Snoddon Kristin 
Published: June 2008

Abstract:Since the beginning of the twenty-first century, the introduction in several countries of universal neonatal hearing screening programs has changed the landscape of education for deaf children. Due to the increasing provision of early intervention services for children identified with hearing loss, public education for deaf children often starts in infancy. While infant hearing screening and intervention programs hold promise for enhancing deaf children's language development, concerns have been raised that these programs may not provide a well-informed or adequate range of options for families with deaf children. In particular, Ontario children who receive cochlear implants have frequently not been provided with support for learning American Sign Language (ASL), despite evidence for the benefits that learning ASL confers on spoken and written English language development in deaf children. This paper presents an applied linguistics perspective on early intervention policies and programs for deaf children.
Peer–Peer Interaction between L2 Learners of Different Proficiency Levels: Their Interactions and Reflections
Authors: Watanabe Yuko 
Published: June 2008

Abstract:This study draws on sociocultural theory to explore how adult ESL learners interact with either a higher- or a lower-proficiency peer during pair problem solving, and how they each perceive the interactions with their partners. Three ESL learners engaged in a three-stage task: pair writing; pair noticing; and individual writing with two learners, one with a higher and one with a lower L2 proficiency level than their own. These three learners engaged in stimulated recall sessions and were interviewed after all the tasks were completed. Each pair's pattern of interaction and attitude towards the interactions were analyzed. Data showed that the higher- and the lower-proficiency peers could both provide opportunities for learning when they worked collaboratively. Moreover, all three learners preferred to work with a partner who ‘shared many ideas,’ regardless of their proficiency level. These findings suggest that proficiency differences are not the decisive factor affecting the nature of peer assistance. Rather, the pattern of interaction co-constructed by learners may have greater impact.
Évaluation du traitement des correspondances phonèmes/phonogrammes chez des lecteurs/scripteurs adultes en début d’apprentissage du français langue seconde
Authors: Daigle Daniel , Mathieu Isabelle , Montésinos-Gelet Isabelle 
Published: June 2008

Abstract: Learning to read and write in an alphabetic language, whether it is the learner's first or second language, requires the development of some sensitivity to correspondences between phonemes and phonograms. The study reported here investigated those correspondences in beginning learners of French as a second language. Three groups of learners participated in the study: anglophones, hispanophones and sinophones. In reading, a similarity judgement task was used at the graphemic level; in writing, participants were asked to write words presented orally. The results reveal that, in both reading and in writing, anglophones obtained the highest scores and sinophones the lowest scores. The results are discussed within the context of the hypothesis related to the effects of L1–L2 distance on L2 acquisition.
Structure Property Relationships in PA 6 and PP Copolymers Blended by Single and Twin Screw Extrusion
Authors: Correa C. A. , Carvalho C. L. , Bezzan A. L. , Razzino C. A. , Hage E. 
Published: June 2008

AbstractPolyamides such as polycaprolactam (PA 6) and poly(hexamethylene adipamide) (PA 6.6), are generally classified as pseudo-ductile materials. Fracture behaviour of PA can be changed by melt compounding with modified olefinic elastomers such as Ethylene-propylene copolymers (EPM and EPDMs) and nitrile rubbers (NBRs). Often, small amounts of a compatibilizer are added to the polymer blend in order to assure good dispersion, morphology stability and consistent end-use properties. Maleated polypropylene (PP-MAH) has been used as compatibilizer in blends of polyamides with polyolefins as they tend to react with amine end groups in the polyamide molecules and also interact by molecular entanglement with non-funcionalized polypropylene chains. This work was intended to optimise stiffness-toughness balance in polyamide/ polypropylene blends by reactive processing of PA 6 with polypropylene heterophase copolymers using the PP-MAH as a compatibilizer. Effects of processing conditions on the blend morphology and mechanical properties were investigated by comparing compatibilized and non-compatibilized blends prepared by single and twin screw extrusion. Such approach was intended to investigate whether blend morphology and its response to processing steps can be controlled by blend composition, changes in rheology and interfacial tension during reactive processing. Viscosity measurements by torque rheometry and particle coalescence in-situ observations were performed in order to provide additional evidence of mechanisms relating to phase morphology definition in such systems.
Polymer Plastication during Injection Molding
Authors: Steller R. , Iwko J. 
Published: June 2008

Abstract
The mathematical model of polymer plastication in a reciprocating screw injection molding machine is presented. It takes into account all characteristic features of working of a real injector, such as periodical action of the three zones screw, to-and-from screw motion with controlled stroke, static and dynamic melting, etc. Methods for description of time changes of the solid bed profile in the screw channel during injection cycle as a function of operating parameters were developed. Ways of determination of pressure and temperature profiles in the screw channel were also discussed. Methods of caculation of the most important flow characteristics such as plasticizing capacity, power requirements, screw torque, energy consumption were analyzed. Results were presented in a form, which is most convenient for numerical applications in computer simulation programs.
Polymer Plastication during Injection Molding
Authors: Iwko J. , Steller R. 
Published: June 2008

Abstract
A computer program for the simulation of polymer plastication in screw injection molding machine created on basis of the theoretical model presented in part 1 of this paper is discussed. As simulation examples various process characteristics, e. g. solid bed, pressure and temperature profiles, are computed using the material parameters for high density polyethylene and three-zones-screw of diameter 20 mm. Effects of different geometric and operating parameters on plastication course are also demonstrated. Simulation results with respect to the screw rotation time are compared with experimental data measured for low density polyethylene, polypropylene, polystyrene, polyoxymethylene and polyamide 6. It was found that the computer program reflects correctly all features of a true plasticating system in injection molding machine. It provides also good agreement of model predictions with experimental data.
Challenges to the Formation of Nano-cells in Foaming Processes
Authors: Zhu Z. , Park C. B. , Zong J. H. 
Published: June 2008

Abstract
This paper uses a finite element analysis to investigate the morphological changes of nano-cells in a polystyrene (PS) – CO2 foaming system. The system was composed of a finite polymer melt with a central cell and eight surrounding cells. The computational domain was discretized using linear triangular elements. The growth and shrinkage of nano-sized cells were tracked using the moving mesh method. The effects of the initial bulk gas concentration, cell size, intercellular distance, and system temperature on cell ripening were examined. The results show that smaller nano-sized cell(s) are doomed to collapse very quickly once they have interacted with larger cell(s), making it difficult to survive. Efforts were made to improve the general understanding of the challenges posed to the formation of nano-cells in foaming processes.
Experimental Study on the Sliding Friction and Wear Characteristics of Roller Burnished Polymers
Authors: Ong L. K. , El-Tayeb N. S. M. , Brevern P. V. 
Published: June 2008

Abstract
The increasing utilization of polymers in sliding members has triggered much research on the enhancement of surface quality and tribological performance. In this regard, no work has considered the application of roller burnishing as a new surface treatment method for polymeric surfaces. The present work aims to investigate the influence of burnishing feed and roller contact width on the sliding friction and wear performance of acetal homopolymer and polyurethane. Dry and lubricated sliding conditions for both parallel and crossed burnished orientations were considered. The results revealed that low burnishing feed rate and smaller roller contact width led to a decrease in coefficient of friction for both polymers while improvement in the wear resistance was observed. Hence, it can be suggested that the roller burnishing process has high potential as a valuable polymer surface treatment technique.
Rheological Behavior of Immiscible PS/PMMA Blends during Dynamic Plasticating Extrusion
Authors: Luo W. H. , Zhou N. Q. , Peng X. F. 
Published: June 2008

Abstract
PS/PMMA blends were prepared using a twin screw extruder and then extruded using an electromagnetic dynamic plasticating extruder equipped with a specially designed split die. During dynamic plasticating extrusion, the dynamic rheological behavior of PS/PMMA blends was investigated. The extrudates were cooled immediately and collected for morphology measurements using a scanning electron microscope (SEM). Results show that the average shear stress decreases with the introduction of vibration force field into the whole extrusion process, and reaches a minimum at the vibration amplitude of 0.15 mm and the vibration frequency of 5 Hz. At the same shear stress, the melt viscosity of the blend under dynamic plasticating extrusion is lower than that under static extrusion and decreases with vibration intensity. With increasing vibration intensity, the power-law index of the blend melt has a tendency to increase. The drop size of the dispersed phase in 25/75 PS/PMMA blend decreases at a faster rate with an increase of shear stress, compared with that in 75/25 PS/PMMA blends, correspondingly, the melt viscosity of 25/75 PS/PMMA blend has a stronger shear rate dependence. During dynamic plasticating extrusion, a negative deviation from the additivity rule is observed for the studied blend compositions.
Inhibition of Thermal Oxidation Destruction of PBT/HDPE Blends by Organic Compounds of Five-valent Phosphorus
Authors: Ozden S. , Borukayev T. A. , Shaov A. K. 
Published: June 2008

Abstract
Polybutylene terephthalate (PBT) and highy density polyethylene (HDPE) were blended and stabilized with four different stabilizers obtained from the organic derivatives of five-valent phosphorus. These stabilizers were cyclohexylphosphonic acid, its metallic salts of cyclohexyl phosponates of bivalent nickel, bivalent iron and trivalent iron. The stabilization improved the thermal stability of the PBT/HDPE blends and increased their mass loss temperature. The blend melts were thermally aged inside a viscometer barrel and the Melt flow Index (MFIs) was measured. All stabilizers increased the melt stability of the blends when used in low rates (< 0.2 % in mass). At higher stabilizer rates, some stabilizers further enhanced the thermal stability, while others decreased it. A melt parameter was introduced to determine the melt stability of the PBT/HDPE blends during extrusion. The best stabilization was obtained with cyclohexylphosphonic acid based on the metallic salts of bivalent nickel. The mechanisms that lead to the inhibition of thermal destruction of the blends were explained in terms of the stabilizers.
Non-isothermal Model for the Drive Power Calculation of Single-screw Plasticating Units
Authors: Potente H. , Bornemann M. 
Published: June 2008

AbstractThis paper presents a non-Isothermal numerical model developed at the KTP for calculating the drive power of single-screw plasticating units. It includes, firstly, a description of the mathematical and physical modeling process and, secondly, an explanation of the systematic approach, based on statistical methods, that was adopted for compiling an approximation equation with the aid of non-isothermal, three-dimensional FEA flow simulation results. In addition, the generated model is verified on the basis of the computation results obtained with a simulation program for screw layout, in which the model was implemented. The simulation results are compared with experimentally recorded power data for selected extrusion and injection molding processes and the quality of the model is subsequently assessed.
How mathematical dispositions of adult learners play a role in their STEM choices
Authors: Jameson Molly M. 
Published: April 2024

AbstractMathematical dispositions, or an individual's behavioral (i.e., things they say and do), cognitive (i.e., attention and memory), and affective (i.e., emotions and beliefs) tendencies related to mathematics, are critical to the learning of mathematics and choices related to STEM. Previous research has suggested that adult learners may possess unproductive mathematical dispositions, such as high math anxiety and low math self‐efficacy. This paper argues that unproductive mathematical dispositions may serve as a barrier to adult learners' STEM choices and provides strategies and techniques to help move adult learners towards productive mathematical dispositions and potentially stronger attraction to STEM fields.
Incorporation of artificial intelligence in healthcare professions and patient education for fostering effective patient care
Authors: Mucci Andrea , Green Wendy M. , Hill Lilian H. 
Published: April 2024

AbstractArtificial intelligence (AI) influences many aspects of modern life and has multiple applications in the delivery of healthcare. AI is designed to mimic human capabilities including pattern recognition, data analysis, and decision‐making and perform tasks more efficiently. It is capable of detecting patterns in large datasets that might elude human beings. AI has potential to improve patient care, patient safety, disease diagnosis and treatment; public health; health research; health administration; and the daily work of health professionals. In 2019, the US National Academy of Medicine emphasized the need for “physicians, nurses, and other clinicians, data scientists, health care administrators, public health officials, policy makers, regulators, purchasers of health care services, and patients to understand the basic concepts, current state of the art, and future implications of the revolution in AI and machine learning.” Therefore, it is incumbent on adult educators to incorporate AI training into health professions education and patient education.
Effects of explainable artificial intelligence in neurology decision support
Authors: Gombolay Grace Y. , Silva Andrew , Schrum Mariah , Gopalan Nakul , Hallman‐Cooper Jamika , Dutt Monideep , Gombolay Matthew 
Published: April 2024

AbstractObjectiveArtificial intelligence (AI)‐based decision support systems (DSS) are utilized in medicine but underlying decision‐making processes are usually unknown. Explainable AI (xAI) techniques provide insight into DSS, but little is known on how to design xAI for clinicians. Here we investigate the impact of various xAI techniques on a clinician's interaction with an AI‐based DSS in decision‐making tasks as compared to a general population.MethodsWe conducted a randomized, blinded study in which members of the Child Neurology Society and American Academy of Neurology were compared to a general population. Participants received recommendations from a DSS via a random assignment of an xAI intervention (decision tree, crowd sourced agreement, case‐based reasoning, probability scores, counterfactual reasoning, feature importance, templated language, and no explanations). Primary outcomes included test performance and perceived explainability, trust, and social competence of the DSS. Secondary outcomes included compliance, understandability, and agreement per question.ResultsWe had 81 neurology participants with 284 in the general population. Decision trees were perceived as the more explainable by the medical versus general population (P < 0.01) and as more explainable than probability scores within the medical population (P < 0.001). Increasing neurology experience and perceived explainability degraded performance (P = 0.0214). Performance was not predicted by xAI method but by perceived explainability.InterpretationxAI methods have different impacts on a medical versus general population; thus, xAI is not uniformly beneficial, and there is no one‐size‐fits‐all approach. Further user‐centered xAI research targeting clinicians and to develop personalized DSS for clinicians is needed.
Fuzzy sliding mode tracking control of discrete‐time nonlinear interconnected systems via a previewable approach
Authors: Qin Xianghui , Ren Junchao 
Published: April 2024

SummaryThis article investigates the fuzzy sliding mode tracking problem for discrete‐time nonlinear interconnected systems (ICSs) via a previewable information approach. First, an augmented system containing tracking errors and previewable reference and disturbance signals is established for discrete‐time nonlinear ICSs according to a previewable length. Second, novel sliding surfaces are given and some sufficient conditions of making the sliding motion asymptotically stable are derived in term of linear matrix inequalities (LMIs). Next, fuzzy sliding mode control (SMC) laws are designed so that the controlled system can reach the sliding surfaces and keep on them thereafter, and compared to not having previewable signals, these designed control laws can also enable system outputs to better track the reference signals asymptotically. Finally, a simulation example is given to demonstrate the effectiveness of the proposed control law.
Fixed time function combination synchronization of perturbed chaotic systems via adaptive control
Authors: Su Haipeng , Luo Runzi 
Published: April 2024

SummaryThe concerns of this article is to investigate the fixed time function combination synchronization (FCS) among three different chaotic systems with disturbances. First, a new stability theorem is presented by virtue of the integral inequality technique and a more accurate upper estimation of the convergence time is given. Next, the fixed time FCS problem is considered for the perturbed chaotic systems in which the scaling functions are generated by the bounded dynamical systems. Besides, the synchronization time is related to the control parameters rather than the initial values. The time upper bound can be calculated out by the simple formula, which is the function of control parameters. Finally, a simulation example is provided to illustrate the correctness of the derived criteria.