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Competitive Processes in Controlled Cationic Ring-Opening Polymerization of Oxetane: aLotka-VolterraPredator-Prey Model of Two Growing Species Competing for the same Resources

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Macromolecular Symposia 2011年第1期308卷

作者： Hassen Bouchékif Allan J. Amass Aston University School of Chemical Engineering & Applied Chemistry (CEAC) Birmingham B4 7ET United Kingdom Department of chemistry Biomolecular Sciences Program Laurentian University 935 Ramsey Lake Rd Sudbury ON PE 2C6 Canada

Summary : The activation-deactivation pseudo-equilibrium coefficient Q t and constant K 0 ( =Q t x P aT1,t = ([A1]x[Ox])/([T1]x[T])) as well as the factor of activation ( P aT1,t ) and rate constants of elementary steps reactions that govern the increase of M n with conversion in controlled cationic ring-opening polymerization of oxetane (Ox) in 1,4-dioxane (1,4-D) and in tetrahydropyran (THP) ( i.e. cyclic ethers which have no homopolymerizability (T)) were determined using terminal-model kinetics. We show analytically that the dynamic behavior of the two growing species (A1 and T1) competing for the same resources (Ox and T) follows a Lotka-Volterra model of predator-prey interactions.

关键词： kinetics living Lotka-Volterra mechanism polymerization

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Lipid Microdomains: Structural Correlations, Fluctuations, and Formation Mechanisms

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Physical Review Letters 2010年第11期104卷 118101-118101页

作者： Jun Fan Maria Sammalkorpi Mikko Haataja Department of Mechanical and Aerospace Engineering Princeton Institute for the Science and Technology of Materials (PRISM) Program in Applied and Computational Mathematics (PACM) Princeton University Princeton New Jersey 08544 USA

Compositional lipid microdomains (“lipid rafts”) in mammalian plasma membranes are believed to facilitate many important cellular processes. While several physically distinct scenarios predicting the presence of finite-sized microdomains in vivo have been proposed in the past, direct experimental verification or falsification of model predictions has remained elusive. Herein, we demonstrate that the combination of the spatial correlation and temporal fluctuation spectra of the lipid domains can be employed to unambiguously differentiate between the existing theoretical scenarios. Furthermore, the differentiation of the raft formation mechanisms using this methodology can be achieved by collecting data at physiologically relevant conditions without the need to tune control parameters.

关键词： Cell membranes

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Influence of nonequilibrium lipid transport, membrane compartmentalization, and membrane proteins on the lateral organization of the plasma membrane

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Physical Review E 2010年第1期81卷 011908-011908页

作者： Jun Fan Maria Sammalkorpi Mikko Haataja Department of Mechanical and Aerospace Engineering Princeton Institute for the Science and Technology of Materials (PRISM) and Program in Applied and Computational Mathematics (PACM) Princeton University Princeton New Jersey 08544 USA

Compositional lipid domains (lipid rafts) in plasma membranes are believed to be important components of many cellular processes. The mechanisms by which cells regulate the sizes, lifetimes, and spatial localization of these domains are rather poorly understood at the moment. We propose a robust mechanism for the formation of finite-sized lipid raft domains in plasma membranes, the competition between phase separation in an immiscible lipid system and active cellular lipid transport processes naturally leads to the formation of such domains. Simulations of a continuum model reveal that the raft size distribution is broad and the average raft size is strongly dependent on the rates of cellular and interlayer lipid transport processes. We demonstrate that spatiotemporal variations in the recycling may enable the cell to localize larger raft aggregates at specific parts along the membrane. Moreover, we show that membrane compartmentalization may further facilitate spatial localization of the raft domains. Finally, we demonstrate that local interactions with immobile membrane proteins can spatially localize the rafts and lead to further clustering.

关键词： Cell membranes

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Special session: Model eliciting activities - Instructor perspectives

Special session: Model eliciting activities - Instructor per...

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2010 ASEE Annual Conference and Exposition

作者： Miller, Ronald Moore, Tamara Self, Brian Kean, Andrew Roehrig, Gillian Patzer, Jack Department of Chemical Engineering Center for Engineering Education Colorado School of Mines United States Department of Mathematics/Engineering Education STEM Education Center University of Minnesota United States Department of Mechanical Engineering California Polytechnic State University San Luis Obispo United States Department of Science Education STEM Education Center University of Minnesota United States Bioartificial Liver Program McGowan Institute for Regenerative Medicine University of Pittsburgh United States

As part of a larger NSF-funded project to develop Model-Eliciting Activities (MEAs) in engineering courses (MEDIA), the authors of this paper have piloted selected MEAs in their courses. This paper will describe their experiences within the context of available student learning data. An MEA is designed to present student teams with a realistic, thought provoking scenario that requires the development of a generalized mathematical model. A well-designed MEA is built around a main concept that the instructor wants students either to discover and/or better understand. Data from these experiments can be used to determine the value added for students completing MEAs compared with other types of problem-solving activities including problem-based learning exercises. Using an MEA also causes documented, positive change in the faculty members themselves. © American Society for engineering Education, 2010.

关键词： Students

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Design a small ultra-wideband bandpass filter on Al2O 3 ceramic

Design a small ultra-wideband bandpass filter on Al2O 3 cera...

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作者： Yang, Cheng-Fu Wu, Sung-Mao Fu, Ming-Yue Tsai, Jen-Hwan Huang, Chien-Jung Huang, Chih-Yu Department of Chemical and Materials Engineering National University of Kaohsiung Kaohsiung Taiwan Department of Electrical Engineering National University of Kaohsiung Kaohsiung Taiwan Department of Avionics Engineering Chinese Air Force Academy Kaohsiung Taiwan Department of Mathematics and Physics Chinese Air Force Academy Kangshan Kaohsiung Taiwan Department of Applied Physics National University of Kaohsiung Kaohsiung Taiwan Department of Electronic Engineering National Kaohsiung Normal University Kaohsiung Taiwan

ISBN: (纸本)9784902339222

In this paper, an ultra-wideband (UWB) bandpass filter (BPF) using a modified multiple-mode resonator (MMR) is proposed, designed and fabricated on Al2O3 ceramic substrate. The length of MMR is 2mm and the width of MMR is changed from 1.35mm to 2.66mm to find the optimal value. Interdigital structure coupling lines are used to couple the input/output microstrip lines. Measured results achieve the insertion loss 0.35dB and the ripple variation 1.17dB in the realized 3.10 to 11.50 GHz ultra-wide passband. We will show that the UWB BPF has a very small size of 10.2mm by 2mm on a rectangle ground size smaller than 14mm by 4mm. © 2010 IEICE Institute of Electronics Informati.

关键词： Bandpass filters

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Systematic Reduction of Combustion Reaction Mechanisms of common Hydrocarbons and Oxygenated Fuels

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AIP Conference Proceedings 2010年第1期1281卷 558-561页

作者： A. L. De Bortoli F. A. Vaz G. S. Lorenzzetti I. Martins aUFRGS‐IM/DMPA‐Department of Pure and Applied Mathematics Bento Gonçalves 9500 P.O. Box 15080 Porto Alegre Brazil bUFRGS‐PPGMAp—Graduate Program in Applied Mathematics Bento Gonçalves 9500 91509‐900 Porto Alegre‐RS Brazil cUFRGS‐PPGEQ‐Graduate Program in Chemical Engineering Engenheiro Luiz Englert s/no 90040‐040 Porto Alegre‐RS Brazil dUFRGS‐PPGEQ‐Graduate Program in Chemical Engineering Engenheiro Luiz Englert s/no 90040‐040 Porto Alegre‐RS Brazil

The aim of this work is the development of a numerical technique for the reduction of reaction mechanisms of common hydrocarbon and oxygenated fuels, such as methane, ethylene, propane, methanol and ethanol, using steady‐state and partial equilibrium assumptions. Numerical tests are carried to establish the basic chain for each fuel as well as to determine the amount of small products of combustion, whose concentration depends on the turbulent mixing and needs to be controlled due to environmental restrictions. The results are in agreement with data in the literature.

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Special session: Model-eliciting activities: A construct for better understanding student knowledge and skills

Special session: Model-eliciting activities: A construct for...

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2010 ASEE Annual Conference and Exposition

作者： Moore, Tamara Self, Brian Miller, Ronald Hjalmarson, Margret Zawojewski, Judith Olds, Barbara Diefes-Dux, Heidi Lesh, Richard Department of Mathematics/Engineering Education STEM Education Center University of Minnesota United States Mechanical Engineering Department California Polytechnic State University San Luis Obispo United States Department of Chemical Engineering Center for Engineering Education Colorado School of Mines United States Graduate School of Education George Mason University United States Department of Mathematics and Science Education Illinois Institute of Technology Chicago IL United States Department of Liberal Arts and International Studies Colorado School of Mines United States School of Engineering Education First-Year Engineering Program Purdue University United States Department of Learning Science Center for Research on Learning and Technology Indiana University United States

The ABET criteria for engineering programs include that students should have "an ability to apply mathematics, science and engineering", "an ability to design a system, component, or process to meet desired needs", "an ability to identify, formulate and solve engineering problems", and "an ability to communicate effectively", and "a knowledge of contemporary issues"1. One manner of integrating teamwork and engineering contexts in undergraduate engineering is through the educational construct of Model-Eliciting Activities (MEAs). MEAs are a class of interdisciplinary problems designed to simulate authentic, client-driven situations in classroom settings. MEAs allow teachers and researchers to observe student development of conceptual models by requiring students to make their models explicit through design-test-revise cycles. The solution of an MEA requires the use of one or more mathematical or engineering concepts that are unspecified by the problem - students must make new sense of their existing knowledge and understandings to formulate a generalizable mathematical model that can be used by the client to solve the given and similar problems. An MEA creates an environment in which skills beyond mathematical abilities are valued because the focus is not on the use of prescribed equations and algorithms but on the use of a broader spectrum of skills required for effective engineering problem solving. Carefully constructed MEAs can begin to prepare students to communicate and work effectively in teams;to adopt and adapt conceptual tools;to construct, describe, and explain complex systems;and to cope with complex systems. MEAs provide a learning environment that is tailored to a more diverse population than typical engineering course experiences as they allow students with different backgrounds and values to emerge as talented, and that adapting these types of activities to engineering courses has the potential to go beyond "filling the gaps" to "opening doors" to wom

关键词： Students

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State estimation in hybrid systems with a bounded number of mode transitions

State estimation in hybrid systems with a bounded number of ...

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International Conference on Information Fusion

作者： Daniel Sigalov Yaakov Oshman Program of Applied Mathematics Technion-Israel Institute of Technology Haifa Israel Department of Aerospace Engineering Technion-Israel Institute of Technology Haifa Israel

We consider the problem of tracking the state of a hybrid system capable of performing a bounded number of mode switches. The system is assumed to follow either a nominal or an anomalous model, where the nominal model may stand for, e.g., the non-maneuvering motion regime of a target or the fault-free operation mode of a sensor, and the anomalous model may stand for, e.g., the abrupt evasive maneuvers of a target or the faulty operation of a sensor. As is well known, the optimal algorithm requires implementation of an exponentially growing number of primitive Kalman filters. On the other hand, the system's switching dynamics is not Markov because of the a priori bounded number of model switches, thus ruling out the use of popular estimation schemes such as the interacting multiple model (IMM) and generalized pseudo-Bayesian (GPB) filters. We derive an efficient scheme that uses a number of primitive Kalman filters that is linear in the number of possible maneuvers. The scheme resembles the IMM algorithm in that it uses interaction between some of the primitive filters before every estimation cycle, thus reducing the number of such filters. The algorithm's performance is evaluated via a simulation study, and shown to outperform the state-of-the-art IMM filter in a typical example.

关键词： Markov processes Estimation Target tracking Switches Heuristic algorithms Computational modeling

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TEXAS HOLD'EM ALGORITHMS FOR DISTRIBUTED COMPRESSIVE SENSING

TEXAS HOLD'EM ALGORITHMS FOR DISTRIBUTED COMPRESSIVE SENSING

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IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Stephen R. Schnelle Jason N. Laska Chinmay Hegde Marco F. Duarte Mark A. Davenport Richard G. Baraniuk Department of Electrical and Computer Engineering Rice University Houston TX 77005 Program in Applied and Computational Mathematics Princeton University Princeton NJ 08544

ISBN: (纸本)9781424442959

This paper develops a new class of algorithms for signal recovery in the distributed compressive sensing (DCS) framework. DCS exploits both intra-signal and inter-signal correlations through the concept of joint sparsity to further reduce the number of measurements required for recovery. DCS is well-suited for sensor network applications due to its universality, computational asymmetry, tolerance to quantization and noise, and robustness to measurement loss. In this paper we propose recovery algorithms for the sparse common and innovation joint sparsity model. Our approach leads to a class of efficient algorithms, the Texas Hold 'Em algorithms, which are scalable both in terms of communication bandwidth and computational complexity.

关键词： Signal reconstruction multisensor systems data compression Multisensor systems Signal reconstruction Data compression New classes algorithms Texas Signal restoration Quantization Scalability

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KRONECKER PRODUCT MATRICES FOR COMPRESSIVE SENSING

KRONECKER PRODUCT MATRICES FOR COMPRESSIVE SENSING

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IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Marco F. Duarte Richard G. Baraniuk Program in Applied and Computational Mathematics Princeton University Princeton NJ 08544 Department of Electrical and Computer Engineering Rice University Houston TX 77005

ISBN: (纸本)9781424442959

Compressive sensing (CS) is an emerging approach for acquisition of signals having a sparse or compressible representation in some basis. While CS literature has mostly focused on problems involving 1-D and 2-D signals, many important applications involve signals that are multidimensional. We propose the use of Kronecker product matrices in CS for two purposes. First, we can use such matrices as sparsifying bases that jointly model the different types of structure present in the signal. Second, the measurement matrices used in distributed measurement settings can be easily expressed as Kronecker products. This new formulation enables the derivation of analytical bounds for sparse approximation and CS recovery of multidimensional signals.

关键词： Data compression multidimensional signal processing signal reconstruction

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