A pseudo-matched filter for chaos

A matched filter maximizes the signal-to-noise ratio of a signal. In the recent work of Corron et al. [Chaos 20, 023123 (2010)], a matched filter is derived for the chaotic waveforms produced by a piecewise-linear system. Motivated by these results, we describe a pseudo-matched filter, which removes noise from the same chaotic signal. It consists of a notch filter followed by a first-order, low-pass filter. We compare quantitatively the matched filter's performance to that of our pseudo-matched filter using correlation functions in a simulated radar application. On average, the pseudo-matched filter performs with a correlation signal-to-noise ratio that is 2.0 dB below that of the matched filter. Our pseudo-matched filter, though somewhat inferior in comparison to the matched filter, is easily realizable at high speed (> 1 GHz) for potential radar applications

Block co-polyMOFs: morphology control of polymer-MOF hybrid materials.

The hybridization of block copolymers and metal-organic frameworks (MOFs) to create novel materials (block co-polyMOFs, BCPMOFs) with controlled morphologies is reported. In this study, block copolymers containing poly(1,4-benzenedicarboxylic acid, H2bdc) and morphology directing poly(ethylene glycol) (PEG) or poly(cyclooctadiene) (poly(COD)) blocks were synthesized for the preparation of BCPMOFs. Block copolymer architecture and weight fractions were found to have a significant impact on the resulting morphology, mediated through the assembly of polymer precursors prior to MOF formation, as determined through dynamic light scattering. Simple modification of block copolymer weight fraction allowed for tuning of particle size and morphology with either faceted and spherical features. Modification of polymer block architecture represents a simple and powerful method to direct morphology in highly crystalline polyMOF materials. Furthermore, the BCPMOFs could be prepared from both Zr4+ and Zn2+ MOFs, yielding hybrid materials with appreciable surface areas and tuneable porosities. The resulting Zn2+ BCPMOF yielded materials with very narrow size distributions and uniform cubic morphologies. The use of topology in BCPMOFs to direct morphology in block copolymer assemblies may open new methodologies to access complex materials far from thermodynamic equilibrium

Service learning and student leadership through environmentally immersive writing

This study examined the impact of environmentally immersive service learning on a focused cluster of the NJASK, self-perception of leadership, attitude toward the environment, and student ability to define and articulate the benefits of service learning. The study compared the 2008-2009 New Jersey Assessment of Skills and Knowledge 7 (NJASK 7) and the 2009-2010 New Jersey Assessment of Skills and Knowledge 8 (NJASK 8) cluster area score of the explanatory task. The difference in the mean score on the explanatory task was analyzed by comparing the state, the Allamuchy Township School District, and the district factor group, representing other communities with relatively similar socioeconomic status. The second section contains a self-analysis of attitudes and perception of participant leadership skills prior to participation in the study, and again after participation in the study using the Student Leadership Practices Inventory (LPI). There are five subscales that are discussed including: modeling the way, inspiring a shared vision, challenging the process, enabling others to act, and encouraging the heart. The third section analyzes the results from Children\u27s Attitudes Towards the Environment Scale (CATES), which measures environmental attitudes of children. The fourth section includes data gathered from structured interviews discussing student ability to define and articulate the benefits of service learning after participating in environmentally immersive service learning. The research indicated a significant increase in attitude toward the environment, and the increase in the cluster area score of explanatory writing demonstrates the need for further research. Self-perception of leadership was not statistically significant, and the ability to define and articulate the benefits of service learning highlighted areas of focus for future research projects

Star Formation and Relaxation in 379 Nearby Galaxy Clusters

We investigate the relationship between star formation (SF) and level of relaxation in a sample of 379 galaxy clusters at z < 0.2. We use data from the Sloan Digital Sky Survey to measure cluster membership and level of relaxation, and to select star-forming galaxies based on mid-infrared emission detected with the Wide-Field Infrared Survey Explorer. For galaxies with absolute magnitudes M_r < -19.5, we find an inverse correlation between SF fraction and cluster relaxation: as a cluster becomes less relaxed, its SF fraction increases. Furthermore, in general, the subtracted SF fraction in all unrelaxed clusters (0.117 +/- 0.003) is higher than that in all relaxed clusters (0.097 +/- 0.005). We verify the validity of our SF calculation methods and membership criteria through analysis of previous work. Our results agree with previous findings that a weak correlation exists between cluster SF and dynamical state, possibly because unrelaxed clusters are less evolved relative to relaxed clusters.Comment: 6 pages, 4 figures, accepted for publication in Ap

To Innovate or Not to Innovate, That Is the Question: The Functions, Failures, and Foibles of the Reward Function Theory of Patent Law in Relation to Computer Software Platforms

The patent system has traditionally been viewed as having two primary functions: the reward function and the prospect function. Although these theories do explain some behavior which results from the practical applications of the patent system, they also overlook some behavior of the patent system which indicates a failure of these functions. In order to properly prevent such failure, this paper proposes that the patent system adopt an orientation that will lead to increased innovative rivalry and competition. In Part I, using the computer operating system software market as an example, I propose a framework for reconceptualizing patent protection as it applies to software operating system platforms. Part II briefly examines both the classical and neoclassical reward function and prospect function theories. Part III defines the innovation market and describes the market dynamics that create disincentives for innovation. These disincentives tend to limit the number of competitors in innovation markets and create conditions which reduce the effectiveness of the reward incentives to the extent that the reward function fails in its entirety. Part IV examines the resulting harms of this failure and identifies how reward function failure affects product markets, which are dependent upon the reward function. Part V discusses why the prospect function does not address the problems related to reward function failure and the reasons that the promotion of innovative rivalry would alleviate some of the problems. Part VI uses the relationship between computer programs to illustrate the shortcomings of the patent system\u27s inability to prevent the problems created by non-competitive innovation. This section also considers how the patent system might be better adjusted to prevent reward function failure. Lastly, Part VI also proposes a series of alternative frameworks for creating a competitively oriented approach to the application of the patent system in the case of computer software platforms

Enhanced photochemical hydrogen production by a molecular diiron catalyst incorporated into a metal-organic framework.

A molecular proton reduction catalyst [FeFe](dcbdt)(CO)6 (1, dcbdt = 1,4-dicarboxylbenzene-2,3-dithiolate) with structural similarities to [FeFe]-hydrogenase active sites has been incorporated into a highly robust Zr(IV)-based metal-organic framework (MOF) by postsynthetic exchange (PSE). The PSE protocol is crucial as direct solvothermal synthesis fails to produce the functionalized MOF. The molecular integrity of the organometallic site within the MOF is demonstrated by a variety of techniques, including X-ray absorption spectroscopy. In conjunction with [Ru(bpy)3](2+) as a photosensitizer and ascorbate as an electron donor, MOF-[FeFe](dcbdt)(CO)6 catalyzes photochemical hydrogen evolution in water at pH 5. The immobilized catalyst shows substantially improved initial rates and overall hydrogen production when compared to a reference system of complex 1 in solution. Improved catalytic performance is ascribed to structural stabilization of the complex when incorporated in the MOF as well as the protection of reduced catalysts 1(-) and 1(2-) from undesirable charge recombination with oxidized ascorbate