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Correction to: npj Computational Materials (2016) 2, 16002; doi:10.1038/npjcompumats.2016.2; published online 18 March 2016 Since the online publication of the above article, it has been noted that an acknowledgement section should have been included and the text should read: ‘This work was supported primarily by the U.
Memristor, the missing fourth passive circuit element predicted forty years ago by Chua was recognized as a nanoscale device in 2008 by researchers of a H. P. Laboratory. Recently the notion of memristive systems was extended to capacitive and inductive elements, namely, memcapacitor and meminductor whose properties depend on the state and history of the system. In this paper, we use fractional calculus to generalize and provide a mathematical paradigm for describing the behavior of such elements with memory. In this framework, we extend Ohm's law to the generalized Ohm's law and prove it.
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With an estimated 4.6 billion units in use, mobile phones have already become the most popular computing device in human history. Their portability and communication capabilities may revolutionize how people do their daily work and interact with other people in ways PCs have done during the past 30 years. Despite decades of experiences in creating modern WIMP (windows, icons, mouse, pointer) interfaces, our knowledge in building effective mobile interfaces is still limited, especially for emerging interaction modalities that are only available on mobile devices. This dissertation explores how emerging sensors on a mobile phone, such as the built-in camera, the microphone, the touch sensor and the GPS module can be leveraged to make everyday interactions easier and more efficient. We present studies and models to quantify the capabilities of these sensing channels, and show how effective interfaces in text entry, gaming, and CSCW can be built on mobile phones. The first such technology is TinyMotion. TinyMotion detects the movements of a mobile phone in real time by analyzing image sequences captured by its built-in camera, providing a usable analog pointing channel to existing mobile phone users. We quantified TinyMotion's human performance as a basic input control sensor. We found target acquisition tasks via TinyMotion follow Fitts' law, and Fitts' law parameters can be used for TinyMotion-based pointing performance measurements. We show that using camera phone as a handwriting capture device and performing large vocabulary, multilingual real time handwriting recognition on the mobile phone are feasible. Based on experiences and lessons learned from TinyMotion, this dissertation also introduces SHRIMP (Small Handheld Rapid Input with Motion and Prediction), a predictive mobile text input method runs on camera phones equipped with a standard 12-key keypad. SHRIMP maintains the speed advantage of Dictionary-Based Disambiguation (DBD) driven predictive text input while enabling the user to overcome collision and OOV problems seamlessly without explicit mode switching. Then, FingerSense is presented as another example of perceptual interface to enhance the expressiveness of physical buttons on space-constrained mobile devices. This dissertation also introduces a context-aware system named GLAZE (Generalized Location Aware ModelZ for End-users). GLAZE allows average user without any programming experiences, to create everyday location-aware applications directly on their mobile phones. Last, this thesis describes the design, implementation and evaluation of Event Maps, a web-based calendaring system targeted at improving the experience of attending and organizing large, multi-track conferences on both desktop computers and mobile devices. Event Maps has been successfully deployed in multiple large, real world conferences.
Several theorems are presented which predict in a qualitative manner the behavior of a large class of dynamic nonlinear networks containing coupled and multiterminal resistors, inductors, and capacitors. A very general and rather surprising result is presented which guarantees that most autonomous and nonautonomous dynamic nonlinear active networks of practical interest have no finite "forward" escape time solutions. In the case of autonomous networks, sufficient conditions are given which guarantee that the solution waveforms possess various forms of stability properties. The concepts of eventual passivity and eventual strict passivity are invoked to guarantee that all solution waveforms are bounded and eventually uniformly bounded, respectively. The properties of reciprocity and monotonicity (local passivity) are invoked to guarantee that all solutions are completely stable. The further imposition of a growth condition guarantees that all solutions will converge to a globally asymptotically stable equilibrium point. In this case, the magnitude of all solutions is shown to be bounded between two exponential waveforms for all time <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t > 0</tex> . An algorithm is presented which computes for the maximum "transient decay" time constant associated with the upper bounding exponential. The main features of the majority of the theorems presented in this paper are that their hypotheses are simple and easily verifiable-often by inspection. The hypotheses are of two types: first, very general conditions on the network state equations and second, conditions on the individual element characteristics and their interconnections. The hypotheses and proofs of the latter type of theorems depend heavily upon the graphtheoretic results of an earlier paper [14] and involve solely the examination of the global nature of each element's constitutive relation and the verification of a topological "loop-cutset" conditions.
Abstract Supported Co is an effective catalyst for the Fischer–Tropsch synthesis of various hydrocarbon products that can be converted to diesel. Recent studies have shown that the formation of methane can be suppressed and the formation of C 5+ products enhanced by promoting Co with Mn. Because the activity and product selectivity of Co‐based catalysts are dependent on the size of Co nanoparticles and the extent of Co promotion by Mn, it is desirable to understand these effects by investigating the performance of Co nanoparticles with well‐defined size and elemental composition. The present study was undertaken with the aim of producing well‐defined nanoparticles of Co and Co–Mn and then supporting them on silica. Co and Co–Mn particles were synthesized through the polyol reduction of Co and Mn acetylacetonates. By controlling synthesis conditions, Co particles with diameters of 7–10 nm and similarly sized Co–Mn (Mn/Co=0.1) particles were prepared. XRD and elemental mapping with scanning TEM‐energy‐dispersive X‐ray spectroscopy and scanning TEM‐electron energy loss spectroscopy studies suggested that most of the Mn species was associated with the Co particles. Ex situ prepared Co and Co–Mn nanoparticles were first supported on silica and then investigated for the catalytic activity for the Fischer–Tropsch synthesis. The turnover frequencies and product distributions obtained with silica‐supported Co and Co–Mn nanoparticles were similar to those obtained with catalysts prepared by using the conventional incipient wetness impregnation method. However, the rate of CO consumption per mass of Co was much lower for the catalysts produced by supporting ex situ prepared nanoparticles. This effect was attributed to the sintering of the nanoparticles during their calcination and reduction. Magnetic interactions among nanoparticles during their immobilization and thermal pretreatment were identified as the primary cause of sintering.
Circularly polarized light opens a gap in the Dirac spectrum of graphene and topological insulator (TI) surfaces, thereby inducing a quantum Hall-like phase. We propose to detect the accompanying edge states and their current by the magnetic field they produce. The topological nature of the edge states is reflected in the mean orbital magnetization of the sample, which shows a universal linear dependence as a function of a generalized chemical potential-independent of the driving details and the properties of the material. The proposed protocol overcomes several typically encountered problems in the realization and measurement of Floquet phases, including the destructive effects of phonons and coupled electron baths and provides a way to occupy the induced edge states selectively. We estimate practical experimental parameters and conclude that the magnetization signature of the Floquet topological phase may be detectable with current techniques.
Fixturing is a fundamental problem in mechanical assembly. Usually, two and a half dimensional objects can be fixtured in many different ways using a fixture vice, especially if pegs of different radii are available. The authors present an algorithm which enumerates all force closure fixture vice configurations and corresponding object poses. Automatic fixture design algorithms are essential for planning because optimal fixturing selections for multiple operations requires examining all of the valid configurations. The algorithm runs in O(A) time, where A is the number of configurations which simultaneously contact the object.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
