13,228 research outputs found

    Calorimetry, activity, and micro-FTIR analysis of CO chemisorption, titration, and oxidation on supported Pt

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    The value of in situ analysis on CO chemisorption, titration and oxidation over supported Pt catalysts using calorimetry, catalytic and micro-FTIR methods is illustrated using silica- and titania-supported samples. Isothermal CO-O and O2-CO titrations have not been widely used on metal surfaces and may be complicated if some oxide supports are reduced by CO titrant. However, they can illuminate the kinetics of CO oxidation on metal/oxide catalysts since during such titrations all O and CO coverages are scanned as a function of time. There are clear advantages in following the rates of the catalyzed CO oxidation via calorimetry and gc-ms simultaneously. At lower temperatures the evidence they provide is complementary. CO oxidation and its catalysis of CO oxidation have been extensively studied with hysteresis and oscillations apparent, and the present results suggest the benefits of a combined approach. Silica support porosity may be important in defining activity-temperature hysteresis. FTIR microspectroscopy reveals the chemical heterogeneity of the catalytic surfaces used; it is interesting that the evidence with regard to the dominant CO surface species and their reactivities with regard to surface oxygen for present oxide-supported Pt are different from those seen on graphite-supported Pt

    Human Capital, Innovation, and Productivity Growth: Tales from Latin America and Caribbean

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    Why have Latin American and Caribbean countries (LAC countries) not replicated Western economic success? We investigate the reasons behind the economic stagnation of LAC countries for the past four decades. We utilize a nonparametric Malmquist productivity index for relevant cross-country and over time productivity growth, technological change, and technical efficiency change comparisons. We document that productivity growth differences between LAC countries and Western countries can only partially be attributed to human capital differences. We argue that along with inefficient production, differences in civil, political, and economic policies and institutions are promising factors in explaining the long-run economic performance of LAC countries.Caribbean; Latin America; Institutions; Malmquist productivity index

    Algorithms as scores: coding live music

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    The author discusses live coding as a new path in the evolution of the musical score. Live-coding practice accentu- ates the score, and whilst it is the perfect vehicle for the performance of algorithmic music it also transforms the compositional process itself into a live event. As a continuation of 20th-century artistic developments of the musical score, live-coding systems often embrace graphical elements and language syntaxes foreign to standard programming languages. The author presents live coding as a highly technologized artistic practice, shedding light on how non-linearity, play and generativity will become prominent in future creative media productions

    The Andean Group: An answer to some problems of LAFTA

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    Regional economic integration is considered as an efficient mean to accelerate economic development of the participating states. It is therefore one of the major themes of the next UNCTAD conference. One famous example of integration between developing countries is LAFTA (Latin American Free Trade Association). LAFTA failed, however, in so far as the smaller members were not able to achieve the gains in industrial development they had hoped for. This seems to have been due to the fact that LAFTA mainly concentrated on trade liberalization. An answer to these shortcomings is the Andean Group, formed by Bolivia, Chile, Colombia, Ecuador, and Peru. The Group tries to solve the problems through implementation of sectorial programs of industrial development and a harmonized investment policy. The Andean Group is therefore a unique example where trial and error lead to a new and possibly more adequate form of economic integration. --

    Finite size scaling approach to dynamic storage allocation problem

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    It is demonstrated how dynamic storage allocation algorithms can be analyzed in terms of finite size scaling. The method is illustrated in the three simple cases of the it first-fit, next-fit and it best-fit algorithms, and the system works at full capacity. The analysis is done from two different points of view - running speed and employed memory. In both cases, and for all algorithms, it is shown that a simple scaling function exists and the relevant exponents are calculated. The method can be applied on similar problems as well.Comment: 9 pages, 4 figures, will apear in Physica

    Tagungsband zum 21. Kolloquium Programmiersprachen und Grundlagen der Programmierung

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    Das 21. Kolloquium Programmiersprachen und Grundlagen der Programmierung (KPS 2021) setzt eine traditionelle Reihe von Arbeitstagungen fort, die 1980 von den Forschungsgruppen der Professoren Friedrich L. Bauer (TU München), Klaus Indermark (RWTH Aachen) und Hans Langmaack(CAU Kiel) ins Leben gerufen wurde.Die Veranstaltung ist ein offenes Forum für alle interessierten deutschsprachigen Wissenschaftlerinnen und Wissenschaftler zum zwanglosen Austausch neuer Ideen und Ergebnisse aus den Forschungsbereichen Entwurf und Implementierung von Programmiersprachen sowie Grundlagen und Methodik des Programmierens. Dieser Tagungsband enthält die wissenschaftlichen Beiträge,die bei dem 21. Kolloquium dieser Tagungsreihe präsentiert wurden, welches vom 27. bis 29. September 2021 in Kiel stattfand und von der Arbeitsgruppe Programmiersprachen und Übersetzerkonstruktion der Christian-Albrechts-Universität zu Kiel organisiert wurde

    Neuroinspired unsupervised learning and pruning with subquantum CBRAM arrays.

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    Resistive RAM crossbar arrays offer an attractive solution to minimize off-chip data transfer and parallelize on-chip computations for neural networks. Here, we report a hardware/software co-design approach based on low energy subquantum conductive bridging RAM (CBRAM®) devices and a network pruning technique to reduce network level energy consumption. First, we demonstrate low energy subquantum CBRAM devices exhibiting gradual switching characteristics important for implementing weight updates in hardware during unsupervised learning. Then we develop a network pruning algorithm that can be employed during training, different from previous network pruning approaches applied for inference only. Using a 512 kbit subquantum CBRAM array, we experimentally demonstrate high recognition accuracy on the MNIST dataset for digital implementation of unsupervised learning. Our hardware/software co-design approach can pave the way towards resistive memory based neuro-inspired systems that can autonomously learn and process information in power-limited settings

    Preaching on social-ethical issues

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