1,742 research outputs found

    Four dimensional observations of clouds from geosynchronous orbit using stereo display and measurement techniques on an interactive information processing system

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    Simultaneous Geosynchronous Operational Environmental Satellite (GOES) 1 km resolution visible image pairs can provide quantitative three dimensional measurements of clouds. These data have great potential for severe storms research and as a basic parameter measurement source for other areas of meteorology (e.g. climate). These stereo cloud height measurements are not subject to the errors and ambiguities caused by unknown cloud emissivity and temperature profiles that are associated with infrared techniques. This effort describes the display and measurement of stereo data using digital processing techniques

    Wind estimates from cloud motions: Preliminary results from phases 1, 2, and 3 of an in situ aircraft verification experiment

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    Low level aircraft equipped with Inertial Navigation Systems (INS) were used to define the vertical extent and horizontal motion of a cloud and to measure the ambient wind field. A high level aircraft, also equipped with an INS, took photographs to describe the horizontal extent of the cloud field and to measure cloud motion. The aerial photographs were also used to make a positive identification in a satellite picture of the cloud observed by the low level aircraft. The experiment was conducted over the tropical oceans in the vicinity of Florida, Puerto Rico, Panama and in the Western Gulf of Mexico. Results for tropical cumulus clouds indicate excellent agreement between the cloud motion and the wind at the cloud base. The magnitude of the vector difference between the cloud motion and the cloud base wind is less than 1.3 m/sec for 67% of the cases with track lengths of 1 hour or longer. The cirrus cloud motions agreed best with the mean wind in the cloud layer with a vector difference of about 1.6 m/sec

    Nonlinear Circuit Analysis via Perturbation Methods and Hardware Prototyping

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    Nonlinear signal processing is necessary in many emerging applications where form factor and power are at a premium. In order to make such complex computation feasible under these constraints, it is necessary to implement the signal processors as analog circuits. Since analog circuit design is largely based on a linear systems perspective, new tools are being introduced to circuit designers that allow them to understand and exploit circuit nonlinearity for useful processing. This paper discusses two such tools, which represent nonlinear circuit behavior in a graphical way, making it easy to develop a qualitative appreciation for the circuits under study

    Defined Contribution Plans and the Challenge of Financial Illiteracy

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    Retirement investing in the United States has changed dramatically. The classic defined-benefit (DB) plan has largely been replaced by the defined contribution (DC) plan. With the latter, individual employees’ decisions about how much to save for retirement and how to invest those savings determine the benefits available upon retirement.We analyze data from the 2015 National Financial Capability Study to show that people whose only exposure to investment decisions is by virtue of their participation in an employer-sponsored 401(k) plan are poorly equipped to make sound investment decisions. Specifically, they suffer from higher levels of financial illiteracy than other investors. This lack of financial literacy is critical both because of the financial consequences of poor financial decisions and because of a legal structure that relies on participant choice to limit the fiduciary obligations of the employer with respect to the structure and options provided by the retirement plan.In response to this concern, we propose mandated employer-provided financial education to address limited employee financial literacy. We identify and discuss three requirements that a financial education program should incorporate – a self-assessment, minimum substantive components, and timing. Formalizing the employer role in evaluating and increasing financial literacy among plan participants is a key step in providing retirement plan participants with the resources necessary to manage important decisions regarding retirement planning and, ultimately, for enhancing the financial security of American workers

    Defined Contribution Plans and the Challenge of Financial Illiteracy

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    Retirement investing in the United States has changed dramatically. The classic defined benefit (DB) plan has largely been replaced by the defined contribution (DC) plan. With the latter, individual employees\u27 decisions about how much to save for retirement and how to invest those savings determine the benefits available upon retirement. We analyze data from the 2015 National Financial Capability Study to show that people whose only exposure to investment decisions is by virtue of their participation in an employer-sponsored 401(k) plan are poorly equipped to make sound investment decisions. Specifcally, they suffer from higher levels of financial illiteracy than other investors. This lack of financial literacy is critical because of both the financial consequences of poor financial decisions and a legal structure that relies on participant choice to limit the fiduciary obligations of the employer with respect to the structure and options provided by the retirement plan. In response to this concern, we propose mandated employer-provided financial education to address limited employee financial literacy. We identify and discuss three requirements that a financial education program should incorporate-a self-assessment, minimum substantive components, and timing. Formalizing the employer role in evaluating and increasing financial literacy among plan participants is a key step in providing retirement plan participants with the resources necessary to manage important decisions regarding retirement planning and, ultimately, for enhancing the financial security of American worker

    A simple circuit realization of the tent map

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    We present a very simple electronic implementation of the tent map, one of the best-known discrete dynamical systems. This is achieved by using integrated circuits and passive elements only. The experimental behavior of the tent map electronic circuit is compared with its numerical simulation counterpart. We find that the electronic circuit presents fixed points, periodicity, period doubling, chaos and intermittency that match with high accuracy the corresponding theoretical valuesComment: 6 pages, 6 figures, 10 references, published versio

    N=2 central charge superspace and a minimal supergravity multiplet

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    We extend the notion of central charge superspace to the case of local supersymmetry. Gauged central charge transformations are identified as diffeomorphisms at the same footing as space-time diffeomorphisms and local supersymmetry transformations. Given the general structure we then proceed to the description of a particular vector-tensor supergravity multiplet of 24+24 components, identified by means of rather radical constraints

    Warum rauchen Schizophreniepatienten?

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    Zusammenfassung: Patienten mit schizophrenen Störungen zeigen eine erhöhte Prävalenz der Nikotinabhängigkeit. Diese Arbeit beleuchtet die Zusammenhänge zwischen Schizophrenie und Nikotinkonsum. Es gibt deutliche Hinweise dafür, dass wesentliche Bereiche kognitiver Funktionen bei Patienten mit schizophrenen Erkrankungen durch Nikotin verbessert werden, insbesondere Daueraufmerksamkeit, gerichtete Aufmerksamkeit, Arbeitsgedächtnis, Kurzzeitgedächtnis und Wiedergabe aus dem Gedächtnis. Auch konnten in einigen Studien mittels ereigniskorrelierten Potenzialen (P50-Paradigma) und der Präpulsinhibition des akustisch ausgelösten Schreckreflexes gezeigt werden, dass präattentive Maße der Informationsverarbeitung, die eine zentrale Rolle in der Schizophrenie spielen, durch Gabe von Nikotin verbessert werden können. Weiterhin kann Rauchen die durch antipsychotische Medikamente hervorgerufenen extrapyramidalen Nebenwirkungen verbessern, und es induziert das Zytochrom P4501A2, das auch an der Metabolisierung einiger Neuroleptika beteiligt ist. Zusammenfassend kann festgestellt werden, dass die Nikotinzufuhr bei Patienten mit schizophrenen Störungen eine Form der "Selbstmedikation" darstellen könnte, um Defizite im Bereich Aufmerksamkeit, Kognition und Informationsverarbeitung zu verbessern und um Nebenwirkungen von Antipsychotika zu reduzieren. Mögliche pharmakotherapeutische Ansätze zur Behandlung der gestörten Neurotransmission am nikotinergen Azetylcholinrezeptor werden diskutier

    Исследование влияния температуры на процесс восстановления ацетилдифенила изопропилатом алюминия

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    We present a compact module, emitting nearly diffraction limited green laser light at 531 nm at an average output power of more than 500 mW. As pump source for the second harmonic generation a DBR tapered laser with a total length of 6 mm was used. The RW section had a length of 2 mm including a 1 mm long passive DBR section. The devices were mounted p-side up on a copper block. For this mounting scheme, the device reaches up to 7 W maximal output power. At the power level of about 3.8 W used in the presented experiment, a wavelength of 1062.6 nm with a line-width below 0.02 nm (FWHM) was determined. More than 80% of the emitted power is originated within the central lobe of the beam waist profile illustrating the nearly diffraction limited beam quality. Using a 30mm long MgO-doped periodically poled LiNbO3 bulk crystal, the second harmonic wave is generated in a single-pass setup. Due to precise alignment and beam shaping based on the results of numerical simulations and a properly temperature control of the PPLN crystal, a maximum optical conversion efficiency of more than 14% (3.7%/W) was achieved. The fluctuation of the output power is far below 1%
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