802 research outputs found

    ITOS VHRR on-board data compression study

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    Data compression methods for ITOS VHRR data were studied for a tape recorder record-and playback application. A playback period of 9 minutes was assumed with a nominal 18 minute record period for a 2-to-1 compression ratio. Both analog and digital methods were considered with the conclusion that digital methods should be used. Two system designs were prepared. One is a PCM system and the other is an entropy-coded predictive-quantization, sometimes called entropy-coded DPCM or just DPCM, system. Both systems use data management principles to transmit only the necessary data. Both systems use a medium capacity standard tape recorder from specifications provided by the technical officer. The 10 to the 9th power bit capacity of the recorder is the basic limitation on the compression ratio. Both systems achieve the minimum desired 2 to 1 compression ratio. A slower playback rate can be used with the DPCM system due to a higher compression factor for better link performance at a given CNR in terms of bandwidth utilization and error rate. The report is divided into two parts. The first part summarizes the theoretical conclusions of the second part and presents the system diagrams. The second part is a detailed analysis based upon an empirically derived random process model arrived at from specifications and measured data provided by the technical officer

    Monte Carlo simulation of wave sensing with a short pulse radar

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    A Monte Carlo simulation is used to study the ocean wave sensing potential of a radar which scatters short pulses at small off-nadir angles. In the simulation, realizations of a random surface are created commensurate with an assigned probability density and power spectrum. Then the signal scattered back to the radar is computed for each realization using a physical optics analysis which takes wavefront curvature and finite radar-to-surface distance into account. In the case of a Pierson-Moskowitz spectrum and a normally distributed surface, reasonable assumptions for a fully developed sea, it has been found that the cumulative distribution of time intervals between peaks in the scattered power provides a measure of surface roughness. This observation is supported by experiments

    Universal approximation of multi-copy states and universal quantum lossless data compression

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    We have proven that there exists a quantum state approximating any multi-copy state universally when we measure the error by means of the normalized relative entropy. While the qubit case was proven by Krattenthaler and Slater (IEEE Trans. IT, 46, 801-819 (2000); quant-ph/9612043), the general case has been open for more than ten years. For a deeper analysis, we have solved the mini-max problem concerning `approximation error' up to the second order. Furthermore, we have applied this result to quantum lossless data compression, and have constructed a universal quantum lossless data compression

    The Locality Problem in Quantum Measurements

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    The locality problem of quantum measurements is considered in the framework of the algebraic approach. It is shown that contrary to the currently widespread opinion one can reconcile the mathematical formalism of the quantum theory with the assumption of the existence of a local physical reality determining the results of local measurements. The key quantum experiments: double-slit experiment on electron scattering, Wheeler's delayed-choice experiment, the Einstein-Podolsky-Rosen paradox, and quantum teleportation are discussed from the locality-problem point of view. A clear physical interpretation for these experiments, which does not contradict the classical ideas, is given.Comment: Latex, 40 pages, 7 figure

    Nutritional care is a human right: Translating principles to clinical practice

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    We have previously advocated that nutritional care be raised to the level of a human right, in close relationship to two well-recognized fundamental rights: the right to food and the right to health. This article aims to analyze the implication of nutritional care as a human right for healthcare practitioners. We will focus on the impact of the Human Rights Basic Approach (HRBA) on healthcare professionals (HCPs), namely how they can translate HRBA into routine clinical practice. Ethics and human rights are guiding values for clinical nutrition practitioners. Together they ensure a patient-centered approach, in which the needs and rights of the patients are of the most significant importance. Human rights are based on the powerful idea of equal dignity for all people while expressing a set of core values, including fairness, respect, equality, dignity, and autonomy (FREDA). Through the analysis of FREDA principles, we have provided the elements to understand human rights and how an HRBA can support clinicians in the decision-making process. Clinical practice guidelines in clinical nutrition should incorporate disease-specific ethical issues and the HRBA. The HRBA should contribute to building conditions for HCPs to provide optimal and timely nutritional care. Nutritional care must be exercised by HCPs with due respect for several fundamental ethical values: attentiveness, responsibility competence, responsiveness, and solidarity

    Nutritional care is a human right: Translating principles to clinical practice

    Get PDF
    We have previously advocated that nutritional care be raised to the level of a human right in a close relationship to two well recognized fundamental rights: the right to food and the right to health. This paper aims to analyze the implication of nutritional care as a human right for healthcare practitioners. We will focus on the impact of the Human Rights Basic Approach (HRBA) on health care professionals (HCPs), namely how they can translate HRBA into routine clinical practice. Ethics and human rights are guiding values for clinical nutrition practitioners. Together they ensure a patient-centered approach, where the needs and rights of the patients are of the most significant importance. Human rights are based on the powerful idea of equal dignity for all people while expressing a set of core values, including fairness, respect, equality, dignity, and autonomy (FREDA). Through the analysis of FREDA principles, we have provided the elements to understand human rights and how a HRBA can support clinicians in the decision-making process. Clinical practice guidelines in clinical nutrition should incorporate disease-specific ethical issues and the HRBA. The HRBA should contribute to build conditions for HCPs to provide optimal and timely nutritional care. Nutritional care must be exercised by HCPs with due respect for several fundamental ethical values: attentiveness, responsibility competence, responsiveness, and solidarity

    de Broglie waves as the "Bridge of Becoming" between quantum theory and relativity

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    It is hypothesized that de Broglie's 'matter waves' provide a dynamical basis for Minkowski spacetime in an antisubstantivalist or relational account. The relativity of simultaneity is seen as an effect of the de Broglie oscillation together with a basic relativity postulate, while the dispersion relation from finite rest mass gives rise to the differentiation of spatial and temporal axes. Thus spacetime is seen as not fundamental, but rather as emergent from the quantum level. A result by Solov'ev which demonstrates that time is not an applicable concept at the quantum level is adduced in support of this claim. Finally, it is noted that de Broglie waves can be seen as the "bridge of becoming" discussed by Elitzur and Dolev (2005).Comment: Forthcoming in Foundations of Science; reference added to recent work of Dolc

    On the verge of Umdeutung in Minnesota: Van Vleck and the correspondence principle (Part One)

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    In October 1924, the Physical Review, a relatively minor journal at the time, published a remarkable two-part paper by John H. Van Vleck, working in virtual isolation at the University of Minnesota. Van Vleck combined advanced techniques of classical mechanics with Bohr's correspondence principle and Einstein's quantum theory of radiation to find quantum analogues of classical expressions for the emission, absorption, and dispersion of radiation. For modern readers Van Vleck's paper is much easier to follow than the famous paper by Kramers and Heisenberg on dispersion theory, which covers similar terrain and is widely credited to have led directly to Heisenberg's "Umdeutung" paper. This makes Van Vleck's paper extremely valuable for the reconstruction of the genesis of matrix mechanics. It also makes it tempting to ask why Van Vleck did not take the next step and develop matrix mechanics himself.Comment: 82 page
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