5,180 research outputs found

    Application of convolve-multiply-convolve SAW processor for satellite communications

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    There is a need for a satellite communications receiver than can perform simultaneous multi-channel processing of single channel per carrier (SCPC) signals originating from various small (mobile or fixed) earth stations. The number of ground users can be as many as 1000. Conventional techniques of simultaneously processing these signals is by employing as many RF-bandpass filters as the number of channels. Consequently, such an approach would result in a bulky receiver, which becomes impractical for satellite applications. A unique approach utilizing a realtime surface acoustic wave (SAW) chirp transform processor is presented. The application of a Convolve-Multiply-Convolve (CMC) chirp transform processor is described. The CMC processor transforms each input channel into a unique timeslot, while preserving its modulation content (in this case QPSK). Subsequently, each channel is individually demodulated without the need of input channel filters. Circuit complexity is significantly reduced, because the output frequency of the CMC processor is common for all input channel frequencies. The results of theoretical analysis and experimental results are in good agreement

    Intersubband transitions in pseudomorphic InGaAs/GaAs/AlGaAs multiple step quantum wells

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    Intersubband transitions from the ground state to the first and second excited states in pseudomorphic AlGaAs/InGaAs/GaAs/AlGaAs multiple step quantum wells have been observed. The step well structure has a configuration of two AlGaAs barriers confining an InGaAs/GaAs step. Multiple step wells were grown on GaAs substrate with each InGaAs layer compressively strained. During the growth, a uniform growth condition was adopted so that inconvenient long growth interruptions and fast temperature ramps when switching the materials were eliminated. The sample was examined by cross‐sectional transmission electron microscopy, an x‐ray rocking curve technique, and the results show good crystal quality using this simple growth method. Theoretical calculations were performed to fit the intersubband absorption spectrum. The calculated energies are in good agreement with the observed peak positions for both the 1→2 and 1→3 transitions

    Immune-Complex Allergic Vasculitis in Association with the Immune-Complex Allergic Vasculitis in Association with the Development of Transverse Myelitis: A Case Report

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    A severe vasculitis, probably therapy related, in a sixty-four-year-old man being treated for possible subacute bacterial endocarditis, was associated with the development of transverse myelitis. It is hypothesized that the vasculitis affected the small vessels to the spinal cord in the same way that systemic vasculitis can also cause a transverse myelitis

    Role of autophagy in chondrocyte differentiation

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    Poster presentation - Theme 3: Development & stem cellsMaintaining cell homeostasis during cellular differentiation is critical for the cell survival. Therefore, the balance between protein biogenesis and degradation is tightly regulated. The removal of the after-used and unwanted substances is not only important for protein turnover but also in regulating cellular differentiation and developmental process. The degradation of protein relies on two well-known systems, the Ubiquitin-proteasome system (UPS) and Autophagy-lysosomal system (ALS). Here, using the unique organization of the growth plate that depicts temporal and spatial “life time” of chondrocytes during ...postprin

    Pengaruh Gaya Kepemimpinan Transformasional dan Motivasi terhadap Kinerja Guru Dimediasikomitmen Organisasional (Studi pada Guru- Guru SMA Swasta di Kecamatan Pati)

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    The purpose of this research is to analyze how far the influence of transformational leadership style and motivation onteacher performance mediated organizational commitment in private high school teachers in the District of Pati. Theuse of this research is to clarify and enlarge the previous research about the influence of transformational leadershipstyles and motivation on teacher performance mediated organizational commitment. This research is an explanatoryresearch.The population is 193 teachers in private high schoolin District of Pati. Data analysis starts frominstrumenttest,normality test, muilticolonearitytest, heterocedastisity test, models test,hypothesis test and mediating effect test.The result showed that transformational leadership style has no influence on organizational commitment,motivation hasa positive influence and significant on organizationalcommitment, transformational leadership style has a positiveinfluence and significant on the teacher performance,motivation has a positive influence and significant on teacherperformance, organizational commitment has a positive influence and significant on teacherperformance,organizational commitment is not efective to mediate on the influence of transformational leadership styleon teacher performance, and organizational commitment is proved to mediate the influence of motivation on teacherperformance

    Catalysis always degrades external quantum correlations

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    Catalysts used in quantum resource theories need not be in isolation and therefore are possibly correlated with external systems, which the agent does not have access to. Do such correlations help or hinder catalysis, and does the classicality or quantumness of such correlations matter? To answer this question, we first focus on the existence of a non-invasively measurable observable that yields the same outcomes for repeated measurements, since this signifies macro-realism, a key property distinguishing classical systems from quantum systems. We show that a system quantumly correlated with an external system so that the joint state is necessarily perturbed by any repeatable quantum measurement, also has the same property against general quantum channels. Our full characterization of such systems called totally quantum systems, solves the open problem of characterizing tomographically sensitive systems raised in [Lie and Jeong, Phys. Rev. Lett. 130, 020802 (2023)]. An immediate consequence is that a totally quantum system cannot catalyze any quantum process, even when a measure of correlation with its environment is arbitrarily low. It generalizes to a stronger result, that the mutual information of totally quantum systems cannot be used as a catalyst either. These results culminate in the conclusion that, out of the correlations that a generic quantum catalyst has with its environment, only classical correlations allow for catalysis, and therefore using a correlated catalyst is equivalent to using an ensemble of uncorrelated catalysts.Comment: 5+7 pages, 1 figure, Comments are welcom

    Uniqueness of quantum state over time function

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    A fundamental asymmetry exists within the conventional framework of quantum theory between space and time, in terms of representing causal relations via quantum channels and acausal relations via multipartite quantum states. Such a distinction does not exist in classical probability theory. In effort to introduce this symmetry to quantum theory, a new framework has recently been proposed, such that dynamical description of a quantum system can be encapsulated by a static quantum state over time. In particular, Fullwood and Parzygnat recently proposed the state over time function based on the Jordan product as a promising candidate for such a quantum state over time function, by showing that it satisfies all the axioms required in the no-go result by Horsman et al. However, it was unclear if the axioms induce a unique state over time function. In this work, we demonstrate that the previously proposed axioms cannot yield a unique state over time function. In response, we therefore propose an alternative set of axioms that is operationally motivated, and better suited to describe quantum states over any spacetime regions beyond two points. By doing so, we establish the Fullwood-Parzygnat state over time function as the essentially unique function satisfying all these operational axioms.Comment: 5+4 pages, comments welcom

    Super-soft symmetry energy encountering non-Newtonian gravity in neutron stars

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    Considering the non-Newtonian gravity proposed in the grand unification theories, we show that the stability and observed global properties of neutron stars can not rule out the super-soft nuclear symmetry energies at supra-saturation densities. The degree of possible violation of the Inverse-Square-Law of gravity in neutron stars is estimated using an Equation of State (EOS) of neutron-rich nuclear matter consistent with the available terrestrial laboratory data.Comment: Version accepted by Physical Review Letter
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