4,095 research outputs found

    Position and Orientation Estimation through Millimeter Wave MIMO in 5G Systems

    Get PDF
    Millimeter wave signals and large antenna arrays are considered enabling technologies for future 5G networks. While their benefits for achieving high-data rate communications are well-known, their potential advantages for accurate positioning are largely undiscovered. We derive the Cram\'{e}r-Rao bound (CRB) on position and rotation angle estimation uncertainty from millimeter wave signals from a single transmitter, in the presence of scatterers. We also present a novel two-stage algorithm for position and rotation angle estimation that attains the CRB for average to high signal-to-noise ratio. The algorithm is based on multiple measurement vectors matching pursuit for coarse estimation, followed by a refinement stage based on the space-alternating generalized expectation maximization algorithm. We find that accurate position and rotation angle estimation is possible using signals from a single transmitter, in either line-of- sight, non-line-of-sight, or obstructed-line-of-sight conditions.Comment: The manuscript has been revised, and increased from 27 to 31 pages. Also, Fig.2, Fig. 10 and Table I are adde

    On the Trade-off Between Accuracy and Delay in Cooperative UWB Navigation

    Get PDF
    In ultra-wide bandwidth (UWB) cooperative navigation, nodes estimate their position by means of shared information. Such sharing has a direct impact on the position accuracy and medium access control (MAC) delay, which needs to be considered when designing UWB navigation systems. We investigate the interplay between UWB position accuracy and MAC delay for cooperative scenarios. We quantify this relation through fundamental lower bounds on position accuracy and MAC delay for arbitrary finite networks. Results show that the traditional ways to increase accuracy (e.g., increasing the number of anchors or the transmission power) as well as inter-node cooperation may lead to large MAC delays. We evaluate one method to mitigate these delays

    Cooperative localization with 802.15.4a CSS radios: Robustness to node failures

    Get PDF
    Cooperative positioning is a solution for location-aware applications where GPS-aided localization is unfeasible. In this paper, we provide a qualitative comparison between cooperative and non-cooperative localization under node-failure scenarios, in a typical indoor environment using off-the-shelf 802.15.4a radios. From our analysis, we observe the improved robustness and coverage offered by the cooperative approach in node-failure scenarios

    Correlates of Smoking Cessation Among Filipino Immigrant Men

    Get PDF
    A survey on tobacco use among 318 Filipino immigrant men aged 40–75 years was conducted in Los Angeles, California. Those who reported more English language use with their family, friends and neighbors (OR = 1.31) and who lived in households with complete smoking prohibition (OR = 3.82) were more likely to be successful in quitting smoking. Those who endorsed more positive beliefs on physical and social consequences of smoking (OR = 0.69) and who had mostly smoking friends (OR = 0.37) were less likely to be successful in quitting smoking. Our findings suggest that prohibiting smoking in households, creating social networks of non-smokers, and education or counseling are important components of a smoking cessation intervention for Filipino immigrant men

    On the Trade-Off Between Accuracy and Delay in Cooperative UWB Localization: Performance Bounds and Scaling Laws

    Get PDF
    Ultra-wide bandwidth (UWB) systems allow for accurate positioning in environments where global navigation satellite systems may fail, especially when complemented with cooperative processing. While cooperative UWB has led to centimeter-level accuracies, the communication overhead is often neglected. We quantify how accuracy and delay trade off in a wide variety of operation conditions. We also derive the asymptotic scaling of accuracy and delay, indicating that, in some conditions, standard cooperation offers the worst possible tradeoff. Both avenues lead to the same conclusion: indiscriminately targeting increased accuracy incurs a significant delay penalty. Simple countermeasures can be taken to reduce this penalty and obtain a meaningful accuracy/delay trade-off

    Satb1 overexpression drives tumor-promoting activities in cancer-associated dendritic cells

    Get PDF
    Special AT-rich sequence-binding protein 1 (Satb1) governs genome-wide transcriptional programs. Using a conditional knockout mouse, we find that Satb1 is required for normal differentiation of conventional dendritic cells (DCs). Furthermore, Satb1 governs the differentiation of inflammatory DCs by regulating major histocompatibility complex class II (MHC II) expression through Notch1 signaling. Mechanistically, Satb1 binds to the Notch1 promoter, activating Notch expression and driving RBPJ occupancy of the H2-Ab1 promoter, which activates MHC II transcription. However, tumor-driven, unremitting expression of Satb1 in activated Zbtb46(+) inflammatory DCs that infiltrate ovarian tumors results in an immunosuppressive phenotype characterized by increased secretion of tumor-promoting Galectin-1 and IL-6. In vivo silencing of Satb1 in tumor-associated DCs reverses their tumorigenic activity and boosts protective immunity. Therefore, dynamic fluctuations in Satb1 expression govern the generation and immunostimulatory activity of steady-state and inflammatory DCs, but continuous Satb1 overexpression in differentiated DCs converts them into tolerogenic/pro-inflammatory cells that contribute to malignant progression.Fil: Tesone, Amelia J.. The Wistar Institute. Tumor Microenvironment and Metastasis Program; Estados UnidosFil: Rutkowski, Melanie R.. The Wistar Institute. Tumor Microenvironment and Metastasis Program; Estados UnidosFil: Brencicova, Eva. The Wistar Institute. Tumor Microenvironment and Metastasis Program; Estados UnidosFil: Svoronos, Nikolaos. The Wistar Institute. Tumor Microenvironment and Metastasis Program; Estados UnidosFil: Perales Puchal, Alfredo. The Wistar Institute. Tumor Microenvironment and Metastasis Program; Estados UnidosFil: Stephen, Tom L.. The Wistar Institute. Tumor Microenvironment and Metastasis Program; Estados UnidosFil: Allegrezza, Michael J.. The Wistar Institute. Tumor Microenvironment and Metastasis Program; Estados UnidosFil: Payne, Kyle K.. The Wistar Institute. Tumor Microenvironment and Metastasis Program; Estados UnidosFil: Nguyen, Jenny M.. The Wistar Institute. Tumor Microenvironment and Metastasis Program; Estados UnidosFil: Wickramasinghe, Jayamanna. The Wistar Institute. Center for Systems and Computational Biology; Estados UnidosFil: Tchou, Julia. University of Pennsylvania; Estados UnidosFil: Borowsky, Mark E.. Christiana Care Health System. Helen F. Graham Cancer Center; Estados UnidosFil: Rabinovich, Gabriel Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Kossenkov, Andrew V.. The Wistar Institute. Center for Systems and Computational Biology; Estados UnidosFil: Conejo Garcia, José R.. The Wistar Institute. Tumor Microenvironment and Metastasis Program; Estados Unido
    corecore