1,220 research outputs found

    Blind Demixing for Low-Latency Communication

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    In the next generation wireless networks, lowlatency communication is critical to support emerging diversified applications, e.g., Tactile Internet and Virtual Reality. In this paper, a novel blind demixing approach is developed to reduce the channel signaling overhead, thereby supporting low-latency communication. Specifically, we develop a low-rank approach to recover the original information only based on a single observed vector without any channel estimation. Unfortunately, this problem turns out to be a highly intractable non-convex optimization problem due to the multiple non-convex rankone constraints. To address the unique challenges, the quotient manifold geometry of product of complex asymmetric rankone matrices is exploited by equivalently reformulating original complex asymmetric matrices to the Hermitian positive semidefinite matrices. We further generalize the geometric concepts of the complex product manifolds via element-wise extension of the geometric concepts of the individual manifolds. A scalable Riemannian trust-region algorithm is then developed to solve the blind demixing problem efficiently with fast convergence rates and low iteration cost. Numerical results will demonstrate the algorithmic advantages and admirable performance of the proposed algorithm compared with the state-of-art methods.Comment: 14 pages, accepted by IEEE Transaction on Wireless Communicatio

    The alternative regenerative strategy of bearded dragon unveils the key processes underlying vertebrate tooth renewal

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    Deep understanding of tooth regeneration is hampered by the lack of lifelong replacing oral dentition in most conventional models. Here, we show that the bearded dragon, one of the rare vertebrate species with both polyphyodont and monophyodont teeth, constitutes a key model for filling this gap, allowing direct comparison of extreme dentition types. Our developmental and high-throughput transcriptomic data of microdissected dental cells unveils the critical importance of successional dental lamina patterning, in addition to maintenance, for vertebrate tooth renewal. This patterning process happens at various levels, including directional growth but also gene expression levels, dynamics, and regionalization, and involves a large number of yet uncharacterized dental genes. Furthermore, the alternative renewal mechanism of bearded dragon dentition, with dual location of slow-cycling cells, demonstrates the importance of cell migration and functional specialization of putative epithelial stem/progenitor niches in tissue regeneration, while expanding the diversity of dental replacement strategies in vertebrates.Peer reviewe

    BABY BOOM target genes provide diverse entry points into cell proliferation and cell growth pathways

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    Ectopic expression of the Brassica napus BABY BOOM (BBM) AP2/ERF transcription factor is sufficient to induce spontaneous cell proliferation leading primarily to somatic embryogenesis, but also to organogenesis and callus formation. We used DNA microarray analysis in combination with a post-translationally regulated BBM:GR protein and cycloheximide to identify target genes that are directly activated by BBM expression in Arabidopsis seedlings. We show that BBM activated the expression of a largely uncharacterized set of genes encoding proteins with potential roles in transcription, cellular signaling, cell wall biosynthesis and targeted protein turnover. A number of the target genes have been shown to be expressed in meristems or to be involved in cell wall modifications associated with dividing/growing cells. One of the BBM target genes encodes an ADF/cofilin protein, ACTIN DEPOLYMERIZING FACTOR9 (ADF9). The consequences of BBM:GR activation on the actin cytoskeleton were followed using the GFP:FIMBRIN ACTIN BINDING DOMAIN2 (GFP:FABD) actin marker. Dexamethasone-mediated BBM:GR activation induced dramatic changes in actin organization resulting in the formation of dense actin networks with high turnover rates, a phenotype that is consistent with cells that are rapidly undergoing cytoplasmic reorganization. Together the data suggest that the BBM transcription factor activates a complex network of developmental pathways associated with cell proliferation and growth

    On the Origins of Land Use Regulations: Theory and Evidence from US Metro Areas

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    We model residential land use constraints as the outcome of a political economy game between owners of developed and owners of undeveloped land. Land use constraints benefit the former group (via increasing property prices) but hurt the latter (via increasing development costs). More desirable locations are more developed and, as a consequence of political economy forces, more regulated. Using an IV approach that directly follows from our model we find strong and robust support for our predictions. The data provide weak or no support for alternative hypotheses whereby regulations reflect the wishes of the majority of households or efficiency motives.Land use regulations, zoning, land ownership, housing supply

    IMPLEMENTASI CCS7 PADA SENTRAL NEAX-61E DI PT TELKOM DIVRE IV JATENG DIY

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    Common Channel Signalling #7 merupakan sistem pensinyalan dimana pertukaran informasi pensinyalan dilakukan melalui kanal terpisah dari kanal bicara. Setiap kanal pensinyalan mampu melayani ribuan kanal bicara, maka setiap gangguan yang terjadi pada kanal pensinyalan dapat menyebabkan terjadinya kegagalan panggilan. Dengan melihat pentingnya peranan kanal pensinyalan tersebut, penulis tertarik untuk meneliti secara lebih mendetail unjuk kerja dari link pensinyalan tersebut khususnya di sentral NEAX61E Divisi Regional IV. Dalam Tugas Akhir ini akan dibuat suatu formulasi yang nantinya dapat digunakan untuk menentukan unjuk kerja dan kebutuhan link pensinyalan di sentral NEAX61E se Jateng dan DIY. Dimana dalam perumusan tersebut dibahas parameter-parameter yang mempengaruhi unjuk kerja jaringan pensinyalan, data parameter - parameter tersebut diambil dengan metoda pengamatan trafik link pensinyalan di sentral NEAX61E Divre IV
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