The principle of Cloud Radio Access Network (C-RAN) is the split of traditional base stations into Radio Remote Units (RRU) as low-cost wireless access points, and Base Band Units (BBU) in a ...centralized location. This new RAN paradigm accepts several choices for a functional split of the protocol stack, with different latency requirements to the front-haul connecting a BBU with those RRUs under its control. In this paper, we focus on the functional split that implements the Medium Access Control layer at the BBU side. Particularly, we analyze the impact of delays on the report of the acknowledgment/negative acknowledgment messages for Hybrid Automatic Repeat reQuest (HARQ). In order to understand the trade-off between the HARQ report delay and user throughput, we define a new metric named as
Net Rate
. This metric is defined as the throughput that a user can reach after certain HARQ report delay while taking into account the actual channel conditions, the resource scheduling period to that user and the transmission window. The
Net Rate
metric can be used to determine the maximum HARQ report delay that can be tolerated by a user without throughput degradation. Our simulation results recommend the use for Mobile Edge Computing solutions to minimize the latencies of the front-haul connection and, thus, the impact of the HARQ delay on the throughput.
Acid-sensing ion channels (ASICs) are the members of the degenerin/epithelial sodium channel (Deg/ENaC) superfamily which mediate different sensory modalities including mechanosensation. ASICs have ...been detected in mechanosensory neurons as well as in peripheral mechanoreceptors. We now investigated the distribution of ASIC1, ASIC2, and ASIC3 proteins in human cutaneous Pacinian corpuscles using immunohistochemistry and laser confocal-scanner microscopy. We detected different patterns of expression of these proteins within Pacinian corpuscles. ASIC1 was detected in the central axon co-expressed with RT-97 protein, ASIC2 was expressed by the lamellar cells of the inner core co-localized with S100 protein, and ASIC3 was absent. These results demonstrate for the first time the differential distribution of ASIC1 and ASIC2 in human rapidly adapting low-threshold mechanoreceptors, and suggest specific roles of both proteins in mechanotransduction.
We studied the melt linear viscoelastic and elongational properties of blends consisting of a Ziegler-Natta linear low-density polyethylene (LLDPE) and different LDPEs. The weight fraction of the ...LDPE used in the blends was 15%. The linear viscoelastic characterization was performed at different temperatures for all of the blends to determine the thermorheological behavior in the melt state. The blends fulfilled the time-temperature superposition but exhibited a broad linear viscoelastic response, which was further than that expected for miscible blends and even immiscible systems with a sharp interface. A rheological study of the application of the Palierne model revealed that in addition to the droplet shape relaxation, another mechanism was present at lower frequencies. We discuss the results by hypothesizing a strong interaction between the high-molecular-weight linear fraction of the LLDPE matrix and a fraction of molecules of the dispersed phase, which formed a thick interface with its own viscoelastic properties. A clear change in this additional mechanism was observed, depending on the dispersed minor-phase properties, which produced an impact on the processing of the blends, and more precisely, on the values of the melt strength in the melt-spinning experiments.
Teaching short-circuit analysis is conducted primarily through case studies; however, there are not many validated short-circuit studies available on the subject, especially when considering ...off-nominal turns ratio transformers. In order to improve the teaching of short-circuit analysis, a three phase short-circuit study in an industrial system according to ANSI/IEEE standards by means of Zmatrix method is presented; two case studies are considered: the industrial system with nominal and offnominal turns ratio transformers, in both cases the step by step solution is given in an explicit manner and the analytical results are validated through software simulation.
Microwave-assisted synthesis of the lipase-catalyzed ring opening polymerization of ε-caprolactone (ε-CL) and ω-pentadecanolactone (ω-PDL) monomers was studied. A series of P(CL-co-PDL), with ...different molar feed ratios, including (ε-CL/ω-PDL) 100/0, 75/25, 50/50, 25/75, and 0/100, were synthesized. The resulting polyesters were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The microwave-assisted polymerization of the monomers reached high conversions (91–95%) within 60 min. FTIR spectra showed the typical absorption bands of these polyesters. A very intense band in the carbonyl region, which was shifted from 1,720 cm
for PCL to 1,732 cm
for PPDL homopolymer, as well as peaks owing to methylene groups in the 2,990–2,850 cm
range. DSC results revealed that all polyester samples were semi-crystalline. Interestingly, the copolymers exhibited only one melting peak (
), and their
values linearly increased from 57°C to 95°C as PPDL concentration was increased. Thermal stability of polyesters also depended on PDL content; an increase in PDL concentration increases polymer degradation temperature (
).
We report the first experimental observation of zero-order Mathieu beams which are fundamental non-diffracting solutions of the wave equation in elliptic cylindrical coordinates.
The first Mesozoic thylacocephalans from the western hemisphere are documented from the Muhi Quarry plattenkalk in the La Negra facies of the El Doctor Formation (Albian–Cenomanian), Zimapán Area, ...northwestern Hidalgo, central Mexico. They all are found in a single horizon at the base of the type section. These specimens represent two new genera and species, and a third undetermined species which likely also represents a new genus and species. Victoriacaris muhiensis is a shorted-bodied thylacocephalan with concave anterior and posterior notches as well as a beveled anterior spine. Polzia eldoctorensis is trapezoidal in outline with a rounded posteroventral corner. The third undetermined species is known only from one broken specimen, but has distinctive marginal spines that are not possessed by any other post-Cambrian thylacocephalan. The occurrence of such a diverse fauna of thylacocephalans markedly increases the diversity and geographic range of Cretaceous thylacocephalans, but does not offer any insights into the tempo of thylacocephalan extinction at the end of the Cretaceous.
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