Modeling and Analysis of Content Caching in Wireless Small Cell Networks

Network densification with small cell base stations is a promising solution to satisfy future data traffic demands. However, increasing small cell base station density alone does not ensure better users quality-of-experience and incurs high operational expenditures. Therefore, content caching on different network elements has been proposed as a mean of offloading he backhaul by caching strategic contents at the network edge, thereby reducing latency. In this paper, we investigate cache-enabled small cells in which we model and characterize the outage probability, defined as the probability of not satisfying users requests over a given coverage area. We analytically derive a closed form expression of the outage probability as a function of signal-to-interference ratio, cache size, small cell base station density and threshold distance. By assuming the distribution of base stations as a Poisson point process, we derive the probability of finding a specific content within a threshold distance and the optimal small cell base station density that achieves a given target cache hit probability. Furthermore, simulation results are performed to validate the analytical model.Comment: accepted for publication, IEEE ISWCS 201

Dirigisme, politique industrielle et rhétorique industrialiste

Le dirigisme économique français relève de ces évidences peu discutées aussi bien par les acteurs que dans la littérature. Pourtant, une étude empirique systématique des politiques publiques industrielles montre que, hors le cas des « grands projets » où sont mobilisés par un Etat de passe-droit la commande, la recherche, le financement et l'entreprise publics au service d'objectifs de souveraineté, les politiques industrielles relèvent en fait de l'accompagnement de stratégies d'entreprises ou de la recherche de la paix civile. La mise en perspective historique n'infirme pas ce résultat, elle révèle des configurations contrastées de relations Etat-Industrie où l'administration économique agit davantage sur l'environnement de l'entreprise qu'elle ne pèse sur les orientations sectorielles des acteurs. Dès lors, la logique partiellement autonome de la rhétorique industrialiste devient objet d'étude

Reduced Complexity Window Decoding Schedules for Coupled LDPC Codes

Window decoding schedules are very attractive for message passing decoding of spatially coupled LDPC codes. They take advantage of the inherent convolutional code structure and allow continuous transmission with low decoding latency and complexity. In this paper we show that the decoding complexity can be further reduced if suitable message passing schedules are applied within the decoding window. An improvement based schedule is presented that easily adapts to different ensemble structures, window sizes, and channel parameters. Its combination with a serial (on-demand) schedule is also considered. Results from a computer search based schedule are shown for comparison

Fungal endophyte misidentified as Neurospora crassa.

The endophytic fungus isolate, ZP5SE, recently described in Rehman et al. 2008 was misidentified identified as Neurospora crassa. The 28S ribosomal gene sequence of the isolate shows 100% sequence similarity with GenBank accession Neurospora crassa M38154

Urban wastewater: A valuable resource for agriculture - A case study from Haroonabad, Pakistan

Waste waters / Irrigation water / Water reuse / Economic analysis / Soil properties / Households / Water availability / Water use / Water quality / Groundwater / Public health / Risks / Case studies

Non-Uniform Window Decoding Schedules for Spatially Coupled LDPC Codes

Spatially coupled low-density parity-check codes can be decoded using a graph-based message passing algorithm applied across the total length of the coupled graph. However, considering practical constraints on decoding latency and complexity, a sliding window decoding approach is normally preferred. In order to reduce decoding complexity compared with standard parallel decoding schedules, serial schedules can be applied within a decoding window. However, uniform serial schedules within a window do not provide the expected reduction in complexity. Hence, we propose non-uniform schedules (parallel and serial) based on measured improvements in the estimated bit error rate (BER). We show that these non-uniform schedules result in a significant reduction in complexity without any loss in performance. Furthermore, based on observations made using density evolution, we propose a non-uniform pragmatic decoding schedule (parallel and serial) that does not require any additional calculations (e.g., BER estimates) within the decoding process

Heartburn\u27s hidden impact: A narrative review exploring gastroesophageal reflux disease (GERD) as a cardiovascular disease risk factor

Gastroesophageal reflux disease (GERD) is a very common disease with an estimated 442 million cases worldwide. It is a well-documented independent risk factor for many gastrointestinal pathologies, however, its role in cardiovascular disease (CVD) is unclear, despite its high prevalence in patients with CVD. Although traditionally considered a causative agent of noncardiac chest pain, a common imitator of cardiac chest pain, or an incidentally shared comorbidity in patients with CVD, a number of studies have implicated GERD and its therapies as risk factors for CVD. This narrative review will explore the relationship between GERD and CVD, including medical and mechanical therapeutic approaches for GERD that could potentially impact the incidence, progression, and mortality of CVD

Stark Tuning and Electrical Charge State Control of Single Divacancies in Silicon Carbide

Neutrally charged divacancies in silicon carbide (SiC) are paramagnetic color centers whose long coherence times and near-telecom operating wavelengths make them promising for scalable quantum communication technologies compatible with existing fiber optic networks. However, local strain inhomogeneity can randomly perturb their optical transition frequencies, which degrades the indistinguishability of photons emitted from separate defects, and hinders their coupling to optical cavities. Here we show that electric fields can be used to tune the optical transition frequencies of single neutral divacancy defects in 4H-SiC over a range of several GHz via the DC Stark effect. The same technique can also control the charge state of the defect on microsecond timescales, which we use to stabilize unstable or non-neutral divacancies into their neutral charge state. Using fluorescence-based charge state detection, we show both 975 nm and 1130 nm excitation can prepare its neutral charge state with near unity efficiency.Comment: 12 pages, 4 figure

Challenges and some new directions in channel coding

Three areas of ongoing research in channel coding are surveyed, and recent developments are presented in each area: Spatially coupled low-density parity-check (LDPC) codes, nonbinary LDPC codes, and polar coding. © 2015 KICS