Search results for "Multiplex"

Side Effects of Ambient Noise Immunity Techniques on Outdoor IEEE 802.11 Deployments

2008

A very common conclusion of many experimental studies about IEEE 802.11 outdoor network deployments is that their poor performance results derive from the unfavorable interference and multi-path signals in which the WLAN-cards are required to operate. Goal of this paper is to show that this condition does not always hold, and unexpected and inaccurated PHY layer implementations can be a primary cause of packet losses. With the support of extensive measurement campaigns led in our campus, we provide the performance evidence that IEEE 802.11 outdoor performance impairments are strongly affected by proprietary interference mitigation techniques that adaptively adjust the WLAN-card receiver sen…

Mononeuropathy multiplex as a result of treatment with interferon-α and ribavirin in a patient with hepatitis C

2008

Spectrally selective holographic optical elements based on a thick polymer medium with diffusional amplification

2000

A thick rigid polymer recording medium with self-amplification of holograms owing to diffusion of phenanthrenequinone molecules was used to find efficient holographic optical elements with high-spectral-selectivity interference filters and multiple demultiplexers. Several examples of practical applications are briefly described in this paper, showing the benefits of such optical elements for the fields of astronomy, spectroscopy and communication technologies.

Hybrid silicon on insulator/polymer electro-optical intensity modulator operating at 780  nm

2014

Currently inorganic materials prevail as the nonlinear active medium for light modulation in electro-optical (EO) device technology. A recent promising trend is to consider organic nonlinear optical materials for application in EO modulators due to their multiple advantages including low costs and high EO coefficients. In this paper, we proposed a new type of polymer EO modulator whose fabrication is compatible with the currently used silicon on insulator technology. Our numerical optimization of the proposed structure demonstrates that it is theoretically possible to achieve a half-wave voltage as low as 1.56 V for a 1 cm long modulator structure operating at 780 nm. Based on the results o…

Detection of Immunoglobulin Heavy Chain Gene Clonality By High-Throughput Sequencing for Minimal Residual Disease Monitoring in Chronic Lymphocytic L…

2019

Introduction: The negative minimal residual disease (MRD) after treatment has been recently accepted as endpoint for Chronic Lymphocytic Leukaemia (CLL) clinical trials. Conventionally, MRD can be detected by using multi-color Flow Cytometry (FC) with high sensitivity. Determination of the clonal immunoglobulin gene rearrangement can be a useful monitoring marker in a broad range of B-cell lymphoproliferative neoplasms. Moreover, the mutational status of immunoglobulin heavy chain variable (IgHV) rearrangement is considered one of the most important prognostic factors in CLL. Therefore, the identification of the IgHV rearrangement can be a useful marker both at diagnostic and as monitoring …

A High speed data link optimization for digitalized transfer to processing FPGA

2021

State-of-the-art arrays of detectors, that require digital processing, may have a sizeable number of digitalized signal links. This is the case in several experimental nuclear physics instruments. Moreover, the data rate of the sampled signals, defined primary by the signal bandwidth of the individual detectors, may not exhaust the capabilities of a single FPGA transceiver input. The preprocessing is usually carried out in a modern FPGA with transceiver data rate capabilities over 10Gbps. Moreover, cost effective FPGA have a limited number of transceivers for given FPGA processing capabilities. The investigation of a cost-effective and efficient solution to the mismatch between both data ra…

FLUMO: FLexible Underwater MOdem

2019

The last years have seen a growing interest in underwater acoustic communications because of its applications in marine research, oceanography, marine commercial operations, the offshore oil industry and defense. High-speed communication in the underwater acoustic channel has been challenging because of limited bandwidth, extended multipath, refractive properties of the medium, severe fading, rapid time variation and large Doppler shifts. In this paper, we show an implementation of a flexible Software-Defined Acoustic (SDA) underwater modem, where modulation parameters are completely tunable to optimize performance. In particular, we develop the system architecture following two key ideas. …

Cladding-Pumped Er/Yb-Co-Doped Fiber Amplifier for Multi-Channel Operation

2022

The Institute of Solid State Physics, University of Latvia, as a Center of Excellence, has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2. We express our gratitude to rer. nat. Nicoletta Haarlammert from Fraunhofer Institute for Applied Optics and Precision Engineering IOF for the refractive index measurements of ytterbium/erbium-co-doped fibers. This work is supported by the European Regional Development Fund project No. 1.1.1.1/18/A/068.

Teschoviruses and sapeloviruses in faecal samples from wild boar in Spain

2013

Teschovirus and Sapelovirus are two genera of the Picornaviridae family, comprising highly variable and heterogeneous enteric viruses, commonly found in faecal samples from domestic pigs. Although both of them are also known to infect wild boar, studies on their presence in these wild suids are scarce. The present study aimed at determining the presence of porcine teschovirus (PTV) and sapelovirus (PSV) in free-living wild boar populations, as well as to study their relationships with similar viruses present in pigs. Fresh faecal samples (n = 63) from wild boar were collected in Doñana Biological Reserve (SW Spain) during 2007 and 2011, and analysed using multiplex RT-PCR for the simultaneo…

Moving RTS/CTS to the frequency domain: an efficient contention scheme for 802.11ax networks

2019

In this paper, we propose a contention mechanism based on the execution of multiple contention rounds in the frequency domain (ReCHo), which is designed to offer high throughput performance and robustness with respect to imperfect carrier sensing. The main idea is using narrow tones as signalling messages for performing channel access contentions and allowing the Access Point (AP) to echo these signals, in order to extend the sensing capabilities to all the stations associated to the AP. In particular, we refer to the emerging IEEE 802.11ax standard, showing how our scheme can boost performance of random access with respect to the current version of IEEE 802.11ax OFDMA Back-Off (OBO), even …