A simple method to infer Wi-Fi conflict graph

International audienceIn Wi-Fi networks, CSMA/CA ensures that access points (AP) in conflict with each others cannot transmit at the same time. An AP detects a conflicting AP when the received signal strength is greater than a certain threshold. This mechanism sets the medium spatial reuse that strongly impacts the throughput that may be offered by the Wi-Fi network and the users quality of experience. The knowledge of the different conflicts is thus crucial if we want to optimize the Wi-Fi network. In this paper we propose to take benefit of all local statistics information gathered by APs wireless interfaces to reconstruct the global conflict graph, i.e. the graph that represents AP in conflict with each others. Our methodology is based on APs statistic information available in profile counters. Consequently, our method does not rely on complex captures or synchronization. The proposed method is a work in progress for which we propose a proof of concept through a first set of simulations

Characterisation of a functional rat hepatocyte spheroid model.

Many in vitro liver cell models, such as 2D systems, that are used to assess the hepatotoxic potential of xenobiotics suffer major limitations arising from a lack of preservation of physiological phenotype and metabolic competence. To circumvent some of these limitations there has been increased focus on producing more representative 3D models. Here we have used a novel approach to construct a size-controllable 3D hepatic spheroid model using freshly isolated primary rat hepatocytes (PRH) utilising the liquid-overlay technique whereby PRH spontaneously self-assemble in to 3D microtissues. This system produces viable spheroids with a compact in vivo-like structure for up to 21 days with sustained albumin production for the duration of the culture period. F-actin was seen throughout the spheroid body and P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 (MRP2) transporters had polarised expression on the canalicular membrane of hepatocytes within the spheroids upon formation (day 3). The MRP2 transporter was able to functionally transport 5 μM 5-chloromethylfluorescein diacetate (CMFDA) substrates into these canalicular structures. These PRH spheroids display in vivo characteristics including direct cell-cell contacts, cellular polarisation, 3D cellular morphology, and formation of functional secondary structures throughout the spheroid. Such a well-characterised system could be readily exploited for pre-clinical and non-clinical repeat-dose investigations and could make a significant contribution to replace, reduce and refine the use of animals for applied research

A simple method to infer Wi-Fi conflict graph

International audienceIn Wi-Fi networks, CSMA/CA ensures that access points (AP) in conflict with each others cannot transmit at the same time. An AP detects a conflicting AP when the received signal strength is greater than a certain threshold. This mechanism sets the medium spatial reuse that strongly impacts the throughput that may be offered by the Wi-Fi network and the users quality of experience. The knowledge of the different conflicts is thus crucial if we want to optimize the Wi-Fi network. In this paper we propose to take benefit of all local statistics information gathered by APs wireless interfaces to reconstruct the global conflict graph, i.e. the graph that represents AP in conflict with each others. Our methodology is based on APs statistic information available in profile counters. Consequently, our method does not rely on complex captures or synchronization. The proposed method is a work in progress for which we propose a proof of concept through a first set of simulations

A simple method to infer Wi-Fi conflict graph

International audienceIn Wi-Fi networks, CSMA/CA ensures that access points (AP) in conflict with each others cannot transmit at the same time. An AP detects a conflicting AP when the received signal strength is greater than a certain threshold. This mechanism sets the medium spatial reuse that strongly impacts the throughput that may be offered by the Wi-Fi network and the users quality of experience. The knowledge of the different conflicts is thus crucial if we want to optimize the Wi-Fi network. In this paper we propose to take benefit of all local statistics information gathered by APs wireless interfaces to reconstruct the global conflict graph, i.e. the graph that represents AP in conflict with each others. Our methodology is based on APs statistic information available in profile counters. Consequently, our method does not rely on complex captures or synchronization. The proposed method is a work in progress for which we propose a proof of concept through a first set of simulations

A new approach to dynamic self-tuning of database buffers

10.1145/1353452.1353455ACM Transactions on Storage4