Dependability investigation of wireless short range embedded systems: hardware platform oriented approach

A new direction in short-range wireless applications has appeared in the form of high-speed data communication devices for distances of hundreds meters. Behind these embedded applications, a complex heterogeneous architecture is built. Moreover, these short range communications are introduced into critical applications, where the dependability/reliability is mandatory. Thus, dependability concerns around reliability evaluation become a major challenge in these systems, and pose several questions to answer. Obviously, in such systems, the attribute reliability has to be investigated for various components and at different abstraction levels. In this paper, we discuss the investigation of dependability in wireless short range systems. We present a hardware platform for wireless system dependability analysis as an alternative for the time consuming simulation techniques. The platform is built using several instances of one of the commercial FPGA platforms available on the market place. We describe the different steps of building the wireless hardware platform for short range systems dependability analysis. Then, we show how this HW platform based dependability investigation framework can be a very interactive approach. Based on this platform we introduce a new methodology and a flow to investigate the different parts of system dependability at different abstraction levels. The benefits to use the proposed framework are three fold: first, it takes care of the whole system (HW/SW -digital part, mixed RF part, and wireless part); Second, the hardware platform enables to explore the application’s reliability under real environmental conditions taking into account the effect of the environment threats on the system; And last, the wireless platform built for dependability investigation present a fast investigation approach in comparison with the time consuming co-simulation technique

Numerical Analysis of Performance Deterioration of a Centrifugal Pump Operating in Two-Phase Flows

Pumps handling two-phase flows are essential parts of industrial process mainly in oil and gas facilities and power plants. It is known that for centrifugal pumps the presence of gas phase in liquid flow causes the performance to deteriorate. Knowledge improvement of the highly complex internal flow is the way to design more efficient and reliable pumps. The paper describes the results of studies conducted in a centrifugal pump operating in two-phase air/water mixture flows, for performance determination and flow field investigation using numerical simulations. The aim is to provide a new highlight on the performance evolution and to identify the physical mechanism responsible for the deterioration. The work is carried out at design flow rate with varying inlet gas volume fraction. The results show significant performance deterioration compared to single-phase situation. The analysis of flow fields in case of two-phase flows reveals an accumulation of the gas in the impeller passages, causing an alteration of the conventional single-phase flow structure. The effect of interaction with volute is also investigated and it is found to play a key role in changing the flow pattern inside the impeller. At the conclusion of the study, special design features are suggested as concepts for enhancing two-phase pumping behavior of centrifugal pumps

A Combined Relay-Selection and Routing Protocol for Cooperative Wireless Sensor Networks

International audienceIn wireless sensor networks several constraints decrease communications performances. In fact, channel randomness and energy restrictions make classical routing protocols inefficient. Therefore, the design of new routing protocols that cope with these constraints become mandatory. The main objective of this paper is to present a multi-objective routing algorithm RBCR that computes routing path based on the energy consumption and channel qualities. Additionally, the channel qualities are evaluated based on the presence of relay nodes. Compared to AODV and AODV associated to a cooperative MAC protocol, RBCR provides better performances in term of delivery ratio, power consumption and traffic load

On boundedness of the generalized Riesz potential in local Morrey-type spaces

For all admissible values of the numerical parameters sharp sufficient conditions on the functional parameters are obtained ensuring the boundedness of the generalized Riesz potential from one general local Morrey-type space to another one, which, for a certain range of the numerical parameters, coincide with the necessary ones

Iterative Reconstructions in Reduced-Dose CT: Which Type Ensures Diagnostic Image Quality in Young Oncology Patients?

To compare adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) algorithms for reduced-dose computed tomography (CT). Forty-four young oncology patients (mean age 30 ± 9 years) were included. After routine thoraco-abdominal CT (dose 100%, average CTDI javax.xml.bind.JAXBElement@e7f585f 9.1 ± 2.4 mGy, range 4.4-16.9 mGy), follow-up CT was acquired at 50% (average CTDI javax.xml.bind.JAXBElement@2e35610f 4.5 ± 1.2 mGy, range 2.2-8.4 mGy) in 29 patients additionally at 20% dose (average CTDI javax.xml.bind.JAXBElement@37ad3473 1.9 ± 0.5 mGy, range 0.9-3.4 mGy). Each reduced-dose CT was reconstructed using both ASIR and MBIR. Four radiologists (two juniors and two seniors) blinded to dose and technique read each set of CT images regarding objective and subjective image qualities (high- or low-contrast structures), subjective noise or pixilated appearance, diagnostic confidence, and lesion detection. At all dose levels, objective image noise was significantly lower with MBIR than with ASIR (P < 0.001). The subjective image quality for low-contrast structures was significantly higher with MBIR than with ASIR (P < 0.001). Reduced-dose abdominal CT images of patients with higher body mass index (BMI) were read with significantly higher diagnostic confidence than images of slimmer patients (P < 0.001) and had higher subjective image quality, regardless of technique. Although MBIR images appeared significantly more pixilated than ASIR images, they were read with higher diagnostic confidence, especially by juniors (P < 0.001). Reduced-dose CT during the follow-up of young oncology patients should be reconstructed with MBIR to ensure diagnostic quality. Elevated body mass index does not hamper the quality of reduced-dose CT

Polyphasic Characterisation of Non-Starter Lactic Acid Bacteria from Algerian Raw Camel’s Milk and Their Technological Aptitudes

Pozadina istraživanja. Spontano fermentirano devino mlijeko često se konzumira u Alžiru, što ga čini održivim izvorom različitih bakterija mliječno-kiselog vrenja, koje se mogu dodati starter kulturi radi poboljšanja kakvoće i sigurnosti fermentiranih mliječnih proizvoda. Eksperimentalni pristup. Dvanaest uzoraka sirovog devinog mlijeka upotrijebljeno je kao izvor autohtonih bakterija mliječno-kiselog vrenja, koje su zatim okarakterizirane pomoću 39 fenotipskih osobina što imaju tehnološki značaj. Rezultati i zaključci. Trideset i devet nestarterskih bakterija mliječno-kiselog vrenja izolirano je iz 12 uzoraka alžirskog sirovog devinog mlijeka, te je mikrobiološki, biokemijski i genetički okarakterizirano. Neki su izolati imali proteolitičku aktivnost, svojstvo zakiseljavanja, sposobnost korištenja citrata i proizvodnje dekstrana i acetoina. Etanol, acetaldehid, metil-acetat, acetoin i octena kiselina glavni su hlapljivi spojevi pronađeni u uzorcima. Klasterskom analizom pomoću metode UPGMA (engl. unweighted pair group method with arithmetic mean) određena je prosječna udaljenost klastera na osnovu trideset i devet ispitanih fenotipskih značajki, te je potvrđena mikrobiološka raznolikost sirovog devinog mlijeka. Novina i znanstveni doprinos. Sojevi izolirani iz netipičnog izvora imali su zanimljive tehnološke značajke koje ih čine prikladnim za dodavanje starter kulturi. Klasterska analiza na osnovu ispitanih fenotipskih osobina pokazala se kao koristan alat za tipiziranje izolata u slučaju kad ne postoje genetske informacije o sojevima. Ove spoznaje mogu se primijeniti u industrijskoj proizvodnji prerađevina devinog mlijeka.Research background. Consumption of spontaneously fermented camel’s milk is common in Algeria, making it a feasible source of diverse lactic acid bacteria (LAB) with the potential to be used as adjunct cultures to improve quality and safety of fermented dairy products. Experimental approach. Twelve raw camel´s milk samples were used as a source of indigenous LAB, which were further characterised by examining 39 phenotypic traits with technological relevance. Results and conclusions. Thirty-five non-starter LAB (NSLAB) were isolated from 12 Algerian raw camel\u27s milk samples and they were microbiologically, biochemically and genetically characterised. Some isolates showed proteolytic activity, acidifying capacity, the ability to use citrate, and to produce dextran and acetoin. Ethanol, acetaldehyde, methyl acetate, acetoin and acetic acid were the major volatile compounds detected. Cluster analysis performed using the unweighted group with arithmetic average (UPGMA) method, and based on the thirty-nine phenotypic characteristics investigated, reflected the microbial diversity that can be found in raw camel´s milk. Novelty and scientific contribution. The isolated strains, from a non-typical source, showed interesting technological traits to be considered as potential adjunct cultures. Cluster analysis based on the examined phenotypic characteristics proved to be a useful tool for the typification of isolates when no genetic information is available. These findings may be of use towards an industrialised production of camel\u27s milk dairy products

Adoption of new health products in low and middle income settings: how product development partnerships can support country decision making

When a new health product becomes available, countries have a choice to adopt the product into their national health systems or to pursue an alternate strategy to address the public health problem. Here, we describe the role for product development partnerships (PDPs) in supporting this decision-making process. PDPs are focused on developing new products to respond to health problems prevalent in low and middle income settings. The impact of these products within public sector health systems can only be realized after a country policy process. PDPs may be the organizations most familiar with the evidence which assists decision making, and this generally translates into involvement in international policy development, but PDPs have limited reach into endemic countries. In a few individual countries, there may be more extensive involvement in tracking adoption activities and generating local evidence. This local PDP involvement begins with geographical prioritization based on disease burden, relationships established during clinical trials, PDP in-country resources, and other factors. Strategies adopted by PDPs to establish a presence in endemic countries vary from the opening of country offices to engagement of part-time consultants or with long-term or ad hoc committees. Once a PDP commits to support country decision making, the approaches vary, but include country consultations, regional meetings, formation of regional, product-specific committees, support of in-country advocates, development of decision-making frameworks, provision of technical assistance to aid therapeutic or diagnostic guideline revision, and conduct of stakeholder and Phase 4 studies. To reach large numbers of countries, the formation of partnerships, particularly with WHO, are essential. At this early stage, impact data are limited. But available evidence suggests PDPs can and do play an important catalytic role in their support of country decision making in a number of target countries