Efficient traceable signatures in the standard model

Traceable signatures (TS), suggested by Kiayias, Tsiounis and Yung (Eurocrypt’04), extend group signatures to address various basic traceability issues beyond merely identifying the anonymous signer of a rogue signature. Namely, they enable the efficient tracing of all signatures produced by a misbehaving party without opening the identity of other parties. They also allow users to provably claim ownership of a previously signed anonymous signature. To date, known TS systems all rely on the random oracle model. In this work we present the first realization of the primitive that avoids resorting to the random oracle methodology in its security proofs. Furthermore, our realization’s efficiency is comparable to that of the latest fastest and shortest standard model group signatures.     

Techno-economic assessment on the implementation of biomass gasifier in conventional parboiling rice mills

Enhancement of efficiency in rice processing mills can help rural farmers to reduce the cost of rice production. Parboiling-the hydrothermal treatment of paddy rice, accounts for a significant portion of total rice processing costs and its quality. A rice husk powered gasifier-based parboiling system is an attractive option for rural rice processing mills but has not been widely adopted due to various constraints. Hence, there is a need for technical and economical analysis on gasifier-based rice parboiling system to generate information on efficiency improvement and the cost-effective ways in rice processing industries. This paper presents a techno-economic evaluation of rice husk powered gasifier-based rice processing systems working in either Producer Gas in Hot Gas Mode (PG-HGM) or Producer Gas in Cold Gas Mode (PG-CGM). MATLAB software has been used for mathematical analysis. The research reveals that the biomass gasifier operated rice parboiling system working in both modes can have the overall system efficiency as 49% to 57% with a lowest payback time of 4-2 years. Positive Net Present Cost is observed for the capacities above 1.5 tons/batch in PG-HGM.     

Multi-scale modelling and hybrid atomistic-continuum simulation of non-isothermal flows in microchannels

A hybrid atomistic-continuum method devoted to the study of multi-scale problems is presented. The simulation domain is decomposed into three regions: the bulk where the continuous Navier–Stokes and energy equations are solved, the neighbourhood of the wall simulated by the molecular dynamics and the overlap region which connects the macroscopic variables (velocity and temperature) between the former two regions. For the simulation of long micro/nanochannels, we adopt multiple molecular blocks along the flow direction, what enables the accurate capture of the velocity and temperature variations from the inlet to the outlet. The validity of the hybrid method is shown by comparisons with both analytical solutions and finite-volume simulations. This method is then applied successfully to the study the hydrodynamic and thermal development of a liquid flow in a long micro/nanochannel.     

Generation of a mono-ubiquitinated PCNA mimic by click chemistry

Genotoxic stress results in more than 50 000 damaged DNA sites per cell per day. During DNA replication, processive high‐fidelity DNA polymerases generally stall at DNA lesions and have to be displaced by translesion synthesis DNA polymerases, which are able to bypass the lesion. This switch is mediated by mono‐ubiquitination of the processivity factor proliferating cell nuclear antigen (PCNA). To further investigate the regulation of the DNA polymerase exchange, we developed an easy and efficient method to synthesize site‐specifically mono‐ubiquitinated PCNA by click chemistry. By incorporating artificial amino acids that carry an azide (Aha) or an alkyne (Plk) in their side chains, into ubiquitin (Ub) and PCNA, respectively, we were able to link the two proteins site‐specifically by the Cu^I‐catalyzed azide–alkyne cycloaddition. Finally, we show that the synthetic PCNA–Ub is able to stimulate DNA synthesis by DNA polymerase δ, and that DNA polymerase η has a higher affinity for PCNA–Ub than to PCNA.     

A survey on wireless body area networks

The increasing use of wireless networks and the constant miniaturization of electrical devices has empowered the development of Wireless Body Area Networks (WBANs). In these networks various sensors are attached on clothing or on the body or even implanted under the skin. The wireless nature of the network and the wide variety of sensors offer numerous new, practical and innovative applications to improve health care and the Quality of Life. The sensors of a WBAN measure for example the heartbeat, the body temperature or record a prolonged electrocardiogram. Using a WBAN, the patient experiences a greater physical mobility and is no longer compelled to stay in the hospital. This paper offers a survey of the concept of Wireless Body Area Networks. First, we focus on some applications with special interest in patient monitoring. Then the communication in a WBAN and its positioning between the different technologies is discussed. An overview of the current research on the physical layer, existing MAC and network protocols is given. Further, cross layer and quality of service is discussed. As WBANs are placed on the human body and often transport private data, security is also considered. An overview of current and past projects is given. Finally, the open research issues and challenges are pointed out.     

Action Mechanism of WS2 Nanoparticles with ZDDP Additive in Boundary Lubrication Regime

The effect in the tribological performance of WS₂ fullerene-like nanoparticles in PAO base oil when adding a ZDDP additive was studied at 100 °C in the boundary lubrication regime. The tribological properties of the dispersion surpass those obtained without one of the two additives. The friction modifier properties of the particles are improved in the presence of ZDDP, while the anti-wear properties of the ZDDP are increased when the particles are added to the dispersion. The composition of the formed tribofilm was investigated. Results show that a 50–60 nm tribofilm is formed on the steel surface composed by WS₂ mixed on the ZDDP chemical tribofilm. A WS₂-rich layer is observed at the top of the tribofilm. A correlation between the chemical composition of the tribofilm and the tribological properties of the “PAO + WS₂ + ZDDP” dispersion was made. Synergy between the two additives was proven.     

Temperature effect on bacterial growth rate: quantitative microbiology approach including cardinal values and variability estimates to perform growth simulations on/in food

Temperature effect on growth rates of Listeria monocytogenes, Salmonella, Escherichia coli, Clostridium perfringens and Bacillus cereus, was studied. Growth rates were obtained in laboratory medium by using a binary dilutions method in which 15 optical density curves were generated to determine one μ value. The temperature was in the range from 2 to 48 °C, depending on the bacterial species. Data were analysed after a square root transformation. No large difference between the strains of a same species was observed, and therefore all the strains of a same species were analysed together with the same secondary model. The variability of the residual error, including both measurements errors and biological strain difference, was homogenous for sub-optimal temperature values. To represent this variability in bacterial kinetic simulation, the 95% confidence interval based on an asymptotic Normal distribution, around the growth rate value was determined. With this modelling approach, the behaviour of bacterial species on food, irrespective of the strain or the laboratory, was described. This growth simulation with confidence limits has several applications, such as to facilitate comparisons between a challenge-test and simulation results, and, to appreciate if the temperature change has or has not a significant effect on a bacterial growth profile, with regard to the uncontrolled factors. The integration of this piece of work in the Sym'Previus software is now in process. Results obtained in five French laboratories will be extended by working on new food and new microbial species and improved by further work on variability estimation.     

Prelimbic cortex specific lesions disrupt delayed-variable response tasks in the rat.

The role of the prelimbic cortex (PL) in rats was investigated with excitotoxic lesions. PL lesions altered the alternation scores in spontaneous and reinforced spatial delayed-alternation tasks. PL lesions induced a delay in conditioning under a temporal go/no-go alternation schedule but not under a continuous food-reinforcement schedule in a runway. PL lesions had no effect on the acquisition of a standard radial-arm-maze task nor on a fixed-goal location task but disrupted the acquisition of a variable-goal location task in a radial-arm maze. The present results indicate that PL lesions replicated most of the behavioral deficits obtained with larger prefrontal lesions. PL lesions disrupted the acquisition of delayed-variable response tasks while leaving unaffected fixed-response tasks. These results are discussed in relation with a working-memory, a response-selection, and an attentional hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimum quality and progressive resolution of video signals

The problem of encoding and transmitting various video formats in a way making possible for all receivers to decode those formats is studied. The quantization for a general subband coder is first optimized using some perceptual criterion. New methods for filtering and decimating are presented, which can be combined with orthogonal transformation. Those operations are analysed. Finally two coding schemes are presented, and simulations are also provided.