Anti-BlUFf: towards counterfeit mitigation in IC supply chains using blockchain and PUF

International Journal of Information Security - The complexity of today’s integrated circuit (IC) supply chain, organised in several tiers and including many companies located in different...     

Cognitive-Mathematical Approaches for Evaluating Architectural Contextual Fit

The main goal of this study is to apply a scientific quantitative approach to the investigation of contextual fit. This is approached mathematically within the framework of cognitive science and research on categorization and prototypes. Two experiments investigated two leading mathematical-cognitive approaches for explaining people’s judgment of contextual fit of a new building with an architectural/urban context: prototype approach and feature frequency approach. The basic concept is that people represent the built environment via architectural prototypes and/or frequencies of encountered architectural features. In the first experiment, a group of twelve participants performed rank order tasks on artificially created architectural patterns, for the purpose of psychological scaling. Perceptual distances among all patterns were mathematically determined. In the second experiment, three groups of architectural patterns were constructed to represent assumed architectural contexts. The prototype of each context was mathematically determined according to prototype cognitive model, and based on the distances calculated in the first experiment. Fifty-six students participated in the main experiment, in which they rank ordered a group of fifteen architectural patterns in terms of contextual fit to each of the three architectural contexts. Participants’ rank order data of the fifteen patterns were regressed on both the perceptual distances from prototypes, and numbers of features shared with each architectural context. Results indicated that both prototype and feature frequency approaches significantly accounted for important portions of participants’ judgments. However, participants tended to prefer one approach to the other according to context composition. Results have implications for both research on utilizing cognitive-mathematical models in architectural research and on urban design guidelines and control.     

The hybrid dynamic parallel scheduling algorithm for load balancing on Chained-Cubic Tree interconnection networks

The Chained-Cubic Tree (CCT) interconnection network topology was recently proposed as a continuation for the extended efforts in the area of interconnection networks’ performance improvement. This topology, which promises to exhibit the best properties of the hypercube and tree topologies, needs to be deeply investigated in order to evaluate its performance among other interconnection networks’ topologies. This work comes as a complementary effort, in which the load balancing technique is investigated as one of the most important aspects of performance improvement. This paper proposes a new load balancing algorithm on CCT interconnection networks. The proposed algorithm, which is called Hybrid Dynamic Parallel Scheduling Algorithm (HD-PSA), is a combination of two common load balancing strategies; dynamic load balancing and parallel scheduling. The performance of the proposed algorithm is evaluated both, analytically and experimentally, in terms of various performance metrics; including, execution time, load balancing accuracy, communication cost, number of tasks hops, and tasks locality.     

A new mechanism for the electrospinning of nanoyarns

A new electromechanical mechanism for spinning “core electrospun nanoyarn” is researched, designed, and implemented. SEM images have shown that the deposited nanofibers were wrapped helically around the core filament resulting in a core electrospun nanoyarn. The parameters of this mechanism such as feed‐in angles, twist rates, and take‐up speeds are analytically investigated. Twist rates of 500 to 750 revolutions per minute, core feed‐in angle of 0°, and take‐up speed of 1.5 cm/s were found optimum for successfully producing core electrospun nanoyarn. This nanoyarn is expected to find many applications in industrial and medical textiles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Optical,Electrical, and Magnetic Studies of Organic Solar Cells Based on Low Bandgap Copolymer with Spin ½ Radical Additives

The charge photogeneration and recombination processes in organic photovoltaic solar cells based on blend of the low bandgap copolymer, PTB7 (fluorinated poly‐thienothiophene‐benzodithiophene) with C60‐PCBM using optical, electrical, and magnetic measurements in thin films and devices is studied. A variety of steady state optical and magneto‐optical techniques were employed, such as photoinduced absorption (PA), magneto‐PA, doping‐induced absorption, and PA‐detected magnetic resonance (PADMR); as well as picosecond time‐resolved PA. The charge polarons and triplet exciton dynamics in films of pristine PTB7, PTB7/fullerene donor–acceptor (D–A) blend is followed. It is found that a major loss mechanism that limits the power conversion efficiency (PCE) of PTB7‐based solar cell devices is the “back reaction” that leads to triplet exciton formation in the polymer donor from the photogenerated charge‐transfer excitons at the D–A interfaces. A method of suppressing this “back reaction” by adding spin½ radicals Galvinoxyl to the D–A blend is presented; this enhances the cell PCE by ≈30%. The same method is not effective for cells based on PTB7/C70‐PCBM blend, where high PCE is reached even without Galvinoxyl radical additives.     

The effect of bovine whey proteins on the ability of poliovirus and Coxsackie virus to infect Vero cell cultures

The antiviral activity of esterified whey proteins (IC₅₀=20–40 μg mL⁻¹) observed against poliovirus type-1 and Coxsackie virus B6 infecting Vero cells depended on five factors (in order of importance): concentration of esterified proteins, multiplicity of infection, duration of incubation, timing of esterified proteins addition after infection, and extent of esterification of proteins. Renewal of cell growth medium after 24 h of incubation with new medium containing the same amount of esterified proteins enhanced the anti Coxsackie virus effect. Difference between start of infection of the reporter Vero cells and the time of addition of esterified proteins significantly decreased their antiviral efficacies. The poliovirus titer reduced gradually in response to the increase of the concentrations of esterified proteins. The relative amounts of viral RNA were less affected by the esterified proteins concentration than was the virus infectious titer, indicating that inhibitory proteins may slow down viral multiplication, yielding reduced amounts of viral RNA.     

The biochemical role and hypocholesterolaemic potential of the legume Cassia fistula in hypercholesterolaemic rats

The hypocholesterolaemic effect of Cassia fistula was investigated using hypercholesterolaemic male albino rats. Hypercholesterolaemia was induced by feeding on a mixture of cholesterol plus cholic acid for a 12 weeks period. Hypercholesterolaemia was characterized by significant increase in the average levels of total lipids, total cholesterol, and triglycerides and significant decrease in phospholipids content. Administration of Cassia fistula significantly reduced blood and liver total lipids. Brain, spleen, kidneys and heart followed nearly the same trend but with moderate effect. Blood, liver, kidneys, spleen and heart total cholesterol was significantly reduced, while that of brain was not affected. The level of triglycerides was markedly improved. There was a moderate rise, however, in phospholipids content in all studied organs. That is to say a marked progress in the correction of lipid metabolism occured. Also, administration of Cassia fistula induced a significant decrease in the high activities of serum GOT, GPT, alkaline and acid phosphatase and the values nearly returned the initial values. Total serum protein, albumin (A), globulin (G), A/G, free amino acids, uric acid and creatinine were also determined and their values were improved and attained nearly the normal values of the control group.