The effects of hydrogen on the plasma polymerization of tetrafluoroethylene

A study was made of the effects of hydrogen containing additives on the polymerization of tetrafluoroethylene in a radiofrequency low pressure plasma. The addition of ethylene and molecular hydrogen were found, under certain circumstances, to significantly increase the rate of polymer deposition. This effect is ascribed to the release of hydrogen atoms from the additive, which enhance the formation of fluorocarbon-free radicals and scavenges fluorine atoms. ESCA (electron spectroscopy for chemical analysis) spectra of the deposited films show that upon addition of hydrogen to the monomer, the F/C ratio of the film decreases and the H/C ratio rises. Hydrogen addition also influences the extent of crosslinking—a decrease being observed at low discharge power and an increase being observed at high discharge power.     

Congenital choledochal cysts

Cystic dilation of the common bile duct is a rare congenital anomaly. The cases of two patients, 2 1/2 and 18 years old, respectively, illustrate the difficulty in preoperative diagnosis, as well as the value of long-term postoperative follow-up. Ascending cholangitis developed in one of the patients after a Roux-en-Y cystojejunostomy nine years after operation. A follow-up of three years after cystoduodenostomy and 14 years after a hepaticojejunostomy is reported. In infants and small children, a cystoduodenostomy is usually done; otherwise, cystojejunostomy should be the preferred initial operation. Excision may be attempted if the cyst is very small, and in selected cases.     

Very-low-threshold 2.4-/spl mu/m GaInAsSb-AlGaAsSb laser diodes operating at room temperature in the continuous-wave regime

A GaInAsSb-AlGaAsSb large optical cavity triple-quantum-well structure was grown by molecular-beam epitaxy. Shallow mesa ridge-waveguide lasers with stripe width of 100 /spl mu/m were fabricated and tested. An internal losses coefficient as low as 4 cm/sup -1/ and a high internal quantum efficiency of 70% were obtained. In the pulsed regime at room temperature, the extrapolated threshold current densities for infinite cavity length is 78 A/cm/sup 2/. The threshold current density per quantum well is as low as 34 A/cm/sup 2/ for a 3-mm-long cavity.     

Some Results on Convolutional Coupled Codes: Distance Properties, Performance, and Design

The class of Convolutional Coupled Codes is a promising alternative to classical Turbo-Codes. A Convolutional Coupled Code consists of a cascade of ν identical recursive systematic convolutional (RSC) outer codes and k inner block codes with parameters (2ν, ν, d_i). The codes are linked together such that only the systematic part of the outer codes is encoded with the inner block encoders. Only the redundancy from the inner and outer codes are transmitted. An estimation of the minimum distance is derived. The influence of number, code memory and code polynomials of the outer RSC codes on the distance properties and the convergence behavior of the iterative decoding scheme is studied. With respect to this results, we present a guideline for the optimal design of the RSC outer codes.     

Homeomorphisms of the Sierpinski curve with periodic properties

In this paper, we study the three following types of homeomorphisms of the Sierpinski curve of the two sphere : pointwise periodic, periodic, and almost periodic, and we prove that they are equivalent. We show that a subgroup of homeomorphisms whose orbits are all finite, is a finite subgroup.     

On the feedback error compensation for adaptive modulation and coding scheme

In this paper, we consider the effect of feedback error on the performance of the joint adaptive modulation and diversity combining (AMDC) scheme which was previously studied with an assumption of perfect feedback channels. We quantify the performance of two joint AMDC schemes in the presence of feedback error, in terms of the average spectral efficiency, the average number of combined paths, and the average bit error rate. The benefit of feedback error compensation with adaptive combining is also quantified. Selected numerical examples are presented and discussed to illustrate the effectiveness of the proposed feedback error compensation strategy with adaptive combining. Copyright © 2011 John Wiley & Sons, Ltd.     

Adaptive hybrid learning for neural networks

A robust locally adaptive learning algorithm is developed via two enhancements of the Resilient Propagation (RPROP) method. Remaining drawbacks of the gradient-based approach are addressed by hybridization with gradient-independent Local Search. Finally, a global optimization method based on recursion of the hybrid is constructed, making use of tabu neighborhoods to accelerate the search for minima through diversification. Enhanced RPROP is shown to be faster and more accurate than the standard RPROP in solving classification tasks based on natural data sets taken from the UCI repository of machine learning databases. Furthermore, the use of Local Search is shown to improve Enhanced RPROP by solving the same classification tasks as part of the global optimization method.     

Bi-level Decision-making Modeling for an Autonomous Driver Agent: Application in the Car-following Driving Behavior

ABSTRACT

Road crashes are present as an epidemic in road traffic and continue to grow up, where, according to World Health Organization; they cause more than 1.24 million deaths each year and 20 to 50 million non-fatal injuries, so they should represent by 2020 the third leading global cause of illness and injury. In this context, we are interested in this paper to the car-following driving behavior problem, since it alone accounts for almost 70% of road accidents, which they are caused by the incorrect judgment of the driver to keep a safe distance. Thus, we propose in this paper a decision-making model based on bi-level modeling, whose objective is to ensure the integration between road safety and the reducing travel time. To ensure this objective, we used the fuzzy logic approach to model the anticipation concept in order to extract more unobservable data from the road environment. Furthermore, we used the fuzzy logic approach in order to model the driver behaviors, in particular, the normative behaviors. The experimental results indicate that the decision to increase in velocity based on our model is ensured in the context of respecting the road safety.     

On the use of many quality attributes for software refactoring: a many-objective search-based software engineering approach

Search-based software engineering (SBSE) solutions are still not scalable enough to handle high-dimensional objectives space. The majority of existing work treats software engineering problems from a single or bi-objective point of view, where the main goal is to maximize or minimize one or two objectives. However, most software engineering problems are naturally complex in which many conflicting objectives need to be optimized. Software refactoring is one of these problems involving finding a compromise between several quality attributes to improve the quality of the system while preserving the behavior. To this end, we propose a novel representation of the refactoring problem as a many-objective one where every quality attribute to improve is considered as an independent objective to be optimized. In our approach based on the recent NSGA-III algorithm, the refactoring solutions are evaluated using a set of 8 distinct objectives. We evaluated this approach on one industrial project and seven open source systems. We compared our findings to: several other many-objective techniques (IBEA, MOEA/D, GrEA, and DBEA-Eps), an existing multi-objective approach a mono-objective technique and an existing refactoring technique not based on heuristic search. Statistical analysis of our experiments over 31 runs shows the efficiency of our approach.