System Level Hardware/Software Partitioning Based on Simulated Annealing and Tabu Search

This paper presents two heuristics for automatic hardware/software partitioning of system level specifications. Partitioning is performed at the granularity of blocks, loops, subprograms, and processes with the objective of performance optimization with a limited hardware and software cost. We define the metric values for partitioning and develop a cost function that guides partitioning towards the desired objective. We consider minimization of communication cost and improvement of the overall parallelism as essential criteria during partitioning. Two heuristics for hardware/software partitioning, formulated as a graph partitioning problem, are presented: one based on simulated annealing and the other on tabu search. Results of extensive experiments, including real-life examples, show the clear superiority of the tabu search based algorithm.     

XRD and XPS Analysis of TiO2 Thin Films Annealed in Different Environments

Undoped and Nb-doped TiO2 thin films have been fabricated on glass substrate by RF magnetron sputtering. The morphologic, structural and surface composition of these films before and after annealing in different environments were investigated by atomic force microscopy （AFM） imaging, X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）. The XRD data reveal that the crystallinity is improved when the films are Nb-doped and annealed in H2 environment. The TiO2 thin films annealed in H2 environment exhibit only the anatase phase. The XPS analysis of TiO2 with Nb indicates the maximum shift in binding energy of the Ti 2p peak. A mechanism for the incorporation of Nb in the TiO2 lattice has been proposed.     

Microdistribution and composition of usewear polish on prehistoric stone tools

The use of prehistoric stone tools can be classified according to the usewear traces on the tool working edge. The polish resulting from the use of the tool contains minute amounts of the original worked material. Using the micro PIXE mapping technique, a comparative study of a set of experimental tools and a set of mesolithic end-scrapers was performed. For both sets of tools, increased concentrations of elements associated with the worked material were found in small localized regions. The composition of these regions was probed by point measurements and two main groups of P, Ca and S, K compounds were identified. The X-ray attenuation in the polish layer suggests that the deposited elements diffuse into the bulk flint.     

Efficient March Tests for a Reduced 3-Coupling and 4-Coupling Faults in Random-Access Memories

This paper presents two new march test algorithms, MT-R3CF and MT-R4CF, for detecting reduced 3-coupling and 4-coupling faults, respectively, in n × 1 random-access memories (RAMs). To reduce the length of the tests, only the coupling faults between physically adjacent memory cells have been considered. The tests assume that the storage cells are arranged in a rectangular grid and that the mapping from logical addresses to physical cell locations is known completely. The march tests need 30n and 41n operations, respectively. In this paper any memory fault is modelled by a set of primitive memory faults called simple faults. We prove, using an Eulerian graph model, the ability of the test algorithms to detect all simple coupling faults. This paper also includes a study regarding the ability of the test MT-R3CF to detect interacting linked 3-coupling faults. This work improves the results presented in [1] where a similar model of reduced 3-coupling faults has been considered and a march test with 38n operations has been proposed. To compare these new march tests with other published tests, simulation results are presented in this paper.     

Structural and spectroscopic effects of Ag–Eu3+ codoping of TeO2–PbO glass ceramics

Structural and spectroscopic behavior of TeO₂–PbO–Eu₂O₃ glass ceramics containing small amounts of Ag₂O (0.5 mol%) or metallic Ag nanoparticles (AgNPs) (0.33 mol%) have been studied by varying their Eu₂O₃ content (0–10 mol%). The structural behavior of these samples was investigated by means of X-ray diffraction (XRD), SEM microscopy, and Fourier transform infrared (FTIR) spectroscopy. The average unit-cell parameters, crystallites size, and the quantitative ratio of the crystallographic phases in the samples were evaluated based on XRD data. FTIR spectroscopy data revealed that the TeO₃ and TeO₄ are the main structural units of these glass ceramics and their ratio, TeO₃/TeO₄, changes as function of the europium oxide content and the codoping of the samples. Luminescence spectroscopy measurements evidenced the important peaks located at 438, 550, and 722 nm due to the Pb²⁺ ions and at 589 and 611 nm due to the Eu³⁺ ions present in the studied samples. The presence of AgNPs in the studied glass ceramics determines a considerable enhancement of the luminescence bands of Eu³⁺ ions from 589 and 611 nm.     

Induction of a p-Coumaroyl Trihydroxy Triterpene Acid in Psylla-Infested and Mechanically Damaged Pear Trees

The pattern of induction and the chemical structure of phenolic compounds in pear trees (Pyrus communis, cv. Conference) that were either infested by pear leaf suckers Psylla pyricola and P. pyri or mechanically damaged, or both, were studied. Chromatographic (HPLC) and mass spectral analysis performed on extracts of leaf samples collected at various time intervals from trees subjected to three treatments demonstrated the induction (and/or amplification) of a phenolic compound, identified as 3-O-trans-p-coumaroyltormentic acid (I). New mass spectrometric data on this phenolic compound are presented. HPLC revealed different peak patterns in the course of the period of Psylla infestation and the lapse of time since mechanical damage was inflicted, compared to a control tree. The new phenolic compound became apparent after 12 hr and reached the highest level 30 days after damage by pear leaf suckers. It was also observed after 24 hr at lower intensity in samples from a mechanically damaged tree and exclusively on day 30 at very low intensity in the leaf extracts from the uninfested control trees. We conclude that damage by pear leaf suckers, and to a lesser extent also mechanical damage, induce the synthesis of the new, late-eluting phenolic compound. We propose that this compound is involved in plant defense against pear leaf suckers.     

Analysis and Optimisation of Hierarchically Scheduled Multiprocessor Embedded Systems

We present an approach to the analysis and optimisation of heterogeneous multiprocessor embedded systems. The systems are heterogeneous not only in terms of hardware components, but also in terms of communication protocols and scheduling policies. When several scheduling policies share a resource, they are organised in a hierarchy. In this paper, we first develop a holistic scheduling and schedulability analysis that determines the timing properties of a hierarchically scheduled system. Second, we address design problems that are characteristic to such hierarchically scheduled systems: assignment of scheduling policies to tasks, mapping of tasks to hardware components, and the scheduling of the activities. We also present several algorithms for solving these problems. Our heuristics are able to find schedulable implementations under limited resources, achieving an efficient utilisation of the system. The developed algorithms are evaluated using extensive experiments and a real-life example.