BDD-versus SAT-based bounded model checking for the existential fragment of linear temporal logic with knowledge: algorithms and their performance

The paper deals with symbolic approaches to bounded model checking (BMC) for the existential fragment of linear temporal logic extended with the epistemic component (ELTLK), interpreted over interleaved interpreted systems. Two translations of BMC for ELTLK to SAT and to operations on BDDs are presented. The translations have been implemented, tested, and compared with each other as well as with another tool on several benchmarks for MAS. Our experimental results reveal advantages and disadvantages of SAT- versus BDD-based BMC for ELTLK.     

Thermal properties of poly(ethylene terephthalate) recovered from municipal solid waste by steam autoclaving

The steam autoclaving of municipal solid waste followed by size separation was shown to be a way to recover virtually 100% of recyclable poly(ethylene terephthalate) (PET); this is a yield not attainable by a typical material recovery facility. The polymer properties of the recovered PET, which had undergone various degrees of thermal processing, were evaluated by thermogravimetric analysis, differential scanning calorimetry, gel permeation chromatography, viscometry, and solid‐state NMR to assess the commercial viability of polymer reuse. The weight‐average molecular weight (M_w) decreased as a result of autoclaving from 61,700 g/mol for postconsumer poly(ethylene terephthalate) (pcPET) to 59,700 g/mol for autoclaved postconsumer poly(ethylene terephthalate) [(apcPET)]. M_w for the reclaimed poly(ethylene terephthalate) (rPET) was slightly lower, at 57,400 g/mol. The melting temperature increased with two heat cycles from 236°C for the heat‐crystallized virgin poly(ethylene terephthalate) (vPET) pellets to 248°C for apcPET and up to 253°C for rPET. Correspondingly, the cold crystallization temperature decreased with increased processing from 134°C for vPET to 120°C for apcPET. The intrinsic viscosity varied from 0.773 dL/g for the vPET to 0.709 dL/g for rPET. Extruded samples were created to assess the potential commercial applications of the recovered rPET samples. The M_w values of the extruded apcPET and rPET samples dropped to 37,000 and 34,000 g/mol, respectively, after extrusion (three heat cycles); this indicated that exposure to heat dictated that these materials would be better suited for downcycled products, such as fibers and injected‐molded products. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012     

Information Gain in Quantum Eavesdropping

Abstract

We analyse the information obtained by an eavesdropper during the various stages of a quantum cryptographic protocol associated with key distribution. We provide both an upper and a lower limit on the amount of information that may have leaked to the eavesdropper at the end of the key distribution procedure. These limits are restricted to intercept/resend eaves-dropping strategies. The upper one is higher than has been estimated so far, and should be taken into account in order to guarantee the secrecy of the final key, which is subsequently obtained via the so-called privacy amplification.     

Visualization of temporal text collections based on Correspondence Analysis

In this paper, we present CatViz—Temporally-Sliced Correspondence Analysis Visualization. This novel method visualizes relationships through time and is suitable for large-scale temporal multivariate data. We couple CatViz with clustering methods, whereupon we introduce the concept of final centroid transfer, which enables the correspondence of clusters in time. Although CatViz can be used on any type of temporal data, we show how it can be applied to the task of exploratory visual analysis of text collections. We present a successful concept of employing feature-type filtering to present different aspects of textual data. We performed case studies on large collections of French and English news articles. In addition, we conducted a user study that confirms the usefulness of our method. We present typical tasks of exploratory text analysis and discuss application procedures that an analyst might perform. We believe that CatViz is general and highly applicable to large data sets because of its intuitiveness, effectiveness, and robustness. We expect that it will enable a better understanding of texts in huge historical archives.     

Cymbopogon citratus leaves: Characterization of flavonoids by HPLC–PDA–ESI/MS/MS and an approach to their potential as a source of bioactive polyphenols

Leaves from cultivated Cymbopogon citratus were extracted with methanol, 80% aqueous ethanol and water (infusion and decoction) and the extracts were assessed for their antiradical capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay; the infusion extract exhibited the strongest activity. Tannins, phenolic acids (caffeic and p-coumaric acid derivatives) and flavone glycosides (apigenin and luteolin derivatives) were identified in three different fractions obtained from an essential oil-free infusion, and a correlation with their scavenger capacity for reactive oxygen species was studied. The tannin and flavonoid fractions were the most active against species involved in oxidative damage processes. In the flavonoid fraction, representing 6.1% of the extract, thirteen compounds (O- and C-glycosylflavones) were tentatively identified by high performance liquid chromatography, coupled to photodiode-array and electrospray ionization mass spectrometry detectors (HPLC–PDA–ESI/MS), nine of which were identified for the first time in this plant, all of them being C-glycosylflavones (mono-C-, di-C- and O,C-diglycosylflavones). The potential beneficial and protective value of the identified polyphenols for human health is discussed.     

Carbohydrate composition and content of organic acids in fresh and stored apples

The contents of low‐molecular‐weight carbohydrates (LMWC; sorbitol, glucose, fructose and sucrose), starch, dietary fibre and organic acids were determined in seven apple cultivars at the start and end of the consumption interval. The cultivars included were Summered, Aroma, Ingrid Marie, Cox Orange, Mutzu, Belle de Boskoop and Jonagold. The total content of LMWC ranged between 615 and 716 g kg⁻¹ dry matter (DM). The dominating sugar was fructose, corresponding to on average 57% (range 48–62%) of the total LMWC. However, in Cox Orange the sucrose content was considerably higher and the fructose and sucrose contents constituted approximately 46% each. Total dietary fibre content was similar in the cultivars (total dietary fibre 160 ± 20 g kg⁻¹ DM), except for Belle de Boskoop which had a higher content (203 g kg⁻¹ DM). Mutzu had a lower proportion of soluble fibre (27% of total dietary fibre) compared with the others (mean 32%). The organic acid content was on average 80 ± 4 g kg⁻¹ DM, except for two of the cultivars (Summered and Belle de Boskoop) which had a higher content (105 ± 6 g kg⁻¹ DM). Interestingly, the organic acid content was only slightly reduced upon storage in the case of Belle de Boskoop, whereas there was a substantial decrease in all the other cultivars (p < 0.001). Sucrose (p < 0.01) and starch (p < 0.05) contents decreased in all cultivars following storage, whereas sorbitol (p < 0.05) and total dietary fibre (p < 0.05) contents increased. It is concluded that the observed differences in composition are of such magnitude that they may affect both nutritional and sensory properties. © 2000 Society of Chemical Industry