Theories on Solving the Travelling Salesman Problem Based on Artificial Neural Network and Their Applications

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面向机器翻译的英语词性标注研究及其应用

A hybrid approach to English Part-of-Speech (PoS) tagging with its target application being English-Chinese machine translation in business domain is presented, demonstrating how a present tagger can be adapted to learn from a small amount of data and handle unknown words for the purpose of machine translation. A small size of 998 k English annotated corpus in business domain is built semi-automatically based on a new tagset; the max-imum entropy model is adopted, and rule-based approach is used in post-processing. The tagger is further applied in Noun Phrase (NP) chunking. Exper-iments show that our tagger achieves an accuracy of 98.14%, which is a quite satisfactory result. In the application to NP chunking, the tagger gives rise to 2.21% increase in F-score, compared with the results using Stanford tagger.     

Combining chromatography and chemometrics for the characterization and authentication of fats and oils from triacylglycerol compositional data—A review

The characterization and authentication of fats and oils is a subject of great importance for market and health aspects. Identification and quantification of triacylglycerols in fats and oils can be excellent tools for detecting changes in their composition due to the mixtures of these products. Most of the triacylglycerol species present in either fats or oils could be analyzed and identified by chromatographic methods. However, the natural variability of these samples and the possible presence of adulterants require the application of chemometric pattern recognition methods to facilitate the interpretation of the obtained data. In view of the growing interest in this topic, this paper reviews the literature of the application of exploratory and unsupervised/supervised chemometric methods on chromatographic data, using triacylglycerol composition for the characterization and authentication of several foodstuffs such as olive oil, vegetable oils, animal fats, fish oils, milk and dairy products, cocoa and coffee.     

Tracing nanoparticles and photosensitizing molecules at transmission electron microscopy by diaminobenzidine photo-oxidation

During the last three decades, diaminobenzidine photo-oxidation has been applied in a variety of studies to correlate light and electron microscopy. Actually, when a fluorophore is excited by light, it can induce the oxidation of diaminobenzidine into an electron-dense osmiophilic product, which precipitates in close proximity to the fluorophore, thereby allowing its ultrastructural detection. This method has very recently been developed for two innovative applications: tracking the fate of fluorescently labeled nanoparticles in single cells, and detecting the subcellular location of photo-active molecules suitable for photodynamic therapy. These studies established that the cytochemical procedures exploiting diaminobenzidine photo-oxidation represent a reliable tool for detecting, inside the cells, with high sensitivity fluorescing molecules. These procedures are trustworthy even if the fluorescing molecules are present in very low amounts, either inside membrane-bounded organelles, or at the surface of the plasma membrane, or free in the cytosol. In particular, diaminobenzidine photo-oxidation allowed elucidating the mechanisms responsible for nanoparticles internalization in neuronal cells and for their escape from lysosomal degradation. As for the photo-active molecules, their subcellular distribution at the ultrastructural level provided direct evidence for the lethal multiorganelle photo-damage occurring after cell photo-sensitization. In addition, DAB photo-oxidized samples are suitable for the ultrastructural detection of organelle-specific molecules by post-embedding gold immunolabeling.     

Lifetime optimization for reliable broadcast and multicast in wireless ad hoc networks

In this paper, we consider the reliable broadcast and multicast lifetime maximization problems in energy‐constrained wireless ad hoc networks, such as wireless sensor networks for environment monitoring and wireless ad hoc networks consisting of laptops or PDAs with limited battery capacities. In packet loss‐free networks, the optimal solution of lifetime maximization problem can be easily obtained by tree‐based algorithms. In unreliable networks, we formulate them as min–max tree problems and prove them NP‐complete by a reduction from a well‐known minimum degree spanning tree problem. A link quality‐aware heuristic algorithm called Maximum Lifetime Reliable Broadcast Tree (MLRBT) is proposed to build a broadcast tree that maximizes the network lifetime. The reliable multicast lifetime maximization problem can be solved as well by pruning the broadcast tree produced by the MLRBT algorithm. The time complexity analysis of both algorithms is also provided. Simulation results show that the proposed algorithms can significantly increase the network lifetime compared with the traditional algorithms under various distributions of error probability on lossy wireless links. Copyright © 2012 John Wiley & Sons, Ltd.     

A new version of an additive scheme for the prediction of gas chromatographic retention indices of the 211 structural isomers of 4-nonylphenol

Control of environmental pollution by 4-nonylphenols (4-NP) and effective risk assessment concerning these xenoestrogens requires the identification of the individual isomers contained in the technical mixtures of 4-NP. A new approach is presented here which supports the identification of these compounds by a combination of experimentally determined gas chromatographic retention indices (I) of reference 4-NP isomers and calculated I-values. In addition to experimental indices, the I-prediction algorithm includes a new version of an additive scheme. The I-values of all structural 4-NP isomers are calculated on the basis of experimentally determined indices of a few available 4-NP isomers and the known retention indices of 75 iso-decanes. A mean deviation of ±11 index units between predicted and experimental I-values demonstrates the feasibility of the new approach. The predicted I-values provide information on the structure of 4-nonylphenol isomers in the technical mixture which has not been considered before. Furthermore, a novel line-coding system is proposed to describe the structure of isomeric 4-NPs and to initiate a current database for the endocrine-disrupting 4-nonylphenols.     

On two questions about feasibly constructive arithmetic

IPV is the intuitionistic theory axiomatized by Cook's equational theory PV plus PIND on NP‐formulas. Two extensions of IPV were introduced by Buss and by Cook and Urquhart by adding PIND for formulas of the form A(x) ∨ B, respectively ¬¬A(x), where A(x) is NP and x is not free in B. Cook and Urquhart posed the question of whether these extensions are proper. We show that in each of the two cases the extension is proper unless the polynomial hierarchy collapses.     

Correlation polytopes: Their geometry and complexity

A family of polytopes, correlation polytopes, which arise naturally in the theory of probability and propositional logic, is defined. These polytopes are tightly connected to combinatorial problems in the foundations of quantum mechanics, and to the Ising spin model. Correlation polytopes exhibit a great deal of symmetry. Exponential size symmetry groups, which leave the polytope invariant and act transitively on its vertices, are defined. Using the symmetries, a large family of facets is determined. A conjecture concerning the full facet structure of correlation polytopes is formulated (the conjecture, however, implies that NP=co-NP).Various complexity results are proved. It is shown that deciding membership in a correlation polytope is an NP-complete problem, and deciding facets is probably not even in NP. The relations between the polytope symmetries and its complexity are indicated.     

A model for virtual network embedding using Artificial Bee Colony

In a network virtualization environment, a significant research problem is that of virtual network embedding. As the network virtualization system is distributed in nature, an effective solution on how to optimally embed a dynamically generated virtual network request on the substrate networks that are owned and managed by multiple infrastructure providers needs proper attention. The problem is computationally hard, and therefore, many approaches, implying heuristics/meta‐heuristics, have been applied for the same. A meta‐heuristic, Artificial Bee Colony algorithm is getting popular due to its robustness toward complex problem solving. A novel approach based on Artificial Bee Colony to address the dynamic virtual network embedding problem in a multiple infrastructure provider scenario is proposed in this work. Bee population is initialized by using a greedy heuristic in which the number of substrate networks together with virtual network requests constructs a bee. Generated solution, in the population, is improvised by using greedy selection that explores a local search method adopted by the bees. In greedy selection, the new candidate source is memorized by the bee if its fitness is better than the fitness of the existing source. The performance study of the proposed model is done by simulation over various metrics such as embedding cost, embedding time, and acceptance ratio. A comparative study is conducted with other nature‐inspired virtual network embedding algorithms on these metrics. The findings affirm that the proposed virtual network embedding approach performs well and produces better results.