一种利用扩展广义表来实现逻辑表达式自动推导的算法

探讨了如何将数据结构中广义表进行扩展 ,并利用这个扩展广义表来设计逻辑表达式在计算机上的逻辑结构和存储结构 ,以及在这种结构上如何实现逻辑表达式的基本运算 ,进而实现其它复杂的表达式自动推导     

Short-term scheduling of multiple source pipelines with simultaneous injections and deliveries

This paper addresses the optimal scheduling of straight pipelines featuring multiple intermediate nodes acting as dual-purpose stations, with a continuous-time Mixed-Integer Linear Programming formulation partly derived from Generalized Disjunctive Programming. The new model allows for an intermediate station to act as an output and input terminal at the same time so as to reduce the number of segment switches between active and idle, and consequently decrease operating costs. Contrary to previous approaches, decisions related to batch sizing, batch sequencing and timing are determined in a single step. Several examples of growing complexity are solved to illustrate the effectiveness and computational advantage of the proposed model in both solution quality and CPU time.     

Review of Nonlinear Mixed-Integer and Disjunctive Programming Techniques

This paper has as a major objective to present a unified overview and derivation of mixed-integer nonlinear programming (MINLP) techniques, Branch and Bound, Outer-Approximation, Generalized Benders and Extended Cutting Plane methods, as applied to nonlinear discrete optimization problems that are expressed in algebraic form. The solution of MINLP problems with convex functions is presented first, followed by a brief discussion on extensions for the nonconvex case. The solution of logic based representations, known as generalized disjunctive programs, is also described. Theoretical properties are presented, and numerical comparisons on a small process network problem.     

Process simulator-based optimization of biorefinery downstream processes under the Generalized Disjunctive Programming framework

Downstream processing of biofuels and bio-based chemicals represents a challenging problem for process synthesis and optimization, due to the intrinsic nonideal thermodynamics of the liquid mixtures derived from the (bio) chemical conversion of biomass. In this work, we propose a new interface between the process simulator PRO/II (SimSci, Schneider-Electric) and the optimization environment of GAMS for the structural and parameter optimization of this type of flowsheets with rigorous and detailed models. The optimization problem is formulated within the Generalized Disjunctive Programming (GDP) framework and the solution of the reformulated MINLP problem is approached with a decomposition strategy based on the Outer-Approximation algorithm, where NLP subproblems are solved with the derivative free optimizer belonging to the BzzMath library, and MILP master problems are solved with CPLEX/GAMS. Several validation examples are proposed spanning from the economic optimization of two different distillation columns, the dewatering task of diluted bio-mixtures, up to the distillation sequencing with simultaneous mixed-integer design of each distillation column for a quaternary mixture in the presence of azeotropes.     

Explicit representation of terms defined by counter examples

Anti-unification guarantees the existence of a term which is an explicit representation of the most specific generalization of a collection of terms. This provides a formal basis for learning from examples. Here we address the dual problem of computing a generalization given a set of counter examples. Unlike learning from examples an explicit, finite representation for the generalization does not always exist. We show that the problem is decidable by providing an algorithm which, given an implicit representation will return a finite explicit representation or report that none exists. Applications of this result to the problem of negation as failure and to the representation of solutions to systems of equations and inequations are also mentioned.Research performed while visiting from the: Dept. of Computer Science, University of Melbourne, Parkville 3052, Australia.     

基于改进模糊集合方法的用户查询词扩展的信息检索

基于模糊集合方法和Wordnet的查询扩展技术,提出了一种用户查询词扩展的信息检索方法。先用Wordnet找出查询词的同义词,再利用广义Jaccard系数来计算2个同义词之间的相似性,选取相似性较大的同义词进行查询词扩展后实现信息检索。此方法不仅保留了模糊集合方法对查询词处理简单且容易理解的特性,还很好地解决了模糊集合方法不能对文档进行精确排序的问题。最后,提出了基于矩阵的布尔式向析取范式转化的算法,该算法转换简单快速,解决了模糊集合方法中随着查询词数量的增加使得布尔表达式转化成析取范式变得很复杂的问题。     

Some properties of involution palindrome languages

This paper extends the understanding of involution palindrome words (θ-palindrome words). This notion is motivated by the DNA strand design in the area of biocomputing where the Watson–Crick complementarity can be abstracted as an antimorphic involution function. A language consisting of involution palindrome words is defined as an involution palindrome language. Some properties of involution palindrome words and languages are surveyed in this paper. Besides involution palindrome words being considered, some algebraic properties of skew involution palindrome words are studied as well. Furthermore, we exhibit certain characteristics of non-involution palindrome words.     

F-Disjunctive languagest

A language L is f-disjunctive if every class of its syntactic congruence is finite. The family of f-disjunctive languages is a natural generalization of the family of disjunctive languages and both families are anti-AFL. Every f-disjunctive language is dense and every class (≠ 1) of its syntactic congruence is an infix code. Five different classes of f-disjunctive languages are considered and it is shown that they form a strict hierarchy. Also some properties of the syntactic monoid of a f-disjunctive language are established, in particular its decomposition as a subdirect product of nil monoids.     

基于基因本体的语义相似度研究

针对基因本体的有向无环图结构,提出一种新的计算基因本体中术语间语义相似度的方法。该方法通过计算2个术语的公共祖先及符合条件的不相交祖先,得到不相交祖先的信息量平均值和2个术语的信息量平均值,并将2个平均值的比值作为2个术语的语义相似度。实验结果证明该方法准确度较高。