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1.
Machine readable dictionaries (Mrds) contain knowledge about language and the world essential for tasks in natural language processing (Nlp). However, this knowledge, collected and recorded by lexicographers for human readers, is not presented in a manner for Mrds to be used directly for Nlp tasks. What is badly needed are machine tractable dictionaries (Mtds): Mrds transformed into a format usable for Nlp. This paper discusses three different but related large-scale computational methods to transform Mrds into Mtds. The Mrd used is The Longman Dictionary of Contemporary English (Ldoce). The three methods differ in the amount of knowledge they start with and the kinds of knowledge they provide. All require some handcoding of initial information but are largely automatic. Method I, a statistical approach, uses the least handcoding. It generates relatedness networks for words in Ldoce and presents a method for doing partial word sense disambiguation. Method II employs the most handcoding because it develops and builds lexical entries for a very carefully controlled defining vocabulary of 2,000 word senses (1,000 words). The payoff is that the method will provide an Mtd containing highly structured semantic information. Method III requires the handcoding of a grammar and the semantic patterns used by its parser, but not the handcoding of any lexical material. This is because the method builds up lexical material from sources wholly within Ldoce. The information extracted is a set of sources of information, individually weak, but which can be combined to give a strong and determinate linguistic data base.  相似文献   

2.
A generalized temporal role-based access control model   总被引:18,自引:0,他引:18  
Role-based access control (RBAC) models have generated a great interest in the security community as a powerful and generalized approach to security management. In many practical scenarios, users may be restricted to assume roles only at predefined time periods. Furthermore, roles may only be invoked on prespecified intervals of time depending upon when certain actions are permitted. To capture such dynamic aspects of a role, a temporal RBAC (TRBAC) model has been recently proposed. However, the TRBAC model addresses the role enabling constraints only. In This work, we propose a generalized temporal role-based access control (GTRBAC) model capable of expressing a wider range of temporal constraints. In particular, the model allows expressing periodic as well as duration constraints on roles, user-role assignments, and role-permission assignments. In an interval, activation of a role can further be restricted as a result of numerous activation constraints including cardinality constraints and maximum active duration constraints. The GTRBAC model extends the syntactic structure of the TRBAC model and its event and trigger expressions subsume those of TRBAC. Furthermore, GTRBAC allows expressing role hierarchies and separation of duty (SoD) constraints for specifying fine-grained temporal semantics.  相似文献   

3.
Dictionary machine is an important VLSI system performing high speed data archival operations. In this paper, we present a design which can efficiently implement dictionary machines in VLSI processor arrays. In order to effectively process the operations of dictionary machine, hexagonal mesh is selected as the host topology in which two different networks for update and query operation are embedded. The proposed design is simple to implement as well as allows high throughput  相似文献   

4.
The development of a machine translation system is one of the most difficult computational tasks. Without a deep semantic analysis of both source and target languages, a machine translation system can not generate good results. This paper describes a machine translation system based on a new method called the Integral Method in which semantic analysis using an active dictionary plays a very important role.  相似文献   

5.
This paper presents a software complex for the computer-aided modeling of a term system. The project is implemented as an expert system that consists of a research team, a terminological knowledge base, a developer interface (the Semograf information system), and a user interface (TSBuilder and TSReader). Computer-aided design of a term system was achieved using data-mining methods, namely, decision-making trees and a modification of Rosenblatt’s perceptron.  相似文献   

6.
生物实体名识别对生物医学文献的信息抽取有重要的意义。本文针对如何识别蛋白质名进行了有益的尝试,主要采用了基于词典的方法,其中运用了近似搭配算法和首词查询的方法进行蛋白质名识别,同时结合机器学习方法训练了一个分类器来过滤候选词以提高识别的准确率。  相似文献   

7.
A lexicon is an essential part of any natural language processing system. The size, content and format of the lexicon is crucial in determining the power and sophistication of a natural language processing system. However, a lexicon which provides comprehensive, consistent and accurate lexical information and which is in a format facilitating fast retrieval is not easily available. This paper reports on a project which aims at the development of such a lexicon. The resulting lexicon is actually the modified and extended version of the machine tractable version of the Oxford Advanced Learner's Dictionary. The modification and extension concentrate mainly on the aspects of comprehensiveness, consistency, explicitness, accuracy and the dictionary format. The modified and extended version is considered a desirable source of lexical information for any natural language processing system.Si-Qing Chen received her Ph.D. in computational linguistics (1992) from Guangzhou Institute of Foreign Languages. His research interests include natural language processing, computer-assisted language teaching, and computational lexicography. She is currently furthering her study and research at the University of Illinois at Urbana-Champaign. She has published several articles on psycholinguistics, language teaching, philosophy of language, and natural language processing in, amongst other journals, Language Learning and the CALICO Journal.Luomai Xu is an associate professor in the Department of English at Guangzhou Institute of Foreign Languages. He has been working on several projects and published several articles on natural language processing.  相似文献   

8.
A dictionary searching technique, originally proposed by A. D. Booth et al., is reconsidered, and found to be critically dependent upon the frequency distribution of the items of which the dictionary is comprised.  相似文献   

9.
In this paper, we address a parallel machine scheduling problem to minimize the total weighted completion time, where product families are involved. Major setups occur when processing jobs of different families, and sequence dependencies are also taken into account. Considering its high practical relevance, we focus on the special case where all jobs of the same family have identical processing times. In order to avoid redundant setups, batching jobs of the same family can be performed. We first develop a variable neighborhood search algorithm (VNS) to solve the interrelated subproblems in a simultaneous manner. To further reduce computing time, we also propose an iterative scheme which alternates between a specific heuristic to form batches and a VNS scheme to schedule entire batches. Computational experiments are conducted which confirm the benefits of batching. Test results also show that both simultaneous and iterative approach outperform heuristics based on a fixed batch size and list scheduling. Furthermore, the iterative procedure succeeds in balancing solution quality and computing time.  相似文献   

10.
The paper addresses the problem of automatic dictionary translation.The proposed method translates a dictionary by means of mining repositories in the source and target languages, without any directly given relationships connecting the two languages. It consists of two stages: (1) translation by lexical similarity, where words are compared graphically, and (2) translation by semantic similarity, where contexts are compared. In the experiments Polish and English version of Wikipedia were used as text corpora. The method and its phases are thoroughly analyzed. The results allow implementing this method in human-in-the-middle systems.  相似文献   

11.
L. Carlucci 《Calcolo》1971,8(3):161-183
This paper presents an algorithmic interpretation of a method for the formal definition of programming lauguages which holds for languages having an ALGOL-like or PL/1-like structure. This algorithm is a Generalized Markov Algorithm (GMA) and models the behaviour of the abstract machine defined by the IBM Vienna Laboratory group for the formal definition of PL/1. The paper provides two extensions of the GMA method: The GMA here defined is nondeterministic and handles tree structured objects. The paper provides a set of rules defining the algorithm along with a technique for generating linear representations of objects having tree structures. The subject of this paper was first developed in a master thesis in mathematics at the University of Pisa (october 1968).  相似文献   

12.
We consider a single machine scheduling problem with changing processing times. The processing conditions are subject to a general cumulative effect, in which the processing time of a job depends on the sum of certain parameters associated with previously scheduled jobs. In previous papers, these parameters are assumed to be equal to the normal processing times of jobs, which seriously limits the practical application of this model. We further generalize this model by allowing every job to respond differently to these cumulative effects. For the introduced model, we solve the problem of minimizing the makespan, with and without precedence constraints. For the problem without precedence constraints, we also consider a situation in which a maintenance activity is included in the schedule, which can improve the processing conditions of the machine, not necessarily to its original state. The resulting problem is reformulated as a variant of a Boolean programming problem with a quadratic objective, known as a half-product, which allows us to develop a fully polynomial-time approximation scheme with the best possible running time.  相似文献   

13.
A new approach to support vector machine (SVM) classification is proposed wherein each of two data sets are proximal to one of two distinct planes that are not parallel to each other. Each plane is generated such that it is closest to one of the two data sets and as far as possible from the other data set. Each of the two nonparallel proximal planes is obtained by a single MATLAB command as the eigenvector corresponding to a smallest eigenvalue of a generalized eigenvalue problem. Classification by proximity to two distinct nonlinear surfaces generated by a nonlinear kernel also leads to two simple generalized eigenvalue problems. The effectiveness of the proposed method is demonstrated by tests on simple examples as well as on a number of public data sets. These examples show the advantages of the proposed approach in both computation time and test set correctness.  相似文献   

14.
In this note, we consider a single machine scheduling problem with generalized total tardiness objective function. A pseudo-polynomial time solution algorithm is proposed for a special case of this problem. Moreover, we present a new graphical algorithm for another special case, which corresponds to the classical problem of minimizing the weighted number of tardy jobs on a single machine. The latter algorithm improves the complexity of an existing pseudo-polynomial algorithm by Lawler. Computational results are presented for both special cases considered.  相似文献   

15.
Chakraborty  M.  Maji  B.  Kandar  D. 《Microsystem Technologies》2021,27(2):379-385
Microsystem Technologies - With the concept of advanced intelligent transportation systems, the integration of data with technology underway with internet of things brings the concept of always...  相似文献   

16.
Che  Zhiyong  Liu  Bo  Xiao  Yanshan  Cai  Hao 《Applied Intelligence》2021,51(10):7245-7261
Applied Intelligence - Recently, dictionary learning has been widely studied, and lots of dictionary learning methods have been developed to solve the problem of classification. In this paper, we...  相似文献   

17.
Hardware bytecode translation is a technique to improve the performance of the Java virtual machine (JVM), especially on the portable devices for which the overhead of dynamic compilation is significant. However, since the translation is done on a single bytecode basis, a naive implementation of the JVM generates frequent memory accesses for local variables which can be not only a performance bottleneck but also an obstacle for instruction folding. A solution to this problem is to add a small register file to the data path of the microprocessor which is dedicated for storing local variables. However, the effectiveness of such a local variable register file depends on the size and the local variable access behavior of the applications.In this paper, we analyze the local variable access behavior of various Java applications. In particular, we will investigate the fraction of local variable accesses that are covered by the register file of a varying size, which determines the chip area overhead and the operation speed. We also evaluate the effectiveness of the sliding register window for parameter passing in context of JVM and on-the-fly optimization of local variable to register file mapping.With two types of exceptions, a 16-entry register file achieves coverages of up to 98%. The first type of exception is represented by the SAXON XSLT processor for which the effect of cold miss is significant. Adding the sliding window feature to the register file for parameter passing turns 6.2-13.3% of total accesses from miss to hit to the register file for the SAXON with XSLTMark. The second type of exception is represented by the FFT, which accesses more than 16 local variables for most of method invocations. In this case, on-the-fly profiling is effective. The hit ratio of a 16-entry register file for the FFT is increased from 44% to 83% by an array of 8-bit counters.  相似文献   

18.
基于最小二乘支持向量机的非线性广义预测控制   总被引:5,自引:2,他引:5  
通过中值定理将一类非线性系统近似为时变线性系统,然后将提出的在线最小二乘支持向量机回归(OLSSVMR)与广义预测控制相结合,提出了一种基于OLS-SVMR的自适应直接广义预测控制.利用OLS-SVMR直接设计预测控制器,并基于广义误差估计对控制器参数和广义误差估计中的未知向量进行自适应调整.理论证明了该方法可使广义误差估计值收敛到原点的一个小邻域内.仿真算例也验证了该方法的有效性.  相似文献   

19.
Suppose that a test customer in anM/D/1queueing system can get service only if he has access to the server and a separate eventEhas occurred. All other customers only require access to the server. The time until the eventEoccurs is assumed to be an exponentially distributed random variable, if the test customer reaches the server beforeEoccurs, he must then return to the back of the queue. At any time, however, the test customer is allowed to give up his place in the queue and join the back of the queue. The test customer represents a computational task that depends upon the results of an associated task. The test customer's mean delay until service is derived assuming that he always maintains his position in the queue until he reaches the server. Conditions are given for which this "move-along" policy is optimal, i.e., minimizes the test customer's mean delay until service. A condition is also given for which the move-along policy is not optimal.  相似文献   

20.
Computer readable dictionaries are produced by the dictionary editor system JISYO, which takes inputs from dictionary data bases produced from type-setting tapes by the DTV (Data Translation and Verification) system of M. Nagao. Topological structuring transforms the dictionaries into thesauri with associative partial ordering by means of which denotations are computed as limits.  相似文献   

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