Space optimization in the FNC-2 attribute grammar system

Projet CHLOEMemory space management for attribute evaluators is a vital requirement in practice. In fact, using attribute grammars (AGs) will very quickly meet the problem of memory space if it isn't taken into special consideration. We consider this problem for evaluators of the simple multi-visit class, also called l-ordered, because it is the largest possible AGs class for which we can find, at construction time, a method for memory space optimization. We present a new algorithm which decides, at generation time, if it is possible to store attribute instances in global stacks or global variables. The purpose of this approach is to reduce not only memory space, but also as much as possible the number of attributes to be stored in the nodes of the tree. This method is implemented in the new attribute grammar processing system, named FNC-2. Finally we present our first practical results which seem very promising

Advances in Computer Science and Engineering

The book Advances in Computer Science and Engineering constitutes the revised selection of 23 chapters written by scientists and researchers from all over the world. The chapters cover topics in the scientific fields of Applied Computing Techniques, Innovations in Mechanical Engineering, Electrical Engineering and Applications and Advances in Applied Modeling

Extending Attribute Grammars to Support Programming-in-the-Large

Attribute grammars add specification of static semantic properties to context-free grammars, which in turn describe the syntactic structure of program units. However, context-free grammars cannot express programming-in-the-large features common in modern programming languages, including unordered collections of units, included units and sharing of included units. We present extensions to context-free grammars, and corresponding extensions to attribute grammars, suitable for defining such features. We explain how batch and incremental attribute evaluation algorithms can be adapted to support these extensions, resulting in a uniform approach to intra-unit and inter-unit static semantic analysis and translation of multi-unit programs

OO-IP hybrid language design and a framework approach to the GIPC

Intensional Programming is a declarative programming paradigm in which expressions are evaluated in an inherently multidimensional context space. The Lucid family of programming languages is, to this day, the only programming languages of true intensional nature. Lucid being a functional language, Lucid programs are inherently parallel and their parallelism can be efficiently exploited by the adjunction of a procedural language to increase the granularity of its parallelism, forming hybrid Lucid languages. That very wide array of possibilities raises the need for an extremely flexible programming language investigation platform to investigate on this plethora of possibilities for Intensional Programming. That is the purpose of the General Intensional Programming System (GIPSY), especially, the General Intensional Programming Compiler (GIPC) component. The modularity, reusability and extensibility aspects of the framework approach make it an obvious candidate for the development of the GIPC. The framework presented in this thesis provides a better solution compared to all other techniques used to this day to implement the different variants of intensional programming. Because of the functionality of hybrid programming support in the GIPC framework, a new OO-IP hybrid language is designed for further research. This new hybrid language combines the essential characteristics of IPL and Java, and introduces the notion of object streams which makes it is possible that each element in an IPL stream could be an object with embedded intensional properties. Interestingly, this hybrid language also brings to Java objects the power which can explicitly express context, creating the novel concept of intensional objects, Le. objects whose evaluation is context-dependent, which are therein demonstrated to be translatable into standard objects. By this new feature, we extend the use and meaning of the notion of object and enrich the meaning of stream in IPL and semantics of Java. At the same time, during the procedure to introduce intensional objects and this OO-IP hybrid language, many factors are considered. These factors include how to integrate the new language with the GIPC framework design and the issues related to its integration in the current GIPSY implementation. Current semantic rules show that the new language can work well with the GIPC framework and the GIPSY implementation, which is another proof of the validity of our GIPC framework design. Ultimately, the proposed design is put into implementation in the GIPSY and the implementation put to test using programs from different application domains written in this new OO-IP languag

Pattern based fact extraction from Estonian free-texts

Vabatekstide töötlus on üks keerulisemaid probleeme arvutiteaduses. Tekstide täpne analüüs on tihti mitmestimõistetavuse tõttu arvutite jaoks keeruline või võimatu. Sellegipoolest on võimalik teatud fakte eraldada. Käesolevas töös uurime mustripõhiseid meetodeid faktide tuletamiseks eesti keelsetest tekstidest. Rakendame oma metoodikat reaalsetel tekstidel ning analüüsime tulemusi. Kirjeldame lühidalt aktiivõppe metoodikat, mis võimaldab suuri korpuseid kiiremini märgendada. Lisaks oleme implementeerinud prototüüplahenduse korpuste märgendamiseks ning mustripõhise faktituletuse läbiviimiseks.Natural language processing is one of the most difficult problems, since words and language constructions have often ambiguous meaning that cannot be resolved without extensive cultural background. However, some facts are easier to deduce than the others. In this work, we consider unary, binary and ternary relations between the words that can be deduced form a single sentence. The relations represented by sets of patterns are combined with basic machine learning methods, that are used to train and deploy patterns for fact extraction. We also describe the process of active learning, which helps to speed up annotating relations in large corpora. Other contributions include a prototype implementation with plain-text preprocessor, corpus annotator, pattern miner and fact extractor. Additionally, we provide empirical study about the efficiency of the prototype implementation with several relations and corpora

Evolutionary Design Model for the design of complex engineered systems : Masdar City as a case study

Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2009."September 2009." Cataloged from PDF version of thesis.Includes bibliographical references (p. 150-157).This thesis develops a framework for constructing an Evolutionary Design Model (EDM) that would enhance the design of complex systems through an efficient process. The framework proposed is generic and suggests a group of systematic methodologies that eventually lead to a fully realized and integrated design model. Within this model, complexities of the design are handled and the uncertainties of the design evolution are managed. Using the framework, vast design spaces can be searched while solutions are intelligently modified, their performance evaluated, and their results aggregated into a compatible set for design decisions. The EDM is composed of several design states as well as design evolving processes. A design state describes a design at a particular point in time and maps the system's object to the system's requirements and identifies its relation to the context in which the system will operate. A design evolving process involves many sub-processes which include formulation, decomposition, modeling, and integration. These sub-processes are not always carried out in a sequential manner, but rather a continuous move back and forth to previous and subsequent stages is expected. The resulting design model is described as an evolutionary model that moves a system's design from simple abstract states to more complex and detailed states throughout its evolution.(cont.) The framework utilizes system modeling methodologies that include both logical and mathematical modeling methods. The type of model used within the EDM's evolving processes is highly dependent on and driven by design needs of each process. As the design progresses a shift from logical models to mathematical models occurs within the EDM. Finally, a partial EDM is implemented within the context of a computational design system for Masdar city to demonstrate the application of the proposed framework.By Anas Alfaris.S.M