A framework for semiqualitative reasoning in engineering applications

In most cases the models for experimentation, analysis, or design in engineering applications take into account only quantitative knowledge. Sometimes there is a qualitative knowledge that is convenient to consider in order to obtain better conclusions. These qualitative concepts can be labels such as ``high,’ ’ ``very negative,’ ’ ``little acid,’ ’ ``monotonically increasing’ ’ or symbols such as ¾; º, etc. . . Engineers have already used this type of knowledge implicitly in many activities. The framework that we present here lets us express explicitly this knowledge. This work makes the following contributions. First, we identify the most important classes of qualitative concepts in engineering activities. Second, we present a novel methodology to integrate both qualitative and quantitative knowledge. Third, we obtain signi® cant conclusions automatically. It is named semiqualitative reasoning. Qualitative concepts are represented by means of closed real intervals. This approximation is accepted in the area of Arti® cial Intelligence. A modeling language is speci® ed to represent qualitative and quantitative knowledge of the model. A numeric constraint satisfaction problem is obtained by means of corresponding rules of transformation of the semantics of this language. In order to obtain conclusions, we have developed algorithms that treat the problem in a symbolic and numeric way. The interval conclusions obtained are transformed into qualitative labels through a linguistic interpretation. Finally, the capabilities of this methodology are illustrated on different problems

Developing a labelled object-relational constraint database architecture for the projection operator

Current relational databases have been developed in order to improve the handling of stored data, however, there are some types of information that have to be analysed for which no suitable tools are available. These new types of data can be represented and treated as constraints, allowing a set of data to be represented through equations, inequations and Boolean combinations of both. To this end, constraint databases were defined and some prototypes were developed. Since there are aspects that can be improved, we propose a new architecture called labelled object-relational constraint database (LORCDB). This provides more expressiveness, since the database is adapted in order to support more types of data, instead of the data having to be adapted to the database. In this paper, the projection operator of SQL is extended so that it works with linear and polynomial constraints and variables of constraints. In order to optimize query evaluation efficiency, some strategies and algorithms have been used to obtain an efficient query plan. Most work on constraint databases uses spatiotemporal data as case studies. However, this paper proposes model-based diagnosis since it is a highly potential research area, and model-based diagnosis permits more complicated queries than spatiotemporal examples. Our architecture permits the queries over constraints to be defined over different sets of variables by using symbolic substitution and elimination of variables.Ministerio de Ciencia y Tecnología DPI2006-15476-C02-0

An Approach to Temporal-Aware Procurement of Web Services

Es también una ponencia de: International Conference on Service-Oriented Computing: ICSOC 2005: Service-Oriented Computing - ICSOC 2005 pp 170-184. book ISBN: 978-3-540-30817-1 e-ISBN: 978-3-540-32294-8In the context of web service procurement (WSP), temporal–awareness refers to managing service demands and offers which are subject to validity periods, i.e. their evaluation depends not only on quality of service (QoS) values but also on time. For example, the QoS of some web services can be considered critical in working hours (9:00 to 17:00 from Monday to Friday) and irrelevant at any other moment. Until now, the expressiveness of such temporal–aware specifications has been quite limited. As far as we know, most proposals have considered validity periods to be composed of a single temporal interval. Other proposals, which could allow more expressive time–dependent specifications, have not performed a detailed study about all the underlying complexities of such approach, in spite of the fact that dealing with complex expressions on temporality is not a trivial task at all. As a matter of fact, it requires a special design of the so–called procurement tasks (consistency and conformance checking, and optimal selection). In this paper, we present a constraint–based approach to temporal–aware WSP. Using constraints allows a great deal of expressiveness, so that not only demands and offers can be assigned validity periods but also their conditions can be assigned (possibly multiple) validity temporal subintervals. Apart from revising the semantics of procurement tasks, which we previously presented in the first edition of the ICSOC conferences, we also introduce the notion of the covering set of a demand, a topic which is closely related to temporality.Ministerio de Ciencia y Tecnología TIC2003-02737-C02-0

MULTI-OBJECTIVE OPTIMIZATION OF SCIENCE PARKS BASED ON QUALITATIVE EQUATIONLESS RELATIONS

Tato dizertační práce řeší optimalizaci vědeckých parků z hlediska potřeby zvyšování konkurenceschopoností regionů a potažmo celé ČR. Je koncipována pro investory, kteří chtějí realizovat projekt VP v různých regionech ČR nebo manažery již existujících vědeckých parků, kteří chtějí udělat další rozhodnutí. Možnost realizovat projekt VP platí pro všechny regiony, včetně regionů, které se dříve mohly spoléhat na dostupnost a těžbu nerostných surovin (tradičně těžba uhlí), jež v minulosti fungovala jako významný faktor pro rozvoj průmyslu a ekonomické aktivity. Tyto regiony se nyní musejí vyrovnat se ztrátou konkurenceschopnosti a přesunout své úsilí do oblasti rozvoje výzkumu a vývoje produkujícího inovace. Kvalitativní modelování je vhodné pro tak málo známé a komplexní systémy jako jsou právě vědecké parky (VP). Modely vědeckých parků obsahují proměnné různého charakteru a různých časových chování. Z tohoto důvodu jsou studovány rychlé a pomalé modely. Pro 11 pomalých proměnných je studován soubor 17 kvalitativních bezrovnicových vazeb typu (např. kvalita výzkumných a vývojových inženýrů, konkurenční status atd.) společně se souborem 14 kvalitativních bezrovnicových vazeb pro 10 rychlých proměnných typu (např. spolupráce mezi průmyslem a akademickými ústavy, výměna průmyslových informací apod.). V této dizertační práci jsou prezentována řešení rychlých a pomalých modelů ve formě souborů rychlých a pomalých scénářů a přechodů mezi nimi a jsou hledána optimální řešení. Analýza/optimalizace málo známých, nelineárních, multidimenzionálních systémů jako jsou vědecké parky je složitá a je obtížné vytvořit smysluplné a dostatečně přesné modely nestabilního chování. Systematická analýza řady kvalitativních řešení je hlavní částí disertační práce a jejím hlavním vědeckým přínosem. Jednotlivé kroky postupu tvorby modelu jsou názorně ilustrované na příkladech. Text obsahuje interpretaci dosažených výsledků a formulaci přínosů pro teorii a praxi.The dissertation deals with the Multi-Objective optimization of the Science parks in terms of increasing competitiveness of the regions and the whole country. The main target of this dissertation is to help the investors, who want to implement Science Park SP project in different regions of Czech Republic or managers of existing science parks, who want to make another decision. This applies to all regions in Czech Republic, including regions, that were previously able to rely on availability and exploitation of mineral resources (traditional coal mining), which previously functioned as an important factor for industrial development and economic activity. Nowadays those regions must cope with the loss of competitiveness and to move their efforts into research and development and produce innovations. Qualitative modelling is suitable for such poorly known and complex systems as SPs. SP models incorporate variables of different nature and different time behaviours. Therefore slow and fast SP models are studied. A set of 17 slow qualitative equationless relations, among 11 slow variables (e.g. Quality of R&D engineers, Competition status ect.) together with a set of 14 fast qualitative equationless relations, among 10 fast variables (e.g.Cooperation between industries and academics, incentives for investment ect.) is studied. The model’s solutions i.e. set of slow and fast scenarios and transitions among them, are presented in this disertation in full details. Analysis/Optimization of ill-known, nonlinear, multidimensional system as Science Park (SP) is a difficult task and it is difficult to develop meaningful and sufficiently accurate models of any unsteady state SP behaviours. A systematic analysis of a sequence of qualitative solutions is the key part of the dissertation and its main scientific contribution. The individual steps of production of the models are graphically illustrated in the examples. The dissertation includes interpretation of the results and benefits for the theory and practice.

Granger Lake Sedimentation and Watershed Conservation Implementation Assessment

Sedimentation rates for many Texas reservoirs may be skewed by overstated estimates of design capacity and assumptions perpetuated through subsequent volumetric surveys. Multi-frequency reservoir surveys offer the means by which we may improve existing reservoir data and validate historic sedimentation rate estimates. To demonstrate application of this technology and value of its data derivatives, a multi-year, multi-frequency acoustic survey of Granger Lake, located in Williamson County, Texas was undertaken. Objectives of the study were to use hydro-acoustic survey techniques to verify assumptions of original reservoir capacity, examine the general accuracy of previously derived sedimentation rate, and document conservation implementation effectiveness. The intended benefit of these pre and post-watershed conservation implementation project surveys was to provide a temporal snapshot of sediment flux. Specifically, these data would be used as a tool to quantitatively estimate project success or non-success in annual sediment delivery reduction to the reservoir. During the course of the Granger Lake Watershed Implementation project, Granger Lake lost on average 343 acre feet of water storage annually to watershed sediment contribution. Sediment profiling results indicate pre-impoundment design estimates were overstated, thus skewing subsequent sediment deliver estimates. Since the mid-1990's, an accelerating sedimentation trend is apparent. Conservation implementation is not plainly responsible for the decrease in sediment delivery, and in fact may be undetectable for the foreseeable future. The study illustrates the value of examining previously established reservoir sedimentation estimates and assumptions of reservoir life based on design capacity estimates and routine volumetric surveys. Insights from this research highlight the importance of validating historic reservoir survey data and significance regarding its use in quantifying historic and future conservation effects, or other reservoir sustaining strategies