Catálogo de publicaciones - libros

Independent from the concrete definition of the term “data quality” consistency always plays a major role. There are two main points when dealing with the data quality of a database: Firstly, the data quality has to be measured, and secondly, if is necessary, it must be improved. A classifier can be used for both purposes regarding consistency demands by calculating the distance of the classified value to the stored value for measuring and using the classified value for correction.

Cost reduction is a constant problem for modern regional utilities. Due to the liberalization of the energy market new possibilities arise. Energy is ordered out of the 110 kV- network of a TSO. Costs for the use- of — system charges and costs for energy trading at the spot market on the European Energy Exchange (EEX) have to be minimized. Technical, economic and legal restrictions must be brought together to reach this aim. There is an approach on the MV- Level chosen to investigate the possibilities of a regional utility. To have a reasonable size of control-, state- and environmental variables the MV- network is simplified by a mathematically and technically equal model witch includes the same complexity of all relevant variables as well as all types of side conditions.

After the development of the formal model the mathematical description for three time horizons (‘intraday’, ‘day ahead’, ‘long term’) will be developed concerning different entrepreneurial targets relating to the different time horizons. This leads to a discrete- continuous optimal control problem.

For investigation of the applicability of different optimization methods the properties of the optimization models were researched and shown by an example regarding the time horizon ‘day ahead’.

During the last decade, the Common Information Model (CIM) has evolved to an extensive ontology for the domain of energy markets. As the CIM does only offer an UML model for the implementation of its objects, an ER model or relational database schema has not been released. Therefore, it is necessary to create a CIM based database schema in order to persist CIM data in a relational database. This schema could either be constructed based on the former mentioned UML model as a relational database schema or based on an already existing RDF/XML serialization of CIM as an RDF database. This paper evaluates these two implementations of the CIM.

A mayor challenge for the integration of renewable energy sources to the existing power supply system is to provide environment-friendly balance energy which compensates temporal fluctuations in the power supply of wind mills or photovoltaics. In this paper, we analyze a centralized approach for demand side management reducing the need for balance energy. The approach assumes a given set of energy consuming jobs that are freely movable within job-specific pre-defined time intervals. Using the meta-heuristics Tabu Search, a schedule of these jobs is searched that leads to an optimal match of energy demand with energy supply. Different initialization strategies for constructing an initial solution and different alternatives of Tabu Search are evaluated in order to enhance the optimization result. Using realistic data for wind power and synthesized but not unrealistic sets of up to 120,000 jobs, the optimization results show that a considerable reduction of balance energy could be possible by our load shifting method.

Contemporary power distribution faces various new challenges. Most of those challenges have a strong impact on the ICT-structure required and on system architecture. This contribution briefly introduces changes and requirements imposed, both for trading and distribution of power. On this basis, alternatives for ICT architectures are discussed, recommendations are made on implementation choices for a meaningful sustainable solution, and communication and security challenges are addressed.

In environmental databases there is a plethora of data, described in different terminologies, stored in different data structures and referring to distinct time periods and locations. Thus it is difficult for non-experts to find the data they are looking for. Adding an ontology-layer, which provides semantic enhancement, provides the underlying data structure for an open and intuitive search interface for non-experts. In this paper, we present the design of a bilingual eco-ontology using fuzzy mappings and loosely bridged ontologies which introduce a semantic layer in an existing environmental database storing data in German and French.

In this paper, the results of the project “Conception of an Environmental Data W” are presented. The actual situation at the Volkswagen AG is shown and the analysis phase is described. After discussing the most important problems that occurred during the project, some of them special to environmental data, it is described what was achieved and what has yet to be done. At the end, the potential of an environmental data warehouse is outlined.

The accelerated growth of the environmental of information volumes on processes, phenomena and reports brings about an increasing interest in the possibility of discovering knowledge from data sets. This is a challenging task because in many cases it deals with extremely large, inherently not structured and fuzzy data, plus the presence of uncertainty. Therefore it is required to know a priori the quality of future procedures without using any additional information. For those reasons, the main goal of this paper is to define and apply new evaluation measures for decision systems by using the rough sets theory in an application of the quality assessment of the decision systems used for learning seasonal weather forecasting. The experimental studies were carried out for demonstrating the feasibility of the proposal.

Ubiquitous Computing allows the use of context-aware applications, a new set of functionalities which adopt contextual information. The structure of such type of information allows the development of more flexible and adaptable services, rich in functions and centered on user demands. The development and management of such services require dynamic mechanisms which consider the nature of contextual information. Service discovery protocols offer such dynamism and ontology is a way to deal with the complexity of the contextual information. Experiments to monitor the environment, like the LBA, due to the diversity of devices, services and contexts, are good examples of ubiquitous environments where service discovery protocols can be a essential tool. SCaSDP is a new service discovery protocol which considers the nature of contextual information and allows a secure management of services and user information. SCaSDP uses a semantic matching algorithm of service descriptions based on ontology’s.

Closed-loop supply chains CLSC) concept is response to a challenge that more and more supply chains meet namely need to include a return flow of materials in they planning and coordination structure. Following paper presents on-going project regarding the application of agent-based systems for supply-chain synchronized production planning including management of raw materials flow as well as flow of returned by customer obsolete products and defected semi-products and products that are refused by quality control within the factory. Authors discuss the main problems that appear by synchronized material flow planning in CLSC. The model for integration of closed-loop supply chain through an agent-based system is proposed.