Экономическая оценка энергосберегающих проектов

В пособии рассмотрены понятия инвестиций проектов и проектного анализа, анализа финансовой деятельности предприятия. Представлены методы оценки экономической эффективности внедрения энергосберегающих проектов, сравнительного анализа их с альтернативными вариантами. Рассмотрены различные схемы финансирования энергосберегающих проектов, включая варианты использования патентов, лицензий. Предназначено для студентов энергетических и экономических специальностей

Generalized energetic model for characterizing the magnetic hysteresis of anisotropic thin films

Zsfassung in dt. SpracheIn der vorliegenden Arbeit wird ein zweidimensionales energiebasiertes Modell zur Beschreibung der ferromagnetischen Hysterese von dünnen Schichten präsentiert. Die Grundlage bildet das 1994 von H. Hauser erstmals publizierte -Energetic Model of Ferromagnetic Hysteresis- (EM), in welchem so genannte statistische Domänenklassen, basierend auf den magnetisch leichten Richtungen im Material, unterschieden werden. Darauf aufbauend, werden in dieser Arbeit zwei wesentliche Erweiterungen beschrieben. In einer ersten Verallgemeinerung wird die Ausrichtung der magnetischen Dipole in einer Domänenklasse nicht auf die leichte Richtung beschränkt, sondern mittels einer statistischen Verteilungsfunktion beschrieben. Damit können einerseits lokale Abweichungen von der parallelen Ausrichtung aufgrund von Material-Inhomogenitäten abgebildet und andererseits die Temperaturabhängigkeit der spontanen Magnetisierung direkt aus dem Modell erklärt werden. Die zweite Erweiterung besteht in einer vollständigen zweidimensionalen Formulierung des Modells. Obwohl Hauser bereits Ansätze zur Behandlung mehrerer leichter Richtungen beschreibt, wurden die meisten Untersuchungen, unter Berücksichtigung der Symmetrie im Kristallgitter, auf Basis eines eindimensionalen Modellansatzes durchgeführt. Die zweidimensionale Erweiterung erfordert insbesondere eine Neuformulierung der Ausdrücke der im Magnetisierungsprozess geleisteten reversiblen und irreversiblen Arbeit. Zusätzlich werden die aus einer magnetokristallinen oder einer induzierten Anisotropie resultierenden Energiebeiträge direkt im Modell berücksichtigt. Damit kann der Magnetisierungsprozess in anisotropen dünnen Schichten für beliebige Richtungen des angelegten Magnetfeldes mit einem Parametersatz beschrieben werden. Darüber hinaus lassen sich kohärente Rotation der Magnetisierung und nicht-kohärente Ummagnetisierungsprozesse durch entsprechend parametrierte Domänenklassen unterscheiden. Die Evaluierung des zweidimensionalen Hysterese-Modells erfolgt am Beispiel von dünnen Permalloy-Schichten, die für den Einsatz in anisotropen magneto-resistiven (AMR) Sensoren hergestellt werden. Insbesondere für AMR-Anwendungen ist die Richtungsabhängigkeit der Magnetisierungskurve, speziell deren Verlauf in der schweren Richtung, von entscheidender Bedeutung. Die Identifizierung des Modells erfolgt durch Abgleich der Simulationsergebnisse mit den, aus magneto-optischen Kerr-Messungen gewonnenen Hysteresekurven in den magnetisch leichten und schweren Richtungen. Alle dazwischen liegenden Kurven können dann direkt aus dem Modell berechnet werden. Ferner spiegeln einige der identifizierten Modellparameter mikrostrukturelle Eigenschaften der dünnen Schichten wider, wie etwa lokale Fehlausrichtungen aufgrund von Inhomogenitäten. Diese Eigenschaften hängen meist von den technologischen Parametern des Herstellungsprozesses, also beispielsweise vom Target-Substrat-Abstand beim Sputtern ab. Das im Rahmen dieser Arbeit vorgestellte Modell erlaubt Rückschlüsse von den gemessenen Hysteresekurven auf die strukturellen Eigenschaften der dünnen Schichten und kann so dazu beitragen, aufwendige und teuere mikroskopische Analysen zu reduzieren. Somit kann der Aufwand bei der Optimierung der technologischen Parameter des Herstellungsprozesses deutlich verringert werden.Within this work, a generalized two-dimensional energetic hysteresis model for characterizing the magnetization process of thin ferromagnetic films is presented. Based on the -Energetic Model of Ferromagnetic Hysteresis- (EM), which has been introduced by H. Hauser in 1994, so called statistical domain classes adapted from the magnetic easy directions of the material sample are distinguished. With respect to Hauser-s formulation of the EM, two major extensions are provided in this work. As a first generalization, the orientation of the elementary magnetic dipoles within a statistical domain class is no longer restricted to the specified easy direction, but is represented by a stochastic circular distribution function that is characterized by a mean orientation and a certain variance. So local misalignments of magnetic moments due to imperfections within the material can be modeled on the one hand, and the temperature dependence of the spontaneous magnetization can be described from the first principles on the other hand. The second key extension is the fully two-dimensional formulation of the EM. Although, the original model of Hauser is intended for a certain number of easy directions, most of the investigations are based on a one-dimensional model setup in consideration of the symmetry properties of the crystalline axes. In particular, the terms for reversible and irreversible work during the magnetization process have to be reformulated in order to allow fully two-dimensional modeling. Further, the magnetocrystalline and induced anisotropy are directly incorporated in the model by corresponding energy terms. Thereby, the two-dimensional approach allows predicting the magnetic hysteresis curves of anisotropic thin films for all directions of the applied field with a single set of parameters. Besides, the generalized model accounts for coherent magnetization rotation as well as non-coherent magnetization reversal mechanisms by using a corresponding parameterization of domain classes. The evaluation of the presented generalized two-dimensional energetic hysteresis model is done by the example of Permalloy thin films used for anisotropic magneto-resistive (AMR) sensors. Especially for AMR sensor applications the directional properties of the magnetization curve are important, particularly the hard-axis characteristics. The model parameters are identified by a comparison of the simulated hysteresis loops to those obtained from a magneto-optical Kerr measurement setup in easy axis and hard axis direction. Then, the magnetization curves can be calculated for any arbitrary direction of the magnetic field with respect to the easy axis. Furthermore, the identified model parameters reflect several microstructural properties of the thin film, like microscopic misalignments due to inhomogeneities, for example. Amongst others, these microstructural properties are related to characteristics of the thin film production process, such as the distance between target and substrate during sputtering. Due to the fact that the magnetic hysteresis model presented within this work allows an inference from measured magnetization curves to the structural properties of the film, laborious and expensive microscopic analyses can be reduced. Hence, significantly less effort is needed to improve the technological parameters of the production process.18

Requirements engineering with interrelated conceptual models and real world scenes

Requirements Engineering (RE) is the process of creating requirements documents with the objective to establish a complete, consistent, and unambiguous conceptual description of intended changes (e.g. in respect to software, hardware, or business processes) for a given application domain. Because RE is also a cooperative communication and learn process of stakeholders and requirements analysts the use of scenarios (i.e. concrete stories of existing or desired system usage) and real world scenes (captured or animated observations of current or future system usage employing rich media like video) becomes more and more popular in industrial practice. However, despite this trend current scenario-based RE approaches and techniques utilising rich media in the analysis process do not provide a tight and fine granular integration of scenarios and scenes with conceptual descriptions. The approach presented in this thesis provides tool-supported fine-granular interrelations between parts of abstract concepts of conceptual models and parts of concrete real world scenes that have influenced the creation of the concept or have been used for validating it. Based on these interrelations I developed methods and a supporting process-integrated modelling environment for a diverse set of extended conceptual modelling applications (e.g. scene-based explanation and negotiation support, formal inspections, model-based comparison of real world scenes) for three different conceptual modelling languages. I also validated the approach in two case studies and experimental research in the industrial field of mechanical engineering

Requirements engineering with interrelated conceptual models and real world scenes

Requirements Engineering (RE) is the process of creating requirements documents with the objective to establish a complete, consistent, and unambiguous conceptual description of intended changes (e.g. in respect to software, hardware, or business processes) for a given application domain. Because RE is also a cooperative communication and learn process of stakeholders and requirements analysts the use of scenarios (i.e. concrete stories of existing or desired system usage) and real world scenes (captured or animated observations of current or future system usage employing rich media like video) becomes more and more popular in industrial practice. However, despite this trend current scenario-based RE approaches and techniques utilising rich media in the analysis process do not provide a tight and fine granular integration of scenarios and scenes with conceptual descriptions. The approach presented in this thesis provides tool-supported fine-granular interrelations between parts of abstract concepts of conceptual models and parts of concrete real world scenes that have influenced the creation of the concept or have been used for validating it. Based on these interrelations I developed methods and a supporting process-integrated modelling environment for a diverse set of extended conceptual modelling applications (e.g. scene-based explanation and negotiation support, formal inspections, model-based comparison of real world scenes) for three different conceptual modelling languages. I also validated the approach in two case studies and experimental research in the industrial field of mechanical engineering

Modelling contextual information about scenarios

Abstract: Scenario-based approaches have proven useful for requirements elicitation, validation and negotiation. Besides the direct and indirect stated requirements current scenario-based approaches capture also contextual information about the existing or future system, but lack in a systematic support for representing and reasoning about this information. Based on a literature survey we define a comprehensive set of concepts needed to represent contextual usage knowledge of scenarios. In contrast to existing approaches, we propose to relate contextual knowledge not only to the whole scenario, but also to the scenario components, e.g. single or sets of interactions between the system and the user of the system. Consequently, we propose two contextual models, a scenario context model (SCM) and an interaction context model (ICM).

HYDRA: A Hypertext Model for Structuring Informal Requirements Representations

: The ultimate measurement for software quality is the degree to which user needs are satisfied by the system. User needs are an essential input for developing a requirements specification and, in the first place, are most often represented using natural language, pictures, or graphics (informal representations). The consideration of user needs as a driving force throughout the development process is only possible if requirements traceability is assured. Therefore, the specified requirements must be related with their sources, e.g. the user needs. Hypertext offers a technology for enabling this interrelation. We propose a formal hypertext model, called HYDRA, for structuring informal requirements information. HYDRA enriches the quasi standard hypertext model Dexter by introducing typed hypertext nodes and links. HYDRA is used to structure informal information during the requirements engineering process by creating formal hypertext objects which refer to the informal representations (or..