The quality of software systems depends on many criteria. Choosing an adequate software process model is essential in meeting quality requirements. When aiming at a rigorous mathematical notion of correctness, formal software development provides an appropriate process model, which ensures that the implementation fulfills the requirements given by a formal specification. The stepwise derivation by transformations represents one approach to formal system development that can be supported by computers. This book first introduces a sound framework for the mechanizable transformation of formal specifications. The framework comprises a specification language, a formal development method and various mechanizable transformation rules. It is then illustrated how the framework is implemented in the Lubeck Transformation System LTS -- a tool for the interactive development of software systems.

Mechanizing the Transformation of Higher-Order Algebraic Specifications for the Development of Software Systems

Computers & Technology

Magnussen, Sönke Johannes

Computer Science

Logos Verlag

Steen Brock paints a cross-disciplinary picture of the philosophical and scientific background for the rise of the quantum theory. He accounts for the unity of Kantian metaphysics of Nature, the Helmholtzian principles, and the Hamiltonian methods of modern pre-quantum physics. Brock shows how Planck's vision of a generalization of classical physics implies that the original quantum mechanics of Heisenberg can be regarded as a successful attempt to maintain this modern unity of physics.However, for Niels Bohr, the unity of science and metaphysics did not end in the world of physics. The development of quantum physics had general implications both for other sciences and for various philosophical issues. Brock discusses these matters with respect to recent topics within the philosophy of science and major interpretations of Bohr's ideas. The author invites the reader to follow a long andwinding route of thought which, in the end, culminates in Bohr's ideas of complementarity, culture and Spirit.

Niels Bohr's Philosophy of Quantum Physics in the Light of the Helmholtzian Tradition of Theoretical Physics

Politics & Social Sciences

Brock, Steen

Philosophy

Neat and binary molecular glass formers are investigated by means of broadband dielectric spectroscopy with the aim of gaining a systematic understanding of the molecular slowing down, which is characteristic for the glass transition. By combining frequency and time domain techniques a dynamic range from 10-6, Hz up to 109, Hz is covered. Particular attention is drawn to the fact that different types of secondary relaxations may appear during the process of supercooling. In certain simple glass formers such secondary processes are clearly of intermolecular origin, and it turns out that in mixtures of small and large molecules secondary relaxations can be systematically altered by changing the concentration of the constituents. Thus, the relation between different types of secondary processes may be clarified. It is typical of glass forming substances that the decay of orientational correlations is non-exponential, and, correspondingly, the dielectric loss spectra are broadened as compared to a simple Debye-like relaxation process. The latter effect is particularly pronounced in binary glass formers, and one aim of the present work is to provide and apply an appropriate tool for a line shape analysis of the relaxation spectra in both neat end binary systems. On the other hand, the nature of spectral broadening is investigated by means of non-resonant dielectric hole burning, which allows to distinguish between heterogeneous and homogeneous dynamics in a system. It turns out that inbinary glass formers dynamic heterogeneities are particularly pronounced and that the effects of dielectric hole burning in both neat and binary systems are very well described within the framework of a model of selective local heating.

Broadband Dielectric Spectroscopy in Neat and Binary Molecular Glass Formers: Frequency and Time Domain Spectroscopy, Non-Resonant Spectral Hole Burning

Science & Math

Blochowicz, Thomas

Physics

Workflow-based Process Controlling Systems provide companies with the ability to measure the operational performance of their business processes in a timely and accurate fashion. The combination of workflow audit trails with data warehouse technology and operational business data allows for complex analyses that can support managers in their assessment of an organization's performance. The increasing maturity of business process management and data warehouse systems enables the design and development of advanced process-oriented management information systems. Michael zur Muehlen discusses the integration of workflow audit trail data with existing data warehouse structures and develops a reference architecture for process-oriented management information systems. Starting with an organizational and technical analysis of process organizations, this book provides a comprehensive documentation of business process management, workflow technology, and existing standardization efforts. The proposed reference architecture is validated in an industry context. A prototypical implementation of the reference architecture and its integration with a commercial business process management system are demonstrated as well. This book is directed at both practitioners and academics in the fields of business process management, management accounting, and information systems research.

Workflow-based Process Controlling. Foundation, Design, and Application of workflow-driven Process Information Systems. (Advances in Information Systems and Management Science)

Muehlen, Michael zur

Business & Money

This dissertation shows that information assurance properties can be both specified within a formal model of systems to which the properties are applied using the same formal theory for modeling, specification, and reasoning and enforced in such a way that enforcement is performed consistently across multiple, heterogeneous nodes and organizational domains while retaining the semantics of the formal model. The properties, referred to as security policies, can be specifically enforced at the operating system level and are constructed in such a way that automated reasoning mechanisms derive lower abstraction layer properties from higher semantic levels specified by administrative personnel based on the formal abstract model and interpretations thereof. Moreover, operations to be performed are permitted based on proofs obtained within the formal model while required operations are also derived within the model. To permit the consistent enforcement of an arbitrarily large set of security policies and scalability across large organizations and networks, externally controlled reference monitors and external reference monitors are introduced which control layered enforcement mechanisms that can be implemented both in systems constructed ab initio and as an add-on to existing, particularly commercially available operating systems even if no source code is available for modification to ease the transition to secure systems while permitting mission fulfillment based on legacy systems. These aspects are demonstrated using the Microsoft Windows 2000 operating system as an example. Enforcement mechanisms are described using the reference interpretation including modification and augmentation of file system and network protocol stack behavior along with the implicit benefits derived from the use of these enforcement mechanisms. Specifically, the implementation of dynamic distributed network firewalling and intrusion detection as well as multilevel security capabilities under the control of consistent policies are discussed. For this purpose the suitability of the framework for modeling multisensor data fusion as applied to intrusion detection is discussed. To demonstrate the capabilities of the layered enforcement system for application-specific domains, the use of visible and invisible labeling mechanisms for hard copy output is furthermore discussed.

A Model-Independent Security Architecture for Distributed Heterogeneous Systems

Wolthusen, Stephen D B

Although all terrestrial planets are presently already separatedinto an iron-rich core and a silicate mantle, the process of theformation of a planetary core is still not well understood. Coreformation is generally thought to have occurred concurrently with orsoon after planet formation and happened rather rapidly. This workshows that planetary core formation by the settling of iron-rich meltbodies in a solid matrix is fast enough, if the viscosity of theplanetary mantle has a strong temperature dependence.

Sinking Iron Diapirs: A Model for Planetary Core Formation

Ziethe, Ruth

Earth Sciences

The restructuring of electricity industry towards a competitive market has resulted in essential changes at the operation of power market. This book illustrates the results of research work made as intersection between technique and economy. Cornerstones of this work are carried out in the fields of congestion and power system fixed costs. A contribution to the study of power losses cost is also included in this book. Considering the system congestions as a main reason for price volatility the book presents a method for the allocation of congestion component of nodal prices for energy to the market participants. Furthermore, a new method for the simulation of zonal pricing using nodal pricing algorithm, in order to assess the Norwegian market, is given. The last part of the book deals with the task of power system fixed cost allocation. For this purpose, game theoretical methods are used.

Power transmission cost calculation in deregulated electricity market

Stamtsis, Georgios C

The exploration of time-variation in survival models can be summarised in two general questions: First, can the effect of a covariate be assumed to be time-constant, or does it distinctly change over time? Secondly, if the effect changes over time, of which form is the dynamic structure? The book investigates possible approaches to explore these two questions. Flexible methods are proposed, which allow for a precise description of the underlying dynamic structures. An essential task in applied statistics is thereby to limit model complexity in order to maintain interpretable solutions. This implies model selection by comparison of models with different complexity. A major focus pursued in the book is to find a statistical model that is as complex as needed and as parsimonious as possible.  Two different statistical concepts are considered: A likelihood based theory and Bayesian statistics. While model estimation in the likelihood framework is realised by maximising variants of the likelihood, in Bayesian statistics inference is based on posterior distributions of the model parameters. In the likelihood framework model selection can then be based on likelihood ratio tests, whereas in the Bayesian framework, Bayesian model criteria are employed to compare different, non-nested models. Beside the theoretical investigations, the particular structure of the data at hand leads to different modelling approaches. This is since survival time can either be continuous or discrete. Both situations are investigated by employing two different models, the dynamic Cox model for continuous survival time and the dynamic logit model for discrete data.Parsimony in modelling is highly relevant in practical work. The book therefore concentrates on methods which are straightforward to implement and use in practice. In particular it is ensured that methods are computationally feasible and easy to understand.

Exploring Time-Variation in Survival Models

Berger, Ursula

A distributed system consists of cooperating interactive components running concurrently and exchanging information by communication. The development of such systems needs a formal design process that step by step transforms an abstract specification into a concrete one by systematic refinement. The book provides definitions, concepts, and examples for correctness preserving refinement techniques explicating the underlying design decisions. The refinement rules are based on specifications which model communication histories with streams. The presentation covers state refinement, property refinement, interface refinement, architecture refinement, and communication refinement. It focusses on state refinement which constitutes the step from a history based to a state based specification of a component. The other notions of refinement are presented particularly regarding their relationship to state refinement.

Stream Based Design of Distributed Systems through Refinement

St|mpel, Annette

An important task in seismic reflection imaging is to estimate subsurface structures from the prestack data. This means that the reflection events in the recorded data have to be transformed into images in the depth domain, the reflectors. A geometrically appealing approach for the corresponding process is Kirchhoff migration which is based on an integral solution of the wave equation. Applied in its original purely kinematic form, this process provides a structural image of the target region under investigation. However, Kirchhoff migration is also able to handle the amplitude-related aspects of wave propagation, thus allowing to assign physically sound amplitude values to reflector images. In such a true-amplitude migration, the geometrical spreading effects are removed from the input data during the imaging process and, thus, reflector amplitudes become basically a measure of the angle-dependent reflection coefficient. Commencing with the basics of wave propagation and ray theory, a complete description of Kirchhoff migration is presented. By relating the strict mathematical derivation of true-amplitude Kirchhoff migration to clear geometrical concepts, the gap between the originally graphical migration schemes and the nowadays available analytical descriptions based on a stationary-phase evaluation is closed. Further aspects relevant to the correct recovery of amplitudes in depth migration, such as the handling of topography and irregular geometries, are explained in a mathematical as well as in a geometrical manner. Finally, Kirchhoff migration is integrated into a seismic reflection imaging workflow based on the data-driven common-reflection-surface (CRS) stack method.

True-amplitude Kirchhoff migration: analytical and geometrical considerations

Hertweck, Thomas

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