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Cloud Computing-based systems (i) are safety- and security-critical systems which have strong qualitative and quantitative formal requirements, (ii) have equally important time-critical performance-based quality of service properties (e.g., availability), and (iii) need to dynamically adapt to changes in the potentially hostile (e.g., distributed denial of service attacks) and often probabilistic environment they operate in. These aspects make distributed and Cloud-based systems complex and hard to design, build, test, and verify; and in this context, Cloud Computing management has to deal with a multitude of obstacles for the growth and adoption of the Cloud Computing paradigm. In this thesis, we focus on three of these obstacles: bugs in large distributed systems, service availability, and performance unpredictability. To tackle these challenges and the aforementioned complexity, we propose solutions based on executable formal specifications and formal analysis, using an adequate semantic framework. We chose rewriting logic as the semantic framework and Maude, a language and system based on rewriting logic that offers the possibility of executing and formally analyzing specifications, as the foundation for our work.

Nitrogen rich compounds are suitable as ingredients in low smoke propellant charges. Several high-N energetic materials are presented which are based on tetrazoles. Tetrazoles are an unique class of compounds, since they combine a high nitrogen content and a high heat of formation with good thermal and kinetic stabilities due to their aromatic ring system. The reaction of 5-azidotetrazole with hydrazine yields hydrazinium 5-azidotetrazolate (1), which is the tetrazole salt with the highest nitrogen content (88.1 %) reported, yet. In addition ammonium and aminoguanidinium 5-azidoterazolate were synthesized and characterized. The detonation and propulsion parameter were calculated using the EXPLO5 program. In addition several outperforming tetrazole derivatives (N% > 80 %), which are currently under our investigation as additives in propellant charges, are presented. Using the heats of formation and the X-ray densities, the detonation parameter of hydrazinium 5-aminotetrazole, 5,5'- bis(1H-tetrazolyl)-hydrazine, 5,5'-bis(1H-tetrazolyl)- amine, 5,5'-bis(1-methyltetrazolyl)-triazene, 1,5-bistetrazole and its ammonium salt were calculated., See also ADM002187. Presented at the Army Science Conference (26th) held in Orlando, Florida on 1-4 December 2008. Sponsored in part by ARDEC and Contract no. W911NF-08-1-0380. The original document contains color images.

High nitrogen energetic materials with astonishing thermal behaviors and performances were synthesized by different metathesis reactions. Particularly the new compound triaminoguanidinium 1-methyl-5-nitriminotetrazolate (TAG-1 Me-AtNO2, 4) shows great explosion performance and may be an alternative to commonly used and toxic RDX. An improved synthesis for the promising energetic compound 4 is also presented. The new compound TAG2-OD (trianinoguanidinium 3,3'-bis-1,2,4-oxadiazol-5-onate, 7) with an N-content of 60% and a relatively low isobaric (20 bar) combustion temperature of 1420 K may well be suitable for a N-rich component in erosion-reduced gun propellants., See also ADM002187. Presented at the Army Science Conference (26th), held in Orlando, Florida on 1-4 December 2008. Sponsored in part by Armament Research, Development and Engineering Center (ARDEC). The original document contains color images.

In this project, we investigated the dragline silk proteins ADF-3 and ADF-4 of the spider Araneus diadematus. Adf-3 and Adf-4 cDNA can each be expressed directly in insect cells using the Baculovirus-expression-System. Recombinant ADF-4 is insolubly produced in the cytoplasm of insect cells and soluble produced upon secretion into the media. Further, parameters influencing stability and solubility of recombinantly produced ADF analogues have been investigated. We detected that intermolecular disulfide bridges formed between monomers of the ADF analogues stabilized formed dimer. Additionally, it was found that potassium phosphate triggers assembly of ADF analogues into spheres and fibrils., The views, opinions and/or findings contained in this report are those of the author(s) and should not contrued as an official Department of the Army position, policy or decision, unless so designated by other documentation. The original document contains color images.

The objective of this project is the development of an integrated suite of technologies focusing on end-to-end software development supporting requirements analysis, design, implementation, and verification. This final progress report summarizes the work that has been performed within this project. It contains an overview about the project's achievements in respect to original problem statement, the technical work of the related work packages, and reports on our cooperation with leading US institutes.

The objective of the proposed research project is to investigate and explore the chemistry of neutral (covalent) high-nitrogen compounds and high-nitrogen salts as potential energetic ingredients for gun propellant charges and replacements for RDX. The new high-nitrogen compounds and salts should be less environmentally hazardous, have no greater sensitivities, and have equal or better performance., The original document contains color images.

This report results from a contract tasking Ludwig-Maximilian University of Munich as follows: The grantee will investigate controlled collisions between atoms in optical lattices production of strongly correlated quantum system with tunable internctions low dimensional degenerate quantum systems and rotating Bose-Einstein condensates in optical lattices -- observing the fractional Quantum Hall effect with bosons., The original document contains color images.

For the investigation of the ignition and reaction of fuel injected into the combustor of a Scramjet at a flight Mach number of 8 high temperature test air at supersonic speed is required. One economic possibility to simulate these inlet conditions experimentally is the use of vitiators which preheat the air by the burning of hydrogen. Downstream of the precombustor the flow is accelerated in a Laval nozzle to a Mach number of 2.15 and enters the combustor. For the numerical simulation of a supersonic reacting flow precise information concerning the physical properties during ignition and reaction are required. Optical measurements are best suited for delivering this information as they do not disturb the supersonic flow like probes and as their application is not limited by thermal stress. Raman scattering offers the possibility of measuring the static temperature and the concentration of majority species., See also ADM001433. International Conference on Methods of Aerophysical Research (11th). Held in Novosibirsk, Russia on 1-7 Jul 2002.

In this work the simulation of the non-reacting supersonic flow is presented. The main task of the simulation was to prepare the non-reacting solution for the simulation of reacting flow in the second phase of the project. The flow in a scramjet with a strut injector was simulated. The shock system, temperature field and hydrogen distribution are presented subsequently. Preliminary simulations of the reactive flow were realized with the Finite Rate Model, which is included in 'Fluent 5', in order to investigate potential ignition zones. The model does not yet include the turbulence-chemistry interaction but can, nevertheless, be applied successfully for the initial analysis of the ignition process., See also ADM001433. International Conference on Methods of Aerophysical Research (11th). Held in Novosibirsk, Russia on 1-7 Jul 2002. The original document contains color images.

The growing importance of on-board diagnosis for automobiles demands for a close integration of diagnostic tasks in the entire design process. This report describes work carried out to date within the European project 'Integrated Design Process for onboard Diagnosis' (IDD). It presents an analysis of the current design process and the model of a new process which allows for a better integration of diagnosis related tasks, such as diagnosability analysis, failure-modes-and-effects analysis (FMEA), on-board diagnosis design, in the overall design process of mechatronic subsystems. We then discuss in what way model-based technology can provide tools to support the actual integration and, in particular, present an approach to model-based diagnosability analysis., Held at Semmering, Austria, 2-4 May 2002. The original document contains color images. This article is from ADA405380 Thirteenth International Workshop on Principles of Diagnosis (DX-2002)

We report on the crystallization of laser cooled Mg(+) ion beams circulating in the table-top rf quadrupole storage ring PALLAS at a velocity of 2800 m/s (beam energy 1 eV). A sudden collapse of the transverse beam size and the low velocity spread clearly indicate the phase transition to a one-dimensional linear string of ions. This crystalline beam shows exceptional stability, surviving for more than 3000 revolutions without cooling. Close to the phase transition, the spatial beam profile of non-crystalline beams was found to exhibit an unexpected two component Gaussian distribution. Although its origin is not yet fully understood, we can exploit this effect for the identification of two- and three-dimensional crystalline beams., This article is from CP606, Non-Neutral Plasma Physics IV, p235-244, 2001. Pub. in AIP Conference Proceedings: volume 606. Prepared in cooperation with Ernst-Moritz-Arndt-Universitaet, Greifswald, Germany. This article is from ADA404831 Non-Neutral Plasma Physics 4. Workshop on Non-Neutral Plasmas (2001) Held in San Diego, California on 30 July-2 August 2001

We report on a new phenomenon specific for a system of spatially interconnected nanocrystal assemblies: efficient low temperature photoluminescence (PL) conversion at resonant optical excitation of porous Si. The upconverted photoluminescence (anti-Stokes PL) is observed at intensities as low as 0.1 W/cm(exp 2) and its intensity is as large as that of the Stokes PL band. The confirmation of the essence of connectivity between nanocrystals comes from the same type of studies performed on systems containing Si nanocrystals surrounded by a thick SiO(2) shell where the anti-Stokes PL is completely absent for any excitation energy and intensity used while the properties of the Stokes PL are very similar to those of porous Si., This article is from ADA408025 Nanostructures: Physics and Technology International Symposium (9th), St. Petersburg, Russia, June 18-22, 2001 Proceedings

Porous Si layers produced by anisotropic electrochemical etching of bulk Si exhibit strong in-plane birefringence which depends on the sizes of Si nanocrystals spacing between them and dielectric properties of their surrounding media. Second harmonic generation experiments have revealed phase matching conditions for wave interaction in the layers. Furthermore they can serve as a phase-matching matrix for optically nonlinear substance incorporated in their pores. This finding can significantly expand the choice of nonlinear optical media since their anomalous dispersion is not strictly required for phase matching conditions., This article is from ADA408025 Nanostructures: Physics and Technology International Symposium (9th), St. Petersburg, Russia, June 18-22, 2001 Proceedings

One important component of model selection using generalized linear models (GLM) is the choice of a link function. Approximate Bayes factors are used to assess the improvement in fit over a GLM with canonical link when a parametric link family is used. For this approximate Bayes factors are calculated using the approximations given in Raftery (1996), together with a reference set of prior distributions. This methodology can also be used to differentiate between different parametric link families, as well as allowing one to jointly select the link family and the independent variables. This involves comparing non nested models. This is illustrated using parametric link families studied in Czado (1997) for two data sets involving binomial responses., The original document contains color images.

About 30 years ago Professor Dieter Vortmeyer, who has been retired in March 1999, started his research in the field of acoustic instabilities in combustion systems and began the research in active combustion control in 1986. To the honour of Prof. Vortmeyer herewith a review on his work in the field of ACC is given., Pres: Symposium RTO Applied Vehicle Tech Panel (AVT), Braunschweig, Germany,p29-1/29-12, 8-11 May 2000. This article is from ADA395700 Active Control Technology for Enhanced Performance Operational Capabilities of Military Aircraft, Land Vehicles and Sea Vehicles (Technologies des systemes a commandes actives pour l'amelioration des performances operationnelles des aeronefs militaires, des vehicules terrestres et des vehicules maritimes)

Several aspects of the development process of correct safety critical discrete and hybrid embedded systems are discussed. The general process and its support by the CASE tool AUTOFOCUS is outlined. This is illustrated along the lines of a simplified version of NASA's Mars Polar Lander. It is argued that specific aspects of hybrid systems do require the modification of classical theories on software development, and these modifications are discussed. The paper concludes by focusing on one part of the development process, namely testing a novel approach to the automated generation of test cases for discrete as well as hybrid systems is presented. The Mars lander's crash serves as an example for the derivation of meaningful test cases., Original document contains color images. Pres. at RTO Information Systems Technology Panel (IST), Istanbul, Turkey 9-11 Oct 2000. This article is from ADA391919 New Information Processing Techniques for Military Systems (les Nouvelles techniques de traitement de l'information pour les systemes militaires) p15-1/15-12.

This report results from a contract tasking Ludwig-Maximilian University of Munich as follows: The contractor will build an extremely all-solid-state spectrometer operating from the GHz up to the lower THz frequency regime with Hertz-level resolution. This method is sensitive up to 400 GHz and will be used to investigate electronic systems of reduced dimension. The contractor will compare the performance of the spectrometer with other microwave sources including gunn oscillators, FIR laser systems and common HP Network analyzers, as well as a high-frequency spectrometer. To accomplish this research plan will consists of 4 phases: (1) Fabricate and assembler power combiner/planar antenna substrates; (2) Perform photoconductive experiments using the terahertz generation system; (3) Combine terahertz generation system with coupled semiconductor quantum dots; (4) Perform photoconductive experiments on a grid of individually tunable coupled semiconductor quantum dots. Report is in electronic format on CD. Final report is in Adobe Postscript format, and interim report is in Microsoft Word format.

This paper presents results of a joint research effort of NASA Dryden Flight Research Center and the Institute of Flight Mechanics and Flight Control of Technische Universitaet Muenchen on longitudinal flight dynamics at hypersonic speeds. At high speeds a large time lag between pitch attitude and flight path angle exists. The mechanisms which cause this path-attitude decoupling are described. It will be shown further that an limiting effect exists. An aggressive stick piloting technique to avoid the shortcomings of the path-attitude lag is described. This type of control is also effective to stabilize phugoid. The simulation facility of Dryden Flight Research Center which was used in the evaluation is described. Simulation results concerning the effect of path-attitude lag on aggressive stick technique, of time delay and scaling of vertical speed information are presented. Furthermore results of flight tests with SR-71 and Tu-144 at high supersonic speeds for similar topics are presented., See also ADM002333. International Congress of Aeronautical Sciences (ICAS) (22nd) Held in Harrogate, United Kingdom on August 27-September 1, 2000. U.S. Government or Federal Purpose Rights License, The original document contains color images.

Due to the growing available computational power, real-time simulations of dynamic turbo engine behavior can be carried out using performance analysis modeling. This partly removes the need for state space or function generator modeling and facilitates one common engine model to be used during engine design, engine control system design, and hardware-in-the-loop verifications, allowing faster design changes. Even if state space modeling is needed, for example during the control design process, these models can be derived from the performance analysis model using automated generation processes. But performance analysis models are not only useful during the control design process, they can also play an important role as onboard models in future engine control systems. If an onboard model can be properly matched with the real engine, it can provide the engine control system with valuable information about the engine's current dynamical state. This information can also be very useful for engine health monitoring purposes. This paper showed two applications of real-time engine models and gave an outlook on how future control design and development processes can benefit from more detailed simulations. One application described is the rapid prototyping of control systems for helicopter engines performed at the Chair of Flight Propulsion, Technical University of Munich. Another possibility provided by real-time engine simulations is the direct use of an on-board model in the control system itself. The advantages of such an approach for designing highly integrated hypersonic engines that can be used in the lower stage of a planned two-stage-to-orbit vehicle are discussed., See also ADM002333. Presented at the International Congress of Aeronautical Sciences (ICAS) (22nd) held in Harrogate, United Kingdom, on August 27-September 1, 2000. U.S. Government or Federal Purpose Rights License. The original document contains color images.

In this paper a new type of frequency-multiplier from 70 GHz to 210 GHz is presented which combines the advantages of a varactor with symmetrical capacitance-voltage characteristic and the low leakage current of Schottky diodes. The varactor structure consists of two inhomogeneously doped Schottky diodes in anti-serial connection which are quasi-monolithically integrated into a microstrip circuit on quartz. A theoretical description of the Schottky diode tripler is given and first experimental results are presented which show an rf-output power of 2 mW at 210 b GHz., Prepared in cooperation with GMM, VDE/VDE-Gesellschaft Mikroelektronik, Mikro- und Feinwerktechnik; ITS, Informationstechnische Gesellschaft im VDE. This article is from the THz Conference 2000 pp69-72. This article is from ADA398789 International Conference on Terahertz Electronics (8th), Held in Darmstadt, Germany on 28-29 September 2000

Bluetooth 1.0 was published in 1999 as an industry standard for short-range wireless data and voice communication. Application profiles cover cordless telephony, wireless access to printers, fax machines or LANs, Personal Area Networking and more. In order to handle this variety of services and nevertheless guarantee interoperability and auto-configuration of different devices from different manufacturers, the Bluetooth specification contains the so-called Service Discovery Protocol (SDP).

Moore's principle predicts that beyond the year 2010 the typical structure dimensions of electronic memory devices will fall below 70 nm. Apart from the necessity to develop suitable lithographic techniques for mass production of sub 100 nm features, the sole reduction of the structure dimensions (top down approach), while maintaining the present day device architecture, will result in physical obstacles, making the invention of novel designs for future devices indispensable. It what follows, we report on novel concepts for the fabrication of a single-electron transistor (SET) and a quantum interference transistor (QUIT), respectively, Pres: 6th Int Symp Nanostructures: Physics and Technology, St Petersburg, Russia. 22-26 Jun 1998. p97-100. This article is from ADA406591 Nanostructures: Physics and Technology International Symposium (6th) held in St. Petersburg, Russia on June 22-26, 1998 Proceedings

The intended focus of the workshop was on unified sets of formal models and associated methods suitable for automation for many aspects of software development, in particular those that address change and those that apply on a large scale. Some of the intended aspects of software evolution are (1) modifiable software architectures, (2) resource changes, (3) context changes, (4) requirements changes, (5) changes to decomposition structures, and (6) changes in plans. These issues are related to formal representations of the version history, and formal representations of the activities that produced existing versions or have been proposed to produce future versions.

Various types of CNNs are summarized and the taxonomy of CNN is given according to the different types of grids, processors, interactions, and modes of operation. Next, the CNN Universal Machine is introduced. The architecture and the key features are outlined. A quite exhaustive list of references completes the paper.

Session topics in this volume include: Large eddy simulations, Separated flows, Compressible flows, Combustion, Buoyant flows and heat transfer, Complex free flow, Closures, Coherent structures, Rotation and curvature effects., See also Volume 1, ADA243809.

The modelling of fields in the time domain describes the evolution of physical quantities in a natural way. Transient phenomena, nonlinear and dispersive behaviour, the characteristics of systems with moving boundaries or with time dependent properties are best described in the time domain. For electromagnetic field modelling numerous techniques have been developed. The modelling of fields and networks in the time domain is highly attractive since it describes the evolution of physical quantities in a natural way. Time domain modeling is especially advantageous in the case of transient electromagnetic fields, fields in nonlinear, dispersive or time-depended media or in regions with moving boundaries. One of the main advantages of time-domain modelling of electromagnetic fields is the local dependence of the field variables on space as well as on time. Within discretized space and time the state of the field in a given point and at a given time depends only on the field states of the neighbouring points at previous times. This allows a highly parallel computation of the time evolution of the discretized field.

The interaction of numerous parameters affect excitation and development of combustion instabilities, and determine the excited acoustic modes. Therefore, to avoid combustion instabilities, it is essential to make out the sources of disturbances and to interrupt the feed back loop. The newly developed method of Active Instability Control' (AIC) opens experimental opportunities for this kind of diagnostics, because after having stabilized the oscillating system it starts to oscillate again if the AIC-system is switched off. It takes about 300 msec until the oscillation is again fully developed. During this transition period we are able to register the combustion chamber pressure, the intensity of chemical reaction and the flame contours time resolved by high-speed/-schlieren-cinematography. Experiments with a laboratory combustor showed, that during the onset of instability various mechanisms of excitation can be observed. Further investigations pointed out that although vortex shedding is an important driving force for oscillations, it is not the origin for instability., This article is from 'Hypersonic Combined Cycle Propulsion Panel Symposium (75th) Held in Madrid, Spain on 28 May - 1 June 1990 (La Propulsion Hypersonique a Cycles Combines),' AD-A253 867, p22-1 thru p22-7.

The Abelson helper integration site 1 (AHI1) gene locus on chromosome 6q23 is among a group of candidate loci for schizophrenia susceptibility that were initially identified by linkage followed by linkage disequilibrium mapping, and subsequent replication of the association in an independent sample. Here, we present results of a replication study of AHI1 locus markers, previously implicated in schizophrenia, in a large European sample (in total 3907 affected and 7429 controls). Furthermore, we perform a meta-analysis of the implicated markers in 4496 affected and 18,920 controls. Both the replication study of new samples and the meta-analysis show evidence for significant overrepresentation of all tested alleles in patients compared with controls (meta-analysis; P = 8.2 x 10(-5)-1.7 x 10(-3), common OR = 1.09-1.11). The region contains two genes, AHI1 and C6orf217, and both genes-as well as the neighbouring phosphodiesterase 7B (PDE7B)-may be considered candidates for involvement in the genetic aetiology of schizophrenia.

Design and measuring method of a cheap and efficient soil pressure gauge are described. Soil tank tests carried out in the laboratory demonstrate some properties of the gauge like indifference towards orientation in soil. In the soil bin the gauge measures pressures below tires rolling over and outside in the field the influence of wheel load, number of passes and vehicle speed are investigated. The results are interpreted with modified formulas of Soehne, which can be managed by a pocket calculator., This article is from 'Proceedings of the International Conference on the Performance of Off-Road Vehicles and Machines (8th). Volume 2. Held at Cambridge, England on August 5-11, 1984,' ADA148635, p675-690.

Aircraft engines always contain gears that have to be lubricated under conditions of high speeds and extremely high temperatures. In this field of application scoring damage can be likely to occur. In Europe and partly also in the USA the scoring load capacity of gear oils is expressed in terms of PZG Scoring Load Stage. The FZG Gear Test Rig is described. The normal test procedure A/8.3/90 as standardized in DIN 51 354 using A-type gears at a pitch line velocity of v = 8.3 m/s and a starting oil temperature of 90 C is presented. A modified procedure at double speed and increased oil temperature A/ 16.6/140 is discussed. The scoring load capacity of aircraft transmission lubricants is worldwide expressed in Ryder Gear Test results. Because of high costs and problems with the availability of test gears a modified PZG Ryder Test was developed. The method is presented and comparative results of typical aircraft engine oils in the FZG, the FZG-Ryder and the original Ryder Gear Test are shown. From this experience it becomes obvious that alternative test methods for the evaluation of scoring load capacity of aircraft transmisssion lubricants can be available in the near future., This article is from 'Conference Proceedings: Aircraft Gear and Bearing Tribological Systems Held in San Antonio, Texas on 22-26 April 1985, ' ADA168241, p17-1 - 17-9.

A modified FZG-Ryder gear machine was developed to run scuffing tests at high speed (n1 = 9700/min) and oil temperatures from 74 C to 200 C. Test oil volume is approximately 3 liters. Good correlation was found between FZG-Ryder and standard Ryder test results when rating ester base lubricants and using ester base reference oils such as Hercolube A . Poor correlation was found when using mineral based reference oil C . Tests on three oils at 200 C showed considerable lower load capacity as compared to ratings at 74 C. However, relative ranking of the lubricant was unchanged. Keywords: Load capacity, Lubricant, Test methods.

Up to now in this book, we have defined a function by introducing a set of axioms. Typically these axioms are computationally suggestive, that is, they have suggested a method for computing the function. But it is not always obvious that the axioms define the function we intend. From these axioms, we have established properties of the function they define, which gives us some assurance that that function is indeed the correct one. Keywords: Specifications; Output; Recursive programs., Presented at the International Summer School on Logic, Algebra and Computation, 25 Jul-6 Aug 1989, Marktoberdorf (Germany, F.R.).

The author presents in a unified framework the basic syntactic structures used to model deductive and computational notions. The guiding principle is propositions as types. These course notes have been prepared for the Institute on Logical Foundations of Functional Programming organized by the University of Texas at Austin in June 1987. They will appear in Logical Foundations of Functional Programming, Addison-Wesley, 1989. We assume known elementary set theory and algebra., Presented at the International Summer School on Logic, Algebra and Computation, 25 Jul-6 Aug 1989, Marktoberdorf (Germany, F.R.).

All of these exercise assume the definitions and results in the paper Semantic Domains by Carl A. Gunter and D.S. Scott. Many exercises require some basic knowledge of category theory; the necessary definitions can all be found in subsections 1-5 of Chapter 0 of the book of J. Lambek and P.J. Sott or any book on category theory. The exercises below cover a wide range of levels of difficulty. In an effort to provide some guide to these levels, we have placed a single star * next to those exercise which we feel are more difficult than the average. An exercise is marked with two stars ** if it requires some specialized knowledge not included or require by the two references mentioned above (such as lambda-calculus, combinatory logic, set theory, topology, categorical logic, etc.). (KR), Presented at the International Summer School on Logic, Algebra and Computation, 25 Jul-6 Aug 89, Marktoberdorf (Germany, F.R.).

Formal (algebraic, combinatorial, logical) treatment of concurrent processes and of distributed systems has started rather recently only, although concurrent and distributed activities dedicated to common tasks are daily practice and have always played an important role for human societies. The traditional notions of computability are all based on the concept of a single person fulfilling a task step by step. This is very explicit in Turing's work - and even if the formalism would allow for consideration of concurrency, as in the case of recursive functions defined by sets of equations, this possibility was not discussed for a long time. Nevertheless there are connections of the current theories of concurrency to the different approaches to formalize the notion of effective computation: Turing machines, lambda-calculus and recursive functions. The two main approaches to concurrency that will be described in the following, namely Petri nets and abstract programming languages, are closely related to them. A Petri net can be understood as a formalization of the joint work of a group of people, the abstract programming languages are greatly influenced by the ideas around the lambda-calculus; their purpose is to prescribe what should be done by cooperating agents. (kr), Presented at the International Summer School on Logic, Algebra and Computation, 25 Jul-6 Aug 1989, Marktoberdorf (Germany, F.R.).

These notes form a brief but reasonably complete account of the ideas underlying resolution. We try to give equal emphasis not only to the logical principles involved but also to the computational issues which arise. We therefore study in some detail the most useful symbolic algorithms (in particular, since it is of greatest importance, the unification algorithm) and treat logical formulas explicity as carefully engineered data structures. One of our aims is to explain resolution in general in such a way that the importance special case of Horn clause resolution can be properly understood within the broader setting. Horn clause resolution is the theoretical framework for the kind of logic programming which is done by users of PROLOG. Indeed many of the ideas we shall discuss are concretely realized although not always in the purest form, in various versions of PROLOG. We shall not be concerned specifically with PROLOG, however, since the surface details often vary considerably from version to version and are often complex enough to hide the relatively simple conceptual system which lies just below the surface. (KR), Presented at the International Summer School on Logic, Algebra and Computation, 25 Jul-6 Aug 1989, Marktoberdorf (Germany, F.R.).

Mobile reception in built-up areas is disturbed by interference-fading effects due to multiple incident waves caused from reflecting and scattering objects in the vicinity. The fading can be reduced with the help of space-diversity systems, i.e. with more than one antenna on the car. The fade-reduction factor or the diversity gain of such a system strongly depends on the cross correlation of the antenna-output voltages. The related correlation factor is a function of frequency, is influenced by the car's surface, and depends on the mounting locations of the antennas. If a space-diversity system shall be established, proper antenna locations on the car in mind have to be determined. This report records the results of determining the cross correlation between antennas for various antenna-mounting configurations for a US Army 1/4-ton truck, M151 A2. The antenna receiving patterns are measured for the various configurations. These signal strength measurements are converted to correlation factors of signal power by assuming a Rayleigh distribution of the multipath signal strengths. The Rayleigh distribution has been shown to accurately characterize multipath reception in the 30-80 MHz band in built-up areas. In this manner, the requirement for time-consuming test drives was eliminated, and a more thorough investigation of the cross correlation phenomena was made possible for the same resources. (Author)

There are numerous publications about forces on tyres acting in or against travel direction, drawbar pull and rolling resistance, but only a few about lateral forces on steered tyres. A test equipment, which provided a wealth of information of lateral-and travel resistance of front wheels in recent years, has been further developed for testing implement tyres. This setup is mounted rigid on a tractor Unimog and provides measurements of longitudinal and lateral forces on tyre at steering angles from 0 deg to 30 deg with different load up to 1,3 t., This article is from 'Proceedings of the International Conference on the Performance of Off-Road Vehicles and Machines (8th). Volume 2. Held at Cambridge, England on August 5-11, 1984,' AD-A148 635, p855-888. Text in German and English.

Previous studies of rotor whirl instability pointed out two different mechanisms inducing lateral forces within non-contacting labyrinth-type seals. Evaluating the part of exciting forces that results from leakage losses is possible by means of variable flow contraction in the gap of a seal with variable clearance at the circumference. The dominating part of exciting forces has its origin in unequal pressure distributions at the circumference of the seal with a shaft in out-of-centre position. The pressure distribution is mainly influenced by swirl-type flow at seal entry., This article is from 'Rotordynamic Instability Problems in High-Performance Turbomachinery - 1982, Proceedings of a Workshop Held at College Station, Texas on 10-12 May 1982,' AD-A123 436.

The results of work done to show the effects of surface roughness, residual stresses, strain rate, microstructure, alternating bending fatigue loading and a non-uniform stress field on the strength of small (2.-8.mm diameter) alumina rods are given. The rods used in the work were characterized by determinations of grain size, porosity, hardness, surface roughness and damping factor. Static bend tests at room temperature are used to determine the Young's modulus, the fracture stress, and the strain at fracture and to show the influence of specimen volume on the fracture stress. The effects of grain size and of porosity on these characteristics are shown. A new tensile test specimen is designed which achieves an almost uniform stress field in the test area. Some test results are given to show the validity of this procedure for brittle specimens.

The report describes three types of active receiving antennas: Nonresonant broadband antennas for frequencies below 30 MHz which are very short compared to the wavelength, and resonant antennas with bandpass characteristic for frequencies between 200 and 1200 MHz, and directive microwave antennas using dielectric spheres and wedges as directive elements. In every case the author gives a theory of optimum signal-to-noise ratio and noise-performance measurements for transistors and for complete active antennas. (Author)

This report contains a series of extensions to the notch stress theory. In Part I an application of the leading-function hypothesis is checked by comparison with exact solutions of non-linear two-dimensional elastic problems. The first refers to the state of shear stress in sharp notches, the second to a symmetric state of plane stress in the neighborhood of a circular hole. Part II refers to problems of stress concentration in notches, loaded by single forces. As typical example the parabolic notch is explained in detail. The problems in Part III refer to the effect of couple-stresses. Exact formulae are given for circular holes and spherical cavities in uniform tension fields by means of a new general solution derived by the author. In Part IV a new interpolation formula for notches of any depth is established. (Author)

To access publisher's full text version of this article click on the hyperlink below, Microbial exposures in homes of asthmatic adults have been rarely investigated; specificities and implications for respiratory health are not well understood. The objectives of this study were to investigate associations of microbial levels with asthma status, asthma symptoms, bronchial hyperresponsiveness (BHR), and atopy. Mattress dust samples of 199 asthmatics and 198 control subjects from 7 European countries participating in the European Community Respiratory Health Survey II study were analyzed for fungal and bacterial cell wall components and individual taxa. We observed trends for protective associations of higher levels of mostly bacterial markers. Increased levels of muramic acid, a cell wall component predominant in Gram-positive bacteria, tended to be inversely associated with asthma (OR's for different quartiles: II 0.71 [0.39-1.30], III 0.44 [0.23-0.82], and IV 0.60 [0.31-1.18] P for trend .07) and with asthma score (P for trend .06) and with atopy (P for trend .02). These associations were more pronounced in northern Europe. This study among adults across Europe supports a potential protective effect of Gram-positive bacteria in mattress dust and points out that this may be more pronounced in areas where microbial exposure levels are generally lower.