Modelling of Multi-Agent Systems: Experiences with Membrane Computing and Future Challenges

Formal modelling of Multi-Agent Systems (MAS) is a challenging task due to high complexity, interaction, parallelism and continuous change of roles and organisation between agents. In this paper we record our research experience on formal modelling of MAS. We review our research throughout the last decade, by describing the problems we have encountered and the decisions we have made towards resolving them and providing solutions. Much of this work involved membrane computing and classes of P Systems, such as Tissue and Population P Systems, targeted to the modelling of MAS whose dynamic structure is a prominent characteristic. More particularly, social insects (such as colonies of ants, bees, etc.), biology inspired swarms and systems with emergent behaviour are indicative examples for which we developed formal MAS models. Here, we aim to review our work and disseminate our findings to fellow researchers who might face similar challenges and, furthermore, to discuss important issues for advancing research on the application of membrane computing in MAS modelling.Comment: In Proceedings AMCA-POP 2010, arXiv:1008.314

Guardianships vs. Special Needs Trusts, and Other Protective Arrangements: Ensuring Judicial Accountability and Beneficiary Autonomy

This article focuses on rising tensions and conflicts (perceived and actual) occurring among guardianships, special needs trusts (SNT) and other protective arrangements. The authors focus on three distinctly different applications, guiding participants through 1) Guardianship versus an SNT; 2) Supported decision-making versus an SNT; and 3) Guardianship versus other less restrictive options, including, but not limited to, an Achieving a Better Life Experience (ABLE) account, a representative payee, and a pooled SNT

Parametric study of a novel groove design for dry gas seals

This paper presents a performance analysis of a novel bidirectional groove design for dry gas seals. The scope of analysis includes the impact of important groove design parameters on the dry gas seal performance. The leakage flow and the axial stiffness and damping force coefficients are taken into account for performance assessment. For varying geometry the pressure field in the lubrication gap of the application is estimated. Based on these pressure fields the performance parameters are calculated. The utilized method to predict the fluid flow through the lubrication gap is founded on the Reynolds theory of lubrication. This two dimensional approach is based on the assumptions of a laminar viscous flow field with isothermal conditions and takes aerostatic as well as aerodynamic effects into account. The 2D approach is solved by a finite difference approximation. The aim of the contribution is to recommend geometrical parameters to ensure large static stiffness and damping force coefficients while still allowing for low seal leakage rates.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

Water droplet evaporation at high pressure and temperature levels – part II: comparison of experimental results with a 1D simulation

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Water injection into gas turbines is subject of investigations since decades, due to a high power and efficiency augmentation potential compared to the simple gas turbine cycle. Based on former research at ambient conditions, some technologies have already been realized, e.g. inlet fogging. Further applications of water injection at higher temperature and pressure levels are limited, because of few experimental data. In order to gain fundamental understanding at these boundary conditions, a novel test facility for droplet evaporation investigations has been built up at the Department of Mechanical Engineering at University of Duisburg-Essen. The resulting spray patterns are recorded by a laser based measuring technology, Phase Doppler Particle Analyzer (PDPA). In this second part of the paper, experimental results from the test facility are compared to simulation results of a 1D- model for droplet evaporation. The focus of this investigation is on the accordance of the simulation results with the experimental data at high pressure and temperature levels.dc201

Water droplet evaporation at high pressure and temperature levels - Part i: Experimental investigations of spray patterns at varied test conditions

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Water injection into gas turbines is subject of investigations since decades, due to a high power and efficiency augmentation potential compared to the simple gas turbine cycle. Based on former research at ambient conditions, some technologies have already been realized, e.g. inlet fogging. Further applications of water injection at higher temperature and pressure levels are limited, because of few experimental data. In order to gain fundamental understanding at these boundary conditions, a novel test facility for droplet evaporation investigations has been built up at the University of Duisburg-Essen. The resulting spray patterns are recorded by a laser based measuring technology, Phase Doppler Particle Analyzer (PDPA). Part I of the paper treats the experimental setup of the test facility; in particular the laser based measuring technology, as well as the measurement results of the spray pattern produced from a nozzle at high pressure and temperature levels. The focus of the investigations is on the droplet evaporation process in dependence on parameter variation of the environmental conditions.dc201

Automated machine learning for remaining useful life estimation of aircraft engines

Algorithms and the Foundations of Software technolog

Testing timed systems modeled by stream X-machines

Stream X-machines have been used to specify real systems where complex data structures. They are a variety of extended finite state machine where a shared memory is used to represent communications between the components of systems. In this paper we introduce an extension of the Stream X-machines formalism in order to specify systems that present temporal requirements. We add time in two different ways. First, we consider that (output) actions take time to be performed. Second, our formalism allows to specify timeouts. Timeouts represent the time a system can wait for the environment to react without changing its internal state. Since timeous affect the set of available actions of the system, a relation focusing on the functional behavior of systems, that is, the actions that they can perform, must explicitly take into account the possible timeouts. In this paper we also propose a formal testing methodology allowing to systematically test a system with respect to a specification. Finally, we introduce a test derivation algorithm. Given a specification, the derived test suite is sound and complete, that is, a system under test successfully passes the test suite if and only if this system conforms to the specification

A Review: Prognostics and Health Management in Automotive and Aerospace

Prognostics and Health Management (PHM) attracts increasing interest of many researchers due to its potentially important applications in diverse disciplines and industries. In general, PHM systems use real-time and historical state information of subsystems and components of the operating systems to provide actionable information, enabling intelligent decision-making for improved performance, safety, reliability, and maintainability. Every year, a substantial number of papers in this area including theory and practical applications, appear in academic journals, conference proceedings and technical reports. This paper aims to summarize and review researches, developments and recent contributions in PHM for automotive- and aerospace industries. It can also be considered as the starting point for researchers and practitioners in general to assist them through PHM implementation and help them to accomplish their work more easily.Algorithms and the Foundations of Software technolog

What we talk about when we talk about "global mindset": managerial cognition in multinational corporations

Recent developments in the global economy and in multinational corporations have placed significant emphasis on the cognitive orientations of managers, giving rise to a number of concepts such as “global mindset” that are presumed to be associated with the effective management of multinational corporations (MNCs). This paper reviews the literature on global mindset and clarifies some of the conceptual confusion surrounding the construct. We identify common themes across writers, suggesting that the majority of studies fall into one of three research perspectives: cultural, strategic, and multidimensional. We also identify two constructs from the social sciences that underlie the perspectives found in the literature: cosmopolitanism and cognitive complexity and use these two constructs to develop an integrative theoretical framework of global mindset. We then provide a critical assessment of the field of global mindset and suggest directions for future theoretical and empirical research

Regioisomeric and substituent effects upon the outcome of the reaction of 1-borodienes with nitrosoarene compounds

A study of the reactivity of 1-borodienes with nitrosoarene compounds has been carried out showing an outcome that differs according to the hybridization state of the boron moiety. Using an sp2 boron substituent, a one-pot hetero-Diels–Alder/ring contraction cascade occurred to afford N-arylpyrroles with low to good yields depending on the electronic properties of the substituents on the borodiene, whereas an sp3 boron substituent led to the formation of stable boro-oxazines with high regioselectivity in most of the cases, in moderate to good yields. 1H and 11B NMR studies on two boro-oxazine regioisomers showed that selective deprotection can be performed. Formation of either the pyrrole or the furan derivative is pH- and regioisomer-structure-dependent. The results obtained, together with previous B3LYP calculations, support mechanistic proposals which suggest that pyrrole, or furan, formation proceeds via oxazine formation, followed by a boryl rearrangement and an intramolecular addition–elimination sequence