Scalability is a critical concern for many software systems. Despite the recognized importance of considering scalability from the earliest stages of development, there is currently little support ...for reasoning about scalability at the requirements level. This paper presents a goal-oriented approach for eliciting, modeling, and reasoning about scalability requirements. The approach consists of systematically identifying scalability-related obstacles to the satisfaction of goals, assessing the likelihood and severity of these obstacles, and generating new goals to deal with them. The result is a consolidated set of requirements in which important scalability concerns are anticipated through the precise, quantified specification of scaling assumptions and scalability goals. The paper presents results from applying the approach to a complex, large-scale financial fraud detection system.
This column introduces the Network Observatory, a human-centered cyber sensemaking system, and discusses the visual and sensemaking design principles employed therein.
This article describes a work-in-progress in the framework of a research project aiming at combining requirements engineering methods with formal methods. The main idea is to extend the SysML ...language with concepts of existing requirements engineering methods. In this article we present extensions to SysML with concepts from the goal model of the KAOS method and we give rules to derive a formal B specification from this goal model. The approach is then illustrated on a case study.
Requirements interaction management (RIM) is the set of activities directed toward the discovery, management, and disposition of critical relationships among sets of requirements, which has become a ...critical area of requirements engineering. This survey looks at the evolution of supporting concepts and their related literature, presents an issues-based framework for reviewing processes and products, and applies the framework in a review of RIM state-of-the-art. Finally, it presents seven research projects that exemplify this emerging discipline.
The future Magneto Dynamics (MagneDyn) beamline will be devoted to study the electronic states and the local magnetic properties of excited and transient states of complex systems by means of the ...time‐resolved X‐ray absorption spectroscopy technique. The beamline will use FERMI's high‐energy source covering the wavelength range from 60 nm down to 1.3 nm. An on‐line photon energy spectrometer will allow spectra to be measured with high resolution while delivering most of the beam to the end‐stations. Downstream the beam will be possibly split and delayed, by means of a delay line, and then focused with a set of active Kirkpatrick–Baez mirrors. These mirrors will be able to focus the radiation in one of the two MagneDyn experimental chambers: the electromagnet end‐station and the resonant inelastic X‐ray scattering end‐station. After an introduction of the MagneDyn scientific case, the layout will be discussed showing the expected performances of the beamline.
This volume sets out the basic applied mathematical and numerical methods of chaotic dynamics and illustrates the wide range of phenomena, inside and outside the laboratory, that can be treated as ...chaotic processes.
Originally published in 1986.
ThePrinceton Legacy Libraryuses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.
The KAOS (Knowledge Acquisition autOmated Specifi cation) goal diagram can be used to hierarchically represent and analyze organizational goals. In the context of the UNC-Method, such goals are often ...written in the aforementioned diagram by using a set of verbs denoting achievement, in order to represent the organizational goals and requirements. Nowadays, the importance of the goals is only established by the diagram hierarchy. However, requirements engineering considers other elements as well as the hierarchy in such a matter. On the other hand, there are proposals that assign importance to the goals on other diagrams, but they neglect the hierarchy and the type of verb that is used in wording. These reasons lead us to propose in this paper, a method for allocating weighted salience to KAOS diagram goals, in the context of the UNC-Method. We consider the verb type and the hierarchy. We explain this proposal by means of a lab study.
Artificial neural networks are commonly accepted as a very successful tool for global function approximation. Because of this reason, they are considered as a good approach to forecasting chaotic ...time series in many studies. For a given time series, the Lyapunov exponent is a good parameter to characterize the series as chaotic or not. In this study, we use three different neural network architectures to test capabilities of the neural network in forecasting time series generated from different dynamical systems. In addition to forecasting time series, using the feedforward neural network with single hidden layer, Lyapunov exponents of the studied systems are forecasted.
Business process models provide a natural way to describe real-world processes to be supported by software-intensive systems. These models can be used to analyze processes in the system-as-is and ...describe potential improvements for the system-to-be. But, how well does a given business process model satisfy its business goals? How can different perspectives be integrated in order to describe an inter-organizational process?
The aim of the present paper is to link the local and the global perspectives of the inter-organizational business process defined in BPMN 2.0 (Business Process Model and Notation) to KAOS goal models (Keep All Objectives Satisfied). We maintain a separation of concerns between the intentional level captured by the goal model and the organizational level captured by the process model. The paper presents the concept of intentional fragment (a set of flow elements of the process with a common purpose) and assess its usefulness.
We conducted empirical experiments where the proposed concepts – here the intentional fragments – are validated by users. Our method relies on an iterative improvement process led by users feedback.
We find that the concept of intentional fragment is useful for (1) analyzing the business process model (2) reasoning about the relations between the goal model and the business process model and (3) identifying new goals. In a previous work we focused on BPMN 2.0 collaboration models (local view). This paper extends the previous work by integrating the global view given by choreography models in the approach.
We conclude that the notion of intentional fragment is a useful mean to relate business process models and goal models while dealing with their different nature (activity oriented vs goal oriented). Intentional fragments can also be used to analyze the process model and to infer new goals in an iterative manner.
Here we consider the influence on the electron spin in the magnetohydrodynamic (MHD) regime. Recently developed models that include spin-velocity correlations are taken as the starting point. A ...theoretical argument is presented, suggesting that in the MHD regime a single-fluid electron model with spin correlations is equivalent to a model with spin-up and spin-down electrons constituting different fluids, but where the spin-velocity correlations are omitted. Three-wave interaction of two shear Alfven waves and a compressional Alfven wave is then taken as a model problem to evaluate the asserted equivalence. The theoretical argument turns out to be supported, because the predictions of the two models agree completely. Furthermore, the three-wave coupling coefficients obey the Manley-Rowe relations, which further support the soundness of the models and the validity of the assumptions made in the derivation. Finally, we point out that the proposed two-fluid model can be incorporated in standard particle-in-cell schemes with only minor modifications.
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