185,373 research outputs found
A Framework for Evaluating Model-Driven Self-adaptive Software Systems
In the last few years, Model Driven Development (MDD), Component-based
Software Development (CBSD), and context-oriented software have become
interesting alternatives for the design and construction of self-adaptive
software systems. In general, the ultimate goal of these technologies is to be
able to reduce development costs and effort, while improving the modularity,
flexibility, adaptability, and reliability of software systems. An analysis of
these technologies shows them all to include the principle of the separation of
concerns, and their further integration is a key factor to obtaining
high-quality and self-adaptable software systems. Each technology identifies
different concerns and deals with them separately in order to specify the
design of the self-adaptive applications, and, at the same time, support
software with adaptability and context-awareness. This research studies the
development methodologies that employ the principles of model-driven
development in building self-adaptive software systems. To this aim, this
article proposes an evaluation framework for analysing and evaluating the
features of model-driven approaches and their ability to support software with
self-adaptability and dependability in highly dynamic contextual environment.
Such evaluation framework can facilitate the software developers on selecting a
development methodology that suits their software requirements and reduces the
development effort of building self-adaptive software systems. This study
highlights the major drawbacks of the propped model-driven approaches in the
related works, and emphasise on considering the volatile aspects of
self-adaptive software in the analysis, design and implementation phases of the
development methodologies. In addition, we argue that the development
methodologies should leave the selection of modelling languages and modelling
tools to the software developers.Comment: model-driven architecture, COP, AOP, component composition,
self-adaptive application, context oriented software developmen
Aspect-Oriented Programming
Aspect-oriented programming is a promising idea that can improve the quality of software by reduce the problem of code tangling and improving the separation of concerns. At ECOOP'97, the first AOP workshop brought together a number of researchers interested in aspect-orientation. At ECOOP'98, during the second AOP workshop the participants reported on progress in some research topics and raised more issues that were further discussed. \ud
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This year, the ideas and concepts of AOP have been spread and adopted more widely, and, accordingly, the workshop received many submissions covering areas from design and application of aspects to design and implementation of aspect languages
Multi-Party Coordination in the Context of MOWS
Separation of concerns has been presented as a promising tool to tackle the design of complex systems
in which cross-cutting properties that do not fit into the scope of a class must be satisfied. In this paper,
we show that interactions amongst a number of objects can also be described separately from functionality,
which enhances reusability of functional code and interaction patterns. We present our proposal in the context
of Multi-Qrganisational Web-Based Systems (MOWS) and also present a framework that provides the infrastructure
needed to implement multiparty coordination as an independent aspect
Employing America's Veterans: Perspectives from Businesses
Employment is an important aspect of reintegration into civilian society for many transitioning service members. Despite general American goodwill and intent to support veterans, many companies must emphasize business-related reasons to hire veterans. Thus, any effort to improve veteran employment outcomes must consider employer perspectives and the institutions and processes in place to facilitate and incentivize the hiring of veterans.This report provides empirical data representing the experiences of 69 companies of varying size, location and industry. In this report, the authors discuss to what extent, and for what reasons, employers think it is good business to hire veterans. Additionally, from the experiences of those employers who hesitate or have concerns about hiring veterans, Harrell and Berglass also describe the challenges to veteran employment and make recommendations for policy changes to improve the employment situation of veterans
Separating polarized cosmological and galactic emissions for CMB B-mode polarization experiments
In this work we study the relevance of the component separation technique
based on the Independent Component Analysis (ICA) and investigate its
performance in the context of a limited sky coverage observation and from the
viewpoint of our ability to differentiate between cosmological models with
different primordial B-mode content. We focus on the low Galactic emission sky
patch, corresponding to the target of several operating and planned CMB
experiments and which, in many respects, adequately represents a typical
"clean" high latitude sky. We consider two fiducial observations, one operating
at low (40, 90 GHz) and one at high (150, 350 GHz) frequencies and thus
dominated by the synchrotron and thermal dust emission, respectively. We use a
parallel version of the FASTICA code to explore a substantial parameter space
including Gaussian pixel noise level, observed sky area and the amplitude of
the foreground emission and employ large Monte Carlo simulations to quantify
errors and biases pertinent to the reconstruction for different choices of the
parameter values. We identify a large subspace of the parameter space for which
the quality of the CMB reconstruction is excellent. For both the cosmological
models, with and without the primordial gravitational waves, we find that
FASTICA performs extremely well even in the cases when the B mode CMB signal is
up to a few times weaker than the foreground contamination and the noise
amplitude is comparable with the total CMB polarized emission. In addition we
discuss limiting cases of the noise and foreground amplitudes, for which the
ICA approach fails.Comment: 19 pages, 12 figures, 5 tables, replaced to match published versio
Education, Dynamic Signaling and Social Distance
The paper enriches a standard signaling model of education with issues of social distance defined over educational achievements. More specifically it considers the effects that the presence of conformist and status seeking individuals has on educational dynamics. Under very reasonable assumptions about the composition of the society, the model endogenously displays a growing average level of schooling. As education rises, signals get noisy and potentially harmful for what concerns firms' profitability. Firms, in order to adjust their screening process, react with an increase of their educational requirements. All these dynamics are in line with recent trends and other stylized facts about education
Enabling High-Level Application Development for the Internet of Things
Application development in the Internet of Things (IoT) is challenging
because it involves dealing with a wide range of related issues such as lack of
separation of concerns, and lack of high-level of abstractions to address both
the large scale and heterogeneity. Moreover, stakeholders involved in the
application development have to address issues that can be attributed to
different life-cycles phases. when developing applications. First, the
application logic has to be analyzed and then separated into a set of
distributed tasks for an underlying network. Then, the tasks have to be
implemented for the specific hardware. Apart from handling these issues, they
have to deal with other aspects of life-cycle such as changes in application
requirements and deployed devices. Several approaches have been proposed in the
closely related fields of wireless sensor network, ubiquitous and pervasive
computing, and software engineering in general to address the above challenges.
However, existing approaches only cover limited subsets of the above mentioned
challenges when applied to the IoT. This paper proposes an integrated approach
for addressing the above mentioned challenges. The main contributions of this
paper are: (1) a development methodology that separates IoT application
development into different concerns and provides a conceptual framework to
develop an application, (2) a development framework that implements the
development methodology to support actions of stakeholders. The development
framework provides a set of modeling languages to specify each development
concern and abstracts the scale and heterogeneity related complexity. It
integrates code generation, task-mapping, and linking techniques to provide
automation. Code generation supports the application development phase by
producing a programming framework that allows stakeholders to focus on the
application logic, while our mapping and linking techniques together support
the deployment phase by producing device-specific code to result in a
distributed system collaboratively hosted by individual devices. Our evaluation
based on two realistic scenarios shows that the use of our approach improves
the productivity of stakeholders involved in the application development
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