130 research outputs found
Success factors for dairy farming in the north of Italy
No full textThe study sets out to assess the relation between structural
and organizational variables in dairy farms and their
capacity for survival. It also highlights a number of factors
influencing the success of a dairy farm.
The main results are the identification of links between a
number of farm variables and their survival potential. The
author also develops a discriminant analysis model to
estimate farm survival. Lastly the author illustrates the
different types of entrepreneurs active in dairy farming in
north Italy
La contumacia nelle cognitiones civile pregiustinianee
No full textDottorato di ricerca in diritto romano e diritti dell'antichita'. 10. ciclo. Coordinatore Alberto Burdese. Tutori Franca de Marini Avonzo e Danilo DallaConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal
Augmenting Static Source Views in IDEs with Dynamic Metrics
No full textMainstream IDEs such as Eclipse support developers in managing software projects mainly by offering static views of the source code. Such a static perspective neglects any information about runtime behavior. However, object-oriented programs heavily rely on polymorphism and late-binding, which makes them difficult to understand just based on their static structure. Developers thus resort to debuggers or profilers to study the system's dynamics. However, the information provided by these tools is volatile and hence cannot be exploited to ease the navigation of the source space. In this paper we present an approach to augment the static source perspective with dynamic metrics such as precise runtime type information, or memory and object allocation statistics. Dynamic metrics can leverage the understanding for the behavior and structure of a system. We rely on dynamic data gathering based on aspects to analyze running Java systems. By solving concrete use cases we illustrate how dynamic metrics directly available in the IDE are useful. We also comprehensively report on the efficiency of our approach to gather dynamic metrics
Senseo: Enriching Eclipse's Static Source Views with Dynamic Metrics
No full textMaintaining object-oriented systems that use inheritance and polymorphism is difficult, since runtime information, such as which methods are actually invoked at a call site, is not visible in the static source code. We have implemented Senseo, an Eclipse plugin enhancing Eclipse's static source views with various dynamic metrics, such as runtime types, the number of objects created, or the amount of memory allocated in particular methods
What to expect when you are consolidating: effective prediction models of application performance on multicore
No full textConsolidation of multiple applications with diverse and changing resource requirements is common in multicore systems as hardware resources are abundant. As opportunities for better system usage become ample, so
are opportunities to degrade individual application performances due to unregulated performance interference between applications and system resources. Can we predict a performance region within which application performance
is expected to lie under different consolidations? Alternatively, can we maximize resource utilization while maintaining individual application performance targets? In this work we provide a methodology that offers answers to the above difficult questions by constructing a queueing-theory based tool that can be used to accurately predict application scalability on multicores. The tool can also provide the optimal consolidation suggestions to maximize system resource utilization while meeting application performance targets. The proposed methodology is based on asymptotic analysis that can quickly provide a range of performance values that the user should expect under various consolidation scenarios.
In addition, when more accurate performance forecasting is
needed, the methodology can provide more accurate predictions using approximate mean value analysis. The methodology is light-weight as it relies on capturing application resource demands using standard system monitoring, via nonintrusive low-level measurements.
We evaluate our approach on an IBM Power7 system using
the DaCapo and SPECjvm2008 benchmark suites. From
900 different consolidations of application instances, our
tool accurately predicts the average iteration time of collocated applications with an average error below 9 per cent.
Experimental and analytical results are in excellent agreement, confirming the robustness of the proposed methodology in suggesting the best consolidations that meet given performance objectives of individual applications while maximizing system resource utilization
Exploiting Dynamic Information in IDEs Improves Speed and Correctness of Software Maintenance Tasks
No full textSuccess Factors for Dairy Farming in the North of Italy
No full textThe study sets out to assess the relation between structural and organizational variables in dairy farms and their capacity for survival. It also highlights a number offactors influencing the success of a dairy farm.
The main results are the identification of links between a number of farm variables and their survival potential. The author also develops a discriminant analysis model to estimate farm survival. Lastly the author illustrates the different types of entrepreneurs active in dairy farming in north Italy
The PIM: an Innovative Robot Coordination Model based on Java Thread Migration
No full textThere is a growing demand to apply multi-robot systems to address many current problems ranging from search and rescue to distributed surveillance to coordination of small satellites in space. Solving these problems effectively requires that teams of robots coordinate effectively. Many of the algorithms for coordination are based on the so-called centralized paradigm, where a central controlling authority is responsible for coordinating the entire team of robots. Unfortunately, centralized approaches often fall short when dealing with rapidly changing situations, unreliability of communications, and failure of robots, especially in hostile environments. Distributed approaches, in an effort to address such issues, tend to introduce complex negotiation or market-based strategies for distributed task execution, sometimes resulting in cumbersome programming models and suboptimal solutions. In this paper, we introduce the readers to the PIM (Process Integrated Mechanism) approach to multi-robot coordination grounded in research on Java thread migration. The core idea of the PIM is to retain the perspective of the single controlling authority but abandon the notion that it must have a fixed location within the system. Instead, the single coordinating thread is rapidly moved among the team members. The PIM leverages on Java thread mobility to preserve the optimality of the centralized approach, while effectively addressing most of its weaknesses (e.g. sluggish response to dynamic conditions, communication difficulties, and a single point of failure). A prototype implementation of such a model is presented on top of the Mobile JikesRVM framework for Java thread migration, along with some preliminary performance results
ADVANCED AND RAPID DEVELOPMENT OF DYNAMIC ANALYSIS TOOLS FOR JAVA
No full textLow-level bytecode instrumentation techniques are widely used in many software-engineering tools for the Java Virtual Machine (JVM), that perform some form of dynamic program analysis, such as profilers or debuggers. While program manipulation at the bytecode level is very flexible, because the possible bytecode transformations are not restricted, tool development based on this technique is tedious and error-prone. As a promising alternative, the specification of bytecode instrumentation at a higher level using aspect-oriented programming (AOP) can reduce tool development time and cost. Unfortunately, prevailing AOP frameworks lack some features that are essential for certain dynamic analyses. In this article, we focus on three common shortcomings in AOP frameworks with respect to the development of aspect-based tools - (1) the lack of mechanisms for passing data between woven advices in local variables, (2) the support for user-defined static analyses at weaving time, and (3) the absence of pointcuts at the level of individual basic blocks of code. We propose @J, an annotation-based AOP language and weaver that integrates support for these three features. The benefits of the proposed features are illustrated with concrete examples
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