1,634,699 research outputs found
An investigation of networking techniques for the ASRM facility
This report is based on the early design concepts for a communications network for the Advanced Solid Rocket Motor (ASRM) facility being built at Yellow Creek near Iuka, MS. The investigators have participated in the early design concepts and in the evaluation of the initial concepts. The continuing system design effort and any modification of the plan will require a careful evaluation of the required bandwidth of the network, the capabilities of the protocol, and the requirements of the controllers and computers on the network. The overall network, which is heterogeneous in protocol and bandwidth, is being modeled, analyzed, simulated, and tested to obtain some degree of confidence in its performance capabilities and in its performance under nominal and heavy loads. The results of the proposed work should have an impact on the design and operation of the ASRM facility
The Application of MIMO to Non-Orthogonal Multiple Access
This paper considers the application of multiple-input multiple-output (MIMO)
techniques to non-orthogonal multiple access (NOMA) systems. A new design of
precoding and detection matrices for MIMO-NOMA is proposed and its performance
is analyzed for the case with a fixed set of power allocation coefficients. To
further improve the performance gap between MIMO-NOMA and conventional
orthogonal multiple access schemes, user pairing is applied to NOMA and its
impact on the system performance is characterized. More sophisticated choices
of power allocation coefficients are also proposed to meet various quality of
service requirements. Finally computer simulation results are provided to
facilitate the performance evaluation of MIMO-NOMA and also demonstrate the
accuracy of the developed analytical results
Impact Evaluation of Interoperability Decision Variables on P2P Collaboration Performances
This article deals with the impact evaluation of interoperability decision variables on performance indicators of business processes. The case of partner companies is studied to show the interest of an Interoperability Service Utility (ISU) on business processes in a peer to peer (P2P) collaboration. Information described in the format and the ontology of a broadcasting entity is transformed by ISU into information with the format and the ontology of the receiving entity depending on the available resources of interoperation. These resources can be human operators with defined skill level or software modules of transformation in predefined languages. A design methodology of a global simulation model for estimating the impact of interoperability decision variables on performance indicators of business processes is proposed. Its implementation in an industrial case of collaboration shows its efficiency and its interest to motivate an investment in the technologies of enterprise interoperability
Urban food strategies in Central and Eastern Europe: what's specific and what's at stake?
Integrating a larger set of instruments into
Rural Development Programmes implied an increasing
focus on monitoring and evaluation. Against the highly
diversified experience with regard to implementation
of policy instruments the Common Monitoring
and Evaluation Framework has been set up by the EU
Commission as a strategic and streamlined method of
evaluating programmes’ impacts. Its indicator-based
approach mainly reflects the concept of a linear,
measure-based intervention logic that falls short of
the true nature of RDP operation and impact capacity
on rural changes. Besides the different phases of the
policy process, i.e. policy design, delivery and evaluation,
the regional context with its specific set of challenges
and opportunities seems critical to the understanding
and improvement of programme performance.
In particular the role of local actors can hardly
be grasped by quantitative indicators alone, but has
to be addressed by assessing processes of social
innovation. This shift in the evaluation focus underpins
the need to take account of regional implementation
specificities and processes of social innovation as
decisive elements for programme performance.
Developing Educational Software: a professional tool perspective
The selection, and use of educational software and its impact in schools are still controversial issues. In this paper we present an alternative conceptualisation of educational software based on considering the software as an instrument for teachers’ professional performance. We review previous work in the areas of the design, development and evaluation of educational software and of the process of educational innovation. The review of these four areas converges to demonstrate the need for knowing and considering the context of use of educational software and for understanding users' perspectives about its roles and possibilities and hence supports a consideration a perspective on educational software which sees it as a professional tool for teachers performance of their teaching role
Research in Geant4 electromagnetic physics design, and its effects on computational performance and quality assurance
The Geant4 toolkit offers a rich variety of electromagnetic physics models;
so far the evaluation of this Geant4 domain has been mostly focused on its
physics functionality, while the features of its design and their impact on
simulation accuracy, computational performance and facilities for verification
and validation have not been the object of comparable attention yet, despite
the critical role they play in many experimental applications. A new project is
in progress to study the application of new design concepts and software
techniques in Geant4 electromagnetic physics, and to evaluate how they can
improve on the current simulation capabilities. The application of a
policy-based class design is investigated as a means to achieve the objective
of granular decomposition of processes; this design technique offers various
advantages in terms of flexibility of configuration and computational
performance. The current Geant4 physics models have been re-implemented
according to the new design as a pilot project. The main features of the new
design and first results of performance improvement and testing simplification
are presented; they are relevant to many Geant4 applications, where
computational speed and the containment of resources invested in simulation
production and quality assurance play a critical role.Comment: 4 pages, 4 figures and images, to appear in proceedings of the
Nuclear Science Symposium and Medical Imaging Conference 2009, Orland
Evaluating Pro-poor Transfers When Targeting is Weak: The Albanian Ndihma Ekonomike Program Revisited
The Albanian Ndihma Ekonomike is one of the first poverty reduction programs launched in transitional economies. Its record has been judged positively during the recession period of the 1990s and negatively during the more recent growth phase. This paper reconsiders the program using a regression-adjusted matching estimator rst suggested by Heckman et al. (1997, 1998) and exploiting discontinuities in program design and targeting failures. We nd the program to have a weak targeting capacity and a negative and signicant impact on welfare. We also nd that recent changes introduced to the program have not improved its performance. An analysis of the distributional impact of treatment based on stochastic dominance theory suggests that our results are robust.Social assistance, Poverty, Impact Evaluation, Albania
Design and Implementation of MPICH2 over InfiniBand with RDMA Support
For several years, MPI has been the de facto standard for writing parallel
applications. One of the most popular MPI implementations is MPICH. Its
successor, MPICH2, features a completely new design that provides more
performance and flexibility. To ensure portability, it has a hierarchical
structure based on which porting can be done at different levels. In this
paper, we present our experiences designing and implementing MPICH2 over
InfiniBand. Because of its high performance and open standard, InfiniBand is
gaining popularity in the area of high-performance computing. Our study focuses
on optimizing the performance of MPI-1 functions in MPICH2. One of our
objectives is to exploit Remote Direct Memory Access (RDMA) in Infiniband to
achieve high performance. We have based our design on the RDMA Channel
interface provided by MPICH2, which encapsulates architecture-dependent
communication functionalities into a very small set of functions. Starting with
a basic design, we apply different optimizations and also propose a
zero-copy-based design. We characterize the impact of our optimizations and
designs using microbenchmarks. We have also performed an application-level
evaluation using the NAS Parallel Benchmarks. Our optimized MPICH2
implementation achieves 7.6 s latency and 857 MB/s bandwidth, which are
close to the raw performance of the underlying InfiniBand layer. Our study
shows that the RDMA Channel interface in MPICH2 provides a simple, yet
powerful, abstraction that enables implementations with high performance by
exploiting RDMA operations in InfiniBand. To the best of our knowledge, this is
the first high-performance design and implementation of MPICH2 on InfiniBand
using RDMA support.Comment: 12 pages, 17 figure
Risk factors affecting the ability for earned value management to accurately assess the performance of infrastructure projects in Australia
Purpose – The purpose of this paper is to investigate a set of risk-related factors influencing the earned
value management (EVM) concept as an assessment technique in evaluating the progress of modern
sustainable infrastructure construction projects.
Design/methodology/approach – A qualitative research approach has been adopted for identifying
risk-related factors influencing EVM concept from a literature review and through interviewing
industry personnel, followed by an inductive process to form sets of key factors and their measuring
items.
Findings – EVM is a common method for assessing project performance. A weakness of this approach
is that EVM assessment in its current form does not measure the impact of a number of project
performance factors that result from the complexity of modern infrastructure construction projects, and
thus does not accurately assess their impact in this performance. This paper discusses and explains a
range of potential risk factors to evaluating project performance such as sustainability, stakeholder
requirements, communication, procurement strategy, weather, experience of staff, site condition, design
issues, financial risk, subcontractor, government requirements and material. In addition, their
measuring items were identified.
Practical implications – This research assists projects managers to improve the evaluation process of
infrastructure construction performance by incorporating a range of factors likely to impact on that
performance and which are not included in current EVM calculations.
Originality/value – This research addresses the need to include in the EVM calculation a range of risk
factors affecting the performance of infrastructure projects in Australia and therefore makes this calculation a more reliable tool for assessing project performance
A methodological comparison between energy and environmental performance evaluation
The European Union is working on strategies in order to increase the energy efficiency of buildings. A useful solution is to identify the energy performance of buildings through the Energy Performance Certificate (EPC), as it provides information for the comparison of buildings with different architectural typology, shape, design technology and geographic location. However, this tool does not assess the real energy consumption of the building and does not always take into account its impact on the environment. In this work, two different types of analysis were carried out: one based only on the energy efficiency and the other one based on the environmental impact. Those analyses were applied on a standard building, set in three different Italian locations, with the purpose of obtaining cross-related information. After the evaluation of the results, interventions on some parameters (walls insulation, windows frame, filler gas in the insulated glazing) have been identified in order to improve the energy behavior of the building with an acceptable environmental impact. The aim of this paper is to propose a methodology that integrates the EPC with green building rating systems, leading to a more conscious choice of retrofit interventions as a compromise between energy performances and environmental impact
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