65,276 research outputs found
Suggestions to Improve Lean Construction Planning
The Last Planner System® has been one of the most popular lean construction tools that offers a solution to tackle the problems of production management on construction sites. Since its inception almost 20 years ago, construction companies across the world have implemented Last Planner with reported success. However, even as Last Planner was originally designed to address some shortcomings of the CPM method, a particular shortcoming – namely task continuity was not addressed directly. Also, excepting PPC and Reasons for Non Completion charts, there are no explicit visual tools offered by the Last Planner system. On the other hand, Line of Balance based approaches intrinsically support the consideration of task continuity, and offer a basic visual management approach in schedule representation. With some exceptions, Line of Balance is seen as a special technique applicable only in linear or repetitive work based schedules. The authors suggest that i) there is a need for a robust theory of planning and scheduling and ii) there is a need for a more suitable approach that addresses critical aspects of planning and scheduling function for example by integrating Line of Balance and Last Planner to provide a more robust support for construction scheduling
Questions of Identity
As an introduction to NuFact '99, the ICFA/ECFA Workshop on Neutrino
Factories Based on Muon Storage Rings, I place the issues of neutrino
properties and neutrino oscillations in the broader context of fermion flavor.Comment: Introduction to NuFact '99, the ICFA/ECFA Workshop on Neutrino
Factories Based on Muon Storage Rings. 15 pages; LaTeX, uses elsar
MATHEMATICAL PROGRAMMING FOR RESOURCE POLICY APPRAISAL UNDER MULTIPLE OBJECTIVES
Mathematical programming is one technique that can be used for resource policy appraisal. Multiple objectives are usually involved in resource policy considerations. This paper discusses issues regarding the use of mathematical programming techniques for the multiobjective resource policy arena. Theoretical models are introduced with a separation called for between producer response models and policy maker models due to a disparity of objectives. The paper draws on the literature citing cases where producer level models have been utilized to simulate the policy outcome implications of alternative policies.Resource /Energy Economics and Policy,
Surface impedance measurements on NbSn at high magnetic fields
NbSn is a superconductor of great relevance for perspective RF
applications. We present for the first time surface impedance
measurements at 15 GHz and low RF field amplitude on NbSn in high
magnetic fields up to 12 T, with the aim of increasing the knowledge of
NbSn behavior in such conditions. is a fundamental material
parameter that directly gives useful information about the dissipative and
reactive phenomena when the superconductor is subjected to high-frequency
excitations. Therefore, we present an analysis of the measured with the
aim of extracting interesting data about pinning in NbSn at high
frequencies. From we extract the vortex motion complex resistivity to
obtain the -parameter and the depinning frequency in high magnetic
fields. The comparison of the results with the literature shows that the
measured on bulk NbSn is several times greater than that of pure
Nb. This demonstrates how NbSn can be a good candidate for RF
technological applications, also in high magnetic fields.Comment: ASC 2018 conference, accepted in IEEE Trans Appl Supercon
An overview on the obsolescence of physical assets for the defence facing the challenges of industry 4.0 and the new operating environments
Libro en Open AccessThis contribution is intended to observe special features presented in physical assets for
defence. Particularly, the management of defence assets has to consider not only the reliability, availability,
maintainability and other factors frequently used in asset management. On the contrary, such systems
should also take into account their adaptation to changing operating environments as well as their capability
to changes on the technological context. This study approaches to the current real situation where, due
to the diversity of conflicts in our international context, the same type of defence systems must be able
to provide services under different boundary conditions in different areas of the globe. At the same time,
new concepts from the Industry 4.0 provide quick changes that should be considered along the life cycle
of a defence asset. As a finding or consequence, these variations in operating conditions and in technology
may accelerate asset degradation by modifying its reliability, its up-to-date status and, in general terms, its
end-of-life estimation, depending of course on a diversity of factors. This accelerated deterioration of the
asset is often known as “obsolescence” and its implications are often evaluated (when possible), in terms
of costs from different natures. The originality of this contribution is the introduction of a discussion on
how a proper analysis may help to reduce errors and mistakes in the decision-making process regarding the
suitability or not of repairing, replacing, or modernizing the asset or system under study. In other words,
the obsolescence analysis, from a reliability and technological point of view, could be used to determine the
conservation or not of a specific asset fleet, in order to understand the effects of operational and technology
factors variation over the functionality and life cycle cost of physical assets for defence
Analytic Metaphysics versus Naturalized Metaphysics: The Relevance of Applied Ontology
The relevance of analytic metaphysics has come under criticism: Ladyman & Ross, for instance, have suggested do discontinue the field. French & McKenzie have argued in defense of analytic metaphysics that it develops tools that could turn out to be useful for philosophy of physics. In this article, we show first that this heuristic defense of metaphysics can be extended to the scientific field of applied ontology, which uses constructs from analytic metaphysics. Second, we elaborate on a parallel by French & McKenzie between mathematics and metaphysics to show that the whole field of analytic metaphysics, being useful not only for philosophy but also for science, should continue to exist as a largely autonomous field
The elderly and the digital inclusion: A brief reference to the initiatives of the European union and Portugal
Background: The world and Europe, in particular, are aging very fast, and in the same vein, digitization is moving very quickly into citizens’ routines. Given the fact that the elderly are the largest group of citizens who are info-excluded, this reality is worrying because it will quickly make them socially excluded. This article briefly presents the main initiatives of the European Union and Portugal to promote greater and faster digital inclusion of the elderly people. In the final section, there is a critical reflection on technology acceptance Model, the concept of universal design and usability in order to propose clues and strategies that can and/or may facilitate the use and access of technologies and digital resources by the elderly.info:eu-repo/semantics/publishedVersio
Signatures from an extra-dimensional seesaw model
We study the generation of small neutrino masses in an extra-dimensional
model, where right-handed neutrinos are allowed to propagate in the extra
dimension, while the Standard Model particles are confined to a brane.
Motivated by the fact that extra-dimensional models are non-renormalizable, we
truncate the Kaluza-Klein towers at a maximal extra-dimensional momentum. The
structure of the bulk Majorana mass term, motivated by the Sherk-Schwarz
mechanism, implies that the right-handed Kaluza-Klein neutrinos pair to form
Dirac neutrinos, except for a number of unpaired Majorana neutrinos at the top
of each tower. These heavy Majorana neutrinos are the only sources of lepton
number breaking in the model, and similarly to the type-I seesaw mechanism,
they naturally generate small masses for the left-handed neutrinos. The lower
Kaluza-Klein modes mix with the light neutrinos, and the mixing effects are not
suppressed with respect to the light-neutrino masses. Compared to conventional
fermionic seesaw models, such mixing can be more significant. We study the
signals of this model at the Large Hadron Collider, and find that the current
low-energy bounds on the non-unitarity of the leptonic mixing matrix are strong
enough to exclude an observation.Comment: 17 pages, 3 figures, REVTeX4. Final version published in Phys. Rev.
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