1,425 research outputs found
Singlet-triplet transitions in highly correlated nanowire quantum dots
We consider a quantum dot embedded in a three-dimensional nanowire with
tunable aspect ratio a. A configuration interaction theory is developed to
calculate the energy spectra of the finite 1D quantum dot systems charged with
two electrons in the presence of magnetic fields B along the wire axis.
Fruitful singlet-triplet transition behaviors are revealed and explained in
terms of the competing exchange interaction, correlation interaction, and spin
Zeeman energy. In the high aspect ratio regime, the singlet-triplet transitions
are shown designable by tuning the parameters a and B. The transitions also
manifest the highly correlated nature of long nanowire quantum dots.Comment: 4 pages, 4 figure
Ammonia emissions from UK non-agricultural sources in 2014: contribution to the National Atmospheric Emission Inventory
Modelling and mapping UK emissions of ammonia, methane and nitrous oxide from agriculture, nature, waste disposal and other miscellaneous sources for 2013
A contribution to the UK National Atmospheric Emission Inventory and Greenhouse Gas Inventory
Hadronic production calculated in the NRQCD factorization formalism
The NRQCD factorization formalism of Bodwin, Braaten, and Lepage prescribes
how to write quarkonium production rates as a sum of products of short-distance
coefficients times non-perturbative long-distance NRQCD matrix elements. We
present, in the true spirit of the factorization formalism, a detailed
calculation of the inclusive cross section for hadronic production. We
find that in addition to the well known {\it color-singlet} production
mechanisms, there are equally important mechanisms in which the pair
that forms the is initially produced in a {\it color-octet} state, in
either a , , or angular-momentum
configuration. In our presentation, we emphasize the ``matching'' procedure,
which %is the method that allows us to determine the short-distance
coefficients appearing in the factorization formula. We also point out how one
may systematically include relativistic corrections in these calculations.Comment: 25 pages, 3 postscript figures, use Revtex and epsfig.sty We fixed
some typos, added some text regarding a reference, and changed some
equations. The file will be available at http://phenom.physics.wisc.edu
Selective CO<sub>2</sub> adsorption in water-stable alkaline-earth based metal–organic frameworks
High value information in engineering organizations
The management of information in engineering organizations is facing a particular challenge in the ever-increasing volume of information. It has been recognized that an effective methodology is required to evaluate information in order to avoid information overload and to retain the right information for reuse. By using, as a starting point, a number of the current tools and techniques which attempt to obtain ‘the value’ of information, it is proposed that an assessment or filter mechanism for information is needed to be developed. This paper addresses this issue firstly by briefly reviewing the information overload problem, the definition of value, and related research work on the value of information in various areas. Then a “characteristic” based framework of information evaluation is introduced using the key characteristics identified from related work as an example. A Bayesian Network diagram method is introduced to the framework to build the linkage between the characteristics and information value in order to quantitatively calculate the quality and value of information. The training and verification process for the model is then described using 60 real engineering documents as a sample. The model gives a reasonable accurate result and the differences between the model calculation and training judgments are summarized as the potential causes are discussed. Finally several further the issues including the challenge of the framework and the implementations of this evaluation assessment method are raised
Information evaluation: empirical investigations in engineering organisations
The management of information in engineering organizations is facing a particular challenge due to the ever-increasing volume of information needs to be dealt with. It has been recognized that an effective methodology is required to evaluate information in order to avoid information overload and to retain the right information for reuse. By whatever approaches, information evaluation judgments are made in those engineering organizations in order to support businesses decisions. Investigating those practical methodologies would benefit the overall information evaluation research. This paper addresses this practical information evaluation issue firstly by briefly reviewing the idea of information evaluation, the definition of value, and related research work on the value of information in various areas. Then a series of industrial empirical investigation activities, based on interviews in engineering organizations, are introduced. The evaluation approaches in those organizations are analyzed and compared according to the nature of each of the organizations. The current practices are then summarized. Finally, several further issues including the impact of the newly developed information evaluation methodologies and the implementation issues associated with this evaluation assessment method are raised
Defining a framework for the evaluation of information
In any enterprise, principled decisions need be made during the entire life
cycle of information about its acquisition, storage, creation, maintenance and disposal.
Such information management requires some form of information evaluation to take
place, yet little is understood about the process of information evaluation within
enterprises. For evaluation support to be both effective and resource efficient,
particularly where decisions are being made about the future of large quantities of
information, it would be invaluable if some sort of automatic or semi-automatic
methods were available for evaluation. Such a method would require an understanding
of the diversity of the contexts in which evaluation takes place so that evaluation
support can have the necessary context-sensitivity. This paper identifies the dimensions
that influence the information evaluation process and defines the elements that
characterize these dimensions, thus providing the foundations for a context-sensitive
framework for information evaluation
Knowledge and information evaluation practice - an exploratory study in a construction firm
There are a number of challenges associated with managing knowledge and information in construction organizations delivering major capital assets. These include the ever-increasing volumes of information, losing people because of retirement or competitors, the continuously changing nature of information, lack of methods on eliciting useful knowledge, development of new information technologies and changes in management and innovation practices. Existing tools and methodologies for valuing intangible assets in fields such as engineering, project management and financial, accounting, do not address fully the issues associated with the valuation of information and knowledge. Information is rarely recorded in a way that a document can be valued, when either produced or subsequently retrieved and re-used. In addition, there is a wealth of tacit personal knowledge which, if codified into documentary information, may prove to be very valuable to operators of the finished asset or future designers. This paper addresses the problem of information overload and identifies the differences between data, information and knowledge. An exploratory study was conducted with a leading construction consultant examining three perspectives (business, project management and document management) by structured interviews and specifically how to value information in practical terms. Major challenges in information management are identified. An through-life Information Evaluation methodology (IEM) is presented to reduce information overload and to make the information more valuable in the future
Overload of information or lack of high value information: lessons learnt from construction
Information and knowledge are strategic assets, processed to attain objectives, perform
actions and make decisions. However, technological innovations can change the format of information
and often result in more complicated project information or knowledge management tools whilst this
can provide information to an individual more easily and quickly. Current systems have little or no
regard for the value of the information they contain. As projects draw to a close, some organisations
are now asking what information is worth retaining and how might it be reused. This paper addresses
the problems of information overload and value in the construction industry. Exploratory studies
compared two major consultants in the UK from three perspectives (business, project management
and document management). Major challenges in the current information evaluation practice in the
industry were identified. Information overload does exist in the industry and is getting worse because
of the heavy but often inappropriate use of search and collaborative technologies. Loss of high value
information due to staff leaving is a major problem, but the companies are reluctant to evaluate
recorded information (before or after storage) for future retrieval. From the strategic point of view,
there is a lack of information evaluation tools that quantify the benefits and costs of performing
information evaluation activities and the effects on storage. Based on these findings, a through-life
Information Evaluation Methodology (IEM) has been proposed to allow high value information to be
easily retrievable in the future in order to support through-life knowledge and information management
(KIM) practice
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