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

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 ψ\psi 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 $\psi$ production. We find that in addition to the well known {\it color-singlet} production mechanisms, there are equally important mechanisms in which the $c\bar{c}$ pair that forms the $\psi$ is initially produced in a {\it color-octet} state, in either a ${}^3S_1$, ${}^1S_0$, ${}^3P_0$ or ${}^3P_2$ 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

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