38,795 research outputs found
Entropy production in a photovoltaic cell
We evaluate entropy production in a photovoltaic cell that is modeled by four
electronic levels resonantly coupled to thermally populated field modes at
different temperatures. We use a formalism recently proposed, the so-called
multiple parallel worlds, to consistently address the nonlinearity of entropy
in terms of density matrix. Our result shows that entropy production is the
difference between two flows: a semiclassical flow that linearly depends on
occupational probabilities, and another flow that depends nonlinearly on
quantum coherence and has no semiclassical analog. We show that entropy
production in the cells depends on environmentally induced decoherence time and
energy detuning. We characterize regimes where reversal flow of information
takes place from a cold to hot bath. Interestingly, we identify a lower bound
on entropy production, which sets limitations on the statistics of dissipated
heat in the cells.Comment: 7 pages, 2 figure
Sutte Indicator: an approach to predict the direction of stock market movements
The purpose of this research is to apply technical analysis of Sutte
Indicator in stock trading which will assist in the investment decision making
process i.e. buying or selling shares. This research takes data of "A" on the
Indonesia Stock Exchange(IDX or BEI) 29 November 2006 until 20 September 2016
period. To see the performance of Sutte Indicator, other technical analysis are
used as a comparison, Simple Moving Average (SMA) and Moving Average
Convergence/Divergence (MACD). To see a comparison of the level of reliability
prediction, the stock data were compared using the mean absolute deviation
(MAD), mean of square error (MSE), and mean absolute percentage error (MAPE).
The result of this research is that Sutte Indicator can be used as a reference
in predicting stock movements, and if it is compared to other indicator methods
(SMA and MACD) via MAD, MSE, and MAPE, the Sutte Indicator has a better level
of reliability
The teaching of Relational On-Line Analytical Processing (ROLAP) in Advanced Database courses.
Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission. © 2012 Higher Education AcademyDatabases are taught as a core subject at undergraduate and postgraduate levels in computer science degrees. The subject is often divided into conceptual database design and database technologies including physical database design. One of the problems with teaching the topic of ROLAP and Data Warehousing is the difficulty of providing practical exposure to the students. The approach taken in this work is intended to help students apply their knowledge learnt throughout the subject and gain some practical understanding leading to its application and implementation which furthermore provides the basis for analysis and evaluation at the level of critical analysis that would be expected on an advanced level course and at the highest level of learning taxonomies. In our work we have reverse engineered a large Oracle sample dataset and adapted it for use in the teaching of ROLAP. We have also produced our own smaller sample dataset for simplification and understanding of complex queries involving Slicing, Dicing , Pivoting, Rollup and Cube operations. In our examples ROLAP operations and their alternative SQL approaches are performed to provide multi-dimensional results
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