Expressive power of binary relevance and chain classifiers based on Bayesian Networks for multi-label classification

Bayesian network classifiers are widely used in machine learning because they intuitively represent causal relations. Multi-label classification problems require each instance to be assigned a subset of a defined set of h labels. This problem is equivalent to finding a multi-valued decision function that predicts a vector of h binary classes. In this paper we obtain the decision boundaries of two widely used Bayesian network approaches for building multi-label classifiers: Multi-label Bayesian network classifiers built using the binary relevance method and Bayesian network chain classifiers. We extend our previous single-label results to multi-label chain classifiers, and we prove that, as expected, chain classifiers provide a more expressive model than the binary relevance method.

3D simulation of complex shading affecting PV systems taking benefit from the power of graphics cards developed for the video game industry

Shading reduces the power output of a photovoltaic (PV) system. The design engineering of PV systems requires modeling and evaluating shading losses. Some PV systems are affected by complex shading scenes whose resulting PV energy losses are very difficult to evaluate with current modeling tools. Several specialized PV design and simulation software include the possibility to evaluate shading losses. They generally possess a Graphical User Interface (GUI) through which the user can draw a 3D shading scene, and then evaluate its corresponding PV energy losses. The complexity of the objects that these tools can handle is relatively limited. We have created a software solution, 3DPV, which allows evaluating the energy losses induced by complex 3D scenes on PV generators. The 3D objects can be imported from specialized 3D modeling software or from a 3D object library. The shadows cast by this 3D scene on the PV generator are then directly evaluated from the Graphics Processing Unit (GPU). Thanks to the recent development of GPUs for the video game industry, the shadows can be evaluated with a very high spatial resolution that reaches well beyond the PV cell level, in very short calculation times. A PV simulation model then translates the geometrical shading into PV energy output losses. 3DPV has been implemented using WebGL, which allows it to run directly from a Web browser, without requiring any local installation from the user. This also allows taken full benefits from the information already available from Internet, such as the 3D object libraries. This contribution describes, step by step, the method that allows 3DPV to evaluate the PV energy losses caused by complex shading. We then illustrate the results of this methodology to several application cases that are encountered in the world of PV systems design. Keywords: 3D, modeling, simulation, GPU, shading, losses, shadow mapping, solar, photovoltaic, PV, WebGL

Entropy production and thermodynamic power of the squeezed thermal reservoir

We analyze the entropy production and the maximal extractable work from a squeezed thermal reservoir. The nonequilibrium quantum nature of the reservoir induces an entropy transfer with a coherent contribution while modifying its thermal part, allowing work extraction from a single reservoir, as well as great improvements in power and efficiency for quantum heat engines. Introducing a modified quantum Otto cycle, our approach fully characterizes operational regimes forbidden in the standard case, such as refrigeration and work extraction at the same time, accompanied by efficiencies equal to unity.

The Power of the Placement of Public Sculpture

The Power of the Placement of Public Sculpture explores the aesthetic effects public sculpture has on the environment around it. The work presented includes a discussion of case studies in select American and international communities. Relevance is brought to the topic through the documentation of the placement of a fabricated eight-foot avocado sculpture displayed on the University of Denver campus. Reflection on the experience exposes additional questions and demonstrates the importance of the placement of a public sculpture.

Power of attorney for Joseph Chip, 1804 December 21

Handwritten draft of a power of attorney, in Croswell's hand, authorizing John Jones to act for mariner Joseph Chip.

Power of Attorney, [?] Wellington for Thomas Durant, Sept. 22, 1787

Signed by Thomas Durant and witnessed by Ebenezer Bradish. It is possible that Shapleigh used this document as a guide when drafting his own power of attorney documents.

Power of Attorney, Samuel Shapleigh for Thomas Adams, Jan. 12, 1791

Signed by Thomas Adams and witnessed by Abraham Biglow and Daniel Clarke Sanders.

Power of Attorney, Samuel Shapleigh for James Otis Prentiss, Aug. 18, 1791

Document also contains what appears to be a bill for medical services rendered by Prentiss, a doctor, to William Boman.

[Power of attorney between Stephen Sewall and Thomas Wigglesworth], 1794 August 21

This one-page printed form appoints Thomas Wigglesworth as the "true and lawful Attorney" for Stephen Sewall. The form is notarized by Samuel Barrett and witnessed by Barrett and his daughter Peggy Barrett.

Power of Attorney, Samuel Shapleigh for Thomas Thompson, May 18, 1791

Signed by Thomas Thompson and witnessed by Thaddeus Mason Harris and Otis(?) Clarke.

Power of attorney for Thomas Whippo, 1798 October 10

A handwritten translation of a power of attorney, on two folio-sized leaves, certified by Francis Sales and dated October 10, 1798. The power of attorney authorizes Isaac Whippo, an American citizen living in Bordeaux, France to act as the attorney general and special for his brother, Thomas Whippo, also an American citizen and captain of the ship the Ganges of New York. The power of attorney was created in the Office of Gabriel Duprat in Bordeaux, with William Henry Vernon translating for Thomas Whippo and was notarized by Joseph Fenwick, Consol of the United States of America on April 14, 1798.