TTC: A Tensor Transposition Compiler for Multiple Architectures

We consider the problem of transposing tensors of arbitrary dimension and describe TTC, an open source domain-specific parallel compiler. TTC generates optimized parallel C++/CUDA C code that achieves a significant fraction of the system's peak memory bandwidth. TTC exhibits high performance across multiple architectures, including modern AVX-based systems (e.g.,~Intel Haswell, AMD Steamroller), Intel's Knights Corner as well as different CUDA-based GPUs such as NVIDIA's Kepler and Maxwell architectures. We report speedups of TTC over a meaningful baseline implementation generated by external C++ compilers; the results suggest that a domain-specific compiler can outperform its general purpose counterpart significantly: For instance, comparing with Intel's latest C++ compiler on the Haswell and Knights Corner architecture, TTC yields speedups of up to $8\times$ and $32\times$, respectively. We also showcase TTC's support for multiple leading dimensions, making it a suitable candidate for the generation of performance-critical packing functions that are at the core of the ubiquitous BLAS 3 routines

Detecting dark matter-dark energy coupling with the halo mass function

We use high-resolution simulations of large-scale structure formation to analyze the effects of interacting dark matter and dark energy on the evolution of the halo mass function. Using a chi-square likelihood analysis, we find significant differences in the mass function between models of coupled dark matter-dark energy and standard concordance cosmology Lambda-CDM out to redshift z=1.5. We also find a preliminary indication that the Dark Energy Survey should be able to distinguish these models from Lambda-CDM within its mass and redshift contraints. While we can distinguish the effects of these models from Lambda-CDM cosmologies with different fundamental parameters, DES will require independent measurements of sigma-8 to confirm these effects.Comment: 5 pages, 3 figures, responded to referee comments, accepted by Ap

Comment on ``Sound velocity and multibranch Bogoliubov spectrum of an elongated Fermi superfluid in the BEC-BCS crossover"

The work by T. K. Ghosh and K. Machida [cond-mat/0510160 and Phys. Rev. A 73, 013613 (2006)] on the sound velocity in a cylindrically confined Fermi superfluid obeying a power-law equation of state is shown to make use of an improper projection of the sound wave equation. This inaccuracy fully accounts for the difference between their results and those previously reported by Capuzzi et al. [cond-mat/0509323 and Phys. Rev. A 73, 021603(R) (2006)]. In this Comment we show that both approaches lead exactly to the same result when the correct weight function is used in the projection. Plots of the correct behavior of the phonon and monopole-mode spectra in the BCS, unitary, and BEC limits are also shown.Comment: Comment on cond-mat/051016

Beryllium fluoride film protects beryllium against corrosion

Film of beryllium fluoride protects beryllium against corrosion and stress corrosion cracking in water containing chloride ion concentrations. The film is formed by exposing the beryllium to fluorine gas at 535 degrees C or higher and makes beryllium suitable for space applications

Women-led Fisheries Management: A Case Study From Bangladesh

This is a case study of a women-led fishery in Bangladesh. Although women constitute 50% of the total population of Asia (Southern)-Bangladesh; only 18% are economically involved inthe total labor force. They are involved in diversified work within their homesteads. However, during times offamily needs and economic crisis, women are involved in non-traditional jobs. In the fisheries sector, Muslimwomen are traditionally not involved in fishing but they are involved in fish drying and salting. In the Hindudominated areas such as Goakhola-Hatiara, women are involved in fish catch as well as the collection of otheraquatic resources as one of their livelihood strategies. Women and subsistence fishers are taking the lead inmanaging a common capture fishery resource in Goakhola-Hatiara with the support from an NGO for perhapsthe first time in Bangladesh. However, the role of women in the Beel Management Committee is not well defined.Under the leadership of women the socio-economic conditions have changed and the social capital has increased

Line element in quantum gravity: the examples of DSR and noncommutative geometry

We question the notion of line element in some quantum spaces that are expected to play a role in quantum gravity, namely non-commutative deformations of Minkowski spaces. We recall how the implementation of the Leibniz rule forbids to see some of the infinitesimal deformed Poincare transformations as good candidates for Noether symmetries. Then we recall the more fundamental view on the line element proposed in noncommutative geometry, and re-interprete at this light some previous results on Connes' distance formula.Comment: some references added. Proceedings of the Second Workshop on Quantum Gravity and Noncommutative Geometry, Universidade Lusofona, Lisbon 22-24 September 200

Automating the Hunt for Volcanoes on Venus

Our long-term goal is to develop a trainable tool for locating patterns of interest in large image databases. Toward this goal we have developed a prototype system, based on classical filtering and statistical pattern recognition techniques, for automatically locating volcanoes in the Magellan SAR database of Venus. Training for the specific volcano-detection task is obtained by synthesizing feature templates (via normalization and principal components analysis) from a small number of examples provided by experts. Candidate regions identified by a focus of attention (FOA) algorithm are classified based on correlations with the feature templates. Preliminary tests show performance comparable to trained human observers