Sandia National Laboratories

About: Sandia National Laboratories is a facility organization based out in Livermore, California, United States. It is known for research contribution in the topics: Laser & Combustion. The organization has 21501 authors who have published 46724 publications receiving 1484388 citations. The organization is also known as: SNL & Sandia National Labs.

Attack of the Clones: Detecting Cloned Applications on Android Markets

Abstract: We present DNADroid, a tool that detects Android application copying, or “cloning”, by robustly computing the similarity between two applications. DNADroid achieves this by comparing program dependency graphs between methods in candidate applications. Using DNADroid, we found at least 141 applications that have been the victims of cloning, some as many as seven times. DNADroid has a very low false positive rate — we manually confirmed that all the applications detected are indeed clones by either visual or behavioral similarity. We present several case studies that give insight into why applications are cloned, including localization and redirecting ad revenue. We describe a case of malware being added to an application and show how DNADroid was able to detect two variants of the same malware. Lastly, we offer examples of an open source cracking tool being used in the wild.

Enhancing reproducibility for computational methods.

Abstract: Over the past two decades, computational methods have radically changed the ability of researchers from all areas of scholarship to process and analyze data and to simulate complex systems. But with these advances come challenges that are contributing to broader concerns over irreproducibility in the scholarly literature, among them the lack of transparency in disclosure of computational methods. Current reporting methods are often uneven, incomplete, and still evolving. We present a novel set of Reproducibility Enhancement Principles (REP) targeting disclosure challenges involving computation. These recommendations, which build upon more general proposals from the Transparency and Openness Promotion (TOP) guidelines ( 1 ) and recommendations for field data ( 2 ), emerged from workshop discussions among funding agencies, publishers and journal editors, industry participants, and researchers representing a broad range of domains. Although some of these actions may be aspirational, we believe it is important to recognize and move toward ameliorating irreproducibility in computational research.

Toward Smart and Ultra-Efficient Solid-State Lighting

Abstract: Solid-state lighting has made tremendous progress this past decade, with the potential to make much more progress over the coming decade. In this article, the current status of solid-state lighting relative to its ultimate potential to be “smart” and ultra-efficient is reviewed. Smart, ultra-efficient solid-state lighting would enable both very high “effective” efficiencies and potentially large increases in human performance. To achieve ultra-efficiency, phosphors must give way to multi-color semiconductor electroluminescence: some of the technological challenges associated with such electroluminescence at the semiconductor level are reviewed. To achieve smartness, additional characteristics such as control of light flux and spectra in time and space will be important: some of the technological challenges associated with achieving these characteristics at the lamp level are also reviewed. It is important to emphasise that smart and ultra-efficient are not either/or, and few compromises need to be made between them. The ultimate route to ultra-efficiency brings with it the potential for smartness, the ultimate route to smartness brings with it the potential for ultra-efficiency, and the long-term ultimate route to both might well be color-mixed RYGB lasers.

Surface self-diffusion on Pt(001) by an atomic exchange mechanism.

Abstract: Field-ion microscopy has been used to map the surface sites visited by an individual Pt adatom migrating at 175 K on the Pt(001) plane and to determine its activation energy for surface diffusion. Atomic displacements are found to occur only in the (100) or (010) directions. A surprisingly low activation energy of 0.47 eV is measured. These results are consistent with a model in which the diffusion occurs by an adatom-substrate exchange mechanism. This mechanism is predicted theoretically for self-diffusion on Al(001).

The Tchebychev iteration for nonsymmetric linear systems

Abstract: In this paper an iterative method for solving nonsymmetric linear systems based on the Tchebychev polynomials in the complex plane is discussed. The iteration is shown to converge whenever the eigenvalues of the linear system lie in the open right half complex plane. An algorithm is developed for finding optimal iteration parameters as a function of the convex hull of the spectrum.