Bolt: Accelerated Data Mining with Fast Vector Compression

Vectors of data are at the heart of machine learning and data mining. Recently, vector quantization methods have shown great promise in reducing both the time and space costs of operating on vectors. We introduce a vector quantization algorithm that can compress vectors over 12x faster than existing techniques while also accelerating approximate vector operations such as distance and dot product computations by up to 10x. Because it can encode over 2GB of vectors per second, it makes vector quantization cheap enough to employ in many more circumstances. For example, using our technique to compute approximate dot products in a nested loop can multiply matrices faster than a state-of-the-art BLAS implementation, even when our algorithm must first compress the matrices. In addition to showing the above speedups, we demonstrate that our approach can accelerate nearest neighbor search and maximum inner product search by over 100x compared to floating point operations and up to 10x compared to other vector quantization methods. Our approximate Euclidean distance and dot product computations are not only faster than those of related algorithms with slower encodings, but also faster than Hamming distance computations, which have direct hardware support on the tested platforms. We also assess the errors of our algorithm's approximate distances and dot products, and find that it is competitive with existing, slower vector quantization algorithms.Comment: Research track paper at KDD 201

LDEF materials data bases

The Long Duration Exposure Facility (LDEF) and the accompanying experiments were composed of and contained a wide variety of materials representing the largest collection of materials flown in low Earth orbit (LEO) and retrieved for ground based analysis to date. The results and implications of the mechanical, thermal, optical, and electrical data from these materials are the foundation on which future LEO space missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been charged with establishing and developing data bases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the spacecraft user community in an easily accessed, user-friendly form. This paper discusses the format and content of the three data bases developed or being developed to accomplish this task. The hardware and software requirements for each of these three data bases are discussed along with current availability of the data bases. This paper also serves as a user's guide to the MAPTIS LDEF Materials Data Base

The preliminary Long Duration Exposure Facility (LDEF) materials data base

A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated for LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux), and author(s) or principal investigator(s). The LDEF Materials Data Base was incorporated into the Materials and Processes Technical Information System (MAPTIS). MAPTIS is a collection of materials data which was computerized and is available to engineers, designers, and researchers in the aerospace community involved in the design and development of spacecraft and related hardware. This paper describes the LDEF Materials Data Base and includes step-by-step example searches using the data base. Information on how to become an authorized user of the system is included

Dynamic Winner-take-all Conflict

This paper develops a model of dynamic conflict featuring probabilistic winner- take-all outcomes and compares its behavior to a model in which combatants emerge with a share of the conflict spoils. While these two models generate the same behavior in a one-shot game, we find that in a repeated conflict setting the winner-take-all model generates richer dynamics than the dynamics generated by the share model. Differences include outcomes that illustrate the rise and fall of great powers, the endogenous extinction of combatants, and frequent changes in the relative dominance of combatants. The model's behavior is compared to real world military, business and political conflict outcomes.Anarchy, Fog of War, Paradox of Power, Winner-take-all conflict

Foreword: A Symposium on Current Constitutional Problems

The place of the Constitution in American life nowhere appears more clearly than in the form of our oaths of allegiance. These do not run to any personal sovereign, or to any nation or government by name. They pledge only the support of the Constitution of the United States, to which is sometimes added the promise to defend it against all enemies foreign and domestic. It must be and it is something more than a mere document which is sanctified by such oaths. It is the embodiment and symbol of nationhood, of a form of government and of a way of life. The document in which these things are enshrined has now been in existence for more than a century and a half, in war and peace. It has survived many crises; it has undergone amendments and additions, and the shelves of many libraries are filled with writings and commentaries concerning it. And yet constitutional questions still persist and controversies continue to rage over the bearing of the Constitution on this or that set of facts. In one of the articles in this Symposium the author (Mr. Curtis) speaks of the Constitution as an ambulatory document. As a figure of speech the phrase is arresting. Yet the apparent movement is not so much in the Constitution itself as in the changing circumstances to which it is to be applied. There are changes, too, in the reasoning and sentiments of the men by whom it is to be interpreted. But the movement, real or apparent, has its limits. Innovation must halt, interpretation must pause, desire for change must be put aside, at the boundary set by an oath to support and defend the Constitution of the United States. Protected by such an oath the Constitution remains the Ark of the Covenant of our national life