20,022 research outputs found

    Robust and Fast 3D Scan Alignment using Mutual Information

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    This paper presents a mutual information (MI) based algorithm for the estimation of full 6-degree-of-freedom (DOF) rigid body transformation between two overlapping point clouds. We first divide the scene into a 3D voxel grid and define simple to compute features for each voxel in the scan. The two scans that need to be aligned are considered as a collection of these features and the MI between these voxelized features is maximized to obtain the correct alignment of scans. We have implemented our method with various simple point cloud features (such as number of points in voxel, variance of z-height in voxel) and compared the performance of the proposed method with existing point-to-point and point-to- distribution registration methods. We show that our approach has an efficient and fast parallel implementation on GPU, and evaluate the robustness and speed of the proposed algorithm on two real-world datasets which have variety of dynamic scenes from different environments

    AUTOSIM: An automated repetitive software testing tool

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    AUTOSIM is a software tool which automates the repetitive run testing of software. This tool executes programming tasks previously performed by a programmer with one year of programming experience. Use of the AUTOSIM tool requires a knowledge base containing information about known faults, code fixes, and the fault diagnosis-correction process. AUTOSIM can be considered as an expert system which replaces a low level of programming expertise. Reference information about the design and implementation of the AUTOSIM software test tool provides flowcharts to assist in maintaining the software code and a description of how to use the tool

    Genetic analysis of the human tumor necrosis factor alpha/cachectin promoter region in a macrophage cell line.

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    The 615-bp 5' flanking region of the human TNF-alpha/cachectin gene was isolated and ligated to the luciferase reporter gene. In addition, a series of truncated promoter constructs was generated by exonuclease III digestion. The promoter activity of these constructs was studied in a transient transfection system using the TNF-alpha-producing U937 cell line. Full-length and truncated TNF promoter constructions extending from -615 to -95 bp relative to the transcription start site (TSS) could be induced by phorbol esters. A construct truncated to within 36 bp of the TSS (and within 11 bp of the TATAA box) was inactive. Therefore, the phorbol ester responsive is localized in the TNF/cachectin promoter to a relatively short region proximal to the TATAA box

    The Profitability of Organic Soybean Production

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    Results from long-term experimental trials suggest that similar yields and lower costs are possible with organic compared to conventional soybeans, but there is little information about the relative costs and returns on commercial farms. This study examines the profitability of commercial soybean production using a nationwide survey of soybean producers for 2006 that includes a targeted sample of organic growers. Treatment-effect models are specified to isolate the impact of choosing the organic approach on various levels of soybean production costs. Organic soybean costs range from about 1to1 to 6 per bushel higher than those for conventional soybeans due to both lower yields and higher per-acre costs, while the average organic price premium in 2006 is more than $9 per bushel. High returns to organic production are attributed to the significant price premiums paid for organic soybeans in 2006, and these price premiums have remained high in 2007 and 2008. However, much higher conventional soybean prices and increased fuel prices may have reduced the incentive for planting organic soybeans.Crop Production/Industries,

    A Comparison of Conventional and Organic Milk Production Systems in the U.S.

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    Replaced with revised version of paper 07/23/07.Farm Management,

    Governance and Norms as Determinants of Arming

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    In this paper, we explore two factors that can limit arming and, more generally, the costs of enforcement within and across states: governance or the formal organizations and institutions that help define and enforce property rights, and norms, or the informal arrangements in settling potential disputes. We examine the effects of these two factors in a simple static contest model, in which two sides choose levels of arming and whether to engage in actual conflict or settle in the shadow of conflict. We show how arming critically depends on both governance and norms, and therefore how societies with potentially conflictual relations can make either high or low levels of expenditures on security without any difference in the levels of security they actually enjoy. We also explore how investments in governance can reduce arming.Interstate and intrastate disputes; Conflict; Governance; Norms; Security

    Combustion Gas Properties I-ASTM Jet a Fuel and Dry Air

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    A series of computations was made to produce the equilibrium temperature and gas composition for ASTM jet A fuel and dry air. The computed tables and figures provide combustion gas property data for pressures from 0.5 to 50 atmospheres and equivalence ratios from 0 to 2.0

    The Environment as an Argument

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    Context-awareness as defined in the setting of Ubiquitous Computing [3] is all about expressing the dependency of a specific computation upon some implicit piece of information. The manipulation and expression of such dependencies may thus be neatly encapsulated in a language where computations are first-class values. Perhaps surprisingly however, context-aware programming has not been explored in a functional setting, where first-class computations and higher-order functions are commonplace. In this paper we present an embedded domain-specific language (EDSL) for constructing context-aware applications in the functional programming language Haskell. © 2012 Springer-Verlag

    Design and analysis of a control system for an optical delay-line circuit used as reconfigurable gain equalizer

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    The design and analysis of a control system for a coherent two-port lattice-form optical delay-line circuit used as reconfigurable gain equalizer is presented. The design of the control system, which is based on a real device model and a least-square optimization method, is described in detail. Analysis on a five-stage device for the 32 possible solutions of phase parameters showed that, for some filter characteristics, the variations in power dissipation can vary up to a factor of 2. Furthermore, the solution selection has influence on the optimization result and number of iterations needed. A sensitivity analysis of the phase parameters showed that the allowable error in the phase parameters should not exceed a standard deviation of /spl pi//500 in order to achieve a total maximal absolute accuracy error not greater than approximately 0.6 dB. A five-stage device has been fabricated using planar lightwave circuit technology that uses the thermooptic effect. Excellent agreement between simulations and measurements has been achieved
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