6,283 research outputs found

    Airloads research study. Volume 2: Airload coefficients derived from wind tunnel data

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    The development of B-1 aircraft rigid wind tunnel data for use in subsequent tasks of the Airloads Research Study is described. Data from the Rockwell International external structural loads data bank were used to generate coefficients of rigid airload shear, bending moment, and torsion at specific component reference stations or both symmetric and asymmetric loadings. Component stations include the movable wing, horizontal and vertical stabilizers, and forward and aft fuselages. The coefficient data cover a Mach number range from 0.7 to 2.2 for a wing sweep position of 67.5 degree

    Airloads research study. Volume 1: Flight test loads acquisition

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    The acquisition of B-1 aircraft flight loads data for use in subsequent tasks of the Airloads Research Study is described. The basic intent is to utilize data acquired during B-1 aircraft tests, analyze these data beyond the scope of Air Force requirements, and prepare research reports that will add to the technology base for future large flexible aircraft. Flight test data obtained during the airloads survey program included condition-describing parameters, surface pressures, strain gage outputs, and loads derived from pressure and strain gauges. Descriptions of the instrumentation, data processing, and flight load survey program are included. Data from windup-turn and steady yaw maneuvers cover a Mach number range from 0.7 to 2.0 for a wing sweep position of 67.5 deg

    Combined local-density and dynamical mean field theory calculations for the compressed lanthanides Ce, Pr, and Nd

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    This paper reports calculations for compressed Ce (4f^1), Pr (4f^2), and Nd (4f^3) using a combination of the local-density approximation (LDA) and dynamical mean field theory (DMFT), or LDA+DMFT. The 4f moment, spectra, and the total energy among other properties are examined as functions of volume and atomic number for an assumed face-centered cubic (fcc) structure.Comment: 15 pages, 9 figure

    Epithelioid hemangioma of the penis: case report and review of literature

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    <p>Abstract</p> <p>Introduction</p> <p>Epithelioid hemangioma is a rare vascular tumor found in the penis. It is essential to avoid misdiagnosis with Peyronie's disease and penile cancer, as management differs significantly.</p> <p>Case presentation</p> <p>We present a case of epithelioid hemangioma of the penis in a 50-year-old Caucasian man. We also review the literature to evaluate the incidence of benign vascular anomalies of the penis and their management.</p> <p>Conclusions</p> <p>Epithelioid hemangioma of the penis should be considered in the differential diagnosis of patients presenting with painful penile lumps. A thorough histological and immunohistochemical examination is required to make the diagnosis. Optimal management is complete local excision and periodic physical examination for local recurrence.</p

    Predictive Model for Human-Unmanned Vehicle Systems

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    Advances in automation are making it possible for a single operator to control multiple unmanned vehicles. However, the complex nature of these teams presents a difficult and exciting challenge for designers of human–unmanned vehicle systems. To build such systems effectively, models must be developed that describe the behavior of the human–unmanned vehicle team and that predict how alterations in team composition and system design will affect the system’s overall performance. In this paper, we present a method for modeling human–unmanned vehicle systems consisting of a single operator and multiple independent unmanned vehicles. Via a case study, we demonstrate that the resulting models provide an accurate description of observed human-unmanned vehicle systems. Additionally, we demonstrate that the models can be used to predict how changes in the human-unmanned vehicle interface and the unmanned vehicles’ autonomy alter the system’s performance.Lincoln Laborator

    Competition-based model of pheromone component ratio detection in the moth

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    For some moth species, especially those closely interrelated and sympatric, recognizing a specific pheromone component concentration ratio is essential for males to successfully locate conspecific females. We propose and determine the properties of a minimalist competition-based feed-forward neuronal model capable of detecting a certain ratio of pheromone components independently of overall concentration. This model represents an elementary recognition unit for the ratio of binary mixtures which we propose is entirely contained in the macroglomerular complex (MGC) of the male moth. A set of such units, along with projection neurons (PNs), can provide the input to higher brain centres. We found that (1) accuracy is mainly achieved by maintaining a certain ratio of connection strengths between olfactory receptor neurons (ORN) and local neurons (LN), much less by properties of the interconnections between the competing LNs proper. An exception to this rule is that it is beneficial if connections between generalist LNs (i.e. excited by either pheromone component) and specialist LNs (i.e. excited by one component only) have the same strength as the reciprocal specialist to generalist connections. (2) successful ratio recognition is achieved using latency-to-first-spike in the LN populations which, in contrast to expectations with a population rate code, leads to a broadening of responses for higher overall concentrations consistent with experimental observations. (3) when longer durations of the competition between LNs were observed it did not lead to higher recognition accuracy

    Plasma Magnetohydrodynamics and Energy Conversion

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    Contains research objectives and reports on four research projects.U.S. Air Force (Aeronautical Systems Division) under Contract AF33(616)-7624 with the Aeronautical Accessories Laboratory, Wright-Patterson Air Force Base, OhioNational Science Foundation under Grant G-24073National Institutes of Health (Grant HTS-5550
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