1,341 research outputs found

    A Data Filter for Identifying Steady-State Operating Points in Engine Flight Data for Condition Monitoring Applications

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    This paper presents an algorithm that automatically identifies and extracts steady-state engine operating points from engine flight data. It calculates the mean and standard deviation of select parameters contained in the incoming flight data stream. If the standard deviation of the data falls below defined constraints, the engine is assumed to be at a steady-state operating point, and the mean measurement data at that point are archived for subsequent condition monitoring purposes. The fundamental design of the steady-state data filter is completely generic and applicable for any dynamic system. Additional domain-specific logic constraints are applied to reduce data outliers and variance within the collected steady-state data. The filter is designed for on-line real-time processing of streaming data as opposed to post-processing of the data in batch mode. Results of applying the steady-state data filter to recorded helicopter engine flight data are shown, demonstrating its utility for engine condition monitoring applications

    Automated Power Assessment for Helicopter Turboshaft Engines

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    An accurate indication of available power is required for helicopter mission planning purposes. Available power is currently estimated on U.S. Army Blackhawk helicopters by performing a Maximum Power Check (MPC), a manual procedure performed by maintenance pilots on a periodic basis. The MPC establishes Engine Torque Factor (ETF), an indication of available power. It is desirable to replace the current manual MPC procedure with an automated approach that will enable continuous real-time assessment of available power utilizing normal mission data. This report presents an automated power assessment approach which processes data currently collected within helicopter Health and Usage Monitoring System (HUMS) units. The overall approach consists of: 1) a steady-state data filter which identifies and extracts steady-state operating points within HUMS data sets; 2) engine performance curve trend monitoring and updating; and 3) automated ETF calculation. The algorithm is coded in MATLAB (The MathWorks, Inc.) and currently runs on a PC. Results from the application of this technique to HUMS mission data collected from UH-60L aircraft equipped with T700-GE-701C engines are presented and compared to manually calculated ETF values. Potential future enhancements are discussed

    A Prototype Lisp-Based Soft Real-Time Object-Oriented Graphical User Interface for Control System Development

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    A prototype Lisp-based soft real-time object-oriented Graphical User Interface for control system development is presented. The Graphical User Interface executes alongside a test system in laboratory conditions to permit observation of the closed loop operation through animation, graphics, and text. Since it must perform interactive graphics while updating the screen in real time, techniques are discussed which allow quick, efficient data processing and animation. Examples from an implementation are included to demonstrate some typical functionalities which allow the user to follow the control system's operation

    Politics, Bureaucracies, and Financial Markets: Bank Entry into Commercial Paper Underwriting in the United States and Japan

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    Americans writing about Japan seem to fall into two camps: those who think the Japanese act according to very different rules than Americans, so that the apparent similarities between the two peoples actually mask deep cultural differences; and those who think that the Japanese and the Americans are really rather similar, so that the obvious cultural differences cover more deep-rooted continuities

    Disentangling Associations Between Frequency of Specific Social Networking Site Platform Use, Normative Discrepancies, and Alcohol Use Among Adolescents and Underage Young Adults

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    Although there is a robust literature examining normative discrepancies for drinking, less is known related to normative discrepancies related to alcohol-posting behavior on social networking sites (SNS). Given that SNS are posited to be an important risk factor for adolescent and young adult alcohol use, the aims of the present study were to: (1) document descriptive and injunctive normative discrepancies for number of alcohol-related posts on SNS, (2) examine associations between frequency of using SNS platforms (Facebook, Instagram, Snapchat) and descriptive and injunctive normative discrepancies, and (3) to examine whether descriptive and injunctive normative discrepancies are associated with willingness to use alcohol and drinking among adolescents and young adults. Data were drawn from the baseline assessment of a larger longitudinal experimental study (N= 306, age 15-20). Overall, participants perceived that their peers are more approving of and post about alcohol use more often than they do themselves, thus indicating significant descriptive and injunctive normative discrepancies. More frequent use of Facebook was associated with having greater descriptive normative discrepancies, whereas frequency of both Facebook and Instagram use were associated with greater injunctive normative discrepancies. Results further indicated that controlling for frequency of SNS use, descriptive normative discrepancies, but not injunctive, were associated with greater willingness to drink and drinks per week. Results provide evidence that in particular, descriptive normative discrepancies for SNS use may be important to target when planning intervention programs to reduce the impact of SNS use on adolescent and young adult alcohol use

    Cloning and sequencing of the depolymerase-like gene from Bacteriophage J25

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    Bacteriophage are viruses that infect, replicate and kill bacteria. Salmonella and EHEC food poisoning are caused by Salmonella and E. coli bacteria. Bacteriophage can be used to prevent food poisoning by application to food products or processing machinery. Bacteriophage J25 specifically infects Salmonella and E. coli bacteria. We cloned fragments of the J25 genome, sequence the DNA and used bioinformatics to identify J25. We used genome data from similar bacteriophage in Genbank to design primers to amplify the depolymerase-like gene. We amplified and cloned this gene. When expressed, the gene product will be test with bacteriophage food treatment where it should augment bacteriophage killing
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