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Thomas Jacqueline - One of the best experts on this subject based on the ideXlab platform.

  • Systems Analysis of Community Noise Impacts of Advanced Flight Procedures for Conventional and Hybrid Electric Aircraft
    2020
    Co-Authors: Thomas Jacqueline
    Abstract:

    Recent changes to aircraft approach and departure Procedures enabled by more precise navigation technologies have created noise concentration problems for communities beneath flight tracks. There may be opportunities to reduce community noise impacts under these concentrated flight tracks through advanced operational approach and departure Procedures and advanced aircraft technologies. A modeling method to assess their impacts must consider the contributions of aircraft engine and airframe noise sources as they vary with the position, thrust, velocity, and configuration of the aircraft during the flight Procedure. The objective is to develop an analysis method to design, model, and assess the community noise reduction possibilities of advanced operational flight Procedures performed by conventional aircraft and advanced Procedures enabled by future aircraft concepts. An integrated analysis framework is developed that combines flight dynamics and noise source models to determine the community noise impacts of aircraft performing advanced operational approach and departure Procedures. Aircraft noise due to the airframe and engine is modeled using an aircraft source noise module as each noise component varies throughout the flight Procedure and requires internal engine performance states, the flight profile, and aircraft geometry. An aircraft performance module is used to obtain engine internal performance states and aircraft flight performance given the aircraft technology level. A force- balance-kinematics flight profile generation module converts the flight Procedure Definition into altitude, position, velocity, configuration, and thrust profiles given flight performance on a segment-by-segment basis. The system generates single-event surface noise grids that are combined with population census data to estimate population noise exposure for a given aircraft technology level and Procedure. The framework was demonstrated for both advanced approach and departure Procedures and advanced aircraft technologies. The advanced Procedure concepts include modified speed and thrust departures as well as continuous descent, steep, and delayed deceleration approaches for conventional aircraft. The ability to model advanced aircraft technologies was demonstrated in the evaluation of using windmilling drag by hybrid electric aircraft on approach to allow the performance of steep and delayed deceleration approaches for noise reduction beyond the performance capability of standard gas-turbine aircraft

Thomas, Jacqueline(jacqueline Leah) - One of the best experts on this subject based on the ideXlab platform.

  • Systems analysis of community noise impacts of advanced flight Procedures for conventional and hybrid electric aircraft
    Massachusetts Institute of Technology, 2020
    Co-Authors: Thomas, Jacqueline(jacqueline Leah)
    Abstract:

    Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, May, 2020Cataloged from the official PDF of thesis.Includes bibliographical references (pages 213-223).Recent changes to aircraft approach and departure Procedures enabled by more precise navigation technologies have created noise concentration problems for communities beneath flight tracks. There may be opportunities to reduce community noise impacts under these concentrated flight tracks through advanced operational approach and departure Procedures and advanced aircraft technologies. A modeling method to assess their impacts must consider the contributions of aircraft engine and airframe noise sources as they vary with the position, thrust, velocity, and configuration of the aircraft during the flight Procedure. The objective is to develop an analysis method to design, model, and assess the community noise reduction possibilities of advanced operational flight Procedures performed by conventional aircraft and advanced Procedures enabled by future aircraft concepts.An integrated analysis framework is developed that combines flight dynamics and noise source models to determine the community noise impacts of aircraft performing advanced operational approach and departure Procedures. Aircraft noise due to the airframe and engine is modeled using an aircraft source noise module as each noise component varies throughout the flight Procedure and requires internal engine performance states, the flight profile, and aircraft geometry. An aircraft performance module is used to obtain engine internal performance states and aircraft flight performance given the aircraft technology level. A force-balance-kinematics flight profile generation module converts the flight Procedure Definition into altitude, position, velocity, configuration, and thrust profiles given flight performance on a segment-by-segment basis.The system generates single-event surface noise grids that are combined with population census data to estimate population noise exposure for a given aircraft technology level and Procedure. The framework was demonstrated for both advanced approach and departure Procedures and advanced aircraft technologies. The advanced Procedure concepts include modified speed and thrust departures as well as continuous descent, steep, and delayed deceleration approaches for conventional aircraft. The ability to model advanced aircraft technologies was demonstrated in the evaluation of using windmilling drag by hybrid electric aircraft on approach to allow the performance of steep and delayed deceleration approaches for noise reduction beyond the performance capability of standard gas-turbine aircraft.by Jacqueline Thomas.Ph. D.Ph.D. Massachusetts Institute of Technology, Department of Aeronautics and Astronautic

Suzuki Shungo - One of the best experts on this subject based on the ideXlab platform.

  • The multidimensionality of second language oral fluency:The interface between cognitive, utterance, and perceived fluency
    Lancaster University, 2021
    Co-Authors: Suzuki Shungo
    Abstract:

    In the context of the learning, teaching, and assessment of second language (L2) speaking skills, L2 fluency has been regarded as one of the important constructs. However, L2 fluency research has witnessed a long debate over the Definition and measurements of L2 oral fluency; scholars have interchangeably used the term, “fluency”, with different connotations, such as speakers’ ability, speech features, and listeners’ perception. In order to distinguish different conceptualizations of fluency, Segalowitz (2010) proposed three subconstructs of fluency: utterance fluency (i.e., observable temporal features of speech), cognitive fluency (i.e., speaker’s ability to manipulate L2 knowledge efficiently), and perceived fluency (i.e., listener’s subjective judgements of fluency). However, it is still unclear how these three subconstructs of L2 fluency are interrelated with each other. The overarching goal of the thesis is to examine the construct of L2 oral fluency, particularly focusing on the interrelationship between cognitive, utterance, and perceived fluency. To this end, this thesis consists of four separate studies. Study 1 took a meta-analytic approach to synthesizing previous findings on the relationship between perceived and utterance fluency. Study 2 compared utterance fluency performance across speaking tasks which were designed to differ in the quality of speech processing demands, operationalized by task design features (i.e., task effects). Study 3 examined the contribution of cognitive fluency to utterance fluency, taking a structural equation modelling (SEM) approach. The study also analysed the stability of the factor structure of utterance fluency (Tavakoli & Skehan, 2005)—speed, breakdown, and repair fluency—and cognitive fluency across speaking tasks. Finally, Study 4 investigated the extent to which L2 utterance fluency can be predicted from L1 utterance fluency with regard to the moderator effects of L2 proficiency on the L1-L2 utterance fluency link. Study 1 collected 263 effect sizes from 22 studies reporting the correlation coefficients between listener-based judgements of fluency and objective measures of temporal features (N = 335–746). Among the pooled utterance fluency measures, Study 1 selected the common measures from four different categories: speed (articulation rate), breakdown (silent pause frequency, silent pause duration), repair (disfluency rate), and composite fluency (mean length of run, speech rate). Methodological moderator variables were selected with respect to the major phases of research into the utterance-perceived fluency link: Speech stimulus preparation (e.g., task type, target L2), Rater background (e.g., L1 vs. L2 listeners), Perceived fluency rating Procedure (Definition of fluency, the number of point scales), and Utterance fluency measure calculation (length of pauses, manual vs. automated annotation). Studies 2–4 were conducted using the same dataset which included a set of cognitive and utterance fluency measures from Japanese-speaking learners of English (N = 128). Using a range of psycholinguistic tests, cognitive fluency was assessed in terms of linguistic resources and processing speed at different linguistic levels: vocabulary (vocabulary size, lexical retrieval speed), grammar (sentence construction speed and accuracy, grammaticality judgement speed and accuracy), and pronunciation (articulatory speed). In order to measure utterance fluency, speech data were elicited via four speaking tasks which differed in the quality of speech processing demands: argumentative task, picture narrative task, and text retelling tasks with/without read-aloud assistance. The speech data were analysed in terms of three subconstructs of utterance fluency (speed, breakdown, and repair fluency). The participants’ L1 fluency was also assessed, using another L1 argumentative speech task. Their proficiency scores were operationalized as two factor scores of cognitive fluency (linguistic resources and processing speed) in Study 3. Study 1 demonstrated that perceived fluency was strongly associated with speed and pause frequency (r = |.59–.62|), moderately with pause duration (r = |.46|), and weakly with repair fluency (r = |.20|), while composite measures showed the strongest effect sizes (r = |.72–.76|). A series of moderator analyses also revealed that the utterance-perceived fluency link may be influenced by methodological variables particularly related to speech stimulus preparation (target L2, task type, length of stimuli) and perceived fluency rating Procedure (the Definition of fluency presented to raters). Study 2 compared utterance fluency across four speaking tasks, using Generalized Linear Mixed-effect modelling (GLMM) with the tasks as a categorical fixed-effects predictor. The results showed that conceptualizing demands (content generation) increased the frequency of filled pauses, while the demands on formulation (activation of linguistic and phonological representations) had an impact on articulation rate, mid-clause pause ratio, and mid-clause pause duration. In Study 3, prior to an SEM analysis, a set of confirmatory factor analyses (CFA) demonstrated that utterance fluency has a three-factor structure (speed, breakdown, and repair fluency) and that cognitive fluency has a two-factor structure (linguistic resource and processing speed). An SEM analysis, based on these factor structures of cognitive and utterance fluency, showed that speed fluency was primarily associated with processing speed, while both linguistic resource and processing speed equally contributed to breakdown fluency. Repair fluency was significantly linked to linguistic resource, only when the content of speech was predefined (picture narrative and text summary tasks). Meanwhile, repair fluency was found to be independent of processing speed in all the speaking tasks. Study 4 examined the L1-L2 utterance fluency link using a set of GLMMs. The results suggested that all the L2 utterance fluency measures were predicted from their L1 counterparts. In addition, significant moderator effects of L2 proficiency on the L1-L2 fluency link were found only in speed fluency measures. The L1-L2 fluency link was weakened as a function of L2 linguistic resource but was strengthened as a function of L2 processing speed. The results of Study 1–4 confirmed that the relative importance of three subdimensions of utterance fluency—speed, breakdown, and repair fluency—can vary, depending on the perspective of assessment (perceived vs. cognitive fluency). These findings provide several practical implications for language assessment, such as the development of assessment tools and guidance for examiner training, as well as for L2 fluency learning and teaching

Tarantino M. - One of the best experts on this subject based on the ideXlab platform.

  • NACIE-UP: an heavy liquid metal loop for mixed convection experiments with instrumented pin bundle
    2013
    Co-Authors: Martelli D., Forgione N., Di Piazza, Agostini P., Tarantino M., Gaggini P., Polazzi G.
    Abstract:

    Since the Lead-cooled Fast Reactor (LFR) has been conceptualized in the frame of GEN IV International Forum (GIF), ENEA is strongly involved on the HLM technology development. Currently ENEA has implemented large competencies and capabilities in the field of HLM thermal-hydraulic, coolant technology, material for high temperature applications, corrosion and material protection, heat transfer and removal, component development and testing, remote maintenance, Procedure Definition and coolant handling. In this frame, the NACIE-UP loop has been designed to perform mixed convection experiment with LBE. A 19-pin wire-spaced Fuel Pin bundle Simulator (FPS) is installed to measure clad temperature and heat transfer coefficients in different conditions in the different ranks of sub-channels of the MYRRHA bundle. NACIE-UP is a rectangular 2.5″-pipe loop where a difference in height H~5 m exists between the heat source (FPS) and the heat sink (Heat Exchanger, HX). This difference in height provides the pressure head Dp~rgβDT×H for the natural circulation of the Heavy Liquid Metal in the loop. A gas-lift system provides a void fraction in the riser promoting an enhanced circulation in the loop. Most of the pressure losses are located in the FPS, and the maximum mass flow rate is around 2 kg/s in natural circulation and 7 kg/s in gas-enhanced circulation. A 7 tube/shell-and-tube Heat Exchanger couples the primary LBE loop with the secondary side with water in pressure at 16 bar. The tube-in-tube technology with LBE tube side, water shell side, steel powder in the gap, and two section for low and high power, is adopted for HX. In the primary side, two prototypical Induction Flow Meters (IFM) are installed, one in the natural circulation range and another one in the enhanced circulation range. Bubble tubes with flowing Ar are adopted to measure pressure losses in the different branches of the loop. Several thermocouples monitor the loop in different points. An ancillary gas system ensures the cover gas and provides flow rate for the gas-lift system. The paper reports the description of the experiment, the proposed test matrix and description the technological solution adopted for the NACIE-UP implementation

  • Thermal-Hydraulic Assessment of HLM-Cooled Pin Bundle in Circe Pool Facility
    2013
    Co-Authors: Martelli D., Forgione N., Di Piazza, Agostini P., Gaggini P., Tarantino M.
    Abstract:

    Since the Lead-cooled Fast Reactor (LFR) has been conceptualized in the frame of GEN IV International Forum (GIF), ENEA is strongly involved on the HLM technology development. Currently ENEA has implemented large competencies and capabilities in the field of HLM thermal-hydraulic, coolant technology, material for high temperature applications, corrosion and material protection, heat transfer and removal, component development and testing, remote maintenance, Procedure Definition and coolant handling. In this frame the CIRCE pool facility has been refurbished to host a suitable test section able to thermal-hydraulically simulate the primary system of a HLM cooled pool reactor. In particular a fuel pin bundle simulator (FPS) has been installed in the CIRCE pool. It has been conceived with a thermal power of about 1 MW and a linear power up to 25 kW/m, relevant values for a LMFR. It consist of 37 fuel pins (electrically simulated) placed on a hexagonal lattice. The LBE, heated by the FPS, flows up through the riser, reaching the Heat Exchanger (HX) inlet though a gas separator placed in the tank upper zone. The primary fluid circulation occurs employing a gas lift system which injects Argon from a nozzle connected to the riser entrance, enhancing the LBE flow. The heat exchanger represents the heat sink of the system and it is designed to have a thermal duty of about 800 kW; it consists of 91 double-wall bayonet tubes (with helium gap) fed by low pressure boiling water. Finally the decay heat removal system (DHR), designed to remove 40 kW and uncoupled from the main flow path. It consists of a bayonet element in which the air is injected from the top, flows downward through the inner tube and then flows upward through the annular region, where heat is removed from primary LBE side. The bayonet element is placed into a suitable shell thermally insulated from the external pool. LBE enters into the shell from the top and flows downwards in a counter flow heat exchanger configuration. The experimental campaign was designed to study the PLOHS+LOF accident, with decay heat removed by the DHR-system. This paper reports the experimental data as well as a preliminary analysis and discussion of the results, focusing on the most relevant tests of the campaign, namely Test IV Temperatures along the three sections of the FPS were reported and the Nusselt number in the FPS sub-channels was investigated. Moreover, the void fraction in the riser was computed and the riser inlet and outlet average temperatures were discussed. Concerning the HX, temperature measurements in the sub-channels were presented, as well as temperatures at the inlet and outlet sections. For the DHR-system, temperatures at the entrance and exit section were analyzed both for the primary lead bismuth eutectic (LBE) circuit and for the secondary air side, estimating the thermal power removed by DHR under the formulated accidental scenario. Finally system codes thermal hydraulics analyses performed adopting the RELAP5/Mod3.3 are presented. A comparison with the data obtained from preliminary experimental tests is presented

John Paul - One of the best experts on this subject based on the ideXlab platform.

  • automated software testing introduction management and performance
    1999
    Co-Authors: Elfriede Dustin, Jeff Rashka, John Paul
    Abstract:

    Preface. I. WHAT IS AUTOMATED TESTING? 1. The Birth and Evolution of Automated Testing. Automated Testing. Background on Software Testing. The Automated Test Life-Cycle Methodology (ATLM). Decision to Automate Test. Test Tool Acquisition. Automated Testing Introduction Phase. Test Planning, Design, and Development. Execution and Management of Tests. Test Program Review and Assessment. ATLM's Role in the Software Testing Universe. ATLM Relationship to System Development Life Cycle. Test Maturity Model (TMM)-Augmented by Automated SoftwareTesting Maturity. Test Automation Development. Test Effort. Software Testing Careers. 2. Decision to Automate Test. Overcoming False Expectations for Automated Testing. Automatic Test Plan Generation. Test Tool Fits All. Immediate Test Effort Reduction. Immediate Schedule Reduction. Tool Ease of Use. Universal Application of Test Automation. One Hundred Percent Test Coverage. Benefits of Automated Testing. Production of a Reliable System. Improvement of the Quality of the Test Effort. Reduction of Test Effort and Minimization of Schedule. Acquiring Management Support. Test Tool Proposal. 3. Automated Test Tool Selection and Evaluation. Organization's Systems Engineering Environment. Third-Party Input from Management, Staff, and Customers andUsers. Tool Criteria Reflecting the Systems Engineering Environment. Level of Software Quality. Help Desk Problem Reports. Budget Constraints. Types of Tests. Long-Term Investment Considerations. Test Tool Process. Avoiding Shortcuts. Tools That Support the Testing Life Cycle. Business Analysis Phase Tools. Requirements Definition Phase Tools. Tools for the Analysis and Design Phase. Programming Phase Tools. Metrics Tools. Other Testing Life-Cycle Support Tools. Testing Phase Tools. Test Tool Research. Improvement Opportunities. Evaluation Domain Definition. Hands-On Tool Evaluation. Evaluation Report. License Agreement. II. INTRODUCTION OF AUTOMATED TESTING TO A PROJECT. 4. Automated Testing Introduction Process. Test Process Analysis. Process Review. Goals and Objectives of Testing. Case Study: Test Objectives and Strategies. Test Strategies. Test Tool Consideration. Review of Project-Specific System Requirements. Application-Under-Test Overview. Review of Project Schedule. Test Tool Compatibility Check. Demonstration of the Tool to the Project Team. Test Tool Support Profile. Review of Training Requirements 5. Test Team Management. Organizational Structure of a Test Team. Stovepipe Test Team. Centralized Test Team. IV&V Test Team. Systems Methodology and Test Team. Test Team Summary. Test Program Tasks. Test Effort Sizing. Test Team Sizing Methods: An Overview. Development Ratio Method. Percentage Method. Test Procedure Method. Task Planning Method. Test Effort Sizing Factors. Test Engineer Recruiting. Test Engineer Qualities. Test Team Composition. Job Requisition. Recruiting Activities. Locating Test Engineers. Test Engineer Interviews. Distinguishing the Best Candidate. Roles and Responsibilities. III. TEST PLANNING AND PREPARATION. 6. Test Planning: Smart Application of Testing. Test Planning Activities. Test Program Scope. System Description. Critical/High-Risk Functions. Test Goals, Objectives, and Strategies. Test Tools. Test Program Parameters. Verification Methods. Test Requirements Definition. Test Requirements Management. Requirements Management Tools. Assessing the Test Requirements Risk. Prioritization of Tests. Requirements Traceability Matrix. Test Program Events, Activities, and Documentation. Events. Activities. Documentation. The Test Environment. Test Environment Preparations. Test Environment Integration and Setup. The Test Plan. Test Completion/Acceptance Criteria. Sample Test Plan. 7. Test Analysis and Design. Test Requirements Analysis. Development-Level Test Analysis (Structural Approach). System-Level Test Analysis (Behavioral Approach). Test Program Design. Test Program Design Models. White-Box Techniques (Development-Level Tests). Black-Box Techniques (System-Level Tests). Test Design Documentation. Test Procedure Design. Test Procedure Definition. Automated Versus Manual Test Analysis. Automated Test Design Standards. Case Study: Naming Conventions. Manual Test Design Guidelines. Detailed Test Design. Test Data Requirements. 8. Test Development. Test Development Architecture. Technical Environment. Environment Readiness Checks. Automation Reuse Analysis. Test Procedure Development/Execution Schedule. Modularity-Relationship Analysis. Explanation of the Sample Modularity- Relationship Matrix. Calibration of the Test Tool. Compatibility Work-Around Solutions. Case Study: Incompatibility Work-Around Solution. Manual Execution of Test Procedures. Test Procedure Inspections-Peer Reviews. Test Procedure Configuration Management. Test Development Guidelines. Design-to-Development Transiftion. Reusable Test Procedures. Case Study: Navigation Using Tabs or Mouse Clicks. Case Study: Testing Bitmaps Using a Capture/Playback Tool. Maintainable Test Procedures. Case Study: Automating Documentation. Case Study: Automated Random Testing. Other Guidelines. Automation Infrastructure. Table-Driven Test Automation. PC Environment Automated Setup Script. Automated Recording Options. Login Function. Exit Function. Navigation. Verifying GUI Standards. Smoke Test. Case Study: Smoke Test Application. Error-Logging Routine. Help Function Verification Script. Timed Message Boxes Function. Advanced Math Functions. IV. TEST EXECUTION AND REVIEW. 9. Test Execution. Executing/Evaluating Test Phases. Unit Test Execution and Evaluation. Integration Test Execution and Evaluation. System Test Execution and Evaluation. Test Results Analysis of Regression Tests. User Acceptance Test Execution and Evaluation. Defect Tracking and New Build Process. Defect Life-Cycle Model. Test Program Status Tracking. Earned Value Management System. Case Study: System Test Status Tracking. Test Metrics Collection and Analysis. 10. Test Program Review and Assessment. Test Program Lessons Learned-Corrective Actions andImprovement Activity. Test Program Return on Investment. Case Study: TestProgram Return on Investment. Case Study: Quantify Tool Return on Investment. V. APPENDIXES. A. How to Test Requirements. Requirements Testing Approach. Abstract. The Quality Gateway. Make the Requirement Measurable. Quantifiable Requirements. Nonquantifiable Requirements. Keeping Track. Coherency and Consistency. Completeness. Relevance. Requirement or Solution? Stakeholder Value. Traceability. Order in a Disorderly World. Conclusions. References. B. Tools That Support the Automated Testing Life Cycle. Introduction. Business Analysis Phase. Business Modeling Tools. Configuration Management Tools. Defect Tracking Tools. Technical Review Management. Documentation Generators. Requirements Definition Phase. Requirements Management Tools. Requirements Verifiers. Use Case Generators. Analysis and Design Phase. Visual Modeling Tools. Structure Charts, Flowcharts, and Sequence Diagrams. Test Procedure Generators. Programming Phase. Syntax Checkers/Debuggers. Memory Leak and Runtime Error Detection Tools. Code Checkers. Static and Dynamic Analyzers. Unit Testing Tools. Metrics Tools. Code (Test) Coverage Analyzers and Code Instrumentors. Usability Measurement Tools. Testing Support Tools. Test Data Generators. File Comparison Tools. Simulation Tools. Testing Phase. Test Management Tools. Network Testing Tools. GUI Application Testing Tools. Load/Performance Testing Tools. Web Testing Tools. Year 24710 Testing Tools. Other Test Tool Vendors. C. Test Engineer Development. Technical Skills Stage. Test Process Stage. Team Effort Stage. Technical Stewardship Stage. Test/Project Management Stage. Business/Product Management Stage. D. Sample Test Plan. Introduction. Purpose. Background. System Overview. Applicable Documents. Master Schedule. Roles and Responsibilities. Project Organization. Project Roles and Responsibilities. Test Task Structure. Test Team Resources. Test Program. Scope. Test Approach. Test Strategies. Automated Tools. Qualification Methods. Test Requirements. Test Design. Test Development. Test Environment. Test Environment Configuration. Test Data. Test Execution. Test Program Reporting. Test Program Metrics. Defect Tracking. Configuration Management. Detailed Test Schedule. Appendixes. D.A Test Procedure Development Guidelines. D.B Test Verification Summary and Matrix. D.C Test Procedures and Test Scripts E. Best Practices. Documented Process. Managing Expectations. Pilot Project. Test Tool Compatibility Checks. Test Tool Upgrades. Baselined System Setup and Configuration. Software Installations in the Test Environment Baseline. Overall Test Program Objectives. Keep Automation Simple. Test Procedure Design and Development Standards. Automated Versus Manual Test Analysis. Reuse Analysis. Test Team Communication with Other Teams. Schedule Compatibility. Customer Involvement. Defect Documentation and Reporting. Automated Test Advocates and Experts. Test Team Assignments. User Group Participation. Test Tool Improvement Suggestions. Become a Beta Testing Site. Specialty Topic Experts. 0201432870T04062001