The Experts below are selected from a list of 24 Experts worldwide ranked by ideXlab platform
Ambar Ghosal - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the Majorana phases of a general Majorana neutrino mass matrix: Testability of hierarchical flavour models
Nuclear Physics, 2016Co-Authors: Rome Samanta, Mainak Chakraborty, Ambar GhosalAbstract:Abstract We evaluate the Majorana phases for a general 3 × 3 complex symmetric neutrino mass matrix on the basis of Mohapatra–Rodejohann's phase convention using the three rephasing invariant quantities I 12 , I 13 and I 23 proposed by Sarkar and Singh. We find them interesting as they allow us to evaluate each Majorana phase in a model independent way even if one eigenvalue is zero. Utilizing the solution of a general complex symmetric mass matrix for eigenvalues and mixing angles we determine the Majorana phases for both the hierarchies, normal and inverted, taking into account the constraints from neutrino oscillation global fit data as well as bound on the sum of the three light neutrino masses ( Σ i m i ) and the neutrinoless double beta decay ( β β 0 ν ) parameter | m 11 | . This methodology of finding the Majorana phases is applied thereafter in some predictive models for both the hierarchical cases (normal and inverted) to evaluate the corresponding Majorana phases and it is shown that all the sub cases presented in inverted Hierarchy Section can be realized in a model with texture zeros and scaling ansatz within the framework of inverse seesaw although one of the sub cases following the normal Hierarchy is yet to be established. Except the case of quasi degenerate neutrinos, the methodology obtained in this work is able to evaluate the corresponding Majorana phases, given any model of neutrino masses.
Jane T. Malin - One of the best experts on this subject based on the ideXlab platform.
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Models Extracted from Text for System-Software Safety Analyses
2013Co-Authors: Jane T. MalinAbstract:This presentation describes extraction and integration of requirements information and safety information in visualizations to support early review of completeness, correctness, and consistency of lengthy and diverse system safety analyses. Software tools have been developed and extended to perform the following tasks: 1) extract model parts and safety information from text in interface requirements documents, failure modes and effects analyses and hazard reports; 2) map and integrate the information to develop system architecture models and visualizations for safety analysts; and 3) provide model output to support virtual system integration testing. This presentation illustrates the methods and products with a rocket motor initiation case. Models Extracted from Text for System-Software Safety Analyses Project: Automated Tool and Method for System Safety Analysis Jane T. Malin, Principal Investigator NASA JSC Team: Land Fleming, Carroll Thronesbery, David Throop Triakis Team: Ted Bennett and Paul Wennberg Software Assurance Symposium August 2010 Essential Early Safety Reviews • Requirements and design problems are the source of most operational software defects – System integration, interfaces, failures and hazard causes • Analysis of information for Preliminary Design Review (PDR) is needed SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 2 SYSTEM and Environment SOFTWARE ‘Activate’ Faults and Influence Failures ‘Activate’ Faults and Influence Failures System Integration Operations and Stresses FAULTS/Reliability FAULTS/Reliability Integrated Review of Scattered Information • Need: Efficient system safety reviews of large sets of contractor documents – Make short-fuse reviews of requirements, safety analyses and plans manageable – Integrate key information from diverse uncoordinated and evolving documents • Interface Requirements Documents (IRD) • Failure Modes and Effects Analysis (FMEA) • Hazard Reports (HR) • Fault Detection, Isolation and Response (FDIR) SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 3 Automated Modeling Solution • Models constructed from information extracted from text documents • Visualizations for integrated insight into information scattered in large documents • Output files and reports for model reuse in virtual testing and analysis for FDIR design SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 4 Model Graph Connection Description Pop up from Arrow NASA Application Cases • Constellation Program (CxP) CEV cases – Launch Abort System (LAS) with focus on Ordnance – Crew Module (CM) – Service Model (SM) Propulsion • Useful in other aerospace projects where safety engineers perform early reviews of contractor products – FMEAs, Hazard Reports, safety requirements SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 5 NASA Automated Modeling Tools • Semantic Text Analysis Tool (STAT) – Parsing and information extraction from text to XML – Multiple information types and document types • Hazard Identification Tool (HIT) – Model construction and visualization – Component-connection models and visualizations – Analyses of redundancy, dependencies, linkages • Output for further modeling and analysis – Information from FMEAs and Hazard Reports for FDIR – Virtual System Integration Lab (VSIL) simulator SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 6 STAT Linguistic Text Extraction • Powerful linguistic tagger and extractor – Advanced natural language processing – Extensive aerospace nomenclature • Extractions for models SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 7 Document Section Model Information FMEA Front matter Section System Hierarchy Worksheet Hierarchy Section System Hierarchy Worksheet: Item Function Components, connections Worksheet: Failure modes and Causes Failure mode descriptions Cause descriptions Hazard Report Cause Descriptions, Cause Control Descriptions Component types Controls IRD Interface requirements Components, connections All Documents Acronym Section Acronyms Titles, identifiers Traceability Information HIT Automated Model Construction Text extractions → Models → Visualizations → Analysis SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 8 Graph Display: Redundant Components and Paths Tree Display: Orion and Subsystems in Model HIT Models for Review and Reuse • Integrated review of multiple FMEAs – Completeness, duplication, consistency and redundant components and paths – Compare versions and re-analyze – Upstream and downstream dependency paths • Review of FMEAs and Hazard Reports that are related to the same components • Reuse of model information – Models and failure modes for simulation tests – Output information for fault analysis and FDIR design SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 9 Source Information Pop ups 10 SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis • Click on components and connections to pop up FMEA and Hazard Report Information Highlighting shows components with Hazard Report references Initiator – Igniter Connection Initiators FMEA Initiators – Hazard Report Model Reuse for Design and Test • Automated generation of fault analysis spreadsheets with HIT model information (from FMEAs and HRs) – Progress in extending CxP functional fault analysis (FFA) spreadsheets with Hazard Report information • Triakis Virtual System Integration Lab simulator uses HIT FMEA Output to test flight software – Automatic translation of HIT FMEA output into failure mode test framework files – Failure mode tests verify integrated system and software • Manifest component failures and record software response • Monitor the state of any simulated part or signals between parts – HIT displays link back to VSIL test results and methods, for analysis and review SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 11 Links to Test Plans and Results • Clicking on components brings up test plans and results. SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 12 Evaluations by Safety Engineers • CEV avionics/software safety engineers – basis for a great leap in productivity of reviews – One-stop rapid integrated review • Thousands of documents for review were beyond human capabilities • Linking to specific information in the source documents makes the information easily accessible – Graph display makes key information stand out • Highlights missing or inconsistent information or terminology • Easy to see architecture and components that have no outputs or insufficient inputs, indicating omissions in design or documentation • Helps engineers check redundancy and review potential hazard paths – Engineers can trace from HRs to linked FMEAs, to find more detailed FMEA information for the HR • Essential but not possible before 13 SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis Software Technology Maturity • Technology Readiness Level 7: Prototypes that fully demonstrate operational and engineering feasibility – Prototype software with all key functionality should be available for demo and test • Distribution image and CEV models delivered to SMA on notebook computer – Prototype code should be relatively clean – ‘tis – Limited documentation should be available • User documentation and the Concept of Operations SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 14 NASA-owned Prototypes • FY10 milestone: Tools on installation CD – Triakis COTS VSIL LAS simulator (C++) and documentation will be delivered separately • STAT implemented in Perl and opensource LISP – Parsers: open-source Stanford and University of Central Florida – Aerospace nomenclature implemented in Protege ontology • HIT implemented in Allegro Common LISP SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 15 Recommended Next Steps • Another Aerospace Case – Safety engineers can use these tools to significantly increase productivity of reviews • Further evaluate feasibility of model reuse – Fault analysis and FDIR design spreadsheets – Virtual system integration testing for safety • Develop software tool products based on existing Concept of Operations and prototypes – Develop according to NPR 7150.2 • Extend to assist developers of FMEAs and Hazard Reports, with evaluation and guidance SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 16 Summary: Models Extracted from Text • Coordinated data and documents are desirable, but virtually impossible • Integrated information for efficient safety review requires text extraction – Important information stands out – Details are a click away • Information for follow-on design and test – Model for virtual safety testing – Information output for FDIR design SAS_10_Malin_Automated_Tool_for_System_Safety_Analysis 17
Rome Samanta - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the Majorana phases of a general Majorana neutrino mass matrix: Testability of hierarchical flavour models
Nuclear Physics, 2016Co-Authors: Rome Samanta, Mainak Chakraborty, Ambar GhosalAbstract:Abstract We evaluate the Majorana phases for a general 3 × 3 complex symmetric neutrino mass matrix on the basis of Mohapatra–Rodejohann's phase convention using the three rephasing invariant quantities I 12 , I 13 and I 23 proposed by Sarkar and Singh. We find them interesting as they allow us to evaluate each Majorana phase in a model independent way even if one eigenvalue is zero. Utilizing the solution of a general complex symmetric mass matrix for eigenvalues and mixing angles we determine the Majorana phases for both the hierarchies, normal and inverted, taking into account the constraints from neutrino oscillation global fit data as well as bound on the sum of the three light neutrino masses ( Σ i m i ) and the neutrinoless double beta decay ( β β 0 ν ) parameter | m 11 | . This methodology of finding the Majorana phases is applied thereafter in some predictive models for both the hierarchical cases (normal and inverted) to evaluate the corresponding Majorana phases and it is shown that all the sub cases presented in inverted Hierarchy Section can be realized in a model with texture zeros and scaling ansatz within the framework of inverse seesaw although one of the sub cases following the normal Hierarchy is yet to be established. Except the case of quasi degenerate neutrinos, the methodology obtained in this work is able to evaluate the corresponding Majorana phases, given any model of neutrino masses.
Mainak Chakraborty - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the Majorana phases of a general Majorana neutrino mass matrix: Testability of hierarchical flavour models
Nuclear Physics, 2016Co-Authors: Rome Samanta, Mainak Chakraborty, Ambar GhosalAbstract:Abstract We evaluate the Majorana phases for a general 3 × 3 complex symmetric neutrino mass matrix on the basis of Mohapatra–Rodejohann's phase convention using the three rephasing invariant quantities I 12 , I 13 and I 23 proposed by Sarkar and Singh. We find them interesting as they allow us to evaluate each Majorana phase in a model independent way even if one eigenvalue is zero. Utilizing the solution of a general complex symmetric mass matrix for eigenvalues and mixing angles we determine the Majorana phases for both the hierarchies, normal and inverted, taking into account the constraints from neutrino oscillation global fit data as well as bound on the sum of the three light neutrino masses ( Σ i m i ) and the neutrinoless double beta decay ( β β 0 ν ) parameter | m 11 | . This methodology of finding the Majorana phases is applied thereafter in some predictive models for both the hierarchical cases (normal and inverted) to evaluate the corresponding Majorana phases and it is shown that all the sub cases presented in inverted Hierarchy Section can be realized in a model with texture zeros and scaling ansatz within the framework of inverse seesaw although one of the sub cases following the normal Hierarchy is yet to be established. Except the case of quasi degenerate neutrinos, the methodology obtained in this work is able to evaluate the corresponding Majorana phases, given any model of neutrino masses.
Mohammed H.a. Tafti - One of the best experts on this subject based on the ideXlab platform.
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A Theoretical Explanation of the Evolving Role of Users in Shaping Corporate Information Systems
Journal of Organizational and End User Computing, 1992Co-Authors: Mohammed H.a. TaftiAbstract:Among important developments in the evolution of information technology is the changing role of users in shaping the corporate information systems (Nolan, 1979; King and Kraemer 1984; Tafti, 1990). Computer and IS literacy is significantly increasing, the gap between computer professionals and users is vanishing, and the users are demanding more control over the corporate information resources. IS users are the subject of a mounting literature from a number of viewpoints: user participation in IS development (Swanson, 1974; Lucas, 1981; Ives and Olson, 1984; Tafti, 1991), user satisfaction (Bailey and Pearson, 1983; Doll and Torkzadeh, 1988), and end-user computing (Rivard and Huff, 1988; Alavi, Nelson, and Weiss 1987; Huff, Munro, and Martin, 1988). For example, as a surrogate measure of IS success in securing user needs, user satisfaction is convincingly stressed in the literature. According to Cyert and March (1965), user satisfaction is reinforced by the success of a formal system in meeting the user’s need for information. Powers and Dickson (1973) found user satisfaction to be the most critical criterion in measuring the success or failure of computer systems. Therefore, the measurement of user satisfaction as a surrogate major of IS effectiveness in meeting user needs is emphasized (Lucas, 1981; Bailey and Pearson, 1983; Ives, Olson, and Baroudi, 1983; Doll and Torkzadeh, 1988). Why have the IS users become the center of attention by IS policy makers, practitioners, and researchers? How can the increasing influence of users on various ISrelated decisions be explained? Why are the users demanding a higher role in shaping the corporate IS strategy? To what extent are the users responsible for such recent IS practices as end-user computing and downsizing? The purpose of this paper is to present a framework that maps user satisfaction onto Maslow’s need Hierarchy in order to shed some light on these questions, and provide a base for further research in this area. The following Section provides an overview of Maslow’s need Hierarchy. Section III derives three dimensions of IS user satisfaction from review of satisfaction literature.