Supporting secure programming in web applications through interactive static analysis.
Zhu, Jun; Xie, Jing; Lipford, Heather Richter; Chu, Bill
2014-07-01
Many security incidents are caused by software developers' failure to adhere to secure programming practices. Static analysis tools have been used to detect software vulnerabilities. However, their wide usage by developers is limited by the special training required to write rules customized to application-specific logic. Our approach is interactive static analysis, to integrate static analysis into Integrated Development Environment (IDE) and provide in-situ secure programming support to help developers prevent vulnerabilities during code construction. No additional training is required nor are there any assumptions on ways programs are built. Our work is motivated in part by the observation that many vulnerabilities are introduced due to failure to practice secure programming by knowledgeable developers. We implemented a prototype interactive static analysis tool as a plug-in for Java in Eclipse. Our technical evaluation of our prototype detected multiple zero-day vulnerabilities in a large open source project. Our evaluations also suggest that false positives may be limited to a very small class of use cases.
Supporting secure programming in web applications through interactive static analysis
Zhu, Jun; Xie, Jing; Lipford, Heather Richter; Chu, Bill
2013-01-01
Many security incidents are caused by software developers’ failure to adhere to secure programming practices. Static analysis tools have been used to detect software vulnerabilities. However, their wide usage by developers is limited by the special training required to write rules customized to application-specific logic. Our approach is interactive static analysis, to integrate static analysis into Integrated Development Environment (IDE) and provide in-situ secure programming support to help developers prevent vulnerabilities during code construction. No additional training is required nor are there any assumptions on ways programs are built. Our work is motivated in part by the observation that many vulnerabilities are introduced due to failure to practice secure programming by knowledgeable developers. We implemented a prototype interactive static analysis tool as a plug-in for Java in Eclipse. Our technical evaluation of our prototype detected multiple zero-day vulnerabilities in a large open source project. Our evaluations also suggest that false positives may be limited to a very small class of use cases. PMID:25685513
Sawja: Static Analysis Workshop for Java
NASA Astrophysics Data System (ADS)
Hubert, Laurent; Barré, Nicolas; Besson, Frédéric; Demange, Delphine; Jensen, Thomas; Monfort, Vincent; Pichardie, David; Turpin, Tiphaine
Static analysis is a powerful technique for automatic verification of programs but raises major engineering challenges when developing a full-fledged analyzer for a realistic language such as Java. Efficiency and precision of such a tool rely partly on low level components which only depend on the syntactic structure of the language and therefore should not be redesigned for each implementation of a new static analysis. This paper describes the Sawja library: a static analysis workshop fully compliant with Java 6 which provides OCaml modules for efficiently manipulating Java bytecode programs. We present the main features of the library, including i) efficient functional data-structures for representing a program with implicit sharing and lazy parsing, ii) an intermediate stack-less representation, and iii) fast computation and manipulation of complete programs. We provide experimental evaluations of the different features with respect to time, memory and precision.
MSC products for the simulation of tire behavior
NASA Technical Reports Server (NTRS)
Muskivitch, John C.
1995-01-01
The modeling of tires and the simulation of tire behavior are complex problems. The MacNeal-Schwendler Corporation (MSC) has a number of finite element analysis products that can be used to address the complexities of tire modeling and simulation. While there are many similarities between the products, each product has a number of capabilities that uniquely enable it to be used for a specific aspect of tire behavior. This paper discusses the following programs: (1) MSC/NASTRAN - general purpose finite element program for linear and nonlinear static and dynamic analysis; (2) MSC/ADAQUS - nonlinear statics and dynamics finite element program; (3) MSC/PATRAN AFEA (Advanced Finite Element Analysis) - general purpose finite element program with a subset of linear and nonlinear static and dynamic analysis capabilities with an integrated version of MSC/PATRAN for pre- and post-processing; and (4) MSC/DYTRAN - nonlinear explicit transient dynamics finite element program.
Static Analysis of Programming Exercises: Fairness, Usefulness and a Method for Application
ERIC Educational Resources Information Center
Nutbrown, Stephen; Higgins, Colin
2016-01-01
This article explores the suitability of static analysis techniques based on the abstract syntax tree (AST) for the automated assessment of early/mid degree level programming. Focus is on fairness, timeliness and consistency of grades and feedback. Following investigation into manual marking practises, including a survey of markers, the assessment…
A Categorization of Dynamic Analyzers
NASA Technical Reports Server (NTRS)
Lujan, Michelle R.
1997-01-01
Program analysis techniques and tools are essential to the development process because of the support they provide in detecting errors and deficiencies at different phases of development. The types of information rendered through analysis includes the following: statistical measurements of code, type checks, dataflow analysis, consistency checks, test data,verification of code, and debugging information. Analyzers can be broken into two major categories: dynamic and static. Static analyzers examine programs with respect to syntax errors and structural properties., This includes gathering statistical information on program content, such as the number of lines of executable code, source lines. and cyclomatic complexity. In addition, static analyzers provide the ability to check for the consistency of programs with respect to variables. Dynamic analyzers in contrast are dependent on input and the execution of a program providing the ability to find errors that cannot be detected through the use of static analysis alone. Dynamic analysis provides information on the behavior of a program rather than on the syntax. Both types of analysis detect errors in a program, but dynamic analyzers accomplish this through run-time behavior. This paper focuses on the following broad classification of dynamic analyzers: 1) Metrics; 2) Models; and 3) Monitors. Metrics are those analyzers that provide measurement. The next category, models, captures those analyzers that present the state of the program to the user at specified points in time. The last category, monitors, checks specified code based on some criteria. The paper discusses each classification and the techniques that are included under them. In addition, the role of each technique in the software life cycle is discussed. Familiarization with the tools that measure, model and monitor programs provides a framework for understanding the program's dynamic behavior from different, perspectives through analysis of the input/output data.
Detection Of Malware Collusion With Static Dependence Analysis On Inter-App Communication
2016-12-08
DETECTION OF MALWARE COLLUSION WITH STATIC DEPENDENCE ANALYSIS ON INTER-APP COMMUNICATION VIRGINIA TECH DECEMBER 2016 FINAL TECHNICAL REPORT... DEPENDENCE ANALYSIS ON INTER-APP COMMUNICATION 5a. CONTRACT NUMBER FA8750-15-2-0076 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER 61101E 6. AUTHOR(S...exploited. 15. SUBJECT TERMS Malware Collusion; Inter-App Communication; Static Dependence Analysis 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF
Automatic Estimation of Verified Floating-Point Round-Off Errors via Static Analysis
NASA Technical Reports Server (NTRS)
Moscato, Mariano; Titolo, Laura; Dutle, Aaron; Munoz, Cesar A.
2017-01-01
This paper introduces a static analysis technique for computing formally verified round-off error bounds of floating-point functional expressions. The technique is based on a denotational semantics that computes a symbolic estimation of floating-point round-o errors along with a proof certificate that ensures its correctness. The symbolic estimation can be evaluated on concrete inputs using rigorous enclosure methods to produce formally verified numerical error bounds. The proposed technique is implemented in the prototype research tool PRECiSA (Program Round-o Error Certifier via Static Analysis) and used in the verification of floating-point programs of interest to NASA.
BEST3D user's manual: Boundary Element Solution Technology, 3-Dimensional Version 3.0
NASA Technical Reports Server (NTRS)
1991-01-01
The theoretical basis and programming strategy utilized in the construction of the computer program BEST3D (boundary element solution technology - three dimensional) and detailed input instructions are provided for the use of the program. An extensive set of test cases and sample problems is included in the manual and is also available for distribution with the program. The BEST3D program was developed under the 3-D Inelastic Analysis Methods for Hot Section Components contract (NAS3-23697). The overall objective of this program was the development of new computer programs allowing more accurate and efficient three-dimensional thermal and stress analysis of hot section components, i.e., combustor liners, turbine blades, and turbine vanes. The BEST3D program allows both linear and nonlinear analysis of static and quasi-static elastic problems and transient dynamic analysis for elastic problems. Calculation of elastic natural frequencies and mode shapes is also provided.
NASA Technical Reports Server (NTRS)
Svalbonas, V.
1973-01-01
The theoretical analysis background for the STARS-2 (shell theory automated for rotational structures) program is presented. The theory involved in the axisymmetric nonlinear and unsymmetric linear static analyses, and the stability and vibrations (including critical rotation speed) analyses involving axisymmetric prestress are discussed. The theory for nonlinear static, stability, and vibrations analyses, involving shells with unsymmetric loadings are included.
NASA Technical Reports Server (NTRS)
Fertis, D. G.; Simon, A. L.
1981-01-01
The requisite methodology to solve linear and nonlinear problems associated with the static and dynamic analysis of rotating machinery, their static and dynamic behavior, and the interaction between the rotating and nonrotating parts of an engine is developed. Linear and nonlinear structural engine problems are investigated by developing solution strategies and interactive computational methods whereby the man and computer can communicate directly in making analysis decisions. Representative examples include modifying structural models, changing material, parameters, selecting analysis options and coupling with interactive graphical display for pre- and postprocessing capability.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Atzeni, Simone; Ahn, Dong; Gopalakrishnan, Ganesh
2017-01-12
Archer is built on top of the LLVM/Clang compilers that support OpenMP. It applies static and dynamic analysis techniques to detect data races in OpenMP programs generating a very low runtime and memory overhead. Static analyses identify data race free OpenMP regions and exclude them from runtime analysis, which is performed by ThreadSanitizer included in LLVM/Clang.
Precise and Efficient Static Array Bound Checking for Large Embedded C Programs
NASA Technical Reports Server (NTRS)
Venet, Arnaud
2004-01-01
In this paper we describe the design and implementation of a static array-bound checker for a family of embedded programs: the flight control software of recent Mars missions. These codes are large (up to 250 KLOC), pointer intensive, heavily multithreaded and written in an object-oriented style, which makes their analysis very challenging. We designed a tool called C Global Surveyor (CGS) that can analyze the largest code in a couple of hours with a precision of 80%. The scalability and precision of the analyzer are achieved by using an incremental framework in which a pointer analysis and a numerical analysis of array indices mutually refine each other. CGS has been designed so that it can distribute the analysis over several processors in a cluster of machines. To the best of our knowledge this is the first distributed implementation of static analysis algorithms. Throughout the paper we will discuss the scalability setbacks that we encountered during the construction of the tool and their impact on the initial design decisions.
Static and dynamic stability analysis of the space shuttle vehicle-orbiter
NASA Technical Reports Server (NTRS)
Chyu, W. J.; Cavin, R. K.; Erickson, L. L.
1978-01-01
The longitudinal static and dynamic stability of a Space Shuttle Vehicle-Orbiter (SSV Orbiter) model is analyzed using the FLEXSTAB computer program. Nonlinear effects are accounted for by application of a correction technique in the FLEXSTAB system; the technique incorporates experimental force and pressure data into the linear aerodynamic theory. A flexible Orbiter model is treated in the static stability analysis for the flight conditions of Mach number 0.9 for rectilinear flight (1 g) and for a pull-up maneuver (2.5 g) at an altitude of 15.24 km. Static stability parameters and structural deformations of the Orbiter are calculated at trim conditions for the dynamic stability analysis, and the characteristics of damping in pitch are investigated for a Mach number range of 0.3 to 1.2. The calculated results for both the static and dynamic stabilities are compared with the available experimental data.
NASA Technical Reports Server (NTRS)
1996-01-01
Solving for the displacements of free-free coupled systems acted upon by static loads is a common task in the aerospace industry. Often, these problems are solved by static analysis with inertia relief. This technique allows for a free-free static analysis by balancing the applied loads with the inertia loads generated by the applied loads. For some engineering applications, the displacements of the free-free coupled system induce additional static loads. Hence, the applied loads are equal to the original loads plus the displacement-dependent loads. A launch vehicle being acted upon by an aerodynamic loading can have such applied loads. The final displacements of such systems are commonly determined with iterative solution techniques. Unfortunately, these techniques can be time consuming and labor intensive. Because the coupled system equations for free-free systems with displacement-dependent loads can be written in closed form, it is advantageous to solve for the displacements in this manner. Implementing closed-form equations in static analysis with inertia relief is analogous to implementing transfer functions in dynamic analysis. An MSC/NASTRAN (MacNeal-Schwendler Corporation/NASA Structural Analysis) DMAP (Direct Matrix Abstraction Program) Alter was used to include displacement-dependent loads in static analysis with inertia relief. It efficiently solved a common aerospace problem that typically has been solved with an iterative technique.
NASA Technical Reports Server (NTRS)
Giles, G. L.; Wallas, M.
1981-01-01
User documentation is presented for a computer program which considers the nonlinear properties of the strain isolator pad (SIP) in the static stress analysis of the shuttle thermal protection system. This program is generalized to handle an arbitrary SIP footprint including cutouts for instrumentation and filler bar. Multiple SIP surfaces are defined to model tiles in unique locations such as leading edges, intersections, and penetrations. The nonlinearity of the SIP is characterized by experimental stress displacement data for both normal and shear behavior. Stresses in the SIP are calculated using a Newton iteration procedure to determine the six rigid body displacements of the tile which develop reaction forces in the SIP to equilibrate the externally applied loads. This user documentation gives an overview of the analysis capabilities, a detailed description of required input data and an example to illustrate use of the program.
Eccentric Training and Static Stretching Improve Hamstring Flexibility of High School Males
Bandy, William D.
2004-01-01
Objective: To determine if the flexibility of high-school-aged males would improve after a 6-week eccentric exercise program. In addition, the changes in hamstring flexibility that occurred after the eccentric program were compared with a 6-week program of static stretching and with a control group (no stretching). Design and Setting: We used a test-retest control group design in a laboratory setting. Subjects were assigned randomly to 1 of 3 groups: eccentric training, static stretching, or control. Subjects: A total of 69 subjects, with a mean age of 16.45 ± 0.96 years and with limited hamstring flexibility (defined as 20° loss of knee extension measured with the thigh held at 90° of hip flexion) were recruited for this study. Measurements: Hamstring flexibility was measured using the passive 90/90 test before and after the 6-week program. Results: Differences were significant for test and for the test-by-group interaction. Follow-up analysis indicated significant differences between the control group (gain = 1.67°) and both the eccentric-training (gain = 12.79°) and static-stretching (gain = 12.05°) groups. No difference was found between the eccentric and static-stretching groups. Conclusions: The gains achieved in range of motion of knee extension (indicating improvement in hamstring flexibility) with eccentric training were equal to those made by statically stretching the hamstring muscles. PMID:15496995
Eccentric Training and Static Stretching Improve Hamstring Flexibility of High School Males.
Nelson, Russell T; Bandy, William D
2004-09-01
OBJECTIVE: To determine if the flexibility of high-school-aged males would improve after a 6-week eccentric exercise program. In addition, the changes in hamstring flexibility that occurred after the eccentric program were compared with a 6-week program of static stretching and with a control group (no stretching). DESIGN AND SETTING: We used a test-retest control group design in a laboratory setting. Subjects were assigned randomly to 1 of 3 groups: eccentric training, static stretching, or control. SUBJECTS: A total of 69 subjects, with a mean age of 16.45 +/- 0.96 years and with limited hamstring flexibility (defined as 20 degrees loss of knee extension measured with the thigh held at 90 degrees of hip flexion) were recruited for this study. MEASUREMENTS: Hamstring flexibility was measured using the passive 90/90 test before and after the 6-week program. RESULTS: Differences were significant for test and for the test-by-group interaction. Follow-up analysis indicated significant differences between the control group (gain = 1.67 degrees ) and both the eccentric-training (gain = 12.79 degrees ) and static-stretching (gain = 12.05 degrees ) groups. No difference was found between the eccentric and static-stretching groups. CONCLUSIONS: The gains achieved in range of motion of knee extension (indicating improvement in hamstring flexibility) with eccentric training were equal to those made by statically stretching the hamstring muscles.
The NASTRAN theoretical manual
NASA Technical Reports Server (NTRS)
1981-01-01
Designed to accommodate additions and modifications, this commentary on NASTRAN describes the problem solving capabilities of the program in a narrative fashion and presents developments of the analytical and numerical procedures that underlie the program. Seventeen major sections and numerous subsections cover; the organizational aspects of the program, utility matrix routines, static structural analysis, heat transfer, dynamic structural analysis, computer graphics, special structural modeling techniques, error analysis, interaction between structures and fluids, and aeroelastic analysis.
User document for computer programs for ring-stiffened shells of revolution
NASA Technical Reports Server (NTRS)
Cohen, G. A.
1973-01-01
A user manual and related program documentation is presented for six compatible computer programs for structural analysis of axisymmetric shell structures. The programs apply to a common structural model but analyze different modes of structural response. In particular, they are: (1) Linear static response under asymmetric loads; (2) Buckling of linear states under asymmetric loads; (3) Nonlinear static response under axisymmetric loads; (4) Buckling nonlinear states under axisymmetric (5) Imperfection sensitivity of buckling modes under axisymmetric loads; and (6) Vibrations about nonlinear states under axisymmetric loads. These programs treat branched shells of revolution with an arbitrary arrangement of a large number of open branches but with at most one closed branch.
Evaluation of verification and testing tools for FORTRAN programs
NASA Technical Reports Server (NTRS)
Smith, K. A.
1980-01-01
Two automated software verification and testing systems were developed for use in the analysis of computer programs. An evaluation of the static analyzer DAVE and the dynamic analyzer PET, which are used in the analysis of FORTRAN programs on Control Data (CDC) computers, are described. Both systems were found to be effective and complementary, and are recommended for use in testing FORTRAN programs.
Some studies on the use of NASTRAN for nuclear power plant structural analysis and design
NASA Technical Reports Server (NTRS)
Setlur, A. V.; Valathur, M.
1973-01-01
Studies made on the use of NASTRAN for nuclear power plant analysis and design are presented. These studies indicate that NASTRAN could be effectively used for static, dynamic and special purpose problems encountered in the design of such plants. Normal mode capability of NASTRAN is extended through a post-processor program to handle seismic analysis. Static and dynamic substructuring is discussed. Extension of NASTRAN to include the needs in the civil engineering industry is discussed.
Analysis and testing of high entrainment single nozzle jet pumps with variable mixing tubes
NASA Technical Reports Server (NTRS)
Hickman, K. E.; Hill, P. G.; Gilbert, G. B.
1972-01-01
An analytical model was developed to predict the performance characteristics of axisymmetric single-nozzle jet pumps with variable area mixing tubes. The primary flow may be subsonic or supersonic. The computer program uses integral techniques to calculate the velocity profiles and the wall static pressures that result from the mixing of the supersonic primary jet and the subsonic secondary flow. An experimental program was conducted to measure mixing tube wall static pressure variations, velocity profiles, and temperature profiles in a variable area mixing tube with a supersonic primary jet. Static pressure variations were measured at four different secondary flow rates. These test results were used to evaluate the analytical model. The analytical results compared well to the experimental data. Therefore, the analysis is believed to be ready for use to relate jet pump performance characteristics to mixing tube design.
NASA Technical Reports Server (NTRS)
Bielawa, Richard L.; Hefner, Rachel E.; Castagna, Andre
1991-01-01
The results are presented of an analytic and experimental research program involving a Sikorsky S-55 helicopter tail cone directed ultimately to the improved structural analysis of airframe substructures typical of moderate sized helicopters of metal semimonocoque construction. Experimental static strain and dynamic shake-testing measurements are presented. Correlation studies of each of these tests with a PC-based finite element analysis (COSMOS/M) are described. The tests included static loadings at the end of the tail cone supported in the cantilever configuration as well as vibrational shake-testing in both the cantilever and free-free configurations.
Random harmonic analysis program, L221 (TEV156). Volume 1: Engineering and usage
NASA Technical Reports Server (NTRS)
Miller, R. D.; Graham, M. L.
1979-01-01
A digital computer program capable of calculating steady state solutions for linear second order differential equations due to sinusoidal forcing functions is described. The field of application of the program, the analysis of airplane response and loads due to continuous random air turbulence, is discussed. Optional capabilities including frequency dependent input matrices, feedback damping, gradual gust penetration, multiple excitation forcing functions, and a static elastic solution are described. Program usage and a description of the analysis used are presented.
Thermal stress analysis of reusable surface insulation for shuttle
NASA Technical Reports Server (NTRS)
Ojalvo, I. U.; Levy, A.; Austin, F.
1974-01-01
An iterative procedure for accurately determining tile stresses associated with static mechanical and thermally induced internal loads is presented. The necessary conditions for convergence of the method are derived. An user-oriented computer program based upon the present method of analysis was developed. The program is capable of analyzing multi-tiled panels and determining the associated stresses. Typical numerical results from this computer program are presented.
Dynamic Analysis of Spur Gear Transmissions (DANST). PC Version 3.00 User Manual
NASA Technical Reports Server (NTRS)
Oswald, Fred B.; Lin, Hsiang Hsi; Delgado, Irebert R.
1996-01-01
DANST is a FORTRAN computer program for static and dynamic analysis of spur gear systems. The program can be used for parametric studies to predict the static transmission error, dynamic load, tooth bending stress and other properties of spur gears as they are influenced by operating speed, torque, stiffness, damping, inertia, and tooth profile. DANST performs geometric modeling and dynamic analysis for low- or high-contact-ratio spur gears. DANST can simulate gear systems with contact ratios ranging from one to three. It was designed to be easy to use and it is extensively documented in several previous reports and by comments in the source code. This report describes installing and using a new PC version of DANST, covers input data requirements and presents examples.
Static analysis of the hull plate using the finite element method
NASA Astrophysics Data System (ADS)
Ion, A.
2015-11-01
This paper aims at presenting the static analysis for two levels of a container ship's construction as follows: the first level is at the girder / hull plate and the second level is conducted at the entire strength hull of the vessel. This article will describe the work for the static analysis of a hull plate. We shall use the software package ANSYS Mechanical 14.5. The program is run on a computer with four Intel Xeon X5260 CPU processors at 3.33 GHz, 32 GB memory installed. In terms of software, the shared memory parallel version of ANSYS refers to running ANSYS across multiple cores on a SMP system. The distributed memory parallel version of ANSYS (Distributed ANSYS) refers to running ANSYS across multiple processors on SMP systems or DMP systems.
The FORTRAN static source code analyzer program (SAP) user's guide, revision 1
NASA Technical Reports Server (NTRS)
Decker, W.; Taylor, W.; Eslinger, S.
1982-01-01
The FORTRAN Static Source Code Analyzer Program (SAP) User's Guide (Revision 1) is presented. SAP is a software tool designed to assist Software Engineering Laboratory (SEL) personnel in conducting studies of FORTRAN programs. SAP scans FORTRAN source code and produces reports that present statistics and measures of statements and structures that make up a module. This document is a revision of the previous SAP user's guide, Computer Sciences Corporation document CSC/TM-78/6045. SAP Revision 1 is the result of program modifications to provide several new reports, additional complexity analysis, and recognition of all statements described in the FORTRAN 77 standard. This document provides instructions for operating SAP and contains information useful in interpreting SAP output.
NASA Technical Reports Server (NTRS)
Ball, R. E.
1972-01-01
A digital computer program known as SATANS (static and transient analysis, nonlinear, shells) for the geometrically nonlinear static and dynamic response of arbitrarily loaded shells of revolution is presented. Instructions for the preparation of the input data cards and other information necessary for the operation of the program are described in detail and two sample problems are included. The governing partial differential equations are based upon Sanders' nonlinear thin shell theory for the conditions of small strains and moderately small rotations. The governing equations are reduced to uncoupled sets of four linear, second order, partial differential equations in the meridional and time coordinates by expanding the dependent variables in a Fourier sine or cosine series in the circumferential coordinate and treating the nonlinear modal coupling terms as pseudo loads. The derivatives with respect to the meridional coordinate are approximated by central finite differences, and the displacement accelerations are approximated by the implicit Houbolt backward difference scheme with a constant time interval. The boundaries of the shell may be closed, free, fixed, or elastically restrained. The program is coded in the FORTRAN 4 language and is dimensioned to allow a maximum of 10 arbitrary Fourier harmonics and a maximum product of the total number of meridional stations and the total number of Fourier harmonics of 200. The program requires 155,000 bytes of core storage.
Plastic and Large-Deflection Analysis of Nonlinear Structures
NASA Technical Reports Server (NTRS)
Thomson, R. G.; Hayduk, R. J.; Robinson, M. P.; Durling, B. J.; Pifko, A.; Levine, H. S.; Armen, H. J.; Levy, A.; Ogilvie, P.
1982-01-01
Plastic and Large Deflection Analysis of Nonlinear Structures (PLANS) system is collection of five computer programs for finite-element static-plastic and large deflection analysis of variety of nonlinear structures. System considers bending and membrane stresses, general three-dimensional bodies, and laminated composites.
Augmenting Traditional Static Analysis With Commonly Available Metadata
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cook, Devin
Developers and security analysts have been using static analysis for a long time to analyze programs for defects and vulnerabilities with some success. Generally a static analysis tool is run on the source code for a given program, flagging areas of code that need to be further inspected by a human analyst. These areas may be obvious bugs like potential bu er over flows, information leakage flaws, or the use of uninitialized variables. These tools tend to work fairly well - every year they find many important bugs. These tools are more impressive considering the fact that they only examinemore » the source code, which may be very complex. Now consider the amount of data available that these tools do not analyze. There are many pieces of information that would prove invaluable for finding bugs in code, things such as a history of bug reports, a history of all changes to the code, information about committers, etc. By leveraging all this additional data, it is possible to nd more bugs with less user interaction, as well as track useful metrics such as number and type of defects injected by committer. This dissertation provides a method for leveraging development metadata to find bugs that would otherwise be difficult to find using standard static analysis tools. We showcase two case studies that demonstrate the ability to find 0day vulnerabilities in large and small software projects by finding new vulnerabilities in the cpython and Roundup open source projects.« less
Programmers manual for static and dynamic reusable surface insulation stresses (resist)
NASA Technical Reports Server (NTRS)
Ogilvie, P. L.; Levy, A.; Austin, F.; Ojalvo, I. U.
1974-01-01
Programming information for the RESIST program for the dynamic and thermal stress analysis of the space shuttle surface insulation is presented. The overall flow chart of the program, overlay chart, data set allocation, and subprogram calling sequence are given along with a brief description of the individual subprograms and typical subprogram output.
Ability-Training-Oriented Automated Assessment in Introductory Programming Course
ERIC Educational Resources Information Center
Wang, Tiantian; Su, Xiaohong; Ma, Peijun; Wang, Yuying; Wang, Kuanquan
2011-01-01
Learning to program is a difficult process for novice programmers. AutoLEP, an automated learning and assessment system, was developed by us, to aid novice programmers to obtain programming skills. AutoLEP is ability-training-oriented. It adopts a novel assessment mechanism, which combines static analysis with dynamic testing to analyze student…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gartling, D.K.
The theoretical and numerical background for the finite element computer program, TORO II, is presented in detail. TORO II is designed for the multi-dimensional analysis of nonlinear, electromagnetic field problems described by the quasi-static form of Maxwell`s equations. A general description of the boundary value problems treated by the program is presented. The finite element formulation and the associated numerical methods used in TORO II are also outlined. Instructions for the use of the code are documented in SAND96-0903; examples of problems analyzed with the code are also provided in the user`s manual. 24 refs., 8 figs.
NASTRAN/FLEXSTAB procedure for static aeroelastic analysis
NASA Technical Reports Server (NTRS)
Schuster, L. S.
1984-01-01
Presented is a procedure for using the FLEXSTAB External Structural Influence Coefficients (ESIC) computer program to produce the structural data necessary for the FLEXSTAB Stability Derivatives and Static Stability (SD&SS) program. The SD&SS program computes trim state, stability derivatives, and pressure and deflection data for a flexible airplane having a plane of symmetry. The procedure used a NASTRAN finite-element structural model as the source of structural data in the form of flexibility matrices. Selection of a set of degrees of freedom, definition of structural nodes and panels, reordering and reformatting of the flexibility matrix, and redistribution of existing point mass data are among the topics discussed. Also discussed are boundary conditions and the NASTRAN substructuring technique.
Parallel program debugging with flowback analysis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Choi, Jongdeok.
1989-01-01
This thesis describes the design and implementation of an integrated debugging system for parallel programs running on shared memory multi-processors. The goal of the debugging system is to present to the programmer a graphical view of the dynamic program dependences while keeping the execution-time overhead low. The author first describes the use of flowback analysis to provide information on causal relationship between events in a programs' execution without re-executing the program for debugging. Execution time overhead is kept low by recording only a small amount of trace during a program's execution. He uses semantic analysis and a technique called incrementalmore » tracing to keep the time and space overhead low. As part of the semantic analysis, he uses a static program dependence graph structure that reduces the amount of work done at compile time and takes advantage of the dynamic information produced during execution time. The cornerstone of the incremental tracing concept is to generate a coarse trace during execution and fill incrementally, during the interactive portion of the debugging session, the gap between the information gathered in the coarse trace and the information needed to do the flowback analysis using the coarse trace. Then, he describes how to extend the flowback analysis to parallel programs. The flowback analysis can span process boundaries; i.e., the most recent modification to a shared variable might be traced to a different process than the one that contains the current reference. The static and dynamic program dependence graphs of the individual processes are tied together with synchronization and data dependence information to form complete graphs that represent the entire program.« less
Precise and Scalable Static Program Analysis of NASA Flight Software
NASA Technical Reports Server (NTRS)
Brat, G.; Venet, A.
2005-01-01
Recent NASA mission failures (e.g., Mars Polar Lander and Mars Orbiter) illustrate the importance of having an efficient verification and validation process for such systems. One software error, as simple as it may be, can cause the loss of an expensive mission, or lead to budget overruns and crunched schedules. Unfortunately, traditional verification methods cannot guarantee the absence of errors in software systems. Therefore, we have developed the CGS static program analysis tool, which can exhaustively analyze large C programs. CGS analyzes the source code and identifies statements in which arrays are accessed out of bounds, or, pointers are used outside the memory region they should address. This paper gives a high-level description of CGS and its theoretical foundations. It also reports on the use of CGS on real NASA software systems used in Mars missions (from Mars PathFinder to Mars Exploration Rover) and on the International Space Station.
NASA Astrophysics Data System (ADS)
Milojević, Slavka; Stojanovic, Vojislav
2017-04-01
Due to the continuous development of the seismic acquisition and processing method, the increase of the signal/fault ratio always represents a current target. The correct application of the latest software solutions improves the processing results and justifies their development. A correct computation and application of static corrections represents one of the most important tasks in pre-processing. This phase is of great importance for further processing steps. Static corrections are applied to seismic data in order to compensate the effects of irregular topography, the difference between the levels of source points and receipt in relation to the level of reduction, of close to the low-velocity surface layer (weathering correction), or any reasons that influence the spatial and temporal position of seismic routes. The refraction statics method is the most common method for computation of static corrections. It is successful in resolving of both the long-period statics problems and determining of the difference in the statics caused by abrupt lateral changes in velocity in close to the surface layer. XtremeGeo FlatironsTM is a program whose main purpose is computation of static correction through a refraction statics method and allows the application of the following procedures: picking of first arrivals, checking of geometry, multiple methods for analysis and modelling of statics, analysis of the refractor anisotropy and tomography (Eikonal Tomography). The exploration area is located on the southern edge of the Pannonian Plain, in the plain area with altitudes of 50 to 195 meters. The largest part of the exploration area covers Deliblato Sands, where the geological structure of the terrain and high difference in altitudes significantly affects the calculation of static correction. Software XtremeGeo FlatironsTM has powerful visualization and tools for statistical analysis which contributes to significantly more accurate assessment of geometry close to the surface layers and therefore more accurately computed static corrections.
NASA Astrophysics Data System (ADS)
Agapov, Vladimir
2018-03-01
The necessity of new approaches to the modeling of rods in the analysis of high-rise constructions is justified. The possibility of the application of the three-dimensional superelements of rods with rectangular cross section for the static and dynamic calculation of the bar and combined structures is considered. The results of the eighteen-story spatial frame free vibrations analysis using both one-dimensional and three-dimensional models of rods are presented. A comparative analysis of the obtained results is carried out and the conclusions on the possibility of three-dimensional superelements application in static and dynamic analysis of high-rise constructions are given on its basis.
High Temperature Composite Analyzer (HITCAN) demonstration manual, version 1.0
NASA Technical Reports Server (NTRS)
Singhal, S. N; Lackney, J. J.; Murthy, P. L. N.
1993-01-01
This manual comprises a variety of demonstration cases for the HITCAN (HIgh Temperature Composite ANalyzer) code. HITCAN is a general purpose computer program for predicting nonlinear global structural and local stress-strain response of arbitrarily oriented, multilayered high temperature metal matrix composite structures. HITCAN is written in FORTRAN 77 computer language and has been configured and executed on the NASA Lewis Research Center CRAY XMP and YMP computers. Detailed description of all program variables and terms used in this manual may be found in the User's Manual. The demonstration includes various cases to illustrate the features and analysis capabilities of the HITCAN computer code. These cases include: (1) static analysis, (2) nonlinear quasi-static (incremental) analysis, (3) modal analysis, (4) buckling analysis, (5) fiber degradation effects, (6) fabrication-induced stresses for a variety of structures; namely, beam, plate, ring, shell, and built-up structures. A brief discussion of each demonstration case with the associated input data file is provided. Sample results taken from the actual computer output are also included.
NASA Technical Reports Server (NTRS)
Osias, J. R.
1974-01-01
Computer programs are presented which provide incremental finite-element analysis capability for problems of quasi-static, finite, elastoplastic deformation in two spatial dimensions (plane strain, plane stress, axisymmetric). Monotonic or cyclic loading of isotropic hardening materials is considered. The only restriction on the form of the stress-strain curve is that the rate of work hardening exceed some small positive value. The user's guide assumes familiarity with both finite-element analysis and FORTRAN IV programming for the CDC 6600. Sufficient information is provided to support problem solving ultization of the programs.
Computer program for preliminary design analysis of axial-flow turbines
NASA Technical Reports Server (NTRS)
Glassman, A. J.
1972-01-01
The program method is based on a mean-diameter flow analysis. Input design requirements include power or pressure ratio, flow, temperature, pressure, and speed. Turbine designs are generated for any specified number of stages and for any of three types of velocity diagrams (symmetrical, zero exit swirl, or impulse). Exit turning vanes can be included in the design. Program output includes inlet and exit annulus dimensions, exit temperature and pressure, total and static efficiencies, blading angles, and last-stage critical velocity ratios. The report presents the analysis method, a description of input and output with sample cases, and the program listing.
Lean and Efficient Software: Whole-Program Optimization of Executables
2015-09-30
libraries. Many levels of library interfaces—where some libraries are dynamically linked and some are provided in binary form only—significantly limit...software at build time. The opportunity: Our objective in this project is to substantially improve the performance, size, and robustness of binary ...executables by using static and dynamic binary program analysis techniques to perform whole-program optimization directly on compiled programs
NASA Technical Reports Server (NTRS)
Whitaker, Mike
1991-01-01
Severe precipitation static problems affecting the communication equipment onboard the P-3B aircraft were recently studied. The study was conducted after precipitation static created potential safety-of-flight problems on Naval Reserve aircraft. A specially designed flight test program was conducted in order to measure, record, analyze, and characterize potential precipitation static problem areas. The test program successfully characterized the precipitation static interference problems while the P-3B was flown in moderate to extreme precipitation conditions. Data up to 400 MHz were collected on the effects of engine charging, precipitation static, and extreme cross fields. These data were collected using a computer controlled acquisition system consisting of a signal generator, RF spectrum and audio analyzers, data recorders, and instrumented static dischargers. The test program is outlined and the computer controlled data acquisition system is described in detail which was used during flight and ground testing. The correlation of test results is also discussed which were recorded during the flight test program and those measured during ground testing.
NASTRAN applications to aircraft propulsion systems
NASA Technical Reports Server (NTRS)
White, J. L.; Beste, D. L.
1975-01-01
The use of NASTRAN in propulsion system structural integration analysis is described. Computer support programs for modeling, substructuring, and plotting analysis results are discussed. Requirements on interface information and data exchange by participants in a NASTRAN substructure analysis are given. Static and normal modes vibration analysis results are given with comparison to test and other analytical results.
2016-03-01
constraints problem. Game rules described valid moves allowing player to generate a memory graph performing improved C program verification . 15. SUBJECT...TERMS Formal Verification , Static Analysis, Abstract Interpretation, Pointer Analysis, Fixpoint Iteration 16. SECURITY CLASSIFICATION OF: 17...36 3.4.12 Example: Game Play . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 3.4.13 Verification
Performance tradeoffs in static and dynamic load balancing strategies
NASA Technical Reports Server (NTRS)
Iqbal, M. A.; Saltz, J. H.; Bokhart, S. H.
1986-01-01
The problem of uniformly distributing the load of a parallel program over a multiprocessor system was considered. A program was analyzed whose structure permits the computation of the optimal static solution. Then four strategies for load balancing were described and their performance compared. The strategies are: (1) the optimal static assignment algorithm which is guaranteed to yield the best static solution, (2) the static binary dissection method which is very fast but sub-optimal, (3) the greedy algorithm, a static fully polynomial time approximation scheme, which estimates the optimal solution to arbitrary accuracy, and (4) the predictive dynamic load balancing heuristic which uses information on the precedence relationships within the program and outperforms any of the static methods. It is also shown that the overhead incurred by the dynamic heuristic is reduced considerably if it is started off with a static assignment provided by either of the other three strategies.
VALIDATION OF ANSYS FINITE ELEMENT ANALYSIS SOFTWARE
DOE Office of Scientific and Technical Information (OSTI.GOV)
HAMM, E.R.
2003-06-27
This document provides a record of the verification and Validation of the ANSYS Version 7.0 software that is installed on selected CH2M HILL computers. The issues addressed include: Software verification, installation, validation, configuration management and error reporting. The ANSYS{reg_sign} computer program is a large scale multi-purpose finite element program which may be used for solving several classes of engineering analysis. The analysis capabilities of ANSYS Full Mechanical Version 7.0 installed on selected CH2M Hill Hanford Group (CH2M HILL) Intel processor based computers include the ability to solve static and dynamic structural analyses, steady-state and transient heat transfer problems, mode-frequency andmore » buckling eigenvalue problems, static or time-varying magnetic analyses and various types of field and coupled-field applications. The program contains many special features which allow nonlinearities or secondary effects to be included in the solution, such as plasticity, large strain, hyperelasticity, creep, swelling, large deflections, contact, stress stiffening, temperature dependency, material anisotropy, and thermal radiation. The ANSYS program has been in commercial use since 1970, and has been used extensively in the aerospace, automotive, construction, electronic, energy services, manufacturing, nuclear, plastics, oil and steel industries.« less
An Aeroelastic Analysis of a Thin Flexible Membrane
NASA Technical Reports Server (NTRS)
Scott, Robert C.; Bartels, Robert E.; Kandil, Osama A.
2007-01-01
Studies have shown that significant vehicle mass and cost savings are possible with the use of ballutes for aero-capture. Through NASA's In-Space Propulsion program, a preliminary examination of ballute sensitivity to geometry and Reynolds number was conducted, and a single-pass coupling between an aero code and a finite element solver was used to assess the static aeroelastic effects. There remain, however, a variety of open questions regarding the dynamic aeroelastic stability of membrane structures for aero-capture, with the primary challenge being the prediction of the membrane flutter onset. The purpose of this paper is to describe and begin addressing these issues. The paper includes a review of the literature associated with the structural analysis of membranes and membrane utter. Flow/structure analysis coupling and hypersonic flow solver options are also discussed. An approach is proposed for tackling this problem that starts with a relatively simple geometry and develops and evaluates analysis methods and procedures. This preliminary study considers a computationally manageable 2-dimensional problem. The membrane structural models used in the paper include a nonlinear finite-difference model for static and dynamic analysis and a NASTRAN finite element membrane model for nonlinear static and linear normal modes analysis. Both structural models are coupled with a structured compressible flow solver for static aeroelastic analysis. For dynamic aeroelastic analyses, the NASTRAN normal modes are used in the structured compressible flow solver and 3rd order piston theories were used with the finite difference membrane model to simulate utter onset. Results from the various static and dynamic aeroelastic analyses are compared.
Design integration and noise studies for jet STOL aircraft. Volume 1: Program summary
NASA Technical Reports Server (NTRS)
Okeefe, V. O.; Kelley, G. S.
1972-01-01
This program was undertaken to develop, through analysis, design, experimental static testing, wind tunnel testing, and design integration studies, an augmentor wing jet flap configuration for a jet STOL transport aircraft having maximum propulsion and aerodynamic performance with minimum noise generation. The program had three basic elements: (1) static testing of a scale wing section to demonstrate augmentor performance and noise characteristics; (2) two-dimensional wind tunnel testing to determine flight speed effects on performance; and (3) system design and evaluation which integrated the augmentor information obtained into a complete system and ensured that the design was compatible with the requirements for a large STOL transport having a 500-ft sideline noise of 95 PNdB or less. This objective has been achieved.
NASA Technical Reports Server (NTRS)
1976-01-01
The application of NASTRAN to a wide variety of static and dynamic structural problems is discussed. The following topics are focused upon: (1) methods of analysis; (2) hydroelastic methods; (3) complete analysis of structures; (4) elements and material studies; (5) critical comparisons with other programs; and (6) pre- and post-processor operations.
PCC Framework for Program-Generators
NASA Technical Reports Server (NTRS)
Kong, Soonho; Choi, Wontae; Yi, Kwangkeun
2009-01-01
In this paper, we propose a proof-carrying code framework for program-generators. The enabling technique is abstract parsing, a static string analysis technique, which is used as a component for generating and validating certificates. Our framework provides an efficient solution for certifying program-generators whose safety properties are expressed in terms of the grammar representing the generated program. The fixed-point solution of the analysis is generated and attached with the program-generator on the code producer side. The consumer receives the code with a fixed-point solution and validates that the received fixed point is indeed a fixed point of the received code. This validation can be done in a single pass.
The theory of interface slicing
NASA Technical Reports Server (NTRS)
Beck, Jon
1993-01-01
Interface slicing is a new tool which was developed to facilitate reuse-based software engineering, by addressing the following problems, needs, and issues: (1) size of systems incorporating reused modules; (2) knowledge requirements for program modification; (3) program understanding for reverse engineering; (4) module granularity and domain management; and (5) time and space complexity of conventional slicing. The definition of a form of static program analysis called interface slicing is addressed.
Parachute Aerodynamics From Video Data
NASA Technical Reports Server (NTRS)
Schoenenberger, Mark; Queen, Eric M.; Cruz, Juan R.
2005-01-01
A new data analysis technique for the identification of static and dynamic aerodynamic stability coefficients from wind tunnel test video data is presented. This new technique was applied to video data obtained during a parachute wind tunnel test program conducted in support of the Mars Exploration Rover Mission. Total angle-of-attack data obtained from video images were used to determine the static pitching moment curve of the parachute. During the original wind tunnel test program the static pitching moment curve had been determined by forcing the parachute to a specific total angle-of -attack and measuring the forces generated. It is shown with the new technique that this parachute, when free to rotate, trims at an angle-of-attack two degrees lower than was measured during the forced-angle tests. An attempt was also made to extract pitch damping information from the video data. Results suggest that the parachute is dynamically unstable at the static trim point and tends to become dynamically stable away from the trim point. These trends are in agreement with limit-cycle-like behavior observed in the video. However, the chaotic motion of the parachute produced results with large uncertainty bands.
NASA Technical Reports Server (NTRS)
Tanner, C. J.; Kruse, G. S.; Oman, B. H.
1975-01-01
A preliminary design analysis tool for rapidly performing trade-off studies involving fatigue, fracture, static strength, weight, and cost is presented. Analysis subprograms were developed for fatigue life, crack growth life, and residual strength; and linked to a structural synthesis module which in turn was integrated into a computer program. The part definition module of a cost and weight analysis program was expanded to be compatible with the upgraded structural synthesis capability. The resultant vehicle design and evaluation program is named VDEP-2. It is an accurate and useful tool for estimating purposes at the preliminary design stage of airframe development. A sample case along with an explanation of program applications and input preparation is presented.
Hill, Kristian J; Robinson, Kendall P; Cuchna, Jennifer W; Hoch, Matthew C
2017-11-01
Clinical Scenario: Increasing hamstring flexibility through clinical stretching interventions may be an effective means to prevent hamstring injuries. However the most effective method to increase hamstring flexibility has yet to be determined. For a healthy individual, are proprioceptive neuromuscular facilitation (PNF) stretching programs more effective in immediately improving hamstring flexibility when compared with static stretching programs? Summary of Key Findings: A thorough literature search returned 195 possible studies; 5 studies met the inclusion criteria and were included. Current evidence supports the use of PNF stretching or static stretching programs for increasing hamstring flexibility. However, neither program demonstrated superior effectiveness when examining immediate increases in hamstring flexibility. Clinical Bottom Line: There were consistent findings from multiple low-quality studies that indicate there is no difference in the immediate improvements in hamstring flexibility when comparing PNF stretching programs to static stretching programs in physically active adults. Strength of Recommendation: Grade B evidence exists that PNF and static stretching programs equally increase hamstring flexibility immediately following the stretching program.
NASA Technical Reports Server (NTRS)
Kenigsberg, I. J.; Dean, M. W.; Malatino, R.
1974-01-01
The correlation achieved with each program provides the material for a discussion of modeling techniques developed for general application to finite-element dynamic analyses of helicopter airframes. Included are the selection of static and dynamic degrees of freedom, cockpit structural modeling, and the extent of flexible-frame modeling in the transmission support region and in the vicinity of large cut-outs. The sensitivity of predicted results to these modeling assumptions are discussed. Both the Sikorsky Finite-Element Airframe Vibration analysis Program (FRAN/Vibration Analysis) and the NASA Structural Analysis Program (NASTRAN) have been correlated with data taken in full-scale vibration tests of a modified CH-53A helicopter.
New reflective symmetry design capability in the JPL-IDEAS Structure Optimization Program
NASA Technical Reports Server (NTRS)
Strain, D.; Levy, R.
1986-01-01
The JPL-IDEAS antenna structure analysis and design optimization computer program was modified to process half structure models of symmetric structures subjected to arbitrary external static loads, synthesize the performance, and optimize the design of the full structure. Significant savings in computation time and cost (more than 50%) were achieved compared to the cost of full model computer runs. The addition of the new reflective symmetry analysis design capabilities to the IDEAS program allows processing of structure models whose size would otherwise prevent automated design optimization. The new program produced synthesized full model iterative design results identical to those of actual full model program executions at substantially reduced cost, time, and computer storage.
ERIC Educational Resources Information Center
SUTTON, MACK C.
THIS SELF-INSTRUCTIONAL PROGRAMED TEXT IS FOR INDIVIDUAL STUDENT USE IN STUDYING STATIC CONTROL IN ELECTRICAL-ELECTRONIC PROGRAMS. IT WAS DEVELOPED BY AN INSTRUCTIONAL MATERIALS SPECIALIST AND ADVISERS AND HAS BEEN TESTED BY STUDENT USE. THE OBJECTIVE OF THE COURSE IS TO HELP THE ELECTRICAL-TECHNICIAN DEVELOP AN UNDERSTANDING OF STATIC CONTROL…
A digital flight control system verification laboratory
NASA Technical Reports Server (NTRS)
De Feo, P.; Saib, S.
1982-01-01
A NASA/FAA program has been established for the verification and validation of digital flight control systems (DFCS), with the primary objective being the development and analysis of automated verification tools. In order to enhance the capabilities, effectiveness, and ease of using the test environment, software verification tools can be applied. Tool design includes a static analyzer, an assertion generator, a symbolic executor, a dynamic analysis instrument, and an automated documentation generator. Static and dynamic tools are integrated with error detection capabilities, resulting in a facility which analyzes a representative testbed of DFCS software. Future investigations will ensue particularly in the areas of increase in the number of software test tools, and a cost effectiveness assessment.
NASA Technical Reports Server (NTRS)
Camarda, C. J.; Adelman, H. M.
1984-01-01
The implementation of static and dynamic structural-sensitivity derivative calculations in a general purpose, finite-element computer program denoted the Engineering Analysis Language (EAL) System is described. Derivatives are calculated with respect to structural parameters, specifically, member sectional properties including thicknesses, cross-sectional areas, and moments of inertia. Derivatives are obtained for displacements, stresses, vibration frequencies and mode shapes, and buckling loads and mode shapes. Three methods for calculating derivatives are implemented (analytical, semianalytical, and finite differences), and comparisons of computer time and accuracy are made. Results are presented for four examples: a swept wing, a box beam, a stiffened cylinder with a cutout, and a space radiometer-antenna truss.
NASA Technical Reports Server (NTRS)
Svalbonas, V.; Ogilvie, P.
1973-01-01
The engineering programming information for the digital computer program for analyzing shell structures is presented. The program is designed to permit small changes such as altering the geometry or a table size to fit the specific requirements. Each major subroutine is discussed and the following subjects are included: (1) subroutine description, (2) pertinent engineering symbols and the FORTRAN coded counterparts, (3) subroutine flow chart, and (4) subroutine FORTRAN listing.
Integrated verification and testing system (IVTS) for HAL/S programs
NASA Technical Reports Server (NTRS)
Senn, E. H.; Ames, K. R.; Smith, K. A.
1983-01-01
The IVTS is a large software system designed to support user-controlled verification analysis and testing activities for programs written in the HAL/S language. The system is composed of a user interface and user command language, analysis tools and an organized data base of host system files. The analysis tools are of four major types: (1) static analysis, (2) symbolic execution, (3) dynamic analysis (testing), and (4) documentation enhancement. The IVTS requires a split HAL/S compiler, divided at the natural separation point between the parser/lexical analyzer phase and the target machine code generator phase. The IVTS uses the internal program form (HALMAT) between these two phases as primary input for the analysis tools. The dynamic analysis component requires some way to 'execute' the object HAL/S program. The execution medium may be an interpretive simulation or an actual host or target machine.
Alkaline static feed electrolyzer based oxygen generation system
NASA Technical Reports Server (NTRS)
Noble, L. D.; Kovach, A. J.; Fortunato, F. A.; Schubert, F. H.; Grigger, D. J.
1988-01-01
In preparation for the future deployment of the Space Station, an R and D program was established to demonstrate integrated operation of an alkaline Water Electrolysis System and a fuel cell as an energy storage device. The program's scope was revised when the Space Station Control Board changed the energy storage baseline for the Space Station. The new scope was aimed at the development of an alkaline Static Feed Electrolyzer for use in an Environmental Control/Life Support System as an oxygen generation system. As a result, the program was divided into two phases. The phase 1 effort was directed at the development of the Static Feed Electrolyzer for application in a Regenerative Fuel Cell System. During this phase, the program emphasized incorporation of the Regenerative Fuel Cell System design requirements into the Static Feed Electrolyzer electrochemical module design and the mechanical components design. The mechanical components included a Pressure Control Assembly, a Water Supply Assembly and a Thermal Control Assembly. These designs were completed through manufacturing drawing during Phase 1. The Phase 2 effort was directed at advancing the Alkaline Static Feed Electrolyzer database for an oxygen generation system. This development was aimed at extending the Static Feed Electrolyzer database in areas which may be encountered from initial fabrication through transportation, storage, launch and eventual Space Station startup. During this Phase, the Program emphasized three major areas: materials evaluation, electrochemical module scaling and performance repeatability and Static Feed Electrolyzer operational definition and characterization.
Static Analysis Numerical Algorithms
2016-04-01
represented by a collection of intervals (one for each variable) or a convex polyhedron (each dimension of the affine space representing a program variable...Another common abstract domain uses a set of linear constraints (i.e. an enclosing polyhedron ) to over-approximate the joint values of several
Hardware-Independent Proofs of Numerical Programs
NASA Technical Reports Server (NTRS)
Boldo, Sylvie; Nguyen, Thi Minh Tuyen
2010-01-01
On recent architectures, a numerical program may give different answers depending on the execution hardware and the compilation. Our goal is to formally prove properties about numerical programs that are true for multiple architectures and compilers. We propose an approach that states the rounding error of each floating-point computation whatever the environment. This approach is implemented in the Frama-C platform for static analysis of C code. Small case studies using this approach are entirely and automatically proved
DESIGN ANALYSIS OF RADIAL INFLOW TURBINES
NASA Technical Reports Server (NTRS)
Glassman, A. J.
1994-01-01
This program performs a velocity-diagram analysis required for determining geometry and estimating performance for radial-inflow turbines. Input design requirements are power, mass flow rate, inlet temperature and pressure, and rotative rate. The design variables include stator-exit angle, rotor-exit-tip to rotor-inlet radius ratio, rotor-exit-hub to tip radius ratio, and the magnitude and radial distribution of rotor-exit tangential velocity. The program output includes diameters, total and static efficiences, all absolute and relative temperatures, pressures, and velocities, and flow angles at stator inlet, stator exit, rotor inlet, and rotor exit. Losses accounted for in this program by the internal loss model are three-dimensional (profile plus end wall) viscous losses in the stator and the rotor, the disk-friction loss on the back side of the rotor, the loss due to the clearance between the rotor tip and the outer casing, and the exit velocity loss. The flow analysis is one-dimensional at the stator inlet, stator exit, and rotor inlet, each of these calculation stations being at a constant radius. At the rotor exit where there is a variation in flow-field radius, an axisymmetric two-dimensional analysis is made using constant height sectors. Simple radial equilibrium is used to establish the static pressure gradient at the rotor exit. This program is written in FORTRAN V and has been implemented on a UNIVAC 1100 series computer with a memory requirement of approximately 22K of 36 bit words.
Nelson, Russell T
2006-05-01
A pre-event static stretching program is often used to prepare an athlete for competition. Recent studies have suggested that static stretching may not be an effective method for stretching the muscle prior to competition. The intent of this study was to compare the immediate effect of static stretching, eccentric training, and no stretching/training on hamstring flexibility in high school and college athletes. Seventy-five athletes, with a mean age of 17.22 (+/- 1.30) were randomly assigned to one of three groups - thirty- second static stretch one time, an eccentric training protocol through a full range of motion, and a control group. All athletes had limited hamstring flexibility, defined as a 20° loss of knee extension measured with the femur held at 90° of hip flexion. A significant difference was indicated by follow up analysis between the control group (gain = -1.08°) and both the static stretch (gain = 5.05°) and the eccentric training group (gain = 9.48°). In addition, the gains in the eccentric training group were significantly greater than the static stretch group. The findings of this study reveal that one session of eccentrically training through a full range of motion improved hamstring flexibility better than the gains made by a static stretch group or a control group.
2006-01-01
Background A pre-event static stretching program is often used to prepare an athlete for competition. Recent studies have suggested that static stretching may not be an effective method for stretching the muscle prior to competition. Objective The intent of this study was to compare the immediate effect of static stretching, eccentric training, and no stretching/training on hamstring flexibility in high school and college athletes. Methods Seventy-five athletes, with a mean age of 17.22 (+/- 1.30) were randomly assigned to one of three groups - thirty- second static stretch one time, an eccentric training protocol through a full range of motion, and a control group. All athletes had limited hamstring flexibility, defined as a 20° loss of knee extension measured with the femur held at 90° of hip flexion. Results A significant difference was indicated by follow up analysis between the control group (gain = -1.08°) and both the static stretch (gain = 5.05°) and the eccentric training group (gain = 9.48°). In addition, the gains in the eccentric training group were significantly greater than the static stretch group. Discussion and Conclusion The findings of this study reveal that one session of eccentrically training through a full range of motion improved hamstring flexibility better than the gains made by a static stretch group or a control group. PMID:21522215
A Model for Speedup of Parallel Programs
1997-01-01
Sanjeev. K Setia . The interaction between mem- ory allocation and adaptive partitioning in message- passing multicomputers. In IPPS Workshop on Job...Scheduling Strategies for Parallel Processing, pages 89{99, 1995. [15] Sanjeev K. Setia and Satish K. Tripathi. A compar- ative analysis of static
NASA Technical Reports Server (NTRS)
Braden, J. A.; Hancock, J. P.; Hackett, J. E.; Lyman, V.
1979-01-01
The experimental data encompassing surface pressure measurements, and wake surveys at static and wind-on conditions are analyzed. Cruise performance trends reflecting nacelle geometric variations, and nozzle operating conditions are presented. Details of the modeling process are included.
Advanced composite aileron for L-1011 transport aircraft: Design and analysis
NASA Technical Reports Server (NTRS)
Griffin, C. F.; Fogg, L. D.; Dunning, E. G.
1981-01-01
Detail design of the composite aileron has been completed. The aileron design is a multi-rib configuration with single piece upper and lower covers mechanically fastened to the substructure. Covers, front, spar and ribs are fabricated with graphite/epoxy tape or fabric composite material. The design has a weight savings of 23 percent compared to the aluminum aileron. The composite aileron has 50 percent fewer fasteners and parts than the metal aileron and is predicted to be cost competitive. Structural integrity of the composite aileron was verified by structural analysis and an extensive test program. Static, failsafe, and vibration analyses have been conducted on the composite aileron using finite element models and specialized computer programs for composite material laminates. The fundamental behavior of the composite materials used in the aileron was determined by coupon tests for a variety of environmental conditions. Critical details of the design were interrogated by static and fatigue tests on full-scale subcomponents and subassemblies of the aileron.
Aerodynamic preliminary analysis system. Part 2: User's manual and program description
NASA Technical Reports Server (NTRS)
Divan, P.; Dunn, K.; Kojima, J.
1978-01-01
A comprehensive aerodynamic analysis program based on linearized potential theory is described. The solution treats thickness and attitude problems at subsonic and supersonic speeds. Three dimensional configurations with or without jet flaps having multiple nonplanar surfaces of arbitrary planform and open or closed slender bodies or noncircular contour are analyzed. Longitudinal and lateral-directional static and rotary derivative solutions are generated. The analysis is implemented on a time sharing system in conjunction with an input tablet digitizer and an interactive graphics input/output display and editing terminal to maximize its responsiveness to the preliminary analysis problem. Nominal case computation time of 45 CPU seconds on the CDC 175 for a 200 panel simulation indicates the program provides an efficient analysis for systematically performing various aerodynamic configuration tradeoff and evaluation studies.
Analytical modeling of transport aircraft crash scenarios to obtain floor pulses
NASA Technical Reports Server (NTRS)
Wittlin, G.; Lackey, D.
1983-01-01
The KRAS program was used to analyze transport aircraft candidate crash scenarios. Aircraft floor pulses and seat/occupant responses are presented. Results show that: (1) longitudinal only pulses can be represented by equivalent step inputs and/or static requirements; (2) the L1649 crash test floor longitudinal pulse for the aft direction (forward inertia) is less than 9g static or an equivalent 5g pulse; aft inertia accelerations are extremely small ((ch76) 3g) for representative crash scenarios; (3) a viable procedure to relate crash scenario floor pulses to standard laboratory dynamic and static test data using state of the art analysis and test procedures was demonstrated; and (4) floor pulse magnitudes are expected to be lower for wide body aircraft than for smaller narrow body aircraft.
a Virtual Trip to the Schwarzschild-De Sitter Black Hole
NASA Astrophysics Data System (ADS)
Bakala, Pavel; Hledík, Stanislav; Stuchlík, Zdenĕk; Truparová, Kamila; Čermák, Petr
2008-09-01
We developed realistic fully general relativistic computer code for simulation of optical projection in a strong, spherically symmetric gravitational field. Standard theoretical analysis of optical projection for an observer in the vicinity of a Schwarzschild black hole is extended to black hole spacetimes with a repulsive cosmological constant, i.e, Schwarzschild-de Sitter (SdS) spacetimes. Influence of the cosmological constant is investigated for static observers and observers radially free-falling from static radius. Simulation includes effects of gravitational lensing, multiple images, Doppler and gravitational frequency shift, as well as the amplification of intensity. The code generates images of static observers sky and a movie simulations for radially free-falling observers. Techniques of parallel programming are applied to get high performance and fast run of the simulation code.
Sofianidis, George; Dimitriou, Anna-Maria; Hatzitaki, Vassilia
2017-07-01
The present study was designed to compare the effectiveness of exercise programs with Pilates and Latin dance on older adults' static and dynamic balance. Thirty-two older adults were divided into three groups: Pilates group, Dance group, and Control group. Static and dynamic balance was assessed with following tasks: (a) tandem stance, (b) one-leg stance, and (c) periodic sway with and without metronome guidance. Analysis revealed a significant reduction of the trunk sway amplitude during the tandem stance with eyes closed, reduction in the center of pressure (CoP) displacement during one-leg stance, and increase in the amplitude of trunk oscillation during the sway task for both intervention groups, and reduction in the standard deviation of the CoP displacement during the metronome paced task only for the dance group. The differences in specific balance indices between the two programs suggest some specific adaptations that may provide useful knowledge for the selection of exercises that are better tailored to the needs of the old adult.
Deep anistropic shell program for tire analysis
NASA Technical Reports Server (NTRS)
Andersen, C. M.
1981-01-01
A finite element program was constructed to model the mechanical response of a tire, treated as a deep anisotropic shell, to specified static loads. The program is based on a Sanders Budiansky type shell theory with the effects of transverse shear deformation and bending-extensional coupling included. A displacement formulation is used together with a total Lagrangian description of the deformation. Sixteen-node quadrilateral elements with bicubic shape functions are employed. The Noor basis reduction technique and various type of symmetry considerations serve to improve the computational efficiency.
Static Analysis of Mobile Programs
2017-02-01
information flow analysis has the potential to significantly aid human auditors , but it is handicapped by high false positive rates. Instead, auditors ...presents these specifications to a human auditor for validation. We have implemented this framework for a taint analysis of An- droid apps that relies on...of queries to a human auditor . 6.4 Inferring Library Information Flow Specifications Using Dynamic Anal- ysis In [15], we present a technique to mine
NASA Technical Reports Server (NTRS)
Gupta, Kajal K.
1991-01-01
The details of an integrated general-purpose finite element structural analysis computer program which is also capable of solving complex multidisciplinary problems is presented. Thus, the SOLIDS module of the program possesses an extensive finite element library suitable for modeling most practical problems and is capable of solving statics, vibration, buckling, and dynamic response problems of complex structures, including spinning ones. The aerodynamic module, AERO, enables computation of unsteady aerodynamic forces for both subsonic and supersonic flow for subsequent flutter and divergence analysis of the structure. The associated aeroservoelastic analysis module, ASE, effects aero-structural-control stability analysis yielding frequency responses as well as damping characteristics of the structure. The program is written in standard FORTRAN to run on a wide variety of computers. Extensive graphics, preprocessing, and postprocessing routines are also available pertaining to a number of terminals.
SIRTF primary mirror design, analysis, and testing
NASA Technical Reports Server (NTRS)
Sarver, George L., III; Maa, Scott; Chang, LI
1990-01-01
The primary mirror assembly (PMA) requirements and concepts for the Space Infrared Telescope Facility (SIRTF) program are discussed. The PMA studies at NASA/ARC resulted in the design of two engineering test articles, the development of a mirror mount cryogenic static load testing system, and the procurement and partial testing of a full scale spherical mirror mounting system. Preliminary analysis and testing of the single arch mirror with conical mount design and the structured mirror with the spherical mount design indicate that the designs will meet all figure and environmental requirements of the SIRTF program.
Automated verification of flight software. User's manual
NASA Technical Reports Server (NTRS)
Saib, S. H.
1982-01-01
(Automated Verification of Flight Software), a collection of tools for analyzing source programs written in FORTRAN and AED is documented. The quality and the reliability of flight software are improved by: (1) indented listings of source programs, (2) static analysis to detect inconsistencies in the use of variables and parameters, (3) automated documentation, (4) instrumentation of source code, (5) retesting guidance, (6) analysis of assertions, (7) symbolic execution, (8) generation of verification conditions, and (9) simplification of verification conditions. Use of AVFS in the verification of flight software is described.
NASA Technical Reports Server (NTRS)
Svalbonas, V.
1973-01-01
A procedure for the structural analysis of stiffened shells of revolution is presented. A digital computer program based on the Love-Reissner first order shell theory was developed. The computer program can analyze orthotropic thin shells of revolution, subjected to unsymmetric distributed loading or concentrated line loads, as well as thermal strains. The geometrical shapes of the shells which may be analyzed are described. The shell wall cross section can be a sheet, sandwich, or reinforced sheet or sandwich. General stiffness input options are also available.
NASA Astrophysics Data System (ADS)
Harris, Christopher
In the U.S., science and math are taking spotlight in education, and rightfully so as they directly impact economic progression. Curiously absent is computer science, which despite its numerous job opportunities and growth does not have as much focus. This thesis develops a source code analysis framework using language translation, and machine learning classifiers to analyze programs written in Bricklayer for the purposes of programmatically identifying relative success or failure of a students Bricklayer program, helping teachers scale in the amount of students they can support, and providing better messaging. The thesis uses as a case study a set of student programs to demonstrate the possibilities of the framework.
A Semantic Analysis Method for Scientific and Engineering Code
NASA Technical Reports Server (NTRS)
Stewart, Mark E. M.
1998-01-01
This paper develops a procedure to statically analyze aspects of the meaning or semantics of scientific and engineering code. The analysis involves adding semantic declarations to a user's code and parsing this semantic knowledge with the original code using multiple expert parsers. These semantic parsers are designed to recognize formulae in different disciplines including physical and mathematical formulae and geometrical position in a numerical scheme. In practice, a user would submit code with semantic declarations of primitive variables to the analysis procedure, and its semantic parsers would automatically recognize and document some static, semantic concepts and locate some program semantic errors. A prototype implementation of this analysis procedure is demonstrated. Further, the relationship between the fundamental algebraic manipulations of equations and the parsing of expressions is explained. This ability to locate some semantic errors and document semantic concepts in scientific and engineering code should reduce the time, risk, and effort of developing and using these codes.
A programing system for research and applications in structural optimization
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, J.; Rogers, J. L., Jr.
1981-01-01
The flexibility necessary for such diverse utilizations is achieved by combining, in a modular manner, a state-of-the-art optimization program, a production level structural analysis program, and user supplied and problem dependent interface programs. Standard utility capabilities in modern computer operating systems are used to integrate these programs. This approach results in flexibility of the optimization procedure organization and versatility in the formulation of constraints and design variables. Features shown in numerical examples include: variability of structural layout and overall shape geometry, static strength and stiffness constraints, local buckling failure, and vibration constraints.
Correlation of AH-1G airframe test data with a NASTRAN mathematical model
NASA Technical Reports Server (NTRS)
Cronkhite, J. D.; Berry, V. L.
1976-01-01
Test data was provided for evaluating a mathematical vibration model of the Bell AH-1G helicopter airframe. The math model was developed and analyzed using the NASTRAN structural analysis computer program. Data from static and dynamic tests were used for comparison with the math model. Static tests of the fuselage and tailboom were conducted to verify the stiffness representation of the NASTRAN model. Dynamic test data were obtained from shake tests of the airframe and were used to evaluate the NASTRAN model for representing the low frequency (below 30 Hz) vibration response of the airframe.
Structural Analysis of Kufasat Using Ansys Program
NASA Astrophysics Data System (ADS)
Al-Maliky, Firas T.; AlBermani, Mohamed J.
2018-03-01
The current work focuses on vibration and modal analysis of KufaSat structure using ANSYS 16 program. Three types of Aluminum alloys (5052-H32, 6061-T6 and 7075-T6) were selected for investigation of the structure under design loads. Finite element analysis (FEA) in design static load of 51 g was performed. The natural frequencies for five modes were estimated using modal analysis. In order to ensure that KufaSat could withstand with various conditions during launch, the Margin of safety was calculated. The results of deformation and Von Mises stress for linear buckling analysis were also performed. The comparison of data was done to select the optimum material for KufaSat structures.
Probabilistic structural analysis by extremum methods
NASA Technical Reports Server (NTRS)
Nafday, Avinash M.
1990-01-01
The objective is to demonstrate discrete extremum methods of structural analysis as a tool for structural system reliability evaluation. Specifically, linear and multiobjective linear programming models for analysis of rigid plastic frames under proportional and multiparametric loadings, respectively, are considered. Kinematic and static approaches for analysis form a primal-dual pair in each of these models and have a polyhedral format. Duality relations link extreme points and hyperplanes of these polyhedra and lead naturally to dual methods for system reliability evaluation.
Embedded data collector (EDC) evaluation, phase II - comparison with instrumented static load tests.
DOT National Transportation Integrated Search
2013-12-01
A total of 139 piles and 213,000 hammer blows were compared between the Embedded Data Collector : (EDC), the Pile Driving Analyzer (PDA), and the CAse Pile Wave Analysis Program (CAPWAP) along with : SmartPile Review versions (3.6, 3.72, 3.73, 3.76 a...
Static analysis techniques for semiautomatic synthesis of message passing software skeletons
Sottile, Matthew; Dagit, Jason; Zhang, Deli; ...
2015-06-29
The design of high-performance computing architectures demands performance analysis of large-scale parallel applications to derive various parameters concerning hardware design and software development. The process of performance analysis and benchmarking an application can be done in several ways with varying degrees of fidelity. One of the most cost-effective ways is to do a coarse-grained study of large-scale parallel applications through the use of program skeletons. The concept of a “program skeleton” that we discuss in this article is an abstracted program that is derived from a larger program where source code that is determined to be irrelevant is removed formore » the purposes of the skeleton. In this work, we develop a semiautomatic approach for extracting program skeletons based on compiler program analysis. Finally, we demonstrate correctness of our skeleton extraction process by comparing details from communication traces, as well as show the performance speedup of using skeletons by running simulations in the SST/macro simulator.« less
NASA Technical Reports Server (NTRS)
Bittker, D. A.; Scullin, V. J.
1972-01-01
A general chemical kinetics program is described for complex, homogeneous ideal-gas reactions in any chemical system. Its main features are flexibility and convenience in treating many different reaction conditions. The program solves numerically the differential equations describing complex reaction in either a static system or one-dimensional inviscid flow. Applications include ignition and combustion, shock wave reactions, and general reactions in a flowing or static system. An implicit numerical solution method is used which works efficiently for the extreme conditions of a very slow or a very fast reaction. The theory is described, and the computer program and users' manual are included.
Visual analysis of forest health using story maps: a tale of two forest insect pests
Susan J. Crocker; Brian F. Walters; Randall S. Morin
2015-01-01
Historically, results of surveys conducted by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service were conveyed in printed reports, featuring text, tables and static figures. Since the advent of the Internet and with the ubiquity of mobile smart devices, technology has changed how people consume information, as well as how they experience and...
FASOR - A second generation shell of revolution code
NASA Technical Reports Server (NTRS)
Cohen, G. A.
1978-01-01
An integrated computer program entitled Field Analysis of Shells of Revolution (FASOR) currently under development for NASA is described. When completed, this code will treat prebuckling, buckling, initial postbuckling and vibrations under axisymmetric static loads as well as linear response and bifurcation under asymmetric static loads. Although these modes of response are treated by existing programs, FASOR extends the class of problems treated to include general anisotropy and transverse shear deformations of stiffened laminated shells. At the same time, a primary goal is to develop a program which is free of the usual problems of modeling, numerical convergence and ill-conditioning, laborious problem setup, limitations on problem size and interpretation of output. The field method is briefly described, the shell differential equations are cast in a suitable form for solution by this method and essential aspects of the input format are presented. Numerical results are given for both unstiffened and stiffened anisotropic cylindrical shells and compared with previously published analytical solutions.
Development of an integrated aeroservoelastic analysis program and correlation with test data
NASA Technical Reports Server (NTRS)
Gupta, K. K.; Brenner, M. J.; Voelker, L. S.
1991-01-01
The details and results are presented of the general-purpose finite element STructural Analysis RoutineS (STARS) to perform a complete linear aeroelastic and aeroservoelastic analysis. The earlier version of the STARS computer program enabled effective finite element modeling as well as static, vibration, buckling, and dynamic response of damped and undamped systems, including those with pre-stressed and spinning structures. Additions to the STARS program include aeroelastic modeling for flutter and divergence solutions, and hybrid control system augmentation for aeroservoelastic analysis. Numerical results of the X-29A aircraft pertaining to vibration, flutter-divergence, and open- and closed-loop aeroservoelastic controls analysis are compared to ground vibration, wind-tunnel, and flight-test results. The open- and closed-loop aeroservoelastic control analyses are based on a hybrid formulation representing the interaction of structural, aerodynamic, and flight-control dynamics.
Integrated Structural Analysis and Test Program
NASA Technical Reports Server (NTRS)
Kaufman, Daniel
2005-01-01
An integrated structural-analysis and structure-testing computer program is being developed in order to: Automate repetitive processes in testing and analysis; Accelerate pre-test analysis; Accelerate reporting of tests; Facilitate planning of tests; Improve execution of tests; Create a vibration, acoustics, and shock test database; and Integrate analysis and test data. The software package includes modules pertaining to sinusoidal and random vibration, shock and time replication, acoustics, base-driven modal survey, and mass properties and static/dynamic balance. The program is commanded by use of ActiveX controls. There is minimal need to generate command lines. Analysis or test files are selected by opening a Windows Explorer display. After selecting the desired input file, the program goes to a so-called analysis data process or test data process, depending on the type of input data. The status of the process is given by a Windows status bar, and when processing is complete, the data are reported in graphical, tubular, and matrix form.
Backtracking and Re-execution in the Automatic Debugging of Parallelized Programs
NASA Technical Reports Server (NTRS)
Matthews, Gregory; Hood, Robert; Johnson, Stephen; Leggett, Peter; Biegel, Bryan (Technical Monitor)
2002-01-01
In this work we describe a new approach using relative debugging to find differences in computation between a serial program and a parallel version of th it program. We use a combination of re-execution and backtracking in order to find the first difference in computation that may ultimately lead to an incorrect value that the user has indicated. In our prototype implementation we use static analysis information from a parallelization tool in order to perform the backtracking as well as the mapping required between serial and parallel computations.
ERIC Educational Resources Information Center
Giagazoglou, Paraskevi; Arabatzi, Fotini; Dipla, Konstantina; Liga, Maria; Kellis, Eleftherios
2012-01-01
The aim of this study was to assess the effects of a hippotherapy program on static balance and strength in adolescents with intellectual disability (ID). Nineteen adolescents with moderate ID were assigned either an experimental group (n = 10) or a control group (n = 9). The experimental group attended a 10-week hippotherapy program. To assess…
Effects of virtual reality programs on balance in functional ankle instability
Kim, Ki-Jong; Heo, Myoung
2015-01-01
[Purpose] The aim of present study was to identify the impact that recent virtual reality training programs used in a variety of fields have had on the ankle’s static and dynamic senses of balance among subjects with functional ankle instability. [Subjects and Methods] This study randomly divided research subjects into two groups, a strengthening exercise group (Group I) and a balance exercise group (Group II), with each group consisting of 10 people. A virtual reality program was performed three times a week for four weeks. Exercises from the Nintendo Wii Fit Plus program were applied to each group for twenty minutes along with ten minutes of warming up and wrap-up exercises. [Results] Group II showed a significant decrease of post-intervention static and dynamic balance overall in the anterior-posterior, and mediolateral directions, compared with the pre-intervention test results. In comparison of post-intervention static and dynamic balance between Group I and Group II, a significant decrease was observed overall. [Conclusion] Virtual reality programs improved the static balance and dynamic balance of subjects with functional ankle instability. Virtual reality programs can be used more safely and efficiently if they are implemented under appropriate monitoring by a physiotherapist. PMID:26644652
Effects of virtual reality programs on balance in functional ankle instability.
Kim, Ki-Jong; Heo, Myoung
2015-10-01
[Purpose] The aim of present study was to identify the impact that recent virtual reality training programs used in a variety of fields have had on the ankle's static and dynamic senses of balance among subjects with functional ankle instability. [Subjects and Methods] This study randomly divided research subjects into two groups, a strengthening exercise group (Group I) and a balance exercise group (Group II), with each group consisting of 10 people. A virtual reality program was performed three times a week for four weeks. Exercises from the Nintendo Wii Fit Plus program were applied to each group for twenty minutes along with ten minutes of warming up and wrap-up exercises. [Results] Group II showed a significant decrease of post-intervention static and dynamic balance overall in the anterior-posterior, and mediolateral directions, compared with the pre-intervention test results. In comparison of post-intervention static and dynamic balance between Group I and Group II, a significant decrease was observed overall. [Conclusion] Virtual reality programs improved the static balance and dynamic balance of subjects with functional ankle instability. Virtual reality programs can be used more safely and efficiently if they are implemented under appropriate monitoring by a physiotherapist.
NASA Astrophysics Data System (ADS)
Peng, Heng; Liu, Yinghua; Chen, Haofeng
2018-05-01
In this paper, a novel direct method called the stress compensation method (SCM) is proposed for limit and shakedown analysis of large-scale elastoplastic structures. Without needing to solve the specific mathematical programming problem, the SCM is a two-level iterative procedure based on a sequence of linear elastic finite element solutions where the global stiffness matrix is decomposed only once. In the inner loop, the static admissible residual stress field for shakedown analysis is constructed. In the outer loop, a series of decreasing load multipliers are updated to approach to the shakedown limit multiplier by using an efficient and robust iteration control technique, where the static shakedown theorem is adopted. Three numerical examples up to about 140,000 finite element nodes confirm the applicability and efficiency of this method for two-dimensional and three-dimensional elastoplastic structures, with detailed discussions on the convergence and the accuracy of the proposed algorithm.
Static Analysis Using Abstract Interpretation
NASA Technical Reports Server (NTRS)
Arthaud, Maxime
2017-01-01
Short presentation about static analysis and most particularly abstract interpretation. It starts with a brief explanation on why static analysis is used at NASA. Then, it describes the IKOS (Inference Kernel for Open Static Analyzers) tool chain. Results on NASA projects are shown. Several well known algorithms from the static analysis literature are then explained (such as pointer analyses, memory analyses, weak relational abstract domains, function summarization, etc.). It ends with interesting problems we encountered (such as C++ analysis with exception handling, or the detection of integer overflow).
JPL-ANTOPT antenna structure optimization program
NASA Technical Reports Server (NTRS)
Strain, D. M.
1994-01-01
New antenna path-length error and pointing-error structure optimization codes were recently added to the MSC/NASTRAN structural analysis computer program. Path-length and pointing errors are important measured of structure-related antenna performance. The path-length and pointing errors are treated as scalar displacements for statics loading cases. These scalar displacements can be subject to constraint during the optimization process. Path-length and pointing-error calculations supplement the other optimization and sensitivity capabilities of NASTRAN. The analysis and design functions were implemented as 'DMAP ALTERs' to the Design Optimization (SOL 200) Solution Sequence of MSC-NASTRAN, Version 67.5.
20 Meter Solar Sail Analysis and Correlation
NASA Technical Reports Server (NTRS)
Taleghani, B. K.; Lively, P. S.; Banik, J.; Murphy, D. M.; Trautt, T. A.
2005-01-01
This paper describes finite element analyses and correlation studies to predict deformations and vibration modes/frequencies of a 20-meter solar sail system developed by ATK Space Systems. Under the programmatic leadership of NASA Marshall Space Flight Center's In-Space Propulsion activity, the 20-meter solar sail program objectives were to verify the design, to assess structural responses of the sail system, to implement lessons learned from a previous 10-meter quadrant system analysis and test program, and to mature solar sail technology to a technology readiness level (TRL) of 5. For this 20 meter sail system, static and ground vibration tests were conducted in NASA Glenn Research Center's 100 meter diameter vacuum chamber at Plum Brook station. Prior to testing, a preliminary analysis was performed to evaluate test conditions and to determine sensor and actuator locations. After testing was completed, an analysis of each test configuration was performed. Post-test model refinements included updated properties to account for the mass of sensors, wiring, and other components used for testing. This paper describes the development of finite element models (FEM) for sail membranes and masts in each of four quadrants at both the component and system levels, as well as an optimization procedure for the static test/analyses correlation.
Complex sample survey estimation in static state-space
Raymond L. Czaplewski
2010-01-01
Increased use of remotely sensed data is a key strategy adopted by the Forest Inventory and Analysis Program. However, multiple sensor technologies require complex sampling units and sampling designs. The Recursive Restriction Estimator (RRE) accommodates this complexity. It is a design-consistent Empirical Best Linear Unbiased Prediction for the state-vector, which...
NASA Technical Reports Server (NTRS)
Scholl, R. E. (Editor)
1979-01-01
Earthquake engineering research capabilities of the National Aeronautics and Space Administration (NASA) facilities at George C. Marshall Space Flight Center (MSFC), Alabama, were evaluated. The results indicate that the NASA/MSFC facilities and supporting capabilities offer unique opportunities for conducting earthquake engineering research. Specific features that are particularly attractive for large scale static and dynamic testing of natural and man-made structures include the following: large physical dimensions of buildings and test bays; high loading capacity; wide range and large number of test equipment and instrumentation devices; multichannel data acquisition and processing systems; technical expertise for conducting large-scale static and dynamic testing; sophisticated techniques for systems dynamics analysis, simulation, and control; and capability for managing large-size and technologically complex programs. Potential uses of the facilities for near and long term test programs to supplement current earthquake research activities are suggested.
SAP- FORTRAN STATIC SOURCE CODE ANALYZER PROGRAM (IBM VERSION)
NASA Technical Reports Server (NTRS)
Manteufel, R.
1994-01-01
The FORTRAN Static Source Code Analyzer program, SAP, was developed to automatically gather statistics on the occurrences of statements and structures within a FORTRAN program and to provide for the reporting of those statistics. Provisions have been made for weighting each statistic and to provide an overall figure of complexity. Statistics, as well as figures of complexity, are gathered on a module by module basis. Overall summed statistics are also accumulated for the complete input source file. SAP accepts as input syntactically correct FORTRAN source code written in the FORTRAN 77 standard language. In addition, code written using features in the following languages is also accepted: VAX-11 FORTRAN, IBM S/360 FORTRAN IV Level H Extended; and Structured FORTRAN. The SAP program utilizes two external files in its analysis procedure. A keyword file allows flexibility in classifying statements and in marking a statement as either executable or non-executable. A statistical weight file allows the user to assign weights to all output statistics, thus allowing the user flexibility in defining the figure of complexity. The SAP program is written in FORTRAN IV for batch execution and has been implemented on a DEC VAX series computer under VMS and on an IBM 370 series computer under MVS. The SAP program was developed in 1978 and last updated in 1985.
SAP- FORTRAN STATIC SOURCE CODE ANALYZER PROGRAM (DEC VAX VERSION)
NASA Technical Reports Server (NTRS)
Merwarth, P. D.
1994-01-01
The FORTRAN Static Source Code Analyzer program, SAP, was developed to automatically gather statistics on the occurrences of statements and structures within a FORTRAN program and to provide for the reporting of those statistics. Provisions have been made for weighting each statistic and to provide an overall figure of complexity. Statistics, as well as figures of complexity, are gathered on a module by module basis. Overall summed statistics are also accumulated for the complete input source file. SAP accepts as input syntactically correct FORTRAN source code written in the FORTRAN 77 standard language. In addition, code written using features in the following languages is also accepted: VAX-11 FORTRAN, IBM S/360 FORTRAN IV Level H Extended; and Structured FORTRAN. The SAP program utilizes two external files in its analysis procedure. A keyword file allows flexibility in classifying statements and in marking a statement as either executable or non-executable. A statistical weight file allows the user to assign weights to all output statistics, thus allowing the user flexibility in defining the figure of complexity. The SAP program is written in FORTRAN IV for batch execution and has been implemented on a DEC VAX series computer under VMS and on an IBM 370 series computer under MVS. The SAP program was developed in 1978 and last updated in 1985.
Technology advancement of the static feed water electrolysis process
NASA Technical Reports Server (NTRS)
Schubert, F. H.; Wynveen, R. A.
1977-01-01
A program to advance the technology of oxygen- and hydrogen-generating subsystems based on water electrolysis was studied. Major emphasis was placed on static feed water electrolysis, a concept characterized by low power consumption and high intrinsic reliability. The static feed based oxygen generation subsystem consists basically of three subassemblies: (1) a combined water electrolysis and product gas dehumidifier module; (2) a product gas pressure controller and; (3) a cyclically filled water feed tank. Development activities were completed at the subsystem as well as at the component level. An extensive test program including single cell, subsystem and integrated system testing was completed with the required test support accessories designed, fabricated, and assembled. Mini-product assurance activities were included throughout all phases of program activities. An extensive number of supporting technology studies were conducted to advance the technology base of the static feed water electrolysis process and to resolve problems.
Kibar, Sibel; Yıldız, Hatice Ecem; Ay, Saime; Evcik, Deniz; Ergin, Emine Süreyya
2015-09-01
To determine the effectiveness of balance exercises on the functional level and quality of life (QOL) of patients with fibromyalgia syndrome (FMS) and to investigate the circumstances associated with balance disorders in FMS. Randomized controlled trial. Physical medicine and rehabilitation clinic. Patients (N=57) (age range, 18-65y) with FMS were randomly assigned into 2 groups. Group 1 was given flexibility and balance exercises for 6 weeks, whereas group 2 received only a flexibility program as the control group. Functional balance was measured by the Berg Balance Scale (BBS), and dynamic and static balance were evaluated by a kinesthetic ability trainer (KAT) device. Fall risk was assessed with the Hendrich II fall risk model. The Nottingham Health Profile, Fibromyalgia Impact Questionnaire (FIQ), and Beck Depression Inventory (BDI) were used to determine QOL and functional and depression levels, respectively. Assessments were performed at baseline and after the 6-week program. In group 1, statistically significant improvements were observed in all parameters (P<.05), but no improvement was seen in group 2 (P>.05). When comparing the 2 groups, there were significant differences in group 1 concerning the KAT static balance test (P=.017) and FIQ measurements (P=.005). In the correlation analysis, the BDI was correlated with the BBS (r=-.434) and Hendrich II results (r=.357), whereas body mass index (BMI) was correlated with the KAT static balance measurements (r=.433), BBS (r=-.285), and fall frequency (r=.328). A 6-week balance training program had a beneficial effect on the static balance and functional levels of patients with FMS. We also observed that depression deterioration was related to balance deficit and fall risk. Higher BMI was associated with balance deficit and fall frequency. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Development of an advanced pitch active control system for a wide body jet aircraft
NASA Technical Reports Server (NTRS)
Guinn, Wiley A.; Rising, Jerry J.; Davis, Walt J.
1984-01-01
An advanced PACS control law was developed for a commercial wide-body transport (Lockheed L-1011) by using modern control theory. Validity of the control law was demonstrated by piloted flight simulation tests on the NASA Langley visual motion simulator. The PACS design objective was to develop a PACS that would provide good flying qualities to negative 10 percent static stability margins that were equivalent to those of the baseline aircraft at a 15 percent static stability margin which is normal for the L-1011. Also, the PACS was to compensate for high-Mach/high-g instabilities that degrade flying qualities during upset recoveries and maneuvers. The piloted flight simulation tests showed that the PACS met the design objectives. The simulation demonstrated good flying qualities to negative 20 percent static stability margins for hold, cruise and high-speed flight conditions. Analysis and wind tunnel tests performed on other Lockheed programs indicate that the PACS could be used on an advanced transport configuration to provide a 4 percent fuel savings which results from reduced trim drag by flying at negative static stability margins.
Daneshjoo, Abdolhamid; Mokhtar, Abdul Halim; Rahnama, Nader; Yusof, Ashril
2012-01-01
Purpose The study investigated the effects of FIFA 11+ and HarmoKnee, both being popular warm-up programs, on proprioception, and on the static and dynamic balance of professional male soccer players. Methods Under 21 year-old soccer players (n = 36) were divided randomly into 11+, HarmoKnee and control groups. The programs were performed for 2 months (24 sessions). Proprioception was measured bilaterally at 30°, 45° and 60° knee flexion using the Biodex Isokinetic Dynamometer. Static and dynamic balances were evaluated using the stork stand test and Star Excursion Balance Test (SEBT), respectively. Results The proprioception error of dominant leg significantly decreased from pre- to post-test by 2.8% and 1.7% in the 11+ group at 45° and 60° knee flexion, compared to 3% and 2.1% in the HarmoKnee group. The largest joint positioning error was in the non-dominant leg at 30° knee flexion (mean error value = 5.047), (p<0.05). The static balance with the eyes opened increased in the 11+ by 10.9% and in the HarmoKnee by 6.1% (p<0.05). The static balance with eyes closed significantly increased in the 11+ by 12.4% and in the HarmoKnee by 17.6%. The results indicated that static balance was significantly higher in eyes opened compared to eyes closed (p = 0.000). Significant improvements in SEBT in the 11+ (12.4%) and HarmoKnee (17.6%) groups were also found. Conclusion Both the 11+ and HarmoKnee programs were proven to be useful warm-up protocols in improving proprioception at 45° and 60° knee flexion as well as static and dynamic balance in professional male soccer players. Data from this research may be helpful in encouraging coaches or trainers to implement the two warm-up programs in their soccer teams. PMID:23251579
Animation, audio, and spatial ability: Optimizing multimedia for scientific explanations
NASA Astrophysics Data System (ADS)
Koroghlanian, Carol May
This study investigated the effects of audio, animation and spatial ability in a computer based instructional program for biology. The program presented instructional material via text or audio with lean text and included eight instructional sequences presented either via static illustrations or animations. High school students enrolled in a biology course were blocked by spatial ability and randomly assigned to one of four treatments (Text-Static Illustration Audio-Static Illustration, Text-Animation, Audio-Animation). The study examined the effects of instructional mode (Text vs. Audio), illustration mode (Static Illustration vs. Animation) and spatial ability (Low vs. High) on practice and posttest achievement, attitude and time. Results for practice achievement indicated that high spatial ability participants achieved more than low spatial ability participants. Similar results for posttest achievement and spatial ability were not found. Participants in the Static Illustration treatments achieved the same as participants in the Animation treatments on both the practice and posttest. Likewise, participants in the Text treatments achieved the same as participants in the Audio treatments on both the practice and posttest. In terms of attitude, participants responded favorably to the computer based instructional program. They found the program interesting, felt the static illustrations or animations made the explanations easier to understand and concentrated on learning the material. Furthermore, participants in the Animation treatments felt the information was easier to understand than participants in the Static Illustration treatments. However, no difference for any attitude item was found for participants in the Text as compared to those in the Audio treatments. Significant differences were found by Spatial Ability for three attitude items concerning concentration and interest. In all three items, the low spatial ability participants responded more positively than high spatial ability participants. In addition, low spatial ability participants reported greater mental effort than high spatial ability participants. Findings for time-in-program and time-in-instruction indicated that participants in the Animation treatments took significantly more time than participants in the Static Illustration treatments. No time differences of any type were found for participants in the Text versus Audio treatments. Implications for the design of multimedia instruction and topics for future research are included in the discussion.
Dynamics of early planetary gear trains
NASA Technical Reports Server (NTRS)
August, R.; Kasuba, R.; Frater, J. L.; Pintz, A.
1984-01-01
A method to analyze the static and dynamic loads in a planetary gear train was developed. A variable-variable mesh stiffness (VVMS) model was used to simulate the external and internal spur gear mesh behavior, and an equivalent conventional gear train concept was adapted for the dynamic studies. The analysis can be applied either involute or noninvolute spur gearing. By utilizing the equivalent gear train concept, the developed method may be extended for use for all types of epicyclic gearing. The method is incorporated into a computer program so that the static and dynamic behavior of individual components can be examined. Items considered in the analysis are: (1) static and dynamic load sharing among the planets; (2) floating or fixed Sun gear; (3) actual tooth geometry, including errors and modifications; (4) positioning errors of the planet gears; (5) torque variations due to noninvolute gear action. A mathematical model comprised of power source, load, and planetary transmission is used to determine the instantaneous loads to which the components are subjected. It considers fluctuating output torque, elastic behavior in the system, and loss of contact between gear teeth. The dynamic model has nine degrees of freedom resulting in a set of simultaneous second order differential equations with time varying coefficients, which are solved numerically. The computer program was used to determine the effect of manufacturing errors, damping and component stiffness, and transmitted load on dynamic behavior. It is indicated that this methodology offers the designer/analyst a comprehensive tool with which planetary drives may be quickly and effectively evaluated.
Jorrakate, Chaiyong; Kongsuk, Jutaluk; Pongduang, Chiraprapa; Sadsee, Boontiwa; Chanthorn, Phatchari
2015-01-01
[Purpose] The aim of the present study was to investigate the effect of yoga training on static and dynamic standing balance in obese individuals with poor standing balance. [Subjects and Methods] Sixteen obese volunteers were randomly assigned into yoga and control groups. The yoga training program was performed for 45 minutes per day, 3 times per week, for 4 weeks. Static and dynamic balance were assessed in volunteers with one leg standing and functional reach tests. Outcome measures were tested before training and after a single week of training. Two-way repeated measure analysis of variance with Tukey’s honestly significant difference post hoc statistics was used to analyze the data. [Results] Obese individuals showed significantly increased static standing balance in the yoga training group, but there was no significant improvement of static or dynamic standing balance in the control group after 4 weeks. In the yoga group, significant increases in static standing balance was found after the 2nd, 3rd, and 4th weeks. Compared with the control group, static standing balance in the yoga group was significantly different after the 2nd week, and dynamic standing balance was significantly different after the 4th week. [Conclusion] Yoga training would be beneficial for improving standing balance in obese individuals with poor standing balance. PMID:25642038
Development and test of advanced composite components. Center Directors discretionary fund program
NASA Technical Reports Server (NTRS)
Faile, G.; Hollis, R.; Ledbetter, F.; Maldonado, J.; Sledd, J.; Stuckey, J.; Waggoner, G.; Engler, E.
1985-01-01
This report describes the design, analysis, fabrication, and test of a complex bathtub fitting. Graphite fibers in an epoxy matrix were utilized in manufacturing of 11 components representing four different design and layup concepts. Design allowables were developed for use in the final stress analysis. Strain gage measurements were taken throughout the static load test and correlation of test and analysis data were performed, yielding good understanding of the material behavior and instrumentation requirements for future applications.
Nonapplicability of linear finite element programs to the stress analysis of tires
NASA Technical Reports Server (NTRS)
Durand, M.; Jankovich, E.
1972-01-01
A static finite element stress analysis of an inflated radial car tire was carried out. The deformed shape of the sidewall presents outward bulging. The analysis of a homogeneous isotropic toroidal shell shows that the problem is common to all solids of this type. The study suggests that the geometric stiffness due to the inflation pressure has to be taken into account. Also, the resulting large displacements make it necessary for the geometry to be updated at each load step.
Lam, Sean Shao Wei; Zhang, Ji; Zhang, Zhong Cheng; Oh, Hong Choon; Overton, Jerry; Ng, Yih Yng; Ong, Marcus Eng Hock
2015-02-01
Dynamically reassigning ambulance deployment locations throughout a day to balance ambulance availability and demands can be effective in reducing response times. The objectives of this study were to model dynamic ambulance allocation plans in Singapore based on the system status management (SSM) strategy and to evaluate the dynamic deployment plans using a discrete event simulation (DES) model. The geographical information system-based analysis and mathematical programming were used to develop the dynamic ambulance deployment plans for SSM based on ambulance calls data from January 1, 2011, to June 30, 2011. A DES model that incorporated these plans was used to compare the performance of the dynamic SSM strategy against static reallocation policies under various demands and travel time uncertainties. When the deployment plans based on the SSM strategy were followed strictly, the DES model showed that the geographical information system-based plans resulted in approximately 13-second reduction in the median response times compared to the static reallocation policy, whereas the mathematical programming-based plans resulted in approximately a 44-second reduction. The response times and coverage performances were still better than the static policy when reallocations happened for only 60% of all the recommended moves. Dynamically reassigning ambulance deployment locations based on the SSM strategy can result in superior response times and coverage performance compared to static reallocation policies even when the dynamic plans were not followed strictly. Copyright © 2014 Elsevier Inc. All rights reserved.
Guide to a condensed form of NASTRAN
NASA Technical Reports Server (NTRS)
Rogers, J. L., Jr.
1978-01-01
A limited capability form of NASTRAN level 16 is presented to meet the needs of universities and small consulting firms. The input cards, the programming language of the direct matrix abstraction program, the plotting, the problem definition, and the modules' diagnostic messages are described. Sample problems relating to the analysis of linear static, vibration, and buckling are included. This guide can serve as a handbook for instructional courses in the use of NASTRAN or for users who need only the capability provided by the condensed form.
Pretest Round Robin Analysis of 1:4-Scale Prestressed Concrete Containment Vessel Model
DOE Office of Scientific and Technical Information (OSTI.GOV)
HESSHEIMER,MICHAEL F.; LUK,VINCENT K.; KLAMERUS,ERIC W.
The purpose of the program is to investigate the response of representative scale models of nuclear containment to pressure loading beyond the design basis accident and to compare analytical predictions to measured behavior. This objective is accomplished by conducting static, pneumatic overpressurization tests of scale models at ambient temperature. This research program consists of testing two scale models: a steel containment vessel (SCV) model (tested in 1996) and a prestressed concrete containment vessel (PCCV) model, which is the subject of this paper.
Statis Program Analysis for Reliable, Trusted Apps
2017-02-01
flexibility to system design. However, it is challenging for a static analysis to compute or verify properties about a system that uses implicit control...sources might affect the variable’s value. The type qualifier @Sink indicates where (information computed from) the value might be output. These...upper bound on the set of sensitive sources that were actually used to compute the value. If the type of x is qualified by @Source({INTERNET, LOCATION
IKOS: A Framework for Static Analysis based on Abstract Interpretation (Tool Paper)
NASA Technical Reports Server (NTRS)
Brat, Guillaume P.; Laserna, Jorge A.; Shi, Nija; Venet, Arnaud Jean
2014-01-01
The RTCA standard (DO-178C) for developing avionic software and getting certification credits includes an extension (DO-333) that describes how developers can use static analysis in certification. In this paper, we give an overview of the IKOS static analysis framework that helps developing static analyses that are both precise and scalable. IKOS harnesses the power of Abstract Interpretation and makes it accessible to a larger class of static analysis developers by separating concerns such as code parsing, model development, abstract domain management, results management, and analysis strategy. The benefits of the approach is demonstrated by a buffer overflow analysis applied to flight control systems.
ERIC Educational Resources Information Center
Mahoney, Joyce; And Others
1988-01-01
Evaluates 10 courseware packages covering topics for introductory physics. Discusses the price; sub-topics; program type; interaction; possible hardware; time; calculus required; graphics; and comments on each program. Recommends two packages in projectile and circular motion, and three packages in statics and rotational dynamics. (YP)
NASA Technical Reports Server (NTRS)
1973-01-01
The proceedings of a conference on NASA Structural Analysis (NASTRAN) to analyze the experiences of users of the program are presented. The subjects discussed include the following: (1) statics and buckling, (2) vibrations and dynamics, (3) substructing, (4) new capability, (5) user's experience, and (6) system experience. Specific applications of NASTRAN to spacecraft, aircraft, nuclear power plants, and materials tests are reported.
Analysis of muscle activation in lower extremity for static balance.
Chakravarty, Kingshuk; Chatterjee, Debatri; Das, Rajat Kumar; Tripathy, Soumya Ranjan; Sinha, Aniruddha
2017-07-01
Balance plays an important role for human bipedal locomotion. Degeneration of balance control is prominent in stroke patients, elderly adults and even for majority of obese people. Design of personalized balance training program, in order to strengthen muscles, requires the analysis of muscle activation during an activity. In this paper we have proposed an affordable and portable approach to analyze the relationship between the static balance strategy and activation of various lower extremity muscles. To do that we have considered Microsoft Kinect XBox 360 as a motion sensing device and Wii balance board for measuring external force information. For analyzing the muscle activation pattern related to static balance, participants are asked to do the single limb stance (SLS) exercise on the balance board and in front of the Kinect. Static optimization to minimize the overall muscle activation pattern is carried out using OpenSim, which is an open-source musculoskeletal simulation software. The study is done on ten normal and ten obese people, grouped according to body mass index (BMI). Results suggest that the lower extremity muscles like biceps femoris, psoas major, sartorius, iliacus play the major role for both maintaining the balance using one limb as well as maintaining the flexion of the other limb during SLS. Further investigations reveal that the higher muscle activations of the flexed leg for normal group demonstrate higher strength. Moreover, the lower muscle activation of the standing leg for normal group demonstrate more headroom for the biceps femoris-short-head and psoas major to withstand the load and hence have better static balance control.
DC-9 Flight Demonstration Program with Refanned JT8D Engines. Volume 3; Performance and Analysis
NASA Technical Reports Server (NTRS)
1975-01-01
The JT8D-109 engine has a sea level static, standard day bare engine takeoff thrust of 73,840 N. At sea level standard day conditions the additional thrust of the JT8D-109 results in 2,040 kg additional takeoff gross weight capability for a given field length. Range loss of the DC-9 Refan airplane for long range cruise was determined. The Refan airplane demonstrated stall, static longitudinal stability, longitudinal control, longitudinal trim, minimum control speeds, and directional control characteristics similar to the DC-9-30 production airplane and complied with airworthiness requirements. Cruise, climb, and thrust reverser performance were evaluated. Structural and dynamic ground test, flight test and analytical results substantiate Refan Program requirements that the nacelle, thrust reverser hardware, and the airplane structural modifications are flightworthy and certifiable and that the airplane meets flutter speed margins. Estimated unit cost of a DC-9 Refan retrofit program is 1.338 million in mid-1975 dollars with about an equal split in cost between airframe and engine.
Experimental characterization of composites. [load test methods
NASA Technical Reports Server (NTRS)
Bert, C. W.
1975-01-01
The experimental characterization for composite materials is generally more complicated than for ordinary homogeneous, isotropic materials because composites behave in a much more complex fashion, due to macroscopic anisotropic effects and lamination effects. Problems concerning the static uniaxial tension test for composite materials are considered along with approaches for conducting static uniaxial compression tests and static uniaxial bending tests. Studies of static shear properties are discussed, taking into account in-plane shear, twisting shear, and thickness shear. Attention is given to static multiaxial loading, systematized experimental programs for the complete characterization of static properties, and dynamic properties.
Current Research in Aircraft Tire Design and Performance
NASA Technical Reports Server (NTRS)
Tanner, J. A.; Mccarthy, J. L.; Clark, S. K.
1981-01-01
A review of the tire research programs which address the various needs identified by landing gear designers and airplane users is presented. The experimental programs are designed to increase tire tread lifetimes, relate static and dynamic tire properties, establish the tire hydroplaning spin up speed, study gear response to tire failures, and define tire temperature profiles during taxi, braking, and cornering operations. The analytical programs are aimed at providing insights into the mechanisms of heat generation in rolling tires and developing the tools necessary to streamline the tire design process and to aid in the analysis of landing gear problems.
NASA Technical Reports Server (NTRS)
Hinnant, Howard E.; Hodges, Dewey H.
1987-01-01
The General Rotorcraft Aeromechanical Stability Program (GRASP) was developed to analyse the steady-state and linearized dynamic behavior of rotorcraft in hovering and axial flight conditions. Because of the nature of problems GRASP was created to solve, the geometrically nonlinear behavior of beams is one area in which the program must perform well in order to be of any value. Numerical results obtained from GRASP are compared to both static and dynamic experimental data obtained for a cantilever beam undergoing large displacements and rotations caused by deformations. The correlation is excellent in all cases.
An Expert System for the Development of Efficient Parallel Code
NASA Technical Reports Server (NTRS)
Jost, Gabriele; Chun, Robert; Jin, Hao-Qiang; Labarta, Jesus; Gimenez, Judit
2004-01-01
We have built the prototype of an expert system to assist the user in the development of efficient parallel code. The system was integrated into the parallel programming environment that is currently being developed at NASA Ames. The expert system interfaces to tools for automatic parallelization and performance analysis. It uses static program structure information and performance data in order to automatically determine causes of poor performance and to make suggestions for improvements. In this paper we give an overview of our programming environment, describe the prototype implementation of our expert system, and demonstrate its usefulness with several case studies.
NASA Astrophysics Data System (ADS)
Derajat; Hariowibowo, Hindawan
2018-04-01
The new proposed In-Flight Pitot Static Calibration Method has been carried out during Development and Qualification of CN235-100 MPA (Military Patrol Aircraft). This method is expected to reduce flight hours, less human resources required, no additional special equipment, simple analysis calculation and finally by using this method it is expected to automatically minimized operational cost. At The Indonesian Aerospace (IAe) Flight Test Center Division, the development and updating of new flight test technique and data analysis method as specially for flight physics test subject are still continued to be developed as long as it safety for flight and give additional value for the industrial side. More than 30 years, Flight Test Data Engineers at The Flight Test center Division work together with the Air Crew (Test Pilots, Co-Pilots, and Flight Test Engineers) to execute the flight test activity with standard procedure for both the existance or development test techniques and test data analysis. In this paper the approximation of mathematical model, data reduction and flight test technique of The In-Flight Pitot Static Calibration by using Radio Altimeter as reference will be described and the test results had been compared with another methods ie. By using Global Position System (GPS) and the traditional method (Tower Fly By Method) which were used previously during this Flight Test Program (Ref. [10]). The flight test data case are using CN235-100 MPA flight test data during development and Qualification Flight Test Program at Cazaux Airport, France, in June-November 2009 (Ref. [2]).
Static aeroelastic analysis and tailoring of missile control fins
NASA Technical Reports Server (NTRS)
Mcintosh, S. C., Jr.; Dillenius, M. F. E.
1989-01-01
A concept for enhancing the design of control fins for supersonic tactical missiles is described. The concept makes use of aeroelastic tailoring to create fin designs (for given planforms) that limit the variations in hinge moments that can occur during maneuvers involving high load factors and high angles of attack. It combines supersonic nonlinear aerodynamic load calculations with finite-element structural modeling, static and dynamic structural analysis, and optimization. The problem definition is illustrated. The fin is at least partly made up of a composite material. The layup is fixed, and the orientations of the material principal axes are allowed to vary; these are the design variables. The objective is the magnitude of the difference between the chordwise location of the center of pressure and its desired location, calculated for a given flight condition. Three types of constraints can be imposed: upper bounds on static displacements for a given set of load conditions, lower bounds on specified natural frequencies, and upper bounds on the critical flutter damping parameter at a given set of flight speeds and altitudes. The idea is to seek designs that reduce variations in hinge moments that would otherwise occur. The block diagram describes the operation of the computer program that accomplishes these tasks. There is an option for a single analysis in addition to the optimization.
Crashworthy airframe design concepts: Fabrication and testing
NASA Technical Reports Server (NTRS)
Cronkhite, J. D.; Berry, V. L.
1982-01-01
Crashworthy floor concepts applicable to general aviation aircraft metal airframe structures were investigated. Initially several energy absorbing lower fuselage structure concepts were evaluated. Full scale floor sections representative of a twin engine, general aviation airplane lower fuselage structure were designed and fabricated. The floors featured an upper high strength platform with an energy absorbing, crushable structure underneath. Eighteen floors were fabricated that incorporated five different crushable subfloor concepts. The floors were then evaluated through static and dynamic testing. Computer programs NASTRAN and KRASH were used for the static and dynamic analysis of the floor section designs. Two twin engine airplane fuselages were modified to incorporate the most promising crashworthy floor sections for test evaluation.
The economics of project analysis: Optimal investment criteria and methods of study
NASA Technical Reports Server (NTRS)
Scriven, M. C.
1979-01-01
Insight is provided toward the development of an optimal program for investment analysis of project proposals offering commercial potential and its components. This involves a critique of economic investment criteria viewed in relation to requirements of engineering economy analysis. An outline for a systems approach to project analysis is given Application of the Leontief input-output methodology to analysis of projects involving multiple processes and products is investigated. Effective application of elements of neoclassical economic theory to investment analysis of project components is demonstrated. Patterns of both static and dynamic activity levels are incorporated.
Nowomiejska, Katarzyna; Oleszczuk, Agnieszka; Zubilewicz, Anna; Krukowski, Jacek; Mańkowska, Anna; Rejdak, Robert; Zagórski, Zbigniew
2007-01-01
To compare the visual field results obtained by static perimetry, microperimetry and rabbit perimetry in patients suffering from dry age related macular degeneration (AMD). Fifteen eyes with dry AMD (hard or soft macula drusen and RPE disorders) were enrolled into the study. Static perimetry was performed using M2 macula program included in Octopus 101 instrument. Microperimetry was performed using macula program (14-2 threshold, 10dB) within 10 degrees of the central visual field. The fovea program within 4 degrees was used while performing rarebit perimetry. The mean sensitivity was significantly lower (p<0.001) during microperimetry (13.5 dB) comparing to static perimetry (26.7 dB). The mean deviation was significantly higher (p<0.001) during microperimetry (-6.32 dB) comparing to static perimetry (-3.11 dB). The fixation was unstable in 47% and eccentric in 40% while performing microperimetry. The median of the "mean hit rate" in rarebit perimetry was 90% (range 40-100%). The mean examination duration was 6.5 min. in static perimetry, 10.6 min. in microperimetry and 5,5 min. in rarebit perimetry (p<0.001). Sensitivity was 30%, 53% and 93% respectively. The visual field defects obtained by microperimetry were more pronounced than those obtained by static perimetry. Microperimetry was the most sensitive procedure although the most time-consuming. Microperimetry enables the control of the fixation position and stability, that is not possible using the remaining methods. Rarebit perimetry revealed slight reduction of the integrity of neural architecture of the retina. Microperimetry and rarebit perimetry provide more information in regard to the visual function than static perimetry, thus are the valuable method in the diagnosis of dry AMD.
Gatica-Rojas, Valeska; Cartes-Velásquez, Ricardo; Méndez-Rebolledo, Guillermo; Guzman-Muñoz, Eduardo; Lizama, L Eduardo Cofré
2017-08-01
This study sought to evaluate the effects of a Nintendo Wii Balance Board (NWBB) intervention on ankle spasticity and static standing balance in young people with spastic cerebral palsy (SCP). Ten children and adolescents (aged 72-204 months) with SCP participated in an exercise program with NWBB. The intervention lasted 6 weeks, 3 sessions per week, 25 minutes for each session. Ankle spasticity was assessed using the Modified Modified Ashworth Scale (MMAS), and static standing balance was quantified using posturographic measures (center-of-pressure [CoP] measures). Pre- and post-intervention measures were compared. Significant decreases of spasticity in the ankle plantar flexor muscles (p < 0.01). There was also a significant reduction in the CoP sway area (p = 0.04), CoP mediolateral velocity (p =0.03), and CoP anterior-posterior velocity (p = 0.03). A 6-session NWBB program reduces the spasticity at the ankle plantar flexors and improves the static standing balance in young people with SCP.
Thermohydrodynamic Analysis of Cryogenic Liquid Turbulent Flow Fluid Film Bearings
NASA Technical Reports Server (NTRS)
San Andres, Luis
1996-01-01
This report describes a thermohydrodynamic analysis and computer programs for the prediction of the static and dynamic force response of fluid film bearings for cryogenic applications. The research performed addressed effectively the most important theoretical and practical issues related to the operation and performance of cryogenic fluid film bearings. Five computer codes have been licensed by the Texas A&M University to NASA centers and contractors and a total of 14 technical papers have been published.
CARES/LIFE Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Powers, Lynn M.; Janosik, Lesley A.; Gyekenyesi, John P.
2003-01-01
This manual describes the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction (CARES/LIFE) computer program. The program calculates the time-dependent reliability of monolithic ceramic components subjected to thermomechanical and/or proof test loading. CARES/LIFE is an extension of the CARES (Ceramic Analysis and Reliability Evaluation of Structures) computer program. The program uses results from MSC/NASTRAN, ABAQUS, and ANSYS finite element analysis programs to evaluate component reliability due to inherent surface and/or volume type flaws. CARES/LIFE accounts for the phenomenon of subcritical crack growth (SCG) by utilizing the power law, Paris law, or Walker law. The two-parameter Weibull cumulative distribution function is used to characterize the variation in component strength. The effects of multiaxial stresses are modeled by using either the principle of independent action (PIA), the Weibull normal stress averaging method (NSA), or the Batdorf theory. Inert strength and fatigue parameters are estimated from rupture strength data of naturally flawed specimens loaded in static, dynamic, or cyclic fatigue. The probabilistic time-dependent theories used in CARES/LIFE, along with the input and output for CARES/LIFE, are described. Example problems to demonstrate various features of the program are also included.
Tools for Designing and Analyzing Structures
NASA Technical Reports Server (NTRS)
Luz, Paul L.
2005-01-01
Structural Design and Analysis Toolset is a collection of approximately 26 Microsoft Excel spreadsheet programs, each of which performs calculations within a different subdiscipline of structural design and analysis. These programs present input and output data in user-friendly, menu-driven formats. Although these programs cannot solve complex cases like those treated by larger finite element codes, these programs do yield quick solutions to numerous common problems more rapidly than the finite element codes, thereby making it possible to quickly perform multiple preliminary analyses - e.g., to establish approximate limits prior to detailed analyses by the larger finite element codes. These programs perform different types of calculations, as follows: 1. determination of geometric properties for a variety of standard structural components; 2. analysis of static, vibrational, and thermal- gradient loads and deflections in certain structures (mostly beams and, in the case of thermal-gradients, mirrors); 3. kinetic energies of fans; 4. detailed analysis of stress and buckling in beams, plates, columns, and a variety of shell structures; and 5. temperature dependent properties of materials, including figures of merit that characterize strength, stiffness, and deformation response to thermal gradients
NASA Astrophysics Data System (ADS)
Wray, Richard B.
1991-12-01
A hybrid requirements analysis methodology was developed, based on the practices actually used in developing a Space Generic Open Avionics Architecture. During the development of this avionics architecture, a method of analysis able to effectively define the requirements for this space avionics architecture was developed. In this methodology, external interfaces and relationships are defined, a static analysis resulting in a static avionics model was developed, operating concepts for simulating the requirements were put together, and a dynamic analysis of the execution needs for the dynamic model operation was planned. The systems engineering approach was used to perform a top down modified structured analysis of a generic space avionics system and to convert actual program results into generic requirements. CASE tools were used to model the analyzed system and automatically generate specifications describing the model's requirements. Lessons learned in the use of CASE tools, the architecture, and the design of the Space Generic Avionics model were established, and a methodology notebook was prepared for NASA. The weaknesses of standard real-time methodologies for practicing systems engineering, such as Structured Analysis and Object Oriented Analysis, were identified.
NASA Technical Reports Server (NTRS)
Wray, Richard B.
1991-01-01
A hybrid requirements analysis methodology was developed, based on the practices actually used in developing a Space Generic Open Avionics Architecture. During the development of this avionics architecture, a method of analysis able to effectively define the requirements for this space avionics architecture was developed. In this methodology, external interfaces and relationships are defined, a static analysis resulting in a static avionics model was developed, operating concepts for simulating the requirements were put together, and a dynamic analysis of the execution needs for the dynamic model operation was planned. The systems engineering approach was used to perform a top down modified structured analysis of a generic space avionics system and to convert actual program results into generic requirements. CASE tools were used to model the analyzed system and automatically generate specifications describing the model's requirements. Lessons learned in the use of CASE tools, the architecture, and the design of the Space Generic Avionics model were established, and a methodology notebook was prepared for NASA. The weaknesses of standard real-time methodologies for practicing systems engineering, such as Structured Analysis and Object Oriented Analysis, were identified.
Cardiovascular responses to static exercise in distance runners and weight lifters
NASA Technical Reports Server (NTRS)
Longhurst, J. C.; Kelly, A. R.; Gonyea, W. J.; Mitchell, J. H.
1980-01-01
Three groups of athletes including long-distance runners, competitive and amateur weight lifters, and age- and sex-matched control subjects have been studied by hemodynamic and echocardiographic methods in order to determine the effect of the training programs on the cardiovascular response to static exercise. Blood pressure, heart rate, and double product data at rest and at fatigue suggest that competitive endurance (dynamic exercise) training alters the cardiovascular response to static exercise. In contrast to endurance exercise, weight lifting (static exercise) training does not alter the cardiovascular response to static exercise: weight lifters responded to static exercise in a manner very similar to that of the control subjects.
Combining Static Analysis and Model Checking for Software Analysis
NASA Technical Reports Server (NTRS)
Brat, Guillaume; Visser, Willem; Clancy, Daniel (Technical Monitor)
2003-01-01
We present an iterative technique in which model checking and static analysis are combined to verify large software systems. The role of the static analysis is to compute partial order information which the model checker uses to reduce the state space. During exploration, the model checker also computes aliasing information that it gives to the static analyzer which can then refine its analysis. The result of this refined analysis is then fed back to the model checker which updates its partial order reduction. At each step of this iterative process, the static analysis computes optimistic information which results in an unsafe reduction of the state space. However we show that the process converges to a fired point at which time the partial order information is safe and the whole state space is explored.
The Effects of Exercise on the Firing Patterns of Single Motor Units.
ERIC Educational Resources Information Center
Cracraft, Joe D.
In this study, the training effects of static and dynamic exercise programs on the firing patterns of 450 single motor units (SMU) in the human tibialis anterior muscle were investigated. In a six week program, the static group (N=5) participated in daily high intensity, short duration, isometric exercises while the dynamic group (N=5)…
Aerodynamic preliminary analysis system. Part 1: Theory. [linearized potential theory
NASA Technical Reports Server (NTRS)
Bonner, E.; Clever, W.; Dunn, K.
1978-01-01
A comprehensive aerodynamic analysis program based on linearized potential theory is described. The solution treats thickness and attitude problems at subsonic and supersonic speeds. Three dimensional configurations with or without jet flaps having multiple non-planar surfaces of arbitrary planform and open or closed slender bodies of non-circular contour may be analyzed. Longitudinal and lateral-directional static and rotary derivative solutions may be generated. The analysis was implemented on a time sharing system in conjunction with an input tablet digitizer and an interactive graphics input/output display and editing terminal to maximize its responsiveness to the preliminary analysis problem. Nominal case computation time of 45 CPU seconds on the CDC 175 for a 200 panel simulation indicates the program provides an efficient analysis for systematically performing various aerodynamic configuration tradeoff and evaluation studies.
Time-dependent reliability analysis of ceramic engine components
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.
1993-01-01
The computer program CARES/LIFE calculates the time-dependent reliability of monolithic ceramic components subjected to thermomechanical and/or proof test loading. This program is an extension of the CARES (Ceramics Analysis and Reliability Evaluation of Structures) computer program. CARES/LIFE accounts for the phenomenon of subcritical crack growth (SCG) by utilizing either the power or Paris law relations. The two-parameter Weibull cumulative distribution function is used to characterize the variation in component strength. The effects of multiaxial stresses are modeled using either the principle of independent action (PIA), the Weibull normal stress averaging method (NSA), or the Batdorf theory. Inert strength and fatigue parameters are estimated from rupture strength data of naturally flawed specimens loaded in static, dynamic, or cyclic fatigue. Two example problems demonstrating proof testing and fatigue parameter estimation are given.
PedVizApi: a Java API for the interactive, visual analysis of extended pedigrees.
Fuchsberger, Christian; Falchi, Mario; Forer, Lukas; Pramstaller, Peter P
2008-01-15
PedVizApi is a Java API (application program interface) for the visual analysis of large and complex pedigrees. It provides all the necessary functionality for the interactive exploration of extended genealogies. While available packages are mostly focused on a static representation or cannot be added to an existing application, PedVizApi is a highly flexible open source library for the efficient construction of visual-based applications for the analysis of family data. An extensive demo application and a R interface is provided. http://www.pedvizapi.org
Aerodynamics for the Mars Phoenix Entry Capsule
NASA Technical Reports Server (NTRS)
Edquist, Karl T.; Desai, Prasun N.; Schoenenberger, Mark
2008-01-01
Pre-flight aerodynamics data for the Mars Phoenix entry capsule are presented. The aerodynamic coefficients were generated as a function of total angle-of-attack and either Knudsen number, velocity, or Mach number, depending on the flight regime. The database was constructed using continuum flowfield computations and data from the Mars Exploration Rover and Viking programs. Hypersonic and supersonic static coefficients were derived from Navier-Stokes solutions on a pre-flight design trajectory. High-altitude data (free-molecular and transitional regimes) and dynamic pitch damping characteristics were taken from Mars Exploration Rover analysis and testing. Transonic static coefficients from Viking wind tunnel tests were used for capsule aerodynamics under the parachute. Static instabilities were predicted at two points along the reference trajectory and were verified by reconstructed flight data. During the hypersonic instability, the capsule was predicted to trim at angles as high as 2.5 deg with an on-axis center-of-gravity. Trim angles were predicted for off-nominal pitching moment (4.2 deg peak) and a 5 mm off-axis center-ofgravity (4.8 deg peak). Finally, hypersonic static coefficient sensitivities to atmospheric density were predicted to be within uncertainty bounds.
Patents, Innovation, and the Welfare Effects of Medicare Part D*
Gailey, Adam; Lakdawalla, Darius; Sood, Neeraj
2013-01-01
Purpose To evaluate the efficiency consequences of the Medicare Part D program. Methods We develop and empirically calibrate a simple theoretical model to examine the static and dynamic welfare effects of Medicare Part D. Findings We show that Medicare Part D can simultaneously reduce static deadweight loss from monopoly pricing of drugs and improve incentives for innovation. We estimate that even after excluding the insurance value of the program, the welfare gain of Medicare Part D roughly equals its social costs. The program generates $5.11 billion of annual static deadweight loss reduction, and at least $3.0 billion of annual value from extra innovation. Implications Medicare Part D and other public prescription drug programs can be welfare-improving, even for risk-neutral and purely self-interested consumers. Furthermore, negotiation for lower branded drug prices may further increase the social return to the program. Originality This study demonstrates that pure efficiency motives, which do not even surface in the policy debate over Medicare Part D, can nearly justify the program on their own merits. PMID:20575239
Cyclic stress analysis of an air-cooled turbine vane
NASA Technical Reports Server (NTRS)
Kaufman, A.; Gauntner, D. J.; Gauntner, J. W.
1975-01-01
The effects of gas pressure level, coolant temperature, and coolant flow rate on the stress-strain history and life of an air-cooled vane were analyzed using measured and calculated transient metal temperatures and a turbine blade stress analysis program. Predicted failure locations were compared to results from cyclic tests in a static cascade and engine. The results indicate that a high gas pressure was detrimental, a high coolant flow rate somewhat beneficial, and a low coolant temperature the most beneficial to vane life.
Advanced composite vertical fin for L-1011 aircraft
NASA Technical Reports Server (NTRS)
Jackson, A. C.
1984-01-01
The structural box of the L-1011 vertical fin was redesigned using advanced composite materials. The box was fabricated and ground tested to verify the structural integrity. This report summarizes the complete program starting with the design and analysis and proceeds through the process development ancillary test program production readiness verification testing, fabrication of the full-scale fin boxes and the full-scale ground testing. The program showed that advanced composites can economically and effectively be used in the design and fabrication of medium primary structures for commercial aircraft. Static-strength variability was demonstrated to be comparable to metal structures and the long term durability of advanced composite components was demonstrated.
NASA Technical Reports Server (NTRS)
Chiappetta, L. M.
1983-01-01
Described is a computer program for the analysis of the subsonic, swirling, reacting turbulent flow in an axisymmetric, bluff-body research combustor. The program features an improved finite-difference procedure designed to reduce the effects of numerical diffusion and a new algorithm for predicting the pressure distribution within the combustor. A research version of the computer program described in the report was supplied to United Technologies Research Center by Professor A. D. Gosman and his students, R. Benodeker and R. I. Issa, of Imperial College, London. The Imperial College staff also supplied much of the program documentation. Presented are a description of the mathematical model for flow within an axisymmetric bluff-body combustor, the development of the finite-difference procedure used to represent the system of equations, an outline of the algorithm for determining the static pressure distribution within the combustor, a description of the computer program including its input format, and the results for representative test cases.
Dynamic stability and handling qualities tests on a highly augmented, statically unstable airplane
NASA Technical Reports Server (NTRS)
Gera, Joseph; Bosworth, John T.
1987-01-01
Initial envelope clearance and subsequent flight testing of a new, fully augmented airplane with an extremely high degree of static instability can place unusual demands on the flight test approach. Previous flight test experience with these kinds of airplanes is very limited or nonexistent. The safe and efficient flight testing may be further complicated by a multiplicity of control effectors that may be present on this class of airplanes. This paper describes some novel flight test and analysis techniques in the flight dynamics and handling qualities area. These techniques were utilized during the initial flight envelope clearance of the X-29A aircraft and were largely responsible for the completion of the flight controls clearance program without any incidents or significant delays.
Lifetime Reliability Evaluation of Structural Ceramic Parts with the CARES/LIFE Computer Program
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Powers, Lynn M.; Janosik, Lesley A.; Gyekenyesi, John P.
1993-01-01
The computer program CARES/LIFE calculates the time-dependent reliability of monolithic ceramic components subjected to thermomechanical and/or proof test loading. This program is an extension of the CARES (Ceramics Analysis and Reliability Evaluation of Structures) computer program. CARES/LIFE accounts for the phenomenon of subcritical crack growth (SCG) by utilizing the power law, Paris law, or Walker equation. The two-parameter Weibull cumulative distribution function is used to characterize the variation in component strength. The effects of multiaxial stresses are modeled using either the principle of independent action (PIA), Weibull's normal stress averaging method (NSA), or Batdorf's theory. Inert strength and fatigue parameters are estimated from rupture strength data of naturally flawed specimens loaded in static, dynamic, or cyclic fatigue. Two example problems demonstrating cyclic fatigue parameter estimation and component reliability analysis with proof testing are included.
NASA Technical Reports Server (NTRS)
Strout, F. G.
1978-01-01
A JT8D-17R engine with inverted primary and fan flows was tested under static conditions as well as in the NASA Ames 40 by 80 Foot Wind Tunnel to determine static and flight noise characteristics, and flow profile of a large scale engine. Test and analysis techniques developed by a previous model and JT8D engine test program were used to determine the in-flight noise. The engine with inverted flow was tested with a conical nozzle and with a plug nozzle, 20 lobe nozzle, and an acoustic shield. Wind tunnel results show that forward velocity causes significant reduction in peak PNL suppression relative to uninverted flow. The loss of EPNL suppression is relatively modest. The in-flight peak PNL suppression of the inverter with conical nozzle was 2.5 PNdb relative to a static value of 5.5 PNdb. The corresponding EPNL suppression was 4.0 EPNdb for flight and 5.0 EPNdb for static operation. The highest in-flight EPNL suppression was 7.5 EPNdb obtained by the inverter with 20 lobe nozzle and acoustic shield. When compared with the JT8D engine with internal mixer, the inverted flow configuration provides more EPNL suppression under both static and flight conditions.
FX-87 performance measurements: data-flow implementation. Technical report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hammel, R.T.; Gifford, D.K.
1988-11-01
This report documents a series of experiments performed to explore the thesis that the FX-87 effect system permits a compiler to schedule imperative programs (i.e., programs that may contain side-effects) for execution on a parallel computer. The authors analyze how much the FX-87 static effect system can improve the execution times of five benchmark programs on a parallel graph interpreter. Three of their benchmark programs do not use side-effects (factorial, fibonacci, and polynomial division) and thus did not have any effect-induced constraints. Their FX-87 performance was comparable to their performance in a purely functional language. Two of the benchmark programsmore » use side effects (DNA sequence matching and Scheme interpretation) and the compiler was able to use effect information to reduce their execution times by factors of 1.7 to 5.4 when compared with sequential execution times. These results support the thesis that a static effect system is a powerful tool for compilation to multiprocessor computers. However, the graph interpreter we used was based on unrealistic assumptions, and thus our results may not accurately reflect the performance of a practical FX-87 implementation. The results also suggest that conventional loop analysis would complement the FX-87 effect system« less
Directed Incremental Symbolic Execution
NASA Technical Reports Server (NTRS)
Person, Suzette; Yang, Guowei; Rungta, Neha; Khurshid, Sarfraz
2011-01-01
The last few years have seen a resurgence of interest in the use of symbolic execution -- a program analysis technique developed more than three decades ago to analyze program execution paths. Scaling symbolic execution and other path-sensitive analysis techniques to large systems remains challenging despite recent algorithmic and technological advances. An alternative to solving the problem of scalability is to reduce the scope of the analysis. One approach that is widely studied in the context of regression analysis is to analyze the differences between two related program versions. While such an approach is intuitive in theory, finding efficient and precise ways to identify program differences, and characterize their effects on how the program executes has proved challenging in practice. In this paper, we present Directed Incremental Symbolic Execution (DiSE), a novel technique for detecting and characterizing the effects of program changes. The novelty of DiSE is to combine the efficiencies of static analysis techniques to compute program difference information with the precision of symbolic execution to explore program execution paths and generate path conditions affected by the differences. DiSE is a complementary technique to other reduction or bounding techniques developed to improve symbolic execution. Furthermore, DiSE does not require analysis results to be carried forward as the software evolves -- only the source code for two related program versions is required. A case-study of our implementation of DiSE illustrates its effectiveness at detecting and characterizing the effects of program changes.
Integrating multiple data sources for malware classification
Anderson, Blake Harrell; Storlie, Curtis B; Lane, Terran
2015-04-28
Disclosed herein are representative embodiments of tools and techniques for classifying programs. According to one exemplary technique, at least one graph representation of at least one dynamic data source of at least one program is generated. Also, at least one graph representation of at least one static data source of the at least one program is generated. Additionally, at least using the at least one graph representation of the at least one dynamic data source and the at least one graph representation of the at least one static data source, the at least one program is classified.
NASA Technical Reports Server (NTRS)
Barnett, Alan R.; Widrick, Timothy W.; Ludwiczak, Damian R.
1995-01-01
Solving for the displacements of free-free coupled systems acted upon by static loads is commonly performed throughout the aerospace industry. Many times, these problems are solved using static analysis with inertia relief. This solution technique allows for a free-free static analysis by balancing the applied loads with inertia loads generated by the applied loads. For some engineering applications, the displacements of the free-free coupled system induce additional static loads. Hence, the applied loads are equal to the original loads plus displacement-dependent loads. Solving for the final displacements of such systems is commonly performed using iterative solution techniques. Unfortunately, these techniques can be time-consuming and labor-intensive. Since the coupled system equations for free-free systems with displacement-dependent loads can be written in closed-form, it is advantageous to solve for the displacements in this manner. Implementing closed-form equations in static analysis with inertia relief is analogous to implementing transfer functions in dynamic analysis. Using a MSC/NASTRAN DMAP Alter, displacement-dependent loads have been included in static analysis with inertia relief. Such an Alter has been used successfully to solve efficiently a common aerospace problem typically solved using an iterative technique.
The Effects of Two Different Stretching Programs on Balance Control and Motor Neuron Excitability
ERIC Educational Resources Information Center
Kaya, Fatih; Biçer, Bilal; Yüktasir, Bekir; Willems, Mark E. T.; Yildiz, Nebil
2018-01-01
We examined the effects of training (4d/wk for 6 wks) with static stretching (SS) or contract-relax proprioceptive neuromuscular facilitation (PNF) on static balance time and motor neuron excitability. Static balance time, H[subscript max]/M[subscript max] ratios and H-reflex recovery curves (HRRC) were measured in 28 healthy subjects (SS: n = 10,…
NASA Technical Reports Server (NTRS)
Collins, J. Scott; Johnson, Eric R.
1989-01-01
Experiments were conducted to measure the three-dimensional static and free vibrational response of two graphite-epoxy, thin-walled, open section frames. The frames are semi-circular with a radius of three feet, and one specimen has an I cross section and the other has a channel cross section. The flexibility influence coefficients were measured in static tests for loads applied at midspan with the ends of the specimens clamped. Natural frequencies and modes were determined from vibrational tests for free and clamped end conditions. The experimental data is used to evaluate a new finite element which was developed specifically for the analysis of curved, thin-walled structures. The formulation of the element is based on a Vlasov-type, thin-walled, curved beam theory. The predictions from the finite element program generally correlated well with the experimental data for the symmetric I-specimen. Discrepancies in some of the data were found to be due to flexibility in the clamped end conditions. With respect to the data for the channel specimen, the correlation was less satisfactory. The finite element analysis predicted the out-of-plane response of the channel specimen reasonably well, but large discrepancies occurred between the predicted in-plane response and the experimental data. The analysis predicted a much more compliant in-plane response than was observed in the experiments.
Forced Mixer Nozzle Optimization
NASA Technical Reports Server (NTRS)
Sheoran, Yogi; Hoover, Robert; Schuster, William; Anderson, Morris; Weir, Donald S.
1999-01-01
Computational fluid dynamic (CFD) and computational acoustic analyses (CAA) were performed for a TFE731-40 compound nozzle, a TFE731-60 mixer nozzle and an Energy Efficient Engine (E(sup 3)) mixer nozzle for comparison with available data. The CFD analyses were performed with a three dimensional, Navier-Stokes solution of the flowfield on an unstructured grid using the RAMPANT program. The CAA analyses were performed with the NASA Glenn MGB program using a structured grid. A successful aerodynamic solution for the TFE731-40 compound nozzle operating statically was obtained, simulating an engine operating on a test stand. Analysis of the CFD results of the TFE731-40 with the MGB program produced predicted sound power levels that agree quite well with the measured data front full-scale static engine tests. Comparison of the predicted sound pressure with the data show good agreement near the jet axis, but the noise levels are overpredicted at angles closer to the inlet. The predicted sound power level for the TFE731-60 did not agree as well with measured static engine data as the TFE731-40. Although a reduction in the predicted noise level due to the mixed flow was observed, the reduction was not as significant as the measured data. The analysis of the V2 mixer from the E(sup 3) study showed that peak temperatures predicted in the mixer exit flowfield were within 5 percent of the values measured by the exit probes. The noise predictions of the V2 mixer nozzle tended to be 3-5 dB higher in peak noise level than the measurements. In addition, the maximum frequency of the noise was also overpredicted. An analysis of the 3 candidate mixer nozzle configurations demonstrated the feasibility of using centerbody lobes and porosity to improve mixing efficiency. A final configuration was designed with a predicted thermal mixing efficiency that was 5 percent higher than the 3 candidate mixers. The results of the MGB noise calculations show that the final design will exceed the design goal of a 3 dB reduction in noise as compared to the baseline TFE731-40.
Using Block-local Atomicity to Detect Stale-value Concurrency Errors
NASA Technical Reports Server (NTRS)
Artho, Cyrille; Havelund, Klaus; Biere, Armin
2004-01-01
Data races do not cover all kinds of concurrency errors. This paper presents a data-flow-based technique to find stale-value errors, which are not found by low-level and high-level data race algorithms. Stale values denote copies of shared data where the copy is no longer synchronized. The algorithm to detect such values works as a consistency check that does not require any assumptions or annotations of the program. It has been implemented as a static analysis in JNuke. The analysis is sound and requires only a single execution trace if implemented as a run-time checking algorithm. Being based on an analysis of Java bytecode, it encompasses the full program semantics, including arbitrarily complex expressions. Related techniques are more complex and more prone to over-reporting.
A programing system for research and applications in structural optimization
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, J.; Rogers, J. L., Jr.
1981-01-01
The paper describes a computer programming system designed to be used for methodology research as well as applications in structural optimization. The flexibility necessary for such diverse utilizations is achieved by combining, in a modular manner, a state-of-the-art optimization program, a production level structural analysis program, and user supplied and problem dependent interface programs. Standard utility capabilities existing in modern computer operating systems are used to integrate these programs. This approach results in flexibility of the optimization procedure organization and versatility in the formulation of contraints and design variables. Features shown in numerical examples include: (1) variability of structural layout and overall shape geometry, (2) static strength and stiffness constraints, (3) local buckling failure, and (4) vibration constraints. The paper concludes with a review of the further development trends of this programing system.
Aerodynamic preliminary analysis system 2. Part 2: User's manuals
NASA Technical Reports Server (NTRS)
Divan, P.
1981-01-01
An aerodynamic analysis system based on potential theory at subsonic/supersonic speeds and impact type finite element solutions at hypersonic conditions is described. Three dimensional configurations having multiple nonplanar surfaces of arbitrary planform and bodies of noncircular contour may be analyzed. Static, rotary, and control longitudinal and lateral directional chracteristics may be generated. The analysis has been implemented on a time sharing system in conjunction with an input tablet digitizer and an interactive graphics input/output display and editing terminal to maximize its responsiveness to the preliminary analysis problem. Typical simulation indicates that program provides an efficient analysis for systematically performing various aerodynamic configuration tradeoff and evaluation studies.
Aerodynamic preliminary analysis system 2. Part 1: Theory
NASA Technical Reports Server (NTRS)
Bonner, E.; Clever, W.; Dunn, K.
1991-01-01
An aerodynamic analysis system based on potential theory at subsonic and/or supersonic speeds and impact type finite element solutions at hypersonic conditions is described. Three dimensional configurations having multiple nonplanar surfaces of arbitrary planform and bodies of noncircular contour may be analyzed. Static, rotary, and control longitudinal and lateral directional characteristics may be generated. The analysis was implemented on a time sharing system in conjunction with an input tablet digitizer and an interactive graphics input/output display and editing terminal to maximize its responsiveness to the preliminary analysis problem. The program provides an efficient analysis for systematically performing various aerodynamic configuration tradeoff and evaluation studies.
Method for Statically Checking an Object-oriented Computer Program Module
NASA Technical Reports Server (NTRS)
Bierhoff, Kevin M. (Inventor); Aldrich, Jonathan (Inventor)
2012-01-01
A method for statically checking an object-oriented computer program module includes the step of identifying objects within a computer program module, at least one of the objects having a plurality of references thereto, possibly from multiple clients. A discipline of permissions is imposed on the objects identified within the computer program module. The permissions enable tracking, from among a discrete set of changeable states, a subset of states each object might be in. A determination is made regarding whether the imposed permissions are violated by a potential reference to any of the identified objects. The results of the determination are output to a user.
Mining Program Source Code for Improving Software Quality
2013-01-01
conduct static verification on the software application under analysis to detect defects around APIs. (a) Papers published in peer-reviewed journals...N/A for none) Enter List of papers submitted or published that acknowledge ARO support from the start of the project to the date of this printing...List the papers , including journal references, in the following categories: Received Paper 05/06/2013 21.00 Tao Xie, Suresh Thummalapenta, David Lo
2016-03-14
DoD Department of Defense EMI electromagnetic induction ESTCP Environmental Security Technology Certification Program ft. foot GPS global...three primary objectives: Test and validate detection and discrimination capabilities of a currently available advanced electromagnetic induction ... induction (EMI) sensors in dynamic and static data acquisition modes and associated analysis software. To achieve these objectives, a controlled test was
Static performance and noise tests on a thrust reverser for an augmentor wing aircraft
NASA Technical Reports Server (NTRS)
Harkonen, D. L.; Marrs, C. C.; Okeefe, J. V.
1974-01-01
A 1/3 scale model static test program was conducted to measure the noise levels and reverse thrust performance characteristics of wing-mounted thrust reverser that could be used on an advanced augmentor wing airplane. The configuration tested represents only the most fundamental designs where installation and packaging restraints are not considered. The thrust reverser performance is presented in terms of horizontal, vertical, and resultant effectiveness ratios and the reverser noise is compared on the basis of peak perceived noise level (PNL) and one-third octave band data (OASPL). From an analysis of the model force and acoustic data, an assessment is made on the stopping distance versus noise for a 90,900 kg (200,000 lb) airplane using this type of thrust reverser.
SRB/SLEEC (Solid Rocket Booster/Shingle Lap Extendible Exit Cone) feasibility study, volume 1
NASA Technical Reports Server (NTRS)
Baker, William H., Jr.
1986-01-01
A preliminary design and analysis was completed for a SLEEC (Shingle Lap Extendible Exit Cone) which could be incorporated on the Space Transportation System (STS) Solid Rocket Booster (SRB). Studies were completed which predicted weights and performance increases and development plans were prepared for the full-scale bench and static test of SLEEC. In conjunction with the design studies, a series of supporting analyses were performed to assure the validity and feasibility of performance, fabrication, cost, and reliability for the selected design. The feasibility and required amounts of bench, static firing, and flight tests considered necessary for the successful incorporation of SLEEC on the Shuttle SRBs were determined. Preliminary plans were completed which define both a follow on study effort and a development program.
User's Manual for Aerofcn: a FORTRAN Program to Compute Aerodynamic Parameters
NASA Technical Reports Server (NTRS)
Conley, Joseph L.
1992-01-01
The computer program AeroFcn is discussed. AeroFcn is a utility program that computes the following aerodynamic parameters: geopotential altitude, Mach number, true velocity, dynamic pressure, calibrated airspeed, equivalent airspeed, impact pressure, total pressure, total temperature, Reynolds number, speed of sound, static density, static pressure, static temperature, coefficient of dynamic viscosity, kinematic viscosity, geometric altitude, and specific energy for a standard- or a modified standard-day atmosphere using compressible flow and normal shock relations. Any two parameters that define a unique flight condition are selected, and their values are entered interactively. The remaining parameters are computed, and the solutions are stored in an output file. Multiple cases can be run, and the multiple case solutions can be stored in another output file for plotting. Parameter units, the output format, and primary constants in the atmospheric and aerodynamic equations can also be changed.
Architectural Visualization of C/C++ Source Code for Program Comprehension
DOE Office of Scientific and Technical Information (OSTI.GOV)
Panas, T; Epperly, T W; Quinlan, D
2006-09-01
Structural and behavioral visualization of large-scale legacy systems to aid program comprehension is still a major challenge. The challenge is even greater when applications are implemented in flexible and expressive languages such as C and C++. In this paper, we consider visualization of static and dynamic aspects of large-scale scientific C/C++ applications. For our investigation, we reuse and integrate specialized analysis and visualization tools. Furthermore, we present a novel layout algorithm that permits a compressive architectural view of a large-scale software system. Our layout is unique in that it allows traditional program visualizations, i.e., graph structures, to be seen inmore » relation to the application's file structure.« less
1976-01-01
a load cell for axial load sensing. The cylindrical spring fluid housing has a self-aligning bearing installed to suit the hoist rtounting provisions...PA dJ A L4 * f5 W 7 1 ~~t~ j"H2 j "xioA"AUSCCRCO El4 "sV. 10% PLA VIE - C : NJrAUk ATK ON AA U - . j4 5’ c IIf -O a ¶ .. ~~r~eF ON *A *~ A*WMA &fi
Synthesis of aircraft structures using integrated design and analysis methods
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, J.; Goetz, R. C.
1978-01-01
A systematic research is reported to develop and validate methods for structural sizing of an airframe designed with the use of composite materials and active controls. This research program includes procedures for computing aeroelastic loads, static and dynamic aeroelasticity, analysis and synthesis of active controls, and optimization techniques. Development of the methods is concerned with the most effective ways of integrating and sequencing the procedures in order to generate structural sizing and the associated active control system, which is optimal with respect to a given merit function constrained by strength and aeroelasticity requirements.
Computer code for preliminary sizing analysis of axial-flow turbines
NASA Technical Reports Server (NTRS)
Glassman, Arthur J.
1992-01-01
This mean diameter flow analysis uses a stage average velocity diagram as the basis for the computational efficiency. Input design requirements include power or pressure ratio, flow rate, temperature, pressure, and rotative speed. Turbine designs are generated for any specified number of stages and for any of three types of velocity diagrams (symmetrical, zero exit swirl, or impulse) or for any specified stage swirl split. Exit turning vanes can be included in the design. The program output includes inlet and exit annulus dimensions, exit temperature and pressure, total and static efficiencies, flow angles, and last stage absolute and relative Mach numbers. An analysis is presented along with a description of the computer program input and output with sample cases. The analysis and code presented herein are modifications of those described in NASA-TN-D-6702. These modifications improve modeling rigor and extend code applicability.
NASA Technical Reports Server (NTRS)
Laird, Philip
1992-01-01
We distinguish static and dynamic optimization of programs: whereas static optimization modifies a program before runtime and is based only on its syntactical structure, dynamic optimization is based on the statistical properties of the input source and examples of program execution. Explanation-based generalization is a commonly used dynamic optimization method, but its effectiveness as a speedup-learning method is limited, in part because it fails to separate the learning process from the program transformation process. This paper describes a dynamic optimization technique called a learn-optimize cycle that first uses a learning element to uncover predictable patterns in the program execution and then uses an optimization algorithm to map these patterns into beneficial transformations. The technique has been used successfully for dynamic optimization of pure Prolog.
Assessment of current AASHTO LRFD methods for static pile capacity analysis in Rhode Island soils.
DOT National Transportation Integrated Search
2013-07-01
This report presents an assessment of current AASHTO LRFD methods for static pile capacity analysis in Rhode : Island soils. Current static capacity methods and associated resistance factors are based on pile load test data in sands : and clays. Some...
Technology advancement of the static feed water electrolysis process
NASA Technical Reports Server (NTRS)
Jensen, F. C.; Schubert, F. H.
1977-01-01
Some results are presented of a research and development program to continue the development of a method to generate oxygen for crew metabolic consumption during extended manned space flights. The concept being pursued is that of static feed water electrolysis. Specific major results of the work included: (1) completion of a 30-day electrode test using a Life Systems, Inc.-developed high performance catalyst. During startup the cell voltages were as low as 1.38 V at current densities of 108 mA/sq cm (100 ASF) and temperatures of 355 K (180 F). At the end of 30 days of testing the cell voltages were still only 1.42 V at 108 mA/sq cm, (2) determination that the Static Feed Water Electrolysis Module does not release an aerosol of the cell electrolyte into the product gas streams after a break-in period of 24 hours following a new electrolyte charge, and (3) completion of a detailed design analysis of an electrochemical Oxygen Generation Subsystem at a three-man level (4.19 kg/day (9.24 lb/day) of oxygen).
Effects of Water-Based Training on Static and Dynamic Balance of Older Women.
Bento, Paulo Cesar Barauce; Lopes, Maria de Fátima A; Cebolla, Elaine Cristine; Wolf, Renata; Rodacki, André L F
2015-08-01
The aim of this study was to evaluate the effects of a water-based exercise program on static and dynamic balance. Thirty-six older women were randomly assigned to a water-based training (3 days/week for 12 weeks) or control group. Water level was kept at the level of the xiphoid process and temperature at ∼28-30°C. Each session included aerobic activities and lower limb strength exercises. The medial-lateral, the anterior-posterior amplitude, and displacement of the center of pressure (CP-D) were measured in a quiet standing position (60 sec eyes opened and closed). The dynamic balance and 8-Foot Up-and-Go tests were also applied. Group comparisons were made using two-way analysis of variance (ANOVA) with repeated measures. No differences were found in the center of pressure variables; however, the WBT group showed better performance in the 8 Foot Up-and-Go Test after training (5.61±0.76 vs. 5.18±0.42; p<0.01). The water-based training was effective in improving dynamic balance, but not static balance.
NASA Technical Reports Server (NTRS)
Watson, Robert A.
1991-01-01
Approximate solutions of static and dynamic beam problems by the p-version of the finite element method are investigated. Within a hierarchy of engineering beam idealizations, rigorous formulations of the strain and kinetic energies for straight and circular beam elements are presented. These formulations include rotating coordinate system effects and geometric nonlinearities to allow for the evaluation of vertical axis wind turbines, the motivating problem for this research. Hierarchic finite element spaces, based on extensions of the polynomial orders used to approximate the displacement variables, are constructed. The developed models are implemented into a general purpose computer program for evaluation. Quality control procedures are examined for a diverse set of sample problems. These procedures include estimating discretization errors in energy norm and natural frequencies, performing static and dynamic equilibrium checks, observing convergence for qualities of interest, and comparison with more exacting theories and experimental data. It is demonstrated that p-extensions produce exponential rates of convergence in the approximation of strain energy and natural frequencies for the class of problems investigated.
Whole body vibration training--improving balance control and muscle endurance.
Ritzmann, Ramona; Kramer, Andreas; Bernhardt, Sascha; Gollhofer, Albert
2014-01-01
Exercise combined with whole body vibration (WBV) is becoming increasingly popular, although additional effects of WBV in comparison to conventional exercises are still discussed controversially in literature. Heterogeneous findings are attributed to large differences in the training designs between WBV and "control" groups in regard to training volume, load and type. In order to separate the additional effects of WBV from the overall adaptations due to the intervention, in this study, a four-week WBV training setup was compared to a matched intervention program with identical training parameters in both training settings except for the exposure to WBV. In a repeated-measures matched-subject design, 38 participants were assigned to either the WBV group (VIB) or the equivalent training group (CON). Training duration, number of sets, rest periods and task-specific instructions were matched between the groups. Balance, jump height and local static muscle endurance were assessed before and after the training period. The statistical analysis revealed significant interaction effects of group×time for balance and local static muscle endurance (p<0.05). Hence, WBV caused an additional effect on balance control (pre vs. post VIB +13%, p<0.05 and CON +6%, p = 0.33) and local static muscle endurance (pre vs. post VIB +36%, p<0.05 and CON +11%, p = 0.49). The effect on jump height remained insignificant (pre vs. post VIB +3%, p = 0.25 and CON ±0%, p = 0.82). This study provides evidence for the additional effects of WBV above conventional exercise alone. As far as balance and muscle endurance of the lower leg are concerned, a training program that includes WBV can provide supplementary benefits in young and well-trained adults compared to an equivalent program that does not include WBV.
Whole Body Vibration Training - Improving Balance Control and Muscle Endurance
Ritzmann, Ramona; Kramer, Andreas; Bernhardt, Sascha; Gollhofer, Albert
2014-01-01
Exercise combined with whole body vibration (WBV) is becoming increasingly popular, although additional effects of WBV in comparison to conventional exercises are still discussed controversially in literature. Heterogeneous findings are attributed to large differences in the training designs between WBV and “control” groups in regard to training volume, load and type. In order to separate the additional effects of WBV from the overall adaptations due to the intervention, in this study, a four-week WBV training setup was compared to a matched intervention program with identical training parameters in both training settings except for the exposure to WBV. In a repeated-measures matched-subject design, 38 participants were assigned to either the WBV group (VIB) or the equivalent training group (CON). Training duration, number of sets, rest periods and task-specific instructions were matched between the groups. Balance, jump height and local static muscle endurance were assessed before and after the training period. The statistical analysis revealed significant interaction effects of group×time for balance and local static muscle endurance (p<0.05). Hence, WBV caused an additional effect on balance control (pre vs. post VIB +13%, p<0.05 and CON +6%, p = 0.33) and local static muscle endurance (pre vs. post VIB +36%, p<0.05 and CON +11%, p = 0.49). The effect on jump height remained insignificant (pre vs. post VIB +3%, p = 0.25 and CON ±0%, p = 0.82). This study provides evidence for the additional effects of WBV above conventional exercise alone. As far as balance and muscle endurance of the lower leg are concerned, a training program that includes WBV can provide supplementary benefits in young and well-trained adults compared to an equivalent program that does not include WBV. PMID:24587114
Vazini Taher, Amir; Parnow, Abdolhossein
2017-05-01
Different methods of warm-up may have implications in improving various aspects of soccer performance. The present study aimed to investigate acute effects of soccer specific warm-up protocols on functional performance tests. This study using randomized within-subject design, investigated the performance of 22 collegiate elite soccer player following soccer specific warm-ups using dynamic stretching, static stretching, and FIFA 11+ program. Post warm-up examinations consisted: 1) Illinois Agility Test; 2) vertical jump; 3) 30 meter sprint; 4) consecutive turns; 5) flexibility of knee. Vertical jump performance was significantly lower following static stretching, as compared to dynamic stretching (P=0.005). Sprint performance declined significantly following static stretching as compared to FIFA 11+ (P=0.023). Agility time was significantly faster following dynamic stretching as compared to FIFA 11+ (P=0.001) and static stretching (P=0.001). Knee flexibility scores were significantly improved following the static stretching as compared to dynamic stretching (P=016). No significant difference was observed for consecutive turns between three warm-up protocol. The present finding showed that a soccer specific warm-up protocol relied on dynamic stretching is preferable in enhancing performance as compared to protocols relying on static stretches and FIFA 11+ program. Investigators suggest that while different soccer specific warm-up protocols have varied types of effects on performance, acute effects of dynamic stretching on performance in elite soccer players are assured, however application of static stretching in reducing muscle stiffness is demonstrated.
NASA Technical Reports Server (NTRS)
Mclain, A. G.; Rao, C. S. R.
1976-01-01
A hybrid chemical kinetic computer program was assembled which provides a rapid solution to problems involving flowing or static, chemically reacting, gas mixtures. The computer program uses existing subroutines for problem setup, initialization, and preliminary calculations and incorporates a stiff ordinary differential equation solution technique. A number of check cases were recomputed with the hybrid program and the results were almost identical to those previously obtained. The computational time saving was demonstrated with a propane-oxygen-argon shock tube combustion problem involving 31 chemical species and 64 reactions. Information is presented to enable potential users to prepare an input data deck for the calculation of a problem.
Prosperini, Luca; Kouleridou, Anna; Petsas, Nikolaos; Leonardi, Laura; Tona, Francesca; Pantano, Patrizia; Pozzilli, Carlo
2011-05-15
The role of static posturography and magnetic resonance imaging (MRI) in identifying patients at high risk of falls was investigated. Relationships between static posturography measures and MRI metrics were also investigated. A total of 31 ambulatory MS patients (EDSS ranging from 2.0 to 5.0) with a predominant balance disorder were recruited. Each patient underwent a static posturography with a monoaxial platform and a conventional 1.5 T brain MRI scan. Measurements of T1-hypointense and T2-hyperintense lesion volumes (LVs), focusing on lesions selectively located at infratentorial levels, were performed by two operators unaware of clinical data. The self-reported number of falls in the previous 6 months was considered as the main outcome measure. Fourteen (45%) patients reported 1 or more falls over the past 6 months. When compared to non-faller patients, they had a higher EDSS score, poorer static standing balance, and greater brainstem and middle cerebellar peduncle (MCP) T2-LVs. A strength correlation between brainstem T2-LV and impaired static standing balance in an open eye condition was also found. In the multivariate analysis, the variables more strictly associated with recurrent falls were greater T2-LV at the MCP (beta: 6.2; p=0.01) and brainstem (beta: 5.8; p=0.001) levels, and a wider displacement of the body center of pressure in the closed eye condition (beta: 0.02; p=0.03). Our data suggests that the damage of specific infratentorial areas negatively affect the static standing balance and may predispose MS patients to accidental falls. These findings might contribute in selecting patients requiring a proper rehabilitation intervention program. Copyright © 2011 Elsevier B.V. All rights reserved.
An Overview-NASA LeRC Structures Program
NASA Technical Reports Server (NTRS)
Zaretsky, Erwin V.
1997-01-01
The Structures and Acoustics Division of the NASA Lewis Research Center has its genesis dating back to 1943. It has been an independent Division at Lewis since 1979. Its two primary capabilities are performance and life analysis of static and dynamic systems such as those found in aircraft and spacecraft propulsion systems and experimental verification of these analyses. Research is conducted in-house, through university grants and contracts, and through cooperative programs with industry. Our work directly supports NASA's Advanced Subsonic Technology (AST), Smart Green Engine, Fast Quiet Engine, High-Temperature Materials and Processing (HiTEMP), Hybrid Hyperspeed Propulsion, Rotorcraft, High-Speed Research (HSR), and Aviation Safety Program (AvSP). A general overview is given discussing these programs and other technologies that are being developed at NASA LeRC.
GnoSys: Raising the Level of Discourse in Programming
2016-03-01
slotting these results into their proper place in the unified whole is still ongoing as of the date of this final report. Approved for Public Release...static restrictions we place on type systems; they can be any computable property. This is in keep- ing with the general design philosophy of GnoSys...different languages. Because contracts are frequently placed on module boundaries, they ease the burden placed on our analysis and verification tools
NASA Technical Reports Server (NTRS)
Jackson, Karen E.
1990-01-01
Scale model technology represents one method of investigating the behavior of advanced, weight-efficient composite structures under a variety of loading conditions. It is necessary, however, to understand the limitations involved in testing scale model structures before the technique can be fully utilized. These limitations, or scaling effects, are characterized. in the large deflection response and failure of composite beams. Scale model beams were loaded with an eccentric axial compressive load designed to produce large bending deflections and global failure. A dimensional analysis was performed on the composite beam-column loading configuration to determine a model law governing the system response. An experimental program was developed to validate the model law under both static and dynamic loading conditions. Laminate stacking sequences including unidirectional, angle ply, cross ply, and quasi-isotropic were tested to examine a diversity of composite response and failure modes. The model beams were loaded under scaled test conditions until catastrophic failure. A large deflection beam solution was developed to compare with the static experimental results and to analyze beam failure. Also, the finite element code DYCAST (DYnamic Crash Analysis of STructure) was used to model both the static and impulsive beam response. Static test results indicate that the unidirectional and cross ply beam responses scale as predicted by the model law, even under severe deformations. In general, failure modes were consistent between scale models within a laminate family; however, a significant scale effect was observed in strength. The scale effect in strength which was evident in the static tests was also observed in the dynamic tests. Scaling of load and strain time histories between the scale model beams and the prototypes was excellent for the unidirectional beams, but inconsistent results were obtained for the angle ply, cross ply, and quasi-isotropic beams. Results show that valuable information can be obtained from testing on scale model composite structures, especially in the linear elastic response region. However, due to scaling effects in the strength behavior of composite laminates, caution must be used in extrapolating data taken from a scale model test when that test involves failure of the structure.
NASA Astrophysics Data System (ADS)
Long, Nicholas James
This thesis serves to develop a preliminary foundational methodology for evaluating the static complexity of future lunar oxygen production systems when extensive information is not yet available about the various systems under consideration. Evaluating static complexity, as part of a overall system complexity analysis, is an important consideration in ultimately selecting a process to be used in a lunar base. When system complexity is higher, there is generally an overall increase in risk which could impact the safety of astronauts and the economic performance of the mission. To evaluate static complexity in lunar oxygen production, static complexity is simplified and defined into its essential components. First, three essential dimensions of static complexity are investigated, including interconnective complexity, strength of connections, and complexity in variety. Then a set of methods is developed upon which to separately evaluate each dimension. Q-connectivity analysis is proposed as a means to evaluate interconnective complexity and strength of connections. The law of requisite variety originating from cybernetic theory is suggested to interpret complexity in variety. Secondly, a means to aggregate the results of each analysis is proposed to create holistic measurement for static complexity using the Single Multi-Attribute Ranking Technique (SMART). Each method of static complexity analysis and the aggregation technique is demonstrated using notional data for four lunar oxygen production processes.
STARS: A general-purpose finite element computer program for analysis of engineering structures
NASA Technical Reports Server (NTRS)
Gupta, K. K.
1984-01-01
STARS (Structural Analysis Routines) is primarily an interactive, graphics-oriented, finite-element computer program for analyzing the static, stability, free vibration, and dynamic responses of damped and undamped structures, including rotating systems. The element library consists of one-dimensional (1-D) line elements, two-dimensional (2-D) triangular and quadrilateral shell elements, and three-dimensional (3-D) tetrahedral and hexahedral solid elements. These elements enable the solution of structural problems that include truss, beam, space frame, plane, plate, shell, and solid structures, or any combination thereof. Zero, finite, and interdependent deflection boundary conditions can be implemented by the program. The associated dynamic response analysis capability provides for initial deformation and velocity inputs, whereas the transient excitation may be either forces or accelerations. An effective in-core or out-of-core solution strategy is automatically employed by the program, depending on the size of the problem. Data input may be at random within a data set, and the program offers certain automatic data-generation features. Input data are formatted as an optimal combination of free and fixed formats. Interactive graphics capabilities enable convenient display of nodal deformations, mode shapes, and element stresses.
Quasi-Static Tensile Stress-Strain Curves. 1, 2024-T3510 Aluminum Alloy
1976-02-01
herein were conducted as part of the Core Materials Program of the Solid Mechanics Branch of the Terminal Ballistics Laboratory. The objective of this...describing the results of the Core Materials Program, covers quasi-static terVsile tests of 2024-T3510 aluminum E’lloy. The results include Young’s...11.31 4 580.6 9.94 TABLE II MATERIAL PROPERTIES OF 2024-T3510 ALUMINUM ALLOYa Results of Results of Results of Tensileb Compres ion Sonic Testing
Thrust imbalance of the Space Shuttle solid rocket motors
NASA Technical Reports Server (NTRS)
Foster, W. A., Jr.; Sforzini, R. H.; Shackelford, B. W., Jr.
1981-01-01
The Monte Carlo statistical analysis of thrust imbalance is applied to both the Titan IIIC and the Space Shuttle solid rocket motors (SRMs) firing in parallel, and results are compared with those obtained from the Space Shuttle program. The test results are examined in three phases: (1) pairs of SRMs selected from static tests of the four developmental motors (DMs 1 through 4); (2) pairs of SRMs selected from static tests of the three quality assurance motors (QMs 1 through 3); (3) SRMs on the first flight test vehicle (STS-1A and STS-1B). The simplified internal ballistic model utilized for computing thrust from head-end pressure measurements on flight tests is shown to agree closely with measured thrust data. Inaccuracies in thrust imbalance evaluation are explained by possible flight test instrumentation errors.
Characteristics of Volcanic Soils in Landslide during the 2016 Kumamoto Earthquake, Japan
NASA Astrophysics Data System (ADS)
Hazarika, H.; Fukuoka, H.; Kokusho, T.; Sumartini, O.; Bhoopendra, D.
2017-12-01
There were many seismic subsidence, debris flows, landslides and slope failures, which occurred in Aso area due to the 2016 Kumamoto earthquake, Japan. This research aims to determine the failure mechanism of many mild slopes, and elucidate the strength characteristics of volcanic soils collected from the sites. A series of undrained static and cyclic triaxial tests, ring shear tests and direct shear tests were performed. Also, for further understanding of volcanic soils' material strength, X-ray powder diffraction analysis (XRD), X-ray fluorescence analysis (XRF), and Scanning electron microscope analysis (SEM) were performed. In this paper, preliminary results of the experimental testing program are discussed.
Software Construction and Analysis Tools for Future Space Missions
NASA Technical Reports Server (NTRS)
Lowry, Michael R.; Clancy, Daniel (Technical Monitor)
2002-01-01
NASA and its international partners will increasingly depend on software-based systems to implement advanced functions for future space missions, such as Martian rovers that autonomously navigate long distances exploring geographic features formed by surface water early in the planet's history. The software-based functions for these missions will need to be robust and highly reliable, raising significant challenges in the context of recent Mars mission failures attributed to software faults. After reviewing these challenges, this paper describes tools that have been developed at NASA Ames that could contribute to meeting these challenges; 1) Program synthesis tools based on automated inference that generate documentation for manual review and annotations for automated certification. 2) Model-checking tools for concurrent object-oriented software that achieve memorability through synergy with program abstraction and static analysis tools.
Information Leakage Analysis by Abstract Interpretation
NASA Astrophysics Data System (ADS)
Zanioli, Matteo; Cortesi, Agostino
Protecting the confidentiality of information stored in a computer system or transmitted over a public network is a relevant problem in computer security. The approach of information flow analysis involves performing a static analysis of the program with the aim of proving that there will not be leaks of sensitive information. In this paper we propose a new domain that combines variable dependency analysis, based on propositional formulas, and variables' value analysis, based on polyhedra. The resulting analysis is strictly more accurate than the state of the art abstract interpretation based analyses for information leakage detection. Its modular construction allows to deal with the tradeoff between efficiency and accuracy by tuning the granularity of the abstraction and the complexity of the abstract operators.
Theoretical analysis of transcranial Hall-effect stimulation based on passive cable model
NASA Astrophysics Data System (ADS)
Yuan, Yi; Li, Xiao-Li
2015-12-01
Transcranial Hall-effect stimulation (THS) is a new stimulation method in which an ultrasonic wave in a static magnetic field generates an electric field in an area of interest such as in the brain to modulate neuronal activities. However, the biophysical basis of simulating the neurons remains unknown. To address this problem, we perform a theoretical analysis based on a passive cable model to investigate the THS mechanism of neurons. Nerve tissues are conductive; an ultrasonic wave can move ions embedded in the tissue in a static magnetic field to generate an electric field (due to Lorentz force). In this study, a simulation model for an ultrasonically induced electric field in a static magnetic field is derived. Then, based on the passive cable model, the analytical solution for the voltage distribution in a nerve tissue is determined. The simulation results showthat THS can generate a voltage to stimulate neurons. Because the THS method possesses a higher spatial resolution and a deeper penetration depth, it shows promise as a tool for treating or rehabilitating neuropsychiatric disorders. Project supported by the National Natural Science Foundation of China (Grant Nos. 61273063 and 61503321), the China Postdoctoral Science Foundation (Grant No. 2013M540215), the Natural Science Foundation of Hebei Province, China (Grant No. F2014203161), and the Youth Research Program of Yanshan University, China (Grant No. 02000134).
Noise characteristics of upper surface blown configurations. Experimental program and results
NASA Technical Reports Server (NTRS)
Brown, W. H.; Searle, N.; Blakney, D. F.; Pennock, A. P.; Gibson, J. S.
1977-01-01
An experimental data base was developed from the model upper surface blowing (USB) propulsive lift system hardware. While the emphasis was on far field noise data, a considerable amount of relevant flow field data were also obtained. The data were derived from experiments in four different facilities resulting in: (1) small scale static flow field data; (2) small scale static noise data; (3) small scale simulated forward speed noise and load data; and (4) limited larger-scale static noise flow field and load data. All of the small scale tests used the same USB flap parts. Operational and geometrical variables covered in the test program included jet velocity, nozzle shape, nozzle area, nozzle impingement angle, nozzle vertical and horizontal location, flap length, flap deflection angle, and flap radius of curvature.
JPL-IDEAS - ITERATIVE DESIGN OF ANTENNA STRUCTURES
NASA Technical Reports Server (NTRS)
Levy, R.
1994-01-01
The Iterative DEsign of Antenna Structures (IDEAS) program is a finite element analysis and design optimization program with special features for the analysis and design of microwave antennas and associated sub-structures. As the principal structure analysis and design tool for the Jet Propulsion Laboratory's Ground Antenna and Facilities Engineering section of NASA's Deep Space Network, IDEAS combines flexibility with easy use. The relatively small bending stiffness of the components of large, steerable reflector antennas allows IDEAS to use pinjointed (three translational degrees of freedom per joint) models for modeling the gross behavior of these antennas when subjected to static and dynamic loading. This facilitates the formulation of the redesign algorithm which has only one design variable per structural element. Input data deck preparation has been simplified by the use of NAMELIST inputs to promote clarity of data input for problem defining parameters, user selection of execution and design options and output requests, and by the use of many attractive and familiar features of the NASTRAN program (in many cases, NASTRAN and IDEAS formatted bulk data cards are interchangeable). Features such as simulation of a full symmetric structure based on analyses of only half the structure make IDEAS a handy and efficient analysis tool, with many features unavailable in any other finite element analysis program. IDEAS can choose design variables such as areas of rods and thicknesses of plates to minimize total structure weight, constrain the structure weight to a specified value while maximizing a natural frequency or minimizing compliance measures, and can use a stress ratio algorithm to size each structural member so that it is at maximum or minimum stress level for at least one of the applied loads. Calculations of total structure weight can be broken down according to material. Center of gravity weight balance, static first and second moments about the center of mass and optionally about a user-specified gridpoint, and lumped structure weight at grid points can also be calculated. Other analysis outputs include calculation of reactions, displacements, and element stresses due to specified gravity, thermal, and external applied loads; calculations of linear combinations of specific node displacements (e.g. to represent motions of rigid attachments not included in the structure model), natural frequency eigenvalues and eigenvectors, structure reactions and element stresses, and coordinates of effective modal masses. Cassegrain antenna boresight error analysis of a best fitting paraboloid and Cassegrain microwave antenna root mean square half-pathlength error analysis of a best fitting paraboloid are also performed. The IDEAS program is written in ATHENA FORTRAN and ASSEMBLER for an EXEC 8 operating system and was implemented on a UNIVAC 1100 series computer. The minimum memory requirement for the program is approximately 42,000 36-bit words. This program is available on a 9-track 1600 BPI magnetic tape in UNIVAC FURPUR format only; since JPL-IDEAS will not run on other platforms, COSMIC will not reformat the code to be readable on other platforms. The program was developed in 1988.
Program Model Checking as a New Trend
NASA Technical Reports Server (NTRS)
Havelund, Klaus; Visser, Willem; Clancy, Daniel (Technical Monitor)
2002-01-01
This paper introduces a special section of STTT (International Journal on Software Tools for Technology Transfer) containing a selection of papers that were presented at the 7th International SPIN workshop, Stanford, August 30 - September 1, 2000. The workshop was named SPIN Model Checking and Software Verification, with an emphasis on model checking of programs. The paper outlines the motivation for stressing software verification, rather than only design and model verification, by presenting the work done in the Automated Software Engineering group at NASA Ames Research Center within the last 5 years. This includes work in software model checking, testing like technologies and static analysis.
Structural weights analysis of advanced aerospace vehicles using finite element analysis
NASA Technical Reports Server (NTRS)
Bush, Lance B.; Lentz, Christopher A.; Rehder, John J.; Naftel, J. Chris; Cerro, Jeffrey A.
1989-01-01
A conceptual/preliminary level structural design system has been developed for structural integrity analysis and weight estimation of advanced space transportation vehicles. The system includes a three-dimensional interactive geometry modeler, a finite element pre- and post-processor, a finite element analyzer, and a structural sizing program. Inputs to the system include the geometry, surface temperature, material constants, construction methods, and aerodynamic and inertial loads. The results are a sized vehicle structure capable of withstanding the static loads incurred during assembly, transportation, operations, and missions, and a corresponding structural weight. An analysis of the Space Shuttle external tank is included in this paper as a validation and benchmark case of the system.
Sensitivity analysis of a wing aeroelastic response
NASA Technical Reports Server (NTRS)
Kapania, Rakesh K.; Eldred, Lloyd B.; Barthelemy, Jean-Francois M.
1991-01-01
A variation of Sobieski's Global Sensitivity Equations (GSE) approach is implemented to obtain the sensitivity of the static aeroelastic response of a three-dimensional wing model. The formulation is quite general and accepts any aerodynamics and structural analysis capability. An interface code is written to convert one analysis's output to the other's input, and visa versa. Local sensitivity derivatives are calculated by either analytic methods or finite difference techniques. A program to combine the local sensitivities, such as the sensitivity of the stiffness matrix or the aerodynamic kernel matrix, into global sensitivity derivatives is developed. The aerodynamic analysis package FAST, using a lifting surface theory, and a structural package, ELAPS, implementing Giles' equivalent plate model are used.
Mammalian carnivores are increasingly the focus of reintroduction attempts in areas from which
they have been extirpated by historic persecution. We used static and dynamic spatial models to evaluate whether a proposed wolf reintroduction to the southern Rocky Mountain region ...
1967-10-01
Workmen at the Marshall Space Flight Center's (MSFC's) dock on the Ternessee River unload S-IB-211, the flight version of the Saturn IB launch vehicle's first stage, from the NASA barge Palaemon. Between December 1967 and April 1968, the stage would undergo seven static test firings in MSFC's S-IB static test stand.
1967-10-01
Workmen at the Marshall Space Flight Center's (MSFC's) dock on the Ternessee River unload S-IB-211, the flight version of the Saturn IB launch vehicle's first stage, from the NASA barge Palaemon. Between December 1967 and April 1968, the stage would undergo seven static test firings in Marshall's S-IB static test stand.
An easily implemented static condensation method for structural sensitivity analysis
NASA Technical Reports Server (NTRS)
Gangadharan, S. N.; Haftka, R. T.; Nikolaidis, E.
1990-01-01
A black-box approach to static condensation for sensitivity analysis is presented with illustrative examples of a cube and a car structure. The sensitivity of the structural response with respect to joint stiffness parameter is calculated using the direct method, forward-difference, and central-difference schemes. The efficiency of the various methods for identifying joint stiffness parameters from measured static deflections of these structures is compared. The results indicate that the use of static condensation can reduce computation times significantly and the black-box approach is only slightly less efficient than the standard implementation of static condensation. The ease of implementation of the black-box approach recommends it for use with general-purpose finite element codes that do not have a built-in facility for static condensation.
Godfrey, A; Culhane, K M; Lyons, G M
2007-10-01
The aim of this study was to assess the accuracy of the 'activPAL Professional' physical activity logger by comparing its output to that of a proven discrete accelerometer-based activity monitor during extended measurements on healthy subjects while performing activities of daily living (ADL). Ten healthy adults, with unrestricted mobility, wore both the activPAL and the discrete dual accelerometer (Analog Devices ADXL202)-based activity monitor that recorded in synchronization with each other. The accelerometer derived data were then compared to that generated by the activPAL and a complete statistical and error analysis was performed using a Matlab program. This program determined trunk and thigh inclination angles to distinguish between sitting/lying, standing and stepping for the discrete accelerometer device and amount of time spent on each activity. Analysis was performed on a second-by-second basis and then categorized at 15s intervals in direct comparison with the activPAL generated data. Of the total time monitored (approximately 60 h) the detection accuracies for static and dynamic activities were approximately 98%. In a population of healthy adults, the data obtained from the activPAL Professional physical activity logger for both static and dynamic activities showed a close match to a proven discrete accelerometer data with an offset of approximately 2% between the two systems.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bezler, P.; Hartzman, M.; Reich, M.
1980-08-01
A set of benchmark problems and solutions have been developed for verifying the adequacy of computer programs used for dynamic analysis and design of nuclear piping systems by the Response Spectrum Method. The problems range from simple to complex configurations which are assumed to experience linear elastic behavior. The dynamic loading is represented by uniform support motion, assumed to be induced by seismic excitation in three spatial directions. The solutions consist of frequencies, participation factors, nodal displacement components and internal force and moment components. Solutions to associated anchor point motion static problems are not included.
Program Helps To Determine Chemical-Reaction Mechanisms
NASA Technical Reports Server (NTRS)
Bittker, D. A.; Radhakrishnan, K.
1995-01-01
General Chemical Kinetics and Sensitivity Analysis (LSENS) computer code developed for use in solving complex, homogeneous, gas-phase, chemical-kinetics problems. Provides for efficient and accurate chemical-kinetics computations and provides for sensitivity analysis for variety of problems, including problems involving honisothermal conditions. Incorporates mathematical models for static system, steady one-dimensional inviscid flow, reaction behind incident shock wave (with boundary-layer correction), and perfectly stirred reactor. Computations of equilibrium properties performed for following assigned states: enthalpy and pressure, temperature and pressure, internal energy and volume, and temperature and volume. Written in FORTRAN 77 with exception of NAMELIST extensions used for input.
NASA Technical Reports Server (NTRS)
Bennett, R. M.; Bland, S. R.; Redd, L. T.
1973-01-01
Computer programs for calculating the stability characteristics of a balloon tethered in a steady wind are presented. Equilibrium conditions, characteristic roots, and modal ratios are calculated for a range of discrete values of velocity for a fixed tether-line length. Separate programs are used: (1) to calculate longitudinal stability characteristics, (2) to calculate lateral stability characteristics, (3) to plot the characteristic roots versus velocity, (4) to plot the characteristic roots in root-locus form, (5) to plot the longitudinal modes of motion, and (6) to plot the lateral modes for motion. The basic equations, program listings, and the input and output data for sample cases are presented, with a brief discussion of the overall operation and limitations. The programs are based on a linearized, stability-derivative type of analysis, including balloon aerodynamics, apparent mass, buoyancy effects, and static forces which result from the tether line.
76 FR 28131 - Federal Motor Vehicle Safety Standards; Motorcycle Helmets
Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-13
..., this final rule sets a quasi-static load application rate for the helmet retention system; revises the... Analysis and Conclusion e. Quasi-Static Retention Test f. Helmet Conditioning Tolerances g. Other... it as a quasi-static test, instead of a static test. Specifying the application rate will aid...
Kibar, Sibel; Yardimci, Fatma Ö; Evcik, Deniz; Ay, Saime; Alhan, Aslıhan; Manço, Miray; Ergin, Emine S
2016-10-01
This randomized controlled study aims to determine the effect of pilates mat exercises on dynamic and static balance, hamstring flexibility, abdominal muscle activity and endurance in healthy adults. Female healthy volunteer university students randomly assigned into two groups. Group 1 followed a pilates program for an hour two times a week. Group 2 continued daily activities as control group. Dynamic and static balance were evaluated by Sport Kinesthetic Ability Trainer (KAT) 4000 device. Hamstring flexibility and abdominal endurance were determined by sit-and-reach test, curl-up test respectively. Pressure biofeedback unit (PBU) was used to measure transversus abdominis and lumbar muscle activity. The physical activity of the participants was followed by International Physical Activity Questionnaire-Short Form. Twenty-three subjects in pilates group and 24 control subjects completed the study. In pilates group, statistical significant improvements were observed in curl-up, sit-and-reach test, PBU scores at sixth week (P<0.001), and KAT static and dynamic balance scores (P<0.001), waist circumference (P=0.007) at eighth week. In the comparison between two groups, there were significant improvements in pilates group for sit-and-reach test (P=0.01) and PBU scores (P<0.001) at sixth week, additionally curl-up and static KAT scores progressed in eighth week (P<0.001). No correlation was found between flexibility, endurance, trunk muscle activity and balance parameters. An eight-week pilates training program has been found to have beneficial effect on static balance, flexibility, abdominal muscle endurance, abdominal and lumbar muscle activity. These parameters have no effect on balance.
Design, analysis, and testing of the Phase 1 CSI Evolutionary Model erectable truss
NASA Technical Reports Server (NTRS)
Gronet, M. J.; Davis, D. A.; Kintis, D. H.; Brillhart, R. D.; Atkins, E. M.
1992-01-01
This report addressed the design, analysis, and testing of the erectable truss structure for the Phase 1 CSI Evolutionary Model (CEM) testbed. The Phase 1 CEM testbed is the second testbed to form part of an ongoing program of focused research at NASA/LaRC in the development of Controls-Structures Integration (CSI) technology. The Phase 1 CEM contains the same overall geometry, weight, and sensor locations as the Phase 0 CEM, but is based in an integrated controller and structure design, whereby both structure and controller design variables are sized simultaneously. The Phase 1 CEM design features seven truss sections composed of struts with tailored mass and stiffness properties. A common erectable joint is used and the strut stiffness is tailored by varying the cross-sectional area. To characterize the structure, static tests were conducted on individual struts and 10-bay truss assemblies. Dynamic tests were conducted on 10-bay truss assemblies as well as the fully-assembled CEM truss. The results indicate that the static and dynamic properties of the structure are predictable, well-characterized, and within the performance requirements established during the Phase 1 CEM integrated controller/structure design analysis.
Fischer, Sean A.; Ueltschi, Tyler W.; El-Khoury, Patrick Z.; ...
2015-07-29
Carbon-hydrogen (C-H) vibration modes serve as key probes in the chemical identification of hydrocarbons and in vibrational sum-frequency generation (SFG) spectroscopy of hydrocarbons at the liquid/gas interface. Their assignments pose a challenge from a theoretical viewpoint. Here in this work, we present a detailed study of the C-H stretching region of dimethyl sulfoxide (DMSO) using a new Gaussian basis set- based ab initio molecular dynamics (AIMD) module that we have implemented in the NWChem computational chemistry program. By combining AIMD simulations and static normal mode analysis, we interpret experimental infrared and Raman spectra and explore the role of anharmonic effectsmore » in this system. Our anharmonic normal mode analysis of the in-phase and out-of-phase symmetric C-H stretching modes challenges the previous experimental assignment of the shoulder in the symmetric C-H stretching peak as an overtone or Fermi resonance. In addition, our AIMD simulations also show significant broadening of the in-phase symmetric C-H stretching resonance, which suggests that the experimentally observed shoulder is due to thermal broadening of the symmetric stretching resonance.« less
Free-To-Roll Analysis of Abrupt Wing Stall on Military Aircraft at Transonic Speeds
NASA Technical Reports Server (NTRS)
Owens, D. Bruce; Capone, Francis J.; Brandon, Jay M.; Cunningham, Kevin; Chambers, Joseph R.
2003-01-01
Transonic free-to-roll and static wind tunnel tests for four military aircraft - the AV-8B, the F/A-18C, the preproduction F/A-18E, and the F-16C - have been analyzed. These tests were conducted in the NASA Langley 16-Foot Transonic Tunnel as a part of the NASA/Navy/Air Force Abrupt Wing Stall Program. The objectives were to evaluate the utility of the free-to-roll test technique as a tool for predicting areas of significant uncommanded lateral motions and for gaining insight into the wing-drop and wing-rock behavior of military aircraft at transonic conditions. The analysis indicated that the free-to-roll results had good agreement with flight data on all four models. A wide range of motions - limit cycle wing rock, occasional and frequent damped wing drop/rock and wing rock divergence - were observed. The analysis shows the effects that the static and dynamic lateral stability can have on the wing drop/rock behavior. In addition, a free-to-roll figure of merit was developed to assist in the interpretation of results and assessment of the severity of the motions.
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.
2002-01-01
Brittle materials are being used, or considered, for a wide variety of high tech applications that operate in harsh environments, including static and rotating turbine parts. thermal protection systems, dental prosthetics, fuel cells, oxygen transport membranes, radomes, and MEMS. Designing components to sustain repeated load without fracturing while using the minimum amount of material requires the use of a probabilistic design methodology. The CARES/Life code provides a general-purpose analysis tool that predicts the probability of failure of a ceramic component as a function of its time in service. For this presentation an interview of the CARES/Life program will be provided. Emphasis will be placed on describing the latest enhancements to the code for reliability analysis with time varying loads and temperatures (fully transient reliability analysis). Also, early efforts in investigating the validity of using Weibull statistics, the basis of the CARES/Life program, to characterize the strength of MEMS structures will be described as as well as the version of CARES/Life for MEMS (CARES/MEMS) being prepared which incorporates single crystal and edge flaw reliability analysis capability. It is hoped this talk will open a dialog for potential collaboration in the area of MEMS testing and life prediction.
Sung, Kiwol
2009-01-01
The purpose of this study was to compare the effects of 16-week group exercise program on the physical function (ie, strength, flexibility, and balance) and mental health (ie, self-esteem and depression) of older elderlyl women (>or=75 years old) compared with younger elderly women (<75 years old). Exercise is crucial in maintaining older women's health and well-being. However, because most elders have at least one chronic disease, their physical function declines, so their dependence on others for instrumental daily living activities often increases. Older women typically have multiple barriers to participation in physical activities including higher disability rates. Of the total of 40 older women (older than 65 years) enrolled, 21 were older elders and 16 were younger elders. Lower body strength (using 30-second chair test), flexibility (sit-and-reach test), and static balance (ability to balance on one leg with open and closed eyes) were assessed. Self-esteem (using Rosenberg's Self-esteem Questionnaire) and depressive symptoms (using Yesavage's Geriatric Depression Scale) were assessed. Two-way analysis of variance was used to examine the differences between the 2 age groups. The intervention program was effective in improving body strength, flexibility, static balance, and self-esteem, regardless of age. Furthermore, older elders receiving the intervention program demonstrated greater improvement in self-esteem than younger elders did, although there were intervention effects in both age groups. Elderly women can realize benefits from a group exercise program that can improve their functional ability and self-esteem, both important to cardiovascular health.
1992-11-01
November 1992 1992 INTERNATIONAL AEROSPACE AND GROUND CONFERENCE 6. Perfrming Orgnis.aten Code ON LIGHTNING AND STATIC ELECTRICITY - ADDENDUM 111...October 6-8 1992 Program and the Federal Aviation Administration 14. Sponsoring Agency Code Technical Center ACD-230 15. Supplementary Metes The NICG...area]. The program runs well on an IBM PC or compatible 386 with a math co-processor 387 chip and a VGA monitor. For this study, streamers were added
Model-Driven Engineering of Machine Executable Code
NASA Astrophysics Data System (ADS)
Eichberg, Michael; Monperrus, Martin; Kloppenburg, Sven; Mezini, Mira
Implementing static analyses of machine-level executable code is labor intensive and complex. We show how to leverage model-driven engineering to facilitate the design and implementation of programs doing static analyses. Further, we report on important lessons learned on the benefits and drawbacks while using the following technologies: using the Scala programming language as target of code generation, using XML-Schema to express a metamodel, and using XSLT to implement (a) transformations and (b) a lint like tool. Finally, we report on the use of Prolog for writing model transformations.
Impact evaluation of composite floor sections
NASA Technical Reports Server (NTRS)
Boitnott, Richard L.; Fasanella, Edwin L.
1989-01-01
Graphite-epoxy floor sections representative of aircraft fuselage construction were statically and dynamically tested to evaluate their response to crash loadings. These floor sections were fabricated using a frame-stringer design typical of present aluminum aircraft without features to enhance crashworthiness. The floor sections were tested as part of a systematic research program developed to study the impact response of composite components of increasing complexity. The ultimate goal of the research program is to develop crashworthy design features for future composite aircraft. Initially, individual frames of six-foot diameter were tested both statically and dynamically. The frames were then used to construct built-up floor sections for dynamic tests at impact velocities of approximately 20 feet/sec to simulate survivable crash velocities. In addition, static tests were conducted to gain a better understanding of the failure mechanisms seen in the dynamic tests.
30 CFR 784.16 - Reclamation plan: Siltation structures, impoundments, and refuse piles.
Code of Federal Regulations, 2011 CFR
2011-07-01
... Resources Conservation Service's Web site athttp://www.info.usda.gov/scripts/lpsiis.dll/TR/TR_210_60.htm... State program approval process engineering design standards that ensure stability comparable to a 1.3 minimum static safety factor in lieu of engineering tests to establish compliance with the minimum static...
NASA Technical Reports Server (NTRS)
Pennock, A. P.; Swift, G.; Marbert, J. A.
1975-01-01
Externally blown flap models were tested for noise and performance at one-fifth scale in a static facility and at one-tenth scale in a large acoustically-treated wind tunnel. The static tests covered two flap designs, conical and ejector nozzles, third-flap noise-reduction treatments, internal blowing, and flap/nozzle geometry variations. The wind tunnel variables were triple-slotted or single-slotted flaps, sweep angle, and solid or perforated third flap. The static test program showed the following noise reductions at takeoff: 1.5 PNdB due to treating the third flap; 0.5 PNdB due to blowing from the third flap; 6 PNdB at flyover and 4.5 PNdB in the critical sideline plane (30 deg elevation) due to installation of the ejector nozzle. The wind tunnel program showed a reduction of 2 PNdB in the sideline plane due to a forward speed of 43.8 m/s (85 kn). The best combination of noise reduction concepts reduced the sideline noise of the reference aircraft at constant field length by 4 PNdB.
NASA Astrophysics Data System (ADS)
Zhu, Ning; Sun, Shou-Guang; Li, Qiang; Zou, Hua
2014-12-01
One of the major problems in structural fatigue life analysis is establishing structural load spectra under actual operating conditions. This study conducts theoretical research and experimental validation of quasi-static load spectra on bogie frame structures of high-speed trains. The quasistatic load series that corresponds to quasi-static deformation modes are identified according to the structural form and bearing conditions of high-speed train bogie frames. Moreover, a force-measuring frame is designed and manufactured based on the quasi-static load series. The load decoupling model of the quasi-static load series is then established via calibration tests. Quasi-static load-time histories, together with online tests and decoupling analysis, are obtained for the intermediate range of the Beijing—Shanghai dedicated passenger line. The damage consistency calibration of the quasi-static discrete load spectra is performed according to a damage consistency criterion and a genetic algorithm. The calibrated damage that corresponds with the quasi-static discrete load spectra satisfies the safety requirements of bogie frames.
Dynamic responses of graphite/epoxy laminated beam to impact of elastic spheres
NASA Technical Reports Server (NTRS)
Sun, C. T.; Wang, T.
1982-01-01
Wave propagation in 90/45/90/-45/902s and 0/45/0/-45/02s laminates of a graphite/epoxy composite due to impact of a steel ball was investigated experimentally and also by using a high order beam finite element. Dynamic strain responses at several locations were obtained using strain gages. The finite element program which incorporated statically determined contact laws was employed to calculate the contact force history as well as the target beam dynamic deformation. The comparison of the finite element solutions with the experimental data indicated that the static contact laws for loading and unloading (developed under this grant) are adequate for the dynamic impact analysis. It was found that for the 0/45/0/-45/02s laminate which has a much larger longitudinal bending rigidity, the use of beam finite elements is not suitable and plate finite element should be used instead.
Biaxial tests of flat graphite/epoxy laminates
NASA Technical Reports Server (NTRS)
Liebowitz, H.; Jones, D. L.
1981-01-01
The influence of biaxially applied loads on the strength of composite materials containing holes was analyzed. The analysis was performed through the development of a three dimensional, finite element computer program that is capable of evaluating fiber breakage, delamination, and matrix failure. Realistic failure criteria were established for each of the failure modes, and the influence of biaxial loading on damage accumulation under monotonically increasing loading was examined in detail. Both static and fatigue testing of specially designed biaxial specimens containing central holes were performed. Static tests were performed to obtain an understanding of the influence of biaxial loads on the fracture strength of composite materials and to provide correlation with the analytical predictions. The predicted distributions and types of damage are in reasonable agreement with the experimental results. A number of fatigue tests were performed to determine the influence of cyclic biaxial loads on the fatigue life and residual strength of several composite laminates.
NASA Technical Reports Server (NTRS)
1981-01-01
The development of several types of graphite/polyimide (GR/PI) bonded and bolted joints is reported. The program consists of two concurrent tasks: (1) design and test of specific built up attachments; and (2) evaluation of standard advanced bonded joint concepts. A data base for the design and analysis of advanced composite joints for use at elevated temperatures (561K (550 deg F)) to design concepts for specific joining applications, and the fundamental parameters controlling the static strength characteristics of such joints are evaluated. Data for design and build GR/PI of lightly loaded flight components for advanced space transportation systems and high speed aircraft are presented. Results for compression and interlaminar shear strengths of Celion 6000/PMR-15 laminates are given. Static discriminator test results for type 3 and type 4 bonded and bolted joints and final joint designs for TASK 1.4 scale up fabrication and testing are presented.
Numerical Simulation of the RTA Combustion Rig
NASA Technical Reports Server (NTRS)
Davoudzadeh, Farhad; Buehrle, Robert; Liu, Nan-Suey; Winslow, Ralph
2005-01-01
The Revolutionary Turbine Accelerator (RTA)/Turbine Based Combined Cycle (TBCC) project is investigating turbine-based propulsion systems for access to space. NASA Glenn Research Center and GE Aircraft Engines (GEAE) planned to develop a ground demonstrator engine for validation testing. The demonstrator (RTA-1) is a variable cycle, turbofan ramjet designed to transition from an augmented turbofan to a ramjet that produces the thrust required to accelerate the vehicle from Sea Level Static (SLS) to Mach 4. The RTA-1 is designed to accommodate a large variation in bypass ratios from sea level static to Mach 4 conditions. Key components of this engine are new, such as a nickel alloy fan, advanced trapped vortex combustor, a Variable Area Bypass Injector (VABI), radial flameholders, and multiple fueling zones. A means to mitigate risks to the RTA development program was the use of extensive component rig tests and computational fluid dynamics (CFD) analysis.
Recent advances in the modelling of crack growth under fatigue loading conditions
NASA Technical Reports Server (NTRS)
Dekoning, A. U.; Tenhoeve, H. J.; Henriksen, T. K.
1994-01-01
Fatigue crack growth associated with cyclic (secondary) plastic flow near a crack front is modelled using an incremental formulation. A new description of threshold behaviour under small load cycles is included. Quasi-static crack extension under high load excursions is described using an incremental formulation of the R-(crack growth resistance)- curve concept. The integration of the equations is discussed. For constant amplitude load cycles the results will be compared with existing crack growth laws. It will be shown that the model also properly describes interaction effects of fatigue crack growth and quasi-static crack extension. To evaluate the more general applicability the model is included in the NASGRO computer code for damage tolerance analysis. For this purpose the NASGRO program was provided with the CORPUS and the STRIP-YIELD models for computation of the crack opening load levels. The implementation is discussed and recent results of the verification are presented.
Reinforcement of composite laminate free edges with U-shaped caps
NASA Technical Reports Server (NTRS)
Howard, W. E.; Gossard, T., Jr.; Jones, R. M.
1986-01-01
Generalized plane strain finite element analysis is used to predict reduction of interlaminar normal stresses when a U-shaped cap is bonded to the edge of a laminate. Three-dimensional composite material failure criteria are used in a progressive laminate failure analysis to predict failure loads of laminates with different edge cap designs. In an experimental program, symmetric 11-layer graphite-epoxy laminates with a one-layer cap of Kevlar-epoxy cloth are shown to be 130 to 140 percent stronger than uncapped laminates under static tensile and tension-tension fatigue loading. In addition, the coefficient of variation of the static tensile failure load decreases from 24 to 8 percent when edge caps are added. The predicted failure load calculated with the finite element results is 10 percent lower than the actual failure load. For both capped and uncapped laminates, actual failure loads are much lower than those predicted using classical lamination theory stresses and a two-dimensional failure criterion. Possible applications of the free edge reinforcement concept are described, and future research is suggested.
Static aeroelastic analysis and tailoring of a single-element racing car wing
NASA Astrophysics Data System (ADS)
Sadd, Christopher James
This thesis presents the research from an Engineering Doctorate research programme in collaboration with Reynard Motorsport Ltd, a manufacturer of racing cars. Racing car wing design has traditionally considered structures to be rigid. However, structures are never perfectly rigid and the interaction between aerodynamic loading and structural flexibility has a direct impact on aerodynamic performance. This interaction is often referred to as static aeroelasticity and the focus of this research has been the development of a computational static aeroelastic analysis method to improve the design of a single-element racing car wing. A static aeroelastic analysis method has been developed by coupling a Reynolds-Averaged Navier-Stokes CFD analysis method with a Finite Element structural analysis method using an iterative scheme. Development of this method has included assessment of CFD and Finite Element analysis methods and development of data transfer and mesh deflection methods. Experimental testing was also completed to further assess the computational analyses. The computational and experimental results show a good correlation and these studies have also shown that a Navier-Stokes static aeroelastic analysis of an isolated wing can be performed at an acceptable computational cost. The static aeroelastic analysis tool was used to assess methods of tailoring the structural flexibility of the wing to increase its aerodynamic performance. These tailoring methods were then used to produce two final wing designs to increase downforce and reduce drag respectively. At the average operating dynamic pressure of the racing car, the computational analysis predicts that the downforce-increasing wing has a downforce of C[1]=-1.377 in comparison to C[1]=-1.265 for the original wing. The computational analysis predicts that the drag-reducing wing has a drag of C[d]=0.115 in comparison to C[d]=0.143 for the original wing.
The design, analysis and experimental evaluation of an elastic model wing
NASA Technical Reports Server (NTRS)
Cavin, R. K., III; Thisayakorn, C.
1974-01-01
An elastic orbiter model was developed to evaluate the effectiveness of aeroelasticity computer programs. The elasticity properties were introduced by constructing beam-like straight wings for the wind tunnel model. A standard influence coefficient mathematical model was used to estimate aeroelastic effects analytically. In general good agreement was obtained between the empirical and analytical estimates of the deformed shape. However, in the static aeroelasticity case, it was found that the physical wing exhibited less bending and more twist than was predicted by theory.
Regenerative Engine Analysis Program (REAP).
1981-01-01
Output Shaft Forged SAE 9310 Performance for the TSE Model 1071 is shown in Figures 41, 42, and 43 for static and flight conditions at three altitudes...Flange - Air Inlet 3 in. dia 2 0.72 Duct - Air Outlet, 3.25 in. OD 0.050 2 0.78 Flange - Air Outlet 3.25 in. dia 2 0.78 Weld and Miscellaneous -- 2.67... 4140 tubes, plus the outer case. (This assumes straight line trajectory with no tumbling.) This would result in leakage of nearly one percent of the
Dynamic stability and handling qualities tests on a highly augmented, statically unstable airplane
NASA Technical Reports Server (NTRS)
Gera, Joseph; Bosworth, John T.
1987-01-01
This paper describes some novel flight tests and analysis techniques in the flight dynamics and handling qualities area. These techniques were utilized during the initial flight envelope clearance of the X-29A aircraft and were largely responsible for the completion of the flight controls clearance program without any incidents or significant delays. The resulting open-loop and closed-loop frequency responses and the time history comparison using flight and linear simulation data are discussed.
Track-train dynamic analysis and test program, truck static test
NASA Technical Reports Server (NTRS)
Nemes, A. G.
1974-01-01
A series of tests were conducted to define the characteristics of an ASF 11 Ride Truck Assembly including joint slop, friction and stiffness. Loading to the truck assembly included vertical load to simulate the car/pool loading combined with lateral or moment loading that resulted in desired truck deflections for the various phases of testing. All seven test conditions were successfully completed with load and deflection data being collected. No attempt is made to reduce the applicable data other than to provide computer plots.
NASA Technical Reports Server (NTRS)
Gabel, R.; Lang, P.; Reed, D.
1993-01-01
Mathematical models based on the finite element method of structural analysis, as embodied in the NASTRAN computer code, are routinely used by the helicopter industry to calculate airframe static internal loads used for sizing structural members. Historically, less reliance has been placed on the vibration predictions based on these models. Beginning in the early 1980's NASA's Langley Research Center initiated an industry wide program with the objective of engendering the needed trust in vibration predictions using these models and establishing a body of modeling guides which would enable confident future prediction of airframe vibration as part of the regular design process. Emphasis in this paper is placed on the successful modeling of the Army/Boeing CH-47D which showed reasonable correlation with test data. A principal finding indicates that improved dynamic analysis requires greater attention to detail and perhaps a finer mesh, especially the mass distribution, than the usual stress model. Post program modeling efforts show improved correlation placing key modal frequencies in the b/rev range with 4 percent of the test frequencies.
Online Program Capacity: Limited, Static, Elastic, or Infinite?
ERIC Educational Resources Information Center
Meyer, Katrina A.
2008-01-01
What is the capacity of online programs? Can these types of programs enroll more students than their face-to-face counterparts or not? This article looks at research on achieving cost-efficiencies through online learning, identifies the parts of an online program that can be changed to increase enrollments, and discusses whether a program's…
Dibai-Filho, Almir Vieira; de Oliveira, Alessandra Kelly; Girasol, Carlos Eduardo; Dias, Fabiana Rodrigues Cancio; Guirro, Rinaldo Roberto de Jesus
2017-04-01
To assess the additional effect of static ultrasound and diadynamic currents on myofascial trigger points in a manual therapy program to treat individuals with chronic neck pain. A single-blind randomized trial was conducted. Both men and women, between ages 18 and 45, with chronic neck pain and active myofascial trigger points in the upper trapezius were included in the study. Subjects were assigned to 3 different groups: group 1 (n = 20) was treated with manual therapy; group 2 (n = 20) was treated with manual therapy and static ultrasound; group 3 (n = 20) was treated with manual therapy and diadynamic currents. Individuals were assessed before the first treatment session, 48 hours after the first treatment session, 48 hours after the tenth treatment session, and 4 weeks after the last session. There was no group-versus-time interaction for Numeric Rating Scale, Neck Disability Index, Pain-Related Self-Statement Scale, pressure pain threshold, cervical range of motion, and skin temperature (F-value range, 0.089-1.961; P-value range, 0.106-0.977). Moreover, we found no differences between groups regarding electromyographic activity (P > 0.05). The use of static ultrasound or diadynamic currents on myofascial trigger points in upper trapezius associated with a manual therapy program did not generate greater benefits than manual therapy alone.
A review of some problems in global-local stress analysis
NASA Technical Reports Server (NTRS)
Nelson, Richard B.
1989-01-01
The various types of local-global finite-element problems point out the need to develop a new generation of software. First, this new software needs to have a complete analysis capability, encompassing linear and nonlinear analysis of 1-, 2-, and 3-dimensional finite-element models, as well as mixed dimensional models. The software must be capable of treating static and dynamic (vibration and transient response) problems, including the stability effects of initial stress, and the software should be able to treat both elastic and elasto-plastic materials. The software should carry a set of optional diagnostics to assist the program user during model generation in order to help avoid obvious structural modeling errors. In addition, the program software should be well documented so the user has a complete technical reference for each type of element contained in the program library, including information on such topics as the type of numerical integration, use of underintegration, and inclusion of incompatible modes, etc. Some packaged information should also be available to assist the user in building mixed-dimensional models. An important advancement in finite-element software should be in the development of program modularity, so that the user can select from a menu various basic operations in matrix structural analysis.
1965-04-01
S-IB-1, the first flight version of the Saturn IB launch vehicle's first stage (S-IB stage), undergoes a full-duration static firing in Saturn IB static test stand at the Marshall Space Flight Center (MSFC) on April 13, 1965. Developed by the MSFC and built by the Chrysler Corporation at the Michoud Assembly Facility (MAF) in New Orleans, Louisiana, the 90,000-pound booster utilized eight H-1 engines to produce a combined thrust of 1,600,000 pounds. Between April 1965 and July 1968, MSFC performed thirty-two static tests on twelve different S-IB stages.
Aerodynamic preliminary analysis system 2. Part 2: User's manual
NASA Technical Reports Server (NTRS)
Sova, G.; Divan, P.; Spacht, L.
1991-01-01
An aerodynamic analysis system based on potential theory at subsonic and/or supersonic speeds and impact type finite element solutions at hypersonic conditions is described. Three dimensional configurations have multiple nonplanar surfaces of arbitrary planforms and bodies of noncircular contour may be analyzed. Static, rotary, and control longitudinal and lateral-directional characteristics may be generated. The analysis was implemented on a time sharing system in conjunction with an input tablet digitizer and an interactive graphics input/output display and editing terminal to maximize its responsiveness to the preliminary analysis. Computation times on an IBM 3081 are typically less than one minute of CPU/Mach number at subsonic, supersonic, or hypersonic speeds. This is a user manual for the computer programming.
An empirical comparison of a dynamic software testability metric to static cyclomatic complexity
NASA Technical Reports Server (NTRS)
Voas, Jeffrey M.; Miller, Keith W.; Payne, Jeffrey E.
1993-01-01
This paper compares the dynamic testability prediction technique termed 'sensitivity analysis' to the static testability technique termed cyclomatic complexity. The application that we chose in this empirical study is a CASE generated version of a B-737 autoland system. For the B-737 system we analyzed, we isolated those functions that we predict are more prone to hide errors during system/reliability testing. We also analyzed the code with several other well-known static metrics. This paper compares and contrasts the results of sensitivity analysis to the results of the static metrics.
NASA Technical Reports Server (NTRS)
Nakazawa, Shohei
1991-01-01
Formulations and algorithms implemented in the MHOST finite element program are discussed. The code uses a novel concept of the mixed iterative solution technique for the efficient 3-D computations of turbine engine hot section components. The general framework of variational formulation and solution algorithms are discussed which were derived from the mixed three field Hu-Washizu principle. This formulation enables the use of nodal interpolation for coordinates, displacements, strains, and stresses. Algorithmic description of the mixed iterative method includes variations for the quasi static, transient dynamic and buckling analyses. The global-local analysis procedure referred to as the subelement refinement is developed in the framework of the mixed iterative solution, of which the detail is presented. The numerically integrated isoparametric elements implemented in the framework is discussed. Methods to filter certain parts of strain and project the element discontinuous quantities to the nodes are developed for a family of linear elements. Integration algorithms are described for linear and nonlinear equations included in MHOST program.
NASA Technical Reports Server (NTRS)
Dewitt, R. L.; Mcintire, T. O.
1974-01-01
Pressurized expulsion tests were conducted to determine the effect of various physical parameters on the pressurant gas (methane, helium, hydrogen, and nitrogen) requirements during the expulsion of liquid methane from a 1.52-meter-(5-ft-) diameter spherical tank and to compare results with those predicted by an analytical program. Also studied were the effects on methane, helium, and hydrogen pressurant requirements of various slosh excitation frequencies and amplitudes, both with and without slosh suppressing baffles in the tank. The experimental results when using gaseous methane, helium, and hydrogen show that the predictions of the analytical program agreed well with the actual pressurant requirements for static tank expulsions. The analytical program could not be used for gaseous nitrogen expulsions because of the large quantities of nitrogen which can dissolve in liquid methane. Under slosh conditions, a pronounced increase in gaseous methane requirements was observed relative to results obtained for the static tank expulsions. Slight decreases in the helium and hydrogen requirements were noted under similar test conditions.
NASA/ASEE Summer Faculty Fellowship Program. 1991 Research Reports
NASA Technical Reports Server (NTRS)
Hosler, E. Ramon (Editor); Beymer, Mark A. (Editor); Armstrong, Dennis W. (Editor)
1991-01-01
Reports from the NASA/ASEE Summer Faculty Fellowship Program are presented. The editors are responsible for selecting appropriately qualified faculty to address some of the many problems of current interest to NASA Kennedy. Some representative titles are as follows: Development of an Accelerated Test Method for the Determination of Susceptibility to Atmospheric Corrosion; Hazardous Gas Leak Analysis in the Space Shuttle; Modeling and Control of the Automated Radiator Inspection Device; Study of the Finite Element Software Packages at KSC; Multispectral Image Processing for Plants; Algorithms for Contours Depicting Static Electric Fields during Adverse Weather Conditions; Transient Study of a Cryogenic Hydrogen Filling System; and Precision Cleaning Verification of Nonvolatile Residues by using Water, Ultrasonics, and Turbidity Analyses.
Kim, Seong-Gil
2018-01-01
Background The purpose of this study was to investigate the effect of ankle ROM and lower-extremity muscle strength on static balance control ability in young adults. Material/Methods This study was conducted with 65 young adults, but 10 young adults dropped out during the measurement, so 55 young adults (male: 19, female: 36) completed the study. Postural sway (length and velocity) was measured with eyes open and closed, and ankle ROM (AROM and PROM of dorsiflexion and plantarflexion) and lower-extremity muscle strength (flexor and extensor of hip, knee, and ankle joint) were measured. Pearson correlation coefficient was used to examine the correlation between variables and static balance ability. Simple linear regression analysis and multiple linear regression analysis were used to examine the effect of variables on static balance ability. Results In correlation analysis, plantarflexion ROM (AROM and PROM) and lower-extremity muscle strength (except hip extensor) were significantly correlated with postural sway (p<0.05). In simple correlation analysis, all variables that passed the correlation analysis procedure had significant influence (p<0.05). In multiple linear regression analysis, plantar flexion PROM with eyes open significantly influenced sway length (B=0.681) and sway velocity (B=0.011). Conclusions Lower-extremity muscle strength and ankle plantarflexion ROM influenced static balance control ability, with ankle plantarflexion PROM showing the greatest influence. Therefore, both contractile structures and non-contractile structures should be of interest when considering static balance control ability improvement. PMID:29760375
Kim, Seong-Gil; Kim, Wan-Soo
2018-05-15
BACKGROUND The purpose of this study was to investigate the effect of ankle ROM and lower-extremity muscle strength on static balance control ability in young adults. MATERIAL AND METHODS This study was conducted with 65 young adults, but 10 young adults dropped out during the measurement, so 55 young adults (male: 19, female: 36) completed the study. Postural sway (length and velocity) was measured with eyes open and closed, and ankle ROM (AROM and PROM of dorsiflexion and plantarflexion) and lower-extremity muscle strength (flexor and extensor of hip, knee, and ankle joint) were measured. Pearson correlation coefficient was used to examine the correlation between variables and static balance ability. Simple linear regression analysis and multiple linear regression analysis were used to examine the effect of variables on static balance ability. RESULTS In correlation analysis, plantarflexion ROM (AROM and PROM) and lower-extremity muscle strength (except hip extensor) were significantly correlated with postural sway (p<0.05). In simple correlation analysis, all variables that passed the correlation analysis procedure had significant influence (p<0.05). In multiple linear regression analysis, plantar flexion PROM with eyes open significantly influenced sway length (B=0.681) and sway velocity (B=0.011). CONCLUSIONS Lower-extremity muscle strength and ankle plantarflexion ROM influenced static balance control ability, with ankle plantarflexion PROM showing the greatest influence. Therefore, both contractile structures and non-contractile structures should be of interest when considering static balance control ability improvement.
Comparison of Measures of Risk for Recidivism in Sexual Offenders
ERIC Educational Resources Information Center
Looman, Jan; Abracen, Jeffrey
2010-01-01
Data for both sexual and violent recidivism for the Static-99, Risk Matrix 2000 (RM 2000), Rapid Risk Assessment for Sex Offense Recidivism (RRASOR), and Static-2002 are reported for 419 released sexual offenders assessed at the Regional Treatment Centre Sexual Offender Treatment Program. Data are analyzed by offender type as well as the group as…
Mobility analysis, simulation, and scale model testing for the design of wheeled planetary rovers
NASA Technical Reports Server (NTRS)
Lindemann, Randel A.; Eisen, Howard J.
1993-01-01
The use of computer based techniques to model and simulate wheeled rovers on rough natural terrains is considered. Physical models of a prototype vehicle can be used to test the correlation of the simulations in scaled testing. The computer approaches include a quasi-static planar or two dimensional analysis and design tool based on the traction necessary for the vehicle to have imminent mobility. The computer program modeled a six by six wheel drive vehicle of original kinematic configuration, called the Rocker Bogie. The Rocker Bogie was optimized using the quasi-static software with respect to its articulation parameters prior to fabrication of a prototype. In another approach used, the dynamics of the Rocker Bogie vehicle in 3-D space was modeled on an engineering workstation using commercial software. The model included the complex and nonlinear interaction of the tire and terrain. The results of the investigation yielded numerical and graphical results of the rover traversing rough terrain on the earth, moon, and Mars. In addition, animations of the rover excursions were also generated. A prototype vehicle was then used in a series of testbed and field experiments. Correspondence was then established between the computer models and the physical model. The results indicated the utility of the quasi-static tool for configurational design, as well as the predictive ability of the 3-D simulation to model the dynamic behavior of the vehicle over short traverses.
Computer program determines gas flow rates in piping systems
NASA Technical Reports Server (NTRS)
Franke, R.
1966-01-01
Computer program calculates the steady state flow characteristics of an ideal compressible gas in a complex piping system. The program calculates the stagnation and total temperature, static and total pressure, loss factor, and forces on each element in the piping system.
1967-08-01
This photograph is a view of the Saturn V S-IC-5 (first) flight stage static test firing at the S-IC-B1 test stand at the Mississippi Test Facility (MTF), Bay St. Louis, Mississippi. Begirning operations in 1966, the MTF has two test stands, a dual-position structure for running the S-IC stage at full throttle, and two separate stands for the S-II (Saturn V third) stage. It became the focus of the static test firing program. The completed S-IC stage was shipped from Michoud Assembly Facility (MAF) to the MTF. The stage was then installed into the 407-foot-high test stand for the static firing tests before shipment to the Kennedy Space Center for final assembly of the Saturn V vehicle. The MTF was renamed to the National Space Technology Laboratory (NSTL) in 1974 and later to the Stennis Space Center (SSC) in May 1988.
NASA Astrophysics Data System (ADS)
Takasaki, Koichi
This paper presents a program for the multidisciplinary optimization and identification problem of the nonlinear model of large aerospace vehicle structures. The program constructs the global matrix of the dynamic system in the time direction by the p-version finite element method (pFEM), and the basic matrix for each pFEM node in the time direction is described by a sparse matrix similarly to the static finite element problem. The algorithm used by the program does not require the Hessian matrix of the objective function and so has low memory requirements. It also has a relatively low computational cost, and is suited to parallel computation. The program was integrated as a solver module of the multidisciplinary analysis system CUMuLOUS (Computational Utility for Multidisciplinary Large scale Optimization of Undense System) which is under development by the Aerospace Research and Development Directorate (ARD) of the Japan Aerospace Exploration Agency (JAXA).
NASA Technical Reports Server (NTRS)
Howell, W. E.
1974-01-01
The structural performance of a boron-epoxy reinforced titanium drag strut, which contains a bonded scarf joint and was designed to the criteria of the Boeing 747 transport, was evaluated. An experimental and analytical investigation was conducted. The strut was exposed to two lifetimes of spectrum loading and was statically loaded to the tensile and compressive design ultimate loads. Throughout the test program no evidence of any damage in the drag strut was detected by strain gage measurements, ultrasonic inspection, or visual observation. An analytical study of the bonded joint was made using the NASA structural analysis computer program NASTRAN. A comparison of the strains predicted by the NASTRAN computer program with the experimentally determined values shows excellent agreement. The NASTRAN computer program is a viable tool for studying, in detail, the stresses and strains induced in a bonded joint.
NASA Technical Reports Server (NTRS)
Minute, Stephen A.
2013-01-01
Mr. Christopher Miller with the Kennedy Space Center (KSC) NASA Safety & Mission Assurance (S&MA) office requested the NASA Engineering and Safety Center's (NESC) technical support on March 15, 2012, to review and make recommendations on the structural analysis being performed for the Orbiter Atlantis static display at the KSC Visitor Center. The principal focus of the assessment was to review the engineering firm's structural analysis for lifting and aligning the orbiter and its static display configuration
Kumar, Neelesh
2014-10-01
Finite element analysis has been universally employed for the stress and strain analysis in lower extremity prosthetics. The socket adapter was the principal subject of interest due to its importance in deciding the knee motion range. This article focused on the static and dynamic stress analysis of the designed hybrid adapter developed by the authors. A standard mechanical design validation approach using von Mises was followed. Four materials were considered for the analysis, namely, carbon fiber, oil-filled nylon, Al-6061, and mild steel. The paper analyses the static and dynamic stress on designed hybrid adapter which incorporates features of conventional male and female socket adapters. The finite element analysis was carried out for possible different angles of knee flexion simulating static and dynamic gait situation. Research was carried out on available design of socket adapter. Mechanical design of hybrid adapter was conceptualized and a CAD model was generated using Inventor modelling software. Static and dynamic stress analysis was carried out on different materials for optimization. The finite element analysis was carried out on the software Autodesk Inventor Professional Ver. 2011. The peak value of von Mises stress occurred in the neck region of the adapter and in the lower face region at rod eye-adapter junction in static and dynamic analyses, respectively. Oil-filled nylon was found to be the best material among the four with respect to strength, weight, and cost. Research investigations on newer materials for development of improved prosthesis will immensely benefit the amputees. The study analyze the static and dynamic stress on the knee joint adapter to provide better material used for hybrid design of adapter. © The International Society for Prosthetics and Orthotics 2013.
Abdel-aziem, Amr Almaz; Mohammad, Walaa Sayed
2012-01-01
The aim of this study was to examine the long-term effects of static stretching of the plantar-flexor muscles on eccentric and concentric torque and ankle dorsiflexion range of motion in healthy subjects. Seventy five healthy male volunteers, with no previous history of trauma to the calf that required surgery, absence of knee flexion contracture and no history of neurologic dysfunction or disease, systemic disease affecting the lower extremities were selected for this study. The participants were divided into three equal groups. The control group did not stretch the plantar-flexor muscles. Two Experimental groups (trained and untrained) were instructed to perform static stretching exercise of 30 second duration and 5 repetitions twice daily. The stretching sessions were carried out 5 days a week for 6 weeks. The dorsiflexion range of motion was measured in all subjects. Also measured was the eccentric and concentric torque of plantar-flexors at angular velocities of 30 and 120°/s pre and post stretching. Analysis of variance showed a significant increase in plantar-flexor eccentric and concentric torque (p < 0.05) of trained and untrained groups, and an increase in dorsiflexion range of motion (p < 0.05) at both angular velocities for the untrained group only. The static stretching program of plantar-flexors was effective in increasing the concentric and eccentric plantarflexion torque at angular velocities of 30 and 120°/s. Increases in plantar-flexors flexibility were observed in untrained subjects. PMID:23486840
LEWICE3D/GlennHT Particle Analysis of the Honeywell Al502 Low Pressure Compressor
NASA Technical Reports Server (NTRS)
Bidwell, Colin S.; Rigby, David L.
2015-01-01
A flow and ice particle trajectory analysis was performed for the booster of the Honeywell AL502 engine. The analysis focused on two closely related conditions one of which produced a rollback and another which did not rollback during testing in the Propulsion Systems Lab at NASA Glenn Research Center. The flow analysis was generated using the NASA Glenn GlennHT flow solver and the particle analysis was generated using the NASA Glenn LEWICE3D v3.56 ice accretion software. The flow and particle analysis used a 3D steady flow, mixing plane approach to model the transport of flow and particles through the engine. The inflow conditions for the rollback case were: airspeed, 145 ms; static pressure, 33,373 Pa; static temperature, 253.3 K. The inflow conditions for the non-roll-back case were: airspeed, 153 ms; static pressure, 34,252 Pa; static temperature, 260.1 K. Both cases were subjected to an ice particle cloud with a median volume diameter of 24 microns, an ice water content of 2.0 gm3 and a relative humidity of 100 percent. The most significant difference between the rollback and non-rollback conditions was the inflow static temperature which was 6.8 K higher for the non-rollback case.
Space Shuttle Flight Support Motor no. 1 (FSM-1)
NASA Technical Reports Server (NTRS)
Hughes, Phil D.
1990-01-01
Space Shuttle Flight Support Motor No. 1 (FSM-1) was static test fired on 15 Aug. 1990 at the Thiokol Corporation Static Test Bay T-24. FSM-1 was a full-scale, full-duration static test fire of a redesigned solid rocket motor. FSM-1 was the first of seven flight support motors which will be static test fired. The Flight Support Motor program validates components, materials, and manufacturing processes. In addition, FSM-1 was the full-scale motor for qualification of Western Electrochemical Corporation ammonium perchlorate. This motor was subjected to all controls and documentation requirements CTP-0171, Revision A. Inspection and instrumentation data indicate that the FSM-1 static test firing was successful. The ambient temperature during the test was 87 F and the propellant mean bulk temperature was 82 F. Ballistics performance values were within the specified requirements. The overall performance of the FSM-1 components and test equipment was nominal.
Recommended Experimental Procedures for Evaluation of Abrupt Wing Stall Characteristics
NASA Technical Reports Server (NTRS)
Capone, F. J.; Hall, R. M.; Owens, D. B.; Lamar, J. E.; McMillin, S. N.
2003-01-01
This paper presents a review of the experimental program under the Abrupt Wing Stall (AWS) Program. Candidate figures of merit from conventional static tunnel tests are summarized and correlated with data obtained in unique free-to-roll tests. Where possible, free-to-roll results are also correlated with flight data. Based on extensive studies of static experimental figures of merit in the Abrupt Wing Stall Program for four different aircraft configurations, no one specific figure of merit consistently flagged a warning of potential lateral activity when actual activity was seen to occur in the free-to-roll experiments. However, these studies pointed out the importance of measuring and recording the root mean square signals of the force balance.
Martínez-Amat, Antonio; Hita-Contreras, Fidel; Lomas-Vega, Rafael; Caballero-Martínez, Isabel; Alvarez, Pablo J; Martínez-López, Emilio
2013-08-01
The purpose of this study was to evaluate the effect of a 12-week-specific proprioceptive training program on postural stability, gait, balance, and fall prevention in adults older than 65 years. The present study was a controlled clinical trial. Forty-four community dwelling elderly subjects (61-90 years; mean age, 78.07 ± 5.7 years) divided into experimental (n = 20) and control (n = 24) groups. The participants performed the Berg balance test before and after the training program, and we assessed participants' gait, balance, and the risk of falling, using the Tinetti scale. Medial-lateral plane and anterior-posterior plane displacements of the center of pressure, Sway area, length and speed, and the Romberg quotient about surface, speed, and distance were calculated in static posturography analysis (EPS pressure platform) under 2 conditions: eyes open and eyes closed. After a first clinical evaluation, patients were submitted to 12 weeks proprioception training program, 2 sessions of 50 minutes every week. This program includes 6 exercises with the BOSU and Swiss ball as unstable training tools that were designed to program proprioceptive training. The training program improved postural balance of older adults in mediolateral plane with eyes open (p < 0.05) and anterior-posterior plane with eyes closed (p < 0.01). Significant improvements were observed in Romberg quotient about surface (p < 0.05) and speed (p < 0.01) but not about distance (p > 0.05). After proprioception training, gait (Tinetti), and balance (Berg) test scores improved 14.66% and 11.47% respectively. These results show that 12 weeks proprioception training program in older adults is effective in postural stability, static, and dynamic balance and could lead to an improvement in gait and balance capacity, and to a decrease in the risk of falling in adults aged 65 years and older.
Performance and Architecture Lab Modeling Tool
DOE Office of Scientific and Technical Information (OSTI.GOV)
2014-06-19
Analytical application performance models are critical for diagnosing performance-limiting resources, optimizing systems, and designing machines. Creating models, however, is difficult. Furthermore, models are frequently expressed in forms that are hard to distribute and validate. The Performance and Architecture Lab Modeling tool, or Palm, is a modeling tool designed to make application modeling easier. Palm provides a source code modeling annotation language. Not only does the modeling language divide the modeling task into sub problems, it formally links an application's source code with its model. This link is important because a model's purpose is to capture application behavior. Furthermore, this linkmore » makes it possible to define rules for generating models according to source code organization. Palm generates hierarchical models according to well-defined rules. Given an application, a set of annotations, and a representative execution environment, Palm will generate the same model. A generated model is a an executable program whose constituent parts directly correspond to the modeled application. Palm generates models by combining top-down (human-provided) semantic insight with bottom-up static and dynamic analysis. A model's hierarchy is defined by static and dynamic source code structure. Because Palm coordinates models and source code, Palm's models are 'first-class' and reproducible. Palm automates common modeling tasks. For instance, Palm incorporates measurements to focus attention, represent constant behavior, and validate models. Palm's workflow is as follows. The workflow's input is source code annotated with Palm modeling annotations. The most important annotation models an instance of a block of code. Given annotated source code, the Palm Compiler produces executables and the Palm Monitor collects a representative performance profile. The Palm Generator synthesizes a model based on the static and dynamic mapping of annotations to program behavior. The model -- an executable program -- is a hierarchical composition of annotation functions, synthesized functions, statistics for runtime values, and performance measurements.« less
Effects of quadriceps strength after static and dynamic whole-body vibration exercise.
Bush, Jill A; Blog, Gabriel L; Kang, Jie; Faigenbaum, Avery D; Ratamess, Nicholas A
2015-05-01
Numerous studies have shown performance benefits including whole-body vibration (WBV) as a training modality or an acute exercise protocol when used as a component of the resistance training program. Some studies have indicated that performing dynamic exercises as compared with static position exercises while exposed to WBV might be beneficial; however, evidence is lacking. Thus, the purpose of this study was to determine if an acute bout of dynamic versus static squats performed during WBV results in increase in quadriceps force production by means of dynamic isokinetic knee extension and flexion exercise. Nonresistance-trained healthy young men and women (N = 21) of 18-25 years participated in 4 protocols with 2-week rest in-between. Protocol 1 consisted of 5 sets of 10 dynamic squats without vibration; Protocol 2: 5 sets of 30-second static squats without vibration; Protocol 3: 5 sets of 10 dynamic squats with 30-Hz WBV for a total of 2.5 minutes; and Protocol 4: 5 sets of 30-second static squats with 30-Hz WBV for a total of 2.5 minutes. Prestrength tests (1 set of 4 repetitions at 100° · s(-1) for the knee extension exercise) was performed within 5 minutes of starting each protocol, and poststrength testing was performed within 1 minute of completing each protocol. Strength outcomes were analyzed by repeated measures analysis of variance with a significance level set at p ≤ 0.05. A significant decrease in strength was observed after dynamic and static squats without WBV (p = 0.002); an increase in strength after dynamic squats with WBV (p = 0.003); and a decrease in strength after static squats with WBV (p = 0.003). The inclusion of WBV to dynamic resistance exercise can be an added modality to increase strength. Whole-body vibration can have varied effects in altering muscle strength in untrained individuals according to the type of resistance training performed. As a dynamic squat with WBV seems to immediately potentiate neuromuscular functioning, the combination of dynamic exercises and WBV could be used as a potential warm-up procedure before resistance exercise.
Learning Enterprise Malware Triage from Automatic Dynamic Analysis
2013-03-01
Kolter and Maloof n-gram method, Dube’s malware target recognition (MaTR) static method performs significantly more accurately at the 95% confidence...from the static method as in Kolter and Maloof. The MIST approach with behavior sequences 9 allows researchers to tailor the level of analysis to the...citations, none publish work that implements it. Only Kolter and Maloof use nearly as long gram structures, although that research uses static grams rather
Treleaven, Julia; Peterson, Gunnel; Ludvigsson, Maria Landén; Kammerlind, Ann-Sofi; Peolsson, Anneli
2016-04-01
Dizziness and unsteadiness are common symptoms following a whiplash injury. To compare the effect of 3 exercise programs on balance, dizziness, proprioception and pain in patients with chronic whiplash complaining of dizziness. A sub-analysis of a randomized study. One hundred and forty subjects were randomized to either a physiotherapist-guided neck-specific exercise (NSE), physiotherapist-guided neck-specific exercise, with a behavioural approach (NSEB) or prescription of general physical activity (PPA) group. Pre intervention, 3, 6 and 12 months post baseline they completed the University of California Los Angeles Dizziness Questionnaire (UCLA-DQ), Visual Analogue Scales (VAS) for, dizziness at rest and during activity and physical measures (static and dynamic clinical balance tests and head repositioning accuracy (HRA)). There were significant time by group differences with respect to dizziness during activity and UCLA-Q favouring the physiotherapy led neck specific exercise group with a behavioural approach. Within group analysis of changes over time also revealed significant changes in most variables apart from static balance. Between and within group comparisons suggest that physiotherapist led neck exercise groups including a behavioural approach had advantages in improving measures of dizziness compared with the general physical activity group, although many still complained of dizziness and balance impairment. Future studies should consider exercises specifically designed to address balance, dizziness and cervical proprioception in those with persistent whiplash. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Razzaq, Zia; Prasad, Venkatesh; Darbhamulla, Siva Prasad; Bhati, Ravinder; Lin, Cai
1987-01-01
Parallel computing studies are presented for a variety of structural analysis problems. Included are the substructure planar analysis of rectangular panels with and without a hole, the static analysis of space mast, using NICE/SPAR and FORCE, and substructure analysis of plane rigid-jointed frames using FORCE. The computations are carried out on the Flex/32 MultiComputer using one to eighteen processors. The NICE/SPAR runstream samples are documented for the panel problem. For the substructure analysis of plane frames, a computer program is developed to demonstrate the effectiveness of a substructuring technique when FORCE is enforced. Ongoing research activities for an elasto-plastic stability analysis problem using FORCE, and stability analysis of the focus problem using NICE/SPAR are briefly summarized. Speedup curves for the panel, the mast, and the frame problems provide a basic understanding of the effectiveness of parallel computing procedures utilized or developed, within the domain of the parameters considered. Although the speedup curves obtained exhibit various levels of computational efficiency, they clearly demonstrate the excellent promise which parallel computing holds for the structural analysis problem. Source code is given for the elasto-plastic stability problem and the FORCE program.
DOE Office of Scientific and Technical Information (OSTI.GOV)
March-Leuba, S.; Jansen, J.F.; Kress, R.L.
A new program package, Symbolic Manipulator Laboratory (SML), for the automatic generation of both kinematic and static manipulator models in symbolic form is presented. Critical design parameters may be identified and optimized using symbolic models as shown in the sample application presented for the Future Armor Rearm System (FARS) arm. The computer-aided development of the symbolic models yields equations with reduced numerical complexity. Important considerations have been placed on the closed form solutions simplification and on the user friendly operation. The main emphasis of this research is the development of a methodology which is implemented in a computer program capablemore » of generating symbolic kinematic and static forces models of manipulators. The fact that the models are obtained trigonometrically reduced is among the most significant results of this work and the most difficult to implement. Mathematica, a commercial program that allows symbolic manipulation, is used to implement the program package. SML is written such that the user can change any of the subroutines or create new ones easily. To assist the user, an on-line help has been written to make of SML a user friendly package. Some sample applications are presented. The design and optimization of the 5-degrees-of-freedom (DOF) FARS manipulator using SML is discussed. Finally, the kinematic and static models of two different 7-DOF manipulators are calculated symbolically.« less
NASA Technical Reports Server (NTRS)
Reddy, T. S. R.
1986-01-01
The process of performing an automated stability analysis for an elastic-bladed helicopter rotor is discussed. A symbolic manipulation program, written in FORTRAN, is used to aid in the derivation of the governing equations of motion for the rotor. The blades undergo coupled bending and torsional deformations. Two-dimensional quasi-steady aerodynamics below stall are used. Although reversed flow effects are neglected, unsteady effects, modeled as dynamic inflow are included. Using a Lagrangian approach, the governing equations are derived in generalized coordinates using the symbolic program. The program generates the steady and perturbed equations and writes into subroutines to be called by numerical routines. The symbolic program can operate on both expressions and matrices. For the case of hovering flight, the blade and dynamic inflow equations are converted to equations in a multiblade coordinate system by rearranging the coefficients of the equations. For the case of forward flight, the multiblade equations are obtained through the symbolic program. The final multiblade equations are capable of accommodating any number of elastic blade modes. The computer implementation of this procedure consists of three stages: (1) the symbolic derivation of equations; (2) the coding of the equations into subroutines; and (3) the numerical study after identifying mass, damping, and stiffness coefficients. Damping results are presented in hover and in forward flight with and without dynamic inflow effects for various rotor blade models, including rigid blade lag-flap, elastic flap-lag, flap-lag-torsion, and quasi-static torsion. Results from dynamic inflow effects which are obtained from a lift deficiency function for a quasi-static inflow model in hover are also presented.
NASA Astrophysics Data System (ADS)
Awwaluddin, Muhammad; Kristedjo, K.; Handono, Khairul; Ahmad, H.
2018-02-01
This analysis is conducted to determine the effects of static and dynamic loads of the structure of mechanical system of Ultrasonic Scanner i.e., arm, column, and connection systems for inservice inspection of research reactors. The analysis is performed using the finite element method with 520 N static load. The correction factor of dynamic loads used is the Gerber mean stress correction (stress life). The results of the analysis show that the value of maximum equivalent von Mises stress is 1.3698E8 Pa for static loading and value of the maximum equivalent alternating stress is 1.4758E7 Pa for dynamic loading. These values are below the upper limit allowed according to ASTM A240 standards i.e. 2.05E8 Pa. The result analysis of fatigue life cycle are at least 1E6 cycle, so it can be concluded that the structure is in the high life cycle category.
ERIC Educational Resources Information Center
Macek, Victor C.
The nine Reactor Statics Modules are designed to introduce students to the use of numerical methods and digital computers for calculation of neutron flux distributions in space and energy which are needed to calculate criticality, power distribution, and fuel burnup for both slow neutron and fast neutron fission reactors. The last module, RS-9,…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1990-01-01
The present conference on flight testing encompasses avionics, flight-testing programs, technologies for flight-test predictions and measurements, testing tools, analysis methods, targeting techniques, and flightline testing. Specific issues addressed include flight testing of a digital terrain-following system, a digital Doppler rate-of-descent indicator, a high-technology testbed, a low-altitude air-refueling flight-test program, techniques for in-flight frequency-response testing for helicopters, limit-cycle oscillation and flight-flutter testing, and the research flight test of a scaled unmanned air vehicle. Also addressed are AV-8B V/STOL performance analysis, incorporating pilot-response time in failure-case testing, the development of pitot static flightline testing, targeting techniques for ground-based hover testing, a low-profilemore » microsensor for aerodynamic pressure measurement, and the use of a variable-capacitance accelerometer for flight-test measurements.« less
Bayraktar, Deniz; Guclu-Gunduz, Arzu; Lambeck, Johan; Yazici, Gokhan; Aykol, Sukru; Demirci, Harun
2016-01-01
To determine and compare the effects of core stability exercise programs performed in two different environments in lumbar disc herniation (LDH) patients. Thirty-one patients who were diagnosed with LDH and were experiencing pain or functional disability for at least 3 months were randomly divided into two groups as land-based exercises or water specific therapy. Also, 15 age-sex-matched healthy individuals were recruited as healthy controls. Both groups underwent an 8-week (3 times/week) core stabilization exercise program. Primary outcomes were pain, trunk muscle static endurance and perceived disability level. The secondary outcome was health-related quality of life. Level of static endurance of trunk muscles was found to be lower in the patients compared to the controls at baseline (p < 0.05). Both treatment groups showed significant improvements in all outcomes (p < 0.05) after 8-week intervention. When two treatment groups were compared, no differences were found in the amount of change after the intervention (p > 0.05). After the treatment, static endurance of trunk muscles of the LDH patients became similar to controls (p > 0.05). According to these results, core stabilization exercise training performed on land or in water both could be beneficial in LDH patients and there is no difference between the environments. An 8-week core stabilization program performed in water or on land decrease pain level and improve functional status in LDH patients. Both programs seem beneficial to increase health-related quality of life and static endurance of trunk muscles. Core stability exercises could be performed in water as well, no differences were found between methods due to environment.
1964-12-01
At the Marshall Space Flight Center (MSFC), the fuel tank assembly for the Saturn V S-IC-T (static test stage) fuel tank assembly is mated to the liquid oxygen (LOX) tank in building 4705. This stage underwent numerous static firings at the newly-built S-IC Static Test Stand at the MSFC west test area. The S-IC (first) stage used five F-1 engines that produced a total thrust of 7,500,000 pounds as each engine produced 1,500,000 pounds of thrust. The S-IC stage lifted the Saturn V vehicle and Apollo spacecraft from the launch pad.
Effects of static tensile load on the thermal expansion of Gr/PI composite material
NASA Technical Reports Server (NTRS)
Farley, G. L.
1981-01-01
The effect of static tensile load on the thermal expansion of Gr/PI composite material was measured for seven different laminate configurations. A computer program was developed which implements laminate theory in a piecewise linear fashion to predict the coupled nonlinear thermomechanical behavior. Static tensile load significantly affected the thermal expansion characteristics of the laminates tested. This effect is attributed to a fiber instability micromechanical behavior of the constituent materials. Analytical results correlated reasonably well with free thermal expansion tests (no load applied to the specimen). However, correlation was poor for tests with an applied load.
Kim, Dong Wook
2015-08-01
The aim of this study was to compare the diagnostic accuracy of real-time and static ultrasonography (US) for the incidental detection of diffuse thyroid disease (DTD). In 118 consecutive patients, a single radiologist performed real-time US before thyroidectomy. For static US, the same radiologist retrospectively investigated the sonographic findings on a picture-archiving and communication system after 3 months. The diagnostic categories of both real-time and static US diagnoses were determined based on the number of abnormal findings, and the diagnostic indices were calculated by a receiver operating characteristic (ROC) curve analysis using the histopathologic results as the reference standard. Histopathologic results included normal thyroid (n = 77), Hashimoto thyroiditis (n = 11), non-Hashimoto lymphocytic thyroiditis (n = 29), and diffuse hyperplasia (n = 1). Normal thyroid and DTD showed significant differences in echogenicity, echotexture, glandular margin, and vascularity on both real-time and static US. There was a positive correlation between US categories and histopathologic results in both real-time and static US. The highest diagnostic indices were obtained when the cutoff criteria of real-time and static US diagnoses were chosen as indeterminate and suspicious for DTD, respectively. The ROC curve analysis showed that real-time US was superior to static US in diagnostic accuracy. Both real-time and static US may be helpful for the detection of incidental DTD, but real-time US is superior to static US for detecting incidental DTD.
Visualizing topography: Effects of presentation strategy, gender, and spatial ability
NASA Astrophysics Data System (ADS)
McAuliffe, Carla
2003-10-01
This study investigated the effect of different presentation strategies (2-D static visuals, 3-D animated visuals, and 3-D interactive, animated visuals) and gender on achievement, time-spent-on visual treatment, and attitude during a computer-based science lesson about reading and interpreting topographic maps. The study also examined the relationship of spatial ability and prior knowledge to gender, achievement, and time-spent-on visual treatment. Students enrolled in high school chemistry-physics were pretested and given two spatial ability tests. They were blocked by gender and randomly assigned to one of three levels of presentation strategy or the control group. After controlling for the effects of spatial ability and prior knowledge with analysis of covariance, three significant differences were found between the versions: (a) the 2-D static treatment group scored significantly higher on the posttest than the control group; (b) the 3-D animated treatment group scored significantly higher on the posttest than the control group; and (c) the 2-D static treatment group scored significantly higher on the posttest than the 3-D interactive animated treatment group. Furthermore, the 3-D interactive animated treatment group spent significantly more time on the visual screens than the 2-D static treatment group. Analyses of student attitudes revealed that most students felt the landform visuals in the computer-based program helped them learn, but not in a way they would describe as fun. Significant differences in attitude were found by treatment and by gender. In contrast to findings from other studies, no gender differences were found on either of the two spatial tests given in this study. Cognitive load, cognitive involvement, and solution strategy are offered as three key factors that may help explain the results of this study. Implications for instructional design include suggestions about the use of 2-D static, 3-D animated and 3-D interactive animations as well as a recommendation about the inclusion of pretests in similar instructional programs. Areas for future research include investigating the effects of combinations of presentation strategies, continuing to examine the role of spatial ability in science achievement, and gaining cognitive insights about what it is that students do when learning to read and interpret topographic maps.
Stability of the Einstein static universe in open cosmological models
DOE Office of Scientific and Technical Information (OSTI.GOV)
Canonico, Rosangela; Parisi, Luca; INFN, Sezione di Napoli, GC di Salerno, Via Ponte Don Melillo, I-84081 Baronissi
2010-09-15
The stability properties of the Einstein static solution of general relativity are altered when corrective terms arising from modification of the underlying gravitational theory appear in the cosmological equations. In this paper the existence and stability of static solutions are considered in the framework of two recently proposed quantum gravity models. The previously known analysis of the Einstein static solutions in the semiclassical regime of loop quantum cosmology with modifications to the gravitational sector is extended to open cosmological models where a static neutrally stable solution is found. A similar analysis is also performed in the framework of Horava-Lifshitz gravitymore » under detailed balance and projectability conditions. In the case of open cosmological models the two solutions found can be either unstable or neutrally stable according to the admitted values of the parameters.« less
NASA Technical Reports Server (NTRS)
Moses, Robert W.; Averill, Robert D.
1992-01-01
The conceptual design and structural analysis for the Spectroscopy of the Atmosphere using Far Infrared Emission (SAFIRE) Instrument are provided. SAFIRE, which is an international effort, is proposed for the Earth Observing Systems (EOS) program for atmospheric ozone studies. A concept was developed which meets mission requirements and is the product of numerous parametric studies and design/analysis iterations. Stiffness, thermal stability, and weight constraints led to a graphite/epoxy composite design for the optical bench and supporting struts. The structural configuration was determined by considering various mounting arrangements of the optical, cryo, and electronic components. Quasi-static, thermal, modal, and dynamic response analyses were performed, and the results are presented for the selected configuration.
Transient analysis techniques in performing impact and crash dynamic studies
NASA Technical Reports Server (NTRS)
Pifko, A. B.; Winter, R.
1989-01-01
Because of the emphasis being placed on crashworthiness as a design requirement, increasing demands are being made by various organizations to analyze a wide range of complex structures that must perform safely when subjected to severe impact loads, such as those generated in a crash event. The ultimate goal of crashworthiness design and analysis is to produce vehicles with the ability to reduce the dynamic forces experienced by the occupants to specified levels, while maintaining a survivable envelope around them during a specified crash event. DYCAST is a nonlinear structural dynamic finite element computer code that started from the plans systems of a finite element program for static nonlinear structural analysis. The essential features of DYCAST are outlined.
The Neglect of Monotone Comparative Statics Methods
ERIC Educational Resources Information Center
Tremblay, Carol Horton; Tremblay, Victor J.
2010-01-01
Monotone methods enable comparative static analysis without the restrictive assumptions of the implicit-function theorem. Ease of use and flexibility in solving comparative static and game-theory problems have made monotone methods popular in the economics literature and in graduate courses, but they are still absent from undergraduate…
Space station structures and dynamics test program
NASA Technical Reports Server (NTRS)
Moore, Carleton J.; Townsend, John S.; Ivey, Edward W.
1987-01-01
The design, construction, and operation of a low-Earth orbit space station poses unique challenges for development and implementation of new technology. The technology arises from the special requirement that the station be built and constructed to function in a weightless environment, where static loads are minimal and secondary to system dynamics and control problems. One specific challenge confronting NASA is the development of a dynamics test program for: (1) defining space station design requirements, and (2) identifying the characterizing phenomena affecting the station's design and development. A general definition of the space station dynamic test program, as proposed by MSFC, forms the subject of this report. The test proposal is a comprehensive structural dynamics program to be launched in support of the space station. The test program will help to define the key issues and/or problems inherent to large space structure analysis, design, and testing. Development of a parametric data base and verification of the math models and analytical analysis tools necessary for engineering support of the station's design, construction, and operation provide the impetus for the dynamics test program. The philosophy is to integrate dynamics into the design phase through extensive ground testing and analytical ground simulations of generic systems, prototype elements, and subassemblies. On-orbit testing of the station will also be used to define its capability.
An Interactive Computer-Based Training Program for Beginner Personal Computer Maintenance.
ERIC Educational Resources Information Center
Summers, Valerie Brooke
A computer-assisted instructional program, which was developed for teaching beginning computer maintenance to employees of Unisys, covered external hardware maintenance, proper diskette care, making software backups, and electro-static discharge prevention. The procedure used in developing the program was based upon the Dick and Carey (1985) model…
Structural Analysis and Test Comparison of a 20-Meter Inflation-Deployed Solar Sail
NASA Technical Reports Server (NTRS)
Sleight, David W.; Mann, Troy; Lichodziejewski, David; Derbes, Billy
2006-01-01
Under the direction of the NASA In-Space Propulsion Technology Office, the team of L Garde, NASA Jet Propulsion Laboratory, Ball Aerospace, and NASA Langley Research Center has been developing a scalable solar sail configuration to address NASA s future space propulsion needs. Prior to a flight experiment of a full-scale solar sail, a comprehensive test program was implemented to advance the technology readiness level of the solar sail design. These tests consisted of solar sail component, subsystem, and sub-scale system ground tests that simulated the aspects of the space environment such as vacuum and thermal conditions. In July 2005, a 20-m four-quadrant solar sail system test article was tested in the NASA Glenn Research Center s Space Power Facility to measure its static and dynamic structural responses. Key to the maturation of solar sail technology is the development of validated finite element analysis (FEA) models that can be used for design and analysis of solar sails. A major objective of the program was to utilize the test data to validate the FEA models simulating the solar sail ground tests. The FEA software, ABAQUS, was used to perform the structural analyses to simulate the ground tests performed on the 20-m solar sail test article. This paper presents the details of the FEA modeling, the structural analyses simulating the ground tests, and a comparison of the pretest and post-test analysis predictions with the ground test results for the 20-m solar sail system test article. The structural responses that are compared in the paper include load-deflection curves and natural frequencies for the beam structural assembly and static shape, natural frequencies, and mode shapes for the solar sail membrane. The analysis predictions were in reasonable agreement with the test data. Factors that precluded better correlation of the analyses and the tests were unmeasured initial conditions in the test set-up.
Parallel Processing with Digital Signal Processing Hardware and Software
NASA Technical Reports Server (NTRS)
Swenson, Cory V.
1995-01-01
The assembling and testing of a parallel processing system is described which will allow a user to move a Digital Signal Processing (DSP) application from the design stage to the execution/analysis stage through the use of several software tools and hardware devices. The system will be used to demonstrate the feasibility of the Algorithm To Architecture Mapping Model (ATAMM) dataflow paradigm for static multiprocessor solutions of DSP applications. The individual components comprising the system are described followed by the installation procedure, research topics, and initial program development.
Static tests of the propulsion system. [Propfan Test Assessment program
NASA Technical Reports Server (NTRS)
Withers, C. C.; Bartel, H. W.; Turnberg, J. E.; Graber, E. J.
1987-01-01
Advanced, highly-loaded, high-speed propellers, called propfans, are promising to revolutionize the transport aircraft industry by offering a 15- to 30-percent fuel savings over the most advanced turbofans without sacrificing passenger comfort or violating community noise standards. NASA Lewis Research Center and industry have been working jointly to develop the needed propfan technology. The NASA-funded Propfan Test Assessment (PTA) Program represents a key element of this joint program. In PTA, Lockheed-Georgia, working in concert with Hamilton Standard, Rohr Industries, Gulfstream Aerospace, and Allison, is developing a propfan propulsion system which will be mounted on the left wing of a modified Gulfstream GII aircraft and flight tested to verify the in-flight characteristics of a 9-foot diameter, single-rotation propfan. The propfan, called SR-7L, was designed and fabricated by Hamilton Standard under a separate NASA contract. Prior to flight testing, the PTA propulsion system was static tested at the Rohr Brown Field facility. In this test, propulsion system operational capability was verified and data was obtained on propfan structural response, system acoustic characteristics, and system performance. This paper reports on the results of the static tests.
Multiple Changes to Reusable Solid Rocket Motors, Identifying Hidden Risks
NASA Technical Reports Server (NTRS)
Greenhalgh, Phillip O.; McCann, Bradley Q.
2003-01-01
The Space Shuttle Reusable Solid Rocket Motor (RSRM) baseline is subject to various changes. Changes are necessary due to safety and quality improvements, environmental considerations, vendor changes, obsolescence issues, etc. The RSRM program has a goal to test changes on full-scale static test motors prior to flight due to the unique RSRM operating environment. Each static test motor incorporates several significant changes and numerous minor changes. Flight motors often implement multiple changes simultaneously. While each change is individually verified and assessed, the potential for changes to interact constitutes additional hidden risk. Mitigating this risk depends upon identification of potential interactions. Therefore, the ATK Thiokol Propulsion System Safety organization initiated the use of a risk interaction matrix to identify potential interactions that compound risk. Identifying risk interactions supports flight and test motor decisions. Uncovering hidden risks of a full-scale static test motor gives a broader perspective of the changes being tested. This broader perspective compels the program to focus on solutions for implementing RSRM changes with minimal/mitigated risk. This paper discusses use of a change risk interaction matrix to identify test challenges and uncover hidden risks to the RSRM program.
Static Schedulers for Embedded Real-Time Systems
1989-12-01
Because of the need for having efficient scheduling algorithms in large scale real time systems , software engineers put a lot of effort on developing...provide static schedulers for he Embedded Real Time Systems with single processor using Ada programming language. The independent nonpreemptable...support the Computer Aided Rapid Prototyping for Embedded Real Time Systems so that we determine whether the system, as designed, meets the required
NASA Technical Reports Server (NTRS)
Jackson, A. C.; Dorwald, F.
1982-01-01
The ground tests conducted on the advanced composite vertical fin (ACVF) program are described. The design and fabrication of the test fixture and the transition structure, static test of Ground Test Article (GTA) No. 1, rework of GTA No. 2, and static, damage tolerance, fail-safe and residual strength tests of GTA No. 2 are described.
1990-10-01
to economic, technological, spatial or logistic concerns, or involve training, man-machine interfaces, or integration into existing systems. Once the...probabilistic reasoning, mixed analysis- and simulation-oriented, mixed computation- and communication-oriented, nonpreemptive static priority...scheduling base, nonrandomized, preemptive static priority scheduling base, randomized, simulation-oriented, and static scheduling base. The selection of both
[Effects of training on static and dynamic balance in elderly subjects who have had a fall or not].
Toulotte, C; Thévenon, A; Fabre, C
2004-11-01
To evaluate the effects of a physical training program on static and dynamic balance during single and dual task conditions in elderly subjects who have had a fall or not. Two groups, comprising a total of 33 elderly subjects, were trained: 16 who had a fall were 69.2 +/- 5.0 years old and 17 who had not had a fall were 67.3 +/- 3.8 years. All subjects underwent an unipedal test with eyes open and eyes closed, followed by gait assessment during single and dual motor task conditions, before and after a physical training program. All subjects showed a significant decrease, by six times for subjects who had fallen and four times by those who had not, in the number of touch-downs in the unipedal test with eyes open (P < 0.05), and by 2.5 and 2 times, respectively, with eyes closed (P < 0.05) after the training program. All subjects showed a significant increase in speed (P < 0.05), cadence (P < 0.05) and stride length (P < 0.05) and a significant decrease in the single support time (P < 0.05) and stride time (P < 0.05) in gait assessment during single and dual task conditions after the training program. During the training program, no subjects fell. The physical training program improved static balance and quality of gait in elderly subjects who had had a fall and those who had not, which could contribute to minimizing and/or retarding the effects of aging and maintaining physical independence.
aSi EPIDs for the in-vivo dosimetry of static and dynamic beams
NASA Astrophysics Data System (ADS)
Piermattei, A.; Cilla, S.; Azario, L.; Greco, F.; Russo, M.; Grusio, M.; Orlandini, L.; Fidanzio, A.
2015-10-01
Portal imaging by amorphous silicon (aSi) photodiode is currently the most applied technology for in-vivo dosimetry (IVD) of static and dynamic radiotherapy beams. The strategy, adopted in this work to perform the IVD procedure by aSi EPID, is based on: in patient reconstruction of the isocenter dose and day to day comparison between 2D-portal images to verify the reproducibility of treatment delivery. About 20.000 tests have been carried out in this last 3 years in 8 radiotherapy centers using the SOFTDISO program. The IVD results show that: (i) the procedure can be implemented for linacs of different manufacturer, (ii) the IVD analysis can be obtained on a computer screen, in quasi real time (about 2 min after the treatment delivery) and (iii) once the causes of the discrepancies were eliminated, all the global IVD tests for single patient were within the acceptance criteria defined by: ±5% for the isocenter dose, and Pγ<1≥90% of the checked points for the 2D portal image γ-analysis. This work is the result of a project supported by the Istituto Nazionale di Fisica Nucleare (INFN) and Università Cattolica del S.Cuore (UCSC).
Duration Dependent Effect of Static Stretching on Quadriceps and Hamstring Muscle Force.
Alizadeh Ebadi, Leyla; Çetin, Ebru
2018-03-13
The aim of this study was to determine the acute effect of static stretching on hamstring and quadriceps muscles' isokinetic strength when applied for various durations to elite athletes, to investigate the effect of different static stretching durations on isokinetic strength, and finally to determine the optimal stretching duration. Fifteen elite male athletes from two different sport branches (10 football and five basketball) participated in this study. Experimental protocol was designed as 17 repetitive static stretching exercises for hamstring and quadriceps muscle groups according to the indicated experimental protocols; ((A) 5 min jogging; (B) 5 min jogging followed by 15 s static stretching; (C) 5 min jogging followed by 30 s static stretching; (D) 5 min jogging, followed by static stretching for 45 s). Immediately after each protocol, an isokinetic strength test consisting of five repetitions at 60°/s speed and 20 repetitions at 180°/s speed was recorded for the right leg by the Isomed 2000 device. Friedman variance analysis test was employed for data analysis. According to the analyzes, it was observed that 5 min jogging and 15 s stretching exercises increased the isokinetic strength, whereas 30 and 45 s stretching exercises caused a decrease.
Duration Dependent Effect of Static Stretching on Quadriceps and Hamstring Muscle Force
Çetin, Ebru
2018-01-01
The aim of this study was to determine the acute effect of static stretching on hamstring and quadriceps muscles’ isokinetic strength when applied for various durations to elite athletes, to investigate the effect of different static stretching durations on isokinetic strength, and finally to determine the optimal stretching duration. Fifteen elite male athletes from two different sport branches (10 football and five basketball) participated in this study. Experimental protocol was designed as 17 repetitive static stretching exercises for hamstring and quadriceps muscle groups according to the indicated experimental protocols; ((A) 5 min jogging; (B) 5 min jogging followed by 15 s static stretching; (C) 5 min jogging followed by 30 s static stretching; (D) 5 min jogging, followed by static stretching for 45 s). Immediately after each protocol, an isokinetic strength test consisting of five repetitions at 60°/s speed and 20 repetitions at 180°/s speed was recorded for the right leg by the Isomed 2000 device. Friedman variance analysis test was employed for data analysis. According to the analyzes, it was observed that 5 min jogging and 15 s stretching exercises increased the isokinetic strength, whereas 30 and 45 s stretching exercises caused a decrease.
DOE Office of Scientific and Technical Information (OSTI.GOV)
March-Leuba, S.; Jansen, J.F.; Kress, R.L.
1992-08-01
A new program package, Symbolic Manipulator Laboratory (SML), for the automatic generation of both kinematic and static manipulator models in symbolic form is presented. Critical design parameters may be identified and optimized using symbolic models as shown in the sample application presented for the Future Armor Rearm System (FARS) arm. The computer-aided development of the symbolic models yields equations with reduced numerical complexity. Important considerations have been placed on the closed form solutions simplification and on the user friendly operation. The main emphasis of this research is the development of a methodology which is implemented in a computer program capablemore » of generating symbolic kinematic and static forces models of manipulators. The fact that the models are obtained trigonometrically reduced is among the most significant results of this work and the most difficult to implement. Mathematica, a commercial program that allows symbolic manipulation, is used to implement the program package. SML is written such that the user can change any of the subroutines or create new ones easily. To assist the user, an on-line help has been written to make of SML a user friendly package. Some sample applications are presented. The design and optimization of the 5-degrees-of-freedom (DOF) FARS manipulator using SML is discussed. Finally, the kinematic and static models of two different 7-DOF manipulators are calculated symbolically.« less
Slope Stability Analysis In Seismic Areas Of The Northern Apennines (Italy)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lo Presti, D.; Fontana, T.; Marchetti, D.
2008-07-08
Several research works have been published on the slope stability in the northern Tuscany (central Italy) and particularly in the seismic areas of Garfagnana and Lunigiana (Lucca and Massa-Carrara districts), aimed at analysing the slope stability under static and dynamic conditions and mapping the landslide hazard. In addition, in situ and laboratory investigations are available for the study area, thanks to the activities undertaken by the Tuscany Seismic Survey. Based on such a huge information the co-seismic stability of few ideal slope profiles have been analysed by means of Limit equilibrium method LEM - (pseudo-static) and Newmark sliding block analysismore » (pseudo-dynamic). The analysis--results gave indications about the most appropriate seismic coefficient to be used in pseudo-static analysis after establishing allowable permanent displacement. Such indications are commented in the light of the Italian and European prescriptions for seismic stability analysis with pseudo-static approach. The stability conditions, obtained from the previous analyses, could be used to define microzonation criteria for the study area.« less
Programming Wireless Handheld Devices for Applications in Teaching Astronomy
NASA Astrophysics Data System (ADS)
Budiardja, R.; Saranathan, V.; Guidry, M.
2002-12-01
Wireless technology implemented with handheld devices has attractive features because of the potential to access large amounts of data and the prospect of on-the-fly computational analysis from a device that can be carried in a shirt pocket. We shall describe applications of such technology to the general paradigm of making digital wireless connections from the field to upload information and queries to network servers, executing (potentially complex) data analysis and/or database operations on fast network computers, and returning real-time information from this analysis to the handheld device in the field. As illustration, we shall describe several client/server programs that we have written for applications in teaching introductory astronomy. For example, one program allows static and dynamic properties of astronomical objects to be accessed in a remote observation laboratory setting using a digital cell phone or PDA. Another implements interactive quizzing over a cell phone or PDA using a 700-question introductory astronomy quiz database, thus permitting students to study for astronomy quizzes in any environment in which they have a few free minutes and a digital cell phone or wireless PDA. The presentation will include hands-on demonstrations with real devices.
Solid rocket booster performance evaluation model. Volume 1: Engineering description
NASA Technical Reports Server (NTRS)
1974-01-01
The space shuttle solid rocket booster performance evaluation model (SRB-II) is made up of analytical and functional simulation techniques linked together so that a single pass through the model will predict the performance of the propulsion elements of a space shuttle solid rocket booster. The available options allow the user to predict static test performance, predict nominal and off nominal flight performance, and reconstruct actual flight and static test performance. Options selected by the user are dependent on the data available. These can include data derived from theoretical analysis, small scale motor test data, large motor test data and motor configuration data. The user has several options for output format that include print, cards, tape and plots. Output includes all major performance parameters (Isp, thrust, flowrate, mass accounting and operating pressures) as a function of time as well as calculated single point performance data. The engineering description of SRB-II discusses the engineering and programming fundamentals used, the function of each module, and the limitations of each module.
NASA Technical Reports Server (NTRS)
Ammer, R. C.; Kutney, J. T.
1977-01-01
A static scale model test program was conducted in the static test area of the NASA-Langley 9.14- by 18.29 m(30- by 60-ft) Full-Scale Wind Tunnel Facility to develop an over-the-wing (OTW) nozzle and reverser configuration for the Quiet Clean Short-Haul Experimental Engine (QCSEE). Three nozzles and one basic reverser configuration were tested over the QCSEE takeoff and approach power nozzle pressure ratio range between 1.1 and 1.3. The models were scaled to 8.53% of QCSEE engine size and tested behind two 13.97-cm (5.5-in.) diameter tip-turbine-driven fan simulators coupled in tandem. An OTW nozzle and reverser configuration was identified which satisfies the QCSEE experimental engine requirements in terms of nozzle cycle area variation capability and reverse thrust level, and provides good jet flow spreading over a wing upper surface for achievement of high propulsive lift performance.
Auditory motion-specific mechanisms in the primate brain
Baumann, Simon; Dheerendra, Pradeep; Joly, Olivier; Hunter, David; Balezeau, Fabien; Sun, Li; Rees, Adrian; Petkov, Christopher I.; Thiele, Alexander; Griffiths, Timothy D.
2017-01-01
This work examined the mechanisms underlying auditory motion processing in the auditory cortex of awake monkeys using functional magnetic resonance imaging (fMRI). We tested to what extent auditory motion analysis can be explained by the linear combination of static spatial mechanisms, spectrotemporal processes, and their interaction. We found that the posterior auditory cortex, including A1 and the surrounding caudal belt and parabelt, is involved in auditory motion analysis. Static spatial and spectrotemporal processes were able to fully explain motion-induced activation in most parts of the auditory cortex, including A1, but not in circumscribed regions of the posterior belt and parabelt cortex. We show that in these regions motion-specific processes contribute to the activation, providing the first demonstration that auditory motion is not simply deduced from changes in static spatial location. These results demonstrate that parallel mechanisms for motion and static spatial analysis coexist within the auditory dorsal stream. PMID:28472038
Does Intellectual Property Restrict Output? An Analysis of Pharmaceutical Markets*
Lakdawalla, Darius; Philipson, Tomas
2013-01-01
Standard normative analysis of intellectual property focuses on the balance between incentives for research and the static welfare costs of reduced price-competition from monopoly. However, static welfare loss from patents is not universal. While patents restrict price competition, they may also provide static welfare benefits by improving incentives for marketing, which is a form of non-price competition. We show theoretically how stronger marketing incentives mitigate, and can even offset, the static costs of monopoly pricing. Empirical analysis in the pharmaceutical industry context suggests that, in the short-run, patent expirations reduce consumer welfare as a result of decreased marketing effort. In the long-run, patent expirations do benefit consumers, but by 30% less than would be implied by the reduction in price alone. The social value of monopoly marketing to consumers alone is roughly on par with its costs to firms. PMID:25221349
Does Intellectual Property Restrict Output? An Analysis of Pharmaceutical Markets.
Lakdawalla, Darius; Philipson, Tomas
2012-02-01
Standard normative analysis of intellectual property focuses on the balance between incentives for research and the static welfare costs of reduced price-competition from monopoly. However, static welfare loss from patents is not universal. While patents restrict price competition, they may also provide static welfare benefits by improving incentives for marketing, which is a form of non -price competition. We show theoretically how stronger marketing incentives mitigate, and can even offset, the static costs of monopoly pricing. Empirical analysis in the pharmaceutical industry context suggests that, in the short-run, patent expirations reduce consumer welfare as a result of decreased marketing effort. In the long-run, patent expirations do benefit consumers, but by 30% less than would be implied by the reduction in price alone. The social value of monopoly marketing to consumers alone is roughly on par with its costs to firms.
Synthesis and analysis of precise spaceborne laser ranging systems, volume 1. [link analysis
NASA Technical Reports Server (NTRS)
Paddon, E. A.
1977-01-01
Measurement accuracy goals of 2 cm rms range estimation error and 0.003 cm/sec rms range rate estimation error, with no more than 1 cm (range) static bias error are requirements for laser measurement systems to be used in planned space-based earth physics investigations. Constraints and parameters were defined for links between a high altitude, transmit/receive satellite (HATRS), and one of three targets: a low altitude target satellite, passive (LATS), and active low altitude target, and a ground-based target, as well as with operations with a primary transmit/receive terminal intended to be carried as a shuttle payload, in conjunction with the Spacelab program.
An Expert Assistant for Computer Aided Parallelization
NASA Technical Reports Server (NTRS)
Jost, Gabriele; Chun, Robert; Jin, Haoqiang; Labarta, Jesus; Gimenez, Judit
2004-01-01
The prototype implementation of an expert system was developed to assist the user in the computer aided parallelization process. The system interfaces to tools for automatic parallelization and performance analysis. By fusing static program structure information and dynamic performance analysis data the expert system can help the user to filter, correlate, and interpret the data gathered by the existing tools. Sections of the code that show poor performance and require further attention are rapidly identified and suggestions for improvements are presented to the user. In this paper we describe the components of the expert system and discuss its interface to the existing tools. We present a case study to demonstrate the successful use in full scale scientific applications.
1967-09-09
This photograph depicts the F-1 engine firing in the Marshall Space Flight Center’s F-1 Engine Static Test Stand. Construction of the S-IC Static test stand complex began in 1961 in the west test area of MSFC, and was completed in 1964. It is a vertical engine firing test stand, 239 feet in elevation and 4,600 square feet in area at the base, designed to assist in the development of the F-1 Engine. Capability is provided for static firing of 1.5 million pounds of thrust using liquid oxygen and kerosene. The foundation of the stand is keyed into the bedrock approximately 40 feet below grade.
Computer program user's manual for advanced general aviation propeller study
NASA Technical Reports Server (NTRS)
Worobel, R.
1972-01-01
A user's manual is presented for a computer program for predicting the performance (static, flight, and reverse), noise, weight and cost of propellers for advanced general aviation aircraft of the 1980 time period. Complete listings of this computer program with detailed instructions and samples of input and output are included.
14 CFR 23.785 - Seats, berths, litters, safety belts, and shoulder harnesses.
Code of Federal Regulations, 2014 CFR
2014-01-01
... combination of structural analysis and static load tests to limit load; or (3) Static load tests to ultimate... OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY... resulting from the ultimate static load factors prescribed in § 23.561(b)(2) of this part. Each occupant...
14 CFR 23.785 - Seats, berths, litters, safety belts, and shoulder harnesses.
Code of Federal Regulations, 2011 CFR
2011-01-01
... combination of structural analysis and static load tests to limit load; or (3) Static load tests to ultimate... OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY... resulting from the ultimate static load factors prescribed in § 23.561(b)(2) of this part. Each occupant...
14 CFR 23.785 - Seats, berths, litters, safety belts, and shoulder harnesses.
Code of Federal Regulations, 2010 CFR
2010-01-01
... combination of structural analysis and static load tests to limit load; or (3) Static load tests to ultimate... OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY... resulting from the ultimate static load factors prescribed in § 23.561(b)(2) of this part. Each occupant...
14 CFR 23.785 - Seats, berths, litters, safety belts, and shoulder harnesses.
Code of Federal Regulations, 2012 CFR
2012-01-01
... combination of structural analysis and static load tests to limit load; or (3) Static load tests to ultimate... OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY... resulting from the ultimate static load factors prescribed in § 23.561(b)(2) of this part. Each occupant...
14 CFR 23.785 - Seats, berths, litters, safety belts, and shoulder harnesses.
Code of Federal Regulations, 2013 CFR
2013-01-01
... combination of structural analysis and static load tests to limit load; or (3) Static load tests to ultimate... OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY... resulting from the ultimate static load factors prescribed in § 23.561(b)(2) of this part. Each occupant...
Hakim, Renée M; Ross, Michael D; Runco, Wendy; Kane, Michael T
2017-02-01
The purpose of this study was to investigate the impact of a community-based aquatic exercise program on physical performance among adults with mild to moderate intellectual disability (ID). Twenty-two community-dwelling adults with mild to moderate ID volunteered to participate in this study. Participants completed an 8-week aquatic exercise program (2 days/wk, 1 hr/session). Measures of physical performance, which were assessed prior to and following the completion of the aquatic exercise program, included the timed-up-and-go test, 6-min walk test, 30-sec chair stand test, 10-m timed walk test, hand grip strength, and the static plank test. When comparing participants' measures of physical performance prior to and following the 8-week aquatic exercise program, improvements were seen in all measures, but the change in scores for the 6-min walk test, 30-sec chair stand test, and the static plank test achieved statistical significance ( P <0.05). An 8-week group aquatic exercise program for adults with ID may promote improvements in endurance and balance/mobility.
Computer program to predict noise of general aviation aircraft: User's guide
NASA Technical Reports Server (NTRS)
Mitchell, J. A.; Barton, C. K.; Kisner, L. S.; Lyon, C. A.
1982-01-01
Program NOISE predicts General Aviation Aircraft far-field noise levels at FAA FAR Part 36 certification conditions. It will also predict near-field and cabin noise levels for turboprop aircraft and static engine component far-field noise levels.
Efficient Ada multitasking on a RISC register window architecture
NASA Technical Reports Server (NTRS)
Kearns, J. P.; Quammen, D.
1987-01-01
This work addresses the problem of reducing context switch overhead on a processor which supports a large register file - a register file much like that which is part of the Berkeley RISC processors and several other emerging architectures (which are not necessarily reduced instruction set machines in the purest sense). Such a reduction in overhead is particularly desirable in a real-time embedded application, in which task-to-task context switch overhead may result in failure to meet crucial deadlines. A storage management technique by which a context switch may be implemented as cheaply as a procedure call is presented. The essence of this technique is the avoidance of the save/restore of registers on the context switch. This is achieved through analysis of the static source text of an Ada tasking program. Information gained during that analysis directs the optimized storage management strategy for that program at run time. A formal verification of the technique in terms of an operational control model and an evaluation of the technique's performance via simulations driven by synthetic Ada program traces are presented.
Modeling of Rolling Element Bearing Mechanics: Computer Program Updates
NASA Technical Reports Server (NTRS)
Ryan, S. G.
1997-01-01
The Rolling Element Bearing Analysis System (REBANS) extends the capability available with traditional quasi-static bearing analysis programs by including the effects of bearing race and support flexibility. This tool was developed under contract for NASA-MSFC. The initial version delivered at the close of the contract contained several errors and exhibited numerous convergence difficulties. The program has been modified in-house at MSFC to correct the errors and greatly improve the convergence. The modifications consist of significant changes in the problem formulation and nonlinear convergence procedures. The original approach utilized sequential convergence for nested loops to achieve final convergence. This approach proved to be seriously deficient in robustness. Convergence was more the exception than the rule. The approach was changed to iterate all variables simultaneously. This approach has the advantage of using knowledge of the effect of each variable on each other variable (via the system Jacobian) when determining the incremental changes. This method has proved to be quite robust in its convergence. This technical memorandum documents the changes required for the original Theoretical Manual and User's Manual due to the new approach.
ESD prevention, combating ESD problem — Solutions
NASA Astrophysics Data System (ADS)
Duban, M.
2002-12-01
In today's Electronic equipment manufacturing, managing an ESD (Electro static Discharge) plan is an integral part of a complete quality program. Every body has been in presence of static electricity one day or an other. But a discharge on a body of man is only felt when the potential of charge before the discharge is higher than 3000 volts but components can have a sensitivity less than 20 Volts !
Participatory action research in corrections: The HITEC 2 program.
Cherniack, Martin; Dussetschleger, Jeffrey; Dugan, Alicia; Farr, Dana; Namazi, Sara; El Ghaziri, Mazen; Henning, Robert
2016-03-01
HITEC 2 (Health Improvement through Employee Control 2) is the follow-up to HITEC, a participatory action research (PAR) program that integrates health and work conditions interventions designed by the workforce. HITEC 2 compares intervention programs between two correctional sites, one using a pure workforce level design team and the other using a more structured and time delineated labor-management kaizen effectiveness team. HITEC 2 utilizes a seven step participatory Intervention Design and Analysis Scorecard (IDEAS) for planning interventions. Consistent with PAR, process and intervention efficacy measures are developed and administered through workforce representation. Participation levels, robustness of participatory structures and sophistication of interventions have increased at each measured interval. Health comparisons between 2008 and 2013 showed increased hypertension, static weight maintenance, and increased 'readiness to change'. The PAR approaches are robust and sustained. Their long-term effectiveness in this population is not yet clear. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.
Durability evaluation of ceramic components using CARES/LIFE
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Powers, Lynn M.; Janosik, Lesley A.; Gyekenyesi, John P.
1994-01-01
The computer program CARES/LIFE calculates the time-dependent reliability of monolithic ceramic components subjected to thermomechanical and/or proof test loading. This program is an extension of the CARES (Ceramics Analysis and Reliability Evaluation of Structures) computer program. CARES/LIFE accounts for the phenomenon of subcritical crack growth (SCG) by utilizing the power law, Paris law, or Walker equation. The two-parameter Weibull cumulative distribution function is used to characterize the variation in component strength. The effects of multiaxial stresses are modeled using either the principle of independent action (PIA), the Weibull normal stress averaging method (NSA), or the Batdorf theory. Inert strength and fatigue parameters are estimated from rupture strength data of naturally flawed specimens loaded in static, dynamic, or cyclic fatigue. Application of this design methodology is demonstrated using experimental data from alumina bar and disk flexure specimens which exhibit SCG when exposed to water.
The YAV-8B simulation and modeling. Volume 2: Program listing
NASA Technical Reports Server (NTRS)
1983-01-01
Detailed mathematical models of varying complexity representative of the YAV-8B aircraft are defined and documented. These models are used in parameter estimation and in linear analysis computer programs while investigating YAV-8B aircraft handling qualities. Both a six degree of freedom nonlinear model and a linearized three degree of freedom longitudinal and lateral directional model were developed. The nonlinear model is based on the mathematical model used on the MCAIR YAV-8B manned flight simulator. This simulator model has undergone periodic updating based on the results of approximately 360 YAV-8B flights and 8000 hours of wind tunnel testing. Qualified YAV-8B flight test pilots have commented that the handling qualities characteristics of the simulator are quite representative of the real aircraft. These comments are validated herein by comparing data from both static and dynamic flight test maneuvers to the same obtained using the nonlinear program.
Durability evaluation of ceramic components using CARES/LIFE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nemeth, N.N.; Janosik, L.A.; Gyekenyesi, J.P.
1996-01-01
The computer program CARES/LIFE calculates the time-dependent reliability of monolithic ceramic components subjected to thermomechanical and/or proof test loading. This program is an extension of the CARES (Ceramics Analysis and Reliability Evaluation of Structures) computer program. CARES/LIFE accounts for the phenomenon of subcritical crack growth (SCG) by utilizing the power law, Paris law, or Walker equation. The two-parameter Weibull cumulative distribution function is used to characterize the variation in component strength. The effects of multiaxial stresses are modeled using either the principle of independent action (PIA), the Weibull normal stress averaging method (NSA), or the Batdorf theory. Inert strength andmore » fatigue parameters are estimated from rupture strength data of naturally flawed specimens loaded in static, dynamic, or cyclic fatigue. Application of this design methodology is demonstrated using experimental data from alumina bar and disk flexure specimens, which exhibit SCG when exposed to water.« less
NASA Technical Reports Server (NTRS)
Smith, Tamara A.; Pavli, Albert J.; Kacynski, Kenneth J.
1987-01-01
The joint Army. Navy, NASA. Air Force (JANNAF) rocket engine peformnace prediction procedure is based on the use of various reference computer programs. One of the reference programs for nozzle analysis is the Two-Dimensional Kinetics (TDK) Program. The purpose of this report is to calibrate the JANNAF procedure incorporated into the December l984 version of the TDK program for the high-area-ratio rocket engine regime. The calibration was accomplished by modeling the performance of a 1030:1 rocket nozzle tested at NASA Lewis Research Center. A detailed description of the experimental test conditions and TDK input parameters is given. The results show that the computer code predicts delivered vacuum specific impulse to within 0.12 to 1.9 percent of the experimental data. Vacuum thrust coefficient predictions were within + or - 1.3 percent of experimental results. Predictions of wall static pressure were within approximately + or - 5 percent of the measured values. An experimental value for inviscid thrust was obtained for the nozzle extension between area ratios of 427.5 and 1030 by using an integration of the measured wall static pressures. Subtracting the measured thrust gain produced by the nozzle between area ratios of 427.5 and 1030 from the inviscid thrust gain yielded experimental drag decrements of 10.85 and 27.00 N (2.44 and 6.07 lb) for mixture ratios of 3.04 and 4.29, respectively. These values correspond to 0.45 and 1.11 percent of the total vacuum thrust. At a mixture ratio of 4.29, the TDK predicted drag decrement was 16.59 N (3.73 lb), or 0.71 percent of the predicted total vacuum thrust.
Evaluation of Relationship between Trunk Muscle Endurance and Static Balance in Male Students
Barati, Amirhossein; SafarCherati, Afsaneh; Aghayari, Azar; Azizi, Faeze; Abbasi, Hamed
2013-01-01
Purpose Fatigue of trunk muscle contributes to spinal instability over strenuous and prolonged physical tasks and therefore may lead to injury, however from a performance perspective, relation between endurance efficient core muscles and optimal balance control has not been well-known. The purpose of this study was to examine the relationship of trunk muscle endurance and static balance. Methods Fifty male students inhabitant of Tehran university dormitory (age 23.9±2.4, height 173.0±4.5 weight 70.7±6.3) took part in the study. Trunk muscle endurance was assessed using Sørensen test of trunk extensor endurance, trunk flexor endurance test, side bridge endurance test and static balance was measured using single-limb stance test. A multiple linear regression analysis was applied to test if the trunk muscle endurance measures significantly predicted the static balance. Results There were positive correlations between static balance level and trunk flexor, extensor and lateral endurance measures (Pearson correlation test, r=0.80 and P<0.001; r=0.71 and P<0.001; r=0.84 and P<0.001, respectively). According to multiple regression analysis for variables predicting static balance, the linear combination of trunk muscle endurance measures was significantly related to the static balance (F (3,46) = 66.60, P<0.001). Endurance of trunk flexor, extensor and lateral muscles were significantly associated with the static balance level. The regression model which included these factors had the sample multiple correlation coefficient of 0.902, indicating that approximately 81% of the variance of the static balance is explained by the model. Conclusion There is a significant relationship between trunk muscle endurance and static balance. PMID:24800004
Seventh NASTRAN User's Colloquium
NASA Technical Reports Server (NTRS)
1978-01-01
The general application of finite element methodology and the specific application of NASTRAN to a wide variety of static and dynamic structural problems are described. Topics include: fluids and thermal applications, NASTRAN programming, substructuring methods, unique new applications, general auxiliary programs, specific applications, and new capabilities.
NASA Technical Reports Server (NTRS)
Smith, Tamara A.; Pavli, Albert J.; Kacynski, Kenneth J.
1987-01-01
The Joint Army, Navy, NASA, Air Force (JANNAF) rocket-engine performance-prediction procedure is based on the use of various reference computer programs. One of the reference programs for nozzle analysis is the Two-Dimensional Kinetics (TDK) Program. The purpose of this report is to calibrate the JANNAF procedure that has been incorporated into the December 1984 version of the TDK program for the high-area-ratio rocket-engine regime. The calibration was accomplished by modeling the performance of a 1030:1 rocket nozzle tested at NASA Lewis. A detailed description of the test conditions and TDK input parameters is given. The reuslts indicate that the computer code predicts delivered vacuum specific impulse to within 0.12 to 1.9 percent of the experimental data. Vacuum thrust coefficient predictions were within + or - 1.3 percent of experimental results. Predictions of wall static pressure were within approximately + or - 5 percent of the measured values.
``Carbon Credits'' for Resource-Bounded Computations Using Amortised Analysis
NASA Astrophysics Data System (ADS)
Jost, Steffen; Loidl, Hans-Wolfgang; Hammond, Kevin; Scaife, Norman; Hofmann, Martin
Bounding resource usage is important for a number of areas, notably real-time embedded systems and safety-critical systems. In this paper, we present a fully automatic static type-based analysis for inferring upper bounds on resource usage for programs involving general algebraic datatypes and full recursion. Our method can easily be used to bound any countable resource, without needing to revisit proofs. We apply the analysis to the important metrics of worst-case execution time, stack- and heap-space usage. Our results from several realistic embedded control applications demonstrate good matches between our inferred bounds and measured worst-case costs for heap and stack usage. For time usage we infer good bounds for one application. Where we obtain less tight bounds, this is due to the use of software floating-point libraries.
A comparison of dynamic and static economic models of uneven-aged stand management
Robert G. Haight
1985-01-01
Numerical techniques have been used to compute the discrete-time sequence of residual diameter distributions that maximize the present net worth (PNW) of harvestable volume from an uneven-aged stand. Results contradicted optimal steady-state diameter distributions determined with static analysis. In this paper, optimality conditions for solutions to dynamic and static...
Development of wide-angle 2D light scattering static cytometry
NASA Astrophysics Data System (ADS)
Xie, Linyan; Liu, Qiao; Shao, Changshun; Su, Xuantao
2016-10-01
We have recently developed a 2D light scattering static cytometer for cellular analysis in a label-free manner, which measures side scatter (SSC) light in the polar angular range from 79 to 101 degrees. Compared with conventional flow cytometry, our cytometric technique requires no fluorescent labeling of the cells, and static cytometry measurements can be performed without flow control. In this paper we present an improved label-free static cytometer that can obtain 2D light scattering patterns in a wider angular range. By illuminating the static microspheres on chip with a scanning optical fiber, wide-angle 2D light scattering patterns of single standard microspheres with a mean diameter of 3.87 μm are obtained. The 2D patterns of 3.87 μm microspheres contain both large-angle forward scatter (FSC) and SSC light in the polar angular range from 40 to 100 degrees, approximately. Experimental 2D patterns of 3.87 μm microspheres are in good agreement with Mie theory simulated ones. The wide-angle light scattering measurements may provide a better resolution for particle analysis as compared with the SSC measurements. Two dimensional light scattering patterns of HL-60 human acute leukemia cells are obtained by using our static cytometer. Compared with SSC 2D light scattering patterns, wide-angle 2D patterns contain richer information of the HL-60 cells. The obtaining of 2D light scattering patterns in a wide angular range could help to enhance the capabilities of our label-free static cytometry for cell analysis.
ERIC Educational Resources Information Center
Hasson, H.; Brown, C.; Hasson, D.
2010-01-01
In web-based health promotion programs, large variations in participant engagement are common. The aim was to investigate determinants of high use of a worksite self-help web-based program for stress management. Two versions of the program were offered to randomly selected departments in IT and media companies. A static version of the program…
Numerical Modeling of Sliding Stability of RCC dam
NASA Astrophysics Data System (ADS)
Mughieda, O.; Hazirbaba, K.; Bani-Hani, K.; Daoud, W.
2017-06-01
Stability and stress analyses are the most important elements that require rigorous consideration in design of a dam structure. Stability of dams against sliding is crucial due to the substantial horizontal load that requires sufficient and safe resistance to develop by mobilization of adequate shearing forces along the base of the dam foundation. In the current research, the static sliding stability of a roller-compacted-concrete (RCC) dam was modelled using finite element method to investigate the stability against sliding. A commercially available finite element software (SAP 2000) was used to analyze stresses in the body of the dam and foundation. A linear finite element static analysis was performed in which a linear plane strain isoperimetric four node elements was used for modelling the dam-foundation system. The analysis was carried out assuming that no slip will occur at the interface between the dam and the foundation. Usual static loading condition was applied for the static analysis. The greatest tension was found to develop in the rock adjacent to the toe of the upstream slope. The factor of safety against sliding along the entire base of the dam was found to be greater than 1 (FS>1), for static loading conditions.
NASA Astrophysics Data System (ADS)
Kubicka, Katarzyna; Radoń, Urszula; Szaniec, Waldemar; Pawlak, Urszula
2017-10-01
The paper concerns the reliability analysis of steel structures subjected to high temperatures of fire gases. Two types of spatial structures were analysed, namely with pinned and rigid nodes. The fire analysis was carried out according to prescriptions of Eurocode. The static-strength analysis was conducted using the finite element method (FEM). The MES3D program, developed by Szaniec (Kielce University of Technology, Poland), was used for this purpose. The results received from MES3D made it possible to carry out the reliability analysis using the Numpress Explore program that was developed at the Institute of Fundamental Technological Research of the Polish Academy of Sciences [9]. The measurement of reliability of structures is the Hasofer-Lind reliability index (β). The reliability analysis was carried out according to approximation (FORM, SORM) and simulation (Importance Sampling, Monte Carlo) methods. As the fire progresses, the value of reliability index decreases. The analysis conducted for the study made it possible to evaluate the impact of node types on those changes. In real structures, it is often difficult to define correctly types of nodes, so some simplifications are made. The presented analysis contributes to the recognition of consequences of such assumptions for the safety of structures, subjected to fire.
2017-03-01
FINAL REPORT Demonstration of Energy Savings in Commercial Buildings for Tiered Trim and Respond Method in Resetting Static Pressure for VAV...release Page Intentionally Left Blank This report was prepared under contract to the Department of Defense Environmental Security Technology...Certification Program (ESTCP). The publication of this report does not indicate endorsement by the Department of Defense, nor should the contents be
Reference Manual for the Ada Programming Language
1983-01-01
Convercions 4-21 4.7 Qualified Expresclions 4-24 4.8 Allocators 4-24 4.9 Static Expressions and Static Subtypes 4-26 , 4.10 Universal Expressions 4-27 5...record type.•: • 2 Access types allow the construction of linked data structures created by the evaluation of / allocators . They allow several...the following: A * An assignment (In assignment statements and Initializations), an allocator , a membership test, or a short-circuit control form, * A
1967-10-01
S-IB-211, the flight version of the Saturn IB launch vehicle's first (S-IVB) stage, arrives at Marshall Space Flight Center's (MSFC's) S-IB static test stand. Between December 1967 and April 1968, the stage would undergo seven static test firings. The S-IB, developed by the MSFC and built by the Chrysler Corporation at the Michoud Assembly Facility near New Orleans, Louisiana, utilized eight H-1 engines and each produced 200,000 pounds of thrust.
1964-10-01
Test firing of the Saturn I S-I Stage (S-1-10) at the Marshall Space Flight Center. This test stand was originally constructed in 1951 and sometimes called the Redstone or T tower. In l961, the test stand was modified to permit static firing of the S-I/S-IB stages, which produced a total thrust of 1,600,000 pounds. The name of the stand was then changed to the S-IB Static Test Stand.
1967-10-01
S-IB-211, the flight version of the Saturn IB launch vehicle's (S-IVB) first stage, after installation at the Marshall Space Flight Center's (MSFC's) S-IB static test stand. Between December 1967 and April 1968, the stage would undergo seven static test firings. The S-IB, developed by the MSFC and built by the Chrysler Corporation at the Michoud Assembly Facility near New Orleans, Louisiana, utilized eight H-1 engines and each produced 200,000 pounds of thrust.
Applying Jlint to Space Exploration Software
NASA Technical Reports Server (NTRS)
Artho, Cyrille; Havelund, Klaus
2004-01-01
Java is a very successful programming language which is also becoming widespread in embedded systems, where software correctness is critical. Jlint is a simple but highly efficient static analyzer that checks a Java program for several common errors, such as null pointer exceptions, and overflow errors. It also includes checks for multi-threading problems, such as deadlocks and data races. The case study described here shows the effectiveness of Jlint in find-false positives in the multi-threading warnings gives an insight into design patterns commonly used in multi-threaded code. The results show that a few analysis techniques are sufficient to avoid almost all false positives. These techniques include investigating all possible callers and a few code idioms. Verifying the correct application of these patterns is still crucial, because their correct usage is not trivial.
Development of a simple, self-contained flight test data acquisition system
NASA Technical Reports Server (NTRS)
Renz, R. R. L.
1981-01-01
A low cost flight test data acquisition system, applicable to general aviation airplanes, was developed which meets criteria for doing longitudinal and lateral stability analysis. Th package consists of (1) a microprocessor controller and data acquisition module; (2) a transducer module; and (3) a power supply module. The system is easy to install and occupies space in the cabin or baggage compartment of the airplane. All transducers are contained in these modules except the total pressure tube, static pressure air temperature transducer, and control position transducers. The NASA-developed MMLE program was placed on a microcomputer on which all data reduction is done. The flight testing program undertaken proved both the flight testing hardware and the data reduction method to be applicable to the current field of general aviation airplanes.
An Economical Method for Static Headspace Enrichment for Arson Analysis
ERIC Educational Resources Information Center
Olesen, Bjorn
2010-01-01
Static headspace analysis of accelerants from suspected arsons is accomplished by placing an arson sample in a sealed container with a carbon strip suspended above the sample. The sample is heated, cooled to room temperature, and then the organic components are extracted from the carbon strip with carbon disulfide followed by gas chromatography…
Three dimensional modeling of rigid pavement : executive summary, February 1995.
DOT National Transportation Integrated Search
1995-02-17
A finite-element program has been developed to model the response of rigid pavement to both static loads and temperature changes. The program is fully three-dimensional and incorporates not only the common twenty-node brick element but also a thin in...
Three-dimensional modeling of rigid pavement : final report, September 1995.
DOT National Transportation Integrated Search
1995-02-17
A finite-element program has been developed to model the response of rigid pavement to both static loads and temperature changes. The program is fully three-dimensional and incorporates not only the common twenty-node brick element but also a thin in...
Communicating spatial uncertainty to non-experts using R
NASA Astrophysics Data System (ADS)
Luzzi, Damiano; Sawicka, Kasia; Heuvelink, Gerard; de Bruin, Sytze
2016-04-01
Effective visualisation methods are important for the efficient use of uncertainty information for various groups of users. Uncertainty propagation analysis is often used with spatial environmental models to quantify the uncertainty within the information. A challenge arises when trying to effectively communicate the uncertainty information to non-experts (not statisticians) in a wide range of cases. Due to the growing popularity and applicability of the open source programming language R, we undertook a project to develop an R package that facilitates uncertainty propagation analysis in spatial environmental modelling. The package has implemented Monte Carlo algorithms for uncertainty propagation, the output of which is represented by an ensemble of model outputs (i.e. a sample from a probability distribution). Numerous visualisation methods exist that aim to present such spatial uncertainty information both statically, dynamically and interactively. To provide the most universal visualisation tools for non-experts, we conducted a survey on a group of 20 university students and assessed the effectiveness of selected static and interactive methods for visualising uncertainty in spatial variables such as DEM and land cover. The static methods included adjacent maps and glyphs for continuous variables. Both allow for displaying maps with information about the ensemble mean, variance/standard deviation and prediction intervals. Adjacent maps were also used for categorical data, displaying maps of the most probable class, as well as its associated probability. The interactive methods included a graphical user interface, which in addition to displaying the previously mentioned variables also allowed for comparison of joint uncertainties at multiple locations. The survey indicated that users could understand the basics of the uncertainty information displayed in the static maps, with the interactive interface allowing for more in-depth information. Subsequently, the R package included a collation of the plotting functions that were evaluated in the survey. The implementation of static visualisations was done via calls to the 'ggplot2' package. This allowed the user to provide control over the content, legend, colours, axes and titles. The interactive methods were implemented using the 'shiny' package allowing users to activate the visualisation of statistical descriptions of uncertainty through interaction with a plotted map of means. This research brings uncertainty visualisation to a broader audience through the development of tools for visualising uncertainty using open source software.
NASA Technical Reports Server (NTRS)
Bedard, A. J., Jr.; Nishiyama, R. T.
1993-01-01
Instruments developed for making meteorological observations under adverse conditions on Earth can be applied to systems designed for other planetary atmospheres. Specifically, a wind sensor developed for making measurements within tornados is capable of detecting induced pressure differences proportional to wind speed. Adding strain gauges to the sensor would provide wind direction. The device can be constructed in a rugged form for measuring high wind speeds in the presence of blowing dust that would clog bearings and plug passages of conventional wind speed sensors. Sensing static pressure in the lower boundary layer required development of an omnidirectional, tilt-insensitive static pressure probe. The probe provides pressure inputs to a sensor with minimum error and is inherently weather-protected. The wind sensor and static pressure probes have been used in a variety of field programs and can be adapted for use in different planetary atmospheres.
Taechasubamorn, Panada; Nopkesorn, Tawesak; Pannarunothai, Supasit
2010-12-01
To compare physical fitness between rice farmers with chronic low back pain (CLBP) and a healthy control group. Sixty-eight rice farmers with CLBP were matched according to age and sex with healthy farmers. All subjects underwent nine physical fitness tests for body composition, lifting capacity, static back extensor endurance, leg strength, static abdominal endurance, handgrip strength, hamstring flexibility, posterior leg and back muscles flexibility and abdominal flexibility. There was no significant difference between CLBP and healthy groups for all tests, except the static back extensor endurance. The back extensor endurance times of the CLBP group was significantly lower than that of the control group (p = 0.002). Static back extensor endurance is the deficient physical fitness in CLBP rice farmers. Back extensor endurance training should be emphasized in both prevention and rehabilitation programs.
NASA Technical Reports Server (NTRS)
Larson, T. J.
1984-01-01
The measurement performance of a hemispherical flow-angularity probe and a fuselage-mounted pitot-static probe was evaluated at high flow angles as part of a test program on an F-14 airplane. These evaluations were performed using a calibrated pitot-static noseboom equipped with vanes for reference flow direction measurements, and another probe incorporating vanes but mounted on a pod under the fuselage nose. Data are presented for angles of attack up to 63, angles of sideslip from -22 deg to 22 deg, and for Mach numbers from approximately 0.3 to 1.3. During maneuvering flight, the hemispherical flow-angularity probe exhibited flow angle errors that exceeded 2 deg. Pressure measurements with the pitot-static probe resulted in very inaccurate data above a Mach number of 0.87 and exhibited large sensitivities with flow angle.
McHugh, Stuart
1976-01-01
The material in this report is concerned with the effects of a vertically oriented rectangular dislocation loop on the tilts observed at the free surface of an elastic half-space. Part I examines the effect of a spatially variable static strike-slip distribution across the slip surface. The tilt components as a function of distance parallel, or perpendicular, to the strike of the slip surface are displayed for different slip-versus-distance profiles. Part II examines the effect of spatially and temporally variable slip distributions across the dislocation loop on the quasi-static tilts at the free surface of an elastic half space. The model discussed in part II may be used to generate theoretical tilt versus time curves produced by creep events.
1963-12-05
The test laboratory of the Marshall Space Flight Center (MSFC) tested the F-1 engine, the most powerful rocket engine ever fired at MSFC. The engine was tested on the newly modified Saturn IB Static Test Stand which had been used for three years to test the Saturn I eight-engine booster, S-I (first) stage. In 1961 the test stand was modified to permit static firing of the S-I/S-IB stage and the name of the stand was then changed to the S-IB Static Test Stand. Producing a combined thrust of 7,500,000 pounds, five F-1 engines powered the S-IC (first) stage of the Saturn V vehicle for the marned lunar mission.
1963-12-01
The test laboratory of the Marshall Space Flight Center (MSFC) tested the F-1 engine, the most powerful rocket engine ever fired at MSFC. The engine was tested on the newly modified Saturn IB static test stand that had been used for three years to test the Saturn I eight-engine booster, S-I (first) stage. In 1961, the test stand was modified to permit static firing of the S-I/S-IB stage and the name of the stand was then changed to the S-IB Static Test Stand. Producing a combined thrust of 7,500,000 pounds, five F-1 engines powered the S-IC (first) stage of the Saturn V vehicle for the marned lunar mission.
Multileaf collimator-based linear accelerator radiosurgery: five-year efficiency analysis.
Lawson, Joshua D; Fox, Tim; Waller, Anthony F; Davis, Lawrence; Crocker, Ian
2009-03-01
In 1989, Emory University initiated a linear accelerator (linac) radiosurgery program using circular collimators. In 2001, the program converted to a multileaf collimator. Since then, the treatment parameters of each patient have been stored in the record-and-verify system. Three major changes have occurred in the radiosurgery program in the past 6 years: in 2002, treatment was changed from static conformal beams to dynamic conformal arc (DCA) therapy, and all patients were imaged before treatment. Beginning in 2005, a linac was used, with the opportunity to treat at higher dose rates (600-1,000 monitor units/min). The aim of this study was to analyze the time required to deliver radiosurgery and the factors affecting treatment delivery. Benchmark data are provided for centers contemplating initiating linac radiosurgery programs. Custom software was developed to mine the record-and-verify system database and automatically perform a chart review on patients who underwent stereotactic radiosurgery from March 2001 to October 2006. The software extracted 510 patients who underwent stereotactic radiosurgery, and the following information was recorded for each patient: treatment technique, treatment time (from initiation of imaging, if done, to completion of therapy), number of isocenters, number of fields, total monitor units, and dose rate. Of the 510 patients, 395 were treated with DCA therapy and 115 with static conformal beams. The average number of isocenters treated was 1.06 (range, 1-4). The average times to deliver treatment were 24.1 minutes for patients who underwent DCA therapy and 19.3 minutes for those treated with static conformal beams, reflecting the lack of imaging in the latter patients. Eighty percent of patients were treated in <30 minutes. For the patients who underwent DCA therapy, the times required to treat 1, 2, 3, and 4 isocenters were 23.9, 24.8, 33.1, and 37.8 minutes, respectively. Average beam-on time for these patients was 11.4 minutes. There has been no significant reduction in treatment delivery with the use of 1,000 monitor units/min, reflecting the fact that beam-on time is not the major determinant of overall treatment time. Multileaf collimator-based linac radiosurgery can be delivered efficiently in <30 minutes in the vast majority of patients. Given the limited treatment room utilization required for stereotactic radiosurgery treatments, this study calls into question the need for a dedicated radiosurgery unit for even busy treatment centers.
Al-Attar, Ghada S T; Bishai, David; El-Gibaly, Omaima
2017-03-01
Cost effectiveness studies of family planning (FP) services are very valuable in providing evidence-based data for decision makers in Egypt. Cost data came from record reviews for all 15 mobile clinics and a matched set of 15 static clinics and interviews with staff members of the selected clinics at Assiut Governorate. Effectiveness measures included couple years of protection (CYPs) and FP visits. Incremental cost-effectiveness ratios (ICER) and sensitivity analyses were calculated. Mobile clinics cost more per facility, produced more CYPs but had fewer FP visits. Sensitivity analysis was done using: total costs, CYP and FP visits of mobile and static clinics and showed that variations in CYP of mobile and static clinics altered the ICER for CYP from $2 -$6. Mobile clinics with their high emphasis on IUDs offer a reasonable cost effectiveness of $4.46 per additional CYP compared to static clinics. The ability of mobile clinics to reach more vulnerable women and to offer more long acting methods might affect a policy decision between these options. Static clinics should consider whether emphasizing IUDs may make their services more cost-effective.
Computer simulation of electron flow in linear-beam microwave tubes
NASA Astrophysics Data System (ADS)
Kumar, Lalit
1990-12-01
The computer simulation of electron flow in linear-beam microwave tubes, such as a travelling-wave tube (TWT) and klystron, is used for designing and optimising the electron gun and collector and for analysing the large-signal beam-wave interaction phenomenon. Major aspects of simulation of electron flow in static and rf fields present in such tubes are discussed. Some advancements made in this respect and results obtained from computer programs developed by the research group at CEERI for a gridded electron gun, depressed collector, and large-signal analysis of TWT and klystron are presented.
Structural/aerodynamic Blade Analyzer (SAB) User's Guide, Version 1.0
NASA Technical Reports Server (NTRS)
Morel, M. R.
1994-01-01
The structural/aerodynamic blade (SAB) analyzer provides an automated tool for the static-deflection analysis of turbomachinery blades with aerodynamic and rotational loads. A structural code calculates a deflected blade shape using aerodynamic loads input. An aerodynamic solver computes aerodynamic loads using deflected blade shape input. The two programs are iterated automatically until deflections converge. Currently, SAB version 1.0 is interfaced with MSC/NASTRAN to perform the structural analysis and PROP3D to perform the aerodynamic analysis. This document serves as a guide for the operation of the SAB system with specific emphasis on its use at NASA Lewis Research Center (LeRC). This guide consists of six chapters: an introduction which gives a summary of SAB; SAB's methodology, component files, links, and interfaces; input/output file structure; setup and execution of the SAB files on the Cray computers; hints and tips to advise the user; and an example problem demonstrating the SAB process. In addition, four appendices are presented to define the different computer programs used within the SAB analyzer and describe the required input decks.
Non-linear programming in shakedown analysis with plasticity and friction
NASA Astrophysics Data System (ADS)
Spagnoli, A.; Terzano, M.; Barber, J. R.; Klarbring, A.
2017-07-01
Complete frictional contacts, when subjected to cyclic loading, may sometimes develop a favourable situation where slip ceases after a few cycles, an occurrence commonly known as frictional shakedown. Its resemblance to shakedown in plasticity has prompted scholars to apply direct methods, derived from the classical theorems of limit analysis, in order to assess a safe limit to the external loads applied on the system. In circumstances where zones of plastic deformation develop in the material (e.g., because of the large stress concentrations near the sharp edges of a complete contact), it is reasonable to expect an effect of mutual interaction of frictional slip and plastic strains on the load limit below which the global behaviour is non dissipative, i.e., both slip and plastic strains go to zero after some dissipative load cycles. In this paper, shakedown of general two-dimensional discrete systems, involving both friction and plasticity, is discussed and the shakedown limit load is calculated using a non-linear programming algorithm based on the static theorem of limit analysis. An illustrative example related to an elastic-plastic solid containing a frictional crack is provided.
Biricocchi, Charlanne; Drake, JaimeLynn; Svien, Lana
2014-01-01
This case report describes the effects of a 6-week progressive tap dance program on static and dynamic balance for a child with type 1 congenital myotonic muscular dystrophy (congenital MMD1). A 6-year-old girl with congenital MMD1 participated in a 1-hour progressive tap dance program. Classes were held once a week for 6 consecutive weeks and included 3 children with adaptive needs and 1 peer with typical development. The Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2) balance subsection and the Pediatric Balance Scale were completed at the beginning of the first class and the sixth class. The participant's BOT-2 score improved from 3 to 14. Her Pediatric Balance Scale score did not change. Participation in a progressive tap dance class by a child with congenital MMD1 may facilitate improvements in static and dynamic balance.
High temperature static strain gage alloy development program
NASA Technical Reports Server (NTRS)
Hulse, C. O.; Bailey, R. S.; Lemkey, F. D.
1985-01-01
The literature, applicable theory and finally an experimental program were used to identify new candidate alloy systems for use as the electrical resistance elements in static strain gages up to 1250K. The program goals were 50 hours of use in the environment of a test stand gas turbine engine with measurement accuracies equal to or better than 10 percent of full scale for strains up to + or - 2000 microstrain. As part of this effort, a computerized electrical resistance measurement system was constructed for use at temperatures between 300K and 1250K and heating and cooling rates of 250K/min and 10K/min. The two best alloys were an iron-chromium-aluminum alloy and a palladium base alloy. Although significant progress was made, it was concluded that a considerable additional effort would be needed to fully optimize and evaluate these candidate systems.
Azarpaikan, Atefeh; Taheri Torbati, Hamidreza
2017-10-23
The aim of this study was to assess the effectiveness of balance training with somatosensory and neurofeedback training on dynamic and static balance in healthy, elderly adults. The sample group consisted of 45 healthy adults randomly assigned to one of the three test groups: somatosensory, neurofeedback, and a control. Individualization of the balance program started with pre-tests for static and dynamic balances. Each group had 15- and 30-min training sessions. All groups were tested for static (postural stability) and dynamic balances (Berg Balance Scale) in acquisition and transfer tests (fall risk of stability and timed up and go). Improvements in static and dynamic balances were assessed by somatosensory and neurofeedback groups and then compared with the control group. Results indicated significant improvements in static and dynamic balances in both test groups in the acquisition test. Results revealed a significant improvement in the transfer test in the neurofeedback and somatosensory groups, in static and dynamic conditions, respectively. The findings suggest that these methods of balance training had a significant influence on balance. Both the methods are appropriate to prevent falling in adults. Neurofeedback training helped the participants to learn static balance, while somatosensory training was effective on dynamic balance learning. Further research is needed to assess the effects of longer and discontinuous stimulation with somatosensory and neurofeedback training on balance in elderly adults.
NASTRAN computer system level 12.1
NASA Technical Reports Server (NTRS)
Butler, T. G.
1971-01-01
Program uses finite element displacement method for solving linear response of large, three-dimensional structures subject to static, dynamic, thermal, and random loadings. Program adapts to computers of different manufacture, permits up-dating and extention, allows interchange of output and input information between users, and is extensively documented.
NASA Astrophysics Data System (ADS)
Masera, D.; Bocca, P.; Grazzini, A.
2011-07-01
In this experimental program the main goal is to monitor the damage evolution in masonry and concrete structures by Acoustic Emission (AE) signal analysis applying a well-know seismic method. For this reason the concept of the coda wave interferometry is applied to AE signal recorded during the tests. Acoustic Emission (AE) are very effective non-destructive techniques applied to identify micro and macro-defects and their temporal evolution in several materials. This technique permits to estimate the velocity of ultrasound waves propagation and the amount of energy released during fracture propagation to obtain information on the criticality of the ongoing process. By means of AE monitoring, an experimental analysis on a set of reinforced masonry walls under variable amplitude loading and strengthening reinforced concrete (RC) beams under monotonic static load has been carried out. In the reinforced masonry wall, cyclic fatigue stress has been applied to accelerate the static creep and to forecast the corresponding creep behaviour of masonry under static long-time loading. During the tests, the evaluation of fracture growth is monitored by coda wave interferometry which represents a novel approach in structural monitoring based on AE relative change velocity of coda signal. In general, the sensitivity of coda waves has been used to estimate velocity changes in fault zones, in volcanoes, in a mining environment, and in ultrasound experiments. This method uses multiple scattered waves, which travelled through the material along numerous paths, to infer tiny temporal changes in the wave velocity. The applied method has the potential to be used as a "damage-gauge" for monitoring velocity changes as a sign of damage evolution into masonry and concrete structures.
Dynamic and static fatigue behavior of sintered silicon nitrides
NASA Technical Reports Server (NTRS)
Chang, J.; Khandelwal, P.; Heitman, P. W.
1987-01-01
The dynamic and static fatigue behavior of Kyocera SN220M sintered silicon nitride at 1000 C was studied. Fractographic analysis of the material failing in dynamic fatigue revealed the presence of slow crack growth (SCG) at stressing rates below 41 MPa/min. Under conditions of static fatigue this material also displayed SCG at stresses below 345 MPa. SCG appears to be controlled by microcracking of the grain boundaries. The crack velocity exponent (n) determined from both dynamic and static fatigue tests ranged from 11 to 16.
High Temperature Metallic Seal Development For Aero Propulsion and Gas Turbine Applications
NASA Technical Reports Server (NTRS)
More, Greg; Datta, Amit
2006-01-01
A viewgraph presentation on metallic high temperature static seal development at NASA for gas turbine applications is shown. The topics include: 1) High Temperature Static Seal Development; 2) Program Review; 3) Phase IV Innovative Seal with Blade Alloy Spring; 4) Spring Design; 5) Phase IV: Innovative Seal with Blade Alloy Spring; 6) PHase IV: Testing Results; 7) Seal Seating Load; 8) Spring Seal Manufacturing; and 9) Other Applications for HIgh Temperature Spring Design
DARKDROID: Exposing the Dark Side of Android Marketplaces
2016-06-01
Moreover, our approaches can detect apps containing both intentional and unintentional vulnerabilities, such as unsafe code loading mechanisms and...Security, Static Analysis, Dynamic Analysis, Malware Detection , Vulnerability Scanning 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18...applications in a DoD context. ................... 1 1.2.2 Develop sophisticated whole-system static analyses to detect malicious Android applications
Effective Use of Multimedia Presentations to Maximize Learning within High School Science Classrooms
ERIC Educational Resources Information Center
Rapp, Eric
2013-01-01
This research used an evidenced-based experimental 2 x 2 factorial design General Linear Model with Repeated Measures Analysis of Covariance (RMANCOVA). For this analysis, time served as the within-subjects factor while treatment group (i.e., static and signaling, dynamic and signaling, static without signaling, and dynamic without signaling)…
Siddique, Musib; Frost, Michelle L; Moore, Amelia E B; Fogelman, Ignac; Blake, Glen M
2014-03-01
The aim of the study was to examine whether (18)F-fluoride PET ((18)F-PET) static scan measurements of bone plasma clearance (Ki) can be corrected for tracer efflux from bone from the time of injection. The efflux of tracer from bone mineral to plasma was described by a first-order rate constant kloss. A modified Patlak analysis was applied to 60-min dynamic (18)F-PET scans of the spine and hip acquired during trials on the bone anabolic agent teriparatide to find the best-fit values of kloss at the lumbar spine, total hip and femoral shaft. The resulting values of kloss were used to extrapolate the modified Patlak plots to 120 min after injection and derive a sequence of static scan estimates of Ki at 4-min intervals that were compared with the Patlak Ki values from the 60-min dynamic scans. A comparison was made with the results of the standard static scan analysis, which assumes kloss=0. The best-fit values of kloss for the spine and hip regions of interest averaged 0.006/min and did not change when patients were treated with teriparatide. Static scan values of Ki calculated using the modified analysis with kloss=0.006/min were independent of time between 10 and 120 min after injection and were in close agreement with findings from the dynamic scans. In contrast, by 2 h after injection the static scan Ki values calculated using the standard analysis underestimated the dynamic scan results by 20%. Using a modified analysis that corrects for F efflux from bone, estimates of Ki from static PET scans can be corrected for time up to 2 h after injection. This simplified approach may obviate the need to perform dynamic scans and hence shorten the scanning procedure for the patient and reduce the cost of studies. It also enables reliable estimates of Ki to be obtained from multiple skeletal sites with a single injection of tracer.
Updated Chemical Kinetics and Sensitivity Analysis Code
NASA Technical Reports Server (NTRS)
Radhakrishnan, Krishnan
2005-01-01
An updated version of the General Chemical Kinetics and Sensitivity Analysis (LSENS) computer code has become available. A prior version of LSENS was described in "Program Helps to Determine Chemical-Reaction Mechanisms" (LEW-15758), NASA Tech Briefs, Vol. 19, No. 5 (May 1995), page 66. To recapitulate: LSENS solves complex, homogeneous, gas-phase, chemical-kinetics problems (e.g., combustion of fuels) that are represented by sets of many coupled, nonlinear, first-order ordinary differential equations. LSENS has been designed for flexibility, convenience, and computational efficiency. The present version of LSENS incorporates mathematical models for (1) a static system; (2) steady, one-dimensional inviscid flow; (3) reaction behind an incident shock wave, including boundary layer correction; (4) a perfectly stirred reactor; and (5) a perfectly stirred reactor followed by a plug-flow reactor. In addition, LSENS can compute equilibrium properties for the following assigned states: enthalpy and pressure, temperature and pressure, internal energy and volume, and temperature and volume. For static and one-dimensional-flow problems, including those behind an incident shock wave and following a perfectly stirred reactor calculation, LSENS can compute sensitivity coefficients of dependent variables and their derivatives, with respect to the initial values of dependent variables and/or the rate-coefficient parameters of the chemical reactions.
Sensitivity Analysis of the Static Aeroelastic Response of a Wing
NASA Technical Reports Server (NTRS)
Eldred, Lloyd B.
1993-01-01
A technique to obtain the sensitivity of the static aeroelastic response of a three dimensional wing model is designed and implemented. The formulation is quite general and accepts any aerodynamic and structural analysis capability. A program to combine the discipline level, or local, sensitivities into global sensitivity derivatives is developed. A variety of representations of the wing pressure field are developed and tested to determine the most accurate and efficient scheme for representing the field outside of the aerodynamic code. Chebyshev polynomials are used to globally fit the pressure field. This approach had some difficulties in representing local variations in the field, so a variety of local interpolation polynomial pressure representations are also implemented. These panel based representations use a constant pressure value, a bilinearly interpolated value. or a biquadraticallv interpolated value. The interpolation polynomial approaches do an excellent job of reducing the numerical problems of the global approach for comparable computational effort. Regardless of the pressure representation used. sensitivity and response results with excellent accuracy have been produced for large integrated quantities such as wing tip deflection and trim angle of attack. The sensitivities of such things as individual generalized displacements have been found with fair accuracy. In general, accuracy is found to be proportional to the relative size of the derivatives to the quantity itself.
The First Static and Dynamic Analysis of 3-D Printed Sintered Ceramics for Body Armor Applications
2016-09-01
evaluate sintered alumina tiles produced by 3-D printing methodology. This report examines the static and quasi -static parameters (including density...Figures iv List of Tables iv Acknowledgments v 1. Introduction 1 2. Processing and Experimental Procedures 1 3. Results and Discussion 7 4...6 Fig. 8 Experimental setup for recording fracture .............................................7 Fig. 9 Rod projectile
The Use of Audio and Animation in Computer Based Instruction.
ERIC Educational Resources Information Center
Koroghlanian, Carol; Klein, James D.
This study investigated the effects of audio, animation, and spatial ability in a computer-based instructional program for biology. The program presented instructional material via test or audio with lean text and included eight instructional sequences presented either via static illustrations or animations. High school students enrolled in a…
Trajectories of Moving Charges in Static Electric Fields.
ERIC Educational Resources Information Center
Kirkup, L.
1986-01-01
Describes the implementation of a trajectory-plotting program for a microcomputer; shows how it may be used to demonstrate the focusing effect of a simple electrostatic lens. The computer program is listed and diagrams are included that show comparisons of trajectories of negative charges in the vicinity of positive charges. (TW)
NASA Technical Reports Server (NTRS)
Oden, J. Tinsley; Fly, Gerald W.; Mahadevan, L.
1987-01-01
A hybrid stress finite element method is developed for accurate stress and vibration analysis of problems in linear anisotropic elasticity. A modified form of the Hellinger-Reissner principle is formulated for dynamic analysis and an algorithm for the determination of the anisotropic elastic and compliance constants from experimental data is developed. These schemes were implemented in a finite element program for static and dynamic analysis of linear anisotropic two dimensional elasticity problems. Specific numerical examples are considered to verify the accuracy of the hybrid stress approach and compare it with that of the standard displacement method, especially for highly anisotropic materials. It is that the hybrid stress approach gives much better results than the displacement method. Preliminary work on extensions of this method to three dimensional elasticity is discussed, and the stress shape functions necessary for this extension are included.
NASA Technical Reports Server (NTRS)
Harvie, E.; Filla, O.; Baker, D.
1993-01-01
Analysis performed in the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) measures error in the static Earth sensor onboard the National Oceanic and Atmospheric Administration (NOAA)-10 spacecraft using flight data. Errors are computed as the difference between Earth sensor pitch and roll angle telemetry and reference pitch and roll attitude histories propagated by gyros. The flight data error determination illustrates the effect on horizon sensing of systemic variation in the Earth infrared (IR) horizon radiance with latitude and season, as well as the effect of anomalies in the global IR radiance. Results of the analysis provide a comparison between static Earth sensor flight performance and that of scanning Earth sensors studied previously in the GSFC/FDD. The results also provide a baseline for evaluating various models of the static Earth sensor. Representative days from the NOAA-10 mission indicate the extent of uniformity and consistency over time of the global IR horizon. A unique aspect of the NOAA-10 analysis is the correlation of flight data errors with independent radiometric measurements of stratospheric temperature. The determination of the NOAA-10 static Earth sensor error contributes to realistic performance expectations for missions to be equipped with similar sensors.
Judge, Lawrence W; Craig, Bruce; Baudendistal, Steve; Bodey, Kimberly J
2009-07-01
Research supports the use of preactivity warm-up and stretching, and the purpose of this study was to determine whether college football programs follow these guidelines. Questionnaires designed to gather demographic, professional, and educational information, as well as specific pre- and postactivity practices, were distributed via e-mail to midwestern collegiate programs from NCAA Division I and III conferences. Twenty-three male coaches (12 from Division IA schools and 11 from Division III schools) participated in the study. Division I schools employed certified strength coaches (CSCS; 100%), whereas Division III schools used mainly strength coordinators (73%), with only 25% CSCS. All programs used preactivity warm-up, with the majority employing 2-5 minutes of sport-specific jogging/running drills. Pre stretching (5-10 minutes) was performed in 19 programs (91%), with 2 (9%) performing no pre stretching. Thirteen respondents used a combination of static/proprioceptive neuromuscular facilitation/ballistic and dynamic flexibility, 5 used only dynamic flexibility, and 1 used only static stretching. All 12 Division I coaches used stretching, whereas only 9 of the 11 Division III coaches did (p = 0.22). The results indicate that younger coaches did not use pre stretching (p = 0.30). The majority of the coaches indicated that they did use post stretching, with 11 of the 12 Division I coaches using stretching, whereas only 5 of the 11 Division III coaches used stretching postactivity (p = 0.027). Divisional results show that the majority of Division I coaches use static-style stretching (p = 0.049). The results of this study indicate that divisional status, age, and certification may influence how well research guidelines are followed. Further research is needed to delineate how these factors affect coaching decisions.
Characterization of Friction Joints Subjected to High Levels of Random Vibration
NASA Technical Reports Server (NTRS)
deSantos, Omar; MacNeal, Paul
2012-01-01
This paper describes the test program in detail including test sample description, test procedures, and vibration test results of multiple test samples. The material pairs used in the experiment were Aluminum-Aluminum, Aluminum- Dicronite coated Aluminum, and Aluminum-Plasmadize coated Aluminum. Levels of vibration for each set of twelve samples of each material pairing were gradually increased until all samples experienced substantial displacement. Data was collected on 1) acceleration in all three axes, 2) relative static displacement between vibration runs utilizing photogrammetry techniques, and 3) surface galling and contaminant generation. This data was used to estimate the values of static friction during random vibratory motion when "stick-slip" occurs and compare these to static friction coefficients measured before and after vibration testing.
ERIC Educational Resources Information Center
Onorato, P.; Mascheretti, P.; DeAmbrosis, A.
2012-01-01
In this paper, we describe how simple experiments realizable by using easily found and low-cost materials allow students to explore quantitatively the magnetic interaction thanks to the help of an Open Source Physics tool, the Tracker Video Analysis software. The static equilibrium of a "column" of permanents magnets is carefully investigated by…
Dead zone analysis of ECAL barrel modules under static and dynamic load
NASA Astrophysics Data System (ADS)
Pierre-Emile, T.; Anduze, M.
2018-03-01
In the context of ILD project, impact studies of environmental loads on the Electromagnetic CALorimeter (ECAL) have been initiated. The ECAL part considered is the barrel and it consists of several independent modules which are mounted on the Hadronic CALorimeter barrel (HCAL) itself mounted on the cryostat coil and the yoke. The estimate of the gap required between each ECAL modules is fundamental to define the assembly step and avoid mechanical contacts over the barrel lifetime. In the meantime, it has to be done in consideration to the dead spaces reduction and detector hermiticity optimization. Several Finite Element Analysis (FEA) with static and dynamic loads have been performed in order to define correctly the minimum values for those gaps. Due to the implantation site of the whole project in Japan, seismic analysis were carried out in addition to the static ones. This article shows results of these analysis done with the Finite Element Method (FEM) in ANSYS. First results show the impact of HCAL design on the ECAL modules motion in static load. The second study dedicated to seismic approach on a larger model (including yoke and cryostat) gives additional results on earthquake consequences.
Predicting System Accidents with Model Analysis During Hybrid Simulation
NASA Technical Reports Server (NTRS)
Malin, Jane T.; Fleming, Land D.; Throop, David R.
2002-01-01
Standard discrete event simulation is commonly used to identify system bottlenecks and starving and blocking conditions in resources and services. The CONFIG hybrid discrete/continuous simulation tool can simulate such conditions in combination with inputs external to the simulation. This provides a means for evaluating the vulnerability to system accidents of a system's design, operating procedures, and control software. System accidents are brought about by complex unexpected interactions among multiple system failures , faulty or misleading sensor data, and inappropriate responses of human operators or software. The flows of resource and product materials play a central role in the hazardous situations that may arise in fluid transport and processing systems. We describe the capabilities of CONFIG for simulation-time linear circuit analysis of fluid flows in the context of model-based hazard analysis. We focus on how CONFIG simulates the static stresses in systems of flow. Unlike other flow-related properties, static stresses (or static potentials) cannot be represented by a set of state equations. The distribution of static stresses is dependent on the specific history of operations performed on a system. We discuss the use of this type of information in hazard analysis of system designs.
NASA Astrophysics Data System (ADS)
Oumaamar, Mohamed El Kamel; Maouche, Yassine; Boucherma, Mohamed; Khezzar, Abdelmalek
2017-02-01
The mixed eccentricity fault detection in a squirrel cage induction motor has been thoroughly investigated. However, a few papers have been related to pure static eccentricity fault and the authors focused on the RSH harmonics presented in stator current. The main objective of this paper is to present an alternative method based on the analysis of line neutral voltage taking place between the supply and the stator neutrals in order to detect air-gap static eccentricity, and to highlight the classification of all RSH harmonics in line neutral voltage. The model of squirrel cage induction machine relies on the rotor geometry and winding layout. Such developed model is used to analyze the impact of the pure static air-gap eccentricity by predicting the related frequencies in the line neutral voltage spectrum. The results show that the line neutral voltage spectrum are more sensitive to the air-gap static eccentricity fault compared to stator current one. The theoretical analysis and simulated results are confirmed by experiments.
Failure mechanics in low-velocity impacts on thin composite plates
NASA Technical Reports Server (NTRS)
Elber, W.
1983-01-01
Eight-ply quasi-isotropic composite plates of Thornel 300 graphite in Narmco 5208 epoxy resin (T300/5208) were tested to establish the degree of equivalence between low-velocity impact and static testing. Both the deformation and failure mechanics under impact were representable by static indentation tests. Under low-velocity impacts such as tool drops, the dominant deformation mode of the plates was the first, or static, mode. Higher modes are excited on contact, but they decay significantly by the time the first-mode load reaches a maximum. The delamination patterns were observed by X-ray analysis. The areas of maximum delamination patterns were observed by X-ray analysis. The areas of maximum delamination coincided with the areas of highest peel stresses. The extent of delamination was similar for static and impact tests. Fiber failure damage was established by tensile tests on small fiber bundles obtained by deplying test specimens. The onset of fiber damage was in internal plies near the lower surface of the plates. The distribution and amount of fiber damage was similar fo impact and static tests.
Compiler-assisted static checkpoint insertion
NASA Technical Reports Server (NTRS)
Long, Junsheng; Fuchs, W. K.; Abraham, Jacob A.
1992-01-01
This paper describes a compiler-assisted approach for static checkpoint insertion. Instead of fixing the checkpoint location before program execution, a compiler enhanced polling mechanism is utilized to maintain both the desired checkpoint intervals and reproducible checkpoint 1ocations. The technique has been implemented in a GNU CC compiler for Sun 3 and Sun 4 (Sparc) processors. Experiments demonstrate that the approach provides for stable checkpoint intervals and reproducible checkpoint placements with performance overhead comparable to a previously presented compiler assisted dynamic scheme (CATCH) utilizing the system clock.
NASA Technical Reports Server (NTRS)
Barclay, D. L.
1980-01-01
Results of an experimental program to develop several types of graphite/polyimide (GR/PI) bonded and bolted joints for lightly loaded flight components for advanced space transportation systems and high speed aircraft are presented. Tasks accomplished include: a literature survey; design of static discriminator specimens; design allowables testing; fabrication of test panels and specimens; small specimen testing; and standard joint testing. Detail designs of static discriminator specimens for each of the four major attachment types are presented. Test results are given for the following: (1) transverse tension of Celion 3000/PMR-15 laminate; (2) net tension of a laminate for both a loaded and unloaded bolt hole; (3) comparative testing of bonded and co-cured doublers along with pull-off tests of single and double bonded angles; (4) single lap shear tests, transverse tension and coefficient of thermal expansion tests of A7F (LARC-13 amide-imide modified) adhesive; and (5) tension tests of standard single lap, double lap, and symmetric step lap bonded joints. Also, included are results of a finite element analysis of a single lap bonded composite joint.
Dynamically corrected gates for singlet-triplet spin qubits with control-dependent errors
NASA Astrophysics Data System (ADS)
Jacobson, N. Tobias; Witzel, Wayne M.; Nielsen, Erik; Carroll, Malcolm S.
2013-03-01
Magnetic field inhomogeneity due to random polarization of quasi-static local magnetic impurities is a major source of environmentally induced error for singlet-triplet double quantum dot (DQD) spin qubits. Moreover, for singlet-triplet qubits this error may depend on the applied controls. This effect is significant when a static magnetic field gradient is applied to enable full qubit control. Through a configuration interaction analysis, we observe that the dependence of the field inhomogeneity-induced error on the DQD bias voltage can vary systematically as a function of the controls for certain experimentally relevant operating regimes. To account for this effect, we have developed a straightforward prescription for adapting dynamically corrected gate sequences that assume control-independent errors into sequences that compensate for systematic control-dependent errors. We show that accounting for such errors may lead to a substantial increase in gate fidelities. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's National Nuclear Security Administration under contract DE-AC04-94AL85000.
Program for narrow-band analysis of aircraft flyover noise using ensemble averaging techniques
NASA Technical Reports Server (NTRS)
Gridley, D.
1982-01-01
A package of computer programs was developed for analyzing acoustic data from an aircraft flyover. The package assumes the aircraft is flying at constant altitude and constant velocity in a fixed attitude over a linear array of ground microphones. Aircraft position is provided by radar and an option exists for including the effects of the aircraft's rigid-body attitude relative to the flight path. Time synchronization between radar and acoustic recording stations permits ensemble averaging techniques to be applied to the acoustic data thereby increasing the statistical accuracy of the acoustic results. Measured layered meteorological data obtained during the flyovers are used to compute propagation effects through the atmosphere. Final results are narrow-band spectra and directivities corrected for the flight environment to an equivalent static condition at a specified radius.
Bone histomorphometry using free and commonly available software.
Egan, Kevin P; Brennan, Tracy A; Pignolo, Robert J
2012-12-01
Histomorphometric analysis is a widely used technique to assess changes in tissue structure and function. Commercially available programs that measure histomorphometric parameters can be cost-prohibitive. In this study, we compared an inexpensive method of histomorphometry to a current proprietary software program. Image J and Adobe Photoshop(®) were used to measure static and kinetic bone histomorphometric parameters. Photomicrographs of Goldner's trichrome-stained femurs were used to generate black-and-white image masks, representing bone and non-bone tissue, respectively, in Adobe Photoshop(®) . The masks were used to quantify histomorphometric parameters (bone volume, tissue volume, osteoid volume, mineralizing surface and interlabel width) in Image J. The resultant values obtained using Image J and the proprietary software were compared and differences found to be statistically non-significant. The wide-ranging use of histomorphometric analysis for assessing the basic morphology of tissue components makes it important to have affordable and accurate measurement options available for a diverse range of applications. Here we have developed and validated an approach to histomorphometry using commonly and freely available software that is comparable to a much more costly, commercially available software program. © 2012 Blackwell Publishing Limited.
Bone histomorphometry using free and commonly available software
Egan, Kevin P.; Brennan, Tracy A.; Pignolo, Robert J.
2012-01-01
Aims Histomorphometric analysis is a widely used technique to assess changes in tissue structure and function. Commercially-available programs that measure histomorphometric parameters can be cost prohibitive. In this study, we compared an inexpensive method of histomorphometry to a current proprietary software program. Methods and results Image J and Adobe Photoshop® were used to measure static and kinetic bone histomorphometric parameters. Photomicrographs of Goldner’s Trichrome stained femurs were used to generate black and white image masks, representing bone and non-bone tissue, respectively, in Adobe Photoshop®. The masks were used to quantify histomorphometric parameters (bone volume, tissue volume, osteoid volume, mineralizing surface, and interlabel width) in Image J. The resultant values obtained using Image J and the proprietary software were compared and found to be statistically non-significant. Conclusions The wide ranging use of histomorphometric analysis for assessing the basic morphology of tissue components makes it important to have affordable and accurate measurement options that are available for a diverse range of applications. Here we have developed and validated an approach to histomorphometry using commonly and freely available software that is comparable to a much more costly, commercially-available software program. PMID:22882309
Methods, media, and systems for detecting attack on a digital processing device
Stolfo, Salvatore J.; Li, Wei-Jen; Keromylis, Angelos D.; Androulaki, Elli
2014-07-22
Methods, media, and systems for detecting attack are provided. In some embodiments, the methods include: comparing at least part of a document to a static detection model; determining whether attacking code is included in the document based on the comparison of the document to the static detection model; executing at least part of the document; determining whether attacking code is included in the document based on the execution of the at least part of the document; and if attacking code is determined to be included in the document based on at least one of the comparison of the document to the static detection model and the execution of the at least part of the document, reporting the presence of an attack. In some embodiments, the methods include: selecting a data segment in at least one portion of an electronic document; determining whether the arbitrarily selected data segment can be altered without causing the electronic document to result in an error when processed by a corresponding program; in response to determining that the arbitrarily selected data segment can be altered, arbitrarily altering the data segment in the at least one portion of the electronic document to produce an altered electronic document; and determining whether the corresponding program produces an error state when the altered electronic document is processed by the corresponding program.
Methods, media, and systems for detecting attack on a digital processing device
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stolfo, Salvatore J.; Li, Wei-Jen; Keromytis, Angelos D.
Methods, media, and systems for detecting attack are provided. In some embodiments, the methods include: comparing at least part of a document to a static detection model; determining whether attacking code is included in the document based on the comparison of the document to the static detection model; executing at least part of the document; determining whether attacking code is included in the document based on the execution of the at least part of the document; and if attacking code is determined to be included in the document based on at least one of the comparison of the document tomore » the static detection model and the execution of the at least part of the document, reporting the presence of an attack. In some embodiments, the methods include: selecting a data segment in at least one portion of an electronic document; determining whether the arbitrarily selected data segment can be altered without causing the electronic document to result in an error when processed by a corresponding program; in response to determining that the arbitrarily selected data segment can be altered, arbitrarily altering the data segment in the at least one portion of the electronic document to produce an altered electronic document; and determining whether the corresponding program produces an error state when the altered electronic document is processed by the corresponding program.« less
A Change Impact Analysis to Characterize Evolving Program Behaviors
NASA Technical Reports Server (NTRS)
Rungta, Neha Shyam; Person, Suzette; Branchaud, Joshua
2012-01-01
Change impact analysis techniques estimate the potential effects of changes made to software. Directed Incremental Symbolic Execution (DiSE) is an intraprocedural technique for characterizing the impact of software changes on program behaviors. DiSE first estimates the impact of the changes on the source code using program slicing techniques, and then uses the impact sets to guide symbolic execution to generate path conditions that characterize impacted program behaviors. DiSE, however, cannot reason about the flow of impact between methods and will fail to generate path conditions for certain impacted program behaviors. In this work, we present iDiSE, an extension to DiSE that performs an interprocedural analysis. iDiSE combines static and dynamic calling context information to efficiently generate impacted program behaviors across calling contexts. Information about impacted program behaviors is useful for testing, verification, and debugging of evolving programs. We present a case-study of our implementation of the iDiSE algorithm to demonstrate its efficiency at computing impacted program behaviors. Traditional notions of coverage are insufficient for characterizing the testing efforts used to validate evolving program behaviors because they do not take into account the impact of changes to the code. In this work we present novel definitions of impacted coverage metrics that are useful for evaluating the testing effort required to test evolving programs. We then describe how the notions of impacted coverage can be used to configure techniques such as DiSE and iDiSE in order to support regression testing related tasks. We also discuss how DiSE and iDiSE can be configured for debugging finding the root cause of errors introduced by changes made to the code. In our empirical evaluation we demonstrate that the configurations of DiSE and iDiSE can be used to support various software maintenance tasks
NASA Technical Reports Server (NTRS)
Skoog, Richard B
1957-01-01
A theoretical analysis has been made of the effects of aeroelasticity on the static longitudinal stability and elevator angle required for balance of an airplane. The analysis is based on the familiar stability equation expressing the contribution of wing and tail to longitudinal stability. Effects of wing, tail, and fuselage flexibility are considered. Calculated effects are shown for a swept-wing bomber of relatively high flexibility.
MASCOT - MATLAB Stability and Control Toolbox
NASA Technical Reports Server (NTRS)
Kenny, Sean; Crespo, Luis
2011-01-01
MASCOT software was created to provide the conceptual aircraft designer accurate predictions of air vehicle stability and control characteristics. The code takes as input mass property data in the form of an inertia tensor, aerodynamic loading data, and propulsion (i.e. thrust) loading data. Using fundamental non-linear equations of motion, MASCOT then calculates vehicle trim and static stability data for any desired flight condition. Common predefined flight conditions are included. The predefined flight conditions include six horizontal and six landing rotation conditions with varying options for engine out, crosswind and sideslip, plus three takeoff rotation conditions. Results are displayed through a unique graphical interface developed to provide stability and control information to the conceptual design engineers using a qualitative scale indicating whether the vehicle has acceptable, marginal, or unacceptable static stability characteristics. This software allows the user to prescribe the vehicle s CG location, mass, and inertia tensor so that any loading configuration between empty weight and maximum take-off weight can be analyzed. The required geometric and aerodynamic data as well as mass and inertia properties may be entered directly, passed through data files, or come from external programs such as Vehicle Sketch Pad (VSP). The current version of MASCOT has been tested with VSP used to compute the required data, which is then passed directly into the program. In VSP, the vehicle geometry is created and manipulated. The aerodynamic coefficients, stability and control derivatives, are calculated using VorLax, which is now available directly within VSP. MASCOT has been written exclusively using the technical computing language MATLAB . This innovation is able to bridge the gap between low-fidelity conceptual design and higher-fidelity stability and control analysis. This new tool enables the conceptual design engineer to include detailed static stability and trim constraints in the conceptual design loop. The unique graphical interface developed for this tool presents the stability data in a format that is understandable by the conceptual designer, yet also provides the detailed quantitative results if desired.
On the Power of Abstract Interpretation
NASA Technical Reports Server (NTRS)
Reddy, Uday S.; Kamin, Samuel N.
1991-01-01
Increasingly sophisticated applications of static analysis place increased burden on the reliability of the analysis techniques. Often, the failure of the analysis technique to detect some information my mean that the time or space complexity of the generated code would be altered. Thus, it is important to precisely characterize the power of static analysis techniques. We follow the approach of Selur et. al. who studied the power of strictness analysis techniques. Their result can be summarized by saying 'strictness analysis is perfect up to variations in constants.' In other words, strictness analysis is as good as it could be, short of actually distinguishing between concrete values. We use this approach to characterize a broad class of analysis techniques based on abstract interpretation including, but not limited to, strictness analysis. For the first-order case, we consider abstract interpretations where the abstract domain for data values is totally ordered. This condition is satisfied by Mycroft's strictness analysis that of Sekar et. al. and Wadler's analysis of list-strictness. For such abstract interpretations, we show that the analysis is complete in the sense that, short of actually distinguishing between concrete values with the same abstraction, it gives the best possible information. We further generalize these results to typed lambda calculus with pairs and higher-order functions. Note that products and function spaces over totally ordered domains are not totally ordered. In fact, the notion of completeness used in the first-order case fails if product domains or function spaces are added. We formulate a weaker notion of completeness based on observability of values. Two values (including pairs and functions) are considered indistinguishable if their observable components are indistinguishable. We show that abstract interpretation of typed lambda calculus programs is complete up to this notion of indistinguishability. We use denotationally-oriented arguments instead of the detailed operational arguments used by Selur et. al.. Hence, our proofs are much simpler. They should be useful for further future improvements.
A lower-limb training program to improve balance in healthy elderly women using the T-bow device.
Chulvi-Medrano, Iván; Colado, Juan C; Pablos, Carlos; Naclerio, Fernando; García-Massó, Xavier
2009-06-01
Ageing impairs balance, which increases the risk of falls. Fall-related injuries are a serious health problem associated with dependency and disability in the elderly and results in high costs to public health systems. This study aims to determine the effects of a training program to develop balance using a new device called the T-Bow. A total of 28 women > 65 years were randomly assigned to an experimental group (EG) (n = 18; 69.50 [0.99] years), or a control group (CG) (n = 10; 70.70 [2.18] years). A program for lower limbs was applied for 8 weeks using 5 exercises on the T-Bow: squat, lateral and frontal swings, lunges, and plantarflexions. The intensity of the exercises was controlled by time of exposure, support base, and ratings of perceived exertion. Clinical tests were used to evaluate variables of balance. Static balance was measured by a 1-leg balance test (unipedal stance test), dynamic balance was measured by the 8-foot-up-and-go test, and overall balance was measured using the Tinetti test. Results for the EG showed an increase of 35.2% in static balance (P < 0.005), 12.7% in dynamic balance (P < 0.005), and 5.9% in overall balance (P > 0.05). Results for the CG showed a decline of 5.79% in static balance (P > 0.05) but no change in the other balance variables. Thus the data suggest that implementing a training program using the T-Bow could improve balance in healthy older women.
The Effect of Audio and Animation in Multimedia Instruction
ERIC Educational Resources Information Center
Koroghlanian, Carol; Klein, James D.
2004-01-01
This study investigated the effects of audio, animation, and spatial ability in a multimedia computer program for high school biology. Participants completed a multimedia program that presented content by way of text or audio with lean text. In addition, several instructional sequences were presented either with static illustrations or animations.…
Orbit attitude processor. STS-1 bench program verification test plan
NASA Technical Reports Server (NTRS)
Mcclain, C. R.
1980-01-01
A plan for the static verification of the STS-1 ATT PROC ORBIT software requirements is presented. The orbit version of the SAPIENS bench program is used to generate the verification data. A brief discussion of the simulation software and flight software modules is presented along with a description of the test cases.
NASA Technical Reports Server (NTRS)
Whetstone, W. D.
1976-01-01
The functions and operating rules of the SPAR system, which is a group of computer programs used primarily to perform stress, buckling, and vibrational analyses of linear finite element systems, were given. The following subject areas were discussed: basic information, structure definition, format system matrix processors, utility programs, static solutions, stresses, sparse matrix eigensolver, dynamic response, graphics, and substructure processors.
Relationship between antigravity control and postural control in young children.
Sellers, J S
1988-04-01
The purposes of this study were 1) to determine the relationship between antigravity control (supine flexion and prone extension) and postural control (static and dynamic balance), 2) to determine the quality of antigravity and postural control, and 3) to determine whether sex and ethnic group differences correlate with differences in antigravity control and postural control in young children. I tested 107 black, Hispanic, and Caucasian children in a Head Start program, with a mean age of 61 months. The study results showed significant relationships between antigravity control and postural control. Subjects' supine flexion performance was significantly related to the quantity and quality of their static and dynamic balance performance, whereas prone extension performance was related only to the quality of dynamic balance performance. Quality scale measurements (r = .90) indicated that the children in this study had not yet developed full antigravity or postural control. The study results revealed differences between sexes in the quality of static balance and prone extension performance and ethnic differences in static balance, dynamic balance, and prone extension performance.
Pile Driving Analysis for Pile Design and Quality Assurance
DOT National Transportation Integrated Search
2017-08-01
Driven piles are commonly used in foundation engineering. The most accurate measurement of pile capacity is achieved from measurements made during static load tests. Static load tests, however, may be too expensive for certain projects. In these case...
Experimental Results from the Active Aeroelastic Wing Wind Tunnel Test Program
NASA Technical Reports Server (NTRS)
Heeg, Jennifer; Spain, Charles V.; Florance, James R.; Wieseman, Carol D.; Ivanco, Thomas G.; DeMoss, Joshua; Silva, Walter A.; Panetta, Andrew; Lively, Peter; Tumwa, Vic
2005-01-01
The Active Aeroelastic Wing (AAW) program is a cooperative effort among NASA, the Air Force Research Laboratory and the Boeing Company, encompassing flight testing, wind tunnel testing and analyses. The objective of the AAW program is to investigate the improvements that can be realized by exploiting aeroelastic characteristics, rather than viewing them as a detriment to vehicle performance and stability. To meet this objective, a wind tunnel model was crafted to duplicate the static aeroelastic behavior of the AAW flight vehicle. The model was tested in the NASA Langley Transonic Dynamics Tunnel in July and August 2004. The wind tunnel investigation served the program goal in three ways. First, the wind tunnel provided a benchmark for comparison with the flight vehicle and various levels of theoretical analyses. Second, it provided detailed insight highlighting the effects of individual parameters upon the aeroelastic response of the AAW vehicle. This parameter identification can then be used for future aeroelastic vehicle design guidance. Third, it provided data to validate scaling laws and their applicability with respect to statically scaled aeroelastic models.
Transputer parallel processing at NASA Lewis Research Center
NASA Technical Reports Server (NTRS)
Ellis, Graham K.
1989-01-01
The transputer parallel processing lab at NASA Lewis Research Center (LeRC) consists of 69 processors (transputers) that can be connected into various networks for use in general purpose concurrent processing applications. The main goal of the lab is to develop concurrent scientific and engineering application programs that will take advantage of the computational speed increases available on a parallel processor over the traditional sequential processor. Current research involves the development of basic programming tools. These tools will help standardize program interfaces to specific hardware by providing a set of common libraries for applications programmers. The thrust of the current effort is in developing a set of tools for graphics rendering/animation. The applications programmer currently has two options for on-screen plotting. One option can be used for static graphics displays and the other can be used for animated motion. The option for static display involves the use of 2-D graphics primitives that can be called from within an application program. These routines perform the standard 2-D geometric graphics operations in real-coordinate space as well as allowing multiple windows on a single screen.
NASA Technical Reports Server (NTRS)
Haftka, R. T.; Adelman, H. M.
1984-01-01
Orbiting spacecraft such as large space antennas have to maintain a highly accurate space to operate satisfactorily. Such structures require active and passive controls to mantain an accurate shape under a variety of disturbances. Methods for the optimum placement of control actuators for correcting static deformations are described. In particular, attention is focused on the case were control locations have to be selected from a large set of available sites, so that integer programing methods are called for. The effectiveness of three heuristic techniques for obtaining a near-optimal site selection is compared. In addition, efficient reanalysis techniques for the rapid assessment of control effectiveness are presented. Two examples are used to demonstrate the methods: a simple beam structure and a 55m space-truss-parabolic antenna.
NASA Technical Reports Server (NTRS)
Hagedorn, N. H.; Prokipius, P. R.
1977-01-01
A test program was conducted to evaluate the design of a heat and product-water removal system to be used with fuel cell having static water removal and evaporative cooling. The program, which was conducted on a breadboard version of the system, provided a general assessment of the design in terms of operational integrity and transient stability. This assessment showed that, on the whole, the concept appears to be inherently sound but that in refining this design, several facets will require additional study. These involve interactions between pressure regulators in the pumping loop that occur when they are not correctly matched and the question of whether an ejector is necessary in the system.
NASA Technical Reports Server (NTRS)
Baumeister, K. J.; Horowitz, S. J.
1982-01-01
An iterative finite element integral technique is used to predict the sound field radiated from the JT15D turbofan inlet. The sound field is divided into two regions: the sound field within and near the inlet which is computed using the finite element method and the radiation field beyond the inlet which is calculated using an integral solution technique. The velocity potential formulation of the acoustic wave equation was employed in the program. For some single mode JT15D data, the theory and experiment are in good agreement for the far field radiation pattern as well as suppressor attenuation. Also, the computer program is used to simulate flight effects that cannot be performed on a ground static test stand.
Walters, Glenn D; Deming, Adam; Casbon, Todd
2015-04-01
The purpose of this study was to determine whether the Psychological Inventory of Criminal Thinking Styles (PICTS) was capable of predicting recidivism in 322 male sex offenders released from prison-based sex offender programs in a Midwestern state. The Static-99R and PICTS General Criminal Thinking (GCT), Reactive (R), and Entitlement (En) scores all correlated significantly with general recidivism, the Static-99R correlated significantly with violent recidivism, and the Static-99R score and PICTS GCT, Proactive (P), and En scores correlated significantly with failure to register as a sex offender (FTR) recidivism. Area under the curve effect size estimates varied from small to large, and Cox regression analyses revealed that the PICTS En score achieved incremental validity relative to the Static-99R in predicting general recidivism and the PICTS GCT, P, and En scores achieved incremental validity relative to the Static-99R in predicting FTR recidivism. It is speculated that the PICTS in general and the En scale in particular may have utility in risk management and treatment planning for sex offenders by virtue of their focus on antisocial thinking. © The Author(s) 2014.
NASA Astrophysics Data System (ADS)
Martinez, P.; Kasper, M.; Costille, A.; Sauvage, J. F.; Dohlen, K.; Puget, P.; Beuzit, J. L.
2013-06-01
Context. Observing sequences have shown that the major noise source limitation in high-contrast imaging is the presence of quasi-static speckles. The timescale on which quasi-static speckles evolve is determined by various factors, mechanical or thermal deformations, among others. Aims: Understanding these time-variable instrumental speckles and, especially, their interaction with other aberrations, referred to as the pinning effect, is paramount for the search for faint stellar companions. The temporal evolution of quasi-static speckles is, for instance, required for quantifying the gain expected when using angular differential imaging (ADI) and to determining the interval on which speckle nulling techniques must be carried out. Methods: Following an early analysis of a time series of adaptively corrected, coronagraphic images obtained in a laboratory condition with the high-order test bench (HOT) at ESO Headquarters, we confirm our results with new measurements carried out with the SPHERE instrument during its final test phase in Europe. The analysis of the residual speckle pattern in both direct and differential coronagraphic images enables the characterization of the temporal stability of quasi-static speckles. Data were obtained in a thermally actively controlled environment reproducing realistic conditions encountered at the telescope. Results: The temporal evolution of the quasi-static wavefront error exhibits a linear power law, which can be used to model quasi-static speckle evolution in the context of forthcoming high-contrast imaging instruments, with implications for instrumentation (design, observing strategies, data reduction). Such a model can be used for instance to derive the timescale on which non-common path aberrations must be sensed and corrected. We found in our data that quasi-static wavefront error increases with ~0.7 Å per minute.
Böhm, Harald; Stief, Felix; Sander, Klaus; Hösl, Matthias; Döderlein, Leonhard
2015-09-01
Malaligned knees are predisposed to the development and progression of unicompartmental degenerations because of the excessive load placed on one side of the knee. Therefore, guided growth in skeletally immature patients is recommended. Indication for correction of varus/valgus deformities are based on static weight bearing radiographs. However, the dynamic knee abduction moment during walking showed only a weak correlation to malalignment determined by static radiographs. Therefore, the aim of the study was to measure the effects of guided growth on the normalization of frontal plane knee joint moments during walking. 15 legs of 8 patients (11-15 years) with idiopathic axial varus or valgus malalignment were analyzed. 16 typically developed peers served as controls. Instrumented gait analysis and clinical assessment were performed the day before implantation and explantation of eight-plates. Correlation between static mechanical tibiofemoral axis angle (MAA) and dynamic frontal plane knee joint moments and their change by guided growth were performed. The changes in dynamic knee moment in the frontal plane following guided growth showed high and significant correlation to the changes in static MAA (R=0.97, p<0.001). Contrary to the correlation of the changes, there was no correlation between static and dynamic measures in both sessions. In consequence two patients that had a natural knee moment before treatment showed a more pathological one after treatment. In conclusion, the changes in the dynamic load situation during walking can be predicted from the changes in static alignment. If pre-surgical gait analysis reveals a natural load situation, despite a static varus or valgus deformity, the intervention must be critically discussed. Copyright © 2015 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Weng, Hanli; Li, Youping
2017-04-01
The working principle, process device and test procedure of runner static balancing test method by weighting with three-pivot pressure transducers are introduced in this paper. Based on an actual instance of a V hydraulic turbine runner, the error and sensitivity of the three-pivot pressure transducer static balancing method are analysed. Suggestions about improving the accuracy and the application of the method are also proposed.
Naryshkin, Nikolai; Druzhinin, Sergei; Revyakin, Andrei; Kim, Younggyu; Mekler, Vladimir; Ebright, Richard H.
2009-01-01
Static site-specific protein-DNA photocrosslinking permits identification of protein-DNA interactions within multiprotein-DNA complexes. Kinetic site-specific protein-DNA photocrosslinking--involving rapid-quench-flow mixing and pulsed-laser irradiation--permits elucidation of pathways and kinetics of formation of protein-DNA interactions within multiprotein-DNA complexes. We present detailed protocols for application of static and kinetic site-specific protein-DNA photocrosslinking to bacterial transcription initiation complexes. PMID:19378179
NASA Technical Reports Server (NTRS)
Martos, Borja; Kiszely, Paul; Foster, John V.
2011-01-01
As part of the NASA Aviation Safety Program (AvSP), a novel pitot-static calibration method was developed to allow rapid in-flight calibration for subscale aircraft while flying within confined test areas. This approach uses Global Positioning System (GPS) technology coupled with modern system identification methods that rapidly computes optimal pressure error models over a range of airspeed with defined confidence bounds. This method has been demonstrated in subscale flight tests and has shown small 2- error bounds with significant reduction in test time compared to other methods. The current research was motivated by the desire to further evaluate and develop this method for full-scale aircraft. A goal of this research was to develop an accurate calibration method that enables reductions in test equipment and flight time, thus reducing costs. The approach involved analysis of data acquisition requirements, development of efficient flight patterns, and analysis of pressure error models based on system identification methods. Flight tests were conducted at The University of Tennessee Space Institute (UTSI) utilizing an instrumented Piper Navajo research aircraft. In addition, the UTSI engineering flight simulator was used to investigate test maneuver requirements and handling qualities issues associated with this technique. This paper provides a summary of piloted simulation and flight test results that illustrates the performance and capabilities of the NASA calibration method. Discussion of maneuver requirements and data analysis methods is included as well as recommendations for piloting technique.
Progress in The Semantic Analysis of Scientific Code
NASA Technical Reports Server (NTRS)
Stewart, Mark
2000-01-01
This paper concerns a procedure that analyzes aspects of the meaning or semantics of scientific and engineering code. This procedure involves taking a user's existing code, adding semantic declarations for some primitive variables, and parsing this annotated code using multiple, independent expert parsers. These semantic parsers encode domain knowledge and recognize formulae in different disciplines including physics, numerical methods, mathematics, and geometry. The parsers will automatically recognize and document some static, semantic concepts and help locate some program semantic errors. These techniques may apply to a wider range of scientific codes. If so, the techniques could reduce the time, risk, and effort required to develop and modify scientific codes.
Spectral contents readout of birefringent sensor
NASA Technical Reports Server (NTRS)
Redner, Alex S.
1989-01-01
The technical objective of this research program was to develop a birefringent sensor, capable of measuring strain/stress up to 2000 F and a readout system based on Spectral Contents analysis. As a result of the research work, a data acquisition system was developed, capable of measuring strain birefringence in a sensor at 2000 F, with multi-point static and dynamic capabilities. The system uses a dedicated spectral analyzer for evaluation of stress-birefringence and a PC-based readout. Several sensor methods were evaluated. Fused silica was found most satisfactory. In the final evaluation, measurements were performed up to 2000 F and the system performance exceeded expectations.
NASA Technical Reports Server (NTRS)
Jackson, A. C.; Crocker, J. F.; Ekvall, J. C.; Eudaily, R. R.; Mosesian, B.; Vancleave, R. R.; Vanhamersveld, J.
1981-01-01
The composite fin design consists of two one-piece cocured covers, two one-piece cocured spars and eleven ribs. The lower ribs are truss ribs with graphite/epoxy caps and aluminum truss members. The upper three ribs are a sandwich design with graphite/epoxy face sheets and a syntactic epoxy core. The design achieves a 27% weight saving compared to the metal box. The fastener count has been reduced from over 40,000 to less than 7000. The structural integrity of the composite fin was verified by analysis and test. The static, fail-safe and flutter analyses were completed. An extensive test program has established the material behavior under a range of conditions and critical subcomponents were tested to verify the structural concepts.
Ergonomic study and static analysis for new design of electric scooter
NASA Astrophysics Data System (ADS)
Fadzly, M. K.; Munirah, Anis; Shayfull, Z.; Saad, Mohd Sazli
2017-09-01
The purposes of this project are to design and diversify the function of a battery powered scooter frame which is more practical for the human factor in ergonomic and optimum design. The new design is based on ideas which are studied from existing scooter frame, United States Patent design and European States International Patent design. The final idea of concept design for scooter frame is based on concept chosen from the best characteristics and it is divided into three main difference ideas and the matrix evaluation method is applied. Analysis that applies to frame design, arm, rim and drive train component is based on Cosmos Express program. As a conclusion, the design that is produce are able to carry the maximum also has more practical features in ergonomic view.
NASA Astrophysics Data System (ADS)
Yang, Zhichun; Zhou, Jian; Gu, Yingsong
2014-10-01
A flow field modified local piston theory, which is applied to the integrated analysis on static/dynamic aeroelastic behaviors of curved panels, is proposed in this paper. The local flow field parameters used in the modification are obtained by CFD technique which has the advantage to simulate the steady flow field accurately. This flow field modified local piston theory for aerodynamic loading is applied to the analysis of static aeroelastic deformation and flutter stabilities of curved panels in hypersonic flow. In addition, comparisons are made between results obtained by using the present method and curvature modified method. It shows that when the curvature of the curved panel is relatively small, the static aeroelastic deformations and flutter stability boundaries obtained by these two methods have little difference, while for curved panels with larger curvatures, the static aeroelastic deformation obtained by the present method is larger and the flutter stability boundary is smaller compared with those obtained by the curvature modified method, and the discrepancy increases with the increasing of curvature of panels. Therefore, the existing curvature modified method is non-conservative compared to the proposed flow field modified method based on the consideration of hypersonic flight vehicle safety, and the proposed flow field modified local piston theory for curved panels enlarges the application range of piston theory.
Deformation behavior of welded steel sandwich panels under quasi-static loading
DOT National Transportation Integrated Search
2011-03-16
This paper summarizes basic research (i.e., testing and analysis) : conducted to examine the deformation behavior of flat-welded : steel sandwich panels under two types of quasi-static loading: : (1) uniaxial compression; and (2) bending through an i...
Commuter rail seat testing and analysis of facing seats
DOT National Transportation Integrated Search
2003-12-01
Tests have been conducted on the Bombardier back-to-back commuter rail car seat in a facing-seat configuration to evaluate its performance under static and dynamic loading conditions. Quasi-static tests have been conducted to establish the load defle...
The FORTRAN static source code analyzer program (SAP) system description
NASA Technical Reports Server (NTRS)
Decker, W.; Taylor, W.; Merwarth, P.; Oneill, M.; Goorevich, C.; Waligora, S.
1982-01-01
A source code analyzer program (SAP) designed to assist personnel in conducting studies of FORTRAN programs is described. The SAP scans FORTRAN source code and produces reports that present statistics and measures of statements and structures that make up a module. The processing performed by SAP and of the routines, COMMON blocks, and files used by SAP are described. The system generation procedure for SAP is also presented.
Automated predesign of aircraft
NASA Technical Reports Server (NTRS)
Poe, C. C., Jr.; Kruse, G. S.; Tanner, C. J.; Wilson, P. J.
1978-01-01
Program uses multistation structural-synthesis to size and design box-beam structures for transport aircraft. Program optimizes static strength and scales up to satisfy fatigue and fracture criteria. It has multimaterial capability and library of materials properties, including advanced composites. Program can be used to evaluate impact on weight of variables such as materials, types of construction, structural configurations, minimum gage limits, applied loads, fatigue lives, crack-growth lives, initial crack sizes, and residual strengths.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gartling, D.K.
User instructions are given for the finite element, electromagnetics program, TORO II. The theoretical background and numerical methods used in the program are documented in SAND95-2472. The present document also describes a number of example problems that have been analyzed with the code and provides sample input files for typical simulations. 20 refs., 34 figs., 3 tabs.
Determination of the static friction coefficient from circular motion
NASA Astrophysics Data System (ADS)
Molina-Bolívar, J. A.; Cabrerizo-Vílchez, M. A.
2014-07-01
This paper describes a physics laboratory exercise for determining the coefficient of static friction between two surfaces. The circular motion of a coin placed on the surface of a rotating turntable has been studied. For this purpose, the motion is recorded with a high-speed digital video camera recording at 240 frames s-1, and the videos are analyzed using Tracker video-analysis software, allowing the students to dynamically model the motion of the coin. The students have to obtain the static friction coefficient by comparing the centripetal and maximum static friction forces. The experiment only requires simple and inexpensive materials. The dynamics of circular motion and static friction forces are difficult for many students to understand. The proposed laboratory exercise addresses these topics, which are relevant to the physics curriculum.
Technical Evaluation Motor no. 5 (TEM-5)
NASA Technical Reports Server (NTRS)
Cook, M.
1990-01-01
Technical Evaluation Motor No. 5 (TEM-5) was static test fired at the Thiokol Corporation Static Test Bay T-97. TEM-5 was a full scale, full duration static test fire of a high performance motor (HPM) configuration solid rocket motor (SRM). The primary purpose of TEM static tests is to recover SRM case and nozzle hardware for use in the redesigned solid rocket motor (RSRM) flight program. Inspection and instrumentation data indicate that the TEM-5 static test firing was successful. The ambient temperature during the test was 41 F and the propellant mean bulk temperature (PMBT) was 72 F. Ballistics performance values were within the specified requirements. The overall performance of the TEM-5 components and test equipment was nominal. Dissembly inspection revealed that joint putty was in contact with the inner groove of the inner primary seal of the ignitor adapter-to-forward dome (inner) joint gasket; this condition had not occurred on any previous static test motor or flight RSRM. While no qualification issues were addressed on TEM-5, two significant component changes were evaluated. Those changes were a new vented assembly process for the case-to-nozzle joint and the installation of two redesigned field joint protection systems. Performance of the vented case-to-nozzle joint assembly was successful, and the assembly/performance differences between the two field joint protection system (FJPS) configurations were compared.
NASA Technical Reports Server (NTRS)
Forbes, R. E.; Smith, M. R.; Farrell, R. R.
1972-01-01
An experimental program was conducted during the static firing of the S-1C stage 13, 14, and 15 rocket engines and the S-2 stage 13, 14, and 15 rocket engines. The data compiled during the experimental program consisted of photographic recordings of the time-dependent growth and diffusion of the exhaust clouds, the collection of meteorological data in the ambient atmosphere, and the acquisition of data on the physical structure of the exhaust clouds which were obtained by flying instrumented aircraft through the clouds. A new technique was developed to verify the previous measurements of evaporation and entrainment of blast deflector cooling water into the cloud. The results of the experimental program indicate that at the lower altitudes the rocket exhaust cloud or plume closely resembles a free-jet type of flow. At the upper altitudes, where the cloud is approaching an equilibrium condition, structure is very similar to a natural cumulus cloud.
Caliandro, Rocco; Sibillano, Teresa; Belviso, B. Danilo; ...
2016-02-02
In this study, we have developed a general X-ray powder diffraction (XPD) methodology for the simultaneous structural and compositional characterization of inorganic nanomaterials. The approach is validated on colloidal tungsten oxide nanocrystals (WO 3-x NCs), as a model polymorphic nanoscale material system. Rod-shaped WO 3-x NCs with different crystal structure and stoichiometry are comparatively investigated under an inert atmosphere and after prolonged air exposure. An initial structural model for the as-synthesized NCs is preliminarily identified by means of Rietveld analysis against several reference crystal phases, followed by atomic pair distribution function (PDF) refinement of the best-matching candidates (static analysis). Subtlemore » stoichiometry deviations from the corresponding bulk standards are revealed. NCs exposed to air at room temperature are monitored by XPD measurements at scheduled time intervals. The static PDF analysis is complemented with an investigation into the evolution of the WO 3-x NC structure, performed by applying the modulation enhanced diffraction technique to the whole time series of XPD profiles (dynamical analysis). Prolonged contact with ambient air is found to cause an appreciable increase in the static disorder of the O atoms in the WO 3-x NC lattice, rather than a variation in stoichiometry. Finally, the time behavior of such structural change is identified on the basis of multivariate analysis.« less
NASA Technical Reports Server (NTRS)
Wright, Geoff
1994-01-01
This report will discuss the design of a liquid hydrogen fuel tank constructed from composite materials. The focus of this report is to recommend a design for a fuel tank which will be able to withstand all static and dynamic forces during manned flight. Areas of study for the design include material selection, material structural analysis, heat transfer, thermal expansion, and liquid hydrogen diffusion. A structural analysis FORTRAN program was developed for analyzing the buckling and yield characteristics of the tank. A thermal analysis Excel spreadsheet was created to determine a specific material thickness which will minimize heat transfer through the wall of the tank. The total mass of the tank was determined by the combination of both structural and thermal analyses. The report concludes with the recommendation of a layered material tank construction. The designed system will include exterior insulation, combination of metal and organize composite matrices and honeycomb.
An Analysis of Ripple and Error Fields Induced by a Blanket in the CFETR
NASA Astrophysics Data System (ADS)
Yu, Guanying; Liu, Xufeng; Liu, Songlin
2016-10-01
The Chinese Fusion Engineering Tokamak Reactor (CFETR) is an important intermediate device between ITER and DEMO. The Water Cooled Ceramic Breeder (WCCB) blanket whose structural material is mainly made of Reduced Activation Ferritic/Martensitic (RAFM) steel, is one of the candidate conceptual blanket design. An analysis of ripple and error field induced by RAFM steel in WCCB is evaluated with the method of static magnetic analysis in the ANSYS code. Significant additional magnetic field is produced by blanket and it leads to an increased ripple field. Maximum ripple along the separatrix line reaches 0.53% which is higher than 0.5% of the acceptable design value. Simultaneously, one blanket module is taken out for heating purpose and the resulting error field is calculated to be seriously against the requirement. supported by National Natural Science Foundation of China (No. 11175207) and the National Magnetic Confinement Fusion Program of China (No. 2013GB108004)
NASA Astrophysics Data System (ADS)
Zabolotnov, Yu. M.
2016-07-01
We analyze the spatial motion of a rigid body fixed to a cable about its center of mass when the orbital cable system is unrolling. The analysis is based on the integral manifold method, which permits separating the rigid body motion into the slow and fast components. The motion of the rigid body is studied in the case of slow variations in the cable tension force and under the action of various disturbances.We estimate the influence of the static and dynamic asymmetry of the rigid body on its spatial motion about the cable fixation point. An example of the analysis of the rigid body motion when the orbital cable system is unrolling is given for a special program of variations in the cable tension force. The conditions of applicability of the integral manifold method are analyzed.
NASA Technical Reports Server (NTRS)
Axelson, John A.; Crown, J. Conrad
1948-01-01
An analysis is presented of the influence of wing aspect ratio and tail location on the effects of compressibility upon static longitudinal stability. The investigation showed that the use of reduced wing aspect ratios or short tail lengths leads to serious reductions in high-speed stability and the possibility of high-speed instability.
Static Analysis Alert Audits: Lexicon and Rules
2016-11-04
collaborators • Includes a standard set of well-defined determinations for static analysis alerts • Includes a set of auditing rules to help auditors make...consistent decisions in commonly-encountered situations Different auditors should make the same determination for a given alert! Improve the quality and...scenarios • Establish assumptions auditors can make • Overall: help make audit determinations more consistent We developed 12 rules • Drew on our own
Analysis for lateral deflection of railroad track under quasi-static loading
DOT National Transportation Integrated Search
2013-10-15
This paper describes analyses to examine the lateral : deflection of railroad track subjected to quasi-static loading. : Rails are assumed to behave as beams in bending. Movement : of the track in the lateral plane is constrained by idealized : resis...
Static Analysis of Large-Scale Multibody System Using Joint Coordinates and Spatial Algebra Operator
Omar, Mohamed A.
2014-01-01
Initial transient oscillations inhibited in the dynamic simulations responses of multibody systems can lead to inaccurate results, unrealistic load prediction, or simulation failure. These transients could result from incompatible initial conditions, initial constraints violation, and inadequate kinematic assembly. Performing static equilibrium analysis before the dynamic simulation can eliminate these transients and lead to stable simulation. Most exiting multibody formulations determine the static equilibrium position by minimizing the system potential energy. This paper presents a new general purpose approach for solving the static equilibrium in large-scale articulated multibody. The proposed approach introduces an energy drainage mechanism based on Baumgarte constraint stabilization approach to determine the static equilibrium position. The spatial algebra operator is used to express the kinematic and dynamic equations of the closed-loop multibody system. The proposed multibody system formulation utilizes the joint coordinates and modal elastic coordinates as the system generalized coordinates. The recursive nonlinear equations of motion are formulated using the Cartesian coordinates and the joint coordinates to form an augmented set of differential algebraic equations. Then system connectivity matrix is derived from the system topological relations and used to project the Cartesian quantities into the joint subspace leading to minimum set of differential equations. PMID:25045732
Omar, Mohamed A
2014-01-01
Initial transient oscillations inhibited in the dynamic simulations responses of multibody systems can lead to inaccurate results, unrealistic load prediction, or simulation failure. These transients could result from incompatible initial conditions, initial constraints violation, and inadequate kinematic assembly. Performing static equilibrium analysis before the dynamic simulation can eliminate these transients and lead to stable simulation. Most exiting multibody formulations determine the static equilibrium position by minimizing the system potential energy. This paper presents a new general purpose approach for solving the static equilibrium in large-scale articulated multibody. The proposed approach introduces an energy drainage mechanism based on Baumgarte constraint stabilization approach to determine the static equilibrium position. The spatial algebra operator is used to express the kinematic and dynamic equations of the closed-loop multibody system. The proposed multibody system formulation utilizes the joint coordinates and modal elastic coordinates as the system generalized coordinates. The recursive nonlinear equations of motion are formulated using the Cartesian coordinates and the joint coordinates to form an augmented set of differential algebraic equations. Then system connectivity matrix is derived from the system topological relations and used to project the Cartesian quantities into the joint subspace leading to minimum set of differential equations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hudson, David
2015-02-01
This report is a compilation of the groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site, Nye County, Nevada. Groundwater samples from the aquifer immediately below the Area 5 RWMS have been collected and analyzed and static water levels have been measured in this aquifer since 1993. This report updates these data to include the 2014 results. Analysis results for leachate contaminants collected from the mixed-waste cell at the Area 5 RWMS (Cell 18) are also included. During 2014, groundwater samples were collected and static water levels were measured at threemore » wells surrounding the Area 5 RWMS. Groundwater samples were collected at wells UE5PW-1, UE5PW-2, and UE5PW-3 on March 11 and August 12, 2014, and static water levels were measured at each of these wells on March 10, June 2, August 11, and October 14, 2014. Groundwater samples were analyzed for the following indicators of contamination: pH, specific conductance, total organic carbon, total organic halides, and tritium. General water chemistry (cations and anions) was also measured. Results from samples collected in 2014 are within the limits established by agreement with the Nevada Division of Environmental Protection for each analyte. The data from the shallow aquifer indicate that there has been no measurable impact to the uppermost aquifer from the Area 5 RWMS, and there were no significant changes in measured groundwater parameters compared to previous years. Leachate from above the primary liner of Cell 18 drains into a sump and is collected in a tank at the ground surface. Cell 18 began receiving waste in January 2011. Samples were collected from the tank when the leachate volume approached the 3,000-gallon tank capacity. Leachate samples have been collected 16 times since January 2011. During 2014, samples were collected on February 25, March 5, May 20, August 12, September 16, November 11, and December 16. Each leachate sample was analyzed for toxicity characteristic contaminants and polychlorinated biphenyls (PCB). Beginning with the sample from July 31, 2013, pH and specific conductance were also measured. Leachate analysis results show no evidence of contamination. Results for toxicity characteristic contaminants are all below regulatory levels and analysis quantification limits. No quantifiable PCB levels were detected in any sample. Results for pH and specific conductance are also within expected ranges. After analysis, leachate was pumped from the collection tank and used in Cell 18 for dust control. The report contains an updated cumulative chronology for the Area 5 RWMS Groundwater Monitoring Program and a brief description of the site hydrogeology.« less
Typical balance exercises or exergames for balance improvement?
Gioftsidou, Asimenia; Vernadakis, Nikolaos; Malliou, Paraskevi; Batzios, Stavros; Sofokleous, Polina; Antoniou, Panagiotis; Kouli, Olga; Tsapralis, Kyriakos; Godolias, George
2013-01-01
Balance training is an effective intervention to improve static postural sway and balance. The purpose of the present study was to investigate the effectiveness of the Nintendo Wii Fit Plus exercises for improving balance ability in healthy collegiate students in comparison with a typical balance training program. Forty students were randomly divided into two groups, a traditional (T group) and a Nintendo Wii group (W group) performed an 8 week balance program. The "W group" used the interactive games as a training method, while the "T group" used an exercise program with mini trampoline and inflatable discs (BOSU). Pre and Post-training participants completed balance assessments. Two-way repeated measures analyses of variance (ANOVAs) were conducted to determine the effect of training program. Analysis of the data illustrated that both training program groups demonstrated an improvement in Total, Anterior-posterior and Medial Lateral Stability Index scores for both limbs. Only at the test performed in the balance board with anterior-posterior motion, the improvement in balance ability was greater in the "T group" than the "W group", when the assessment was performed post-training (p=0.023). Findings support the effectiveness of using the Nintendo Wii gaming console as a balance training intervention tool.
NASA Astrophysics Data System (ADS)
Matsakis, Nicholas D.; Gross, Thomas R.
Intervals are a new, higher-level primitive for parallel programming with which programmers directly construct the program schedule. Programs using intervals can be statically analyzed to ensure that they do not deadlock or contain data races. In this paper, we demonstrate the flexibility of intervals by showing how to use them to emulate common parallel control-flow constructs like barriers and signals, as well as higher-level patterns such as bounded-buffer producer-consumer. We have implemented intervals as a publicly available library for Java and Scala.
ERIC Educational Resources Information Center
Kesselman, Jonathan Rhys
Static and dynamic incentive effects of the following fiscal transfer forms are examined: income subsidy (negative income tax), wage subsidy, categorical income subsidy (work requirement), and overtime wage subsidy. Budgetary costs, aggregate labor-market impacts, and welfare effects are analyzed. A program for categorically combining wage and…
ERIC Educational Resources Information Center
Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Alberti, Gloria; Perilli, Viviana; Zimbaro, Carmen; Boccasini, Adele; Mazzola, Carlo; Russo, Roberto
2018-01-01
This study assessed a technology-aided program (monitoring responding, and ensuring preferred stimulation and encouragements) for promoting physical activity with 11 participants with severe/profound intellectual and multiple disabilities. Each participant was provided with an exercise device (e.g. a static bicycle and a stepper) and exposed to…
Trautmann-Lengsfeld, Sina Alexa; Domínguez-Borràs, Judith; Escera, Carles; Herrmann, Manfred; Fehr, Thorsten
2013-01-01
A recent functional magnetic resonance imaging (fMRI) study by our group demonstrated that dynamic emotional faces are more accurately recognized and evoked more widespread patterns of hemodynamic brain responses than static emotional faces. Based on this experimental design, the present study aimed at investigating the spatio-temporal processing of static and dynamic emotional facial expressions in 19 healthy women by means of multi-channel electroencephalography (EEG), event-related potentials (ERP) and fMRI-constrained regional source analyses. ERP analysis showed an increased amplitude of the LPP (late posterior positivity) over centro-parietal regions for static facial expressions of disgust compared to neutral faces. In addition, the LPP was more widespread and temporally prolonged for dynamic compared to static faces of disgust and happiness. fMRI constrained source analysis on static emotional face stimuli indicated the spatio-temporal modulation of predominantly posterior regional brain activation related to the visual processing stream for both emotional valences when compared to the neutral condition in the fusiform gyrus. The spatio-temporal processing of dynamic stimuli yielded enhanced source activity for emotional compared to neutral conditions in temporal (e.g., fusiform gyrus), and frontal regions (e.g., ventromedial prefrontal cortex, medial and inferior frontal cortex) in early and again in later time windows. The present data support the view that dynamic facial displays trigger more information reflected in complex neural networks, in particular because of their changing features potentially triggering sustained activation related to a continuing evaluation of those faces. A combined fMRI and EEG approach thus provides an advanced insight to the spatio-temporal characteristics of emotional face processing, by also revealing additional neural generators, not identifiable by the only use of an fMRI approach. PMID:23818974
NASA Astrophysics Data System (ADS)
Wang, Rui; Tomikawa, Yoshihiro; Nakamura, Takuji; Huang, Kaiming; Zhang, Shaodong; Zhang, Yehui; Yang, Huigen; Hu, Hongqiao
2016-10-01
The mechanism to explain the variations of tropopause and tropopause inversion layer (TIL) in the Arctic region during a sudden stratospheric warming (SSW) in 2009 was studied with the Modern-Era Retrospective analysis for Research and Applications reanalysis data and GPS/Constellation Observing system for Meteorology, Ionosphere, and Climate (COSMIC) temperature data. During the prominent SSW in 2009, the cyclonic system changed to the anticyclonic system due to the planetary wave with wave number 2 (wave2). The GPS/COSMIC temperature data showed that during the SSW in 2009, the tropopause height in the Arctic decreased accompanied with the tropopause temperature increase and the TIL enhancement. The variations of the tropopause and TIL were larger in higher latitudes. A static stability analysis showed that the variations of the tropopause and TIL were associated with the variations of the residual circulation and the static stability due to the SSW. Larger static stability appeared in the upper stratosphere and moved downward to the narrow region just above the tropopause. The descent of strong downward flow was faster in higher latitudes. The static stability tendency analysis showed that the strong downward residual flow induced the static stability change in the stratosphere and around the tropopause. The strong downwelling in the stratosphere was mainly induced by wave2, which led to the tropopause height and temperature changes due to the adiabatic heating. Around the tropopause, a pair of downwelling above the tropopause and upwelling below the tropopause due to wave2 contributed to the enhancement of static stability in the TIL immediately after the SSW.
Deformation and failure mechanisms of graphite/epoxy composites under static loading
NASA Technical Reports Server (NTRS)
Clements, L. L.
1981-01-01
The mechanisms of deformation and failure of graphite epoxy composites under static loading were clarified. The influence of moisture and temperature upon these mechanisms were also investigated. Because the longitudinal tensile properties are the most critical to the performance of the composite, these properties were investigated in detail. Both ultimate and elastic mechanical properties were investigated, but the study of mechanisms emphasized those leading to failure of the composite. The graphite epoxy composite selected for study was the system being used in several NASA sponsored flight test programs.
Noise-Source Separation Using Internal and Far-Field Sensors for a Full-Scale Turbofan Engine
NASA Technical Reports Server (NTRS)
Hultgren, Lennart S.; Miles, Jeffrey H.
2009-01-01
Noise-source separation techniques for the extraction of the sub-dominant combustion noise from the total noise signatures obtained in static-engine tests are described. Three methods are applied to data from a static, full-scale engine test. Both 1/3-octave and narrow-band results are discussed. The results are used to assess the combustion-noise prediction capability of the Aircraft Noise Prediction Program (ANOPP). A new additional phase-angle-based discriminator for the three-signal method is also introduced.
View looking north west showing the boom, top of the ...
View looking north west showing the boom, top of the center mast and boom angle reeving of the 175-ton derrick. Note in the background of the view, just above the center mast is the F-1 Static-Test Stand used for test firing the Saturn V engines and subsequent program's engine testing. Also in the background center is the Redstone Static Test Stand (center right) and it's cold calibration tower (center left). - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL
Jeon, Mi Yang; Jeong, HyeonCheol; Petrofsky, Jerrold; Lee, Haneul; Yim, JongEun
2014-11-14
Falling can lead to severe health issues in the elderly and importantly contributes to morbidity, death, immobility, hospitalization, and early entry to long-term care facilities. The aim of this study was to devise a recurrent fall prevention program for elderly women in rural areas. This study adopted an assessor-blinded, randomized, controlled trial methodology. Subjects were enrolled in a 12-week recurrent fall prevention program, which comprised strength training, balance training, and patient education. Muscle strength and endurance of the ankles and the lower extremities, static balance, dynamic balance, depression, compliance with preventive behavior related to falls, fear of falling, and fall self-efficacy at baseline and immediately after the program were assessed. Sixty-two subjects (mean age 69.2±4.3 years old) completed the program--31 subjects in the experimental group and 31 subjects in the control group. When the results of the program in the 2 groups were compared, significant differences were found in ankle heel rise test, lower extremity heel rise test, dynamic balance, depression, compliance with fall preventative behavior, fear of falling, and fall self-efficacy (p<0.05), but no significant difference was found in static balance. This study shows that the fall prevention program described effectively improves muscle strength and endurance, balance, and psychological aspects in elderly women with a fall history.
Filament wound data base development, revision 1
NASA Technical Reports Server (NTRS)
Sharp, R. Scott; Braddock, William F.
1985-01-01
The objective was to update the present Space Shuttle Solid Rocket Booster (SRB) baseline reentry aerodynamic data base and to develop a new reentry data base for the filament wound case SRB along with individual protuberance increments. Lockheed's procedures for performing these tasks are discussed. Free fall of the SRBs after separation from the Space Shuttle Launch Vehicle is completely uncontrolled. However, the SRBs must decelerate to a velocity and attitude that is suitable for parachute deployment. To determine the SRB reentry trajectory parameters, including the rate of deceleration and attitude history during free-fall, engineers at Marshall Space Flight Center are using a six-degree-of-freedom computer program to predict dynamic behavior. Static stability aerodynamic coefficients are part of the information required for input into this computer program. Lockheed analyzed the existing reentry aerodynamic data tape (Data Tape 5) for the current steel case SRB. This analysis resulted in the development of Data Tape 7.
Statistical inference of static analysis rules
NASA Technical Reports Server (NTRS)
Engler, Dawson Richards (Inventor)
2009-01-01
Various apparatus and methods are disclosed for identifying errors in program code. Respective numbers of observances of at least one correctness rule by different code instances that relate to the at least one correctness rule are counted in the program code. Each code instance has an associated counted number of observances of the correctness rule by the code instance. Also counted are respective numbers of violations of the correctness rule by different code instances that relate to the correctness rule. Each code instance has an associated counted number of violations of the correctness rule by the code instance. A respective likelihood of the validity is determined for each code instance as a function of the counted number of observances and counted number of violations. The likelihood of validity indicates a relative likelihood that a related code instance is required to observe the correctness rule. The violations may be output in order of the likelihood of validity of a violated correctness rule.
Factors affecting measured aircraft sound levels in the vicinity of start-of-takeoff roll
NASA Astrophysics Data System (ADS)
Richard, Horonjeff; Fleming, Gregg G.; Rickley, Edward J.; Connor, Thomas L.
This paper presents the findings of a recently conducted measurement and analysis program of jet transport aircraft sound levels in the vicinity of the star-of-takeoff roll. The purpose of the program was two-fold: (1) to evaluate the computational accuracy of the Federal Aviation Administration's Integrated Noise Model (INM) in the vicinity of start-of-takeoff roll with a recently updated database (INM 3.10), and (2) to provide guidance for future model improvements. Focusing on the second of these two goals, this paper examines several factors affecting Sound Exposure Levels (SELs) in the hemicircular area behind the aircraft brake release point at the start-of-takeoff. In addition to the aircraft type itself, these factors included the geometric relationship of the measurement site to the runway, the wind velocity (speed and direction), aircraft grow weight, and start-of-roll mode (static or rolling start).
NASA Astrophysics Data System (ADS)
Wang, Guang; Liu, Yingli; Zhou, Zhenfeng; Wang, Jingsong; Xue, Qingguo
2018-01-01
The liquid-phase flow behavior of slag in the lower zone of a blast furnace affects the furnace permeability, performance, and productivity. The effects of pulverized coal injection (PCI) on the behavior of simulated primary slag flow were investigated by quantifying the effect of key variables including Al/Si ratio [Al2O3 (wt.%) to SiO2 (wt.%)] and the amount of unburnt pulverized coal (UPC) at 1500°C. Viscosity analysis demonstrated that the slag fluidity decreased as the Al/Si ratio was increased (from 0.35 to 0.50), resulting in gradual increase of the static holdup. Increasing the amount of UPC resulted in a significant increase of the static holdup. Flooding analysis was applied to determine the maximum static holdup, which was found to be 11.5%. It was inferred that the burnout rates of pulverized coal should exceed 78.6% and 83.9% in traditional and oxygen blast furnaces, respectively.
Teaching citizen science skills online: Implications for invasive species training programs
Newman, G.; Crall, A.; Laituri, M.; Graham, J.; Stohlgren, T.; Moore, J.C.; Kodrich, K.; Holfelder, K.A.
2010-01-01
Citizen science programs are emerging as an efficient way to increase data collection and help monitor invasive species. Effective invasive species monitoring requires rigid data quality assurances if expensive control efforts are to be guided by volunteer data. To achieve data quality, effective online training is needed to improve field skills and reach large numbers of remote sentinel volunteers critical to early detection and rapid response. The authors evaluated the effectiveness of online static and multimedia tutorials to teach citizen science volunteers (n = 54) how to identify invasive plants; establish monitoring plots; measure percent cover; and use Global Positioning System (GPS) units. Participants trained using static and multimedia tutorials provided less (p <.001) correct species identifications (63% and 67%) than did professionals (83%) across all species, but they did not differ (p =.125) between each other. However, their ability to identify conspicuous species was comparable to that of professionals. The variability in percent plant cover estimates between static (??10%) and multimedia (??13%) participants did not differ (p =.86 and.08, respectively) from those of professionals (??9%). Trained volunteers struggled with plot setup and GPS skills. Overall, the online approach used did not influence conferred field skills and abilities. Traditional or multimedia online training augmented with more rigorous, repeated, and hands-on, in-person training in specialized skills required for more difficult tasks will likely improve volunteer abilities, data quality, and overall program effectiveness. ?? Taylor & Francis Group, LLC.
Characterization of Triaxial Braided Composite Material Properties for Impact Simulation
NASA Technical Reports Server (NTRS)
Roberts, Gary D.; Goldberg, Robert K.; Biniendak, Wieslaw K.; Arnold, William A.; Littell, Justin D.; Kohlman, Lee W.
2009-01-01
The reliability of impact simulations for aircraft components made with triaxial braided carbon fiber composites is currently limited by inadequate material property data and lack of validated material models for analysis. Improvements to standard quasi-static test methods are needed to account for the large unit cell size and localized damage within the unit cell. The deformation and damage of a triaxial braided composite material was examined using standard quasi-static in-plane tension, compression, and shear tests. Some modifications to standard test specimen geometries are suggested, and methods for measuring the local strain at the onset of failure within the braid unit cell are presented. Deformation and damage at higher strain rates is examined using ballistic impact tests on 61- by 61- by 3.2-mm (24- by 24- by 0.125-in.) composite panels. Digital image correlation techniques were used to examine full-field deformation and damage during both quasi-static and impact tests. An impact analysis method is presented that utilizes both local and global deformation and failure information from the quasi-static tests as input for impact simulations. Improvements that are needed in test and analysis methods for better predictive capability are examined.
NASA Technical Reports Server (NTRS)
Webb, L. D.; Washington, H. P.
1972-01-01
Static pressure position error calibrations for a compensated and an uncompensated XB-70 nose boom pitot static probe were obtained in flight. The methods (Pacer, acceleration-deceleration, and total temperature) used to obtain the position errors over a Mach number range from 0.5 to 3.0 and an altitude range from 25,000 feet to 70,000 feet are discussed. The error calibrations are compared with the position error determined from wind tunnel tests, theoretical analysis, and a standard NACA pitot static probe. Factors which influence position errors, such as angle of attack, Reynolds number, probe tip geometry, static orifice location, and probe shape, are discussed. Also included are examples showing how the uncertainties caused by position errors can affect the inlet controls and vertical altitude separation of a supersonic transport.
Adaptation of MSC/NASTRAN to a supercomputer
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gloudeman, J.F.; Hodge, J.C.
1982-01-01
MSC/NASTRAN is a large-scale general purpose digital computer program which solves a wider variety of engineering analysis problems by the finite element method. The program capabilities include static and dynamic structural analysis (linear and nonlinear), heat transfer, acoustics, electromagnetism and other types of field problems. It is used worldwide by large and small companies in such diverse fields as automotive, aerospace, civil engineering, shipbuilding, offshore oil, industrial equipment, chemical engineering, biomedical research, optics and government research. The paper presents the significant aspects of the adaptation of MSC/NASTRAN to the Cray-1. First, the general architecture and predominant functional use of MSC/NASTRANmore » are discussed to help explain the imperatives and the challenges of this undertaking. The key characteristics of the Cray-1 which influenced the decision to undertake this effort are then reviewed to help identify performance targets. An overview of the MSC/NASTRAN adaptation effort is then given to help define the scope of the project. Finally, some measures of MSC/NASTRAN's operational performance on the Cray-1 are given, along with a few guidelines to help avoid improper interpretation. 17 references.« less
Design, Static Analysis And Fabrication Of Composite Joints
NASA Astrophysics Data System (ADS)
Mathiselvan, G.; Gobinath, R.; Yuvaraja, S.; Raja, T.
2017-05-01
The Bonded joints will be having one of the important issues in the composite technology is the repairing of aging in aircraft applications. In these applications and also for joining various composite material parts together, the composite materials fastened together either using adhesives or mechanical fasteners. In this paper, we have carried out design, static analysis of 3-D models and fabrication of the composite joints (bonded, riveted and hybrid). The 3-D model of the composite structure will be fabricated by using the materials such as epoxy resin, glass fibre material and aluminium rivet for preparing the joints. The static analysis was carried out with different joint by using ANSYS software. After fabrication, parametric study was also conducted to compare the performance of the hybrid joint with varying adherent width, adhesive thickness and overlap length. Different joint and its materials tensile test result have compared.
Static analysis of a sonar dome rubber window
NASA Technical Reports Server (NTRS)
Lai, J. L.
1978-01-01
The application of NASTRAN (level 16.0.1) to the static analysis of a sonar dome rubber window (SDRW) was demonstrated. The assessment of the conventional model (neglecting the enclosed fluid) for the stress analysis of the SDRW was made by comparing its results to those based on a sophisticated model (including the enclosed fluid). The fluid was modeled with isoparametric linear hexahedron elements with approximate material properties whose shear modulus was much smaller than its bulk modulus. The effect of the chosen material property for the fluid is discussed.
Transient analysis using conical shell elements
NASA Technical Reports Server (NTRS)
Yang, J. C. S.; Goeller, J. E.; Messick, W. T.
1973-01-01
The use of the NASTRAN conical shell element in static, eigenvalue, and direct transient analyses is demonstrated. The results of a NASTRAN static solution of an externally pressurized ring-stiffened cylinder agree well with a theoretical discontinuity analysis. Good agreement is also obtained between the NASTRAN direct transient response of a uniform cylinder to a dynamic end load and one-dimensional solutions obtained using a method of characteristics stress wave code and a standing wave solution. Finally, a NASTRAN eigenvalue analysis is performed on a hydroballistic model idealized with conical shell elements.
General Rotorcraft Aeromechanical Stability Program (GRASP): Theory manual
NASA Technical Reports Server (NTRS)
Hodges, Dewey H.; Hopkins, A. Stewart; Kunz, Donald L.; Hinnant, Howard E.
1990-01-01
The general rotorcraft aeromechanical stability program (GRASP) was developed to calculate aeroelastic stability for rotorcraft in hovering flight, vertical flight, and ground contact conditions. GRASP is described in terms of its capabilities and its philosophy of modeling. The equations of motion that govern the physical system are described, as well as the analytical approximations used to derive them. The equations include the kinematical equation, the element equations, and the constraint equations. In addition, the solution procedures used by GRASP are described. GRASP is capable of treating the nonlinear static and linearized dynamic behavior of structures represented by arbitrary collections of rigid-body and beam elements. These elements may be connected in an arbitrary fashion, and are permitted to have large relative motions. The main limitation of this analysis is that periodic coefficient effects are not treated, restricting rotorcraft flight conditions to hover, axial flight, and ground contact. Instead of following the methods employed in other rotorcraft programs. GRASP is designed to be a hybrid of the finite-element method and the multibody methods used in spacecraft analysis. GRASP differs from traditional finite-element programs by allowing multiple levels of substructure in which the substructures can move and/or rotate relative to others with no small-angle approximations. This capability facilitates the modeling of rotorcraft structures, including the rotating/nonrotating interface and the details of the blade/root kinematics for various types. GRASP differs from traditional multibody programs by considering aeroelastic effects, including inflow dynamics (simple unsteady aerodynamics) and nonlinear aerodynamic coefficients.
Dang, Fuquan; Maeda, Eiki; Osafune, Tomo; Nakajima, Kazuki; Kakehi, Kazuaki; Ishikawa, Mitsuru; Baba, Yoshinobu
2009-12-15
We developed a novel method for rapid screening of carbohydrate-protein interactions using poly(methyl methacrylate) (PMMA) channels statically coated with hydrophobically modified hydroxyethylcellulose (HM-HEC). We found that a self-assembled monolayer (SAM) of HM-HEC on a PMMA surface intact by water allows rapid and reproducible separations of glycan samples using a 20 mM phosphate without HM-HEC. The underlying mechanism for dynamic and static coatings on the PMMA surface is discussed. Simultaneous analysis of the molecular interaction between a complex mixture of carbohydrates from alpha1-acid glycoprotein and proteins has been successfully achieved in PMMA channels statically coated with a SAM of HM-HEC.
Simulations to study the static polarization limit for RHIC lattice
NASA Astrophysics Data System (ADS)
Duan, Zhe; Qin, Qing
2016-01-01
A study of spin dynamics based on simulations with the Polymorphic Tracking Code (PTC) is reported, exploring the dependence of the static polarization limit on various beam parameters and lattice settings for a practical RHIC lattice. It is shown that the behavior of the static polarization limit is dominantly affected by the vertical motion, while the effect of beam-beam interaction is small. In addition, the “nonresonant beam polarization” observed and studied in the lattice-independent model is also observed in this lattice-dependent model. Therefore, this simulation study gives insights of polarization evolution at fixed beam energies, that are not available in simple spin tracking. Supported by the U.S. Department of Energy (DE-AC02-98CH10886), Hundred-Talent Program (Chinese Academy of Sciences), and National Natural Science Foundation of China (11105164)
NASA Technical Reports Server (NTRS)
Silva, Walter A.; Bennett, Robert M.
1990-01-01
The CAP-TSD (Computational Aeroelasticity Program - Transonic Small Disturbance) code, developed at the NASA - Langley Research Center, is applied to the Active Flexible Wing (AFW) wind tunnel model for prediction of the model's transonic aeroelastic behavior. Static aeroelastic solutions using CAP-TSD are computed. Dynamic (flutter) analyses are then performed as perturbations about the static aeroelastic deformations of the AFW. The accuracy of the static aeroelastic procedure is investigated by comparing analytical results to those from previous AFW wind tunnel experiments. Dynamic results are presented in the form of root loci at different Mach numbers for a heavy gas and air. The resultant flutter boundaries for both gases are also presented. The effects of viscous damping and angle-of-attack, on the flutter boundary in air, are presented as well.
Response, analysis, and design of pile groups subjected to static & dynamic lateral loads.
DOT National Transportation Integrated Search
2003-06-01
Static and dynamic lateral load tests were performed on four full-scale pile groups driven at four different spacings. P-multipliers to account for group : interaction effects were back-calculated for each test. P-multipliers were found to be a funct...
Production against static electricity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shteiner, A.L.; Minaev, G.S.; Shatkov, O.P.
1978-01-01
Coke industry shops process electrifiable, highly inflammable and explosive substances (benzene, toluene, xylenes, sulfur, coal dust, and coke-oven gas). The electrification of those materials creates a danger of buildup of static electricity charges in them and on the surface of objects interacting with them, followed by an electrical discharge which may cause explosion, fire, or disruption of the technological process. Some of the regulations for protection against static electricity do not reflect modern methods of static electricity control. The regulations are not always observed by workers in the plant services. The main means of protection used to remove static electricitymore » charges in grounding. In many cases it completely drains the charge from the surface of the electrifiable bodies. However, in the processing of compounds with a high specific volumetric electrical resistence grounding is insufficient, since it does not drain the charge from the interior of the substance. Gigh adsorption capacity) are generally met by brown coal low-temperature ompared with predictions using the hourly computer program. The concept of a lumped thermal network for predicting heat losses from in-ground heat storage tanks, developed earlier in the project, has beethe cased-hole log data from various companies and additional comparison factors were calculated for the cased-hole log data. These comparison factors allow for some quantification of these uncalibrated log data.« less
Antonova, A A; Absatova, K A; Korneev, A A; Kurgansky, A V
2015-01-01
The production of drawing movements was studied in 29 right-handed children of 9-to-11 years old. The movements were the sequences of horizontal and vertical linear stokes conjoined at right angle (open polygonal chains) referred to throughout the paper as trajectories. The length of a trajectory varied from 4 to 6. The trajectories were presented visually to a subject in static (linedrawing) and dynamic (moving cursor that leaves no trace) modes. The subjects were asked to draw (copy) a trajectory in response to delayed go-signal (short click) as fast as possible without lifting the pen. The production latency time, the average movement duration along a trajectory segment, and overall number of errors committed by a subject during trajectory production were analyzed. A comparison of children's data with similar data in adults (16 subjects) shows the following. First, a substantial reduction in error rate is observed in the age range between 9 and 11 years old for both static and dynamic modes of trajectory presentation, with children of 11 still committing more error than adults. Second, the averaged movement duration shortens with age while the latency time tends to increase. Third, unlike the adults, the children of 9-11 do not show any difference in latency time between static and dynamic modes of visual presentation of trajectories. The difference in trajectory production between adult and children is attributed to the predominant involvement of on-line programming in children and pre-programming in adults.
1965-02-01
This photograph shows a fuel tank lower half for the Saturn V S-IC-T stage (the S-IC stage for static testing) on a C-frame transporter inside the vertical assembly building at the Marshall Space Flight Center.
NASA Technical Reports Server (NTRS)
Sutter, Thomas R.; Wu, K. Chauncey; Riutort, Kevin T.; Laufer, Joseph B.; Phelps, James E.
1992-01-01
A first-generation space crane articulated-truss joint was statically and dynamically characterized in a configuration that approximated an operational environment. The articulated-truss joint was integrated into a test-bed for structural characterization. Static characterization was performed by applying known loads and measuring the corresponding deflections to obtain load-deflection curves. Dynamic characterization was performed using modal testing to experimentally determine the first six mode shapes, frequencies, and modal damping values. Static and dynamic characteristics were also determined for a reference truss that served as a characterization baseline. Load-deflection curves and experimental frequency response functions are presented for the reference truss and the articulated-truss joint mounted in the test-bed. The static and dynamic experimental results are compared with analytical predictions obtained from finite element analyses. Load-deflection response is also presented for one of the linear actuators used in the articulated-truss joint. Finally, an assessment is presented for the predictability of the truss hardware used in the reference truss and articulated-truss joint based upon hardware stiffness properties that were previously obtained during the Precision Segmented Reflector (PSR) Technology Development Program.
Certified In-lined Reference Monitoring on .NET
2006-06-01
Introduction Language -based approaches to computer security have employed two major strategies for enforcing security policies over untrusted programs. • Low...automatically verify IRM’s using a static type-checker. Mobile (MOnitorable BIL with Effects) is an exten- sion of BIL (Baby Intermediate Language ) [15], a...AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES Proceedings of the 2006 Programming Languages and
NASA Technical Reports Server (NTRS)
1989-01-01
NBOD2, a program developed at Goddard Space Flight Center to solve equations of motion coupled N-body systems is used by E.I. DuPont de Nemours & Co. to model potential drugs as a series of elements. The program analyses the vibrational and static motions of independent components in drugs. Information generated from this process is used to design specific drugs to interact with enzymes in designated ways.
A Switching-Mode Power Supply Design Tool to Improve Learning in a Power Electronics Course
ERIC Educational Resources Information Center
Miaja, P. F.; Lamar, D. G.; de Azpeitia, M.; Rodriguez, A.; Rodriguez, M.; Hernando, M. M.
2011-01-01
The static design of ac/dc and dc/dc switching-mode power supplies (SMPS) relies on a simple but repetitive process. Although specific spreadsheets, available in various computer-aided design (CAD) programs, are widely used, they are difficult to use in educational applications. In this paper, a graphic tool programmed in MATLAB is presented,…
ERIC Educational Resources Information Center
Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Oliva, Doretta; Campodonico, Francesca; Lang, Russell
2012-01-01
The present three single-case studies assessed the effectiveness of technology-based programs to help three persons with multiple disabilities exercise adaptive response schemes independently. The response schemes included (a) left and right head movements for a man who kept his head increasingly static on his wheelchair's headrest (Study I), (b)…
NASA Astrophysics Data System (ADS)
Nasaruddin, N. H.; Yusoff, A. N.; Kaur, S.
2014-11-01
The objective of this multiple-subjects functional magnetic resonance imaging (fMRI) study was to identify the common brain areas that are activated when viewing black-and-white checkerboard pattern stimuli of various shapes, pattern and size and to investigate specific brain areas that are involved in processing static and moving visual stimuli. Sixteen participants viewed the moving (expanding ring, rotating wedge, flipping hour glass and bowtie and arc quadrant) and static (full checkerboard) stimuli during an fMRI scan. All stimuli have black-and-white checkerboard pattern. Statistical parametric mapping (SPM) was used in generating brain activation. Differential analyses were implemented to separately search for areas involved in processing static and moving stimuli. In general, the stimuli of various shapes, pattern and size activated multiple brain areas mostly in the left hemisphere. The activation in the right middle temporal gyrus (MTG) was found to be significantly higher in processing moving visual stimuli as compared to static stimulus. In contrast, the activation in the left calcarine sulcus and left lingual gyrus were significantly higher for static stimulus as compared to moving stimuli. Visual stimulation of various shapes, pattern and size used in this study indicated left lateralization of activation. The involvement of the right MTG in processing moving visual information was evident from differential analysis, while the left calcarine sulcus and left lingual gyrus are the areas that are involved in the processing of static visual stimulus.
Experiments with Test Case Generation and Runtime Analysis
NASA Technical Reports Server (NTRS)
Artho, Cyrille; Drusinsky, Doron; Goldberg, Allen; Havelund, Klaus; Lowry, Mike; Pasareanu, Corina; Rosu, Grigore; Visser, Willem; Koga, Dennis (Technical Monitor)
2003-01-01
Software testing is typically an ad hoc process where human testers manually write many test inputs and expected test results, perhaps automating their execution in a regression suite. This process is cumbersome and costly. This paper reports preliminary results on an approach to further automate this process. The approach consists of combining automated test case generation based on systematically exploring the program's input domain, with runtime analysis, where execution traces are monitored and verified against temporal logic specifications, or analyzed using advanced algorithms for detecting concurrency errors such as data races and deadlocks. The approach suggests to generate specifications dynamically per input instance rather than statically once-and-for-all. The paper describes experiments with variants of this approach in the context of two examples, a planetary rover controller and a space craft fault protection system.
Chronic effect of static stretching on strength performance and basal serum IGF-1 levels.
Borges Bastos, Carmen L; Miranda, Humberto; Vale, Rodrigo Gomes de Souza; Portal, Maria de Nazaré; Gomes, M Thiago; Novaes, Jefferson da Silva; Winchester, Jason B
2013-09-01
Improving the process of how physical performance is enhanced is one of the main topics evaluated by physiologists. This process often involves athletes and nonathletic populations. The purpose of this study was to assess the chronic response to 10 weeks of static stretching exercises carried out before and during a strength training program for 8 exercises on an 8 repetition maximum (8RM) test performance, and basal serum insulinlike growth factor (IGF-1) levels. Thirty recreationally trained volunteers were randomly assigned to 1 of 3 training groups: (a) SBST (performed a warm-up with a static stretching protocol before each strength training session); (b) SDST (before each training set, a static stretching exercise was performed); and (c) OST (entire session was performed without any type of stretching exercise). Strength and IGF-1 levels were collected at the beginning (pretest) and end (posttest) of the entire experimental procedure. All the exercises showed a significant increase in muscle strength for the OST group. However, the results revealed a significant increase in the muscle strength for only a few exercises in the SBST (LP, LE) and SDST (LP) experimental conditions. Significant statistical differences were found between SBST and SDST for all the exercises in the OST experimental condition. Furthermore, the IGF-1 expression showed no significant differences in the intragroup analysis. However, the OST group showed higher values (p < 0.05) in the posttest when compared with those of the other groups (increased significantly only in the OST experimental condition). It has been concluded that, although all the groups showed an increase in muscular strength, the strength training performed without any type of stretching exercise, regardless of whether the stretching is performed before or during the lifting session, can more effectively increase muscle strength and basal serum IGF-1 levels. It was concluded that strength training, with or without the use of stretching exercises, increased muscular strength in the studied groups, and can induce an increase in IGF-1 levels.
[Three-dimensional reconstruction of functional brain images].
Inoue, M; Shoji, K; Kojima, H; Hirano, S; Naito, Y; Honjo, I
1999-08-01
We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: 1) routine images by SPM, 2) three-dimensional static images, and 3) three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface model is the most common method of three-dimensional display. However, the volume rendering method may be more effective for imaging regions such as the brain.
Assessing the Utility of Temporally Dynamic Terrain Indices in Alaskan Moose Resource Selection
NASA Astrophysics Data System (ADS)
Jennewein, J. S.; Hebblewhite, M.; Meddens, A. J.; Gilbert, S.; Vierling, L. A.; Boelman, N.; Eitel, J.
2017-12-01
The accelerated warming in arctic and boreal regions impacts ecosystem structure and plant species distribution, which have secondary effects on wildlife. In summer months, moose (Alces alces) are especially vulnerable to changes in the availability and quality of forage and foliage cover due to their thermoregulatory needs and high energetic demands post calving. Resource selection functions (RSFs) have been used with great success to model such tradeoffs in habitat selection. Recently, RSFs have expanded to include more dynamic representations of habitat selection through the use of time-varying covariates such as dynamic habitat indices. However, to date few studies have investigated dynamic terrain indices, which incorporate long-term, highly-dynamic meteorological data (e.g., albedo, air temperature) and their utility in modeling habitat selection. The purpose of this study is to compare two dynamic terrain indices (i.e., solar insolation and topographic wetness) to their static counterparts in Alaskan moose resource selection over a ten-year period (2008-2017). Additionally, the utility of a dynamic wind-shelter index is assessed. Three moose datasets (n=130 total), spanning a north-to-south gradient in Alaska, are analyzed independently to assess location-specific resource selection. The newly-released, high-resolution Arctic Digital Elevation Model (5m2) is used as the terrain input into both dynamic and static indices. Dynamic indices are programmed with meteorological data from the North American Regional Analysis (NARR) and NASA's Goddard Earth Sciences Data and Information Services Center (GES-DISC) databases. Static wetness and solar insolation indices are estimated using only topographic parameters (e.g., slope, aspect). Preliminary results from pilot analyses suggest that dynamic terrain indices may provide novel insights into resource selection of moose that could not be gained when using static counterparts. Future applications of such dynamic terrain indices that incorporate time-varying meteorological data may be increasingly important in modelling habitat selection under continued climate change scenarios.
Nondestructive Measurement of Dynamic Modulus for Cellulose Nanofibril Films
Yan Qing; Robert J. Ross; Zhiyong Cai; Yiqiang Wu
2013-01-01
Nondestructive evaluation of cellulose nanofibril (CNF) films was performed using cantilever beam vibration (CBV) and acoustic methods to measure dynamic modulus. Static modulus was tested using tensile tension method. Correlation analysis shows the data measured by CBV has little linear relationship with static modulus, possessing a correlation coefficient (R
Analysis of the Static Strength and Relative Endurance of Women Athletes
ERIC Educational Resources Information Center
Heyward, Vivian; McCreary, Leslie
1977-01-01
Investigations of static strength and relative endurance of the grip muscles of women athletes revealed that mean endurance time was significantly greater than for men. Results were discussed in light of evidence suggesting possible sex differences in muscle hypertrophy, capillarization of muscle tissue, critical occluding tension level, and…
1960-06-15
The Saturn Project was approved on January 18, 1960 as a program of the highest national priority. The formal test program to prove out the clustered-booster concept was well underway. A series of static tests of the Saturn I booster (S-I stage) began June 3, 1960 at the Marshall Space Flight Center (MSFC). This photograph depicts the Saturn I S-I stage equipped with eight H-1 engines, being successfully test-fired for the duration of 121 seconds on June 15, 1960.
NASA Technical Reports Server (NTRS)
Barret, C.
1997-01-01
This publication presents the control requirements, the details of the designed Flight Control Augmentor's (FCA's), the static stability and dynamic stability wind tunnel test programs, the static stability and control analyses, the dynamic stability characteristics of the experimental Launch Vehicle (LV) with the designed FCA's, and a consideration of the elastic vehicle. Dramatic improvements in flight stability have been realized with all the FCA designs; these ranged from 41 percent to 72 percent achieved by the blunt TE design. The control analysis showed that control increased 110 percent with only 3 degrees of FCA deflection. The dynamic stability results showed improvements with all FCA designs tested at all Mach numbers tested. The blunt TE FCA's had the best overall dynamic stability results. Since the lowest elastic vehicle frequency must be well separated from that of the control system, the significant frequencies and modes of vibration have been identified, and the response spectra compared for the experimental LV in both the conventional and the aft cg configuration. Although the dynamic response was 150 percent greater in the aft cg configuration, the lowest bending mode frequency decreased by only 2.8 percent.
Advanced electromagnetic methods for aerospace vehicles
NASA Technical Reports Server (NTRS)
Balanis, Constantine A.; El-Sharawy, El-Budawy; Hashemi-Yeganeh, Shahrokh; Aberle, James T.; Birtcher, Craig R.
1991-01-01
The Advanced Helicopter Electromagnetics is centered on issues that advance technology related to helicopter electromagnetics. Progress was made on three major topics: composite materials; precipitation static corona discharge; and antenna technology. In composite materials, the research has focused on the measurements of their electrical properties, and the modeling of material discontinuities and their effect on the radiation pattern of antennas mounted on or near material surfaces. The electrical properties were used to model antenna performance when mounted on composite materials. Since helicopter platforms include several antenna systems at VHF and UHF bands, measuring techniques are being explored that can be used to measure the properties at these bands. The effort on corona discharge and precipitation static was directed toward the development of a new two dimensional Voltage Finite Difference Time Domain computer program. Results indicate the feasibility of using potentials for simulating electromagnetic problems in the cases where potentials become primary sources. In antenna technology the focus was on Polarization Diverse Conformal Microstrip Antennas, Cavity Backed Slot Antennas, and Varactor Tuned Circular Patch Antennas. Numerical codes were developed for the analysis of two probe fed rectangular and circular microstrip patch antennas fed by resistive and reactive power divider networks.
A Multi-Objective Optimization Technique to Model the Pareto Front of Organic Dielectric Polymers
NASA Astrophysics Data System (ADS)
Gubernatis, J. E.; Mannodi-Kanakkithodi, A.; Ramprasad, R.; Pilania, G.; Lookman, T.
Multi-objective optimization is an area of decision making that is concerned with mathematical optimization problems involving more than one objective simultaneously. Here we describe two new Monte Carlo methods for this type of optimization in the context of their application to the problem of designing polymers with more desirable dielectric and optical properties. We present results of applying these Monte Carlo methods to a two-objective problem (maximizing the total static band dielectric constant and energy gap) and a three objective problem (maximizing the ionic and electronic contributions to the static band dielectric constant and energy gap) of a 6-block organic polymer. Our objective functions were constructed from high throughput DFT calculations of 4-block polymers, following the method of Sharma et al., Nature Communications 5, 4845 (2014) and Mannodi-Kanakkithodi et al., Scientific Reports, submitted. Our high throughput and Monte Carlo methods of analysis extend to general N-block organic polymers. This work was supported in part by the LDRD DR program of the Los Alamos National Laboratory and in part by a Multidisciplinary University Research Initiative (MURI) Grant from the Office of Naval Research.
Lin, Ying-he; Man, Yi; Liang, Xing; Qu, Yi-li; Lu, Xuan
2004-11-01
To study the stress distribution and displacement of edentulous alveolar ridge of removable partial denture which is retained by using conical telescope. An ideal three dimensional finite element model was constructed by using SCT image reconstruction technique, self-programming and ANSYS software. The static load was applied. The stress and displacement characteristics of these different types of materials which form the metal part of the conical telescope were compared and analyzed. Generally, the four materials produced almost the same stress and displacement at the site of the edentulous alveolar ridge. From the viewpoint of dynamics, the application of different materials in making the metal part of conical telescope is feasible.
Application of triggered lightning numerical models to the F106B and extension to other aircraft
NASA Technical Reports Server (NTRS)
Ng, Poh H.; Dalke, Roger A.; Horembala, Jim; Rudolph, Terence; Perala, Rodney A.
1988-01-01
The goal of the F106B Thunderstorm Research Program is to characterize the lightning environment for aircraft in flight. This report describes the application of numerical electromagnetic models to this problem. Topics include: (1) Extensive application of linear triggered lightning to F106B data; (2) Electrostatic analysis of F106B field mill data; (3) Application of subgrid modeling to F106B nose region, including both static and nonlinear models; (4) Extension of F106B results to other aircraft of varying sizes and shapes; and (5) Application of nonlinear model to interaction of F106B with lightning leader-return stroke event.
Constrained posture in dentistry - a kinematic analysis of dentists.
Ohlendorf, Daniela; Erbe, Christina; Nowak, Jennifer; Hauck, Imke; Hermanns, Ingo; Ditchen, Dirk; Ellegast, Rolf; Groneberg, David A
2017-07-05
How a dentist works, such as the patterns of movements performed daily, is also largely affected by the workstation Dental tasks are often executed in awkward body positions, thereby causing a very high degree of strain on the corresponding muscles. The objective of this study is to detect those dental tasks, during which awkward postures occur most frequently. The isolated analysis of static postures will examine the duration for which these postures are maintained during the corresponding dental, respectively non-dental, activities. 21 (11f/10 m) dentists (age: 40.1 ± 10.4 years) participated in this study. An average dental workday was collected for every subject. To collect kinematic data of all activities, the CUELA system was used. Parallel to the kinematic examination, a detailed computer-based task analysis was conducted. Afterwards, both data sets were synchronized based on the chronological order of the postures assumed in the trunk and the head region. All tasks performed were assigned to the categories "treatment" (I), "office" (II) and "other activities" (III). The angle values of each body region (evaluation parameter) were examined and assessed corresponding to ergonomic standards. Moreover, this study placed a particular focus on static positions, which are held statically for 4 s and longer. For "treatment" (I), the entire head and trunk area is anteriorly tilted while the back is twisted to the right, in (II) and (III) the back is anteriorly tilted and twisted to the right (non-neutral position). Static positions in (I) last for 4-10s, static postures (approx. 60%) can be observed while in (II) and (III) in the back area static positions for more than 30 s are most common. Moreover, in (II) the back is twisted to the right for more than 60 s in 26.8%. Awkward positions are a major part of a dentists' work. This mainly pertains to static positions of the trunk and head in contrast to "office work." These insights facilitate the quantitative description of the dentist profession with regard to the related physical load along with the health hazards to the musculoskeletal system. Moreover, the results allow for a selective extraction of the most unfavorable static body positions that dentists assume for each of the activities performed.
Propfan test assessment testbed aircraft flutter model test report
NASA Technical Reports Server (NTRS)
Jenness, C. M. J.
1987-01-01
The PropFan Test Assessment (PTA) program includes flight tests of a propfan power plant mounted on the left wind of a modified Gulfstream II testbed aircraft. A static balance boom is mounted on the right wing tip for lateral balance. Flutter analyses indicate that these installations reduce the wing flutter stabilizing speed and that torsional stiffening and the installation of a flutter stabilizing tip boom are required on the left wing for adequate flutter safety margins. Wind tunnel tests of a 1/9th scale high speed flutter model of the testbed aircraft were conducted. The test program included the design, fabrication, and testing of the flutter model and the correlation of the flutter test data with analysis results. Excellent correlations with the test data were achieved in posttest flutter analysis using actual model properties. It was concluded that the flutter analysis method used was capable of accurate flutter predictions for both the (symmetric) twin propfan configuration and the (unsymmetric) single propfan configuration. The flutter analysis also revealed that the differences between the tested model configurations and the current aircraft design caused the (scaled) model flutter speed to be significantly higher than that of the aircraft, at least for the single propfan configuration without a flutter boom. Verification of the aircraft final design should, therefore, be based on flutter predictions made with the test validated analysis methods.
Towards a Certified Lightweight Array Bound Checker for Java Bytecode
NASA Technical Reports Server (NTRS)
Pichardie, David
2009-01-01
Dynamic array bound checks are crucial elements for the security of a Java Virtual Machines. These dynamic checks are however expensive and several static analysis techniques have been proposed to eliminate explicit bounds checks. Such analyses require advanced numerical and symbolic manipulations that 1) penalize bytecode loading or dynamic compilation, 2) complexify the trusted computing base. Following the Foundational Proof Carrying Code methodology, our goal is to provide a lightweight bytecode verifier for eliminating array bound checks that is both efficient and trustable. In this work, we define a generic relational program analysis for an imperative, stackoriented byte code language with procedures, arrays and global variables and instantiate it with a relational abstract domain as polyhedra. The analysis has automatic inference of loop invariants and method pre-/post-conditions, and efficient checking of analysis results by a simple checker. Invariants, which can be large, can be specialized for proving a safety policy using an automatic pruning technique which reduces their size. The result of the analysis can be checked efficiently by annotating the program with parts of the invariant together with certificates of polyhedral inclusions. The resulting checker is sufficiently simple to be entirely certified within the Coq proof assistant for a simple fragment of the Java bytecode language. During the talk, we will also report on our ongoing effort to scale this approach for the full sequential JVM.
Finite element modeling of ROPS in static testing and rear overturns.
Harris, J R; Mucino, V H; Etherton, J R; Snyder, K A; Means, K H
2000-08-01
Even with the technological advances of the last several decades, agricultural production remains one of the most hazardous occupations in the United States. Death due to tractor rollover is a prime contributor to this hazard. Standards for rollover protective structures (ROPS) performance and certification have been developed by groups such as the Society of Automotive Engineers (SAE) and the American Society of Agricultural Engineers (ASAE) to combat these problems. The current ROPS certification standard, SAE J2194, requires either a dynamic or static testing sequence or both. Although some ROPS manufacturers perform both the dynamic and static phases of SAE J2194 testing, it is possible for a ROPS to be certified for field operation using static testing alone. This research compared ROPS deformation response from a simulated SAE J2194 static loading sequence to ROPS deformation response as a result of a simulated rearward tractor rollover. Finite element analysis techniques for plastic deformation were used to simulate both the static and dynamic rear rollover scenarios. Stress results from the rear rollover model were compared to results from simulated static testing per SAE J2194. Maximum stress values from simulated rear rollovers exceeded maximum stress values recorded during simulated static testing for half of the elements comprising the uprights. In the worst case, the static model underpredicts dynamic model results by approximately 7%. In the best case, the static model overpredicts dynamic model results by approximately 32%. These results suggest the need for additional experimental work to characterize ROPS stress levels during staged overturns and during testing according to the SAE standard.
Static sign language recognition using 1D descriptors and neural networks
NASA Astrophysics Data System (ADS)
Solís, José F.; Toxqui, Carina; Padilla, Alfonso; Santiago, César
2012-10-01
A frame work for static sign language recognition using descriptors which represents 2D images in 1D data and artificial neural networks is presented in this work. The 1D descriptors were computed by two methods, first one consists in a correlation rotational operator.1 and second is based on contour analysis of hand shape. One of the main problems in sign language recognition is segmentation; most of papers report a special color in gloves or background for hand shape analysis. In order to avoid the use of gloves or special clothing, a thermal imaging camera was used to capture images. Static signs were picked up from 1 to 9 digits of American Sign Language, a multilayer perceptron reached 100% recognition with cross-validation.
Static magnetotherapy for the treatment of insomnia.
Shieh, Yao Y; Tsai, Fong Y
2008-01-01
Magnets have been used for centuries to treat a number of physical disorders. The vast majority of research, however, on static magnet therapy for insomnia has been confined to the auricular type of therapy, with publications limited to Chinese journals. Most of these studies have depended on the subjective self-assessment of participants rather than objective scientific measurements. In this study, the authors report the positive preliminary results of insomnia treatment using pillows with embedded magnets, magnetic insoles and TriPhase bracelets. The analysis is based on objective actigraphic and polysomnographic data. A theory of accelerated transition from wakefulness to sleep is proposed to explain the process of insomnia relief through low-strength static magnetic fields. Analysis by functional Magnetic Resonance Imaging (fMRI) is used to further investigate the theory.
Modeling of composite beams and plates for static and dynamic analysis
NASA Technical Reports Server (NTRS)
Hodges, Dewey H.; Atilgan, Ali R.; Lee, Bok Woo
1990-01-01
A rigorous theory and corresponding computational algorithms was developed for a variety of problems regarding the analysis of composite beams and plates. The modeling approach is intended to be applicable to both static and dynamic analysis of generally anisotropic, nonhomogeneous beams and plates. Development of a theory for analysis of the local deformation of plates was the major focus. Some work was performed on global deformation of beams. Because of the strong parallel between beams and plates, the two were treated together as thin bodies, especially in cases where it will clarify the meaning of certain terminology and the motivation behind certain mathematical operations.
Dynamic analysis of solid propellant grains subjected to ignition pressurization loading
NASA Astrophysics Data System (ADS)
Chyuan, Shiang-Woei
2003-11-01
Traditionally, the transient analysis of solid propellant grains subjected to ignition pressurization loading was not considered, and quasi-elastic-static analysis was widely adopted for structural integrity because the analytical task gets simplified. But it does not mean that the dynamic effect is not useful and could be neglected arbitrarily, and this effect usually plays a very important role for some critical design. In order to simulate the dynamic response for solid rocket motor, a transient finite element model, accompanied by concepts of time-temperature shift principle, reduced integration and thermorheologically simple material assumption, was used. For studying the dynamic response, diverse ignition pressurization loading cases were used and investigated in the present paper. Results show that the dynamic effect is important for structural integrity of solid propellant grains under ignition pressurization loading. Comparing the effective stress of transient analysis and of quasi-elastic-static analysis, one can see that there is an obvious difference between them because of the dynamic effect. From the work of quasi-elastic-static and transient analyses, the dynamic analysis highlighted several areas of interest and a more accurate and reasonable result could be obtained for the engineer.
Analysis of dynamics and fit of diving suits
NASA Astrophysics Data System (ADS)
Mahnic Naglic, M.; Petrak, S.; Gersak, J.; Rolich, T.
2017-10-01
Paper presents research on dynamical behaviour and fit analysis of customised diving suits. Diving suits models are developed using the 3D flattening method, which enables the construction of a garment model directly on the 3D computer body model and separation of discrete 3D surfaces as well as transformation into 2D cutting parts. 3D body scanning of male and female test subjects was performed with the purpose of body measurements analysis in static and dynamic postures and processed body models were used for construction and simulation of diving suits prototypes. All necessary parameters, for 3D simulation were applied on obtained cutting parts, as well as parameters values for mechanical properties of neoprene material. Developed computer diving suits prototypes were used for stretch analysis on areas relevant for body dimensional changes according to dynamic anthropometrics. Garment pressures against the body in static and dynamic conditions was also analysed. Garments patterns for which the computer prototype verification was conducted were used for real prototype production. Real prototypes were also used for stretch and pressure analysis in static and dynamic conditions. Based on the obtained results, correlation analysis between body changes in dynamic positions and dynamic stress, determined on computer and real prototypes, was performed.
Design and evaluation of a wireless sensor network based aircraft strength testing system.
Wu, Jian; Yuan, Shenfang; Zhou, Genyuan; Ji, Sai; Wang, Zilong; Wang, Yang
2009-01-01
The verification of aerospace structures, including full-scale fatigue and static test programs, is essential for structure strength design and evaluation. However, the current overall ground strength testing systems employ a large number of wires for communication among sensors and data acquisition facilities. The centralized data processing makes test programs lack efficiency and intelligence. Wireless sensor network (WSN) technology might be expected to address the limitations of cable-based aeronautical ground testing systems. This paper presents a wireless sensor network based aircraft strength testing (AST) system design and its evaluation on a real aircraft specimen. In this paper, a miniature, high-precision, and shock-proof wireless sensor node is designed for multi-channel strain gauge signal conditioning and monitoring. A cluster-star network topology protocol and application layer interface are designed in detail. To verify the functionality of the designed wireless sensor network for strength testing capability, a multi-point WSN based AST system is developed for static testing of a real aircraft undercarriage. Based on the designed wireless sensor nodes, the wireless sensor network is deployed to gather, process, and transmit strain gauge signals and monitor results under different static test loads. This paper shows the efficiency of the wireless sensor network based AST system, compared to a conventional AST system.
Design and Evaluation of a Wireless Sensor Network Based Aircraft Strength Testing System
Wu, Jian; Yuan, Shenfang; Zhou, Genyuan; Ji, Sai; Wang, Zilong; Wang, Yang
2009-01-01
The verification of aerospace structures, including full-scale fatigue and static test programs, is essential for structure strength design and evaluation. However, the current overall ground strength testing systems employ a large number of wires for communication among sensors and data acquisition facilities. The centralized data processing makes test programs lack efficiency and intelligence. Wireless sensor network (WSN) technology might be expected to address the limitations of cable-based aeronautical ground testing systems. This paper presents a wireless sensor network based aircraft strength testing (AST) system design and its evaluation on a real aircraft specimen. In this paper, a miniature, high-precision, and shock-proof wireless sensor node is designed for multi-channel strain gauge signal conditioning and monitoring. A cluster-star network topology protocol and application layer interface are designed in detail. To verify the functionality of the designed wireless sensor network for strength testing capability, a multi-point WSN based AST system is developed for static testing of a real aircraft undercarriage. Based on the designed wireless sensor nodes, the wireless sensor network is deployed to gather, process, and transmit strain gauge signals and monitor results under different static test loads. This paper shows the efficiency of the wireless sensor network based AST system, compared to a conventional AST system. PMID:22408521
NARC Rayon Replacement Program for the RSRM Nozzle, Phase IV Qualification and Implementation Status
NASA Technical Reports Server (NTRS)
Haddock, M. Reed; Wendel, Gary M.; Cook, Roger V.
2005-01-01
The Space Shuttle NARC Rayon Replacement Program has down-selected Enka rayon as a replacement for the obsolete NARC rayon in the nozzle carbon cloth phenolic (CCP) ablative insulators. Full qualification testing of the Enka rayon-based carbon cloth phenolic is underway, including processing, thmal/structural properties, and hot-fire subscale tests. Required thermal-structural capabilities, together with confidence in erosio/char performance in simulated and subscale hot fire tests such as Wright-Patterson Air Force Base Laser Hardened Materials Evaluation Laboratory testing, NASA-MSFC 24-inch motor tests, NASA-MSFC Solid Fuel Torch - Super Sonic Blast Tube, NASA-MSFC Plasma Torch Test Bed, ATK Thiokol Forty Pound Charge and NASA-MSFC MNASA justified the testing of the new Enka-rayon candidate on full-scale static test motors. The first RSRM full-scale static test motor nozzle, fabricated using the new Enka rayon-based CCP, was successfully demonstrated in June 2004. Two additional static test motors are planned with the new Enka rayon in the next two years along with additional A-basis property characterization. Process variation or "corner-of-the-box" testing together with cured and uncured aging studies are also planned as some of the pre-flight implementation activities with 5-year cured aging studies over-lapping flight hardware fabrication.
Track Geometry Measurement System
DOT National Transportation Integrated Search
1980-09-01
This report contains a summary of the results of the test program that was conducted to validate the TGMS under various static and dynamic conditions. The TGMS has the capability to measure or derive gage, crosslevel (superelevation), warp (twist), c...
Multibody dynamic simulation of knee contact mechanics
Bei, Yanhong; Fregly, Benjamin J.
2006-01-01
Multibody dynamic musculoskeletal models capable of predicting muscle forces and joint contact pressures simultaneously would be valuable for studying clinical issues related to knee joint degeneration and restoration. Current three-dimensional multi-body knee models are either quasi-static with deformable contact or dynamic with rigid contact. This study proposes a computationally efficient methodology for combining multibody dynamic simulation methods with a deformable contact knee model. The methodology requires preparation of the articular surface geometry, development of efficient methods to calculate distances between contact surfaces, implementation of an efficient contact solver that accounts for the unique characteristics of human joints, and specification of an application programming interface for integration with any multibody dynamic simulation environment. The current implementation accommodates natural or artificial tibiofemoral joint models, small or large strain contact models, and linear or nonlinear material models. Applications are presented for static analysis (via dynamic simulation) of a natural knee model created from MRI and CT data and dynamic simulation of an artificial knee model produced from manufacturer’s CAD data. Small and large strain natural knee static analyses required 1 min of CPU time and predicted similar contact conditions except for peak pressure, which was higher for the large strain model. Linear and nonlinear artificial knee dynamic simulations required 10 min of CPU time and predicted similar contact force and torque but different contact pressures, which were lower for the nonlinear model due to increased contact area. This methodology provides an important step toward the realization of dynamic musculoskeletal models that can predict in vivo knee joint motion and loading simultaneously. PMID:15564115
Static characteristics design of hydrostatic guide-ways based on fluid-structure interactions
NASA Astrophysics Data System (ADS)
Lin, Shuo; Yin, YueHong
2016-10-01
With the raising requirements in micro optical systems, the available machines become hard to achieve the process dynamic and accuracy in all aspects. This makes compact design based on fluid/structure interactions (FSI) important. However, there is a difficulty in studying FSI with oil film as fluid domain. This paper aims at static characteristic design of a hydrostatic guide-way with capillary restrictors based on FSI. The pressure distribution of the oil film land is calculated by solving the Reynolds-equation with Galerkin technique. The deformation of structure is calculated by commercial FEM software, MSC. Nastran. A matlab program is designed to realize the coupling progress by modifying the load boundary in the submitting file and reading the deformation result. It's obvious that the stiffness of the hydrostatic bearing decreases with the weakening of the bearing structure. This program is proposed to make more precise prediction of bearing stiffness.
Cold flow testing of the Space Shuttle Main Engine high pressure fuel turbine model
NASA Technical Reports Server (NTRS)
Hudson, Susan T.; Gaddis, Stephen W.; Johnson, P. D.; Boynton, James L.
1991-01-01
In order to experimentally determine the performance of the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) turbine, a 'cold' air flow turbine test program was established at NASA's Marshall Space Flight Center. As part of this test program, a baseline test of Rocketdyne's HPFTP turbine has been completed. The turbine performance and turbine diagnostics such as airfoil surface static pressure distributions, static pressure drops through the turbine, and exit swirl angles were investigated at the turbine design point, over its operating range, and at extreme off-design points. The data was compared to pretest predictions with good results. The test data has been used to improve meanline prediction codes and is now being used to validate various three-dimensional codes. The data will also be scaled to engine conditions and used to improve the SSME steady-state performance model.
1967-01-01
This photograph is a view of the Saturn V S-IC-5 (first) flight stage being hoisted into the S-IC-B1 test stand at the Mississippi Test Facility (MTF), Bay St. Louis, Mississippi. Begirning operations in 1966, the MTF has two test stands, a dual-position structure for running the S-IC stage at full throttle, and two separate stands for the S-II (Saturn V third) stage. It became the focus of the static test firing program. The completed S-IC stage was shipped from Michoud Assembly Facility (MAF) to the MTF. The stage was then installed into the 124-meter-high test stand for static firing tests before shipment to the Kennedy Space Center for final assembly of the Saturn V vehicle. The MTF was renamed to the National Space Technology Laboratory (NSTL) in 1974 and later to the Stennis Space Center (SSC) in May 1988.
1967-01-01
This photograph is a view of the Saturn V S-IC (first) test stage being hoisted into the S-IC-B1 test stand at the Mississippi Test Facility (MTF), Bay St. Louis, Mississippi. This stage was used to prove the operational readiness of the stand. Begirning operations in 1966, the MTF has two test stands; a dual-position structure for running the S-IC stage at full throttle, and two separate stands for the S-II (Saturn V third) stage. It became the focus of the static test firing program. The completed S-IC stage was shipped from the Michoud Assembly Facility (MAF) to the MTF. The stage was then installed into the 124-meter-high test stand for static firing tests before shipment to the Kennedy Space Center for final assembly of the Saturn V vehicle. The MTF was renamed to the National Space Technology Laboratory (NSTL) in 1974 and later to the Stennis Space Center (SSC) in May 1988.
1988-02-01
9 cyclic 8980 936 0.2071 0.2472 10 static 13470 --- 0.4606 11 cyclic 13470 337 0.4181 0.4299 12 static 22450 --- 1.2874 13 cyclic 19085 237 0.8992...8217%’. ’ ,i’nch z 10 feet W ’ ’,,....¢." 0-0 0 0 __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 0 04 N 0 0 I- 0 4 CA * 0 - u* -U.. LU C LUL...IDENTIFICATION NUMBER ORGANIZATION j(if applicable) Sc. ADDRESS (City, State, and ZIP Code) 10 . SOURCE OF FUNDING NUMBERS PROGRAM PROJECT TASK WORK UNIT
A nonlinear auxetic structural vibration damper with metal rubber particles
NASA Astrophysics Data System (ADS)
Ma, Yanhong; Scarpa, Fabrizio; Zhang, Dayi; Zhu, Bin; Chen, Lulu; Hong, Jie
2013-08-01
The work describes the mechanical performance of a metal rubber particles (MRP) damper design based on an auxetic (negative Poisson’s ratio) cellular configuration. The auxetic damper configuration is constituted by an anti-tetrachiral honeycomb, where the cylinders are filled with the MRP material. The MRP samples have been subjected to quasi-static loading to measure the stiffness and loss factor from the static hysteresis curve. A parametric experimental analysis has been carried out to investigate the effect of relative density and filling percentage on the static performance of the MRP, and to identify design guidelines for best use of MRP devices. An experimental assessment of the integrated auxetic-MRP damper concept has been provided through static and dynamic force response techniques.
Jeon, Mi Yang; Jeong, HyeonCheol; Petrofsky, Jerrold; Lee, Haneul; Yim, JongEun
2014-01-01
Background Falling can lead to severe health issues in the elderly and importantly contributes to morbidity, death, immobility, hospitalization, and early entry to long-term care facilities. The aim of this study was to devise a recurrent fall prevention program for elderly women in rural areas. Material/Methods This study adopted an assessor-blinded, randomized, controlled trial methodology. Subjects were enrolled in a 12-week recurrent fall prevention program, which comprised strength training, balance training, and patient education. Muscle strength and endurance of the ankles and the lower extremities, static balance, dynamic balance, depression, compliance with preventive behavior related to falls, fear of falling, and fall self-efficacy at baseline and immediately after the program were assessed. Sixty-two subjects (mean age 69.2±4.3 years old) completed the program – 31 subjects in the experimental group and 31 subjects in the control group. Results When the results of the program in the 2 groups were compared, significant differences were found in ankle heel rise test, lower extremity heel rise test, dynamic balance, depression, compliance with fall preventative behavior, fear of falling, and fall self-efficacy (p<0.05), but no significant difference was found in static balance. Conclusions This study shows that the fall prevention program described effectively improves muscle strength and endurance, balance, and psychological aspects in elderly women with a fall history. PMID:25394805
NASA Technical Reports Server (NTRS)
Krueger, Ronald
2012-01-01
The development of benchmark examples for quasi-static delamination propagation prediction is presented and demonstrated for a commercial code. The examples are based on finite element models of the Mixed-Mode Bending (MMB) specimen. The examples are independent of the analysis software used and allow the assessment of the automated delamination propagation prediction capability in commercial finite element codes based on the virtual crack closure technique (VCCT). First, quasi-static benchmark examples were created for the specimen. Second, starting from an initially straight front, the delamination was allowed to propagate under quasi-static loading. Third, the load-displacement relationship from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. Good agreement between the results obtained from the automated propagation analysis and the benchmark results could be achieved by selecting input parameters that had previously been determined during analyses of mode I Double Cantilever Beam and mode II End Notched Flexure specimens. The benchmarking procedure proved valuable by highlighting the issues associated with choosing the input parameters of the particular implementation. Overall the results are encouraging, but further assessment for mixed-mode delamination fatigue onset and growth is required.
NASA Astrophysics Data System (ADS)
Wing, Allison; Camargo, Suzana; Sobel, Adam; Kim, Daehyun; Murakami, Hiroyuki; Reed, Kevin; Vecchi, Gabriel; Wehner, Michael; Zarzycki, Colin; Zhao, Ming
2017-04-01
In recent years, climate models have improved such that high-resolution simulations are able to reproduce the climatology of tropical cyclone activity with some fidelity and show some skill in seasonal forecasting. However biases remain in many models, motivating a better understanding of what factors control the representation of tropical cyclone activity in climate models. We explore the tropical cyclogenesis processes in five high-resolution climate models, including both coupled and uncoupled configurations. Our analysis framework focuses on how convection, moisture, clouds and related processes are coupled and employs budgets of column moist static energy and the spatial variance of column moist static energy. The latter was originally developed to study the mechanisms of tropical convective organization in idealized cloud-resolving models, and allows us to quantify the different feedback processes responsible for the amplification of moist static energy anomalies associated with the organization of convection and cyclogenesis. We track the formation and evolution of tropical cyclones in the climate model simulations and apply our analysis both along the individual tracks and composited over many tropical cyclones. We then compare the genesis processes; in particular, the role of cloud-radiation interactions, to those of spontaneous tropical cyclogenesis in idealized cloud-resolving model simulations.
NASA Astrophysics Data System (ADS)
Jiang, Feng-Jian; Ye, Jian-Feng; Jiao, Zheng; Jiang, Jun; Ma, Kun; Yan, Xin-Hu; Lv, Hai-Jiang
2018-05-01
We perform a proof-of-principle experiment that uses a single negatively charged nitrogen–vacancy (NV) color center with a nearest neighbor 13C nuclear spin in diamond to detect the strength and direction (including both polar and azimuth angles) of a static vector magnetic field by optical detection magnetic resonance (ODMR) technique. With the known hyperfine coupling tensor between an NV center and a nearest neighbor 13C nuclear spin, we show that the information of static vector magnetic field could be extracted by observing the pulsed continuous wave (CW) spectrum. Project supported by the National Natural Science Foundation of China (Grant Nos. 11305074, 11135002, and 11275083), the Key Program of the Education Department Outstanding Youth Foundation of Anhui Province, China (Grant No. gxyqZD2017080), and the Education Department Natural Science Foundation of Anhui Province, China (Grant No. KJHS2015B09).
Quasi-Static Analysis of Round LaRC THUNDER Actuators
NASA Technical Reports Server (NTRS)
Campbell, Joel F.
2007-01-01
An analytic approach is developed to predict the shape and displacement with voltage in the quasi-static limit of round LaRC Thunder Actuators. The problem is treated with classical lamination theory and Von Karman non-linear analysis. In the case of classical lamination theory exact analytic solutions are found. It is shown that classical lamination theory is insufficient to describe the physical situation for large actuators but is sufficient for very small actuators. Numerical results are presented for the non-linear analysis and compared with experimental measurements. Snap-through behavior, bifurcation, and stability are presented and discussed.
Quasi-Static Analysis of LaRC THUNDER Actuators
NASA Technical Reports Server (NTRS)
Campbell, Joel F.
2007-01-01
An analytic approach is developed to predict the shape and displacement with voltage in the quasi-static limit of LaRC Thunder Actuators. The problem is treated with classical lamination theory and Von Karman non-linear analysis. In the case of classical lamination theory exact analytic solutions are found. It is shown that classical lamination theory is insufficient to describe the physical situation for large actuators but is sufficient for very small actuators. Numerical results are presented for the non-linear analysis and compared with experimental measurements. Snap-through behavior, bifurcation, and stability are presented and discussed.
NASA Astrophysics Data System (ADS)
Barton, E.; Middleton, C.; Koo, K.; Crocker, L.; Brownjohn, J.
2011-07-01
This paper presents the results from collaboration between the National Physical Laboratory (NPL) and the University of Sheffield on an ongoing research project at NPL. A 50 year old reinforced concrete footbridge has been converted to a full scale structural health monitoring (SHM) demonstrator. The structure is monitored using a variety of techniques; however, interrelating results and converting data to knowledge are not possible without a reliable numerical model. During the first stage of the project, the work concentrated on static loading and an FE model of the undamaged bridge was created, and updated, under specified static loading and temperature conditions. This model was found to accurately represent the response under static loading and it was used to identify locations for sensor installation. The next stage involves the evaluation of repair/strengthening patches under both static and dynamic loading. Therefore, before deliberately introducing significant damage, the first set of dynamic tests was conducted and modal properties were estimated. The measured modal properties did not match the modal analysis from the statically updated FE model; it was clear that the existing model required updating. This paper introduces the results of the dynamic testing and model updating. It is shown that the structure exhibits large non-linear, amplitude dependant characteristics. This creates a difficult updating process, but we attempt to produce the best linear representation of the structure. A sensitivity analysis is performed to determine the most sensitive locations for planned damage/repair scenarios and is used to decide whether additional sensors will be necessary.
Eisen, Lars; Lozano-Fuentes, Saul
2009-01-01
The aims of this review paper are to 1) provide an overview of how mapping and spatial and space-time modeling approaches have been used to date to visualize and analyze mosquito vector and epidemiologic data for dengue; and 2) discuss the potential for these approaches to be included as routine activities in operational vector and dengue control programs. Geographical information system (GIS) software are becoming more user-friendly and now are complemented by free mapping software that provide access to satellite imagery and basic feature-making tools and have the capacity to generate static maps as well as dynamic time-series maps. Our challenge is now to move beyond the research arena by transferring mapping and GIS technologies and spatial statistical analysis techniques in user-friendly packages to operational vector and dengue control programs. This will enable control programs to, for example, generate risk maps for exposure to dengue virus, develop Priority Area Classifications for vector control, and explore socioeconomic associations with dengue risk. PMID:19399163