SCAN_59-01

59-01 APPLIED MATHEMATICS
Feb 8, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
A Synthetic Quadrature Phase Detector/Demodulator for Fourier Transform Transform Spectrometers
Document ID:
20090004449
Report #:
LAR-17694-1
Sales Agency:
Other Sources No Copyright
Author(s):
Campbell, Joel (NASA Langley Research Center)
Published:
20080101
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
10
Contract #:
None
Abstract:
A method is developed to demodulate (velocity correct) Fourier transform spectrometer (FTS) data that is taken with an analog to digital converter that digitizes equally spaced in time. This method makes it possible to use simple low cost, high resolution audio digitizers to record high quality data without the need for an event timer or quadrature laser hardware, and makes it possible to use a metrology laser of any wavelength. The reduced parts count and simplicity implementation makes it an attractive alternative in space based applications when compared to previous methods such as the Brault algorithm.
Language:
English
Notes:
To be published in Journal of Applied Optics, volume 47, no. 36, pp. 6889-6894, December 2008

Title:
Automated Ontology Alignment with Fuselets for Community of Interest (COI) Integration
Document ID:
20090004470
Report #:
AD-A487022
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Starz, James Roberts, Joe
Published:
20080901
Source:
Lockheed Martin Advanced Technology Labs. (Cherry Hill, NJ United States)
Pages:
33
Contract #:
FA8750-07-C-0084
Abstract:
Discusses the ontology alignment problem by presenting a tool called Ontrapro-the Ontology Translation Protocol, which allows users to apply a myriad of ontology alignment algorithms in an iterative fashion. This particular work explores the specific cases where a human can augment the capabilities of the machine. The report also discusses situations where the current state of the art in semantic interoperability research can be applied to solve real world problems. Finally we describe operational scenarios that demonstrate the use of Ontrapro/Semantic interoperability using new, semi-automatic alignment techniques. These scenarios and lessons learned describe how future work will result in more reliable ontology alignments, further enabling the possibility of semantic interoperability and taking us one step closer towards the original vision of the Semantic Web.
Language:
English

Title:
A-law/Mu-law Dynamic Range Compression Deconvolution (Preprint)
Document ID:
20090004490
Report #:
AD-A486862, AFRL-RY-HS-TP-2008-0025
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Haji-saeed, Bahareh Khoury, Jed Goodhue, William D Woods, Charles L Kierstead, John
Published:
20080204
Source:
Air Force Research Lab. (Hanscom AFB, MA United States)
Pages:
39
Contract #:
None
Abstract:
In this paper the A-law/Mu-law Dynamic Range Compression algorithm used in telecommunication systems is proposed for the first time for nonlinear Dynamic Range Compression image restoration of blurred signals embedded in very high noise environment. Our simulation results demonstrate that the dynamic range compression image deconvolution via the A-law/Mu-law outperforms image restoration based on the well-established image restoration filters that have been used for the last fifty years such as Wiener filter and Inverse filter. The deconvolution orders have been analyzed using the nonlinear transform method.
Language:
English
Notes:
Submitted for publication in the journal Applied Optics. Prepared in collaboration with Solid State Scientific Corporation, Hollis, NH, and University of Massachusetts, Lowell, MA. The original document contains color images

Title:
General Nonparametric Test for Misspecification
Document ID:
20090004591
Report #:
PB2008-105380
Sales Agency:
CASI Hardcopy A03 No Copyright
Author(s):
Bradley, R. McClelland, R.
Published:
20080101
Source:
Bureau of Labor Statistics (Washington, DC, United States)
Pages:
34
Contract #:
None
Abstract:
We establish a new consistent, uniformly most powerful test for misspecification. Unlike most previous work, we use a constrained cross-validation scheme for smoothing parameter selection, so that the test does not require arbitrary parameter selections. We address the degeneracy issue through a bootstrap procedure that also allows us to establish the asymptotic distribution of our test statistic. By allowing the use of higher-order kernels without the calculation of higher order derivatives, our test should be simpler to calculate and more powerful than similar tests. Finally, we show that our test can be applied to discrete as well as continuous regressors.
Language:
English

59-02 DATA PROCESSING
Feb 8, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Feasibility Study of Encoding Operational Mission Metadata into IPv6 Packet Headers
Document ID:
20090004472
Report #:
AD-A487077, AFIT/GE/ENG/08-23
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Policarpio, Timothy R
Published:
20080301
Source:
Air Force Inst. of Tech. (Wright-Patterson AFB, OH United States)
Pages:
113
Contract #:
None
Abstract:
The purpose of this research is to determine the feasibility of using the header fields and header extensions of IPv6 packets to encode mission metadata into computer network streams. Specifically, this thesis seeks to answer several research questions addressing the performance of different packet header encoding methods, specifically which method provides the least end-to-end delay of a file transfer over a hypothetical network as well as which method produces the least amount of additional network overhead during its operation in the hypothetical network. The research questions are answered through a comprehensive literature review and with the use of several network performance calculations. Results are analyzed and a final recommendation is given for which method would best meet the stated need. Ultimately, this research highlights a new way of tracking and reporting to military leaders the status of operational missions and tasks should a network outage or degradation occur.
Language:
English

Title:
Supporting Safe Content-Inspection of Web Traffic
Document ID:
20090004476
Report #:
AD-A487087
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Pal, Partha Atighetchi, Michael
Published:
20080901
Source:
Bolt, Beranek, and Newman, Inc. (Cambridge, MA United States)
Pages:
6
Contract #:
NBCHCO50096
Abstract:
Interception of software interaction for the purpose of introducing additional functionality or alternative behavior is a well-known software engineering technique that has been used successfully for various reasons, including security. Software wrappers, firewalls, Web proxies, and a number of middleware constructs all depend on interception to achieve their respective security, fault tolerance, interoperability, or load balancing objectives. Web proxies, as used by organizations to monitor and secure Web traffic into and out of their internal networks, provide another important example.
Language:
English
Notes:
Published in CrossTalk: The Journal of Defense Software Engineering, v21 n9 p19-23, September 2008

60-01 DIGITAL AND ANALOG COMPUTERS
Feb 8, 2009 -- Additions to the NASA scientific and technical information knowledge base

61-01 COMPUTER SOFTWARE
Feb 8, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Source Code Vulnerability Assessment Methodology
Document ID:
20090004483
Report #:
AD-A486804, ARL-TR-4571
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Villa, Diana Landin, Daniel
Published:
20080901
Source:
Army Research Lab. (White Sands Missile Range, NM United States)
Pages:
34
Contract #:
None
Abstract:
Coding errors and security vulnerabilities are routinely introduced into application source code for both malicious and non-malicious purposes. The U.S. Army Research Laboratory (ARL) Survivability/Lethality Analysis Directorate (SLAD), Information and Electronic Protection Division (IEPD) has developed a security-focused source Code Analysis Methodology (CAM) to identify, exploit, and mitigate vulnerabilities found in software developed for use in U.S. Army systems. Because of the classified nature of the results obtained via the CAM on actual systems, it is not possible to present these results in an unclassified forum. Instead, the work presented here provides a proof-of-concept of the CAM and exploit development process by generating an exploit for a buffer overflow vulnerability found in a free software application. A buffer overflow vulnerability presents a serious threat to the security of a software system and provides one example of the coding errors and security issues that the CAM is designed to detect, exploit, and mitigate against. The work described here provides an example of the process that is followed to ultimately determine the appropriate mitigations and countermeasures that will protect and enhance Soldier and system survivability via the CAM.
Language:
English

Title:
Governance in Open Source Software Development Projects: Towards a Model for Network-Centric Edge Organizations
Document ID:
20090004487
Report #:
AD-A486838
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Scacchi, Walt Jensen, Chris
Published:
20080601
Source:
California Univ. (Irvine, CA United States)
Pages:
21
Contract #:
None
Abstract:
Open source software development (OSSD) is a community-oriented, network-centric approach to building complex software systems. OSSD projects are typically organized as edge organizations that lack an explicit management regime to control and coordinate decentralized project work. However, a growing number of OSSD projects are developing, delivering, and supporting large-scale software systems that are displacing proprietary software alternatives. The U.S. Department of Defense is now committed to the adoption and deployment of software-intensive systems with open architectures and OSS components for application areas including command and control systems. Recent empirical studies of OSSD projects reveal that OSS developers often self-organize into organizational forms we characterize as evolving socio-technical interaction networks (STINs). These STINs emerge in ways that effectively control semi-autonomous OSS developers and coordinate project activities to produce reliable and adaptive software systems. In this paper, we examine how practices and processes enable and govern edge organizations like OSSD projects when coalesced and configured as contingent, sociotechnical interaction networks. In so doing, we draw on results from two ongoing case studies of governance activities and elements in a small and a large OSSD project.
Language:
English
Notes:
Sponsored in part by National Science Foundation Grant no. 0534771.Presented at the International Command and Control Research and Technology Symposia (13th), ICCRTS 2008, Seattle, WA on 17-19 Jun 2008. The original document contains color images

Title:
Analyzing the Core Flight Software (CFS) with SAVE
Document ID:
20090004613
Report #:
None
Sales Agency:
CASI Hardcopy A03 Copyright
Author(s):
Ganesan, Dharmalingam (Fraunhofer USA, Inc.) Lindvall, Mikael (Fraunhofer USA, Inc.) McComas, David (NASA Goddard Space Flight Center)
Published:
20081113
Source:
NASA Goddard Space Flight Center (Greenbelt, MD, United States)
Pages:
22
Contract #:
None
Abstract:
This viewgraph presentation describes the SAVE tool and it's application to Core Flight Software (CFS). The contents include: 1) Fraunhofer-a short intro; 2) Context of this Collaboration; 3) CFS-Core Flight Software?; 4) The SAVE Tool; 5) Applying SAVE to CFS -A few example analyses; and 6) Goals.
Language:
English
Notes:
Flight Software Workshop 2008 (FSW-08) Laurel, MD 13-14 Nov. 2008

61-02 CAD/CAM
Feb 8, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

63-01 CYBERNETICS AND BIONICS
Feb 8, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Behavior-Based Power Management in Autonomous Mobile Robots
Document ID:
20090004473
Report #:
AD-A487084, AFIT/GCE/ENG/08-05
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Fetzek, Charles A
Published:
20080327
Source:
Air Force Inst. of Tech. (Wright-Patterson AFB, OH United States)
Pages:
99
Contract #:
None
Abstract:
Current attempts to prolong a robot's battery life focus on outdated techniques that have high overhead and are not built in to the underlying robotic architecture. In this thesis, battery life is extended through development of a behavior-based power management system, including a Markov decision process (MDP) power planner. This system examines sensors needed by the currently active behavior set and powers down those not required. Predictive power planning models the domain as an MDP problem in the Deliberator. The planner creates a power policy that accounts for current and future power requirements in stochastic domains. This provides a power plan that uses lower-power consuming devices at the start of a goal sequence in order to save power for the areas where higher-power consuming sensors are needed. Power savings are observed in two case studies: Low and high sensor intensity environments. Testing reveals that in a real life scenario involving multiple goals and multiple sensors, the robot's battery charge can be extended up to 96% longer when using this system over robots that rely on traditional power management.
Language:
English

Title:
Conceptual Study of Rotary-Wing Microrobotics
Document ID:
20090004475
Report #:
AD-A487086, AFIT/GE/ENG/08-03
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Chabak, Kelson D
Published:
20080327
Source:
Air Force Inst. of Tech. (Wright-Patterson AFB, OH United States)
Pages:
170
Contract #:
None
Abstract:
This thesis presents a novel rotary-wing micro-electro-mechanical systems (MEMS) robot design. Two MEMS wing designs were designed, fabricated and tested including one that possesses features conducive to insect level aerodynamics. Two methods for fabricating an angled wing were also attempted with photoresist and CrystalBond(Trademark) to create an angle of attack. One particular design consisted of the wing designs mounted on a gear which are driven by MEMS actuators. MEMS comb drive actuators were analyzed, simulated and tested as a feasible drive system. The comb drive resonators were also designed orthogonally which successfully rotated a gear without wings. With wings attached to the gear, orthogonal MEMS thermal actuators demonstrated wing rotation with limited success. Multi-disciplinary theoretical expressions were formulated to account for necessary mechanical force, allowable mass for lift, and electrical power requirements. The robot design did not achieve flight, but the small pieces presented in this research with minor modifications are promising for a potential complete robot design under 1 cm2 wingspan. The complete robot design would work best in a symmetrical quad-rotor configuration for simpler maneuverability and control. The military?s method to gather surveillance, reconnaissance and intelligence could be transformed given a MEMS rotary-wing robot?s diminutive size and multi-role capabilities.
Language:
English

Title:
The Distributed Cognitive Components of C2
Document ID:
20090004494
Report #:
AD-A486894
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Hansberger, Jeffrey T
Published:
20080601
Source:
Army Research Lab. (Suffolk, VA United States)
Pages:
23
Contract #:
None
Abstract:
Distributed cognition (Hutchins, 1995a) is a theoretical framework that explains cognitive activities embodied and situated within the work setting and the artifacts used in the environment. Distributed cognition emphasizes the distributed nature of cognitive phenomena across individuals, tools/technologies, and internal/external representations. The unit of analysis goes beyond the cognitions of a single individual and focuses on the functional system as a whole. Distributed cognition examines the relation between individuals, the task environment, and artifacts used for task completion. Among some of the distributed cognitive attributes are: 1) Coordination across agents; 2) situation assessment; 3) mental models; 4) memory demands; 5) adaptability; and 6) workload management. Command & Control (C2) systems can greatly benefit when examined and analyzed as a distributed cognitive system through its emphasis on these cognitive attributes of the system. The theoretical and analytical implications of applying this approach to C2 systems will be discussed based on recent application and analysis to a series of C2 experiments.
Language:
English

Title:
C2 Network Analysis: Insights into Coordination and Understanding
Document ID:
20090004495
Report #:
AD-A486895
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Hansberger, Jeffrey T Schreiber, Craig Spain, Randall D
Published:
20080601
Source:
Army Research Lab. (Suffolk, VA United States)
Pages:
34
Contract #:
None
Abstract:
The distributed cognitive framework (Hutchins, 1995) provides a structured and theoretical approach for analyzing cognitive characteristics beyond that of a single individual to that of a system comprising of multiple individuals, tools, and the task environment. Among some of the attributes of a distributed cognitive system are: 1) coordination across agents 2) mental models, 3) situation assessment, 4) memory demands, 5) adaptability, and 6) workload management. This paper will address recent efforts, tools, and approaches on measuring and analyzing two of these distributed cognitive attributes through network analysis, coordination across agents and mental models. Network analysis was applied with different methods and emphasis to both attribute areas. The analysis of the coordination across agents applied network analysis to analyze the patterns of interactions across human and technological agents over-time. Collecting data related to coordination over time required specific capabilities that was not readily found among observational data collection tools and therefore required a custom program that we designed. Description of the requirements and implementation of this new observational network analysis tool as well as methods to visualize longitudinal network change is addressed. The analysis of mental models also utilizes a basic network analysis approach, namely structural knowledge. The examination of structural knowledge to assess individual mental models will be discussed to provide insight into understanding. Specifically applied to C2, this analysis can provide insight into the commander and/or staff's understanding.
Language:
English

Title:
Distributed Planning in a Mixed-Initiative Environment
Document ID:
20090004496
Report #:
AD-A486896
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
DeStefano, Chad Lachevet, Kurt Carozzoni, Joseph
Published:
20080601
Source:
Air Force Research Lab. (Rome, NY United States)
Pages:
46
Contract #:
None
Abstract:
The USAF Command and Control (C2) is undergoing a transformation to enable a full-spectrum, joint warfighting capability. To be able to meet the future challenge of employing forces anywhere in the world in support of national security objectives, the USAF requires a highly synchronized, distributed planning and replanning capability that is flexible to adapt to any level of conflict. This paper describes an in-house program underway at the USAF Research Laboratory Information Directorate that is developing technologies to support the concepts of Network-Centric Operations (NCO). The research focus of this program is on the concepts and architecture needed to support the distributed, mixed-initiative planning required for NCO. Our system builds upon distributed blackboards and multi-agent systems to provide automated opportunistic planning capabilities for distributed C2 operations. An extensible UML model of plans has also been developed to support human-machine dialog for mix-initiative planning. The plan representation is object oriented, recursive, and supports plan fragment operations, a key concept for distributed planning. This paper will also discuss our future research directions, including the encoding of human-planner experience and expertise for rapid formation of distributed expert planning teams.
Language:
English

Title:
Polymer Materials for Ground Mobile Millimeter-Scale Robotics
Document ID:
20090004556
Report #:
AD-A490766, ARL-TR-4659
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Rudy, Ryan Polcawich, Ronald G Pulskamp, Jeff
Published:
20081201
Source:
Army Research Lab. (Adelphi, MD United States)
Pages:
22
Contract #:
None
Abstract:
This project is closely tied with the ongoing work of visiting Professor Kenn Oldham and the U.S. Army Research Laboratory's (ARL) joint effort on creating highly flexible, large payload capacity joints for a ground mobile millimeter-scale robot. The fabrication process to add parylene coatings to the piezo-microelectromechanical systems (piezoMEMS) actuator process has been characterized using test structures. Scanning electron and optical microscopy of the joint assemblies; analysis of the coating technology for trench fill; process robustness to exposure to solvents and photolithographic processing; and adhesion of parylene to both platinum and lead zirconate titanate (PZT) thin films have been completed on two separate fabrication sequences. Parylene coatings have been successfully applied to both platinum and PZT thin films and the challenges associated with parylene survival with multiple fabrication process steps have been evaluated. Future work will include full release of test structures on the existing wafers in fabrication as well as implementation of process improvements into a fully functional piezoMEMS plus parylene actuator joint.
Language:
English

Title:
Defense Advanced Research Projects Agency (DARPA) Improving Warfighter Information Intake under Stress: Augmented Cognition - Phases 2, 3, and 4
Document ID:
20090004655
Report #:
AD-A490871
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Dorneich, Michael C Ververs, Patricia M Mathan, Santosh Whitlow, Stephen D
Published:
20081101
Source:
Honeywell, Inc. (Minneapolis, MN United States)
Pages:
231
Contract #:
DAAD16-03-C-0054
Abstract:
This report is a comprehensive summary of a multi-year effort by the Honeywell team on the Improving Warfighter Information Intake Under Stress/AugCog program jointly sponsored by the Defense Advanced Research Project Agency (DARPA) and the U.S. Army. The team, which spanned industry, government, and academia, studied the measurable cognitive states of the dismounted Soldier. The first seven months of Honeywell's involvement consisted of studies that developed neurophysiological and physiological measures of cognitive states, particularly attention. The next two years of the program focused on the challenges of assessing the cognitive state of a mobile participant and the development of mitigation strategies to improve the overall throughput of the joint human-machine system. The final year?s effort proved the feasibility of the AugCog technology for the dismounted Soldier by testing the system in a military Mobile Operations in Urban Terrain (MOUT) environment with a platoon of Soldiers. The Honeywell team believes it was the first ever to demonstrate robust real-time cognitive state classification in the harsh operational MOUT environment. The classification accuracies obtained in the final study match those of the more pristine laboratory environment despite the motion, noise, and physical challenges posed by collecting physiological data in the field during real operations.
Language:
English

63-02 ARTIFICIAL INTELLIGENCE
Feb 8, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

64-01 NUMERICAL ANALYSIS
Feb 8, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Towards Verification of Unstructured-Grid Solvers
Document ID:
20090004444
Report #:
None
Sales Agency:
CASI Hardcopy A03 Copyright
Author(s):
Thomas, James L. (NASA Langley Research Center) Diskin, Boris (National Inst. of Aerospace) Rumsey, Christopher L. (NASA Langley Research Center)
Published:
20081201
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
20
Contract #:
None
Abstract:
New methodology for verification of finite-volume computational methods using unstructured grids is presented. The discretization order properties are studied in computational windows, easily constructed within a collection of grids or a single grid. Tests are performed within each window and address a combination of problem-, solution-, and discretization/grid-related features affecting discretization error convergence. The windows can be adjusted to isolate particular elements of the computational scheme, such as the interior discretization, the boundary discretization, or singularities. Studies can use traditional grid-refinement computations within a fixed window or downscaling, a recently-introduced technique in which computations are made within windows contracting toward a focal point of interest. Grids within the windows are constrained to be consistently refined, allowing a meaningful assessment of asymptotic error convergence on unstructured grids. Demonstrations of the method are shown, including a comparative accuracy assessment of commonly-used schemes on general mixed grids and the identification of local accuracy deterioration at boundary intersections. Recommendations to enable attainment of design-order discretization errors for large-scale computational simulations are given.
Language:
English
Notes:
To be published in AIAA Journal, volume 46, no. 12, pp. 3070-3079, Dec. 2008, published by AIAA

Title:
Analytic Formulation and Numerical Implementation of an Acoustic Pressure Gradient Prediction
Document ID:
20090004704
Report #:
None
Sales Agency:
CASI Hardcopy A03 Copyright
Author(s):
Lee, Seongkyu (Pennsylvania State Univ.) Brentner, Kenneth S. (Pennsylvania State Univ.) Farassat, F. (NASA Langley Research Center) Morris, Philip J. (Pennsylvania State Univ.)
Published:
20080424
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
48
Contract #:
NNL05AD50P
Abstract:
Two new analytical formulations of the acoustic pressure gradient have been developed and implemented in the PSU-WOPWOP rotor noise prediction code. The pressure gradient can be used to solve the boundary condition for scattering problems and it is a key aspect to solve acoustic scattering problems. The first formulation is derived from the gradient of the Ffowcs Williams-Hawkings (FW-H) equation. This formulation has a form involving the observer time differentiation outside the integrals. In the second formulation, the time differentiation is taken inside the integrals analytically. This formulation avoids the numerical time differentiation with respect to the observer time, which is computationally more efficient. The acoustic pressure gradient predicted by these new formulations is validated through comparison with available exact solutions for a stationary and moving monopole sources. The agreement between the predictions and exact solutions is excellent. The formulations are applied to the rotor noise problems for two model rotors. A purely numerical approach is compared with the analytical formulations. The agreement between the analytical formulations and the numerical method is excellent for both stationary and moving observer cases.
Language:
English
Notes:
To be published in Journal of Sound and Vibration, volume 219, nos. 3-5, pp. 1200-1221, Jan. 2009

Title:
Benchmark Analysis of Pion Contribution from Galactic Cosmic Rays
Document ID:
20090004883
Report #:
NASA/TP-2008-215556, L-19400
Sales Agency:
CASI Hardcopy A03 Copyright
Author(s):
Aghara, Sukesh K. (Prairie View Agricultural and Mechanical Coll.) Blattnig, Steve R. (NASA Langley Research Center) Norbury, John W. (NASA Langley Research Center) Singleterry, Robert C., Jr. (NASA Langley Research Center)
Published:
20081201
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
40
Contract #:
None
Abstract:
Shielding strategies for extended stays in space must include a comprehensive resolution of the secondary radiation environment inside the spacecraft induced by the primary, external radiation. The distribution of absorbed dose and dose equivalent is a function of the type, energy and population of these secondary products. A systematic verification and validation effort is underway for HZETRN, which is a space radiation transport code currently used by NASA. It performs neutron, proton and heavy ion transport explicitly, but it does not take into account the production and transport of mesons, photons and leptons. The question naturally arises as to what is the contribution of these particles to space radiation. The pion has a production kinetic energy threshold of about 280 MeV. The Galactic cosmic ray (GCR) spectra, coincidentally, reaches flux maxima in the hundreds of MeV range, corresponding to the pion production threshold. We present results from the Monte Carlo code MCNPX, showing the effect of lepton and meson physics when produced and transported explicitly in a GCR environment.
Language:
English

65-01 PROBABILITY AND STATISTICS
Feb 8, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Assuring Life in Composite Systems
Document ID:
20090004421
Report #:
NASA/TM-2008-215452, E-16526-1
Available Online:
http://hdl.handle.net/2060/20090004421
Sales Agency:
CASI Hardcopy A03 No Copyright
Author(s):
Chamis, Christos c. (NASA Glenn Research Center)
Published:
20081101
Source:
NASA Glenn Research Center (Cleveland, OH, United States)
Pages:
21
Contract #:
None
Abstract:
A computational simulation method is presented to assure life in composite systems by using dynamic buckling of smart composite shells as an example. The combined use of composite mechanics, finite element computer codes, and probabilistic analysis enable the effective assessment of the dynamic buckling load of smart composite shells. A universal plot is generated to estimate the dynamic buckling load of composite shells at various load rates and probabilities. The shell structure is also evaluated with smart fibers embedded in the plies right below the outer plies. The results show that, on the average, the use of smart fibers improved the shell buckling resistance by about 9% at different probabilities and delayed the buckling occurrence time. The probabilistic sensitivities results indicate that uncertainties in the fiber volume ratio and ply thickness have major effects on the buckling load. The uncertainties in the electric field strength and smart material volume fraction have moderate effects and thereby in the assured life of the shell.
Language:
English

Title:
Completion of the Edward Air Force Base Statistical Guidance Wind Tool
Document ID:
20090004912
Report #:
NASA/CR-2008-214751
Sales Agency:
CASI Hardcopy A03 Copyright
Author(s):
Dreher, Joseph G. (ENSCO, Inc.)
Published:
20081001
Source:
ENSCO, Inc. (Cocoa Beach, FL, United States)
Pages:
21
Contract #:
NNK06MA70C
Abstract:
The goal of this task was to develop a GUI using EAFB wind tower data similar to the KSC SLF peak wind tool that is already in operations at SMG. In 2004, MSFC personnel began work to replicate the KSC SLF tool using several wind towers at EAFB. They completed the analysis and QC of the data, but due to higher priority work did not start development of the GUI. MSFC personnel calculated wind climatologies and probabilities of 10-minute peak wind occurrence based on the 2-minute average wind speed for several EAFB wind towers. Once the data were QC'ed and analyzed the climatologies were calculated following the methodology outlined in Lambert (2003). The climatologies were calculated for each tower and month, and then were stratified by hour, direction (10" sectors), and direction (45" sectors)/hour. For all climatologies, MSFC calculated the mean, standard deviation and observation counts of the Zminute average and 10-minute peak wind speeds. MSFC personnel also calculated empirical and modeled probabilities of meeting or exceeding specific 10- minute peak wind speeds using PDFs. The empirical PDFs were asymmetrical and bounded on the left by the 2- minute average wind speed. They calculated the parametric PDFs by fitting the GEV distribution to the empirical distributions. Parametric PDFs were calculated in order to smooth and interpolate over variations in the observed values due to possible under-sampling of certain peak winds and to estimate probabilities associated with average winds outside the observed range. MSFC calculated the individual probabilities of meeting or exceeding specific 10- minute peak wind speeds by integrating the area under each curve. The probabilities assist SMG forecasters in assessing the shuttle FR for various Zminute average wind speeds. The A M ' obtained the processed EAFB data from Dr. Lee Bums of MSFC and reformatted them for input to Excel PivotTables, which allow users to display different values with point-click-drag techniques. The GUI was created from the PivotTables using VBA code. It is run through a macro within Excel and allows forecasters to quickly display and interpret peak wind climatology and probabilities in a fast-paced operational environment. The GUI was designed to look and operate exactly the same as the KSC SLF tool since SMG forecasters were already familiar with that product. SMG feedback was continually incorporated into the GUI ensuring the end product met their needs. The final version of the GUI along with all climatologies, PDFs, and probabilities has been delivered to SMG and will be put into operational use.
Language:
English