Sample records for ansoft hfss software

  1. Design of 2.5 GHz broad bandwidth microwave bandpass filter at operating frequency of 10 GHz using HFSS

    NASA Astrophysics Data System (ADS)

    Jasim, S. E.; Jusoh, M. A.; Mahmud, S. N. S.; Zamani, A. H.

    2018-04-01

    Development of low losses, small size and broad bandwidth microwave bandpass filter operating at higher frequencies is an active area of research. This paper presents a new route used to design and simulate microwave bandpass filter using finite element modelling and realized broad bandwidth, low losses, small dimension microwave bandpass filter operating at 10 GHz frequency using return loss method. The filter circuit has been carried out using Computer Aid Design (CAD), Ansoft HFSS software and designed with four parallel couple line model and small dimension (10 × 10 mm2) using LaAlO3 substrate. The response of the microwave filter circuit showed high return loss -50 dB at operating frequency at 10.4 GHz and broad bandwidth of 2.5 GHz from 9.5 to 12 GHz. The results indicate the filter design and simulation using HFSS is reliable and have the opportunity to transfer from lab potential experiments to the industry.

  2. Proceedings of the 2009 Antenna Applications Symposium held in Monticello, Illinois on 22-24 September 2009. Volume 1

    DTIC Science & Technology

    2009-12-12

    Circuit Design, Theory and Applications. Prentice-Hall, 1 ed., 2000. 39 MEASUREMENT OF ELECTRICALLY SMALL ANTENNAS Suhail Barot, Paul E. Mayes, Paul ...2] “Ansoft HFSS, Version 9.2.1,” Ansoft Corporation, Pittsburgh, PA. 50 REDUCED-SIZE LINEAR ANTENNA ELEMENTS Paul E. Mayes, Paul W. Klock and...structures," IRE Internation convention, vol. 5, pp. 119-129, Mar 1957. [2] K. M. P. Aghdam, R. Faraji- Dana , and J. Rashed-Mohassel, "Compact dual

  3. Multilayered tissues model for wave propagation loss assessment in cochlear implants

    NASA Astrophysics Data System (ADS)

    Paun, Maria-Alexandra; Dehollain, Catherine

    2017-05-01

    In this paper, a study of the power loss attenuation of the plane wave travelling through the tissue layers, from the outside to the inside of the skull within a cochlear implant, is performed. Different implantation depths of the internal antenna from 10 to 30 mm are considered. To this purpose, the gain and attenuation in dB are studied. A multilayer tissue model is developed, consisting of mainly skin, mastoid bone and brain. An s-parameter analysis is also carried out, using loop antennas and simulated head tissue. Ansoft Ansys® HFSS software is used for electro-magnetic simulations of the antennas, placed in different types of human tissues. Smith charts for antenna placed in both skin and multi-tissue model are included.

  4. Modeling and characteristic of the SMT Board Plug connector in high speed optical communication system

    NASA Astrophysics Data System (ADS)

    Wu, Haoran; Dong, Zhenzhen; Wang, Tanglin; Zhao, Heng; Feng, Junbo; Cui, Naidi; Teng, Jie; Guo, Jin

    2015-04-01

    Modeling and characteristic of the SMT Board Plug connector, which is used to connect micro optical transceiver to the main board, are proposed and analyzed in this paper. When the high speed signal transfers from the PCB of transceiver to main board through SMT Board Plug connector, the structure and material discontinuity of the connector causes insertion losses and impedance mismatches. This makes the performance of high speed digital system exacerbated. So it is essential to analyze the signal transfer characteristics of the connector and find out what factors affected the signal quality at the design stage of the digital system. To solve this problem, Ansoft's High Frequency Structure Simulator (HFSS), based on the finite element method, was employed to build accurate 3D models, analyze the effects of various structure parameters, and obtain the full-wave characteristics of the SMT Board Plug connectors in this paper. Then an equivalent circuit model was developed. The circuit parameters were extracted precisely in the frequency range of interests by using the curve fitting method in ADS software, and the result was in good agreement with HFSS simulations up to 8GHz with different structure parameters. At last, the measurement results of S-parameter and eye diagram were given and the S-parameters showed good coincidence between the measurement and HFSS simulation up to 4GHz.

  5. The difference of detecting water mist and smoke by electromagnetic wave in simulation experiments

    NASA Astrophysics Data System (ADS)

    Zhang, Jingdi; Cui, Bing; Xiao, Si

    2015-10-01

    Although mist is similar to smoke in morphology, their compositions are very different. Therefore there is a significant difference between mist and smoke when detected by electromagnetic wave. This paper puts forward a kind of feasible solution based on Ansoft HFSS software about how to determine the forest fire by distinguishing mist and smoke above the forest. The experiments simulate the difference between mist and smoke model when detected by electromagnetic wave in different wavelengths. We find the mist and smoke model cannot absorb or reflect electromagnetic wave efficiently in Megahertz band. While in Gigahertz band mist model began to absorb and reflect electromagnetic wave above 650 Gigahertz band, but no change in smoke model. And the biggest difference appears in Terahertz band.

  6. High Current Density Scandate Cathodes for Future Vacuum Electronics Applications

    DTIC Science & Technology

    2008-05-30

    of Technology HFSS Ansoft Corporation’s High Frequency Structure Simulator TWT Traveling Wave Tube - device for generating high levels of RF power ...cathodes are practical for high power RF sources. Typical thermi- onic cathodes consists of a tungsten matrix impregnated with a mixture of barium oxide...electron beam with the largest possible diameter, consistent with high gain, bandwidth, and efficiency at W- Band . The research concentrated on photonic

  7. Study on W-band sheet-beam traveling-wave tube based on flat-roofed sine waveguide

    NASA Astrophysics Data System (ADS)

    Fang, Shuanzhu; Xu, Jin; Jiang, Xuebing; Lei, Xia; Wu, Gangxiong; Li, Qian; Ding, Chong; Yu, Xiang; Wang, Wenxiang; Gong, Yubin; Wei, Yanyu

    2018-05-01

    A W-band sheet electron beam (SEB) traveling-wave tube (TWT) based on flat-roofed sine waveguide slow-wave structure (FRSWG-SWS) is proposed. The sine wave of the metal grating is replaced by a flat-roofed sine wave around the electron beam tunnel. The slow-wave characteristics including the dispersion properties and interaction impedance have been investigated by using the eigenmode solver in the 3-D electromagnetic simulation software Ansoft HFSS. Through calculations, the FRSWG SWS possesses the larger average interaction impedance than the conventional sine waveguide (SWG) SWS in the frequency range of 86-110 GHz. The beam-wave interaction was studied and particle-in-cell simulation results show that the SEB TWT can produce output power over 120 W within the bandwidth ranging from 90 to 100 GHz, and the maximum output power is 226 W at typical frequency 94 GHz, corresponding electron efficiency of 5.89%.

  8. Absorption and emission properties of photonic crystals and metamaterials

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Peng, Lili

    We study the emission and absorption properties of photonic crystals and metamaterials using Comsol Multiphysics and Ansoft HFSS as simulation tools. We calculate the emission properties of metallic designs using drude model and the results illustrate that an appropriate termination of the surface of the metallic structure can significantly increase the absorption and therefore the thermal emissivity. We investigate the spontaneous emission rate modifications that occur for emitters inside two-dimensional photonic crystals and find the isotropic and directional emissions with respect to different frequencies as we have expected.

  9. A comparative study between different approaches to improve the RCS of a compact double-layer absorber

    NASA Astrophysics Data System (ADS)

    El-Hakim, H. A.; Mahmoud, K. R.

    2017-10-01

    In this paper, straightforward and efficient techniques have been addressed into double-layer structure to enlarge the operating bandwidth to include the X, Ku and K bands, in addition to increase the electromagnetic wave absorption for wide varieties of incident angles and both polarization types. To increase the band-stop resonating frequency up to 26 GHz, an additional layer of meta-surface, circuit analog radar absorber material (CAR), or a thin radar absorber material (RAM) layer is engineered. The synthesized layers are designed based on optimization process with genetic algorithm (GA) through numerical technique (Ansoft design software HFSS) for both transmission line (T.L) and the free space method to get optimal material properties suitable for the design. For different approaches, the designed structures achieved a reflectivity value less than -16 dB on average in the desired bandwidth from 8 to 26 GHz for TE/TM modes with incidence angle up to 50o.

  10. Design and Fabrication of Graphene Reinforced Polymer Conductive Patch-Based Inset Fed Microstrip Antenna

    NASA Astrophysics Data System (ADS)

    Deepak, A.; Kannan, P. Muthu; Shankar, P.

    This work explores the design and fabrication of graphene reinforced polyvinylidene fluoride (PVDF) patch-based microstrip antenna. Primarily, antenna was designed at 6GHz frequency and simulation results were obtained using Ansoft HFSS tool. Later fabrication of antenna was carried out with graphene-PVDF films as conducting patch deposited on bakelite substrate and copper as ground plane. Graphene-PVDF films were prepared using solvent casting process. The radiation efficiency of fabricated microstrip patch antenna was 48% entailing it to be adapted as a practically functional antenna. Both simulated and the practical results were compared and analyzed.

  11. An improved ultra-wideband bandpass filter design using split ring resonator with coupled microstrip line

    NASA Astrophysics Data System (ADS)

    Umeshkumar, Dubey Suhmita; Kumar, Manish

    2018-04-01

    This paper incorporates an improved design of Ultra Wideband Bandpass filter by using split ring resonators (SRR) along with the coupled microstrip lines. The use of split ring resonators and shunt step impedance open circuit stub enhances the stability due to transmission zeroes at the ends. The designing of filter and simulation of parameters is carried out using Ansoft's HFSS 13.0 software on RT/Duroid 6002 as a substrate with dielectric constant of 2.94. The design utilizes a frequency band from 22GHz to 29GHz. This band is reserved for Automotive Radar system and sensors as per FCC specifications. The proposed design demonstrates insertion loss less than 0.6dB and return loss better than 12dB at mid frequency i.e. 24.4GHz. The reflection coefficient shows high stability of about 12.47dB at mid frequency. The fractional bandwidth of the proposed filter is about 28.7% and size of filter design is small due to thickness of 0.127mm.

  12. Computed a multiple band metamaterial absorber and its application based on the figure of merit value

    NASA Astrophysics Data System (ADS)

    Chen, Chao; Sheng, Yuping; Jun, Wang

    2018-01-01

    A high performed multiple band metamaterial absorber is designed and computed through the software Ansofts HFSS 10.0, which is constituted with two kinds of separated metal particles sub-structures. The multiple band absorption property of the metamaterial absorber is based on the resonance of localized surface plasmon (LSP) modes excited near edges of metal particles. The damping constant of gold layer is optimized to obtain a near-perfect absorption rate. Four kinds of dielectric layers is computed to achieve the perfect absorption perform. The perfect absorption perform of the metamaterial absorber is enhanced through optimizing the structural parameters (R = 75 nm, w = 80 nm). Moreover, a perfect absorption band is achieved because of the plasmonic hybridization phenomenon between LSP modes. The designed metamaterial absorber shows high sensitive in the changed of the refractive index of the liquid. A liquid refractive index sensor strategy is proposed based on the computed figure of merit (FOM) value of the metamaterial absorber. High FOM values (116, 111, and 108) are achieved with three liquid (Methanol, Carbon tetrachloride, and Carbon disulfide).

  13. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gündoğan, M. Tural, E-mail: mugetural@yahoo.com; Yavaş, Ö., E-mail: yavas@ankara.edu.tr; Kaya, Ç., E-mail: c.kaya@ankara.edu.tr

    Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) facility is proposed as an IR FEL and Bremsstrahlung facility as the first facility of Turkish Accelerator Center (TAC). TARLA is essentially proposed to generate oscillator mode FEL in 3-250 microns wavelengths range, will consist of normal conducting injector system with 250 keV beam energy, two superconducting RF accelerating modules in order to accelerate the beam 15-40 MeV. The TARLA facility is expected to provide two modes, Continuous wave (CW) and pulsed mode. Longitudinal electron bunch length will be changed between 1 and 10 ps. The bunch charge will be limited by 77pC.more » The design of the Button-type Beam Position Monitor for TARLA IR FEL is studied to operate in 1.3 GHz. Mechanical antenna design and simulations are completed considering electron beam parameters of TARLA. Ansoft HFSS and CST Particle Studio is used to compare with results of simulations.« less

  14. Simulation analysis on miniature wireless power transfer system

    NASA Astrophysics Data System (ADS)

    Liu, Tao; Wei, Zhiqiang; Yin, Bo; Chi, Haokun; Du, Panpan

    2018-03-01

    In recent years, the research on implantable medical devices has become a hot scientific topic, and the power supply of these devices are especially concerned. Generally, these devices are usually powered by disposable batteries. However, for some of the long-term human implant devices, such as pacemakers, once the battery has been exhausted after several years, the patient has to replace the battery by surgery, which increases the patient’s economic burden and pain. Wireless power transfer technology, using non-contact way for power transfer, can be a good solution to this problem. In this paper, a micro induction coil was designed, and the transfer efficiency in the air and human tissue model of two-layers were simulated by Ansoft HFSS. The results showed that the system could achieve the energy transfer in both cases, meanwhile, it indicated that the transfer efficiency was lower in a relative larger permittivity of transmission medium.

  15. A button - type beam position monitor design for TARLA facility

    NASA Astrophysics Data System (ADS)

    Gündoǧan, M. Tural; Kaya, ć.; Yavaş, Ö.

    2016-03-01

    Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) facility is proposed as an IR FEL and Bremsstrahlung facility as the first facility of Turkish Accelerator Center (TAC). TARLA is essentially proposed to generate oscillator mode FEL in 3-250 microns wavelengths range, will consist of normal conducting injector system with 250 keV beam energy, two superconducting RF accelerating modules in order to accelerate the beam 15-40 MeV. The TARLA facility is expected to provide two modes, Continuous wave (CW) and pulsed mode. Longitudinal electron bunch length will be changed between 1 and 10 ps. The bunch charge will be limited by 77pC. The design of the Button-type Beam Position Monitor for TARLA IR FEL is studied to operate in 1.3 GHz. Mechanical antenna design and simulations are completed considering electron beam parameters of TARLA. Ansoft HFSS and CST Particle Studio is used to compare with results of simulations.

  16. Large/Complex Antenna Performance Validation for Spaceborne Radar/Radiometeric Instruments

    NASA Technical Reports Server (NTRS)

    Focardi, Paolo; Harrell, Jefferson; Vacchione, Joseph

    2013-01-01

    Over the past decade, Earth observing missions which employ spaceborne combined radar & radiometric instruments have been developed and implemented. These instruments include the use of large and complex deployable antennas whose radiation characteristics need to be accurately determined over 4 pisteradians. Given the size and complexity of these antennas, the performance of the flight units cannot be readily measured. In addition, the radiation performance is impacted by the presence of the instrument's service platform which cannot easily be included in any measurement campaign. In order to meet the system performance knowledge requirements, a two pronged approach has been employed. The first is to use modeling tools to characterize the system and the second is to build a scale model of the system and use RF measurements to validate the results of the modeling tools. This paper demonstrates the resulting level of agreement between scale model and numerical modeling for two recent missions: (1) the earlier Aquarius instrument currently in Earth orbit and (2) the upcoming Soil Moisture Active Passive (SMAP) mission. The results from two modeling approaches, Ansoft's High Frequency Structure Simulator (HFSS) and TICRA's General RF Applications Software Package (GRASP), were compared with measurements of approximately 1/10th scale models of the Aquarius and SMAP systems. Generally good agreement was found between the three methods but each approach had its shortcomings as will be detailed in this paper.

  17. An efficient hexagonal switched beam antenna structure based on Fabry-Perot cavity leaky-wave antenna

    NASA Astrophysics Data System (ADS)

    Aymen El Cafsi, Mohamed; Nedil, Mourad; Osman, Lotfi; Gharsallah, Ali

    2015-11-01

    A novel design of switched beam antenna (SBA) system based on Fabry-Perot cavity leaky-wave antenna (FPC LWA) is designed and fabricated for base station operating in the unlicensed ISM central frequency band at 5.8 GHz of the wireless local area network (WLAN) standard. The proposed SBA is designed with hexagonal shape of FPC LWA Arrays in order to get 360° of coverage. The single element of FPC LWA array is composed of a patch antenna and covered by a Partially Reflective Surface (PRS), which is composed of a Metal Strip Grating and printed on a high permittivity Superstrate. First, the Transmission Line Model of FPC LWA is introduced to analyse and calculate the far-field components in E- and H planes by using the Transverse Equivalent Network. This approach is then compared with other full wave's commercial software such as Ansoft HFSS and CST Microwave Studio. Second, a parametric study is performed to evaluate the effect of the angle formed by the two successive FPC LWA on the radiation efficiency of the activate sector. To examine the performance of the proposed SBA, experimental prototype was fabricated and measured. As a result, multiple orthogonal beams (six beams) of 10 dBi of gain with low Side Lobes Level and 360° of coverage are produced. This SBA structure is suitable for WLAN communication systems.

  18. Design Investigation of a Laminated Waveguide Fed Multi-Band DRA for Military Applications

    NASA Astrophysics Data System (ADS)

    Kumar, Pramod; Dwari, Santanu; Singh, Shailendra; Agrawal, N. K.

    2017-12-01

    In this paper a laminated waveguide fed DR Antenna is investigated. It can use for moderate power military applications. Cylindrical DRA is excited by two closely spaced asymmetric longitudinal slots on the broad wall of the laminated cavity are responsible for producing three different frequency bands. Parametric study of slots has been done with the help of commercial software ANSOFT HFSS. All the bands have sharp rejection. The final model of the antenna is simulated, fabricated and experimentally measured. Measured results are in quite accordant with design results. SIW feeding structures have small losses, moderate power handling capacity, low costs, compact sizes and can be seamlessly integrated with planar circuits. At all the bands 9.76 GHz, 10.53 GHz and 11.8 GHz resonant frequency, the antenna shows 56 MHz, 160 MHz, and 250 MHz impedance bandwidth (for VSWR<2) with 6 dB,6.2 dB and 6.8 dB gain respectively. Simulated and measured results reveal outstanding performance with a cross-polar level of 29 dB lower than that of the co-polar level at 9.76 GHz, the cross-polar level of 32 dB lower than that of the co-polar level at 10.53, GHz, and similarly cross-polar level of 30 dB lower than that of the co-polar level at 11.8 GHz.

  19. Multipurpose EPR loop-gap resonator and cylindrical TE011 cavity for aqueous samples at 94 GHz.

    PubMed

    Sidabras, Jason W; Mett, Richard R; Froncisz, Wojciech; Camenisch, Theodore G; Anderson, James R; Hyde, James S

    2007-03-01

    A loop-gap resonator (LGR) and a cylindrical TE(011) cavity resonator for use at W band, 94 GHz, have been designed and characterized using the Ansoft (Pittsburgh, PA) high frequency structure simulator (HFSS; Version 10.0). Field modulation penetration was analyzed using Ansoft MAXWELL 3D (Version 11.0). Optimizing both resonators to the same sample sizes shows that EPR signal intensities of the LGR and TE(011) are similar. The 3 dB bandwidth of the LGR, on the order of 1 GHz, is a new advantage for high frequency experiments. Ultraprecision electric discharge machining (EDM) was used to fabricate the resonators from silver. The TE(011) cavity has slots that are cut into the body to allow penetration of 100 kHz field modulation. The resonator body is embedded in graphite, also cut by EDM techniques, for a combination of reasons that include (i) reduced microwave leakage and improved TE(011) mode purity, (ii) field modulation penetration, (iii) structural support for the cavity body, and (iv) machinability by EDM. Both resonators use a slotted iris. Variable coupling is provided by a three-stub tuning element. A collet system designed to hold sample tubes has been implemented, increasing repeatability of sample placement and reducing sample vibration noise. Initial results include multiquantum experiments up to 9Q using the LGR to examine 1 mM 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) in aqueous solution at room temperature and field modulation experiments using the TE(011) cavity to obtain an EPR spectrum of 1 microM TEMPO.

  20. Temperature field simulation and phantom validation of a Two-armed Spiral Antenna for microwave thermotherapy.

    PubMed

    Du, Yongxing; Zhang, Lingze; Sang, Lulu; Wu, Daocheng

    2016-04-29

    In this paper, an Archimedean planar spiral antenna for the application of thermotherapy was designed. This type of antenna was chosen for its compact structure, flexible application and wide heating area. The temperature field generated by the use of this Two-armed Spiral Antenna in a muscle-equivalent phantom was simulated and subsequently validated by experimentation. First, the specific absorption rate (SAR) of the field was calculated using the Finite Element Method (FEM) by Ansoft's High Frequency Structure Simulation (HFSS). Then, the temperature elevation in the phantom was simulated by an explicit finite difference approximation of the bioheat equation (BHE). The temperature distribution was then validated by a phantom heating experiment. The results showed that this antenna had a good heating ability and a wide heating area. A comparison between the calculation and the measurement showed a fair agreement in the temperature elevation. The validated model could be applied for the analysis of electromagnetic-temperature distribution in phantoms during the process of antenna design or thermotherapy experimentation.

  1. Spectral definition of the ArTeMiS instrument

    NASA Astrophysics Data System (ADS)

    Haynes, Vic; Maffei, Bruno; Pisano, Giampaolo; Dubreuil, Didier; Delisle, Cyrille; Le Pennec, Jean; Hurtado, Norma

    2014-07-01

    ArTeMiS is a sub-millimetre camera to be operated, on the Atacama Pathfinder Experiment Telescope (APEX). The ultimate goal is to observe simultaneously in three atmospheric spectral windows in the region of 200, 350 and 450 microns. We present the filtering scheme, which includes the cryostat window, thermal rejection elements, band separation and spectral isolation, which has been adopted for this instrument. This was achieved using a combination of scattering, Yoshinaga filters, organic dyes and Ulrich type embedded metallic mesh devices. Design of the quasi-optical mesh components has been developed by modelling with an in-house developed code. For the band separating dichroics, which are used with an incidence angle of 35 deg, further modelling has been performed with HFSS (Ansoft). Spectral characterization of the components for the 350 and 450 bands have been performed with a Martin-Puplett Polarizing Fourier Transform Spectrometer. While for the first commissioning and observation campaign, one spectral band only was operational (350 microns), we report on the design of the 200, 350 and 450 micron bands.

  2. Design and Experimental Verification of Deployable/Inflatable Ultra-Lightweight Structures

    NASA Technical Reports Server (NTRS)

    Pai, P. Frank

    2004-01-01

    Because launch cost of a space structural system is often proportional to the launch volume and mass and there is no significant gravity in space, NASA's space exploration programs and various science missions have stimulated extensive use of ultra-lightweight deployable/inflatable structures. These structures are named here as Highly Flexible Structures (HFSs) because they are designed to undergo large displacements, rotations, and/or buckling without plastic deformation under normal operation conditions. Except recent applications to space structural systems, HFSs have been used in many mechanical systems, civil structures, aerospace vehicles, home appliances, and medical devices to satisfy space limitations, provide special mechanisms, and/or reduce structural weight. The extensive use of HFSs in today's structural engineering reveals the need of a design and analysis software and a database system with design guidelines for practicing engineers to perform computer-aided design and rapid prototyping of HFSs. Also to prepare engineering students for future structural engineering requires a new and easy-to- understand method of presenting the complex mathematics of the modeling and analysis of HFSs. However, because of the high flexibility of HFSs, many unique challenging problems in the modeling, design and analysis of HFSs need to be studied. The current state of research on HFSs needs advances in the following areas: (1) modeling of large rotations using appropriate strain measures, (2) modeling of cross-section warpings of structures, (3) how to account for both large rotations and cross- section warpings in 2D (two-dimensional) and 1D structural theories, (4) modeling of thickness thinning of membranes due to inflation pressure, pretension, and temperature change, (5) prediction of inflated shapes and wrinkles of inflatable structures, (6) development of efficient numerical methods for nonlinear static and dynamic analyses, and (7) filling the gap between geometrically exact elastic analysis and elastoplastic analysis. The objectives of this research project were: (1) to study the modeling, design, and analysis of deployable/inflatable ultra-lightweight structures, (2) to perform numerical and experimental studies on the static and dynamic characteristics and deployability of HFSs, (3) to derive guidelines for designing HFSs, (4) to develop a MATLAB toolbox for the design, analysis, and dynamic animation of HFSs, and (5) to perform experiments and establish an adequate database of post-buckling characteristics of HFSs.

  3. Finite element analysis and performance study of switched reluctance generator

    NASA Astrophysics Data System (ADS)

    Zhang, Qianhan; Guo, Yingjun; Xu, Qi; Yu, Xiaoying; Guo, Yajie

    2017-03-01

    Analyses a three-phase 12/8 switched reluctance generator (SRG) which is based on its structure and performance principle. The initial size data were calculated by MathCAD, and the simulation model was set up in the ANSOFT software environment with the maximum efficiency and the maximum output power as the main reference parameters. The outer diameter of the stator and the inner diameter of the rotor were parameterized. The static magnetic field distribution, magnetic flux, magnetic energy, torque, inductance characteristics, back electromotive force and phase current waveform of SRG is obtained by analyzing the static magnetic field and the steady state motion of two-dimensional transient magnetic field in ANSOFT environment. Finally, the experimental data of the prototype are compared with the simulation results, which provide a reliable basis for the design and research of SRG wind turbine system.

  4. A Study of Direct Digital Manufactured RF/Microwave Packaging

    NASA Astrophysics Data System (ADS)

    Stratton, John W. I.

    Various facets of direct digital manufactured (DDM) microwave packages are studied. The rippled surface inherent in fused deposition modeling (FDM) fabricated geometries is modeled in Ansoft HFSS, and its effect on the performance of microstrip transmission lines is assessed via simulation and measurement. The thermal response of DDM microstrip transmission lines is analyzed over a range of RF input powers, and linearity is confirmed over that range. Two IC packages are embedded into DDM printed circuit boards, and their performance is analyzed. The first is a low power RF switch, and the second is an RF front end device that includes a low noise amplifier (LNA) and a power amplifier (PA). The RF switch is shown to perform well, as compared to a layout designed for a Rogers 4003C microwave laminate substrate. The LNA performs within datasheet specifications. The power amplifier generates substantial heat, so a thermal management attempt is described. Finally, a capacitively loaded 6dB Wilkinson power divider is designed and fabricated using DDM techniques and materials. Its performance is analyzed and compared to simulation. The device is shown to compare favorably to a similar device fabricated on a Rogers 4003C microwave laminate using traditional printed circuit board techniques.

  5. A novel electromagnetic design and a new manufacturing process for the cavity BPM (Beam Position Monitor)

    NASA Astrophysics Data System (ADS)

    Dal Forno, Massimo; Craievich, Paolo; Baruzzo, Roberto; De Monte, Raffaele; Ferianis, Mario; Lamanna, Giuseppe; Vescovo, Roberto

    2012-01-01

    The Cavity Beam Position Monitor (BPM) is a beam diagnostic instrument which, in a seeded Free Electron Laser (FEL), allows the measurement of the electron beam position in a non-destructive way and with sub-micron resolution. It is composed by two resonant cavities called reference and position cavity, respectively. The measurement exploits the dipole mode that arises when the electron bunch passes off axis. In this paper we describe the Cavity BPM that has been designed and realized in the context of the FERMI@Elettra project [1]. New strategies have been adopted for the microwave design, for both the reference and the position cavities. Both cavities have been simulated by means of Ansoft HFSS [2] and CST Particle Studio [3], and have been realized using high precision lathe and wire-EDM (Electro-Discharge) machine, with a new technique that avoids the use of the sinker-EDM machine. Tuners have been used to accurately adjust the working frequencies for both cavities. The RF parameters have been estimated, and the modifications of the resonant frequencies produced by brazing and tuning have been evaluated. Finally, the Cavity BPM has been installed and tested in the presence of the electron beam.

  6. Modelling, analysis and validation of microwave techniques for the characterisation of metallic nanoparticles

    NASA Astrophysics Data System (ADS)

    Sulaimalebbe, Aslam

    In the last decade, the study of nanoparticle (NP) systems has become a large and interesting research area due to their novel properties and functionalities, which are different from those of the bulk materials, and also their potential applications in different fields. It is vital to understand the behaviour and properties of nano-materials aiming at implementing nanotechnology, controlling their behaviour and designing new material systems with superior performance. Physical characterisation of NPs falls into two main categories, property and structure analysis, where the properties of the NPs cannot be studied without the knowledge of size and structure. The direct measurement of the electrical properties of metal NPs presents a key challenge and necessitates the use of innovative experimental techniques. There have been numerous reports of two/four point resistance measurements of NPs films and also electrical conductivity of NPs films using the interdigitated microarray (IDA) electrode. However, using microwave techniques such as open ended coaxial probe (OCP) and microwave dielectric resonator (DR) for electrical characterisation of metallic NPs are much more accurate and effective compared to other traditional techniques. This is because they are inexpensive, convenient, non-destructive, contactless, hazardless (i.e. at low power) and require no special sample preparation. This research is the first attempt to determine the microwave properties of Pt and Au NP films, which were appealing materials for nano-scale electronics, using the aforementioned microwave techniques. The ease of synthesis, relatively cheap, unique catalytic activities and control over the size and the shape were the main considerations in choosing Pt and Au NPs for the present study. The initial phase of this research was to implement and validate the aperture admittance model for the OCP measurement through experiments and 3D full wave simulation using the commercially available Ansoft High Frequency Structure Simulator (HFSS), followed by the electrical characterisation of synthesised Pt NP films using the novel miniature fabricated OCP technique. The results obtained from this technique provided the inspiration to synthesise and evaluate the microwave properties of Au NPs. The findings from this technique provided the motivation to characterise both the Pt and Au NP films using the DR technique. Unlike the OCP technique, the DR method is highly sensitive but the achievable measurement accuracy is limited since this technique does not have broadband frequency capability like the OCP method. The results obtained from the DR technique show a good agreement with the theoretical prediction. In the last phase of this research, a further validation of the aperture admittance models on different types OCP (i.e. RG-405 and RG-402 cables and SMA connector) have been carried out on the developed 3D full wave models using HFSS software, followed by the development of universal models for the aforementioned OCPs based on the same 3D full wave models.

  7. Frequency swept microwaves for hyperfine decoupling and time domain dynamic nuclear polarization

    PubMed Central

    Hoff, Daniel E.M.; Albert, Brice J.; Saliba, Edward P.; Scott, Faith J.; Choi, Eric J.; Mardini, Michael; Barnes, Alexander B.

    2015-01-01

    Hyperfine decoupling and pulsed dynamic nuclear polarization (DNP) are promising techniques to improve high field DNP NMR. We explore experimental and theoretical considerations to implement them with magic angle spinning (MAS). Microwave field simulations using the high frequency structural simulator (HFSS) software suite are performed to characterize the inhomogeneous phase independent microwave field throughout a 198 GHz MAS DNP probe. Our calculations show that a microwave power input of 17 W is required to generate an average EPR nutation frequency of 0.84 MHz. We also present a detailed calculation of microwave heating from the HFSS parameters and find that 7.1% of the incident microwave power contributes to dielectric sample heating. Voltage tunable gyrotron oscillators are proposed as a class of frequency agile microwave sources to generate microwave frequency sweeps required for the frequency modulated cross effect, electron spin inversions, and hyperfine decoupling. Electron spin inversions of stable organic radicals are simulated with SPINEVOLUTION using the inhomogeneous microwave fields calculated by HFSS. We calculate an electron spin inversion efficiency of 56% at a spinning frequency of 5 kHz. Finally, we demonstrate gyrotron acceleration potentials required to generate swept microwave frequency profiles for the frequency modulated cross effect and electron spin inversions. PMID:26482131

  8. Frequency swept microwaves for hyperfine decoupling and time domain dynamic nuclear polarization.

    PubMed

    Hoff, Daniel E M; Albert, Brice J; Saliba, Edward P; Scott, Faith J; Choi, Eric J; Mardini, Michael; Barnes, Alexander B

    2015-11-01

    Hyperfine decoupling and pulsed dynamic nuclear polarization (DNP) are promising techniques to improve high field DNP NMR. We explore experimental and theoretical considerations to implement them with magic angle spinning (MAS). Microwave field simulations using the high frequency structural simulator (HFSS) software suite are performed to characterize the inhomogeneous phase independent microwave field throughout a 198GHz MAS DNP probe. Our calculations show that a microwave power input of 17W is required to generate an average EPR nutation frequency of 0.84MHz. We also present a detailed calculation of microwave heating from the HFSS parameters and find that 7.1% of the incident microwave power contributes to dielectric sample heating. Voltage tunable gyrotron oscillators are proposed as a class of frequency agile microwave sources to generate microwave frequency sweeps required for the frequency modulated cross effect, electron spin inversions, and hyperfine decoupling. Electron spin inversions of stable organic radicals are simulated with SPINEVOLUTION using the inhomogeneous microwave fields calculated by HFSS. We calculate an electron spin inversion efficiency of 56% at a spinning frequency of 5kHz. Finally, we demonstrate gyrotron acceleration potentials required to generate swept microwave frequency profiles for the frequency modulated cross effect and electron spin inversions. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Experimental and Simulation Investigation of Tri-Sector Cylindrical Dielectric Resonator Antenna in composite forms for Wireless Applications

    NASA Astrophysics Data System (ADS)

    Ranjan, Pinku; Gangwar, Ravi Kumar

    2016-11-01

    In this article, a tri-sector cylindrical dielectric resonator antenna (t-CDRA) has been introduced by splitting CDRA into three uniform sectors and all three uniform sectors are packed together in a compact way on a metallic ground plane. A coaxial probe feed is used to excite the proposed composite t-CDRA at the center position. Multi-segmentation approach has been applied for further improvement in bandwidth of proposed t-CDRA. The proposed composite t-CDRA has been designed using HFSS simulation software and analyzed using theoretical analysis. The prototype of t-CDRA, three elements t-CDRA and three elements dual segment t-CDRA has been fabricated for measurement. The input characteristics, near field, far field distribution of the proposed t-CDRAs have been studied through HFSS simulation software and their results are compared with corresponding experimental results. Proposed segmented t-CDRA has wide impedance bandwidth (|S11|≤-10 dB) of 85 % with monopole-like radiation pattern. The peak gain of segmented t-CDRA has 5.1 dBi with 98.5 % radiation efficiency. The proposed segmented t-CDRA may find suitable applications in 5.0 GHz WLAN and WiMAX band.

  10. New 2D diffraction model and its applications to terahertz parallel-plate waveguide power splitters

    PubMed Central

    Zhang, Fan; Song, Kaijun; Fan, Yong

    2017-01-01

    A two-dimensional (2D) diffraction model for the calculation of the diffraction field in 2D space and its applications to terahertz parallel-plate waveguide power splitters are proposed in this paper. Compared with the Huygens-Fresnel principle in three-dimensional (3D) space, the proposed model provides an approximate analytical expression to calculate the diffraction field in 2D space. The diffraction filed is regarded as the superposition integral in 2D space. The calculated results obtained from the proposed diffraction model agree well with the ones by software HFSS based on the element method (FEM). Based on the proposed 2D diffraction model, two parallel-plate waveguide power splitters are presented. The splitters consist of a transmitting horn antenna, reflectors, and a receiving antenna array. The reflector is cylindrical parabolic with superimposed surface relief to efficiently couple the transmitted wave into the receiving antenna array. The reflector is applied as computer-generated holograms to match the transformed field to the receiving antenna aperture field. The power splitters were optimized by a modified real-coded genetic algorithm. The computed results of the splitters agreed well with the ones obtained by software HFSS verify the novel design method for power splitter, which shows good applied prospects of the proposed 2D diffraction model. PMID:28181514

  11. Design of a dual linear polarization antenna using split ring resonators at X-band

    NASA Astrophysics Data System (ADS)

    Ahmed, Sadiq; Chandra, Madhukar

    2017-11-01

    Dual linear polarization microstrip antenna configurations are very suitable for high-performance satellites, wireless communication and radar applications. This paper presents a new method to improve the co-cross polarization discrimination (XPD) for dual linear polarized microstrip antennas at 10 GHz. For this, three various configurations of a dual linear polarization antenna utilizing metamaterial unit cells are shown. In the first layout, the microstrip patch antenna is loaded with two pairs of spiral ring resonators, in the second model, a split ring resonator is placed between two microstrip feed lines, and in the third design, a complementary split ring resonators are etched in the ground plane. This work has two primary goals: the first is related to the addition of metamaterial unit cells to the antenna structure which permits compensation for an asymmetric current distribution flow on the microstrip antenna and thus yields a symmetrical current distribution on it. This compensation leads to an important enhancement in the XPD in comparison to a conventional dual linear polarized microstrip patch antenna. The simulation reveals an improvement of 7.9, 8.8, and 4 dB in the E and H planes for the three designs, respectively, in the XPD as compared to the conventional dual linear polarized patch antenna. The second objective of this paper is to present the characteristics and performances of the designs of the spiral ring resonator (S-RR), split ring resonator (SRR), and complementary split ring resonator (CSRR) metamaterial unit cells. The simulations are evaluated using the commercial full-wave simulator, Ansoft High-Frequency Structure Simulator (HFSS).

  12. Effect of restrictions on television food advertising to children on exposure to advertisements for 'less healthy' foods: repeat cross-sectional study.

    PubMed

    Adams, Jean; Tyrrell, Rachel; Adamson, Ashley J; White, Martin

    2012-01-01

    In 2007, new scheduling restrictions on television food advertising to children in the UK were announced. The aim of the restrictions was to "reduce significantly the exposure of children under 16 to high fat, salt or sugar (HFSS) advertising". We explored the impact of the restrictions on relative exposure to HFSS food advertising among all viewers and among child television viewers, as well as adherence to the restrictions. We conducted two cross-sectional studies of all advertisements broadcast in one region of the UK over one week periods--the first (week 1) six months before the restrictions were introduced, and the second (week 2) six months after. Data on what products were advertised were linked to data on how many people watched each advertisement. Nutritional content of foods advertised was added to the dataset and used to calculate HFSS status. Relative exposure was calculated as the proportion of all advertising person-minute-views (PMVs) that were for HFSS foods. 1,672,417 advertising PMV were included. 14.6% of advertising PMV were for food and 51.1% of these were for HFSS food. Relative exposure of all viewers to HFSS food advertising increased between study weeks 1 and 2 (odds ratio (99% confidence intervals) = 1·54 (1·51 to 1·57)). Exposure of children to HFSS food advertising did not change between study weeks 1 and 2 (odds ratio (99% confidence intervals) = 1·05 (0·99 to 1·12)). There was almost universal adherence to the restrictions. Despite good adherence to the restrictions, they did not change relative exposure of children to HFSS advertising and were associated with an increase in relative exposure of all viewers to HFSS advertising. Stronger restrictions targeting a wider range of advertisements are necessary to reduce exposure of children to marketing of less healthful foods.

  13. Effect of Restrictions on Television Food Advertising to Children on Exposure to Advertisements for ‘Less Healthy’ Foods: Repeat Cross-Sectional Study

    PubMed Central

    Adams, Jean; Tyrrell, Rachel; Adamson, Ashley J.; White, Martin

    2012-01-01

    Background In 2007, new scheduling restrictions on television food advertising to children in the UK were announced. The aim of the restrictions was to “reduce significantly the exposure of children under 16 to high fat, salt or sugar (HFSS) advertising”. We explored the impact of the restrictions on relative exposure to HFSS food advertising among all viewers and among child television viewers, as well as adherence to the restrictions. Methods We conducted two cross-sectional studies of all advertisements broadcast in one region of the UK over one week periods – the first (week 1) six months before the restrictions were introduced, and the second (week 2) six months after. Data on what products were advertised were linked to data on how many people watched each advertisement. Nutritional content of foods advertised was added to the dataset and used to calculate HFSS status. Relative exposure was calculated as the proportion of all advertising person-minute-views (PMVs) that were for HFSS foods. Results 1,672,417 advertising PMV were included. 14.6% of advertising PMV were for food and 51.1% of these were for HFSS food. Relative exposure of all viewers to HFSS food advertising increased between study weeks 1 and 2 (odds ratio (99% confidence intervals) = 1·54 (1·51 to 1·57)). Exposure of children to HFSS food advertising did not change between study weeks 1 and 2 (odds ratio (99% confidence intervals) = 1·05 (0·99 to 1·12)). There was almost universal adherence to the restrictions. Conclusions Despite good adherence to the restrictions, they did not change relative exposure of children to HFSS advertising and were associated with an increase in relative exposure of all viewers to HFSS advertising. Stronger restrictions targeting a wider range of advertisements are necessary to reduce exposure of children to marketing of less healthful foods. PMID:22355376

  14. Risk stratification in middle-aged patients with congestive heart failure: prospective comparison of the Heart Failure Survival Score (HFSS) and a simplified two-variable model.

    PubMed

    Zugck, C; Krüger, C; Kell, R; Körber, S; Schellberg, D; Kübler, W; Haass, M

    2001-10-01

    The performance of a US-American scoring system (Heart Failure Survival Score, HFSS) was prospectively evaluated in a sample of ambulatory patients with congestive heart failure (CHF). Additionally, it was investigated whether the HFSS might be simplified by assessment of the distance ambulated during a 6-min walk test (6'WT) instead of determination of peak oxygen uptake (peak VO(2)). In 208 middle-aged CHF patients (age 54+/-10 years, 82% male, NYHA class 2.3+/-0.7; follow-up 28+/-14 months) the seven variables of the HFSS: CHF aetiology; heart rate; mean arterial pressure; serum sodium concentration; intraventricular conduction time; left ventricular ejection fraction (LVEF); and peak VO(2), were determined. Additionally, a 6'WT was performed. The HFSS allowed discrimination between patients at low, medium and high risk, with mortality rates of 16, 39 and 50%, respectively. However, the prognostic power of the HFSS was not superior to a two-variable model consisting only of LVEF and peak VO(2). The areas under the receiver operating curves (AUC) for prediction of 1-year survival were even higher for the two-variable model (0.84 vs. 0.74, P<0.05). Replacing peak VO(2) with 6'WT resulted in a similar AUC (0.83). The HFSS continued to predict survival when applied to this patient sample. However, the HFSS was inferior to a two-variable model containing only LVEF and either peak VO(2) or 6'WT. As the 6'WT requires no sophisticated equipment, a simplified two-variable model containing only LVEF and 6'WT may be more widely applicable, and is therefore recommended.

  15. Nanogranular soft magnetic material and on-package integrated inductors

    NASA Astrophysics Data System (ADS)

    Li, Liangliang

    2007-12-01

    Integrated inductors used in electronic circuits are mainly spiral-shaped aluminum devices fabricated on Si chip. They have several disadvantages---large silicon area consumption, high DC resistance and high cost. An attractive approach to address these issues is directly integrating inductors into package substrates, which provide plenty of usage area, low resistance and low cost. The goals of this dissertation are designing and fabricating magnetic and air-core inductors with characteristic low resistance and high quality factor on package substrates. The research work includes three parts which are summarized below. First, the CoFeHfO nanogranular magnetic material developed on Si wafers and package substrates by pulsed DC reactive sputtering were investigated. On Si wafers, the optimized CoFeHfO film has soft magnetic properties. On printed circuit board (PCB) substrates, these magnetic properties degrade due to the rough surface. Surface planarization such as chemical-mechanical polishing can be applied on PCB substrates to reduce the surface roughness and hence improve these properties. Second, on-package inductors with small resistances and high quality factors were designed, fabricated, measured and analyzed. Air-core and magnetic inductors (20 design variations) were built on 8-inch PCB substrates. The DC resistances of these inductors are less than 12 mO, one of the lowest values ever reported. The maximum quality factors can be as large as ˜80 at around 1 GHz for the air-core inductors and ˜25 at 200 MHz for the magnetic inductors. Third, inductor simulation was carried out to study the effects of magnetic materials on the properties of inductors using the Ansoft HFSS software package. The measurement data for the permeability spectra of the CoFeHfO film and the tensor nature of the permeability were taken into account in the simulation. The simulation results matched the experimental data for the inductances, resistances and quality factors. This established an accurate method for modeling high-frequency magnetic devices. Using this method, an inductor with a closed magnetic core was studied by varying the geometry of the core and copper coil. It has been found that the inductance of this inductor depends strongly on whether the permeability of the magnetic core is isotropic or anisotropic.

  16. Magnetic field simulation and shimming analysis of 3.0T superconducting MRI system

    NASA Astrophysics Data System (ADS)

    Yue, Z. K.; Liu, Z. Z.; Tang, G. S.; Zhang, X. C.; Duan, L. J.; Liu, W. C.

    2018-04-01

    3.0T superconducting magnetic resonance imaging (MRI) system has become the mainstream of modern clinical MRI system because of its high field intensity and high degree of uniformity and stability. It has broad prospects in scientific research and other fields. We analyze the principle of magnet designing in this paper. We also perform the magnetic field simulation and shimming analysis of the first 3.0T/850 superconducting MRI system in the world using the Ansoft Maxwell simulation software. We guide the production and optimization of the prototype based on the results of simulation analysis. Thus the magnetic field strength, magnetic field uniformity and magnetic field stability of the prototype is guided to achieve the expected target.

  17. Socio-economic differences in exposure to television food advertisements in the UK: a cross-sectional study of advertisements broadcast in one television region.

    PubMed

    Adams, Jean; Tyrrell, Rachel; Adamson, Ashley J; White, Martin

    2012-03-01

    To document socio-economic differences in exposure to food advertising, including advertisements for foods high in fat, salt and sugar (HFSS) as defined by the UK Food Standards Agency's Nutrient Profiling Model. A cross-sectional survey. Information (including product advertised and viewing figures) on all advertisements broadcast in one UK region over one week (6-12 July 2009) was obtained. Food advertisements were identified and linked to nutritional information on the content of advertised foods. UK Tyne-Tees television region. Data were sourced from a UK-wide television viewing panel. Eleven per cent of advertising seen was for food and 63 % of food advertising seen was for HFSS foods. The proportion of all advertising seen that was for food was smaller among viewers in the least v. most affluent social grade (OR = 0·98, 99 % CI 0·95, 1·00). There was no difference in the proportion of food advertising seen that was for HFSS food between viewers in the most and least affluent social grades. Total exposure to both all food advertising and HFSS food advertising was 2·1 times greater among the least v. the most affluent viewers. While the least affluent viewers saw relatively fewer food advertisements, their absolute exposure to all food and HFSS food advertisements was higher than that of the most affluent viewers. Current UK restrictions prohibit advertisements for HFSS foods during programmes with a high proportion of child viewers. Extending these to all programming may reduce socio-economic inequalities in exposure to these advertisements and in diet and obesity.

  18. Study on magnetic force of electromagnetic levitation circular knitting machine

    NASA Astrophysics Data System (ADS)

    Wu, X. G.; Zhang, C.; Xu, X. S.; Zhang, J. G.; Yan, N.; Zhang, G. Z.

    2018-06-01

    The structure of the driving coil and the electromagnetic force of the test prototype of electromagnetic-levitation (EL) circular knitting machine are studied. In this paper, the driving coil’s structure and working principle of the EL circular knitting machine are firstly introduced, then the mathematical modelling analysis of the driving electromagnetic force is carried out, and through the Ansoft Maxwell finite element simulation software the coil’s magnetic induction intensity and the needle’s electromagnetic force is simulated, finally an experimental platform is built to measure the coil’s magnetic induction intensity and the needle’s electromagnetic force. The results show that the theoretical analysis, the simulation analysis and the results of the test are very close, which proves the correctness of the proposed model.

  19. A miniaturized micro strip antenna based on sinusoidal patch geometry for implantable biomedical applications

    NASA Astrophysics Data System (ADS)

    Ibrahim, Omar A.; Elwi, Taha A.; Islam, Naz E.

    2012-11-01

    A miniaturized microstrip antenna is analyzed for implantable biomedical applications. The antenna is designed using two different commercial software packages, CST Microwave Studio and HFSS, to validate the results. The proposed design operates in the WMTS frequency band. The antenna performance is tested inside the human body, Hugo model. The antenna design is readjusted to get the desired resonant frequency. The resonant frequency, bandwidth, gain, and radiation pattern of the proposed antenna are provided in this paper. Furthermore, the effect of losses inside human body due to the fat layer is recognized.

  20. Design, simulation and analysis a microstrip antenna using PU-EFB substrate

    NASA Astrophysics Data System (ADS)

    Mahmud, S. N. S.; Jusoh, M. A.; Jasim, S. E.; Zamani, A. H.; Abdullah, M. H.

    2018-04-01

    A low cost, light weight and easy to fabricate are the most important factor for future antennas. Microstrip patch antennas offer these advantages and suitable for communication and sensor application. This paper presents a design of simple microstrip patch antenna working on operating frequency of 2.4 GHz. The designed process has been carried out using MATLAB and HFSS software by entering 2.3 for the dielectric constant of PU-EFB. The results showed that high return loss, low bandwidth and good antenna radiation efficiency of which are -21.98 dB, 0.28 dB and 97.33%, respectively.

  1. Evaluation of tinnitus patients by audiometric configuration.

    PubMed

    Kim, Su Il; Kim, Myung Gu; Kim, Sung Su; Byun, Jae Yong; Park, Moon Suh; Yeo, Seung Geun

    2016-01-01

    Although tinnitus patients have different audiometric configuration, we evaluated them using the same approach. Thus we analyzed the clinical features of patients with subjective tinnitus classified according to audiometric configuration. The study cohort consisted of 123 patients with subjective tinnitus who visited the tinnitus clinic from April 2013 to April 2014. Patients with a previous history of otologic disease or migrainous vertigo were excluded. Factors evaluated included pure tone audiometry, tinnitogram, auditory brainstem response (ABR), distortion product otoacoustic emissions (DPOAEs) and transient evoked otoacoustic emissions (TEOAEs). Tinnitus patients could be divided into three groups: Flat, high frequency gently sloping (HFGS) and high frequency steeply sloping (HFSS). HFGS showed female predominance and HFSS male predominance (p<0.05 each). THI score was higher in the HFGS than in the other groups (p<0.05). Tinnitus pitch and occupations varied, but showed specific tendencies in each group. On ABR, the HFSS group showed significant prolongation of wave I, III, and V latencies (p<0.05 each). On DPOAEs, the HFSS group showed significantly lower response rates at 3, 4, and 6 kHz (p<0.05 each). TEOAE normal rates were significantly higher in the Flat than in the HFGS and HFSS groups (p<0.05). Average pure tone thresholds were similar, but threshold values at high frequencies, ABR, DPOAEs, and TEOAEs differed among the groups. Therefore, different access to tinnitus patients could be required according to audiometric shape. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Identifying 'unhealthy' food advertising on television: a case study applying the UK Nutrient Profile model.

    PubMed

    Jenkin, Gabrielle; Wilson, Nick; Hermanson, Nicole

    2009-05-01

    To evaluate the feasibility of the UK Nutrient Profile (NP) model for identifying 'unhealthy' food advertisements using a case study of New Zealand television advertisements. Four weeks of weekday television from 15.30 hours to 18.30 hours was videotaped from a state-owned (free-to-air) television channel popular with children. Food advertisements were identified and their nutritional information collected in accordance with the requirements of the NP model. Nutrient information was obtained from a variety of sources including food labels, company websites and a national nutritional database. From the 60 h sample of weekday afternoon television, there were 1893 advertisements, of which 483 were for food products or retailers. After applying the NP model, 66 % of these were classified as advertising high-fat, high-salt and high-sugar (HFSS) foods; 28 % were classified as advertising non-HFSS foods; and the remaining 2 % were unclassifiable. More than half (53 %) of the HFSS food advertisements were for 'mixed meal' items promoted by major fast-food franchises. The advertising of non-HFSS food was sparse, covering a narrow range of food groups, with no advertisements for fresh fruit or vegetables. Despite the NP model having some design limitations in classifying real-world televised food advertisements, it was easily applied to this sample and could clearly identify HFSS products. Policy makers who do not wish to completely restrict food advertising to children outright should consider using this NP model for regulating food advertising.

  3. Methods and apparatus for laser beam scanners with different actuating mechanisms

    NASA Astrophysics Data System (ADS)

    Chen, Si-hai; Xiang, Si-hua; Wu, Xin; Dong, Shan; Xiao, Ding; Zheng, Xia-wei

    2009-07-01

    In this paper, 3 types of laser beam scanner are introduced. One is transmissive beam scanner, which is composed of convex and concave microlens arrays (MLAs). By moving the concave lens in the plane vertical to the optical axis, the incident beam can be deflected in two dimensions. Those two kinds of MLAs are fabricated by thermal reflow and replication process. A set of mechanical scanner frame is fabricated with the two MLAs assembling in it. The testing result shown that the beam deflection angles are 9.5° and 9.6°, in the 2 dimension(2D) with the scanning frequency of 2 HZ and 8 HZ, respectively. The second type of laser beam scanner is actuated by voice coil actuators (VCAs). Based on ANSOFT MAXWELL software, we have designed VCAs with small size and large force which have optimized properties. The model of VCAs is built using AutoCAD and is analyzed by Ansoft maxwell. According to the simulation results, high performance VCAs are fabricated and tested. The result is that the force of the VCAs is 6.39N/A, and the displacement is +/-2.5mm. A set up of beam scanner is fabricated and actuated by the designed VCAs. The testing result shown that the two dimensional scanning angle is 15° and 10° respectively at the frequency of 60HZ. The two dimensional scanning angle is 8.3° and 6° respectively at the frequency of 100HZ. The third type of scanner is actuated by amplified piezoelectric actuators (APAs). The scanning mirror is actuated by the piezoelectric (PZ) actuators with the scanning frequency of 700HZ, 250HZ and 87HZ respectively. The optical scanning angle is +/-0.5° at the three frequencies.

  4. Optimization of the High-speed On-off Valve of an Automatic Transmission

    NASA Astrophysics Data System (ADS)

    Li-mei, ZHAO; Huai-chao, WU; Lei, ZHAO; Yun-xiang, LONG; Guo-qiao, LI; Shi-hao, TANG

    2018-03-01

    The response time of the high-speed on-off solenoid valve has a great influence on the performance of the automatic transmission. In order to reduce the response time of the high-speed on-off valve, the simulation model of the valve was built by use of AMESim and Ansoft Maxwell softwares. To reduce the response time, an objective function based on ITAE criterion was built and the Genetic Algorithms was used to optimize five parameters including circle number, working air gap, et al. The comparison between experiment and simulation shows that the model is verified. After optimization, the response time of the valve is reduced by 38.16%, the valve can meet the demands of the automatic transmission well. The results can provide theoretical reference for the improvement of automatic transmission performance.

  5. A compact microwave patch applicator for hyperthermia treatment of cancer.

    PubMed

    Chakaravarthi, Geetha; Arunachalam, Kavitha

    2014-01-01

    Design and development of a compact microstrip C-type patch applicator for hyperthermia treatment of cancer is presented. The patch antenna is optimized for resonance at 434 MHz, return loss (S11) better than -15dB and co-polarized electric field in tissue. Effect of water bolus thickness on power delivery is studied for improved power coupling. Numerical simulations for antenna design optimization carried out using EM simulation software, Ansys HFSS(®), USA were experimentally verified. The effective field coverage for the optimized patch antenna and experimental results indicate that the compact antenna resonates at ISM frequency 434 MHz with better than -15 dB power coupling.

  6. Usefulness of peak exercise oxygen consumption and the heart failure survival score to predict survival in patients >65 years of age with heart failure.

    PubMed

    Parikh, Mona N; Lund, Lars H; Goda, Ayumi; Mancini, Donna

    2009-04-01

    Peak exercise oxygen consumption (Vo(2)) and the Heart Failure (HF) Survival Score (HFSS) were developed in middle-aged patient cohorts referred for heart transplantation with HF. The prognostic value of Vo(2) in patients >65 years has not been well studied. Accordingly, the prognostic value of peak Vo(2) was evaluated in these patients with HF. A retrospective analysis of 396 patients with HF >65 years with cardiopulmonary exercise testing was performed. Peak Vo(2) and components of the HFSS (presence of coronary artery disease, left ventricular ejection fraction, heart rate, mean arterial blood pressure, presence of intraventricular conduction defects, and serum sodium) were collected. Follow-up averaged 1,038 +/- 983 days. Outcome events were defined as death, implantation of a left ventricular assist device, or urgent transplantation. Patients were divided into risk strata for peak Vo(2) and HFSS based on previous cut-off points. Survival curves were derived using Kaplan-Meier analysis and compared using log-rank analysis. Survival differed markedly by Vo(2) stratum (p <0.0001), with significantly better survival rates for the low- (>14 ml/kg/min) versus medium- (10 to 14 ml/kg/min), low- versus high- (<10 ml/kg/min), and medium- versus high-risk strata (all p <0.05). Survival also differed markedly by HFSS stratum (p <0.0001), with significantly better survival rates for the low- (> or =8.10) versus medium- (7.20 to 8.09), low- versus high- (< or =7.19), and medium- versus high-risk strata (all p <0.0001). In conclusion, peak Vo(2) and the HFSS were both excellent parameters to predict survival in patients >65 years with HF.

  7. Effect of acute swim stress on plasma corticosterone and brain monoamine levels in bidirectionally selected DxH recombinant inbred mouse strains differing in fear recall and extinction.

    PubMed

    Browne, Caroline A; Hanke, Joachim; Rose, Claudia; Walsh, Irene; Foley, Tara; Clarke, Gerard; Schwegler, Herbert; Cryan, John F; Yilmazer-Hanke, Deniz

    2014-12-01

    Stress-induced changes in plasma corticosterone and central monoamine levels were examined in mouse strains that differ in fear-related behaviors. Two DxH recombinant inbred mouse strains with a DBA/2J background, which were originally bred for a high (H-FSS) and low fear-sensitized acoustic startle reflex (L-FSS), were used. Levels of noradrenaline, dopamine, and serotonin and their metabolites 3,4-dihydroxyphenyacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were studied in the amygdala, hippocampus, medial prefrontal cortex, striatum, hypothalamus and brainstem. H-FSS mice exhibited increased fear levels and a deficit in fear extinction (within-session) in the auditory fear-conditioning test, and depressive-like behavior in the acute forced swim stress test. They had higher tissue noradrenaline and serotonin levels and lower dopamine and serotonin turnover under basal conditions, although they were largely insensitive to stress-induced changes in neurotransmitter metabolism. In contrast, acute swim stress increased monoamine levels but decreased turnover in the less fearful L-FSS mice. L-FSS mice also showed a trend toward higher basal and stress-induced corticosterone levels and an increase in noradrenaline and serotonin in the hypothalamus and brainstem 30 min after stress compared to H-FSS mice. Moreover, the dopaminergic system was activated differentially in the medial prefrontal cortex and striatum of the two strains by acute stress. Thus, H-FSS mice showed increased basal noradrenaline tissue levels compatible with a fear phenotype or chronic stressed condition. Low corticosterone levels and the poor monoamine response to stress in H-FSS mice may point to mechanisms similar to those found in principal fear disorders or post-traumatic stress disorder.

  8. Effect of Acute Swim Stress on Plasma Corticosterone and Brain Monoamine Levels in Bidirectionally Selected DxH Recombinant Inbred Mouse Strains Differing in Fear Recall and Extinction

    PubMed Central

    Browne, Caroline A.; Hanke, Joachim; Rose, Claudia; Walsh, Irene; Foley, Tara; Clarke, Gerard; Schwegler, Herbert; Cryan, John F.; Yilmazer-Hanke, Deniz

    2015-01-01

    Stress-induced changes in plasma corticosterone and central monoamine levels were examined in mouse strains that differ in fear-related behaviors. Two DxH recombinant inbred mouse strains with a DBA/2J background, which were originally bred for a high (H-FSS) and low fear-sensitized acoustic startle reflex (L-FSS), were used. Levels of noradrenaline, dopamine, and serotonin and their metabolites (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were studied in the amygdala, hippocampus, medial prefrontal cortex, striatum, hypothalamus, and brainstem. H-FSS mice exhibited increased fear levels and a deficit in fear extinction (within-session) in the auditory fear-conditioning test, and depressive-like behavior in the acute forced swim stress test. They had higher tissue noradrenaline and serotonin levels and lower dopamine and serotonin turnover under basal conditions, although they were largely insensitive to stress-induced changes in neurotransmitter metabolism. In contrast, acute swim stress increased monoamine levels but decreased turnover in the less fearful L-FSS mice. L-FSS mice also showed a trend toward higher basal and stress-induced corticosterone levels and an increase in noradrenaline and serotonin in the hypothalamus and brainstem 30 minutes after stress compared to H-FSS mice. Moreover, the dopaminergic system was activated differentially in the medial prefrontal cortex and striatum of the two strains by acute stress. Thus, H-FSS mice showed increased basal noradrenaline tissue levels compatible with a fear phenotype or chronic stressed condition. Low corticosterone levels and the poor monoamine response to stress in H-FSS mice may point to mechanisms similar to those found in principal fear disorders or posttraumatic stress disorder. PMID:25117886

  9. Electric field numerical simulation of disc type electrostatic spinning spinneret

    NASA Astrophysics Data System (ADS)

    Wei, L.; Deng, ZL; Qin, XH; Liang, ZY

    2018-01-01

    Electrospinning is a new type of free-end spinning built on electric field. Different from traditional single needle spinneret, in this study, a new disc type free surface spinneret is used to produce multiple jets, this will greatly improve production efficiency of nanofiber. The electric-field distribution of spinneret is the crux of the formation and trajectory of jets. In order to probe the electric field intensity of the disc type spinneret, computational software of Ansoft Maxwell 12 is adopted for a precise and intuitive analysis. The results showed that the whole round cambered surface of the spinning solution at edge of each layer of the spinneret with the maximum curvature has the highest electric field intensity, and through the simulation of the electric field distribution of different spinneret parameters such as layer, the height and radius of the spinneret. Influences of various parameters on the electrostatic spinning are obtained.

  10. The design and simulation of UHF RFID microstrip antenna

    NASA Astrophysics Data System (ADS)

    Chen, Xiangqun; Huang, Rui; Shen, Liman; Liu, Liping; Xiong, Dezhi; Xiao, Xiangqi; Liu, Mouhai; Renheng, Xu

    2018-02-01

    At present, China has delineated UHF RFID communicating frequency range which is 840 ∼ 845 MHz and 920 ∼ 925 MHz, but most UHF microstrip antenna don’t carry out this standard, that leads to radio frequency pollution. In order to solve the problems above, a method combining theory and simulation is adopted. Combining with a new ceramic material, a 925.5 MHz RFID microstrip antenna is designed, which is optimized and simulated by HFSS software. The results show that the VSWR of this RFID microstrip antenna is relatively small in the vicinity of 922.5 MHz, the gain is 2.1 dBi, which can be widely used in China’s UHF RFID communicating equipments.

  11. Implementation for wideband applications using UWB fractal patch antenna

    NASA Astrophysics Data System (ADS)

    Kumar, D. Naresh

    2018-04-01

    This paper defines in detail about the diverse fractal patch antenna. Microstrip patch antennas has evolved in the field of research and development extending its impact across wide range of applications. A combination of patch antenna with fractal patterns has become a tryout to outspread it further. Because of its low profile nature patch antennas have added to a lot of prominence. Apart from have this property it can also be renovated further for wide bandwidth (2929 MHz) applications, as it exhibits self-analogous property. This antenna is premeditated on a patch using Sierpinski(4.040 GHz, 6.566 GHz) and Koch fractal geometries respectively. The antenna is designed using HFSS software.

  12. Radio Frequency and Optical Metamaterials

    DTIC Science & Technology

    2013-03-01

    nanoparticle ring resonating at 560THz. Since the nanoring in Figure 17 was modeled as four silver nanospheres suspended in air, this nanoring could not be...nanoparticles means our nanorings will not behave like the modeled silver nanoparticle ring suspended in air. To confirm the HFSS simulation results of our...it in HFSS. We modeled the Engheta and Alù’s nanoring with silver and gold since we planned to use gold for the initial study. The results from the

  13. The extent and nature of food advertising to children on Spanish television in 2012 using an international food-based coding system and the UK nutrient profiling model.

    PubMed

    Royo-Bordonada, M Á; León-Flández, K; Damián, J; Bosqued-Estefanía, M J; Moya-Geromini, M Á; López-Jurado, L

    2016-08-01

    To examine the extent and nature of food television advertising directed at children in Spain using an international food-based system and the United Kingdom nutrient profile model (UKNPM). Cross-sectional study of advertisements of food and drinks shown on five television channels over 7 days in 2012 (8am-midnight). Showing time and duration of each advertisement was recorded. Advertisements were classified as core (nutrient-rich/calorie-low products), non-core, or miscellaneous based on the international system, and either healthy/less healthy, i.e., high in saturated fats, trans-fatty acids, salt, or free sugars (HFSS), according to UKNPM. The food industry accounted for 23.7% of the advertisements (4212 out of 17,722) with 7.5 advertisements per hour of broadcasting. The international food-based coding system classified 60.2% of adverts as non-core, and UKNPM classified 64.0% as HFSS. Up to 31.5% of core, 86.8% of non-core, and 8.3% of miscellaneous advertisements were for HFSS products. The percentage of advertisements for HFSS products was higher during reinforced protected viewing times (69.0%), on weekends (71.1%), on channels of particular appeal to children and teenagers (67.8%), and on broadcasts regulated by the Spanish Code of self-regulation of the advertising of food products directed at children (70.7%). Both schemes identified that a majority of foods advertised were unhealthy, although some classification differences between the two systems are important to consider. The food advertising Code is not limiting Spanish children's exposure to advertisements for HFSS products, which were more frequent on Code-regulated broadcasts and during reinforced protected viewing time. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  14. New VHP-Female v. 2.0 full-body computational phantom and its performance metrics using FEM simulator ANSYS HFSS.

    PubMed

    Yanamadala, Janakinadh; Noetscher, Gregory M; Rathi, Vishal K; Maliye, Saili; Win, Htay A; Tran, Anh L; Jackson, Xavier J; Htet, Aung T; Kozlov, Mikhail; Nazarian, Ara; Louie, Sara; Makarov, Sergey N

    2015-01-01

    Simulation of the electromagnetic response of the human body relies heavily upon efficient computational models or phantoms. The first objective of this paper is to present a new platform-independent full-body electromagnetic computational model (computational phantom), the Visible Human Project(®) (VHP)-Female v. 2.0 and to describe its distinct features. The second objective is to report phantom simulation performance metrics using the commercial FEM electromagnetic solver ANSYS HFSS.

  15. Simulation on measurement of five-DOF motion errors of high precision spindle with cylindrical capacitive sensor

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Wang, Wen; Xiang, Kui; Lu, Keqing; Fan, Zongwei

    2015-02-01

    This paper describes a novel cylindrical capacitive sensor (CCS) to measure the spindle five degree-of-freedom (DOF) motion errors. The operating principle and mathematical models of the CCS are presented. Using Ansoft Maxwell software to calculate the different capacitances in different configurations, structural parameters of end face electrode are then investigated. Radial, axial and tilt motions are also simulated by making comparisons with the given displacements and the simulation values respectively. It could be found that the proposed CCS has a high accuracy for measuring radial motion error when the average eccentricity is about 15 μm. Besides, the maximum relative error of axial displacement is 1.3% when the axial motion is within [0.7, 1.3] mm, and the maximum relative error of the tilt displacement is 1.6% as rotor tilts around a single axis within [-0.6, 0.6]°. Finally, the feasibility of the CCS for measuring five DOF motion errors is verified through simulation and analysis.

  16. The Potential Cost-Effectiveness and Equity Impacts of Restricting Television Advertising of Unhealthy Food and Beverages to Australian Children.

    PubMed

    Brown, Vicki; Ananthapavan, Jaithri; Veerman, Lennert; Sacks, Gary; Lal, Anita; Peeters, Anna; Backholer, Kathryn; Moodie, Marjory

    2018-05-15

    Television (TV) advertising of food and beverages high in fat, sugar and salt (HFSS) influences food preferences and consumption. Children from lower socioeconomic position (SEP) have higher exposure to TV advertising due to more time spent watching TV. This paper sought to estimate the cost-effectiveness of legislation to restrict HFSS TV advertising until 9:30 pm, and to examine how health benefits and healthcare cost-savings differ by SEP. Cost-effectiveness modelling was undertaken (i) at the population level, and (ii) by area-level SEP. A multi-state multiple-cohort lifetable model was used to estimate obesity-related health outcomes and healthcare cost-savings over the lifetime of the 2010 Australian population. Incremental cost-effectiveness ratios (ICERs) were reported, with assumptions tested through sensitivity analyses. An intervention restricting HFSS TV advertising would cost AUD5.9M (95% UI AUD5.8M⁻AUD7M), resulting in modelled reductions in energy intake (mean 115 kJ/day) and body mass index (BMI) (mean 0.352 kg/m²). The intervention is likely to be cost-saving, with 1.4 times higher total cost-savings and 1.5 times higher health benefits in the most disadvantaged socioeconomic group (17,512 HALYs saved (95% UI 10,372⁻25,155); total cost-savings AUD126.3M (95% UI AUD58.7M⁻196.9M) over the lifetime) compared to the least disadvantaged socioeconomic group (11,321 HALYs saved (95% UI 6812⁻15,679); total cost-savings AUD90.9M (95% UI AUD44.3M⁻136.3M)). Legislation to restrict HFSS TV advertising is likely to be cost-effective, with greater health benefits and healthcare cost-savings for children with low SEP.

  17. The Potential Cost-Effectiveness and Equity Impacts of Restricting Television Advertising of Unhealthy Food and Beverages to Australian Children

    PubMed Central

    Veerman, Lennert; Lal, Anita; Peeters, Anna; Backholer, Kathryn; Moodie, Marjory

    2018-01-01

    Television (TV) advertising of food and beverages high in fat, sugar and salt (HFSS) influences food preferences and consumption. Children from lower socioeconomic position (SEP) have higher exposure to TV advertising due to more time spent watching TV. This paper sought to estimate the cost-effectiveness of legislation to restrict HFSS TV advertising until 9:30 pm, and to examine how health benefits and healthcare cost-savings differ by SEP. Cost-effectiveness modelling was undertaken (i) at the population level, and (ii) by area-level SEP. A multi-state multiple-cohort lifetable model was used to estimate obesity-related health outcomes and healthcare cost-savings over the lifetime of the 2010 Australian population. Incremental cost-effectiveness ratios (ICERs) were reported, with assumptions tested through sensitivity analyses. An intervention restricting HFSS TV advertising would cost AUD5.9M (95% UI AUD5.8M–AUD7M), resulting in modelled reductions in energy intake (mean 115 kJ/day) and body mass index (BMI) (mean 0.352 kg/m2). The intervention is likely to be cost-saving, with 1.4 times higher total cost-savings and 1.5 times higher health benefits in the most disadvantaged socioeconomic group (17,512 HALYs saved (95% UI 10,372–25,155); total cost-savings AUD126.3M (95% UI AUD58.7M–196.9M) over the lifetime) compared to the least disadvantaged socioeconomic group (11,321 HALYs saved (95% UI 6812–15,679); total cost-savings AUD90.9M (95% UI AUD44.3M–136.3M)). Legislation to restrict HFSS TV advertising is likely to be cost-effective, with greater health benefits and healthcare cost-savings for children with low SEP. PMID:29762517

  18. Selection of patients for heart transplantation in the current era of heart failure therapy.

    PubMed

    Butler, Javed; Khadim, Ghazanfar; Paul, Kimberly M; Davis, Stacy F; Kronenberg, Marvin W; Chomsky, Don B; Pierson, Richard N; Wilson, John R

    2004-03-03

    We sought to assess the relationship between survival, peak exercise oxygen consumption (VO(2)), and heart failure survival score (HFSS) in the current era of heart failure (HF) therapy. Based on predicted survival, HF patients with peak VO(2) <14 ml/min/kg or medium- to high-risk HFSS are currently considered eligible for heart transplantation. However, these criteria were developed before the widespread use of beta-blockers, spironolactone, and defibrillators-interventions known to improve the survival of HF patients. Peak VO(2) and HFSS were assessed in 320 patients followed from 1994 to 1997 (past era) and in 187 patients followed from 1999 to 2001 (current era). Outcomes were compared between these two groups of patients and those who underwent heart transplantation from 1993 to 2000. Survival in the past era was 78% at one year and 67% at two years, as compared with 88% and 79%, respectively, in the current era (both p < 0.01). One-year event-free survival (without urgent transplantation or left ventricular assist device) was improved in the current era, regardless of initial peak VO(2): 64% vs. 48% for peak VO(2) <10 ml/min/kg (p = 0.09), 81% vs. 70% for 10 to 14 ml/min/kg (p = 0.05), and 93% vs. 82% for >14 ml/min/kg (p = 0.04). Of the patients with peak VO(2) of 10 to 14 ml/min/kg, 55% had low-risk HFSS and exhibited 88% one-year event-free survival. One-year survival after transplantation was 88%, which is similar to the 85% rate reported by the United Network for Organ Sharing for 1999 to 2000. Survival for HF patients in the current era has improved significantly, necessitating re-evaluation of the listing criteria for heart transplantation.

  19. Risk stratification of patients with severe heart failure awaiting heart transplantation-prospective national registry POLKARD HF.

    PubMed

    Zieliński, T; Browarek, A; Zembala, M; Sadowski, J; Zakliczyński, M; Przybylowski, P; Roguski, K; Kosakowska, A B; Korewicki, J

    2009-10-01

    Most methods used in the risk assessment of heart transplant candidates do not include new biomarkers. The aim of the study was to examine the value of NTproBNP and hsCRP and their combined use together with HFSS score in the risk assessment of patients with heart failure enlisted for heart transplantation. Data of 658 patients enlisted for heart transplantation in all active transplantation centers were stored in a prospective registry. The composite end point-death or urgent transplantation was recorded during the follow-up. Death or urgent transplantation was recorded in 161 (24%) of pts. 102 (15%) patients died and 59 (9%) were transplanted urgently. Kaplan-Meier curves for risk of death or urgent transplantation where highly significant when pts were stratified by the quartiles of NT proBNP (P < .000001) or quartiles according to the hsCRP level on admission (P < .002). In the multivariate Cox proportional hazard model, the significance was observed for NTproBNP (P < .01) and HFSS (P < .02), and borderline significance for hsCRP (P = .057). When ROC analyses of the area under the curve (AUC) values were considered, AUC area was for HFSS - 0.645, for NTproBNP - 0.653 and for hsCRP - 0.566. When all those variables were included together in the model, the AUC value rose to 0.6943. Based on those results a weighted risk model with all three parameters was proposed. HFSS, NTproBNP and hsCRP levels are independent stratification variables of survival or need for urgent heart transplantation. Their predictive value is moderately increased when they are analyzed together.

  20. Modified Minkowski Fractal Antenna for Wireless Applications

    NASA Astrophysics Data System (ADS)

    Brar, Amandeep Singh; Sivia, Jagtar Singh

    2018-06-01

    A multiband Modified Minkowski Fractal Antenna which can operate at UHF, L, S, C and X band of IEEE standard is presented in this paper. The proposed antenna is simple and low cost. It can work on many bands starting from few hundred megahertz (500 MHz) frequency up to gigahertz (7.1 GHz) frequency. Structure of antenna has been designed by combining Minkowski curve with its inverted Minkowski curve. A maximum gain up to 20 dB, VSWR, radiation pattern and twenty resonant frequencies has been achieved using proposed antenna structure. Simulated results executed in HFSS software. Proposed antenna works on resonant frequencies of 496 MHz to 1.06 GHz (wide band), 1.45, 2.09, 2.38, 3.23, 3.79, 4.06, 4.35, 4.65, 4.82, 5.24, 5.62, 6.12 GHz etc.

  1. NREL: News - Advisor 2002-A Powerful Vehicle Simulation Tool Gets Better

    Science.gov Websites

    Advisor 2002-A Powerful Vehicle Simulation Tool Gets Better Golden, Colo., June 11, 2002 A powerful analysis is made possible by co-simulation links to Avant!'s Saber and Ansoft's SIMPLORER�. Transient air conditioning system analysis is possible by co-simulation with C&R Technologies' SINDA/FLUINT

  2. A new type of coil structure called pan-shaped coil of wireless charging system based on magnetic resonance

    NASA Astrophysics Data System (ADS)

    Yue, Z. K.; Liu, Z. Z.; Hou, Y. J.; Zeng, H.; Liang, L. H.; Cui, S.

    2017-11-01

    The problem that misalignment between the transmitting coil and the receiving coil significantly impairs the transmission power and efficiency of the system has been attached more and more attention. In order to improve the uniformity of the magnetic field between the two coils to solve this problem, a new type of coil called pan-shaped coil is proposed. Three-dimension simulation models of the planar-core coil and the pan-shaped coil are established using Ansoft Maxwell software. The coupling coefficient between the transmitting coil and the receiving coil is obtained by simulating the magnetic field with the receiving coil misalignment or not. And the maximum percentage difference strength along the radial direction which is defined as the magnetic field uniformity factor is calculated. According to the simulation results of the two kinds of coil structures, it is found that the new type of coil structure can obviously improve the uniformity of the magnetic field, coupling coefficient and power transmission properties between the transmitting coil and the receiving coil.

  3. Responsiveness to healthy advertisements in adults: An experiment assessing beyond brand snack selection and the impact of restrained eating.

    PubMed

    Dovey, Terence M; Torab, Tina; Yen, Dorothy; Boyland, E J; Halford, Jason C G

    2017-05-01

    The objective of this study was to explore the impact of different advertising messages on adults' snack choice. Eighty participants (18-24 years old) were offered the choice between two snack packs following exposure to one of three advertising conditions. The snack packs contained either healthy or high fat, sugar or salt (HFSS) foods. Participants were exposed to commercials containing either non-food products, healthy food products or HFSS food products and their subsequent choice of snack pack was recorded. The Dutch Eating Behaviour Questionnaire (DEBQ) was used to assess the impact of external, restrained and emotional eating behaviour on snack pack selection following exposure to advertisements. The majority of unrestrained participants preferentially choose the HFSS snack pack irrespective of advertisement condition. In contrast, high restrained individuals exposed to the healthy eating advertisement condition preferentially selected the healthy snack pack while those in other advertisement conditions refused to take either snack pack. The healthy eating message, when distributed through mass media, resonated with restrained eaters only. Exposure to healthy food adverts provoked restrained eaters into choosing a snack pack; while exposure to other messages results in restrained eaters refusing to take any foods. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Numerical Simulation of Liquid Metal RF MEMS Switch Based on EWOD

    NASA Astrophysics Data System (ADS)

    Liu, Tingting; Gao, Yang; Yang, Tao; Guo, Huihui

    2018-03-01

    Conventional RF MEMS switches rely on metal-to-dielectric or metal-to-metal contacts. Some problems in the “solid-solid” contact, such as contact degradation, signal bounce and poor reliability, can be solved by using “liquid-solid” contact. The RF MEMS switch based on liquid metal is characterized by small contact resistance, no moving parts, high reliability and long life. Using electrowetting-on-dielectric (EWOD) way to control the movement of liquid metal in the RF MEMS switch, to achieve the “on” and “off” of the switch. In this paper, the electrical characteristics and RF characteristics of RF MEMS switches are simulated by fluid mechanics software FLUENT and electromagnetic simulation software HFSS. The effects of driving voltage, switching time, dielectric layer, hydrophobic layer material and thickness, switching channel height on the RF characteristics are studied. The results show that to increase the external voltage to the threshold voltage of 58V, the liquid metal began to move, and the switching time from “off” state to “on” state is 16ms. In the 0~20GHz frequency range, the switch insertion loss is less than 0.28dB, isolation is better than 23.32dB.

  5. Design of 5.8 GHz Integrated Antenna on 180nm Complementary Metal Oxide Semiconductor (CMOS) Technology

    NASA Astrophysics Data System (ADS)

    Razak, A. H. A.; Shamsuddin, M. I. A.; Idros, M. F. M.; Halim, A. K.; Ahmad, A.; Junid, S. A. M. Al

    2018-03-01

    This project discusses the design and simulation performances of integrated loop antenna. Antenna is one of the main parts in any wireless radio frequency integrated circuit (RFIC). Naturally, antenna is the bulk in any RFIC design. Thus, this project aims to implement an integrated antenna on a single chip making the end product more compact. This project targets 5.8 GHz as the operating frequency of the integrated antenna for a transceiver module based on Silterra CMOS 180nm technology. The simulation of the antenna was done by using High Frequency Structure Simulator (HFSS). This software is industrial standard software that been used to simulate all electromagnetic effect including antenna simulation. This software has ability to simulate frequency at range of 100 MHz to 4 THz. The simulation set up in 3 dimension structure with driven terminal. The designed antenna has 1400um of diameter and placed on top metal layer. Loop configuration of the antenna has been chosen as the antenna design. From the configuration, it is able to make the chip more compact. The simulation shows that the antenna has single frequency band at center frequency 5.8 GHz with -48.93dB. The antenna radiation patterns shows, the antenna radiate at omnidirectional. From the simulation result, it could be concluded that the antenna have a good radiation pattern and propagation for wireless communication.

  6. Reducing the volume, exposure and negative impacts of advertising for foods high in fat, sugar and salt to children: A systematic review of the evidence from statutory and self-regulatory actions and educational measures.

    PubMed

    Chambers, Stephanie A; Freeman, Ruth; Anderson, Annie S; MacGillivray, Steve

    2015-06-01

    To identify and review evidence on 1) the effectiveness of statutory and self-regulatory actions to reduce the volume, exposure or wider impact of advertising for foods high in fat, sugar and salt (HFSS) to children, and 2) the role of educational measures. A systematic review of three databases (Medline, CINAHL and PsycINFO) and grey literature was carried out. Relevant evidence included studies evaluating advertising bans and restrictions, advertising literacy programmes and parental communication styles. Relevant media included TV, internet, radio, magazines and newspaper advertising. No studies were excluded based on language or publication date. Forty-seven publications were included: 19 provided evidence for the results of statutory regulation, 25 for self-regulation, and six for educational approaches. Outcome measures varied in approach, quality and results. Findings suggested statutory regulation could reduce the volume of and children's exposure to advertising for foods HFSS, and had potential to impact more widely. Self-regulatory approaches showed varied results in reducing children's exposure. There was some limited support for educational measures. Consistency in measures from evaluations over time would assist the development and interpretation of the evidence base on successful actions and measures to reduce the volume, exposure and impact of advertising for foods HFSS to children. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Design, experiments and simulation of voltage transformers on the basis of a differential input D-dot sensor.

    PubMed

    Wang, Jingang; Gao, Can; Yang, Jie

    2014-07-17

    Currently available traditional electromagnetic voltage sensors fail to meet the measurement requirements of the smart grid, because of low accuracy in the static and dynamic ranges and the occurrence of ferromagnetic resonance attributed to overvoltage and output short circuit. This work develops a new non-contact high-bandwidth voltage measurement system for power equipment. This system aims at the miniaturization and non-contact measurement of the smart grid. After traditional D-dot voltage probe analysis, an improved method is proposed. For the sensor to work in a self-integrating pattern, the differential input pattern is adopted for circuit design, and grounding is removed. To prove the structure design, circuit component parameters, and insulation characteristics, Ansoft Maxwell software is used for the simulation. Moreover, the new probe was tested on a 10 kV high-voltage test platform for steady-state error and transient behavior. Experimental results ascertain that the root mean square values of measured voltage are precise and that the phase error is small. The D-dot voltage sensor not only meets the requirement of high accuracy but also exhibits satisfactory transient response. This sensor can meet the intelligence, miniaturization, and convenience requirements of the smart grid.

  8. Gain and Bandwidth Enhancement of Ferrite-Loaded CBS Antenna Using Material Shaping and Positioning

    NASA Astrophysics Data System (ADS)

    Askarian Amiri, Mikal

    Loading a cavity-backed slot (CBS) antenna with ferrite material and applying a biasing static magnetic field can be used to control its resonant frequency. Such a mechanism results in a frequency reconfigurable antenna. However, placing a lossy ferrite material inside the cavity can reduce the gain or negatively impact the impedance bandwidth. This thesis develops guidelines, based on a non-uniform applied magnetic field and non-uniform magnetic field internal to the ferrite specimen, for the design of ferrite-loaded CBS antennas which enhance their gain and tunable bandwidth by shaping the ferrite specimen and judiciously locating it within the cavity. To achieve these objectives, it is necessary to examine the influence of the shape and relative location of the ferrite material, and also the proximity of the ferrite specimen from the probe on the DC magnetic field and RF electric field distributions inside the cavity. The geometry of the probe and its impacts on figures-of-merit of the antenna is of interest as well. Two common cavity backed-slot antennas (rectangular and circular cross-section) were designed, and corresponding simulations and measurements were performed and compared. The cavities were mounted on 30 cm × 30 cm perfect electric conductor (PEC) ground planes and partially loaded with ferrite material. The ferrites were biased with an external magnetic field produced by either an electromagnet or permanent magnets. Simulations were performed using FEM-based commercial software, Ansys' Maxwell 3D and HFSS. Maxwell 3D is utilized to model the non-uniform DC applied magnetic field and non-uniform magnetic field internal to the ferrite specimen; HFSS however, is used to simulate and obtain the RF characteristics of the antenna. To validate the simulations they were compared with measurements performed in ASU's EM Anechoic Chamber. After many examinations using simulations and measurements, some optimal designs guidelines with respect to the gain, return loss and tunable impedance bandwidth, were obtained and recommended for ferrite-loaded CBS antennas.

  9. Magnetic materials for mobile communication antennas substrate application

    NASA Astrophysics Data System (ADS)

    Chen, Hui; Liang, Difei; Li, Weijia; Pang, Chao

    2017-11-01

    In this work, 3Ba0.7Sr0.3O·2CoO·10.8Fe2O3 and Ba2Co2Fe12O22 had been fabricated successfully by conventional ceramic process. Crystallographic structure and electromagnetic properties of two kind of hexagonal ferrite with different sintering temperature were investigated. X-ray Diffraction (XRD), Agilent-N5230A Network Analyzer were used to measure ferrite samples. The mobile phone antenna performance was analysed by HFSS. The results revealed that the main phase of two ferrite samples generated at lower temperature due to additive. The optimized parameters of ferrite are sintering temperature at 1000°C. And to emulate antenna model by HFSS find that Z-type and Y-type ferrite substrate can contribute to antenna frequency shifting, radiation efficiency were affected a little.

  10. Design of high-speed optical transmission module with an integrated Ti:Er:LiNbO3 waveguide laser/ LiNbO3 electro-optic modulator

    NASA Astrophysics Data System (ADS)

    Bai, Yang; Chen, Shufen; Fu, Li; Fang, Wei; Lu, Junjun

    2005-01-01

    A high bit rate more than 10Gbit/s optical pulse generation device is the key to achieving high-speed and broadband optical fiber communication network system .Now, we propose a novel high-speed optical transmission module(TM) consisting of a Ti:Er:LiNbO3 waveguide laser and a Mach-Zehnder-type encoding modulator on the same Er-doped substrate. According to the standard of ITU-T, we design the 10Gbit/ s transmission module at 1.53μm on the Z cut Y propagation LiNbO3 slice. A dynamic model and the corresponding numerical code are used to analyze the waveguide laser while the electrooptic effect to design the modulator. Meanwhile, the working principle, key technology, typical characteristic parameters of the module are given. The transmission module has a high extinction ratio and a low driving voltage, which supplies the efficient, miniaturized light source for wavelength division multiplexing(WDM) system. In additional, the relation of the laser gain with the cavity parameter, as well as the relation of the bandwidth of the electrooptic modulator with some key factors are discussed .The designed module structure is simulated by BPM software and HFSS software.

  11. Design and Analysis of a Micromachined LC Low Pass Filter For 2.4GHz Application

    NASA Astrophysics Data System (ADS)

    Saroj, Samruddhi R.; Rathee, Vishal R.; Pande, Rajesh S.

    2018-02-01

    This paper reports design and analysis of a passive low pass filter with cut-off frequency of 2.4 GHz using MEMS (Micro Electro-Mechanical Systems) technology. The passive components such as suspended spiral inductors and metal-insulator-metal (MIM) capacitor are arranged in T network form to implement LC low pass filter design. This design employs a simple approach of suspension thereby reducing parasitic losses to eliminate the performance degrading effects caused by integrating an off-chip inductor in the filter circuit proposed to be developed on a low cost silicon substrate using RF-MEMS components. The filter occupies only 2.1 mm x 0.66 mm die area and is designed using micro-strip transmission line placed on a silicon substrate. The design is implemented in High Frequency Structural Simulator (HFSS) software and fabrication flow is proposed for its implementation. The simulated results show that the design has an insertion loss of -4.98 dB and return loss of -2.60dB.

  12. Decomposition of Composite Electric Field in a Three-Phase D-Dot Voltage Transducer Measuring System

    PubMed Central

    Hu, Xueqi; Wang, Jingang; Wei, Gang; Deng, Xudong

    2016-01-01

    In line with the wider application of non-contact voltage transducers in the engineering field, transducers are required to have better performance for different measuring environments. In the present study, the D-dot voltage transducer is further improved based on previous research in order to meet the requirements for long-distance measurement of electric transmission lines. When measuring three-phase electric transmission lines, problems such as synchronous data collection and composite electric field need to be resolved. A decomposition method is proposed with respect to the superimposed electric field generated between neighboring phases. The charge simulation method is utilized to deduce the decomposition equation of the composite electric field and the validity of the proposed method is verified by simulation calculation software. With the deduced equation as the algorithm foundation, this paper improves hardware circuits, establishes a measuring system and constructs an experimental platform for examination. Under experimental conditions, a 10 kV electric transmission line was tested for steady-state errors, and the measuring results of the transducer and the high-voltage detection head were compared. Ansoft Maxwell Stimulation Software was adopted to obtain the electric field intensity in different positions under transmission lines; its values and the measuring values of the transducer were also compared. Experimental results show that the three-phase transducer is characterized by a relatively good synchronization for data measurement, measuring results with high precision, and an error ratio within a prescribed limit. Therefore, the proposed three-phase transducer can be broadly applied and popularized in the engineering field. PMID:27754340

  13. Hazards Caused by UV Rays of Xenon Light Based High Performance Solar Simulators.

    PubMed

    Dibowski, Gerd; Esser, Kai

    2017-09-01

    Solar furnaces are used worldwide to conduct experiments to demonstrate the feasibility of solar-chemical processes with the aid of concentrated sunlight, or to qualify high temperature-resistant components. In recent years, high-flux solar simulators (HFSSs) based on short-arc xenon lamps are more frequently used. The emitted spectrum is very similar to natural sunlight but with dangerous portions of ultraviolet light as well. Due to special benefits of solar simulators the increase of construction activity for HFSS can be observed worldwide. Hence, it is quite important to protect employees against serious injuries caused by ultraviolet radiation (UVR) in a range of 100 nm to 400 nm. The UV measurements were made at the German Aerospace Center (DLR), Cologne and Paul-Scherrer-Institute (PSI), Switzerland, during normal operations of the HFSS, with a high-precision UV-A/B radiometer using different experiment setups at different power levels. Thus, the measurement results represent UV emissions which are typical when operating a HFSS. Therefore, the biological effects on people exposed to UVR was investigated systematically to identify the existing hazard potential. It should be noted that the permissible workplace exposure limits for UV emissions significantly exceeded after a few seconds. One critical value was strongly exceeded by a factor of 770. The prevention of emissions must first and foremost be carried out by structural measures. Furthermore, unambiguous protocols have to be defined and compliance must be monitored. For short-term activities in the hazard area, measures for the protection of eyes and skin must be taken.

  14. Magnetostatic simulation on a novel design of axially multi-coiled magnetorheological brakes

    NASA Astrophysics Data System (ADS)

    Ubaidillah, Permata, A. N. S.; Wibowo, A.; Budiana, E. P.; Yahya, I.; Mazlan, S. A.

    2016-03-01

    This paper describes the 3D magnetostatic simulation of a novel design axially multi-coiled magnetorheological (MRB). The proposed model is expected to produce a concentrated magnetic flux on the surface of the rotor disk brake. Thus, the braking torque enhancement is expected to be higher than that of conventional big size single-coil-equipped disk-type MRB. The axially multi-coiled MRB design features multiple electromagnetic poles from by several coils placed in the axial direction outside the MRB body. The magnetostatic analysis was developed utilizing finite element software namely ANSOFT-MAXWELL in 3D environment. The distribution of magnetic flux was investigated in a pair of the coil that represents the other pairs of electromagnetic parts. The simulation was done in 0.5 mm gap filled by magnetorheological fluids (MRFs) (MRF-132DG). The simulation was performed in various applied currents i.e. 0.25, 0.5, 0.75, 1, 1.5, and 2 Amperes. The results showed that the axially multi-coiled MRB provides a considerable magnetic flux (maximum of 337 mT/area). The active energizing areas of the MRB are proven to be more intensive than the conventional MRB. The proposed MRB exhibited a compact and robust design for achieving high torque MRB.

  15. Design, Experiments and Simulation of Voltage Transformers on the Basis of a Differential Input D-dot Sensor

    PubMed Central

    Wang, Jingang; Gao, Can; Yang, Jie

    2014-01-01

    Currently available traditional electromagnetic voltage sensors fail to meet the measurement requirements of the smart grid, because of low accuracy in the static and dynamic ranges and the occurrence of ferromagnetic resonance attributed to overvoltage and output short circuit. This work develops a new non-contact high-bandwidth voltage measurement system for power equipment. This system aims at the miniaturization and non-contact measurement of the smart grid. After traditional D-dot voltage probe analysis, an improved method is proposed. For the sensor to work in a self-integrating pattern, the differential input pattern is adopted for circuit design, and grounding is removed. To prove the structure design, circuit component parameters, and insulation characteristics, Ansoft Maxwell software is used for the simulation. Moreover, the new probe was tested on a 10 kV high-voltage test platform for steady-state error and transient behavior. Experimental results ascertain that the root mean square values of measured voltage are precise and that the phase error is small. The D-dot voltage sensor not only meets the requirement of high accuracy but also exhibits satisfactory transient response. This sensor can meet the intelligence, miniaturization, and convenience requirements of the smart grid. PMID:25036333

  16. Circular Microstrip Antenna with Fractal Slots for Multiband Applications

    NASA Astrophysics Data System (ADS)

    Singh, Sivia Jagtar; Singh, Gurpreet; Bharti, Gurpreet

    2017-10-01

    In this paper, a multiband, fractal, slotted, Circular Microstrip Patch Antenna for GSM, WiMAX, C and X bands (satellite communication applications) is presented. A cantor set theory is used to make fractal slots for obtaining the desired multiband. The projected antenna is simulated using Ansys HFSS v13.0 software. Simulation test of this antenna has been carried out for a frequency range of 1 GHz-10 GHz and a peak gain of 9.19 dB at a resonance frequency of 1.9 GHz is obtained. The antenna also resonates at 3.7 GHz, 6.06 GHz and 7.9 GHz with gains of 3.04 dB, 5.19 dB and 5.39 dB respectively. Parameters like voltage standing wave ratio, return loss, and gain are used to compare the results of the projected antenna with conventional CMPA's of same dimensions with full and defective grounds. The projected antenna is fabricated on a glass epoxy material and is tested using Vector Network Analyzer. The performance parameters of the antenna are found to in good agreement with each both using simulated and measured data.

  17. Printed wide-slot antenna design with bandwidth and gain enhancement on low-cost substrate.

    PubMed

    Samsuzzaman, M; Islam, M T; Mandeep, J S; Misran, N

    2014-01-01

    This paper presents a printed wide-slot antenna design and prototyping on available low-cost polymer resin composite material fed by a microstrip line with a rotated square slot for bandwidth enhancement and defected ground structure for gain enhancement. An I-shaped microstrip line is used to excite the square slot. The rotated square slot is embedded in the middle of the ground plane, and its diagonal points are implanted in the middle of the strip line and ground plane. To increase the gain, four L-shaped slots are etched in the ground plane. The measured results show that the proposed structure retains a wide impedance bandwidth of 88.07%, which is 20% better than the reference antenna. The average gain is also increased, which is about 4.17 dBi with a stable radiation pattern in the entire operating band. Moreover, radiation efficiency, input impedance, current distribution, axial ratio, and parametric studies of S11 for different design parameters are also investigated using the finite element method-based simulation software HFSS.

  18. Printed Wide-Slot Antenna Design with Bandwidth and Gain Enhancement on Low-Cost Substrate

    PubMed Central

    Samsuzzaman, M.; Islam, M. T.; Mandeep, J. S.; Misran, N.

    2014-01-01

    This paper presents a printed wide-slot antenna design and prototyping on available low-cost polymer resin composite material fed by a microstrip line with a rotated square slot for bandwidth enhancement and defected ground structure for gain enhancement. An I-shaped microstrip line is used to excite the square slot. The rotated square slot is embedded in the middle of the ground plane, and its diagonal points are implanted in the middle of the strip line and ground plane. To increase the gain, four L-shaped slots are etched in the ground plane. The measured results show that the proposed structure retains a wide impedance bandwidth of 88.07%, which is 20% better than the reference antenna. The average gain is also increased, which is about 4.17 dBi with a stable radiation pattern in the entire operating band. Moreover, radiation efficiency, input impedance, current distribution, axial ratio, and parametric studies of S11 for different design parameters are also investigated using the finite element method-based simulation software HFSS. PMID:24696661

  19. Characterization of a plasma photonic crystal using a multi-fluid plasma model

    NASA Astrophysics Data System (ADS)

    Thomas, W. R.; Shumlak, U.; Wang, B.; Righetti, F.; Cappelli, M. A.; Miller, S. T.

    2017-10-01

    Plasma photonic crystals have the potential to significantly expand the capabilities of current microwave filtering and switching technologies by providing high speed (μs) control of energy band-gap/pass characteristics in the GHz through low THz range. While photonic crystals consisting of dielectric, semiconductor, and metallic matrices have seen thousands of articles published over the last several decades, plasma-based photonic crystals remain a relatively unexplored field. Numerical modeling efforts so far have largely used the standard methods of analysis for photonic crystals (the Plane Wave Expansion Method, Finite Difference Time Domain, and ANSYS finite element electromagnetic code HFSS), none of which capture nonlinear plasma-radiation interactions. In this study, a 5N-moment multi-fluid plasma model is implemented using University of Washington's WARPXM finite element multi-physics code. A two-dimensional plasma-vacuum photonic crystal is simulated and its behavior is characterized through the generation of dispersion diagrams and transmission spectra. These results are compared with theory, experimental data, and ANSYS HFSS simulation results. This research is supported by a Grant from United States Air Force Office of Scientific Research.

  20. Wireless Interconnects for Intra-chip & Inter-chip Transmission

    NASA Astrophysics Data System (ADS)

    Narde, Rounak Singh

    With the emergence of Internet of Things and information revolution, the demand of high performance computing systems is increasing. The copper interconnects inside the computing chips have evolved into a sophisticated network of interconnects known as Network on Chip (NoC) comprising of routers, switches, repeaters, just like computer networks. When network on chip is implemented on a large scale like in Multicore Multichip (MCMC) systems for High Performance Computing (HPC) systems, length of interconnects increases and so are the problems like power dissipation, interconnect delays, clock synchronization and electrical noise. In this thesis, wireless interconnects are chosen as the substitute for wired copper interconnects. Wireless interconnects offer easy integration with CMOS fabrication and chip packaging. Using wireless interconnects working at unlicensed mm-wave band (57-64GHz), high data rate of Gbps can be achieved. This thesis presents study of transmission between zigzag antennas as wireless interconnects for Multichip multicores (MCMC) systems and 3D IC. For MCMC systems, a four-chips 16-cores model is analyzed with only four wireless interconnects in three configurations with different antenna orientations and locations. Return loss and transmission coefficients are simulated in ANSYS HFSS. Moreover, wireless interconnects are designed, fabricated and tested on a 6'' silicon wafer with resistivity of 55O-cm using a basic standard CMOS process. Wireless interconnect are designed to work at 30GHz using ANSYS HFSS. The fabricated antennas are resonating around 20GHz with a return loss of less than -10dB. The transmission coefficients between antenna pair within a 20mm x 20mm silicon die is found to be varying between -45dB to -55dB. Furthermore, wireless interconnect approach is extended for 3D IC. Wireless interconnects are implemented as zigzag antenna. This thesis extends the work of analyzing the wireless interconnects in 3D IC with different configurations of antenna orientations and coolants. The return loss and transmission coefficients are simulated using ANSYS HFSS.

  1. Randomised controlled trial comparing hypnotherapy versus gabapentin for the treatment of hot flashes in breast cancer survivors: a pilot study

    PubMed Central

    MacLaughlan David, Shannon; Salzillo, Sandra; Bowe, Patrick; Scuncio, Sandra; Malit, Bridget; Raker, Christina; Gass, Jennifer S; Granai, C O; Dizon, Don S

    2013-01-01

    Objectives To compare the efficacy of hypnotherapy versus gabapentin for the treatment of hot flashes in breast cancer survivors, and to evaluate the feasibility of conducting a clinical trial comparing a drug with a complementary or alternative method (CAM). Design Prospective randomised trial. Setting Breast health centre of a tertiary care centre. Participants 15 women with a personal history of breast cancer or an increased risk of breast cancer who reported at least one daily hot flash. Interventions Gabapentin 900 mg daily in three divided doses (control) compared with standardised hypnotherapy. Participation lasted 8 weeks. Outcome measures The primary endpoints were the number of daily hot flashes and hot flash severity score (HFSS). The secondary endpoint was the Hot Flash Related Daily Interference Scale (HFRDIS). Results 27 women were randomised and 15 (56%) were considered evaluable for the primary endpoint (n=8 gabapentin, n=7 hypnotherapy). The median number of daily hot flashes at enrolment was 4.5 in the gabapentin arm and 5 in the hypnotherapy arm. HFSS scores were 7.5 in the gabapentin arm and 10 in the hypnotherapy arm. After 8 weeks, the median number of daily hot flashes was reduced by 33.3% in the gabapentin arm and by 80% in the hypnotherapy arm. The median HFSS was reduced by 33.3% in the gabapentin arm and by 85% in the hypnotherapy arm. HFRDIS scores improved by 51.6% in the gabapentin group and by 55.2% in the hypnotherapy group. There were no statistically significant differences between groups. Conclusions Hypnotherapy and gabapentin demonstrate efficacy in improving hot flashes. A definitive trial evaluating traditional interventions against CAM methods is feasible, but not without challenges. Further studies aimed at defining evidence-based recommendations for CAM are necessary. Trial registration clinicaltrials.gov (NCT00711529). PMID:24022390

  2. Optimization of a Circularly Polarized Patch Antenna for Two Frequency Bands

    DTIC Science & Technology

    2015-09-01

    the various techniques that can be used to improve the performance of a circularly polarized microstrip patch antenna . These adjustments include... microstrip antenna . 15. SUBJECT TERMS Patch Antenna , Circular Polarization 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT...Frequency Structural Simulator (HFSS) has allowed engineers to create scalable multiband microstrip antennas . Several factors were taken into

  3. Innovative Inverted Magnetron Experiments and Theory

    DTIC Science & Technology

    2015-06-01

    and characterized the Recirculating Planar Magnetron (RPM), a new type of High Power Microwave (HPM) device. Researchers have simulated the operation... power extraction is desired. In simulation, the RPM-CACE was up to 70% efficient, producing peak microwave powers of 420 MW. 15. SUBJECT TERMS High ...type of High Power Microwave (HPM) device. Using HFSS, MAGIC, and ICEPIC, researchers have simulated the operation of the device in both a

  4. Calculation and Analysis of Dynamic Characteristics of Multilink Permanent Magnetic Actuator in Vacuum Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Liu, Yingyi; Yuan, Haiwen; Zhang, Qingjie; Chen, Degui; Yuan, Haibin

    The dynamic characteristics are the key issues in the optimum design of a permanent magnetic actuator (PMA). A new approach to forecast the dynamic characteristics of the multilink PMA is proposed. By carrying out further developments of ADAMS and ANSOFT, a mathematic calculation model describing the coupling of mechanical movement, electric circuit and magnetic field considering eddy current effect, is constructed. With this model, the dynamic characteristics of the multilink PMA are calculated and compared with the experimental results. Factors that affect the opening time of the multilink PMA are analyzed with the model as well. The method is capable of providing a reference for the design of the PMA.

  5. Design and Fabrication of a Miniaturized GMI Magnetic Sensor Based on Amorphous Wire by MEMS Technology

    PubMed Central

    Chen, Jiawen; Li, Jianhua; Li, Yiyuan; Chen, Yulong

    2018-01-01

    A miniaturized Co-based amorphous wire GMI (Giant magneto-impedance) magnetic sensor was designed and fabricated in this paper. The Co-based amorphous wire was used as the sense element due to its high sensitivity to the magnetic field. A three-dimensional micro coil surrounding the Co-based amorphous wire was fabricated by MEMS (Micro-Electro-Mechanical System) technology, which was used to extract the electrical signal. The three-dimensional micro pick-up coil was designed and simulated with HFSS (High Frequency Structure Simulator) software to determine the key parameters. Surface micro machining MEMS (Micro-Electro-Mechanical System) technology was employed to fabricate the three-dimensional coil. The size of the developed amorphous wire magnetic sensor is 5.6 × 1.5 × 1.1 mm3. Helmholtz coil was used to characterize the performance of the device. The test results of the sensor sample show that the voltage change is 130 mV/Oe and the linearity error is 4.83% in the range of 0~45,000 nT. The results indicate that the developed miniaturized magnetic sensor has high sensitivity. By testing the electrical resistance of the samples, the results also showed high uniformity of each device. PMID:29494477

  6. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Djidel, S.; Bouamar, M.; Khedrouche, D., E-mail: dkhedrouche@yahoo.com

    This paper presents a performances study of UWB monopole antenna using half-elliptic radiator conformed on elliptical surface. The proposed antenna, simulated using microwave studio computer CST and High frequency simulator structure HFSS, is designed to operate in frequency interval over 3.1 to 40 GHz. Good return loss and radiation pattern characteristics are obtained in the frequency band of interest. The proposed antenna structure is suitable for ultra-wideband applications, which is, required for many wearable electronics applications.

  7. Radio Frequency and Optical Metamaterials

    DTIC Science & Technology

    2011-10-01

    nanoparticle ring resonating at 560THz. Since the nanoring in Figure 12 was modeled as four silver nanospheres suspended in air, this nanoring could not be...of the substrate and the change in the shape of the nanoparticles means our nanorings will not behave like the modeled silver nanoparticle ring...Engheta and Alù’s 4- sphere nanoring suspended in air and simulated it in HFSS. We modeled the Engheta and Alù’s nanoring with silver and gold since

  8. Performances study of UWB monopole antennas using half-elliptic radiator conformed on elliptical surface

    NASA Astrophysics Data System (ADS)

    Djidel, S.; Bouamar, M.; Khedrouche, D.

    2016-04-01

    This paper presents a performances study of UWB monopole antenna using half-elliptic radiator conformed on elliptical surface. The proposed antenna, simulated using microwave studio computer CST and High frequency simulator structure HFSS, is designed to operate in frequency interval over 3.1 to 40 GHz. Good return loss and radiation pattern characteristics are obtained in the frequency band of interest. The proposed antenna structure is suitable for ultra-wideband applications, which is, required for many wearable electronics applications.

  9. Computer-aided design of the RF-cavity for a high-power S-band klystron

    NASA Astrophysics Data System (ADS)

    Kant, D.; Bandyopadhyay, A. K.; Pal, D.; Meena, R.; Nangru, S. C.; Joshi, L. M.

    2012-08-01

    This article describes the computer-aided design of the RF-cavity for a S-band klystron operating at 2856 MHz. State-of-the-art electromagnetic simulation tools SUPERFISH, CST Microwave studio, HFSS and MAGIC have been used for cavity design. After finalising the geometrical details of the cavity through simulation, it has been fabricated and characterised through cold testing. Detailed results of the computer-aided simulation and cold measurements are presented in this article.

  10. Higher order mode of a microstripline fed cylindrical dielectric resonator antenna

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kumar, A. V. Praveen, E-mail: praveen.kumar@pilani.bits-pilani.ac.in

    2016-03-09

    A microstrip transmission line can be used to excite the broadside radiating mode of a cylindrical dielectric resonator antenna (CDRA). The same is found to excite considerably well a higher order mode (HOM) as well. However unlike the broadside mode, the higher order mode gives distorted radiation pattern which makes this mode less useful for practical applications. The cause of distortion in the HOM radiation and the dependence of HOM coupling on the microstrip feed line are explored using HFSS simulations.

  11. Simulation-based analysis of performance parameters of microstrip antennas with criss-cross metamaterial-based artificial substrate

    NASA Astrophysics Data System (ADS)

    Inamdar, Kirti; Kosta, Y. P.; Patnaik, S.

    2014-10-01

    In this paper, we present the design of a metamaterial-based microstrip patch antenna, optimized for bandwidth and multiple frequency operations. A criss-cross structure has been proposed, this shape has been inspired from the famous Jerusalem cross. The theory and design formulas to calculate various parameters of the proposed antenna have been presented. Design starts with the analysis of the proposed unit cell structure, and validating the response using software- HFSS Version 13, to obtain negative response of ε and μ- metamaterial. Following this, a metamaterial-based-microstrip-patch-antenna is designed. A detailed comparative study is conducted exploring the response of the designed patch made of metamaterial and that of the conventional patch. Finally, antenna parameters such as gain, bandwidth, radiation pattern, and multiple frequency responses are investigated and optimised for the same and present in table and response graphs. It is also observed that the physical dimension of the metamaterial-based patch antenna is smaller compared to its conventional counterpart operating at the same fundamental frequency. The challenging part was to develop metamaterial based on some signature structures and techniques that would offer advantage in terms of BW and multiple frequency operation, which is demonstrated in this paper. The unique shape proposed in this paper gives improvement in bandwidth without reducing the gain of the antenna.

  12. Slot Optimization Design of Induction Motor for Electric Vehicle

    NASA Astrophysics Data System (ADS)

    Shen, Yiming; Zhu, Changqing; Wang, Xiuhe

    2018-01-01

    Slot design of induction motor has a great influence on its performance. The RMxprt module based on magnetic circuit method can be used to analyze the influence of rotor slot type on motor characteristics and optimize slot parameters. In this paper, the authors take an induction motor of electric vehicle for a typical example. The first step of the design is to optimize the rotor slot by RMxprt, and then compare the main performance of the motor before and after the optimization through Ansoft Maxwell 2D. After that, the combination of optimum slot type and the optimum parameters are obtained. The results show that the power factor and the starting torque of the optimized motor have been improved significantly. Furthermore, the electric vehicle works at a better running status after the optimization.

  13. Design and Simulation Test of an Open D-Dot Voltage Sensor

    PubMed Central

    Bai, Yunjie; Wang, Jingang; Wei, Gang; Yang, Yongming

    2015-01-01

    Nowadays, sensor development focuses on miniaturization and non-contact measurement. According to the D-dot principle, a D-dot voltage sensor with a new structure was designed based on the differential D-dot sensor with a symmetrical structure, called an asymmetric open D-dot voltage sensor. It is easier to install. The electric field distribution of the sensor was analyzed through Ansoft Maxwell and an open D-dot voltage sensor was designed. This open D-voltage sensor is characteristic of accessible insulating strength and small electric field distortion. The steady and transient performance test under 10 kV-voltage reported satisfying performances of the designed open D-dot voltage sensor. It conforms to requirements for a smart grid measuring sensor in intelligence, miniaturization and facilitation. PMID:26393590

  14. Multi-Step Ka/Ka Dichroic Plate with Rounded Corners for NASA's 34m Beam Waveguide Antenna

    NASA Technical Reports Server (NTRS)

    Veruttipong, Watt; Khayatian, Behrouz; Hoppe, Daniel; Long, Ezra

    2013-01-01

    A multi-step Ka/Ka dichroic plate Frequency Selective Surface (FSS structure) is designed, manufactured and tested for use in NASA's Deep Space Network (DSN) 34m Beam Waveguide (BWG) antennas. The proposed design allows ease of manufacturing and ability to handle the increased transmit power (reflected off the FSS) of the DSN BWG antennas from 20kW to 100 kW. The dichroic is designed using HFSS and results agree well with measured data considering the manufacturing tolerances that could be achieved on the dichroic.

  15. The extent of food advertising to children on UK television in 2008.

    PubMed

    Boyland, Emma J; Harrold, Joanne A; Kirkham, Tim C; Halford, Jason C G

    2011-10-01

    To provide the most comprehensive analysis to date of the extent of food advertising on UK television channels popular with young people following regulatory reform of this type of marketing activity. UK television was recorded 06:00-22:00 h for a weekday and a weekend day every month between January and December 2008 for 14 of the most popular commercial channels broadcasting children's/family viewing. Recordings were screened for advertisements, which were coded according to predefined categories including whether they were broadcast in peak/non-peak children's viewing time. Food advertisements were coded as core (healthy)/non-core (unhealthy)/miscellaneous foods. Food and drinks were the third most heavily advertised product category, and there were a significantly greater proportion of advertisements for food/drinks during peak compared to non-peak children's viewing times. A significantly greater proportion of the advertisements broadcast around soap operas than around children's programmes were for food/drinks. Children's channels broadcast a significantly greater proportion of non-core food advertisements than the family channels. There were significant differences between recording months for the proportion of core/non-core/miscellaneous food advertisements. Despite regulation, children in the UK are exposed to more TV advertising for unhealthy than healthy food items, even at peak children's viewing times. There remains scope to strengthen the rules regarding advertising of HFSS foods around programming popular with children and adults alike, where current regulations do not apply. Ongoing, systematic monitoring is essential for evaluation of the effectiveness of regulations designed to reduce children's exposure to HFSS food advertising on television in the UK.

  16. An efficient self-collimating photonic crystal coupling technique in the RF regime

    NASA Astrophysics Data System (ADS)

    Sabas, Jerico N.; Mirza, Iftekhar O.; Shi, Shouyuan; Prather, Dennis W.

    2010-02-01

    In this paper, we present both numerical and experimental results for the waveguiding of light using a low-index-contrast (LIC) self-collimating photonic crystal (SCPhC) in the RF frequency regime. This waveguiding structure utilizes the unique interactions of light with the periodic structure of the photonic crystal (PhC) to propagate a beam of light without divergence. This design also employs materials with a low index contrast (LIC), which reduces the electromagnetic signature of the PhC. This SCPhC was designed by extracting its dispersion contours and numerically simulating it using HFSS, a commercial 3-D, full-wave FEM software. In particular, we addressed the issue of coupling the PhC to a coaxial medium by designing an input/output (I/O) coupler consisting of a coaxial-to-waveguide transition, a rectangular waveguide and a tapered dielectric transition. We fabricated the SCPhC with a rigid polyurethane foam slab and Rexolite polystyrene rods using an automated CNC router to drill the periodic lattice in the slab. We also fabricated the dielectric segments of the I/O couplers with Rexolite slabs using an automated milling machine. Using these I/O couplers and SCPhC slab, we simulated and subsequently measured experimentally an insertion loss, for the entire system, of -3.3 dB through a 24" PhC slab, and a coupling loss of -0.95 dB at each coupler-PhC interface.

  17. Design of Miniaturized Dual-Band Microstrip Antenna for WLAN Application.

    PubMed

    Yang, Jiachen; Wang, Huanling; Lv, Zhihan; Wang, Huihui

    2016-06-27

    Wireless local area network (WLAN) is a technology that combines computer network with wireless communication technology. The 2.4 GHz and 5 GHz frequency bands in the Industrial Scientific Medical (ISM) band can be used in the WLAN environment. Because of the development of wireless communication technology and the use of the frequency bands without the need for authorization, the application of WLAN is becoming more and more extensive. As the key part of the WLAN system, the antenna must also be adapted to the development of WLAN communication technology. This paper designs two new dual-frequency microstrip antennas with the use of electromagnetic simulation software-High Frequency Structure Simulator (HFSS). The two antennas adopt ordinary FR4 material as a dielectric substrate, with the advantages of low cost and small size. The first antenna adopts microstrip line feeding, and the antenna radiation patch is composed of a folded T-shaped radiating dipole which reduces the antenna size, and two symmetrical rectangular patches located on both sides of the T-shaped radiating patch. The second antenna is a microstrip patch antenna fed by coaxial line, and the size of the antenna is diminished by opening a stepped groove on the two edges of the patch and a folded slot inside the patch. Simulation experiments prove that the two designed antennas have a higher gain and a favourable transmission characteristic in the working frequency range, which is in accordance with the requirements of WLAN communication.

  18. An RF phased array applicator designed for hyperthermia breast cancer treatments

    PubMed Central

    Wu, Liyong; McGough, Robert J; Arabe, Omar Ali; Samulski, Thaddeus V

    2007-01-01

    An RF phased array applicator has been constructed for hyperthermia treatments in the intact breast. This RF phased array consists of four antennas mounted on a Lexan water tank, and geometric focusing is employed so that each antenna points in the direction of the intended target. The operating frequency for this phased array is 140 MHz. The RF array has been characterized both by electric field measurements in a water tank and by electric field simulations using the finite-element method. The finite-element simulations are performed with HFSS software, where the mesh defined for finite-element calculations includes the geometry of the tank enclosure and four end-loaded dipole antennas. The material properties of the water tank enclosure and the antennas are also included in each simulation. The results of the finite-element simulations are compared to the measured values for this configuration, and the results, which include the effects of amplitude shading and phase shifting, show that the electric field predicted by finite-element simulations is similar to the measured field. Simulations also show that the contributions from standing waves are significant, which is consistent with measurement results. Simulated electric field and bio-heat transfer results are also computed within a simple 3D breast model. Temperature simulations show that, although peak temperatures are generated outside the simulated tumour target, this RF phased array applicator is an effective device for regional hyperthermia in the intact breast. PMID:16357427

  19. Smart reconfigurable parabolic space antenna for variable electromagnetic patterns

    NASA Astrophysics Data System (ADS)

    Kalra, Sahil; Datta, Rituparna; Munjal, B. S.; Bhattacharya, Bishakh

    2018-02-01

    An application of reconfigurable parabolic space antenna for satellite is discussed in this paper. The present study focuses on shape morphing of flexible parabolic antenna actuated with Shape Memory Alloy (SMA) wires. The antenna is able to transmit the signals to the desired footprint on earth with a desired gain value. SMA wire based actuation with a locking device is developed for a precise control of Antenna shape. The locking device is efficient to hold the structure in deformed configuration during power cutoff from the system. The maximum controllable deflection at any point using such actuation system is about 25mm with a precision of ±100 m. In order to control the shape of the antenna in a closed feedback loop, a Proportional, Integral and Derivative (PID) based controller is developed using LabVIEW (NI) and experiments are performed. Numerical modeling and analysis of the structure is carried out using finite element software ABAQUS. For data reduction and fast computation, stiffness matrix generated by ABAQUS is condensed by Guyan Reduction technique and shape optimization is performed using Non-dominated Sorting Genetic Algorithm (NSGA-II). The matching in comparative study between numerical and experimental set-up shows efficacy of our method. Thereafter, Electro-Magnetic (EM) simulations of the deformed shape is carried out using electromagnetic field simulation, High Frequency Structure Simulator (HFSS). The proposed design is envisaged to be very effective for multipurpose application of satellite system in the future missions of Indian Space Research Organization (ISRO).

  20. Antenna design for propagating spin wave spectroscopy in ferromagnetic thin films

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Yu, Ting; Chen, Ji-lei; Zhang, You-guang; Feng, Jian; Tu, Sa; Yu, Haiming

    2018-03-01

    In this paper, we investigate the characteristics of antenna for propagating-spin-wave-spectroscopy (PSWS) experiment in ferromagnetic thin films. Firstly, we simulate the amplitude and phase distribution of the high-frequency magnetic field around antenna by high frequency structure simulator (HFSS). And then k distribution of the antenna is obtained by fast Fourier transformation (FFT). Furthermore, three kinds of antenna designs, i.e. micro-strip line, coplanar waveguide (CPW), loop, are studied and compared. How the dimension parameter of antenna influence the corresponding high-frequency magnetic field amplitude and k distribution are investigated in details.

  1. Television food advertising to children in Malta.

    PubMed

    Cauchi, Daniel; Reiff, Sascha; Knai, Cecile; Gauci, Charmaine; Spiteri, Joanna

    2017-06-01

    To undertake a cross-sectional survey of the extent and nature of food and beverage advertising to children on Maltese national television stations. Seven national free-to-air channels were recorded for seven consecutive days in March 2014 between 07:00 and 22:00 h. Advertisements were coded according to predefined categories, with a focus on advertisements aired during 'peak' children's viewing times, defined as periods during which more than 25% of children were likely to be watching television on any channel. Food and beverage advertisements were classified as core (healthy), non-core (unhealthy) or miscellaneous foods. Malta. Whole population, with a focus on children. Food and drinks were the most heavily advertised product category (26.9% of all advertisements) across all channels. The proportion of non-core food/drink advertisements was significantly greater during peak compared with non-peak children's viewing times (52 vs 44.6%; p ≤ 0.001). A majority of advertisements aimed at children are for non-core foods, and are typically shown during family-oriented programmes in the late evening rather than being restricted to children's programmes. 'Taste', 'enjoyment' and 'peer status' were the primary persuasive appeals used in adolescent and child-focused advertisements. This first content analysis of television advertising in Malta suggests that there is scope for the implementation of statutory regulation regarding advertising of foods high in fat, sugar and salt (HFSS) during times when children are likely to watch television, rather than during children's programmes only. Ongoing, systematic monitoring is essential for evaluation of the effectiveness of regulations designed to reduce children's exposure to HFSS food advertising on television. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Severe chronic heart failure in patients considered for heart transplantation in Poland.

    PubMed

    Korewicki, Jerzy; Leszek, Przemysław; Zieliński, Tomasz; Rywik, Tomasz; Piotrowski, Walerian; Kurjata, Paweł; Kozar-Kamińska, Katarzyna; Kodziszewska, Katarzyna

    2012-01-01

    Based on the results of clinical trials, the prognosis for patients with severe heart failure (HF) has improved over the last 20 years. However, clinical trials do not reflect 'real life' due to patient selection. Thus, the aim of the POLKARD-HF registry was the analysis of survival of patients with refractory HF referred for orthotopic heart transplantation (OHT). Between 1 November 2003 and 31 October 2007, 983 patients with severe HF, referred for OHT in Poland, were included into the registry. All patients underwent routine clinical and hemodynamic evaluation, with NT-proBNP and hsCRP assessment. Death or an emergency OHT were assumed as the endpoints. The average observation period was 601 days. Kaplan-Meier curves with log-rank and univariate together with multifactor Cox regression model the stepwise variable selection method were used to determine the predictive value of analyzed variables. Among the 983 patients, the probability of surviving for one year was approximately 80%, for two years 70%, and for three years 67%. Etiology of the HF did not significantly influence the prognosis. The patients in NYHA class IV had a three-fold higher risk of death or emergency OHT. The univariate/multifactor Cox regression analysis revealed that NYHA IV class (HR 2.578, p < 0.0001), HFSS score (HR 2.572, p < 0.0001) and NT-proBNP plasma level (HR 1.600, p = 0.0200), proved to influence survival without death or emergency OHT. Despite optimal treatment, the prognosis for patients with refractory HF is still not good. NYHA class IV, NT-proBNP and HFSS score can help define the highest risk group. The results are consistent with the prognosis of patients enrolled into the randomized trials.

  3. Free-Space Measurements of Dielectrics and Three-Dimensional Periodic Metamaterials

    NASA Astrophysics Data System (ADS)

    Kintner, Clifford E.

    This thesis presents the free-space measurements of a periodic metamaterial structure. The metamaterial unit cell consists of two dielectric sheets intersecting at 90 degrees. The dielectric is a polyetherimide-based material 0.001" thick. Each sheet has a copper capacitively-loaded loop (CLL) structure on the front and a cut-wire structure on the back. Foam material is used to support the unit cells. The unit cell repeats 40 times in the x-direction, 58 times in the y-direction and 5 times in the z-direction. The sample measures 12" x 12" x 1" in total. We use a free-space broadband system comprised of a pair of dielectric-lens horn antennas with bandwidth from 5.8 GHz to 110 GHz, which are connected to a HP PNA series network analyzer. The dielectric lenses focus the incident beam to a footprint measuring 1 wavelength by 1 wavelength. The sample holder is positioned at the focal point between the two antennas. In this work, the coefficients of transmission and reflection (the S-parameters S21 and S11) are measured at frequencies from 12.4 GHz up to 30 GHz. Simulations are used to validate the measurements, using the Ansys HFSS commercial software package on the Arkansas High Performance Computing Center cluster. The simulation results successfully validate the S-parameters measurements, in particular the amplitudes. An algorithm based on the Nicolson-Ross-Weir (NRW) method is implemented to extract the permittivity and permeability values of the metamaterial under test. The results show epsilon-negative, mu-negative and double-negative parameters within the measured frequency range.

  4. Design and measurement of a direct-drillable smooth walled feedhorn at 1.2 THz for the next generation BLASTPol experiment

    NASA Astrophysics Data System (ADS)

    Groppi, Christopher E.; Mauskopf, P. M.; Ade, P. A. R.; Underhill, M.

    2016-07-01

    We present the design and measurement of a direct-drillable smooth walled feedhorn for the Next Generation BLASTPol balloon experiment. Custom milling cutters were obtained commercially and used to fabricate a two feedhorn structures with UG-387 flanges, each with 0.5mm section of circular waveguide, which were then mated back to back. These horns were then tested at Cardiff University using a rotation stage scanner to measure E and H plane cuts of the horn. The measurements show good agreement in both the beam FWHM and sidelobes as compared to HFSS simulations of the horn.

  5. A compact planar multi-broad band monopole antenna for mobile devices

    NASA Astrophysics Data System (ADS)

    Zhong, Xiaoqing; Yao, Bin; Zheng, Qinhong; Yang, Jikong; Cao, Xiangqi

    2015-10-01

    A Multiple-frequency broadband planar monopole antenna is proposed in this Paper. The antenna is stimulated and numerically optimized by HFSS13.0 (High Frequency Structure Simulator). The size of it is 39mm×22mm×1.7mm. The antenna resonates at many frequencies. The parameter S11<=-6dB means the proposed antenna matches well with its feed-line and covers many useful operation frequency bands, including 2G(DCS1800 and PCS1900), 3G(UMTS), 4G(LTE2300 and LTE2500), ISM, WLAN. It is quiet appropriate for the present ultra-thin smart phones

  6. Implantable multilayer microstrip antenna for retinal prosthesis: antenna testing.

    PubMed

    Permana, Hans; Fang, Qiang; Rowe, Wayne S T

    2012-01-01

    Retinal prosthesis has come to a more mature stage and become a very strategic answer to Retinitis Pigmentosa (RP) and Age-related Macular Degeneration (AMD) diseases. In a retinal prosthesis system, wireless link holds a great importance for the continuity of the system. In this paper, an implantable multilayer microstrip antenna was proposed for the retinal prosthesis system. Simulations were performed in High Frequency Structure Simulator (HFSS) with the surrounding material of air and Vitreous Humor fluid. The fabricated antenna was measured for characteristic validation in free space. The results showed that the real antenna possessed similar return loss and radiation pattern, while there was discrepancy with the gain values.

  7. Offset fed slot antenna for broadband operation

    NASA Astrophysics Data System (ADS)

    Ritish, K.; Piyush, S.; Praveen Kumar, A. V.

    2018-03-01

    In this paper, a microstrip fed rectangular slot antenna with wideband characteristics is proposed. Both the impedance and radiation characteristics of the proposed antenna are presented. It is shown that a properly offset feed can give a dual resonance nature, which can be optimized to enable wideband behavior. From HFSS simulation, an impedance bandwidth (-10 dB) of 49.92 % (2.51 GHz to 4.18 GHz) about the center frequency of the band is obtained. Prototype measurement demonstrates a bandwidth of 45.30 % (2.51 GHz to 3.98 GHz). Simulated radiation patterns show bidirectional behavior, which is stable in the band with a peak gain of 5.7 dBi and a gain variation of 2 dBi.

  8. Design and optimization of an ultra wideband and compact microwave antenna for radiometric monitoring of brain temperature.

    PubMed

    Rodrigues, Dario B; Maccarini, Paolo F; Salahi, Sara; Oliveira, Tiago R; Pereira, Pedro J S; Limao-Vieira, Paulo; Snow, Brent W; Reudink, Doug; Stauffer, Paul R

    2014-07-01

    We present the modeling efforts on antenna design and frequency selection to monitor brain temperature during prolonged surgery using noninvasive microwave radiometry. A tapered log-spiral antenna design is chosen for its wideband characteristics that allow higher power collection from deep brain. Parametric analysis with the software HFSS is used to optimize antenna performance for deep brain temperature sensing. Radiometric antenna efficiency (η) is evaluated in terms of the ratio of power collected from brain to total power received by the antenna. Anatomical information extracted from several adult computed tomography scans is used to establish design parameters for constructing an accurate layered 3-D tissue phantom. This head phantom includes separate brain and scalp regions, with tissue equivalent liquids circulating at independent temperatures on either side of an intact skull. The optimized frequency band is 1.1-1.6 GHz producing an average antenna efficiency of 50.3% from a two turn log-spiral antenna. The entire sensor package is contained in a lightweight and low-profile 2.8 cm diameter by 1.5 cm high assembly that can be held in place over the skin with an electromagnetic interference shielding adhesive patch. The calculated radiometric equivalent brain temperature tracks within 0.4 °C of the measured brain phantom temperature when the brain phantom is lowered 10 °C and then returned to the original temperature (37 °C) over a 4.6-h experiment. The numerical and experimental results demonstrate that the optimized 2.5-cm log-spiral antenna is well suited for the noninvasive radiometric sensing of deep brain temperature.

  9. Synthesis and characterisation of novel low temperature ceramic and its implementation as substrate in dual segment CDRA

    NASA Astrophysics Data System (ADS)

    Kumari, Preeti; Tripathi, Pankaj; Sahu, Bhagirath; Singh, S. P.; Parkash, Om; Kumar, Devendra

    2018-02-01

    Li2O-(2-3x)MgO-(x)Al2O3-P2O5 (LMAP) (x = 0.00-0.08) ceramic system was prepared through solid state synthesis route at different sintering temperatures (800-925 °C). A small addition of Al2O3 (x = 0.02) in LMAP ceramics lowers the sintering temperature by more than 100 °C with good relative density of 94.13%. The sintered samples were characterized in terms of density, apparent porosity, water absorption, crystal structure, micro-structure and microwave dielectric properties. Silver compatibility test is also performed for its use as electrode material in low temperature co-fired ceramic (LTCC) application. To check the performance of the prepared LTCC as substrate, a microstrip-fed aperture-coupled dual segment cylindrical dielectric resonator antenna (DS-CDRA) is designed using LMAP (x = 0.02) ceramic as substrate material and Barium Strontium Titanate with 10 wt% of PbO-BaO-B2O3-SiO2 glass (BSTG) and Teflon as the components of resonating material. The simulation study of the DS-CDRA is performed using the Ansys High Frequency Structure Simulator (HFSS) software. A conductive coating of silver is used on the substrate. The simulated and measured -10 dB reflection coefficient bandwidths of 910 MHz (9.07-9.98 GHz at resonant frequency of 9.49 GHz) and 1080 MHz (8.68-9.76 GHz at resonant frequency of 9.36 GHz), respectively are achieved. The measured results of the fabricated antenna are found in good agreement with the simulation results. The prepared material can find potential applications in radar and radio navigation as well as radio astronomy and military satellite communication.

  10. Interaction of ICRF Fields with the Plasma Boundary in AUG and JET and Guidelines for Antenna Optimization

    NASA Astrophysics Data System (ADS)

    Bobkov, V.; Bilato, R.; Braun, F.; Colas, L.; Dux, R.; Van Eester, D.; Giannone, L.; Goniche, M.; Herrmann, A.; Jacquet, P.; Kallenbach, A.; Krivska, A.; Lerche, E.; Mayoral, M.-L.; Milanesio, D.; Monakhov, I.; Müller, H. W.; Neu, R.; Noterdaeme, J.-M.; Pütterich, Th.; Rohde, V.

    2009-11-01

    W sputtering during ICRF on ASDEX Upgrade (AUG) and temperature rise on JET A2 antenna septa are considered in connection with plasma conditions at the antenna plasma facing components and E‖ near-fields. Large antenna-plasma clearance, high gas puff and low light impurity content are favorable to reduce W sputtering in AUG. The spatial distribution of spectroscopically measured effective W sputtering yields clearly points to the existence of strong E‖ fields at the antenna box ("feeder fields") which dominate over the fields in front of the antenna straps. The picture of E‖ fields, obtained by HFSS code, corroborates the dominant role of E‖ at the antenna box on the formation of sheath-driving RF voltages for AUG. Large antenna-plasma clearance and low gas puff are favorable to reduce septum temperature of JET A2 antennas. Assuming a linear relation between the septum temperature and the sheath driving RF voltage calculated by HFSS, the changes of the temperature with dipole phasing (00ππ, 0ππ0 or 0π0π) are well described by the related changes of the RF voltages. Similarly to the AUG antenna, the strongest E‖ are found at the limiters of the JET A2 antenna for all used dipole phasings and at the septum for the phasings different from 0π0π. A simple general rule can be used to minimize E‖ at the antenna: image currents can be allowed only at the surfaces which do not intersect magnetic field lines at large angles of incidence. Possible antenna modifications generally rely either on a reduction of the image currents, on their short-circuiting by introducing additional conducting surfaces or on imposing the E‖ = 0 boundary condition. On the example of AUG antenna, possible options to minimize the sheath driving voltages are presented.

  11. Excitation of Higher Order Modes of Cylindrical Dielectric Resonator Antenna using Dual-slot feed

    NASA Astrophysics Data System (ADS)

    Ojha, A. K.; Praveen Kumar, A. V.

    2018-03-01

    Excitation of the higher order modes (HOM) of a cylindrical dielectric resonator antenna(DRA) of high relative permittivity, using dual feed scheme is investigated. The feed scheme uses a pair of narrow slots and is chosen on the basis of the field distribution of the desired DRA modes. Numerical studies using ANSYS HFSS show that the dual-feed excited a combination of two HOMs, which are identified as HEM21δ and TM01δ. The mixed-up nature is further verified through studying the radiation pattern of the DRA which shows azimuthal asymmetry and low gain. It is suggested that if one of the HOM is suppressed, better antenna performance can be achieved.

  12. Investigation of fluorine-doped tin oxide based optically transparent E-shaped patch antenna for terahertz communications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Anand, S., E-mail: anand.s.krishna@gmail.com, E-mail: darak.mayur@gmail.com, E-mail: srk@nitt.edu; Darak, Mayur Sudesh, E-mail: anand.s.krishna@gmail.com, E-mail: darak.mayur@gmail.com, E-mail: srk@nitt.edu; Kumar, D. Sriram, E-mail: anand.s.krishna@gmail.com, E-mail: darak.mayur@gmail.com, E-mail: srk@nitt.edu

    2014-10-15

    In this paper, a fluorine-doped tin oxide based optically transparent E-shaped patch antenna is designed and its radiation performance is analyzed in the 705 – 804 GHz band. As optically transparent antennas can be mounted on optical display, they facilitate the reduction of overall system size. The proposed antenna design is simulated using electromagnetic solver - Ansys HFSS and its characteristics such as impedance bandwidth, directivity, radiation efficiency and gain are observed. Results show that the fluorine-doped tin oxide based optically transparent patch antenna overcomes the conventional patch antenna limitations and thus the same can be used for solar cellmore » antenna used in satellite systems.« less

  13. [Design of an microwave applicator using for tumor in superficial layer].

    PubMed

    Sun, Bing; Lu, Xiaofeng; Cao, Yi

    2010-05-01

    A 2.45 GHz microstrip applicator using single rectangle sheet structure is presented. Based on the radiant principle of microstrip antenna, the applicator's parameter is designed and the simulating model is set and optimized in HFSS. Measured by network analyzer, the technical target of this applicator is complied with design demand. During irradiation experiment, based on 30 W power, 30 mm radiation distance and 15 min duration experiment condition, the thermal field distribution map of phantom is obtained from the far-infrared image instrument. The 3D map shows that the region of thermal field centre has small radius and deep heat penetration. The microwave energy from this applicator can reach the tumor in superficial layer without heat injuring normal tissue around it.

  14. The theoretical simulation on electrostatic distribution of 1st proximity region in proximity focusing low-light-level image intensifier

    NASA Astrophysics Data System (ADS)

    Zhang, Liandong; Bai, Xiaofeng; Song, De; Fu, Shencheng; Li, Ye; Duanmu, Qingduo

    2015-03-01

    Low-light-level night vision technology is magnifying low light level signal large enough to be seen by naked eye, which uses the photons - photoelectron as information carrier. Until the micro-channel plate was invented, it has been possibility for the realization of high performance and miniaturization of low-light-level night vision device. The device is double-proximity focusing low-light-level image intensifier which places a micro-channel plate close to photocathode and phosphor screen. The advantages of proximity focusing low-light-level night vision are small size, light weight, small power consumption, no distortion, fast response speed, wide dynamic range and so on. It is placed parallel to each other for Micro-channel plate (both sides of it with metal electrode), the photocathode and the phosphor screen are placed parallel to each other. The voltage is applied between photocathode and the input of micro-channel plate when image intensifier works. The emission electron excited by photo on the photocathode move towards to micro-channel plate under the electric field in 1st proximity focusing region, and then it is multiplied through the micro-channel. The movement locus of emission electrons can be calculated and simulated when the distributions of electrostatic field equipotential lines are determined in the 1st proximity focusing region. Furthermore the resolution of image tube can be determined. However the distributions of electrostatic fields and equipotential lines are complex due to a lot of micro-channel existing in the micro channel plate. This paper simulates electrostatic distribution of 1st proximity region in double-proximity focusing low-light-level image intensifier with the finite element simulation analysis software Ansoft maxwell 3D. The electrostatic field distributions of 1st proximity region are compared when the micro-channel plates' pore size, spacing and inclination angle ranged. We believe that the electron beam movement trajectory in 1st proximity region will be better simulated when the electronic electrostatic fields are simulated.

  15. Characterization of Personal Privacy Devices (PPD) radiation pattern impact on the ground and airborne segments of the local area augmentation system (LAAS) at GPS L1 frequency

    NASA Astrophysics Data System (ADS)

    Alkhateeb, Abualkair M. Khair

    Personal Privacy Devices (PPDs) are radio-frequency transmitters that intentionally transmit in a frequency band used by other devices for the intent purpose of denying service to those devices. These devices have shown the potential to interfere with the ground and air sub-systems of the Local Area Augmentation Systems (LAAS), a GPS-based navigation aids at commercial airports. The Federal Aviation Administration (FAA) is concerned by the potential impact of these devices to GPS navigation aids at airports and has commenced an activity to determine the severity of this threat. In support of this situation, the research in this dissertation has been conducted under (FAA) Cooperative Agreement 2011-G-012, to investigate the impact of these devices on the LAAS. In order to investigate the impact of PPDs Radio Frequency Interference (RFI) on the ground and air sub-systems of the LAAS, the work presented in phase one of this research is intended to characterize the vehicle's impact on the PPD's Effective Isotropic Radiated Power (EIRP). A study was conceived in this research to characterize PPD performance by examining the on-vehicle radiation patterns as a function of vehicle type, jammer type, jammer location inside a vehicle and jammer orientation at each location. Phase two was to characterize the GPS Radiation Pattern on Multipath Limiting Antenna. MLA has to meet stringent requirements for acceptable signal detection and multipath rejection. The ARL-2100 is the most recent MLA antenna proposed to be used in the LAAS ground segment. The ground-based antenna's radiation pattern was modeled. This was achieved via (HFSS) a commercial-off the shelf CAD-based modeling code with a full-wave electromagnetic software simulation package that uses the Finite Element Analysis. Phase three of this work has been conducted to study the characteristics of the GPS Radiation Pattern on Commercial Aircraft. The airborne GPS antenna was modeled and the resulting radiation pattern on a Bombardier Global 5000 commercial full aircraft was studied. This was achieved via CAD-based modeling with a full-wave electromagnetic software simulation package (FEKO). It is important because the aircraft comes in approach on a 3° glideslope angle. Elevation relative to PPD jammer is changing.

  16. Food references in UK children's magazines - an oral health perspective.

    PubMed

    Chapman, K J; Fairchild, R M; Morgan, M Z

    2014-11-01

    Children's magazines are popular in the United Kingdom, but their content is poorly regulated. Consequently, food and beverages high in fat, salt and sugar (HFSS), detrimental to oral and wider health, make unrestricted appearances. The study aim was to assess the amount of HFSS food and drink children are exposed to while reading magazines; with particular focus on foods containing free sugars due to their known cariogenic properties, and foods with low pH due to their erosive potential. Eleven of the most popular UK children's magazines were selected and purchased at four separate time points in 2012. These 44 magazines were examined using content analysis; any references to food/beverages (in advertisements, free gifts, editorial and general content) were recorded. Of the 508 food references observed, 73.6% (374/508) were for foods detrimental to oral health owing to their high sugar and/or acid content. 5.9% (30/508) were considered 'unhealthy' due to their fat or salt content. 20.5% of references were for 'healthy' foods (104/508). The most common food categories referenced were baked goods (181/508) and sweets (86/508). Over a third (36.4%, 16/44) of magazines came with free sweets. In terms of positioning, the food/drink references were predominantly found in the general content of the magazines, including the editorial spreads. Direct advertisements for food/drink only accounted for 9.6% (36/374) of the total number of references counted. Food references within children's magazines are biased towards unhealthy foods especially those detrimental to oral health; these permeate throughout the general and editorial content and are not restricted to direct advertisements. Magazine editors, journalists and illustrators are responsible for the editorial and general content of magazines. Without regulation, subliminal placement of advertisements within editorial and general content leads to 'advertorials' which are known to confuse children and parents alike. This study concludes that regulation may therefore need to cover more than just the direct advertisements. Dental professionals need to be aware of current trends in children's media when giving health education advice or designing health promotion initiatives.

  17. Design and multiphysics analysis of a 176Â MHz continuous-wave radio-frequency quadrupole

    NASA Astrophysics Data System (ADS)

    Kutsaev, S. V.; Mustapha, B.; Ostroumov, P. N.; Barcikowski, A.; Schrage, D.; Rodnizki, J.; Berkovits, D.

    2014-07-01

    We have developed a new design for a 176 MHz cw radio-frequency quadrupole (RFQ) for the SARAF upgrade project. At this frequency, the proposed design is a conventional four-vane structure. The main design goals are to provide the highest possible shunt impedance while limiting the required rf power to about 120 kW for reliable cw operation, and the length to about 4 meters. If built as designed, the proposed RFQ will be the first four-vane cw RFQ built as a single cavity (no resonant coupling required) that does not require π-mode stabilizing loops or dipole rods. For this, we rely on very detailed 3D simulations of all aspects of the structure and the level of machining precision achieved on the recently developed ATLAS upgrade RFQ. A full 3D model of the structure including vane modulation was developed. The design was optimized using electromagnetic and multiphysics simulations. Following the choice of the vane type and geometry, the vane undercuts were optimized to produce a flat field along the structure. The final design has good mode separation and should not need dipole rods if built as designed, but their effect was studied in the case of manufacturing errors. The tuners were also designed and optimized to tune the main mode without affecting the field flatness. Following the electromagnetic (EM) design optimization, a multiphysics engineering analysis of the structure was performed. The multiphysics analysis is a coupled electromagnetic, thermal and mechanical analysis. The cooling channels, including their paths and sizes, were optimized based on the limiting temperature and deformation requirements. The frequency sensitivity to the RFQ body and vane cooling water temperatures was carefully studied in order to use it for frequency fine-tuning. Finally, an inductive rf power coupler design based on the ATLAS RFQ coupler was developed and simulated. The EM design optimization was performed using cst Microwave Studio and the results were verified using both hfss and ansys. The engineering analysis was performed using hfss and ansys and most of the results were verified using the newly developed cst Multiphysics package.

  18. Television advertising and branding. Effects on eating behaviour and food preferences in children.

    PubMed

    Boyland, Emma J; Halford, Jason C G

    2013-03-01

    Television provides one of the first, and most intimate, experiences of commercial food promotion. Therefore, unsurprisingly, the effects of television advertising on children's brand preferences are well established. However, its effect on actual food intake and the food choices in children of various weight statuses has only recently been characterised. Despite regulation, children in the UK are exposed to considerable numbers of food adverts on television. These are predominantly for foods high in fat, salt and sugar (HFSS), which are marketed to children using promotional characters and themes of fun. Such adverts have been shown to cause significant increases in intake, particularly in overweight and obese children, and enhanced preference for high carbohydrate and high fat foods in children who consume the greatest amounts of televisual media. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Dual-Band Operation of a Microstrip Patch Antenna on a Duroid 5870 Substrate for Ku- and K-Bands

    PubMed Central

    Islam, M. M.; Islam, M. T.; Faruque, M. R. I.

    2013-01-01

    The dual-band operation of a microstrip patch antenna on a Duroid 5870 substrate for Ku- and K-bands is presented. The fabrication of the proposed antenna is performed with slots and a Duroid 5870 dielectric substrate and is excited by a 50 Ω microstrip transmission line. A high-frequency structural simulator (HFSS) is used which is based on the finite element method (FEM) in this research. The measured impedance bandwidth (2 : 1 VSWR) achieved is 1.07 GHz (15.93 GHz–14.86 GHz) on the lower band and 0.94 GHz (20.67–19.73 GHz) on the upper band. A stable omnidirectional radiation pattern is observed in the operating frequency band. The proposed prototype antenna behavior is discussed in terms of the comparisons of the measured and simulated results. PMID:24385878

  20. Dual-band operation of a microstrip patch antenna on a Duroid 5870 substrate for Ku- and K-bands.

    PubMed

    Islam, M M; Islam, M T; Faruque, M R I

    2013-01-01

    The dual-band operation of a microstrip patch antenna on a Duroid 5870 substrate for Ku- and K-bands is presented. The fabrication of the proposed antenna is performed with slots and a Duroid 5870 dielectric substrate and is excited by a 50 Ω microstrip transmission line. A high-frequency structural simulator (HFSS) is used which is based on the finite element method (FEM) in this research. The measured impedance bandwidth (2 : 1 VSWR) achieved is 1.07 GHz (15.93 GHz-14.86 GHz) on the lower band and 0.94 GHz (20.67-19.73 GHz) on the upper band. A stable omnidirectional radiation pattern is observed in the operating frequency band. The proposed prototype antenna behavior is discussed in terms of the comparisons of the measured and simulated results.

  1. Substrate integrated waveguide filter showing improved stopband performance and fractional bandwidth using different input/output topologies

    NASA Astrophysics Data System (ADS)

    Kumari, Puja; Mudiganti, Jagadish Chandra

    2017-11-01

    In this work bandpass filter based on SIW technology with an adequate fractional bandwidth as well as refinement in the stopband performance is presented. Its application lies with the receiver filter working in the Ka band used mainly in the ground terminal for satellite communication. Additionally analysis of divergent input/output arrangement is also demonstrated. Three SIW filter having a varying passband from 19.2GHz -21.2GHz depending on the input/output are synthesized on a planar substrate having height of 0.508mm RT/duroid 6002 using periodically arranged metal via holes through a regulated PCB process. Simulated outputs has a in-band insertion loss 0.9dB and the improved stopband attenuation within the frequency range of 29.5GHz - 31GHz is around 45 dB. It is observed that the experimented results coincide completely with the results simulated in HFSS/CST.

  2. Design and development of a 6 MW peak, 24 kW average power S-band klystron

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Joshi, L.M.; Meena, Rakesh; Nangru, Subhash

    2011-07-01

    A 6 MW peak, 24 kW average power S-band Klystron is under development at CEERI, Pilani under an MoU between BARC and CEERI. The design of the klystron has been completed. The electron gun has been designed using TRAK and MAGIC codes. RF cavities have been designed using HFSS and CST Microwave Studio while the complete beam wave interaction simulation has been done using MAGIC code. The thermal design of collector and RF window has been done using ANSYS code. A Gun Collector Test Module (GCTM) was developed before making actual klystron to validate gun perveance and thermal design ofmore » collector. A high voltage solid state pulsed modulator has been installed for performance valuation of the tube. The paper will cover the design aspects of the tube and experimental test results of GCTM and klystron. (author)« less

  3. Modified Sierpenski Antenna With Metamaterial For Wireless Applications

    NASA Astrophysics Data System (ADS)

    Aggarwal, Ishita; Pandey, Sujata

    2017-08-01

    This paper presents a multiband antenna based on modified sierpenski fractal structure along with metamaterials for wireless applications. Multi bands are obtained at 2.1 GHz, 5.73 GHz, 7.6 GHz and 8.4 GHz with return losses -21.49 dB,-36.36 dB,-45dB, and -23.46 dBrespectively. The dimension of the substrate used for this antenna is 52 x 60 x 1.6 mm3 and dielectric constant is 4.4 with tanδ of 0.002. The peak gain of 6.6 dB, return loss of -45 dB and VSWR of 1 are obtained at 7.6 GHz. Metamaterial unit cells are loaded on ground to improve the antenna parameters. This is a simple and compact design and has multiband features suitable for WIMAX, WLAN, C-band and X-band applications. This design is simulated by using HFSS 14.

  4. Design and parameter estimation of hybrid magnetic bearings for blood pump applications

    NASA Astrophysics Data System (ADS)

    Lim, Tau Meng; Zhang, Dongsheng; Yang, Juanjuan; Cheng, Shanbao; Low, Sze Hsien; Chua, Leok Poh; Wu, Xiaowei

    2009-10-01

    This paper discusses the design and parameter estimation of the dynamics characteristics of a high-speed hybrid magnetic bearings (HMBs) system for axial flow blood pump applications. The rotor/impeller of the pump is driven by a three-phase permanent magnet (PM) brushless and sensorless DC motor. It is levitated by two HMBs at both ends in five-degree-of-freedom with proportional-integral-derivative (PID) controllers; among which four radial directions are actively controlled and one axial direction is passively controlled. Test results show that the rotor can be stably supported to speeds of 14,000 rpm. The frequency domain parameter estimation technique with statistical analysis is adopted to validate the stiffness and damping coefficients of the HMBs system. A specially designed test rig facilitated the estimation of the bearing's coefficients in air—in both the radial and axial directions. The radial stiffness of the HMBs is compared to the Ansoft's Maxwell 2D/3D finite element magnetostatic results. Experimental estimation showed that the dynamics characteristics of the HMBs system are dominated by the frequency-dependent stiffness coefficients. The actuator gain was also successfully calibrated and may potentially extend the parameter estimation technique developed in the study of identification and monitoring of the pump's dynamics properties under normal operating conditions with fluid.

  5. Research on key factors and their interaction effects of electromagnetic force of high-speed solenoid valve.

    PubMed

    Liu, Peng; Fan, Liyun; Hayat, Qaisar; Xu, De; Ma, Xiuzhen; Song, Enzhe

    2014-01-01

    Analysis consisting of numerical simulations along with lab experiments of interaction effects between key parameters on the electromagnetic force based on response surface methodology (RSM) has been also proposed to optimize the design of high-speed solenoid valve (HSV) and improve its performance. Numerical simulation model of HSV has been developed in Ansoft Maxwell environment and its accuracy has been validated through lab experiments. Effect of change of core structure, coil structure, armature structure, working air gap, and drive current on the electromagnetic force of HSV has been analyzed through simulation model and influence rules of various parameters on the electromagnetic force have been established. The response surface model of the electromagnetic force has been utilized to analyze the interaction effect between major parameters. It has been concluded that six interaction factors including working air gap with armature radius, drive current with armature thickness, coil turns with side pole radius, armature thickness with its radius, armature thickness with side pole radius, and armature radius with side pole radius have significant influence on the electromagnetic force. Optimal match values between coil turns and side pole radius; armature thickness and side pole radius; and armature radius and side pole radius have also been determined.

  6. Research on Key Factors and Their Interaction Effects of Electromagnetic Force of High-Speed Solenoid Valve

    PubMed Central

    Fan, Liyun; Xu, De; Ma, Xiuzhen; Song, Enzhe

    2014-01-01

    Analysis consisting of numerical simulations along with lab experiments of interaction effects between key parameters on the electromagnetic force based on response surface methodology (RSM) has been also proposed to optimize the design of high-speed solenoid valve (HSV) and improve its performance. Numerical simulation model of HSV has been developed in Ansoft Maxwell environment and its accuracy has been validated through lab experiments. Effect of change of core structure, coil structure, armature structure, working air gap, and drive current on the electromagnetic force of HSV has been analyzed through simulation model and influence rules of various parameters on the electromagnetic force have been established. The response surface model of the electromagnetic force has been utilized to analyze the interaction effect between major parameters. It has been concluded that six interaction factors including working air gap with armature radius, drive current with armature thickness, coil turns with side pole radius, armature thickness with its radius, armature thickness with side pole radius, and armature radius with side pole radius have significant influence on the electromagnetic force. Optimal match values between coil turns and side pole radius; armature thickness and side pole radius; and armature radius and side pole radius have also been determined. PMID:25243217

  7. Studies on the coupling transformer to improve the performance of microwave ion source.

    PubMed

    Misra, Anuraag; Pandit, V S

    2014-06-01

    A 2.45 GHz microwave ion source has been developed and installed at the Variable Energy Cyclotron Centre to produce high intensity proton beam. It is operational and has already produced more than 12 mA of proton beam with just 350 W of microwave power. In order to optimize the coupling of microwave power to the plasma, a maximally flat matching transformer has been used. In this paper, we first describe an analytical method to design the matching transformer and then present the results of rigorous simulation performed using ANSYS HFSS code to understand the effect of different parameters on the transformed impedance and reflection and transmission coefficients. Based on the simulation results, we have chosen two different coupling transformers which are double ridged waveguides with ridge widths of 24 mm and 48 mm. We have fabricated these transformers and performed experiments to study the influence of these transformers on the coupling of microwave to plasma and extracted beam current from the ion source.

  8. Studies on the coupling transformer to improve the performance of microwave ion source

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Misra, Anuraag, E-mail: pandit@vecc.gov.in, E-mail: vspandit12@gmail.com, E-mail: anuraag@vecc.gov.in; Pandit, V. S., E-mail: pandit@vecc.gov.in, E-mail: vspandit12@gmail.com, E-mail: anuraag@vecc.gov.in

    A 2.45 GHz microwave ion source has been developed and installed at the Variable Energy Cyclotron Centre to produce high intensity proton beam. It is operational and has already produced more than 12 mA of proton beam with just 350 W of microwave power. In order to optimize the coupling of microwave power to the plasma, a maximally flat matching transformer has been used. In this paper, we first describe an analytical method to design the matching transformer and then present the results of rigorous simulation performed using ANSYS HFSS code to understand the effect of different parameters on themore » transformed impedance and reflection and transmission coefficients. Based on the simulation results, we have chosen two different coupling transformers which are double ridged waveguides with ridge widths of 24 mm and 48 mm. We have fabricated these transformers and performed experiments to study the influence of these transformers on the coupling of microwave to plasma and extracted beam current from the ion source.« less

  9. Multicriteria Decision-Making Approach with Hesitant Interval-Valued Intuitionistic Fuzzy Sets

    PubMed Central

    Peng, Juan-juan; Wang, Jian-qiang; Wang, Jing; Chen, Xiao-hong

    2014-01-01

    The definition of hesitant interval-valued intuitionistic fuzzy sets (HIVIFSs) is developed based on interval-valued intuitionistic fuzzy sets (IVIFSs) and hesitant fuzzy sets (HFSs). Then, some operations on HIVIFSs are introduced in detail, and their properties are further discussed. In addition, some hesitant interval-valued intuitionistic fuzzy number aggregation operators based on t-conorms and t-norms are proposed, which can be used to aggregate decision-makers' information in multicriteria decision-making (MCDM) problems. Some valuable proposals of these operators are studied. In particular, based on algebraic and Einstein t-conorms and t-norms, some hesitant interval-valued intuitionistic fuzzy algebraic aggregation operators and Einstein aggregation operators can be obtained, respectively. Furthermore, an approach of MCDM problems based on the proposed aggregation operators is given using hesitant interval-valued intuitionistic fuzzy information. Finally, an illustrative example is provided to demonstrate the applicability and effectiveness of the developed approach, and the study is supported by a sensitivity analysis and a comparison analysis. PMID:24983009

  10. A Design of Terahertz Parallel Plate Dielectric Waveguide with Signal Line inserted for Ballistic Deflection Transistor Travelling Wave Amplifier

    NASA Astrophysics Data System (ADS)

    Wang, H.; Knepper, R.; Hossain, N.; Marthi, P.; Milithaler, J.-F.; Margala, M.

    2017-10-01

    In this paper a new waveguide design is proposed to be implemented as part of Ballistic Deflection Transistor (BDT) Traveling Wave Amplifier Design. The BDT is designed to be operated in the Terahertz regime. Due to its relatively low transconductance (gm=200µA/V), the entire structure will consist of ten stages, with 15 BDTs/stage, to reach a total gain of 30mA/V. In this case, the total length of the transmission line will be more than 400µm. We did the investigation for different structures and materials of the transmission line. For our Parallel Plate Dielectric Waveguide with Signal Line inserted (PPDWS) design, we are able to get an average loss of 0.46dB/mm at 0.8-1.4THz from ANSYS HFSS simulation. The return loss for input and output are better than -20dB at 0.8-1.7THz. Although it is designed for our future travelling wave amplifier, it can also be used for various other THz frequency applications.

  11. Robust Wireless Power Transmission to mm-Sized Free-Floating Distributed Implants.

    PubMed

    Mirbozorgi, S Abdollah; Yeon, Pyungwoo; Ghovanloo, Maysam

    2017-06-01

    This paper presents an inductive link for wireless power transmission (WPT) to mm-sized free-floating implants (FFIs) distributed in a large three-dimensional space in the neural tissue that is insensitive to the exact location of the receiver (Rx). The proposed structure utilizes a high-Q resonator on the target wirelessly powered plane that encompasses randomly positioned multiple FFIs, all powered by a large external transmitter (Tx). Based on resonant WPT fundamentals, we have devised a detailed method for optimization of the FFIs and explored design strategies and safety concerns, such as coil segmentation and specific absorption rate limits using realistic finite element simulation models in HFSS including head tissue layers, respectively. We have built several FFI prototypes to conduct accurate measurements and to characterize the performance of the proposed WPT method. Measurement results on 1-mm receivers operating at 60 MHz show power transfer efficiency and power delivered to the load at 2.4% and 1.3 mW, respectively, within 14-18 mm of Tx-Rx separation and 7 cm 2 of brain surface.

  12. Performance analysis and comparison of ITO- and FTO-based optically transparent terahertz U-shaped patch antennas

    NASA Astrophysics Data System (ADS)

    Thampy, Anand Sreekantan; Dhamodharan, Sriram Kumar

    2015-02-01

    An indium-doped tin oxide (ITO) and a fluorine-doped tin oxide (FTO)-based optically transparent U-shaped patch antennas are designed to resonate at 750 GHz and their performances are analyzed. Impedance bandwidth, radiation efficiency, directivity and gain of the proposed antennas are investigated. The proposed transparent antenna's characteristics are compared with the copper-based non-transparent U-shaped patch antenna, which is also designed to resonate at 750 GHz. Terahertz antennas are essential for inter-satellite communications systems to enable the adequate spatial resolution, broad bandwidth, higher data rates and highly directional beam with secured data transfer. The proposed ITO- and FTO-based transparent antennas have yielded impedance bandwidth of 9.54% and 11.49%, respectively, in the band 719-791 GHz and 714-801 GHz, respectively. The peak gain for ITO and FTO based transparent antennas is 3.35 dB and 2.26 dB at 732 GHz and 801 GHz, respectively. The proposed antennas are designed and simulated by using a finite element method based electromagnetic solver, Ansys - HFSS.

  13. Inductive power transmission to millimeter-sized biomedical implants using printed spiral coils.

    PubMed

    Ibrahim, Ahmed; Kiani, Mehdi

    2016-08-01

    The operation frequency (f) has been a key parameter in optimizing wireless power transmission links for biomedical implants with millimeter (mm) dimensions. This paper studies the feasibility of using printed spiral coils (PSCs) for powering mm-sized implants with high power transmission efficiency (PTE) at different fps. Compared to wire-wound coils (WWCs), using a PSC in the implant side allows batch fabrication on rigid or flexible substrates, which can also be used as a platform for integrating implant components. For powering an implant with 1 mm diameter, located 10 mm inside the tissue, the geometries of transmitter (Tx) and receiver (Rx) PSCs were optimized at different fPs of 50 MHz, 200 MHz, and 500 MHz using a commercial field solver (HFSS). In simulations, PSC- and WWC-based links achieved maximum PTE of 0.13% and 3.3%, and delivered power of 65.7 μW and 720 μW under specific absorption rate (SAR) constraints at the optimal fp of 50 MHz and 100 MHz, respectively, suggesting that the performance of the PSC-based link is significantly inferior to that of the WWC-based link.

  14. Operation of ICRF antennas in a full tungsten environment in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Bobkov, Vl.; Braun, F.; Dux, R.; Giannone, L.; Herrmann, A.; Kallenbach, A.; Müller, H. W.; Neu, R.; Noterdaeme, J.-M.; Pütterich, Th.; Rohde, V.; ASDEX Upgrade Team

    2009-06-01

    In the 2007 and early part of 2008 experimental campaigns, ASDEX Upgrade operated with full tungsten (W) wall without boronization. Use of ICRF power results in a significant increase of W source. Low temperature conditions at the plasma facing components, achieved by a large clearance between the separatrix and the antenna (>6 cm) and by elevated gas puff rates (>5×1021 s) help to lower W sputtering yield during ICRF. Operation of neighboring ICRF antennas at the phase difference close to -90° can lead to a reduction in the W source. However, a reduction of parallel near-fields by antenna design is needed to further minimize the W source. A relation has been established between the HFSS code calculations predicting a dominant role of box currents in the formation of parallel antenna near-fields and the experiment. The shapes of the measured vertical profile of effective sputtering yields and the calculated sheath driving voltages show a qualitative agreement. This confirms that the existing tools are a good basis to design an improved antenna.

  15. A Very Compact and Low Profile UWB Planar Antenna with WLAN Band Rejection.

    PubMed

    Syed, Avez; Aldhaheri, Rabah W

    2016-01-01

    A low-cost coplanar waveguide fed compact ultrawideband (UWB) antenna with band rejection characteristics for wireless local area network (WLAN) is proposed. The notch band characteristic is achieved by etching half wavelength C-shaped annular ring slot in the radiating patch. By properly choosing the radius and position of the slot, the notch band can be adjusted and controlled. With an overall size of 18.7 mm × 17.6 mm, the antenna turns out to be one of the smallest UWB antennas with band-notched characteristics. It has a wide fractional bandwidth of 130% (2.9-13.7 GHz) with VSWR < 2 and rejecting IEEE 802.11a and HIPERLAN/2 frequency band of 5.1-5.9 GHz. Stable omnidirectional radiation patterns in the H plane with an average gain of 4.4 dBi are obtained. The band-notch mechanism of the proposed antenna is examined by HFSS simulator. A good agreement is found between measured and simulated results indicating that the proposed antenna is well suited for integration into portable devices for UWB applications.

  16. Design, Simulation and Experiments on the Recirculating Crossed-Field Planar Amplifier

    NASA Astrophysics Data System (ADS)

    Exelby, Steven; Greening, Geoffrey; Jordan, Nicholas; Packard, Drew; Lau, Yue Ying; Gilgenbach, Ronald; Simon, David; Hoff, Brad

    2017-10-01

    The Recirculating Planar Crossed-Field Amplifier (RPCFA) is the focus of simulation and experimental work. This amplifier, inspired by the Recirculating Planar Magnetron, is driven by the Michigan Electron Long Beam Accelerator (MELBA), configured to deliver a -300 kV, 1-10 kA, 0.3-1.0 µs pulse. For these parameters, a slow wave structure (SWS), cathode, and housing were designed using the finite element frequency domain code Ansys HFSS, and verified using the PIC code, MAGIC. Simulations of this device demonstrated amplification of 1.3 MW, 3 GHz signal to approximately 29 MW (13.5 dB) with nearly 53% electronic efficiency. Simulations have also shown the device is zero-drive stable, operates under a range of voltages, with bandwidth of 10%, on par with existing CFAs. The RPCFA SWS has been fabricated using 3D printing, while the rest of the device has been developed using traditional machining. Experimental RPCFA cold tube characteristics matched those from simulation. Experiments on MELBA have demonstrated zero-drive stability and amplifier experiments are underway. This work was supported by the AFOSR Grant FA9550-15-1-0097.

  17. Beam current enhancement of microwave plasma ion source utilizing double-port rectangular cavity resonator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Yuna; Park, Yeong-Shin; Jo, Jong-Gab

    2012-02-15

    Microwave plasma ion source with rectangular cavity resonator has been examined to improve ion beam current by changing wave launcher type from single-port to double-port. The cavity resonators with double-port and single-port wave launchers are designed to get resonance effect at TE-103 mode and TE-102 mode, respectively. In order to confirm that the cavities are acting as resonator, the microwave power for breakdown is measured and compared with the E-field strength estimated from the HFSS (High Frequency Structure Simulator) simulation. Langmuir probe measurements show that double-port cavity enhances central density of plasma ion source by modifying non-uniform plasma density profilemore » of the single-port cavity. Correspondingly, beam current from the plasma ion source utilizing the double-port resonator is measured to be higher than that utilizing single-port resonator. Moreover, the enhancement in plasma density and ion beam current utilizing the double-port resonator is more pronounced as higher microwave power applied to the plasma ion source. Therefore, the rectangular cavity resonator utilizing the double-port is expected to enhance the performance of plasma ion source in terms of ion beam extraction.« less

  18. Low-cost dielectric substrate for designing low profile multiband monopole microstrip antenna.

    PubMed

    Ahsan, M R; Islam, M T; Habib Ullah, M; Arshad, H; Mansor, M F

    2014-01-01

    This paper proposes a small sized, low-cost multiband monopole antenna which can cover the WiMAX bands and C-band. The proposed antenna of 20 × 20 mm(2) radiating patch is printed on cost effective 1.6 mm thick fiberglass polymer resin dielectric material substrate and fed by 4 mm long microstrip line. The finite element method based, full wave electromagnetic simulator HFSS is efficiently utilized for designing and analyzing the proposed antenna and the antenna parameters are measured in a standard far-field anechoic chamber. The experimental results show that the prototype of the antenna has achieved operating bandwidths (voltage stand wave ratio (VSWR) less than 2) 360 MHz (2.53-2.89 GHz) and 440 MHz (3.47-3.91 GHz) for WiMAX and 1550 MHz (6.28-7.83 GHz) for C-band. The simulated and measured results for VSWR, radiation patterns, and gain are well matched. Nearly omnidirectional radiation patterns are achieved and the peak gains are of 3.62 dBi, 3.67 dBi, and 5.7 dBi at 2.66 GHz, 3.65 GHz, and 6.58 GHz, respectively.

  19. Beam current enhancement of microwave plasma ion source utilizing double-port rectangular cavity resonator.

    PubMed

    Lee, Yuna; Park, Yeong-Shin; Jo, Jong-Gab; Yang, J J; Hwang, Y S

    2012-02-01

    Microwave plasma ion source with rectangular cavity resonator has been examined to improve ion beam current by changing wave launcher type from single-port to double-port. The cavity resonators with double-port and single-port wave launchers are designed to get resonance effect at TE-103 mode and TE-102 mode, respectively. In order to confirm that the cavities are acting as resonator, the microwave power for breakdown is measured and compared with the E-field strength estimated from the HFSS (High Frequency Structure Simulator) simulation. Langmuir probe measurements show that double-port cavity enhances central density of plasma ion source by modifying non-uniform plasma density profile of the single-port cavity. Correspondingly, beam current from the plasma ion source utilizing the double-port resonator is measured to be higher than that utilizing single-port resonator. Moreover, the enhancement in plasma density and ion beam current utilizing the double-port resonator is more pronounced as higher microwave power applied to the plasma ion source. Therefore, the rectangular cavity resonator utilizing the double-port is expected to enhance the performance of plasma ion source in terms of ion beam extraction.

  20. Tunable Reduced Size Planar Folded Slot Antenna Utilizing Varactor Diodes

    NASA Technical Reports Server (NTRS)

    Scardelletti, Maximilian C.; Ponchak, George E.; Jordan, Jennifer L.; Jastram, Nathan; Mahaffey, Joshua V.

    2010-01-01

    A tunable folded slot antenna that utilizes varactor diodes is presented. The antenna is fabricated on Rogers 6006 Duriod with a dielectric constant and thickness of 6.15 and 635 m, respectively. A copper cladding layer of 17 m defines the antenna on the top side (no ground on backside). The antenna is fed with a CPW 50 (Omega) feed line, has a center frequency of 3 GHz, and incorporates Micrometrics microwave hyper-abrupt 500MHV varactors to tune the resonant frequency. The varactors have a capacitance range of 2.52 pF at 0 V to 0.4 pF at 20 V; they are placed across the radiating slot of the antenna. The tunable 10 dB bandwidth of the 3 GHz antenna is 150 MHz. The varactors also reduce the size of the antenna by 30% by capacitively loading the resonating slot line. At the center frequency, 3 GHz, the antenna has a measured return loss of 44 dB and a gain of 1.6 dBi. Full-wave electromagnetic simulations using HFSS are presented that validate the measured data. Index Terms capacitive loading, Duriod, folded slot antenna, varactor.

  1. Evolutions in food marketing, quantifying the impact, and policy implications.

    PubMed

    Cairns, Georgina

    2013-03-01

    A case study on interactive digital marketing examined the adequacy of extant policy controls and their underpinning paradigms to constrain the effects of this rapidly emerging practice. Findings were interactive digital marketing is expanding the strategies available to promote products, brands and consumer behaviours. It facilitates relational marketing; the collection of personal data for marketing; integration of the marketing mix, and provides a platform for consumers to engage in the co-creation of marketing communications. The paradigmatic logic of current policies to constrain youth-oriented food marketing does not address the interactive nature of digital marketing. The evidence base on the effects of HFSS marketing and policy interventions is based on conceptualizations of marketing as a force promoting transactions rather than interactions. Digital technologies are generating rich consumer data. Interactive digital technologies increase the complexity of the task of quantifying the impact of marketing. The rapidity of its uptake also increases urgency of need to identify appropriate effects measures. Independent analysis of commercial consumer data (appropriately transformed to protect commercial confidentiality and personal privacy) would provide evidence sources for policy on the impacts of commercial food and beverage marketing and policy controls. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. A Very Compact and Low Profile UWB Planar Antenna with WLAN Band Rejection

    PubMed Central

    Syed, Avez; Aldhaheri, Rabah W.

    2016-01-01

    A low-cost coplanar waveguide fed compact ultrawideband (UWB) antenna with band rejection characteristics for wireless local area network (WLAN) is proposed. The notch band characteristic is achieved by etching half wavelength C-shaped annular ring slot in the radiating patch. By properly choosing the radius and position of the slot, the notch band can be adjusted and controlled. With an overall size of 18.7 mm × 17.6 mm, the antenna turns out to be one of the smallest UWB antennas with band-notched characteristics. It has a wide fractional bandwidth of 130% (2.9–13.7 GHz) with VSWR < 2 and rejecting IEEE 802.11a and HIPERLAN/2 frequency band of 5.1–5.9 GHz. Stable omnidirectional radiation patterns in the H plane with an average gain of 4.4 dBi are obtained. The band-notch mechanism of the proposed antenna is examined by HFSS simulator. A good agreement is found between measured and simulated results indicating that the proposed antenna is well suited for integration into portable devices for UWB applications. PMID:27088125

  3. Application of Cross-Correlation Greens Function Along With FDTD for Fast Computation of Envelope Correlation Coefficient Over Wideband for MIMO Antennas

    NASA Astrophysics Data System (ADS)

    Sarkar, Debdeep; Srivastava, Kumar Vaibhav

    2017-02-01

    In this paper, the concept of cross-correlation Green's functions (CGF) is used in conjunction with the finite difference time domain (FDTD) technique for calculation of envelope correlation coefficient (ECC) of any arbitrary MIMO antenna system over wide frequency band. Both frequency-domain (FD) and time-domain (TD) post-processing techniques are proposed for possible application with this FDTD-CGF scheme. The FDTD-CGF time-domain (FDTD-CGF-TD) scheme utilizes time-domain signal processing methods and exhibits significant reduction in ECC computation time as compared to the FDTD-CGF frequency domain (FDTD-CGF-FD) scheme, for high frequency-resolution requirements. The proposed FDTD-CGF based schemes can be applied for accurate and fast prediction of wideband ECC response, instead of the conventional scattering parameter based techniques which have several limitations. Numerical examples of the proposed FDTD-CGF techniques are provided for two-element MIMO systems involving thin-wire half-wavelength dipoles in parallel side-by-side as well as orthogonal arrangements. The results obtained from the FDTD-CGF techniques are compared with results from commercial electromagnetic solver Ansys HFSS, to verify the validity of proposed approach.

  4. Development of Balanced SIS Mixers for ALMA Band-10

    NASA Astrophysics Data System (ADS)

    Shitov, Sergey V.; Koryukin, Oleg V.; Uzawa, Yoshinory; Noguchi, Takashi; Uvarov, Andrey V.; Cohn, Ilya A.

    2006-05-01

    A few concepts of a wide-band balanced SIS mixer employing submicron-sized SIS junctions are under development for 787-950 GHz frequency range. A quasioptical DSB balanced mixer with integrated cross-slot antenna is considered as the less laborious and cheaper option. The silicon lens-antenna beam efficiency is expected above 80 % across the whole band with first-order sidelobe below -16 dB. To use the conservative horn antenna solution, a single chamber waveguide DSB balanced mixer is developed. Two equal probe-type SIS chips are inserted into a full-height waveguide through its opposite broad walls; these two mixers are driven by the signal waveguide in series. The LO current is transferred to the mixers in parallel via a capacitive probe inserted through the narrow wall of the signal waveguide from the neighboring LO waveguide. The HFSS model demonstrated the LO power coupling efficiency above -3 dB, almost perfect signal transfer and the LO cross talk below -30 dB that take into account misalignment (misbalance) of the chips. It is demonstrated numerically using Tucker's 3-port model that unequal pump of junctions of a twin-SIS mixer can lead, in spite of the perfect signal coupling, to degradation of the gain performance up to -3 dB, especially at the top of the ALMA Band-10.

  5. Thermoelectric Oxide Modules (TOMs) for the Direct Conversion of Simulated Solar Radiation into Electrical Energy

    PubMed Central

    Tomeš, Petr; Trottmann, Matthias; Suter, Clemens; Aguirre, Myriam Heidi; Steinfeld, Aldo; Haueter, Philipp; Weidenkaff, Anke

    2010-01-01

    The direct conversion of concentrated high temperature solar heat into electrical energy was demonstrated with a series of four–leg thermoelectric oxide modules (TOM). These temperature stable modules were not yet optimized for high efficiency conversion, but served as proof-of-principle for high temperature conversion. They were constructed by connecting two p- (La1.98Sr0.02CuO4) and two n-type (CaMn0.98Nb0.02O3) thermoelements electrically in series and thermally in parallel. The temperature gradient ΔT was applied by a High–Flux Solar Simulator source (HFSS) which generates a spectrum similar to solar radiation. The influence of the graphite layer coated on the hot side of the Al2O3 substrate compared to the uncoated surface on ΔT, Pmax and η was studied in detail. The measurements show an almost linear temperature profile along the thermoelectric legs. The maximum output power of 88.8 mW was reached for a TOM with leg length of 5 mm at ΔT = 622 K. The highest conversion efficiency η was found for a heat flux of 4–8 W cm-2 and the dependence of η on the leg length was investigated.

  6. Preliminary investigation of the microwave pyrolysis mechanism of sludge based on high frequency structure simulator simulation of the electromagnetic field distribution.

    PubMed

    Ma, Rui; Yuan, Nana; Sun, Shichang; Zhang, Peixin; Fang, Lin; Zhang, Xianghua; Zhao, Xuxin

    2017-06-01

    Under microwave irradiation, raw sludge was pyrolyzed mainly by evaporation of water, with a weight loss ratio of 84.8% and a maximum temperature not exceeding 200°C. High-temperature pyrolysis of SiC sludge could be realized, with a weight loss ratio of 93.4% and a final pyrolysis temperature of 1131.7°C. Variations between the electric field intensity distribution are the main reason for the differences of pyrolysis efficiencies. HFSS simulation showed that the electric field intensity of the raw sludge gradually decreased from 2.94×10 4 V/m to 0.88×10 4 V/m when pyrolysis ends, while that of SiC sludge decreased from 3.73×10 4 V/m at the beginning to 1.28×10 4 V/m, then increased to 4.03×10 4 V/m. The electromagnetic effect is the main factor (r≥0.91) influencing the temperature increase and weight loss of raw sludge. Both the electromagnetic effect and heat conduction effect influenced temperature rise and weight loss of SiC sludge, but the former's influence was comparatively larger. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Low-Cost Dielectric Substrate for Designing Low Profile Multiband Monopole Microstrip Antenna

    PubMed Central

    Ahsan, M. R.; Islam, M. T.; Habib Ullah, M.; Arshad, H.; Mansor, M. F.

    2014-01-01

    This paper proposes a small sized, low-cost multiband monopole antenna which can cover the WiMAX bands and C-band. The proposed antenna of 20 × 20 mm2 radiating patch is printed on cost effective 1.6 mm thick fiberglass polymer resin dielectric material substrate and fed by 4 mm long microstrip line. The finite element method based, full wave electromagnetic simulator HFSS is efficiently utilized for designing and analyzing the proposed antenna and the antenna parameters are measured in a standard far-field anechoic chamber. The experimental results show that the prototype of the antenna has achieved operating bandwidths (voltage stand wave ratio (VSWR) less than 2) 360 MHz (2.53–2.89 GHz) and 440 MHz (3.47–3.91 GHz) for WiMAX and 1550 MHz (6.28–7.83 GHz) for C-band. The simulated and measured results for VSWR, radiation patterns, and gain are well matched. Nearly omnidirectional radiation patterns are achieved and the peak gains are of 3.62 dBi, 3.67 dBi, and 5.7 dBi at 2.66 GHz, 3.65 GHz, and 6.58 GHz, respectively. PMID:25136648

  8. A Near-Zero Refractive Index Meta-Surface Structure for Antenna Performance Improvement.

    PubMed

    Ullah, Mohammad Habib; Islam, Mohammad Tariqul; Faruque, Mohammad Rashed Iqbal

    2013-11-06

    A new meta-surface structure (MSS) with a near-zero refractive index (NZRI) is proposed to enhance the performance of a square loop antenna array. The main challenge to improve the antenna performance is increment of the overall antenna volume that is mitigated by assimilating the planar NZRI MSS at the back of the antenna structure. The proposed NZRI MSS-loaded CPW-fed (Co-Planar Waveguide) four-element array antenna is designed on ceramic-bioplastic-ceramic sandwich substrate using high-frequency structure simulator (HFSS), a finite-element-method-based simulation tool. The gain and directivity of the antenna are significantly enhanced by incorporating the NZRI MSS with a 7 × 6 set of elements at the back of the antenna structure. Measurement results show that the maximum gains of the antenna increased from 6.21 dBi to 8.25 dBi, from 6.52 dBi to 9.05 dBi and from 10.54 dBi to 12.15 dBi in the first, second and third bands, respectively. The effect of the slot configuration in the ground plane on the reflection coefficient of the antenna was analyzed and optimized. The overall performance makes the proposed antenna appropriate for UHFFM (Ultra High Frequency Frequency Modulation) telemetry-based space applications as well as mobile satellite, microwave radiometry and radio astronomy applications.

  9. EBG Based Microstrip Patch Antenna for Brain Tumor Detection via Scattering Parameters in Microwave Imaging System.

    PubMed

    Inum, Reefat; Rana, Md Masud; Shushama, Kamrun Nahar; Quader, Md Anwarul

    2018-01-01

    A microwave brain imaging system model is envisaged to detect and visualize tumor inside the human brain. A compact and efficient microstrip patch antenna is used in the imaging technique to transmit equivalent signal and receive backscattering signal from the stratified human head model. Electromagnetic band gap (EBG) structure is incorporated on the antenna ground plane to enhance the performance. Rectangular and circular EBG structures are proposed to investigate the antenna performance. Incorporation of circular EBG on the antenna ground plane provides an improvement of 22.77% in return loss, 5.84% in impedance bandwidth, and 16.53% in antenna gain with respect to the patch antenna with rectangular EBG. The simulation results obtained from CST are compared to those obtained from HFSS to validate the design. Specific absorption rate (SAR) of the modeled head tissue for the proposed antenna is determined. Different SAR values are compared with the established standard SAR limit to provide a safety regulation of the imaging system. A monostatic radar-based confocal microwave imaging algorithm is applied to generate the image of tumor inside a six-layer human head phantom model. S -parameter signals obtained from circular EBG loaded patch antenna in different scanning modes are utilized in the imaging algorithm to effectively produce a high-resolution image which reliably indicates the presence of tumor inside human brain.

  10. EBG Based Microstrip Patch Antenna for Brain Tumor Detection via Scattering Parameters in Microwave Imaging System

    PubMed Central

    Rana, Md. Masud; Shushama, Kamrun Nahar; Quader, Md. Anwarul

    2018-01-01

    A microwave brain imaging system model is envisaged to detect and visualize tumor inside the human brain. A compact and efficient microstrip patch antenna is used in the imaging technique to transmit equivalent signal and receive backscattering signal from the stratified human head model. Electromagnetic band gap (EBG) structure is incorporated on the antenna ground plane to enhance the performance. Rectangular and circular EBG structures are proposed to investigate the antenna performance. Incorporation of circular EBG on the antenna ground plane provides an improvement of 22.77% in return loss, 5.84% in impedance bandwidth, and 16.53% in antenna gain with respect to the patch antenna with rectangular EBG. The simulation results obtained from CST are compared to those obtained from HFSS to validate the design. Specific absorption rate (SAR) of the modeled head tissue for the proposed antenna is determined. Different SAR values are compared with the established standard SAR limit to provide a safety regulation of the imaging system. A monostatic radar-based confocal microwave imaging algorithm is applied to generate the image of tumor inside a six-layer human head phantom model. S-parameter signals obtained from circular EBG loaded patch antenna in different scanning modes are utilized in the imaging algorithm to effectively produce a high-resolution image which reliably indicates the presence of tumor inside human brain. PMID:29623087

  11. RF-MEMS for future mobile applications: experimental verification of a reconfigurable 8-bit power attenuator up to 110 GHz

    NASA Astrophysics Data System (ADS)

    Iannacci, J.; Tschoban, C.

    2017-04-01

    RF-MEMS technology is proposed as a key enabling solution for realising the high-performance and highly reconfigurable passive components that future communication standards will demand. In this work, we present, test and discuss a novel design concept for an 8-bit reconfigurable power attenuator, manufactured using the RF-MEMS technology available at the CMM-FBK, in Italy. The device features electrostatically controlled MEMS ohmic switches in order to select/deselect the resistive loads (both in series and shunt configuration) that attenuate the RF signal, and comprises eight cascaded stages (i.e. 8-bit), thus implementing 256 different network configurations. The fabricated samples are measured (S-parameters) from 10 MHz to 110 GHz in a wide range of different configurations, and modelled/simulated with Ansys HFSS. The device exhibits attenuation levels (S21) in the range from  -10 dB to  -60 dB, up to 110 GHz. In particular, S21 shows flatness from 15 dB down to 3-5 dB and from 10 MHz to 50 GHz, as well as fewer linear traces up to 110 GHz. A comprehensive discussion is developed regarding the voltage standing wave ratio, which is employed as a quality indicator for the attenuation levels. The margins of improvement at design level which are needed to overcome the limitations of the presented RF-MEMS device are also discussed.

  12. A Near-Zero Refractive Index Meta-Surface Structure for Antenna Performance Improvement

    PubMed Central

    Ullah, Mohammad Habib; Islam, Mohammad Tariqul; Faruque, Mohammad Rashed Iqbal

    2013-01-01

    A new meta-surface structure (MSS) with a near-zero refractive index (NZRI) is proposed to enhance the performance of a square loop antenna array. The main challenge to improve the antenna performance is increment of the overall antenna volume that is mitigated by assimilating the planar NZRI MSS at the back of the antenna structure. The proposed NZRI MSS-loaded CPW-fed (Co-Planar Waveguide) four-element array antenna is designed on ceramic-bioplastic-ceramic sandwich substrate using high-frequency structure simulator (HFSS), a finite-element-method-based simulation tool. The gain and directivity of the antenna are significantly enhanced by incorporating the NZRI MSS with a 7 × 6 set of elements at the back of the antenna structure. Measurement results show that the maximum gains of the antenna increased from 6.21 dBi to 8.25 dBi, from 6.52 dBi to 9.05 dBi and from 10.54 dBi to 12.15 dBi in the first, second and third bands, respectively. The effect of the slot configuration in the ground plane on the reflection coefficient of the antenna was analyzed and optimized. The overall performance makes the proposed antenna appropriate for UHFFM (Ultra High Frequency Frequency Modulation) telemetry-based space applications as well as mobile satellite, microwave radiometry and radio astronomy applications. PMID:28788376

  13. The influence of the recipient's body weight on the probability to obtain a heart transplant-POLKARD HF registry.

    PubMed

    Zieliński, T; Sobieszczańska-Małek, M; Browarek, A; Piotrowska, M; Zakliczyński, M; Przybyłowski, P; Roguski, K; Sadowski, J; Zembala, M; Korewicki, J

    2009-10-01

    The aim of the study was to analyze the influence of body weight of the adult heart recipient on the chance to obtain a transplant. We analyzed the data from all 658 patients listed for heart transplantation. During the follow-up period, 325 (49%) of listed patients underwent transplantation with 102 (15%) succumbing before heart transplantation. The mean weight of transplanted patients was 73.7 +/- 13.7 kg and 81.2 +/- 15.4 kg for those not transplanted (P < .00001). Patients were divided according to body weight in two groups: light = below 80 kg (n = 360) or heavy > or = 80 kg or above (n = 297). On the transplant list, 111 heavy patients (37%) versus 213 light patients (59%) underwent the procedure, a significant difference. The waiting time among light patients was 255 versus heavy patients of 395 days (P < .005). There was a similar number of deaths before transplantation among the light (n = 56 360 patients; 15.5%) versus the heavy group (49/297; 16%). Upon multivariate Cox mode analysis independent factors related to not receiving a heart transplant were greater weight, systolic blood pressure, pulmonary vascular resistance, Heart Failure Survival Score (HFSS) score and lower N-terminal pro-brain natriuretic peptide (NTproBNP) levels. Among adult heart transplant candidates, the chance to receive a heart transplant significantly decreased when the recipient's weight exceeded 80 kg. Patients with a body weight more than 110 kg had a poor chance to receive a heart transplantation.

  14. Design of Miniaturized Dual-Band Microstrip Antenna for WLAN Application

    PubMed Central

    Yang, Jiachen; Wang, Huanling; Lv, Zhihan; Wang, Huihui

    2016-01-01

    Wireless local area network (WLAN) is a technology that combines computer network with wireless communication technology. The 2.4 GHz and 5 GHz frequency bands in the Industrial Scientific Medical (ISM) band can be used in the WLAN environment. Because of the development of wireless communication technology and the use of the frequency bands without the need for authorization, the application of WLAN is becoming more and more extensive. As the key part of the WLAN system, the antenna must also be adapted to the development of WLAN communication technology. This paper designs two new dual-frequency microstrip antennas with the use of electromagnetic simulation software—High Frequency Structure Simulator (HFSS). The two antennas adopt ordinary FR4 material as a dielectric substrate, with the advantages of low cost and small size. The first antenna adopts microstrip line feeding, and the antenna radiation patch is composed of a folded T-shaped radiating dipole which reduces the antenna size, and two symmetrical rectangular patches located on both sides of the T-shaped radiating patch. The second antenna is a microstrip patch antenna fed by coaxial line, and the size of the antenna is diminished by opening a stepped groove on the two edges of the patch and a folded slot inside the patch. Simulation experiments prove that the two designed antennas have a higher gain and a favourable transmission characteristic in the working frequency range, which is in accordance with the requirements of WLAN communication. PMID:27355954

  15. Broadband High Efficiency Fractal-Like and Diverse Geometry Silicon Nanowire Arrays for Photovoltaic Applications

    NASA Astrophysics Data System (ADS)

    AL-Zoubi, Omar H.

    Solar energy has many advantages over conventional sources of energy. It is abundant, clean and sustainable. One way to convert solar energy directly into electrical energy is by using the photovoltaic solar cells (PVSC). Despite PVSC are becoming economically competitive, they still have high cost and low light to electricity conversion efficiency. Therefore, increasing the efficiency and reducing the cost are key elements for producing economically more competitive PVSC that would have significant impact on energy market and saving environment. A significant percentage of the PVSC cost is due to the materials cost. For that, thin films PVSC have been proposed which offer the benefits of the low amount of material and fabrication costs. Regrettably, thin film PVSC show poor light to electricity conversion efficiency because of many factors especially the high optical losses. To enhance conversion efficiency, numerous techniques have been proposed to reduce the optical losses and to enhance the absorption of light in thin film PVSC. One promising technique is the nanowire (NW) arrays in general and the silicon nanowire (SiNW) arrays in particular. The purpose of this research is to introduce vertically aligned SiNW arrays with enhanced and broadband absorption covering the entire solar spectrum while simultaneously reducing the amount of material used. To this end, we apply new concept for designing SiNW arrays based on employing diversity of physical dimensions, especially radial diversity within certain lattice configurations. In order to study the interaction of light with SiNW arrays and compute their optical properties, electromagnetic numerical modeling is used. A commercial numerical electromagnetic solver software package, high frequency structure simulation (HFSS), is utilized to model the SiNW arrays and to study their optical properties. We studied different geometries factors that affect the optical properties of SiNW arrays. Based on this study, we found that the optical properties of SiNW arrays are strongly affected by the radial diversity, the arrangement of SiNW in a lattice, and the configuration of such lattice. The proper selection of these parameters leads to broaden and enhance the light absorption of the SiNW arrays. Inspired by natural configurations, fractal geometry and diamond lattice structures, we introduced two lattice configurations: fractal-like array (FLA) that is inspired by fractal geometry, and diamond-like array (DLA) that is inspired by diamond crystal lattice structure. Optimization, using parametric analysis, of the introduced arrays parameters for the light absorption level and the amount of used material has been performed. Both of the introduced SiNW arrays show broadband, strong light absorption coupled with reduction of the amount of the used material. DLA in specific showed significantly enhanced absorption covering the entire solar spectrum of interest, where near-unity absorption spectrum could be achieved. We studied the optical properties of complete PVSC devices that are based on SiNW array. Moreover, the performance of PVSC device that is based on SiNW has been investigated by using numerical modeling. SILVACO software package is used for performing the numerical simulation of the PVSC device performance, which can simultaneously handle the different coupled physical mechanisms contributing to the photovoltaic effect. The effect of the geometry of PVSC device that is based on SiNW is investigated, which shows that the geometry of such PVSC has a role in enhancing its electrical properties. The outcome of this study introduces new SiNW array configurations that have enhanced optical properties using a low amount of material that can be utilized for producing higher efficiency thin film PVCS. The overall conclusion of this work is that a weak absorption indirect band gap material, silicon, in the form of properly designed SiNW and SiNC arrays has the potentials to achieve near-unity ideal absorption spectrum using reduced amount of material, which can lead to produce new generation of lower cost and enhanced efficiency thin film PVSC.

  16. Terahertz Bandpass Frequency Selective Surfaces on Glass Substrates Using a Wet Micromachining Process

    NASA Astrophysics Data System (ADS)

    Ramzan, Mehrab; Khan, Talha Masood; Bolat, Sami; Nebioglu, Mehmet Ali; Altan, Hakan; Okyay, Ali Kemal; Topalli, Kagan

    2017-08-01

    This paper presents terahertz (THz) frequency selective surfaces (FSS) implemented on glass substrate using standard microfabrication techniques. These FSS structures are designed for frequencies around 0.8 THz. A fabrication process is proposed where a 100-μm-thick glass substrate is formed through the HF etching of a standard 500-μm-thick low cost glass wafer. Using this fabrication process, three separate robust designs consisting of single-layer FSS are investigated using high-frequency structural simulator (HFSS). Based on the simulation results, the first design consists of a circular ring slot in a square metallic structure on top of a 100-μm-thick Pyrex glass substrate with 70% transmission bandwidth of approximately 0.07 THz, which remains nearly constant till 30° angle of incidence. The second design consists of a tripole structure on top of a 100-μm-thick Pyrex glass substrate with 65% transmission bandwidth of 0.035 THz, which remains nearly constant till 30° angle of incidence. The third structure consists of a triangular ring slot in a square metal on top of a 100-μm-thick Pyrex glass substrate with 70% transmission bandwidth of 0.051 THz, which remains nearly constant up to 20° angle of incidence. These designs show that the reflections from samples can be reduced compared to the conventional sample holders used in THz spectroscopy applications, by using single layer FSS structures manufactured through a relatively simple fabrication process. Practically, these structures are achieved on a fabricated 285-μm-thick glass substrate. Taking into account the losses and discrepancies in the substrate thickness, the measured results are in good agreement with the electromagnetic simulations.

  17. A microwave resonator for limiting depth sensitivity for electron paramagnetic resonance spectroscopy of surfaces.

    PubMed

    Sidabras, Jason W; Varanasi, Shiv K; Mett, Richard R; Swarts, Steven G; Swartz, Harold M; Hyde, James S

    2014-10-01

    A microwave Surface Resonator Array (SRA) structure is described for use in Electron Paramagnetic Resonance (EPR) spectroscopy. The SRA has a series of anti-parallel transmission line modes that provides a region of sensitivity equal to the cross-sectional area times its depth sensitivity, which is approximately half the distance between the transmission line centers. It is shown that the quarter-wave twin-lead transmission line can be a useful element for design of microwave resonators at frequencies as high as 10 GHz. The SRA geometry is presented as a novel resonator for use in surface spectroscopy where the region of interest is either surrounded by lossy material, or the spectroscopist wishes to minimize signal from surrounding materials. One such application is in vivo spectroscopy of human finger-nails at X-band (9.5 GHz) to measure ionizing radiation dosages. In order to reduce losses associated with tissues beneath the nail that yield no EPR signal, the SRA structure is designed to limit depth sensitivity to the thickness of the fingernail. Another application, due to the resonator geometry and limited depth penetration, is surface spectroscopy in coating or material science. To test this application, a spectrum of 1.44 μM of Mg(2+) doped polystyrene 1.1 mm thick on an aluminum surface is obtained. Modeling, design, and simulations were performed using Wolfram Mathematica (Champaign, IL; v. 9.0) and Ansys High Frequency Structure Simulator (HFSS; Canonsburg, PA; v. 15.0). A micro-strip coupling circuit is designed to suppress unwanted modes and provide a balanced impedance transformation to a 50 Ω coaxial input. Agreement between simulated and experimental results is shown.

  18. Different synaptic stimulation patterns influence the local androgenic and estrogenic neurosteroid availability triggering hippocampal synaptic plasticity in the male rat.

    PubMed

    Di Mauro, Michela; Tozzi, Alessandro; Calabresi, Paolo; Pettorossi, Vito Enrico; Grassi, Silvarosa

    2017-02-01

    Electrophysiological recordings were used to investigate the role of the local synthesis of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) on synaptic long-term effects induced in the hippocampal CA1 region of male rat slices. Long-term depression (LTD) and long-term potentiation (LTP), induced by different stimulation patterns, were examined under the block of the DHT synthesis by finasteride (FIN), and the E2 synthesis by letrozole (LET). We used low frequency stimulation (LFS) for LTD, high frequency stimulation (HFS) for LTP, and intermediate patterns differing in duration or frequency. We found that FIN reverted the LFS-LTD into LTP and enhanced LTP induced by intermediate and HFSs. These effects were abolished by exogenous DHT at concentration higher than the basal one, suggesting a stimulus dependent increase in DHT availability. No effect on the synaptic responses was observed giving DHT alone. Moreover, we found that the inhibition of E2 synthesis influenced the HFS-LTP by reducing its amplitude, and the exogenous E2 either enhanced HFS-LTP or reverted the LFS-LTD into LTP. The equivalence of the E2 concentration for rescuing the full HFS-LTP under LET and reverting the LFS-LTD into LTP suggests an enhancement of the endogenous E2 availability that is specifically driven by the HFS. No effect of FIN or LET was observed on the responses to stimuli that did not induce either LTD or LTP. This study provides evidence that the E2 and DHT availability combined with specific stimulation patterns is determinant for the sign and amplitude of the long-term effects. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  19. Towards lightweight and flexible high performance nanocrystalline silicon solar cells through light trapping and transport layers

    NASA Astrophysics Data System (ADS)

    Gray, Zachary R.

    This thesis investigates ways to enhance the efficiency of thin film solar cells through the application of both novel nano-element array light trapping architectures and nickel oxide hole transport/electron blocking layers. Experimental results independently demonstrate a 22% enhancement in short circuit current density (JSC) resulting from a nano-element array light trapping architecture and a ˜23% enhancement in fill factor (FF) and ˜16% enhancement in open circuit voltage (VOC) resulting from a nickel oxide transport layer. In each case, the overall efficiency of the device employing the light trapping or transport layer was superior to that of the corresponding control device. Since the efficiency of a solar cell scales with the product of JSC, FF, and VOC, it follows that the results of this thesis suggest high performance thin film solar cells can be realized in the event light trapping architectures and transport layers can be simultaneously optimized. The realizations of these performance enhancements stem from extensive process optimization for numerous light trapping and transport layer fabrication approaches. These approaches were guided by numerical modeling techniques which will also be discussed. Key developments in this thesis include (1) the fabrication of nano-element topographies conducive to light trapping using various fabrication approaches, (2) the deposition of defect free nc-Si:H onto structured topographies by switching from SiH4 to SiF 4 PECVD gas chemistry, and (3) the development of the atomic layer deposition (ALD) growth conditions for NiO. Keywords: light trapping, nano-element array, hole transport layer, electron blocking layer, nickel oxide, nanocrystalline silicon, aluminum doped zinc oxide, atomic layer deposition, plasma enhanced chemical vapor deposition, electron beam lithography, ANSYS HFSS.

  20. Microstrip Patch Sensor for Salinity Determination.

    PubMed

    Lee, Kibae; Hassan, Arshad; Lee, Chong Hyun; Bae, Jinho

    2017-12-18

    In this paper, a compact microstrip feed inset patch sensor is proposed for measuring the salinities in seawater. The working principle of the proposed sensor depends on the fact that different salinities in liquid have different relative permittivities and cause different resonance frequencies. The proposed sensor can obtain better sensitivity to salinity changes than common sensors using conductivity change, since the relative permittivity change to salinity is 2.5 times more sensitive than the conductivity change. The patch and ground plane of the proposed sensor are fabricated by conductive copper spray coating on the masks made by 3D printer. The fabricated patch and the ground plane are bonded to a commercial silicon substrate and then attached to 5 mm-high chamber made by 3D printer so that it contains only 1 mL seawater. For easy fabrication and testing, the maximum resonance frequency was selected under 3 GHz and to cover salinities in real seawater, it was assumed that the salinity changes from 20 to 35 ppt. The sensor was designed by the finite element method-based ANSYS high-frequency structure simulator (HFSS), and it can detect the salinity with 0.01 ppt resolution. The designed sensor has a resonance frequency separation of 37.9 kHz and reflection coefficients under -20 dB at the resonant frequencies. The fabricated sensor showed better performance with average frequency separation of 48 kHz and maximum reflection coefficient of -35 dB. By comparing with the existing sensors, the proposed compact and low-cost sensor showed a better detection capability. Therefore, the proposed patch sensor can be utilized in radio frequency (RF) tunable sensors for salinity determination.

  1. Excitation of a Parallel Plate Waveguide by an Array of Rectangular Waveguides

    NASA Technical Reports Server (NTRS)

    Rengarajan, Sembiam

    2011-01-01

    This work addresses the problem of excitation of a parallel plate waveguide by an array of rectangular waveguides that arises in applications such as the continuous transverse stub (CTS) antenna and dual-polarized parabolic cylindrical reflector antennas excited by a scanning line source. In order to design the junction region between the parallel plate waveguide and the linear array of rectangular waveguides, waveguide sizes have to be chosen so that the input match is adequate for the range of scan angles for both polarizations. Electromagnetic wave scattered by the junction of a parallel plate waveguide by an array of rectangular waveguides is analyzed by formulating coupled integral equations for the aperture electric field at the junction. The integral equations are solved by the method of moments. In order to make the computational process efficient and accurate, the method of weighted averaging was used to evaluate rapidly oscillating integrals encountered in the moment matrix. In addition, the real axis spectral integral is evaluated in a deformed contour for speed and accuracy. The MoM results for a large finite array have been validated by comparing its reflection coefficients with corresponding results for an infinite array generated by the commercial finite element code, HFSS. Once the aperture electric field is determined by MoM, the input reflection coefficients at each waveguide port, and coupling for each polarization over the range of useful scan angles, are easily obtained. Results for the input impedance and coupling characteristics for both the vertical and horizontal polarizations are presented over a range of scan angles. It is shown that the scan range is limited to about 35 for both polarizations and therefore the optimum waveguide is a square of size equal to about 0.62 free space wavelength.

  2. Microwave Imaging Sensor Using Compact Metamaterial UWB Antenna with a High Correlation Factor.

    PubMed

    Islam, Md Moinul; Islam, Mohammad Tariqul; Faruque, Mohammad Rashed Iqbal; Samsuzzaman, Md; Misran, Norbahiah; Arshad, Haslina

    2015-07-23

    The design of a compact metamaterial ultra-wideband (UWB) antenna with a goal towards application in microwave imaging systems for detecting unwanted cells in human tissue, such as in cases of breast cancer, heart failure and brain stroke detection is proposed. This proposed UWB antenna is made of four metamaterial unit cells, where each cell is an integration of a modified split ring resonator (SRR), capacitive loaded strip (CLS) and wire, to attain a design layout that simultaneously exhibits both a negative magnetic permeability and a negative electrical permittivity. This design results in an astonishing negative refractive index that enables amplification of the radiated power of this reported antenna, and therefore, high antenna performance. A low-cost FR4 substrate material is used to design and print this reported antenna, and has the following characteristics: thickness of 1.6 mm, relative permeability of one, relative permittivity of 4.60 and loss tangent of 0.02. The overall antenna size is 19.36 mm × 27.72 mm × 1.6 mm where the electrical dimension is 0.20 λ × 0.28 λ × 0.016 λ at the 3.05 GHz lower frequency band. Voltage Standing Wave Ratio (VSWR) measurements have illustrated that this antenna exhibits an impedance bandwidth from 3.05 GHz to more than 15 GHz for VSWR < 2 with an average gain of 4.38 dBi throughout the operating frequency band. The simulations (both HFSS and computer simulation technology (CST)) and the measurements are in high agreement. A high correlation factor and the capability of detecting tumour simulants confirm that this reported UWB antenna can be used as an imaging sensor.

  3. Dual-band LTCC antenna based on 0.95Zn2SiO4-0.05CaTiO3 ceramics for GPS/UMTS applications

    NASA Astrophysics Data System (ADS)

    Dou, Gang; Li, Yu-Xia; Guo, Mei

    2015-10-01

    In this paper, we present a compact low-temperature co-fired ceramic (LTCC) dual-band antenna by using the electromagnetic coupling effect concept for global positioning system (GPS) and universal mobile telecommunication system (UMTS) applications. The overall dimension of the antenna is 8.6 mm × 13.0 mm × 1.1 mm. It consists of double meander lines and a via hole line. The top meander line operates at the upper band, and the bottom radiating patch is designed for the lower band. The via-hole line is employed to connect the double meander lines. Because of the effect of the coupled line, total dimension of the proposed antenna is greatly reduced. With the 2.5: voltage standing wave ratio (VSWR) impedance bandwidth definition, the lower and upper bands have the bandwidths of 110 MHz and 150 MHz, respectively. The proposed antenna is successfully designed, simulated, and analyzed by a high frequency structure simulator (HFSS). And the antenna is manufactured by using the 0.95Zn2SiO4-0.05CaTiO3 ceramics (εr = 7.1, tanδ = 0.00038) that is prepared by ourselves. The results show that the antenna is compact, efficient, and of near omnidirectional radiation pattern. Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20133718120009), the Natural Science Foundation of Shandong Provence, China (Grant Nos. ZR2013FQ002 and ZR2014FQ006), the China Postdoctoral Science Foundation (Grant No. 2014M551935), the Qingdao Municipality Postdoctoral Science Foundation, China, and the Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents, China (Grant Nos. 2013RCJJ042 and 2014RCJJ052).

  4. Electromagnetic characterization of photo-definable ferrite loaded polymers and their applications in micro-rectangular coaxial phase shifters

    NASA Astrophysics Data System (ADS)

    Sholiyi, Olusegun Samuel

    As the demand for smaller size, lighter weight, lower loss and cost of communications transmit and receive (T/R) modules increases, there is an urgent need to focus investigation to the major subsystem or components that can improve these parameters. Phase shifters contribute greatly to the cost of T/R modules, and thus this research investigation examines a new way to reduce the weight and cost by miniaturizing the phaser design. Characterization of hexaferrite powders compatible with the sequential multilayer micro-fabrication technology and numerical simulations of a novel rectangular micro-coaxial phase shifter are investigated. This effort aims to integrate ferrite material into a rectangular micro-coaxial waveguide at Ka-band using electromagnetic finite element numerical tools. The proposed technique exploits rectangular coaxial waveguide with a symmetrically placed inner signal conductor inside an outer conductor connected to the ground. Strontium ferrite-SU8 composite is used as an anisotropic material of choice in the modelled design. Numerical modeling is employed using High Frequency Structure Simulator, HFSS, a 3-D full wave electromagnetic solver for analyzing the performance of the device. Two model structures were designed for reciprocal and non-reciprocal applications. The first model (Model A) produced a tunable phase shift of almost 60 degrees /cm across 0 to 400 kA/m applied field and at 1800 Gauss. In model B, a non-reciprocal phase shift performance of 20 degrees /cm from a reference phase of 24 degrees at 0 A/m was realized at the same saturation magnetization. A return loss better than 20 dB and an insertion loss less than 1.5 dB were obtained for both models.

  5. A microwave resonator for limiting depth sensitivity for electron paramagnetic resonance spectroscopy of surfaces

    PubMed Central

    Sidabras, Jason W.; Varanasi, Shiv K.; Mett, Richard R.; Swarts, Steven G.; Swartz, Harold M.; Hyde, James S.

    2014-01-01

    A microwave Surface Resonator Array (SRA) structure is described for use in Electron Paramagnetic Resonance (EPR) spectroscopy. The SRA has a series of anti-parallel transmission line modes that provides a region of sensitivity equal to the cross-sectional area times its depth sensitivity, which is approximately half the distance between the transmission line centers. It is shown that the quarter-wave twin-lead transmission line can be a useful element for design of microwave resonators at frequencies as high as 10 GHz. The SRA geometry is presented as a novel resonator for use in surface spectroscopy where the region of interest is either surrounded by lossy material, or the spectroscopist wishes to minimize signal from surrounding materials. One such application is in vivo spectroscopy of human finger-nails at X-band (9.5 GHz) to measure ionizing radiation dosages. In order to reduce losses associated with tissues beneath the nail that yield no EPR signal, the SRA structure is designed to limit depth sensitivity to the thickness of the fingernail. Another application, due to the resonator geometry and limited depth penetration, is surface spectroscopy in coating or material science. To test this application, a spectrum of 1.44 μM of Mg2+ doped polystyrene 1.1 mm thick on an aluminum surface is obtained. Modeling, design, and simulations were performed using Wolfram Mathematica (Champaign, IL; v. 9.0) and Ansys High Frequency Structure Simulator (HFSS; Canonsburg, PA; v. 15.0). A micro-strip coupling circuit is designed to suppress unwanted modes and provide a balanced impedance transformation to a 50 Ω coaxial input. Agreement between simulated and experimental results is shown. PMID:25362434

  6. Microwave Imaging Sensor Using Compact Metamaterial UWB Antenna with a High Correlation Factor

    PubMed Central

    Islam, Md. Moinul; Islam, Mohammad Tariqul; Faruque, Mohammad Rashed Iqbal; Samsuzzaman, Md.; Misran, Norbahiah; Arshad, Haslina

    2015-01-01

    The design of a compact metamaterial ultra-wideband (UWB) antenna with a goal towards application in microwave imaging systems for detecting unwanted cells in human tissue, such as in cases of breast cancer, heart failure and brain stroke detection is proposed. This proposed UWB antenna is made of four metamaterial unit cells, where each cell is an integration of a modified split ring resonator (SRR), capacitive loaded strip (CLS) and wire, to attain a design layout that simultaneously exhibits both a negative magnetic permeability and a negative electrical permittivity. This design results in an astonishing negative refractive index that enables amplification of the radiated power of this reported antenna, and therefore, high antenna performance. A low-cost FR4 substrate material is used to design and print this reported antenna, and has the following characteristics: thickness of 1.6 mm, relative permeability of one, relative permittivity of 4.60 and loss tangent of 0.02. The overall antenna size is 19.36 mm × 27.72 mm × 1.6 mm where the electrical dimension is 0.20 λ × 0.28 λ × 0.016 λ at the 3.05 GHz lower frequency band. Voltage Standing Wave Ratio (VSWR) measurements have illustrated that this antenna exhibits an impedance bandwidth from 3.05 GHz to more than 15 GHz for VSWR < 2 with an average gain of 4.38 dBi throughout the operating frequency band. The simulations (both HFSS and computer simulation technology (CST)) and the measurements are in high agreement. A high correlation factor and the capability of detecting tumour simulants confirm that this reported UWB antenna can be used as an imaging sensor. PMID:28793461

  7. A microwave resonator for limiting depth sensitivity for electron paramagnetic resonance spectroscopy of surfaces

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sidabras, Jason W.; Varanasi, Shiv K.; Hyde, James S.

    2014-10-15

    A microwave Surface Resonator Array (SRA) structure is described for use in Electron Paramagnetic Resonance (EPR) spectroscopy. The SRA has a series of anti-parallel transmission line modes that provides a region of sensitivity equal to the cross-sectional area times its depth sensitivity, which is approximately half the distance between the transmission line centers. It is shown that the quarter-wave twin-lead transmission line can be a useful element for design of microwave resonators at frequencies as high as 10 GHz. The SRA geometry is presented as a novel resonator for use in surface spectroscopy where the region of interest is eithermore » surrounded by lossy material, or the spectroscopist wishes to minimize signal from surrounding materials. One such application is in vivo spectroscopy of human finger-nails at X-band (9.5 GHz) to measure ionizing radiation dosages. In order to reduce losses associated with tissues beneath the nail that yield no EPR signal, the SRA structure is designed to limit depth sensitivity to the thickness of the fingernail. Another application, due to the resonator geometry and limited depth penetration, is surface spectroscopy in coating or material science. To test this application, a spectrum of 1.44 μM of Mg{sup 2+} doped polystyrene 1.1 mm thick on an aluminum surface is obtained. Modeling, design, and simulations were performed using Wolfram Mathematica (Champaign, IL; v. 9.0) and Ansys High Frequency Structure Simulator (HFSS; Canonsburg, PA; v. 15.0). A micro-strip coupling circuit is designed to suppress unwanted modes and provide a balanced impedance transformation to a 50 Ω coaxial input. Agreement between simulated and experimental results is shown.« less

  8. Office Computer Software: A Comprehensive Review of Software Programs.

    ERIC Educational Resources Information Center

    Secretary, 1992

    1992-01-01

    Describes types of software including system software, application software, spreadsheets, accounting software, graphics packages, desktop publishing software, database, desktop and personal information management software, project and records management software, groupware, and shareware. (JOW)

  9. Software Past, Present, and Future: Views from Government, Industry and Academia

    NASA Technical Reports Server (NTRS)

    Holcomb, Lee; Page, Jerry; Evangelist, Michael

    2000-01-01

    Views from the NASA CIO NASA Software Engineering Workshop on software development from the past, present, and future are presented. The topics include: 1) Software Past; 2) Software Present; 3) NASA's Largest Software Challenges; 4) 8330 Software Projects in Industry Standish Groups 1994 Report; 5) Software Future; 6) Capability Maturity Model (CMM): Software Engineering Institute (SEI) levels; 7) System Engineering Quality Also Part of the Problem; 8) University Environment Trends Will Increase the Problem in Software Engineering; and 9) NASA Software Engineering Goals.

  10. Space Flight Software Development Software for Intelligent System Health Management

    NASA Technical Reports Server (NTRS)

    Trevino, Luis C.; Crumbley, Tim

    2004-01-01

    The slide presentation examines the Marshall Space Flight Center Flight Software Branch, including software development projects, mission critical space flight software development, software technical insight, advanced software development technologies, and continuous improvement in the software development processes and methods.

  11. 48 CFR 227.7202 - Commercial computer software and commercial computer software documentation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... software and commercial computer software documentation. 227.7202 Section 227.7202 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202 Commercial computer software and commercial computer software documentation. ...

  12. 48 CFR 227.7203 - Noncommercial computer software and noncommercial computer software documentation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... software and noncommercial computer software documentation. 227.7203 Section 227.7203 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203 Noncommercial computer software and noncommercial computer software documentation. ...

  13. 48 CFR 227.7203 - Noncommercial computer software and noncommercial computer software documentation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... software and noncommercial computer software documentation. 227.7203 Section 227.7203 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203 Noncommercial computer software and noncommercial computer software documentation. ...

  14. 48 CFR 227.7203 - Noncommercial computer software and noncommercial computer software documentation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... software and noncommercial computer software documentation. 227.7203 Section 227.7203 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203 Noncommercial computer software and noncommercial computer software documentation. ...

  15. 48 CFR 227.7202 - Commercial computer software and commercial computer software documentation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... software and commercial computer software documentation. 227.7202 Section 227.7202 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202 Commercial computer software and commercial computer software documentation. ...

  16. 48 CFR 227.7203 - Noncommercial computer software and noncommercial computer software documentation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... software and noncommercial computer software documentation. 227.7203 Section 227.7203 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203 Noncommercial computer software and noncommercial computer software documentation. ...

  17. 48 CFR 227.7202 - Commercial computer software and commercial computer software documentation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... software and commercial computer software documentation. 227.7202 Section 227.7202 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202 Commercial computer software and commercial computer software documentation. ...

  18. 48 CFR 227.7202 - Commercial computer software and commercial computer software documentation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... software and commercial computer software documentation. 227.7202 Section 227.7202 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202 Commercial computer software and commercial computer software documentation. ...

  19. 48 CFR 227.7202 - Commercial computer software and commercial computer software documentation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... software and commercial computer software documentation. 227.7202 Section 227.7202 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202 Commercial computer software and commercial computer software documentation. ...

  20. 48 CFR 227.7203 - Noncommercial computer software and noncommercial computer software documentation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... software and noncommercial computer software documentation. 227.7203 Section 227.7203 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203 Noncommercial computer software and noncommercial computer software documentation. ...

  1. Software system safety

    NASA Technical Reports Server (NTRS)

    Uber, James G.

    1988-01-01

    Software itself is not hazardous, but since software and hardware share common interfaces there is an opportunity for software to create hazards. Further, these software systems are complex, and proven methods for the design, analysis, and measurement of software safety are not yet available. Some past software failures, future NASA software trends, software engineering methods, and tools and techniques for various software safety analyses are reviewed. Recommendations to NASA are made based on this review.

  2. 48 CFR 227.7203-16 - Providing computer software or computer software documentation to foreign governments, foreign...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... software or computer software documentation to foreign governments, foreign contractors, or international... Rights in Computer Software and Computer Software Documentation 227.7203-16 Providing computer software or computer software documentation to foreign governments, foreign contractors, or international...

  3. 48 CFR 227.7203-16 - Providing computer software or computer software documentation to foreign governments, foreign...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... software or computer software documentation to foreign governments, foreign contractors, or international... Rights in Computer Software and Computer Software Documentation 227.7203-16 Providing computer software or computer software documentation to foreign governments, foreign contractors, or international...

  4. 48 CFR 227.7203-16 - Providing computer software or computer software documentation to foreign governments, foreign...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... software or computer software documentation to foreign governments, foreign contractors, or international... Rights in Computer Software and Computer Software Documentation 227.7203-16 Providing computer software or computer software documentation to foreign governments, foreign contractors, or international...

  5. 48 CFR 227.7203-16 - Providing computer software or computer software documentation to foreign governments, foreign...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... software or computer software documentation to foreign governments, foreign contractors, or international... Rights in Computer Software and Computer Software Documentation 227.7203-16 Providing computer software or computer software documentation to foreign governments, foreign contractors, or international...

  6. 48 CFR 227.7203-16 - Providing computer software or computer software documentation to foreign governments, foreign...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... software or computer software documentation to foreign governments, foreign contractors, or international... Rights in Computer Software and Computer Software Documentation 227.7203-16 Providing computer software or computer software documentation to foreign governments, foreign contractors, or international...

  7. Avoidable Software Procurements

    DTIC Science & Technology

    2012-09-01

    software license, software usage, ELA, Software as a Service , SaaS , Software Asset...PaaS Platform as a Service SaaS Software as a Service SAM Software Asset Management SMS System Management Server SEWP Solutions for Enterprise Wide...delivery of full Cloud Services , we will see the transition of the Cloud Computing service model from Iaas to SaaS , or Software as a Service . Software

  8. 48 CFR 227.7203-15 - Subcontractor rights in computer software or computer software documentation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... computer software or computer software documentation. 227.7203-15 Section 227.7203-15 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-15 Subcontractor rights in computer software or computer software documentation. (a...

  9. 48 CFR 227.7203-15 - Subcontractor rights in computer software or computer software documentation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... computer software or computer software documentation. 227.7203-15 Section 227.7203-15 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-15 Subcontractor rights in computer software or computer software documentation. (a...

  10. 48 CFR 227.7203-15 - Subcontractor rights in computer software or computer software documentation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... computer software or computer software documentation. 227.7203-15 Section 227.7203-15 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-15 Subcontractor rights in computer software or computer software documentation. (a...

  11. 48 CFR 227.7203-15 - Subcontractor rights in computer software or computer software documentation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... computer software or computer software documentation. 227.7203-15 Section 227.7203-15 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-15 Subcontractor rights in computer software or computer software documentation. (a...

  12. 48 CFR 227.7203-15 - Subcontractor rights in computer software or computer software documentation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... computer software or computer software documentation. 227.7203-15 Section 227.7203-15 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-15 Subcontractor rights in computer software or computer software documentation. (a...

  13. 48 CFR 227.7202-3 - Rights in commercial computer software or commercial computer software documentation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... computer software or commercial computer software documentation. 227.7202-3 Section 227.7202-3 Federal... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202-3 Rights in commercial computer software or commercial computer software documentation...

  14. 48 CFR 227.7202-3 - Rights in commercial computer software or commercial computer software documentation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... computer software or commercial computer software documentation. 227.7202-3 Section 227.7202-3 Federal... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202-3 Rights in commercial computer software or commercial computer software documentation...

  15. 48 CFR 227.7203-2 - Acquisition of noncommercial computer software and computer software documentation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... noncommercial computer software and computer software documentation. 227.7203-2 Section 227.7203-2 Federal... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-2 Acquisition of noncommercial computer software and computer software documentation. (a...

  16. 48 CFR 227.7203-2 - Acquisition of noncommercial computer software and computer software documentation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... noncommercial computer software and computer software documentation. 227.7203-2 Section 227.7203-2 Federal... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-2 Acquisition of noncommercial computer software and computer software documentation. (a...

  17. 48 CFR 227.7203-2 - Acquisition of noncommercial computer software and computer software documentation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... noncommercial computer software and computer software documentation. 227.7203-2 Section 227.7203-2 Federal... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-2 Acquisition of noncommercial computer software and computer software documentation. (a...

  18. 48 CFR 227.7203-10 - Contractor identification and marking of computer software or computer software documentation to...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... and marking of computer software or computer software documentation to be furnished with restrictive... Rights in Computer Software and Computer Software Documentation 227.7203-10 Contractor identification and marking of computer software or computer software documentation to be furnished with restrictive markings...

  19. 48 CFR 227.7203-2 - Acquisition of noncommercial computer software and computer software documentation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... noncommercial computer software and computer software documentation. 227.7203-2 Section 227.7203-2 Federal... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-2 Acquisition of noncommercial computer software and computer software documentation. (a...

  20. 48 CFR 227.7202-3 - Rights in commercial computer software or commercial computer software documentation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... computer software or commercial computer software documentation. 227.7202-3 Section 227.7202-3 Federal... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202-3 Rights in commercial computer software or commercial computer software documentation...

  1. 48 CFR 227.7203-10 - Contractor identification and marking of computer software or computer software documentation to...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... and marking of computer software or computer software documentation to be furnished with restrictive... Rights in Computer Software and Computer Software Documentation 227.7203-10 Contractor identification and marking of computer software or computer software documentation to be furnished with restrictive markings...

  2. 48 CFR 227.7202-3 - Rights in commercial computer software or commercial computer software documentation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... computer software or commercial computer software documentation. 227.7202-3 Section 227.7202-3 Federal... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202-3 Rights in commercial computer software or commercial computer software documentation...

  3. 48 CFR 227.7203-10 - Contractor identification and marking of computer software or computer software documentation to...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... and marking of computer software or computer software documentation to be furnished with restrictive... Rights in Computer Software and Computer Software Documentation 227.7203-10 Contractor identification and marking of computer software or computer software documentation to be furnished with restrictive markings...

  4. 48 CFR 227.7202-3 - Rights in commercial computer software or commercial computer software documentation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... computer software or commercial computer software documentation. 227.7202-3 Section 227.7202-3 Federal... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202-3 Rights in commercial computer software or commercial computer software documentation...

  5. 48 CFR 227.7203-10 - Contractor identification and marking of computer software or computer software documentation to...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... and marking of computer software or computer software documentation to be furnished with restrictive... Rights in Computer Software and Computer Software Documentation 227.7203-10 Contractor identification and marking of computer software or computer software documentation to be furnished with restrictive markings...

  6. 48 CFR 227.7203-10 - Contractor identification and marking of computer software or computer software documentation to...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... and marking of computer software or computer software documentation to be furnished with restrictive... Rights in Computer Software and Computer Software Documentation 227.7203-10 Contractor identification and marking of computer software or computer software documentation to be furnished with restrictive markings...

  7. 48 CFR 227.7203-2 - Acquisition of noncommercial computer software and computer software documentation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... noncommercial computer software and computer software documentation. 227.7203-2 Section 227.7203-2 Federal... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-2 Acquisition of noncommercial computer software and computer software documentation. (a...

  8. Software analysis handbook: Software complexity analysis and software reliability estimation and prediction

    NASA Technical Reports Server (NTRS)

    Lee, Alice T.; Gunn, Todd; Pham, Tuan; Ricaldi, Ron

    1994-01-01

    This handbook documents the three software analysis processes the Space Station Software Analysis team uses to assess space station software, including their backgrounds, theories, tools, and analysis procedures. Potential applications of these analysis results are also presented. The first section describes how software complexity analysis provides quantitative information on code, such as code structure and risk areas, throughout the software life cycle. Software complexity analysis allows an analyst to understand the software structure, identify critical software components, assess risk areas within a software system, identify testing deficiencies, and recommend program improvements. Performing this type of analysis during the early design phases of software development can positively affect the process, and may prevent later, much larger, difficulties. The second section describes how software reliability estimation and prediction analysis, or software reliability, provides a quantitative means to measure the probability of failure-free operation of a computer program, and describes the two tools used by JSC to determine failure rates and design tradeoffs between reliability, costs, performance, and schedule.

  9. 48 CFR 227.7203-3 - Early identification of computer software or computer software documentation to be furnished to...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... computer software or computer software documentation to be furnished to the Government with restrictions on..., DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-3 Early identification of computer software or computer software documentation to be furnished to the Government with...

  10. 48 CFR 227.7203-3 - Early identification of computer software or computer software documentation to be furnished to...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... computer software or computer software documentation to be furnished to the Government with restrictions on..., DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-3 Early identification of computer software or computer software documentation to be furnished to the Government with...

  11. 48 CFR 227.7203-3 - Early identification of computer software or computer software documentation to be furnished to...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... computer software or computer software documentation to be furnished to the Government with restrictions on..., DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-3 Early identification of computer software or computer software documentation to be furnished to the Government with...

  12. 48 CFR 227.7203-3 - Early identification of computer software or computer software documentation to be furnished to...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... computer software or computer software documentation to be furnished to the Government with restrictions on..., DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-3 Early identification of computer software or computer software documentation to be furnished to the Government with...

  13. 48 CFR 227.7203-3 - Early identification of computer software or computer software documentation to be furnished to...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... computer software or computer software documentation to be furnished to the Government with restrictions on..., DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-3 Early identification of computer software or computer software documentation to be furnished to the Government with...

  14. Automated Reuse of Scientific Subroutine Libraries through Deductive Synthesis

    NASA Technical Reports Server (NTRS)

    Lowry, Michael R.; Pressburger, Thomas; VanBaalen, Jeffrey; Roach, Steven

    1997-01-01

    Systematic software construction offers the potential of elevating software engineering from an art-form to an engineering discipline. The desired result is more predictable software development leading to better quality and more maintainable software. However, the overhead costs associated with the formalisms, mathematics, and methods of systematic software construction have largely precluded their adoption in real-world software development. In fact, many mainstream software development organizations, such as Microsoft, still maintain a predominantly oral culture for software development projects; which is far removed from a formalism-based culture for software development. An exception is the limited domain of safety-critical software, where the high-assuiance inherent in systematic software construction justifies the additional cost. We believe that systematic software construction will only be adopted by mainstream software development organization when the overhead costs have been greatly reduced. Two approaches to cost mitigation are reuse (amortizing costs over many applications) and automation. For the last four years, NASA Ames has funded the Amphion project, whose objective is to automate software reuse through techniques from systematic software construction. In particular, deductive program synthesis (i.e., program extraction from proofs) is used to derive a composition of software components (e.g., subroutines) that correctly implements a specification. The construction of reuse libraries of software components is the standard software engineering solution for improving software development productivity and quality.

  15. Annotated bibliography of Software Engineering Laboratory literature

    NASA Technical Reports Server (NTRS)

    Morusiewicz, Linda; Valett, Jon D.

    1991-01-01

    An annotated bibliography of technical papers, documents, and memorandums produced by or related to the Software Engineering Laboratory is given. More than 100 publications are summarized. These publications cover many areas of software engineering and range from research reports to software documentation. All materials have been grouped into eight general subject areas for easy reference: The Software Engineering Laboratory; The Software Engineering Laboratory: Software Development Documents; Software Tools; Software Models; Software Measurement; Technology Evaluations; Ada Technology; and Data Collection. Subject and author indexes further classify these documents by specific topic and individual author.

  16. SAGA: A project to automate the management of software production systems

    NASA Technical Reports Server (NTRS)

    Campbell, Roy H.; Beckman-Davies, C. S.; Benzinger, L.; Beshers, G.; Laliberte, D.; Render, H.; Sum, R.; Smith, W.; Terwilliger, R.

    1986-01-01

    Research into software development is required to reduce its production cost and to improve its quality. Modern software systems, such as the embedded software required for NASA's space station initiative, stretch current software engineering techniques. The requirements to build large, reliable, and maintainable software systems increases with time. Much theoretical and practical research is in progress to improve software engineering techniques. One such technique is to build a software system or environment which directly supports the software engineering process, i.e., the SAGA project, comprising the research necessary to design and build a software development which automates the software engineering process. Progress under SAGA is described.

  17. The social disutility of software ownership.

    PubMed

    Douglas, David M

    2011-09-01

    Software ownership allows the owner to restrict the distribution of software and to prevent others from reading the software's source code and building upon it. However, free software is released to users under software licenses that give them the right to read the source code, modify it, reuse it, and distribute the software to others. Proponents of free software such as Richard M. Stallman and Eben Moglen argue that the social disutility of software ownership is a sufficient justification for prohibiting it. This social disutility includes the social instability of disregarding laws and agreements covering software use and distribution, inequality of software access, and the inability to help others by sharing software with them. Here I consider these and other social disutility claims against withholding specific software rights from users, in particular, the rights to read the source code, duplicate, distribute, modify, imitate, and reuse portions of the software within new programs. I find that generally while withholding these rights from software users does cause some degree of social disutility, only the rights to duplicate, modify and imitate cannot legitimately be denied to users on this basis. The social disutility of withholding the rights to distribute the software, read its source code and reuse portions of it in new programs is insufficient to prohibit software owners from denying them to users. A compromise between the software owner and user can minimise the social disutility of withholding these particular rights from users. However, the social disutility caused by software patents is sufficient for rejecting such patents as they restrict the methods of reducing social disutility possible with other forms of software ownership.

  18. Proceedings of the Seventeenth Annual Software Engineering Workshop

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Proceedings of the Seventeenth Annual Software Engineering Workshop are presented. The software Engineering Laboratory (SEL) is an organization sponsored by NASA/Goddard Space Flight Center and created to investigate the effectiveness of software engineering technologies when applied to the development of applications software. Topics covered include: the Software Engineering Laboratory; process measurement; software reuse; software quality; lessons learned; and is Ada dying.

  19. Four applications of a software data collection and analysis methodology

    NASA Technical Reports Server (NTRS)

    Basili, Victor R.; Selby, Richard W., Jr.

    1985-01-01

    The evaluation of software technologies suffers because of the lack of quantitative assessment of their effect on software development and modification. A seven-step data collection and analysis methodology couples software technology evaluation with software measurement. Four in-depth applications of the methodology are presented. The four studies represent each of the general categories of analyses on the software product and development process: blocked subject-project studies, replicated project studies, multi-project variation studies, and single project strategies. The four applications are in the areas of, respectively, software testing, cleanroom software development, characteristic software metric sets, and software error analysis.

  20. Third-Party Software's Trust Quagmire.

    PubMed

    Voas, J; Hurlburt, G

    2015-12-01

    Current software development has trended toward the idea of integrating independent software sub-functions to create more complete software systems. Software sub-functions are often not homegrown - instead they are developed by unknown 3 rd party organizations and reside in software marketplaces owned or controlled by others. Such software sub-functions carry plausible concern in terms of quality, origins, functionality, security, interoperability, to name a few. This article surveys key technical difficulties in confidently building systems from acquired software sub-functions by calling out the principle software supply chain actors.

  1. Space Station Software Issues

    NASA Technical Reports Server (NTRS)

    Voigt, S. (Editor); Beskenis, S. (Editor)

    1985-01-01

    Issues in the development of software for the Space Station are discussed. Software acquisition and management, software development environment, standards, information system support for software developers, and a future software advisory board are addressed.

  2. Software Acquisition: Evolution, Total Quality Management, and Applications to the Army Tactical Missile System

    DTIC Science & Technology

    1992-06-01

    presents the concept of software Total Quality Management (TQM) which focuses on the entire process of software acquisition, as a partial solution to...software TQM can be applied to software acquisition. Software Development, Software Acquisition, Total Quality management (TQM), Army Tactical Missile

  3. 48 CFR 252.227-7014 - Rights in noncommercial computer software and noncommercial computer software documentation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... computer software and noncommercial computer software documentation. 252.227-7014 Section 252.227-7014... Rights in noncommercial computer software and noncommercial computer software documentation. As prescribed in 227.7203-6(a)(1), use the following clause. Rights in Noncommercial Computer Software and...

  4. 48 CFR 252.227-7014 - Rights in noncommercial computer software and noncommercial computer software documentation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... computer software and noncommercial computer software documentation. 252.227-7014 Section 252.227-7014... Rights in noncommercial computer software and noncommercial computer software documentation. As prescribed in 227.7203-6(a)(1), use the following clause. Rights in Noncommercial Computer Software and...

  5. 48 CFR 227.7203-14 - Conformity, acceptance, and warranty of computer software and computer software documentation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., and warranty of computer software and computer software documentation. 227.7203-14 Section 227.7203-14... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-14 Conformity, acceptance, and warranty of computer software and computer...

  6. 48 CFR 252.227-7014 - Rights in noncommercial computer software and noncommercial computer software documentation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... computer software and noncommercial computer software documentation. 252.227-7014 Section 252.227-7014... Rights in noncommercial computer software and noncommercial computer software documentation. As prescribed in 227.7203-6(a)(1), use the following clause. Rights in Noncommercial Computer Software and...

  7. 48 CFR 227.7203-14 - Conformity, acceptance, and warranty of computer software and computer software documentation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., and warranty of computer software and computer software documentation. 227.7203-14 Section 227.7203-14... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-14 Conformity, acceptance, and warranty of computer software and computer...

  8. 48 CFR 252.227-7014 - Rights in noncommercial computer software and noncommercial computer software documentation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... computer software and noncommercial computer software documentation. 252.227-7014 Section 252.227-7014... Rights in noncommercial computer software and noncommercial computer software documentation. As prescribed in 227.7203-6(a)(1), use the following clause. Rights in Noncommercial Computer Software and...

  9. 48 CFR 227.7203-14 - Conformity, acceptance, and warranty of computer software and computer software documentation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., and warranty of computer software and computer software documentation. 227.7203-14 Section 227.7203-14... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-14 Conformity, acceptance, and warranty of computer software and computer...

  10. 48 CFR 227.7203-14 - Conformity, acceptance, and warranty of computer software and computer software documentation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., and warranty of computer software and computer software documentation. 227.7203-14 Section 227.7203-14... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-14 Conformity, acceptance, and warranty of computer software and computer...

  11. 48 CFR 227.7203-14 - Conformity, acceptance, and warranty of computer software and computer software documentation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., and warranty of computer software and computer software documentation. 227.7203-14 Section 227.7203-14... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-14 Conformity, acceptance, and warranty of computer software and computer...

  12. 48 CFR 252.227-7014 - Rights in noncommercial computer software and noncommercial computer software documentation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... computer software and noncommercial computer software documentation. 252.227-7014 Section 252.227-7014... Rights in noncommercial computer software and noncommercial computer software documentation. As prescribed in 227.7203-6(a)(1), use the following clause. Rights in Noncommercial Computer Software and...

  13. Software Quality Assurance Metrics

    NASA Technical Reports Server (NTRS)

    McRae, Kalindra A.

    2004-01-01

    Software Quality Assurance (SQA) is a planned and systematic set of activities that ensures conformance of software life cycle processes and products conform to requirements, standards and procedures. In software development, software quality means meeting requirements and a degree of excellence and refinement of a project or product. Software Quality is a set of attributes of a software product by which its quality is described and evaluated. The set of attributes includes functionality, reliability, usability, efficiency, maintainability, and portability. Software Metrics help us understand the technical process that is used to develop a product. The process is measured to improve it and the product is measured to increase quality throughout the life cycle of software. Software Metrics are measurements of the quality of software. Software is measured to indicate the quality of the product, to assess the productivity of the people who produce the product, to assess the benefits derived from new software engineering methods and tools, to form a baseline for estimation, and to help justify requests for new tools or additional training. Any part of the software development can be measured. If Software Metrics are implemented in software development, it can save time, money, and allow the organization to identify the caused of defects which have the greatest effect on software development. The summer of 2004, I worked with Cynthia Calhoun and Frank Robinson in the Software Assurance/Risk Management department. My task was to research and collect, compile, and analyze SQA Metrics that have been used in other projects that are not currently being used by the SA team and report them to the Software Assurance team to see if any metrics can be implemented in their software assurance life cycle process.

  14. Software Configuration Management Guidebook

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The growth in cost and importance of software to NASA has caused NASA to address the improvement of software development across the agency. One of the products of this program is a series of guidebooks that define a NASA concept of the assurance processes which are used in software development. The Software Assurance Guidebook, SMAP-GB-A201, issued in September, 1989, provides an overall picture of the concepts and practices of NASA in software assurance. Lower level guidebooks focus on specific activities that fall within the software assurance discipline, and provide more detailed information for the manager and/or practitioner. This is the Software Configuration Management Guidebook which describes software configuration management in a way that is compatible with practices in industry and at NASA Centers. Software configuration management is a key software development process, and is essential for doing software assurance.

  15. Computer-Aided Software Engineering - An approach to real-time software development

    NASA Technical Reports Server (NTRS)

    Walker, Carrie K.; Turkovich, John J.

    1989-01-01

    A new software engineering discipline is Computer-Aided Software Engineering (CASE), a technology aimed at automating the software development process. This paper explores the development of CASE technology, particularly in the area of real-time/scientific/engineering software, and a history of CASE is given. The proposed software development environment for the Advanced Launch System (ALS CASE) is described as an example of an advanced software development system for real-time/scientific/engineering (RT/SE) software. The Automated Programming Subsystem of ALS CASE automatically generates executable code and corresponding documentation from a suitably formatted specification of the software requirements. Software requirements are interactively specified in the form of engineering block diagrams. Several demonstrations of the Automated Programming Subsystem are discussed.

  16. Product-oriented Software Certification Process for Software Synthesis

    NASA Technical Reports Server (NTRS)

    Nelson, Stacy; Fischer, Bernd; Denney, Ewen; Schumann, Johann; Richardson, Julian; Oh, Phil

    2004-01-01

    The purpose of this document is to propose a product-oriented software certification process to facilitate use of software synthesis and formal methods. Why is such a process needed? Currently, software is tested until deemed bug-free rather than proving that certain software properties exist. This approach has worked well in most cases, but unfortunately, deaths still occur due to software failure. Using formal methods (techniques from logic and discrete mathematics like set theory, automata theory and formal logic as opposed to continuous mathematics like calculus) and software synthesis, it is possible to reduce this risk by proving certain software properties. Additionally, software synthesis makes it possible to automate some phases of the traditional software development life cycle resulting in a more streamlined and accurate development process.

  17. Software engineering laboratory series: Annotated bibliography of software engineering laboratory literature

    NASA Technical Reports Server (NTRS)

    Morusiewicz, Linda; Valett, Jon

    1992-01-01

    This document is an annotated bibliography of technical papers, documents, and memorandums produced by or related to the Software Engineering Laboratory. More than 100 publications are summarized. These publications cover many areas of software engineering and range from research reports to software documentation. This document has been updated and reorganized substantially since the original version (SEL-82-006, November 1982). All materials have been grouped into eight general subject areas for easy reference: (1) the Software Engineering Laboratory; (2) the Software Engineering Laboratory: Software Development Documents; (3) Software Tools; (4) Software Models; (5) Software Measurement; (6) Technology Evaluations; (7) Ada Technology; and (8) Data Collection. This document contains an index of these publications classified by individual author.

  18. SAGA: A project to automate the management of software production systems

    NASA Technical Reports Server (NTRS)

    Campbell, Roy H.; Laliberte, D.; Render, H.; Sum, R.; Smith, W.; Terwilliger, R.

    1987-01-01

    The Software Automation, Generation and Administration (SAGA) project is investigating the design and construction of practical software engineering environments for developing and maintaining aerospace systems and applications software. The research includes the practical organization of the software lifecycle, configuration management, software requirements specifications, executable specifications, design methodologies, programming, verification, validation and testing, version control, maintenance, the reuse of software, software libraries, documentation, and automated management.

  19. Annotated bibliography of software engineering laboratory literature

    NASA Technical Reports Server (NTRS)

    Groves, Paula; Valett, Jon

    1990-01-01

    An annotated bibliography of technical papers, documents, and memorandums produced by or related to the Software Engineering Laboratory is given. More than 100 publications are summarized. These publications cover many areas of software engineering and range from research reports to software documentation. This document has been updated and reorganized substantially since the original version (SEL-82-006, November 1982). All materials have been grouped into eight general subject areas for easy reference: the Software Engineering Laboratory; the Software Engineering Laboratory-software development documents; software tools; software models; software measurement; technology evaluations; Ada technology; and data collection. Subject and author indexes further classify these documents by specific topic and individual author.

  20. Annotated bibliography of Software Engineering Laboratory literature

    NASA Technical Reports Server (NTRS)

    Morusiewicz, Linda; Valett, Jon

    1993-01-01

    This document is an annotated bibliography of technical papers, documents, and memorandums produced by or related to the Software Engineering Laboratory. Nearly 200 publications are summarized. These publications cover many areas of software engineering and range from research reports to software documentation. This document has been updated and reorganized substantially since the original version (SEL-82-006, November 1982). All materials have been grouped into eight general subject areas for easy reference: the Software Engineering Laboratory; the Software Engineering Laboratory: software development documents; software tools; software models; software measurement; technology evaluations; Ada technology; and data collection. This document contains an index of these publications classified by individual author.

  1. 48 CFR 227.7203-8 - Deferred delivery and deferred ordering of computer software and computer software documentation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... deferred ordering of computer software and computer software documentation. 227.7203-8 Section 227.7203-8... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-8 Deferred delivery and deferred ordering of computer software and computer...

  2. 48 CFR 227.7203-8 - Deferred delivery and deferred ordering of computer software and computer software documentation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... deferred ordering of computer software and computer software documentation. 227.7203-8 Section 227.7203-8... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-8 Deferred delivery and deferred ordering of computer software and computer...

  3. 48 CFR 227.7203-8 - Deferred delivery and deferred ordering of computer software and computer software documentation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... deferred ordering of computer software and computer software documentation. 227.7203-8 Section 227.7203-8... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-8 Deferred delivery and deferred ordering of computer software and computer...

  4. 48 CFR 227.7203-8 - Deferred delivery and deferred ordering of computer software and computer software documentation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... deferred ordering of computer software and computer software documentation. 227.7203-8 Section 227.7203-8... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-8 Deferred delivery and deferred ordering of computer software and computer...

  5. 48 CFR 227.7203-8 - Deferred delivery and deferred ordering of computer software and computer software documentation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... deferred ordering of computer software and computer software documentation. 227.7203-8 Section 227.7203-8... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-8 Deferred delivery and deferred ordering of computer software and computer...

  6. A Framework of the Use of Information in Software Testing

    ERIC Educational Resources Information Center

    Kaveh, Payman

    2010-01-01

    With the increasing role that software systems play in our daily lives, software quality has become extremely important. Software quality is impacted by the efficiency of the software testing process. There are a growing number of software testing methodologies, models, and initiatives to satisfy the need to improve software quality. The main…

  7. NASA's Approach to Software Assurance

    NASA Technical Reports Server (NTRS)

    Wetherholt, Martha

    2015-01-01

    NASA defines software assurance as: the planned and systematic set of activities that ensure conformance of software life cycle processes and products to requirements, standards, and procedures via quality, safety, reliability, and independent verification and validation. NASA's implementation of this approach to the quality, safety, reliability, security and verification and validation of software is brought together in one discipline, software assurance. Organizationally, NASA has software assurance at each NASA center, a Software Assurance Manager at NASA Headquarters, a Software Assurance Technical Fellow (currently the same person as the SA Manager), and an Independent Verification and Validation Organization with its own facility. An umbrella risk mitigation strategy for safety and mission success assurance of NASA's software, software assurance covers a wide area and is better structured to address the dynamic changes in how software is developed, used, and managed, as well as it's increasingly complex functionality. Being flexible, risk based, and prepared for challenges in software at NASA is essential, especially as much of our software is unique for each mission.

  8. Wideband Low Side Lobe Aperture Coupled Patch Phased Array Antennas

    NASA Astrophysics Data System (ADS)

    Poduval, Dhruva

    Low profile printed antenna arrays with wide bandwidth, high gain, and low Side Lobe Level (SLL) are in great demand for current and future commercial and military communication systems and radar. Aperture coupled patch antennas have been proposed to obtain wide impedance bandwidths in the past. Aperture coupling is preferred particularly for phased arrays because of their advantage of integration to other active devices and circuits, e.g. phase shifters, power amplifiers, low noise amplifiers, mixers etc. However, when designing such arrays, the interplay between array performance characteristics, such as gain, side lobe level, back lobe level, mutual coupling etc. must be understood and optimized under multiple design constraints, e.g. substrate material properties and thicknesses, element to element spacing, and feed lines and their orientation and arrangements with respect to the antenna elements. The focus of this thesis is to investigate, design, and develop an aperture coupled patch array with wide operating bandwidth (30%), high gain (17.5 dBi), low side lobe level (20 dB), and high Forward to Backward (F/B) ratio (21.8 dB). The target frequency range is 2.4 to 3 GHz given its wide application in WLAN, LTE (Long Term Evolution) and other communication systems. Notwithstanding that the design concept can very well be adapted at other frequencies. Specifically, a 16 element, 4 by 4 planar microstrip patch array is designed using HFSS and experimentally developed and tested. Starting from mutual coupling minimization a corporate feeding scheme is designed to achieve the needed performance. To reduce the SLL the corporate feeding network is redesigned to obtain a specific amplitude taper. Studies are conducted to determine the optimum location for a metallic reflector under the feed line to improve the F/B. An experimental prototype of the antenna was built and tested validating and demonstrating the performance levels expected from simulation predictions. Finally, simulated beam scanning in several angles of the array is shown considering specific phases for each antenna element in the array.

  9. Current indications for transplantation: stratification of severe heart failure and shared decision-making

    PubMed Central

    Vucicevic, Darko; Honoris, Lily; Raia, Federica

    2018-01-01

    Heart failure (HF) is a complex clinical syndrome that results from structural or functional cardiovascular disorders causing a mismatch between demand and supply of oxygenated blood and consecutive failure of the body’s organs. For those patients with stage D HF, advanced therapies, such as mechanical circulatory support (MCS) or heart transplantation (HTx), are potentially life-saving options. The role of risk stratification of patients with stage D HF in a value-based healthcare framework is to predict which subset might benefit from advanced HF (AdHF) therapies, to improve outcomes related to the individual patient including mortality, morbidity and patient experience as well as to optimize health care delivery system outcomes such as cost-effectiveness. Risk stratification and subsequent outcome prediction as well as therapeutic recommendation-making need to be based on the comparative survival benefit rationale. A robust model needs to (I) have the power to discriminate (i.e., to correctly risk stratify patients); (II) calibrate (i.e., to show agreement between the predicted and observed risk); (III) to be applicable to the general population; and (IV) provide good external validation. The Seattle Heart Failure Model (SHFM) and the Heart Failure Survival Score (HFSS) are two of the most widely utilized scores. However, outcomes for patients with HF are highly variable which make clinical predictions challenging. Despite our clinical expertise and current prediction tools, the best short- and long-term survival for the individual patient, particularly the sickest patient, is not easy to identify because among the most severely ill, elderly and frail patients, most preoperative prediction tools have the tendency to be imprecise in estimating risk. They should be used as a guide in a clinical encounter grounded in a culture of shared decision-making, with the expert healthcare professional team as consultants and the patient as an empowered decision-maker in a trustful safe therapeutic relationship. PMID:29492383

  10. Current indications for transplantation: stratification of severe heart failure and shared decision-making.

    PubMed

    Vucicevic, Darko; Honoris, Lily; Raia, Federica; Deng, Mario

    2018-01-01

    Heart failure (HF) is a complex clinical syndrome that results from structural or functional cardiovascular disorders causing a mismatch between demand and supply of oxygenated blood and consecutive failure of the body's organs. For those patients with stage D HF, advanced therapies, such as mechanical circulatory support (MCS) or heart transplantation (HTx), are potentially life-saving options. The role of risk stratification of patients with stage D HF in a value-based healthcare framework is to predict which subset might benefit from advanced HF (AdHF) therapies, to improve outcomes related to the individual patient including mortality, morbidity and patient experience as well as to optimize health care delivery system outcomes such as cost-effectiveness. Risk stratification and subsequent outcome prediction as well as therapeutic recommendation-making need to be based on the comparative survival benefit rationale. A robust model needs to (I) have the power to discriminate (i.e., to correctly risk stratify patients); (II) calibrate (i.e., to show agreement between the predicted and observed risk); (III) to be applicable to the general population; and (IV) provide good external validation. The Seattle Heart Failure Model (SHFM) and the Heart Failure Survival Score (HFSS) are two of the most widely utilized scores. However, outcomes for patients with HF are highly variable which make clinical predictions challenging. Despite our clinical expertise and current prediction tools, the best short- and long-term survival for the individual patient, particularly the sickest patient, is not easy to identify because among the most severely ill, elderly and frail patients, most preoperative prediction tools have the tendency to be imprecise in estimating risk. They should be used as a guide in a clinical encounter grounded in a culture of shared decision-making, with the expert healthcare professional team as consultants and the patient as an empowered decision-maker in a trustful safe therapeutic relationship.

  11. Long range ultra-high frequency (UHF) radio frequency identification (RFID) antenna design

    NASA Astrophysics Data System (ADS)

    Reynolds, Nathan D.

    There is an ever-increasing demand for radio frequency identification (RFID) tags that are passive, long range, and mountable on multiple surfaces. Currently, RFID technology is utilized in numerous applications such as supply chain management, access control, and public transportation. With the combination of sensory systems in recent years, the applications of RFID technology have been extended beyond tracking and identifying. This extension includes applications such as environmental monitoring and healthcare applications. The available sensory systems usually operate in the medium or high frequency bands and have a low read range. However, the range limitations of these systems are being overcome by the development of RFID sensors focused on utilizing tags in the ultra-high frequency (UHF) band. Generally, RFID tags have to be mounted to the object that is being identified. Often the objects requiring identification are metallic. The inherent properties of metallic objects have substantial effects on nearby electromagnetic radiation; therefore, the operation of the tag antenna is affected when mounted on a metallic surface. This outlines one of the most challenging problems for RFID systems today: the optimization of tag antenna performance in a complex environment. In this research, a novel UHF RFID tag antenna, which has a low profile, long range, and is mountable on metallic surfaces, is designed analytically and simulated using a 3-D electromagnetic simulator, ANSYS HFSS. A microstrip patch antenna is selected as the antenna structure, as patch antennas are low profile and suitable for mounting on metallic surfaces. Matching and theoretical models of the microstrip patch antenna are investigated. Once matching and theory of a microstrip patch antenna is thoroughly understood, a unique design technique using electromagnetic band gap (EBG) structures is explored. This research shows that the utilization of an EBG structure in the patch antenna design yields an improvement in gain, or range, and in the ability to be mounted on multiple metallic surfaces.

  12. The Limit of Resolution and Detectability of the ArcCHECK QA Phantom in small field Volumetric Modulated Arc Therapy and Stereotactic Radiosurgery Quality Assurance

    NASA Astrophysics Data System (ADS)

    Geiler, Michael

    Yittrium Iron Garnet Y3Fe6O12 and Lithium ferrite LiFe5O8 mono and poly crystals were investigated for their spinwave linewidth ΔHk, ferromagnetic resonance linewidth ΔH and complex magnetic losses μ’ and μ’’ at L and S bands. Conventional methods of Spinwave linewidth typically require very high power microwave sources and associated high power components. Therefore, we developed a Dielectric Resonator (DR) based test method that allows for measurement of ΔHk using low power, common microwave laboratory equipment, while providing additional capability to measure the other relevant magnetic material characteristics. The samples used in this research were 0.030” diameter, abrasive milled spheres provided by Pacific Ceramics Inc, and Ferrisphere Inc. and included a variety of standard off-the-shelf material offerings. The saturation magnetization Ms of the samples ranged from 75 Gauss to 3700 Gauss. The ΔH and ΔHk of the samples were in the ranges of 0.5 to 200 Oersteds, and 0.5 to 30 Oersteds, respectively. Practical frequencies of operation for this system are 1 GHz to 20 GHz with less than 20W required RF power. Operation below 1 GHz and up to 40 GHz is possible. Reduction of intrinsic Ms in YIG in achieved by doping with Gadolinium and/or Aluminum. These additions were found to affect the microwave properties of the materials as well. Dopants like Cobalt, Manganese and Holmium do not effect the saturation magnetization but they do alter the high power microwave properties of the material similarly to Gd and Al. Several DRs were designed and modeled using Ansys HFSS electromagnetic finite element solver. We designed experiments that allow the measurement of all relevant microwave properties in one convenient test setup. This includes simultaneous control of multiple variables including RF field, frequency and power, and DC field strength.

  13. The Implications of Using Integrated Software Support Environment for Design of Guidance and Control Systems Software

    DTIC Science & Technology

    1990-02-01

    inspections are performed before each formal review of each software life cycle phase. * Required software audits are performed . " The software is acceptable... Audits : Software audits are performed bySQA consistent with thegeneral audit rules and an auditreportis prepared. Software Quality Inspection (SQI...DSD Software Development Method 3-34 DEFINITION OF ACRONYMS Acronym Full Name or Description MACH Methode d’Analyse et de Conception Flierarchisee

  14. Evolution of Secondary Software Businesses: Understanding Industry Dynamics

    NASA Astrophysics Data System (ADS)

    Tyrväinen, Pasi; Warsta, Juhani; Seppänen, Veikko

    Primary software industry originates from IBM's decision to unbundle software-related computer system development activities to external partners. This kind of outsourcing from an enterprise internal software development activity is a common means to start a new software business serving a vertical software market. It combines knowledge of the vertical market process with competence in software development. In this research, we present and analyze the key figures of the Finnish secondary software industry, in order to quantify its interaction with the primary software industry during the period of 2000-2003. On the basis of the empirical data, we present a model for evolution of a secondary software business, which makes explicit the industry dynamics. It represents the shift from internal software developed for competitive advantage to development of products supporting standard business processes on top of standardized technologies. We also discuss the implications for software business strategies in each phase.

  15. Secure software practices among Malaysian software practitioners: An exploratory study

    NASA Astrophysics Data System (ADS)

    Mohamed, Shafinah Farvin Packeer; Baharom, Fauziah; Deraman, Aziz; Yahya, Jamaiah; Mohd, Haslina

    2016-08-01

    Secure software practices is increasingly gaining much importance among software practitioners and researchers due to the rise of computer crimes in the software industry. It has become as one of the determinant factors for producing high quality software. Even though its importance has been revealed, its current practice in the software industry is still scarce, particularly in Malaysia. Thus, an exploratory study is conducted among software practitioners in Malaysia to study their experiences and practices in the real-world projects. This paper discusses the findings from the study, which involved 93 software practitioners. Structured questionnaire is utilized for data collection purpose whilst statistical methods such as frequency, mean, and cross tabulation are used for data analysis. Outcomes from this study reveal that software practitioners are becoming increasingly aware on the importance of secure software practices, however, they lack of appropriate implementation, which could affect the quality of produced software.

  16. The Role and Quality of Software Safety in the NASA Constellation Program

    NASA Technical Reports Server (NTRS)

    Layman, Lucas; Basili, Victor R.; Zelkowitz, Marvin V.

    2010-01-01

    In this study, we examine software safety risk in the early design phase of the NASA Constellation spaceflight program. Obtaining an accurate, program-wide picture of software safety risk is difficult across multiple, independently-developing systems. We leverage one source of safety information, hazard analysis, to provide NASA quality assurance managers with information regarding the ongoing state of software safety across the program. The goal of this research is two-fold: 1) to quantify the relative importance of software with respect to system safety; and 2) to quantify the level of risk presented by software in the hazard analysis. We examined 154 hazard reports created during the preliminary design phase of three major flight hardware systems within the Constellation program. To quantify the importance of software, we collected metrics based on the number of software-related causes and controls of hazardous conditions. To quantify the level of risk presented by software, we created a metric scheme to measure the specificity of these software causes. We found that from 49-70% of hazardous conditions in the three systems could be caused by software or software was involved in the prevention of the hazardous condition. We also found that 12-17% of the 2013 hazard causes involved software, and that 23-29% of all causes had a software control. Furthermore, 10-12% of all controls were software-based. There is potential for inaccuracy in these counts, however, as software causes are not consistently scoped, and the presence of software in a cause or control is not always clear. The application of our software specificity metrics also identified risks in the hazard reporting process. In particular, we found a number of traceability risks in the hazard reports may impede verification of software and system safety.

  17. A UML-based metamodel for software evolution process

    NASA Astrophysics Data System (ADS)

    Jiang, Zuo; Zhou, Wei-Hong; Fu, Zhi-Tao; Xiong, Shun-Qing

    2014-04-01

    A software evolution process is a set of interrelated software processes under which the corresponding software is evolving. An object-oriented software evolution process meta-model (OO-EPMM), abstract syntax and formal OCL constraint of meta-model are presented in this paper. OO-EPMM can not only represent software development process, but also represent software evolution.

  18. 48 CFR 227.7202-4 - Contract clause.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Software and Computer Software Documentation 227.7202-4 Contract clause. A specific contract clause governing the Government's rights in commercial computer software or commercial computer software..., release, perform, display, or disclose computer software or computer software documentation shall be...

  19. 48 CFR 227.7202-4 - Contract clause.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Software and Computer Software Documentation 227.7202-4 Contract clause. A specific contract clause governing the Government's rights in commercial computer software or commercial computer software..., release, perform, display, or disclose computer software or computer software documentation shall be...

  20. 48 CFR 227.7202-4 - Contract clause.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Software and Computer Software Documentation 227.7202-4 Contract clause. A specific contract clause governing the Government's rights in commercial computer software or commercial computer software..., release, perform, display, or disclose computer software or computer software documentation shall be...

  1. 48 CFR 227.7202-4 - Contract clause.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Software and Computer Software Documentation 227.7202-4 Contract clause. A specific contract clause governing the Government's rights in commercial computer software or commercial computer software..., release, perform, display, or disclose computer software or computer software documentation shall be...

  2. 48 CFR 227.7202-4 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Software and Computer Software Documentation 227.7202-4 Contract clause. A specific contract clause governing the Government's rights in commercial computer software or commercial computer software..., release, perform, display, or disclose computer software or computer software documentation shall be...

  3. Models for Deploying Open Source and Commercial Software to Support Earth Science Data Processing and Distribution

    NASA Astrophysics Data System (ADS)

    Yetman, G.; Downs, R. R.

    2011-12-01

    Software deployment is needed to process and distribute scientific data throughout the data lifecycle. Developing software in-house can take software development teams away from other software development projects and can require efforts to maintain the software over time. Adopting and reusing software and system modules that have been previously developed by others can reduce in-house software development and maintenance costs and can contribute to the quality of the system being developed. A variety of models are available for reusing and deploying software and systems that have been developed by others. These deployment models include open source software, vendor-supported open source software, commercial software, and combinations of these approaches. Deployment in Earth science data processing and distribution has demonstrated the advantages and drawbacks of each model. Deploying open source software offers advantages for developing and maintaining scientific data processing systems and applications. By joining an open source community that is developing a particular system module or application, a scientific data processing team can contribute to aspects of the software development without having to commit to developing the software alone. Communities of interested developers can share the work while focusing on activities that utilize in-house expertise and addresses internal requirements. Maintenance is also shared by members of the community. Deploying vendor-supported open source software offers similar advantages to open source software. However, by procuring the services of a vendor, the in-house team can rely on the vendor to provide, install, and maintain the software over time. Vendor-supported open source software may be ideal for teams that recognize the value of an open source software component or application and would like to contribute to the effort, but do not have the time or expertise to contribute extensively. Vendor-supported software may also have the additional benefits of guaranteed up-time, bug fixes, and vendor-added enhancements. Deploying commercial software can be advantageous for obtaining system or software components offered by a vendor that meet in-house requirements. The vendor can be contracted to provide installation, support and maintenance services as needed. Combining these options offers a menu of choices, enabling selection of system components or software modules that meet the evolving requirements encountered throughout the scientific data lifecycle.

  4. Adopting Open Source Software to Address Software Risks during the Scientific Data Life Cycle

    NASA Astrophysics Data System (ADS)

    Vinay, S.; Downs, R. R.

    2012-12-01

    Software enables the creation, management, storage, distribution, discovery, and use of scientific data throughout the data lifecycle. However, the capabilities offered by software also present risks for the stewardship of scientific data, since future access to digital data is dependent on the use of software. From operating systems to applications for analyzing data, the dependence of data on software presents challenges for the stewardship of scientific data. Adopting open source software provides opportunities to address some of the proprietary risks of data dependence on software. For example, in some cases, open source software can be deployed to avoid licensing restrictions for using, modifying, and transferring proprietary software. The availability of the source code of open source software also enables the inclusion of modifications, which may be contributed by various community members who are addressing similar issues. Likewise, an active community that is maintaining open source software can be a valuable source of help, providing an opportunity to collaborate to address common issues facing adopters. As part of the effort to meet the challenges of software dependence for scientific data stewardship, risks from software dependence have been identified that exist during various times of the data lifecycle. The identification of these risks should enable the development of plans for mitigating software dependencies, where applicable, using open source software, and to improve understanding of software dependency risks for scientific data and how they can be reduced during the data life cycle.

  5. Software technology insertion: A study of success factors

    NASA Technical Reports Server (NTRS)

    Lydon, Tom

    1990-01-01

    Managing software development in large organizations has become increasingly difficult due to increasing technical complexity, stricter government standards, a shortage of experienced software engineers, competitive pressure for improved productivity and quality, the need to co-develop hardware and software together, and the rapid changes in both hardware and software technology. The 'software factory' approach to software development minimizes risks while maximizing productivity and quality through standardization, automation, and training. However, in practice, this approach is relatively inflexible when adopting new software technologies. The methods that a large multi-project software engineering organization can use to increase the likelihood of successful software technology insertion (STI), especially in a standardized engineering environment, are described.

  6. Software archeology: a case study in software quality assurance and design

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Macdonald, John M; Lloyd, Jane A; Turner, Cameron J

    2009-01-01

    Ideally, quality is designed into software, just as quality is designed into hardware. However, when dealing with legacy systems, demonstrating that the software meets required quality standards may be difficult to achieve. As the need to demonstrate the quality of existing software was recognized at Los Alamos National Laboratory (LANL), an effort was initiated to uncover and demonstrate that legacy software met the required quality standards. This effort led to the development of a reverse engineering approach referred to as software archaeology. This paper documents the software archaeology approaches used at LANL to document legacy software systems. A case studymore » for the Robotic Integrated Packaging System (RIPS) software is included.« less

  7. Annotated bibliography of software engineering laboratory literature

    NASA Technical Reports Server (NTRS)

    Kistler, David; Bristow, John; Smith, Don

    1994-01-01

    This document is an annotated bibliography of technical papers, documents, and memorandums produced by or related to the Software Engineering Laboratory. Nearly 200 publications are summarized. These publications cover many areas of software engineering and range from research reports to software documentation. This document has been updated and reorganized substantially since the original version (SEL-82-006, November 1982). All materials have been grouped into eight general subject areas for easy reference: (1) The Software Engineering Laboratory; (2) The Software Engineering Laboratory: Software Development Documents; (3) Software Tools; (4) Software Models; (5) Software Measurement; (6) Technology Evaluations; (7) Ada Technology; and (8) Data Collection. This document contains an index of these publications classified by individual author.

  8. Reuse Metrics for Object Oriented Software

    NASA Technical Reports Server (NTRS)

    Bieman, James M.

    1998-01-01

    One way to increase the quality of software products and the productivity of software development is to reuse existing software components when building new software systems. In order to monitor improvements in reuse, the level of reuse must be measured. In this NASA supported project we (1) derived a suite of metrics which quantify reuse attributes for object oriented, object based, and procedural software, (2) designed prototype tools to take these measurements in Ada, C++, Java, and C software, (3) evaluated the reuse in available software, (4) analyzed the relationship between coupling, cohesion, inheritance, and reuse, (5) collected object oriented software systems for our empirical analyses, and (6) developed quantitative criteria and methods for restructuring software to improve reusability.

  9. 48 CFR 12.212 - Computer software.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Computer software. 12.212... software. (a) Commercial computer software or commercial computer software documentation shall be acquired... required to— (1) Furnish technical information related to commercial computer software or commercial...

  10. 48 CFR 12.212 - Computer software.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Computer software. 12.212... software. (a) Commercial computer software or commercial computer software documentation shall be acquired... required to— (1) Furnish technical information related to commercial computer software or commercial...

  11. 48 CFR 227.7203-9 - Copyright.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Software and Computer Software Documentation 227.7203-9 Copyright. (a) Copyright license. (1) The clause at 252.227-7014, Rights in Noncommercial Computer Software and Noncommercial Computer Software... Government to reproduce the software or documentation, distribute copies, perform or display the software or...

  12. 48 CFR 227.7203-9 - Copyright.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Software and Computer Software Documentation 227.7203-9 Copyright. (a) Copyright license. (1) The clause at 252.227-7014, Rights in Noncommercial Computer Software and Noncommercial Computer Software... Government to reproduce the software or documentation, distribute copies, perform or display the software or...

  13. 48 CFR 227.7203-9 - Copyright.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Software and Computer Software Documentation 227.7203-9 Copyright. (a) Copyright license. (1) The clause at 252.227-7014, Rights in Noncommercial Computer Software and Noncommercial Computer Software... Government to reproduce the software or documentation, distribute copies, perform or display the software or...

  14. 48 CFR 12.212 - Computer software.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Computer software. 12.212... software. (a) Commercial computer software or commercial computer software documentation shall be acquired... required to— (1) Furnish technical information related to commercial computer software or commercial...

  15. 48 CFR 12.212 - Computer software.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Computer software. 12.212... software. (a) Commercial computer software or commercial computer software documentation shall be acquired... required to— (1) Furnish technical information related to commercial computer software or commercial...

  16. 48 CFR 227.7203-9 - Copyright.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Software and Computer Software Documentation 227.7203-9 Copyright. (a) Copyright license. (1) The clause at 252.227-7014, Rights in Noncommercial Computer Software and Noncommercial Computer Software... Government to reproduce the software or documentation, distribute copies, perform or display the software or...

  17. 48 CFR 12.212 - Computer software.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Computer software. 12.212... software. (a) Commercial computer software or commercial computer software documentation shall be acquired... required to— (1) Furnish technical information related to commercial computer software or commercial...

  18. 48 CFR 227.7203-9 - Copyright.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Software and Computer Software Documentation 227.7203-9 Copyright. (a) Copyright license. (1) The clause at 252.227-7014, Rights in Noncommercial Computer Software and Noncommercial Computer Software... Government to reproduce the software or documentation, distribute copies, perform or display the software or...

  19. Educational Software Acquisition for Microcomputers.

    ERIC Educational Resources Information Center

    Erikson, Warren; Turban, Efraim

    1985-01-01

    Examination of issues involved in acquiring appropriate microcomputer software for higher education focuses on the following points: developing your own software; finding commercially available software; using published evaluations; pre-purchase testing; customizing and adapting commercial software; post-purchase testing; and software use. A…

  20. A Model for Assessing the Liability of Seemingly Correct Software

    NASA Technical Reports Server (NTRS)

    Voas, Jeffrey M.; Voas, Larry K.; Miller, Keith W.

    1991-01-01

    Current research on software reliability does not lend itself to quantitatively assessing the risk posed by a piece of life-critical software. Black-box software reliability models are too general and make too many assumptions to be applied confidently to assessing the risk of life-critical software. We present a model for assessing the risk caused by a piece of software; this model combines software testing results and Hamlet's probable correctness model. We show how this model can assess software risk for those who insure against a loss that can occur if life-critical software fails.

  1. NASA space station software standards issues

    NASA Technical Reports Server (NTRS)

    Tice, G. D., Jr.

    1985-01-01

    The selection and application of software standards present the NASA Space Station Program with the opportunity to serve as a pacesetter for the United States software in the area of software standards. The strengths and weaknesses of each of the NASA defined software standards issues are summerized and discussed. Several significant standards issues are offered for NASA consideration. A challenge is presented for the NASA Space Station Program to serve as a pacesetter for the U.S. Software Industry through: (1) Management commitment to software standards; (2) Overall program participation in software standards; and (3) Employment of the best available technology to support software standards

  2. Statistical modelling of software reliability

    NASA Technical Reports Server (NTRS)

    Miller, Douglas R.

    1991-01-01

    During the six-month period from 1 April 1991 to 30 September 1991 the following research papers in statistical modeling of software reliability appeared: (1) A Nonparametric Software Reliability Growth Model; (2) On the Use and the Performance of Software Reliability Growth Models; (3) Research and Development Issues in Software Reliability Engineering; (4) Special Issues on Software; and (5) Software Reliability and Safety.

  3. Software Engineering Guidebook

    NASA Technical Reports Server (NTRS)

    Connell, John; Wenneson, Greg

    1993-01-01

    The Software Engineering Guidebook describes SEPG (Software Engineering Process Group) supported processes and techniques for engineering quality software in NASA environments. Three process models are supported: structured, object-oriented, and evolutionary rapid-prototyping. The guidebook covers software life-cycles, engineering, assurance, and configuration management. The guidebook is written for managers and engineers who manage, develop, enhance, and/or maintain software under the Computer Software Services Contract.

  4. A measurement system for large, complex software programs

    NASA Technical Reports Server (NTRS)

    Rone, Kyle Y.; Olson, Kitty M.; Davis, Nathan E.

    1994-01-01

    This paper describes measurement systems required to forecast, measure, and control activities for large, complex software development and support programs. Initial software cost and quality analysis provides the foundation for meaningful management decisions as a project evolves. In modeling the cost and quality of software systems, the relationship between the functionality, quality, cost, and schedule of the product must be considered. This explicit relationship is dictated by the criticality of the software being developed. This balance between cost and quality is a viable software engineering trade-off throughout the life cycle. Therefore, the ability to accurately estimate the cost and quality of software systems is essential to providing reliable software on time and within budget. Software cost models relate the product error rate to the percent of the project labor that is required for independent verification and validation. The criticality of the software determines which cost model is used to estimate the labor required to develop the software. Software quality models yield an expected error discovery rate based on the software size, criticality, software development environment, and the level of competence of the project and developers with respect to the processes being employed.

  5. Certification Processes for Safety-Critical and Mission-Critical Aerospace Software

    NASA Technical Reports Server (NTRS)

    Nelson, Stacy

    2003-01-01

    This document is a quick reference guide with an overview of the processes required to certify safety-critical and mission-critical flight software at selected NASA centers and the FAA. Researchers and software developers can use this guide to jumpstart their understanding of how to get new or enhanced software onboard an aircraft or spacecraft. The introduction contains aerospace industry definitions of safety and safety-critical software, as well as, the current rationale for certification of safety-critical software. The Standards for Safety-Critical Aerospace Software section lists and describes current standards including NASA standards and RTCA DO-178B. The Mission-Critical versus Safety-Critical software section explains the difference between two important classes of software: safety-critical software involving the potential for loss of life due to software failure and mission-critical software involving the potential for aborting a mission due to software failure. The DO-178B Safety-critical Certification Requirements section describes special processes and methods required to obtain a safety-critical certification for aerospace software flying on vehicles under auspices of the FAA. The final two sections give an overview of the certification process used at Dryden Flight Research Center and the approval process at the Jet Propulsion Lab (JPL).

  6. NASA PC software evaluation project

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Kuan, Julie C.

    1986-01-01

    The USL NASA PC software evaluation project is intended to provide a structured framework for facilitating the development of quality NASA PC software products. The project will assist NASA PC development staff to understand the characteristics and functions of NASA PC software products. Based on the results of the project teams' evaluations and recommendations, users can judge the reliability, usability, acceptability, maintainability and customizability of all the PC software products. The objective here is to provide initial, high-level specifications and guidelines for NASA PC software evaluation. The primary tasks to be addressed in this project are as follows: to gain a strong understanding of what software evaluation entails and how to organize a structured software evaluation process; to define a structured methodology for conducting the software evaluation process; to develop a set of PC software evaluation criteria and evaluation rating scales; and to conduct PC software evaluations in accordance with the identified methodology. Communication Packages, Network System Software, Graphics Support Software, Environment Management Software, General Utilities. This report represents one of the 72 attachment reports to the University of Southwestern Louisiana's Final Report on NASA Grant NGT-19-010-900. Accordingly, appropriate care should be taken in using this report out of context of the full Final Report.

  7. User systems guidelines for software projects

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Abrahamson, L.

    1986-04-01

    This manual presents guidelines for software standards which were developed so that software project-development teams and management involved in approving the software could have a generalized view of all phases in the software production procedure and the steps involved in completing each phase. Guidelines are presented for six phases of software development: project definition, building a user interface, designing software, writing code, testing code, and preparing software documentation. The discussions for each phase include examples illustrating the recommended guidelines. 45 refs. (DWL)

  8. 48 CFR 208.7400 - Scope of subpart.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... OF DEFENSE ACQUISITION PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Enterprise Software... commercial software and software maintenance, including software and software maintenance that is acquired...

  9. 48 CFR 208.7400 - Scope of subpart.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... OF DEFENSE ACQUISITION PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Enterprise Software... commercial software and software maintenance, including software and software maintenance that is acquired...

  10. 48 CFR 208.7400 - Scope of subpart.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OF DEFENSE ACQUISITION PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Enterprise Software... commercial software and software maintenance, including software and software maintenance that is acquired...

  11. 48 CFR 208.7400 - Scope of subpart.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OF DEFENSE ACQUISITION PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Enterprise Software... commercial software and software maintenance, including software and software maintenance that is acquired...

  12. Guidance and Control Software Project Data - Volume 1: Planning Documents

    NASA Technical Reports Server (NTRS)

    Hayhurst, Kelly J. (Editor)

    2008-01-01

    The Guidance and Control Software (GCS) project was the last in a series of software reliability studies conducted at Langley Research Center between 1977 and 1994. The technical results of the GCS project were recorded after the experiment was completed. Some of the support documentation produced as part of the experiment, however, is serving an unexpected role far beyond its original project context. Some of the software used as part of the GCS project was developed to conform to the RTCA/DO-178B software standard, "Software Considerations in Airborne Systems and Equipment Certification," used in the civil aviation industry. That standard requires extensive documentation throughout the software development life cycle, including plans, software requirements, design and source code, verification cases and results, and configuration management and quality control data. The project documentation that includes this information is open for public scrutiny without the legal or safety implications associated with comparable data from an avionics manufacturer. This public availability has afforded an opportunity to use the GCS project documents for DO-178B training. This report provides a brief overview of the GCS project, describes the 4-volume set of documents and the role they are playing in training, and includes the planning documents from the GCS project. Volume 1 contains five appendices: A. Plan for Software Aspects of Certification for the Guidance and Control Software Project; B. Software Development Standards for the Guidance and Control Software Project; C. Software Verification Plan for the Guidance and Control Software Project; D. Software Configuration Management Plan for the Guidance and Control Software Project; and E. Software Quality Assurance Activities.

  13. Improving Software Engineering on NASA Projects

    NASA Technical Reports Server (NTRS)

    Crumbley, Tim; Kelly, John C.

    2010-01-01

    Software Engineering Initiative: Reduces risk of software failure -Increases mission safety. More predictable software cost estimates and delivery schedules. Smarter buyer of contracted out software. More defects found and removed earlier. Reduces duplication of efforts between projects. Increases ability to meet the challenges of evolving software technology.

  14. A Quantitative Study of Global Software Development Teams, Requirements, and Software Projects

    ERIC Educational Resources Information Center

    Parker, Linda L.

    2016-01-01

    The study explored the relationship between global software development teams, effective software requirements, and stakeholders' perception of successful software development projects within the field of information technology management. It examined the critical relationship between Global Software Development (GSD) teams creating effective…

  15. Software Assurance Competency Model

    DTIC Science & Technology

    2013-03-01

    COTS) software , and software as a service ( SaaS ). L2: Define and analyze risks in the acquisition of contracted software , COTS software , and SaaS ...2010a]: Application of technologies and processes to achieve a required level of confidence that software systems and services function in the...

  16. The Elements of an Effective Software Development Plan - Software Development Process Guidebook

    DTIC Science & Technology

    2011-11-11

    standards and practices required for all XMPL software development. This SDP implements the <corporate> Standard Software Process (SSP). as tailored...Developing and integrating reusable software products • Approach to managing COTS/Reuse software implementation • COTS/Reuse software selection...final selection and submit to change board for approval MAINTENANCE Monitor current products for obsolescence or end of support Track new

  17. Software safety - A user's practical perspective

    NASA Technical Reports Server (NTRS)

    Dunn, William R.; Corliss, Lloyd D.

    1990-01-01

    Software safety assurance philosophy and practices at the NASA Ames are discussed. It is shown that, to be safe, software must be error-free. Software developments on two digital flight control systems and two ground facility systems are examined, including the overall system and software organization and function, the software-safety issues, and their resolution. The effectiveness of safety assurance methods is discussed, including conventional life-cycle practices, verification and validation testing, software safety analysis, and formal design methods. It is concluded (1) that a practical software safety technology does not yet exist, (2) that it is unlikely that a set of general-purpose analytical techniques can be developed for proving that software is safe, and (3) that successful software safety-assurance practices will have to take into account the detailed design processes employed and show that the software will execute correctly under all possible conditions.

  18. Predicting Software Suitability Using a Bayesian Belief Network

    NASA Technical Reports Server (NTRS)

    Beaver, Justin M.; Schiavone, Guy A.; Berrios, Joseph S.

    2005-01-01

    The ability to reliably predict the end quality of software under development presents a significant advantage for a development team. It provides an opportunity to address high risk components earlier in the development life cycle, when their impact is minimized. This research proposes a model that captures the evolution of the quality of a software product, and provides reliable forecasts of the end quality of the software being developed in terms of product suitability. Development team skill, software process maturity, and software problem complexity are hypothesized as driving factors of software product quality. The cause-effect relationships between these factors and the elements of software suitability are modeled using Bayesian Belief Networks, a machine learning method. This research presents a Bayesian Network for software quality, and the techniques used to quantify the factors that influence and represent software quality. The developed model is found to be effective in predicting the end product quality of small-scale software development efforts.

  19. The Effects of Development Team Skill on Software Product Quality

    NASA Technical Reports Server (NTRS)

    Beaver, Justin M.; Schiavone, Guy A.

    2006-01-01

    This paper provides an analysis of the effect of the skill/experience of the software development team on the quality of the final software product. A method for the assessment of software development team skill and experience is proposed, and was derived from a workforce management tool currently in use by the National Aeronautics and Space Administration. Using data from 26 smallscale software development projects, the team skill measures are correlated to 5 software product quality metrics from the ISO/IEC 9126 Software Engineering Product Quality standard. in the analysis of the results, development team skill is found to be a significant factor in the adequacy of the design and implementation. In addition, the results imply that inexperienced software developers are tasked with responsibilities ill-suited to their skill level, and thus have a significant adverse effect on the quality of the software product. Keywords: software quality, development skill, software metrics

  20. An ontology based trust verification of software license agreement

    NASA Astrophysics Data System (ADS)

    Lu, Wenhuan; Li, Xiaoqing; Gan, Zengqin; Wei, Jianguo

    2017-08-01

    When we install software or download software, there will show up so big mass document to state the rights and obligations, for which lots of person are not patient to read it or understand it. That would may make users feel distrust for the software. In this paper, we propose an ontology based verification for Software License Agreement. First of all, this work proposed an ontology model for domain of Software License Agreement. The domain ontology is constructed by proposed methodology according to copyright laws and 30 software license agreements. The License Ontology can act as a part of generalized copyright law knowledge model, and also can work as visualization of software licenses. Based on this proposed ontology, a software license oriented text summarization approach is proposed which performances showing that it can improve the accuracy of software licenses summarizing. Based on the summarization, the underline purpose of the software license can be explicitly explored for trust verification.

  1. 77 FR 50726 - Software Requirement Specifications for Digital Computer Software and Complex Electronics Used in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ... Computer Software and Complex Electronics Used in Safety Systems of Nuclear Power Plants AGENCY: Nuclear...-1209, ``Software Requirement Specifications for Digital Computer Software and Complex Electronics used... Electronics Engineers (ANSI/IEEE) Standard 830-1998, ``IEEE Recommended Practice for Software Requirements...

  2. Impact of Agile Software Development Model on Software Maintainability

    ERIC Educational Resources Information Center

    Gawali, Ajay R.

    2012-01-01

    Software maintenance and support costs account for up to 60% of the overall software life cycle cost and often burdens tightly budgeted information technology (IT) organizations. Agile software development approach delivers business value early, but implications on software maintainability are still unknown. The purpose of this quantitative study…

  3. 77 FR 50724 - Developing Software Life Cycle Processes for Digital Computer Software Used in Safety Systems of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Developing Software Life Cycle Processes for Digital... Software Life Cycle Processes for Digital Computer Software used in Safety Systems of Nuclear Power Plants... clarifications, the enhanced consensus practices for developing software life-cycle processes for digital...

  4. Proceedings of Tenth Annual Software Engineering Workshop

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Papers are presented on the following topics: measurement of software technology, recent studies of the Software Engineering Lab, software management tools, expert systems, error seeding as a program validation technique, software quality assurance, software engineering environments (including knowledge-based environments), the Distributed Computing Design System, and various Ada experiments.

  5. Reducing Risk in DoD Software-Intensive Systems Development

    DTIC Science & Technology

    2016-03-01

    intensive systems development risk. This research addresses the use of the Technical Readiness Assessment (TRA) using the nine-level software Technology...The software TRLs are ineffective in reducing technical risk for the software component development. • Without the software TRLs, there is no...effective method to perform software TRA or reduce the technical development risk. The software component will behave as a new, untried technology in nearly

  6. Software Formal Inspections Standard

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This Software Formal Inspections Standard (hereinafter referred to as Standard) is applicable to NASA software. This Standard defines the requirements that shall be fulfilled by the software formal inspections process whenever this process is specified for NASA software. The objective of this Standard is to define the requirements for a process that inspects software products to detect and eliminate defects as early as possible in the software life cycle. The process also provides for the collection and analysis of inspection data to improve the inspection process as well as the quality of the software.

  7. Annotated bibliography of software engineering laboratory literature

    NASA Technical Reports Server (NTRS)

    Buhler, Melanie; Valett, Jon

    1989-01-01

    An annotated bibliography is presented of technical papers, documents, and memorandums produced by or related to the Software Engineering Laboratory. The bibliography was updated and reorganized substantially since the original version (SEL-82-006, November 1982). All materials were grouped into eight general subject areas for easy reference: (1) The Software Engineering Laboratory; (2) The Software Engineering Laboratory: Software Development Documents; (3) Software Tools; (4) Software Models; (5) Software Measurement; (6) Technology Evaluations; (7) Ada Technology; and (8) Data Collection. Subject and author indexes further classify these documents by specific topic and individual author.

  8. Software Program: Software Management Guidebook

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The purpose of this NASA Software Management Guidebook is twofold. First, this document defines the core products and activities required of NASA software projects. It defines life-cycle models and activity-related methods but acknowledges that no single life-cycle model is appropriate for all NASA software projects. It also acknowledges that the appropriate method for accomplishing a required activity depends on characteristics of the software project. Second, this guidebook provides specific guidance to software project managers and team leaders in selecting appropriate life cycles and methods to develop a tailored plan for a software engineering project.

  9. Network, system, and status software enhancements for the autonomously managed electrical power system breadboard. Volume 1: Project summary

    NASA Technical Reports Server (NTRS)

    Mckee, James W.

    1990-01-01

    This volume (1 of 4) gives a summary of the original AMPS software system configuration, points out some of the problem areas in the original software design that this project is to address, and in the appendix collects all the bimonthly status reports. The purpose of AMPS is to provide a self reliant system to control the generation and distribution of power in the space station. The software in the AMPS breadboard can be divided into three levels: the operating environment software, the protocol software, and the station specific software. This project deals only with the operating environment software and the protocol software. The present station specific software will not change except as necessary to conform to new data formats.

  10. Guidance and Control Software Project Data - Volume 4: Configuration Management and Quality Assurance Documents

    NASA Technical Reports Server (NTRS)

    Hayhurst, Kelly J. (Editor)

    2008-01-01

    The Guidance and Control Software (GCS) project was the last in a series of software reliability studies conducted at Langley Research Center between 1977 and 1994. The technical results of the GCS project were recorded after the experiment was completed. Some of the support documentation produced as part of the experiment, however, is serving an unexpected role far beyond its original project context. Some of the software used as part of the GCS project was developed to conform to the RTCA/DO-178B software standard, "Software Considerations in Airborne Systems and Equipment Certification," used in the civil aviation industry. That standard requires extensive documentation throughout the software development life cycle, including plans, software requirements, design and source code, verification cases and results, and configuration management and quality control data. The project documentation that includes this information is open for public scrutiny without the legal or safety implications associated with comparable data from an avionics manufacturer. This public availability has afforded an opportunity to use the GCS project documents for DO-178B training. This report provides a brief overview of the GCS project, describes the 4-volume set of documents and the role they are playing in training, and includes configuration management and quality assurance documents from the GCS project. Volume 4 contains six appendices: A. Software Accomplishment Summary for the Guidance and Control Software Project; B. Software Configuration Index for the Guidance and Control Software Project; C. Configuration Management Records for the Guidance and Control Software Project; D. Software Quality Assurance Records for the Guidance and Control Software Project; E. Problem Report for the Pluto Implementation of the Guidance and Control Software Project; and F. Support Documentation Change Reports for the Guidance and Control Software Project.

  11. A Probabilistic Software System Attribute Acceptance Paradigm for COTS Software Evaluation

    NASA Technical Reports Server (NTRS)

    Morris, A. Terry

    2005-01-01

    Standard software requirement formats are written from top-down perspectives only, that is, from an ideal notion of a client s needs. Despite the exactness of the standard format, software and system errors in designed systems have abounded. Bad and inadequate requirements have resulted in cost overruns, schedule slips and lost profitability. Commercial off-the-shelf (COTS) software components are even more troublesome than designed systems because they are often provided as is and subsequently delivered with unsubstantiated validation of described capabilities. For COTS software, there needs to be a way to express the client s software needs in a consistent and formal manner using software system attributes derived from software quality standards. Additionally, the format needs to be amenable to software evaluation processes that integrate observable evidence garnered from historical data. This paper presents a paradigm that effectively bridges the gap between what a client desires (top-down) and what has been demonstrated (bottom-up) for COTS software evaluation. The paradigm addresses the specification of needs before the software evaluation is performed and can be used to increase the shared understanding between clients and software evaluators about what is required and what is technically possible.

  12. Modular Rocket Engine Control Software (MRECS)

    NASA Technical Reports Server (NTRS)

    Tarrant, Charlie; Crook, Jerry

    1997-01-01

    The Modular Rocket Engine Control Software (MRECS) Program is a technology demonstration effort designed to advance the state-of-the-art in launch vehicle propulsion systems. Its emphasis is on developing and demonstrating a modular software architecture for a generic, advanced engine control system that will result in lower software maintenance (operations) costs. It effectively accommodates software requirements changes that occur due to hardware. technology upgrades and engine development testing. Ground rules directed by MSFC were to optimize modularity and implement the software in the Ada programming language. MRECS system software and the software development environment utilize Commercial-Off-the-Shelf (COTS) products. This paper presents the objectives and benefits of the program. The software architecture, design, and development environment are described. MRECS tasks are defined and timing relationships given. Major accomplishment are listed. MRECS offers benefits to a wide variety of advanced technology programs in the areas of modular software, architecture, reuse software, and reduced software reverification time related to software changes. Currently, the program is focused on supporting MSFC in accomplishing a Space Shuttle Main Engine (SSME) hot-fire test at Stennis Space Center and the Low Cost Boost Technology (LCBT) Program.

  13. Software Reuse Within the Earth Science Community

    NASA Technical Reports Server (NTRS)

    Marshall, James J.; Olding, Steve; Wolfe, Robert E.; Delnore, Victor E.

    2006-01-01

    Scientific missions in the Earth sciences frequently require cost-effective, highly reliable, and easy-to-use software, which can be a challenge for software developers to provide. The NASA Earth Science Enterprise (ESE) spends a significant amount of resources developing software components and other software development artifacts that may also be of value if reused in other projects requiring similar functionality. In general, software reuse is often defined as utilizing existing software artifacts. Software reuse can improve productivity and quality while decreasing the cost of software development, as documented by case studies in the literature. Since large software systems are often the results of the integration of many smaller and sometimes reusable components, ensuring reusability of such software components becomes a necessity. Indeed, designing software components with reusability as a requirement can increase the software reuse potential within a community such as the NASA ESE community. The NASA Earth Science Data Systems (ESDS) Software Reuse Working Group is chartered to oversee the development of a process that will maximize the reuse potential of existing software components while recommending strategies for maximizing the reusability potential of yet-to-be-designed components. As part of this work, two surveys of the Earth science community were conducted. The first was performed in 2004 and distributed among government employees and contractors. A follow-up survey was performed in 2005 and distributed among a wider community, to include members of industry and academia. The surveys were designed to collect information on subjects such as the current software reuse practices of Earth science software developers, why they choose to reuse software, and what perceived barriers prevent them from reusing software. In this paper, we compare the results of these surveys, summarize the observed trends, and discuss the findings. The results are very similar, with the second, larger survey confirming the basic results of the first, smaller survey. The results suggest that reuse of ESE software can drive down the cost and time of system development, increase flexibility and responsiveness of these systems to new technologies and requirements, and increase effective and accountable community participation.

  14. Sandia National Laboratories Advanced Simulation and Computing (ASC) software quality plan. Part 1: ASC software quality engineering practices, Version 2.0.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sturtevant, Judith E.; Heaphy, Robert; Hodges, Ann Louise

    2006-09-01

    The purpose of the Sandia National Laboratories Advanced Simulation and Computing (ASC) Software Quality Plan is to clearly identify the practices that are the basis for continually improving the quality of ASC software products. The plan defines the ASC program software quality practices and provides mappings of these practices to Sandia Corporate Requirements CPR 1.3.2 and 1.3.6 and to a Department of Energy document, ASCI Software Quality Engineering: Goals, Principles, and Guidelines. This document also identifies ASC management and software project teams responsibilities in implementing the software quality practices and in assessing progress towards achieving their software quality goals.

  15. The Knowledge-Based Software Assistant: Beyond CASE

    NASA Technical Reports Server (NTRS)

    Carozzoni, Joseph A.

    1993-01-01

    This paper will outline the similarities and differences between two paradigms of software development. Both support the whole software life cycle and provide automation for most of the software development process, but have different approaches. The CASE approach is based on a set of tools linked by a central data repository. This tool-based approach is data driven and views software development as a series of sequential steps, each resulting in a product. The Knowledge-Based Software Assistant (KBSA) approach, a radical departure from existing software development practices, is knowledge driven and centers around a formalized software development process. KBSA views software development as an incremental, iterative, and evolutionary process with development occurring at the specification level.

  16. Implementing Software Safety in the NASA Environment

    NASA Technical Reports Server (NTRS)

    Wetherholt, Martha S.; Radley, Charles F.

    1994-01-01

    Until recently, NASA did not consider allowing computers total control of flight systems. Human operators, via hardware, have constituted the ultimate safety control. In an attempt to reduce costs, NASA has come to rely more and more heavily on computers and software to control space missions. (For example. software is now planned to control most of the operational functions of the International Space Station.) Thus the need for systematic software safety programs has become crucial for mission success. Concurrent engineering principles dictate that safety should be designed into software up front, not tested into the software after the fact. 'Cost of Quality' studies have statistics and metrics to prove the value of building quality and safety into the development cycle. Unfortunately, most software engineers are not familiar with designing for safety, and most safety engineers are not software experts. Software written to specifications which have not been safety analyzed is a major source of computer related accidents. Safer software is achieved step by step throughout the system and software life cycle. It is a process that includes requirements definition, hazard analyses, formal software inspections, safety analyses, testing, and maintenance. The greatest emphasis is placed on clearly and completely defining system and software requirements, including safety and reliability requirements. Unfortunately, development and review of requirements are the weakest link in the process. While some of the more academic methods, e.g. mathematical models, may help bring about safer software, this paper proposes the use of currently approved software methodologies, and sound software and assurance practices to show how, to a large degree, safety can be designed into software from the start. NASA's approach today is to first conduct a preliminary system hazard analysis (PHA) during the concept and planning phase of a project. This determines the overall hazard potential of the system to be built. Shortly thereafter, as the system requirements are being defined, the second iteration of hazard analyses takes place, the systems hazard analysis (SHA). During the systems requirements phase, decisions are made as to what functions of the system will be the responsibility of software. This is the most critical time to affect the safety of the software. From this point, software safety analyses as well as software engineering practices are the main focus for assuring safe software. While many of the steps proposed in this paper seem like just sound engineering practices, they are the best technical and most cost effective means to assure safe software within a safe system.

  17. Software and the future of programming languages.

    PubMed

    Aho, Alfred V

    2004-02-27

    Although software is the key enabler of the global information infrastructure, the amount and extent of software in use in the world today are not widely understood, nor are the programming languages and paradigms that have been used to create the software. The vast size of the embedded base of existing software and the increasing costs of software maintenance, poor security, and limited functionality are posing significant challenges for the software R&D community.

  18. Software engineering and the role of Ada: Executive seminar

    NASA Technical Reports Server (NTRS)

    Freedman, Glenn B.

    1987-01-01

    The objective was to introduce the basic terminology and concepts of software engineering and Ada. The life cycle model is reviewed. The application of the goals and principles of software engineering is applied. An introductory understanding of the features of the Ada language is gained. Topics addressed include: the software crises; the mandate of the Space Station Program; software life cycle model; software engineering; and Ada under the software engineering umbrella.

  19. 40 CFR 725.54 - Suspension of the review period.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... generated using e-PMN reporting software and be completed through the finalization step of the software, and e-PMN software must be used to print the request for suspension for submission to EPA. Paper... reporting software and be completed through the finalization step of the software, and e-PMN software must...

  20. 47 CFR 2.944 - Software defined radios.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Software defined radios. 2.944 Section 2.944... Authorization § 2.944 Software defined radios. (a) Manufacturers must take steps to ensure that only software that has been approved with a software defined radio can be loaded into the radio. The software must...

  1. 47 CFR 2.944 - Software defined radios.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Software defined radios. 2.944 Section 2.944... Authorization § 2.944 Software defined radios. (a) Manufacturers must take steps to ensure that only software that has been approved with a software defined radio can be loaded into the radio. The software must...

  2. 40 CFR 725.54 - Suspension of the review period.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... generated using e-PMN reporting software and be completed through the finalization step of the software, and e-PMN software must be used to print the request for suspension for submission to EPA. Paper... reporting software and be completed through the finalization step of the software, and e-PMN software must...

  3. 40 CFR 725.54 - Suspension of the review period.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... generated using e-PMN reporting software and be completed through the finalization step of the software, and e-PMN software must be used to print the request for suspension for submission to EPA. Paper... reporting software and be completed through the finalization step of the software, and e-PMN software must...

  4. 77 FR 50722 - Software Unit Testing for Digital Computer Software Used in Safety Systems of Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Software Unit Testing for Digital Computer Software...) is issuing for public comment draft regulatory guide (DG), DG-1208, ``Software Unit Testing for Digital Computer Software used in Safety Systems of Nuclear Power Plants.'' The DG-1208 is proposed...

  5. 47 CFR 2.944 - Software defined radios.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Software defined radios. 2.944 Section 2.944... Authorization § 2.944 Software defined radios. (a) Manufacturers must take steps to ensure that only software that has been approved with a software defined radio can be loaded into the radio. The software must...

  6. 78 FR 47011 - Software Unit Testing for Digital Computer Software Used in Safety Systems of Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-02

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Software Unit Testing for Digital Computer Software... revised regulatory guide (RG), revision 1 of RG 1.171, ``Software Unit Testing for Digital Computer Software Used in Safety Systems of Nuclear Power Plants.'' This RG endorses American National Standards...

  7. 47 CFR 2.944 - Software defined radios.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Software defined radios. 2.944 Section 2.944... Authorization § 2.944 Software defined radios. (a) Manufacturers must take steps to ensure that only software that has been approved with a software defined radio can be loaded into the radio. The software must...

  8. Software Quality Perceptions of Stakeholders Involved in the Software Development Process

    ERIC Educational Resources Information Center

    Padmanabhan, Priya

    2013-01-01

    Software quality is one of the primary determinants of project management success. Stakeholders involved in software development widely agree that quality is important (Barney and Wohlin 2009). However, they may differ on what constitutes software quality, and which of its attributes are more important than others. Although, software quality…

  9. 47 CFR 2.944 - Software defined radios.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Software defined radios. 2.944 Section 2.944... Authorization § 2.944 Software defined radios. (a) Manufacturers must take steps to ensure that only software that has been approved with a software defined radio can be loaded into the radio. The software must...

  10. 40 CFR 725.54 - Suspension of the review period.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... generated using e-PMN reporting software and be completed through the finalization step of the software, and e-PMN software must be used to print the request for suspension for submission to EPA. Paper... reporting software and be completed through the finalization step of the software, and e-PMN software must...

  11. High/Scope Buyer's Guide to Children's Software. 11th Edition.

    ERIC Educational Resources Information Center

    Hohmann, Charles; And Others

    This 11th edition of the High/Scope Buyer's Guide to Children's Software was designed to help teachers, caregivers, and parents make good choices when purchasing software to enhance children's learning. The book consists of an introduction, a chapter on finding the best software, software reviews for 48 different software products. The…

  12. Study of fault tolerant software technology for dynamic systems

    NASA Technical Reports Server (NTRS)

    Caglayan, A. K.; Zacharias, G. L.

    1985-01-01

    The major aim of this study is to investigate the feasibility of using systems-based failure detection isolation and compensation (FDIC) techniques in building fault-tolerant software and extending them, whenever possible, to the domain of software fault tolerance. First, it is shown that systems-based FDIC methods can be extended to develop software error detection techniques by using system models for software modules. In particular, it is demonstrated that systems-based FDIC techniques can yield consistency checks that are easier to implement than acceptance tests based on software specifications. Next, it is shown that systems-based failure compensation techniques can be generalized to the domain of software fault tolerance in developing software error recovery procedures. Finally, the feasibility of using fault-tolerant software in flight software is investigated. In particular, possible system and version instabilities, and functional performance degradation that may occur in N-Version programming applications to flight software are illustrated. Finally, a comparative analysis of N-Version and recovery block techniques in the context of generic blocks in flight software is presented.

  13. Sandia National Laboratories Advanced Simulation and Computing (ASC) software quality plan : ASC software quality engineering practices Version 3.0.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Turgeon, Jennifer L.; Minana, Molly A.; Hackney, Patricia

    2009-01-01

    The purpose of the Sandia National Laboratories (SNL) Advanced Simulation and Computing (ASC) Software Quality Plan is to clearly identify the practices that are the basis for continually improving the quality of ASC software products. Quality is defined in the US Department of Energy/National Nuclear Security Agency (DOE/NNSA) Quality Criteria, Revision 10 (QC-1) as 'conformance to customer requirements and expectations'. This quality plan defines the SNL ASC Program software quality engineering (SQE) practices and provides a mapping of these practices to the SNL Corporate Process Requirement (CPR) 001.3.6; 'Corporate Software Engineering Excellence'. This plan also identifies ASC management's and themore » software project teams responsibilities in implementing the software quality practices and in assessing progress towards achieving their software quality goals. This SNL ASC Software Quality Plan establishes the signatories commitments to improving software products by applying cost-effective SQE practices. This plan enumerates the SQE practices that comprise the development of SNL ASC's software products and explains the project teams opportunities for tailoring and implementing the practices.« less

  14. Shuttle mission simulator software conceptual design

    NASA Technical Reports Server (NTRS)

    Burke, J. F.

    1973-01-01

    Software conceptual designs (SCD) are presented for meeting the simulator requirements for the shuttle missions. The major areas of the SCD discussed include: malfunction insertion, flight software, applications software, systems software, and computer complex.

  15. SAO mission support software and data standards, version 1.0

    NASA Technical Reports Server (NTRS)

    Hsieh, P.

    1993-01-01

    This document defines the software developed by the SAO AXAF Mission Support (MS) Program and defines standards for the software development process and control of data products generated by the software. The SAO MS is tasked to develop and use software to perform a variety of functions in support of the AXAF mission. Software is developed by software engineers and scientists, and commercial off-the-shelf (COTS) software is used either directly or customized through the use of scripts to implement analysis procedures. Software controls real-time laboratory instruments, performs data archiving, displays data, and generates model predictions. Much software is used in the analysis of data to generate data products that are required by the AXAF project, for example, on-orbit mirror performance predictions or detailed characterization of the mirror reflection performance with energy.

  16. Statistical modeling of software reliability

    NASA Technical Reports Server (NTRS)

    Miller, Douglas R.

    1992-01-01

    This working paper discusses the statistical simulation part of a controlled software development experiment being conducted under the direction of the System Validation Methods Branch, Information Systems Division, NASA Langley Research Center. The experiment uses guidance and control software (GCS) aboard a fictitious planetary landing spacecraft: real-time control software operating on a transient mission. Software execution is simulated to study the statistical aspects of reliability and other failure characteristics of the software during development, testing, and random usage. Quantification of software reliability is a major goal. Various reliability concepts are discussed. Experiments are described for performing simulations and collecting appropriate simulated software performance and failure data. This data is then used to make statistical inferences about the quality of the software development and verification processes as well as inferences about the reliability of software versions and reliability growth under random testing and debugging.

  17. Promoting Science Software Best Practices: A Scientist's Perspective (Invited)

    NASA Astrophysics Data System (ADS)

    Blanton, B. O.

    2013-12-01

    Software is at the core of most modern scientific activities, and as societal awareness of, and impacts from, extreme weather, disasters, and climate and global change continue to increase, the roles that scientific software play in analyses and decision-making are brought more to the forefront. Reproducibility of research results (particularly those that enter into the decision-making arena) and open access to the software is essential for scientific and scientists' credibility. This has been highlighted in a recent article by Joppa et al (Troubling Trends in Scientific Software Use, Science Magazine, May 2013) that describes reasons for particular software being chosen by scientists, including that the "developer is well-respected" and on "recommendation from a close colleague". This reliance on recommendation, Joppa et al conclude, is fraught with risks to both sciences and scientists. Scientists must frequently take software for granted, assuming that it performs as expected and advertised and that the software itself has been validated and results verified. This is largely due to the manner in which much software is written and developed; in an ad hoc manner, with an inconsistent funding stream, and with little application of core software engineering best practices. Insufficient documentation, limited test cases, and code unavailability are significant barriers to informed and intelligent science software usage. This situation is exacerbated when the scientist becomes the software developer out of necessity due to resource constraints. Adoption of, and adherence to, best practices in scientific software development will substantially increase intelligent software usage and promote a sustainable evolution of the science as encoded in the software. We describe a typical scientist's perspective on using and developing scientific software in the context of storm surge research and forecasting applications that have real-time objectives and regulatory constraints. This include perspectives on what scientists/users of software can contribute back to the software development process and examples of successful scientist/developer interactions, and the competition between "getting it done" and "getting it done right".

  18. ICESat (GLAS) Science Processing Software Document Series. Volume 1; Science Software Management Plan; 3.0

    NASA Technical Reports Server (NTRS)

    Hancock, David W., III

    1999-01-01

    This document provides the Software Management Plan for the GLAS Standard Data Software (SDS) supporting the GLAS instrument of the EOS ICESat Spacecraft. The SDS encompasses the ICESat Science Investigator-led Processing System (I-SIPS) Software and the Instrument Support Terminal (IST) Software. For the I-SIPS Software, the SDS will produce Level 0, Level 1, and Level 2 data products as well as the associated product quality assessments and descriptive information. For the IST Software, the SDS will accommodate the GLAS instrument support areas of engineering status, command, performance assessment, and instrument health status.

  19. Coordination and organization of security software process for power information application environment

    NASA Astrophysics Data System (ADS)

    Wang, Qiang

    2017-09-01

    As an important part of software engineering, the software process decides the success or failure of software product. The design and development feature of security software process is discussed, so is the necessity and the present significance of using such process. Coordinating the function software, the process for security software and its testing are deeply discussed. The process includes requirement analysis, design, coding, debug and testing, submission and maintenance. In each process, the paper proposed the subprocesses to support software security. As an example, the paper introduces the above process into the power information platform.

  20. Software Engineering Improvement Activities/Plan

    NASA Technical Reports Server (NTRS)

    2003-01-01

    bd Systems personnel accomplished the technical responsibilities for this reporting period, as planned. A close working relationship was maintained with personnel of the MSFC Avionics Department Software Group (ED14). Work accomplishments included development, evaluation, and enhancement of a software cost model, performing literature search and evaluation of software tools available for code analysis and requirements analysis, and participating in other relevant software engineering activities. Monthly reports were submitted. This support was provided to the Flight Software Group/ED 1 4 in accomplishing the software engineering improvement engineering activities of the Marshall Space Flight Center (MSFC) Software Engineering Improvement Plan.

  1. A Prototype for the Support of Integrated Software Process Development and Improvement

    NASA Astrophysics Data System (ADS)

    Porrawatpreyakorn, Nalinpat; Quirchmayr, Gerald; Chutimaskul, Wichian

    An efficient software development process is one of key success factors for quality software. Not only can the appropriate establishment but also the continuous improvement of integrated project management and of the software development process result in efficiency. This paper hence proposes a software process maintenance framework which consists of two core components: an integrated PMBOK-Scrum model describing how to establish a comprehensive set of project management and software engineering processes and a software development maturity model advocating software process improvement. Besides, a prototype tool to support the framework is introduced.

  2. The relationships between software publications and software systems

    NASA Astrophysics Data System (ADS)

    Hogg, David W.

    2017-01-01

    When we build software systems or software tools for astronomy, we sometimes do and sometimes don't also write and publish standard scientific papers about those software systems. I will discuss the pros and cons of writing such publications. There are impacts of writing such papers immediately (they can affect the design and structure of the software project itself), in the short term (they can promote adoption and legitimize the software), in the medium term (they can provide a platform for all the literature's mechanisms for citation, criticism, and reuse), and in the long term (they can preserve ideas that are embodied in the software, possibly on timescales much longer than the lifetime of any software context). I will argue that as important as pure software contributions are to astronomy—and I am both a preacher and a practitioner—software contributions are even more valuable when they are associated with traditional scientific publications. There are exceptions and complexities of course, which I will discuss.

  3. Building quality into medical product software design.

    PubMed

    Mallory, S R

    1993-01-01

    The software engineering and quality assurance disciplines are a requisite to the design of safe and effective software-based medical devices. It is in the areas of software methodology and process that the most beneficial application of these disciplines to software development can be made. Software is a product of complex operations and methodologies and is not amenable to the traditional electromechanical quality assurance processes. Software quality must be built in by the developers, with the software verification and validation engineers acting as the independent instruments for ensuring compliance with performance objectives and with development and maintenance standards. The implementation of a software quality assurance program is a complex process involving management support, organizational changes, and new skill sets, but the benefits are profound. Its rewards provide safe, reliable, cost-effective, maintainable, and manageable software, which may significantly speed the regulatory review process and therefore potentially shorten the overall time to market. The use of a trial project can greatly facilitate the learning process associated with the first-time application of a software quality assurance program.

  4. Achieving Better Buying Power through Acquisition of Open Architecture Software Systems. Volume 2 Understanding Open Architecture Software Systems: Licensing and Security Research and Recommendations

    DTIC Science & Technology

    2016-01-06

    of- breed software components and software products lines (SPLs) that are subject to different IP license and cybersecurity requirements. The... commercially priced closed source software components, to be used in the design, implementation, deployment, and evolution of open architecture (OA... breed software components and software products lines (SPLs) that are subject to different IP license and cybersecurity requirements. The Department

  5. Using software metrics and software reliability models to attain acceptable quality software for flight and ground support software for avionic systems

    NASA Technical Reports Server (NTRS)

    Lawrence, Stella

    1992-01-01

    This paper is concerned with methods of measuring and developing quality software. Reliable flight and ground support software is a highly important factor in the successful operation of the space shuttle program. Reliability is probably the most important of the characteristics inherent in the concept of 'software quality'. It is the probability of failure free operation of a computer program for a specified time and environment.

  6. Artificial intelligence approaches to software engineering

    NASA Technical Reports Server (NTRS)

    Johannes, James D.; Macdonald, James R.

    1988-01-01

    Artificial intelligence approaches to software engineering are examined. The software development life cycle is a sequence of not so well-defined phases. Improved techniques for developing systems have been formulated over the past 15 years, but pressure continues to attempt to reduce current costs. Software development technology seems to be standing still. The primary objective of the knowledge-based approach to software development presented in this paper is to avoid problem areas that lead to schedule slippages, cost overruns, or software products that fall short of their desired goals. Identifying and resolving software problems early, often in the phase in which they first occur, has been shown to contribute significantly to reducing risks in software development. Software development is not a mechanical process but a basic human activity. It requires clear thinking, work, and rework to be successful. The artificial intelligence approaches to software engineering presented support the software development life cycle through the use of software development techniques and methodologies in terms of changing current practices and methods. These should be replaced by better techniques that that improve the process of of software development and the quality of the resulting products. The software development process can be structured into well-defined steps, of which the interfaces are standardized, supported and checked by automated procedures that provide error detection, production of the documentation and ultimately support the actual design of complex programs.

  7. Software dependability in the Tandem GUARDIAN system

    NASA Technical Reports Server (NTRS)

    Lee, Inhwan; Iyer, Ravishankar K.

    1995-01-01

    Based on extensive field failure data for Tandem's GUARDIAN operating system this paper discusses evaluation of the dependability of operational software. Software faults considered are major defects that result in processor failures and invoke backup processes to take over. The paper categorizes the underlying causes of software failures and evaluates the effectiveness of the process pair technique in tolerating software faults. A model to describe the impact of software faults on the reliability of an overall system is proposed. The model is used to evaluate the significance of key factors that determine software dependability and to identify areas for improvement. An analysis of the data shows that about 77% of processor failures that are initially considered due to software are confirmed as software problems. The analysis shows that the use of process pairs to provide checkpointing and restart (originally intended for tolerating hardware faults) allows the system to tolerate about 75% of reported software faults that result in processor failures. The loose coupling between processors, which results in the backup execution (the processor state and the sequence of events) being different from the original execution, is a major reason for the measured software fault tolerance. Over two-thirds (72%) of measured software failures are recurrences of previously reported faults. Modeling, based on the data, shows that, in addition to reducing the number of software faults, software dependability can be enhanced by reducing the recurrence rate.

  8. Testing Scientific Software: A Systematic Literature Review.

    PubMed

    Kanewala, Upulee; Bieman, James M

    2014-10-01

    Scientific software plays an important role in critical decision making, for example making weather predictions based on climate models, and computation of evidence for research publications. Recently, scientists have had to retract publications due to errors caused by software faults. Systematic testing can identify such faults in code. This study aims to identify specific challenges, proposed solutions, and unsolved problems faced when testing scientific software. We conducted a systematic literature survey to identify and analyze relevant literature. We identified 62 studies that provided relevant information about testing scientific software. We found that challenges faced when testing scientific software fall into two main categories: (1) testing challenges that occur due to characteristics of scientific software such as oracle problems and (2) testing challenges that occur due to cultural differences between scientists and the software engineering community such as viewing the code and the model that it implements as inseparable entities. In addition, we identified methods to potentially overcome these challenges and their limitations. Finally we describe unsolved challenges and how software engineering researchers and practitioners can help to overcome them. Scientific software presents special challenges for testing. Specifically, cultural differences between scientist developers and software engineers, along with the characteristics of the scientific software make testing more difficult. Existing techniques such as code clone detection can help to improve the testing process. Software engineers should consider special challenges posed by scientific software such as oracle problems when developing testing techniques.

  9. Programming Makes Software; Support Makes Users

    NASA Astrophysics Data System (ADS)

    Batcheller, A. L.

    2010-12-01

    Skilled software engineers may build fantastic software for climate modeling, yet fail to achieve their project’s objectives. Software support and related activities are just as critical as writing software. This study followed three different software projects in the climate sciences, using interviews, observation, and document analysis to examine the value added by support work. Supporting the project and interacting with users was a key task for software developers, who often spent 50% of their time on it. Such support work most often involved replying to questions on an email list, but also included talking to users on teleconference calls and in person. Software support increased adoption by building the software’s reputation and showing individuals how the software can meet their needs. In the process of providing support, developers often learned new of requirements as users reported features they desire and bugs they found. As software matures and gains widespread use, support work often increases. In fact, such increases can be one signal that the software has achieved broad acceptance. Maturing projects also find demand for instructional classes, online tutorials and detailed examples of how to use the software. The importance of support highlights the fact that building software systems involves both social and technical aspects. Yes, we need to build the software, but we also need to “build” the users and practices that can take advantage of it.

  10. How Safe Is Control Software

    NASA Technical Reports Server (NTRS)

    Dunn, William R.; Corliss, Lloyd D.

    1991-01-01

    Paper examines issue of software safety. Presents four case histories of software-safety analysis. Concludes that, to be safe, software, for all practical purposes, must be free of errors. Backup systems still needed to prevent catastrophic software failures.

  11. Software Selection: A Primer on Source and Evaluation.

    ERIC Educational Resources Information Center

    Burston, Jack

    2003-01-01

    Provides guidance on making decisions regarding the selection of foreign language instructional software. Identifies sources of foreign language software, indicates sources of foreign language software reviews, and outlines essential procedures of software evaluation. (Author/VWL)

  12. Software Engineering Laboratory Series: Proceedings of the Twentieth Annual Software Engineering Workshop

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Software Engineering Laboratory (SEL) is an organization sponsored by NASA/GSFC and created to investigate the effectiveness of software engineering technologies when applied to the development of application software. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that includes this document.

  13. Software Engineering Laboratory Series: Collected Software Engineering Papers. Volume 15

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Software Engineering Laboratory (SEL) is an organization sponsored by NASA/GSFC and created to investigate the effectiveness of software engineering technologies when applied to the development of application software. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that includes this document.

  14. Integrating Testing into Software Engineering Courses Supported by a Collaborative Learning Environment

    ERIC Educational Resources Information Center

    Clarke, Peter J.; Davis, Debra; King, Tariq M.; Pava, Jairo; Jones, Edward L.

    2014-01-01

    As software becomes more ubiquitous and complex, the cost of software bugs continues to grow at a staggering rate. To remedy this situation, there needs to be major improvement in the knowledge and application of software validation techniques. Although there are several software validation techniques, software testing continues to be one of the…

  15. Software Engineering Laboratory Series: Collected Software Engineering Papers. Volume 14

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Software Engineering Laboratory (SEL) is an organization sponsored by NASA/GSFC and created to investigate the effectiveness of software engineering technologies when applied to the development of application software. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that includes this document.

  16. Software Engineering Laboratory Series: Collected Software Engineering Papers. Volume 13

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Software Engineering Laboratory (SEL) is an organization sponsored by NASA/GSFC and created to investigate the effectiveness of software engineering technologies when applied to the development of application software. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that includes this document.

  17. Exploring the Process of Adult Computer Software Training Using Andragogy, Situated Cognition, and a Minimalist Approach

    ERIC Educational Resources Information Center

    Hurt, Andrew C.

    2007-01-01

    With technology advances, computer software becomes increasingly difficult to learn. Adults often rely on software training to keep abreast of these changes. Instructor-led software training is frequently used to teach adults new software skills; however there is limited research regarding the best practices in adult computer software training.…

  18. Software cost/resource modeling: Software quality tradeoff measurement

    NASA Technical Reports Server (NTRS)

    Lawler, R. W.

    1980-01-01

    A conceptual framework for treating software quality from a total system perspective is developed. Examples are given to show how system quality objectives may be allocated to hardware and software; to illustrate trades among quality factors, both hardware and software, to achieve system performance objectives; and to illustrate the impact of certain design choices on software functionality.

  19. MFV-class: a multi-faceted visualization tool of object classes.

    PubMed

    Zhang, Zhi-meng; Pan, Yun-he; Zhuang, Yue-ting

    2004-11-01

    Classes are key software components in an object-oriented software system. In many industrial OO software systems, there are some classes that have complicated structure and relationships. So in the processes of software maintenance, testing, software reengineering, software reuse and software restructure, it is a challenge for software engineers to understand these classes thoroughly. This paper proposes a class comprehension model based on constructivist learning theory, and implements a software visualization tool (MFV-Class) to help in the comprehension of a class. The tool provides multiple views of class to uncover manifold facets of class contents. It enables visualizing three object-oriented metrics of classes to help users focus on the understanding process. A case study was conducted to evaluate our approach and the toolkit.

  20. Software Quality Assurance Audits Guidebooks

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The growth in cost and importance of software to NASA has caused NASA to address the improvement of software development across the agency. One of the products of this program is a series of guidebooks that define a NASA concept of the assurance processes that are used in software development. The Software Assurance Guidebook, NASA-GB-A201, issued in September, 1989, provides an overall picture of the NASA concepts and practices in software assurance. Second level guidebooks focus on specific activities that fall within the software assurance discipline, and provide more detailed information for the manager and/or practitioner. This is the second level Software Quality Assurance Audits Guidebook that describes software quality assurance audits in a way that is compatible with practices at NASA Centers.

  1. Four simple recommendations to encourage best practices in research software

    PubMed Central

    Jiménez, Rafael C.; Kuzak, Mateusz; Alhamdoosh, Monther; Barker, Michelle; Batut, Bérénice; Borg, Mikael; Capella-Gutierrez, Salvador; Chue Hong, Neil; Cook, Martin; Corpas, Manuel; Flannery, Madison; Garcia, Leyla; Gelpí, Josep Ll.; Gladman, Simon; Goble, Carole; González Ferreiro, Montserrat; Gonzalez-Beltran, Alejandra; Griffin, Philippa C.; Grüning, Björn; Hagberg, Jonas; Holub, Petr; Hooft, Rob; Ison, Jon; Katz, Daniel S.; Leskošek, Brane; López Gómez, Federico; Oliveira, Luis J.; Mellor, David; Mosbergen, Rowland; Mulder, Nicola; Perez-Riverol, Yasset; Pergl, Robert; Pichler, Horst; Pope, Bernard; Sanz, Ferran; Schneider, Maria V.; Stodden, Victoria; Suchecki, Radosław; Svobodová Vařeková, Radka; Talvik, Harry-Anton; Todorov, Ilian; Treloar, Andrew; Tyagi, Sonika; van Gompel, Maarten; Vaughan, Daniel; Via, Allegra; Wang, Xiaochuan; Watson-Haigh, Nathan S.; Crouch, Steve

    2017-01-01

    Scientific research relies on computer software, yet software is not always developed following practices that ensure its quality and sustainability. This manuscript does not aim to propose new software development best practices, but rather to provide simple recommendations that encourage the adoption of existing best practices. Software development best practices promote better quality software, and better quality software improves the reproducibility and reusability of research. These recommendations are designed around Open Source values, and provide practical suggestions that contribute to making research software and its source code more discoverable, reusable and transparent. This manuscript is aimed at developers, but also at organisations, projects, journals and funders that can increase the quality and sustainability of research software by encouraging the adoption of these recommendations. PMID:28751965

  2. Four simple recommendations to encourage best practices in research software.

    PubMed

    Jiménez, Rafael C; Kuzak, Mateusz; Alhamdoosh, Monther; Barker, Michelle; Batut, Bérénice; Borg, Mikael; Capella-Gutierrez, Salvador; Chue Hong, Neil; Cook, Martin; Corpas, Manuel; Flannery, Madison; Garcia, Leyla; Gelpí, Josep Ll; Gladman, Simon; Goble, Carole; González Ferreiro, Montserrat; Gonzalez-Beltran, Alejandra; Griffin, Philippa C; Grüning, Björn; Hagberg, Jonas; Holub, Petr; Hooft, Rob; Ison, Jon; Katz, Daniel S; Leskošek, Brane; López Gómez, Federico; Oliveira, Luis J; Mellor, David; Mosbergen, Rowland; Mulder, Nicola; Perez-Riverol, Yasset; Pergl, Robert; Pichler, Horst; Pope, Bernard; Sanz, Ferran; Schneider, Maria V; Stodden, Victoria; Suchecki, Radosław; Svobodová Vařeková, Radka; Talvik, Harry-Anton; Todorov, Ilian; Treloar, Andrew; Tyagi, Sonika; van Gompel, Maarten; Vaughan, Daniel; Via, Allegra; Wang, Xiaochuan; Watson-Haigh, Nathan S; Crouch, Steve

    2017-01-01

    Scientific research relies on computer software, yet software is not always developed following practices that ensure its quality and sustainability. This manuscript does not aim to propose new software development best practices, but rather to provide simple recommendations that encourage the adoption of existing best practices. Software development best practices promote better quality software, and better quality software improves the reproducibility and reusability of research. These recommendations are designed around Open Source values, and provide practical suggestions that contribute to making research software and its source code more discoverable, reusable and transparent. This manuscript is aimed at developers, but also at organisations, projects, journals and funders that can increase the quality and sustainability of research software by encouraging the adoption of these recommendations.

  3. Software Design Improvements. Part 2; Software Quality and the Design and Inspection Process

    NASA Technical Reports Server (NTRS)

    Lalli, Vincent R.; Packard, Michael H.; Ziemianski, Tom

    1997-01-01

    The application of assurance engineering techniques improves the duration of failure-free performance of software. The totality of features and characteristics of a software product are what determine its ability to satisfy customer needs. Software in safety-critical systems is very important to NASA. We follow the System Safety Working Groups definition for system safety software as: 'The optimization of system safety in the design, development, use and maintenance of software and its integration with safety-critical systems in an operational environment. 'If it is not safe, say so' has become our motto. This paper goes over methods that have been used by NASA to make software design improvements by focusing on software quality and the design and inspection process.

  4. Science and Software

    NASA Astrophysics Data System (ADS)

    Zelt, C. A.

    2017-12-01

    Earth science attempts to understand how the earth works. This research often depends on software for modeling, processing, inverting or imaging. Freely sharing open-source software is essential to prevent reinventing the wheel and allows software to be improved and applied in ways the original author may never have envisioned. For young scientists, releasing software can increase their name ID when applying for jobs and funding, and create opportunities for collaborations when scientists who collect data want the software's creator to be involved in their project. However, we frequently hear scientists say software is a tool, it's not science. Creating software that implements a new or better way of earth modeling or geophysical processing, inverting or imaging should be viewed as earth science. Creating software for things like data visualization, format conversion, storage, or transmission, or programming to enhance computational performance, may be viewed as computer science. The former, ideally with an application to real data, can be published in earth science journals, the latter possibly in computer science journals. Citations in either case should accurately reflect the impact of the software on the community. Funding agencies need to support more software development and open-source releasing, and the community should give more high-profile awards for developing impactful open-source software. Funding support and community recognition for software development can have far reaching benefits when the software is used in foreseen and unforeseen ways, potentially for years after the original investment in the software development. For funding, an open-source release that is well documented should be required, with example input and output files. Appropriate funding will provide the incentive and time to release user-friendly software, and minimize the need for others to duplicate the effort. All funded software should be available through a single web site, ideally maintained by someone in a funded position. Perhaps the biggest challenge is the reality that researches who use software, as opposed to develop software, are more attractive university hires because they are more likely to be "big picture" scientists that publish in the highest profile journals, although sometimes the two go together.

  5. The Computational Infrastructure for Geodynamics: An Example of Software Curation and Citation in the Geodynamics Community

    NASA Astrophysics Data System (ADS)

    Hwang, L.; Kellogg, L. H.

    2017-12-01

    Curation of software promotes discoverability and accessibility and works hand in hand with scholarly citation to ascribe value to, and provide recognition for software development. To meet this challenge, the Computational Infrastructure for Geodynamics (CIG) maintains a community repository built on custom and open tools to promote discovery, access, identification, credit, and provenance of research software for the geodynamics community. CIG (geodynamics.org) originated from recognition of the tremendous effort required to develop sound software and the need to reduce duplication of effort and to sustain community codes. CIG curates software across 6 domains and has developed and follows software best practices that include establishing test cases, documentation, and a citable publication for each software package. CIG software landing web pages provide access to current and past releases; many are also accessible through the CIG community repository on github. CIG has now developed abc - attribution builder for citation to enable software users to give credit to software developers. abc uses zenodo as an archive and as the mechanism to obtain a unique identifier (DOI) for scientific software. To assemble the metadata, we searched the software's documentation and research publications and then requested the primary developers to verify. In this process, we have learned that each development community approaches software attribution differently. The metadata gathered is based on guidelines established by groups such as FORCE11 and OntoSoft. The rollout of abc is gradual as developers are forward-looking, rarely willing to go back and archive prior releases in zenodo. Going forward all actively developed packages will utilize the zenodo and github integration to automate the archival process when a new release is issued. How to handle legacy software, multi-authored libraries, and assigning roles to software remain open issues.

  6. Software platform virtualization in chemistry research and university teaching

    PubMed Central

    2009-01-01

    Background Modern chemistry laboratories operate with a wide range of software applications under different operating systems, such as Windows, LINUX or Mac OS X. Instead of installing software on different computers it is possible to install those applications on a single computer using Virtual Machine software. Software platform virtualization allows a single guest operating system to execute multiple other operating systems on the same computer. We apply and discuss the use of virtual machines in chemistry research and teaching laboratories. Results Virtual machines are commonly used for cheminformatics software development and testing. Benchmarking multiple chemistry software packages we have confirmed that the computational speed penalty for using virtual machines is low and around 5% to 10%. Software virtualization in a teaching environment allows faster deployment and easy use of commercial and open source software in hands-on computer teaching labs. Conclusion Software virtualization in chemistry, mass spectrometry and cheminformatics is needed for software testing and development of software for different operating systems. In order to obtain maximum performance the virtualization software should be multi-core enabled and allow the use of multiprocessor configurations in the virtual machine environment. Server consolidation, by running multiple tasks and operating systems on a single physical machine, can lead to lower maintenance and hardware costs especially in small research labs. The use of virtual machines can prevent software virus infections and security breaches when used as a sandbox system for internet access and software testing. Complex software setups can be created with virtual machines and are easily deployed later to multiple computers for hands-on teaching classes. We discuss the popularity of bioinformatics compared to cheminformatics as well as the missing cheminformatics education at universities worldwide. PMID:20150997

  7. Software platform virtualization in chemistry research and university teaching.

    PubMed

    Kind, Tobias; Leamy, Tim; Leary, Julie A; Fiehn, Oliver

    2009-11-16

    Modern chemistry laboratories operate with a wide range of software applications under different operating systems, such as Windows, LINUX or Mac OS X. Instead of installing software on different computers it is possible to install those applications on a single computer using Virtual Machine software. Software platform virtualization allows a single guest operating system to execute multiple other operating systems on the same computer. We apply and discuss the use of virtual machines in chemistry research and teaching laboratories. Virtual machines are commonly used for cheminformatics software development and testing. Benchmarking multiple chemistry software packages we have confirmed that the computational speed penalty for using virtual machines is low and around 5% to 10%. Software virtualization in a teaching environment allows faster deployment and easy use of commercial and open source software in hands-on computer teaching labs. Software virtualization in chemistry, mass spectrometry and cheminformatics is needed for software testing and development of software for different operating systems. In order to obtain maximum performance the virtualization software should be multi-core enabled and allow the use of multiprocessor configurations in the virtual machine environment. Server consolidation, by running multiple tasks and operating systems on a single physical machine, can lead to lower maintenance and hardware costs especially in small research labs. The use of virtual machines can prevent software virus infections and security breaches when used as a sandbox system for internet access and software testing. Complex software setups can be created with virtual machines and are easily deployed later to multiple computers for hands-on teaching classes. We discuss the popularity of bioinformatics compared to cheminformatics as well as the missing cheminformatics education at universities worldwide.

  8. Software Fault Tolerance: A Tutorial

    NASA Technical Reports Server (NTRS)

    Torres-Pomales, Wilfredo

    2000-01-01

    Because of our present inability to produce error-free software, software fault tolerance is and will continue to be an important consideration in software systems. The root cause of software design errors is the complexity of the systems. Compounding the problems in building correct software is the difficulty in assessing the correctness of software for highly complex systems. After a brief overview of the software development processes, we note how hard-to-detect design faults are likely to be introduced during development and how software faults tend to be state-dependent and activated by particular input sequences. Although component reliability is an important quality measure for system level analysis, software reliability is hard to characterize and the use of post-verification reliability estimates remains a controversial issue. For some applications software safety is more important than reliability, and fault tolerance techniques used in those applications are aimed at preventing catastrophes. Single version software fault tolerance techniques discussed include system structuring and closure, atomic actions, inline fault detection, exception handling, and others. Multiversion techniques are based on the assumption that software built differently should fail differently and thus, if one of the redundant versions fails, it is expected that at least one of the other versions will provide an acceptable output. Recovery blocks, N-version programming, and other multiversion techniques are reviewed.

  9. Software and package applicating for network meta-analysis: A usage-based comparative study.

    PubMed

    Xu, Chang; Niu, Yuming; Wu, Junyi; Gu, Huiyun; Zhang, Chao

    2017-12-21

    To compare and analyze the characteristics and functions of software applications for network meta-analysis (NMA). PubMed, EMbase, The Cochrane Library, the official websites of Bayesian inference Using Gibbs Sampling (BUGS), Stata and R, and Google were searched to collect the software and packages for performing NMA; software and packages published up to March 2016 were included. After collecting the software, packages, and their user guides, we used the software and packages to calculate a typical example. All characteristics, functions, and computed results were compared and analyzed. Ten types of software were included, including programming and non-programming software. They were developed mainly based on Bayesian or frequentist theory. Most types of software have the characteristics of easy operation, easy mastery, exact calculation, or excellent graphing. However, there was no single software that performed accurate calculations with superior graphing; this could only be achieved through the combination of two or more types of software. This study suggests that the user should choose the appropriate software according to personal programming basis, operational habits, and financial ability. Then, the choice of the combination of BUGS and R (or Stata) software to perform the NMA is considered. © 2017 Chinese Cochrane Center, West China Hospital of Sichuan University and John Wiley & Sons Australia, Ltd.

  10. Modular Rocket Engine Control Software (MRECS)

    NASA Technical Reports Server (NTRS)

    Tarrant, C.; Crook, J.

    1998-01-01

    The Modular Rocket Engine Control Software (MRECS) Program is a technology demonstration effort designed to advance the state-of-the-art in launch vehicle propulsion systems. Its emphasis is on developing and demonstrating a modular software architecture for advanced engine control systems that will result in lower software maintenance (operations) costs. It effectively accommodates software requirement changes that occur due to hardware technology upgrades and engine development testing. Ground rules directed by MSFC were to optimize modularity and implement the software in the Ada programming language. MRECS system software and the software development environment utilize Commercial-Off-the-Shelf (COTS) products. This paper presents the objectives, benefits, and status of the program. The software architecture, design, and development environment are described. MRECS tasks are defined and timing relationships given. Major accomplishments are listed. MRECS offers benefits to a wide variety of advanced technology programs in the areas of modular software architecture, reuse software, and reduced software reverification time related to software changes. MRECS was recently modified to support a Space Shuttle Main Engine (SSME) hot-fire test. Cold Flow and Flight Readiness Testing were completed before the test was cancelled. Currently, the program is focused on supporting NASA MSFC in accomplishing development testing of the Fastrac Engine, part of NASA's Low Cost Technologies (LCT) Program. MRECS will be used for all engine development testing.

  11. An Interoperability Framework and Capability Profiling for Manufacturing Software

    NASA Astrophysics Data System (ADS)

    Matsuda, M.; Arai, E.; Nakano, N.; Wakai, H.; Takeda, H.; Takata, M.; Sasaki, H.

    ISO/TC184/SC5/WG4 is working on ISO16100: Manufacturing software capability profiling for interoperability. This paper reports on a manufacturing software interoperability framework and a capability profiling methodology which were proposed and developed through this international standardization activity. Within the context of manufacturing application, a manufacturing software unit is considered to be capable of performing a specific set of function defined by a manufacturing software system architecture. A manufacturing software interoperability framework consists of a set of elements and rules for describing the capability of software units to support the requirements of a manufacturing application. The capability profiling methodology makes use of the domain-specific attributes and methods associated with each specific software unit to describe capability profiles in terms of unit name, manufacturing functions, and other needed class properties. In this methodology, manufacturing software requirements are expressed in terns of software unit capability profiles.

  12. Wildlife software: procedures for publication of computer software

    USGS Publications Warehouse

    Samuel, M.D.

    1990-01-01

    Computers and computer software have become an integral part of the practice of wildlife science. Computers now play an important role in teaching, research, and management applications. Because of the specialized nature of wildlife problems, specific computer software is usually required to address a given problem (e.g., home range analysis). This type of software is not usually available from commercial vendors and therefore must be developed by those wildlife professionals with particular skill in computer programming. Current journal publication practices generally prevent a detailed description of computer software associated with new techniques. In addition, peer review of journal articles does not usually include a review of associated computer software. Thus, many wildlife professionals are usually unaware of computer software that would meet their needs or of major improvements in software they commonly use. Indeed most users of wildlife software learn of new programs or important changes only by word of mouth.

  13. A Case Study of Measuring Process Risk for Early Insights into Software Safety

    NASA Technical Reports Server (NTRS)

    Layman, Lucas; Basili, Victor; Zelkowitz, Marvin V.; Fisher, Karen L.

    2011-01-01

    In this case study, we examine software safety risk in three flight hardware systems in NASA's Constellation spaceflight program. We applied our Technical and Process Risk Measurement (TPRM) methodology to the Constellation hazard analysis process to quantify the technical and process risks involving software safety in the early design phase of these projects. We analyzed 154 hazard reports and collected metrics to measure the prevalence of software in hazards and the specificity of descriptions of software causes of hazardous conditions. We found that 49-70% of 154 hazardous conditions could be caused by software or software was involved in the prevention of the hazardous condition. We also found that 12-17% of the 2013 hazard causes involved software, and that 23-29% of all causes had a software control. The application of the TPRM methodology identified process risks in the application of the hazard analysis process itself that may lead to software safety risk.

  14. AVE-SESAME program for the REEDA System

    NASA Technical Reports Server (NTRS)

    Hickey, J. S.

    1981-01-01

    The REEDA system software was modified and improved to process the AVE-SESAME severe storm data. A random access file system for the AVE storm data was designed, tested, and implemented. The AVE/SESAME software was modified to incorporate the random access file input and to interface with new graphics hardware/software now available on the REEDA system. Software was developed to graphically display the AVE/SESAME data in the convention normally used by severe storm researchers. Software was converted to AVE/SESAME software systems and interfaced with existing graphics hardware/software available on the REEDA System. Software documentation was provided for existing AVE/SESAME programs underlining functional flow charts and interacting questions. All AVE/SESAME data sets in random access format was processed to allow developed software to access the entire AVE/SESAME data base. The existing software was modified to allow for processing of different AVE/SESAME data set types including satellite surface and radar data.

  15. Space Station Software Recommendations

    NASA Technical Reports Server (NTRS)

    Voigt, S. (Editor)

    1985-01-01

    Four panels of invited experts and NASA representatives focused on the following topics: software management, software development environment, languages, and software standards. Each panel deliberated in private, held two open sessions with audience participation, and developed recommendations for the NASA Space Station Program. The major thrusts of the recommendations were as follows: (1) The software management plan should establish policies, responsibilities, and decision points for software acquisition; (2) NASA should furnish a uniform modular software support environment and require its use for all space station software acquired (or developed); (3) The language Ada should be selected for space station software, and NASA should begin to address issues related to the effective use of Ada; and (4) The space station software standards should be selected (based upon existing standards where possible), and an organization should be identified to promulgate and enforce them. These and related recommendations are described in detail in the conference proceedings.

  16. A Novel Method for Mining SaaS Software Tag via Community Detection in Software Services Network

    NASA Astrophysics Data System (ADS)

    Qin, Li; Li, Bing; Pan, Wei-Feng; Peng, Tao

    The number of online software services based on SaaS paradigm is increasing. However, users usually find it hard to get the exact software services they need. At present, tags are widely used to annotate specific software services and also to facilitate the searching of them. Currently these tags are arbitrary and ambiguous since mostly of them are generated manually by service developers. This paper proposes a method for mining tags from the help documents of software services. By extracting terms from the help documents and calculating the similarity between the terms, we construct a software similarity network where nodes represent software services, edges denote the similarity relationship between software services, and the weights of the edges are the similarity degrees. The hierarchical clustering algorithm is used for community detection in this software similarity network. At the final stage, tags are mined for each of the communities and stored as ontology.

  17. Orbiter subsystem hardware/software interaction analysis. Volume 8: AFT reaction control system, part 2

    NASA Technical Reports Server (NTRS)

    Becker, D. D.

    1980-01-01

    The orbiter subsystems and interfacing program elements which interact with the orbiter computer flight software are analyzed. The failure modes identified in the subsystem/element failure mode and effects analysis are examined. Potential interaction with the software is examined through an evaluation of the software requirements. The analysis is restricted to flight software requirements and excludes utility/checkout software. The results of the hardware/software interaction analysis for the forward reaction control system are presented.

  18. Semantic Metrics for Analysis of Software

    NASA Technical Reports Server (NTRS)

    Etzkorn, Letha H.; Cox, Glenn W.; Farrington, Phil; Utley, Dawn R.; Ghalston, Sampson; Stein, Cara

    2005-01-01

    A recently conceived suite of object-oriented software metrics focus is on semantic aspects of software, in contradistinction to traditional software metrics, which focus on syntactic aspects of software. Semantic metrics represent a more human-oriented view of software than do syntactic metrics. The semantic metrics of a given computer program are calculated by use of the output of a knowledge-based analysis of the program, and are substantially more representative of software quality and more readily comprehensible from a human perspective than are the syntactic metrics.

  19. Current Practice in Software Development for Computational Neuroscience and How to Improve It

    PubMed Central

    Gewaltig, Marc-Oliver; Cannon, Robert

    2014-01-01

    Almost all research work in computational neuroscience involves software. As researchers try to understand ever more complex systems, there is a continual need for software with new capabilities. Because of the wide range of questions being investigated, new software is often developed rapidly by individuals or small groups. In these cases, it can be hard to demonstrate that the software gives the right results. Software developers are often open about the code they produce and willing to share it, but there is little appreciation among potential users of the great diversity of software development practices and end results, and how this affects the suitability of software tools for use in research projects. To help clarify these issues, we have reviewed a range of software tools and asked how the culture and practice of software development affects their validity and trustworthiness. We identified four key questions that can be used to categorize software projects and correlate them with the type of product that results. The first question addresses what is being produced. The other three concern why, how, and by whom the work is done. The answers to these questions show strong correlations with the nature of the software being produced, and its suitability for particular purposes. Based on our findings, we suggest ways in which current software development practice in computational neuroscience can be improved and propose checklists to help developers, reviewers, and scientists to assess the quality of software and whether particular pieces of software are ready for use in research. PMID:24465191

  20. Current practice in software development for computational neuroscience and how to improve it.

    PubMed

    Gewaltig, Marc-Oliver; Cannon, Robert

    2014-01-01

    Almost all research work in computational neuroscience involves software. As researchers try to understand ever more complex systems, there is a continual need for software with new capabilities. Because of the wide range of questions being investigated, new software is often developed rapidly by individuals or small groups. In these cases, it can be hard to demonstrate that the software gives the right results. Software developers are often open about the code they produce and willing to share it, but there is little appreciation among potential users of the great diversity of software development practices and end results, and how this affects the suitability of software tools for use in research projects. To help clarify these issues, we have reviewed a range of software tools and asked how the culture and practice of software development affects their validity and trustworthiness. We identified four key questions that can be used to categorize software projects and correlate them with the type of product that results. The first question addresses what is being produced. The other three concern why, how, and by whom the work is done. The answers to these questions show strong correlations with the nature of the software being produced, and its suitability for particular purposes. Based on our findings, we suggest ways in which current software development practice in computational neuroscience can be improved and propose checklists to help developers, reviewers, and scientists to assess the quality of software and whether particular pieces of software are ready for use in research.

  1. The Influence of Software Complexity on the Maintenance Effort: Case Study on Software Developed within Educational Process

    ERIC Educational Resources Information Center

    Radulescu, Iulian Ionut

    2006-01-01

    Software complexity is the most important software quality attribute and a very useful instrument in the study of software quality. Is one of the factors that affect most of the software quality characteristics, including maintainability. It is very important to quantity this influence and identify the means to keep it under control; by using…

  2. Proceedings of the Ninth Annual Software Engineering Workshop

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Experiences in measurement, utilization, and evaluation of software methodologies, models, and tools are discussed. NASA's involvement in ever larger and more complex systems, like the space station project, provides a motive for the support of software engineering research and the exchange of ideas in such forums. The topics of current SEL research are software error studies, experiments with software development, and software tools.

  3. Software Engineering Laboratory Series: Proceedings of the Twenty-First Annual Software Engineering Workshop

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Software Engineering Laboratory (SEL) is an organization sponsored by NASA/GSFC and created to investigate the effectiveness of software engineering technologies when applied to the development of application software. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that includes this document.

  4. FMT (Flight Software Memory Tracker) For Cassini Spacecraft-Software Engineering Using JAVA

    NASA Technical Reports Server (NTRS)

    Kan, Edwin P.; Uffelman, Hal; Wax, Allan H.

    1997-01-01

    The software engineering design of the Flight Software Memory Tracker (FMT) Tool is discussed in this paper. FMT is a ground analysis software set, consisting of utilities and procedures, designed to track the flight software, i.e., images of memory load and updatable parameters of the computers on-board Cassini spacecraft. FMT is implemented in Java.

  5. Software Engineering Laboratory Series: Proceedings of the Twenty-Second Annual Software Engineering Workshop

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Software Engineering Laboratory (SEL) is an organization sponsored by NASA/GSFC and created to investigate the effectiveness of software engineering technologies when applied to the development of application software. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that includes this document.

  6. In the right order of brush strokes: a sketch of a software philosophy retrospective.

    PubMed

    Pyshkin, Evgeny

    2014-01-01

    This paper follows a discourse on software recognized as a product of art and human creativity progressing probably for as long as software exists. A retrospective view on computer science and software philosophy development is introduced. In so doing we discover parallels between software and various branches of human creative manifestations. Aesthetic properties and mutual dependency of the form and matter of art works are examined in their application to software programs. While exploring some philosophical and even artistic reflection on software we consider extended comprehension of technical sciences of programming and software engineering within the realm of liberal arts.

  7. OntoSoft: A Software Registry for Geosciences

    NASA Astrophysics Data System (ADS)

    Garijo, D.; Gil, Y.

    2017-12-01

    The goal of the EarthCube OntoSoft project is to enable the creation of an ecosystem for software stewardship in geosciences that will empower scientists to manage their software as valuable scientific assets. By sharing software metadata in OntoSoft, scientists enable broader access to that software by other scientists, software professionals, students, and decision makers. Our work to date includes: 1) an ontology for describing scientific software metadata, 2) a distributed scientific software repository that contains more than 750 entries that can be searched and compared across metadata fields, 3) an intelligent user interface that guides scientists to publish software and allows them to crowdsource its corresponding metadata. We have also developed a training program where scientists learn to describe and cite software in their papers in addition to data and provenance, and we are using OntoSoft to show them the benefits of publishing their software metadata. This training program is part of a Geoscience Papers of the Future Initiative, where scientists are reflecting on their current practices, benefits and effort for sharing software and data. This journal paper can be submitted to a Special Section of the AGU Earth and Space Science Journal.

  8. Requirements: Towards an understanding on why software projects fail

    NASA Astrophysics Data System (ADS)

    Hussain, Azham; Mkpojiogu, Emmanuel O. C.

    2016-08-01

    Requirement engineering is at the foundation of every successful software project. There are many reasons for software project failures; however, poorly engineered requirements process contributes immensely to the reason why software projects fail. Software project failure is usually costly and risky and could also be life threatening. Projects that undermine requirements engineering suffer or are likely to suffer from failures, challenges and other attending risks. The cost of project failures and overruns when estimated is very huge. Furthermore, software project failures or overruns pose a challenge in today's competitive market environment. It affects the company's image, goodwill, and revenue drive and decreases the perceived satisfaction of customers and clients. In this paper, requirements engineering was discussed. Its role in software projects success was elaborated. The place of software requirements process in relation to software project failure was explored and examined. Also, project success and failure factors were also discussed with emphasis placed on requirements factors as they play a major role in software projects' challenges, successes and failures. The paper relied on secondary data and empirical statistics to explore and examine factors responsible for the successes, challenges and failures of software projects in large, medium and small scaled software companies.

  9. Workflow-Based Software Development Environment

    NASA Technical Reports Server (NTRS)

    Izygon, Michel E.

    2013-01-01

    The Software Developer's Assistant (SDA) helps software teams more efficiently and accurately conduct or execute software processes associated with NASA mission-critical software. SDA is a process enactment platform that guides software teams through project-specific standards, processes, and procedures. Software projects are decomposed into all of their required process steps or tasks, and each task is assigned to project personnel. SDA orchestrates the performance of work required to complete all process tasks in the correct sequence. The software then notifies team members when they may begin work on their assigned tasks and provides the tools, instructions, reference materials, and supportive artifacts that allow users to compliantly perform the work. A combination of technology components captures and enacts any software process use to support the software lifecycle. It creates an adaptive workflow environment that can be modified as needed. SDA achieves software process automation through a Business Process Management (BPM) approach to managing the software lifecycle for mission-critical projects. It contains five main parts: TieFlow (workflow engine), Business Rules (rules to alter process flow), Common Repository (storage for project artifacts, versions, history, schedules, etc.), SOA (interface to allow internal, GFE, or COTS tools integration), and the Web Portal Interface (collaborative web environment

  10. Sandia National Laboratories Advanced Simulation and Computing (ASC) software quality plan. Part 1 : ASC software quality engineering practices version 1.0.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Minana, Molly A.; Sturtevant, Judith E.; Heaphy, Robert

    2005-01-01

    The purpose of the Sandia National Laboratories (SNL) Advanced Simulation and Computing (ASC) Software Quality Plan is to clearly identify the practices that are the basis for continually improving the quality of ASC software products. Quality is defined in DOE/AL Quality Criteria (QC-1) as conformance to customer requirements and expectations. This quality plan defines the ASC program software quality practices and provides mappings of these practices to the SNL Corporate Process Requirements (CPR 1.3.2 and CPR 1.3.6) and the Department of Energy (DOE) document, ASCI Software Quality Engineering: Goals, Principles, and Guidelines (GP&G). This quality plan identifies ASC management andmore » software project teams' responsibilities for cost-effective software engineering quality practices. The SNL ASC Software Quality Plan establishes the signatories commitment to improving software products by applying cost-effective software engineering quality practices. This document explains the project teams opportunities for tailoring and implementing the practices; enumerates the practices that compose the development of SNL ASC's software products; and includes a sample assessment checklist that was developed based upon the practices in this document.« less

  11. The development and technology transfer of software engineering technology at NASA. Johnson Space Center

    NASA Technical Reports Server (NTRS)

    Pitman, C. L.; Erb, D. M.; Izygon, M. E.; Fridge, E. M., III; Roush, G. B.; Braley, D. M.; Savely, R. T.

    1992-01-01

    The United State's big space projects of the next decades, such as Space Station and the Human Exploration Initiative, will need the development of many millions of lines of mission critical software. NASA-Johnson (JSC) is identifying and developing some of the Computer Aided Software Engineering (CASE) technology that NASA will need to build these future software systems. The goal is to improve the quality and the productivity of large software development projects. New trends are outlined in CASE technology and how the Software Technology Branch (STB) at JSC is endeavoring to provide some of these CASE solutions for NASA is described. Key software technology components include knowledge-based systems, software reusability, user interface technology, reengineering environments, management systems for the software development process, software cost models, repository technology, and open, integrated CASE environment frameworks. The paper presents the status and long-term expectations for CASE products. The STB's Reengineering Application Project (REAP), Advanced Software Development Workstation (ASDW) project, and software development cost model (COSTMODL) project are then discussed. Some of the general difficulties of technology transfer are introduced, and a process developed by STB for CASE technology insertion is described.

  12. Software Engineering for Human Spaceflight

    NASA Technical Reports Server (NTRS)

    Fredrickson, Steven E.

    2014-01-01

    The Spacecraft Software Engineering Branch of NASA Johnson Space Center (JSC) provides world-class products, leadership, and technical expertise in software engineering, processes, technology, and systems management for human spaceflight. The branch contributes to major NASA programs (e.g. ISS, MPCV/Orion) with in-house software development and prime contractor oversight, and maintains the JSC Engineering Directorate CMMI rating for flight software development. Software engineering teams work with hardware developers, mission planners, and system operators to integrate flight vehicles, habitats, robotics, and other spacecraft elements. They seek to infuse automation and autonomy into missions, and apply new technologies to flight processor and computational architectures. This presentation will provide an overview of key software-related projects, software methodologies and tools, and technology pursuits of interest to the JSC Spacecraft Software Engineering Branch.

  13. Software Design Improvements. Part 1; Software Benefits and Limitations

    NASA Technical Reports Server (NTRS)

    Lalli, Vincent R.; Packard, Michael H.; Ziemianski, Tom

    1997-01-01

    Computer hardware and associated software have been used for many years to process accounting information, to analyze test data and to perform engineering analysis. Now computers and software also control everything from automobiles to washing machines and the number and type of applications are growing at an exponential rate. The size of individual program has shown similar growth. Furthermore, software and hardware are used to monitor and/or control potentially dangerous products and safety-critical systems. These uses include everything from airplanes and braking systems to medical devices and nuclear plants. The question is: how can this hardware and software be made more reliable? Also, how can software quality be improved? What methodology needs to be provided on large and small software products to improve the design and how can software be verified?

  14. Software Engineering Improvement Plan

    NASA Technical Reports Server (NTRS)

    2006-01-01

    In performance of this task order, bd Systems personnel provided support to the Flight Software Branch and the Software Working Group through multiple tasks related to software engineering improvement and to activities of the independent Technical Authority (iTA) Discipline Technical Warrant Holder (DTWH) for software engineering. To ensure that the products, comments, and recommendations complied with customer requirements and the statement of work, bd Systems personnel maintained close coordination with the customer. These personnel performed work in areas such as update of agency requirements and directives database, software effort estimation, software problem reports, a web-based process asset library, miscellaneous documentation review, software system requirements, issue tracking software survey, systems engineering NPR, and project-related reviews. This report contains a summary of the work performed and the accomplishments in each of these areas.

  15. Designing Computerized Provider Order Entry Software in Iran: The Nurses' and Physicians' Viewpoints.

    PubMed

    Khammarnia, Mohammad; Sharifian, Roxana; Zand, Farid; Keshtkaran, Ali; Barati, Omid

    2016-09-01

    This study aimed to identify the functional requirements of computerized provider order entry software and design this software in Iran. This study was conducted using review documentation, interview, and focus group discussions in Shiraz University of Medical Sciences, as the medical pole in Iran, in 2013-2015. The study sample consisted of physicians (n = 12) and nurses (n = 2) in the largest hospital in the southern part of Iran and information technology experts (n = 5) in Shiraz University of Medical Sciences. Functional requirements of the computerized provider order entry system were examined in three phases. Finally, the functional requirements were distributed in four levels, and accordingly, the computerized provider order entry software was designed. The software had seven main dimensions: (1) data entry, (2) drug interaction management system, (3) warning system, (4) treatment services, (5) ability to write in software, (6) reporting from all sections of the software, and (7) technical capabilities of the software. The nurses and physicians emphasized quick access to the computerized provider order entry software, order prescription section, and applicability of the software. The software had some items that had not been mentioned in other studies. Ultimately, the software was designed by a company specializing in hospital information systems in Iran. This study was the first specific investigation of computerized provider order entry software design in Iran. Based on the results, it is suggested that this software be implemented in hospitals.

  16. Testing Scientific Software: A Systematic Literature Review

    PubMed Central

    Kanewala, Upulee; Bieman, James M.

    2014-01-01

    Context Scientific software plays an important role in critical decision making, for example making weather predictions based on climate models, and computation of evidence for research publications. Recently, scientists have had to retract publications due to errors caused by software faults. Systematic testing can identify such faults in code. Objective This study aims to identify specific challenges, proposed solutions, and unsolved problems faced when testing scientific software. Method We conducted a systematic literature survey to identify and analyze relevant literature. We identified 62 studies that provided relevant information about testing scientific software. Results We found that challenges faced when testing scientific software fall into two main categories: (1) testing challenges that occur due to characteristics of scientific software such as oracle problems and (2) testing challenges that occur due to cultural differences between scientists and the software engineering community such as viewing the code and the model that it implements as inseparable entities. In addition, we identified methods to potentially overcome these challenges and their limitations. Finally we describe unsolved challenges and how software engineering researchers and practitioners can help to overcome them. Conclusions Scientific software presents special challenges for testing. Specifically, cultural differences between scientist developers and software engineers, along with the characteristics of the scientific software make testing more difficult. Existing techniques such as code clone detection can help to improve the testing process. Software engineers should consider special challenges posed by scientific software such as oracle problems when developing testing techniques. PMID:25125798

  17. Software engineering methodologies and tools

    NASA Technical Reports Server (NTRS)

    Wilcox, Lawrence M.

    1993-01-01

    Over the years many engineering disciplines have developed, including chemical, electronic, etc. Common to all engineering disciplines is the use of rigor, models, metrics, and predefined methodologies. Recently, a new engineering discipline has appeared on the scene, called software engineering. For over thirty years computer software has been developed and the track record has not been good. Software development projects often miss schedules, are over budget, do not give the user what is wanted, and produce defects. One estimate is there are one to three defects per 1000 lines of deployed code. More and more systems are requiring larger and more complex software for support. As this requirement grows, the software development problems grow exponentially. It is believed that software quality can be improved by applying engineering principles. Another compelling reason to bring the engineering disciplines to software development is productivity. It has been estimated that productivity of producing software has only increased one to two percent a year in the last thirty years. Ironically, the computer and its software have contributed significantly to the industry-wide productivity, but computer professionals have done a poor job of using the computer to do their job. Engineering disciplines and methodologies are now emerging supported by software tools that address the problems of software development. This paper addresses some of the current software engineering methodologies as a backdrop for the general evaluation of computer assisted software engineering (CASE) tools from actual installation of and experimentation with some specific tools.

  18. Software Engineering Education Directory

    DTIC Science & Technology

    1990-04-01

    and Engineering (CMSC 735) Codes: GPEV2 * Textiooks: IEEE Tutoria on Models and Metrics for Software Management and Engameeing by Basi, Victor R...Software Engineering (Comp 227) Codes: GPRY5 Textbooks: IEEE Tutoria on Software Design Techniques by Freeman, Peter and Wasserman, Anthony 1. Software

  19. Finding Helpful Software Reviews.

    ERIC Educational Resources Information Center

    Kruse, Ted, Comp.

    1987-01-01

    Provides a list of evaluation services currently producing critical reviews of educational software. Includes information about The Apple K-12 Curriculum Software Reference, The Educational Software Preview, The Educational Software Selector, MicroSIFT, and Only The Best: The Discriminating Guide for Preschool-Grade 12. (TW)

  20. Proceedings of the Thirteenth Annual Software Engineering Workshop

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Topics covered in the workshop included studies and experiments conducted in the Software Engineering Laboratory (SEL), a cooperative effort of NASA Goddard Space Flight Center, the University of Maryland, and Computer Sciences Corporation; software models; software products; and software tools.

  1. TMT approach to observatory software development process

    NASA Astrophysics Data System (ADS)

    Buur, Hanne; Subramaniam, Annapurni; Gillies, Kim; Dumas, Christophe; Bhatia, Ravinder

    2016-07-01

    The purpose of the Observatory Software System (OSW) is to integrate all software and hardware components of the Thirty Meter Telescope (TMT) to enable observations and data capture; thus it is a complex software system that is defined by four principal software subsystems: Common Software (CSW), Executive Software (ESW), Data Management System (DMS) and Science Operations Support System (SOSS), all of which have interdependencies with the observatory control systems and data acquisition systems. Therefore, the software development process and plan must consider dependencies to other subsystems, manage architecture, interfaces and design, manage software scope and complexity, and standardize and optimize use of resources and tools. Additionally, the TMT Observatory Software will largely be developed in India through TMT's workshare relationship with the India TMT Coordination Centre (ITCC) and use of Indian software industry vendors, which adds complexity and challenges to the software development process, communication and coordination of activities and priorities as well as measuring performance and managing quality and risk. The software project management challenge for the TMT OSW is thus a multi-faceted technical, managerial, communications and interpersonal relations challenge. The approach TMT is using to manage this multifaceted challenge is a combination of establishing an effective geographically distributed software team (Integrated Product Team) with strong project management and technical leadership provided by the TMT Project Office (PO) and the ITCC partner to manage plans, process, performance, risk and quality, and to facilitate effective communications; establishing an effective cross-functional software management team composed of stakeholders, OSW leadership and ITCC leadership to manage dependencies and software release plans, technical complexities and change to approved interfaces, architecture, design and tool set, and to facilitate effective communications; adopting an agile-based software development process across the observatory to enable frequent software releases to help mitigate subsystem interdependencies; defining concise scope and work packages for each of the OSW subsystems to facilitate effective outsourcing of software deliverables to the ITCC partner, and to enable performance monitoring and risk management. At this stage, the architecture and high-level design of the software system has been established and reviewed. During construction each subsystem will have a final design phase with reviews, followed by implementation and testing. The results of the TMT approach to the Observatory Software development process will only be preliminary at the time of the submittal of this paper, but it is anticipated that the early results will be a favorable indication of progress.

  2. Improving Software Sustainability: Lessons Learned from Profiles in Science.

    PubMed

    Gallagher, Marie E

    2013-01-01

    The Profiles in Science® digital library features digitized surrogates of historical items selected from the archival collections of the U.S. National Library of Medicine as well as collaborating institutions. In addition, it contains a database of descriptive, technical and administrative metadata. It also contains various software components that allow creation of the metadata, management of the digital items, and access to the items and metadata through the Profiles in Science Web site [1]. The choices made building the digital library were designed to maximize the sustainability and long-term survival of all of the components of the digital library [2]. For example, selecting standard and open digital file formats rather than proprietary formats increases the sustainability of the digital files [3]. Correspondingly, using non-proprietary software may improve the sustainability of the software--either through in-house expertise or through the open source community. Limiting our digital library software exclusively to open source software or to software developed in-house has not been feasible. For example, we have used proprietary operating systems, scanning software, a search engine, and office productivity software. We did this when either lack of essential capabilities or the cost-benefit trade-off favored using proprietary software. We also did so knowing that in the future we would need to replace or upgrade some of our proprietary software, analogous to migrating from an obsolete digital file format to a new format as the technological landscape changes. Since our digital library's start in 1998, all of its software has been upgraded or replaced, but the digitized items have not yet required migration to other formats. Technological changes that compelled us to replace proprietary software included the cost of product licensing, product support, incompatibility with other software, prohibited use due to evolving security policies, and product abandonment. Sometimes these changes happen on short notice, so we continually monitor our library's software for signs of endangerment. We have attempted to replace proprietary software with suitable in-house or open source software. When the replacement involves a standalone piece of software with a nearly equivalent version, such as replacing a commercial HTTP server with an open source HTTP server, the replacement is straightforward. Recently we replaced software that functioned not only as our search engine but also as the backbone of the architecture of our Web site. In this paper, we describe the lessons learned and the pros and cons of replacing this software with open source software.

  3. Automated support for experience-based software management

    NASA Technical Reports Server (NTRS)

    Valett, Jon D.

    1992-01-01

    To effectively manage a software development project, the software manager must have access to key information concerning a project's status. This information includes not only data relating to the project of interest, but also, the experience of past development efforts within the environment. This paper describes the concepts and functionality of a software management tool designed to provide this information. This tool, called the Software Management Environment (SME), enables the software manager to compare an ongoing development effort with previous efforts and with models of the 'typical' project within the environment, to predict future project status, to analyze a project's strengths and weaknesses, and to assess the project's quality. In order to provide these functions the tool utilizes a vast corporate memory that includes a data base of software metrics, a set of models and relationships that describe the software development environment, and a set of rules that capture other knowledge and experience of software managers within the environment. Integrating these major concepts into one software management tool, the SME is a model of the type of management tool needed for all software development organizations.

  4. Software Architecture for Big Data Systems

    DTIC Science & Technology

    2014-03-27

    Software Architecture: Trends and New Directions #SEIswArch © 2014 Carnegie Mellon University Software Architecture for Big Data Systems...AND SUBTITLE Software Architecture for Big Data Systems 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...ih - . Software Architecture: Trends and New Directions #SEIswArch © 2014 Carnegie Mellon University WHAT IS BIG DATA ? FROM A SOFTWARE

  5. Statistical Software Engineering

    DTIC Science & Technology

    1998-04-13

    multiversion software subject to coincident errors. IEEE Trans. Software Eng. SE-11:1511-1517. Eckhardt, D.E., A.K Caglayan, J.C. Knight, L.D. Lee, D.F...J.C. and N.G. Leveson. 1986. Experimental evaluation of the assumption of independence in multiversion software. IEEE Trans. Software

  6. University Approaches to Software Copyright and Licensure Policies.

    ERIC Educational Resources Information Center

    Hawkins, Brian L.

    Issues of copyright policy and software licensure at Drexel University that were developed during the introduction of a new microcomputing program are discussed. Channels for software distribution include: individual purchase of externally-produced software, distribution of internally-developed software, institutional licensure, and "read…

  7. Software Reviews Since Acquisition Reform - The Artifact Perspective

    DTIC Science & Technology

    2004-01-01

    Risk Management OLD NEW Slide 13Acquisition of Software Intensive Systems 2004 – Peter Hantos Single, basic software paradigm Single processor Low...software risk mitigation related trade-offs must be done together Integral Software Engineering Activities Process Maturity and Quality Frameworks Quality

  8. 48 CFR 227.7203-1 - Policy.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OF DEFENSE GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-1 Policy. (a) DoD policy is to acquire only the computer software and computer software documentation, and the rights in such software or documentation, necessary...

  9. 48 CFR 227.7203-1 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OF DEFENSE GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-1 Policy. (a) DoD policy is to acquire only the computer software and computer software documentation, and the rights in such software or documentation, necessary...

  10. 48 CFR 227.7203-4 - License rights.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Software and Computer Software Documentation 227.7203-4 License rights. (a) Grant of license. The Government obtains rights in computer software or computer software documentation, including a copyright license, under an irrevocable license granted or obtained by the contractor which developed the software...

  11. 48 CFR 227.7203-1 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OF DEFENSE GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-1 Policy. (a) DoD policy is to acquire only the computer software and computer software documentation, and the rights in such software or documentation, necessary...

  12. 48 CFR 227.7203-4 - License rights.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Software and Computer Software Documentation 227.7203-4 License rights. (a) Grant of license. The Government obtains rights in computer software or computer software documentation, including a copyright license, under an irrevocable license granted or obtained by the contractor which developed the software...

  13. 48 CFR 227.7203-1 - Policy.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... OF DEFENSE GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-1 Policy. (a) DoD policy is to acquire only the computer software and computer software documentation, and the rights in such software or documentation, necessary...

  14. 48 CFR 227.7203-4 - License rights.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Software and Computer Software Documentation 227.7203-4 License rights. (a) Grant of license. The Government obtains rights in computer software or computer software documentation, including a copyright license, under an irrevocable license granted or obtained by the contractor which developed the software...

  15. 48 CFR 227.7203-1 - Policy.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... OF DEFENSE GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-1 Policy. (a) DoD policy is to acquire only the computer software and computer software documentation, and the rights in such software or documentation, necessary...

  16. 48 CFR 227.7203-4 - License rights.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Software and Computer Software Documentation 227.7203-4 License rights. (a) Grant of license. The Government obtains rights in computer software or computer software documentation, including a copyright license, under an irrevocable license granted or obtained by the contractor which developed the software...

  17. 48 CFR 227.7203-4 - License rights.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Software and Computer Software Documentation 227.7203-4 License rights. (a) Grant of license. The Government obtains rights in computer software or computer software documentation, including a copyright license, under an irrevocable license granted or obtained by the contractor which developed the software...

  18. 48 CFR 227.7205 - Contracts for special works.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Computer Software and Computer Software Documentation 227.7205 Contracts for special works. (a) Use the... a specific need to control the distribution of computer software or computer software documentation..., modification, reproduction, release, performance, display, or disclosure of such software or documentation. Use...

  19. Low Cost Ways to Keep Software Current.

    ERIC Educational Resources Information Center

    Schultheis, Robert A.

    1992-01-01

    Discusses strategies for providing students with current computer software technology including acquiring previous versions of software, obtaining demonstration software, using student versions, getting examination software, buying from mail order firms, buying few copies, exploring site licenses, acquiring shareware or freeware, and applying for…

  20. 48 CFR 227.7205 - Contracts for special works.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Computer Software and Computer Software Documentation 227.7205 Contracts for special works. (a) Use the... a specific need to control the distribution of computer software or computer software documentation..., modification, reproduction, release, performance, display, or disclosure of such software or documentation. Use...

  1. 48 CFR 208.7400 - Scope of subpart.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OF DEFENSE ACQUISITION PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Enterprise Software... commercial software and software maintenance, including software and software maintenance that is acquired— (a) As part of a system or system upgrade, where practicable; (b) Under a service contract; (c) Under...

  2. Infusing Reliability Techniques into Software Safety Analysis

    NASA Technical Reports Server (NTRS)

    Shi, Ying

    2015-01-01

    Software safety analysis for a large software intensive system is always a challenge. Software safety practitioners need to ensure that software related hazards are completely identified, controlled, and tracked. This paper discusses in detail how to incorporate the traditional reliability techniques into the entire software safety analysis process. In addition, this paper addresses how information can be effectively shared between the various practitioners involved in the software safety analyses. The author has successfully applied the approach to several aerospace applications. Examples are provided to illustrate the key steps of the proposed approach.

  3. Software for aerospace education: A bibliography, 2nd edition

    NASA Technical Reports Server (NTRS)

    Vogt, Gregory L.; Roth, Susan Kies; Phelps, Malcom V.

    1990-01-01

    This is the second aerospace education software bibliography to be published by the NASA Educational Technology Branch in Washington, DC. Unlike many software bibliographies, this bibliography does not evaluate and grade software according to its quality and value to the classroom, nor does it make any endorsements or warrant scientific accuracy. Rather, it describes software, its subject, approach, and technical details. This bibliography is intended as a convenience to educators. The specific software included represents replies to more than 300 queries to software producers for aerospace education programs.

  4. QuantWorm: a comprehensive software package for Caenorhabditis elegans phenotypic assays.

    PubMed

    Jung, Sang-Kyu; Aleman-Meza, Boanerges; Riepe, Celeste; Zhong, Weiwei

    2014-01-01

    Phenotypic assays are crucial in genetics; however, traditional methods that rely on human observation are unsuitable for quantitative, large-scale experiments. Furthermore, there is an increasing need for comprehensive analyses of multiple phenotypes to provide multidimensional information. Here we developed an automated, high-throughput computer imaging system for quantifying multiple Caenorhabditis elegans phenotypes. Our imaging system is composed of a microscope equipped with a digital camera and a motorized stage connected to a computer running the QuantWorm software package. Currently, the software package contains one data acquisition module and four image analysis programs: WormLifespan, WormLocomotion, WormLength, and WormEgg. The data acquisition module collects images and videos. The WormLifespan software counts the number of moving worms by using two time-lapse images; the WormLocomotion software computes the velocity of moving worms; the WormLength software measures worm body size; and the WormEgg software counts the number of eggs. To evaluate the performance of our software, we compared the results of our software with manual measurements. We then demonstrated the application of the QuantWorm software in a drug assay and a genetic assay. Overall, the QuantWorm software provided accurate measurements at a high speed. Software source code, executable programs, and sample images are available at www.quantworm.org. Our software package has several advantages over current imaging systems for C. elegans. It is an all-in-one package for quantifying multiple phenotypes. The QuantWorm software is written in Java and its source code is freely available, so it does not require use of commercial software or libraries. It can be run on multiple platforms and easily customized to cope with new methods and requirements.

  5. Ground Software Maintenance Facility (GSMF) system manual

    NASA Technical Reports Server (NTRS)

    Derrig, D.; Griffith, G.

    1986-01-01

    The Ground Software Maintenance Facility (GSMF) is designed to support development and maintenance of spacelab ground support software. THE GSMF consists of a Perkin Elmer 3250 (Host computer) and a MITRA 125s (ATE computer), with appropriate interface devices and software to simulate the Electrical Ground Support Equipment (EGSE). This document is presented in three sections: (1) GSMF Overview; (2) Software Structure; and (3) Fault Isolation Capability. The overview contains information on hardware and software organization along with their corresponding block diagrams. The Software Structure section describes the modes of software structure including source files, link information, and database files. The Fault Isolation section describes the capabilities of the Ground Computer Interface Device, Perkin Elmer host, and MITRA ATE.

  6. Software reliability models for critical applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pham, H.; Pham, M.

    This report presents the results of the first phase of the ongoing EG G Idaho, Inc. Software Reliability Research Program. The program is studying the existing software reliability models and proposes a state-of-the-art software reliability model that is relevant to the nuclear reactor control environment. This report consists of three parts: (1) summaries of the literature review of existing software reliability and fault tolerant software reliability models and their related issues, (2) proposed technique for software reliability enhancement, and (3) general discussion and future research. The development of this proposed state-of-the-art software reliability model will be performed in the secondmore » place. 407 refs., 4 figs., 2 tabs.« less

  7. Software reliability models for critical applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pham, H.; Pham, M.

    This report presents the results of the first phase of the ongoing EG&G Idaho, Inc. Software Reliability Research Program. The program is studying the existing software reliability models and proposes a state-of-the-art software reliability model that is relevant to the nuclear reactor control environment. This report consists of three parts: (1) summaries of the literature review of existing software reliability and fault tolerant software reliability models and their related issues, (2) proposed technique for software reliability enhancement, and (3) general discussion and future research. The development of this proposed state-of-the-art software reliability model will be performed in the second place.more » 407 refs., 4 figs., 2 tabs.« less

  8. Advanced software development workstation project: Engineering scripting language. Graphical editor

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Software development is widely considered to be a bottleneck in the development of complex systems, both in terms of development and in terms of maintenance of deployed systems. Cost of software development and maintenance can also be very high. One approach to reducing costs and relieving this bottleneck is increasing the reuse of software designs and software components. A method for achieving such reuse is a software parts composition system. Such a system consists of a language for modeling software parts and their interfaces, a catalog of existing parts, an editor for combining parts, and a code generator that takes a specification and generates code for that application in the target language. The Advanced Software Development Workstation is intended to be an expert system shell designed to provide the capabilities of a software part composition system.

  9. Developing sustainable software solutions for bioinformatics by the “ Butterfly” paradigm

    PubMed Central

    Ahmed, Zeeshan; Zeeshan, Saman; Dandekar, Thomas

    2014-01-01

    Software design and sustainable software engineering are essential for the long-term development of bioinformatics software. Typical challenges in an academic environment are short-term contracts, island solutions, pragmatic approaches and loose documentation. Upcoming new challenges are big data, complex data sets, software compatibility and rapid changes in data representation. Our approach to cope with these challenges consists of iterative intertwined cycles of development (“ Butterfly” paradigm) for key steps in scientific software engineering. User feedback is valued as well as software planning in a sustainable and interoperable way. Tool usage should be easy and intuitive. A middleware supports a user-friendly Graphical User Interface (GUI) as well as a database/tool development independently. We validated the approach of our own software development and compared the different design paradigms in various software solutions. PMID:25383181

  10. Software engineering and Ada in design

    NASA Technical Reports Server (NTRS)

    Oneill, Don

    1986-01-01

    Modern software engineering promises significant reductions in software costs and improvements in software quality. The Ada language is the focus for these software methodology and tool improvements. The IBM FSD approach, including the software engineering practices that guide the systematic design and development of software products and the management of the software process are examined. The revised Ada design language adaptation is revealed. This four level design methodology is detailed including the purpose of each level, the management strategy that integrates the software design activity with the program milestones, and the technical strategy that maps the Ada constructs to each level of design. A complete description of each design level is provided along with specific design language recording guidelines for each level. Finally, some testimony is offered on education, tools, architecture, and metrics resulting from project use of the four level Ada design language adaptation.

  11. Simple solution to the medical instrumentation software problem

    NASA Astrophysics Data System (ADS)

    Leif, Robert C.; Leif, Suzanne B.; Leif, Stephanie H.; Bingue, E.

    1995-04-01

    Medical devices now include a substantial software component, which is both difficult and expensive to produce and maintain. Medical software must be developed according to `Good Manufacturing Practices', GMP. Good Manufacturing Practices as specified by the FDA and ISO requires the definition and compliance to a software processes which ensures quality products by specifying a detailed method of software construction. The software process should be based on accepted standards. US Department of Defense software standards and technology can both facilitate the development and improve the quality of medical systems. We describe the advantages of employing Mil-Std-498, Software Development and Documentation, and the Ada programming language. Ada provides the very broad range of functionalities, from embedded real-time to management information systems required by many medical devices. It also includes advanced facilities for object oriented programming and software engineering.

  12. Open Architecture Standard for NASA's Software-Defined Space Telecommunications Radio Systems

    NASA Technical Reports Server (NTRS)

    Reinhart, Richard C.; Johnson, Sandra K.; Kacpura, Thomas J.; Hall, Charles S.; Smith, Carl R.; Liebetreu, John

    2008-01-01

    NASA is developing an architecture standard for software-defined radios used in space- and ground-based platforms to enable commonality among radio developments to enhance capability and services while reducing mission and programmatic risk. Transceivers (or transponders) with functionality primarily defined in software (e.g., firmware) have the ability to change their functional behavior through software alone. This radio architecture standard offers value by employing common waveform software interfaces, method of instantiation, operation, and testing among different compliant hardware and software products. These common interfaces within the architecture abstract application software from the underlying hardware to enable technology insertion independently at either the software or hardware layer. This paper presents the initial Space Telecommunications Radio System (STRS) Architecture for NASA missions to provide the desired software abstraction and flexibility while minimizing the resources necessary to support the architecture.

  13. Software assurance standard

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This standard specifies the software assurance program for the provider of software. It also delineates the assurance activities for the provider and the assurance data that are to be furnished by the provider to the acquirer. In any software development effort, the provider is the entity or individual that actually designs, develops, and implements the software product, while the acquirer is the entity or individual who specifies the requirements and accepts the resulting products. This standard specifies at a high level an overall software assurance program for software developed for and by NASA. Assurance includes the disciplines of quality assurance, quality engineering, verification and validation, nonconformance reporting and corrective action, safety assurance, and security assurance. The application of these disciplines during a software development life cycle is called software assurance. Subsequent lower-level standards will specify the specific processes within these disciplines.

  14. Clinical software development for the Web: lessons learned from the BOADICEA project

    PubMed Central

    2012-01-01

    Background In the past 20 years, society has witnessed the following landmark scientific advances: (i) the sequencing of the human genome, (ii) the distribution of software by the open source movement, and (iii) the invention of the World Wide Web. Together, these advances have provided a new impetus for clinical software development: developers now translate the products of human genomic research into clinical software tools; they use open-source programs to build them; and they use the Web to deliver them. Whilst this open-source component-based approach has undoubtedly made clinical software development easier, clinical software projects are still hampered by problems that traditionally accompany the software process. This study describes the development of the BOADICEA Web Application, a computer program used by clinical geneticists to assess risks to patients with a family history of breast and ovarian cancer. The key challenge of the BOADICEA Web Application project was to deliver a program that was safe, secure and easy for healthcare professionals to use. We focus on the software process, problems faced, and lessons learned. Our key objectives are: (i) to highlight key clinical software development issues; (ii) to demonstrate how software engineering tools and techniques can facilitate clinical software development for the benefit of individuals who lack software engineering expertise; and (iii) to provide a clinical software development case report that can be used as a basis for discussion at the start of future projects. Results We developed the BOADICEA Web Application using an evolutionary software process. Our approach to Web implementation was conservative and we used conventional software engineering tools and techniques. The principal software development activities were: requirements, design, implementation, testing, documentation and maintenance. The BOADICEA Web Application has now been widely adopted by clinical geneticists and researchers. BOADICEA Web Application version 1 was released for general use in November 2007. By May 2010, we had > 1200 registered users based in the UK, USA, Canada, South America, Europe, Africa, Middle East, SE Asia, Australia and New Zealand. Conclusions We found that an evolutionary software process was effective when we developed the BOADICEA Web Application. The key clinical software development issues identified during the BOADICEA Web Application project were: software reliability, Web security, clinical data protection and user feedback. PMID:22490389

  15. Clinical software development for the Web: lessons learned from the BOADICEA project.

    PubMed

    Cunningham, Alex P; Antoniou, Antonis C; Easton, Douglas F

    2012-04-10

    In the past 20 years, society has witnessed the following landmark scientific advances: (i) the sequencing of the human genome, (ii) the distribution of software by the open source movement, and (iii) the invention of the World Wide Web. Together, these advances have provided a new impetus for clinical software development: developers now translate the products of human genomic research into clinical software tools; they use open-source programs to build them; and they use the Web to deliver them. Whilst this open-source component-based approach has undoubtedly made clinical software development easier, clinical software projects are still hampered by problems that traditionally accompany the software process. This study describes the development of the BOADICEA Web Application, a computer program used by clinical geneticists to assess risks to patients with a family history of breast and ovarian cancer. The key challenge of the BOADICEA Web Application project was to deliver a program that was safe, secure and easy for healthcare professionals to use. We focus on the software process, problems faced, and lessons learned. Our key objectives are: (i) to highlight key clinical software development issues; (ii) to demonstrate how software engineering tools and techniques can facilitate clinical software development for the benefit of individuals who lack software engineering expertise; and (iii) to provide a clinical software development case report that can be used as a basis for discussion at the start of future projects. We developed the BOADICEA Web Application using an evolutionary software process. Our approach to Web implementation was conservative and we used conventional software engineering tools and techniques. The principal software development activities were: requirements, design, implementation, testing, documentation and maintenance. The BOADICEA Web Application has now been widely adopted by clinical geneticists and researchers. BOADICEA Web Application version 1 was released for general use in November 2007. By May 2010, we had > 1200 registered users based in the UK, USA, Canada, South America, Europe, Africa, Middle East, SE Asia, Australia and New Zealand. We found that an evolutionary software process was effective when we developed the BOADICEA Web Application. The key clinical software development issues identified during the BOADICEA Web Application project were: software reliability, Web security, clinical data protection and user feedback.

  16. Telescience Resource Kit (TReK)

    NASA Technical Reports Server (NTRS)

    Lippincott, Jeff

    2015-01-01

    Telescience Resource Kit (TReK) is one of the Huntsville Operations Support Center (HOSC) remote operations solutions. It can be used to monitor and control International Space Station (ISS) payloads from anywhere in the world. It is comprised of a suite of software applications and libraries that provide generic data system capabilities and access to HOSC services. The TReK Software has been operational since 2000. A new cross-platform version of TReK is under development. The new software is being released in phases during the 2014-2016 timeframe. The TReK Release 3.x series of software is the original TReK software that has been operational since 2000. This software runs on Windows. It contains capabilities to support traditional telemetry and commanding using CCSDS (Consultative Committee for Space Data Systems) packets. The TReK Release 4.x series of software is the new cross platform software. It runs on Windows and Linux. The new TReK software will support communication using standard IP protocols and traditional telemetry and commanding. All the software listed above is compatible and can be installed and run together on Windows. The new TReK software contains a suite of software that can be used by payload developers on the ground and onboard (TReK Toolkit). TReK Toolkit is a suite of lightweight libraries and utility applications for use onboard and on the ground. TReK Desktop is the full suite of TReK software -most useful on the ground. When TReK Desktop is released, the TReK installation program will provide the option to choose just the TReK Toolkit portion of the software or the full TReK Desktop suite. The ISS program is providing the TReK Toolkit software as a generic flight software capability offered as a standard service to payloads. TReK Software Verification was conducted during the April/May 2015 timeframe. Payload teams using the TReK software onboard can reference the TReK software verification. TReK will be demonstrated on-orbit running on an ISS provided T61p laptop. Target Timeframe: September 2015 -2016. The on-orbit demonstration will collect benchmark metrics, and will be used in the future to provide live demonstrations during ISS Payload Conferences. Benchmark metrics and demonstrations will address the protocols described in SSP 52050-0047 Ku Forward section 3.3.7. (Associated term: CCSDS File Delivery Protocol (CFDP)).

  17. 48 CFR 227.7203-6 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Software and Computer Software Documentation 227.7203-6 Contract clauses. (a)(1) Use the clause at 252.227-7014, Rights in Noncommercial Computer Software and Noncommercial Computer Software Documentation, in solicitations and contracts when the successful offeror(s) will be required to deliver computer software or...

  18. 48 CFR 227.7203-17 - Overseas contracts with foreign sources.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-17 Overseas contracts with foreign sources. (a) The clause at 252.227-7032, Rights in Technical Data and Computer Software... Noncommercial Computer Software and Noncommercial Computer Software Documentation, when the Government requires...

  19. 48 CFR 227.7203-17 - Overseas contracts with foreign sources.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-17 Overseas contracts with foreign sources. (a) The clause at 252.227-7032, Rights in Technical Data and Computer Software... Noncommercial Computer Software and Noncommercial Computer Software Documentation, when the Government requires...

  20. 48 CFR 227.7203-6 - Contract clauses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Software and Computer Software Documentation 227.7203-6 Contract clauses. (a)(1) Use the clause at 252.227-7014, Rights in Noncommercial Computer Software and Noncommercial Computer Software Documentation, in solicitations and contracts when the successful offeror(s) will be required to deliver computer software or...

  1. 48 CFR 227.7203-17 - Overseas contracts with foreign sources.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-17 Overseas contracts with foreign sources. (a) The clause at 252.227-7032, Rights in Technical Data and Computer Software... Noncommercial Computer Software and Noncommercial Computer Software Documentation, when the Government requires...

  2. 48 CFR 227.7203-6 - Contract clauses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Software and Computer Software Documentation 227.7203-6 Contract clauses. (a)(1) Use the clause at 252.227-7014, Rights in Noncommercial Computer Software and Noncommercial Computer Software Documentation, in solicitations and contracts when the successful offeror(s) will be required to deliver computer software or...

  3. 48 CFR 227.7203-6 - Contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Software and Computer Software Documentation 227.7203-6 Contract clauses. (a)(1) Use the clause at 252.227-7014, Rights in Noncommercial Computer Software and Noncommercial Computer Software Documentation, in solicitations and contracts when the successful offeror(s) will be required to deliver computer software or...

  4. 48 CFR 227.7203-17 - Overseas contracts with foreign sources.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-17 Overseas contracts with foreign sources. (a) The clause at 252.227-7032, Rights in Technical Data and Computer Software... Noncommercial Computer Software and Noncommercial Computer Software Documentation, when the Government requires...

  5. 48 CFR 227.7203-17 - Overseas contracts with foreign sources.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-17 Overseas contracts with foreign sources. (a) The clause at 252.227-7032, Rights in Technical Data and Computer Software... Noncommercial Computer Software and Noncommercial Computer Software Documentation, when the Government requires...

  6. 48 CFR 227.7203-6 - Contract clauses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Software and Computer Software Documentation 227.7203-6 Contract clauses. (a)(1) Use the clause at 252.227-7014, Rights in Noncommercial Computer Software and Noncommercial Computer Software Documentation, in solicitations and contracts when the successful offeror(s) will be required to deliver computer software or...

  7. Software security checklist for the software life cycle

    NASA Technical Reports Server (NTRS)

    Gilliam, D. P.; Wolfe, T. L.; Sherif, J. S.

    2002-01-01

    A formal approach to security in the software life cycle is essential to protect corporate resources. However, little thought has been given to this aspect of software development. Due to its criticality, security should be integrated as a formal approach in the software life cycle.

  8. NASA's Software Safety Standard

    NASA Technical Reports Server (NTRS)

    Ramsay, Christopher M.

    2005-01-01

    NASA (National Aeronautics and Space Administration) relies more and more on software to control, monitor, and verify its safety critical systems, facilities and operations. Since the 1960's there has hardly been a spacecraft (manned or unmanned) launched that did not have a computer on board that provided vital command and control services. Despite this growing dependence on software control and monitoring, there has been no consistent application of software safety practices and methodology to NASA's projects with safety critical software. Led by the NASA Headquarters Office of Safety and Mission Assurance, the NASA Software Safety Standard (STD-18l9.13B) has recently undergone a significant update in an attempt to provide that consistency. This paper will discuss the key features of the new NASA Software Safety Standard. It will start with a brief history of the use and development of software in safety critical applications at NASA. It will then give a brief overview of the NASA Software Working Group and the approach it took to revise the software engineering process across the Agency.

  9. Software Safety Risk in Legacy Safety-Critical Computer Systems

    NASA Technical Reports Server (NTRS)

    Hill, Janice; Baggs, Rhoda

    2007-01-01

    Safety-critical computer systems must be engineered to meet system and software safety requirements. For legacy safety-critical computer systems, software safety requirements may not have been formally specified during development. When process-oriented software safety requirements are levied on a legacy system after the fact, where software development artifacts don't exist or are incomplete, the question becomes 'how can this be done?' The risks associated with only meeting certain software safety requirements in a legacy safety-critical computer system must be addressed should such systems be selected as candidates for reuse. This paper proposes a method for ascertaining formally, a software safety risk assessment, that provides measurements for software safety for legacy systems which may or may not have a suite of software engineering documentation that is now normally required. It relies upon the NASA Software Safety Standard, risk assessment methods based upon the Taxonomy-Based Questionnaire, and the application of reverse engineering CASE tools to produce original design documents for legacy systems.

  10. A study of software standards used in the avionics industry

    NASA Technical Reports Server (NTRS)

    Hayhurst, Kelly J.

    1994-01-01

    Within the past decade, software has become an increasingly common element in computing systems. In particular, the role of software used in the aerospace industry, especially in life- or safety-critical applications, is rapidly expanding. This intensifies the need to use effective techniques for achieving and verifying the reliability of avionics software. Although certain software development processes and techniques are mandated by government regulating agencies, no one methodology has been shown to consistently produce reliable software. The knowledge base for designing reliable software simply has not reached the maturity of its hardware counterpart. In an effort to increase our understanding of software, the Langley Research Center conducted a series of experiments over 15 years with the goal of understanding why and how software fails. As part of this program, the effectiveness of current industry standards for the development of avionics is being investigated. This study involves the generation of a controlled environment to conduct scientific experiments on software processes.

  11. OAST Space Theme Workshop. Volume 3: Working group summary. 4: Software (E-4). A. Summary. B. Technology needs (form 1). C. Priority assessment (form 2)

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Only a few efforts are currently underway to develop an adequate technology base for the various themes. Particular attention must be given to software commonality and evolutionary capability, to increased system integrity and autonomy; and to improved communications among the program users, the program developers, and the programs themselves. There is a need for quantum improvement in software development methods and increasing the awareness of software by all concerned. Major thrusts identified include: (1) data and systems management; (2) software technology for autonomous systems; (3) technology and methods for improving the software development process; (4) advances related to systems of software elements including their architecture, their attributes as systems, and their interfaces with users and other systems; and (5) applications of software including both the basic algorithms used in a number of applications and the software specific to a particular theme or discipline area. The impact of each theme on software is assessed.

  12. Modeling SMAP Spacecraft Attitude Control Estimation Error Using Signal Generation Model

    NASA Technical Reports Server (NTRS)

    Rizvi, Farheen

    2016-01-01

    Two ground simulation software are used to model the SMAP spacecraft dynamics. The CAST software uses a higher fidelity model than the ADAMS software. The ADAMS software models the spacecraft plant, controller and actuator models, and assumes a perfect sensor and estimator model. In this simulation study, the spacecraft dynamics results from the ADAMS software are used as CAST software is unavailable. The main source of spacecraft dynamics error in the higher fidelity CAST software is due to the estimation error. A signal generation model is developed to capture the effect of this estimation error in the overall spacecraft dynamics. Then, this signal generation model is included in the ADAMS software spacecraft dynamics estimate such that the results are similar to CAST. This signal generation model has similar characteristics mean, variance and power spectral density as the true CAST estimation error. In this way, ADAMS software can still be used while capturing the higher fidelity spacecraft dynamics modeling from CAST software.

  13. NASA's Software Safety Standard

    NASA Technical Reports Server (NTRS)

    Ramsay, Christopher M.

    2007-01-01

    NASA relies more and more on software to control, monitor, and verify its safety critical systems, facilities and operations. Since the 1960's there has hardly been a spacecraft launched that does not have a computer on board that will provide command and control services. There have been recent incidents where software has played a role in high-profile mission failures and hazardous incidents. For example, the Mars Orbiter, Mars Polar Lander, the DART (Demonstration of Autonomous Rendezvous Technology), and MER (Mars Exploration Rover) Spirit anomalies were all caused or contributed to by software. The Mission Control Centers for the Shuttle, ISS, and unmanned programs are highly dependant on software for data displays, analysis, and mission planning. Despite this growing dependence on software control and monitoring, there has been little to no consistent application of software safety practices and methodology to NASA's projects with safety critical software. Meanwhile, academia and private industry have been stepping forward with procedures and standards for safety critical systems and software, for example Dr. Nancy Leveson's book Safeware: System Safety and Computers. The NASA Software Safety Standard, originally published in 1997, was widely ignored due to its complexity and poor organization. It also focused on concepts rather than definite procedural requirements organized around a software project lifecycle. Led by NASA Headquarters Office of Safety and Mission Assurance, the NASA Software Safety Standard has recently undergone a significant update. This new standard provides the procedures and guidelines for evaluating a project for safety criticality and then lays out the minimum project lifecycle requirements to assure the software is created, operated, and maintained in the safest possible manner. This update of the standard clearly delineates the minimum set of software safety requirements for a project without detailing the implementation for those requirements. This allows the projects leeway to meet these requirements in many forms that best suit a particular project's needs and safety risk. In other words, it tells the project what to do, not how to do it. This update also incorporated advances in the state of the practice of software safety from academia and private industry. It addresses some of the more common issues now facing software developers in the NASA environment such as the use of Commercial-Off-the-Shelf Software (COTS), Modified OTS (MOTS), Government OTS (GOTS), and reused software. A team from across NASA developed the update and it has had both NASA-wide internal reviews by software engineering, quality, safety, and project management. It has also had expert external review. This presentation and paper will discuss the new NASA Software Safety Standard, its organization, and key features. It will start with a brief discussion of some NASA mission failures and incidents that had software as one of their root causes. It will then give a brief overview of the NASA Software Safety Process. This will include an overview of the key personnel responsibilities and functions that must be performed for safety-critical software.

  14. Working Notes from the 1992 AAAI Workshop on Automating Software Design. Theme: Domain Specific Software Design

    NASA Technical Reports Server (NTRS)

    Keller, Richard M. (Editor); Barstow, David; Lowry, Michael R.; Tong, Christopher H.

    1992-01-01

    The goal of this workshop is to identify different architectural approaches to building domain-specific software design systems and to explore issues unique to domain-specific (vs. general-purpose) software design. Some general issues that cut across the particular software design domain include: (1) knowledge representation, acquisition, and maintenance; (2) specialized software design techniques; and (3) user interaction and user interface.

  15. Empirical studies of software design: Implications for SSEs

    NASA Technical Reports Server (NTRS)

    Krasner, Herb

    1988-01-01

    Implications for Software Engineering Environments (SEEs) are presented in viewgraph format for characteristics of projects studied; significant problems and crucial problem areas in software design for large systems; layered behavioral model of software processes; implications of field study results; software project as an ecological system; results of the LIFT study; information model of design exploration; software design strategies; results of the team design study; and a list of publications.

  16. Formal Validation of Aerospace Software

    NASA Astrophysics Data System (ADS)

    Lesens, David; Moy, Yannick; Kanig, Johannes

    2013-08-01

    Any single error in critical software can have catastrophic consequences. Even though failures are usually not advertised, some software bugs have become famous, such as the error in the MIM-104 Patriot. For space systems, experience shows that software errors are a serious concern: more than half of all satellite failures from 2000 to 2003 involved software. To address this concern, this paper addresses the use of formal verification of software developed in Ada.

  17. Cost Estimation of Software Development and the Implications for the Program Manager

    DTIC Science & Technology

    1992-06-01

    Software Lifecycle Model (SLIM), the Jensen System-4 model, the Software Productivity, Quality, and Reliability Estimator ( SPQR \\20), the Constructive...function models in current use are the Software Productivity, Quality, and Reliability Estimator ( SPQR /20) and the Software Architecture Sizing and...Estimator ( SPQR /20) was developed by T. Capers Jones of Software Productivity Research, Inc., in 1985. The model is intended to estimate the outcome

  18. Software Library: A Reusable Software Issue.

    DTIC Science & Technology

    1984-06-01

    On reverse aide it neceeary aid Identify by block number) Software Library; Program Library; Reusability; Generator 20 ABSTRACT (Cmlnue on revere... Software Library. A particular example of the Software Library, the Program Library, is described as a prototype of a reusable library. A hierarchical... programming libraries are described. Finally, non code products in the Software Library are discussed. Accesson Fo NTIS R~jS DrrC TA Availability Codes 0

  19. Self-assembling software generator

    DOEpatents

    Bouchard, Ann M [Albuquerque, NM; Osbourn, Gordon C [Albuquerque, NM

    2011-11-25

    A technique to generate an executable task includes inspecting a task specification data structure to determine what software entities are to be generated to create the executable task, inspecting the task specification data structure to determine how the software entities will be linked after generating the software entities, inspecting the task specification data structure to determine logic to be executed by the software entities, and generating the software entities to create the executable task.

  20. Software Assurance: Five Essential Considerations for Acquisition Officials

    DTIC Science & Technology

    2007-05-01

    May 2007 www.stsc.hill.af.mil 17 2 • address security concerns in the software development life cycle ( SDLC )? • Are there formal software quality...What threat modeling process, if any, is used when designing the software ? What analysis, design, and construction tools are used by your software design...the-shelf (COTS), government off-the-shelf (GOTS), open- source, embedded, and legacy software . Attackers exploit unintentional vulnerabil- ities or

  1. Factors That Affect Software Testability

    NASA Technical Reports Server (NTRS)

    Voas, Jeffrey M.

    1991-01-01

    Software faults that infrequently affect software's output are dangerous. When a software fault causes frequent software failures, testing is likely to reveal the fault before the software is releases; when the fault remains undetected during testing, it can cause disaster after the software is installed. A technique for predicting whether a particular piece of software is likely to reveal faults within itself during testing is found in [Voas91b]. A piece of software that is likely to reveal faults within itself during testing is said to have high testability. A piece of software that is not likely to reveal faults within itself during testing is said to have low testability. It is preferable to design software with higher testabilities from the outset, i.e., create software with as high of a degree of testability as possible to avoid the problems of having undetected faults that are associated with low testability. Information loss is a phenomenon that occurs during program execution that increases the likelihood that a fault will remain undetected. In this paper, I identify two brad classes of information loss, define them, and suggest ways of predicting the potential for information loss to occur. We do this in order to decrease the likelihood that faults will remain undetected during testing.

  2. Survey of Verification and Validation Techniques for Small Satellite Software Development

    NASA Technical Reports Server (NTRS)

    Jacklin, Stephen A.

    2015-01-01

    The purpose of this paper is to provide an overview of the current trends and practices in small-satellite software verification and validation. This document is not intended to promote a specific software assurance method. Rather, it seeks to present an unbiased survey of software assurance methods used to verify and validate small satellite software and to make mention of the benefits and value of each approach. These methods include simulation and testing, verification and validation with model-based design, formal methods, and fault-tolerant software design with run-time monitoring. Although the literature reveals that simulation and testing has by far the longest legacy, model-based design methods are proving to be useful for software verification and validation. Some work in formal methods, though not widely used for any satellites, may offer new ways to improve small satellite software verification and validation. These methods need to be further advanced to deal with the state explosion problem and to make them more usable by small-satellite software engineers to be regularly applied to software verification. Last, it is explained how run-time monitoring, combined with fault-tolerant software design methods, provides an important means to detect and correct software errors that escape the verification process or those errors that are produced after launch through the effects of ionizing radiation.

  3. Distributed and Collaborative Software Analysis

    NASA Astrophysics Data System (ADS)

    Ghezzi, Giacomo; Gall, Harald C.

    Throughout the years software engineers have come up with a myriad of specialized tools and techniques that focus on a certain type of software analysissoftware analysis such as source code analysis, co-change analysis or bug prediction. However, easy and straight forward synergies between these analyses and tools rarely exist because of their stand-alone nature, their platform dependence, their different input and output formats and the variety of data to analyze. As a consequence, distributed and collaborative software analysiscollaborative software analysis scenarios and in particular interoperability are severely limited. We describe a distributed and collaborative software analysis platform that allows for a seamless interoperability of software analysis tools across platform, geographical and organizational boundaries. We realize software analysis tools as services that can be accessed and composed over the Internet. These distributed analysis services shall be widely accessible in our incrementally augmented Software Analysis Broker software analysis broker where organizations and tool providers can register and share their tools. To allow (semi-) automatic use and composition of these tools, they are classified and mapped into a software analysis taxonomy and adhere to specific meta-models and ontologiesontologies for their category of analysis.

  4. Guidance and Control Software Project Data - Volume 3: Verification Documents

    NASA Technical Reports Server (NTRS)

    Hayhurst, Kelly J. (Editor)

    2008-01-01

    The Guidance and Control Software (GCS) project was the last in a series of software reliability studies conducted at Langley Research Center between 1977 and 1994. The technical results of the GCS project were recorded after the experiment was completed. Some of the support documentation produced as part of the experiment, however, is serving an unexpected role far beyond its original project context. Some of the software used as part of the GCS project was developed to conform to the RTCA/DO-178B software standard, "Software Considerations in Airborne Systems and Equipment Certification," used in the civil aviation industry. That standard requires extensive documentation throughout the software development life cycle, including plans, software requirements, design and source code, verification cases and results, and configuration management and quality control data. The project documentation that includes this information is open for public scrutiny without the legal or safety implications associated with comparable data from an avionics manufacturer. This public availability has afforded an opportunity to use the GCS project documents for DO-178B training. This report provides a brief overview of the GCS project, describes the 4-volume set of documents and the role they are playing in training, and includes the verification documents from the GCS project. Volume 3 contains four appendices: A. Software Verification Cases and Procedures for the Guidance and Control Software Project; B. Software Verification Results for the Pluto Implementation of the Guidance and Control Software; C. Review Records for the Pluto Implementation of the Guidance and Control Software; and D. Test Results Logs for the Pluto Implementation of the Guidance and Control Software.

  5. SU-E-P-43: A Knowledge Based Approach to Guidelines for Software Safety

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Salomons, G; Kelly, D

    Purpose: In the fall of 2012, a survey was distributed to medical physicists across Canada. The survey asked the respondents to comment on various aspects of software development and use in their clinic. The survey revealed that most centers employ locally produced (in-house) software of some kind. The respondents also indicated an interest in having software guidelines, but cautioned that the realities of cancer clinics include variations, that preclude a simple solution. Traditional guidelines typically involve periodically repeating a set of prescribed tests with defined tolerance limits. However, applying a similar formula to software is problematic since it assumes thatmore » the users have a perfect knowledge of how and when to apply the software and that if the software operates correctly under one set of conditions it will operate correctly under all conditions Methods: In the approach presented here the personnel involved with the software are included as an integral part of the system. Activities performed to improve the safety of the software are done with both software and people in mind. A learning oriented approach is taken, following the premise that the best approach to safety is increasing the understanding of those associated with the use or development of the software. Results: The software guidance document is organized by areas of knowledge related to use and development of software. The categories include: knowledge of the underlying algorithm and its limitations; knowledge of the operation of the software, such as input values, parameters, error messages, and interpretation of output; and knowledge of the environment for the software including both data and users. Conclusion: We propose a new approach to developing guidelines which is based on acquiring knowledge-rather than performing tests. The ultimate goal is to provide robust software guidelines which will be practical and effective.« less

  6. Software Development as Music Education Research

    ERIC Educational Resources Information Center

    Brown, Andrew R.

    2007-01-01

    This paper discusses how software development can be used as a method for music education research. It explains how software development can externalize ideas, stimulate action and reflection, and provide evidence to support the educative value of new software-based experiences. Parallels between the interactive software development process and…

  7. Software Trends and Trendsetters: How They're Shaping an Industry.

    ERIC Educational Resources Information Center

    McGinty, Tony; And Others

    1987-01-01

    Discusses trends in educational software and the effects of new developments on publishers and on the computer industry. Marketing prospects for software are examined, and recent advances are highlighted, including integrated learning systems, skill-based software, software tied to textbooks, networking, and freeware. (LRW)

  8. Requirements Engineering in Building Climate Science Software

    ERIC Educational Resources Information Center

    Batcheller, Archer L.

    2011-01-01

    Software has an important role in supporting scientific work. This dissertation studies teams that build scientific software, focusing on the way that they determine what the software should do. These requirements engineering processes are investigated through three case studies of climate science software projects. The Earth System Modeling…

  9. 75 FR 10439 - Cognitive Radio Technologies and Software Defined Radios

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-08

    ... Technologies and Software Defined Radios AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY... concerning the use of open source software to implement security features in software defined radios (SDRs... ongoing technical developments in cognitive and software defined radio (SDR) technologies. 2. On April 20...

  10. A Legal Guide for the Software Developer.

    ERIC Educational Resources Information Center

    Minnesota Small Business Assistance Office, St. Paul.

    This booklet has been prepared to familiarize the inventor, creator, or developer of a new computer software product or software invention with the basic legal issues involved in developing, protecting, and distributing the software in the United States. Basic types of software protection and related legal matters are discussed in detail,…

  11. Students' Different Understandings of Class Diagrams

    ERIC Educational Resources Information Center

    Boustedt, Jonas

    2012-01-01

    The software industry needs well-trained software designers and one important aspect of software design is the ability to model software designs visually and understand what visual models represent. However, previous research indicates that software design is a difficult task to many students. This article reports empirical findings from a…

  12. Proceedings of the Eighth Annual Software Engineering Workshop

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The four major topics of discussion included: the NASA Software Engineering Laboratory, software testing, human factors in software engineering and software quality assessment. As in the past years, there were 12 position papers presented (3 for each topic) followed by questions and very heavy participation by the general audience.

  13. Software Piracy, Ethics, and the Academician.

    ERIC Educational Resources Information Center

    Bassler, Richard A.

    The numerous software programs available for easy, low-cost copying raise ethical questions. The problem can be examined from the viewpoints of software users, teachers, authors, vendors, and distributors. Software users might hesitate to purchase or use software which prevents the making of back-up copies for program protection. Teachers in…

  14. Software engineering as an engineering discipline

    NASA Technical Reports Server (NTRS)

    Gibbs, Norman

    1988-01-01

    The goals of the Software Engineering Institute's Education Program are as follows: to increase the number of highly qualified software engineers--new software engineers and existing practitioners; and to be the leading center of expertise for software engineering education and training. A discussion of these goals is presented in vugraph form.

  15. Agile Software Development

    ERIC Educational Resources Information Center

    Biju, Soly Mathew

    2008-01-01

    Many software development firms are now adopting the agile software development method. This method involves the customer at every level of software development, thus reducing the impact of change in the requirement at a later stage. In this article, the principles of the agile method for software development are explored and there is a focus on…

  16. Center for Adaptive Optics | Software

    Science.gov Websites

    Center for Adaptive Optics A University of California Science and Technology Center home Adaptive Optics Software The Center for Adaptive Optics acts as a clearing house for distributing Software to Institutes it gives specialists in Adaptive Optics a place to distribute their software. All software is

  17. Commercial Literacy Software.

    ERIC Educational Resources Information Center

    Balajthy, Ernest

    1997-01-01

    Presents the first year's results of a continuing project to monitor the availability of software of relevance for literacy education purposes. Concludes there is an enormous amount of software available for use by teachers of reading and literacy--whereas drill-and-practice software is the largest category of software available, large numbers of…

  18. 21 CFR 801.50 - Labeling requirements for stand-alone software.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Labeling requirements for stand-alone software....50 Labeling requirements for stand-alone software. (a) Stand-alone software that is not distributed... in packaged form, stand-alone software regulated as a medical device must provide its unique device...

  19. 48 CFR 227.7203-13 - Government right to review, verify, challenge and validate asserted restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227..., reproduce, release, or disclose computer software or computer software documentation do not, by themselves, determine the extent of the Government's rights in such software or documentation. The Government may...

  20. 22 CFR 121.8 - End-items, components, accessories, attachments, parts, firmware, software, and systems.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., parts, firmware, software, and systems. 121.8 Section 121.8 Foreign Relations DEPARTMENT OF STATE...-items, components, accessories, attachments, parts, firmware, software, and systems. (a) An end-item is.... Firmware includes but is not limited to circuits into which software has been programmed. (f) Software...

  1. 48 CFR 227.7203-13 - Government right to review, verify, challenge and validate asserted restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227..., reproduce, release, or disclose computer software or computer software documentation do not, by themselves, determine the extent of the Government's rights in such software or documentation. The Government may...

  2. 22 CFR 121.8 - End-items, components, accessories, attachments, parts, firmware, software and systems.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., parts, firmware, software and systems. 121.8 Section 121.8 Foreign Relations DEPARTMENT OF STATE...-items, components, accessories, attachments, parts, firmware, software and systems. (a) An end-item is.... Firmware includes but is not limited to circuits into which software has been programmed. (f) Software...

  3. 22 CFR 121.8 - End-items, components, accessories, attachments, parts, firmware, software and systems.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., parts, firmware, software and systems. 121.8 Section 121.8 Foreign Relations DEPARTMENT OF STATE...-items, components, accessories, attachments, parts, firmware, software and systems. (a) An end-item is.... Firmware includes but is not limited to circuits into which software has been programmed. (f) Software...

  4. 48 CFR 227.7203-13 - Government right to review, verify, challenge and validate asserted restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227..., reproduce, release, or disclose computer software or computer software documentation do not, by themselves, determine the extent of the Government's rights in such software or documentation. The Government may...

  5. 48 CFR 227.7203-13 - Government right to review, verify, challenge and validate asserted restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227..., reproduce, release, or disclose computer software or computer software documentation do not, by themselves, determine the extent of the Government's rights in such software or documentation. The Government may...

  6. 22 CFR 121.8 - End-items, components, accessories, attachments, parts, firmware, software and systems.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., parts, firmware, software and systems. 121.8 Section 121.8 Foreign Relations DEPARTMENT OF STATE...-items, components, accessories, attachments, parts, firmware, software and systems. (a) An end-item is.... Firmware includes but is not limited to circuits into which software has been programmed. (f) Software...

  7. 78 FR 47015 - Software Requirement Specifications for Digital Computer Software Used in Safety Systems of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-02

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Software Requirement Specifications for Digital Computer Software Used in Safety Systems of Nuclear Power Plants AGENCY: Nuclear Regulatory Commission... issuing a revised regulatory guide (RG), revision 1 of RG 1.172, ``Software Requirement Specifications for...

  8. 48 CFR 227.7203-13 - Government right to review, verify, challenge and validate asserted restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227..., reproduce, release, or disclose computer software or computer software documentation do not, by themselves, determine the extent of the Government's rights in such software or documentation. The Government may...

  9. 22 CFR 121.8 - End-items, components, accessories, attachments, parts, firmware, software and systems.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., parts, firmware, software and systems. 121.8 Section 121.8 Foreign Relations DEPARTMENT OF STATE...-items, components, accessories, attachments, parts, firmware, software and systems. (a) An end-item is.... Firmware includes but is not limited to circuits into which software has been programmed. (f) Software...

  10. Software Engineering Laboratory (SEL) data base reporting software user's guide and system description. Volume 1: Introduction and user's guide

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Reporting software programs provide formatted listings and summary reports of the Software Engineering Laboratory (SEL) data base contents. The operating procedures and system information for 18 different reporting software programs are described. Sample output reports from each program are provided.

  11. The Emergence of Open-Source Software in China

    ERIC Educational Resources Information Center

    Pan, Guohua; Bonk, Curtis J.

    2007-01-01

    The open-source software movement is gaining increasing momentum in China. Of the limited numbers of open-source software in China, "Red Flag Linux" stands out most strikingly, commanding 30 percent share of Chinese software market. Unlike the spontaneity of open-source movement in North America, open-source software development in…

  12. 15 CFR 30.37 - Miscellaneous exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... requirements of the licensing Federal agency. (f) Exports of technology and software as defined in 15 CFR 772... required for mass-market software. For purposes of this part, mass-market software is defined as software... of commodities and software intended for use by individual USPPIs or by employees or representatives...

  13. 15 CFR 30.37 - Miscellaneous exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... requirements of the licensing Federal agency. (f) Exports of technology and software as defined in 15 CFR 772... required for mass-market software. For purposes of this part, mass-market software is defined as software... of commodities and software intended for use by individual USPPIs or by employees or representatives...

  14. 15 CFR 30.37 - Miscellaneous exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... requirements of the licensing Federal agency. (f) Exports of technology and software as defined in 15 CFR 772... required for mass-market software. For purposes of this part, mass-market software is defined as software... of commodities and software intended for use by individual USPPIs or by employees or representatives...

  15. 15 CFR 30.37 - Miscellaneous exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... requirements of the licensing Federal agency. (f) Exports of technology and software as defined in 15 CFR 772... required for mass-market software. For purposes of this part, mass-market software is defined as software... of commodities and software intended for use by individual USPPIs or by employees or representatives...

  16. Toward Baseline Software Anomalies in NASA Missions

    NASA Technical Reports Server (NTRS)

    Layman, Lucas; Zelkowitz, Marvin; Basili, Victor; Nikora, Allen P.

    2012-01-01

    In this fast abstract, we provide preliminary findings an analysis of 14,500 spacecraft anomalies from unmanned NASA missions. We provide some baselines for the distributions of software vs. non-software anomalies in spaceflight systems, the risk ratings of software anomalies, and the corrective actions associated with software anomalies.

  17. Understanding Acceptance of Software Metrics--A Developer Perspective

    ERIC Educational Resources Information Center

    Umarji, Medha

    2009-01-01

    Software metrics are measures of software products and processes. Metrics are widely used by software organizations to help manage projects, improve product quality and increase efficiency of the software development process. However, metrics programs tend to have a high failure rate in organizations, and developer pushback is one of the sources…

  18. Considerations for the Evaluation of Software.

    ERIC Educational Resources Information Center

    Fields, Thomas A.

    1984-01-01

    The paper describes the decision process in the determination of software purchase for the professional's use of the microcomputer. Consideration to ensure that the software purchased will be a success, which software will be needed, and options that will facilitate the location and evaluation of software are discussed. (Author/CL)

  19. Evaluation and selection of security products for authentication of computer software

    NASA Astrophysics Data System (ADS)

    Roenigk, Mark W.

    2000-04-01

    Software Piracy is estimated to cost software companies over eleven billion dollars per year in lost revenue worldwide. Over fifty three percent of all intellectual property in the form of software is pirated on a global basis. Software piracy has a dramatic effect on the employment figures for the information industry as well. In the US alone, over 130,000 jobs are lost annually as a result of software piracy.

  20. Modernizing Systems and Software: How Evolving Trends in Future Trends in Systems and Software Technology Bode Well for Advancing the Precision of Technology

    DTIC Science & Technology

    2009-04-23

    of Code Need for increased functionality will be a forcing function to bring the fields of software and systems engineering... of Software-Intensive Systems is Increasing 3 How Evolving Trends in Systems and Software Technologies Bode Well for Advancing the Precision of ...Engineering in Continued Partnership 4 How Evolving Trends in Systems and Software Technologies Bode Well for Advancing the

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