Design verification of SIFT

A SIFT reliable aircraft control computer system, designed to meet the ultrahigh reliability required for safety critical flight control applications by use of processor replications and voting, was constructed for SRI, and delivered to NASA Langley for evaluation in the AIRLAB. To increase confidence in the reliability projections for SIFT, produced by a Markov reliability model, SRI constructed a formal specification, defining the meaning of reliability in the context of flight control. A further series of specifications defined, in increasing detail, the design of SIFT down to pre- and post-conditions on Pascal code procedures. Mechanically checked mathematical proofs were constructed to demonstrate that the more detailed design specifications for SIFT do indeed imply the formal reliability requirement. An additional specification defined some of the assumptions made about SIFT by the Markov model, and further proofs were constructed to show that these assumptions, as expressed by that specification, did indeed follow from the more detailed design specifications for SIFT. This report provides an outline of the methodology used for this hierarchical specification and proof, and describes the various specifications and proofs performed

Effects of Repression-Sensitization, Arousal, and Sex on Physical Aggression

In the past two decades, numerous experiments have focused on a wide variety of situational factors influencing the arousal, intensity, and direction of aggressive behavior. In contrast, few studies have considered the role of individual difference variables in producing aggression. The present study was concerned with a personality variable which theoretically should have some relevance to the expression of physical aggression. This variable was repression-sensitization (R-S) as measured\u27by the revised Repress ion-Sensitization Scale (Byrne, Barry, and Nelson, 1963). In an attempt to improve upon the predictive validity of R-S, defensive and nondefensive repressors were differentiated through the use of Marlowe-Crowne Social Desirability Scale scores . Arousal and subject sex were also included as independent variables. Arousal was manipulated by means of instructions. The dependent variables in the present experiment were mean shock intensity administered on an apparatus similar to the Buss Aggression Machine, Multiple Affect Adjective Check List (MAACL) scale scores, and subscale scores on a Mood Scale constructed by the author. The experimental design was a 3x2x2 factorial with three levels of R-S (sensitizers, nondefensive repressors, and defensive repressors), two levels of sex (male and female), and two conditions of arousal (high and low). Seventy-two subjects were led to believe that a confederate was also a student participating in a learning experiment. Subjects were told that they would be teaching a concept through the use of reward (a correct light) and punishment (shock). Instructions were designed to produce more frustration in the high arousal group than in the low arousal condition. After the experimental procedure, the MAACL, the Mood Scale, and a Post Experiment Questionnaire were administered. No differences in mean shock intensity were found among the R-S groups. Males and females also did not differ in aggressive responding. Only the arousal main effect reached significance. Contrary to expectations, the low arousal group administered significantly more shock than the high arousal subjects. A possible explanation in terms of aggression anxiety lowering the aggressive responses of high arousal subjects was offered . On the hostility, anxiety, and depression subscales of the MAACL and Mood Scale, sensitizers scored higher than repressors. No differences in mean shock intensity or affect scale responses were found between nondefensive and defensive repressors. These data were compared to results of previous R-S experimentation in which defensive and nondefensive repressors were differentiated. In conclusion, while sensitizers describe themselves as more hostile than repressors, their overt aggressive behavior does not appear to differ

Transcript analysis and comparative evaluation of shaker and slowmo gene homologues from the European corn borer, Ostrinia nubilalis

The movement and dispersal of larval Lepidoptera impact their survival and distribution within the natural landscape. Homologues of the Drosophila behaviour-linked genes shaker (shkr) and slowmo (slmo) were identified from Ostrinia nubilalis (Lepidoptera: Crambidae). Onshkr was isolated as a 1610-nucleotide (nt) constitutively expressed transcript encoding a membrane-localized 469-amino-acid (aa) protein with a conserved tetramerization domain and the six-domain architecture necessary for the molecule to fold into an active K(+) channel. Three expressed splice variants of 682, 970 and 1604 nt were identified for the Onslmo gene, and encode predicted 141 and 228 aa proteins with a conserved protein of relevant evolutionary and lymphoid interest (PRELI) domain that may function in mitochondrial protein sorting and perinuclear protein localization. Onshkr and Onslmo protein sequences aligned within monophyletic lepidopteran groups

Do Learning And Study Skills Affect Academic Performance? An Empirical Investigation

Universities and colleges are very interested in understanding the factors that influence their students academic performance. This paper describes a study that was conducted at a mid-sized public university in the mid-south, USA, to examine this issue. In this study, the 10-scale, Learning and Study Strategies Inventory (LASSI) (Weinstein et al., 1987) assessment device was administered to 107 students to measure receptivity to several skills and strategies that purportedly enhance a students ability to learn and successfully perform in an academic setting. The results of this study showed that the LASSI scales dealing with attitude, concentration, information processing skill, motivation, self-testing and review techniques, use of study support techniques, time management, and effective test-taking strategies all correlated positively (with statistical significance) to student GPA. There were also statistically significant differences between males and females in their mean scores for several of the above mentioned LASSI scales. Every LASSI subscale, where females significantly outscored males, positively correlated with superior academic performance (i.e., GPA). However, after controlling for variance explained by the LASSI scores, there were no statistically significant correlations between gender and academic performance. The primary conclusion from this study is that contrary to prior research that suggests that females predominantly outperform males in academics, such differences can be better explained by mediating variables such as learning and study strategies. This debunking of the female stereotype of superior academic performance merely because of gender has pedagogical implications

Modeling the Impact of Cross-Pollination and Low Toxin Expression in Corn Kernels on Adaptation of European Corn Borer (Lepidoptera: Crambidae) to Transgenic Insecticidal Corn

We used a mathematical model with processes reflecting larval mortality resulting from feeding on cross-pollinated ears or Bt ears of corn to analyze the risk of evolution of Cry-toxin resistance in Ostrinia nubilalis (Hübner). In the simulations, evolution of resistance was delayed equally well by both seed mixtures and blocks with the same proportion of refuge. Our results showed that Bt-pollen drift has little impact on the evolution of Bt resistance in O. nubilalis. However, low-toxin expression in ears of transgenic corn can reduce the durability of transgenic corn expressing single toxin, whereas durability of pyramided corn hybrids is not significantly reduced. The toxinsurvival rate of heterozygous larvae in Bt-corn ears expressing one or two proteins has more impact on evolution of Bt resistance in O. nubilalis than the parameters related to larval movement to Bt ears or the toxin-survival rate of the homozygous susceptible larvae in Bt ears. Bt resistance evolves slower when toxin mortality is distributed across the first two larval stadia than when only the first instars are susceptible to Bt toxins. We suggest that stakeholders examine toxin-survival rates for insect pests and take into account that instars may feed on different parts of Bt corn

How Do Quantitative And Qualitative Factors Influence The Selection Of Comparable, Competitive, And Aspirant Groups Under The Proposed AACSB Accreditation Maintenance Process?

The AACSB Blue Ribbon Committee on Accreditation Quality was “formed to do a thorough review of AACSB International's accreditation standards and procedures and to propose changes appropriate for global quality leadership in the next decade...” Within the proposal from the Blue Ribbon Committee is a change from a reaffirmation process with a site visit every ten years to a maintenance program resulting in a team visit in the sixth year of the cycle. Under the old standards applicants were required to submit “to the appropriate accreditation committee chair, in care of the AACSB International office, five nominations for each team role; i.e., five names for chair, five names for advisor, five for member, and if accounting accreditation were applicable, five names for vice-chair and five names for accounting advisor.” The proposed standards include a team selection process whereby the “applicant submits three comparison groups selected from members of the Accreditation Council... AACSB International will develop an on-line system to assist the applicant to identify potential comparison schools, officially select schools for each comparison group, and continuously maintain comparison group listings in an AACSB International database. Some information is currently available. The on-line service, www.aacsb.edu/knowledgeservices, offers advanced search functions that produce institution lists based on optionally selected criteria.” This AACSB provided information as well as information from other sources constitutes the basis for the recommended comparison group selection process

Imbalance mitigation strategy via flexible PV ancillary services: The Italian case study

Abstract Large share of solar energy imposes a higher system flexibility to resolve the increased demand/supply imbalance due to the inherent intermittency and variability of the resource. In this work, we demonstrate that the additional solar-induced flexibility requirement can be fully provided by a special kind of solar farms, namely flexible PV. These plants are able to provide ancillary services by proactive generation curtailment and storage power injection and they can be managed exactly as the secondary reserve currently used. At the current and future penetration levels, we sized the flexible PV fleet required to reduce the Italian imbalance by 36 % (with respect to its 2016 value) while keeping the curtailment at 6 % of the national PV generation. We show how this result can be achieved at an equal or lower dispatching cost than current cost (depending on the solar share). In addition, we found that a fleet composed of many flexible PV plants with different capacity randomly distributed throughout the country provides an optimal solar regulation performance. Finally, we showed that the effectiveness of the proposed imbalance mitigation strategy depends only slightly on the year-specific load, wind, PV and energy prices profiles used to size the capacity of the flexible fleet

BAE Systems Radiation Hardened SpaceWire ASIC and Roadmap

An Application Specific Integrated Circuit (ASIC) that implements the SpaceWire protocol has been developed in a radiation hardened 0.25 micron CMOS, technology. This effort began in March 2003 as a joint development between the NASA Goddard Space Flight Center (GSFC) and BAE Systems. The BAE Systems SpaceWire ASlC is comprised entirely of reusable core elements, many of which are already flight-proven. It incorporates a 4-port SpaceWire router with two local ports, dual PC1 bus interfaces, a microcontroller, 32KB of internal memory, -and a memory controller for additional external memory use. The SpaceWire ASlC is planned for use on both the Geostationary Operational Environmental Satellites (GOES)-R and the Lunar Reconnaissance Orbiter (LRO). Engineering parts have already been delivered to both programs. This paper discusses the SpaceWire protocol and those elements of it that have been built into the current SpaceWire reusable core. There are features within the core that go beyond the current standard that can be enabled or disabled by the user and these will be described. The adaptation of SpaceWire to BAE Systems' On Chip Bus (OCB) for compatibility with the other reusable cores will be discussed. Optional configurations within user systems will be shown. The physical imp!ementation of the design will be described and test results from the hardware will be discussed. Finally, the BAE Systems roadmap for SpaceWire developments will be discussed, including some products already in design as well as longer term plans

Embedded NiTi wires for improved dynamic thermomechanical performance of silicone elastomers

The extraordinary properties of shape memory NiTi alloy are combined with the inherent viscoelastic behavior of a silicon elastomer. NiTi wires are incorporated in a silicon elastomer matrix. Benefits include features as electrical/thermal conductivity, reinforcement along with enhanced damping performance and flexibility. To gain more insight of this composite, a comprehensive dynamic thermomechanical analysis is performed and the temperature- as well as frequency-dependent storage modulus and the mechanical loss factor are obtained. The analyses are realized for the composite and single components. Moreover, the models to express the examined properties and their temperature along with the frequency dependencies are also presented