4,728 research outputs found
An assessment of various side-stick controller/stability and control augmentation systems for night nap-of-Earth flight using piloted simulation
Several night nap-of-the-earth mission tasks were evaluated using a helmet-mounted display which provided a limited field-of-view image with superimposed flight control symbology. A wide range of stability and control augmentation designs was investigated. Variations in controller force-deflection characteristics and the number of axes controlled through an integrated side-stick controller were studied. In general, a small displacement controller is preferred over a stiffstick controller particularly for maneuvering flight. Higher levels of stability augmentation were required for IMC tasks to provide handling qualities comparable to those achieved for the same tasks conducted under simulated visual flight conditions
Acoustic characteristics of a large scale wind-tunnel model of a jet flap aircraft
The expanding-duct jet flap (EJF) concept is studied to determine STOL performance in turbofan-powered aircraft. The EJF is used to solve the problem of ducting the required volume of air into the wing by providing an expanding cavity between the upper and lower surfaces of the flap. The results are presented of an investigation of the acoustic characteristics of the EJF concept on a large-scale aircraft model powered by JT15D engines. The noise of the EJF is generated by acoustic dipoles as shown by the sixth power dependence of the noise on jet velocity. These sources result from the interaction of the flow turbulence with flap of internal and external surfaces and the trailing edges. Increasing the trailing edge jet from 70 percent span to 100 percent span increased the noise 2 db for the equivalent nozzle area. Blowing at the knee of the flap rather than the trailing edge reduced the noise 5 to 10 db by displacing the jet from the trailing edge and providing shielding from high-frequency noise. Deflecting the flap and varying the angle of attack modified the directivity of the underwing noise but did not affect the peak noise. A forward speed of 33.5 m/sec (110 ft/sec) reduced the dipole noise less than 1 db
The marine fisheries of Jamaica
The marine fisheries of Jamaica are almost entirely artisanal, with at least 15 000 fishers and an annual catch of approximately 7 000 t. A recent development is a small industrial fishery for queen conch and spiny lobster that earns significant foreign exchange for the country. The major aquatic resources are coral reef fishes, conch, lobster, small pelagics and seasonal large pelagics. The major fishing grounds are the southern island shelf and Pedro Bank, a large oceanic bank 150 km to the southwest of Kingston. The fisheries are rated as overfished, except the queen conch fishery which is relatively well managed. A new Fisheries Bill is currently being reviewed with the intention of improving the efficiency of management measures and of fisheries administration. There are plans for rehabilitating the fisheries and developing them with a focus on their sustainability in the future
Are You Satisfied With the Services You Receive? : An Examination of the Level of Satisfaction Among Developmentally Disabled Adults Living in the Residential Program at Partnerships For People, Inc.
Does Being Attractive Always Help? Positive and Negative Effects of Attractiveness on Social Decision Making
Previous studies of organizational decision making demonstrate an abundance of positive biases directed toward highly attractive individuals. The current research, in contrast, suggests that when the person being evaluated is of the same sex as the evaluator, attractiveness hurts, rather than helps. Three experiments assessing evaluations of potential job candidates (Studies 1 and 3) and university applicants (Study 2) demonstrated positive biases toward highly attractive other-sex targets but negative biases toward highly attractive same-sex targets. This pattern was mediated by variability in participants’ desire to interact with versus avoid the target individual (Studies 1 and 2) and was moderated by participants’ level of self-esteem (Study 3); the derogation of attractive same-sex targets was not observed among people with high self-esteem. Findings demonstrate an important exception to the positive effects of attractiveness in organizational settings and suggest that negative responses to attractive same-sex targets stem from perceptions of self-threat
Large-scale V/STOL testing
Several facets of large-scale testing of V/STOL aircraft configurations are discussed with particular emphasis on test experience in the Ames 40- by 80-Foot Wind Tunnel. Examples of powered-lift test programs are presented in order to illustrate tradeoffs confronting the planner of V/STOL test programs. Large-scale V/STOL wind-tunnel testing can sometimes compete with small-scale testing in the effort required (overall test time) and program costs because of the possibility of conducting a number of different tests with a single large-scale model where several small-scale models would be required. The benefits of both high- or full-scale Reynolds numbers, more detailed configuration simulation, and number and type of onboard measurements are studied
CC-DRIVER Policy Brief No. 8: European Youth Survey
This policy brief contains key findings from the CC-DRIVER 2021 European Youth Survey and corresponding conclusions. This brief is designed for all professionals working within the area of cybercrime and key stakeholders, including LEAs, Academics, Criminal Justice, Policy Makers, and Educators. The lack of clarity surrounding the term cybercrime has significant impact on society, cybercrime policy, legal intervention, and academic research. No single classification system fully encapsulated cybercrime concepts or accurately reflected the nebulous nature of cybercrime acts. There is remaining ambiguity as to what exactly constitutes a cybercrime, and it is likely that a clear conceptualisation of cybercrime will continue to be challenged. This review presents key cybercrime definitions, categorisations of cybercrime and typologies of cybercrime. This review presents a new framework with which to conceptualise cybercrime
European Youth Cybercrime, Online Harm and Online Risk Taking: 2022 Research Report
Researching cybercriminality to design new methods to prevent, investigate and mitigate cybercriminal behaviour. This is one of the largest studies to date exploring youth cybercriminality. The survey is informed by 5 key disciplines: cyberpsychology, criminology, psychology, neuroscience, and digital anthropology Results confirm that cybercrime and cyberdeviance is prevalent-survey finds that two thirds (69%) of European youth self-report to have committed at least one form of cybercrime or online harm or risk taking, and just under half 47.76% (N=3808) report to have engaged in criminal behaviour online, from summer of 2020 to the summer of 2021 Survey finds that males are more likely (74%) than females (65%) to self-report having been involved in at least one form of cybercrime or online harm or risk taking in the last year and results confirm that the majority of cybercrime and cyberdeviant behaviours are gendered. Survey analysis demonstrates that cybercriminal and online harm or risk taking behaviours form a cluster of 11 behaviours that are highly interrelated (CcCd-Cluster) and that cybercrime and online harm or risk taking behaviours represent a spectrum (CcCd-Spectrum) A significant shift from a siloed, categorical approach is needed in terms of how cybercrimes are conceptualised, investigated, and legislated
Removal of terrestrial DOC in aquatic ecosystems of a temperate river network
Surface waters play a potentially important role in the global carbon balance. Dissolved organic carbon (DOC) fluxes are a major transfer of terrestrial carbon to river systems, and the fate of DOC in aquatic systems is poorly constrained. We used a unique combination of spatially distributed sampling of three DOC fractions throughout a river network and modeling to quantify the net removal of terrestrial DOC during a summer base flow period. We found that aquatic reactivity of terrestrial DOC leading to net loss is low, closer to conservative chloride than to reactive nitrogen. Net removal occurred mainly from the hydrophobic organic acid fraction, while hydrophilic and transphilic acids showed no net change, indicating that partitioning of bulk DOC into different fractions is critical for understanding terrestrial DOC removal. These findings suggest that river systems may have only a modest ability to alter the amounts of terrestrial DOC delivered to coastal zones
Direct contact and authoritarianism as moderators between extended contact and reduced prejudice: Lower threat and greater trust as mediators
Using a representative sample of Dutch adults (N = 1238), we investigated the moderating influence of direct contact and authoritarianism on the potential of extended contact to reduce prejudice. As expected, direct contact and authoritarianism moderated the effect of extended contact on prejudice. Moreover, the third-order moderation effect was also significant, revealing that extended contact has the strongest effect among high authoritarians with low levels of direct contact. We identified trust and perceived threat as the mediating processes underlying these moderation effects. The present study thus attests to the theoretical and practical relevance of reducing prejudice via extended contact. The discussion focuses on the role of extended contact in relation to direct contact and authoritarianism as well as on the importance of trust in intergroup contexts
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