3,195 research outputs found
Evaluating human performance modeling for system assessment: Promise and problems
The development and evaluation of computational human performance models is examined. An intention is to develop models which can be used to interact with system prototypes and simulations to perform system assessment. Currently LR is working on a set of models emulating cognitive, psychomotor, auditory, and visual activity for multiple operator positions of a command and control simulation system. These models, developed in conjunction with BBN Systems and Technologies, function within the simulation environment and allow for both unmanned system assessment and manned (human-in-loop) assessment of system interface and team interactions. These are relatively generic models with built-in flexibility which allows modification of some model parameters. These models have great potential for improving the efficiency and effectiveness of system design, test, and evaluation. However, the extent of the practical utility of these models is unclear. Initial verification efforts comparing model performance within the simulation to actual human operators on a similar, independent simulation have been performed and current efforts are directed at comparing human and model performance within the same simulation environment
A Study of the Trypsinlike Protease of the Adult Stable Fly, Stomoxys Calcitrans (L.)
Author Institution: Department of Zoology and Entomology, The Ohio State University, Columbu
A Fistful of Polemoniaceae: New Names and Combinations
New taxa, names, and combinations are provided for five genera in Polemoniaceae: Dayia, Giliastrum, Leptosiphon, Linanthus, and Loeselia. Combinations include the transfer to Dayia of two species formerly included in Ipomopsis and one in Bryantiella (Dayia glutinosa, D. havardii, and D. sonorae), as well as the return of Giliastrum stewartii to species rank. A new name is offered for Linanthus aureus when transferred into Leptosiphon: Leptosiphon chrysanthus and its subspecies, L. chrysanthus subsp. decorus. New combinations for infraspecific taxa are made available for Linanthus californicus (subspp. glandulosus and tomentosus) and L. pungens (subspp. hookeri, pulchriflorus, and hallii). New subspecies are described for Linanthus bigelovii (subsp. johnsonii), L. dichotomus (subsp. pattersonii), L. maculatus (subsp. emaculatus), L. watsonii (subspp. laccolithicus and dolomiticus), and Loeselia glandulosa (subsp. sonorae). Linanthus maricopensis is described as new. In addition, 10 lectotypes are designated, associated with Dayia, Leptosiphon, and Linanthus
Hypercube technology
The JPL designed MARKIII hypercube supercomputer has been in application service since June 1988 and has had successful application to a broad problem set including electromagnetic scattering, discrete event simulation, plasma transport, matrix algorithms, neural network simulation, image processing, and graphics. Currently, problems that are not homogeneous are being attempted, and, through this involvement with real world applications, the software is evolving to handle the heterogeneous class problems efficiently
Small Acreage Irrigation System Operation and Maintenance
Surface irrigation includes flood (sometimes denoted “wild flood,” as in uncontrolled), furrow, border, and basin. Surface irrigation operation and maintenance may be more of an art than a science
Diverter AI based decision aid, phases 1 and 2
It was determined that a system to incorporate artificial intelligence (AI) into airborne flight management computers is feasible. The AI functions that would be most useful to the pilot are to perform situational assessment, evaluate outside influences on the contemplated rerouting, perform flight planning/replanning, and perform maneuver planning. A study of the software architecture and software tools capable of demonstrating Diverter was also made. A skeletal planner known as the Knowledge Acquisition Development Tool (KADET), which is a combination script-based and rule-based system, was used to implement the system. A prototype system was developed which demonstrates advanced in-flight planning/replanning capabilities
Computers and Productivity : Evidence from Laptop Use in the College Classroom
This paper evaluates the effect of classroom computer use on academic performance. Using a quasi-experimental design and administrative data, we find that computer use in college classrooms has a negative impact on course grades. Our study exploits institutional policies that generate plausibly random variation in laptop use within the classroom. Compared to students who are not affected by computer policies, students who are induced to use computers in class perform significantly worse and students who are influenced not to use computers perform significantly better. We find that the negative effects of computer use are concentrated among males and low-performing students and more prominent in quantitative courses
Establishing, Growing, and Running a Sales Program: An Analysis of Certified University Sales Centers
Nodulation, Nitrogen Fixation, and Organ Dry Weight of Soybean Infested with Southern Corn Rootworm (Coleoptera: Chrysomelidae) Larvae
Nitrogen fixation, nodulation, and organ dry weights of soybean infested with the larvae of the southern corn rootworm, Diabrotica undecimpunctata howardi Barber, were estimated under controlled conditions. Larval southern com rootworm reduced the nitrogen-fixing activity of mid-vegetative and early reproductive soybean, Glycine max Merrill. Soybean of both stages responded to the infestation and subsequent injury by increasing nodulation and organ dry weights of below-ground tissues relative to above-ground tissues. Infestation increased the dry weight of small nodules on vegetative plants and caused a 78.6% increase in the total number of nodules on R5 plants. Leaf area as well as leaf and stem dry weight was reduced in vegetative plants by infestatio
Maternal Influenza Infection Causes Marked Behavioral and Pharmacological Changes in the Offspring
Maternal viral infection is known to increase the risk for schizophrenia and autism in the offspring. Using this observation in an animal model, we find that respiratory infection of pregnant mice (both BALB/c and C57BL/6 strains) with the human influenza virus yields offspring that display highly abnormal behavioral responses as adults. As in schizophrenia and autism, these offspring display deficits in prepulse inhibition (PPI) in the acoustic startle response. Compared with control mice, the infected mice also display striking responses to the acute administration of antipsychotic (clozapine and chlorpromazine) and psychomimetic (ketamine) drugs. Moreover, these mice are deficient in exploratory behavior in both open-field and novel-object tests, and they are deficient in social interaction. At least some of these behavioral changes likely are attributable to the maternal immune response itself. That is, maternal injection of the synthetic double-stranded RNA polyinosinic-polycytidylic acid causes a PPI deficit in the offspring in the absence of virus. Therefore, maternal viral infection has a profound effect on the behavior of adult offspring, probably via an effect of the maternal immune response on the fetus
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