Characterizations of reduction classes modulo oracle conditions

It is known that nondeterministic polynomial time truth-table reducibility is exactly the same as nondeterministic polynomial time Turing reducibility. Here we study the standard nondeterministic reducibilities (conjunctive, bounded truth-table, bounded positive truth-table, and many-one) and show that each is a restriction of nondeterministic polynomial time Turing reducibility corresponding to acceptance modulo a set of oracle conditions. Then we show that the reduction classes of these reducibilities are classes of formal languages and as such have language theoretic characterization theorems. The same program is carried out for polynomial space.This research was supported in part by the National Science Foundation under Grants MCS77-23493, MSC80-11979, MCS81-20263, and MCS83-12472. The work of the second author was also supported by the United States-Israel Educational Foundation (Fulbright Award).     

A cross-cultural, multidisciplinary proof of the newly discovered developmental linguistic law of concordance of speech and motor development in children.

Humorously describes fictional studies "proving" that motor and language development occur concurrently ("hand in hand") and that this development is independent of culture. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On languages with a certain prefix property

A languageL has theprefix property if for allx, y L, eitherx is a prefix ofy ory is a prefix ofx. It is shown that for certain classes of languages, if a language in the class has the prefix property, then it is a regular set. The results provide new distinctions between classes as well as new profs of previously known distinctions.This research was supported in part by the National Science Foundation under Grant DCR-75-15945 and Grant MCS76-05744.     

Sex, Age, and Training Modulate Spatial Memory in the Rhesus Monkey (Macaca mulatta).

The authors tested 90 rhesus monkeys (Macaca mulatta) on a task of spatial memory, the spatial Delayed Recognition Span Test. The results showed that performance declined significantly with age, males had greater scores than females, and the rate of apparent decline with age was greater in males than in females. Both working and reference memory declined with age, but only working memory showed sex differences. The authors compared these data with that of 22 monkeys who were trained on a simpler version of the task before formal testing. Training had no effect on males but dramatically improved working memory in young females. The results confirm a male advantage in spatial working memory at a young age and confirm a greater decline with age in males than in females. It is important to note that prior training completely reverses the deficits of young females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recent Advances in Pharmacotherapies for the Externalizing Disorders.

This article provides a review of various psychotropic agents employed for children and adolescents with externalizing disorders. With the exception of the stimulants, clinical use of psychotropic medications for children with externalizing disorders far exceeds the available empirical literature. Further, there are insufficient data pertaining to the safety and efficacy of most psychotropics. Studies that examine the combination of psychotherapy and pharmacotherapy are also reviewed, with particular attention to the National Institutes of Health Multimodal Treatment Study for Children with Attention-Deficit/Hyperactivity Disorder. Recommendations are made for future multimodal studies all externalizing disorders and with all psychotropics in addition to the stimulants. Future goals for research over the next decade include studies that examine treatment acceptability, adherence and satisfaction, adherence with various psychotropic agents, and ecologically valid investigations of pharmacotherapies for both symptom reduction and enhancement of functional behaviors among children and adolescents with externalizing behavioral problems. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Reliability analysis of pipe whip impacts

A probability-based approach is presented as the integration of probabilistic methods and deterministic modelling based on the finite element method. An existing finite element software package was linked to an existing probabilistic package to analyse the complex mechanics that occur during the transient non-linear analysis of impact problems. This methodology is applied to a pipe whip analysis of a group-distribution-header, which results from a guillotine break, and subsequent impact with the adjacent building wall; this is a postulated accident for the Ignalina Nuclear Power Plant RBMK-1500 reactors. The uncertainties of material properties, component geometry data and loads were taken into consideration. The probabilities of failure of the impacted header and of the header support-wall were estimated given uncertainties in material properties, geometrical parameters and loading. The software ProFES was used for the probabilistic analysis and the finite element software NEPTUNE for deterministic structural integrity evaluation. The Monte Carlo Simulation, First Order Reliability method and Response Surface method were used in the probabilistic analysis.     

Segmented object manufacturing

Rapid Prototyping (RP) is a technology based on a “divide-and-conquer” strategy that enables automatic physical realization of a design without any special tooling. However, existing RP processes suffer from staircase defects since they are all based on 2.5-axis kinematics. To minimize the error due to staircase defects parts are normally built from very thin layers typically with thickness values of 0.010 to 0.300 mm. Therefore, hundreds of layers are required to produce a typical object making RP a slow and costly process. To overcome these limitations, a new RP process called Segmented Object Manufacturing (SOM) is proposed in this paper. SOM makes use of three-axis kinematics in conjunction with a novel slicing method. Slicing in SOM is based on certain visibility-based considerations and is independent of the part accuracy. Since only a few thick layers are used in the SOM technique, a part can be produced faster and cheaper with an accuracy comparable to that of CNC machining.     

Development of a Position Sensitive Neutron Detector with High Efficiency and Energy Resolution for Use at High-Flux Beam Sources

We are developing a high-efficiency neutron detector with 1 cm position resolution and coarse energy resolution for use at high-flux neutron source facilities currently proposed or under construction. The detector concept integrates a segmented ³He ionization chamber with the position sensitive, charged particle collection methods of a MicroMegas detector. Neutron absorption on the helium produces protons and tritons that ionize the fill gas. The charge is amplified in the field region around a wire mesh and subsequently detected in current mode by wire strips mounted on a substrate. One module consisting of a high-voltage plate, a field-shaping high-voltage plate, a grid and wire strips defines a detection region. For 100 % efficiency, detector modules are consecutively placed along the beam axis. Analysis over several regions with alternating wire strip orientation provides a two-dimensional beam profile. By using ³He, a 1/v absorption gas, each axial region captures neutrons of a different energy range, providing an energy-sensitive detection scheme especially useful at continuous beam sources.     

Reasoning about Knowledge: A Response by the Authors

Minds and Machines -