Improving the Scalability of Multi-Agent Systems

There is an increasing demand for designers and developers to construct ever larger multi-agent systems. Such systems will be composed of hundreds or even thousands of autonomous agents. Moreover, in open and dynamic environments, the number of agents in the system at any one time will fluctuate significantly. To cope with these twin issues of scalability and variable numbers, we hypothesize that multi-agent systems need to be both /self-building/ (able to determine the most appropriate organizational structure for the system by themselves at run-time) and /adaptive/ (able to change this structure as their environment changes). To evaluate this hypothesis we have implemented such a multi-agent system and have applied it to the domain of automated trading. Preliminary results supporting the first part of this hypothesis are presented: adaption and self-organization do indeed make the system better able to cope with large numbers of agents

Skylab food system

A review of the Skylab food system requirements, package designs, and launch configurations was presented. In-flight anomalies were discussed, and between-mission changes in design were described. A discussion of support for Skylab 3 and Skylab 4 mission extensions and of new items launched on these missions is included

A two-axis pointing system for an orbiting astronomical instrument

The system described was built for incorporation into a solar flare X-ray instrument due to be orbited as one of a number of instruments on the NASA Solar Maximum Mission (SMM) satellite in late 1979. It enables the instrument to be rotated about 2 mutually perpendicular axes in 5 arc-second steps within a range of 7 arc-minutes, thus giving the instrument the capability to map areas of the sun

Alessi 95 and the short period Cepheid SU Cassiopeiae

The parameters for the newly-discovered open cluster Alessi 95 are established on the basis of available photometric and spectroscopic data, in conjunction with new observations. Colour excesses for spectroscopically-observed B and A-type stars near SU Cas follow a reddening relation described by E(U-B)/E(B-V)=0.83+0.02*E(B-V), implying a value of R=Av/E(B-V)~2.8 for the associated dust. Alessi 95 has a mean reddening of E(B-V)_(B0)=0.35+-0.02 s.e., an intrinsic distance modulus of Vo-Mv=8.16+-0.04 s.e. (+-0.21 s.d.), d=429+-8 pc, and an estimated age of 10^8.2 yr from ZAMS fitting of available UBV, CCD BV, NOMAD, and 2MASS JHKs observations of cluster stars. SU Cas is a likely cluster member, with an inferred space reddening of E(B-V)=0.33+-0.02 and a luminosity of =-3.15+-0.07 s.e., consistent with overtone pulsation (P_FM=2.75 d), as also implied by the Cepheid's light curve parameters, rate of period increase, and Hipparcos parallaxes for cluster stars. There is excellent agreement of the distance estimates for SU Cas inferred from cluster ZAMS fitting, its pulsation parallax derived from the infrared surface brightness technique, and Hipparcos parallaxes, which all agree to within a few percent.Comment: Accepted for Publication (MNRAS

Continuously observing a dynamically decoupled spin-1 quantum gas

We continuously observe dynamical decoupling in a spin-1 quantum gas using a weak optical measurement of spin precession. Continuous dynamical decoupling aims to dramatically modify the character and energy spectrum of spin states to render them insensitive to parasitic fluctuations. Continuous observation measures this new spectrum in a single-preparation of the quantum gas. The measured time-series contains seven tones, which spectrogram analysis parses as splittings, coherences, and coupling strengths between the decoupled states in real-time. With this we locate a regime where a transition between two states is decoupled from magnetic field instabilities up to fourth order, complementary to the parallel work at higher fields by Trypogeorgos et al. (arXiv:1706.07876). The decoupled microscale quantum gas offers magnetic sensitivity in a tunable band, persistent over many milliseconds: the length scales, frequencies, and durations relevant to many applications, including sensing biomagnetic phenomena such as neural spike trains.Comment: 5+ pages, 4 figures, 1 table; revised citation of Trypogeorgos et al. (2017

Diversity and Community Structure of Stream Insects in a Minimally Disturbed Forested Watershed in Southern Illinois

The Lusk Creek Watershed, located in Pope County, IL, long has been rec- ognized as a high quality area of biological significance, but surveys of the stream macroinvertebrate fauna have been limited. Thus, a survey of the benthic insect community at 11 sites in the upper portion of Lusk Creek was conducted from May 2003 to April 2005. A total of 20,888 specimens, mostly immatures, were examined during the study and represented eight orders. The Diptera, by far, was the most abundant order, with 18,590 specimens, almost all of which were members of the Chironomidae or Simuliidae. Members of the EPT (Ephemer- optera, Plecoptera, Trichoptera) contributed 1,550 specimens. The Coleoptera was represented by 647 specimens, most of which were members of Stenelmis (Elmidae) (n = 612). The Shannon diversity index (H ́) ranged from 1.07-2.01 for individual sites and was indicative of relatively undisturbed streams in this region. Jackknife analyses of richness estimated that as many as 37 taxa were unobserved in this survey. Results provide information on reference conditions in the region and a foundation for future monitoring

Maxometers (peak wind speed anemometers)

An instrument for measuring peak wind speeds under severe environmental conditions is described, comprising an elongated cylinder housed in an outer casing. The cylinder contains a piston attached to a longitudinally movable guided rod having a pressure disk mounted on one projecting end. Wind pressure against the pressure disk depresses the movable rod. When the wind reaches its maximum speed, the rod is locked by a ball clutch mechanism in the position of maximum inward movement. Thereafter maximum wind speed or pressure readings may be taken from calibrated indexing means

Atmospheric radiation model for water surfaces

An atmospheric correction model was extended to account for various atmospheric radiation components in remotely sensed data. Components such as the atmospheric path radiance which results from singly scattered sky radiation specularly reflected by the water surface are considered. A component which is referred to as the virtual Sun path radiance, i.e. the singly scattered path radiance which results from the solar radiation which is specularly reflected by the water surface is also considered. These atmospheric radiation components are coded into a computer program for the analysis of multispectral remote sensor data over the Great Lakes of the United States. The user must know certain parameters, such as the visibility or spectral optical thickness of the atmosphere and the geometry of the sensor with respect to the Sun and the target elements under investigation

A Machian Model of Dark Energy

Einstein believed that Mach's principle should play a major role in finding a meaningful spacetime geometry, though it was discovered later that his field equations gave some solutions which were not Machian. It is shown, in this essay, that the kinematical $\Lambda$ models, which are invoked to solve the cosmological constant problem, are in fact consistent with Mach's ideas. One particular model in this category is described which results from the microstructure of spacetime and seems to explain the current observations successfully and also has some benefits over the conventional models. This forces one to think whether the Mach's ideas and the cosmological constant are interrelated in some way.Comment: Received an Honorable mention in the Essay Contest-2002 sponsored by the Gravity Research Foundation; A paragraph added on how the model can explain the CMB anisotropy observations; To appear in the Classical and Quantum Gravit