Gamma-Ray Bursts Detected From BATSE DISCLA Data

We have searched for gamma-ray bursts (GRB) in the BATSE DISCLA data covering the period TJD 8365-10528. We employ an algorithm that uses the background both before and after the onset of the burst, and that requires an excess of at least 5 sigma over background in the energy range 50-300 keV. For the initial set of 7536 triggers, we find strong concentrations at given geographic locations of the satellite. After excluding these geographic areas, we are left with 4485 triggers. We exclude triggers close in position to solar flares, CygX-1, and Nova Persei 1992 when active, as well as soft bursts close to the sun. We accept 1018 triggers that occur within 230 sec of a GRB listed in the BATSE catalog, and upon visual inspection classify 881 triggers as magnetospheric events and 404 as GRBs. The final sample of 1422 GRBs represents effectively 2.0 years of isotropic exposure, for an annual rate of 710 GRBs per year.Comment: 4 pages, 3 figures, Astronomy & Astrophysics Suppl. Ser. in press, proceedings of the Workshop "Gamma Ray Bursts in the Afterglow Era" held in Rome, November 199

An improvement in blackbody cavity design

Setting the axis of the conical cavity at an angle to the axis of observation removes the imperfection at the apex of the cone from the direct observation area of the radiometer. Fillet no longer behaves as a nonuniformity in the blackbody

Two-stage emitter follower is temperature stabilized

Two-stage temperature stabilized circuit using two transistors is described. Increase in temperature causes the base-to-emitter voltage of n-p-n transistor to become less positive whereas the base-to-emitter voltage of p-n-p transistor becomes less negative, so the temperature-induced variation in V sub 1 and V sub 2 cancel out

Contractions, Removals and How to Certify 3-Connectivity in Linear Time

It is well-known as an existence result that every 3-connected graph G=(V,E) on more than 4 vertices admits a sequence of contractions and a sequence of removal operations to K_4 such that every intermediate graph is 3-connected. We show that both sequences can be computed in optimal time, improving the previously best known running times of O(|V|^2) to O(|V|+|E|). This settles also the open question of finding a linear time 3-connectivity test that is certifying and extends to a certifying 3-edge-connectivity test in the same time. The certificates used are easy to verify in time O(|E|).Comment: preliminary versio

Standards, Innovation Incentives, and the Formation of Patent Pools

Technological standards give rise to a complements problem that affects pricing and innovation incentives of technology producers. In this paper I discuss how patent pools can be used to solve these problems and what incentives patent holders have to form a patent pool. I offer some suggestions how competition authorities can foster the formation of welfare increasing patent pools