In order to improve bitrates of lossless JPEG 2000, we propose to modify the discrete wavelet transform (DWT) by skipping selected steps of its computation. We employ a heuristic to construct the skipped steps DWT (SS-DWT) in an image-adaptive way and define fixed SS-DWT variants. For a large and diverse set of images, we find that SS-DWT significantly improves bitrates of non-photographic images. From a practical standpoint, the most interesting results are obtained by applying entropy estimation of coding effects for selecting among the fixed SS-DWT variants. This way we get the compression scheme that, as opposed to the general SS-DWT case, is compliant with the JPEG 2000 part 2 standard. It provides average bitrate improvement of roughly 5% for the entire test-set, whereas the overall compression time becomes only 3% greater than that of the unmodified JPEG 2000. Bitrates of photographic and non-photographic images are improved by roughly 0.5% and 14%, respectively. At a significantly increased cost of exploiting a heuristic, selecting the steps to be skipped based on the actual bitrate instead of an estimated one, and by applying reversible denoising and lifting steps to SS-DW
This is a survey written in 2000 about upper chromatic numbers
The Nasdaq Composite fell another $\approx 10 %$ on Friday the 14'th of April 2000 signaling the end of a remarkable speculative high-tech bubble starting in spring 1997. The closing of the Nasdaq Composite at 3321 corresponds to a total loss of over 35% since its all-time high of 5133 on the 10'th of March 2000. Similarities to the speculative bubble preceding the infamous crash of October 1929 are quite striking: the belief in what was coined a ``New Economy'' both in 1929 and presently made share-prices of companies with three digits price-earning ratios soar. Furthermore, we show that the largest draw downs of the Nasdaq are outliers with a confidence level better than 99% and that these two speculative bubbles, as well as others, both nicely fit into the quantitative framework proposed by the authors in a series of recent papers.
SIMPLE 2000 (Superheated Instrument for Massive ParticLE searches) will consist of an array of eight to sixteen large active mass ($\sim15$ g) Superheated Droplet Detectors(SDDs) to be installed in the new underground laboratory of Rustrel-Pays d'Apt. Several factors make of SDDs an attractive approach for the detection of Weakly Interacting Massive Particles (WIMPs), namely their intrinsic insensitivity to minimum ionizing particles, high fluorine content, low cost and operation near ambient pressure and temperature. We comment here on the fabrication, calibration and already-competitive first limits from SIMPLE prototype SDDs, as well as on the expected immediate increase in sensitivity of the program, which aims at an exposure of $>$25 kg-day during the year 2000. The ability of modest-mass fluorine-rich detectors to explore regions of neutralino parameter space beyond the reach of the most ambitious cryogenic projects is pointed out.
We present low- and medium resolution spectra of the recurrent nova CI Aquilae taken at 14 epochs in May and June, 2000. The overall appearance is similar to other U Sco-type recurrent novae (U Sco, V394 CrA). Medium resolution (R=7000-10000) hydrogen and iron profiles suggest an early expansion velocity of 2000-2500 km/s. The Hαevolution is followed from Dt = -0.6 d to +53 d, starting from a nearly Gaussian shape to a double peaked profile through strong P-Cyg profiles. The interstellar component of the sodium D line and two diffuse interstellar bands put constraints on the interstellar reddening which is estimated to be E(B-V)=0.85\pm0.3. The available visual and CCD-V observations are used to determine t0,t2 and t3. The resulting parameters are: t0=2451669.5\pm0.1, t2=30\pm1 d, t3=36\pm1 d. The recent lightcurve is found to be generally similar to that observed in 1917 with departures as large as 1-2 mag in certain phases. This behaviour is also typical for the U Sco subclass.
Recently, OGLE team have reported clear quasar microlensing signal in Q2237+0305. We have analyzed the microlens event of ``image C'' by using their finely and densely sampled lightcurves. From lightcurve fitting, we can unambiguously set the source size of $\lsim 0.98$ Einstein Ring radius as a conservative limit. This limit corresponds to $2000 {\rm (AU)}$, if we adopt $M_{\rm lens} \sim 0.1M_{\odot}$ obtained by a recent statistical study of mean mass of lens object. This gives a clear evidence for the existence of an accretion disk in the central region of the quasar.
This summary of the working group 2 of DIS 2000 encompasses experimental and theoretical results of jet physics, open and bound state heavy flavour production, prompt photon production, next-to-leading order QCD calculations and beyond, instantons, fragmentation, event shapes, and power corrections, primarily from deep-inelastic scattering and photoproduction at HERA, but also from the LEP and Tevatron colliders.
The Advanced Accelerator Concepts 2000 (AAC2K) Workshop was held in Santa Fe in June, 2000, and included a wide array of conceptual and theoretical advances at the frontier of accelerator physics. This paper reviews the highlights of the workshop, with subjects ranging from acceleration using lasers, plasmas and microstructures, to the beam physics of muon colliders. Particular emphasis is given to the topics which are relevant to research at existing linear accelerator facilities, and the effect of this research on the capabilities of such facilities.
Over the past decades automated debugging has seen major achievements. However, as debugging is by necessity attached to particular programming paradigms, the results are scattered. The aims of the workshop are to gather common themes and solutions across programming communities, and to cross-fertilize ideas. AADEBUG 2000 in Munich follows AADEBUG'93 in Linkoeping, Sweden; AADEBUG'95 in Saint Malo, France; AADEBUG'97 in Linkoeping, Sweden.
We developed a new technology for global detection of atmospheric disturbances, on the basis of phase measurements of the total electron content (TEC) using an international GPS networks. Temporal dependencies of TEC are obtained for a set of spaced receivers of the GPS network simultaneously for the entire set of visible satellites. These series are subjected to filtering in the selected range of oscillation periods using known algorithms for spatio-temporal analysis of signals. An "instantaneous" ionospheric response to the sudden commencement of a strong magnetic storm of April 6, 2000 was detected. On the dayside of the Earth the largest value of the net response amplitude was found to be of order 0.8*10^16 m^-2 (1--2 % of the background TEC value), and the delay with respect to the SC in mid-latitudes was about 200 s. In higher latitudes the delay goes as long as 15 min. On the nightside these values are 0.2*10^16 m^-2 and 30 min, respectively. The velocity of the traveling disturbance from the middle to high latitudes on the dayside as well as from the dayside to the nightside was about 10-20 km/s.
We describe the discovery circumstances and photometric properties of 2000 EB173, now one of the brightest trans-Neptunian objects (TNOs) with opposition magnitude m_R=18.9 and also one of the largest Plutinos, found with the drift-scanning camera of the QUEST Collaboration, attached to the 1-m Schmidt telescope of the National Observatory of Venezuela. We measure B-V = 0.99 +/- 0.14 and V-R = 0.57 +/- 0.05, a red color observed for many fainter TNOs. At our magnitude limit m_R = 20.1 +/- 0.20, our single detection reveals a sky density of 0.015 (+0.034, -0.012) TNOs per deg^2 (the error bars are 68% confidence limits), consistent with fainter surveys showing a cumulative number proportional to 10^0.5m_R. Assuming an inclination distribution of TNOs with FWHM exceeding 30 deg, it is likely that one hundred to several hundred objects brighter than m_R=20.1 remain to be discovered.
This document is a summary of the physics research carried out by the Nuclear Theory Group at the University of Washington during the last twelve-month period, 1999-2000.
In April 2000 the single bunch energy spread, bunch length, horizontal emittance, and vertical emittance were measured as functions of current in KEK's ATF damping ring. In this report the measurement results are analyzed in light of intrabeam scattering theory. The measurements are found to be relatively consistent with theory, although the measured effects appear to be stronger than theory. In addition, the factor of 3 growth in vertical emittance at a current of 3 mA does not seem to be supported.
A new, very forward proton spectrometer (VFPS) with large acceptance is proposed to be installed in the proton beam of the H1 experiment after the luminosity upgrade in the year 2000. The spectrometer, located at 220 m downstream of the interaction point is based on the Roman Pot technique and consists of two stations situated in the cold section of the proton beam line. Physics motivations and a brief description of the proton spectrometer are presented.
We summarize the experimental and theoretical results presented in the "Physics at the Highest Q^2 and p^2_t" working group at the DIS 2000 Workshop. High Q^2 and p^2_t processes measured at current and future colliders allow to improve our knowledge of Standard Model (SM) physics, by providing precise measurements of the SM parameters and, consequently, consistency checks of the SM. Moreover, they give information on key quantities for the calculation of the SM expectations in a yet unexplored domain, such as the parton densities of the proton or the photon. In addition to these experimental inputs, higher-order calculations are also needed to obtain precise expectations for SM processes, which are a key ingredient for the searches for new phenomena in high Q^2 and p^2_t processes at current and future experiments. The experimental and theoretical status of SM physics at high Q^2 and p^2_t is reviewed in the first part of this summary, with the remaining being dedicated to physics beyond the Standard Model.
We give here a compilation of papers presented at Lattice 2000 (XVIII Intl. Symposium on Lattice Field Theory, Bangalore, India, 17-22 August 2000). The table of contents provides links to papers on the e-print arXiv.
This review is based on lectures on technicolor and extended technicolor presented at the Frascati Spring School in May 2000. I summarize the motivation and structure of this theory of dynamical breaking of electroweak and flavor symmetries. Particular attention is paid to the main phenomenological obstacles to this picture-flavor-changing neutral currents, precision electroweak measurements, and the large top-quark mass-and their proposed resolutions-walking technicolor and topcolor-assisted technicolor. I then discuss the signatures for technicolor and the existing and upcoming searches for them at LEP, the Tevatron Collider, and the Large Hadron Collider. The final section lists some outstanding theoretical questions.
We describe the CoNLL-2000 shared task: dividing text into syntactically related non-overlapping groups of words, so-called text chunking. We give background information on the data sets, present a general overview of the systems that have taken part in the shared task and briefly discuss their performance.
Observational data on the bursting activity of all five known Soft Gamma Repeaters are presented. This information was obtained with Konus gamma-ray burst experiments on board Venera 11-14, Wind, and Kosmos-2326 spacecraft in the period from 1978 to 2000. These data on appearance rates, time histories, and energy spectra of repeated soft bursts obtained with similar instruments and collected together in a comparable form should be useful for further studies of SGRs. (available at http://www.ioffe.rssi.ru/LEA/SGR/Catalog/).
The 3x+1 problem concerns iteration of the map T(n) =(3n+1)/2 if n odd; n/2 if n even. The 3x +1 Conjecture asserts that for every positive integer n>1 the forward orbit of n includes the integer 1. This paper is an annotated bibliography of work done on the 3x+1 problem published from 2000 through 2009, plus some later papers that were preprints by 2009. This is a sequel to an annotated bibliography on the 3x+1 problem covering 1963-1999. At present the 3x+1 Conjecture remains unsolved.