Small Number Of Classes Research Articles

Effects of Particle Size Distribution on the Kinetics of Hydration of Tricalcium Silicate

An analysis of the validity of approximating selected particle size distributions by small numbers of size classes was carried out. It was determined that the selection of a small number of particle size classes is not adequate to describe a particle size distribution. One consequence of this is that the particle size distribution, if not properly accounted for, can mask the kinetics of a hydration process. The hydration rates of two finnesses of tricalcium silicate, each with known particle size distributions, were measured by isothermal calorimetry for a period of 28 d. These data were integrated, normalized, and represented as α‐time curves as a basis for comparison with kinetic models of hydration. Agreement with kinetic models was found to be strongly influenced by the effect of particle size distribution. However, the rate‐limiting mechanisms appear to be independent of particle size distribution No single kinetic model was adequate to describe C3S hydration over the first 28 d. A kinetic model that assumes initial surface‐area control with diffusion control dominating subsequently provided an excellent fit to the experimental data.

Cloud cover distribution in Indonesia

Abstract Indonesian spatio-temporal cloud cover distribution was quantified to allow planners to forecast probabilities for remote sensing data acquisition. The original data consisted of four randomly chosen Geostationary Meteorological Satellite displays per month from 1981 to 1985, which were analysed with a microcomputer after a 1 °15'pixel size digitization. Iterative interactive factorial analyses combined with a parallelepiped classifier clustered data by grouping pixels with similar profiles. For all classes, pixel profiles were linearly combined to provide a small number of classes with high pixel-class correlations. A 0–7 correlation threshold led to 18 classes for all land areas. Statistics of Landsat and SPOT images, grouped by class, were used to verify, calibrate and improve class profiles. This led to quantified temporal profiles of probability of acquiring remotely-sensed data with a given cloud cover percentage for any Indonesian land and marine area.

Canonical structures for the hypervariable regions of immunoglobulins

We have analysed the atomic structures of Fab and V L fragments of immunoglobulins to determine the relationship between their amino acid sequences and the three-dimensional structures of their antigen binding sites. We identify the relatively few residues that, through their packing, hydrogen bonding or the ability to assume unusual φ, ψ or ω conformations, are primarily responsible for the main-chain conformations of the hypervariable regions. These residues are found to occur at sites within the hypervariable regions and in the conserved β-sheet framework. Examination of the sequences of immunoglobulins of unknown structure shows that many have hypervariable regions that are similar in size to one of the known structures and contain identical residues at the sites responsible for the observed conformation. This implies that these hypervariable regions have conformations close to those in the known structures. For five of the hypervariable regions, the repertoire of conformations appears to be limited to a relatively small number of discrete structural classes. We call the commonly occurring main-chain conformations of the hypervariable regions “canonical structures”. The accuracy of the analysis is being tested and refined by the prediction of immunoglobulin structures prior to their experimental determination.

Simple groups with a small number of conjugacy classes

All finite non-Abelian simple groups whose number of conjugacy classes does not exceed 10 are computed (with application of a computer).

Summarizing and propagating uncertain information with triangular norms

A wide variety of numerical or symbolic approaches to reasoning with uncertainty have been proposed in the artificial intelligence (AI) literature. This article postulates a list of desiderata that any such formalism should try to satisfy. The author then proposes a new approach to reasoning with uncertainty, which is organized in three layers: representation, inference, and control. In the representation layer the structure required to capture information used in the inference layer and meta-information used in the control layer are described. In this structure, numerical slots take values on linguistic term sets with fuzzy-valued semantics. These term sets capture the input granularity usually provided by users or experts. In the inference layer a large number of uncertainty calculi based on triangular norms (T-norms), intersection operators whose truth functionality entails low computational complexity, are described. It is shown that for a common negation operator, the selection of a T-norm uniquely and completely describes an uncertainty calculus. Previous experiments have determined the existence of a small number of equivalence classes among the uncertainty calculi (as a function of the input granularity). This property drastically reduces the number of different combining rules to be considered. In the control layer the policy selection for the different calculi used in the inference layer, based on their meanings, properties, and contextual information, is specified. Conflicts and ignorance measurements are also defined. The proposed formalism is compared against the requirements of the desiderata and contrasted with existing schemes for reasoning with uncertainty.

A Lower Bound for the Class Number of Certain Cubic Number Fields

Let K be a cyclic number field with generating polynomial X3 a 3 32 - a + 3 X - 1 2 2 and conductor m. We will derive a lower bound for the class number of these fields and list all such fields with prime conductor m = (a2 + 27)/4 or m = (1 + 27b2)/4 and small class number. 1. Introduction. Let h.,, denote the class number of the cyclotomic field Q(,m), and h +, the class number of its maximal real subfield Q(cos(2T/m)). It is a well-known conjecture of Vandiver that p + h+ holds for all primes p E P. This is a customary assumption for proving the second case of Fermat's Last Theorem (for more details see Washington (16)). Since h+ grows slowly (h+ = 1 for p 1 the exact value of h + is known without using GRH. Masley suggested that P P perhaps h + 1. Using the quadratic subfield, Ankeny, Chowla and Hasse (1) showed that h + > 1 if p belongs to certain quadratic sequences in N, and S.-D. Lang (9) and Takeuchi (15) found more such sequences. Similar results were

A lower bound for the class number of certain cubic number fields

Let K be a cyclic number field with generating polynomial \[ X 3 − a − 3 2 X 2 − a + 3 2 X − 1 {X^3} - \frac {{a - 3}}{2}{X^2} - \frac {{a + 3}}{2}X - 1 \] and conductor m. We will derive a lower bound for the class number of these fields and list all such fields with prime conductor m = ( a 2 + 27 ) / 4 m = ({a^2} + 27)/4 or m = ( 1 + 27 b 2 ) / 4 m = (1 + 27{b^2})/4 and small class number.

The mosaic genome of warm-blooded vertebrates.

Most of the nuclear genome of warm-blooded vertebrates is a mosaic of very long (much greater than 200 kilobases) DNA segments, the isochores; these isochores are fairly homogeneous in base composition and belong to a small number of major classes distinguished by differences in guanine-cytosine (GC) content. The families of DNA molecules derived from such classes can be separated and used to study the genome distribution of any sequence which can be probed. This approach has revealed (i) that the distribution of genes, integrated viral sequences, and interspersed repeats is highly nonuniform in the genome, and (ii) that the base composition and ratio of CpG to GpC in both coding and noncoding sequences, as well as codon usage, mainly depend on the GC content of the isochores harboring the sequences. The compositional compartmentalization of the genome of warm-blooded vertebrates is discussed with respect to its evolutionary origin, its causes, and its effects on chromosome structure and function.

Gauss’ class number problem for imaginary quadratic fields

a result first proved by Heilbronn [H] in 1934. The Disquisitiones also contains tables of binary quadratic forms with small class numbers (actually tables of imaginary quadratic fields of small class number with even discriminant which is a much easier problem to deal with) and Gauss conjectured that his tables were complete. In modern parlance, we can rewrite Gauss’ tables (we are including both even and odd discriminants) in the following form.

An approximation technique for central server queueing models with a priority dispatching rule

Abstract An approximation technique to solve central server queueing models with a priority dispatching rule is described in this paper. This technique reduces the problem size by aggregating I/O activities and combining different classes into a smaller number of classes, so that the reduced problem can be solved numerical examples considered, throughputs and mean CPU queue sizes calculated by the approximation differ from simulation results by less than 15 percent.

An approximation technique for central server queueing models with a priority dispatching rule

An approximation technique to solve central server queueing models with a priority dispatching rule is described in this paper. This technique reduces the problem size by aggregating I/O activities and combining different classes into a smaller number of classes, so that the reduced problem can be solved numerical examples considered, throughputs and mean CPU queue sizes calculated by the approximation differ from simulation results by less than 15 percent.

Generation of F contours for English sentences from partially specified fundamental frequency templates

English sentences are assigned to a small number of intonational classes. Each class has an associated fundamental frequency template, which characterizes the F0 contour by specifying up to two frequency points per word—typically a peak frequency and a final frequency. The F0 contour for a particular sentence is elaborated by cubic polynomial interpolation of the template's frequency points, fixed in time by the actual durations of the words of the sentence. Similar sentences with different numbers of words can be assigned to the same intonational class if short phrases are described by a single pair of frequency points, which are then algorithmically elaborated. In a practical application the name of a template is stored with the text of a sentence, and the spoken sentence is synthesized by applying the template to the sequence of LPC-encoded words in real time. A demonstration tape will be played.

Endogenous type C retroviral sequences of mice are organized in a small number of virus-like classes and have been acquired recently.

We studied endogenous type C virus-related sequences of mice by annealing Moloney murine leukemia virus DNA to agarose gel blot transfers of uninfected mouse cell DNA which had been cleaved with restriction enzymes. We found that many of the endogenous murine leukemia virus-related sequences in mice consist of two organizational classes that are integrated into many different loci. Both of these classes resemble standard murine leukemia virus proviral DNA in both size and sequence organization. All lines of inbred mice examined contained both organizational classes, as did feral isolates of Mus musculus domesticus. However, a related Asian subspecies, Mus musculus molossinus, contained different organizational classes of endogenous murine leukemia virus-related sequences. Among inbred strains and feral isolates of M. musculus domesticus, the murine leukemia virus-related sequences were present at different loci. This suggested that most of these sequences were acquired relatively recently during subspeciation and inbreeding.

Evaluation of a Linear Type Program in Holsteins

Data of 18 traits in the linearized type appraisal program of Midwest Breeders Cooperative were analyzed. Mean scores ranged from 25.1 to 32.8, with scoring 1 to 50, except for disposition (mean 2.0 and scoring 1 to 3) and milkout (mean 2.1 and scoring 1 to 4). Parity, sire, and stage of lactation were sources of variation for most traits. Evaluator by parity interaction, which indicated differential age adjustment by evaluators, was a source of variation for basic form, strength, udder depth, and rear udder width. Heritabilities ranged from .07 for disposition to .67 for basic form, with most greater than .25. Heritabilities were similar to but slightly larger than estimates reported for a scoring system based on a small number of nonlinear classes. Basic form with strength, rear udder height with rear udder width, and teats with median suspensory ligament had genetic correlations in excess of .90. Phenotypic correlations were often small (<.10), possibly because of scoring linearly versus in relation to an ideal. Type appraisal on a linear basis is recommended over scoring in relation to an ideal because heritabilities of linear traits were slightly larger and correlations between linearly scored traits are interpreted easily.

The Northernmost Population of Podarcis muralis (Lacertilia, Lacertidae)

Abstract In a one year study we collected ecological data of the northernmost population of P. muralis in Maastricht (50° 51' N. Lat. in the Netherlands). This population consisted of about 100 adult lizards. It was probably definitely divided in two subpopulations situated close to each other which were subdivided into 5 and 2 colonies respectively, between which there was no or hardly any exchange. Sex ratio did not significantly differ from 1.0. Compared with the wall lizards of more southern populations they were found to be rather small and to grow more slowly. The age structure of the population was out of balance on account of the small numbers of some younger year classes. Only good, i.e. warmer years are likely to enable a reasonable reproduction success. The total period of activity does not differ from that in more southern regions but the reproduction period is clearly retarded and the incubation period of eggs is distinctly longer. The frequent partial reproduction failure is probably compensated by a rather high longevity, which, however, renders the population very sensitive to each factor that increases mortality. The animals have home ranges of 15-25 m2 (no significant differences between sexes) and they have a considerable home range overlap. These home range sizes do not differ from those in more southern regions but the overlaps are much more frequent and therefore it can be concluded that there is a strong concentration on ecologically suitable and spatially very restricted spots. From a list of prey species based on faeces analysis P. muralis appears to be a non-selective feeder. On two adult specimens we found the acarine ectoparasite Ophionyssus lacertinus.

Variability of the tropical oceans

The western tropical Atlantic Ocean is a very energetic and highly variable region. It is one of the main contributors to the inter-hemispheric mass and heat transports. This study aim is to give a new picture of the space and time variability of this region using statistical tools applied to five different satellite measurements (Sea Surface Temperature, Sea Surface Salinity, ocean topography, wind stress vectors). We first processed each data set by using a Self-Organizing Maps (SOM), which is an efficient clustering methodology based on non-linear artificial neural networks to compress the information embedded in the data. The SOM was then combined with a Hierarchical Ascendant Classification (HAC) to cluster the different phenomena in a small number of classes whose physical characteristics are easy to identify. Three classes were identified which allowed us to analyse the dynamics of the North Brazil Current, and the North Equatorial Countercurrent, respectively, and their links with the Inter-Tropical Convergence Zone and the Amazon and Orinoco river runoffs. The SOM + HAC analysis gave a coherent picture of the concomitant seasonal variability of the variables. Furthermore, we were able to point out the correlations existing between salinity features recently discovered and wind, temperature, and dynamic topography structures. Applying our method to the interannual signals, we showed a year to year variability which deserves further analysis.

Patterns of integration of viral dna sequences in the genomes of adenovirus type 12-transformed hamster cells

The patterns of integration of the viral genome have been analyzed in four hamster cell lines transformed by adenovirus type 12 (Ad12). It has previously been shown that in each of the cell lines HA12/7, T637, A2497-2 and A2497-3, the viral genome persists in multiple copies, and that different parts of the viral DNA are represented non-stoichiometrically ( Fanning and Doerfler, 1976). All four cell lines are oncogenic when injected into hamsters. The DNA from each of the cell lines was extracted and cleaved in different experiments with restriction endonucleases Bam HI, Bgl II, Eco RI, Hind III, Hpa II or Sma I. The DNA fragments were separated on 1% agarose slab gels and transferred to nitrocellulose filters by the Southern technique. Ad12 DNA sequences were detected by hybridization to Ad12 DNA, which was 32P-labeled by nick translation, and by subsequent autoradiography. In some experiments, the 32P-labeled Eco RI restriction endonuclease fragments of Ad12 DNA were used to investigate the distribution of specific segments of the viral genome in the cellular DNA. For each cell line, a distinct and specific pattern of integrated viral DNA sequences is observed for each of the restriction endonucleases used. Moreover, viral sequences complementary to the isolated Eco RI restriction endonuclease fragments are also distributed in patterns specific for each cell line. There are striking differences in integration patterns among the four different lines; there are also similarities. Because the organization of cellular genes in virus-transformed as compared to normal cells has not yet been determined, conclusions about the existence or absence of specific integration sites for adenovirus DNA appear premature. Analysis of the integration patterns of Ad12 DNA in the four hamster lines investigated reveals that some of the viral DNA molecules are fragmented prior to or during integration. Analysis with specific restriction endonuclease fragments demonstrates that the Eco RI B, D and E fragments, comprising a contiguous segment from 0.17–0.62 fractional length units of the viral DNA, remain intact during integration in a portion of the viral DNA molecules. Although each cell line carries multiple copies of Ad12 DNA, the viral DNA sequences are concentrated in a small number of distinct size classes of fragments. This finding is compatible with, but does not prove, the notion that at least a portion of the viral DNA sequences is integrated into repetitive sequences, or else that the integrated viral sequences have been amplified after integration. In the three cell lines which were tested, the integration pattern is stable over many generations, with continuous passage-twice weekly-of cells for 6–7 months. In the three cell lines which were examined, the integration pattern is identical in a number of randomly isolated clones. Hence it can be concluded that the patterns of integration are identical among all cells in a population of a given line of transformed cells.

Automatic interpretation of infrared aerial color photographs of citrus orchards having infestations of insect pests and diseases

This paper describes a system designed to analyze aerial color infrared photographs of citrus orchards. The input to the system is a 35-mm transparency of the infrared aerial photograph mounted in a three-color film digitizer which is controlled by an XDS 930 computer. An algorithm locates the outline of each individual tree in the photograph and then cluster analysis is applied. For the trees of a transparency, the center of gravity (CG) of the set of trees is determined and then the distance of each individual tree from CG is computed by using an empirical distance function which we have derived. Sorting, performed on the basis of the computed distances, clusters the trees. The cluster identifying algorithm separates out the individual clusters which are then grouped together into a smaller number of classes by applying the same algorithm. Fifteen transparencies having mealybugs, brown soft scale, gummosis, and root rot infestations were analyzed and experimental results show very satisfactory classification of the infestations.

Small Class Numbers and Extreme Values of L-Functions of Quadratic Fields

Small Class Numbers and Extreme Values of L-Functions of Quadratic Fields

Algebraic function fields with small class number

It is proved that there is no congruence function field of genus 4 over GF(2) which has no prime of degree less than 4 and precisely one prime of degree 4. This shows the nonexistence of function fields of genus 4 with class number one and gives an example of an isogeny class of abelian varieties which contains no jacobian. It is shown that, up to isomorphism, there are two congruence function fields of genus 3 with class number one. It follows that there are seven nonisomorphic function fields of genus different from zero with class number one. Congruence function fields with class number 2 are fully classified. Finally, it is proved that there are eight imaginary quadratic function fields FK(x) for which the integral closure of K[x] in F has class number 2.