Forecasting Call Centre Arrivals

This article presents a novel neural network?based approach to the intra?day forecasting of call arrivals in call centres. We apply the method to individual time series of arrivals for different customer call groups. To train the model, we use historical call data from three months and, for each day, we aggregate the call volume in 288 intervals of 5 minutes. With these data, our method can be used for predicting the call volume in the next 5?minute interval using either previous real data or previous predictions to iteratively produce multi?step?ahead forecasts. We compare our approach with other conventional forecasting techniques. Experimental results provide factual evidence in favour of our approach. Copyright © 2013 John Wiley & Sons, Ltd.     

On the Uniqueness of the Selection Criterion in Neighbor-Joining

The Neighbor-Joining (NJ) method of Saitou and Nei is the most widely used distance based method in phylogenetic analysis. Central to the method is the selection criterion, the formula used to choose which pair of objects to amalgamate next. Here we analyze the NJ selection criterion using an axiomatic approach. We show that any selection criterion that is linear, permutation equivariant, statistically consistent and based solely on distance data will give the same trees as those created by NJ.     

Twisted plasma waves driven by twisted ponderomotive force

We present the results of twisted plasma waves driven by twisted ponderomotive force. With the beating of two, co-propagating, Laguerre-Gaussian (LG) orbital angular momentum (OAM) laser pulses with different frequencies and also different twist indices, we can obtain the twisted ponderomotive force. Three-dimensional particle-in-cell simulations are used to demonstrate the twisted plasma waves driven by lasers. The twisted plasma waves have an electron density perturbation with a helical rotating structure. Different from the predictions of the linear fluid theory, the simulation results show a nonlinear rotating current and a static axial magnetic field. Along with the rotating current is the axial OAM carried by particles in the twisted plasma waves. A detailed theoretical analysis of twisted plasma waves is also given.     

Changes in Mule Deer Size in Utah

Trends in age-specific, eviscerated carcass weights were determined for hunter-harvested yearling and two-year-old buck mule deer. Carcass weights declined over an 11-year period from two areas of similar management, but with independenly collected data sets. Carcass weights also declined between the opening and second weekends of the hunt. Management implications are discussed.     

Knowledge transfer in agent-based computational social science

This article addresses knowledge transfer dynamics in agent-based computational social science. The goal of the text is twofold. First, it describes the tensions arising from the convergence of different disciplinary traditions in the emergence of this new area of study and, second, it shows how these tensions are dealt with through the articulation of distinctive practices of knowledge production and transmission. To achieve this goal, three major instances of knowledge transfer dynamics in agent-based computational social science are analysed. The first instance is the emergence of the research field. Relations of knowledge transfer and cross-fertilisation between agent-based computational social science and wider and more established disciplinary areas: complexity science, computational science and social science, are discussed. The second instance is the approach to scientific modelling in the field. It is shown how the practice of agent-based modelling is affected by the conflicting coexistence of shared methodological commitments transferred from both empirical and formal disciplines. Lastly, the third instance pertains internal practices of knowledge production and transmission. Through the discussion of these practices, the tensions arising from converging dissimilar disciplinary traditions in agent-based computational social science are highlighted.     

Habitat evaluation procedure for Rocky Mountain bighorn sheep in the Intermountain West

Several habitat evaluation procedures have been developed for bighorn sheep. However, none of these procedures specifically addresses the Rocky Mountain subspecies nor analyzes both the quantity and quality of potential bighorn habitat with regard to minimum viable population (MVP) criteria. This bighorn habitat evaluation procedure combines (1) a quantitative assessment of bighorn range to determine if there are adequate quantities of resources to support an MVP of bighorn sheep, and (2) a qualitative assessment of a range to predict the probable density of bighorns the range can support. Extensive literature review, intensive bighorn research, and a modeling tool, pattern recognition (PATREC), facilitate critical analysis of proposed bighorn reintroduction sites. The resultant stepwise approach to bighorn habitat evaluation enhances the ability of wildlife biologists to make timely and accurate bighorn habitat assessments.     

Foot loadings and pad and track widths of Yellowstone grizzly bears

I used measurements of grizzly bears ( Ursus arctos horribilis ) from the Yellowstone region, USA, to investigate relationships between widths of foot pads and widths of tracks, foot loading and pad size, incidence of tracks and type of activity, and widths of front-foot pads and gender and age-class. Track width was affected by substrates and increased relative to pad width as sizes of both pads and tracks increased. Foot loading (kg · cm -2 ) did not vary substantially with foot size and so did not explain the proportionately larger tracks of larger animals. Tracks were most commonly associated with feeding activity that entailed excavation of fossorial foods (roots and rodents); they were least common when bears were feeding in the forest, feeding on ungulates, or traveling. Adult males and females could be differentiated by the width of their front-foot pads. Virtually all pads > 14.5 cm wide belonged to adult or large subadult males. The pads of subadult females were most commonly < 12.5 cm wide, whereas those of adult females were most commonly 12.5--14.5 cm wide.     

Black-tailed prairie dog population dynamics at Scotts Bluff National Monument, Nebraska: a 28-year record

Black-tailed prairie dogs, Cynomys ludovicianus, now inhabit a small fraction of their original range in the Great Plains. We monitored a population of black-tailed prairie dogs at Scotts Bluff National Monument, Nebraska, from colonization in 1981 until 2009 (28 years). Colony boundaries were mapped by delineating clip lines and active burrows; population densities were estimated via visual counts. Estimates of total population size revealed 4 distinct periods of changing dynamics: (1) a linear increase, (2) a decline and prolonged depression, (3) an exponential increase, and (4) a period of high variability. Area occupied revealed similar, although less-defined trends, whereas densities fluctuated greatly (8&ndash;80 individuals &middot; ha &ndash;1 ). Even after almost 30 years, this population remains relatively small. Decreases in the population may have been due, in part, to predation by badgers, although sylvatic plague cannot be ruled out. Black-tailed prairie dogs are recognized as keystone grassland species, and attempts are underway to reintroduce them to parts of their historic range. Our data suggest that black-tailed prairie dogs possess high potential for rapid population growth and decline, regardless of colony size. Therefore, either human-assisted or natural dispersal events may be important in establishing colonies in suitable habitat. El perrito de pradera de cola negra, Cynomys ludovicianus, habita en una peque&ntilde;a fracci&oacute;n de su distribuci&oacute;n original en las Grandes Llanuras. Monitoreamos una poblaci&oacute;n de perritos de pradera de cola negra en Scotts Bluff National Monument, Nebraska, por 28 a&ntilde;os, desde la colonizaci&oacute;n en 1981 hasta 2009. Trazamos los l&iacute;mites de las colonias usando de referencia las l&iacute;neas de ramoneo y las madrigueras activas, y estimamos la densidad de las poblaciones mediante un recuento visual. Los estimados de poblaci&oacute;n total revelaron cuatro per&iacute;odos distintos de din&aacute;micas cambiantes: (1) un aumento lineal, (2) una disminuci&oacute;n y depresi&oacute;n prolongada, (3) un aumento exponencial y (4) un per&iacute;odo de alta variabilidad. El &aacute;rea ocupada revel&oacute; tendencias similares, aunque menos definidas, mientras que las densidades fluctuaron mucho (8&ndash;80 individuos &middot; ha &ndash;1 ). A&uacute;n despu&eacute;s de casi 30 a&ntilde;os, esta poblaci&oacute;n permanece relativamente peque&ntilde;a. Los decrementos en la poblaci&oacute;n pueden haber sido provocadas en parte por la depredaci&oacute;n por tejones, aunque no se puede descartar como causa la plaga silv&aacute;tica. El perrito de pradera de cola negra se considera una especie clave de la pradera, y est&aacute;n en proceso esfuerzos por reintroducirlos en partes de su distribuci&oacute;n hist&oacute;rica. Nuestros datos indican que los perritos de pradera de cola negra tienen alto potencial de crecimiento y disminuci&oacute;n de su poblaci&oacute;n, sin importar el tama&ntilde;o de la colonia. Por lo tanto, los eventos de dispersi&oacute;n, ya sean naturales o con asistencia humana, podr&iacute;an ser importantes para establecer colonias en h&aacute;bitats adecuados.     

Caddisfly (Trichoptera) assemblages along major river drainages in Arizona

Seventy-two caddisfly species in 36 genera and 15 families were collected along the Little Colorado, Verde, Gila, and Colorado rivers in Arizona. Brachycentrids, hydropsychids, limnephilids, and uenoids made up nearly 50% of the assemblage in forested sites above 2200 m. Hydropsychids, hydroptilids, and leptocerids made up 75% of the assemblage in grassland watersheds between 2200 and 1000 m, and 80% at sites below 1000 m in desert watersheds. Species richness averaged 16 at sites above 2200 m elevation, 7 between 2200 and 1000 m, and 3 below 1000 m. H' diversity was typically >3 at sites above 2200 m and <2.5 below 2200 m. Each river had distinct faunas likely due to isolation of drainages across semiarid landscapes. Low S&oslash;rensen similarity values were measured for caddisfly assemblages in the highly regulated Colorado River and the other 3 rivers. Only 17 species were collected at 14 sites along 700 km of the Colorado River. Indicator caddisfly species are provided for altered and less disturbed drainages. We added 7 species not previously reported in Arizona for a total of 154 caddisfly species in the state. We provide a baseline of caddisfly indicators for monitoring changes in ecosystem health during the predicted long-term drought and population expansion in southwestern USA.