Showing papers in "Virginia journal of science in 2017"
TL;DR: The researchers investigate the speed and the efficiency of these machine learning algorithms in terms of several selected benchmarks such as time to build models, kappa statistic, root mean squared error, accuracy by attack class, and percentage of correctly classified instances of the classifier algorithms.
Abstract: Network security specialists use machine learning algorithms to detect computer network attacks and prevent unauthorized access to their networks. Traditionally, signature and anomaly detection techniques have been used for network defense. However, detection techniques must adapt to keep pace with continuously changing security attacks. Therefore, machine learning algorithms always learn from experience and are appropriate tools for this adaptation. In this paper, ten machine learning algorithms were trained with the KDD99 dataset with labels, then they were tested with different dataset without labels. The researchers investigate the speed and the efficiency of these machine learning algorithms in terms of several selected benchmarks such as time to build models, kappa statistic, root mean squared error, accuracy by attack class, and percentage of correctly classified instances of the classifier algorithms.
4 citations
TL;DR: This study provides support for the presence of spring and autumn cohorts of the most common small mammal, Sigmodon hispidus (hispid cotton rat), in an old field at its northern limit of distribution on the Atlantic Coast.
Abstract: Department of Biological Sciences, Old Dominion University, Norfolk, VA 23529-0266 (HGS: 15 Fillmore Avenue, Danbury, CT 06811) *Corresponding author: brose@odu.edu ABSTRACT We used monthly live trapping for 2.5 years to evaluate the life-history features of the most common small mammal, Sigmodon hispidus (hispid cotton rat), in an old field at its northern limit of distribution on the Atlantic Coast. Peak densities, achieved in late autumn or early winter, were among the highest recorded for the species and were more typical of geographically marginal populations rather than of central ones. Unlike some other marginal populations, hispid cotton rats in southeastern Virginia did not lose significant body mass over the winter (when few juveniles were present) and survival in winter was not significantly different from that of other seasons, perhaps due to the moderating effects on winter temperatures of the nearby Atlantic Ocean and Chesapeake Bay. Our study provides support for the presence of spring and autumn cohorts, with long-lived animals being drawn almost entirely from the latter. INTRODUCTION Sigmodon hispidus Say and Ord (hispid cotton rat), a 100-g herbivorous rodent, is the sole member of a tropical genus broadly distributed across the southern US, for which the northward expansion of its distributional range into the central states and along the
2 citations
TL;DR: The Ordinary Least Squares (OLS) regression model suggested moisture conditions late in the growing season of the previous year and current year had a significant positive influence on the growth of T. occidentalis, and maximum temperature in March of the current year negatively influenced the growth.
Abstract: Understanding the geographic range and growth of species is essential for effective land management in a landscape affected by anthropogenic activity and climate change. Climate change is expected to alter the distribution and growth of many tree species in eastern North America, including northern white cedar (Thuja occidentalis L.). This research examined the effects of climate on radial growth of T. occidentalis in disjunct populations south of its continuous range margin in eastern North America. A T. occidentalis tree-ring chronology was developed and examined for growth-climate interactions. Mean sensitivity of the T. occidentalis chronology was within the range of values reported for the species in northern portions of its range. Significant positive correlations existed between the T. occidentalis chronology and moisture variables late in the growing season of the previous year and current year. The relationship between the T. occidentalis chronology and temperature was more variable with significant positive and negative correlations throughout the previous year and current year. The Ordinary Least Squares (OLS) regression model suggested moisture conditions late in the growing season of the previous year and current year had a significant positive influence on the growth of T. occidentalis. In contrast, maximum temperature in March of the current year negatively influenced the growth of T. occidentalis. While the mean sensitivity of T. occidentalis appears similar throughout its range, there is geographic variability in the climate-growth response of T. occidentalis. More research is necessary to expand the scope of our knowledge concerning T. occidentalis growth throughout its range.
2 citations
TL;DR: This work describes an erythristic morph of P. cinereus collected at Mountain Lake Biological Station, Virginia, which is a mimetic morph with coloration patterns similar to that of toxic Eastern Newt efts.
Abstract: Eight different color polymorphisms of the Red-backed Salamander (Plethodon cinereus) have been described throughout its range. Among them, the erythristic phenotype is a mimetic morph with coloration patterns similar to that of toxic Eastern Newt efts (Notophthalmus viridescens). We describe an erythristic morph of P. cinereus collected at Mountain Lake Biological Station, Virginia. To our knowledge, there are no prior published records of this morph in Virginia.