ns-3 Airborne Network Simulation

Airborne networks, consisting of aircraft-to-aircraft and aircraft-to-ground communications, are critical for future aviation information systems and remote Internet access. A major knowledge gap, however, is the reliability and security challenges of airborne networks in such civilian application domains. Field tests and emulations of airborne networks are expensive undertakings and would be better informed by simulation findings. This paper, hence, reports about a study that aims to simulate airborne networks to understand and characterize their performance and risks. We choose ns-3, an open source network simulation tool, to construct and evaluate airborne networks. We implement 3-D mobility models in ns-3 to capture the realistic movement of aircraft and assess the performance of elemental airborne network configurations in terms of metrics such as throughput and packet drop ratio. We conclude with lessons learnt and some future research directions

Stock structure and environmental effects on year class formation and population trends of Pacific herring, Clupea pallasi, in Prince William Sound, Alaska

Thesis (Ph.D.) University of Alaska Fairbanks, 2003Fluctuating forage fish populations trigger large ecosystem responses in the North Pacific. A representative species, Pacific herring, Clupea pallasi, was chosen to model environmental effects on population fluctuations and recruitment with a case example in Prince William Sound (PWS), Alaska. A unique approach was used to 1) develop a spatially-explicit, life history-based conceptual stock model, 2) quantify population level effects of climatic trends, and 3) model key environmental factors affecting recruitment. Framed as a simulation model, the stock model was compartmentalized by life-history stages based on shared habitats and environmental forcing. Initial model conditions impacting year-class formation were adult size-at-age, spawn timing, location and spawner density, and conditions during egg incubation, all impacting a two-stage larval mortality rate. Larval survival probably dictates the extremes in year-class strength. Age-1 abundance should reflect recruitment levels 2-3 yrs later, unless a predator pit exists. A metapopulation structure was proposed with at least two local population groupings with spatial complexity required to maintain stock levels. Herring abundance correlated with long-term climate trends supporting hypotheses of bottom up environmental forcing. Adult growth was oscillatory over a 13 yr period in phase with zooplankton production and climatic trends. Spawn timing occurred progressively earlier over the last 30 yr period with a concurrent regional spawn allocation shift and decrease in recruits per spawner. Incorporating local stock structure and local environmental variables into nonlinear herring recruitment models improved explanatory power over traditional models. Best-fit variables were eastern PWS SST, salinity, SST variance, and salinity variance from spring to fall. Eight critical life stage periods were defined based on the season and lag of the best-fitting varibles. Examining other variables in these critical periods led to defining potential key processes affecting year class formation. Allocation of spawn and age-3 recruits to metapopulation regions also impacted recruitment to PWS as a whole and these results supported the metapopulation theory. The results led to formulation of a new theory, entitled 'opposing response', explaining the mechanism producing the observed pattern of alternating strong and week year class strengths in northern Pacific herring

beta-Glucuronidase

1) A method has been devised for the purification of ox liver beta-glucuronidase utilising the interactions of proteins with metallic ions and organic solvents. An 800 fold purification has been achieved by such means with a 5% recovery of the enzyme. 2) The properties of the purified material indicate that beta-glucuronidase is a complex enzyme system with at least three and possibly four independent centres of activity. 3) Virtually complete separation of two of the liver glucuronidase fractions with pH optima at pH 4.5 and 5.2 has been achieved by means of organic solvent fractionation, while preparations overwhelmingly rich in activity at pH 3.4 can also be obtained by such means. 4) Kinetic studies on the fractionated material emphasise the independent nature of the separated entities. Significantly different values for the energies of activation and enzyme substrate dissociation constants have been obtained for such fractions from both liver and spleen, and their behaviour towards various inhibitors also show marked differences. 5) A comparative study of the fractionated liver and spleen glucuronidases indicates that the liver glucuronidases are catalytically more efficient than those of the spleen. 6) No evidence can be adduced to show that deoxyribonucleic acid functions as the coenzyme of either liver or spleen beta-glucuronidase as has previously been suggested. 7) A study of the relationship between liver glucuronidase activity and tissue damage and growth has shown no direct correlation between these factors as has been postulated by earlier workers. 8) Studies on chemically induced rat hepatoma indicate that the glucuronidase activity is lower in hepatoma than in normal liver and this in no way permits the conclusion that increased beta-glucuronidase activities are characteristic of malignant neoplasms. 9) The glucuronide decomposing enzyme of Esch. coli has been identified as a beta-glucuronidase, and a study has been made of a few of the reaction characteristics of this enzyme. 10) The beta-glucuronidase of Esch. coli is physically distinct from the complex enzyme system operative in animal tissues. 11) These results have been discussed in relation to previous work in this field

Recognizing the Interdependent Self: The Perception of the Production and Consumption of Meat at Bard College

Senior Project submitted to The Division of Social Studies of Bard College

Influence of Media Sources and Political Affiliation on COVID-19 Information Believability

The goal of this research project was to see if one\u27s political affiliation affected the news sources they read regarding their beliefs about COVID-19. Participants read the same article from one out of three news sources: Fox News, CNN, or no news source. Afterwords, they rated the accuracy of the article. We hypothesized that participants who read news from a source that aligned with their political affiliation were more likely to believe the information stated in that article than those who read from sources that did not align with their political affiliation

Auto-Deficit Households: Determinants, Travel Behavior, and the Gender Division of Household Car Use

To explore the characteristics of car-deficit households, researchers at UCLA examined California household travel survey data.Their findings can inform discussions on the factors that lead to car-deficit households, the mobility outcomes of car-deficit households, and the role of gender in access to household vehicles. Planners and policymakers can use these findings to better accommodate car-deficit households in the transportation system

A work sampling study of five positions in a residence hall kitchen

Call number: LD2668 .T4 1964 B87Master of Scienc

References to Clothing in Hawthorne's Major Romances

Through a close study of Hawthorne's four major romances--The Scarlet Letter, The House of the Seven Gables, The Blithedale Romance, and The Marble Faun-—this thesis singles out all significant references to apparel or accessories and evaluates the use he makes of them

Promoting VCU Community Solutions

This promotional project focuses on VCU Community Solutions — the new interdisciplinary initiative for education, research, and service. Since this initiative demonstrates the synergy that students, faculty, and community members can create by working together, the promotional video captures their perspectives. Through interviews and footage of community programs, the video shows how VCU Community Solutions engages university and community partners in addressing critical social issues — creating more imovative approaches by working together