Understanding Traffic Characteristics in a Server to Server Data Center Network

The number of Data Centers and the servers present in them has been on the rise over the last decade with the advent of cloud computing, social networking, Big data analytics etc. This has eventually led to the increase in the power consumption of the Data Center due to the power hungry interconnection fabric which consists of switches and routers. The scalability of the data center has also become a problem due to the interconnect cabling complexity which is also responsible for the increase in the energy used for cooling the data center as these bundles of wires reduce the air flow in the data center. The maintenance costs of the data center is high due to this reason. This brings the challenge of reducing the power consumption as well as improving the scalability of the data center. There is a lot of cost involved in the establishment of a network in a data center and this network is one of the main source of power consumption. Therefore, there is a need to accurately characterize the data center network before its construction which requires the simulation of the data center models. For the simulation of data center models, we require the traffic which is identical to that of an actual data center so that the results will be similar to a real time data center. Traditional data center networks have a wired communication fabric, which is not scalable and contributes largely to the power consumption. This has led to the investigation of other methods. There have been transceivers designed that can support the unlicensed 60 GHz spectrum, supporting high bandwidth similar to the wired network present in traditional data centers. These wireless links have spatial reusability and the data centers can make use of this communication medium to meet the high bandwidth demands and also reduce the use of cable thereby bringing down the cost and the power consumption. This thesis studies the previous traffic models used in the simulation of a data center network. Traffic collected from ten different data centers is then characterized and modelled based on various probability distributions. The implementation of the model tries to generate traffic similar to that of an actual data center. The Data Center Network is then simulated using the traffic generated and the performance of the wired data center is quantified in terms of metrics like throughput, latency and the power consumption of the data center networks

Flooding attacks to internet threat monitors (ITM): Modeling and counter measures using botnet and honeypots

The Internet Threat Monitoring (ITM),is a globally scoped Internet monitoring system whose goal is to measure, detect, characterize, and track threats such as distribute denial of service(DDoS) attacks and worms. To block the monitoring system in the internet the attackers are targeted the ITM system. In this paper we address flooding attack against ITM system in which the attacker attempt to exhaust the network and ITM's resources, such as network bandwidth, computing power, or operating system data structures by sending the malicious traffic. We propose an information-theoretic frame work that models the flooding attacks using Botnet on ITM. Based on this model we generalize the flooding attacks and propose an effective attack detection using Honeypots

A three-dimensional macroscopic fundamental diagram for mixed bi-modal urban networks

Recent research has studied the existence and the properties of a macroscopic fundamental diagram (MFD) for large urban networks. The MFD should not be universally expected as high scatter or hysteresis might appear for some type of networks, like heterogeneous networks or freeways. In this paper, we investigate if aggregated relationships can describe the performance of urban bi-modal networks with buses and cars sharing the same road infrastructure and identify how this performance is influenced by the interactions between modes and the effect of bus stops. Based on simulation data, we develop a three-dimensional vehicle MFD (3D-vMFD) relating the accumulation of cars and buses, and the total circulating vehicle flow in the network. This relation experiences low scatter and can be approximated by an exponential-family function. We also propose a parsimonious model to estimate a three-dimensional passenger MFD (3D-pMFD), which provides a different perspective of the flow characteristics in bi-modal networks, by considering that buses carry more passengers. We also show that a constant Bus-Car Unit (BCU) equivalent value cannot describe the influence of buses in the system as congestion develops. We then integrate a partitioning algorithm to cluster the network into a small number of regions with similar mode composition and level of congestion. Our results show that partitioning unveils important traffic properties of flow heterogeneity in the studied network. Interactions between buses and cars are different in the partitioned regions due to higher density of buses. Building on these results, various traffic management strategies in bi-modal multi-region urban networks can then be integrated, such as redistribution of urban space among different modes, perimeter signal control with preferential treatment of buses and bus priority

MIXED-USE SAFETY ON RURAL FACILITIES IN THE PACIFIC NORTHWEST: Consideration of Vehicular, Non-Traditional, and Non-Motorized Users

In the United States, one in 12 households do not own a personal automobile and approximately 13% of those who are old enough to drive do not. Trips by these individuals are being made in one of many other possible modes, creating the need to “share space” between many forms of travel. The goal of this project is to: improve safety and minimize the dangers for all transportation mode types while traveling in mixed-use environments on rural facilities through the development and use of engineering and education safety measures. To that end, this report documents three specific efforts by the project team. First, a comprehensive literature review of mixed-use safety issues with consideration of non-motorized and non-traditional forms of transportation. Second, a novel analysis of trauma registry data. Third, development, execution and analysis of the Pacific Northwest Transportation Survey geared toward understanding safety perceptions of mixed-use users. Most notably, findings indicate that ATVs (and similar non-traditional-type vehicles) are used on or near roads 24% of the time and snowmachines are used on or near roads 23% of the time. There are significantly more (twice as many) ATV-related on-road traumas in connected places than isolated places in Alaska and three times more traumas in highway connected places than in secondary road connected places. Comparably, bicycles had 449 on-road traumas between 2004 and 2011 whereas ATVs had 352 on-road traumas. Users of all modes who received formalized training felt safer in mixed-use environments than those who reported having no training at all

Comparison study on AIS data of ship traffic behavior

AIS (Automatic Identification System) data provides valuable input parameters in ship traffic simulation models for maritime risk analysis and the prevention of shipping accidents. This article reports on the detailed comparisons of AIS data analysis between a Dutch case and a Chinese case. This analys is focuses on restricted waterways to support inland waterway simulations, comparing the differences between a narrow waterway in the Netherlands (the Port of Rotterdam) and a wide one in China (wide water way of Yangtze River close to the SuTong Bridge). It is shown that straightforward statistical distributions can be used to characterise lateral position, speed, heading and interval times for different types and sizes of ships. However, the distributions for different characteristics of ship behaviours differ significantly

Transportation Construction Work-Zone Safety Impact on Time-Related Incentive Contracting Projects

Work-zone safety on highway projects continues to be a national concern, and project safety performance is one of the indicators of project success. Many contractors and State Transportation Agencies believe that expedited construction time under incentive contracting contributes to reducing the safety risk of road users traveling through work zones. However, the truth of this belief has never been measured or supported by any statistical evidence. Therefore, this research investigates the statistical relationship between time-related incentive road construction projects and frequency of vehicle crashes in California to understand the impact of time-related incentive provisions on project safety performance. The research team collected incentive and non-incentive project data from the California Department of Transportation. Additionally, vehicle crash data was collected from the California Statewide Integrated Traffic Records System. Using Geographic Information System (GIS) software, the locations of construction projects and crashes at the project locations were then pinpointed on GIS centerline layers. The research team performed statistical analyses to test the relationship between the frequency and characteristics of crashes at incentive project sites and ones at non-incentive project sites before, during, and after construction. Finally, the analysis results for both time-related incentive projects and non-incentive projects were summarized to provide project planners and managers with a better understanding of the impact of time-related incentive contracting on project safety performance

Parental safety concerns and active school commute: correlates across multiple domains in the home-to-school journey

Abiodun O. Oluyomi, Eileen Nehme, and Deanna M. Hoelscher are with The Michael and Susan Dell Center for Healthy Living, UT School of Public Health, Austin Regional Campus, The University of Texas Health Science Center at Houston, Austin, TX USA -- Chanam Lee is with the Department of Landscape Architecture and Urban Planning, College of Architecture, Texas AM University, College Station, TX USA -- Diane Dowdy and Marci G. Ory are with the School of Rural Public Health, Texas AM HeaBackground: Empirical evidence of the relationship between safety concerns and walking to school (WTS) is growing. However, current research offers limited understanding of the multiple domains of parental safety concerns and the specific mechanisms through which parents articulate safety concerns about WTS. A more detailed understanding is needed to inform environmental and policy interventions. This study examined the relationships between both traffic safety and personal safety concerns and WTS in the U.S. Methods: This cross-sectional analysis examined data from the Texas Childhood Obesity Prevention Policy Evaluation (T-COPPE) project, an evaluation of state-wide obesity prevention policy interventions. All study data were from the survey (n = 830) of parents with 4th grade students attending 81 elementary schools across Texas, and living within two miles from their children's schools. Traffic safety and personal safety concerns were captured for the home neighborhood, en-route to school, and school environments. Binary logistic regression analysis was used to assess the odds of WTS controlling for significant covariates. Results: Overall, 18% of parents reported that their child walked to school on most days of the week. For traffic safety, students were more likely to walk to school if their parent reported favorable perceptions about the following items in the home neighborhood environment: higher sidewalk availability, well maintained sidewalks and safe road crossings. For the route to school, the odds of WTS were higher for those who reported "no problem" with each one of the following: traffic speed, amount of traffic, sidewalks/pathways, intersection/crossing safety, and crossing guards, when compared to those that reported "always a problem". For personal safety in the en-route to school environment, the odds of WTS were lower when parents reported concerns about: stray or dangerous animals and availability of others with whom to walk. Conclusions: Findings offered insights into the specific issues that drive safety concerns for elementary school children’s WTS behaviors. The observed associations between more favorable perceptions of safety and WTS provide further justification for practical intervention strategies to reduce WTS barriers that can potentially bring long-term physical activity and health benefits to school-aged children.Public [email protected]

Noise Pollution? What\u27s the solution?: Understanding Traffic Noise Pollution in Gettysburg, Pennsylvania

Noise pollution can be damaging to a community by impacting its atmosphere as well as the health of its residents, local quality of life, and local economy. Our study sought to gain insight into the level of noise pollution in Gettysburg, both in-town and on the Gettysburg College campus, and how noise pollution may be affecting the local residents and students. We selected 9 sampling sites, 6 in-town and 3 on the college campus, and measured the noise pollution in dBA with portable sound meters three days a week and three times a day over a three week period. Our data showed no major trends in terms of time of day or day of the week, but there were clear differences in noise pollution levels between the different sites in that town sites were generally louder than on campus sites. Noise pollution in town was often louder than 70 dBA, the noise threshold that indicates possible hearing damage overtime set by the World Health Organization. Gettysburg has recently enacted a noise ordinance; our study suggests the Borough possibly could do more to mitigate traffic noise by repairing roads and manipulating road design