Unified clustering and communication protocol for wireless sensor networks

In this paper we present an energy-efficient cross layer protocol for providing application specific reservations in wireless senor networks called the “Unified Clustering and Communication Protocol ” (UCCP). Our modular cross layered framework satisfies three wireless sensor network requirements, namely, the QoS requirement of heterogeneous applications, energy aware clustering and data forwarding by relay sensor nodes. Our unified design approach is motivated by providing an integrated and viable solution for self organization and end-to-end communication is wireless sensor networks. Dynamic QoS based reservation guarantees are provided using a reservation-based TDMA approach. Our novel energy-efficient clustering approach employs a multi-objective optimization technique based on OR (operations research) practices. We adopt a simple hierarchy in which relay nodes forward data messages from cluster head to the sink, thus eliminating the overheads needed to maintain a routing protocol. Simulation results demonstrate that UCCP provides an energy-efficient and scalable solution to meet the application specific QoS demands in resource constrained sensor nodes. Index Terms — wireless sensor networks, unified communication, optimization, clustering and quality of service

The Males Of Some Texan Ecitons

Integrative Biolog

Litter on Wheels: An Ocean Garbage Art Car

In the Fall term of 2018, Gettysburg College seniors Bill LeConey and Will Gibson created the world\u27s first Ocean Garbage Art Car, by covering an old Ford truck with plastic bottles (and other trash commonly found in our oceans), to raise awareness about anthropogenic pollution in our seas. Since the 1950’s, plastics have been an essential and ubiquitous commodity in nearly every society on the planet. Plastics find their way into just about every aspect of our lives - from water bottles and cell phone cases, to even advanced medical equipment and space shuttles - it’s no secret how prevalent plastic is. Unfortunately, an overwhelming majority of the ≈450 million tons of plastic produced annually ends up in our oceans, posing a substantial threat to our aquatic life and the ecosystems they reside in. Much of this waste coalesces into gyres called garbage patches - some as large as countries - floating within the water column, and harming the tranquility of the environment they are intruding on. Several environmental art forms similar to our Ocean Garbage Art Car were studied and compared to give a more in depth background on our issue. Many other artists have utilized ocean trash, but ours is a one of a kind. An urgent call to action must take place to cleanup our oceans and to stop the excessive waste of plastic before irreversible repercussions occur. It is our hope that the Ocean Garbage Art Car created in the ES 400 seminar will help raise awareness about this dire issue threatening our planet as we know it

Practical experiences with worm gearing for spacecraft power transmission applications

Experiences of several organizations using worm gearing for spacecraft are discussed. Practical aspects and subtleties of using worm gearing for design and operation is included. Knowledge gained from these applications is analyzed, and guidelines for usage are proposed

The Supply Side of Innovation: H-1B Visa Reforms and US Ethnic Invention

This study evaluates the impact of high-skilled immigrants on US technology formation. We use reduced-form specifications that exploit large changes in the H-1B visa program. Higher H-1B admissions increase immigrant science and engineering (SE) employment and patenting by inventors with Indian and Chinese names in cities and firms dependent upon the program relative to their peers. Most specifications find limited effects for native SE employment or patenting. We are able to rule out displacement effects, and small crowding-in effects may exist. Total SE employment and invention increases with higher admissions primarily through direct contributions of immigrants.Innovation, Research and Development, Patents, Scientists, Engineers, Inventors, H-1B, Immigration, Ethnicity, India, China, Endogenous Growth

Educational attainment and household location: the case of Chicago's lakefront

The authors focus on the relationship between being a college graduate (that is, having a bachelor’s degree or higher) and household location in the city of Chicago’s lakefront neighborhoods, other parts of the city, and the suburbs in Illinois. Overall, their results indicate that being a college graduate is associated with living in the city’s lakefront neighborhoods relative to the suburbs. These results hold for non-Hispanic whites, blacks, and Hispanics across the metropolitan region.Education - Middle West - Chicago (Ill.) ; Education - Economic aspects