Content Delivery Latency of Caching Strategies for Information-Centric IoT

In-network caching is a central aspect of Information-Centric Networking (ICN). It enables the rapid distribution of content across the network, alleviating strain on content producers and reducing content delivery latencies. ICN has emerged as a promising candidate for use in the Internet of Things (IoT). However, IoT devices operate under severe constraints, most notably limited memory. This means that nodes cannot indiscriminately cache all content; instead, there is a need for a caching strategy that decides what content to cache. Furthermore, many applications in the IoT space are timesensitive; therefore, finding a caching strategy that minimises the latency between content request and delivery is desirable. In this paper, we evaluate a number of ICN caching strategies in regards to latency and hop count reduction using IoT devices in a physical testbed. We find that the topology of the network, and thus the routing algorithm used to generate forwarding information, has a significant impact on the performance of a given caching strategy. To the best of our knowledge, this is the first study that focuses on latency effects in ICN-IoT caching while using real IoT hardware, and the first to explicitly discuss the link between routing algorithm, network topology, and caching effects.Comment: 10 pages, 9 figures, journal pape

The Age of the Ordovician Kirkfield Formation in Ontario

Author Institution: Department of Geology and Geography, Ohio Wesleyan University Delaware, Ohi

Sequence distribution studies of dichloroprotoanemonin-methyl methacrylate copolymers

Chloride elimination and ultraviolet bands in dichloroprotoanemonin/methyl methacrylate copolymer

Diagnostic procedures for antenna hydraulic drive systems

Diagnostic, testing, and maintenance procedures for hydraulic drive systems for large steerable antenna

Redescription of Aspidichthys : Arthrodira, Devonian

Author Institution: Ohio Wesleyan University, Delaware, Ohi

The Great Recession, the Resulting Budget Shortfalls, the 2010 Elections and the Attack on Public Sector Collective Bargaining in the United States

American public sector unions and collective bargaining have been subjected to a vicious attack under the auspices of balancing government budgets, promoting equity between private and public employees and limiting the impact of special interests on government policy. The American and world financial crisis of 2007 resulted in the Great Recession of 2008 and substantial budget shortfalls for local and national governments world-wide. This financial crisis and the resulting disintegration of aggregate demand and employment are eerily similar to the financial crisis and collapse that led to the Great Depression of the 1930’s. However, unlike the calamity of the 1930’s, in the present emergency American conservatives, funded by the moneyed class, are attempting to use the predicament as an opportunity to attack collective bargaining and other institutions of support and power for the American middle class. This grasp for power represents and assertion of power and control by the American upper class not experienced since rise of scientific management and the deskilling of jobs and the destruction of the trade union system of collective bargaining in the 1890’s. In this paper I will outline the recent attack on public sector unions’ power in the American economy and the accompanying changes, and proposed changes, in American law. I will briefly describe the impact of the recent financial crisis on the American economy and the balance sheets of American state and national governments and the opportunism of the American plutocracy in using this crisis to propose and enact legislation to undermine the institution of collective bargaining and political proponents for the Middle and Lower classes. In particular I will discuss the recent efforts in Indiana, Wisconsin, Ohio, and Michigan to severely limit or prohibit public sector collective bargaining and the political influence American public sector workers. This attack on collective bargaining amounts to the largest grab for economic and political power by the American upper class since the destruction of the labor guilds in the 1890’s and the rise of the gilded age from the 1890’s-1930’s

Study of disposable microdevices for DNA electrophoresis

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, September 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. [77]-[79]).A study was undertaken to determine if a microfluidic chip, made of economical plastic materials, is feasible. The chip was designed to perform gel electrophoresis, specifically of DNA fragments for either sequencing or identification purposes. With a disposable version of such a chip, constraints on the gel type are relaxed and lifetime issues become nonexistent. Such a chip was created using polydimethylsiloxane(PDMS) as the plastic material, with a cast molding process. The chip was subsequently sealed against a piece of PDMS, mounted on a glass slide for structural support. Fluidic and electrical interconnects were added to the chip. A polyacrylarnide solution was injected into the chip for use in DNA separations. The chip was then placed into an apparatus designed for laser induced fluorescence(LIF) detection. Several different samples were run on the chip, including polystyrene beads, organic dye molecules, and single tandem repeat (STR) allelic ladders. The chip demonstrated its electrophoretic efficiency, evincing a low, almost negligible amount of electroosmotic flow. The separation of the dye and DNA was accomplished with good fidelity, allowing for identification of the various substitutents of the loaded sample.(cont.) The PDMS chip, though demonstrably efficient at DNA separation, needs work before it can move out of the prototype phase. Substantial work on the fluidic interconnection, as well as the basic plastic formulation is needed to move this idea forward. However, the chip is sufficient for a clear proof of the principle of disposable chips use in electrophoretic separations.by Winston Timp.S.M

Study of cell-cell communication using 3D living cell microarrays

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 135-152).Cellular behavior is not dictated solely from within; it is also guided by a myriad of external cues. If cells are removed from their natural environment, apart from the microenvironment and social context they are accustomed to, it is difficult to study their behavior in any meaningful way. To that end, I describe a method for using optical trapping for positioning cells with submicron accuracy in three dimensions, then encapsulating them in hydrogel, in order to mimic the in vivo microenvironment. This process has been carefully optimized for cell viability, checking both prokaryotic and eukaryotic cells for membrane integrity and metabolic activity. To demonstrate the utility of this system, I have looked at a model "quorum sensing" system in Vibrio Fischeri, which operates by the emission and detection of a small chemical signal, an acyl-homoserine lactone. Through synthetic biology, I have engineered plasmids which express "sending" and "receiving" genes. Bacteria containing these plasmids were formed into complex 3D patterns, designed to assay signaling response. The gene expression of the bacteria was tracked over time using fluorescent proteins as reporters. A model for this system was composed using a finite element method to simulate signal transport through the hydrogel, and simple mass-action kinetic equations to simulate the resulting protein expression over time.by Winston Timp.Ph.D