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

Analisis Faktor Penyebab Tandan Buah Segar (TBS) Busuk Dan Bahaya Kecelakaan Menggunakan Fishbone Chart (Studi Kasus Pada Bagian Sortasi di PT Sutopo Lestari Jaya)

At the PT Sutopo Lestari Jaya sorting work station it was seen that the sorting work environment had an open working environment so that when hot weather operators quickly experienced fatigue and the oil content in FFB would shrink, during the rain the work floor sorting would be slippery caused by FFB oil so makes the operator slip and the loader operator is difficult to drive then FFB quickly decays. So improvements are needed by finding the root cause of the problem experienced by using a fishbone diagram. The results obtained are that the sorting work station needs to be repaired by installing a roof in the sorting work environment. With the roof in the sorting work environment, the company can minimize the losses that occur and can eliminate the causes of problems that exist in the sorting work station

Flexible dielectric waveguides with powder cores

Flexible dielectric waveguides have been demonstrated at 10 GHz and 94 GHz using thin-wall polymer tubing filled with low-loss, high-dielectric-constant powders. Absorptive losses of the order of 10 dB/m were measured at 94 GHz. with nickel-aluminium titanate and barium tetratitanate powder in polytetrafluoroethylene (PTFE) lightweight electrical tubing. Bending losses at 94 GHz were negligible for curvature radii greater than 4 cm. M.H. Kuhn's (1974) theory of three-region cylindrical dielectric waveguide was used to calculate dispersion curves for the lower-order modes for several combinations of dimensions and dielectric constants. Good agreement was obtained between experimental and theoretical values of guide wavelength. A scheme is proposed for classifying hybrid modes of three-region guides based on the ratio |Ez/Hz|. For two-region guides, this reduces to E. Snitzer's (1961) familiar scheme

A Review of Accelerated Test Models

Engineers in the manufacturing industries have used accelerated test (AT) experiments for many decades. The purpose of AT experiments is to acquire reliability information quickly. Test units of a material, component, subsystem or entire systems are subjected to higher-than-usual levels of one or more accelerating variables such as temperature or stress. Then the AT results are used to predict life of the units at use conditions. The extrapolation is typically justified (correctly or incorrectly) on the basis of physically motivated models or a combination of empirical model fitting with a sufficient amount of previous experience in testing similar units. The need to extrapolate in both time and the accelerating variables generally necessitates the use of fully parametric models. Statisticians have made important contributions in the development of appropriate stochastic models for AT data [typically a distribution for the response and regression relationships between the parameters of this distribution and the accelerating variable(s)], statistical methods for AT planning (choice of accelerating variable levels and allocation of available test units to those levels) and methods of estimation of suitable reliability metrics. This paper provides a review of many of the AT models that have been used successfully in this area.Comment: Published at http://dx.doi.org/10.1214/088342306000000321 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org