Estimating Dynamic Traffic Matrices by using Viable Routing Changes

Abstract: In this paper we propose a new approach for dealing with the ill-posed nature of traffic matrix estimation. We present three solution enhancers: an algorithm for deliberately changing link weights to obtain additional information that can make the underlying linear system full rank; a cyclo-stationary model to capture both long-term and short-term traffic variability, and a method for estimating the variance of origin-destination (OD) flows. We show how these three elements can be combined into a comprehensive traffic matrix estimation procedure that dramatically reduces the errors compared to existing methods. We demonstrate that our variance estimates can be used to identify the elephant OD flows, and we thus propose a variant of our algorithm that addresses the problem of estimating only the heavy flows in a traffic matrix. One of our key findings is that by focusing only on heavy flows, we can simplify the measurement and estimation procedure so as to render it more practical. Although there is a tradeoff between practicality and accuracy, we find that increasing the rank is so helpful that we can nevertheless keep the average errors consistently below the 10% carrier target error rate. We validate the effectiveness of our methodology and the intuition behind it using commercial traffic matrix data from Sprint's Tier-1 backbon

Development and fabrication of improved Schottky power diodes, phases I and II

Reproducible methods for the fabrication of silicon Schottky diodes were developed for the metals tungsten, aluminum, conventional platinum silicide and low temperature platinum silicide. Barrier heights and barrier lowering were measured permitting the accurate prediction of ideal forward and reverse diode performance. Processing procedures were developed which permit the fabrication of large area (approximately 1 sqcm) mesa-geometry power Schottky diodes with forward and reverse characteristics that approach theoretical values

Structure of Kuroshio south of Japan

In June-July 1971 four deep hydrographic sections were made across the Kuroshio south of Japan, eight near-bottom current meters were placed under the Kuroshio on the continental slope, and the near-surface current structure was measured by XBT mapping of the temperature field and tracking four surface drogues...

PROBLEMS OF THE SUCCESSOR TRUSTEE AS TO CLAIMS ARISING OUT OF SELF DEALING PURCHASES

Although, under certain circumstances, the beneficiaries also may be able to enforce them, it is well settled that a successor trustee has the power to assert and enforce claims against his predecessor trustee for breaches of trust by the predecessor. Generally, wherever the circumstances are such that certain action or inaction by beneficiaries would bar them from taking advantage of a particular remedy if they were not under any incapacity, such action or inaction by the successor trustee will likewise be a bar. Therefore, in considering what remedies are available to the successor trustee and what activity or inactivity of that trustee may bar those remedies, reference will be made not only to those authorities dealing with claims by a successor trustee against his predecessor but also those authorities dealing with claims asserted directly by a beneficiary against his trustee

Carbon offsets and certification: how and why offset providers choose to certify

2011 Fall.Includes bibliographical references.In a world that is increasingly concerned about carbon emissions and the atmospheric impacts of those emissions, carbon offsets have become a broadly accepted form of emissions reductions. While the UN set the initial standard for governing those offsets with the Clean Development Mechanism, a voluntary carbon market and a wide variety of private carbon offset certifications have gained an important role in that voluntary market. Because these private certifications take a variety of forms and have their own specialty niches, it is important to understand the intricacies of these certifications for the growing number of carbon offset producers. This research studies the reasons why a small non-profit carbon offset producer would seek certification, as well as how that producer went about choosing among a wide range of offset standards. The research revealed that for an organization to certify, the increased market share and legitimacy must outweigh the cost of certification. In addition, the choice in certification largely depends on cost, suitability, and the perception that the standard will uphold its legitimacy in the long term

Distribution of salinity and dissolved oxygen on surfaces of uniform potential specific volume in the South Atlantic, South Pacific, and Indian Oceans

Maps are presented that show the distributions of the salinity, dissolved oxygen, and depth of four potential specific-volume anomaly surfaces: 125, 100, 80, and 60 cl/t. Evidence indicates an anticyclonic circulation of water at intermediate depth in the Atlantic, Pacific, and Indian oceans. Only in the South Pacific does water from the Circumpolar Current penetrate to low latitudes in a relatively unmixed condition. In the South Atlantic and South Indian oceans there is no counterpart for the poleward directed Peru-Chile Undercurrent. Low-salinity water from the Banda and Timor seas penetrates to the western South Indian Ocean on the 125-cl/t surface...

Development and fabrication of improved Schottky power diodes

Reproducible methods for the fabrication of silicon Schottky diodes have been developed for tungsten, aluminum, conventional platinum silicide, and low temperature platinum silicide. Barrier heights and barrier lowering under reverse bias have been measured, permitting the accurate prediction of forward and reverse diode characteristics. Processing procedures have been developed that permit the fabrication of large area (about 1 sq cm) mesageometry power Schottky diodes with forward and reverse characteristics that approach theoretical values. A theoretical analysis of the operation of bridge rectifier circuits has been performed, which indicates the ranges of frequency and voltage for which Schottky rectifiers are preferred to p-n junctions. Power Schottky rectifiers have been fabricated and tested for voltage ratings up to 140 volts