Indirect Estimation of Link Delays by Directly Observing a Triplet of Network Metrics

AbstractThis paper presents an improved indirect estimation link delays from a triplet of network metrics; path delays, packet loss rate (PLR), and jitter by using indirect inverse modeling techniques. conventionally a network metric is estimated by directly observing another network parameter. Based on the evidence in the literature that path delays, PLR, and jitter are interdependent, this work exploits this mutual interdependent of this triplet of metrics based on the notion that a better observation leads to better estimation. We applied NTF1 model, a variation of non negative tensor factorization (NTF) for this purpose and estimated link delay from a triplet of metrics. Evaluation process used data from an experimental test bed that consists of standard networking devices. The estimated link delays were correlated to actual link delays to benchmark the accuracy of estimation. Results showed a better correlation between the estimated and measured link delays when a triplet of metrics is used

Achieving Universal Coverage Through Comprehensive Health Reform: The Vermont Experience -- Report of Findings

Presents findings on the role of Vermont's health reform programs in increasing insurance coverage between 2005 and 2009. Examines changes by insurance type, contributing factors such as outreach campaigns, financial sustainability, and implications

Aviation Safety as a Function of Pilot Experience: Rationale or Rationalization?

Editor\u27s Note: This article originally appeared in the Spring 1992 issue. It is reprinted due to its continuing value and timeliness. This study tests the effectiveness of an experience model in predicting aviation safety behavior. The elements comprising the model include: (a) flight hours, (b) ratings and flight characteristics, (c) career status, and (d) malfunction history. Data were derived from a random sample of U.S. pilots in Fall 1990 by means of a survey instrument. Significant variance in aviation safety is not explained by the model. The key predictor of safety behavior is the career status (i.e., certificate duration) of the pilot. Flight hours, ratings, and malfunction history are negatively and non-significantly associated with aviation safety. The research: (a) questions the use of these variables in ex post facto explanations of aviation safety, and (b) suggests a topology for examining safety behavior

Aviation Safety as a Function of Pilot Experience: Rationale or Rationalization?

This study tests the effectiveness of an experience model in predicting aviation safety behavior. The elements comprising the model include: (a) flight hours, (b) ratings and flight characteristics, (c) career status, and (d) malfunction history. Data were derived from a random sample of U.S. pilots in the fall of 1990 by means of a survey instrument. Significant variance in aviation safety is not explained by the model. The key predictor of safety behavior is the career status (i.e., certificate duration) of the pilot. Flight hours, ratings, and malfunction history are negatively and non-significantly associated with aviation safety. The research: (a) questions the use of these variables in ex post facto “explanations” of aviation safety, and (b) suggests a topology for examining safety behavior

An Algorithmic Approach for Identifying Critical Distance Relays for Transient Stability Studies

After major disturbances, power system behavior is governed by the dynamic characteristics of its assets and protection schemes. Therefore, modeling protection devices is essential for performing accurate stability studies. Modeling all the protection devices in a bulk power system is an intractable task due to the limitations of current stability software, and the difficulty of maintaining and updating the data for thousands of protection devices. One of the critical protection schemes that is not adequately modeled in stability studies is distance relaying. Therefore, this paper proposes an algorithm that uses two methods to identify the critical distance relays to be modeled in stability studies: (i) apparent impedance monitoring, and (ii) the minimum voltage evaluation (MVE). The algorithm is implemented in Python 3.6 and uses the GE positive sequence load flow analysis (PSLF) software for performing stability studies. The performance of the algorithm is evaluated on the Western Electricity Coordinating Council (WECC) system data representing the 2018 summer-peak load. The results of the case studies representing various types of contingencies show that to have an accurate assessment of system behavior, modeling the critical distance relays identified by the algorithm suffices, and there is no need for modeling all the distance relays

Global water cycle

The primary objective is to determine the scope and interactions of the global water cycle with all components of the Earth system and to understand how it stimulates and regulates changes on both global and regional scales. The following subject areas are covered: (1) water vapor variability; (2) multi-phase water analysis; (3) diabatic heating; (4) MSU (Microwave Sounding Unit) temperature analysis; (5) Optimal precipitation and streamflow analysis; (6) CCM (Community Climate Model) hydrological cycle; (7) CCM1 climate sensitivity to lower boundary forcing; and (8) mesoscale modeling of atmosphere/surface interaction

Scaling Up a Multifaceted Violence Prevention Package: County-Level Impact of the North Carolina Youth Violence Prevention Center

OBJECTIVE: Multifaceted approaches to youth-violence prevention package evidence-based programs into initiatives that yield large-scale impact. This study assessed the impact of a package of evidence-based violence prevention programs, implemented as part of the North Carolina Youth Violence Prevention Center, on county-level violence indicators. METHOD: Using growth-curve modeling, the target county was compared to all other counties in North Carolina and a comparison county. RESULTS: Results reveal downward trends on several county-level indicators (i.e., undisciplined/delinquent complaints, total delinquent complaints, juvenile arrests–aggravated assaults, and short-term suspensions) throughout the intervention period. However, statistical tests were unable to confirm that intervention-period scores on youth-violence indicators were significantly different than expected scores given the relationship between pretest and intervention-period scores in other North Carolina counties. CONCLUSIONS: Although additional administrative data points are needed to support the hypotheses, this study provides preliminary evidence of the effectiveness of North Carolina Youth Violence Prevention Center interventions

Hail Damage – Grain Quality Survey

There were two major hail events this summer during grain fill that resulted in significant corn crop damage in the path of the storm. The damage occurred over several thousand acres with some fields being a total loss and other fields having varying degrees of damage. This resulted in several crop hail damage meetings across the state to help farmers make informed harvest decisions. A common question from farmers and grain merchandisers dealt with grain quality issues. Specifically, what impact will the hail damage have on grain quality, ear rot severity and mycotoxin contamination in my corn crop

Nuclear Physics Neutrino PreTown Meeting: Summary and Recommendations

In preparation for the nuclear physics Long Range Plan exercise, a group of 104 neutrino physicists met in Seattle September 21-23 to discuss both the present state of the field and the new opportunities of the next decade. This report summarizes the conclusions of that meeting and presents its recommendations. Further information is available at the workshop's web site. This report will be further reviewed at the upcoming Oakland Town Meeting.Comment: Latex, 31 pages. This version has been updated to include final Comments from the working group