Networking technology adoption : system dynamics modeling of fiber-to-the-home

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, Technology, Management, and Policy Program, 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Page 244 blank.Includes bibliographical references (p. 241-243).A system dynamics model is developed and run to study the adoption of fiber-to-the-home as a residential broadband technology. Communities that currently do not have broadband in the United States are modeled. This case is of particular interest to U.S. policymakers, but also relevant to other regions concerned with economic development in rural areas. The model is used to explore the effects of government policy on fiber-to-the-home deployment and on the telecommunications supply chain. The research finds that government policy relating to broadband deployment has been based on a weak understanding of the dynamics involved, resulting in trial and error policy making that has unintended consequences. The thesis shows that the current monitoring of broadband deployment by the Federal Communications Commission is inadequate to contribute to the formation of reasoned policy decisions. The model is used to explore the consequences that different regulatory scenarios have on fiber-to-the-home deployment. Among the policy choices considered are: resale of fiber-to-the-home lines to competitive providers; low cost government loans for commercial deployments; rapid deployment to all communities currently without service; and a ban on municipal deployments. The current Rural Utilities Service loan program is also included in the model and its effects are analyzed. The model is used to examine the consequences for the optoelectronics industry of different deployment scenarios. It shows that the interests of consumers, regulators, and even service providers are in conflict with the interests of the optoelectronics industry which provides a critical component necessary for the service.(cont.) Strategies to help mitigate that conflict and to promote the health of the components industry are explored. Deployment of fiber-to-the-home is costly, and cost recovery is difficult for both incumbent and competitive service providers, especially in rural and suburban regions that do not currently have service. The interests of policy makers, service providers, and component suppliers need to be aligned to implement effective policy that encourages the deployment of broadband to unserved regions. The Federal Communications Commission needs to rearchitect its monitoring of service providers and their activities to better understand the status of deployment and how its policies can help or hinder.by Andjelka Kelic.Ph.D

Assessing the technical and financial viability of broadband satellite systems using a cost per T1 minute metric

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics; and, Thesis (S.M.)--Massachusetts Institute of Technology, Technology and Policy Program, 1998.Includes bibliographical references (p. 109-111).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.A cost per 1.544 Mbps (T1) link per minute metric is developed for systems evaluation of satellite based broadband communications systems. Global market models based on Internet growth and computer penetration are developed. Initially systems are limited by the available market, however as the market increases, the design of the system becomes the limiting factor. These limits include satellite power resources, achievable link margins, and rain attenuation. A computer simulation is developed to model the complex interactions between the capacity limits and distributed market models.by Andjelka Kelic.S.M

Cyber and physical infrastructure interdependencies.

The goal of the work discussed in this document is to understand the risk to the nation of cyber attacks on critical infrastructures. The large body of research results on cyber attacks against physical infrastructure vulnerabilities has not resulted in clear understanding of the cascading effects a cyber-caused disruption can have on critical national infrastructures and the ability of these affected infrastructures to deliver services. This document discusses current research and methodologies aimed at assessing the translation of a cyber-based effect into a physical disruption of infrastructure and thence into quantification of the economic consequences of the resultant disruption and damage. The document discusses the deficiencies of the existing methods in correlating cyber attacks with physical consequences. The document then outlines a research plan to correct those deficiencies. When completed, the research plan will result in a fully supported methodology to quantify the economic consequences of events that begin with cyber effects, cascade into other physical infrastructure impacts, and result in degradation of the critical infrastructure's ability to deliver services and products. This methodology enables quantification of the risks to national critical infrastructure of cyber threats. The work addresses the electric power sector as an example of how the methodology can be applied

Energy and water sector policy strategies for drought mitigation.

Tensions between the energy and water sectors occur when demand for electric power is high and water supply levels are low. There are several regions of the country, such as the western and southwestern states, where the confluence of energy and water is always strained due to population growth. However, for much of the country, this tension occurs at particular times of year (e.g., summer) or when a region is suffering from drought conditions. This report discusses prior work on the interdependencies between energy and water. It identifies the types of power plants that are most likely to be susceptible to water shortages, the regions of the country where this is most likely to occur, and policy options that can be applied in both the energy and water sectors to address the issue. The policy options are designed to be applied in the near term, applicable to all areas of the country, and to ease the tension between the energy and water sectors by addressing peak power demand or decreased water supply

Patterns of geohelminth infection, impact of albendazole treatment and re-infection after treatment in schoolchildren from rural KwaZulu-Natal/South-Africa

BACKGROUND: Geohelminth infection is a major health problem of children from rural areas of developing countries. In an attempt to reduce this burden, the Department of Health of the province of KwaZulu-Natal (KZN) established in 1998 a programme for helminth control that aimed at regularly treating primary school children for schistosomiasis and intestinal helminths. This article describes the baseline situation and the effect of treatment on geohelminth infection in a rural part of the province. METHODS: Grade 3 schoolchildren from Maputaland in northern KZN were examined for infections with hookworm, Ascaris lumbricoides, and Trichuris trichiura, treated twice with 400 mg albendazole and re-examined several times over one year after the first treatment in order to assess the impact of treatment and patterns of infection and re-infection. RESULTS: The hookworm prevalence in the study population (83.2%) was considerably higher than in other parts of the province whereas T. trichiura and especially A. lumbricoides prevalences (57.2 and 19.4%, respectively) were much lower than elsewhere on the KZN coastal plain. Single dose treatment with albendazole was very effective against hookworm and A. lumbricoides with cure rates (CR) of 78.8 and 96.4% and egg reduction rates (ERR) of 93.2 and 97.7%, respectively. It was exceptionally ineffective against T. trichiura (CR = 12.7%, ERR = 24.8%). Re-infection with hookworm and A. lumbricoides over 29 weeks after treatment was considerable but still well below pre-treatment levels. CONCLUSION: High geohelminth prevalences and re-infection rates in the study population confirm the need for regular treatment of primary school children in the area. The low effectiveness of single course albendazole treatment against T. trichiura infection however demands consideration of alternative treatment approaches

Phoenix : Complex Adaptive System of Systems (CASoS) engineering version 1.0.

Complex Adaptive Systems of Systems, or CASoS, are vastly complex ecological, sociological, economic and/or technical systems which we must understand to design a secure future for the nation and the world. Perturbations/disruptions in CASoS have the potential for far-reaching effects due to pervasive interdependencies and attendant vulnerabilities to cascades in associated systems. Phoenix was initiated to address this high-impact problem space as engineers. Our overarching goals are maximizing security, maximizing health, and minimizing risk. We design interventions, or problem solutions, that influence CASoS to achieve specific aspirations. Through application to real-world problems, Phoenix is evolving the principles and discipline of CASoS Engineering while growing a community of practice and the CASoS engineers to populate it. Both grounded in reality and working to extend our understanding and control of that reality, Phoenix is at the same time a solution within a CASoS and a CASoS itself

Career Attractiveness 1

A system dynamics model was developed in response to the apparent decline in STEM candidates in the United States and a pending shortage. The model explores the attractiveness of STEM and STEM careers focusing on employers and the workforce. Policies such as boosting STEM literacy, lifting the H-1B visa cap, limiting the offshoring of jobs, maintaining training and a combination of strategies are explored as possible solutions. The system is complex, with many feedbacks and long time delays, so solutions that focus on a single point of the system are not effective and cannot solve the problem. A deeper understanding of parts of the system that have not been explored to date is necessary to find a workable solution

SAND2011-8777 C Creating interaction environments: Defining a twosided

market model of the development and dominance of platform