Most vital segment barriers

We study continuous analogues of "vitality" for discrete network flows/paths, and consider problems related to placing segment barriers that have highest impact on a flow/path in a polygonal domain. This extends the graph-theoretic notion of "most vital arcs" for flows/paths to geometric environments. We give hardness results and efficient algorithms for various versions of the problem, (almost) completely separating hard and polynomially-solvable cases

Street Egohood: An Alternative Perspective of Measuring Neighborhood and Spatial Patterns of Crime

Objectives: The current study proposes an approach that accounts for the importance of streets while at the same time accounting for the overlapping spatial nature of social and physical environments captured by the egohood approach. Our approach utilizes overlapping clusters of streets based on the street network distance, which we term street egohoods. Methods: We used the street segment as a base unit and employed two strategies in clustering the street segments: (1) based on the First Order Queen Contiguity; and (2) based on the street network distance considering physical barriers. We utilized our approaches for measuring ecological factors and estimated crime rates in the Los Angeles metropolitan area. Results: We found that whereas certain socio-demographics, land use, and business employee measures show stronger relationships with crime when measured at the smaller street based unit, a number of them actually exhibited stronger relationships when measured using our larger street egohoods. We compared the results for our three-sized street egohoods to street segments and two sizes of block egohoods proposed by Hipp and Boessen (Criminology 51(2):287–327, 2013) and found that two egohood strategies essentially are not different at the quarter mile egohood level but this similarity appears lower when looking at the half mile egohood level. Also, the street egohood models are a better fit for predicting violent and property crime compared to the block egohood models. Conclusions: A primary contribution of the current study is to develop and propose a new perspective of measuring neighborhood based on urban streets. We empirically demonstrated that whereas certain socio-demographic measures show the strongest relationship with crime when measured at the micro geographic unit of street segments, a number of them actually exhibited the strongest relationship when measured using our larger street egohoods. We hope future research can use egohoods to expand understanding of neighborhoods and crime

Low-Stress Bicycling and Network Connectivity

For a bicycling network to attract the widest possible segment of the population, its most fundamental attribute should be low-stress connectivity, that is, providing routes between people’s origins and destinations that do not require cyclists to use links that exceed their tolerance for traffic stress, and that do not involve an undue level of detour. The objective of this study is to develop measures of low-stress connectivity that can be used to evaluate and guide bicycle network planning. We propose a set of criteria by which road segments can be classified into four levels of traffic stress (LTS). LTS 1 is suitable for children; LTS 2, based on Dutch bikeway design criteria, represents the traffic stress that most adults will tolerate; LTS 3 and 4 represent greater levels of stress. As a case study, every street in San Jose, California, was classified by LTS. Maps in which only bicycle-friendly links are displayed reveal a city divided into islands within which low-stress bicycling is possible, but separated from one another by barriers that can be crossed only by using high-stress links. Two points in the network are said to be connected at a given level of traffic stress if the subnetwork of links that do not exceed the specified level of stress connects them with a path whose length does not exceed a detour criterion (25% longer than the most direct path). For the network as a whole, we demonstrate two measures of connectivity that can be applied for a given level of traffic stress. One is “percent trips connected,” defined as the fraction of trips in the regional trip table that can be made without exceeding a specified level of stress and without excessive detour. This study used the home-to-work trip table, though in principle any trip table, including all trips, could be used. The second is “percent nodes connected,” a cruder measure that does not require a regional trip table, but measures the fraction of nodes in the street network (mostly street intersections) that are connected to each other. Because traffic analysis zones (TAZs) are too coarse a geographic unit for evaluating connectivity by bicycle, we also demonstrate a method of disaggregating the trip table from the TAZ level to census blocks. For any given TAZ, origins in the home-to-work trip table are allocated in proportion to population, while destinations are allocated based on land-use data. In the base case, the fraction of work trips up to six miles long that are connected at LTS 2 is 4.7%, providing a plausible explanation for the city’s low bicycling share. We show that this figure would almost triple if a proposed slate of improvements, totaling 32 miles in length but with strategically placed segments that provide low-stress connectivity across barriers, were implemented

Identifying attack surfaces in the evolving space industry using reference architectures

The space environment is currently undergoing a substantial change and many new entrants to the market are deploying devices, satellites and systems in space; this evolution has been termed as NewSpace. The change is complicated by technological developments such as deploying machine learning based autonomous space systems and the Internet of Space Things (IoST). In the IoST, space systems will rely on satellite-to-x communication and interactions with wider aspects of the ground segment to a greater degree than existing systems. Such developments will inevitably lead to a change in the cyber security threat landscape of space systems. Inevitably, there will be a greater number of attack vectors for adversaries to exploit, and previously infeasible threats can be realised, and thus require mitigation. In this paper, we present a reference architecture (RA) that can be used to abstractly model in situ applications of this new space landscape. The RA specifies high-level system components and their interactions. By instantiating the RA for two scenarios we demonstrate how to analyse the attack surface using attack trees

A Quest for Equality: Breaking the Barriers for People with Disabilities

Over the past decade, significant advances in accessibility of infrastructure, public transportation, housing and public accommodations have positively impacted the lives of people with disabilities across the country. In Illinois, Chicago is fast becoming a national leader in opportunity, inclusion and accessibility for people with disabilities. However, theChicago Public Schools do not keep pace with the rest of the state in serving students with disabilities. Although some areas of the state have made great progress, Illinois significantly lags behind other states in the implementation of progressive policies and fiscal resources that ensure the true integration of individuals with disabilities into their communities.This report highlights key areas where Illinois' programs and policies require more serious attention: community living, education and youth transition, and employment. The report provides problem statements, illustrative statistics, goals and recommendations for each of these topics.Within each of the key topics, a target date of 2015 has been set for the implementation or achievement of the proposed goals. This date coincides with the 40th anniversary of the federal Individuals with Disabilities Education Act and the 25th anniversary of the Americans with Disabilities Act, two vital pieces of legislation in the disability rights movement. To uphold the promise of these important laws, this report discusses issues that are key to improving the quality of life for Illinoisans with disabilities

Low-Income Single Mothers at Community Colleges: Recommendations for Practices to Improve Completion

Low-income, single mothers beginning or returning to higher education overwhelmingly choose to pursue their goals at community colleges. These schools often provide the best fit of available institutions because of their relative affordability, variety of offerings, ease of entry, and proximity to the student. Like other higher learning institutions, however, many community colleges struggle to address the challenges low-income, single mothers can face. Colleges often unwittingly place more obstacles in the path of these students.Many colleges are taking action and trying a variety of approaches to improve their institutions and better serve low-income, single mother students. While some interventions have been rigorously studied, most have not. Many promising interventions, though so far lacking empirical support, have shown great success based on student and provider testimony. When taken as a whole, it is clear that community colleges can undertake effective interventions to help student parents complete their programs and meet their goals

Scaling Up Inclusive Business -- Solutions to Overcome Internal Barriers

Sustainability challenges including poverty, social unrest, climate change and environmental degradation have become ever more urgent. Business has the technology, innovation capacity, resources, and skills to play a key role in providing the radical solutions the world desperately needs.The objective of this brief is to kick off greater dialogue on the internal barriers companies face along the pathway to scale in inclusive business and how to overcome them. Building on the hands-on experience of businesses active in this space and the valuable insights of experts, the following pages identify some of the most common internal barriers and the solutions that leading companies are using to tackle them. We gained new insights by looking at the work of thirteen companies: CEMEX, Grundfos, Grupo Corona, ITC Ltd., Lafarge, Masisa, Nestlé, Novartis, Novozymes, SABMiller, Schneider Electric, The Coca-Cola Company, and Vodafone. We also interviewed two leading academics doing research in this area, Cornell University's Erik Simanis (United States) and Universidad de los Andes' Ezequiel Reficco (Colombia)

The Green Economy and Job Creation: Inclusion of People with Disabilities

The percentage of total employment associated with green goods and services has increased in the United States over the past several years, presenting employment opportunities in a number of related emerging fields. As employment options arise to provide green goods and services, people with disabilities should have equitable employment opportunities in this growth sector of the American economy. A focused strategy to train and engage people with disabilities in the green economy can provide a talented and largely untapped segment of the U.S. workforce, a greater opportunity to participate in this growing employment sector than previously realized