56,085 research outputs found

    Proactive Assessment of Accident Risk to Improve Safety on a System of Freeways, Research Report 11-15

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    This report describes the development and evaluation of real-time crash risk-assessment models for four freeway corridors: U.S. Route 101 NB (northbound) and SB (southbound) and Interstate 880 NB and SB. Crash data for these freeway segments for the 16-month period from January 2010 through April 2011 are used to link historical crash occurrences with real-time traffic patterns observed through loop-detector data. \u27The crash risk-assessment models are based on a binary classification approach (crash and non-crash outcomes), with traffic parameters measured at surrounding vehicle detection station (VDS) locations as the independent variables. The analysis techniques used in this study are logistic regression and classification trees. Prior to developing the models, some data-related issues such as data cleaning and aggregation were addressed. The modeling efforts revealed that the turbulence resulting from speed variation is significantly associated with crash risk on the U.S. 101 NB corridor. The models estimated with data from U.S. 101 NB were evaluated on the basis of their classification performance, not only on U.S. 101 NB, but also on the other three freeway segments for transferability assessment. It was found that the predictive model derived from one freeway can be readily applied to other freeways, although the classification performance decreases. The models that transfer best to other roadways were determined to be those that use the least number of VDSs–that is, those that use one upstream or downstream station rather than two or three.\ The classification accuracy of the models is discussed in terms of how the models can be used for real-time crash risk assessment. The models can be applied to developing and testing variable speed limits (VSLs) and ramp-metering strategies that proactively attempt to reduce crash risk

    Assessment of mining activities with respect to the environmental protection

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    This paper deals with the impact of mining on the environment. Coal mining is still among the most widespread and most intense mining activity, which disturbs the landscape around us bringing regional environmental, economic and aesthetic problems. However, for many countries in the world, including the Czech Republic, deposits of raw materials play an important role, especially for purposes of producing electricity and thermal energy. At the same time, growing emphasis laid on the environmental protection can be observed worldwide. To meet the increasing ecological demands, it is reasonable to consider the most significant aspects of mining activities from the environmental point of view, as well as to consider the possibilities of the abandoned mines utilization as possible waste dumps. Parts of this problem consist in: the monitoring, environmental impacts assessment of exploration and mining activities and waste disposal mining, which may significantly contribute to the environmental protection in the future. Several parameters that can significantly affect the usability of the waste disposal mining, such as geological structure, hydro-geological conditions, material composition and physical and mechanical properties of rocks are discussed in detail in this work. The article also includes a practical example of Environmental Impact Assessment process for the particular activity of OKD stock company, which is the only producer of hard coal (bituminous coal) in the Czech Republic. Its coal is mined in the southern part of the Upper Silesian Coal Basin - in the Ostrava-Karvina coal district. KeywordsWeb of Science221937

    Alaska University Transportation Center 2012 Annual Report

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    Кибербезопасность в образовательных сетях

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    The paper discusses the possible impact of digital space on a human, as well as human-related directions in cyber-security analysis in the education: levels of cyber-security, social engineering role in cyber-security of education, “cognitive vaccination”. “A Human” is considered in general meaning, mainly as a learner. The analysis is provided on the basis of experience of hybrid war in Ukraine that have demonstrated the change of the target of military operations from military personnel and critical infrastructure to a human in general. Young people are the vulnerable group that can be the main goal of cognitive operations in long-term perspective, and they are the weakest link of the System.У статті обговорюється можливий вплив цифрового простору на людину, а також пов'язані з людиною напрямки кібербезпеки в освіті: рівні кібербезпеки, роль соціального інжинірингу в кібербезпеці освіти, «когнітивна вакцинація». «Людина» розглядається в загальному значенні, головним чином як та, що навчається. Аналіз надається на основі досвіду гібридної війни в Україні, яка продемонструвала зміну цілей військових операцій з військовослужбовців та критичної інфраструктури на людину загалом. Молодь - це вразлива група, яка може бути основною метою таких операцій в довгостроковій перспективі, і вони є найслабшою ланкою системи.В документе обсуждается возможное влияние цифрового пространства на человека, а также связанные с ним направления в анализе кибербезопасности в образовании: уровни кибербезопасности, роль социальной инженерии в кибербезопасности образования, «когнитивная вакцинация». «Человек» рассматривается в общем смысле, в основном как ученик. Анализ представлен на основе опыта гибридной войны в Украине, которая продемонстрировала изменение цели военных действий с военного персонала и критической инфраструктуры на человека в целом. Молодые люди являются уязвимой группой, которая может быть главной целью когнитивных операций в долгосрочной перспективе, и они являются самым слабым звеном Систем

    Marine Ship Automatic Identification System (AIS) for Enhanced Coastal Security Capabilities: An Oil Spill Tracking Application

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    National and international trade via shipping is already significant, and expected to continue increasing rapidly over the next decade. Both more ships and larger ships will contribute to this trade, includingships from countries with less rigorous shipping maintenance and inspection standards than the United States, and less strict pollution monitoring regulations. Changes in ship traffic management protocols have been implemented in recent years in the U.S. to minimize damage to coastlines, particularly near sensitive or protected marine environments. For example, to reduce risk to coastal resources off central California, shipping lanes for larger vessels were moved further offshore to allow for additional response time in case of accidents before such vessels might drift into coastal areas. Similarly, shipsare now routed via specific approach channels when entering Boston Harbor to reduce impacts within adjacent National Marine Sanctuary resources. Several recent high profile cases have occurred where \u27mystery\u27 oil spills were found near shipping channels, but no vessel could be readily identified as their source. These incidents lead to extensive and expensive efforts to attempt to identify the shipsresponsible. As time passes in responding to these incidents, the likelihood of confirming the identity of the ships diminishes. Unfortunately, reports of vessels engaging in illegal oily waste discharge to reduce fees for offloading the waste in port are ongoing. We here discuss use of improved capabilities of near-continuous real-time position location monitoring of shipping traffic using marine AutomaticIdentification Systems (AIS) for ships that would facilitate identification of ships responsible for illegal oily waste discharge. The next phase of the National AIS, N-AIS Increment 2, can supply additional spatial coverage not currently included in the N-AIS Increment 1, which can provide an enhanced capability for monitoring shipping and improving managem- ent of coastal ship traffic and response to pollution incidents. These methods will not only improve response time, but reduce cost of response as well

    European Arctic Initiatives Compendium

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