Subways and urban growth: evidence from earth

We investigate the relationship between the extent of a city’s subway network, its population and its spatial configuration. To accomplish this investigation, for the 632 largest cities in the world, we construct panel data describing the extent of each of the 138 subway systems in these cities, their population, and measures of centralization calculated from lights at night data. These data indicate that large cities are more likely to have subways, but that subways have an economically insignificant effect on urban population growth. Consistent with economic theory and with other studies of the effects of transportation improvements on cities, our data also indicate that subways cause cities to be more decentralized. For a subset of subway cities we also observe panel data describing subway and bus ridership. We find that a 10% increase in subway extent causes about a 6% increase in subway ridership and has no effect on bus ridership. Consistent with the available literature describing the effect of roads on cities, our results are consistent with subways having a larger effect on the configuration of cities than on their sizes, and with subways having a larger effect on discretionary than commute travel

Micro-Macro Analysis of Complex Networks

Complex systems have attracted considerable interest because of their wide range of applications, and are often studied via a \u201cclassic\u201d approach: study a specific system, find a complex network behind it, and analyze the corresponding properties. This simple methodology has produced a great deal of interesting results, but relies on an often implicit underlying assumption: the level of detail on which the system is observed. However, in many situations, physical or abstract, the level of detail can be one out of many, and might also depend on intrinsic limitations in viewing the data with a different level of abstraction or precision. So, a fundamental question arises: do properties of a network depend on its level of observability, or are they invariant? If there is a dependence, then an apparently correct network modeling could in fact just be a bad approximation of the true behavior of a complex system. In order to answer this question, we propose a novel micro-macro analysis of complex systems that quantitatively describes how the structure of complex networks varies as a function of the detail level. To this extent, we have developed a new telescopic algorithm that abstracts from the local properties of a system and reconstructs the original structure according to a fuzziness level. This way we can study what happens when passing from a fine level of detail (\u201cmicro\u201d) to a different scale level (\u201cmacro\u201d), and analyze the corresponding behavior in this transition, obtaining a deeper spectrum analysis. The obtained results show that many important properties are not universally invariant with respect to the level of detail, but instead strongly depend on the specific level on which a network is observed. Therefore, caution should be taken in every situation where a complex network is considered, if its context allows for different levels of observability

Mineta Transportation Institute Says Subways Are Still in Terrorists’ Sights

The FBI arrested a California National Guard reservist on March 17 as he headed for the Canadian border on his way to Syria. Once in Syria, Nicholas Michael Teausant, who is also a student at San Joaquin Delta Community College in Stockton CA, planned to join the Islamic State of Iraq and the Levant (ISIL). Although he had never attended the army’s basic training course and was in the process of being discharged by the National Guard for failing to meet “basic education requirements,” Teausant thought he could teach the Syrian jihadists shooting skills and urban warfare tactic

Sense, Model and Identify the Load Signatures of HVAC Systems in Metro Stations

The HVAC systems in subway stations are energy consuming giants, each of which may consume over 10, 000 Kilowatts per day for cooling and ventilation. To save energy for the HVAC systems, it is critically important to firstly know the "load signatures" of the HVAC system, i.e., the quantity of heat imported from the outdoor environments and by the passengers respectively in different periods of a day, which will significantly benefit the design of control policies. In this paper, we present a novel sensing and learning approach to identify the load signature of the HVAC system in the subway stations. In particular, sensors and smart meters were deployed to monitor the indoor, outdoor temperatures, and the energy consumptions of the HVAC system in real-time. The number of passengers was counted by the ticket checking system. At the same time, the cooling supply provided by the HVAC system was inferred via the energy consumption logs of the HVAC system. Since the indoor temperature variations are driven by the difference of the loads and the cooling supply, linear regression model was proposed for the load signature, whose coefficients are derived via a proposed algorithm . We collected real sensing data and energy log data from HaiDianHuangZhuang Subway station, which is in line 4 of Beijing from the duration of July 2012 to Sept. 2012. The data was used to evaluate the coefficients of the regression model. The experiment results show typical variation signatures of the loads from the passengers and from the outdoor environments respectively, which provide important contexts for smart control policies.Comment: 5 pages, 5 figure

Carnage Interrupted: An Analysis of Fifteen Terrorist Plots against Public Surface Transportation, Research Report 11-20

This report examines 13 terrorist plots against public surface transportation that were uncovered and foiled by authorities between 1997 and 2010 and two failed attempts to carry out attacks. Certainly, this is not the total universe of foiled or failed terrorist plots in these years, but they were selected on the basis of what is known about them and the accessibility of information. The report focuses on terrorist plots in the West. Seven of the 15 plots took place in the United States, and four occurred in the United Kingdom. These two countries figure prominently as targets of terrorism, and in addition, American and British officials have dealt with terrorist plots through publicized arrests and trials, which provide additional information. Although motive was not a criterion in the selection of the plots, all but one involve individuals or groups inspired by al Qaeda’s ideology of violent global jihad against the West. The exception is the 1997 Flatbush plot, in which two terrorists, both of whom had connections with Hamas, angered by events in Palestine, simply wanted to kill as many Jews as possible to express their opposition to U.S. support for Israel. Other sources suggest that the Flatbush plotters wanted to force the release of jailed Islamist terrorists in the United States, including Ramzi Yousef, who participated in the 1993 World Trade Center bombing, and Sheik Omar Abdul-Rahman, who was convicted for his involvement in a plot to carry out additional bombings in New York

State of New York Public Employment Relations Board Decisions from October 29, 1976

10_29_1976_PERB_BD_DecisionsOCR.pdf: 55 downloads, before Oct. 1, 2020