Observations of freeway traffic flow are usually quite scattered about an underlying curve when plotted versus density or occupancy. Although increasing the sampling intervals can reduce the scatter, whenever an experiment encompasses a rush hour with transitions in and out of congestion, some outlying data stubbornly remain beneath the "equilibrium" curve. The existence of these non-equilibrium points is an ill-understood phenomenon that appears to contradict the simple kinematic wave (KW) model of traffic flow. This paper provides a tentative explanation of the phenomenon, based on experimental evidence. The evidence was a queue that grew and receded over two detector stations, generating typical flow-density scatter-plots at both locations. The locations were far from other interacting traffic streams. The data revealed that a transition zone where vehicles decelerated gradually existed immediately behind the queue. The transition zone was quite wide (about 1 km at both locations), moved slowly (approximately with the "shock" velocityof KW theory) and spent many minutes over each detector station. Disequilibrium flow-density points arose only when the transition zone was over the detectors, suggesting that the transition zone explains their occurrence. The disequilibrium points drifted gradually from one branch of the curve to the other, as KW theory would have predicted if "shocks" had a characteristic width equal to the dimension of the transition zone. Nothing was found in the data to contradict this view. The paper also shows that if one neglects the shocks' physical dimension, the resulting errors are unimportant for practical purposes. Thus, it appears that KW theory can predict traffic behavior at the back of queues when the lanes at the back of the queue are equally attractive to all drivers.

This report describes field observations of multi-lane freeway traffic upstream of an oversaturated off-ramp. It is based on empirical evidence from freeway I-880 (northbound) near Oakland, California. The report presents two diagnostic tools that reveal hidden features of the traffic stream and, based on these findings, proposes congestion mitigation strategies that could work for similar locations with little or no construction.

Ask most commuters and they will agree that congestion has reached an intolerable level. To reduce this congestion, engineers need detailed traffic information. Highly detailed information is also prized by traffic scientists, as a prerequisite to improve current traffic theories. Ideally, engineers and scientists would like to obtain from field data the position of each vehicle on a particular facility at every moment in time. The technology to record space-time vehicle trajectories on a massive scale is in its infancy; therefore, analysts must work with much less data. Many freeways are equipped with primitive sensors that can record only anonymous vehicle passages at specific locations with a time series of 0's and 1's. Typically, these detectors are installed on all lanes at sites, called stations, which are spaced about 1 km apart. This article will show that, despite the anonymity and the spatial discreteness of the measurements, a treasure trove of detailed information can be recovered from 0-1 detector data, if one analyzes the data with the right tools. Field data from a 5-lane freeway in Oakland, California (see Figure 1) is used to demonstrate the ideas.

Tuberculosis (TB) is an airborne disease that kills 1.5 million people and affects ~ 9 million worldwide. Its etiological agent, Mycobacterium tuberculosis (Mtb), persists in a third of the general population. There is also an emergent problem of drug and multidrug resistance in Mtb that creates the need for novel drugs. In the treatment against TB, one target of antibiotics is the prokaryotic RNA polymerase (RNAP), an essential multitask enzyme that catalyzes RNA synthesis during transcription. Rifampicin, the first-line antibiotic anti-TB, binds and inhibits the MtbRNAP.Consequently, combatting TB requires a better understanding of the primary mechanism of transcription by MtbRNAP. In fact, during Mtb transcription, unique and essential factors might affect the MtbRNAP dynamics and regulate its activity. That regulation plays a significant role in the adaptation and pathogenesis of the parasite. Therefore, understanding how these factors and new antibiotics modulate together the MtbRNAP activity will contribute valid information to address TB. To this end, we use a single-molecule approach based on high-resolution optical tweezers to study transcription elongation by MtbRNAP in the context of its DNA elements, transcriptional factors, and antibiotics.

This paper presents the most complete picture yet of moving bottlenecks on freeways, including experimental observations and a theory. The experimental observations include the “fingerprint” of a moving bottleneck on a series of loop detectors, and a set of controlled experiments in which moving bottlenecks were artificially introduced in the traffic stream. The paper also contrasts this evidence with current theories and describes a new one that is consistent with the data.

High-resolution oblique plots of loop detector data from freeway I-880 in Oakland (California) are used to analyze the aforementioned fingerprint. They clearly display the presence of the bottleneck and its evolution in time and space, including the precise location in space-time where it appeared. The data also reveal a fleeting but real change in the drivers’ car-following attitude shortly after the bottleneck’s appearance.

The controlled experiments reveal that the flow downstream of the bottleneck increases with the speed of the bottleneck when the bottleneck holds back a queue—in contradiction with two previous theories (Gazis and Herman, 1992, and Newell, 1993).

The new theory includes these as special cases. It treats the moving bottleneck as a boundary condition that can be integrated with kinematic wave (KW) theory and also with variants of this theory that account for multiple vehicle types and changes in driver psychology. The empirical evidence suggests that the lengths of queues upstream of moving bottlenecks and the ensuing vehicle delays can now be predicted with good accuracy.

This report presents ten strategies for improving freeway performance that have become feasible with the advent of new software and hardware technologies for traffic control. Most of the strategies can be applied with advanced implementations of existing hardware. The strategies have in common that they can be rigorously tested. heir measures of performance can be reliably obtained and do not depend on the accuracy of data- hungry, large-scale models.

O presente artigo investiga a exposição de Paulo Climachauska Ronda noturna realizada em 2015. Momentos centrais das narrativas sobre a modernidade e a arte brasileiras são colocados em xeque nesse conjunto de trabalhos por meio do contraste da racionalidade construtiva com a violência das metrópoles brasileiras. Ronda Noturna elabora, assim, nexos sociais, políticos, culturais e econômicos da realidade e da arte promovendo uma leitura complexa das relações de poder transnacionais.

(MAVs) is limited due to the large but necessary onboard technology, obstacles involving the overall weight, and the need for ideal wing designs. These challenges are Over the last decade, the MAV (micro air vehicle) field has developed in that there have been great improvements in designs due to advances in computer aided technology, power supply due to better battery technology, and visual communications due to better transmitters and receivers. Different kinds of MAVs are now in existence, all with their own specific capabilities and limitations.

Despite the progress in various areas, the advancement of Micro Air Vehicles due to the need to have onboard MAV technology must include sensors and processors in order to fully achieve autonomous flight operation. Unfortunately, current hardware is too big to be handled by smaller components than those in present day UAVs. One of the biggest concerns is the battery life since there are multiple things operating on an MAV. Further research must be done in order to shrink the battery to a promising size while still providing the MAV hardware with enough energy to function. Weight is an important element to consider on an air vehicle for it effects what is referred to as the turning radius; the angle at which a flying vehicle can make a sharp turn around an obstacle, e.g., a building. Furthermore, weight also affects other key elements for flight such as drag and lift. While comparing biological wing models, there is noticeable, recurring “flapping” wing design such as on birds or insects. For most of today’s flight technology, they are mainly focused on using static wing designs. As these two wing designs have difference advantages, the overall issue then becomes the determination on whether or not one is more expedient than the other when implemented into an MAV design.

A Micro Air Vehicle is not whole all on its own; it is composed of multiple, independent concepts that must harmonize in such a way that they simultaneously compensate for each other’s flaws while reinforcing their strengths for optimizing performance and efficiency. Primarily, an object’s weight is what is noticed first when flight is a desired task. Because MAVs must carry specific tools for designated missions, their own weight is important. For example, the more it weighs, the less they can carry. Closely related to this concept, another crucial element to an MAV’s development and performance is its size. While examining this thought, it can be acknowledged that there are many biological and synthetic objects of many sizes that possess the ability of flight. With this fact, we can initially conclude that size has no correlation with flight, but when observed closely, the style and efficiency of flight is directly dependent on the weight of the object. Furthermore, if we look at a biological example, the flight of a honeybee is completely different to that of a fully-grown hawk. However, when looking one step forward, observations would reveal their wings are completely different. Today, when thinking about flying objects, there are only a few ideas that come to mind when thinking about their wings. An MAV’s performance strongly relies on the kind of wing design it has. More specifically, with the example of the honeybee and the hawk, though both excellent candidates of flight, the honeybee’s wing design allows it to be much more maneuverable while flying than the hawk and its different wing design. Thus based off of this example, should an MAV’s wing design be more carefully decided? It is evident that putting an efficient MAV together is a challenge, but in the individual research for these independent elements, an ideal relationship will arise. For these reasons, researchers must take into account various factors to try to create a balance in design.