788 research outputs found
Capacity analysis of suburban rail networks
As is well known, capacity evaluation and the identification of bottlenecks on rail networks are complex issues depending upon several technical elements. This is even more perceptible in metropolitan areas where different services (freight, long distance, metro/regional, etc.) are operated using the same limited infrastructures; as a consequence, these facilities may represent bottlenecks of the rail system since they are often highly utilized and congested. This paper tries to explore the issue of capacity evaluation of complex rail networks, proposing synthetic indicators
and analyses for feasibility studies or strategic planning. The presented methodology suggests taking into account the main differences in infrastructure characteristics (e.g. single or double lines, signalling systems, terminus or passing stations, etc.) and rail services (e.g. diverse rolling stock, various frequencies, average distances and number of stops, etc.) in order to propose a general approach applicable for capacity analysis of a network as a whole, hence evaluating the utilization rate and the congestion on both lines and stations. To better explore and
validate the methodology, an application to a line of the Naples’ suburban network is presented. The results confirm the applicability and effectiveness of the proposed approach; the outcomes indicate the capacity utilization rate of the considered facilities, pointing out likely bottlenecks and possible actions to improve the system efficiency
Where is the ball? Behavioral and neural responses elicited by a magic trick
We present results from two experiments, in which subjects watched continuous videos of a professional magician repeatedly performing a maneuver in which a ball could “magically” appear under a cup. In all cases, subjects were asked to predict whether the ball would appear under the cup or not, while scalp EEG recordings were performed. Both experiments elicited strong and consistent behavioral and neural responses. In the first experiment, we used two blocks of videos with different probabilities of the ball appearing in the cup and found that, first, based on the behavioral responses, the subjects could track this probability change; and second, the different probabilities modulated the neural responses. In the second experiment, we introduced a control condition in which the magician performed the maneuver under the table, out of subjects' view. Comparing the two conditions (i.e., performing the maneuver within or out of the subjects' view), we found that, first, the magic trick dramatically biased the subjects' behavioral responses; and second, the two conditions led to differential neural responses, in spite of the fact that the stimulus triggering the evoked responses (seeing the ball in the cup) was exactly the same. Altogether, our results show how new insights into sensory and cognitive processing can be obtained using adapted magic tricks. Moreover, the approach of analyzing responses to continuous video presentations offers a more ecological setting compared to classic evoked potential paradigms, which are typically based on presenting static images flashed at the center of the screen
Mitochondrial cytochrome oxidase I in tetranychid mites : a comparison between molecular phylogeny and changes of morphological and life history traits
Spider mites, #Tetranychidae, represent one of the most cosmopolitan and economically important groups of terrestrial arthropods ; however, many aspects of their evolutionary relationships remain uncertain. We sequenced part of the mitochondrial cytochrome oxidase subunit I (COI) gene in 20 species of phytophagous mites belonging to nine genera and two families (#Tetranychidae and #Tenuipalpidae there seems to have been convergent evolution of these morphological characters together with independent development of a common adaptation to this mode of life in different genera. (Résumé d'auteur
Use of nile blue-doped silica nanoparticles as labels in heterogeneous immunoassays for antibiotic determination
III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce
Utilidad analítica del uso combinado de nanopartículas de Tb4O7 y Laccasa para la determinación de antioxidantes en alimentos
Association between Types of Soda Consumption and Overall Diet Quality: Evidence from National Health and Nutrition Examination Survey (NHANES)
Background and Purpose: Daily soda consumption may lead to high energy intake and poor diet quality. Although diet sodas contain no calories, they lack healthful nutrients. The study examined different types of soda consumption [regular (sugar-sweetened) sodas, diet sodas, and non-sodas] associated with overall diet quality. Methods: Cross sectional, 24-hour dietary recall data from the National Health and Nutrition Examination Survey (NHANES) from 2005-2012 were utilized for the study. Majority of the participants (n = 4,427) were female (57%), adults aged 19-55 years (51%), and non-Hispanic whites (67%). Nutritional Quality Index (NQI) was calculated as an indicator of diet quality. Multiple linear regression models were used to estimate the significant association between types of soda consumption and NQI stratified by body mass index. Results: Regular soda drinkers had lower NQI than diet soda drinkers, but only for overweight
Long-wavelength homogeneous fluoroimmunoassay for the veterinary antibiotic monensin using nile-blue doped silica nanoparticles
II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC
IoTsafe, Decoupling Security from Applications for a Safer IoT
The use of robust security solutions is a must for the Internet of Things (IoT) devices and their applications: regulators in different countries are creating frameworks for certifying those devices with an acceptable security level. However, even for already certified devices, security protocols have to be updated when a breach is found or a certain version becomes obsolete. Many approaches for securing IoT applications are nowadays based on the integration of a security layer [e.g., using transport layer security, (TLS)], but this may result in difficulties when upgrading the security algorithms, as the whole application has to be updated. This fact may shorten the life of IoT devices. As a way to overcome these difficulties, this paper presents IoTsafe, a novel approach relying on secure socket shell (SSH), a feasible alternative to secure communications in IoT applications based on hypertext transfer protocol (HTTP and HTTP/2). In order to illustrate its advantages, a comparison between the traditional approach (HTTP with TLS) and our scheme (HTTP with SSH) is performed over low-power wireless personal area networks (6loWPAN) through 802.15.4 interfaces. The results show that the proposed approach not only provides a more robust and easy-To-update solution, but it also brings an improvement to the overall performance in terms of goodput and energy consumption. Core server stress tests are also presented, and the server performance is also analyzed in terms of RAM consumption and escalation strategies
Sittin'On the Dock of the (WiFi) Bay: On the Frame Aggregation under IEEE 802.11 DCF
It is well known that frame aggregation in Internet communications improves
transmission efficiency. However, it also causes a delay that for some
real-time communications is inappropriate, thus creating a trade-off between
efficiency and delay. In this paper, we establish the conditions for frame
aggregation under the IEEE 802.11 DCF protocol to be beneficial on average
delay. To do so, we first describe the transmission time in IEEE 802.11 in a
stochastic framework and then we calculate the optimal value of the frames
that, when aggregated, saves transmission time in the long term. Our findings,
discussed with numerical experimentation, show that frame aggregation reduces
transmission congestion and transmission delays
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