Highway Crossing Control Using PTC Technology

Author(s):  
David F. Thurston

Positive Train Control (PTC) was mandated by Congress in 2008 to be installed on an extensive network of rail carriers within the United States before the end of 2015. As such, the short time frame for implementation has dictated that several key features that could be adopted within the train control area not be considered until the base development is finished. One of the areas that has been pushed off until later is the interface to Highway crossings. This is being explored in part by Caltrain in their Communications Based Overlay Signal System (CBOSS) project that adapts Incremental Train Control System (ITCS) protocols; however this approach does not undertake the full replacement of existing technology. This paper investigates the concept of operations for PTC controlled highway crossings with the premise that the existing train detection technology will be fully replaced by PTC and its train detection system. This will allow for much reduced hardware in the field while potentially adding additional functionality. Detailed analysis of the safety case will be introduced and interface logic will be included. Additional functions such as prediction, preemption, near side control and switching scenarios will be included in the research for both freight and passenger operations and how these situations can be addressed with available PTC technology.

Author(s):  
Stacie Pettit ◽  
Laura Rychly ◽  
Milisa Ziegler ◽  
Katie Walker

In this chapter, middle schools are presented metaphorically as layover airports, and the need to see middle schools as more like destinations is explored. How can positive learning experiences in middle schools be created given the short time frame and the transitional nature inherent in even the most effective middle schools? The metaphor of a layover airport that students often enter middle school expecting is juxtaposed to illustrating the characteristics of and potential for middle schools in the United States as destinations. This is done using exemplar experiences and middle schools from vastly different locations with varying characteristics and needs, yet all providing positive experiences for young adolescents. This comparison will be made based on what is known about the developmental nature and needs of young adolescents served in middle schools and also on recommendations for effective middle schools made by the Association for Middle Level Education.


2019 ◽  
Vol 131 ◽  
pp. 01045
Author(s):  
Songtong Han ◽  
Xiaoli Rong ◽  
Leixiang Bian ◽  
Mingyou Zhong ◽  
Lining Zhang

This paper introduces the physical model of unexploded ordnance (UXO) in the magnetization process and the formula derivation of the magnetic dipole model. The application of magnetometers and electromagnetic induction sensors in the detection of UXO is introduced. The magnetometers introduce the total field measurements technology of the CS optical-pump marine magnetometer and the MagSTAR (Magnetic Scalar Triangulation and Ranging) gradient detection technology. The electromagnetic induction sensors introduce the working theories and the popular product models of Geophex company and Geonics Ltd. The method of detecting UXO by MTADS of United States Naval Research Laboratory (The multisensor towed array detection system) compares the difference between the United States Naval Research Laboratory for target recognition.


Author(s):  
Martin Paul ◽  
Georg Tscheuschner ◽  
Stefan Herrmann ◽  
Michael G. Weller

The illegal use of explosives by terrorists and other criminals is an increasing issue in public spaces, such as airports, railway stations, highways, sports arenas, theaters, and other large buildings. Security in these environments can be achieved by a set of different means, including the installation of scanners and other analytical devices to detect ultra-small traces of explosives in a very short time-frame to be able to take action as early as possible to prevent the detonation of such devices. Unfortunately, an ideal explosive detection system still does not exist, which means that a compromise is needed in practice. Most detection devices lack the extreme analytical sensitivity, which is nevertheless necessary due to the low vapor pressure of nearly all explosives. In addition, the rate of false positives needs to be virtually zero, which is also very difficult to achieve. Here we present an immunosensor system based on kinetic competition, which is known to be very fast and may even overcome affinity limitation, which impairs the performance of many traditional competitive assays. This immunosensor consists of a monolithic glass column with a vast excess of immobilized hapten, which traps the fluorescently labeled antibody as long as no explosive is present. In the case of TNT occurring, some binding sites of the antibody will be blocked, which leads to an immediate breakthrough of the labeled protein, detectable by highly sensitive laser-induced fluorescence with the help of a Peltier-cooled CMOS camera. Liquid handling is performed with high-precision syringe pumps and chip-based mixing-devices and flow-cells. The system achieved limits of detection of 1 pM (1 ppt) of the fluorescent label and around 100 pM (20 ppt) of the explosive 2,4,6-trinitrotoluene (TNT). The total assay time is less than 8 min. A cross-reactivity test with 5000 pM solutions showed no signal by PETN, RDX, and HMX. This immunosensor belongs to the most sensitive and fastest detectors for TNT with no significant cross-reactivity by non-related compounds.


2015 ◽  
Author(s):  
Sierra Rayne ◽  
Kaya Forest

Annual and summertime trends towards increasingly variable values of the Palmer Drought Severity Index (PDSI) over a sub-decadal period (five years) were investigated within the contiguous United States between 1895 and the present. For the contiguous U.S. as a whole, there is a significant increasing trend in the five-year running minimum-maximum ranges for the annual PDSI (aPDSI5yr(min|max range)). During this time frame, the averageaPDSI5yr(min|max range)has increased by about one full unit, indicating a substantial increase is drought variability over short time scales across the United States. The end members of the runningaPDSI5yr(min|max range)highlight even more rapid changes in the drought index variability within the past 120 years. This increasing variability in theaPDSI5yr(min|max range)is driven primarily by changes taking place in the Pacific and Atlantic Ocean coastal climate regions, climate regions which collectively comprise one-third the area of the contiguous U.S. Overall, interannual drought patterns are becoming more extreme and difficult to predict, posing a challenge to agricultural and other water-resource related planning efforts.


1987 ◽  
Vol 81 (3) ◽  
pp. 961-966 ◽  
Author(s):  
Laura L. Vertz ◽  
John P. Frendreis ◽  
James L. Gibson

A current debate within the field of U.S. politics revolves around the extent to which the electorate is nationalized, that is, responds to national-level political forces. We provide additional evidence to help resolve this debate. Using the variance-components model of political effects developed by Stokes, we analyze presidential, senatorial, gubernatorial, and congressional races for the period 1962–1984. The results indicate that presidential races are highly nationalized, and congressional races largely localized. Senate and gubernatorial races are found to have a large state-level component to them. The analysis is also split into two segments to ascertain if a change in political effects is seen during this relatively short time frame; no such differences are found. We conclude that nationalization is not a process that can be understood from evidence provided by congressional races alone. Our results suggest that constituencies respond to political forces in a complex way, reacting to factors that are most relevant to a particular electoral contest.


1994 ◽  
Vol 33 (4I) ◽  
pp. 327-356 ◽  
Author(s):  
Richard G. Lipsey

I am honoured to be invited to give this lecture before so distinguished an audience of development economists. For the last 21/2 years I have been director of a project financed by the Canadian Institute for Advanced Research and composed of a group of scholars from Canada, the United States, and Israel.I Our brief is to study the determinants of long term economic growth. Although our primary focus is on advanced industrial countries such as my own, some of us have come to the conclusion that there is more common ground between developed and developing countries than we might have first thought. I am, however, no expert on development economics so I must let you decide how much of what I say is applicable to economies such as your own. Today, I will discuss some of the grand themes that have arisen in my studies with our group. In the short time available, I can only allude to how these themes are rooted in our more detailed studies. In doing this, I must hasten to add that I speak for myself alone; our group has no corporate view other than the sum of our individual, and very individualistic, views.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 801-807
Author(s):  
Nathaniel A Young ◽  
Ryan L Lambert ◽  
Angela M Buch ◽  
Christen L Dahl ◽  
Jackson D Harris ◽  
...  

ABSTRACT Introduction Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic compounds used industrially for a wide variety of applications. These PFAS compounds are very stable and persist in the environment. The PFAS contamination is a growing health issue as these compounds have been reported to impact human health and have been detected in both domestic and global water sources. Contaminated water found on military bases poses a potentially serious health concern for active duty military, their families, and the surrounding communities. Previous detection methods for PFAS in contaminated water samples require expensive and time-consuming testing protocols that limit the ability to detect this important global pollutant. The main objective of this work was to develop a novel detection system that utilizes a biological reporter and engineered bacteria as a way to rapidly and efficiently detect PFAS contamination. Materials and Methods The United States Air Force Academy International Genetically Engineered Machine team is genetically engineering Rhodococcus jostii strain RHA1 to contain novel DNA sequences composed of a propane 2-monooxygenase alpha (prmA) promoter and monomeric red fluorescent protein (mRFP). The prmA promoter is activated in the presence of PFAS and transcribes the mRFP reporter. Results The recombinant R. jostii containing the prmA promoter and mRFP reporter respond to exposure of PFAS by activating gene expression of the mRFP. At 100 µM of perfluorooctanoic acid, the mRFP expression was increased 3-fold (qRT-PCR). Rhodococcus jostii without exposure to PFAS compounds had no mRFP expression. Conclusions This novel detection system represents a synthetic biology approach to more efficiently detect PFAS in contaminated samples. With further refinement and modifications, a similar system could be readily deployed in the field around the world to detect this critical pollutant.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3872
Author(s):  
Klytaimnistra Katsara ◽  
George Kenanakis ◽  
Zacharias Viskadourakis ◽  
Vassilis M. Papadakis

For multiple years, food packaging migration has been a major concern in food and health sciences. Plastics, such as polyethylene, are continuously utilized in food packaging for preservation and easy handling purposes during transportation and storage. In this work, three types of cheese, Edam, Kefalotyri and Parmesan, of different hardness were studied under two complementary vibrational spectroscopy methods, ATR-FTIR and Raman spectroscopy, to determine the migration of low-density polyethylene from plastic packaging to the surface of cheese samples. The experimental duration of this study was set to 28 days due to the degradation time of the selected cheese samples, which is clearly visible after 1 month in refrigerated conditions at 4 °C. Raman and ATR-FTIR measurements were performed at a 4–3–4–3 day pattern to obtain comparative results. Initially, consistency/repeatability measurement tests were performed on Day0 for each sample of all cheese specimens to understand if there is any overlap between the characteristic Raman and ATR-FTIR peaks of the cheese with the ones from the low-density polyethylene package. We provide evidence that on Day14, peaks of low-density polyethylene appeared due to polymeric migration in all three cheese types we tested. In all cheese samples, microbial outgrowth started to develop after Day21, as observed visually and under the bright-field microscope, causing peak reverse. Food packaging migration was validated using two different approaches of vibrational spectroscopy (Raman and FT-IR), revealing that cheese needs to be consumed within a short time frame in refrigerated conditions at 4 °C.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1081
Author(s):  
Tamon Miyake ◽  
Shintaro Yamamoto ◽  
Satoshi Hosono ◽  
Satoshi Funabashi ◽  
Zhengxue Cheng ◽  
...  

Gait phase detection, which detects foot-contact and foot-off states during walking, is important for various applications, such as synchronous robotic assistance and health monitoring. Gait phase detection systems have been proposed with various wearable devices, sensing inertial, electromyography, or force myography information. In this paper, we present a novel gait phase detection system with static standing-based calibration using muscle deformation information. The gait phase detection algorithm can be calibrated within a short time using muscle deformation data by standing in several postures; it is not necessary to collect data while walking for calibration. A logistic regression algorithm is used as the machine learning algorithm, and the probability output is adjusted based on the angular velocity of the sensor. An experiment is performed with 10 subjects, and the detection accuracy of foot-contact and foot-off states is evaluated using video data for each subject. The median accuracy is approximately 90% during walking based on calibration for 60 s, which shows the feasibility of the static standing-based calibration method using muscle deformation information for foot-contact and foot-off state detection.


Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 673 ◽  
Author(s):  
John Clifton-Brown ◽  
Kai-Uwe Schwarz ◽  
Danny Awty-Carroll ◽  
Antonella Iurato ◽  
Heike Meyer ◽  
...  

Miscanthus, a C4 perennial grass native to Eastern Asia, is being bred to provide biomass for bioenergy and biorenewable products. Commercial expansion with the clonal hybrid M. × giganteus is limited by low multiplication rates, high establishment costs and drought sensitivity. These limitations can be overcome by breeding more resilient Miscanthus hybrids propagated by seed. Naturally occurring fast growing indigenous Miscanthus species are found in diverse environments across Eastern Asia. The natural diversity provides for plant breeders, the genetic resources to improve yield, quality, and resilience for a wide range of climates and adverse abiotic stresses. The challenge for Miscanthus breeding is to harness the diversity through selections of outstanding wild types, parents, and progenies over a short time frame to deploy hybrids that make a significant contribution to a world less dependent on fossil resources. Here are described the strategies taken by the Miscanthus breeding programme at Aberystwyth, UK and its partners. The programme built up one of the largest Miscanthus germplasm collections outside Asia. We describe the initial strategies to exploit the available genetic diversity to develop varieties. We illustrate the success of combining diverse Miscanthus germplasm and the selection criteria applied across different environments to identify promising hybrids and to develop these into commercial varieties. We discuss the potential for molecular selections to streamline the breeding process.


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