Methods and computer executable instructions for rapidly calculating simulated particle transport through geometrically modeled treatment volumes having uniform volume elements for use in radiotherapy

DOEpatents

Frandsen, Michael W.; Wessol, Daniel E.; Wheeler, Floyd J.

2001-01-16

Methods and computer executable instructions are disclosed for ultimately developing a dosimetry plan for a treatment volume targeted for irradiation during cancer therapy. The dosimetry plan is available in "real-time" which especially enhances clinical use for in vivo applications. The real-time is achieved because of the novel geometric model constructed for the planned treatment volume which, in turn, allows for rapid calculations to be performed for simulated movements of particles along particle tracks there through. The particles are exemplary representations of neutrons emanating from a neutron source during BNCT. In a preferred embodiment, a medical image having a plurality of pixels of information representative of a treatment volume is obtained. The pixels are: (i) converted into a plurality of substantially uniform volume elements having substantially the same shape and volume of the pixels; and (ii) arranged into a geometric model of the treatment volume. An anatomical material associated with each uniform volume element is defined and stored. Thereafter, a movement of a particle along a particle track is defined through the geometric model along a primary direction of movement that begins in a starting element of the uniform volume elements and traverses to a next element of the uniform volume elements. The particle movement along the particle track is effectuated in integer based increments along the primary direction of movement until a position of intersection occurs that represents a condition where the anatomical material of the next element is substantially different from the anatomical material of the starting element. This position of intersection is then useful for indicating whether a neutron has been captured, scattered or exited from the geometric model. From this intersection, a distribution of radiation doses can be computed for use in the cancer therapy. The foregoing represents an advance in computational times by multiple factors of time magnitudes.

A geometry package for generation of input data for a three-dimensional potential-flow program

NASA Technical Reports Server (NTRS)

Halsey, N. D.; Hess, J. L.

1978-01-01

The preparation of geometric data for input to three-dimensional potential flow programs was automated and simplified by a geometry package incorporated into the NASA Langley version of the 3-D lifting potential flow program. Input to the computer program for the geometry package consists of a very sparse set of coordinate data, often with an order of magnitude of fewer points than required for the actual potential flow calculations. Isolated components, such as wings, fuselages, etc. are paneled automatically, using one of several possible element distribution algorithms. Curves of intersection between components are calculated, using a hybrid curve-fit/surface-fit approach. Intersecting components are repaneled so that adjacent elements on either side of the intersection curves line up in a satisfactory manner for the potential-flow calculations. Many cases may be run completely (from input, through the geometry package, and through the flow calculations) without interruption. Use of the package significantly reduces the time and expense involved in making three-dimensional potential flow calculations.

Analytical Investigation of Elastic Thin-Walled Cylinder and Truncated Cone Shell Intersection Under Internal Pressure.

PubMed

Zamani, J; Soltani, B; Aghaei, M

2014-10-01

An elastic solution of cylinder-truncated cone shell intersection under internal pressure is presented. The edge solution theory that has been used in this study takes bending moments and shearing forces into account in the thin-walled shell of revolution element. The general solution of the cone equations is based on power series method. The effect of cone apex angle on the stress distribution in conical and cylindrical parts of structure is investigated. In addition, the effect of the intersection and boundary locations on the circumferential and longitudinal stresses is evaluated and it is shown that how quantitatively they are essential.

Climate Change and a Global City: An Assessment of the Metropolitan East Coast Region

NASA Technical Reports Server (NTRS)

Rosenzweig, Cynthia; Solecki, William

1999-01-01

The objective of the research is to derive an assessment of the potential climate change impacts on a global city - in this case the 31 county region that comprises the New York City metropolitan area. This study comprises one of the regional components that contribute to the ongoing U.S. National Assessment: The Potential Consequences of Climate Variability and Change and is an application of state-of-the-art climate change science to a set of linked sectoral assessment analyses for the Metro East Coast (MEC) region. We illustrate how three interacting elements of global cities react and respond to climate variability and change with a broad conceptual model. These elements include: people (e.g., socio- demographic conditions), place (e.g., physical systems), and pulse (e.g., decision-making and economic activities). The model assumes that a comprehensive assessment of potential climate change can be derived from examining the impacts within each of these elements and at their intersections. Thus, the assessment attempts to determine the within-element and the inter-element effects. Five interacting sector studies representing the three intersecting elements are evaluated. They include the Coastal Zone, Infrastructure, Water Supply, Public Health, and Institutional Decision-making. Each study assesses potential climate change impacts on the sector and on the intersecting elements, through the analysis of the following parts: 1. Current conditions of sector in the region; 2. Lessons and evidence derived from past climate variability; 3. Scenario predictions affecting sector; potential impacts of scenario predictions; 4. Knowledge/information gaps and critical issues including identification of additional research questions, effectiveness of modeling efforts, equity of impacts, potential non-local interactions, and policy recommendations; and 5. Identification of coping strategies - i.e., resilience building, mitigation strategies, new technologies, education that affects decision-making, and better preparedness for contingencies.

Multistate metadynamics for automatic exploration of conical intersections

NASA Astrophysics Data System (ADS)

Lindner, Joachim O.; Röhr, Merle I. S.; Mitrić, Roland

2018-05-01

We introduce multistate metadynamics for automatic exploration of conical intersection seams between adiabatic Born-Oppenheimer potential energy surfaces in molecular systems. By choosing the energy gap between the electronic states as a collective variable the metadynamics drives the system from an arbitrary ground-state configuration toward the intersection seam. Upon reaching the seam, the multistate electronic Hamiltonian is extended by introducing biasing potentials into the off-diagonal elements, and the molecular dynamics is continued on a modified potential energy surface obtained by diagonalization of the latter. The off-diagonal bias serves to locally open the energy gap and push the system to the next intersection point. In this way, the conical intersection energy landscape can be explored, identifying minimum energy crossing points and the barriers separating them. We illustrate the method on the example of furan, a prototype organic molecule exhibiting rich photophysics. The multistate metadynamics reveals plateaus on the conical intersection energy landscape from which the minimum energy crossing points with characteristic geometries can be extracted. The method can be combined with the broad spectrum of electronic structure methods and represents a generally applicable tool for the exploration of photophysics and photochemistry in complex molecules and materials.

Determination of the sequence of intersecting lines using Focused Ion Beam/Scanning Electron Microscope.

PubMed

Kim, Jiye; Kim, MinJung; An, JinWook; Kim, Yunje

2016-05-01

The aim of this study was to verify that the combination of focused ion beam (FIB) and scanning electron microscope/energy-dispersive X-ray (SEM/EDX) could be applied to determine the sequence of line crossings. The samples were transferred into FIB/SEM for FIB milling and an imaging operation. EDX was able to explore the chemical components and the corresponding elemental distribution in the intersection. The technique was successful in determining the sequence of heterogeneous line intersections produced using gel pens and red sealing ink with highest success rate (100% correctness). These observations show that the FIB/SEM was the appropriate instrument for an overall examination of document. © 2016 American Academy of Forensic Sciences.

High density associative memory

NASA Technical Reports Server (NTRS)

Moopenn, Alexander W. (Inventor); Thakoor, Anilkumar P. (Inventor); Daud, Taher (Inventor); Lambe, John J. (Inventor)

1989-01-01

A multi-layered, thin-film, digital memory having associative recall. There is a first memory matrix and a second memory matrix. Each memory matrix comprises, a first layer comprising a plurality of electrically separated row conductors; a second layer comprising a plurality of electrically separated column conductors intersecting but electrically separated from the row conductors; and, a plurality of resistance elements electrically connected between the row condutors and the column conductors at respective intersections of the row conductors and the column conductors, each resistance element comprising, in series, a first resistor of sufficiently high ohmage to conduct a sensible element current therethrough with virtually no heat-generating power consumption when a low voltage as employed in thin-film applications is applied thereacross and a second resistor of sufficiently high ohmage to conduct no sensible current therethrough when a low voltage as employed in thin-film applications is applied thereacross, the second resistor having the quality of breaking down to create a short therethrough upon the application of a breakdown level voltage across the first and second resistors.

Precise deformation measurement of prestressed concrete beam during a strain test using the combination of intersection photogrammetry and micro-network measurement

NASA Astrophysics Data System (ADS)

Urban, Rudolf; Braun, Jaroslav; Štroner, Martin

2015-05-01

The prestressed thin-walled concrete elements enable the bridge a relatively large span. These structures are advantageous in economic and environmental way due to their thickness and lower consumption of materials. The bending moments can be effectively influenced by using the pre-stress. The experiment was done to monitor deformation of the under load. During the experiment the discrete points were monitored. To determine a large number of points, the intersection photogrammetry combined with precise micro-network were chosen. Keywords:

Intersection of Intimate Partner Violence and HIV in Women

MedlinePlus

... and recommended data elements, version 1.0. Atlanta, GA: Centers for Disease Control and Prevention, National Center ... Sexual Violence Survey (NISVS): 2010 Summary Report. Atlanta, GA: National Center for Injury Prevention and Control, Centers ...

Method of forming a variable width channel

NASA Technical Reports Server (NTRS)

Andrews, James T. (Inventor)

1989-01-01

A method of forming a channel of varying width in a body comprises the steps of forming a plurality of masking elements having an opening therethrough intersecting a plurality of the elements on a surface of the body, partially flowing the elements into the opening to form a masking pattern having a variable width opening therethrough, and removing portions of the exposed body to form the channel with a sidewall having a surface contour corresponding to an edge of the masking pattern.

A Qualitative Approach to the Intersection of Sexual, Ethnic, and Gender Identities.

PubMed

Narvaez, Rafael F; Meyer, Ilan H; Kertzner, Robert M; Ouellette, Suzanne C; Gordon, Allegra R

In this paper we report on a new qualitative instrument designed to study the intersection of identities related to sexuality and race/ethnicity, and how people who hold those identities interact with social contexts. Researchers often resort to using separate measures to assess race/ethnicity, sexual orientation, and other target identities. But this approach can miss elements of a self-system that stem from the intersection of identities, the interactions between identities and social contexts, related shifts in identity over time, and related changes in the prominence and valence of identities. Using a small sub-sample, we demonstrate how our instrument can help researchers overcome these limitations. Our instrument was also designed for economy in administration and analysis, so that it could be used as a qualitative complement in large survey research.

A Qualitative Approach to the Intersection of Sexual, Ethnic, and Gender Identities

PubMed Central

Narvaez, Rafael F.; Meyer, Ilan H.; Kertzner, Robert M.; Ouellette, Suzanne C.; Gordon, Allegra R.

2016-01-01

In this paper we report on a new qualitative instrument designed to study the intersection of identities related to sexuality and race/ethnicity, and how people who hold those identities interact with social contexts. Researchers often resort to using separate measures to assess race/ethnicity, sexual orientation, and other target identities. But this approach can miss elements of a self-system that stem from the intersection of identities, the interactions between identities and social contexts, related shifts in identity over time, and related changes in the prominence and valence of identities. Using a small sub-sample, we demonstrate how our instrument can help researchers overcome these limitations. Our instrument was also designed for economy in administration and analysis, so that it could be used as a qualitative complement in large survey research PMID:27683200

Moving Particles Through a Finite Element Mesh

PubMed Central

Peskin, Adele P.; Hardin, Gary R.

1998-01-01

We present a new numerical technique for modeling the flow around multiple objects moving in a fluid. The method tracks the dynamic interaction between each particle and the fluid. The movements of the fluid and the object are directly coupled. A background mesh is designed to fit the geometry of the overall domain. The mesh is designed independently of the presence of the particles except in terms of how fine it must be to track particles of a given size. Each particle is represented by a geometric figure that describes its boundary. This figure overlies the mesh. Nodes are added to the mesh where the particle boundaries intersect the background mesh, increasing the number of nodes contained in each element whose boundary is intersected. These additional nodes are then used to describe and track the particle in the numerical scheme. Appropriate element shape functions are defined to approximate the solution on the elements with extra nodes. The particles are moved through the mesh by moving only the overlying nodes defining the particles. The regular finite element grid remains unchanged. In this method, the mesh does not distort as the particles move. Instead, only the placement of particle-defining nodes changes as the particles move. Element shape functions are updated as the nodes move through the elements. This method is especially suited for models of moderate numbers of moderate-size particles, where the details of the fluid-particle coupling are important. Both the complications of creating finite element meshes around appreciable numbers of particles, and extensive remeshing upon movement of the particles are simplified in this method. PMID:28009377

Determining partial differential cross sections for low-energy electron photodetachment involving conical intersections using the solution of a Lippmann-Schwinger equation constructed with standard electronic structure techniques.

PubMed

Han, Seungsuk; Yarkony, David R

2011-05-07

A method for obtaining partial differential cross sections for low energy electron photodetachment in which the electronic states of the residual molecule are strongly coupled by conical intersections is reported. The method is based on the iterative solution to a Lippmann-Schwinger equation, using a zeroth order Hamiltonian consisting of the bound nonadiabatically coupled residual molecule and a free electron. The solution to the Lippmann-Schwinger equation involves only standard electronic structure techniques and a standard three-dimensional free particle Green's function quadrature for which fast techniques exist. The transition dipole moment for electron photodetachment, is a sum of matrix elements each involving one nonorthogonal orbital obtained from the solution to the Lippmann-Schwinger equation. An expression for the electron photodetachment transition dipole matrix element in terms of Dyson orbitals, which does not make the usual orthogonality assumptions, is derived.

Simplified welding distortion analysis for fillet welding using composite shell elements

NASA Astrophysics Data System (ADS)

Kim, Mingyu; Kang, Minseok; Chung, Hyun

2015-09-01

This paper presents the simplified welding distortion analysis method to predict the welding deformation of both plate and stiffener in fillet welds. Currently, the methods based on equivalent thermal strain like Strain as Direct Boundary (SDB) has been widely used due to effective prediction of welding deformation. Regarding the fillet welding, however, those methods cannot represent deformation of both members at once since the temperature degree of freedom is shared at the intersection nodes in both members. In this paper, we propose new approach to simulate deformation of both members. The method can simulate fillet weld deformations by employing composite shell element and using different thermal expansion coefficients according to thickness direction with fixed temperature at intersection nodes. For verification purpose, we compare of result from experiments, 3D thermo elastic plastic analysis, SDB method and proposed method. Compared of experiments results, the proposed method can effectively predict welding deformation for fillet welds.

Concept mapping applied to the intersection between older adults' outdoor walking and the built and social environments.

PubMed

Hanson, Heather M; Schiller, Claire; Winters, Meghan; Sims-Gould, Joanie; Clarke, Philippa; Curran, Eileen; Donaldson, Meghan G; Pitman, Beverley; Scott, Vicky; McKay, Heather A; Ashe, Maureen C

2013-12-01

For older adults, the ability to navigate walking routes in the outdoor environment allows them to remain active and socially engaged, facilitating community participation and independence. In order to enhance outdoor walking, it is important to understand the interaction of older adults within their local environments and the influence of broader stakeholder priorities that impact these environments. Thus, we aimed to synthesize perspectives from stakeholders to identify elements of the built and social environments that influence older adults' ability to walk outdoors. We applied a concept mapping approach with the input of diverse stakeholders (N=75) from British Columbia, Canada in 2012. A seven-cluster map best represented areas that influence older adults' outdoor walking. Priority areas identified included sidewalks, crosswalks, and neighborhood features. Individual perceptions and elements of the built and social environments intersect to influence walking behaviors, although targeted studies that address this area are needed. © 2013.

A rigorous approach to the formulation of extended Born-Oppenheimer equation for a three-state system

NASA Astrophysics Data System (ADS)

Sarkar, Biplab; Adhikari, Satrajit

If a coupled three-state electronic manifold forms a sub-Hilbert space, it is possible to express the non-adiabatic coupling (NAC) elements in terms of adiabatic-diabatic transformation (ADT) angles. Consequently, we demonstrate: (a) Those explicit forms of the NAC terms satisfy the Curl conditions with non-zero Divergences; (b) The formulation of extended Born-Oppenheimer (EBO) equation for any three-state BO system is possible only when there exists coordinate independent ratio of the gradients for each pair of ADT angles leading to zero Curls at and around the conical intersection(s). With these analytic advancements, we formulate a rigorous EBO equation and explore its validity as well as necessity with respect to the approximate one (Sarkar and Adhikari, J Chem Phys 2006, 124, 074101) by performing numerical calculations on two different models constructed with different chosen forms of the NAC elements.

Analysis of silicon on insulator (SOI) optical microring add-drop filter based on waveguide intersections

NASA Astrophysics Data System (ADS)

Kaźmierczak, Andrzej; Bogaerts, Wim; Van Thourhout, Dries; Drouard, Emmanuel; Rojo-Romeo, Pedro; Giannone, Domenico; Gaffiot, Frederic

2008-04-01

We present a compact passive optical add-drop filter which incorporates two microring resonators and a waveguide intersection in silicon-on-insulator (SOI) technology. Such a filter is a key element for designing simple layouts of highly integrated complex optical networks-on-chip. The filter occupies an area smaller than 10μm×10μm and exhibits relatively high quality factors (up to 4000) and efficient signal dropping capabilities. In the present work, the influence of filter parameters such as the microring-resonators radii and the coupling section shape are analyzed theoretically and experimentally

Modeling 3D PCMI using the Extended Finite Element Method with higher order elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, W.; Spencer, Benjamin W.

2017-03-31

This report documents the recent development to enable XFEM to work with higher order elements. It also demonstrates the application of higher order (quadratic) elements to both 2D and 3D models of PCMI problems, where discrete fractures in the fuel are represented using XFEM. The modeling results demonstrate the ability of the higher order XFEM to accurately capture the effects of a crack on the response in the vicinity of the intersecting surfaces of cracked fuel and cladding, as well as represent smooth responses in the regions away from the crack.

Minimizing Actuator-Induced Residual Error in Active Space Telescope Primary Mirrors

DTIC Science & Technology

2010-09-01

actuator geometry, and rib-to-facesheet intersection geometry are exploited to achieve improved performance in silicon carbide ( SiC ) mirrors . A...are exploited to achieve improved performance in silicon carbide ( SiC ) mirrors . A parametric finite element model is used to explore the trade space...MOST) finite element model. The move to lightweight actively-controlled silicon carbide ( SiC ) mirrors is traced back to previous generations of space

A re-evaluation of finite-element models and stress-intensity factors for surface cracks emanating from stress concentrations

NASA Technical Reports Server (NTRS)

Tan, P. W.; Raju, I. S.; Shivakumar, K. N.; Newman, J. C., Jr.

1988-01-01

A re-evaluation of the 3-D finite-element models and methods used to analyze surface crack at stress concentrations is presented. Previous finite-element models used by Raju and Newman for surface and corner cracks at holes were shown to have ill-shaped elements at the intersection of the hole and crack boundaries. These ill-shaped elements tended to make the model too stiff and, hence, gave lower stress-intensity factors near the hole-crack intersection than models without these elements. Improved models, without these ill-shaped elements, were developed for a surface crack at a circular hole and at a semi-circular edge notch. Stress-intensity factors were calculated by both the nodal-force and virtual-crack-closure methods. Both methods and different models gave essentially the same results. Comparisons made between the previously developed stress-intensity factor equations and the results from the improved models agreed well except for configurations with large notch-radii-to-plate-thickness ratios. Stress-intensity factors for a semi-elliptical surface crack located at the center of a semi-circular edge notch in a plate subjected to remote tensile loadings were calculated using the improved models. The ratio of crack depth to crack length ranged form 0.4 to 2; the ratio of crack depth to plate thickness ranged from 0.2 to 0.8; and the ratio of notch radius to the plate thickness ranged from 1 to 3. The models had about 15,000 degrees-of-freedom. Stress-intensity factors were calculated by using the nodal-force method.

Comparison of Geothermobarometers with Different Closure Behavior to Constrain P-T Paths

NASA Astrophysics Data System (ADS)

Hora, J.; Simon, K.; Kronz, A.; Xiao, Y.; Worner, G.

2014-12-01

Temperatures obtained from geothermobarometers depend not only on minerals reaching equilibrium, but also on preservation of those compositions through subsequent thermal history. In the case of step-function cooling histories (volcanic systems), each of several geothermometry equations (with P-dependence) can be treated as a line in P-T space for a given composition. In the absence of independent P-constraint, intersection of those lines corresponds to the simultaneous solution of the equations involved and is indicative of crystallization and storage conditions. Multiple calibrations of a given thermometer can be evaluated by their degree of match. For protracted plutonic or metamorphic cooling histories, a single intersection is not expected - instead, calculated temperatures will reflect a sequence of mineral closure based on diffusivity of the element(s) of interest in the various phases. We apply this multi-thermometer approach to quartz, rutile, and titanite formed along the retrograde path in gneiss and eclogite at Bixiling, Dabie UHP terrane, China. Using the Huang and Audetat (2012) Ti-in-quartz thermometer calibration, all available Zr-in-rutile equations intersect at approximately 7-10 kbar and 560-580°C. Zr-in-rutile calibrations diverge at higher P, and intersect the Thomas et al. (2010) Ti-in-quartz calibration over a broader range of 13-16 kbar and 550-600°C. Regardless of which intersection is used, it appears that both of these minerals have reequilibrated far below the previously reported peak conditions of >30 kbar and >750°C. Titanite, where diffusion is slower, is present in the gneiss unit as late-stage overgrowths on rutile, but records T that are approximately 150°C higher than the rutile inclusions at all P. This appears to be consistent with all minerals forming above 750°C and possibly much higher P, with quartz and rutile being reset along the retrograde path due to more rapid diffusion. When crystal sizes are taken into account, rutile and quartz are predicted to close to Zr and Ti exchange at similar T ≈ 600-650°C. Intersections of P-T lines among two or more minerals with similar closure behavior may reflect P,T at points along a retrograde path or can be used to constrain cooling rate, and may have advantages relative to using a single thermobarometer.

Wave function continuity and the diagonal Born-Oppenheimer correction at conical intersections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meek, Garrett A.; Levine, Benjamin G., E-mail: levine@chemistry.msu.edu

2016-05-14

We demonstrate that though exact in principle, the expansion of the total molecular wave function as a sum over adiabatic Born-Oppenheimer (BO) vibronic states makes inclusion of the second-derivative nonadiabatic energy term near conical intersections practically problematic. In order to construct a well-behaved molecular wave function that has density at a conical intersection, the individual BO vibronic states in the summation must be discontinuous. When the second-derivative nonadiabatic terms are added to the Hamiltonian, singularities in the diagonal BO corrections (DBOCs) of the individual BO states arise from these discontinuities. In contrast to the well-known singularities in the first-derivative couplingsmore » at conical intersections, these singularities are non-integrable, resulting in undefined DBOC matrix elements. Though these singularities suggest that the exact molecular wave function may not have density at the conical intersection point, there is no physical basis for this constraint. Instead, the singularities are artifacts of the chosen basis of discontinuous functions. We also demonstrate that continuity of the total molecular wave function does not require continuity of the individual adiabatic nuclear wave functions. We classify nonadiabatic molecular dynamics methods according to the constraints placed on wave function continuity and analyze their formal properties. Based on our analysis, it is recommended that the DBOC be neglected when employing mixed quantum-classical methods and certain approximate quantum dynamical methods in the adiabatic representation.« less

Wave function continuity and the diagonal Born-Oppenheimer correction at conical intersections

NASA Astrophysics Data System (ADS)

Meek, Garrett A.; Levine, Benjamin G.

2016-05-01

We demonstrate that though exact in principle, the expansion of the total molecular wave function as a sum over adiabatic Born-Oppenheimer (BO) vibronic states makes inclusion of the second-derivative nonadiabatic energy term near conical intersections practically problematic. In order to construct a well-behaved molecular wave function that has density at a conical intersection, the individual BO vibronic states in the summation must be discontinuous. When the second-derivative nonadiabatic terms are added to the Hamiltonian, singularities in the diagonal BO corrections (DBOCs) of the individual BO states arise from these discontinuities. In contrast to the well-known singularities in the first-derivative couplings at conical intersections, these singularities are non-integrable, resulting in undefined DBOC matrix elements. Though these singularities suggest that the exact molecular wave function may not have density at the conical intersection point, there is no physical basis for this constraint. Instead, the singularities are artifacts of the chosen basis of discontinuous functions. We also demonstrate that continuity of the total molecular wave function does not require continuity of the individual adiabatic nuclear wave functions. We classify nonadiabatic molecular dynamics methods according to the constraints placed on wave function continuity and analyze their formal properties. Based on our analysis, it is recommended that the DBOC be neglected when employing mixed quantum-classical methods and certain approximate quantum dynamical methods in the adiabatic representation.

Wave function continuity and the diagonal Born-Oppenheimer correction at conical intersections.

PubMed

Meek, Garrett A; Levine, Benjamin G

2016-05-14

We demonstrate that though exact in principle, the expansion of the total molecular wave function as a sum over adiabatic Born-Oppenheimer (BO) vibronic states makes inclusion of the second-derivative nonadiabatic energy term near conical intersections practically problematic. In order to construct a well-behaved molecular wave function that has density at a conical intersection, the individual BO vibronic states in the summation must be discontinuous. When the second-derivative nonadiabatic terms are added to the Hamiltonian, singularities in the diagonal BO corrections (DBOCs) of the individual BO states arise from these discontinuities. In contrast to the well-known singularities in the first-derivative couplings at conical intersections, these singularities are non-integrable, resulting in undefined DBOC matrix elements. Though these singularities suggest that the exact molecular wave function may not have density at the conical intersection point, there is no physical basis for this constraint. Instead, the singularities are artifacts of the chosen basis of discontinuous functions. We also demonstrate that continuity of the total molecular wave function does not require continuity of the individual adiabatic nuclear wave functions. We classify nonadiabatic molecular dynamics methods according to the constraints placed on wave function continuity and analyze their formal properties. Based on our analysis, it is recommended that the DBOC be neglected when employing mixed quantum-classical methods and certain approximate quantum dynamical methods in the adiabatic representation.

Density of convex intersections and applications

PubMed Central

Rautenberg, C. N.; Rösel, S.

2017-01-01

In this paper, we address density properties of intersections of convex sets in several function spaces. Using the concept of Γ-convergence, it is shown in a general framework, how these density issues naturally arise from the regularization, discretization or dualization of constrained optimization problems and from perturbed variational inequalities. A variety of density results (and counterexamples) for pointwise constraints in Sobolev spaces are presented and the corresponding regularity requirements on the upper bound are identified. The results are further discussed in the context of finite-element discretizations of sets associated with convex constraints. Finally, two applications are provided, which include elasto-plasticity and image restoration problems. PMID:28989301

Method for Balancing Detector Output to a Desired Level of Balance at a Frequency

NASA Technical Reports Server (NTRS)

Sachse, Glenn W. (Inventor)

2003-01-01

A multi-gas sensor is provided which modulates a polarized light beam over a broadband of wavelengths between two alternating orthogonal polarization components. The two orthogonal polarization components of the polarization modulated beam are directed along two distinct optical paths. At least one optical path contains one or more spectral discrimination elements, with each spectral discrimination element having spectral absorption features of one or more gases of interest being measured. The two optical paths then intersect, and one orthogonal component of the intersected components is transmitted and the other orthogonal component is reflected. The combined polarization modulated beam is partitioned into one or more smaller spectral regions of interest where one or more gases of interest has an absorption band. The difference in intensity between the two orthogonal polarization components is then determined in each partitioned spectral region of interest as an indication of the spectral emission/absorption of the light beam by the gases of interest in the measurement path. The spectral emission/absorption is indicative of the concentration of the one or more gases of interest in the measurement path. More specifically, one embodiment of the present invention is a gas filter correlation radiometer which comprises a polarizer, a polarization modulator, a polarization beam splitter, a beam combiner, wavelength partitioning element, and detection element. The gases of interest are measured simultaneously and, further, can be measured independently or non-independently. Furthermore, optical or electronic element are provided to balance optical intensities between the two optical paths.

Multi-Gas Sensor

NASA Technical Reports Server (NTRS)

Sachse, Glenn W. (Inventor); Wang, Liang-Guo (Inventor); LeBel, Peter J. (Inventor); Steele, Tommy C. (Inventor); Rana, Mauro (Inventor)

1999-01-01

A multi-gas sensor is provided which modulates a polarized light beam over a broadband of wavelengths between two alternating orthogonal polarization components. The two orthogonal polarization components of the polarization modulated beam are directed along two distinct optical paths. At least one optical path contains one or more spectral discrimination element, with each spectral discrimination element having spectral absorption features of one or more gases of interest being measured. The two optical paths then intersect, and one orthogonal component of the intersected components is transmitted and the other orthogonal component is reflected. The combined polarization modulated beam is partitioned into one or more smaller spectral regions of interest where one or more gases of interest has an absorption band. The difference in intensity between the two orthogonal polarization components is then determined in each partitioned spectral region of interest as an indication of the spectral emission/absorption of the light beam by the gases of interest in the measurement path. The spectral emission/absorption is indicative of the concentration of the one or more gases of interest in the measurement path. More specifically, one embodiment of the present invention is a gas filter correlation radiometer which comprises a polarizer, a polarization modulator, a polarization beam splitter, a beam combiner, wavelength partitioning element, and detection element. The gases of interest are measured simultaneously and, further, can be measured independently or non-independently. Furthermore, optical or electronic element are provided to balance optical intensities between the two optical paths.

High-mast light poles anchor nut loosening in Alaska : an investigation of field monitoring and finite-element analysis.

DOT National Transportation Integrated Search

2014-09-01

High mast lighting poles (HMLPs) are tall, roadside structures effective for lighting large areas of highways and intersections. The Alaska Department of Transportation : and Public Facilities (AKDOT&PF) maintains 118 such poles in the greater Anchor...

Target intersection probabilities for parallel-line and continuous-grid types of search

USGS Publications Warehouse

McCammon, R.B.

1977-01-01

The expressions for calculating the probability of intersection of hidden targets of different sizes and shapes for parallel-line and continuous-grid types of search can be formulated by vsing the concept of conditional probability. When the prior probability of the orientation of a widden target is represented by a uniform distribution, the calculated posterior probabilities are identical with the results obtained by the classic methods of probability. For hidden targets of different sizes and shapes, the following generalizations about the probability of intersection can be made: (1) to a first approximation, the probability of intersection of a hidden target is proportional to the ratio of the greatest dimension of the target (viewed in plane projection) to the minimum line spacing of the search pattern; (2) the shape of the hidden target does not greatly affect the probability of the intersection when the largest dimension of the target is small relative to the minimum spacing of the search pattern, (3) the probability of intersecting a target twice for a particular type of search can be used as a lower bound if there is an element of uncertainty of detection for a particular type of tool; (4) the geometry of the search pattern becomes more critical when the largest dimension of the target equals or exceeds the minimum spacing of the search pattern; (5) for elongate targets, the probability of intersection is greater for parallel-line search than for an equivalent continuous square-grid search when the largest dimension of the target is less than the minimum spacing of the search pattern, whereas the opposite is true when the largest dimension exceeds the minimum spacing; (6) the probability of intersection for nonorthogonal continuous-grid search patterns is not greatly different from the probability of intersection for the equivalent orthogonal continuous-grid pattern when the orientation of the target is unknown. The probability of intersection for an elliptically shaped target can be approximated by treating the ellipse as intermediate between a circle and a line. A search conducted along a continuous rectangular grid can be represented as intermediate between a search along parallel lines and along a continuous square grid. On this basis, an upper and lower bound for the probability of intersection of an elliptically shaped target for a continuous rectangular grid can be calculated. Charts have been constructed that permit the values for these probabilities to be obtained graphically. The use of conditional probability allows the explorationist greater flexibility in considering alternate search strategies for locating hidden targets. ?? 1977 Plenum Publishing Corp.

Robust Seismic Normal Modes Computation in Radial Earth Models and A Novel Classification Based on Intersection Points of Waveguides

NASA Astrophysics Data System (ADS)

Ye, J.; Shi, J.; De Hoop, M. V.

2017-12-01

We develop a robust algorithm to compute seismic normal modes in a spherically symmetric, non-rotating Earth. A well-known problem is the cross-contamination of modes near "intersections" of dispersion curves for separate waveguides. Our novel computational approach completely avoids artificial degeneracies by guaranteeing orthonormality among the eigenfunctions. We extend Wiggins' and Buland's work, and reformulate the Sturm-Liouville problem as a generalized eigenvalue problem with the Rayleigh-Ritz Galerkin method. A special projection operator incorporating the gravity terms proposed by de Hoop and a displacement/pressure formulation are utilized in the fluid outer core to project out the essential spectrum. Moreover, the weak variational form enables us to achieve high accuracy across the solid-fluid boundary, especially for Stoneley modes, which have exponentially decaying behavior. We also employ the mixed finite element technique to avoid spurious pressure modes arising from discretization schemes and a numerical inf-sup test is performed following Bathe's work. In addition, the self-gravitation terms are reformulated to avoid computations outside the Earth, thanks to the domain decomposition technique. Our package enables us to study the physical properties of intersection points of waveguides. According to Okal's classification theory, the group velocities should be continuous within a branch of the same mode family. However, we have found that there will be a small "bump" near intersection points, which is consistent with Miropol'sky's observation. In fact, we can loosely regard Earth's surface and the CMB as independent waveguides. For those modes that are far from the intersection points, their eigenfunctions are localized in the corresponding waveguides. However, those that are close to intersection points will have physical features of both waveguides, which means they cannot be classified in either family. Our results improve on Okal's classification, demonstrating that dispersion curves from independent waveguides should be considered to break at intersection points.

40 CFR 52.1162 - Regulation for bicycle use.

Code of Federal Regulations, 2010 CFR

2010-07-01

... painted lanes, pavement coloring or other appropriate markings. A peak hour bike lane means a bike lane... following elements: (1) The physical design for bikeways, intersections involving bikeways, and means of... conversion from auto use; (11) The special problems related to the design and incorporation in the bikeway...

40 CFR 52.1162 - Regulation for bicycle use.

Code of Federal Regulations, 2013 CFR

2013-07-01

... painted lanes, pavement coloring or other appropriate markings. A peak hour bike lane means a bike lane... following elements: (1) The physical design for bikeways, intersections involving bikeways, and means of... conversion from auto use; (11) The special problems related to the design and incorporation in the bikeway...

40 CFR 52.1162 - Regulation for bicycle use.

Code of Federal Regulations, 2012 CFR

2012-07-01

... painted lanes, pavement coloring or other appropriate markings. A peak hour bike lane means a bike lane... following elements: (1) The physical design for bikeways, intersections involving bikeways, and means of... conversion from auto use; (11) The special problems related to the design and incorporation in the bikeway...

40 CFR 52.1162 - Regulation for bicycle use.

Code of Federal Regulations, 2011 CFR

2011-07-01

... painted lanes, pavement coloring or other appropriate markings. A peak hour bike lane means a bike lane... following elements: (1) The physical design for bikeways, intersections involving bikeways, and means of... conversion from auto use; (11) The special problems related to the design and incorporation in the bikeway...

40 CFR 52.1162 - Regulation for bicycle use.

Code of Federal Regulations, 2014 CFR

2014-07-01

... painted lanes, pavement coloring or other appropriate markings. A peak hour bike lane means a bike lane... following elements: (1) The physical design for bikeways, intersections involving bikeways, and means of... conversion from auto use; (11) The special problems related to the design and incorporation in the bikeway...

Investigation of anchor nut loosening in high-mast light poles using field monitoring and finite element analysis.

DOT National Transportation Integrated Search

2014-09-01

High mast lighting poles (HMLPs) are cost effective structures for lighting highways and intersections. They are 100 to 250 feet (30m to 76m) tall, and can hold a variety of lamp configurations. They are : commonly used at highway interchanges becaus...

Interlaminar stress singularities at a straight free edge in composite laminates

NASA Technical Reports Server (NTRS)

Raju, I. S.; Crews, J. H., Jr.

1980-01-01

A quasi three dimensional finite element analysis was used to analyze the edge stress problem in four-ply, composite laminates. Convergence studies were made to explore the existence of stress singularities near the free edge. The existence of stress singularities at the intersection of the interface and the free edge is confirmed.

Fatima's Rules and Other Elements of an Unintended Chemistry Curriculum.

ERIC Educational Resources Information Center

Larson, Jane O.

Descriptions of curriculum often divide it into components entitled intended, implemented, and learned. Each domain intersects with the next to form a sequence of events in which curriculum, teacher, and students are major participants in the process of curriculum modulation. The focus of the research reported in this paper was to study the…

Teachers from Five Nations Share Perspectives on Culture and Citizenship

ERIC Educational Resources Information Center

Sunal, Cynthia Szymanski; Christensen, Lois McFadyen; Shwery, Craig S.; Lovorn, Michael; Sunal, Dennis W.

2010-01-01

Online discussions enabled preK-12 teachers (n = 125) from five nations (Brazil, Colombia, Ecuador, Paraguay, and the United States) to share their perspectives of culture and citizenship and the intersections of those concepts. Discussion moved between elements of personal and others' theory into effects of theory on practice. Teachers identified…

Artificial Intelligence, Computational Thinking, and Mathematics Education

ERIC Educational Resources Information Center

Gadanidis, George

2017-01-01

Purpose: The purpose of this paper is to examine the intersection of artificial intelligence (AI), computational thinking (CT), and mathematics education (ME) for young students (K-8). Specifically, it focuses on three key elements that are common to AI, CT and ME: agency, modeling of phenomena and abstracting concepts beyond specific instances.…

Elemental line scanning of an increment core using EDXRF: from fundamental research to environmental forensics applications

Treesearch

Kevin T. Smith; Jean Christophe Balouet; Gil Oudijk

2008-01-01

Environmental forensics seeks to determine the responsible parties for contamination from leaks or spills of petroleum or other toxic products. Dendrochemistry contributes to environmental forensics at the intersection of analytical chemistry, tree biology, and environmental responsibility. To be useful, dendrochemistry requires the rigorous application of analytical...

Multiflavor string-net models

NASA Astrophysics Data System (ADS)

Lin, Chien-Hung

2017-05-01

We generalize the string-net construction to multiple flavors of strings, each of which is labeled by the elements of an Abelian group Gi. The same flavor of strings can branch, while different flavors of strings can cross one another and thus they form intersecting string nets. We systematically construct the exactly soluble lattice Hamiltonians and the ground-state wave functions for the intersecting string-net condensed phases. We analyze the braiding statistics of the low-energy quasiparticle excitations and find that our model can realize all the topological phases as the string-net model with group G =∏iGi . In this respect, our construction provides various ways of building lattice models which realize topological order G , corresponding to different partitions of G and thus different flavors of string nets. In fact, our construction concretely demonstrates the Künneth formula by constructing various lattice models with the same topological order. As an example, we construct the G =Z2×Z2×Z2 string-net model which realizes a non-Abelian topological phase by properly intersecting three copies of toric codes.

Interacting Effects Induced by Two Neighboring Pits Considering Relative Position Parameters and Pit Depth

PubMed Central

Huang, Yongfang; Gang, Tieqiang; Chen, Lijie

2017-01-01

For pre-corroded aluminum alloy 7075-T6, the interacting effects of two neighboring pits on the stress concentration are comprehensively analyzed by considering various relative position parameters (inclination angle θ and dimensionless spacing parameter λ) and pit depth (d) with the finite element method. According to the severity of the stress concentration, the critical corrosion regions, bearing high susceptibility to fatigue damage, are determined for intersecting and adjacent pits, respectively. A straightforward approach is accordingly proposed to conservatively estimate the combined stress concentration factor induced by two neighboring pits, and a concrete application example is presented. It is found that for intersecting pits, the normalized stress concentration factor Ktnor increases with the increase of θ and λ and always reaches its maximum at θ = 90°, yet for adjacent pits, Ktnor decreases with the increase of λ and the maximum value appears at a slight asymmetric location. The simulations reveal that Ktnor follows a linear and an exponential relationship with the dimensionless depth parameter Rd for intersecting and adjacent cases, respectively. PMID:28772758

Wide-Field Retroreflectors

NASA Technical Reports Server (NTRS)

Page, Norman A.; Tubbs, Eldred F.

1994-01-01

Retroreflectors made of concentric spherical optical elements developed for use in interferometric metrological systems. Used to provide reference point on structure to be aligned precisely in two or three dimensions by use of intersecting laser beams. Acceptance angle much larger than that of cat's-eye or corner-cube retroreflector: Simultaneously reflects laser beams separated by angles as large as 180 degrees.

As technology and generations in medical education change, what remains is the intersection between educator, learners, assessment and context.

PubMed

Azzam, Amin

2013-06-01

The information era has begun to create major shifts in educational systems, including those in undergraduate medical and graduate psychiatric training programmes. Despite these changes, teaching and learning in formal educational settings remains predominately the product of the intersection between educator, learners, assessment and context. This article reviews intrinsic and external forces influencing each of these elements, such as intergenerational differences in teaching and learning styles, education technologies as they relate to delivery and maintenance of curricula, competency frameworks of assessment, and individual learning and teaching development plans. Maintaining a focus on the relationship between these factors and re-conceptualizing psychiatric education and formal medical education systems in general as a mutual two-way learning exchange between participants will promote careers of lifelong learning.

The Productivity of Students' Schoolwork: An Exercise in Marxist Rigour

ERIC Educational Resources Information Center

Baldino, Roberto Ribeiro; Cabral, Tânia Cristina Baptista

2013-01-01

In this article we will use central elements in Mature Marx's theory of productive labour to prove that not only the work of teachers and staff but also the expenditure of students' muscles and nerves is productive labour. This theme has some intersection with the work of housewives that autonomist Marxism asserts to be productive labour…

Obtaining Approximate Values of Exterior Orientation Elements of Multi-Intersection Images Using Particle Swarm Optimization

NASA Astrophysics Data System (ADS)

Li, X.; Li, S. W.

2012-07-01

In this paper, an efficient global optimization algorithm in the field of artificial intelligence, named Particle Swarm Optimization (PSO), is introduced into close range photogrammetric data processing. PSO can be applied to obtain the approximate values of exterior orientation elements under the condition that multi-intersection photography and a small portable plane control frame are used. PSO, put forward by an American social psychologist J. Kennedy and an electrical engineer R.C. Eberhart, is a stochastic global optimization method based on swarm intelligence, which was inspired by social behavior of bird flocking or fish schooling. The strategy of obtaining the approximate values of exterior orientation elements using PSO is as follows: in terms of image coordinate observed values and space coordinates of few control points, the equations of calculating the image coordinate residual errors can be given. The sum of absolute value of each image coordinate is minimized to be the objective function. The difference between image coordinate observed value and the image coordinate computed through collinear condition equation is defined as the image coordinate residual error. Firstly a gross area of exterior orientation elements is given, and then the adjustment of other parameters is made to get the particles fly in the gross area. After iterative computation for certain times, the satisfied approximate values of exterior orientation elements are obtained. By doing so, the procedures like positioning and measuring space control points in close range photogrammetry can be avoided. Obviously, this method can improve the surveying efficiency greatly and at the same time can decrease the surveying cost. And during such a process, only one small portable control frame with a couple of control points is employed, and there are no strict requirements for the space distribution of control points. In order to verify the effectiveness of this algorithm, two experiments are carried out. In the first experiment, images of a standard grid board are taken according to multi-intersection photography using digital camera. Three points or six points which are located on the left-down corner of the standard grid are regarded as control points respectively, and the exterior orientation elements of each image are computed through PSO, and compared with these elements computed through bundle adjustment. In the second experiment, the exterior orientation elements obtained from the first experiment are used as approximate values in bundle adjustment and then the space coordinates of other grid points on the board can be computed. The coordinate difference of grid points between these computed space coordinates and their known coordinates can be used to compute the accuracy. The point accuracy computed in above experiments are ±0.76mm and ±0.43mm respectively. The above experiments prove the effectiveness of PSO used in close range photogrammetry to compute approximate values of exterior orientation elements, and the algorithm can meet the requirement of higher accuracy. In short, PSO can get better results in a faster, cheaper way compared with other surveying methods in close range photogrammetry.

Variable-Resistivity Material For Memory Circuits

NASA Technical Reports Server (NTRS)

Nagasubramanian, Ganesan; Distefano, Salvador; Moacanin, Jovan

1989-01-01

Nonvolatile memory elements packed densely. Electrically-erasable, programmable, read-only memory matrices made with newly-synthesized organic material of variable electrical resistivity. Material, polypyrrole doped with tetracyanoquinhydrone (TCNQ), changes reversibly between insulating or higher-resistivity state and conducting or low-resistivity state. Thin film of conductive polymer separates layer of row conductors from layer of column conductors. Resistivity of film at each intersection and, therefore, resistance of memory element defined by row and column, increased or decreased by application of suitable switching voltage. Matrix circuits made with this material useful for experiments in associative electronic memories based on models of neural networks.

Thin, nearly wireless adaptive optical device

NASA Technical Reports Server (NTRS)

Knowles, Gareth (Inventor); Hughes, Eli (Inventor)

2008-01-01

A thin, nearly wireless adaptive optical device capable of dynamically modulating the shape of a mirror in real time to compensate for atmospheric distortions and/or variations along an optical material is provided. The device includes an optical layer, a substrate, at least one electronic circuit layer with nearly wireless architecture, an array of actuators, power electronic switches, a reactive force element, and a digital controller. Actuators are aligned so that each axis of expansion and contraction intersects both substrate and reactive force element. Electronics layer with nearly wireless architecture, power electronic switches, and digital controller are provided within a thin-film substrate. The size and weight of the adaptive optical device is solely dominated by the size of the actuator elements rather than by the power distribution system.

Thin, nearly wireless adaptive optical device

NASA Technical Reports Server (NTRS)

Knowles, Gareth (Inventor); Hughes, Eli (Inventor)

2007-01-01

A thin, nearly wireless adaptive optical device capable of dynamically modulating the shape of a mirror in real time to compensate for atmospheric distortions and/or variations along an optical material is provided. The device includes an optical layer, a substrate, at least one electronic circuit layer with nearly wireless architecture, an array of actuators, power electronic switches, a reactive force element, and a digital controller. Actuators are aligned so that each axis of expansion and contraction intersects both substrate and reactive force element. Electronics layer with nearly wireless architecture, power electronic switches, and digital controller are provided within a thin-film substrate. The size and weight of the adaptive optical device is solely dominated by the size of the actuator elements rather than by the power distribution system.

Thin nearly wireless adaptive optical device

NASA Technical Reports Server (NTRS)

Knowles, Gareth J. (Inventor); Hughes, Eli (Inventor)

2009-01-01

A thin nearly wireless adaptive optical device capable of dynamically modulating the shape of a mirror in real time to compensate for atmospheric distortions and/or variations along an optical material is provided. The device includes an optical layer, a substrate, at least one electronic circuit layer with nearly wireless architecture, an array of actuators, power electronic switches, a reactive force element, and a digital controller. Actuators are aligned so that each axis of expansion and contraction intersects both substrate and reactive force element. Electronics layer with nearly wireless architecture, power electronic switches, and digital controller are provided within a thin-film substrate. The size and weight of the adaptive optical device is solely dominated by the size of the actuator elements rather than by the power distribution system.

Computational Analysis of Enhanced Magnetic Bioseparation in Microfluidic Systems with Flow-Invasive Magnetic Elements

PubMed Central

Khashan, S. A.; Alazzam, A.; Furlani, E. P.

2014-01-01

A microfluidic design is proposed for realizing greatly enhanced separation of magnetically-labeled bioparticles using integrated soft-magnetic elements. The elements are fixed and intersect the carrier fluid (flow-invasive) with their length transverse to the flow. They are magnetized using a bias field to produce a particle capture force. Multiple stair-step elements are used to provide efficient capture throughout the entire flow channel. This is in contrast to conventional systems wherein the elements are integrated into the walls of the channel, which restricts efficient capture to limited regions of the channel due to the short range nature of the magnetic force. This severely limits the channel size and hence throughput. Flow-invasive elements overcome this limitation and enable microfluidic bioseparation systems with superior scalability. This enhanced functionality is quantified for the first time using a computational model that accounts for the dominant mechanisms of particle transport including fully-coupled particle-fluid momentum transfer. PMID:24931437

Adaptive Meshing of Ship Air-Wake Flowfields

DTIC Science & Technology

2014-10-21

performs cut- cell operations at geometry boundaries. A second-order spatial finite-volume scheme has been incorporated with explicit first order...The cells intersected by the geometry are handled using the “cut- cell ” approach, which is basically creating arbitrary polyhedral elements with...appropriate surface boundary conditions. Any cells completely outside the computational domain are tagged external and not solved in the flow solution

Method of determining the orbits of the small bodies in the solar system based on an exhaustive search of orbital planes

NASA Astrophysics Data System (ADS)

Bondarenko, Yu. S.; Vavilov, D. E.; Medvedev, Yu. D.

2014-05-01

A universal method of determining the orbits of newly discovered small bodies in the Solar System using their positional observations has been developed. The proposed method suggests determining geocentric distances of a small body by means of an exhaustive search for heliocentric orbital planes and subsequent determination of the distance between the observer and the points at which the chosen plane intersects with the vectors pointing to the object. Further, the remaining orbital elements are determined using the classical Gauss method after eliminating those heliocentric distances that have a fortiori low probabilities. The obtained sets of elements are used to determine the rms between the observed and calculated positions. The sets of elements with the least rms are considered to be most probable for newly discovered small bodies. Afterwards, these elements are improved using the differential method.

Multilane Traffic Flow Modeling Using Cellular Automata Theory

NASA Astrophysics Data System (ADS)

Chechina, Antonina; Churbanova, Natalia; Trapeznikova, Marina

2018-02-01

The paper deals with the mathematical modeling of traffic flows on urban road networks using microscopic approach. The model is based on the cellular automata theory and presents a generalization of the Nagel-Schreckenberg model to a multilane case. The created program package allows to simulate traffic on various types of road fragments (T or X type intersection, strait road elements, etc.) and on road networks that consist of these elements. Besides that, it allows to predict the consequences of various decisions regarding road infrastructure changes, such as: number of lanes increasing/decreasing, putting new traffic lights into operation, building new roads, entrances/exits, road junctions.

A feminist perspective on risk factor research and on the prevention of eating disorders.

PubMed

Piran, Niva

2010-01-01

This review utilizes a feminist lens to discuss risk factor research and prevention work in the field of eating disorders. The article suggests that feminist informed risk factor research needs to consider gender as it intersects with other social variables as a relevant higher level risk factor and examine its relationship to individual level risk factors such as the internalization of thinness or negative body image. The article also highlights the key elements of participatory approaches and systemic changes to feminist informed prevention work. Prevention work conducted to date suggests the relevance of these elements to achieving behavioral changes in prevention work.

Inelastic behavior of structural components

NASA Technical Reports Server (NTRS)

Hussain, N.; Khozeimeh, K.; Toridis, T. G.

1980-01-01

A more accurate procedure was developed for the determination of the inelastic behavior of structural components. The actual stress-strain curve for the mathematical of the structure was utilized to generate the force-deformation relationships for the structural elements, rather than using simplified models such as elastic-plastic, bilinear and trilinear approximations. relationships were generated for beam elements with various types of cross sections. In the generational of these curves, stress or load reversals, kinematic hardening and hysteretic behavior were taken into account. Intersections between loading and unloading branches were determined through an iterative process. Using the inelastic properties obtained, the plastic static response of some simple structural systems composed of beam elements was computed. Results were compared with known solutions, indicating a considerable improvement over response predictions obtained by means of simplified approximations used in previous investigations.

The origin and evolution of terrestrial and Martian rock labyrinths

NASA Technical Reports Server (NTRS)

Brook, G. A.

1984-01-01

The morphological characteristics and evolutionary development of rock labyrinths on Earth (in sandstone, volcanics, and carbonates) are compared with those on Mars. On Earth rock labyrinths originate as parallel, an echelon, or intersecting narrow grabens, or develop where fault and joint networks are selectively eroded. Labyrinths frequently contain both downfaulted and erosional elements. Closed labyrinths contain depressions; open labyrinths do not, they are simple part of a fluvial network generally of low order. As closed labyrinths made up of intersecting grabens or made up of connected erosional depressions are extremely common on Mars, the research focussed on an understanding of these labyrinth types. Field investigations were carried out in Canyonlands National Park, Utah, and in the Chirachahua Mountains of Arizona. Martian labyrinths were investigated using Viking orbiter images. In addition, research was undertaken on apparent thermokarst features in Lunae Planum and Chryse Planitia where closed depressions are numerous and resemble atlas topography.

Evaluation of finite-element models and stress-intensity factors for surface cracks emanating from stress concentrations

NASA Technical Reports Server (NTRS)

Tan, P. W.; Raju, I. S.; Shivakumar, K. N.; Newman, J. C., Jr.

1990-01-01

A re-evaluation of the 3-D finite-element models and methods used to analyze surface crack at stress concentrations is presented. Previous finite-element models used by Raju and Newman for surface and corner cracks at holes were shown to have ill-shaped elements at the intersection of the hole and crack boundaries. Improved models, without these ill-shaped elements, were developed for a surface crack at a circular hole and at a semi-circular edge notch. Stress-intensity factors were calculated by both the nodal-force and virtual-crack-closure methods. Comparisons made between the previously developed stress-intensity factor equations and the results from the improved models agreed well except for configurations with large notch-radii-to-plate-thickness ratios. Stress-intensity factors for a semi-elliptical surface crack located at the center of a semi-circular edge notch in a plate subjected to remote tensile loadings were calculated using the improved models.

Extension of RCC Topological Relations for 3d Complex Objects Components Extracted from 3d LIDAR Point Clouds

NASA Astrophysics Data System (ADS)

Xing, Xu-Feng; Abolfazl Mostafavia, Mir; Wang, Chen

2016-06-01

Topological relations are fundamental for qualitative description, querying and analysis of a 3D scene. Although topological relations for 2D objects have been extensively studied and implemented in GIS applications, their direct extension to 3D is very challenging and they cannot be directly applied to represent relations between components of complex 3D objects represented by 3D B-Rep models in R3. Herein we present an extended Region Connection Calculus (RCC) model to express and formalize topological relations between planar regions for creating 3D model represented by Boundary Representation model in R3. We proposed a new dimension extended 9-Intersection model to represent the basic relations among components of a complex object, including disjoint, meet and intersect. The last element in 3*3 matrix records the details of connection through the common parts of two regions and the intersecting line of two planes. Additionally, this model can deal with the case of planar regions with holes. Finally, the geometric information is transformed into a list of strings consisting of topological relations between two planar regions and detailed connection information. The experiments show that the proposed approach helps to identify topological relations of planar segments of point cloud automatically.

"Hoping to see the future I prefer": an element of life-world for older women living alone.

PubMed

Porter, Eileen J; Oyesanya, Tolu O; Johnson, Kathy A

2013-01-01

We interact with Dorcy's earlier work in Advances in Nursing Science on hope, noting that scholars have emphasized hope in suffering rather than exploring hoping in everyday life. We did a secondary analysis of 4 descriptive phenomenological studies with older women (N = 81, aged 75-98). Findings included a 4-level taxonomy of life-world. Four future-related subelements (such as, having a future I cannot see, down the road) intersected with the element hoping to see the future I prefer. Five of its subelements were common across the sample, including hoping that I do not get to that point. Findings have implications for expanding scholarship pertaining to hoping.

Avoided crossings: A study of the nonadiabatic transition probabilities

NASA Astrophysics Data System (ADS)

Desouter-Lecomte, M.; Leyh-Nihant, B.; Praet, M. T.; Lorquet, J. C.

1987-06-01

An approximate solution to the problem of constructing a pair of diabatic states exists only if certain requirements are fulfilled, for example, when the nonadiabatic coupling results from an interaction between two electronic configurations which are doubly excited with respect to one another. It is then possible to build up a model in which the series expansion of the elements of the Hamiltonian matrix is truncated after the first nonzero term. This leads to several conclusions concerning the nonadiabatic transition probability which differentiate conical intersections from avoided crossings. For the latter, the nonadiabatic coupling matrix elements (which are Lorentzians with an area equal to π/2) reach their maximum at the nuclear geometry for which ΔE (the energy gap between adiabatic surfaces) is a minimum. The loci along which the angle θ of the orthogonal transformation which relates adiabatic and diabatic wave functions keeps a constant value are a set of parallel straight lines which coincides with the loci along which ΔE remains constant. This reference direction in the configuration space corresponds to nuclear trajectories which are unable to bring about a nonadiabatic transition. In the case of avoided crossings, there exists only one nuclear degree of freedom which gives rise to surface hopping. Conical intersections, on the other hand, have two such active degrees of freedom. This creates a qualitative difference between the two cases which makes conical intersections more efficient as funnels than avoided crossings. A two-dimensional extension of the Landau-Zener formula is derived for avoided crossings. It contains a factor of anisotropy. It is possible, at least in favorable cases, to extract approximate diabatic quantities from ab initio calculations and to compare them with the predictions of these models. This has been done for two 2A1 electronic states of the CH+2 ion. The results are found to agree with the predictions of the model, at least in a restricted range of internuclear distances.

Behavior as a common focus of toxicology and nutrition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiss, B.

1980-01-01

Behavior as an index of toxicity parallels its role as an index of nutritional impairment, just as toxicology and nutrition share other common themes. Intersections among the three disciplines arise because foodstuffs serve as one of the major routes of toxic exposure and also because food elements modify toxicity. With this perspective, the safety of our food supply is examined in the contexts of essential nutrients, toxins, toxic metals, manufactured contaminants, self-administered toxicants, and food additives.

Support grid for fuel elements in a nuclear reactor

DOEpatents

Finch, Lester M.

1977-01-01

A support grid is provided for holding nuclear fuel rods in a rectangular array. Intersecting sheet metal strips are interconnected using opposing slots in the strips to form a rectangular cellular grid structure for engaging the sides of a multiplicity of fuel rods. Spring and dimple supports for engaging fuel and guide rods extending through each cell in the support grid are formed in the metal strips with the springs thus formed being characterized by nonlinear spring rates.

Connectivity-based, all-hexahedral mesh generation method and apparatus

DOEpatents

Tautges, T.J.; Mitchell, S.A.; Blacker, T.D.; Murdoch, P.

1998-06-16

The present invention is a computer-based method and apparatus for constructing all-hexahedral finite element meshes for finite element analysis. The present invention begins with a three-dimensional geometry and an all-quadrilateral surface mesh, then constructs hexahedral element connectivity from the outer boundary inward, and then resolves invalid connectivity. The result of the present invention is a complete representation of hex mesh connectivity only; actual mesh node locations are determined later. The basic method of the present invention comprises the step of forming hexahedral elements by making crossings of entities referred to as ``whisker chords.`` This step, combined with a seaming operation in space, is shown to be sufficient for meshing simple block problems. Entities that appear when meshing more complex geometries, namely blind chords, merged sheets, and self-intersecting chords, are described. A method for detecting invalid connectivity in space, based on repeated edges, is also described, along with its application to various cases of invalid connectivity introduced and resolved by the method. 79 figs.

Connectivity-based, all-hexahedral mesh generation method and apparatus

DOEpatents

Tautges, Timothy James; Mitchell, Scott A.; Blacker, Ted D.; Murdoch, Peter

1998-01-01

The present invention is a computer-based method and apparatus for constructing all-hexahedral finite element meshes for finite element analysis. The present invention begins with a three-dimensional geometry and an all-quadrilateral surface mesh, then constructs hexahedral element connectivity from the outer boundary inward, and then resolves invalid connectivity. The result of the present invention is a complete representation of hex mesh connectivity only; actual mesh node locations are determined later. The basic method of the present invention comprises the step of forming hexahedral elements by making crossings of entities referred to as "whisker chords." This step, combined with a seaming operation in space, is shown to be sufficient for meshing simple block problems. Entities that appear when meshing more complex geometries, namely blind chords, merged sheets, and self-intersecting chords, are described. A method for detecting invalid connectivity in space, based on repeated edges, is also described, along with its application to various cases of invalid connectivity introduced and resolved by the method.

High performance volume-of-intersection projectors for 3D-PET image reconstruction based on polar symmetries and SIMD vectorisation.

PubMed

Scheins, J J; Vahedipour, K; Pietrzyk, U; Shah, N J

2015-12-21

For high-resolution, iterative 3D PET image reconstruction the efficient implementation of forward-backward projectors is essential to minimise the calculation time. Mathematically, the projectors are summarised as a system response matrix (SRM) whose elements define the contribution of image voxels to lines-of-response (LORs). In fact, the SRM easily comprises billions of non-zero matrix elements to evaluate the tremendous number of LORs as provided by state-of-the-art PET scanners. Hence, the performance of iterative algorithms, e.g. maximum-likelihood-expectation-maximisation (MLEM), suffers from severe computational problems due to the intensive memory access and huge number of floating point operations. Here, symmetries occupy a key role in terms of efficient implementation. They reduce the amount of independent SRM elements, thus allowing for a significant matrix compression according to the number of exploitable symmetries. With our previous work, the PET REconstruction Software TOolkit (PRESTO), very high compression factors (>300) are demonstrated by using specific non-Cartesian voxel patterns involving discrete polar symmetries. In this way, a pre-calculated memory-resident SRM using complex volume-of-intersection calculations can be achieved. However, our original ray-driven implementation suffers from addressing voxels, projection data and SRM elements in disfavoured memory access patterns. As a consequence, a rather limited numerical throughput is observed due to the massive waste of memory bandwidth and inefficient usage of cache respectively. In this work, an advantageous symmetry-driven evaluation of the forward-backward projectors is proposed to overcome these inefficiencies. The polar symmetries applied in PRESTO suggest a novel organisation of image data and LOR projection data in memory to enable an efficient single instruction multiple data vectorisation, i.e. simultaneous use of any SRM element for symmetric LORs. In addition, the calculation time is further reduced by using simultaneous multi-threading (SMT). A global speedup factor of 11 without SMT and above 100 with SMT has been achieved for the improved CPU-based implementation while obtaining equivalent numerical results.

High performance volume-of-intersection projectors for 3D-PET image reconstruction based on polar symmetries and SIMD vectorisation

NASA Astrophysics Data System (ADS)

Scheins, J. J.; Vahedipour, K.; Pietrzyk, U.; Shah, N. J.

2015-12-01

For high-resolution, iterative 3D PET image reconstruction the efficient implementation of forward-backward projectors is essential to minimise the calculation time. Mathematically, the projectors are summarised as a system response matrix (SRM) whose elements define the contribution of image voxels to lines-of-response (LORs). In fact, the SRM easily comprises billions of non-zero matrix elements to evaluate the tremendous number of LORs as provided by state-of-the-art PET scanners. Hence, the performance of iterative algorithms, e.g. maximum-likelihood-expectation-maximisation (MLEM), suffers from severe computational problems due to the intensive memory access and huge number of floating point operations. Here, symmetries occupy a key role in terms of efficient implementation. They reduce the amount of independent SRM elements, thus allowing for a significant matrix compression according to the number of exploitable symmetries. With our previous work, the PET REconstruction Software TOolkit (PRESTO), very high compression factors (>300) are demonstrated by using specific non-Cartesian voxel patterns involving discrete polar symmetries. In this way, a pre-calculated memory-resident SRM using complex volume-of-intersection calculations can be achieved. However, our original ray-driven implementation suffers from addressing voxels, projection data and SRM elements in disfavoured memory access patterns. As a consequence, a rather limited numerical throughput is observed due to the massive waste of memory bandwidth and inefficient usage of cache respectively. In this work, an advantageous symmetry-driven evaluation of the forward-backward projectors is proposed to overcome these inefficiencies. The polar symmetries applied in PRESTO suggest a novel organisation of image data and LOR projection data in memory to enable an efficient single instruction multiple data vectorisation, i.e. simultaneous use of any SRM element for symmetric LORs. In addition, the calculation time is further reduced by using simultaneous multi-threading (SMT). A global speedup factor of 11 without SMT and above 100 with SMT has been achieved for the improved CPU-based implementation while obtaining equivalent numerical results.

Proposal for generating synthetic magnetic fields in hexagonal optical lattices

NASA Astrophysics Data System (ADS)

Tian, Binbin; Endres, Manuel; Pekker, David

2015-05-01

We propose a new approach to generating synthetic magnetic fields in ultra cold atom systems that does not rely on either Raman transitions nor periodic drive. Instead, we consider a hexagonal optical lattice produced by the intersection of three laser beams at 120 degree angles, where the intensity of one or more of the beams is spatially non-uniform. The resulting optical lattice remains hexagonal, but has spatially varying hopping matrix elements. For atoms near the Dirac points, these spatial variations appear as a gauge field, similar to the fictitious gauge field that is induced for for electrons in strained graphene. We suggest that a robust way to generate a gauge field that corresponds to a uniform flux is to aligning three gaussian beams to intersect in an equilateral triangle. Using realistic experimental parameters, we show how the proposed setup can be used to observe cyclotron motion of an atom cloud - the conventional Hall effect and distinct Landau levels - the integer quantum Hall effect.

Simulation of two-phase flow in horizontal fracture networks with numerical manifold method

NASA Astrophysics Data System (ADS)

Ma, G. W.; Wang, H. D.; Fan, L. F.; Wang, B.

2017-10-01

The paper presents simulation of two-phase flow in discrete fracture networks with numerical manifold method (NMM). Each phase of fluids is considered to be confined within the assumed discrete interfaces in the present method. The homogeneous model is modified to approach the mixed fluids. A new mathematical cover formation for fracture intersection is proposed to satisfy the mass conservation. NMM simulations of two-phase flow in a single fracture, intersection, and fracture network are illustrated graphically and validated by the analytical method or the finite element method. Results show that the motion status of discrete interface significantly depends on the ratio of mobility of two fluids rather than the value of the mobility. The variation of fluid velocity in each fracture segment and the driven fluid content are also influenced by the ratio of mobility. The advantages of NMM in the simulation of two-phase flow in a fracture network are demonstrated in the present study, which can be further developed for practical engineering applications.

Road Network Extraction from Dsm by Mathematical Morphology and Reasoning

NASA Astrophysics Data System (ADS)

Li, Yan; Wu, Jianliang; Zhu, Lin; Tachibana, Kikuo

2016-06-01

The objective of this research is the automatic extraction of the road network in a scene of the urban area from a high resolution digital surface model (DSM). Automatic road extraction and modeling from remote sensed data has been studied for more than one decade. The methods vary greatly due to the differences of data types, regions, resolutions et al. An advanced automatic road network extraction scheme is proposed to address the issues of tedium steps on segmentation, recognition and grouping. It is on the basis of a geometric road model which describes a multiple-level structure. The 0-dimension element is intersection. The 1-dimension elements are central line and side. The 2-dimension element is plane, which is generated from the 1-dimension elements. The key feature of the presented approach is the cross validation for the three road elements which goes through the entire procedure of their extraction. The advantage of our model and method is that linear elements of the road can be derived directly, without any complex, non-robust connection hypothesis. An example of Japanese scene is presented to display the procedure and the performance of the approach.

Comparing the effects of infrastructure on bicycling injury at intersections and non-intersections using a case–crossover design

PubMed Central

Harris, M Anne; Reynolds, Conor C O; Winters, Meghan; Cripton, Peter A; Shen, Hui; Chipman, Mary L; Cusimano, Michael D; Babul, Shelina; Brubacher, Jeffrey R; Friedman, Steven M; Hunte, Garth; Monro, Melody; Vernich, Lee; Teschke, Kay

2013-01-01

Background This study examined the impact of transportation infrastructure at intersection and non-intersection locations on bicycling injury risk. Methods In Vancouver and Toronto, we studied adult cyclists who were injured and treated at a hospital emergency department. A case–crossover design compared the infrastructure of injury and control sites within each injured bicyclist's route. Intersection injury sites (N=210) were compared to randomly selected intersection control sites (N=272). Non-intersection injury sites (N=478) were compared to randomly selected non-intersection control sites (N=801). Results At intersections, the types of routes meeting and the intersection design influenced safety. Intersections of two local streets (no demarcated traffic lanes) had approximately one-fifth the risk (adjusted OR 0.19, 95% CI 0.05 to 0.66) of intersections of two major streets (more than two traffic lanes). Motor vehicle speeds less than 30 km/h also reduced risk (adjusted OR 0.52, 95% CI 0.29 to 0.92). Traffic circles (small roundabouts) on local streets increased the risk of these otherwise safe intersections (adjusted OR 7.98, 95% CI 1.79 to 35.6). At non-intersection locations, very low risks were found for cycle tracks (bike lanes physically separated from motor vehicle traffic; adjusted OR 0.05, 95% CI 0.01 to 0.59) and local streets with diverters that reduce motor vehicle traffic (adjusted OR 0.04, 95% CI 0.003 to 0.60). Downhill grades increased risks at both intersections and non-intersections. Conclusions These results provide guidance for transportation planners and engineers: at local street intersections, traditional stops are safer than traffic circles, and at non-intersections, cycle tracks alongside major streets and traffic diversion from local streets are safer than no bicycle infrastructure. PMID:23411678

Calculations of Intersection Cross-Slip Activation Energies in FCC Metals Using Nudged Elastic Band Method

DTIC Science & Technology

2011-08-01

PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES...AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM( S ) 11. SPONSOR/MONITOR’S REPORT NUMBER( S ) 12. DISTRIBUTION/AVAILABILITY STATEMENT...References [1] Puschl W. Prog Mater Sci 2002;47:415. [2] Jackson PJ. Prog Mater Sci 1985;29:139. [3] Rao S , Parthasarathy TA, Woodward C. Philos Mag A

Atomistic Simulations of Intersection Cross-Slip Nucleation in Ll2 Ni3Al (Preprint)

DTIC Science & Technology

2011-11-01

CROSS-SLIP NUCLEATION IN Ll2 Ni3Al (Preprint) 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6. AUTHOR( S ...PROJECT NUMBER 4347 5e. TASK NUMBER 20 5f. WORK UNIT NUMBER LM121100 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) 8. PERFORMING...SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSORING/MONITORING AGENCY ACRONYM( S ) Air Force Research Laboratory Materials and

Crash rates at intersections.

DOT National Transportation Integrated Search

2003-08-01

The objective of this study were to develop a database of intersections, match traffic crashes to these intersections, calculate rates for intersections, and identify intersections with the highest crash rates. A procedure was used to: a) identify in...

Geo-PUMMA: Urban and Periurban Landscape Representation Toolbox for Hydrological Distributed Modeling

NASA Astrophysics Data System (ADS)

Sanzana, Pedro; Gironas, Jorge; Braud, Isabelle; Branger, Flora; Rodriguez, Fabrice; Vargas, Ximena; Hitschfeld, Nancy; Francisco Munoz, Jose

2016-04-01

In addition to land use changes, the process of urbanization can modify the direction of the surface and sub-surface flows, generating complex environments and increasing the types of connectivity between pervious and impervious areas. Thus, hydrological pathways in urban and periurban areas are significantly affected by artificial elements like channels, pipes, streets and other elements of storm water systems. This work presents Geo-PUMMA, a new GIS toolbox to generate vectorial meshes for distributed hydrological modeling and extract the drainage network in urban and periurban terrain. Geo-PUMMA gathers spatial information maps (e.g. cadastral, soil types, geology and digital elevation models) to produce Hydrological Response Units (HRU) and Urban Hydrological Elements (UHE). Geo-PUMMA includes tools to improve the initial mesh derived from GIS layers intersection in order to respect geometrical constraints, which ensures numerical stability while preserving the shape of the initial HRUs and minimizing the small elements to lower computing times. The geometrical constraints taken into account include: elements convexity, limitation of the number of sliver elements (e.g. roads) and of very small or very large elements. This toolbox allows the representation of basins at small scales (0.1-10km2), as it takes into account the hydrological connectivity of the main elements explicitly, and improves the representation of water pathways compared with classical raster approaches. Geo-PUMMA also allows the extraction of basin morphologic properties such as the width function, the area function and the imperviousness function. We applied this new toolbox to two periurban catchments: the Mercier catchment located near Lyon, France, and the Estero El Guindo catchment located in the Andean piedmont in the Maipo River, Chile. We use the capability of Geo-PUMMA to generate three different meshes. The first one is the initial mesh derived from the direct intersection of GIS layers. The second one is based on fine triangulation of HRUs and is considered the best one we can obtain (reference mesh). The third one is the recommended mesh, preserving the shape of the initial HRUs and limiting the number of elements. The representation of the drainage network and its morphological properties is compared between the three meshes. This comparison shows that the drainage network representation is particularly improved at small to medium spatial scales when using the recommended meshes (i.e. 120-150 m for the El Guindo catchment and 80-150 m for the Mercier catchment). The results also show that the recommended mesh correctly represents the main features of the drainage network as compared to the reference mesh. KEYWORDS: GRASS-GIS, Computer-assisted mesh generation, periurban catchments

Large-size space debris flyby in low earth orbits

NASA Astrophysics Data System (ADS)

Baranov, A. A.; Grishko, D. A.; Razoumny, Y. N.

2017-09-01

the analysis of NORAD catalogue of space objects executed with respect to the overall sizes of upper-stages and last stages of carrier rockets allows the classification of 5 groups of large-size space debris (LSSD). These groups are defined according to the proximity of orbital inclinations of the involved objects. The orbits within a group have various values of deviations in the Right Ascension of the Ascending Node (RAAN). It is proposed to use the RAANs deviations' evolution portrait to clarify the orbital planes' relative spatial distribution in a group so that the RAAN deviations should be calculated with respect to the concrete precessing orbital plane of the concrete object. In case of the first three groups (inclinations i = 71°, i = 74°, i = 81°) the straight lines of the RAAN relative deviations almost do not intersect each other. So the simple, successive flyby of group's elements is effective, but the significant value of total Δ V is required to form drift orbits. In case of the fifth group (Sun-synchronous orbits) these straight lines chaotically intersect each other for many times due to the noticeable differences in values of semi-major axes and orbital inclinations. The intersections' existence makes it possible to create such a flyby sequence for LSSD group when the orbit of one LSSD object simultaneously serves as the drift orbit to attain another LSSD object. This flyby scheme requiring less Δ V was called "diagonal." The RAANs deviations' evolution portrait built for the fourth group (to be studied in the paper) contains both types of lines, so the simultaneous combination of diagonal and successive flyby schemes is possible. The value of total Δ V and temporal costs were calculated to cover all the elements of the 4th group. The article is also enriched by the results obtained for the flyby problem solution in case of all the five mentioned LSSD groups. The general recommendations are given concerned with the required reserve of total Δ V and with amount of detachable de-orbiting units onboard the maneuvering platform and onboard the refueling vehicle.

GIS-based intersection inventory system (GIS-IIS) : integrating GIS, traffic signal data and intersection images

DOT National Transportation Integrated Search

2005-02-25

This study developed a GIS-based Intersection Inventory System (GIS-IIS) for the signalized : intersections on the state-maintained highway system of IDOT District 6. GIS-IIS is a tool to have an : easy access to intersection inventory data, photogra...

Improving cultural competence education: the utility of an intersectional framework.

PubMed

Powell Sears, Karen

2012-06-01

Most US medical schools have instituted cultural competence education in the undergraduate curriculum. This training is intended to improve the quality of care that doctors, the majority of whom are White, deliver to ethnic and racial minority patients. Research into the outcomes of cultural competence training programmes reveals that they have been largely ineffective in improving doctors' skills. In varied curricular formats, programmes tend to teach group-specific cultural knowledge, despite the vast heterogeneity of racial and ethnic groups. This cultural essentialism diminishes training effectiveness. This paper proposes key curriculum content changes and suggests the inclusion of an intersectional framework in the cultural competence curriculum. This framework maintains that racial and ethnic minority groups hold multiple social statuses, called social locations, which interact with one another to uniquely shape the health views, needs and experiences of the individuals within the groups. Social locations include those defined by race, ethnicity, gender, social class and sexuality, which are experienced multiplicatively, not additively, within a particular social context. Cultural competence education must go beyond simplified cultural understandings to explore these more complex meanings. Doctors' ability to understand, communicate with and treat diverse groups can be vastly improved by applying an intersectional framework in academic research, self-awareness exercises and clinical training. Integrating an intersectional framework into cultural competency education can better prepare doctors for caring for racial and ethnic minority patients. This paper recommends curriculum elements for the classroom and clinical training that can improve doctor knowledge and skills for caring for diverse groups. Medical schools can use the proposed model to facilitate the development of new educational strategies and learning experiences. These improvements can lead to more equitable care and ultimately diminish disparities in health care. Although these recommendations are designed with US schools in mind, they may improve doctor understanding and care of marginal populations across the world. © Blackwell Publishing Ltd 2012.

Diabatic models with transferrable parameters for generalized chemical reactions

NASA Astrophysics Data System (ADS)

Reimers, Jeffrey R.; McKemmish, Laura K.; McKenzie, Ross H.; Hush, Noel S.

2017-05-01

Diabatic models applied to adiabatic electron-transfer theory yield many equations involving just a few parameters that connect ground-state geometries and vibration frequencies to excited-state transition energies and vibration frequencies to the rate constants for electron-transfer reactions, utilizing properties of the conical-intersection seam linking the ground and excited states through the Pseudo Jahn-Teller effect. We review how such simplicity in basic understanding can also be obtained for general chemical reactions. The key feature that must be recognized is that electron-transfer (or hole transfer) processes typically involve one electron (hole) moving between two orbitals, whereas general reactions typically involve two electrons or even four electrons for processes in aromatic molecules. Each additional moving electron leads to new high-energy but interrelated conical-intersection seams that distort the shape of the critical lowest-energy seam. Recognizing this feature shows how conical-intersection descriptors can be transferred between systems, and how general chemical reactions can be compared using the same set of simple parameters. Mathematical relationships are presented depicting how different conical-intersection seams relate to each other, showing that complex problems can be reduced into an effective interaction between the ground-state and a critical excited state to provide the first semi-quantitative implementation of Shaik’s “twin state” concept. Applications are made (i) demonstrating why the chemistry of the first-row elements is qualitatively so different to that of the second and later rows, (ii) deducing the bond-length alternation in hypothetical cyclohexatriene from the observed UV spectroscopy of benzene, (iii) demonstrating that commonly used procedures for modelling surface hopping based on inclusion of only the first-derivative correction to the Born-Oppenheimer approximation are valid in no region of the chemical parameter space, and (iv), demonstrating the types of chemical reactions that may be suitable for exploitation as a chemical qubit in some quantum information processor.

Turning movements, vehicle offsets and ageing drivers driving behaviour at channelized and unchannelized intersections.

PubMed

Choi, Jaisung; Tay, Richard; Kim, Sangyoup; Jeong, Seungwon

2017-11-01

Ageing drivers experience a higher risk of intersection crashes because of their decrease in driving efficiency, including the decline in cognitive ability, head and neck flexibility, and visual acuity. Although several studies have been conducted to examine the factors associated with ageing driver crashes at intersections, little research has been conducted to examine the differences in the factors related to ageing drivers' turning paths and intersection geometric features. This study aims to improve the safety of ageing drivers at intersections by identifying the maneuvers that are risky for them and tracking their turning movements at selected intersections. We find that ageing drivers experience more crashes at intersections than younger drivers, especially crashes involving turning movements. Furthermore, ageing drivers experience more crashes at unchannelized intersections compared to channelized intersections. In addition, this study finds that ageing drivers exhibit greater and more inconsistent offsets during turning movements compared to those of younger drivers at both channelized and unchannelized intersections. Ageing drivers also tend to make relatively sharper or tighter turns than younger drivers. Hence, transportation engineers and road safety professionals should consider appropriate countermeasures to reduce the risks of crashes involving ageing drivers at intersections. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multiuse trail intersection safety analysis: A crowdsourced data perspective.

PubMed

Jestico, Ben; Nelson, Trisalyn A; Potter, Jason; Winters, Meghan

2017-06-01

Real and perceived concerns about cycling safety are a barrier to increased ridership in many cities. Many people prefer to bike on facilities separated from motor vehicles, such as multiuse trails. However, due to underreporting, cities lack data on bike collisions, especially along greenways and multiuse paths. We used a crowdsourced cycling incident dataset (2005-2016) from BikeMaps.org for the Capital Regional District (CRD), BC, Canada. Our goal was to identify design characteristics associated with unsafe intersections between multiuse trails and roads. 92.8% of mapped incidents occurred between 2014 and 2016. We extracted both collision and near miss incidents at intersections from BikeMaps.org. We conducted site observations at 32 intersections where a major multiuse trail intersected with roads. We compared attributes of reported incidents at multiuse trail-road intersections to those at road-road intersections. We then used negative binomial regression to model the relationship between the number of incidents and the infrastructure characteristics at multiuse trail-road intersections. We found a higher proportion of collisions (38%, or 17/45 total reports) at multiuse trail-road intersections compared to road-road intersections (23%, or 62/268 total reports). A higher proportion of incidents resulted in an injury at multiuse trail-road intersections compared to road-road intersections (33% versus 15%). Cycling volumes, vehicle volumes, and trail sight distance were all associated with incident frequency at multiuse trail-road intersections. Supplementing traditional crash records with crowdsourced cycling incident data provides valuable evidence on cycling safety at intersections between multiuse trails and roads, and more generally, when conflicts occur between diverse transportation modes. Copyright © 2017. Published by Elsevier Ltd.

Proposal of a Roundabout Solution within a Particular Traflc Operation

NASA Astrophysics Data System (ADS)

Ližbetin, Ján; Stopka, Ondrej

2016-11-01

This paper presents the practical solution of the transport telematics elements within a particular traffic operation when providing a transport and logistics services. A roundabout helps to increase the fluency and safety of transport and logistics services in cities and urban areas, however, the positive effect can be achieved only after determining the proper intersection parameters. Based on a survey performed in a real traffic situation, the practical application of roundabout in the city of Pilsen is processed in the most important part of the paper.

System for conversion between the boundary representation model and a constructive solid geometry model of an object

DOEpatents

Christensen, Noel C.; Emery, James D.; Smith, Maurice L.

1988-04-05

A system converts from the boundary representation of an object to the constructive solid geometry representation thereof. The system converts the boundary representation of the object into elemental atomic geometrical units or I-bodies which are in the shape of stock primitives or regularized intersections of stock primitives. These elemental atomic geometrical units are then represented in symbolic form. The symbolic representations of the elemental atomic geometrical units are then assembled heuristically to form a constructive solid geometry representation of the object usable for manufacturing thereof. Artificial intelligence is used to determine the best constructive solid geometry representation from the boundary representation of the object. Heuristic criteria are adapted to the manufacturing environment for which the device is to be utilized. The surface finish, tolerance, and other information associated with each surface of the boundary representation of the object are mapped onto the constructive solid geometry representation of the object to produce an enhanced solid geometry representation, particularly useful for computer-aided manufacture of the object.

Protactinium and the intersection of actinide and transition metal chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, Richard E.; De Sio, Stephanie; Vallet, Valérie

The role of the 5f and 6d orbitals in the chemistry of the actinide elements has been of considerable interest since their discovery and synthesis. Relativistic effects cause the energetics of the 5f and 6d orbitals to change as the actinide series is traversed left to right imparting a rich and complex chemistry. The 5f and 6d atomic states cross in energy at protactinium (Pa), making it a potential intersection between transition metal and actinide chemistries. Herein, we report the synthesis of a Pa-peroxo cluster, A(6)(Pa4O(O-2)(6)F-12) [A = Rb, Cs, (CH3)(4)N], formed in pursuit of an actinide polyoxometalate. Quantum chemicalmore » calculations at the density functional theory level demonstrate equal 5f and 6d orbital participation in the chemistry of Pa and increasing 5f orbital participation for the heavier actinides. Periodic changes in orbital character to the bonding in the early actinides highlights the influence of the 5f orbitals in their reactivity and chemical structure.« less

Characteristics of traffic flow at a non-signalized intersection in the framework of game theory

NASA Astrophysics Data System (ADS)

Fan, Hongqiang; Jia, Bin; Tian, Junfang; Yun, Lifen

2014-12-01

At a non-signalized intersection, some vehicles violate the traffic rules to pass the intersection as soon as possible. These behaviors may cause many traffic conflicts even traffic accidents. In this paper, a simulation model is proposed to research the effects of these behaviors at a non-signalized intersection. Vehicle’s movement is simulated by the cellular automaton (CA) model. The game theory is introduced for simulating the intersection dynamics. Two types of driver participate the game process: cooperator (C) and defector (D). The cooperator obey the traffic rules, but the defector does not. A transition process may occur when the cooperator is waiting before the intersection. The critical value of waiting time follows the Weibull distribution. One transition regime is found in the phase diagram. The simulation results illustrate the applicability of the proposed model and reveal a number of interesting insights into the intersection management, including that the existence of defectors is benefit for the capacity of intersection, but also reduce the safety of intersection.

Detection and enforcement of failure-to-yield in an emergency vehicle preemption system

NASA Technical Reports Server (NTRS)

Bachelder, Aaron (Inventor); Wickline, Richard (Inventor)

2007-01-01

An intersection controlled by an intersection controller receives trigger signals from on-coming emergency vehicles responding to an emergency call. The intersection controller initiates surveillance of the intersection via cameras installed at the intersection in response to a received trigger signal. The surveillance may begin immediately upon receipt of the trigger signal from an emergency vehicle, or may wait until the intersection controller determines that the signaling emergency vehicle is in the field of view of the cameras at the intersection. Portions of the captured images are tagged by the intersection controller based on tag signals transmitted by the vehicle or based on detected traffic patterns that indicate a potential traffic violation. The captured images are downloaded to a processing facility that analyzes the images and automatically issues citations for captured traffic violations.

At the cross-roads: an on-road examination of driving errors at intersections.

PubMed

Young, Kristie L; Salmon, Paul M; Lenné, Michael G

2013-09-01

A significant proportion of road trauma occurs at intersections. Understanding the nature of driving errors at intersections therefore has the potential to lead to significant injury reductions. To further understand how the complexity of modern intersections shapes behaviour of these errors are compared to errors made mid-block, and the role of wider systems failures in intersection error causation is investigated in an on-road study. Twenty-five participants drove a pre-determined urban route incorporating 25 intersections. Two in-vehicle observers recorded the errors made while a range of other data was collected, including driver verbal protocols, video, driver eye glance behaviour and vehicle data (e.g., speed, braking and lane position). Participants also completed a post-trial cognitive task analysis interview. Participants were found to make 39 specific error types, with speeding violations the most common. Participants made significantly more errors at intersections compared to mid-block, with misjudgement, action and perceptual/observation errors more commonly observed at intersections. Traffic signal configuration was found to play a key role in intersection error causation, with drivers making more errors at partially signalised compared to fully signalised intersections. Copyright © 2012 Elsevier Ltd. All rights reserved.

Identifying Blocks Formed by Curbed Fractures Using Exact Arithmetic

NASA Astrophysics Data System (ADS)

Zheng, Y.; Xia, L.; Yu, Q.; Zhang, X.

2015-12-01

Identifying blocks formed by fractures is important in rock engineering. Most studies assume the fractures to be perfect planar whereas curved fractures are rarely considered. However, large fractures observed in the field are often curved. This paper presents a new method for identifying rock blocks formed by both curved and planar fractures based on the element-block-assembling approach. The curved and planar fractures are represented as triangle meshes and planar discs, respectively. In the beginning of the identification method, the intersection segments between different triangle meshes are calculated and the intersected triangles are re-meshed to construct a piecewise linear complex (PLC). Then, the modeling domain is divided into tetrahedral subdomains under the constraint of the PLC and these subdomains are further decomposed into element blocks by extended planar fractures. Finally, the element blocks are combined and the subdomains are assembled to form complex blocks. The combination of two subdomains is skipped if and only if the common facet lies on a curved fracture. In this study, the exact arithmetic is used to handle the computational errors, which may threat the robustness of the block identification program when the degenerated cases are encountered. Specifically, a real number is represented as the ratio between two integers and the basic arithmetic such as addition, subtraction, multiplication and division between different real numbers can be performed exactly if an arbitrary precision integer package is used. In this way, the exact construction of blocks can be achieved without introducing computational errors. Several analytical examples are given in this paper and the results show effectiveness of this method in handling arbitrary shaped blocks. Moreover, there is no limitation on the number of blocks in a block system. The results also show (suggest) that the degenerated cases can be handled without affecting the robustness of the identification program.

Integrated Miniature Arrays of Optical Biomolecule Detectors

NASA Technical Reports Server (NTRS)

Iltchenko, Vladimir; Maleki, Lute; Lin, Ying; Le, Thanh

2009-01-01

Integrated miniature planar arrays of optical sensors for detecting specific biochemicals in extremely small quantities have been proposed. An array of this type would have an area of about 1 cm2. Each element of the array would include an optical microresonator that would have a high value of the resonance quality factor (Q . 107). The surface of each microresonator would be derivatized to make it bind molecules of a species of interest, and such binding would introduce a measurable change in the optical properties of the microresonator. Because each microresonator could be derivatized for detection of a specific biochemical different from those of the other microresonators, it would be possible to detect multiple specific biochemicals by simultaneous or sequential interrogation of all the elements in the array. Moreover, the derivatization would make it unnecessary to prepare samples by chemical tagging. Such interrogation would be effected by means of a grid of row and column polymer-based optical waveguides that would be integral parts of a chip on which the array would be fabricated. The row and column polymer-based optical waveguides would intersect at the elements of the array (see figure). At each intersection, the row and column waveguides would be optically coupled to one of the microresonators. The polymer-based waveguides would be connected via optical fibers to external light sources and photodetectors. One set of waveguides and fibers (e.g., the row waveguides and fibers) would couple light from the sources to the resonators; the other set of waveguides and fibers (e.g., the column waveguides and fibers) would couple light from the microresonators to the photodetectors. Each microresonator could be addressed individually by row and column for measurement of its optical transmission. Optionally, the chip could be fabricated so that each microresonator would lie inside a microwell, into which a microscopic liquid sample could be dispensed.

Low-cost safety enhancements for stop-controlled and signalized intersections

DOT National Transportation Integrated Search

2009-05-01

The purpose of this document is to present information on suggested effective, low-cost intersection countermeasures developed using intersection safety research results and input from an intersection safety expert panel. These low-cost countermeasur...

Safety Evaluation of Destination Lighting at Stop-Controlled Cross Intersections

DOT National Transportation Integrated Search

2018-02-02

Unlit or inadequately lit intersections reduce the ability of drivers to recognize upcoming intersections during nighttime hours. Drivers also face difficulty in properly negotiating the intersection because lack of adequate lighting increases the li...

Guidelines for signal operations at intersections with wide medians.

DOT National Transportation Integrated Search

2010-03-01

The objective of this project is to evaluate the operations at signalized intersections with wide medians in : order to improve safety and efficiency. Intersections with wide medians are characterized by two : intersections and operate differently co...

Self organized spatio-temporal structure within the fractured Vadose Zone: The influence of dynamic overloading at fracture intersections

NASA Astrophysics Data System (ADS)

LaViolette, Randall A.; Glass, Robert J.

2004-09-01

Under low flow conditions (where gravity and capillary forces dominate) within an unsaturated fracture network, fracture intersections act as capillary barriers to integrate flow from above and then release it as a pulse below. Water exiting a fracture intersection is often thought to enter the single connected fracture with the lowest invasion pressure. When the accumulated volume varies between intersections, the smaller volume intersections can be overloaded to cause all of the available fractures exiting an intersection to flow. We included the dynamic overloading process at fracture intersections within our previously discussed model where intersections were modeled as tipping buckets connected within a two-dimensional diamond lattice. With dynamic overloading, the flow behavior transitioned smoothly from diverging to converging flow with increasing overload parameter, as a consequence of a heterogeneous field, and they impose a dynamic structure where additional pathways activate or deactivate in time.

Trace elements at the intersection of marine biological and geochemical evolution

USGS Publications Warehouse

Robbins, Leslie J.; Lalonde, Stefan V.; Planavsky, Noah J.; Partin, Camille A.; Reinhard, Christopher T.; Kendall, Brian; Scott, Clinton T.; Hardisty, Dalton S.; Gill, Benjamin C.; Alessi, Daniel S.; Dupont, Christopher L.; Saito, Mak A.; Crowe, Sean A.; Poulton, Simon W.; Bekker, Andrey; Lyons, Timothy W.; Konhauser, Kurt O.

2016-01-01

Life requires a wide variety of bioessential trace elements to act as structural components and reactive centers in metalloenzymes. These requirements differ between organisms and have evolved over geological time, likely guided in some part by environmental conditions. Until recently, most of what was understood regarding trace element concentrations in the Precambrian oceans was inferred by extrapolation, geochemical modeling, and/or genomic studies. However, in the past decade, the increasing availability of trace element and isotopic data for sedimentary rocks of all ages has yielded new, and potentially more direct, insights into secular changes in seawater composition – and ultimately the evolution of the marine biosphere. Compiled records of many bioessential trace elements (including Ni, Mo, P, Zn, Co, Cr, Se, and I) provide new insight into how trace element abundance in Earth's ancient oceans may have been linked to biological evolution. Several of these trace elements display redox-sensitive behavior, while others are redox-sensitive but not bioessential (e.g., Cr, U). Their temporal trends in sedimentary archives provide useful constraints on changes in atmosphere-ocean redox conditions that are linked to biological evolution, for example, the activity of oxygen-producing, photosynthetic cyanobacteria. In this review, we summarize available Precambrian trace element proxy data, and discuss how temporal trends in the seawater concentrations of specific trace elements may be linked to the evolution of both simple and complex life. We also examine several biologically relevant and/or redox-sensitive trace elements that have yet to be fully examined in the sedimentary rock record (e.g., Cu, Cd, W) and suggest several directions for future studies.

Non-adiabatic dynamics around a conical intersection with surface-hopping coupled coherent states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humeniuk, Alexander; Mitrić, Roland, E-mail: roland.mitric@uni-wuerzburg.de

A surface-hopping extension of the coupled coherent states-method [D. Shalashilin and M. Child, Chem. Phys. 304, 103-120 (2004)] for simulating non-adiabatic dynamics with quantum effects of the nuclei is put forward. The time-dependent Schrödinger equation for the motion of the nuclei is solved in a moving basis set. The basis set is guided by classical trajectories, which can hop stochastically between different electronic potential energy surfaces. The non-adiabatic transitions are modelled by a modified version of Tully’s fewest switches algorithm. The trajectories consist of Gaussians in the phase space of the nuclei (coherent states) combined with amplitudes for an electronicmore » wave function. The time-dependent matrix elements between different coherent states determine the amplitude of each trajectory in the total multistate wave function; the diagonal matrix elements determine the hopping probabilities and gradients. In this way, both interference effects and non-adiabatic transitions can be described in a very compact fashion, leading to the exact solution if convergence with respect to the number of trajectories is achieved and the potential energy surfaces are known globally. The method is tested on a 2D model for a conical intersection [A. Ferretti, J. Chem. Phys. 104, 5517 (1996)], where a nuclear wavepacket encircles the point of degeneracy between two potential energy surfaces and interferes with itself. These interference effects are absent in classical trajectory-based molecular dynamics but can be fully incorpo rated if trajectories are replaced by surface hopping coupled coherent states.« less

Who gains, who loses and how: leveraging gender and class intersections to secure health entitlements.

PubMed

Sen, Gita; Iyer, Aditi

2012-06-01

This paper argues that a focus on the middle groups in a multi-dimensional socioeconomic ordering can provide valuable insights into how different axes of advantage and disadvantage intersect with each other. It develops the elements of a framework to analyse the middle groups through an intersectional analysis, and uses it to explore how such groups leverage economic class or gender advantages to secure entitlements to treatment for long-term illness. The study draws upon household survey data on health-seeking for long-term ailments from 60 villages of Koppal district, Karnataka (India). The survey was designed to capture gender, economic class, caste, age and life stage-based inequalities in access to health care during pregnancy and for short and long-term illnesses. There were striking similarities between two important middle groups--non-poor women and poor men--in some key outcomes: their rates of non-treatment when ill, treatment discontinuation and treatment continuation, and the amounts they spent for treatment. These two groups are the obverse of each other in terms of gender and economic class advantage and disadvantage. Non-poor women have an economic advantage and a gender disadvantage, while poor men have the exact opposite. However, despite the similarities in outcomes, the processes by which gender and class advantage were leveraged by each of the groups varied sharply. Similar patterns held for the poorest men except that the class disadvantage they had to overcome was greater, and the results are modified by this. Copyright © 2011 Elsevier Ltd. All rights reserved.

Computational biomechanics to simulate the femoropopliteal intersection during knee flexion: a preliminary study.

PubMed

Diehm, Nicolas; Sin, Sangmun; Hoppe, Hanno; Baumgartner, Iris; Büchler, Philippe

2011-06-01

To assess if finite element (FE) models can be used to predict deformation of the femoropopliteal segment during knee flexion. Magnetic resonance angiography (MRA) images were acquired on the lower limbs of 8 healthy volunteers (5 men; mean age 28 ± 4 years). Images were taken in 2 natural positions, with the lower limb fully extended and with the knee bent at ~ 40°. Patient-specific FE models were developed and used to simulate the experimental situation. The displacements of the artery during knee bending as predicted by the numerical model were compared to the corresponding positions measured on the MRA images. The numerical predictions showed a good overall agreement between the calculated displacements of the motion measures from MRA images. The average position error comparing the calculated vs. actual displacements of the femoropopliteal intersection measured on the MRA was 8 ± 4 mm. Two of the 8 subjects showed large prediction errors (average 13 ± 5 mm); these 2 volunteers were the tallest subjects involved in the study and had a low body mass index (20.5 kg/m²). The present computational model is able to capture the gross mechanical environment of the femoropopliteal intersection during knee bending and provide a better understanding of the complex biomechanical behavior. However, results suggest that patient-specific mechanical properties and detailed muscle modeling are required to provide accurate patient-specific numerical predictions of arterial displacement. Further adaptation of this model is expected to provide an improved ability to predict the multiaxial deformation of this arterial segment during leg movements and to optimize future stent designs.

3D Numerical Modeling of the Propagation of Hydraulic Fracture at Its Intersection with Natural (Pre-existing) Fracture

NASA Astrophysics Data System (ADS)

Dehghan, Ali Naghi; Goshtasbi, Kamran; Ahangari, Kaveh; Jin, Yan; Bahmani, Aram

2017-02-01

A variety of 3D numerical models were developed based on hydraulic fracture experiments to simulate the propagation of hydraulic fracture at its intersection with natural (pre-existing) fracture. Since the interaction between hydraulic and pre-existing fractures is a key condition that causes complex fracture patterns, the extended finite element method was employed in ABAQUS software to simulate the problem. The propagation of hydraulic fracture in a fractured medium was modeled in two horizontal differential stresses (Δ σ) of 5e6 and 10e6 Pa considering different strike and dip angles of pre-existing fracture. The rate of energy release was calculated in the directions of hydraulic and pre-existing fractures (G_{{frac}} /G_{{rock}}) at their intersection point to determine the fracture behavior. Opening and crossing were two dominant fracture behaviors during the hydraulic and pre-existing fracture interaction at low and high differential stress conditions, respectively. The results of numerical studies were compared with those of experimental models, showing a good agreement between the two to validate the accuracy of the models. Besides the horizontal differential stress, strike and dip angles of the natural (pre-existing) fracture, the key finding of this research was the significant effect of the energy release rate on the propagation behavior of the hydraulic fracture. This effect was more prominent under the influence of strike and dip angles, as well as differential stress. The obtained results can be used to predict and interpret the generation of complex hydraulic fracture patterns in field conditions.

Modelling Internal Heterogeneities in Debris-Covered Glaciers: the Potential to Link Morphology and Climate

NASA Astrophysics Data System (ADS)

Stuurman, C. M.; Holt, J.; Levy, J.

2016-12-01

On Earth and Mars, debris-covered glaciers (DCGs) often exhibit arcuate ridges transverse to the flow direction. Additionally, there exists some evidence linking internal structure (which is controlled in part by climate) in DCGs with surface microtopography. A better understanding of the relationship between englacial debris bands, compressional stresses, and debris-covered glacier microtopography will augment understanding of formational environments and mechanisms for terrestrial and martian DCGs. In order to better understand relationships between DCG surface morphology and internal debris bands, we combine field observations with finite-element modeling techniques to relate internal structure of DCGs to their surface morphologies. A geophysical survey including time-domain electromagnetic and ground-penetrating radar techniques of the Galena Creek Rock Glacier, WY was conducted over two field seasons in 2015/2016. Geomorphic analysis by surface observation and photogrammetry, including examination of a cirque-based thermokarst, was used to guide and complement geophysical sounding methods. Very clean ice below a 1 m thick layer of debris was directly observed on the walls of a 40 m diameter thermokarst pond near the accumulation zone. An englacial debris band 0.7 m thick dipping 30o intersected the wall of the pond. Transverse ridges occur at varying ridge-to-ridge wavelengths at different locations on the glacier. The GPR data supports the idea that surface ridges correlate with the intersection of debris layers and the surface. Modelling evidence is consistent with the observation of ridges at debris-layer/surface intersections, with compressional stresses buckling ice up-stream of the debris band.

An exact general remeshing scheme applied to physically conservative voxelization

DOE PAGES

Powell, Devon; Abel, Tom

2015-05-21

We present an exact general remeshing scheme to compute analytic integrals of polynomial functions over the intersections between convex polyhedral cells of old and new meshes. In physics applications this allows one to ensure global mass, momentum, and energy conservation while applying higher-order polynomial interpolation. We elaborate on applications of our algorithm arising in the analysis of cosmological N-body data, computer graphics, and continuum mechanics problems. We focus on the particular case of remeshing tetrahedral cells onto a Cartesian grid such that the volume integral of the polynomial density function given on the input mesh is guaranteed to equal themore » corresponding integral over the output mesh. We refer to this as “physically conservative voxelization.” At the core of our method is an algorithm for intersecting two convex polyhedra by successively clipping one against the faces of the other. This algorithm is an implementation of the ideas presented abstractly by Sugihara [48], who suggests using the planar graph representations of convex polyhedra to ensure topological consistency of the output. This makes our implementation robust to geometric degeneracy in the input. We employ a simplicial decomposition to calculate moment integrals up to quadratic order over the resulting intersection domain. We also address practical issues arising in a software implementation, including numerical stability in geometric calculations, management of cancellation errors, and extension to two dimensions. In a comparison to recent work, we show substantial performance gains. We provide a C implementation intended to be a fast, accurate, and robust tool for geometric calculations on polyhedral mesh elements.« less

Intersection collision avoidance using ITS countermeasures. Task 9, Intersection collision avoidance system performance guidelines

DOT National Transportation Integrated Search

2000-09-01

Phase III of the Intersection Collision Avoidance Using ITS Countermeasures program developed testbed systems, implemented the systems on a vehicle, and performed testing to determine the potential effectiveness of this system in preventing intersect...

Lane assignment traffic control devices on frontage roads and conventional roads at interchanges : technical report.

DOT National Transportation Integrated Search

2011-11-01

The intersection and mandatory movement lane control signs placed on intersection approaches are critical to : safe and efficient intersection operations. Ramp, frontage road, and cross-street approaches to interchanges : often widen at intersections...

Intersectionality, Race-Gender Subordination, and Education

ERIC Educational Resources Information Center

Harris, Angela; Leonardo, Zeus

2018-01-01

In this chapter, we unpack "intersectionality as an analytical framework." First, we cite Black Lives Matter as an impetus for discussing intersectionality's current traction. Second, we review the genealogy of "intersectionality" beginning with Kimberlé Crenshaw's formulation, which brought a Black Studies provocation into…

Intersection decision support : evaluation of a violation warning system to mitigate straight crossing path collisions.

DOT National Transportation Integrated Search

2006-01-01

This project entailed the design, development, testing, and evaluation of intersection decision support (IDS) systems to address straight crossing path (SCP) intersection crashes. This type of intersection crash is responsible for more than 100,000 c...

The problem with the phrase women and minorities: intersectionality-an important theoretical framework for public health.

PubMed

Bowleg, Lisa

2012-07-01

Intersectionality is a theoretical framework that posits that multiple social categories (e.g., race, ethnicity, gender, sexual orientation, socioeconomic status) intersect at the micro level of individual experience to reflect multiple interlocking systems of privilege and oppression at the macro, social-structural level (e.g., racism, sexism, heterosexism). Public health's commitment to social justice makes it a natural fit with intersectionality's focus on multiple historically oppressed populations. Yet despite a plethora of research focused on these populations, public health studies that reflect intersectionality in their theoretical frameworks, designs, analyses, or interpretations are rare. Accordingly, I describe the history and central tenets of intersectionality, address some theoretical and methodological challenges, and highlight the benefits of intersectionality for public health theory, research, and policy.

Sealing intersecting vane machines

DOEpatents

Martin, Jedd N.; Chomyszak, Stephen M.

2005-06-07

The invention provides a toroidal intersecting vane machine incorporating intersecting rotors to form primary and secondary chambers whose porting configurations minimize friction and maximize efficiency. Specifically, it is an object of the invention to provide a toroidal intersecting vane machine that greatly reduces the frictional losses through intersecting surfaces without the need for external gearing by modifying the width of one or both tracks at the point of intermeshing. The inventions described herein relate to these improvements.

Sealing intersecting vane machines

DOEpatents

Martin, Jedd N [Providence, RI; Chomyszak, Stephen M [Attleboro, MA

2007-06-05

The invention provides a toroidal intersecting vane machine incorporating intersecting rotors to form primary and secondary chambers whose porting configurations minimize friction and maximize efficiency. Specifically, it is an object of the invention to provide a toroidal intersecting vane machine that greatly reduces the frictional losses through intersecting surfaces without the need for external gearing by modifying the width of one or both tracks at the point of intermeshing. The inventions described herein relate to these improvements.

Influence of the three-dimensional heterogeneous roughness on electrokinetic transport in microchannels.

PubMed

Hu, Yandong; Werner, Carsten; Li, Dongqing

2004-12-15

Surface roughness has been considered as a passive means of enhancing species mixing in electroosmotic flow through microfluidic systems. It is highly desirable to understand the synergetic effect of three-dimensional (3D) roughness and surface heterogeneity on the electrokinetic flow through microchannels. In this study, we developed a three-dimensional finite-volume-based numerical model to simulate electroosmotic transport in a slit microchannel (formed between two parallel plates) with numerous heterogeneous prismatic roughness elements arranged symmetrically and asymmetrically on the microchannel walls. We consider that all 3D prismatic rough elements have the same surface charge or zeta potential, the substrate (the microchannel wall) surface has a different zeta potential. The results showed that the rough channel's geometry and the electroosmotic mobility ratio of the roughness elements' surface to that of the substrate, epsilon(mu), have a dramatic influence on the induced-pressure field, the electroosmotic flow patterns, and the electroosmotic flow rate in the heterogeneous rough microchannels. The associated sample-species transport presents a tidal-wave-like concentration field at the intersection between four neighboring rough elements under low epsilon(mu) values and has a concentration field similar to that of the smooth channels under high epsilon(mu) values.

Where to locate transit stops: Cross-intersection profiles of ultrafine particles and implications for pedestrian exposure.

PubMed

Choi, Wonsik; Ranasinghe, Dilhara; DeShazo, J R; Kim, Jae-Jin; Paulson, Suzanne E

2018-02-01

Epidemiological studies have shown that exposure to traffic-related pollutants increases incidence of adverse health outcomes. Transit users in cities across the globe commonly spend 15-45 min or more waiting at transit stops each day, often at locations with high levels of pollution from traffic. Here, we investigate the characteristics of concentration profiles of ultrafine particles (UFP) with 5 m spatial resolution across intersections, to determine the best place to site transit stops to minimize exposures. Cross-intersection UFP profiles were derived from 1744 profiles covering 90 m before and after each intersection center with a mobile monitoring platform. Measurements were made at 10 signalized intersections located at six urban sites, each with a distinct built environment, during both mornings and afternoons. Measurements were made within 1.5 m of the sidewalk and approximately at breathing height (1.5 m above ground level) to approximate sidewalk exposures. UFP profiles were strongly influenced by high emissions from vehicle stops and accelerations, and peaked within 30 m of intersection centers; from there concentrations decreased sharply with distance. Peak concentrations averaged about 90% higher than the minima along the block. They were accompanied by more frequent and larger transient concentration spikes, increasing the chance of people near the intersection being exposed to both short-term extremely high concentration spikes and higher average concentrations. The decays are somewhat larger before the intersection than after the intersection, however as siting transit stops after intersections is preferred for smooth traffic flow, we focus on after the intersection. Simple time-duration exposure calculations combined with breathing rates suggest moving a bus stop from 20 to 40-50 m after the intersection can reduce transit-users' exposure levels to total UFP substantially, in proportion to the reciprocal of the magnitude of elevation at the intersection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Landscaping of highway medians and roadway safety at unsignalized intersections.

PubMed

Chen, Hongyun; Fabregas, Aldo; Lin, Pei-Sung

2016-05-01

Well-planted and maintained landscaping can help reduce driving stress, provide better visual quality, and decrease over speeding, thus improving roadway safety. Florida Department of Transportation (FDOT) Standard Index (SI-546) is one of the more demanding standards in the U.S. for landscaping design criteria at highway medians near intersections. The purposes of this study were to (1) empirically evaluate the safety results of SI-546 at unsignalized intersections and (2) quantify the impacts of geometrics, traffic, and landscaping design features on total crashes and injury plus fatal crashes. The studied unsignalized intersections were divided into (1) those without median trees near intersections, (2) those with median trees near intersections that were compliant with SI-546, and (3) those with median trees near intersections that were non-compliant with SI-546. A total of 72 intersections were selected, for which five-year crash data from 2006-2010 were collected. The sites that were compliant with SI-546 showed the best safety performance in terms of the lowest crash counts and crash rates. Four crash predictive models-two for total crashes and two for injury crashes-were developed. The results indicated that improperly planted and maintained median trees near highway intersections can increase the total number of crashes and injury plus fatal crashes at a 90% confidence level; no significant difference could be found in crash rates between sites that were compliant with SI-546 and sites without trees. All other conditions remaining the same, an intersection with trees that was not compliant with SI-546 had 63% more crashes and almost doubled injury plus fatal crashes than those at intersections without trees. The study indicates that appropriate landscaping in highway medians near intersections can be an engineering technology that not only improves roadway environmental quality but also maintains intersection safety. Copyright © 2016. Published by Elsevier Ltd.

Justification of the Expediency of Creating Circular Intersections in Modern Cities

NASA Astrophysics Data System (ADS)

Vasilyeva, Elena; Sazonova, Tatiana

2017-10-01

The article resumes the principles of driving on Circular Intersections, which causes difficulties for some road users. Referring to certain foreign Traffic regulations, the author points out that such intersections are still stated imprecisely in Traffic regulations. Advantages and disadvantages of circular intersections as well as the expediency of their creation in the cities are considered in the article. The author offers to distinguish several types of circular intersections and claims that the most part of disadvantages listed in the article belong to circular intersections of the old type. On the contrary, the author presumes that creation of modern circular intersections will allow to regulate the planning of cities, make heavy traffic of transport possible while increasing the traffic safety at the same time, to improve the ecological situation of the city as well as its appearance, to carry out energy saving in the transport infrastructure of the city. All these aims could be feasible due to the creation of modern intersections of the Roundabout type.

Women's health, men's health, and gender and health: implications of intersectionality.

PubMed

Hankivsky, Olena

2012-06-01

Although intersectionality is now recognized in the context of women's health, men's health, and gender and health, its full implications for research, policy, and practice have not yet been interrogated. This paper investigates, from an intersectionality perspective, the common struggles within each field to confront the complex interplay of factors that shape health inequities. Drawing on developments within intersectionality scholarship and various sources of research and policy evidence (including examples from the field of HIV/AIDS), the paper demonstrates the methodological feasibility of intersectionality and in particular, the wide-ranging benefits of de-centering gender through intersectional analyses. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Intersection Challenge

ERIC Educational Resources Information Center

Roman, Harry T.

2011-01-01

Street intersections are a source of accidents--for both automobiles and pedestrians. This article presents an intersection challenge that allows students to explore some possible ways to change the traditional intersection. In this challenge, teachers open up the boundaries and allow students to redesign their world. The first step is to help…

Characterizing Containment and Related Classes of Graphs,

DTIC Science & Technology

1985-01-01

Math . to appear. [G2] Golumbic,. Martin C., D. Rotem and J. Urrutia. "Comparability graphs and intersection graphs" Discrete Math . 43 (1983) 37-40. [G3...intersection classes of graphs" Discrete Math . to appear. [S2] Scheinerman, Edward R. Intersection Classes and Multiple Intersection Parameters of Graphs...graphs and of interval graphs" Canad. Jour. of blath. 16 (1964) 539-548. [G1] Golumbic, Martin C. "Containment graphs: and. intersection graphs" Discrete

Intersectionality research in counseling psychology.

PubMed

Grzanka, Patrick R; Santos, Carlos E; Moradi, Bonnie

2017-10-01

This article introduces the special section on intersectionality research in counseling psychology. Across the 4 manuscripts that constitute this special section, a clear theme emerges: a need to return to the roots and politics of intersectionality. Importantly, the 2 empirical articles in this special section (Jerald, Cole, Ward, & Avery, 2017; Lewis, Williams, Peppers, & Gadson, 2017) are studies of Black women's experiences: a return, so to speak, to the subject positions and social locations from which intersectionality emanates. Shin et al. (2017) explore why this focus on Black feminist thought and social justice is so important by highlighting the persistent weaknesses in how much research published in leading counseling psychology journals has tended to use intersectionality as a way to talk about multiple identities, rather than as a framework for critiquing systemic, intersecting forms of oppression and privilege. Shin and colleagues also point to the possibilities intersectionality affords us when scholars realize the transformative potential of this critical framework. Answers to this call for transformative practices are foregrounded in Moradi and Grzanka's (2017) contribution, which surveys the interdisciplinary literature on intersectionality and presents a series of guidelines for using intersectionality responsibly. We close with a discussion of issues concerning the applications of intersectionality to counseling psychology research that spans beyond the contributions of each manuscript in this special section. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner.

PubMed

An, Jhonghyun; Choi, Baehoon; Sim, Kwee-Bo; Kim, Euntai

2016-07-20

There are several types of intersections such as merge-roads, diverge-roads, plus-shape intersections and two types of T-shape junctions in urban roads. When an autonomous vehicle encounters new intersections, it is crucial to recognize the types of intersections for safe navigation. In this paper, a novel intersection type recognition method is proposed for an autonomous vehicle using a multi-layer laser scanner. The proposed method consists of two steps: (1) static local coordinate occupancy grid map (SLOGM) building and (2) intersection classification. In the first step, the SLOGM is built relative to the local coordinate using the dynamic binary Bayes filter. In the second step, the SLOGM is used as an attribute for the classification. The proposed method is applied to a real-world environment and its validity is demonstrated through experimentation.

Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner

PubMed Central

An, Jhonghyun; Choi, Baehoon; Sim, Kwee-Bo; Kim, Euntai

2016-01-01

There are several types of intersections such as merge-roads, diverge-roads, plus-shape intersections and two types of T-shape junctions in urban roads. When an autonomous vehicle encounters new intersections, it is crucial to recognize the types of intersections for safe navigation. In this paper, a novel intersection type recognition method is proposed for an autonomous vehicle using a multi-layer laser scanner. The proposed method consists of two steps: (1) static local coordinate occupancy grid map (SLOGM) building and (2) intersection classification. In the first step, the SLOGM is built relative to the local coordinate using the dynamic binary Bayes filter. In the second step, the SLOGM is used as an attribute for the classification. The proposed method is applied to a real-world environment and its validity is demonstrated through experimentation. PMID:27447640

Investigations on the system boron-carbon silicon

NASA Technical Reports Server (NTRS)

Kieffer, R.; Gugel, E.; Leimer, G.; Ettmayer, P.

1983-01-01

The above elements form with each other binary compounds which are very interesting from the point of view of their structure and their chemistry and which are important for technology. The present investigation is concerned with the three-component system and the behavior of the binary compounds occurring in it. Investigations employing various techniques, such as X-ray, chemical analysis, microscopy and fusion experiments showed that no ternary phase exists within the boundary of the ternary system. There is no compound with a higher abrasion capacity than boron carbide. The probable phase field divisions at two isothermic intersections and the fusion isotherms are indicated.

The disconnections between space, place and learning in interprofessional education: an overview of key issues.

PubMed

Kitto, Simon; Nordquist, Jonas; Peller, Jennifer; Grant, Rachel; Reeves, Scott

2013-09-01

This article explores and discusses current conceptual and empirical dimensions of the study of space, place, education and interprofessional education (IPE) within a health professions context. This article addresses defining elements of the concepts, their use in nursing and medical literature and their positioning within educational theories. It outlines a series of ideas and approaches for future research aimed at investigating the intersections and relationships amongst these concepts. Importantly, this article argues that the conceptualization of space and place in IPE can potentially impact how educational space, places and curricular are (re)conducted and utilized.

Electrically reconfigurable logic array

NASA Technical Reports Server (NTRS)

Agarwal, R. K.

1982-01-01

To compose the complicated systems using algorithmically specialized logic circuits or processors, one solution is to perform relational computations such as union, division and intersection directly on hardware. These relations can be pipelined efficiently on a network of processors having an array configuration. These processors can be designed and implemented with a few simple cells. In order to determine the state-of-the-art in Electrically Reconfigurable Logic Array (ERLA), a survey of the available programmable logic array (PLA) and the logic circuit elements used in such arrays was conducted. Based on this survey some recommendations are made for ERLA devices.

Interlaminar stress singularities at a straight free edge in composite laminates

NASA Technical Reports Server (NTRS)

Raju, I. S.; Crews, J. H., Jr.

1981-01-01

A quasi-three-dimensional finite-element analysis was used to analyze the edge-stress problem in four-ply, composite laminates. The seven laminates that were considered belong to the laminate family where the outer ply angle is between 0 and 90 deg. Systematic convergence studies were made to explore the existence of stress singularities near the free edge. The present analysis appears to confirm the existence of stress singularities at the intersection of the interface and the free edge. The power of the stress singularity was the same for all seven laminates considered.

30 CFR 56.7055 - Intersecting holes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Intersecting holes. 56.7055 Section 56.7055... Piercing Drilling § 56.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives blasting agents, or detonators. [56 FR 46508, Sept...

30 CFR 56.7055 - Intersecting holes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Intersecting holes. 56.7055 Section 56.7055... Piercing Drilling § 56.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives blasting agents, or detonators. [56 FR 46508, Sept...

30 CFR 57.7055 - Intersecting holes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Intersecting holes. 57.7055 Section 57.7055... Jet Piercing Drilling-Surface and Underground § 57.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives, blasting agents...

30 CFR 57.7055 - Intersecting holes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Intersecting holes. 57.7055 Section 57.7055... Jet Piercing Drilling-Surface and Underground § 57.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives, blasting agents...

30 CFR 56.7055 - Intersecting holes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Intersecting holes. 56.7055 Section 56.7055... Piercing Drilling § 56.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives blasting agents, or detonators. [56 FR 46508, Sept...

30 CFR 57.7055 - Intersecting holes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Intersecting holes. 57.7055 Section 57.7055... Jet Piercing Drilling-Surface and Underground § 57.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives, blasting agents...

30 CFR 57.7055 - Intersecting holes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Intersecting holes. 57.7055 Section 57.7055... Jet Piercing Drilling-Surface and Underground § 57.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives, blasting agents...

30 CFR 56.7055 - Intersecting holes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Intersecting holes. 56.7055 Section 56.7055... Piercing Drilling § 56.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives blasting agents, or detonators. [56 FR 46508, Sept...

30 CFR 57.7055 - Intersecting holes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Intersecting holes. 57.7055 Section 57.7055... Jet Piercing Drilling-Surface and Underground § 57.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives, blasting agents...

30 CFR 56.7055 - Intersecting holes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Intersecting holes. 56.7055 Section 56.7055... Piercing Drilling § 56.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives blasting agents, or detonators. [56 FR 46508, Sept...

Crash Models For Rural Intersections: Four-Lane By Two-Lane Stop-Controlled And Two-Lane By Two-Lane Signalized

DOT National Transportation Integrated Search

1999-10-01

This report describes the collection, analysis, and modeling of crash and roadway data for intersections on rural roads in California and Michigan for the years 1993-1995. Three classes of intersections are considered: (1) three-legged intersections ...

Induced gravity on intersecting brane worlds. II. Cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corradini, Olindo; Koyama, Kazuya; Tasinato, Gianmassimo

2008-12-15

We explore cosmology of intersecting brane worlds with induced gravity on the branes. We find the cosmological equations that control the evolution of a moving codimension-one brane and a codimension-two brane that sits at the intersection. We study the Friedmann equation at the intersection, finding new contributions from the six-dimensional bulk. These higher dimensional contributions allow us to find new examples of self-accelerating configurations for the codimension-two brane at the intersection and we discuss their features.

Comparison of intersecting pedestrian flows based on experiments

NASA Astrophysics Data System (ADS)

Zhang, J.; Seyfried, A.

2014-07-01

Intersections of pedestrian flows feature multiple types, varying in the numbers of flow directions as well as intersecting angles. In this article results from intersecting flow experiments with two different intersecting angles are compared. To analyze the transport capabilities the Voronoi method is used to resolve the fine structure of the resulting velocity-density relations and spatial dependence of the measurements. The fundamental diagrams of various flow types are compared and show no apparent difference with respect to the intersecting angle 90° and 180°. This result indicates that head-on conflicts of different types of flow have the same influence on the transport properties of the system, which demonstrates the high self-organization capabilities of pedestrians.

A Procedure for 3-D Contact Stress Analysis of Spiral Bevel Gears

NASA Technical Reports Server (NTRS)

Kumar, A.; Bibel, G.

1994-01-01

Contact stress distribution of spiral bevel gears using nonlinear finite element static analysis is presented. Procedures have been developed to solve the nonlinear equations that identify the gear and pinion surface coordinates based on the kinematics of the cutting process and orientate the pinion and the gear in space to mesh with each other. Contact is simulated by connecting GAP elements along the intersection of a line from each pinion point (parallel to the normal at the contact point) with the gear surface. A three dimensional model with four gear teeth and three pinion teeth is used to determine the contact stresses at two different contact positions in a spiral bevel gearset. A summary of the elliptical contact stress distribution is given. This information will be helpful to helicopter and aircraft transmission designers who need to minimize weight of the transmission and maximize reliability.

Noncoherent Tracking of a Source of a Data-Modulated Signal

NASA Technical Reports Server (NTRS)

Arndt, G. Dickey; Ngo, Phong; Chen, Henry; Phan, Chau T.; Hill, Brent; Bourgeois, Brian; Dusl, John

2003-01-01

A proposed tracking receiver system containing three suitably positioned antenna elements and special signal-processing equipment would determine the direction of incidence of a microwave signal containing spread-spectrum digital data modulation. If the system were to contain two sets of antenna elements separated by a known baseline, it could determine the location of the transmitter as the intersection of the lines of incidence on the two antennas. Such systems could be used for diverse purposes in outer space and on Earth, including tracking astronauts and small robotic spacecraft working outside a spacecraft or space station, and locating cellular telephones from which distress calls have been made. The principle of operation does not require the transmission of a special identifying or distress signal by the cellular telephone or other transmitter to be tracked; instead, the system could utilize the data signal routinely sent by the transmitter, provided that the signal had the characteristics needed for processing.

3-D thermal analysis using finite difference technique with finite element model for improved design of components of rocket engine turbomachines for Space Shuttle Main Engine SSME

NASA Technical Reports Server (NTRS)

Sohn, Kiho D.; Ip, Shek-Se P.

1988-01-01

Three-dimensional finite element models were generated and transferred into three-dimensional finite difference models to perform transient thermal analyses for the SSME high pressure fuel turbopump's first stage nozzles and rotor blades. STANCOOL was chosen to calculate the heat transfer characteristics (HTCs) around the airfoils, and endwall effects were included at the intersections of the airfoils and platforms for the steady-state boundary conditions. Free and forced convection due to rotation effects were also considered in hollow cores. Transient HTCs were calculated by taking ratios of the steady-state values based on the flow rates and fluid properties calculated at each time slice. Results are presented for both transient plots and three-dimensional color contour isotherm plots; they were also converted into universal files to be used for FEM stress analyses.

Representations of S{sub {infinity}} admissible with respect to Young subgroups

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nessonov, Nikolai I

2012-03-31

Let N be the set of positive integers and S{sub {infinity}} the set of finite permutations of N. For a partition {Pi} of the set N into infinite parts A{sub 1},A{sub 2},... we denote by S{sub {Pi}} the subgroup of S{sub {infinity}} whose elements leave invariant each of the sets A{sub j}. We set S{sub {infinity}}{sup (N)}={l_brace}s element of S{sub {infinity}:} s(i)=i for any i=1,2,...,N{r_brace}. A factor representation T of the group S{sub {infinity}} is said to be {Pi}-admissible if for some N it contains a nontrivial identity subrepresentation of the subgroup S{sub {Pi}} intersection S{sub {infinity}}{sup (N)}. In themore » paper, we obtain a classification of the {Pi}-admissible factor representations of S{sub {infinity}}. Bibliography: 14 titles.« less

Finite temperature corrections to tachyon mass in intersecting D-branes

NASA Astrophysics Data System (ADS)

Sethi, Varun; Chowdhury, Sudipto Paul; Sarkar, Swarnendu

2017-04-01

We continue with the analysis of finite temperature corrections to the Tachyon mass in intersecting branes which was initiated in [1]. In this paper we extend the computation to the case of intersecting D3 branes by considering a setup of two intersecting branes in flat-space background. A holographic model dual to BCS superconductor consisting of intersecting D8 branes in D4 brane background was proposed in [2]. The background considered here is a simplified configuration of this dual model. We compute the one-loop Tachyon amplitude in the Yang-Mills approximation and show that the result is finite. Analyzing the amplitudes further we numerically compute the transition temperature at which the Tachyon becomes massless. The analytic expressions for the one-loop amplitudes obtained here reduce to those for intersecting D1 branes obtained in [1] as well as those for intersecting D2 branes.

The trend of road traffic crashes at urban signalised intersection

NASA Astrophysics Data System (ADS)

Farhana Nasarrudin, Nurul; Razelan, Intan Suhana Mohd

2018-04-01

Road traffic crash is one of the main contributing factors for deaths in the world. Intersection is listed as the second road type which road crashes occurred frequently. Hence, the traffic light was installed to minimise the road crashes at intersection. However, the crashes are still occurring and arising. The objective of this study was to exhibit the trend of road crashes at the signalised intersections. The data of road crashes for the past 6 years were analysed using descriptive analysis. The results showed that the road traffic crashes at three- and four-legged signalised intersection recorded the increasing trend. In conclusion, this finding shows that the road traffic crashes for these types of signalised intersection in Malaysia is rising. It is also one the contributors to the increasing number of crashes in Malaysia. This finding will encourage the local authority to conduct awareness programs on the safety at the signalised intersection.

Characteristics of traffic flow at nonsignalized T-shaped intersection with U-turn movements.

PubMed

Fan, Hong-Qiang; Jia, Bin; Li, Xin-Gang; Tian, Jun-Fang; Yan, Xue-Dong

2013-01-01

Most nonsignalized T-shaped intersections permit U-turn movements, which make the traffic conditions of intersection complex. In this paper, a new cellular automaton (CA) model is proposed to characterize the traffic flow at the intersection of this type. In present CA model, new rules are designed to avoid the conflicts among different directional vehicles and eliminate the gridlock. Two kinds of performance measures (i.e., flux and average control delay) for intersection are compared. The impacts of U-turn movements are analyzed under different initial conditions. Simulation results demonstrate that (i) the average control delay is more practical than flux in measuring the performance of intersection, (ii) U-turn movements increase the range and degree of high congestion, and (iii) U-turn movements on the different direction of main road have asymmetrical influences on the traffic conditions of intersection.

The design of a minimal sensor configuration for a Cooperative Intersection Collision Avoidance System - Stop Sign Assist : (CICAS-SSA report #2).

DOT National Transportation Integrated Search

2010-08-01

The deployment of a Cooperative Intersection Collision Avoidance System Stop Sign Assist (CICAS-SSA) can save lives by addressing the causal factor of crashes at rural thru-Stop intersection: drivers who stop on the minor leg of the intersection,...

Tracer Flux Balance at an Urban Canyon Intersection

NASA Astrophysics Data System (ADS)

Carpentieri, Matteo; Robins, Alan G.

2010-05-01

Despite their importance for pollutant dispersion in urban areas, the special features of dispersion at street intersections are rarely taken into account by operational air quality models. Several previous studies have demonstrated the complex flow patterns that occur at street intersections, even with simple geometry. This study presents results from wind-tunnel experiments on a reduced scale model of a complex but realistic urban intersection, located in central London. Tracer concentration measurements were used to derive three-dimensional maps of the concentration field within the intersection. In combination with a previous study (Carpentieri et al., Boundary-Layer Meteorol 133:277-296, 2009) where the velocity field was measured in the same model, a methodology for the calculation of the mean tracer flux balance at the intersection was developed and applied. The calculation highlighted several limitations of current state-of-the-art canyon dispersion models, arising mainly from the complex geometry of the intersection. Despite its limitations, the proposed methodology could be further developed in order to derive, assess and implement street intersection dispersion models for complex urban areas.

Using the event analysis of systemic teamwork (EAST) to explore conflicts between different road user groups when making right hand turns at urban intersections.

PubMed

Salmon, Paul M; Lenne, Michael G; Walker, Guy H; Stanton, Neville A; Filtness, Ashleigh

2014-01-01

Collisions between different types of road users at intersections form a substantial component of the road toll. This paper presents an analysis of driver, cyclist, motorcyclist and pedestrian behaviour at intersections that involved the application of an integrated suite of ergonomics methods, the Event Analysis of Systemic Teamwork (EAST) framework, to on-road study data. EAST was used to analyse behaviour at three intersections using data derived from an on-road study of driver, cyclist, motorcyclist and pedestrian behaviour. The analysis shows the differences in behaviour and cognition across the different road user groups and pinpoints instances where this may be creating conflicts between different road users. The role of intersection design in creating these differences in behaviour and resulting conflicts is discussed. It is concluded that currently intersections are not designed in a way that supports behaviour across the four forms of road user studied. Interventions designed to improve intersection safety are discussed. Practitioner Summary: Intersection safety currently represents a key road safety issue worldwide. This paper presents a novel application of a framework of ergonomics methods for studying differences in road user behaviour at intersections. The findings support development of interventions that consider all road users as opposed to one group in isolation.

Complex Road Intersection Modelling Based on Low-Frequency GPS Track Data

NASA Astrophysics Data System (ADS)

Huang, J.; Deng, M.; Zhang, Y.; Liu, H.

2017-09-01

It is widely accepted that digital map becomes an indispensable guide for human daily traveling. Traditional road network maps are produced in the time-consuming and labour-intensive ways, such as digitizing printed maps and extraction from remote sensing images. At present, a large number of GPS trajectory data collected by floating vehicles makes it a reality to extract high-detailed and up-to-date road network information. Road intersections are often accident-prone areas and very critical to route planning and the connectivity of road networks is mainly determined by the topological geometry of road intersections. A few studies paid attention on detecting complex road intersections and mining the attached traffic information (e.g., connectivity, topology and turning restriction) from massive GPS traces. To the authors' knowledge, recent studies mainly used high frequency (1 s sampling rate) trajectory data to detect the crossroads regions or extract rough intersection models. It is still difficult to make use of low frequency (20-100 s) and easily available trajectory data to modelling complex road intersections geometrically and semantically. The paper thus attempts to construct precise models for complex road intersection by using low frequency GPS traces. We propose to firstly extract the complex road intersections by a LCSS-based (Longest Common Subsequence) trajectory clustering method, then delineate the geometry shapes of complex road intersections by a K-segment principle curve algorithm, and finally infer the traffic constraint rules inside the complex intersections.

Effects of digital countdown timer on intersection safety and efficiency: A systematic review.

PubMed

Fu, Chuanyun; Zhang, Yaping; Qi, Weiwei; Cheng, Shaowu

2016-01-01

To investigate the available evidence referring to the effectiveness of digital countdown timers (DCTs) in improving the safety and operational efficiency of signalized intersection. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines. Relevant literature was searched from electronic databases using key terms. Based on study selection and methodological quality assessment, 14 studies were included in the review. Findings of the studies were synthesized in a narrative analysis. Three types of DCT had different effects on intersection safety and operational efficiency. Green signal countdown timers (GSCTs) reduced red light violations, type I dilemma zone distributions, and rear-end collision likelihood but increased crossing after yellow onset and had mixed impacts on type II dilemma zone distributions and intersection capacity. In contrast, red signal countdown timers (RSCTs) increased intersection capacity, although their effectiveness in reducing red light violations dissipated over time. Likewise, continuous countdown timers (CCTs) significantly enhanced intersection capacity but had mixed influences on red light violations and crossing after yellow onset. Due to the limited and inconsistent evidence regarding DCTs' effects on intersection safety and efficiency, it is not sufficient to recommend any type of DCT to be installed at signalized intersections to improve safety and operational efficiency. Nevertheless, it is apparent that both RSCTs and CCTs enhance intersection capacity, though their impacts on intersection safety are unclear. Future studies need to further verify those anticipated safe and operational benefits of DCTs with enriched field observation data.

System for conversion between the boundary representation model and a constructive solid geometry model of an object

DOEpatents

Christensen, N.C.; Emery, J.D.; Smith, M.L.

1985-04-29

A system converts from the boundary representation of an object to the constructive solid geometry representation thereof. The system converts the boundary representation of the object into elemental atomic geometrical units or I-bodies which are in the shape of stock primitives or regularized intersections of stock primitives. These elemental atomic geometrical units are then represented in symbolic form. The symbolic representations of the elemental atomic geometrical units are then assembled heuristically to form a constructive solid geometry representation of the object usable for manufacturing thereof. Artificial intelligence is used to determine the best constructive solid geometry representation from the boundary representation of the object. Heuristic criteria are adapted to the manufacturing environment for which the device is to be utilized. The surface finish, tolerance, and other information associated with each surface of the boundary representation of the object are mapped onto the constructive solid geometry representation of the object to produce an enhanced solid geometry representation, particularly useful for computer-aided manufacture of the object. 19 figs.

Robust pattern decoding in shape-coded structured light

NASA Astrophysics Data System (ADS)

Tang, Suming; Zhang, Xu; Song, Zhan; Song, Lifang; Zeng, Hai

2017-09-01

Decoding is a challenging and complex problem in a coded structured light system. In this paper, a robust pattern decoding method is proposed for the shape-coded structured light in which the pattern is designed as grid shape with embedded geometrical shapes. In our decoding method, advancements are made at three steps. First, a multi-template feature detection algorithm is introduced to detect the feature point which is the intersection of each two orthogonal grid-lines. Second, pattern element identification is modelled as a supervised classification problem and the deep neural network technique is applied for the accurate classification of pattern elements. Before that, a training dataset is established, which contains a mass of pattern elements with various blurring and distortions. Third, an error correction mechanism based on epipolar constraint, coplanarity constraint and topological constraint is presented to reduce the false matches. In the experiments, several complex objects including human hand are chosen to test the accuracy and robustness of the proposed method. The experimental results show that our decoding method not only has high decoding accuracy, but also owns strong robustness to surface color and complex textures.

Warped AdS 6 × S 2 in Type IIB supergravity III. Global solutions with seven-branes

NASA Astrophysics Data System (ADS)

D'Hoker, Eric; Gutperle, Michael; Uhlemann, Christoph F.

2017-11-01

We extend our previous construction of global solutions to Type IIB super-gravity that are invariant under the superalgebra F(4) and are realized on a spacetime of the form AdS 6 × S 2 warped over a Riemann surface Σ by allowing the supergravity fields to have non-trivial SL(2, ℝ) monodromy at isolated punctures on Σ. We obtain explicit solutions for the case where Σ is a disc, and the monodromy generators are parabolic elements of SL(2, ℝ) physically corresponding to the monodromy allowed in Type IIB string theory. On the boundary of Σ the solutions exhibit singularities at isolated points which correspond to semi-infinite five-branes, as is familiar from the global solutions without monodromy. In the interior of Σ, the solutions are everywhere regular, except at the punctures where SL(2, ℝ) monodromy resides and which physically correspond to the locations of [ p, q] seven-branes. The solutions have a compelling physical interpretation corresponding to fully localized five-brane intersections with additional seven-branes, and provide candidate holographic duals to the five-dimensional superconformal field theories realized on such intersections.

Finite Element Analysis of Geodesically Stiffened Cylindrical Composite Shells Using a Layerwise Theory

NASA Technical Reports Server (NTRS)

Gerhard, Craig Steven; Gurdal, Zafer; Kapania, Rakesh K.

1996-01-01

Layerwise finite element analyses of geodesically stiffened cylindrical shells are presented. The layerwise laminate theory of Reddy (LWTR) is developed and adapted to circular cylindrical shells. The Ritz variational method is used to develop an analytical approach for studying the buckling of simply supported geodesically stiffened shells with discrete stiffeners. This method utilizes a Lagrange multiplier technique to attach the stiffeners to the shell. The development of the layerwise shells couples a one-dimensional finite element through the thickness with a Navier solution that satisfies the boundary conditions. The buckling results from the Ritz discrete analytical method are compared with smeared buckling results and with NASA Testbed finite element results. The development of layerwise shell and beam finite elements is presented and these elements are used to perform the displacement field, stress, and first-ply failure analyses. The layerwise shell elements are used to model the shell skin and the layerwise beam elements are used to model the stiffeners. This arrangement allows the beam stiffeners to be assembled directly into the global stiffness matrix. A series of analytical studies are made to compare the response of geodesically stiffened shells as a function of loading, shell geometry, shell radii, shell laminate thickness, stiffener height, and geometric nonlinearity. Comparisons of the structural response of geodesically stiffened shells, axial and ring stiffened shells, and unstiffened shells are provided. In addition, interlaminar stress results near the stiffener intersection are presented. First-ply failure analyses for geodesically stiffened shells utilizing the Tsai-Wu failure criterion are presented for a few selected cases.

Intersections of a Circle and a Square: An Investigation

ERIC Educational Resources Information Center

Canada, Dan; Blair, Stephen

2007-01-01

The investigation of how a circle and square lying in the same plane could intersect each other is an excellent example of geometric problem-solving. This paper explores three facets of the investigation: (1) finding out how many points of intersection are possible, (2) classifying the different ways of intersection, and (3) determining which ways…

Information Points and Optimal Discharging Speed: Effects on the Saturation Flow at Signalized Intersections

ERIC Educational Resources Information Center

Gao, Lijun

2015-01-01

An information point was defined in this study as any object, structure, or activity located outside of a traveling vehicle that could potentially attract the visual attention of the driver. Saturation flow rates were studied for three pairs of signalized intersections in Toledo, Ohio. Each pair of intersections consisted of one intersection with…

Electronic and Structural Elements That Regulate the Excited-State Dynamics in Purine Nucleobase Derivatives

PubMed Central

2015-01-01

The excited-state dynamics of the purine free base and 9-methylpurine are investigated using experimental and theoretical methods. Femtosecond broadband transient absorption experiments reveal that excitation of these purine derivatives in aqueous solution at 266 nm results primarily in ultrafast conversion of the S2(ππ*) state to the vibrationally excited 1nπ* state. Following vibrational and conformational relaxation, the 1nπ* state acts as a doorway state in the efficient population of the triplet manifold with an intersystem crossing lifetime of hundreds of picoseconds. Experiments show an almost 2-fold increase in the intersystem crossing rate on going from polar aprotic to nonpolar solvents, suggesting that a solvent-dependent energy barrier must be surmounted to access the singlet-to-triplet crossing region. Ab initio static and surface-hopping dynamics simulations lend strong support to the proposed relaxation mechanism. Collectively, the experimental and computational results demonstrate that the accessibility of the nπ* states and the topology of the potential energy surfaces in the vicinity of conical intersections are key elements in controlling the excited-state dynamics of the purine derivatives. From a structural perspective, it is shown that the purine chromophore is not responsible for the ultrafast internal conversion in the adenine and guanine monomers. Instead, C6 functionalization plays an important role in regulating the rates of radiative and nonradiative relaxation. C6 functionalization inhibits access to the 1nπ* state while simultaneously facilitating access to the 1ππ*(La)/S0 conical intersection, such that population of the 1nπ* state cannot compete with the relaxation pathways to the ground state involving ring puckering at the C2 position. PMID:25763596

Structural evolution of fault zones in sandstone by multiple deformation mechanisms: Moab fault, southeast Utah

USGS Publications Warehouse

Davatzes, N.C.; Eichhubl, P.; Aydin, A.

2005-01-01

Faults in sandstone are frequently composed of two classes of structures: (1) deformation bands and (2) joints and sheared joints. Whereas the former structures are associated with cataclastic deformation, the latter ones represent brittle fracturing, fragmentation, and brecciation. We investigated the distribution of these structures, their formation, and the underlying mechanical controls for their occurrence along the Moab normal fault in southeastern Utah through the use of structural mapping and numerical elastic boundary element modeling. We found that deformation bands occur everywhere along the fault, but with increased density in contractional relays. Joints and sheared joints only occur at intersections and extensional relays. In all locations , joints consistently overprint deformation bands. Localization of joints and sheared joints in extensional relays suggests that their distribution is controlled by local variations in stress state that are due to mechanical interaction between the fault segments. This interpretation is consistent with elastic boundary element models that predict a local reduction in mean stress and least compressive principal stress at intersections and extensional relays. The transition from deformation band to joint formation along these sections of the fault system likely resulted from the combined effects of changes in remote tectonic loading, burial depth, fluid pressure, and rock properties. In the case of the Moab fault, we conclude that the structural heterogeneity in the fault zone is systematically related to the geometric evolution of the fault, the local state of stress associated with fault slip , and the remote loading history. Because the type and distribution of structures affect fault permeability and strength, our results predict systematic variations in these parameters with fault evolution. ?? 2004 Geological Society of America.

Using micro-simulation to investigate the safety impacts of transit design alternatives at signalized intersections.

PubMed

Li, Lu; Persaud, Bhagwant; Shalaby, Amer

2017-03-01

This study investigates the use of crash prediction models and micro-simulation to develop an effective surrogate safety assessment measure at the intersection level. With the use of these tools, hypothetical scenarios can be developed and explored to evaluate the safety impacts of design alternatives in a controlled environment, in which factors not directly associated with the design alternatives can be fixed. Micro-simulation models are developed, calibrated, and validated. Traffic conflicts in the micro-simulation models are estimated and linked with observed crash frequency, which greatly alleviates the lengthy time needed to collect sufficient crash data for evaluating alternatives, due to the rare and infrequent nature of crash events. A set of generalized linear models with negative binomial error structure is developed to correlate the simulated conflicts with the observed crash frequency in Toronto, Ontario, Canada. Crash prediction models are also developed for crashes of different impact types and for transit-involved crashes. The resulting statistical significance and the goodness-of-fit of the models suggest adequate predictive ability. Based on the established correlation between simulated conflicts and observed crashes, scenarios are developed in the micro-simulation models to investigate the safety effects of individual transit line elements by making hypothetical modifications to such elements and estimating changes in crash frequency from the resulting changes in conflicts. The findings imply that the existing transit signal priority schemes can have a negative effect on safety performance, and that the existing near-side stop positioning and streetcar transit type can be safer at their current state than if they were to be replaced by their respective counterparts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Usage of Video Analysis of Traffic Conflicts for the Evaluation of Inappropriately Designed Building Elements on Intersections

NASA Astrophysics Data System (ADS)

Krivda, Vladislav; Petru, Jan

2018-04-01

Human society is constantly evolving in all areas. The transport is no exception – especially development of road transport is considerable and visible on all levels. However, it is necessary to look for tools that can harmonize economic and social progress with the full preservation of the environment for future generations. The so-called sustainable development of road transport is also closely related to the issue of creating safe transport infrastructure. For example, roads must be in compliance with technical rules on one hand and on the other one they have to be clearly understandable for all road participants (drivers, pedestrians, etc.). Unfortunately, even if the designer of transport construction meets the technical requirements, the result is a dangerous place where very frequently the accidents or traffic conflicts take place. There exist statistics of accidents, but on the contrary, there are not any statistics of traffic conflicts. And simply monitoring the traffic conflicts can lead to early detection of problematic places in road infrastructure and thus increasing the safety in the road traffic. There are many methods used for monitoring traffic conflicts. The method used in the Czech Republic is described in the submitted paper. The original method, which monitored mainly and only the behaviour of drivers and their mistakes, was innovated, so that it could be used also for evaluation of inappropriately designed building elements of road constructions. Therefore, the paper deals with the description of so-called Innovated Video Analysis of Traffic Conflicts (IVATC) and with the usage of this method for one particular example of intersection, where larger vehicles (buses, trucks, etc.) had problems with passing through it. It points out to the fact that even a relatively small change can lead to the increase of the road safety.

Rigorous accuracy assessment for 3D reconstruction using time-series Dual Fluoroscopy (DF) image pairs

NASA Astrophysics Data System (ADS)

Al-Durgham, Kaleel; Lichti, Derek D.; Kuntze, Gregor; Ronsky, Janet

2017-06-01

High-speed biplanar videoradiography, or clinically referred to as dual fluoroscopy (DF), imaging systems are being used increasingly for skeletal kinematics analysis. Typically, a DF system comprises two X-ray sources, two image intensifiers and two high-speed video cameras. The combination of these elements provides time-series image pairs of articulating bones of a joint, which permits the measurement of bony rotation and translation in 3D at high temporal resolution (e.g., 120-250 Hz). Assessment of the accuracy of 3D measurements derived from DF imaging has been the subject of recent research efforts by several groups, however with methodological limitations. This paper presents a novel and simple accuracy assessment procedure based on using precise photogrammetric tools. We address the fundamental photogrammetry principles for the accuracy evaluation of an imaging system. Bundle adjustment with selfcalibration is used for the estimation of the system parameters. The bundle adjustment calibration uses an appropriate sensor model and applies free-network constraints and relative orientation stability constraints for a precise estimation of the system parameters. A photogrammetric intersection of time-series image pairs is used for the 3D reconstruction of a rotating planar object. A point-based registration method is used to combine the 3D coordinates from the intersection and independently surveyed coordinates. The final DF accuracy measure is reported as the distance between 3D coordinates from image intersection and the independently surveyed coordinates. The accuracy assessment procedure is designed to evaluate the accuracy over the full DF image format and a wide range of object rotation. Experiment of reconstruction of a rotating planar object reported an average positional error of 0.44 +/- 0.2 mm in the derived 3D coordinates (minimum 0.05 and maximum 1.2 mm).

Countering Brutality to Wildlife, Relationism and Ethics: Conservation, Welfare and the ‘Ecoversity’

PubMed Central

Garlick, Steve; Matthews, Julie; Carter, Jennifer

2011-01-01

Simple Summary Wildlife cruelty is commonplace in society. We argue for a new engagement with wildlife through three elements: a relational ethic based on intrinsic understanding of the way wildlife and humans might view each other; a geography of place and space, where there are implications for how we ascribe contextual meaning and practice in human-animal relations; and, engaged learning designed around our ethical relations with others, beyond the biophysical and novel, and towards the reflective metaphysical. We propose the ‘ecoversity’, as a scholarly and practical tool for focusing on the intersection of these three elements as an ethical place-based learning approach. Abstract Wildlife objectification and cruelty are everyday aspects of Australian society that eschew values of human kindness, empathy, and an understanding of the uniqueness and importance of non-human life in the natural world. Fostered by institutional failure, greed and selfishness, and the worst aspects of human disregard, the objectification of animals has its roots in longstanding Western anthropocentric philosophical perspectives, post colonialism, and a global uptake of neoliberal capitalism. Conservation, animal rights and welfare movements have been unable to stem the ever-growing abuse of wildlife, while ‘greenwash’ language such as ‘resource use’, ‘management’, ‘pests’, ‘over-abundance’, ‘conservation hunting’ and ‘ecology’ coat this violence with a respectable public veneer. We propose an engaged learning approach to address the burgeoning culture of wildlife cruelty and objectification that comprises three elements: a relational ethic based on intrinsic understanding of the way wildlife and humans might view each other [1,2,3]; geography of place and space [4], where there are implications for how we ascribe contextual meaning and practice in human-animal relations; and, following [5], engaged learning designed around our ethical relations with others, beyond the biophysical and novel and towards the reflective metaphysical. We propose the ‘ecoversity’ [6], as a scholarly and practical tool for focusing on the intersection of these three elements as an ethical place-based learning approach to wildlife relationism. We believe it provides a mechanism to help bridge the gap between human and non-human animals, conservation and welfare, science and understanding, and between objectification and relationism as a means of addressing entrenched cruelty to wildlife. PMID:26486221

Intersectional perspective in elderly care.

PubMed

Cuesta, Marta; Rämgård, Margareta

2016-01-01

Earlier research has shown that power relationships at workplaces are constructed by power structures. Processes related to power always influence the working conditions for (in this study in elderly care) the working groups involved. Power structures are central for intersectional analysis, in the sense that the intersectional perspective highlights aspects such as gender and ethnicity (subjective dimensions) and interrelates them to processes of power (objective dimension). This qualitative study aims to explore in what way an intersectional perspective could contribute to increased knowledge of power structures in a nursing home where the employees were mostly immigrants from different countries. By using reflexive dialogues related to an intersectional perspective, new knowledge which contributes to the employees' well-being could develop. Narrative analysis was the method used to conduct this study. Through a multi-stage focus group on six occasions over 6 months, the staff were engaged in intersectional and critical reflections about power relationship with the researchers, by identifying patterns in their professional activities that could be connected to their subjectivities (gender, ethnicity, etc.). The result of this study presents three themes that express the staff's experiences and connect these experiences to structural discrimination. 1) Intersectionality, knowledge, and experiences of professionalism; 2) Intersectionality, knowledge, and experiences of collaboration; and 3) Intersectionality, knowledge, and experiences of discrimination. The result demonstrates that an intersectional perspective reinforces the involved abilities, during the conversations, into being clear about, for example, their experiences of discrimination, and consequently developing a better understanding of their professionalism and collaboration. Such deeper reflections became possible through a process of consciousness raising, strengthening the employee's self-confidence, in a positive way.

Traffic Feasibility Study for a Grade Separator at a Busy Intersection in Vellore

NASA Astrophysics Data System (ADS)

Vasantha Kumar, S.; Gulati, Himanshu; Arora, Shivam

2017-11-01

One of the byproduct of urbanization is traffic congestion and before suggesting any solutions to reduce congestion, understanding the present context becomes very important. Study of traffic volumes at busy intersections to find the percentage composition of different vehicle types, directional distribution and peak hour traffic volume is a first step towards understanding the present context of traffic. Hence in the present study, one of the busy intersections in Vellore, namely, Gandhi nagar intersection in Vellore-Katpadi road was selected and traffic flow data was collected using video surveys. It was found that at the selected intersection, the two wheelers and three wheelers alone share 80% of the total traffic when compared to other vehicle types. Nearly 700 trucks and multi axle trailers were observed to pass through the intersection during the analysis period of five hours. That is, on an average 2 trucks/multi axle trailers were passing through the intersection in each minute. As like in other major cities, entry of trucks and other heavy vehicles such as multi axle trailers into the city needs to be banned during peak hours for smooth flow of traffic within city limits. A highest hourly volume of 6939 PCU’s was observed between 4 and 5 pm at the selected intersection. By assuming a 10% uniform traffic growth every year, it was found that after about 4 years, i.e., in 2019, the traffic volume at the intersection may reach 10,000 PCU’s and may warrant for a grade separator or interchange at the intersection.

Intersectional perspective in elderly care

PubMed Central

Cuesta, Marta; Rämgård, Margareta

2016-01-01

Earlier research has shown that power relationships at workplaces are constructed by power structures. Processes related to power always influence the working conditions for (in this study in elderly care) the working groups involved. Power structures are central for intersectional analysis, in the sense that the intersectional perspective highlights aspects such as gender and ethnicity (subjective dimensions) and interrelates them to processes of power (objective dimension). This qualitative study aims to explore in what way an intersectional perspective could contribute to increased knowledge of power structures in a nursing home where the employees were mostly immigrants from different countries. By using reflexive dialogues related to an intersectional perspective, new knowledge which contributes to the employees’ well-being could develop. Narrative analysis was the method used to conduct this study. Through a multi-stage focus group on six occasions over 6 months, the staff were engaged in intersectional and critical reflections about power relationship with the researchers, by identifying patterns in their professional activities that could be connected to their subjectivities (gender, ethnicity, etc.). The result of this study presents three themes that express the staff's experiences and connect these experiences to structural discrimination. 1) Intersectionality, knowledge, and experiences of professionalism; 2) Intersectionality, knowledge, and experiences of collaboration; and 3) Intersectionality, knowledge, and experiences of discrimination. The result demonstrates that an intersectional perspective reinforces the involved abilities, during the conversations, into being clear about, for example, their experiences of discrimination, and consequently developing a better understanding of their professionalism and collaboration. Such deeper reflections became possible through a process of consciousness raising, strengthening the employee's self-confidence, in a positive way. PMID:27167554

Expanding the Therapy Paradigm with Queer Couples: A Relational Intersectional Lens.

PubMed

Addison, Sheila M; Coolhart, Deborah

2015-09-01

North American and global cultures in general-and the field of Couple and Family Therapy in particular-have made significant strides toward recognizing and validating LGBTQ identities and relationships. However, clinical assessment and conceptualization of queer couples still lack the complexity needed to encompass the issues involved in treatment. Existing literature provides clinicians a basic understanding of queer couples and the dynamics that make them unique from nonqueer couples. However, much of this knowledge has been normed on White middle-class couples and has rarely included couples with transgender or bisexual members. This article invites clinicians and researchers to apply a feminist model of intersectionality to understand queer couples. Our proposed intersectional lens considers multiple axes of identity and power and their interrelationships (Crenshaw, 1989, 1991). We argue that intersectionality is important for understanding all identities, whether privileged or marginalized (Falicov, 2003). This application of the concept of intersectionality is unique in its relational focus, emphasizing how partners' complex individual identities overlap with and intersect with one another. Additionally, this lens considers how the therapists' and clients' multidimensional identities intersect. Three case studies are presented to illustrate application of the intersectional lens. In each case, exploring the partners' multiple social locations, their influences on one another, and the therapist's intersections of identity all proved critical to the direction of therapy. © 2015 Family Process Institute.

How to Best Name a Place? Facilitation and Inhibition of Route Learning Due to Descriptive and Arbitrary Location Labels.

PubMed

Meilinger, Tobias; Schulte-Pelkum, Jörg; Frankenstein, Julia; Hardiess, Gregor; Laharnar, Naima; Mallot, Hanspeter A; Bülthoff, Heinrich H

2016-01-01

Establishing verbal memory traces for non-verbal stimuli was reported to facilitate or inhibit memory for the non-verbal stimuli. We show that these effects are also observed in a domain not indicated before-wayfinding. Fifty-three participants followed a guided route in a virtual environment. They were asked to remember half of the intersections by relying on the visual impression only. At the other 50% of the intersections, participants additionally heard a place name, which they were asked to memorize. For testing, participants were teleported to the intersections and were asked to indicate the subsequent direction of the learned route. In Experiment 1, intersections' names were arbitrary (i.e., not related to the visual impression). Here, participants performed more accurately at unnamed intersections. In Experiment 2, intersections' names were descriptive and participants' route memory was more accurate at named intersections. Results have implications for naming places in a city and for wayfinding aids.

How to Best Name a Place? Facilitation and Inhibition of Route Learning Due to Descriptive and Arbitrary Location Labels

PubMed Central

Meilinger, Tobias; Schulte-Pelkum, Jörg; Frankenstein, Julia; Hardiess, Gregor; Laharnar, Naima; Mallot, Hanspeter A.; Bülthoff, Heinrich H.

2016-01-01

Establishing verbal memory traces for non-verbal stimuli was reported to facilitate or inhibit memory for the non-verbal stimuli. We show that these effects are also observed in a domain not indicated before—wayfinding. Fifty-three participants followed a guided route in a virtual environment. They were asked to remember half of the intersections by relying on the visual impression only. At the other 50% of the intersections, participants additionally heard a place name, which they were asked to memorize. For testing, participants were teleported to the intersections and were asked to indicate the subsequent direction of the learned route. In Experiment 1, intersections' names were arbitrary (i.e., not related to the visual impression). Here, participants performed more accurately at unnamed intersections. In Experiment 2, intersections' names were descriptive and participants' route memory was more accurate at named intersections. Results have implications for naming places in a city and for wayfinding aids. PMID:26869975

NOx profile around a signalized intersection of busy roadway

NASA Astrophysics Data System (ADS)

Kim, Kyung Hwan; Lee, Seung-Bok; Woo, Sung Ho; Bae, Gwi-Nam

2014-11-01

The NOx pollution profile around a signalized intersection of a busy roadway was investigated to understand the effect of traffic control on urban air pollution. Traffic flow patterns were classified into three categories of quasi-cruising, a combination of deceleration and acceleration, and a combination of deceleration, idling, and acceleration. The spatial distribution of air pollution levels around an intersection could be represented as a quasi-normal distribution, whose peak height was aggravated by increased emissions due to transient driving patterns. The peak concentration of NOx around the signalized intersection for the deceleration, idling, and acceleration category was five times higher than that for the quasi-cruising category. Severe levels of NOx pollution tailed off approximately 400 m from the center of the intersection. Approximately 200-1000 ppb of additional NOx was observed when traffic was decelerating, idling, and accelerating within the intersection zone, resulting in high exposure levels for pedestrians around the intersection. We propose a fluctuating horizontal distribution of motor vehicle-induced air pollutants as a function of time.

Using intersectionality responsibly: Toward critical epistemology, structural analysis, and social justice activism.

PubMed

Moradi, Bonnie; Grzanka, Patrick R

2017-10-01

The increasing popularity of the concept of intersectionality in the social sciences, including in psychology, represents an opportunity to reflect on the state of stewardship of this concept, its roots, and its promise. In this context, the authors aim to promote responsible stewardship of intersectionality and to tip the momentum of intersectionality's flourishing toward fuller use and engagement of its roots and promise for understanding and challenging dynamics of power, privilege, and oppression. To this end, this article provides a set of guidelines for reflection and action. The authors organize these guidelines along 3 major formulations of intersectionality: intersectionality as a field of study, as analytic strategy or disposition, and as critical praxis for social justice. Ultimately, the authors call for expanding the use of intersectionality toward fuller engagement with its roots in Black feminist thought, its current interdisciplinary richness and potential, and its central aims to challenge and transform structures and systems of power, privilege, and oppression. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Intersecting surface defects and two-dimensional CFT

NASA Astrophysics Data System (ADS)

Gomis, Jaume; Le Floch, Bruno; Pan, Yiwen; Peelaers, Wolfger

2017-08-01

We initiate the study of intersecting surface operators/defects in 4D quantum field theories (QFTs). We characterize these defects by coupled 4D/2D/0D theories constructed by coupling the degrees of freedom localized at a point and on intersecting surfaces in spacetime to each other and to the 4D QFT. We construct supersymmetric intersecting surface defects preserving just two supercharges in N =2 gauge theories. These defects are amenable to exact analysis by localization of the partition function of the underlying 4D/2D/0D QFT. We identify the 4D/2D/0D QFTs that describe intersecting surface operators in N =2 gauge theories realized by intersecting M2 branes ending on N M5 branes wrapping a Riemann surface. We conjecture and provide evidence for an explicit equivalence between the squashed four-sphere partition function of these intersecting defects and correlation functions in Liouville/Toda CFT with the insertion of arbitrary degenerate vertex operators, which are labeled by two representations of S U (N ).

Authenticity in Leadership: Intersectionality of Identities.

PubMed

Jones, Susan R

2016-12-01

This chapter situates leadership and the process of becoming a leader within an understanding of identity, particularly intersecting social identities and intersectionality. © 2016 Wiley Periodicals, Inc., A Wiley Company.

The intersectionality framework and identity intersections in the Journal of Counseling Psychology and The Counseling Psychologist: A content analysis.

PubMed

Shin, Richard Q; Welch, Jamie C; Kaya, Aylin E; Yeung, Jeffrey G; Obana, Chynna; Sharma, Rajni; Vernay, Collin N; Yee, Stephanie

2017-10-01

The framework of intersectionality is a powerful analytical tool for making sense of how interlocking systems of privilege and oppression are experienced by individuals and groups. Despite the long history of the concept, intersectionality has only recently gained attention in psychology. We conducted a content analysis to assess counseling psychology's engagement with an intersectional perspective. All articles published in the Journal of Counseling Psychology (n = 4,800) and The Counseling Psychologist (n = 1,915) from their first issues until July 2016 were reviewed to identify conceptual and empirical work focused on intersectionality. A total of 40 articles were identified and examined for themes. Limitations and future directions are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A speed guidance strategy for multiple signalized intersections based on car-following model

NASA Astrophysics Data System (ADS)

Tang, Tie-Qiao; Yi, Zhi-Yan; Zhang, Jian; Wang, Tao; Leng, Jun-Qiang

2018-04-01

Signalized intersection has great roles in urban traffic system. The signal infrastructure and the driving behavior near the intersection are paramount factors that have significant impacts on traffic flow and energy consumption. In this paper, a speed guidance strategy is introduced into a car-following model to study the driving behavior and the fuel consumption in a single-lane road with multiple signalized intersections. The numerical results indicate that the proposed model can reduce the fuel consumption and the average stop times. The findings provide insightful guidance for the eco-driving strategies near the signalized intersections.

Estimating intersection turning movements.

DOT National Transportation Integrated Search

1999-05-01

Turning movement (TM) counts are used for a variety of intersection analyses, including traffic operations analyses, : intersection design, and transportation planning applications. For many planning and design applications, especially in the case of...

Spatial database for intersections.

DOT National Transportation Integrated Search

2015-08-01

Deciding which intersections in the state of Kentucky warrant safety improvements requires a comprehensive inventory : with information on every intersection in the public roadway network. The Kentucky Transportation Cabinet (KYTC) : had previously c...

Investigating operation at geometrically unconventional intersections.

DOT National Transportation Integrated Search

2014-08-01

This report documents the development of decision assistance curves (DAC) for unconventional intersections, particularly : median U-turns (MUT), continuous flow intersections (CFI), and jughandles. The operational measure of effectiveness : such as d...

Research on traffic flow characteristics at signal intersection

NASA Astrophysics Data System (ADS)

Zeng, Jun-Wei; Yu, Sen-Bin; Qian, Yong-Sheng; Wei, Xu-Ting; Feng, Xiao; Wang, Hui

2017-09-01

Based on the cautious driving behavior and the principle of the vehicles at left-side having priority to pass in the intersection, a two-dimensional cellular automata model for planar signalized intersection (NS-STCA) is established. The different turning vehicles are regarded as the research objects and the effect of the left-turn probability, signal cycle, vehicle flow density on traffic flow at the intersection is investigated.

10 Best resources on… intersectionality with an emphasis on low- and middle-income countries.

PubMed

Larson, Elizabeth; George, Asha; Morgan, Rosemary; Poteat, Tonia

2016-10-01

Intersectionality has emerged as an important framework for understanding and responding to health inequities by making visible the fluid and interconnected structures of power that create them. It promotes an understanding of the dynamic nature of the privileges and disadvantages that permeate health systems and affect health. It considers the interaction of different social stratifiers (e.g. 'race'/ethnicity, indigeneity, gender, class, sexuality, geography, age, disability/ability, migration status, religion) and the power structures that underpin them at multiple levels. In doing so, it is a departure from previous health inequalities research that looked at these forms of social stratification in isolation from one another or in an additive manner. Despite its potential use and long history in other disciplines, intersectionality is uncommonly used in health systems research in low- and middle-income countries (LMICs). To orient readers to intersectionality theory and research, we first define intersectionality and describe its role in public health, and then we review resources on intersectionality. We found that applications in public health mostly increased after 2009, with only 14 out of 86 articles focused on LMICs. To arrive at 10 best resources, we selected articles based on the proportion of the article that was devoted to intersectionality, the strength of the intersectionality analysis, and its relevance to LMICs. The first four resources explain intersectionality as a methodology. The subsequent six articles apply intersectionality to research in LMIC with quantitative and qualitative analysis. We provide examples from India, Swaziland, Uganda and Mexico. Topics for the studies range from HIV, violence and sexual abuse to immunization and the use of health entitlements. Through these 10 resources, we hope to spark interest and open a needed conversation on the importance and use of intersectional analysis in LMICs as part of understanding people-centred health systems. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

27 CFR 9.59 - Arroyo Seco.

Code of Federal Regulations, 2011 CFR

2011-04-01

... intersection with Paraiso Road. (12) Then south following Paraiso Road to the intersection with Clark Road. (13) Then east-northeasterly along Clark Road for approximately 1,000 feet to its intersection with an...

27 CFR 9.59 - Arroyo Seco.

Code of Federal Regulations, 2010 CFR

2010-04-01

... intersection with Paraiso Road. (12) Then south following Paraiso Road to the intersection with Clark Road. (13) Then east-northeasterly along Clark Road for approximately 1,000 feet to its intersection with an...

Guided waves dispersion equations for orthotropic multilayered pipes solved using standard finite elements code.

PubMed

Predoi, Mihai Valentin

2014-09-01

The dispersion curves for hollow multilayered cylinders are prerequisites in any practical guided waves application on such structures. The equations for homogeneous isotropic materials have been established more than 120 years ago. The difficulties in finding numerical solutions to analytic expressions remain considerable, especially if the materials are orthotropic visco-elastic as in the composites used for pipes in the last decades. Among other numerical techniques, the semi-analytical finite elements method has proven its capability of solving this problem. Two possibilities exist to model a finite elements eigenvalue problem: a two-dimensional cross-section model of the pipe or a radial segment model, intersecting the layers between the inner and the outer radius of the pipe. The last possibility is here adopted and distinct differential problems are deduced for longitudinal L(0,n), torsional T(0,n) and flexural F(m,n) modes. Eigenvalue problems are deduced for the three modes classes, offering explicit forms of each coefficient for the matrices used in an available general purpose finite elements code. Comparisons with existing solutions for pipes filled with non-linear viscoelastic fluid or visco-elastic coatings as well as for a fully orthotropic hollow cylinder are all proving the reliability and ease of use of this method. Copyright © 2014 Elsevier B.V. All rights reserved.

Finite Element Method Analysis of An Out Flow With Free Surface In Transition Zones

NASA Astrophysics Data System (ADS)

Saoula, R. Iddir S.; Mokhtar, K. Ait

The object of this work is to present this part of the fluid mechanics that relates to out-flows of the fluid to big speeds in transitions. Results usually gotten by the classic processes can only have a qualitative aspect. The method fluently used for the count of these out-flows to big speeds is the one of characteristics, this approach remains interesting so much that doesn't appear within the out-flow of intersections of shock waves, as well as of reflections of these. In the simple geometry case, the method of finite differences satisfying result, But when the complexity of this geometry imposes itself, it is the method of finite elements that is proposed to solve this type of prob- lem, in particular for problems Trans critic. The goal of our work is to analyse free surface flows in channels no prismatic has oblong transverse section in zone of tran- sition. (Convergent, divergent). The basic mathematical model of this study is Saint Venant derivatives partial equations. To solve these equations we use the finite ele- ment method, the element of reference is the triangular element with 6 nodes which are quadratic in speed and linear in height (pressure). Our results and their obtains by others are very close to experimental results.

Eco-Approach and Departure at Signalized Intersections

DOT National Transportation Integrated Search

2014-11-01

The Eco-Approach and Departure at Signalized Intersections application uses wireless communications to give drivers recommendations that encourage "green" approaches to signalized intersections. The purpose of the application is to increase the fuel ...

Helping Students Understand Intersectionality: Reflections from a Dialogue Project in Residential Life

ERIC Educational Resources Information Center

Claros, Sharon Chia; Garcia, Gina A.; Johnston-Guerrero, Marc P.; Mata, Christine

2017-01-01

In this chapter, the authors share insights from a dialogue project focused on intersectionality within a residential life setting and discuss additional strategies for helping students understand intersectionality.

14 CFR 93.53 - Description of area.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Parkway; thence northerly along Lake Otis Parkway to its intersection with Abbott Road; thence east along Abbott Road to its intersection with Abbott Loop Road; thence north to its intersection with Tudor Road...

Delay correction model for estimating bus emissions at signalized intersections based on vehicle specific power distributions.

PubMed

Song, Guohua; Zhou, Xixi; Yu, Lei

2015-05-01

The intersection is one of the biggest emission points for buses and also the high exposure site for people. Several traffic performance indexes have been developed and widely used for intersection evaluations. However, few studies have focused on the relationship between these indexes and emissions at intersections. This paper intends to propose a model that relates emissions to the two commonly used measures of effectiveness (i.e. delay time and number of stops) by using bus activity data and emission data at intersections. First, with a large number of field instantaneous emission data and corresponding activity data collected by the Portable Emission Measurement System (PEMS), emission rates are derived for different vehicle specific power (VSP) bins. Then, 2002 sets of trajectory data, an equivalent of about 140,000 sets of second-by-second activity data, are obtained from Global Position Systems (GPSs)-equipped diesel buses in Beijing. The delay and the emission factors of each trajectory are estimated. Then, by using baseline emission factors for two types of intersections, e.g. the Arterial @ Arterial Intersection and the Arterial @ Collector, delay correction factors are calculated for the two types of intersections at different congestion levels. Finally, delay correction models are established for adjusting emission factors for each type of intersections and different numbers of stops. A comparative analysis between estimated and field emission factors demonstrates that the delay correction model is reliable. Copyright © 2015 Elsevier B.V. All rights reserved.

Near-road sampling of PM2. 5, BC, and fine-particle chemical components in Kathmandu Valley, Nepal

NASA Astrophysics Data System (ADS)

Shakya, Kabindra M.; Rupakheti, Maheswar; Shahi, Anima; Maskey, Rejina; Pradhan, Bidya; Panday, Arnico; Puppala, Siva P.; Lawrence, Mark; Peltier, Richard E.

2017-06-01

Semicontinuous PM2. 5 and black carbon (BC) concentrations, and 24 h integrated PM2. 5 filter samples were collected near roadways in the Kathmandu Valley, Nepal. Instruments were carried by a group of volunteer traffic police officers in the vicinity of six major roadway intersections in the Kathmandu Valley across two sampling periods in 2014. Daily PM2. 5 filter samples were analyzed for water-soluble inorganic ions, elemental carbon (EC) and organic carbon (OC), and 24 elements. Mean PM2. 5 and BC concentrations were 124.76 µg m-3 and 16.74 µgC m-3 during the drier spring sampling period, and 45.92 µg m-3 and 13.46 µgC m-3 during monsoonal sampling. Despite the lower monsoonal PM2. 5 concentrations, BC and several elements were not significantly lower during the monsoon, which indicates an important contribution of vehicle-related emissions throughout both seasons in this region. During the monsoon, there was an enhanced contribution of chemical species (elements and water-soluble inorganic ions), except secondary inorganic ions, and BC to PM2. 5 (crustal elements: 19 %; heavy metals: 5 %; and BC: 39 %) compared to those in spring (crustal elements: 9 %; heavy metals: 1 %; and BC: 18 %). Silica, calcium, aluminum, and iron were the most abundant elements during both spring and the monsoon, with total concentrations of 12.13 and 8.85 µg m-3, respectively. PM2. 5 and BC showed less spatial variation compared to that for individual chemical species.

Relative contribution of lateral inhibition to the Delboeuf and Wundt-Hering illusions.

PubMed

Coren, S

1999-06-01

It has been suggested that lateral neural interactions contribute to some illusions with intersecting or converging line elements but cannot be present in figures that lack these components. Most attempts to ascertain the contribution of neural interactions in visual illusions have involved changes in the actual pattern of illusion. It has now been demonstrated that certain forms of intermittent light stimulation can enhance lateral inhibitory activity. The Wundt-Hering and the Delboeuf illusions were tested under continuous illumination and "shaped" intermittent illumination which augments lateral inhibition. As expected, the Delboeuf illusion was unchanged with increased lateral inhibition while the magnitude of the Wundt-Hering illusion increased.

Development of an in-vehicle intersection collision countermeasure

NASA Astrophysics Data System (ADS)

Pierowicz, John A.

1997-02-01

Intersection collisions constitute approximately twenty-six percent of all accidents in the United States. Because of their complexity, and demands on the perceptual and decision making abilities of the driver, intersections present an increased risk of collisions between automobiles. This situation provides an opportunity to apply advanced sensor and processing capabilities to prevent these collisions. A program to determine the characteristics of intersection collisions and identify potential countermeasures will be described. This program, sponsored by the National Highway Traffic Safety Administration, utilized accident data to develop a taxonomy of intersection crashes. This taxonomy was used to develop a concept for an intersection collision avoidance countermeasure. The concept utilizes in-vehicle position, dynamic status, and millimeter wave radar system and an in-vehicle computer system to provide inputs to an intersection collision avoidance algorithm. Detection of potential violation of traffic control device, or proceeding into the intersection with inadequate gap will lead to the presentation of a warning to the driver. These warnings are presented to the driver primarily via a head-up display and haptic feedback. Roadside to vehicle communication provides information regarding phased traffic signal information. Active control of the vehicle's brake and steering systems are described. Progress in the development of the systems will be presented along with the schedule of future activities.

Emergency vehicle traffic signal preemption system

NASA Technical Reports Server (NTRS)

Bachelder, Aaron D. (Inventor); Foster, Conrad F. (Inventor)

2011-01-01

An emergency vehicle traffic light preemption system for preemption of traffic lights at an intersection to allow safe passage of emergency vehicles. The system includes a real-time status monitor of an intersection which is relayed to a control module for transmission to emergency vehicles as well as to a central dispatch office. The system also provides for audio warnings at an intersection to protect pedestrians who may not be in a position to see visual warnings or for various reasons cannot hear the approach of emergency vehicles. A transponder mounted on an emergency vehicle provides autonomous control so the vehicle operator can attend to getting to an emergency and not be concerned with the operation of the system. Activation of a priority-code (i.e. Code-3) situation provides communications with each intersection being approached by an emergency vehicle and indicates whether the intersection is preempted or if there is any conflict with other approaching emergency vehicles. On-board diagnostics handle various information including heading, speed, and acceleration sent to a control module which is transmitted to an intersection and which also simultaneously receives information regarding the status of an intersection. Real-time communications and operations software allow central and remote monitoring, logging, and command of intersections and vehicles.

The research of single intersection sensor signal control based on section data

NASA Astrophysics Data System (ADS)

Liu, Yunxiang; Huang, Yue; Wang, Hao

2016-12-01

Propose a sensing signal intersection control design electronic license based on the design by setting the intersection readers to interact with active electronic tags equipped vehicles, vehicle information obtained on the road section. In the vehicle detection sensor may control the green density as evaluation criteria are extended when the vehicle is higher than the threshold, the green density continuity, whereas the switching phases. Induction showed improved control strategy can achieve real-time traffic signal control effectively in high saturation intersection, to overcome the traditional sensor control failure at high saturation drawbacks and improve the utilization of urban Intersection comparative analysis by simulation.

An Intersectional Perspective on Access to HIV-Related Healthcare for Transgender Women

PubMed Central

Lacombe-Duncan, Ashley

2016-01-01

Abstract Transgender women experience decreased access to HIV-related healthcare relative to cisgender people, in part due to pervasive transphobia in healthcare. This perspective describes intersectionality as a salient theoretical approach to understanding this disparity, moving beyond transphobia to explore how intersecting systems of oppression, including cisnormativity, sexism/transmisogyny, classism, racism, and HIV-related, gender nonconformity, substance use, and sex work stigma influence HIV-related healthcare access for transgender women living with HIV. This perspective concludes with a discussion of how intersectionality-informed studies can be enhanced through studying underexplored intersections and bringing attention to women's resiliency and empowerment. PMID:29159304

Teaching Domestic Violence in the New Millennium: Intersectionality as a Framework for Social Change.

PubMed

McQueeney, Krista

2016-10-01

This article describes an intersectional approach to teaching about domestic violence (DV), which aims to empower students as critical thinkers and agents of change by merging theory, service learning, self-reflection, and activism. Three intersectional strategies and techniques for teaching about DV are discussed: promoting difference-consciousness, complicating gender-only power frameworks, and organizing for change. The author argues that to empower future generations to end violence, educators should put intersectionality into action through their use of scholarship, teaching methods, and pedagogical authority. Finally, the benefits and challenges of intersectional pedagogy for social justice education are considered. © The Author(s) 2016.

Identification of abnormal accident patterns at intersections

DOT National Transportation Integrated Search

1999-08-01

This report presents the findings and recommendations based on the Identification of Abnormal Accident Patterns at Intersections. This project used a statistically valid sampling method to determine whether a specific intersection has an abnormally h...

Using Intersectionality in Student Affairs Research

ERIC Educational Resources Information Center

Strayhorn, Terrell L.

2017-01-01

This chapter presents intersectionality as a useful heuristic for conducting research in higher education and student affairs contexts. Much more than just another theory, intersectionality can powerfully shape student affairs research in both obvious and tacit ways.

Improved traffic operations through real-time data collection and control.

DOT National Transportation Integrated Search

2016-05-01

Intersections are a major source of delay in urban networks, and reservation-based intersection control for : autonomous vehicles has great potential to improve intersection throughput. However, despite the high : flexibility in reservations, existin...

Automated accident detection at intersections.

DOT National Transportation Integrated Search

2004-03-01

This research aims to provide a timely and accurate accident detection method at intersections, which is : very important for the Traffic Management System(TMS). This research uses acoustic signals to detect : accident at intersections. A system is c...

Improved intersection operations during detector failures.

DOT National Transportation Integrated Search

2010-03-01

The objective of this project was to develop three modules that would improve the efficiency of : intersection operations at isolated signalized intersections. The motivation for these modules was to use the : existing detectors more efficiently. Thi...

Cooperative and Integrated Vehicle and Intersection Control for Energy Efficiency (CIVIC-E²)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hou, Yunfei; Seliman, Salaheldeen M. S.; Wang, Enshu

Recent advances in connected vehicle technologies enable vehicles and signal controllers to cooperate and improve the traffic management at intersections. This paper explores the opportunity for cooperative and integrated vehicle and intersection control for energy efficiency (CIVIC-E 2) to contribute to a more sustainable transportation system. We propose a two-level approach that jointly optimizes the traffic signal timing and vehicles' approach speed, with the objective being to minimize total energy consumption for all vehicles passing through an isolated intersection. More specifically, at the intersection level, a dynamic programming algorithm is designed to find the optimal signal timing by explicitly consideringmore » the arrival time and energy profile of each vehicle. At the vehicle level, a model predictive control strategy is adopted to ensure that vehicles pass through the intersection in a timely fashion. Our simulation study has shown that the proposed CIVIC-E 2 system can significantly improve intersection performance under various traffic conditions. Compared with conventional fixed-time and actuated signal control strategies, the proposed algorithm can reduce energy consumption and queue length by up to 31% and 95%, respectively.« less

Cooperative and Integrated Vehicle and Intersection Control for Energy Efficiency (CIVIC-E²)

DOE PAGES

Hou, Yunfei; Seliman, Salaheldeen M. S.; Wang, Enshu; ...

2018-02-15

Recent advances in connected vehicle technologies enable vehicles and signal controllers to cooperate and improve the traffic management at intersections. This paper explores the opportunity for cooperative and integrated vehicle and intersection control for energy efficiency (CIVIC-E 2) to contribute to a more sustainable transportation system. We propose a two-level approach that jointly optimizes the traffic signal timing and vehicles' approach speed, with the objective being to minimize total energy consumption for all vehicles passing through an isolated intersection. More specifically, at the intersection level, a dynamic programming algorithm is designed to find the optimal signal timing by explicitly consideringmore » the arrival time and energy profile of each vehicle. At the vehicle level, a model predictive control strategy is adopted to ensure that vehicles pass through the intersection in a timely fashion. Our simulation study has shown that the proposed CIVIC-E 2 system can significantly improve intersection performance under various traffic conditions. Compared with conventional fixed-time and actuated signal control strategies, the proposed algorithm can reduce energy consumption and queue length by up to 31% and 95%, respectively.« less

The computation of all plane/surface intersections for CAD/CAM applications

NASA Technical Reports Server (NTRS)

Hoitsma, D. H., Jr.; Roche, M.

1984-01-01

The problem of the computation and display of all intersections of a given plane with a rational bicubic surface patch for use on an interactive CAD/CAM system is examined. The general problem of calculating all intersections of a plane and a surface consisting of rational bicubic patches is reduced to the case of a single generic patch by applying a rejection algorithm which excludes all patches that do not intersect the plane. For each pertinent patch the algorithm presented computed the intersection curves by locating an initial point on each curve, and computes successive points on the curve using a tolerance step equation. A single cubic equation solver is used to compute the initial curve points lying on the boundary of a surface patch, and the method of resultants as applied to curve theory is used to determine critical points which, in turn, are used to locate initial points that lie on intersection curves which are in the interior of the patch. Examples are given to illustrate the ability of this algorithm to produce all intersection curves.

Emergency vehicle traffic signal preemption system

NASA Technical Reports Server (NTRS)

Foster, Conrad F. (Inventor); Bachelder, Aaron D. (Inventor)

2005-01-01

An emergency vehicle traffic light preemption system for preemption of traffic lights at an intersection to allow safe passage of emergency vehicles. The system includes a real-time status monitor of an intersection which is relayed to a communications controller for transmission to emergency vehicles as well as to a central dispatch office. The system also provides for audio warnings at an intersection to protect pedestrians who may not be in a position to see visual warnings or for various reasons cannot hear the approach of emergency vehicles. A transponder mounted on an emergency vehicle provides autonomous control so the vehicle operator can attend to getting to an emergency and not be concerned with the operation of the system. Activation of a Code 3 situation provides communications with each intersection being approached by an emergency vehicle and indicates whether the intersection is preempted or if there is any conflict with other approaching emergency vehicles. On-board diagnostics handle various information including heading, speed, and acceleration sent to a communications controller which is transmitted to an intersection and which also simultaneously receives information regarding the status of an intersection.

Revised Extended Grid Library

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martz, Roger L.

The Revised Eolus Grid Library (REGL) is a mesh-tracking library that was developed for use with the MCNP6TM computer code so that (radiation) particles can track on an unstructured mesh. The unstructured mesh is a finite element representation of any geometric solid model created with a state-of-the-art CAE/CAD tool. The mesh-tracking library is written using modern Fortran and programming standards; the library is Fortran 2003 compliant. The library was created with a defined application programmer interface (API) so that it could easily integrate with other particle tracking/transport codes. The library does not handle parallel processing via the message passing interfacemore » (mpi), but has been used successfully where the host code handles the mpi calls. The library is thread-safe and supports the OpenMP paradigm. As a library, all features are available through the API and overall a tight coupling between it and the host code is required. Features of the library are summarized with the following list: Can accommodate first and second order 4, 5, and 6-sided polyhedra; any combination of element types may appear in a single geometry model; parts may not contain tetrahedra mixed with other element types; pentahedra and hexahedra can be together in the same part; robust handling of overlaps and gaps; tracks element-to-element to produce path length results at the element level; finds element numbers for a given mesh location; finds intersection points on element faces for the particle tracks; produce a data file for post processing results analysis; reads Abaqus .inp input (ASCII) files to obtain information for the global mesh-model; supports parallel input processing via mpi; and support parallel particle transport by both mpi and OpenMP.« less

Fracture Capabilities in Grizzly with the extended Finite Element Method (X-FEM)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dolbow, John; Zhang, Ziyu; Spencer, Benjamin

Efforts are underway to develop fracture mechanics capabilities in the Grizzly code to enable it to be used to perform deterministic fracture assessments of degraded reactor pressure vessels (RPVs). A capability was previously developed to calculate three-dimensional interaction- integrals to extract mixed-mode stress-intensity factors. This capability requires the use of a finite element mesh that conforms to the crack geometry. The eXtended Finite Element Method (X-FEM) provides a means to represent a crack geometry without explicitly fitting the finite element mesh to it. This is effected by enhancing the element kinematics to represent jump discontinuities at arbitrary locations inside ofmore » the element, as well as the incorporation of asymptotic near-tip fields to better capture crack singularities. In this work, use of only the discontinuous enrichment functions was examined to see how accurate stress intensity factors could still be calculated. This report documents the following work to enhance Grizzly’s engineering fracture capabilities by introducing arbitrary jump discontinuities for prescribed crack geometries; X-FEM Mesh Cutting in 3D: to enhance the kinematics of elements that are intersected by arbitrary crack geometries, a mesh cutting algorithm was implemented in Grizzly. The algorithm introduces new virtual nodes and creates partial elements, and then creates a new mesh connectivity; Interaction Integral Modifications: the existing code for evaluating the interaction integral in Grizzly was based on the assumption of a mesh that was fitted to the crack geometry. Modifications were made to allow for the possibility of a crack front that passes arbitrarily through the mesh; and Benchmarking for 3D Fracture: the new capabilities were benchmarked against mixed-mode three-dimensional fracture problems with known analytical solutions.« less

Human factors literature reviews on intersections, speed management, pedestrians and bicyclists, and visibility

DOT National Transportation Integrated Search

2006-07-01

The Federal Highway Administration (FHWA) is currently addressing several general safety areas, including examining driver behavior at intersections, developing tools and procedures for intersection design, and conducting human factors literature rev...

Assessment of statewide intersection safety performance.

DOT National Transportation Integrated Search

2011-06-01

This report summarizes the results of an analysis of the safety performance of Oregons intersections. Following a pilot : study, a database of 500 intersections randomly sampled from around the state of Oregon in both urban and rural : environment...

Intersection collision warning system

DOT National Transportation Integrated Search

1999-04-01

Safety at unsignalized intersections is a major concern. Intersection collisions are one of the most common types of crash, and in the United States, they account for nearly 2 million accidents and 6,700 fatalities every year. However, a fully signal...

Manual traffic control for planned special events and emergencies.

DOT National Transportation Integrated Search

2015-11-01

Manual traffic control is a common intersection control strategy in which trained personnel, : typically police law enforcement officers, allocate intersection right-of-way to approaching vehicles. : Manual intersection control is a key part of manag...

Modeling electric bicycle's lane-changing and retrograde behaviors

NASA Astrophysics Data System (ADS)

Tang, Tie-Qiao; Luo, Xiao-Feng; Zhang, Jian; Chen, Liang

2018-01-01

Recently, electric bicycle (EB) has been one important traffic tool due to its own merits. However, EB's motion behaviors (especially at a signalized/non-signalized intersection) are more complex than those of vehicle since it always has lane-changing and retrograde behaviors. In this paper, we propose a model to explore EB's lane-changing and retrograde behaviors on a road with a signalized intersection. The numerical results indicate that the proposed model can qualitatively describe each EB's lane-changing and retrograde behaviors near a signalized intersection, and that lane-changing and retrograde behaviors have prominent impacts on the signalized intersection (i.e., prominent jams and congestions occur). The above results show that EB should be controlled as a vehicle, i.e., lane-changing and retrograde behaviors at a signalized intersection should strictly be prohibited to improve the operational efficiency and traffic safety at the signalized intersection.

Refined open intersection numbers and the Kontsevich-Penner matrix model

NASA Astrophysics Data System (ADS)

Alexandrov, Alexander; Buryak, Alexandr; Tessler, Ran J.

2017-03-01

A study of the intersection theory on the moduli space of Riemann surfaces with boundary was recently initiated in a work of R. Pandharipande, J.P. Solomon and the third author, where they introduced open intersection numbers in genus 0. Their construction was later generalized to all genera by J.P. Solomon and the third author. In this paper we consider a refinement of the open intersection numbers by distinguishing contributions from surfaces with different numbers of boundary components, and we calculate all these numbers. We then construct a matrix model for the generating series of the refined open intersection numbers and conjecture that it is equivalent to the Kontsevich-Penner matrix model. An evidence for the conjecture is presented. Another refinement of the open intersection numbers, which describes the distribution of the boundary marked points on the boundary components, is also discussed.

Analysis of Driver Evasive Maneuvering Prior to Intersection Crashes Using Event Data Recorders.

PubMed

Scanlon, John M; Kusano, Kristofer D; Gabler, Hampton C

2015-01-01

Intersection crashes account for over 4,500 fatalities in the United States each year. Intersection Advanced Driver Assistance Systems (I-ADAS) are emerging vehicle-based active safety systems that have the potential to help drivers safely navigate across intersections and prevent intersection crashes and injuries. The performance of an I-ADAS is expected to be highly dependent upon driver evasive maneuvering prior to an intersection crash. Little has been published, however, on the detailed evasive kinematics followed by drivers prior to real-world intersection crashes. The objective of this study was to characterize the frequency, timing, and kinematics of driver evasive maneuvers prior to intersection crashes. Event data recorders (EDRs) downloaded from vehicles involved in intersection crashes were investigated as part of NASS-CDS years 2001 to 2013. A total of 135 EDRs with precrash vehicle speed and braking application were downloaded to investigate evasive braking. A smaller subset of 59 EDRs that collected vehicle yaw rate was additionally analyzed to investigate evasive steering. Each vehicle was assigned to one of 3 precrash movement classifiers (traveling through the intersection, completely stopped, or rolling stop) based on the vehicle's calculated acceleration and observed velocity profile. To ensure that any significant steering input observed was an attempted evasive maneuver, the analysis excluded vehicles at intersections that were turning, driving on a curved road, or performing a lane change. Braking application at the last EDR-recorded time point was assumed to indicate evasive braking. A vehicle yaw rate greater than 4° per second was assumed to indicate an evasive steering maneuver. Drivers executed crash avoidance maneuvers in four-fifths of intersection crashes. A more detailed analysis of evasive braking frequency by precrash maneuver revealed that drivers performing complete or rolling stops (61.3%) braked less often than drivers traveling through the intersection without yielding (79.0%). After accounting for uncertainty in the timing of braking and steering data, the median evasive braking time was found to be between 0.5 to 1.5 s prior to impact, and the median initial evasive steering time was found to occur between 0.5 and 0.9 s prior to impact. The median average evasive braking deceleration for all cases was found to be 0.58 g. The median of the maximum evasive vehicle yaw rates was found to be 8.2° per second. Evasive steering direction was found to be most frequently in the direction of travel of the approaching vehicle. The majority of drivers involved in intersection crashes were alert enough to perform an evasive action. Most drivers used a combination of steering and braking to avoid a crash. The average driver attempted to steer and brake at approximately the same time prior to the crash.

The role of intersection and street design on severity of bicycle-motor vehicle crashes

PubMed Central

Verma, Santosh; Mekary, Rania A; Courtney, Theodore K; Christiani, David C

2017-01-01

Background Safety concerns are a major barrier to cycling. Intersection and street design variables such as intersection angles and street width might contribute to the severity of crashes and the safety concerns. In this study we examined whether these design variables were associated with bicycle-motor vehicle crashes (BMVC) severity. Methods Using the geographical information system and latitudes/longitudes recorded by the police using a global positioning device, we extracted intersection angles, street width, bicycle facilities, posted speed limits and annual average daily traffic from 3266 BMVC data from New York City police records. Additional variables about BMVC, including age and sex of the bicyclist, time of the day, road surface conditions, road character, vehicle type and injury severity, were obtained from police reports. Injury severity was classified as severe (incapacitating or killed) or non-severe (non-incapacitating, possible injury). The associations between injury severity and environment design variables were examined using multivariate log-binomial regression model. Findings Compared with crashes at orthogonal intersections, crashes at non-orthogonal intersections had 1.37 times (95% CI 1.05 to 1.80) and non-intersection street segments had 1.31 times (95% CI 1.01 to 1.70) higher risk of a severe injury. Crashes that involved a truck or a bus were twice as likely to result in a severe injury outcome; street width was not significantly associated with injury severity. Conclusion Crashes at non-orthogonal intersections and non-intersection segments are more likely to result in higher injury severity. The findings can be used to improve road design and develop effective safety interventions. PMID:27881469

In-Street Wind Direction Variability in the Vicinity of a Busy Intersection in Central London

NASA Astrophysics Data System (ADS)

Balogun, Ahmed A.; Tomlin, Alison S.; Wood, Curtis R.; Barlow, Janet F.; Belcher, Stephen E.; Smalley, Robert J.; Lingard, Justin J. N.; Arnold, Sam J.; Dobre, Adrian; Robins, Alan G.; Martin, Damien; Shallcross, Dudley E.

2010-09-01

We present results from fast-response wind measurements within and above a busy intersection between two street canyons (Marylebone Road and Gloucester Place) in Westminster, London taken as part of the DAPPLE (Dispersion of Air Pollution and Penetration into the Local Environment; www.dapple.org.uk ) 2007 field campaign. The data reported here were collected using ultrasonic anemometers on the roof-top of a building adjacent to the intersection and at two heights on a pair of lamp-posts on opposite sides of the intersection. Site characteristics, data analysis and the variation of intersection flow with the above-roof wind direction ( θ ref ) are discussed. Evidence of both flow channelling and recirculation was identified within the canyon, only a few metres from the intersection for along-street and across-street roof-top winds respectively. Results also indicate that for oblique roof-top flows, the intersection flow is a complex combination of bifurcated channelled flows, recirculation and corner vortices. Asymmetries in local building geometry around the intersection and small changes in the background wind direction (changes in 15- min mean θ ref of 5°-10°) were also observed to have profound influences on the behaviour of intersection flow patterns. Consequently, short time-scale variability in the background flow direction can lead to highly scattered in-street mean flow angles masking the true multi-modal features of the flow and thus further complicating modelling challenges.

Intersection life cycle cost comparison tool user guide version 1.0.

DOT National Transportation Integrated Search

2016-05-01

The Intersection Life Cycle Cost Comparison Tool User Guide was developed as part of North : Carolina Department of Transportation Research Project No. 201411: Evaluation of Life Cycle : Impacts of Intersection Control Type Selection. : This sprea...

Development of a framework for evaluating yellow timing at signalized intersections.

DOT National Transportation Integrated Search

2011-02-01

Studies show that the proper design of clearance intervals has significant implications for intersection safety. For : example, in 2001, approximately 218,000 red-light-running crashes occurred at signalized intersections in the United States. : Thes...

Development of performance matrices for evaluating innovative intersections and interchanges.

DOT National Transportation Integrated Search

2015-09-01

Innovative intersections and interchanges, primarily Continuous Flow Intersection (CFI) and Diverging Diamond : Interchange (DDI), have seen an increase in numbers in the State of Utah over the past several years, making Utah a : leader in the countr...

Conceptual development of an impact-attenuation system for intersecting roadways.

DOT National Transportation Integrated Search

2015-09-01

Longitudinal barriers are commonly used to shield hazards, including stiff bridge rail ends and slopes. In some locations, : a secondary roadway intersects the primary roadway within the guardrails length-of-need (LON). Some intersections may : ha...

Simulation of femtosecond two-dimensional electronic spectra of conical intersections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krčmář, Jindřich; Gelin, Maxim F.; Domcke, Wolfgang

2015-08-21

We have simulated femtosecond two-dimensional (2D) electronic spectra for an excited-state conical intersection using the wave-function version of the equation-of-motion phase-matching approach. We show that 2D spectra at fixed values of the waiting time provide information on the structure of the vibronic eigenstates of the conical intersection, while the evolution of the spectra with the waiting time reveals predominantly ground-state wave-packet dynamics. The results show that 2D spectra of conical intersection systems differ significantly from those obtained for chromophores with well separated excited-state potential-energy surfaces. The spectral signatures which can be attributed to conical intersections are discussed.

Are signalized intersections with cycle tracks safer? A case-control study based on automated surrogate safety analysis using video data.

PubMed

Zangenehpour, Sohail; Strauss, Jillian; Miranda-Moreno, Luis F; Saunier, Nicolas

2016-01-01

Cities in North America have been building bicycle infrastructure, in particular cycle tracks, with the intention of promoting urban cycling and improving cyclist safety. These facilities have been built and expanded but very little research has been done to investigate the safety impacts of cycle tracks, in particular at intersections, where cyclists interact with turning motor-vehicles. Some safety research has looked at injury data and most have reached the conclusion that cycle tracks have positive effects of cyclist safety. The objective of this work is to investigate the safety effects of cycle tracks at signalized intersections using a case-control study. For this purpose, a video-based method is proposed for analyzing the post-encroachment time as a surrogate measure of the severity of the interactions between cyclists and turning vehicles travelling in the same direction. Using the city of Montreal as the case study, a sample of intersections with and without cycle tracks on the right and left sides of the road were carefully selected accounting for intersection geometry and traffic volumes. More than 90h of video were collected from 23 intersections and processed to obtain cyclist and motor-vehicle trajectories and interactions. After cyclist and motor-vehicle interactions were defined, ordered logit models with random effects were developed to evaluate the safety effects of cycle tracks at intersections. Based on the extracted data from the recorded videos, it was found that intersection approaches with cycle tracks on the right are safer than intersection approaches with no cycle track. However, intersections with cycle tracks on the left compared to no cycle tracks seem to be significantly safer. Results also identify that the likelihood of a cyclist being involved in a dangerous interaction increases with increasing turning vehicle flow and decreases as the size of the cyclist group arriving at the intersection increases. The results highlight the important role of cycle tracks and the factors that increase or decrease cyclist safety. Results need however to be confirmed using longer periods of video data. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluating safety and operations of high-speed signalized intersections.

DOT National Transportation Integrated Search

2010-03-01

This Final Report reviews a research effort to evaluate the safety and operations of high-speed intersections in the State of : Oregon. In particular, this research effort focuses on four-leg, signalized intersections with speed limits of 45 mph or :...

Evaluating safety and operation of high-speed intersections.

DOT National Transportation Integrated Search

2010-03-01

This Final Report reviews a research effort to evaluate the safety and operations of high-speed intersections in the State of : Oregon. In particular, this research effort focuses on four-leg, signalized intersections with speed limits of 45 mph or :...

Evaluation of j-turn intersection design performance in Missouri.

DOT National Transportation Integrated Search

2013-12-01

Research shows that a high percentage of crashes that take place on high-speed rural expressways occur at intersections with : minor roads. One low-cost alternative design for improving the safety of at-grade intersections on such expressways is the ...

Evaluation of the cost-effectiveness of illumination as a safety treatment at rural intersections.

DOT National Transportation Integrated Search

2016-09-01

This research study seeks to improve current understanding of the relationship between rural intersection safety and different illumination levels. It uses three parallel studies: a survey of rural intersection illumination practices among US state d...

Evaluation of intersection countermeasures on high-speed rural multi-lane facilities.

DOT National Transportation Integrated Search

2012-01-01

The primary objective of this study is the evaluation of the effectiveness of several proposed safety : treatments at two intersections in Habersham County, Georgia. The intersections selected for this study had high : crash rates leading to a Georgi...

Evaluation of life cycle impacts of intersection control type selection [final report].

DOT National Transportation Integrated Search

2016-05-05

The methodology provided in this report provides guidance for NCDOT conversions of twoway : stop controlled intersections to other intersection types to enhance the effective allocation of : public funds. The findings of this project have been inc...

Considering Gender and Student Leadership Through the Lens of Intersectionality.

PubMed

Tillapaugh, Daniel; Mitchell, Donald; Soria, Krista M

2017-06-01

This chapter explores the concept of intersectionality and its applicability to student leadership development as well as recommendations on how intersectionality can provide transformative learning for students of all gender identities. © 2017 Wiley Periodicals, Inc., A Wiley Company.

Analysis and methods of improvement of safety at high-speed rural intersections.

DOT National Transportation Integrated Search

2012-04-01

Since 2006, INDOT has been preparing an annual fivepercent report that identifies intersections and segments on Indiana : state roads that require attention due to the excessive number and severity of crashes. Many of the identified intersections ...

76 FR 50446 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-15

... intersection of Inspiration Avenue and D Avenue, and comments pertaining to the Sal Taylor Creek Tributary 2... modified BFE is approximately 0.51 mile upstream of the intersection of Inspiration Avenue and D Avenue... mile upstream of the intersection of [[Page 50447

Modeling traffic accidents at signalized intersections in the city of Norfolk, VA.

DOT National Transportation Integrated Search

2010-12-31

This study was an attempt to apply a proactive approach using traffic pattern and signalized intersection characteristics to predict accident rates at signalized intersections in a citys arterial network. An earlier analysis of accident data at se...

An evaluation of Winnipeg's photo enforcement safety program: results of time series analyses and an intersection camera experiment.

PubMed

Vanlaar, Ward; Robertson, Robyn; Marcoux, Kyla

2014-01-01

The objective of this study was to evaluate the impact of Winnipeg's photo enforcement safety program on speeding, i.e., "speed on green", and red-light running behavior at intersections as well as on crashes resulting from these behaviors. ARIMA time series analyses regarding crashes related to red-light running (right-angle crashes and rear-end crashes) and crashes related to speeding (injury crashes and property damage only crashes) occurring at intersections were conducted using monthly crash counts from 1994 to 2008. A quasi-experimental intersection camera experiment was also conducted using roadside data on speeding and red-light running behavior at intersections. These data were analyzed using logistic regression analysis. The time series analyses showed that for crashes related to red-light running, there had been a 46% decrease in right-angle crashes at camera intersections, but that there had also been an initial 42% increase in rear-end crashes. For crashes related to speeding, analyses revealed that the installation of cameras was not associated with increases or decreases in crashes. Results of the intersection camera experiment show that there were significantly fewer red light running violations at intersections after installation of cameras and that photo enforcement had a protective effect on speeding behavior at intersections. However, the data also suggest photo enforcement may be less effective in preventing serious speeding violations at intersections. Overall, Winnipeg's photo enforcement safety program had a positive net effect on traffic safety. Results from both the ARIMA time series and the quasi-experimental design corroborate one another. However, the protective effect of photo enforcement is not equally pronounced across different conditions so further monitoring is required to improve the delivery of this measure. Results from this study as well as limitations are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influences of hydraulic gradient, surface roughness, intersecting angle, and scale effect on nonlinear flow behavior at single fracture intersections

NASA Astrophysics Data System (ADS)

Li, Bo; Liu, Richeng; Jiang, Yujing

2016-07-01

Fluid flow tests were conducted on two crossed fracture models for which the geometries of fracture segments and intersections were measured by utilizing a visualization technique using a CCD (charged coupled device) camera. Numerical simulations by solving the Navier-Stokes equations were performed to characterize the fluid flow at fracture intersections. The roles of hydraulic gradient, surface roughness, intersecting angle, and scale effect in the nonlinear fluid flow behavior through single fracture intersections were investigated. The simulation results of flow rate agreed well with the experimental results for both models. The experimental and simulation results showed that with the increment of the hydraulic gradient, the ratio of the flow rate to the hydraulic gradient, Q/J, decreases and the relative difference of Q/J between the calculation results employing the Navier-Stokes equations and the cubic law, δ, increases. When taking into account the fracture surface roughness quantified by Z2 ranging 0-0.42 for J = 1, the value of δ would increase by 0-10.3%. The influences of the intersecting angle on the normalized flow rate that represents the ratio of the flow rate in a segment to the total flow rate, Ra, and the ratio of the hydraulic aperture to the mechanical aperture, e/E, are negligible when J < 10-3, whereas their values change significantly when J > 10-2. Based on the regression analysis on simulation results, a mathematical expression was proposed to quantify e/E, involving variables of J and Rr, where Rr is the radius of truncating circles centered at an intersection. For E/Rr > 10-2, e/E varies significantly and the scale of model has large impacts on the nonlinear flow behavior through intersections, while for E/Rr < 10-3, the scale effect is negligibly small. Finally, a necessary condition to apply the cubic law to fluid flow through fracture intersections is suggested as J < 10-3, E/Rr < 10-3, and Z2 = 0.

Incorporating intersectionality theory into population health research methodology: challenges and the potential to advance health equity.

PubMed

Bauer, Greta R

2014-06-01

Intersectionality theory, developed to address the non-additivity of effects of sex/gender and race/ethnicity but extendable to other domains, allows for the potential to study health and disease at different intersections of identity, social position, processes of oppression or privilege, and policies or institutional practices. Intersectionality has the potential to enrich population health research through improved validity and greater attention to both heterogeneity of effects and causal processes producing health inequalities. Moreover, intersectional population health research may serve to both test and generate new theories. Nevertheless, its implementation within health research to date has been primarily through qualitative research. In this paper, challenges to incorporation of intersectionality into population health research are identified or expanded upon. These include: 1) confusion of quantitative terms used metaphorically in theoretical work with similar-sounding statistical methods; 2) the question of whether all intersectional positions are of equal value, or even of sufficient value for study; 3) distinguishing between intersecting identities, social positions, processes, and policies or other structural factors; 4) reflecting embodiment in how processes of oppression and privilege are measured and analysed; 5) understanding and utilizing appropriate scale for interactions in regression models; 6) structuring interaction or risk modification to best convey effects, and; 7) avoiding assumptions of equidistance or single level in the design of analyses. Addressing these challenges throughout the processes of conceptualizing and planning research and in conducting analyses has the potential to improve researchers' ability to more specifically document inequalities at varying intersectional positions, and to study the potential individual- and group-level causes that may drive these observed inequalities. A greater and more thoughtful incorporation of intersectionality can promote the creation of evidence that is directly useful in population-level interventions such as policy changes, or that is specific enough to be applicable within the social contexts of affected communities. Copyright © 2014 The Author. Published by Elsevier Ltd.. All rights reserved.

The intersection syndrome: Ultrasound findings and their diagnostic value

PubMed Central

Montechiarello, S.; Miozzi, F.; D’Ambrosio, I.; Giovagnorio, F.

2010-01-01

Introduction The intersection syndrome is a well-known overuse syndrome of the distal forearm. It is characterized by noninfectious, inflammatory changes involving the area of intersection of the first (abductor pollicis longus and extensor pollicis brevis) and second (extensor carpi radialis longus and extensor carpi radialis brevis) extensor compartments in the dorsoradial aspect of the distal forearm. Imaging modalities used to diagnosis this syndrome include ultrasonography (US) and magnetic resonance imaging. The purpose of this report is to describe typical US findings in the intersection syndrome and to demonstrate the diagnostic value of this approach. Materials and methods We reviewed US findings in 4 patients (mean age 40 years) referred to our staff for symptoms suggestive of the intersection syndrome (pain, swelling, erythema, and edema of the wrist). Results In all 4 cases, the US examination revealed peritendinous edema and synovial fluid within the tendon sheaths at the intersection between the first and the second dorsal extensor tendon compartments. Discussion Our experience shows that the intersection syndrome is associated with typical signs on US. This imaging modality can be considered a reliable tool for diagnosing this syndrome and may eliminate the need for other more expensive tests. PMID:23396515

Intersection assistance: a safe solution for older drivers?

PubMed

Dotzauer, Mandy; Caljouw, Simone R; de Waard, Dick; Brouwer, Wiebo H

2013-10-01

Within the next few decades, the number of older drivers operating a vehicle will increase rapidly (Eurostat, 2011). As age increases so does physical vulnerability, age-related impairments, and the risk of being involved in a fatal crashes. Older drivers experience problems in driving situations that require divided attention and decision making under time pressure as reflected by their overrepresentation in at-fault crashes on intersections. Advanced Driver Assistance Systems (ADAS) especially designed to support older drivers crossing intersections might counteract these difficulties. In a longer-term driving simulator study, the effects of an intersection assistant on driving were evaluated. 18 older drivers (M=71.44 years) returned repeatedly completing a ride either with or without a support system in a driving simulator. In order to test the intersection assistance, eight intersections were depicted for further analyses. Results show that ADAS affects driving. Equipped with ADAS, drivers allocated more attention to the road center rather than the left and right, crossed intersections in shorter time, engaged in higher speeds, and crossed more often with a critical time-to-collision (TTC) value. The implications of results are discussed in terms of behavioral adaptation and safety. Copyright © 2013 Elsevier Ltd. All rights reserved.

Understanding the micro and macro politics of health: Inequalities, intersectionality & institutions - A research agenda.

PubMed

Gkiouleka, Anna; Huijts, Tim; Beckfield, Jason; Bambra, Clare

2018-03-01

This essay brings together intersectionality and institutional approaches to health inequalities, suggesting an integrative analytical framework that accounts for the complexity of the intertwined influence of both individual social positioning and institutional stratification on health. This essay therefore advances the emerging scholarship on the relevance of intersectionality to health inequalities research. We argue that intersectionality provides a strong analytical tool for an integrated understanding of health inequalities beyond the purely socioeconomic by addressing the multiple layers of privilege and disadvantage, including race, migration and ethnicity, gender and sexuality. We further demonstrate how integrating intersectionality with institutional approaches allows for the study of institutions as heterogeneous entities that impact on the production of social privilege and disadvantage beyond just socioeconomic (re)distribution. This leads to an understanding of the interaction of the macro and the micro facets of the politics of health. Finally, we set out a research agenda considering the interplay/intersections between individuals and institutions and involving a series of methodological implications for research - arguing that quantitative designs can incorporate an intersectional institutional approach. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Complicating Counterspaces: Intersectionality and the Michigan Womyn's Music Festival.

PubMed

McConnell, Elizabeth A; Todd, Nathan R; Odahl-Ruan, Charlynn; Shattell, Mona

2016-06-01

The counterspaces framework articulated by Case and Hunter (2012), follows from community psychology's long-standing interest in the potential for settings to promote well-being and liberatory responses to oppression. This framework proposes that certain settings (i.e., "counterspaces") facilitate a specific set of processes that promote the well-being of marginalized groups. We argue that an intersectional analysis is crucial to understand whether and how counterspaces achieve these goals. We draw from literature on safe spaces and present a case study of the Michigan Womyn's Music Festival (Michfest) to illustrate the value of an intersectional analysis and explore how these processes operate. Based on 20 in-person interviews, 23 responses to an online survey, and ethnographic field notes, we show how Michfest was characterized by a particular intersection of identities at the setting level, and intersectional diversity complicated experiences at the individual level. Moreover, intersectional identities provided opportunities for dialogue and change at the setting level, including the creation of counterspaces within counterspaces. Overall, we demonstrate the need to attend to intersectionality in counterspaces, and more broadly in how we conceptualize settings in community psychology. © Society for Community Research and Action 2016.

Evaluation and analysis of noise levels at traffic intersections of Nagpur city, India.

PubMed

Vijay, Ritesh; Popat, Rishabh; Pisode, Mayur; Sharma, Asheesh; Manoj, Kumar; Chakrabarti, T; Gupta, Rajesh

2013-04-01

The objective of the present study was to monitor and assess the noise levels at traffic intersections in Napgur city under heterogenic traffic activities. For this, traffic volume and noise level were measured at intersections on highways, major roads andring road during morning and evening peak hours. Traffic volume was categorized in light, medium and heavy vehicles while noise levels were measured for Lmin, Lmax, Leq , L10 and L90. Equivalent noise was observed in the range of 71.3 to 79.3 dB(A) at the traffic intersections. Due to heterogenic traffic conditions and activities at the intersection like honking, idling, gear noise, bearing noise, breaking noise, tyre-road noise and exhaust noise, no correlation was established between traffic volume and observed noise levels except West High Court road. A strong correlation was found at West High Court road due to controlled traffic flow and less impact of heavy vehicles. Impact of noisy vehicles on general traffic was also assessed at the traffic intersections based on noise pollution levels and traffic noise index. The study suggests that control measures are required at the traffic intersections to minimize noise pollution levels.

Assessing the 'system' in safe systems-based road designs: using cognitive work analysis to evaluate intersection designs.

PubMed

Cornelissen, M; Salmon, P M; Stanton, N A; McClure, R

2015-01-01

While a safe systems approach has long been acknowledged as the underlying philosophy of contemporary road safety strategies, systemic applications are sparse. This article argues that systems-based methods from the discipline of Ergonomics have a key role to play in road transport design and evaluation. To demonstrate, the Cognitive Work Analysis framework was used to evaluate two road designs - a traditional Melbourne intersection and a cut-through design for future intersections based on road safety safe systems principles. The results demonstrate that, although the cut-through intersection appears different in layout from the traditional intersection, system constraints are not markedly different. Furthermore, the analyses demonstrated that redistribution of constraints in the cut-through intersection resulted in emergent behaviour, which was not anticipated and could prove problematic. Further, based on the lack of understanding of emergent behaviour, similar design induced problems are apparent across both intersections. Specifically, incompatibilities between infrastructure, vehicles and different road users were not dealt with by the proposed design changes. The importance of applying systems methods in the design and evaluation of road transport systems is discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Experimental analysis and numerical modeling of mollusk shells as a three dimensional integrated volume.

PubMed

Faghih Shojaei, M; Mohammadi, V; Rajabi, H; Darvizeh, A

2012-12-01

In this paper, a new numerical technique is presented to accurately model the geometrical and mechanical features of mollusk shells as a three dimensional (3D) integrated volume. For this purpose, the Newton method is used to solve the nonlinear equations of shell surfaces. The points of intersection on the shell surface are identified and the extra interior parts are removed. Meshing process is accomplished with respect to the coordinate of each point of intersection. The final 3D generated mesh models perfectly describe the spatial configuration of the mollusk shells. Moreover, the computational model perfectly matches with the actual interior geometry of the shells as well as their exterior architecture. The direct generation technique is employed to generate a 3D finite element (FE) model in ANSYS 11. X-ray images are taken to show the close similarity of the interior geometry of the models and the actual samples. A scanning electron microscope (SEM) is used to provide information on the microstructure of the shells. In addition, a set of compression tests were performed on gastropod shell specimens to obtain their ultimate compressive strength. A close agreement between experimental data and the relevant numerical results is demonstrated. Copyright © 2012 Elsevier Ltd. All rights reserved.

A combined dislocation fan-finite element (DF-FE) method for stress field simulation of dislocations emerging at the free surfaces of 3D elastically anisotropic crystals

NASA Astrophysics Data System (ADS)

Balusu, K.; Huang, H.

2017-04-01

A combined dislocation fan-finite element (DF-FE) method is presented for efficient and accurate simulation of dislocation nodal forces in 3D elastically anisotropic crystals with dislocations intersecting the free surfaces. The finite domain problem is decomposed into half-spaces with singular traction stresses, an infinite domain, and a finite domain with non-singular traction stresses. As such, the singular and non-singular parts of the traction stresses are addressed separately; the dislocation fan (DF) method is introduced to balance the singular traction stresses in the half-spaces while the finite element method (FEM) is employed to enforce the non-singular boundary conditions. The accuracy and efficiency of the DF method is demonstrated using a simple isotropic test case, by comparing it with the analytical solution as well as the FEM solution. The DF-FE method is subsequently used for calculating the dislocation nodal forces in a finite elastically anisotropic crystal, which produces dislocation nodal forces that converge rapidly with increasing mesh resolutions. In comparison, the FEM solution fails to converge, especially for nodes closer to the surfaces.

Pretest 3-D finite element modeling of the wedge pillar portion of the WIPP (Waste Isolation Pilot Plant) Geomechanical Evaluation (Room G) in situ experiment. [Waste Isolation Pilot Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Preece, D.S.

Pretest 3-D finite element calculations have been performed on the wedge pillar portion of the WIPP Geomechanical Evaluation Experiment. The wedge pillar separates two drifts that intersect at an angle of 7.5/sup 0/. Purpose of the experiment is to provide data on the creep behavior of the wedge and progressive failure at the tip. The first set of calculations utilized a symmetry plane on the center-line of the wedge which allowed treatment of the entire configuration by modeling half of the geometry. Two 3-D calculations in this first set were performed with different drift widths to study the influence ofmore » drift size on closure and maximum stress. A cross-section perpendicular to the wedge was also analyzed with 2-D finite element models and the results compared to the 3-D results. In another set of 3-D calculations both drifts were modeled but with less distance between the drifts and the outer boundaries. Results of these calculations are compared with results from the other calculations to better understand the influence of boundary conditions.« less

Lighting levels for isolated intersections : leading to safety improvements : final report.

DOT National Transportation Integrated Search

2015-01-01

A number of studies have linked the benefits of roadway lighting to a reduction in crash rates at night for a variety : of roadway types including rural intersections. Assessing the effectiveness of intersection lighting has primarily : relied upon c...

Analysis and methods of improvement of safety at high-speed rural intersections : appendix C.

DOT National Transportation Integrated Search

2012-04-01

Since 2006, INDOT has been preparing an annual fivepercent report that identifies intersections and segments on Indiana state roads that require attention due to the excessive number and severity of crashes. Many of the identified intersections ar...

Analysis and methods of improvement of safety at high-speed rural intersections : appendix A.

DOT National Transportation Integrated Search

2012-04-01

Since 2006, INDOT has been preparing an annual fivepercent report that identifies intersections and segments on Indiana state roads that require attention due to the excessive number and severity of crashes. Many of the identified intersections ar...

Analysis and methods of improvement of safety at high-speed rural intersections : appendix B.

DOT National Transportation Integrated Search

2012-04-01

Since 2006, INDOT has been preparing an annual fivepercent report that identifies intersections and segments on Indiana state roads that require attention due to the excessive number and severity of crashes. Many of the identified intersections ar...

Analysis of Driver Behavior and Operations at Intersection Short Lanes

DOT National Transportation Integrated Search

2016-08-01

With the ever-increasing demand to add roadway capacity in a safe and efficient manner, the application of auxiliary through lanes (ATLs) at intersections has increased in recent years. ATL intersections exist when there is an added through lane intr...

Real-time prediction of queues at signalized intersections to support eco-driving applications.

DOT National Transportation Integrated Search

2014-10-01

The overall objective of this research is to develop models for predicting queue lengths at signalized intersections based on : the data from probe vehicles. The time and space coordinates of the probe vehicles going through signalized intersections ...

Complete intersections : a guide to reconstructing intersections and interchanges for bicyclists and pedestrians.

DOT National Transportation Integrated Search

2010-01-01

Intersections and interchanges are major points of conflict for road users and are the frequent site of injuries and fatalities. In California, nearly 20 percent of pedestrian fatalities, and nearly a quarter of bicyclist fatalities occur at intersec...

Evaluation of j-turn intersection design performance in Missouri, final report.

DOT National Transportation Integrated Search

2013-12-01

Research shows that a high percentage of crashes that take place on high-speed rural expressways occur at intersections : with minor roads. One low-cost alternative design for improving the safety of at-grade intersections on such expressways is : th...

Evaluation of energy absorption of new concepts of aircraft composite subfloor intersections

NASA Technical Reports Server (NTRS)

Jones, Lisa E.; Carden, Huey D.

1989-01-01

Forty-one composite aircraft subfloor intersection specimens were tested to determine the effects of geometry and material on the energy absorbing behavior, failure characteristics, and post-crush structural integrity of the specimens. The intersections were constructed of twelve ply + or - 45 sub 6 laminates of either Kevlar 49/934 or AS-4/934 graphite-epoxy in heights of 4, 8, and 12 inches. The geometry of the specimens varied in the designs of the intersection attachment angle. Four different geometries were tested.

Non-adiabatic dynamics close to conical intersections and the surface hopping perspective

PubMed Central

Malhado, João Pedro; Bearpark, Michael J.; Hynes, James T.

2014-01-01

Conical intersections play a major role in the current understanding of electronic de-excitation in polyatomic molecules, and thus in the description of photochemistry and photophysics of molecular systems. This article reviews aspects of the basic theory underlying the description of non-adiabatic transitions at conical intersections, with particular emphasis on the important case when the dynamics of the nuclei are treated classically. Within this classical nuclear motion framework, the main aspects of the surface hopping methodology in the conical intersection context are presented. The emerging picture from this treatment is that of electronic transitions around conical intersections dominated by the interplay of the nuclear velocity and the derivative non-adiabatic coupling vector field. PMID:25485263

Transnational Intersectionality in Family Therapy With Resettled Refugees.

PubMed

Gangamma, Rashmi; Shipman, Daran

2018-04-01

In this article, we discuss incorporating the transnational intersectionality framework in family therapy with resettled refugees. Transnational intersectionality is an extension of the framework of intersectionality which helps to better understand complexities of power and oppression across national contexts and their influence on refugees' lives. Adopting this framework alerts family therapists to: (a) develop critical awareness of refugee's transnational contexts; (b) understand differences in experiences of social identities across contexts; (c) acknowledge postmigration factors of oppression affecting resettlement; and (d) critically reflect upon therapist-interpreter-client intersectionalities. This shifts our conceptualization of therapy with refugees to actively consider transnational contexts which refugees uniquely occupy. We describe the framework and provide two case illustrations to highlight its usefulness. © 2017 American Association for Marriage and Family Therapy.

Guidelines and Capabilities for Designing Human Missions

NASA Technical Reports Server (NTRS)

2002-01-01

The human element is likely the most complex and difficult one of mission design; it significantly influences every aspect of mission planning, from the basic parameters like duration to the more complex tradeoffs between mass, volume, power, risk, and cost. For engineers who rely on precise specifications in data books and other such technical references, dealing with the uncertainty and the variability of designing for human beings can be frustrating. When designing for the human element, questions arise more often than definitive answers. Nonetheless, we do not doubt that the most captivating discoveries in future space missions will necessitate human explorers. These guidelines and capabilities are meant to identify the points of intersection between humans and mission considerations such as architecture, vehicle design, technologies, operations, and science requirements. We seek to provide clear, top-level guidelines for human-related exploration studies and technology research that address common questions and requirements. As a result, we hope that ongoing mission trade studies consider common, standard, and practical criteria for human interfaces.

Honorary Authorship Practices in Environmental Science Teams: Structural and Cultural Factors and Solutions.

PubMed

Elliott, Kevin C; Settles, Isis H; Montgomery, Georgina M; Brassel, Sheila T; Cheruvelil, Kendra Spence; Soranno, Patricia A

2017-01-01

Overinclusive authorship practices such as honorary or guest authorship have been widely reported, and they appear to be exacerbated by the rise of large interdisciplinary collaborations that make authorship decisions particularly complex. Although many studies have reported on the frequency of honorary authorship and potential solutions to it, few have probed how the underlying dynamics of large interdisciplinary teams contribute to the problem. This article reports on a qualitative study of the authorship standards and practices of six National Science Foundation-funded interdisciplinary environmental science teams. Using interviews of the lead principal investigator and an early-career member on each team, our study explores the nature of honorary authorship practices as well as some of the motivating factors that may contribute to these practices. These factors include both structural elements (policies and procedures) and cultural elements (values and norms) that cross organizational boundaries. Therefore, we provide recommendations that address the intersection of these factors and that can be applied at multiple organizational levels.

Guidelines and Capabilities for Designing Human Missions

NASA Astrophysics Data System (ADS)

2002-03-01

The human element is likely the most complex and difficult one of mission design; it significantly influences every aspect of mission planning, from the basic parameters like duration to the more complex tradeoffs between mass, volume, power, risk, and cost. For engineers who rely on precise specifications in data books and other such technical references, dealing with the uncertainty and the variability of designing for human beings can be frustrating. When designing for the human element, questions arise more often than definitive answers. Nonetheless, we do not doubt that the most captivating discoveries in future space missions will necessitate human explorers. These guidelines and capabilities are meant to identify the points of intersection between humans and mission considerations such as architecture, vehicle design, technologies, operations, and science requirements. We seek to provide clear, top-level guidelines for human-related exploration studies and technology research that address common questions and requirements. As a result, we hope that ongoing mission trade studies consider common, standard, and practical criteria for human interfaces.

Networks with fourfold connectivity in two dimensions.

PubMed

Tessier, Frédéric; Boal, David H; Discher, Dennis E

2003-01-01

The elastic properties of planar, C4-symmetric networks under stress and at nonzero temperature are determined by simulation and mean field approximations. Attached at fourfold coordinated junction vertices, the networks are self-avoiding in that their elements (or bonds) may not intersect each other. Two different models are considered for the potential energy of the elements: either Hooke's law springs or flexible tethers (square well potential). For certain ranges of stress and temperature, the properties of the networks are captured by one of several models: at large tensions, the networks behave like a uniform system of square plaquettes, while at large compressions or high temperatures, they display many characteristics of an ideal gas. Under less severe conditions, mean field models with more general shapes (parallelograms) reproduce many essential features of both networks. Lastly, the spring network expands without limit at a two-dimensional tension equal to the force constant of the spring; however, it does not appear to collapse under compression, except at zero temperature.

Local delamination in laminates with angle ply matrix cracks. Part 1: Tension tests and stress analysis

NASA Technical Reports Server (NTRS)

Obrien, T. Kevin; Hooper, S. J.

1991-01-01

Quasi-static tension tests were conducted on AS4/3501-6 graphite epoxy laminates. Dye penetrant enhanced x-radiography was used to document the onset of matrix cracking and the onset of local delaminations at the intersection of the matrix cracks and the free edge. Edge micrographs taken after the onset of damage were used to verify the location of the matrix cracks and local delamination through the laminate thickness. A quasi-3D finite element analysis was conducted to calculate the stresses responsible for matrix cracking in the off-axis plies. Laminated plate theory indicated that the transverse normal stresses were compressive. However, the finite element analysis yielded tensile transverse normal stresses near the free edge. Matrix cracks formed in the off-axis plies near the free edge where in-plane transverse stresses were tensile and had their greatest magnitude. The influence of the matrix crack on interlaminar stresses is also discussed.

Evaluating the Impacts of Red Light Camera Deployment on Intersection Traffic Safety

DOT National Transportation Integrated Search

2018-06-01

Red-light cameras (RLC) are a popular countermeasure to reduce red-light running and improve intersection safety. Studies show that the reduction in side impact crashes at RLC intersections are often accompanied by no-change or an increase in the num...

Intersection negotiation problems of older drivers. Volume 2, Background synthesis on age and intersection driving difficulties

DOT National Transportation Integrated Search

1998-09-01

This project included a background literature synthesis and observational field study. The research goals were to document driving problems and errors at intersections, for older drivers using their own cars to travel familiar and unfamiliar routes, ...

Evaluating safety and operation of high-speed signalized intersections : final report, March 2010.

DOT National Transportation Integrated Search

2010-03-01

This Final Report reviews a research effort to evaluate the safety and operations of high-speed intersections in the State of : Oregon. In particular, this research effort focuses on four-leg, signalized intersections with speed limits of 45 mph or :...

Cooperative intersection collision avoidance system limited to stop sign and traffic signal violations (CICAS-V).

DOT National Transportation Integrated Search

2008-09-30

The objective of the Cooperative Intersection Collision Avoidance System for Violations (CICAS-V) Project is to develop and field-test a comprehensive system to reduce the number of crashes at intersections due to violations of traffic control device...

Development of left-turn lane guidelines for signalized and unsignalized intersections.

DOT National Transportation Integrated Search

2004-01-01

It is generally accepted that the level of service (LOS) at intersections significantly affects the overall LOS of the road system. It is also known that the LOS at an intersection can be adversely affected by frequently allowing left-turning vehicle...

Evaluation of the Norridgewock intersection collision avoidance warning system on Route 201A, Norridgewock, Maine.

DOT National Transportation Integrated Search

2006-11-01

Review of the Norridgewock Intersection Collision Avoidance Warning System : demonstrates that the system appears to effectively reduce the number of potential : crashes at the intersection of River Road, Sophie May Lane and Route 201A. : Results sho...

Intersection Collision Avoidance Using Its Countermeasures. Task 9: Final Report: Intersection Collision Avoidance System Performance Guidelines

DOT National Transportation Integrated Search

2000-09-01

Roadway intersections are areas of potential conflict that increase risk exposure for vehicles attempting to pass through these locations. Advances in sensor and data processing technology during the past decade have enabled the collection of large a...

EnviroAtlas - New York, NY - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Paterson, NJ - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Fresno, CA - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Green Bay, WI - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Des Moines, IA - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Minneapolis/St. Paul, MN - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Woodbine, IA - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Phoenix, AZ - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Pittsburgh, PA - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - New Bedford, MA - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Milwaukee, WI - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Austin, TX - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

Vehicular crash data used to rank intersections by injury crash frequency and severity.

PubMed

Liu, Yi; Li, Zongzhi; Liu, Jingxian; Patel, Harshingar

2016-09-01

This article contains data on research conducted in "A double standard model for allocating limited emergency medical service vehicle resources ensuring service reliability" (Liu et al., 2016) [1]. The crash counts were sorted out from comprehensive crash records of over one thousand major signalized intersections in the city of Chicago from 2004 to 2010. For each intersection, vehicular crashes were counted by crash severity levels, including fatal, injury Types A, B, and C for major, moderate, and minor injury levels, property damage only (PDO), and unknown. The crash data was further used to rank intersections by equivalent injury crash frequency. The top 200 intersections with the highest number of crash occurrences identified based on crash frequency- and severity-based scenarios are shared in this brief. The provided data would be a valuable source for research in urban traffic safety analysis and could also be utilized to examine the effectiveness of traffic safety improvement planning and programming, intersection design enhancement, incident and emergency management, and law enforcement strategies.

Safety analysis of urban signalized intersections under mixed traffic.

PubMed

S, Anjana; M V L R, Anjaneyulu

2015-02-01

This study examined the crash causative factors of signalized intersections under mixed traffic using advanced statistical models. Hierarchical Poisson regression and logistic regression models were developed to predict the crash frequency and severity of signalized intersection approaches. The prediction models helped to develop general safety countermeasures for signalized intersections. The study shows that exclusive left turn lanes and countdown timers are beneficial for improving the safety of signalized intersections. Safety is also influenced by the presence of a surveillance camera, green time, median width, traffic volume, and proportion of two wheelers in the traffic stream. The factors that influence the severity of crashes were also identified in this study. As a practical application, the safe values of deviation of green time provided from design green time, with varying traffic volume, is presented in this study. This is a useful tool for setting the appropriate green time for a signalized intersection approach with variations in the traffic volume. Copyright © 2014 Elsevier Ltd. All rights reserved.

Increasing motorist compliance and caution at stop signs.

PubMed Central

Van Houten, R; Retting, R A

2001-01-01

This study evaluated strategies to improve motorist compliance and caution at three stop-sign-controlled intersections with a history of motor vehicle crashes. The primary intervention was a light-emitting diode (LED) sign that featured animated eyes scanning left and right to prompt drivers to look left and right for approaching traffic. Data were scored from videotape on the percentage of drivers coming to a complete stop and the percentage of drivers looking right before entering the intersection. Observational data were collected on the percentage of right-angle conflicts (defined as braking suddenly or swerving from the path to avoid an intersection crash). The introduction of the LED sign according to a multiple baseline across the three intersections was associated with an increase in the percentage of vehicles coming to a complete stop at all three intersections and a small increase in the percentage of drivers looking right before entering the intersections. Conflicts between vehicles on the major and minor road were also reduced following the introduction of the animated eyes prompt. PMID:11421311

Watching Electrons at Conical Intersections and Funnels

NASA Astrophysics Data System (ADS)

Jonas, David M.; Smith, Eric R.; Peters, William K.; Kitney, Katherine A.

2009-06-01

The electronic motion at conical intersections and funnels is probed after polarized excitation of aligned electronic wavepackets. The pulses have bandwidth sufficient to observe vibrations mainly through their effect on the electrons. Vibrational symmetry can be identified by the polarization anisotropy of vibrational quantum beats. The polarized transients show signatures of electronic wavepacket motion (due to the energy gaps) and of electron transfer between orbitals (due to the couplings) driven by the conical intersection. For a conical intersection in a four-fold symmetric symmetry silicon naphthalocyanine molecule, electronic motions on a 100 fs timescale are driven by couplings of 1 meV. In the lower symmetry free-base naphthalocyanine, the conical intersection may be missed or missing (conical funnel), and the motions are nearly as rapid, but electronic equilibration is incomplete for red-edge excitation. These experiments probe non-adiabatic electronic dynamics with near-zero nuclear momentum - the electronic motions are determined by the principal slopes of the conical intersection and the width of the vibrational wavepacket.

EnviroAtlas - Cleveland, OH - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Portland, ME - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Portland, OR - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Durham, NC - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Tampa, FL - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Memphis, TN - Estimated Intersection Density of Walkable Roads

EPA Pesticide Factsheets

This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections are defined as any point where 3 or more roads meet and density is calculated using kernel density, where closer intersections are weighted higher than further intersections. Intersection density is highly correlated with walking for transportation. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

Intersectionality and risk for ischemic heart disease in Sweden: Categorical and anti-categorical approaches.

PubMed

Wemrell, Maria; Mulinari, Shai; Merlo, Juan

2017-03-01

Intersectionality theory can contribute to epidemiology and public health by furthering understanding of power dynamics driving production of health disparities, and increasing knowledge about heterogeneities within, and overlap between, social categories. Drawing on McCall, we relate the first of these potential contributions to categorical intersectionality and the second to anti-categorical intersectionality. Both approaches are used in study of risk of ischemic heart disease (IHD), based on register data on 3.6 million adults residing in Sweden by 2010, followed for three years. Categorical intersectionality is here coupled with between-group differences in average risk calculation, as we use intersectional categorizations while estimating odds ratios through logistic regressions. The anti-categorical approach is operationalized through measurement of discriminatory accuracy (DA), i.e., capacity to accurately categorize individuals with or without a certain outcome, through computation of the area under the curve (AUC). Our results show substantial differences in average risk between intersectional groupings. The DA of social categorizations is found to be low, however, due to outcome variability within and overlap between categories. We argue that measures of DA should be used for proper interpretation of differences in average risk between social (or any other) categories. Tension between average between-group risk and the DA of categorizations, which can be related to categorical and anti-categorical intersectional analyses, should be made explicit and discussed to a larger degree in epidemiology and public health. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Re-entry experiences of Black men living with HIV/AIDS after release from prison: Intersectionality and implications for care.

PubMed

Sun, Shufang; Crooks, Natasha; Kemnitz, Rebecca; Westergaard, Ryan P

2018-06-12

Both the HIV epidemic and incarceration disproportionately affect Black men in the United States. A critical period for incarcerated Black men living with HIV/AIDS is re-entry into the community, which is often associated with adverse health outcomes. Additionally, Black men living with HIV/AIDS involved in the criminal justice system are burdened by multiple, intersecting disadvantaged identities and social positions. This study aimed to examine community re-entry experiences among Black men living with HIV/AIDS from an intersectional perspective. In-depth, semi-structured interviews were conducted with 16 incarcerated Black men in Wisconsin, at pre-release from prison and six months after re-entry. Thematic analysis guided by intersectionality theory was used to analyze interview transcripts. Seven emerged themes included Intersectional Identities and Social Positions, Family Support, Neighborhood Violence, Relationship with Law Enforcement, Employment, Mental Health Concerns, and Medical Care and Medication Management. Intersecting identities and social positions interact with factors at multiple levels to inform health and HIV care. A conceptual framework was developed to illustrate relationships among themes. Findings demonstrate the relevance of intersectionality theory in HIV care with Black men involved in criminal justice system. Incorporating a social-ecological perspective into intersectionality framework could be useful in theoretical and empirical research. Disenfranchised communities may particularly benefit from interventions that address community- and systemic-level issues. Copyright © 2018 Elsevier Ltd. All rights reserved.

Superior spatial resolution in confocal X-ray techniques using collimating channel array optics: elemental mapping and speciation in archaeological human bone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choudhury, S.; Agyeman-Budu, D. N.; Woll, A. R.

Confocal X-ray fluorescence imaging (CXFI) and confocal X-ray absorption spectroscopy (CXAS) respectively enable the study of three dimensionally resolved localization and speciation of elements. Applied to a thick sample, essentially any volume element of interest within the X-ray fluorescence escape depth can be examined without the need for physical thin sectioning. To date, X-ray confocal detection generally has employed a polycapillary optic in front of the detector to collect fluorescence from the probe volume formed at the intersection of its focus with the incident microfocus beam. This work demonstrates the capability of a novel Collimating Channel Array (CCA) optic inmore » providing an improved and essentially energy independent depth resolution approaching 2 μm. By presenting a comparison of elemental maps of archaeological bone collected without confocal detection, and with polycapillary- and CCA-based confocal detection, this study highlights the strengths and limitations of each mode. Unlike the polycapillary, the CCA shows similar spatial resolution in maps for both low (Ca) and high (Pb and Sr) energy X-ray fluorescence, thus illustrating the energy independent nature of the CCA optic resolution. While superior spatial resolution is demonstrated for all of these elements, the most significant improvement is observed for Ca, demonstrating the advantage of employing the CCA optic in examining light elements. In addition to CXFI, this configuration also enables the collection of Pb L3 CXAS data from micro-volumes with dimensions comparable to bone microstructures of interest. Our CXAS result, which represents the first CCA-based biological CXAS, demonstrates the ability of CCA optics to collect site specific spectroscopic information. The demonstrated combination of site-specific elemental localization and speciation data will be useful in diverse fields.« less

Technology of welding aluminum alloys-I

NASA Technical Reports Server (NTRS)

Harrison, J. R.; Korb, L. J.; Oleksiak, C. E.

1978-01-01

Systems approach to high-quality aluminum welding uses square-butt joints, kept away from sharp contour changes. Intersecting welds are configured for T-type intersections rather than crossovers. Differences in panel thickness are accommodated with transition step areas where thickness increases or decreases within weld, but never at intersection.

Intersectionality and Critical Race Parenting

ERIC Educational Resources Information Center

DePouw, Christin

2018-01-01

This conceptual article employs critical race theory (CRT) as a theoretical framework to explore the importance of intersectionality in critical race parenting. In particular, I focus on intersectionality to understand better how Whiteness and racial power play out in intimate relationships within the family, particularly between White parents and…

Intersectionality and the Canadian Museum for Human Rights

ERIC Educational Resources Information Center

Dhamoon, Rita Kaur; Hankivsky, Olena

2015-01-01

In this commentary, the authors propose than an intersectionality perspective can transform understandings of the contentious content of the Canadian Museum for Human Rights (CMHR). The use of an intersectionality perspective starts from the position that such discourses as racialization, gendering, capitalism, and ableism are mutually…

An Intersectional Analysis of Latin@ College Women's Counter-Stories in Mathematics

ERIC Educational Resources Information Center

Leyva, Luis A.

2016-01-01

In this article, the author discusses the intersectionality of mathematics experiences for two Latin@ college women pursuing mathematics-intensive STEM (science, technology, engineering, and mathematics) majors at a large, predominantly White university. The author employs intersectionality and poststructural theories to explore and make meaning…

Road safety audit for the intersection of US 59 and IA 9 in Osceola County, Iowa.

DOT National Transportation Integrated Search

2012-03-01

The Iowa Department of Transportation (DOT) requested a road safety audit (RSA) of the US 59/IA 9 intersection in northwestern Iowa, just south of the Minnesota border, to assess intersection environmental issues and crash history and recommend appro...

Teaching Intersectional and Transnational Feminisms through Fiction and Film

ERIC Educational Resources Information Center

Mahrouse, Gada

2016-01-01

Author Gada Mahrouse begins this article by saying that the terms "intersectional" and "transnational" are widely misunderstood and misused by academics. She writes that the first, "intersectionality," has become a buzzword, not only in feminist courses but also in mainstream disciplines and areas of research. She…

Exploring Class-Based Intersectionality

ERIC Educational Resources Information Center

Block, David; Corona, Victor

2014-01-01

This paper argues that language, culture and identity researchers need to take the intersectionality of identity inscriptions seriously and, further to this, that an intersectional approach which emanates from an interest in social class provides a productive way to examine the lives and experience of individuals living in multicultural societies.…

Intersection of Three Planes Revisited--An Algebraic Approach

ERIC Educational Resources Information Center

Trenkler, Götz; Trenkler, Dietrich

2017-01-01

Given three planes in space, a complete characterization of their intersection is provided. Special attention is paid to the case when the intersection set does not exist of one point only. Besides the vector cross product, the tool of generalized inverse of a matrix is used extensively.

The Effect of Gender and Race Intersectionality on Student Learning Outcomes in Engineering

ERIC Educational Resources Information Center

Ro, Hyun Kyoung; Loya, Karla I.

2015-01-01

Women and underrepresented minorities in traditionally White and male-dominated disciplines tend to report lower learning outcomes than their White peers. Adopting a feminist intersectionality framework, this study looks at the intersections of gender and race to investigate differences in self-assessed learning outcomes in engineering…

A novel approach to modeling and predicting crash frequency at rural intersections by crash type and injury severity level.

DOT National Transportation Integrated Search

2015-04-01

Safety at intersections is of significant interest to transportation professionals due to the large number of : possible conflicts that occur at those locations. In particular, rural intersections have been recognized as : one of the most hazardous l...

A "Nation-ized" Intersectional Analysis: The Politics of Transnational Campus Unity

ERIC Educational Resources Information Center

Okazawa-Rey, Margo

2017-01-01

The author introduces the concept of "nation" as an analytic category in contemporary diversity discourse and intersectional analysis of social relations in U.S. higher educational institutions. She then suggests how an intersectional lens that includes nation can expand possibilities for understanding the experiences of international…

(Re)Centering Quality in Early Childhood Education: Toward Intersectional Justice for Minoritized Children

ERIC Educational Resources Information Center

Souto-Manning, Mariana; Rabadi-Raol, Ayesha

2018-01-01

In this chapter, we offer a critical intersectional analysis of quality in early childhood education with the aim of moving away from a singular understanding of "best practice," thereby interrupting the inequities such a concept fosters. While acknowledging how injustices are intersectionally constructed, we specifically identified…

Intersectionality and Educational Leadership: A Critical Review

ERIC Educational Resources Information Center

Agosto, Vonzell; Roland, Ericka

2018-01-01

In this review of research, we explore intersectionality in the literature on K-12 educational leadership. We seek to understand how researchers have used intersectionality and what their findings or arguments reveal about the work of leading to reduce inequities in education. We ask, What traditions and trends associated with intersectionality…

Methodology for evaluating effectiveness of traffic-responsive systems on intersection congestion and traffic safety

DOT National Transportation Integrated Search

1997-01-01

In 1986, the city of Milwaukee applied for and received approval for a hazard elimination grant to reduce congestion and traffic accidents at the intersection of two major and one minor arterial on the northwest side of the city. The intersection com...

78 FR 54453 - Notice of Public Meeting-Intersection of Cloud Computing and Mobility Forum and Workshop

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-04

...--Intersection of Cloud Computing and Mobility Forum and Workshop AGENCY: National Institute of Standards and.../intersection-of-cloud-and-mobility.cfm . SUPPLEMENTARY INFORMATION: NIST hosted six prior Cloud Computing Forum... interoperability, portability, and security, discuss the Federal Government's experience with cloud computing...

Field testing and implementation of dilemma zone protection and signal coordination at closely-spaced high-speed intersections : executive summary report.

DOT National Transportation Integrated Search

2005-05-01

The area close to a signalized intersection, : called the dilemma zone, poses a high accident : potential for the driver in stopping safely during the : yellow interval or in proceeding through the : intersection before the beginning of red. Generall...

Shifting Identities: Negotiating Intersections of Race and Gender in Canadian Administrative Contexts

ERIC Educational Resources Information Center

Armstrong, Denise; Mitchell, Coral

2017-01-01

This qualitative study used a critical intersectional lens to examine how two black female Canadian principals negotiated their professional identities in administrative contexts. Both principals encountered gender and race-related pressures to fit normative expectations of administrators as white males. Navigating their intersecting identities…

Modeling the dynamics of driver's dilemma zone perception using machine learning methods for safer intersection control.

DOT National Transportation Integrated Search

2014-04-01

The "dilemma zone" (DZ) is defined as the area where drivers approaching a signalized intersection must decide to either proceed or stop at the onset of the yellow indication. Drivers that might perceive themselves to be too close to an intersection ...

Aging road user studies of intersection safety : lab and simulator-based studies of crosswalk markings and flashing yellow arrow comprehension -- phase 2 : [summary].

DOT National Transportation Integrated Search

2014-10-01

Nearly half of all traffic-related fatalities occur : at intersections, so engineering intersections : for greater safety remains a priority for the : Florida Department of Transportation (FDOT). : Engineering in this case must take into accoun...

State of the art studies/FY87 : task 5 - increasing intersection capacity with additional through lanes

DOT National Transportation Integrated Search

1987-10-01

A review of the literature and a state-of-the-practice survey were conducted of procedures relating to the addition of through lanes at intersections. The capacity and level of service change at the intersection is of interest, since the reduction in...

Two low-cost safety concepts for two-way STOP-controlled, rural intersections on high-speed two-lane, two-way roadways.

DOT National Transportation Integrated Search

2008-09-01

The Federal Highway Administration (FHWA) Office of Safety has identified intersections as one of its safety focus areas. As part of the FHWA efforts to reduce intersection crashes and the related injuries and fatalities, two concepts have been ident...

Safety and operational analysis of lane widths in mid-block segments and intersection approaches in the urban environment in Nebraska.

DOT National Transportation Integrated Search

2015-04-01

This research examined the safety and operational effects of roadway lane width on mid-block segments between : signalized intersections as well as on signalized intersection approaches in the urban environments of Lincoln and Omaha, : Nebraska. In t...

Application of Mixed-Methods Approaches to Higher Education and Intersectional Analyses

ERIC Educational Resources Information Center

Griffin, Kimberly A.; Museus, Samuel D.

2011-01-01

In this article, the authors discuss the utility of combining quantitative and qualitative methods in conducting intersectional analyses. First, they discuss some of the paradigmatic underpinnings of qualitative and quantitative research, and how these methods can be used in intersectional analyses. They then consider how paradigmatic pragmatism…

14 CFR 25.1387 - Position light system dihedral angles.

Code of Federal Regulations, 2010 CFR

2010-01-01

... this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the first... two intersecting vertical planes, the first parallel to the longitudinal axis of the airplane, and the... axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of 70...

14 CFR 27.1387 - Position light system dihedral angles.

Code of Federal Regulations, 2010 CFR

2010-01-01

... this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the first... two intersecting vertical planes, the first parallel to the longitudinal axis of the rotorcraft, and... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of 70...

An efficient quantum scheme for Private Set Intersection

NASA Astrophysics Data System (ADS)

Shi, Run-hua; Mu, Yi; Zhong, Hong; Cui, Jie; Zhang, Shun

2016-01-01

Private Set Intersection allows a client to privately compute set intersection with the collaboration of the server, which is one of the most fundamental and key problems within the multiparty collaborative computation of protecting the privacy of the parties. In this paper, we first present a cheat-sensitive quantum scheme for Private Set Intersection. Compared with classical schemes, our scheme has lower communication complexity, which is independent of the size of the server's set. Therefore, it is very suitable for big data services in Cloud or large-scale client-server networks.

Intersecting vane machines

DOEpatents

Bailey, H. Sterling; Chomyszak, Stephen M.

2007-01-16

The invention provides a toroidal intersecting vane machine incorporating intersecting rotors to form primary and secondary chambers whose porting configurations minimize friction and maximize efficiency. Specifically, it is an object of the invention to provide a toroidal intersecting vane machine that greatly reduces the frictional losses through meshing surfaces without the need for external gearing by modifying the function of one or the other of the rotors from that of "fluid moving" to that of "valving" thereby reducing the pressure loads and associated inefficiencies at the interface of the meshing surfaces. The inventions described herein relate to these improvements.

Collar grids for intersecting geometric components within the Chimera overlapped grid scheme

NASA Technical Reports Server (NTRS)

Parks, Steven J.; Buning, Pieter G.; Chan, William M.; Steger, Joseph L.

1991-01-01

A method for overcoming problems with using the Chimera overset grid scheme in the region of intersecting geometry components is presented. A 'collar grid' resolves the intersection region and provides communication between the component grids. This approach is validated by comparing computed and experimental data for a flow about a wing/body configuration. Application of the collar grid scheme to the Orbiter fuselage and vertical tail intersection in a computation of the full Space Shuttle launch vehicle demonstrates its usefulness for simulation of flow about complex aerospace vehicles.

Calabi-Yau metrics for quotients and complete intersections

DOE PAGES

Braun, Volker; Brelidze, Tamaz; Douglas, Michael R.; ...

2008-05-22

We extend previous computations of Calabi-Yau metrics on projective hypersurfaces to free quotients, complete intersections, and free quotients of complete intersections. In particular, we construct these metrics on generic quintics, four-generation quotients of the quintic, Schoen Calabi-Yau complete intersections and the quotient of a Schoen manifold with Z₃ x Z₃ fundamental group that was previously used to construct a heterotic standard model. Various numerical investigations into the dependence of Donaldson's algorithm on the integration scheme, as well as on the Kähler and complex structure moduli, are also performed.

The Problem With the Phrase Women and Minorities: Intersectionality—an Important Theoretical Framework for Public Health

PubMed Central

2012-01-01

Intersectionality is a theoretical framework that posits that multiple social categories (e.g., race, ethnicity, gender, sexual orientation, socioeconomic status) intersect at the micro level of individual experience to reflect multiple interlocking systems of privilege and oppression at the macro, social-structural level (e.g., racism, sexism, heterosexism). Public health’s commitment to social justice makes it a natural fit with intersectionality’s focus on multiple historically oppressed populations. Yet despite a plethora of research focused on these populations, public health studies that reflect intersectionality in their theoretical frameworks, designs, analyses, or interpretations are rare. Accordingly, I describe the history and central tenets of intersectionality, address some theoretical and methodological challenges, and highlight the benefits of intersectionality for public health theory, research, and policy. PMID:22594719

The impact of iterated games on traffic flow at noncontrolled intersections

NASA Astrophysics Data System (ADS)

Zhao, Chao; Jia, Ning

2015-05-01

Intersections without signal control widely exist in urban road networks. This paper studied the traffic flow in a noncontrolled intersection within an iterated game framework. We assume drivers have learning ability and can repetitively adjust their strategies (to give way or to rush through) in the intersection according to memories. A cellular automata model is applied to investigate the characteristics of the traffic flow. Numerical experiments indicate two main findings. First, the traffic flow experiences a "volcano-shaped" fundamental diagram with three different phases. Second, most drivers choose to give way in the intersection, but the aggressive drivers cannot be completely eliminated, which is coincident with field observations. Analysis are also given out to explain the observed phenomena. These findings allow deeper insight of the real-world bottleneck traffic flow.

Capacity Estimation Model for Signalized Intersections under the Impact of Access Point

PubMed Central

Zhao, Jing; Li, Peng; Zhou, Xizhao

2016-01-01

Highway Capacity Manual 2010 provides various factors to adjust the base saturation flow rate for the capacity analysis of signalized intersections. No factors, however, is considered for the potential change of signalized intersections capacity caused by the access point closeing to the signalized intersection. This paper presented a theoretical model to estimate the lane group capacity at signalized intersections with the consideration of the effects of access points. Two scenarios of access point locations, upstream or downstream of the signalized intersection, and impacts of six types of access traffic flow are taken into account. The proposed capacity model was validated based on VISSIM simulation. Results of extensive numerical analysis reveal the substantial impact of access point on the capacity, which has an inverse correlation with both the number of major street lanes and the distance between the intersection and access point. Moreover, among the six types of access traffic flows, the access traffic flow 1 (right-turning traffic from major street), flow 4 (left-turning traffic from access point), and flow 5 (left-turning traffic from major street) cause a more significant effect on lane group capacity than others. Some guidance on the mitigation of the negative effect is provided for practitioners. PMID:26726998

Polar User’s Manual.

DTIC Science & Technology

1985-10-01

elements with BOTTON faces. 5. Thin plates may only intersect each other at the edges or corners. 6. Double points must be assigned TOP and BOTTOM sets...10 ExPONEP4T 1.7� INCNE) 1.7B.CZC (NONE) 11 YIELDC FOR IKEV PROTONS 𔃾.9C-CC! INCNE) N.-’O S(ONE) 12 AX oC/ aw FRa PROTONS ..zz0=2 KEY ±.Z:-CCZ...AEV 13 PHCTOCURPE~t Z.90-C:S Aw ..Z 1.91-,cE 1/"’sZ I& SURFACE RESISTIVITY -i.Z.C *0 OH*PS -6.d5-C1! v-Sic is SPACE DISCHARGE POT’L I.3IC*CC; VCLTS 1.Z

Exploring the promises of intersectionality for advancing women's health research

PubMed Central

2010-01-01

Women's health research strives to make change. It seeks to produce knowledge that promotes action on the variety of factors that affect women's lives and their health. As part of this general movement, important strides have been made to raise awareness of the health effects of sex and gender. The resultant base of knowledge has been used to inform health research, policy, and practice. Increasingly, however, the need to pay better attention to the inequities among women that are caused by racism, colonialism, ethnocentrism, heterosexism, and able-bodism, is confronting feminist health researchers and activists. Researchers are seeking new conceptual frameworks that can transform the design of research to produce knowledge that captures how systems of discrimination or subordination overlap and "articulate" with one another. An emerging paradigm for women's health research is intersectionality. Intersectionality places an explicit focus on differences among groups and seeks to illuminate various interacting social factors that affect human lives, including social locations, health status, and quality of life. This paper will draw on recently emerging intersectionality research in the Canadian women's health context in order to explore the promises and practical challenges of the processes involved in applying an intersectionality paradigm. We begin with a brief overview of why the need for an intersectionality approach has emerged within the context of women's health research and introduce current thinking about how intersectionality can inform and transform health research more broadly. We then highlight novel Canadian research that is grappling with the challenges in addressing issues of difference and diversity. In the analysis of these examples, we focus on a largely uninvestigated aspect of intersectionality research - the challenges involved in the process of initiating and developing such projects and, in particular, the meaning and significance of social locations for researchers and participants who utilize an intersectionality approach. The examples highlighted in the paper represent important shifts in the health field, demonstrating the potential of intersectionality for examining the social context of women's lives, as well as developing methods which elucidate power, create new knowledge, and have the potential to inform appropriate action to bring about positive social change. PMID:20181225

Exploring the promises of intersectionality for advancing women's health research.

PubMed

Hankivsky, Olena; Reid, Colleen; Cormier, Renee; Varcoe, Colleen; Clark, Natalie; Benoit, Cecilia; Brotman, Shari

2010-02-11

Women's health research strives to make change. It seeks to produce knowledge that promotes action on the variety of factors that affect women's lives and their health. As part of this general movement, important strides have been made to raise awareness of the health effects of sex and gender. The resultant base of knowledge has been used to inform health research, policy, and practice. Increasingly, however, the need to pay better attention to the inequities among women that are caused by racism, colonialism, ethnocentrism, heterosexism, and able-bodism, is confronting feminist health researchers and activists. Researchers are seeking new conceptual frameworks that can transform the design of research to produce knowledge that captures how systems of discrimination or subordination overlap and "articulate" with one another. An emerging paradigm for women's health research is intersectionality. Intersectionality places an explicit focus on differences among groups and seeks to illuminate various interacting social factors that affect human lives, including social locations, health status, and quality of life. This paper will draw on recently emerging intersectionality research in the Canadian women's health context in order to explore the promises and practical challenges of the processes involved in applying an intersectionality paradigm. We begin with a brief overview of why the need for an intersectionality approach has emerged within the context of women's health research and introduce current thinking about how intersectionality can inform and transform health research more broadly. We then highlight novel Canadian research that is grappling with the challenges in addressing issues of difference and diversity. In the analysis of these examples, we focus on a largely uninvestigated aspect of intersectionality research - the challenges involved in the process of initiating and developing such projects and, in particular, the meaning and significance of social locations for researchers and participants who utilize an intersectionality approach. The examples highlighted in the paper represent important shifts in the health field, demonstrating the potential of intersectionality for examining the social context of women's lives, as well as developing methods which elucidate power, create new knowledge, and have the potential to inform appropriate action to bring about positive social change.

Power, Penalty, and Critical Praxis: Employing Intersectionality in Educator Practices to Achieve School Equity

ERIC Educational Resources Information Center

Carey, Roderick L.; Yee, Laura S.; DeMatthews, David

2018-01-01

Intersectionality describes the ways interlocking systems of oppression, evidenced in various identity facets (e.g., race, class, gender, sexuality, religion, ability, and language), frame individuals' social worlds. An awareness of intersectionality can ensure PreK-12 school policies and practices meet the needs of a student population…

Teaching Note--Teaching Intersectionality: Transforming Cultural Competence Content in Social Work Education

ERIC Educational Resources Information Center

Robinson, Michael Allen; Cross-Denny, Bronwyn; Lee, Karen Kyeunghae; Werkmeister Rozas, Lisa Marie; Yamada, Ann-Marie

2016-01-01

Intersectionality has been gaining momentum among social workers as a framework to allow a fuller understanding of the complexity of diverse social identities and the impact of social structures on power, privilege, and oppression. However, the application of intersectionality to teaching in social work education has been relatively absent in the…

Intersection of Language, Class, Ethnicity, and Policy: Toward Disrupting Inequality for English Language Learners

ERIC Educational Resources Information Center

Jiménez-Castellanos, Oscar; García, Eugene

2017-01-01

This chapter proposes a conceptual framework that merges intersectionality and policy analysis as an analytical tool to understand the nuanced, multilayered, compounded educational inequality encountered specifically by low-income, Latino Spanish-speaking students in Arizona K-12 public schools as a function of intersecting educational policies.…

The Intersection of Gender and Age: An Exploration

ERIC Educational Resources Information Center

Gander, Michelle

2014-01-01

The understanding of gender inequality for women entering work has not been subject to significant research or theorizing. This small study indicated that young women entering the workplace are subject to direct discrimination and by using an intersectionality approach this paper proposes that the intersection of gender and young age results in…

Scattering Amplitudes from Intersection Theory

NASA Astrophysics Data System (ADS)

Mizera, Sebastian

2018-04-01

We use Picard-Lefschetz theory to prove a new formula for intersection numbers of twisted cocycles associated with a given arrangement of hyperplanes. In a special case when this arrangement produces the moduli space of punctured Riemann spheres, intersection numbers become tree-level scattering amplitudes of quantum field theories in the Cachazo-He-Yuan formulation.

Objects of Protection, Enduring Nodes of Difference: Disability Intersections with "Other" Differences, 1916 to 2016

ERIC Educational Resources Information Center

Artiles, Alfredo J.; Dorn, Sherman; Bal, Aydin

2016-01-01

The purpose of this chapter is to contribute a cultural-historical analytical perspective on disability and its intersections. We assume that disability is socially, historically, and spatially constructed. This standpoint enables us to understand and disrupt disparities in education that affect students living at the intersection of disability…

VIEW OF DATE DRIVE, FROM INTERSECTION WITH BIRCH CIRCLE, WITH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF DATE DRIVE, FROM INTERSECTION WITH BIRCH CIRCLE, WITH FACILITY 809 ON LEFT, 816 ON RIGHT. NOTE THE MANY DATE PALMS. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

40 CFR 81.182 - Northwest Maine Intrastate Air Quality Control Region.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Fort Kent Township and running due south to the intersection of the said line with the Aroostook... intersected by a line common to the northern boundary of Township No. 6, Phillips Town, Salem Township, and Freeman Township to the intersection of the said line with the Franklin-Somerset County boundary, which is...

40 CFR 81.182 - Northwest Maine Intrastate Air Quality Control Region.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Fort Kent Township and running due south to the intersection of the said line with the Aroostook... intersected by a line common to the northern boundary of Township No. 6, Phillips Town, Salem Township, and Freeman Township to the intersection of the said line with the Franklin-Somerset County boundary, which is...

Appropriate Pupilness: Social Categories Intersecting in School

ERIC Educational Resources Information Center

Kofoed, Jette

2008-01-01

The analytical focus in this article is on how social categories intersect in daily school life and how intersections intertwine with other empirically relevant categories such as normality, pupilness and (in)appropriatedness. The point of empirical departure is a daily ritual where teams for football are selected. The article opens up for a…

Mapping Intersectionality and Latina/o and Chicana/o Students along Educational Frameworks of Power

ERIC Educational Resources Information Center

Alemán, Sonya M.

2018-01-01

This chapter reviews scholarship using intersectional analyses to assess how Latina/o and Chicana/o youth navigate imbricated systems of privilege and oppression in their educational trajectories. Scholars have explored the navigational tactics Latina/o and Chicana/o students use to negotiate their intersectional identities and the institutional…

9. Looking northeast, foreground Clenny Run Road, duck pond and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Looking northeast, foreground Clenny Run Road, duck pond and Clenny Run, with intersection of State Routes 92 and 100 beyond, Brandywine Creek State Park in background, mixed deciduous trees along top of hill - Winterthur Farms, Intersection State Routes 92 & 100, Intersection State Routes 92 & 100, Winterthur, New Castle County, DE

Domestic Violence among the Black Poor: Intersectionality and Social Justice

ERIC Educational Resources Information Center

Conwill, William Louis

2010-01-01

There are striking gender, race, and class variations in rates of domestic violence. Some leading family theorists called for an intersectional analysis of how gender, race and class systems interact to improve domestic violence theory. This article improves domestic violence theory by: 1) using the discourse, or language, of intersectionality; 2)…

14 CFR 29.1387 - Position light system dihedral angles.

Code of Federal Regulations, 2010 CFR

2010-01-01

... described in this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the... formed by two intersecting vertical planes, the first parallel to the longitudinal axis of the rotorcraft... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of 70...

14 CFR 23.1387 - Position light system dihedral angles.

Code of Federal Regulations, 2010 CFR

2010-01-01

... described in this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the... formed by two intersecting vertical planes, the first parallel to the longitudinal axis of the airplane... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of 70...

Cargos Rotate at Microtubule Intersections during Intracellular Trafficking.

PubMed

Gao, Yuan; Anthony, Stephen M; Yu, Yanqi; Yi, Yi; Yu, Yan

2018-06-19

Intracellular cargos are transported by molecular motors along actin and microtubules, but how their dynamics depends on the complex structure of the cytoskeletal network remains unclear. In this study, we investigated this longstanding question by measuring simultaneously the rotational and translational dynamics of cargos at microtubule intersections in living cells. We engineered two-faced particles that are fluorescent on one hemisphere and opaque on the other and used their optical anisotropy to report the rotation of cargos. We show that cargos undergo brief episodes of unidirectional and rapid rotation while pausing at microtubule intersections. Probability and amplitude of the cargo rotation depend on the geometry of the intersecting filaments. The cargo rotation is not random motion due to detachment from microtubules, as revealed by statistical analyses of the translational and rotational dynamics. Instead, it is an active rotation driven by motor proteins. Although cargos are known to pause at microtubule intersections, this study reveals a different dimension of dynamics at this seemingly static state and, more importantly, provides direct evidence showing the correlation between cargo rotation and the geometry of underlying microtubule intersections. Copyright © 2018 Biophysical Society. All rights reserved.

Analysis of Crossing Speed of the Pedestrians in Marked and Unmarked Crosswalks in the Signalized and Un-Signalized Intersections (Case Study: Rasht city)

NASA Astrophysics Data System (ADS)

Behbahani, Hamid; Najafi Moghaddam Gilani, Vahid; Jahangir Samet, Mehdi; Salehfard, Reza

2017-10-01

Pedestrians affect the traffic in the signalized and un-signalized intersections. Therefore, identifying the behavioural features of the pedestrians is of great importance and may result in better designing facilities for them. In this study, by shooting the four intersections in Rasht for 15 hours and inventory from 4568 pedestrians, crossing speed of the pedestrians in the marked crosswalks and unmarked crosswalks was evaluated and analysed. Results showed that pedestrians‧ crossing speed in the marked crosswalks is higher than their crossing speed in the unmarked crosswalks in both signalized and un-signalized intersections. Moreover, in the unmarked crosswalks in the signalized intersections, 15th percentile speed of male pedestrians, female pedestrians and group of pedestrians’ decrease 6.4%, 5.4% and 12.2%, respectively, compared with the 15th percentile speed in the marked crosswalks. Above-mentioned values in the unmarked crosswalks in the un-signalized intersections for male pedestrians, female pedestrians, and group of pedestrians decrease 1.2%, 3.8%, and 1.4%, respectively.

From "Buzzword" to Best Practice: Applying Intersectionality to Children Exposed to Intimate Partner Violence.

PubMed

Etherington, Nicole; Baker, Linda

2016-03-07

Empirical studies on the impact of intimate partner violence (IPV) on children have burgeoned over the last three decades. Notably absent from existing approaches to studying children exposed to IPV, however, is attention to how various positionalities intersect to impact the experiences of children and their families. In fact, while the importance of an intersectional framework for understanding IPV has been discussed for over two decades, little or no attention has been given to issues of children's exposure to IPV. In this article, we examine the current state of the literature on children exposed to IPV through an exploratory meta-analysis, finding limited application of intersectionality and a focus on discrete categories of difference. We then demonstrate why and how an intersectional framework should be applied to children exposed to IPV, with specific strategies for research and policy. We suggest a child-centered approach that recognizes diversity among children exposed to IPV, extending the challenge to traditional "one-size-fits-all" models to include an intersectionality-informed stance. © The Author(s) 2016.

Neighborhood Social Inequalities in Road Traffic Injuries: The Influence of Traffic Volume and Road Design

PubMed Central

Gauvin, Lise; Plante, Céline; Fournier, Michel; Morency, Catherine

2012-01-01

Objectives. We examined the extent to which differential traffic volume and road geometry can explain social inequalities in pedestrian, cyclist, and motor vehicle occupant injuries across wealthy and poor urban areas. Methods. We performed a multilevel observational study of all road users injured over 5 years (n = 19 568) at intersections (n = 17 498) in a large urban area (Island of Montreal, Canada). We considered intersection-level (traffic estimates, major roads, number of legs) and area-level (population density, commuting travel modes, household income) characteristics in multilevel Poisson regressions that nested intersections in 506 census tracts. Results. There were significantly more injured pedestrians, cyclists, and motor vehicle occupants at intersections in the poorest than in the richest areas. Controlling for traffic volume, intersection geometry, and pedestrian and cyclist volumes greatly attenuated the event rate ratios between intersections in the poorest and richest areas for injured pedestrians (−70%), cyclists (−44%), and motor vehicle occupants (−44%). Conclusions. Roadway environment can explain a substantial portion of the excess rate of road traffic injuries in the poorest urban areas. PMID:22515869

Capacity analysis of a bypass of roundabouts

NASA Astrophysics Data System (ADS)

Sedlačik, Ivan; Slabý, Petr

2017-09-01

The capacity of the roads network mainly depends on the capacity of its nodal points - intersections. A connecting branch or a bypass is a lane or lanes inserted between two adjacent branches of a roundabout, providing redirection of vehicles, that would otherwise burden a circular lane. A bypass effect to the capacity of roundabouts, but also other types of level intersections, is undeniable. A connecting branch increases the total capacity of an intersection that takes a part of vehicles performing a manoeuver of the first right turn completely out of an intersection area. Redirecting vehicles reduces delay times at intersections and reduces queues at the entrance to an intersection. Bypasses improve the quality of transport. Limiting for the capacity of bypasses is the point of disconnection from the entrance into the roundabout and the connection point into the exit from the roundabout. Central parts of the bypasses have minimal effects on the capacity. The length of a bypass has to match with the maximum length of a queue of waiting vehicles at a given intensity level. The article deals with analysis of the bypass capacity at the roundabouts.

Sum rules for zeros and intersections of Bessel functions from quantum mechanical perturbation theory

NASA Astrophysics Data System (ADS)

Pedersen, Thomas Garm

2018-07-01

Bessel functions play an important role for quantum states in spherical and cylindrical geometries. In cases of perfect confinement, the energy of Schrödinger and massless Dirac fermions is determined by the zeros and intersections of Bessel functions, respectively. In an external electric field, standard perturbation theory therefore expresses the polarizability as a sum over these zeros or intersections. Both non-relativistic and relativistic polarizabilities can be calculated analytically, however. Hence, by equating analytical expressions to perturbation expansions, several sum rules for the zeros and intersections of Bessel functions emerge.

Electric-field-induced domain intersection in BaTiO3 single crystal

NASA Astrophysics Data System (ADS)

He, Ming; Wang, Mengxia; Zhang, Zhihua

2017-03-01

Large-angle convergent beam electron diffraction was used to determine the directions of polarization vectors in a BaTiO3 single crystal. Domain intersections driven by an electric field were investigated by in situ transmission electron microscopy. The dark triangles observed in the domain intersection region can be accounted for by dislocations and the strain field. Domains nucleate at the domain tip depending on the dislocations and strain field to relieve the accumulated stress. Schematic representations of the intersecting domains and the microscopic structure are given, clarifying the special electric-field-induced domain structure.

Integrating intersectionality and biomedicine in health disparities research.

PubMed

Kelly, Ursula A

2009-01-01

Persisting health disparities have lead to calls for an increase in health research to address them. Biomedical scientists call for research that stratifies individual indicators associated with health disparities, for example, ethnicity. Feminist social scientists recommend feminist intersectionality research. Intersectionality is the multiplicative effect of inequalities experienced by nondominant marginalized groups, for example, ethnic minorities, women, and the poor. The elimination of health disparities necessitates integration of both paradigms in health research. This study provides a practical application of the integration of biomedical and feminist intersectionality paradigms in nursing research, using a psychiatric intervention study with battered Latino women as an example.

Applying Bayesian hierarchical models to examine motorcycle crashes at signalized intersections.

PubMed

Haque, Md Mazharul; Chin, Hoong Chor; Huang, Helai

2010-01-01

Motorcycles are overrepresented in road traffic crashes and particularly vulnerable at signalized intersections. The objective of this study is to identify causal factors affecting the motorcycle crashes at both four-legged and T signalized intersections. Treating the data in time-series cross-section panels, this study explores different Hierarchical Poisson models and found that the model allowing autoregressive lag-1 dependence specification in the error term is the most suitable. Results show that the number of lanes at the four-legged signalized intersections significantly increases motorcycle crashes largely because of the higher exposure resulting from higher motorcycle accumulation at the stop line. Furthermore, the presence of a wide median and an uncontrolled left-turn lane at major roadways of four-legged intersections exacerbate this potential hazard. For T signalized intersections, the presence of exclusive right-turn lane at both major and minor roadways and an uncontrolled left-turn lane at major roadways increases motorcycle crashes. Motorcycle crashes increase on high-speed roadways because they are more vulnerable and less likely to react in time during conflicts. The presence of red light cameras reduces motorcycle crashes significantly for both four-legged and T intersections. With the red light camera, motorcycles are less exposed to conflicts because it is observed that they are more disciplined in queuing at the stop line and less likely to jump start at the start of green.

Differences in passenger car and large truck involved crash frequencies at urban signalized intersections: an exploratory analysis.

PubMed

Dong, Chunjiao; Clarke, David B; Richards, Stephen H; Huang, Baoshan

2014-01-01

The influence of intersection features on safety has been examined extensively because intersections experience a relatively large proportion of motor vehicle conflicts and crashes. Although there are distinct differences between passenger cars and large trucks-size, operating characteristics, dimensions, and weight-modeling crash counts across vehicle types is rarely addressed. This paper develops and presents a multivariate regression model of crash frequencies by collision vehicle type using crash data for urban signalized intersections in Tennessee. In addition, the performance of univariate Poisson-lognormal (UVPLN), multivariate Poisson (MVP), and multivariate Poisson-lognormal (MVPLN) regression models in establishing the relationship between crashes, traffic factors, and geometric design of roadway intersections is investigated. Bayesian methods are used to estimate the unknown parameters of these models. The evaluation results suggest that the MVPLN model possesses most of the desirable statistical properties in developing the relationships. Compared to the UVPLN and MVP models, the MVPLN model better identifies significant factors and predicts crash frequencies. The findings suggest that traffic volume, truck percentage, lighting condition, and intersection angle significantly affect intersection safety. Important differences in car, car-truck, and truck crash frequencies with respect to various risk factors were found to exist between models. The paper provides some new or more comprehensive observations that have not been covered in previous studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Cooperative Traffic Control of Vehicle–Intersection (CTCVI) for the Reduction of Traffic Delays and Fuel Consumption

PubMed Central

Li, Jinjian; Dridi, Mahjoub; El-Moudni, Abdellah

2016-01-01

The problem of reducing traffic delays and decreasing fuel consumption simultaneously in a network of intersections without traffic lights is solved by a cooperative traffic control algorithm, where the cooperation is executed based on the connection of Vehicle-to-Infrastructure (V2I). This resolution of the problem contains two main steps. The first step concerns the itinerary of which intersections are chosen by vehicles to arrive at their destination from their starting point. Based on the principle of minimal travel distance, each vehicle chooses its itinerary dynamically based on the traffic loads in the adjacent intersections. The second step is related to the following proposed cooperative procedures to allow vehicles to pass through each intersection rapidly and economically: on one hand, according to the real-time information sent by vehicles via V2I in the edge of the communication zone, each intersection applies Dynamic Programming (DP) to cooperatively optimize the vehicle passing sequence with minimal traffic delays so that the vehicles may rapidly pass the intersection under the relevant safety constraints; on the other hand, after receiving this sequence, each vehicle finds the optimal speed profiles with the minimal fuel consumption by an exhaustive search. The simulation results reveal that the proposed algorithm can significantly reduce both travel delays and fuel consumption compared with other papers under different traffic volumes. PMID:27999333

GLSM realizations of maps and intersections of Grassmannians and Pfaffians

NASA Astrophysics Data System (ADS)

Căldăraru, Andrei; Knapp, Johanna; Sharpe, Eric

2018-04-01

In this paper we give gauged linear sigma model (GLSM) realizations of a number of geometries not previously presented in GLSMs. We begin by describing GLSM realizations of maps including Veronese and Segre embeddings, which can be applied to give GLSMs explicitly describing non-complete intersection constructions such as the intersection of one hypersurface with the image under some map of another. We also discuss GLSMs for intersections of Grassmannians and Pfaffians with one another, and with their images under various maps, which sometimes form exotic constructions of Calabi-Yaus, as well as GLSMs for other exotic Calabi-Yau constructions of Kanazawa. Much of this paper focuses on a specific set of examples of GLSMs for intersections of Grassmannians G(2 , N ) with themselves after a linear rotation, including the Calabi-Yau case N = 5. One phase of the GLSM realizes an intersection of two Grassmannians, the other phase realizes an intersection of two Pfaffians. The GLSM has two nonabelian factors in its gauge group, and we consider dualities in those factors. In both the original GLSM and a double-dual, one geometric phase is realized perturbatively (as the critical locus of a superpotential), and the other via quantum effects. Dualizing on a single gauge group factor yields a model in which each geometry is realized through a simultaneous combination of perturbative and quantum effects.

a Zero-Order Picture of the Infrared Spectrum for the Methoxy Radical: Assignment of States

NASA Astrophysics Data System (ADS)

Johnson, Britta; Sibert, Edwin

2016-06-01

The ground tilde{X}^2E vibrations of the methoxy radical have intrigued both experimentalists and theorists alike due to the presence of a conical intersection at the C3v molecular geometry. This conical intersection causes methoxy's vibrational spectrum to be strongly influenced by Jahn-Teller vibronic coupling which leads to large amplitude vibrations and extensive mixing of the two lowest electronic states. This coupling combined with spin-orbit and Fermi couplings greatly complicates the assignments of states. Using the potential force field and calculated spectra of Nagesh and Sibert1,2, we assign quantum numbers to the infrared spectrum. When the zero-order states are the diabatic normal mode states, there is sufficient mode mixing that the normal mode quantum numbers are poor labels for the final states. We define a series of zero-order Hamiltonians which include additional coupling elements beyond the normal mode picture but still allow for the assignment of Jahn-Teller quantum numbers. In methoxy, the two lowest frequency e} modes, the bend (q_5) and the rock (q_6), are the modes with the strongest Jahn-Teller coupling. In general, a zero-order Hamiltonian which includes first-order Jahn-Teller coupling in q_6 is sufficient for most states of interest. Working in a representation which includes first-order Jahn-Teller coupling in q_6, we identify states in which additional coupling elements must be included; these couplings include first-order Jahn-Teller coupling in q_5, higher order Jahn-Teller coupling in q_5 and q_6, and, in the dueterated case, Jahn-Teller coupling which is modulated by the corresponding a modes. [^1] Nagesh, J.; Sibert, E. L. J. Phys. Chem. A 2012, 116, 3846-3855. Lee, Y.F.; Chou, W.T.; Johnson, B.A.; Tabor, D.P. ; Sibert, E.L.; Lee, Y.P. J. Mol. Spectrosc. 2015, 310, 57-67. Barckholtz, T. A.; Miller, T. A. Int. Revs. in Phys. Chem. 1998, 17, 435-524.

Intersectionality and Social Work: Omissions of Race, Class, and Sexuality in Graduate School Education

ERIC Educational Resources Information Center

Bubar, Roe; Cespedes, Karina; Bundy-Fazioli, Kimberly

2016-01-01

In 2008 EPAS Standards on "Engaging Diversity and Difference in Practice" (2.1.4) added intersectionality (a theory developed by feminist of color) as one aspect to understand diversity, difference, and power in social work curriculum. We consider how intersectionality is omitted in graduate student learning even when class assignments…

New Visual Methods for Teaching Intersectionality from a Spatial Perspective in a Geography and Gender Course

ERIC Educational Resources Information Center

Baylina Ferré, Mireia; Rodó de Zárate, Maria

2016-01-01

Intersectionality is a complex concept to deal with when doing research but also when teaching the interrelationships between space and social relations. Here we present "Relief Maps" as a visual tool for teaching intersectionality and its spatial dimension in higher education courses. "Relief Maps" are a model developed for…

(Un)Hidden Figures: A Synthesis of Research Examining the Intersectional Experiences of Black Women and Girls in STEM Education

ERIC Educational Resources Information Center

Ireland, Danyelle T.; Freeman, Kimberley Edelin; Winston-Proctor, Cynthia E.; DeLaine, Kendra D.; McDonald Lowe, Stacey; Woodson, Kamilah M.

2018-01-01

In this chapter, we argue that intersectionality is a theoretical and methodological framework by which education researchers can critically examine why and how students in STEM fields who are members of intersecting marginalized groups have distinctive experiences related to their social identities, other psychological processes, and educational…

27 CFR 9.218 - Sierra Pelona Valley.

Code of Federal Regulations, 2013 CFR

2013-04-01

... line 0.15 mile, crossing over the Agua Dulce Road, to the line's intersection with the 2,400-foot... boundary line onto the Sleepy Valley map 0.6 mile to the line's intersection with the 2,800-foot elevation... the section 22 north boundary line 0.2 mile to the line's intersection with the 2,600-foot elevation...

27 CFR 9.218 - Sierra Pelona Valley.

Code of Federal Regulations, 2012 CFR

2012-04-01

... line 0.15 mile, crossing over the Agua Dulce Road, to the line's intersection with the 2,400-foot... boundary line onto the Sleepy Valley map 0.6 mile to the line's intersection with the 2,800-foot elevation... the section 22 north boundary line 0.2 mile to the line's intersection with the 2,600-foot elevation...

27 CFR 9.218 - Sierra Pelona Valley.

Code of Federal Regulations, 2014 CFR

2014-04-01

... line 0.15 mile, crossing over the Agua Dulce Road, to the line's intersection with the 2,400-foot... boundary line onto the Sleepy Valley map 0.6 mile to the line's intersection with the 2,800-foot elevation... the section 22 north boundary line 0.2 mile to the line's intersection with the 2,600-foot elevation...

Does My Story Belong? An Intersectional Critical Race Feminist Analysis of Student Silence in a Diverse Classroom

ERIC Educational Resources Information Center

Vaccaro, Annemarie

2017-01-01

This article offers an intersectional critical race feminist analysis of student silence in a diverse university classroom. Findings from a case study with six Women of Color and four White women revealed students remained silent because they felt their complicated intersectional realities did not fit with the acceptable classroom…

The Promises and Challenges of Teaching from an Intersectional Perspective: Core Components and Applied Strategies

ERIC Educational Resources Information Center

Jones, Susan R.; Wijeyesinghe, Charmaine L.

2011-01-01

This chapter explores how the framework of intersectionality can be used by faculty in course development and classroom teaching. An overview of intersectionality, highlighting core assumptions and tenets of the framework, is presented first. These assumptions and tenets are then applied to classroom dynamics and the practice of teaching in…

Linguistic Documentation of Metal System

DTIC Science & Technology

1978-05-01

of the set- theoretical operations intersection, union , and complement. These are used to express relations which may hold between the values of...means of the set-theoretical operations union , intersection, and difference. Union is represented by "+M, intersection by ".", and difference by...RAILway RELigion = RELIGion RHETorical RUGby SCIENTific SCULPture SKIing ... SOCIOLOGY SPINning SPORT STATistics ■ MATHematics STock

Music Teacher Knowledge: An Examination of the Intersections between Instrumental Music Teaching and Conducting

ERIC Educational Resources Information Center

Forrester, Sommer H.

2018-01-01

The purpose of this study was to examine the complexities of instrumental music teacher knowledge as they relate to the intersection between instrumental music teaching and conducting, and to explore how participants describe and perceive these intersections. The key research question guiding this study was, How do high school instrumental music…

Investigating the Intersection of Poverty and Race in Gifted Education Journals: A 15-Year Analysis

ERIC Educational Resources Information Center

Goings, Ramon B.; Ford, Donna Y.

2018-01-01

Using a two-phase content analysis approach, this study examined how education scholars have discussed the intersection of giftedness, race, and poverty in gifted academic journals from 2000 to 2015. Specifically, the authors explored the following questions: (a) What are the characteristics of studies published that explore the intersection of…

Race, gender, class, and sexual orientation: intersecting axes of inequality and self-rated health in Canada

PubMed Central

2011-01-01

Background Intersectionality theory, a way of understanding social inequalities by race, gender, class, and sexuality that emphasizes their mutually constitutive natures, possesses potential to uncover and explicate previously unknown health inequalities. In this paper, the intersectionality principles of "directionality," "simultaneity," "multiplicativity," and "multiple jeopardy" are applied to inequalities in self-rated health by race, gender, class, and sexual orientation in a Canadian sample. Methods The Canadian Community Health Survey 2.1 (N = 90,310) provided nationally representative data that enabled binary logistic regression modeling on fair/poor self-rated health in two analytical stages. The additive stage involved regressing self-rated health on race, gender, class, and sexual orientation singly and then as a set. The intersectional stage involved consideration of two-way and three-way interaction terms between the inequality variables added to the full additive model created in the previous stage. Results From an additive perspective, poor self-rated health outcomes were reported by respondents claiming Aboriginal, Asian, or South Asian affiliations, lower class respondents, and bisexual respondents. However, each axis of inequality interacted significantly with at least one other: multiple jeopardy pertained to poor homosexuals and to South Asian women who were at unexpectedly high risks of fair/poor self-rated health and mitigating effects were experienced by poor women and by poor Asian Canadians who were less likely than expected to report fair/poor health. Conclusions Although a variety of intersections between race, gender, class, and sexual orientation were associated with especially high risks of fair/poor self-rated health, they were not all consistent with the predictions of intersectionality theory. I conclude that an intersectionality theory well suited for explicating health inequalities in Canada should be capable of accommodating axis intersections of multiple kinds and qualities. PMID:21241506

Chow groups of intersections of quadrics via homological projective duality and (Jacobians of) non-commutative motives

NASA Astrophysics Data System (ADS)

Bernardara, M.; Tabuada, G.

2016-06-01

Conjectures of Beilinson-Bloch type predict that the low-degree rational Chow groups of intersections of quadrics are one-dimensional. This conjecture was proved by Otwinowska in [20]. By making use of homological projective duality and the recent theory of (Jacobians of) non-commutative motives, we give an alternative proof of this conjecture in the case of a complete intersection of either two quadrics or three odd-dimensional quadrics. Moreover, we prove that in these cases the unique non-trivial algebraic Jacobian is the middle one. As an application, we make use of Vial's work [26], [27] to describe the rational Chow motives of these complete intersections and show that smooth fibrations into such complete intersections over bases S of small dimension satisfy Murre's conjecture (when \\dim (S)≤ 1), Grothendieck's standard conjecture of Lefschetz type (when \\dim (S)≤ 2), and Hodge's conjecture (when \\dim(S)≤ 3).

The Benefit Impact of Air Pollution Reduction Through ATCS Implementation at Intersections

NASA Astrophysics Data System (ADS)

Budihardjo, Mochamad Arief; Huboyo, Haryono Setiyo; Samadikun, Budi Prasetyo

2018-02-01

The field study in five intersections that had ATCS, such as Krapyak, Tugu Muda, Polda, Bangkong and Fatmawati were done to investigate the effectivity of air pollution reduction. The study was done by estimating the differences between the vehicle speed due to the cycle duration of green light by field observation and video recording in each intersection. In five intersections that had been observed, the percentage of fuel consumption savings for two-wheeled vehicles were between 15 - 18%, meanwhile for four-wheel vehicles were between 30 - 46%. Based on the calculation that adopt the emission factor from CORINAIR and USEPA emission, the emission reduction based on pollutant types were TSP (12-17%), NOx (22-36%), CO (15-25%), HC (16-28%) and SO2 (22-35%). The result to the vehicles' speed that passed the intersections through ATCS has also indicated that the ATCS could increase vehicle speed and consequently reduce the emission.

Compositions of professionalism in counselling work: An embodied and embedded intersectionality framework.

PubMed

Adamson, Maria; Johansson, Marjana

2016-12-01

This article explores the embodied compositions of professionalism in the context of the counselling psychology profession in Russia. Specifically, we develop an embodied intersectionality framework for theorizing compositions of professionalism, which allows us to explain how multiple embodied categories of difference intersect and are relationally co-constitutive in producing credible professionals, and, importantly, how these intersections are contingent on intercorporeal encounters that take place in localized professional settings. Our exploration of how professionalism and professional credibility are established in Russian counselling shows that, rather than assuming that a hegemonic 'ideal body' is given preference in a professional context, different embodied compositions may be deemed credible in various work settings within the same profession. An embodied intersectionality framework allows us to challenge the notion of a single professional ideal and offer a dynamic and contextually situated analysis of the lived experiences of professional privilege and disadvantage.

Compositions of professionalism in counselling work: An embodied and embedded intersectionality framework

PubMed Central

Adamson, Maria; Johansson, Marjana

2016-01-01

This article explores the embodied compositions of professionalism in the context of the counselling psychology profession in Russia. Specifically, we develop an embodied intersectionality framework for theorizing compositions of professionalism, which allows us to explain how multiple embodied categories of difference intersect and are relationally co-constitutive in producing credible professionals, and, importantly, how these intersections are contingent on intercorporeal encounters that take place in localized professional settings. Our exploration of how professionalism and professional credibility are established in Russian counselling shows that, rather than assuming that a hegemonic ‘ideal body’ is given preference in a professional context, different embodied compositions may be deemed credible in various work settings within the same profession. An embodied intersectionality framework allows us to challenge the notion of a single professional ideal and offer a dynamic and contextually situated analysis of the lived experiences of professional privilege and disadvantage. PMID:27904172

Clinical and ultrasound features in patients with intersection syndrome or de Quervain's disease.

PubMed

Sato, J; Ishii, Y; Noguchi, H

2016-02-01

We investigated the demographic characteristics of patients who were diagnosed with intersection syndrome and also investigated the dominance of the affected hand, duration of symptoms and any precipitating factor for pain of the wrist. These features were compared with patients who had de Quervain's disease. Ultrasonography was used to confirm the clinical diagnosis. Intersection syndrome occurred more frequently in men and in the dominant hand than de Quervain's disease when all the patients were compared and when peripartum women were excluded. It occurred at a younger age than de Quervain's disease only when the comparison excluded peripartum women. Patients with intersection syndrome presented with a much shorter duration of symptoms. These results were consistent with previous reports about occupational factors in intersection syndrome, and might be helpful in the understanding of epidemiological difference between the two conditions. Level 3. © The Author(s) 2015.

Integration of uncooled scraper elements and its diagnostics into Wendelstein 7-X

DOE PAGES

Fellinger, Joris; Loesser, Doug; Neilson, Hutch; ...

2017-08-08

The modular stellarator Wendelstein 7-X in Greifswald (Germany) successfully started operation in 2015 with short pulse limiter plasmas. In 2017, the next operation phase (OP) OP1.2 will start once 10 uncooled test divertor units (TDU) with graphite armor will be installed. The TDUs allow for plasma pulses of 10 s with 8 MW heating. OP2, allowing for steady state operation, is planned for 2020 after the TDUs will be replaced by 10 water cooled CFC armored divertors. Due to the development of plasma currents like bootstrap currents in long pulse plasmas in OP2, the plasma could hit the edge ofmore » the divertor targets which has a reduced cooling capacity compared to the central part of the target tiles. To prevent overloading of these edges, a so-called scraper element can be positioned in front of the divertor, intersecting those strike lines that would otherwise hit the divertor edges. As a result, these edges are protected but as a drawback the pumping efficiency of neutrals is also reduced. As a test an uncooled scraper element with graphite tiles will be placed in two out of ten half modules in OP1.2. A decision to install ten water cooled scraper elements for OP2 is pending on the results of this test in OP1.2. To monitor the impact of the scraper element on the plasma, Langmuir probes are integrated in the plasma facing surface, and a neutral gas manometer measures the neutral density directly behind the plasma facing surface. Moreover, IR and VIS cameras observe the plasma facing surface and thermocouples monitor the temperatures of the graphite tiles and underlying support structure. This paper describes the integration of the scraper element and its diagnostics in Wendelstein 7-X.« less

Dynamic stability of rolling particles between elastic plates

NASA Astrophysics Data System (ADS)

Guzev, Mikhail; Dmitriev, Aleksandr; Dyskin, Arcady; Pasternak, Elena

2017-04-01

Mechanical behaviour of a large class of engineering materials from granular materials and interlocking structures to damaged rock and fragmented rock masses is controlled by rotations of the constituents leading to the necessity to introduce internal rotations and rotational degrees of freedom into the constitutive laws. An important (and underappreciated) factor in these cases is the shape of rotating elements as it imposes, in the presence of compressive stress, kinematic constraints that provide additional resistance to rotations. (Despite the universal acknowledgement that the particles in geomaterial and concrete are far from being spherical, the vast majority of models, from the Cosserat continuum to the very recent are still based on spherical or circular elements, e.g. [1]). In the presence of high compressive loading the combination of rotation and non-sphericity of the constituents produces qualitatively new effects: the effect of apparent negative stiffness and a possibility of instability [2]. In order to simplify the analysis we investigate the stability of interacting rotating particles is a sympathetic oscillator [3]. A modified model of the oscillating system, given their rods slide without friction relative to each other was proposed in [4]. An important property of the system is the possibility of bifurcations depending on the distance between the suspension points. Here we study the stability of two linearly - interacting oscillators in a uniform gravity field. The simplest models pertinent to the analysis of stability of such systems is a system of two linked oscillators (masses on rods) with a modification that allows the rods to intersect and slide without friction relative to each other thus providing a simplified modelling of 3D situations. We demonstrate that the analysis of the system trajectories is the most convenient in a 2D parametric space which is generated by the initial relative distance between the masses and the potential energy of the oscillator normalised by the spring's effective energy. We found that the system has symmetrical and asymmetrical equilibrium solutions. In the dynamical case, the asymmetric solutions ensue when the system is deviated from its symmetrical equilibrium. We point out a few features of the global dynamics of the system: 1) at the symmetric equilibrium, the stability region of the sympathetic oscillators does not intersect the stability region of the modified oscillator system below the horizontal suspension line; 2) at the asymmetric equilibrium, the stability region of the sympathetic oscillators intersect the stability region of the modified oscillator system below the suspension line. References [1] Kun, F., I. Varga, S. Lennartz-Sassinek & I.G. Main, 2014. Rupture cascades in a discrete element model of a porous sedimentary rock. Phys. Rev. Lett. 112, 065501. [2] Dyskin, A.V. & E. Pasternak, 2012. Mechanical effect of rotating non-spherical particles on failure in compression. Phil. Mag. 92, 3451-3473. [3] A. Sommerfeld, Vorlesungen uber Theoretische Physik, Band 1: Mechanik, Verlag Harri Deutsch, Thun, 1994. [4] P. Ramachandran, S. G. Krishna, Y. M. Ram, Instability of a constrained pendulum system, Am. J. Phys. 79 (4) (2011) 395-400.

An Introductory Mixed-Methods Intersectionality Analysis of College Access and Equity: An Examination of First-Generation Asian Americans and Pacific Islanders

ERIC Educational Resources Information Center

Museus, Samuel D.

2011-01-01

In this article, the author discusses how researchers can use mixed-methods approaches and intersectional analyses to understand college access among first-generation Asian American and Pacific Islanders (AAPIs). First, he discusses the utility of mixed-methods approaches and intersectionality research in studying college access. Then, he…

27 CFR 9.34 - Finger Lakes.

Code of Federal Regulations, 2012 CFR

2012-04-01

... approximately 56 miles (45 miles due east) to the intersection of New York State Highway 89 (NY-89). (3) Then south on NY-89 four miles to the intersection of highway US-20. (4) Then east on US-20 for 36 miles to the intersection of interstate 81 (I-81). (5) Then south along I-81 for ten miles to NY-281. (6) Then...

27 CFR 9.34 - Finger Lakes.

Code of Federal Regulations, 2010 CFR

2010-04-01

... approximately 56 miles (45 miles due east) to the intersection of New York State Highway 89 (NY-89). (3) Then south on NY-89 four miles to the intersection of highway US-20. (4) Then east on US-20 for 36 miles to the intersection of interstate 81 (I-81). (5) Then south along I-81 for ten miles to NY-281. (6) Then...

27 CFR 9.34 - Finger Lakes.

Code of Federal Regulations, 2011 CFR

2011-04-01

... approximately 56 miles (45 miles due east) to the intersection of New York State Highway 89 (NY-89). (3) Then south on NY-89 four miles to the intersection of highway US-20. (4) Then east on US-20 for 36 miles to the intersection of interstate 81 (I-81). (5) Then south along I-81 for ten miles to NY-281. (6) Then...

27 CFR 9.34 - Finger Lakes.

Code of Federal Regulations, 2013 CFR

2013-04-01

... approximately 56 miles (45 miles due east) to the intersection of New York State Highway 89 (NY-89). (3) Then south on NY-89 four miles to the intersection of highway US-20. (4) Then east on US-20 for 36 miles to the intersection of interstate 81 (I-81). (5) Then south along I-81 for ten miles to NY-281. (6) Then...

27 CFR 9.34 - Finger Lakes.

Code of Federal Regulations, 2014 CFR

2014-04-01

... approximately 56 miles (45 miles due east) to the intersection of New York State Highway 89 (NY-89). (3) Then south on NY-89 four miles to the intersection of highway US-20. (4) Then east on US-20 for 36 miles to the intersection of interstate 81 (I-81). (5) Then south along I-81 for ten miles to NY-281. (6) Then...

Intersecting Work and Learning: Assembling Advanced Liberal Regimes of Governing Workers in Australia

ERIC Educational Resources Information Center

Reich, Ann

2008-01-01

Much had been written over the past few years on the intersections of work and learning. This article suggests that the analysis of the intersections of work and learning can benefit greatly from understanding the ways in which governing workers as individuals and populations has changed in Western liberal democracies in the latter part of the…

Statistical analysis of traversal behavior under different types of traffic lights

NASA Astrophysics Data System (ADS)

Wang, Boran; Wang, Ziyang; Li, Zhiyin

2017-12-01

According to the video observation, it is found that the traffic signal type signal has a significant effect on the illegal crossing behavior of pedestrians at the intersection. Through the method of statistical analysis and variance analysis, the difference between the violation rate and the waiting position of pedestrians at different intersecting lights is compared, and the influence of traffic signal type on pedestrian crossing behavior is evaluated. The results show that the violation rate of the intersection of the static pedestrian lights is significantly higher than that of the countdown signal lights. There are significant differences in the waiting position of the intersection of different signal lights.

LiPISC: A Lightweight and Flexible Method for Privacy-Aware Intersection Set Computation

PubMed Central

Huang, Shiyong; Ren, Yi; Choo, Kim-Kwang Raymond

2016-01-01

Privacy-aware intersection set computation (PISC) can be modeled as secure multi-party computation. The basic idea is to compute the intersection of input sets without leaking privacy. Furthermore, PISC should be sufficiently flexible to recommend approximate intersection items. In this paper, we reveal two previously unpublished attacks against PISC, which can be used to reveal and link one input set to another input set, resulting in privacy leakage. We coin these as Set Linkage Attack and Set Reveal Attack. We then present a lightweight and flexible PISC scheme (LiPISC) and prove its security (including against Set Linkage Attack and Set Reveal Attack). PMID:27326763

LiPISC: A Lightweight and Flexible Method for Privacy-Aware Intersection Set Computation.

PubMed

Ren, Wei; Huang, Shiyong; Ren, Yi; Choo, Kim-Kwang Raymond

2016-01-01

Privacy-aware intersection set computation (PISC) can be modeled as secure multi-party computation. The basic idea is to compute the intersection of input sets without leaking privacy. Furthermore, PISC should be sufficiently flexible to recommend approximate intersection items. In this paper, we reveal two previously unpublished attacks against PISC, which can be used to reveal and link one input set to another input set, resulting in privacy leakage. We coin these as Set Linkage Attack and Set Reveal Attack. We then present a lightweight and flexible PISC scheme (LiPISC) and prove its security (including against Set Linkage Attack and Set Reveal Attack).

Modeling Driver Behavior near Intersections in Hidden Markov Model

PubMed Central

Li, Juan; He, Qinglian; Zhou, Hang; Guan, Yunlin; Dai, Wei

2016-01-01

Intersections are one of the major locations where safety is a big concern to drivers. Inappropriate driver behaviors in response to frequent changes when approaching intersections often lead to intersection-related crashes or collisions. Thus to better understand driver behaviors at intersections, especially in the dilemma zone, a Hidden Markov Model (HMM) is utilized in this study. With the discrete data processing, the observed dynamic data of vehicles are used for the inference of the Hidden Markov Model. The Baum-Welch (B-W) estimation algorithm is applied to calculate the vehicle state transition probability matrix and the observation probability matrix. When combined with the Forward algorithm, the most likely state of the driver can be obtained. Thus the model can be used to measure the stability and risk of driver behavior. It is found that drivers’ behaviors in the dilemma zone are of lower stability and higher risk compared with those in other regions around intersections. In addition to the B-W estimation algorithm, the Viterbi Algorithm is utilized to predict the potential dangers of vehicles. The results can be applied to driving assistance systems to warn drivers to avoid possible accidents. PMID:28009838

The Intersectionality of Stigmas among Key Populations of Older Adults Affected by HIV: a Thematic Analysis.

PubMed

Johnson Shen, Megan; Freeman, Ryann; Karpiak, Stephen; Brennan-Ing, Mark; Seidel, Liz; Siegler, Eugenia L

2018-03-26

The present study examined the intersectionality of stigma across varying groups of older persons living with HIV (PWH). Four focus groups of older PWH (gay/bisexual men, heterosexual men, heterosexual and bisexualwomen, and Spanish-speaking) were audio-recorded and transcribed. Inductive thematic text analysis was used to identify qualitative themes. Five major themes emerged from the data: 1) disclosure of HIV status; 2) types of stigma experienced; 3) discrimination experienced; 4) other outcomes associated with experiencing stigma; and 5) influence of aging on social isolation experienced due to stigma. Findings indicate women did not suffer from the intersection of stigmas. Other groups suffered from the intersection of stigma due to HIV status and age (gay/bisexual males); HIV status and perceived stigma of sexual orientation or drug use (heterosexual males); and HIV status and culture/ethnicity (Spanish-speaking). Results indicate that many at-risk groups, including heterosexual men, homosexual men, and Spanish-speaking individuals, experience an intersection of stigma between aging and their sexuality, HIV status, or real or perceived drug use. Results highlight the need for HIV support, especially social support, to address intersection of stigmas for unique groups of individuals disproportionately affected by HIV.

Solution of the flyby problem for large space debris at sun-synchronous orbits

NASA Astrophysics Data System (ADS)

Baranov, A. A.; Grishko, D. A.; Medvedevskikh, V. V.; Lapshin, V. V.

2016-05-01

the paper considers the flyby problem related to large space debris (LSD) objects at low earth orbits. The data on the overall dimensions of known last and upper stages of launch vehicles makes it possible to single out five compact groups of such objects from the NORAD catalog in the 500-2000 km altitude interval. The orbits of objects of each group have approximately the same inclinations. The features of the mutual distribution of the orbital planes of LSD objects in the group are shown in a portrait of the evolution of deviations of the right ascension of ascending nodes (RAAN). In the case of the first three groups (inclinations of 71°, 74°, and 81°), the straight lines of relative RAAN deviations of object orbits barely intersect each other. The fourth (83°) and fifth (97°-100°) LSD groups include a considerable number of objects whose orbits are described by straight lines (diagonals), which intersect other lines many times. The use of diagonals makes it possible to significantly reduce the temporal and total characteristic velocity expenditures required for object flybys, but it complicates determination of the flyby sequence. Diagonal solutions can be obtained using elements of graph theory. A solution to the flyby problem is presented for the case of group 5, formed of LSD objects at sun-synchronous orbits.

Dehydrin gene expression provides an indicator of low temperature and drought stress: transcriptome-based analysis of barley (Hordeum vulgare L.).

PubMed

Tommasini, Livia; Svensson, Jan T; Rodriguez, Edmundo M; Wahid, Abdul; Malatrasi, Marina; Kato, Kenji; Wanamaker, Steve; Resnik, Josh; Close, Timothy J

2008-11-01

Low temperature and drought have major influences on plant growth and productivity. To identify barley genes involved in responses to these stresses and to specifically test the hypothesis that the dehydrin (Dhn) multigene family can serve as an indicator of the entire transcriptome response, we investigated the response of barley cv. Morex to: (1) gradual drought over 21 days and (2) low temperature including chilling, freeze-thaw cycles, and deacclimation over 33 days. We found 4,153 genes that responded to at least one component of these two stress regimes, about one fourth of all genes called "present" under any condition. About 44% (1,822 of 4,153) responded specifically to drought, whereas only 3.8% (158 of 4,153) were chilling specific and 2.8% (119 of 4,153) freeze-thaw specific, with 34.1% responsive to freeze-thaw and drought. The intersection between chilling and drought (31.9%) was somewhat smaller than the intersection between freeze-thaw and drought, implying an element of osmotic stress response to freeze-thaw. About 82.4% of the responsive genes were similar to Arabidopsis genes. The expression of 13 barley Dhn genes mirrored the global clustering of all transcripts, with specific combinations of Dhn genes providing an excellent indicator of each stress response. Data from these studies provide a robust reference data set for abiotic stress.

Engaging police to identify challenging school crossings and potential improvements.

PubMed

Bull, Catherine B; Von Hagen, Leigh Ann; Lubin, Andrea; Shivaraman, Gayathri; Chibbaro, Daniel

2018-04-26

This paper discusses the value of police officers as vital sources of information regarding pedestrian safety in their communities by presenting results from a survey of traffic safety police officers. The survey requested information on school crossings that the officers considered most challenging for pedestrians. Officers specified the intersections or mid-block locations with school crossings, and answered questions about elements of the locations, such as what makes the locations challenging, and what might be done to improve conditions at these locations. A key finding from the survey is the police officers' identification of challenging intersections or other crossing locations by criteria other than the occurrence of crashes, including reported pedestrian-vehicle near-miss incidents. A broad literature review of pedestrian safety studies provides context for the use of near-miss data in discussions of improvements to pedestrian crossings. Although not typically considered a primary resource for pedestrian safety information, police officers are most often very familiar with their communities, work in locations where pedestrian and motor vehicle traffic can be experienced and observed, and receive information from their staff and members of the public who use pedestrian crossings. The survey findings demonstrate that police officer insights and near-miss data may serve as important supplementary sources of information in the effort to identify locations in need of interventions before crash occurrence. Copyright © 2018 Elsevier Ltd. All rights reserved.

Role of geomechanically grown fractures on dispersive transport in heterogeneous geological formations.

PubMed

Nick, H M; Paluszny, A; Blunt, M J; Matthai, S K

2011-11-01

A second order in space accurate implicit scheme for time-dependent advection-dispersion equations and a discrete fracture propagation model are employed to model solute transport in porous media. We study the impact of the fractures on mass transport and dispersion. To model flow and transport, pressure and transport equations are integrated using a finite-element, node-centered finite-volume approach. Fracture geometries are incrementally developed from a random distributions of material flaws using an adoptive geomechanical finite-element model that also produces fracture aperture distributions. This quasistatic propagation assumes a linear elastic rock matrix, and crack propagation is governed by a subcritical crack growth failure criterion. Fracture propagation, intersection, and closure are handled geometrically. The flow and transport simulations are separately conducted for a range of fracture densities that are generated by the geomechanical finite-element model. These computations show that the most influential parameters for solute transport in fractured porous media are as follows: fracture density and fracture-matrix flux ratio that is influenced by matrix permeability. Using an equivalent fracture aperture size, computed on the basis of equivalent permeability of the system, we also obtain an acceptable prediction of the macrodispersion of poorly interconnected fracture networks. The results hold for fractures at relatively low density.

A real-time traffic control method for the intersection with pre-signals under the phase swap sorting strategy

PubMed Central

Bie, Yiming; Wang, Yinhai

2017-01-01

To deal with the conflicts between left-turn and through traffic streams and increase the discharge capacity, this paper addresses the pre-signal which is implemented at a signalized intersection. Such an intersection with pre-signal is termed as a tandem intersection. For the tandem intersection, phase swap sorting strategy is deemed as the most effective phasing scheme in view of some exclusive merits, such as easier compliance of drivers, and shorter sorting area. However, a major limitation of the phase swap sorting strategy is not considered in previous studies: if one or more vehicle is left at the sorting area after the signal light turns to red, the capacity of the approach would be dramatically dropped. Besides, previous signal control studies deal with a fixed timing plan that is not adaptive with the fluctuation of traffic flows. Therefore, to cope with these two gaps, this paper firstly takes an in-depth analysis of the traffic flow operations at the tandem intersection. Secondly, three groups of loop detectors are placed to obtain the real-time vehicle information for adaptive signalization. The lane selection behavior in the sorting area is considered to set the green time for intersection signals. With the objective of minimizing the vehicle delay, the signal control parameters are then optimized based on a dynamic programming method. Finally, numerical experiments show that average vehicle delay and maximum queue length can be reduced under all scenarios. PMID:28531198

Safety evaluation of intersections with dynamic use of exit-lanes for left-turn using field data.

PubMed

Zhao, Jing; Liu, Yue

2017-05-01

As a newly proposed unconventional intersection design, the exit-lanes for left-turn (EFL) intersection is found to be effective in increasing the intersection capacity with high level of application flexibility, especially under heavy left-turn traffic conditions. However, the operational safety of EFL is of most concern to the authority prior to its implementation. This paper evaluates the safety of the EFL intersections by studying the behavior of left-turn maneuvers using field data collected at 7 locations in China. A total of 22830 left-turn vehicles were captured, in which 9793 vehicles turned left using the mixed-usage area. Four potential safety problems, including the red-light violations, head-on collision risks, trapped vehicles, and rear-end crash risks, were discussed. Statistical analyses were carried out to compare the safety risk between the EFL intersection and the conventional one. Results indicate that the safety problems of EFL intersections mainly lie in higher percentages in red-light violations at the pre-signal (1.83% higher), wrong-way violation problems during the peak hours (the violation rate reaches up to 11.07%), and the lower travel speeds in the mixed-usage area (18.75% lower). Such risks can be counteracted, however, by providing more guiding information, installing cameras to investigate and punish violation maneuvers, and adjusting design parameter values for layout design and signal timing, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

A real-time traffic control method for the intersection with pre-signals under the phase swap sorting strategy.

PubMed

Bie, Yiming; Liu, Zhiyuan; Wang, Yinhai

2017-01-01

To deal with the conflicts between left-turn and through traffic streams and increase the discharge capacity, this paper addresses the pre-signal which is implemented at a signalized intersection. Such an intersection with pre-signal is termed as a tandem intersection. For the tandem intersection, phase swap sorting strategy is deemed as the most effective phasing scheme in view of some exclusive merits, such as easier compliance of drivers, and shorter sorting area. However, a major limitation of the phase swap sorting strategy is not considered in previous studies: if one or more vehicle is left at the sorting area after the signal light turns to red, the capacity of the approach would be dramatically dropped. Besides, previous signal control studies deal with a fixed timing plan that is not adaptive with the fluctuation of traffic flows. Therefore, to cope with these two gaps, this paper firstly takes an in-depth analysis of the traffic flow operations at the tandem intersection. Secondly, three groups of loop detectors are placed to obtain the real-time vehicle information for adaptive signalization. The lane selection behavior in the sorting area is considered to set the green time for intersection signals. With the objective of minimizing the vehicle delay, the signal control parameters are then optimized based on a dynamic programming method. Finally, numerical experiments show that average vehicle delay and maximum queue length can be reduced under all scenarios.

Telemetry location error in a forested habitat

USGS Publications Warehouse

Chu, D.S.; Hoover, B.A.; Fuller, M.R.; Geissler, P.H.; Amlaner, Charles J.

1989-01-01

The error associated with locations estimated by radio-telemetry triangulation can be large and variable in a hardwood forest. We assessed the magnitude and cause of telemetry location errors in a mature hardwood forest by using a 4-element Yagi antenna and compass bearings toward four transmitters, from 21 receiving sites. The distance error from the azimuth intersection to known transmitter locations ranged from 0 to 9251 meters. Ninety-five percent of the estimated locations were within 16 to 1963 meters, and 50% were within 99 to 416 meters of actual locations. Angles with 20o of parallel had larger distance errors than other angles. While angle appeared most important, greater distances and the amount of vegetation between receivers and transmitters also contributed to distance error.

Determining the Young's modulus of a cellular titanium implant by FEM simulation

NASA Astrophysics Data System (ADS)

Loginov, Yu. N.; Golodnov, A. I.; Stepanov, S. I.; Kovalev, E. Yu.

2017-12-01

The role of additive manufacturing is noted for the construction of titanium medical implants. The purpose of the study is to determine the Young's modulus of cellular titanium implants, which is based on calculations performed by finite element analysis. A honeycomb structure from intersecting cylinder surfaces is offered for the implant made of the Ti-6Al-4V alloy. Boundary conditions are stated for the loading of the implant structure. It is demonstrated that the Young's modulus can be reduced more than three times comparing to a solid titanium alloy. Zones of strain and stress localization located near the abutment of the cylindrical surfaces. Recommendations for the further improvement of the implant architecture are generated.

Crossed Ga2O3/SnO2 multiwire architecture: a local structure study with nanometer resolution.

PubMed

Martínez-Criado, Gema; Segura-Ruiz, Jaime; Chu, Manh-Hung; Tucoulou, Remi; López, Iñaki; Nogales, Emilio; Mendez, Bianchi; Piqueras, Javier

2014-10-08

Crossed nanowire structures are the basis for high-density integration of a variety of nanodevices. Owing to the critical role of nanowires intersections in creating hybrid architectures, it has become a challenge to investigate the local structure in crossing points in metal oxide nanowires. Thus, if intentionally grown crossed nanowires are well-patterned, an ideal model to study the junction is formed. By combining electron and synchrotron beam nanoprobes, we show here experimental evidence of the role of impurities in the coupling formation, structural modifications, and atomic site configuration based on crossed Ga2O3/SnO2 nanowires. Our experiment opens new avenues for further local structure studies with both nanometer resolution and elemental sensitivity.

Rett Syndrome: Crossing the Threshold to Clinical Translation

PubMed Central

Katz, David M.; Bird, Adrian; Coenraads, Monica; Gray, Steven J.; Menon, Debashish U.; Philpot, Benjamin D.; Tarquinio, Daniel C.

2016-01-01

Lying at the intersection between neurobiology and epigenetics, Rett syndrome (RTT) has garnered intense interest in recent years, not only from a broad range of academic scientists, but also from the pharmaceutical and biotechnology industries. In addition to the critical need for treatments for this devastating disorder, optimism for developing RTT treatments derives from a unique convergence of factors, including a known monogenic cause, reversibility of symptoms in preclinical models, a strong clinical research infrastructure highlighted by an NIH-funded natural history study and well-established clinics with significant patient populations. Here, we review recent advances in understanding the biology of RTT, particularly promising preclinical findings, lessons from past clinical trials, and critical elements of trial design for rare disorders. PMID:26830113

Multivariate statistical analysis: Principles and applications to coorbital streams of meteorite falls

NASA Technical Reports Server (NTRS)

Wolf, S. F.; Lipschutz, M. E.

1993-01-01

Multivariate statistical analysis techniques (linear discriminant analysis and logistic regression) can provide powerful discrimination tools which are generally unfamiliar to the planetary science community. Fall parameters were used to identify a group of 17 H chondrites (Cluster 1) that were part of a coorbital stream which intersected Earth's orbit in May, from 1855 - 1895, and can be distinguished from all other H chondrite falls. Using multivariate statistical techniques, it was demonstrated that a totally different criterion, labile trace element contents - hence thermal histories - or 13 Cluster 1 meteorites are distinguishable from those of 45 non-Cluster 1 H chondrites. Here, we focus upon the principles of multivariate statistical techniques and illustrate their application using non-meteoritic and meteoritic examples.

The General Penrose Inequality: Lessons from Numerical Evidence

NASA Astrophysics Data System (ADS)

Karkowski, J.; Malec, E.

2005-01-01

Formulation of the Penrose inequality becomes ambiguous when the past and future apparent horizons do cross. We test numerically several natural possibilities of stating the inequality in punctured and boosted single- and double-black holes, in a Dain--Friedrich class of initial data and in conformally flat spheroidal data. The Penrose inequality holds true in vacuum configurations for the outermost element amongst the set of disjoint future and past apparent horizons (as expected) and (unexpectedly) for each of the outermost past and future apparent horizons, whenever these two bifurcate from an outermost minimal surface, regardless of whether they intersect or remain disjoint. In systems with matter the conjecture breaks down only if matter does not obey the dominant energy condition.

Intersectionality Dis/ability Research: How Dis/ability Research in Education Engages Intersectionality to Uncover the Multidimensional Construction of Dis/abled Experiences

ERIC Educational Resources Information Center

Hernández-Saca, David I.; Gutmann Kahn, Laurie; Cannon, Mercedes A.

2018-01-01

The purpose of this chapter is to systematically review the research within the field of education that explicitly examined how various social constructions of identity intersect with dis/ability to qualitatively affect young adults' experiences by asking the following question: What are the key findings in education research focusing on youth and…

Effectiveness of transverse grooves in rigid pavement

NASA Astrophysics Data System (ADS)

Gurney, G. F.; Bryden, J. E.

1982-10-01

Transverse grooves were installed at 11 intersection approaches on worn rigid pavement to reduce a high rate of wet road accidents. In most cases, accident reductions were experienced only at intersections with multiple negative operational characteristics, including higher approach speeds, limited sight distances, and frequent vehicle stopping for turns or stop signs. Intersections with no more than one negative characteristic generally did not benefit from grooving.

Iterating the Number of Intersection Points of the Diagonals of Irregular Convex Polygons, or C (n, 4) the Hard Way!

ERIC Educational Resources Information Center

Hathout, Leith

2007-01-01

Counting the number of internal intersection points made by the diagonals of irregular convex polygons where no three diagonals are concurrent is an interesting problem in discrete mathematics. This paper uses an iterative approach to develop a summation relation which tallies the total number of intersections, and shows that this total can be…

27 CFR 9.212 - Leona Valley.

Code of Federal Regulations, 2013 CFR

2013-04-01

... approximately 0.25 mile to its intersection with a trail and the 3,800-foot elevation line, T6N, R13W; then (9... mile to its intersection with the 3,600-foot elevation line, T6N, R14W; then (15) Proceed northwest... north boundary line 0.35 mile to its intersection with the 3,600-foot elevation line, T6N, R14W; then...

27 CFR 9.212 - Leona Valley.

Code of Federal Regulations, 2014 CFR

2014-04-01

... approximately 0.25 mile to its intersection with a trail and the 3,800-foot elevation line, T6N, R13W; then (9... mile to its intersection with the 3,600-foot elevation line, T6N, R14W; then (15) Proceed northwest... north boundary line 0.35 mile to its intersection with the 3,600-foot elevation line, T6N, R14W; then...

27 CFR 9.212 - Leona Valley.

Code of Federal Regulations, 2012 CFR

2012-04-01

... approximately 0.25 mile to its intersection with a trail and the 3,800-foot elevation line, T6N, R13W; then (9... mile to its intersection with the 3,600-foot elevation line, T6N, R14W; then (15) Proceed northwest... north boundary line 0.35 mile to its intersection with the 3,600-foot elevation line, T6N, R14W; then...

Quantifying the yellow signal driver behavior based on naturalistic data from digital enforcement cameras.

PubMed

Bar-Gera, H; Musicant, O; Schechtman, E; Ze'evi, T

2016-11-01

The yellow signal driver behavior, reflecting the dilemma zone behavior, is analyzed using naturalistic data from digital enforcement cameras. The key variable in the analysis is the entrance time after the yellow onset, and its distribution. This distribution can assist in determining two critical outcomes: the safety outcome related to red-light-running angle accidents, and the efficiency outcome. The connection to other approaches for evaluating the yellow signal driver behavior is also discussed. The dataset was obtained from 37 digital enforcement cameras at non-urban signalized intersections in Israel, over a period of nearly two years. The data contain more than 200 million vehicle entrances, of which 2.3% (∼5million vehicles) entered the intersection during the yellow phase. In all non-urban signalized intersections in Israel the green phase ends with 3s of flashing green, followed by 3s of yellow. In most non-urban signalized roads in Israel the posted speed limit is 90km/h. Our analysis focuses on crossings during the yellow phase and the first 1.5s of the red phase. The analysis method consists of two stages. In the first stage we tested whether the frequency of crossings is constant at the beginning of the yellow phase. We found that the pattern was stable (i.e., the frequencies were constant) at 18 intersections, nearly stable at 13 intersections and unstable at 6 intersections. In addition to the 6 intersections with unstable patterns, two other outlying intersections were excluded from subsequent analysis. Logistic regression models were fitted for each of the remaining 29 intersection. We examined both standard (exponential) logistic regression and four parameters logistic regression. The results show a clear advantage for the former. The estimated parameters show that the time when the frequency of crossing reduces to half ranges from1.7 to 2.3s after yellow onset. The duration of the reduction of the relative frequency from 0.9 to 0.1 ranged from 1.9 to 2.9s. Copyright © 2015 Elsevier Ltd. All rights reserved.

Validating a driving simulator using surrogate safety measures.

PubMed

Yan, Xuedong; Abdel-Aty, Mohamed; Radwan, Essam; Wang, Xuesong; Chilakapati, Praveen

2008-01-01

Traffic crash statistics and previous research have shown an increased risk of traffic crashes at signalized intersections. How to diagnose safety problems and develop effective countermeasures to reduce crash rate at intersections is a key task for traffic engineers and researchers. This study aims at investigating whether the driving simulator can be used as a valid tool to assess traffic safety at signalized intersections. In support of the research objective, this simulator validity study was conducted from two perspectives, a traffic parameter (speed) and a safety parameter (crash history). A signalized intersection with as many important features (including roadway geometries, traffic control devices, intersection surroundings, and buildings) was replicated into a high-fidelity driving simulator. A driving simulator experiment with eight scenarios at the intersection were conducted to determine if the subjects' speed behavior and traffic risk patterns in the driving simulator were similar to what were found at the real intersection. The experiment results showed that speed data observed from the field and in the simulator experiment both follow normal distributions and have equal means for each intersection approach, which validated the driving simulator in absolute terms. Furthermore, this study used an innovative approach of using surrogate safety measures from the simulator to contrast with the crash analysis for the field data. The simulator experiment results indicated that compared to the right-turn lane with the low rear-end crash history record (2 crashes), subjects showed a series of more risky behaviors at the right-turn lane with the high rear-end crash history record (16 crashes), including higher deceleration rate (1.80+/-1.20 m/s(2) versus 0.80+/-0.65 m/s(2)), higher non-stop right-turn rate on red (81.67% versus 57.63%), higher right-turn speed as stop line (18.38+/-8.90 km/h versus 14.68+/-6.04 km/h), shorter following distance (30.19+/-13.43 m versus 35.58+/-13.41 m), and higher rear-end probability (9/59=0.153 versus 2/60=0.033). Therefore, the relative validity of driving simulator was well established for the traffic safety studies at signalized intersections.

Conical intersection in a bilirubin model A possible pathway for phototherapy of neonatal jaundice

NASA Astrophysics Data System (ADS)

Zietz, Burkhard; Blomgren, Fredrik

2006-03-01

Phototherapy of neonatal jaundice involves Z- E-isomerisation around an exocyclic double bond in bilirubin. Our results of a CASSCF study on dipyrrinone, a bilirubin model, show a conical intersection between the ground and first excited singlet states associated with the Z- E-isomerisation. The conical intersection, located ca. 50 kJ/mol below the Franck-Condon-point, together with the S 1 minimum, ca. 50 kJ/mol below the conical intersection, are able to explain the available time-resolved spectroscopic data (the very short lifetime of the initially excited state and transient 'dark state' intermediate) as well as bilirubin's very low fluorescence quantum yield and the medium-efficient photoisomerisation reaction.

UpSetR: an R package for the visualization of intersecting sets and their properties.

PubMed

Conway, Jake R; Lex, Alexander; Gehlenborg, Nils

2017-09-15

Venn and Euler diagrams are a popular yet inadequate solution for quantitative visualization of set intersections. A scalable alternative to Venn and Euler diagrams for visualizing intersecting sets and their properties is needed. We developed UpSetR, an open source R package that employs a scalable matrix-based visualization to show intersections of sets, their size, and other properties. UpSetR is available at https://github.com/hms-dbmi/UpSetR/ and released under the MIT License. A Shiny app is available at https://gehlenborglab.shinyapps.io/upsetr/ . nils@hms.harvard.edu. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

Absolute flatness measurements of silicon mirrors by a three-intersection method by near-infrared interferometry

PubMed Central

2013-01-01

Absolute flatness of three silicon plane mirrors have been measured by a three-intersection method based on the three-flat method using a near-infrared interferometer. The interferometer was constructed using a near-infrared laser diode with a 1,310-nm wavelength light where the silicon plane mirror is transparent. The height differences at the coordinate values between the absolute line profiles by the three-intersection method have been evaluated. The height differences of the three flats were 4.5 nm or less. The three-intersection method using the near-infrared interferometer was useful for measuring the absolute flatness of the silicon plane mirrors. PMID:23758916

Using Plate Finite Elements for Modeling Fillets in Design, Optimization, and Dynamic Analysis

NASA Technical Reports Server (NTRS)

Brown, A. M.; Seugling, R. M.

2003-01-01

A methodology has been developed that allows the use of plate elements instead of numerically inefficient solid elements for modeling structures with 90 degree fillets. The technique uses plate bridges with pseudo Young's modulus (Eb) and thickness (tb) values placed between the tangent points of the fillets. These parameters are obtained by solving two nonlinear simultaneous equations in terms of the independent variables rlt and twallt. These equations are generated by equating the rotation at the tangent point of a bridge system with that of a fillet, where both rotations are derived using beam theory. Accurate surface fits of the solutions are also presented to provide the user with closed-form equations for the parameters. The methodology was verified on the subcomponent level and with a representative filleted structure, where the technique yielded a plate model exhibiting a level of accuracy better than or equal to a high-fidelity solid model and with a 90-percent reduction in the number of DOFs. The application of this method for parametric design studies, optimization, and dynamic analysis should prove extremely beneficial for the finite element practitioner. Although the method does not attempt to produce accurate stresses in the filleted region, it can also be used to obtain stresses elsewhere in the structure for preliminary analysis. A future avenue of study is to extend the theory developed here to other fillet geometries, including fillet angles other than 90 and multifaceted intersections.

Geologic, hydrologic, and geochemical interpretations of mineral deposits as analogs for understanding transport of environmental contaminants

USGS Publications Warehouse

Wanty, R.B.; Berger, B.R.

2006-01-01

Base- and precious-metal mineral deposits comprise anomalous concentrations of metals and associated elements, which may be useful subjects for study as analogs for migration of environmental contaminants. In the geologic past, hydrothermal mineral deposits formed at the intersection of favorable geologic, hydrologic and geochemical gradients. In the present, weathering of these sulfide-rich deposits occurs as a result of the interplay between rates of oxygen supply versus rates of ground or surface-water flow. Transport and spatial dispersion of elements from a mineral deposit occurs as a function of competing rates of water flow versus rates of attenuation mechanisms such as adsorption, dilution, or (co)precipitation. In this paper we present several case studies from mineralized and altered sedimentary and crystalline aquifers in the western United States to illustrate the geologic control of ground-water flow and solute transport, and to demonstrate how this combined approach leads to a more complete understanding of the systems under study as well as facilitating some capability to predict major flow directions in aquifers.

Analysis of tectonic features in US southwest from Skylab photographs

NASA Technical Reports Server (NTRS)

Abdel-Gawad, M. (Principal Investigator); Tubbesing, L.

1975-01-01

The author has identified the following significant results. Skylab photographs were utilized to study faults and tectonic lines in selected areas of the U.S. Southwest. Emphasis was on elements of the Texas Zone in the Mojave Desert and the tectonic intersection in southern Nevada. Transverse faults believed to represent the continuation of the Texas Zone were found to be anomalous in strike. This suggests that the Mojave Desert block was rotated counterclockwise as a unit with the Sierra Nevada. Left-lateral strike-slip faults in Lake Mead area are interpreted as elements of the Wasatch tectonic zone; their anomalous trend indicates that the Lake Mead area has rotated clockwise with the Colorado Plateau. A tectonic model relating major fault zones to fragmentation and rotation of crustal blocks was developed. Detailed correlation of the high resolution S190B metric camera photographs with U-2 photographs and geologic maps demonstrates the feasibility of utilizing S190B photographs for the identification of geomorphic features associated with recent and active faults and for the assessment of seismic hazards.

The odd couple: using biomedical and intersectional approaches to address health inequities

PubMed Central

Hankivsky, Olena; Doyal, Lesley; Einstein, Gillian; Kelly, Ursula; Shim, Janet; Weber, Lynn; Repta, Robin

2017-01-01

ABSTRACT Background: Better understanding and addressing health inequities is a growing global priority. Objective: In this paper, we contribute to the literature examining complex relationships between biological and social dimensions in the field of health inequalities. Specifically, we explore the potential of intersectionality to advance current approaches to socio-biological entwinements. Design: We provide a brief overview of current approaches to combining both biological and social factors in a single study, and then investigate the contributions of an intersectional framework to such work. Results: We offer a number of concrete examples of how intersectionality has been used empirically to bring both biological and social factors together in the areas of HIV, post-traumatic stress disorder, female genital circumcision/mutilation/cutting, and cardiovascular disease. Conclusion: We argue that an intersectional approach can further research that integrates biological and social aspects of human lives and human health and ultimately generate better and more precise evidence for effective policies and practices aimed at tackling health inequities. PMID:28641056

Can intersectional innovations reduce hospital infection?

PubMed

Saint, S

2017-02-01

Preventing healthcare-associated infection remains an international priority given the clinical and economic consequences of this largely preventable patient safety harm. Whereas important strides have been made in preventing hospital infections over the past several decades, thorny issues remain, including how to consistently improve hand hygiene rates and further reduce device-related complications such as catheter-associated urinary tract infection. Rather than relying solely on directional innovations - incremental changes that continue to serve as the bedrock of scientific advancement - perhaps we should also search for 'intersectional innovations', which represent breakthrough discoveries that emanate from the intersection of often widely divergent disciplines. Several intersectional innovations that have the potential to greatly impact infection prevention efforts include human factors engineering, sociology, and engaging the senses. Indeed, Professor Edward Joseph Lister Lowbury, the namesake of this lecture, exemplified intersectional thinking in his own life, having been both an accomplished bacteriologist and poet. By incorporating approaches outside of traditional biomedical science we may hope to provide patients with the safe care they expect and deserve. Published by Elsevier Ltd.

The odd couple: using biomedical and intersectional approaches to address health inequities.

PubMed

Hankivsky, Olena; Doyal, Lesley; Einstein, Gillian; Kelly, Ursula; Shim, Janet; Weber, Lynn; Repta, Robin

Better understanding and addressing health inequities is a growing global priority. In this paper, we contribute to the literature examining complex relationships between biological and social dimensions in the field of health inequalities. Specifically, we explore the potential of intersectionality to advance current approaches to socio-biological entwinements. We provide a brief overview of current approaches to combining both biological and social factors in a single study, and then investigate the contributions of an intersectional framework to such work. We offer a number of concrete examples of how intersectionality has been used empirically to bring both biological and social factors together in the areas of HIV, post-traumatic stress disorder, female genital circumcision/mutilation/cutting, and cardiovascular disease. We argue that an intersectional approach can further research that integrates biological and social aspects of human lives and human health and ultimately generate better and more precise evidence for effective policies and practices aimed at tackling health inequities.

Computer Generated Pictorial Stores Management Displays for Fighter Aircraft.

DTIC Science & Technology

1983-05-01

questionnaire rating-scale data. KRISHNAIAH FINITE INTERSECTION TESTS (FITs) - A set of tests conducted after significant MANOVA results are found to...the Social Sciences (SPSS) (Reference 2). To further examine significant performance differences, the Krishnaiah Finite Intersection Test (FIT), a...New York: McGraw-Hill Book Company, 1975. 3. C. M. Cox, P. R. Krishnaiah , J. C. Lee, J. M. Reising, and F. J. Schuurman, A study on Finite Intersection

Roadside-based communication system and method

NASA Technical Reports Server (NTRS)

Bachelder, Aaron D. (Inventor)

2007-01-01

A roadside-based communication system providing backup communication between emergency mobile units and emergency command centers. In the event of failure of a primary communication, the mobile units transmit wireless messages to nearby roadside controllers that may take the form of intersection controllers. The intersection controllers receive the wireless messages, convert the messages into standard digital streams, and transmit the digital streams along a citywide network to a destination intersection or command center.

Intersectional inequalities in immunization in India, 1992-93 to 2005-06: a progress assessment.

PubMed

Joe, William

2015-05-01

Immunization in India is marked with stark disparities across gender, caste, wealth and place of residence with severe shortfalls among those disadvantaged in more than one dimension. In this regard, an explicit recognition of intersectionality and intersectional inequalities has 2-fold relevance; one, being the pathway of health inequality and the other being its role as a deterrent of progress particularly at higher (better) levels of health. Against this backdrop, this study examines intersectional inequalities in immunization in India and also suggests a level-sensitive progress assessment method. The study uses group analogue of Gini coefficient for highlighting the magnitude of intersectional inequality and for comprehending its association with immunization level. The results unravel the plight of vulnerable intersectional groups and draw attention to disquieting shortfalls among female SCST (scheduled castes and tribes) children from rural areas. There is also some evidence to indicate leveraging among rural males in matters of immunization and it is further discerned that such gender advantage is greater among rural non-SCST community than the rural SCST group. In concluding, the study calls for intensive immunization planning to improve coverage among vulnerable communities in both rural and urban areas. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2014; all rights reserved.

Study on Performance of Intersection Around The Underpass Using Micro Simulation Program

NASA Astrophysics Data System (ADS)

Arliansyah, J.; Bawono, R. T.

2018-03-01

In order to overcome the problems of congestion at the major intersections in Palembang City, there have been grade separation constructions in the form of flyover or underpass. One of them is the intersection of Patal Pusri Underpass. The smooth traffic due to the underpass construction needs to be balanced by the arrangement management at the intersections located close to the underpass to get the best network performance since both affect each other performance. The Taman Kenten and Seduduk Putih junctions which are just 569 and 226 meters from the underpass of Patal Pusri has to be analyzed for its needs of management and traffic arrangements to reduce its impact on the performance of the intersection of Patal Pusri or vice versa. Some alternatives of management and traffic arrangements were developed to get the best solutions and the Vissim 8.00 microsimulation program was used to evaluate the performance of intersections in the network where the compared parameters are the value of the queue length and average delay. The results of the analysis and the conducted modeling show that the best solution to optimize the performance of the two junctions are to make geometric changes and diversion of traffic flow at Seduduk Putih Junction and making geometric changes at Taman Kenten Junction.

A Novel Way to Relate Ontology Classes

PubMed Central

Choksi, Ami T.; Jinwala, Devesh C.

2015-01-01

The existing ontologies in the semantic web typically have anonymous union and intersection classes. The anonymous classes are limited in scope and may not be part of the whole inference process. The tools, namely, the pellet, the jena, and the protégé, interpret collection classes as (a) equivalent/subclasses of union class and (b) superclasses of intersection class. As a result, there is a possibility that the tools will produce error prone inference results for relations, namely, sub-, union, intersection, equivalent relations, and those dependent on these relations, namely, complement. To verify whether a class is complement of other involves utilization of sub- and equivalent relations. Motivated by the same, we (i) refine the test data set of the conference ontology by adding named, union, and intersection classes and (ii) propose a match algorithm to (a) calculate corrected subclasses list, (b) correctly relate intersection and union classes with their collection classes, and (c) match union, intersection, sub-, complement, and equivalent classes in a proper sequence, to avoid error prone match results. We compare the results of our algorithms with those of a candidate reasoner, namely, the pellet reasoner. To the best of our knowledge, ours is a unique attempt in establishing a novel way to relate ontology classes. PMID:25984560

On the description of conical intersections—A continuous representation of the local topography of seams of conical intersection of three or more electronic states: A generalization of the two state result

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Xiaolei, E-mail: virtualzx@gmail.com; Yarkony, David R., E-mail: yarkony@jhu.edu

2014-11-07

For conical intersections of two states (I,J = I + 1) the vectors defining the branching or g-h plane, the energy difference gradient vector g{sup I,J}, and the interstate coupling vector h{sup I,J}, can be made orthogonal by a one parameter rotation of the degenerate electronic eigenstates. The representation obtained from this rotation is used to construct the parameters that describe the vicinity of the conical intersection seam, the conical parameters, s{sup I,J}{sub x} (R), s{sup I,J}{sub y} (R), g{sup I,J}(R), and h{sup I,J}(R). As a result of the orthogonalization these parameters can be made continuous functions of R, themore » internuclear coordinates. In this work we generalize this notion to construct continuous parametrizations of conical intersection seams of three or more states. The generalization derives from a recently introduced procedure for using non-degenerate electronic states to construct coupled diabatic states that represent adiabatic states coupled by conical intersections. The procedure is illustrated using the seam of conical intersections of three states in parazolyl as an example.« less

Differential arrest and adhesion of tumor cells and microbeads in the microvasculature

PubMed Central

Guo, Peng; Cai, Bin; Lei, Ming; Liu, Yang

2013-01-01

To investigate the mechanical mechanisms behind tumor cell arrest in the microvasculature, we injected fluorescently labeled human breast carcinoma cells or similarly sized rigid beads into the systemic circulation of a rat. Their arrest patterns in the microvasculature of mesentery were recorded and quantified. We found that 93% of rigid beads were arrested either at arteriole–capillary intersections or in capillaries. Only 3% were at the capillary–postcapillary venule intersections and in postcapillary venules. In contrast, most of the flexible tumor cells were either entrapped in capillaries or arrested at capillary or postcapillary venule–postcapillary venule intersections and in postcapillary venules. Only 12% of tumor cells were arrested at the arteriole–capillary intersections. The differential arrest and adhesion of tumor cells and microbeads in the microvasculature was confirmed by a χ2 test (p < 0.001). These results demonstrate that mechanical trapping was responsible for almost all the arrest of beads and half the arrest of tumor cells. Based on the measured geometry and blood flow velocities at the intersections, we also performed a numerical simulation using commercial software (ANSYS CFX 12.01) to depict the detailed distribution profiles of the velocity, shear rate, and vorticity at the intersections where tumor cells preferred to arrest and adhere. Simulation results reveal the presence of localized vorticity and shear rate regions at the turning points of the microvessel intersections, implying that hemodynamic factors play an important role in tumor cell arrest in the microcirculation. Our study helps elucidate long-debated issues related to the dominant factors in early-stage tumor hematogenous metastasis. PMID:23880911

Differential arrest and adhesion of tumor cells and microbeads in the microvasculature.

PubMed

Guo, Peng; Cai, Bin; Lei, Ming; Liu, Yang; Fu, Bingmei M

2014-06-01

To investigate the mechanical mechanisms behind tumor cell arrest in the microvasculature, we injected fluorescently labeled human breast carcinoma cells or similarly sized rigid beads into the systemic circulation of a rat. Their arrest patterns in the microvasculature of mesentery were recorded and quantified. We found that 93% of rigid beads were arrested either at arteriole-capillary intersections or in capillaries. Only 3% were at the capillary-postcapillary venule intersections and in postcapillary venules. In contrast, most of the flexible tumor cells were either entrapped in capillaries or arrested at capillary or postcapillary venule-postcapillary venule intersections and in postcapillary venules. Only 12% of tumor cells were arrested at the arteriole-capillary intersections. The differential arrest and adhesion of tumor cells and microbeads in the microvasculature was confirmed by a χ(2) test (p < 0.001). These results demonstrate that mechanical trapping was responsible for almost all the arrest of beads and half the arrest of tumor cells. Based on the measured geometry and blood flow velocities at the intersections, we also performed a numerical simulation using commercial software (ANSYS CFX 12.01) to depict the detailed distribution profiles of the velocity, shear rate, and vorticity at the intersections where tumor cells preferred to arrest and adhere. Simulation results reveal the presence of localized vorticity and shear rate regions at the turning points of the microvessel intersections, implying that hemodynamic factors play an important role in tumor cell arrest in the microcirculation. Our study helps elucidate long-debated issues related to the dominant factors in early-stage tumor hematogenous metastasis.

Evaluation of a Risk Awareness Perception Training Program on Novice Teen Driver Behavior at Left-Turn Intersections.

PubMed

McDonald, Catherine C; Kandadai, Venk; Loeb, Helen; Seacrist, Thomas; Lee, Yi-Ching; Bonfiglio, Dana; Fisher, Donald L; Winston, Flaura K

Collisions at left turn intersections are among the most prevalent types of teen driver serious crashes, with inadequate surveillance as a key factor. Risk awareness perception training (RAPT) has shown effectiveness in improving hazard anticipation for latent hazards. The goal of this study was to determine if RAPT version 3 (RAPT-3) improved intersection turning behaviors among novice teen drivers when the hazards were not latent and frequent glancing to multiple locations at the intersection was needed. Teens aged 16-18 with ≤180 days of licensure were randomly assigned to: 1) an intervention group (n=18) that received RAPT-3 (Trained); or 2) a control group (n=19) that received no training (Untrained). Both groups completed RAPT-3 Baseline Assessment and the Trained group completed RAPT-3 Training and RAPT-3 Post Assessment. Training effects were evaluated on a driving simulator. Simulator ( gap selection errors and collisions ) and eye tracker ( traffic check errors) metrics from six left-turn stop sign controlled intersections in the Simulated Driving Assessment (SDA) were analyzed. The Trained group scored significantly higher in RAPT-3 Post Assessment than RAPT-3 Baseline Assessment (p< 0.0001). There were no significant differences in either traffic check and gap selection errors or collisions among Trained and Untrained teens in the SDA. Though Trained teens learned about hazard anticipation related to latent hazards, learning did not translate to performance differences in left-turn stop sign controlled intersections where the hazards were not latent. Our findings point to further research to better understand the challenges teens have with left turn intersections.

Evaluating the Operational Features of an Unconventional Dual-Bay U-Turn Design for Intersections

PubMed Central

Xiang, Yun; Li, Zhibin; Wang, Wei; Chen, Jingxu; Wang, Hao; Li, Ye

2016-01-01

Median U-turn intersection treatment (MUTIT) has been considered an alternative measure to reduce congestion and traffic conflict at intersection areas. The MUTIT is sometimes difficult to implement in the field because it requires wide median on arterials for U-turn vehicles. The objective of this study is to introduce an unconventional U-turn treatment (UUT) for intersections which requires less median space but is also effective. The UUT has a dual-bay design with different turning radiuses for small and large vehicles. The VISSIM simulation model was developed to evaluate the operational features of the UUT. The model was calibrated using data collected from intersections in China. The capacity, delay and number of stops were evaluated and compared with the direct-left-turn (DLT) for the same intersections. The results showed that the UUT significantly improved the operations at intersection areas, especially when volume/capacity ratio is small, and ratio of left-turn to through traffic is small. With the UUT, the capacity is increased by 9.81% to 10.38%, vehicle delay is decreased by 18.5% to 40.1%, and number of stops is decreased by 23.19% to 36.62%, when volume/capacity ratio is less than 0.50. The study also found that traffic efficiency could be further improved when the UUT is designed in conjunction with signal control. In the case, the UUT plus signalized control increases the capacity by 25% to 26.02%, decreases vehicle delay by 50.5% to 55.8%, and reduces number of stops by 69.5%, compared with the traditional DLT. PMID:27467127

Evaluating the Operational Features of an Unconventional Dual-Bay U-Turn Design for Intersections.

PubMed

Xiang, Yun; Li, Zhibin; Wang, Wei; Chen, Jingxu; Wang, Hao; Li, Ye

2016-01-01

Median U-turn intersection treatment (MUTIT) has been considered an alternative measure to reduce congestion and traffic conflict at intersection areas. The MUTIT is sometimes difficult to implement in the field because it requires wide median on arterials for U-turn vehicles. The objective of this study is to introduce an unconventional U-turn treatment (UUT) for intersections which requires less median space but is also effective. The UUT has a dual-bay design with different turning radiuses for small and large vehicles. The VISSIM simulation model was developed to evaluate the operational features of the UUT. The model was calibrated using data collected from intersections in China. The capacity, delay and number of stops were evaluated and compared with the direct-left-turn (DLT) for the same intersections. The results showed that the UUT significantly improved the operations at intersection areas, especially when volume/capacity ratio is small, and ratio of left-turn to through traffic is small. With the UUT, the capacity is increased by 9.81% to 10.38%, vehicle delay is decreased by 18.5% to 40.1%, and number of stops is decreased by 23.19% to 36.62%, when volume/capacity ratio is less than 0.50. The study also found that traffic efficiency could be further improved when the UUT is designed in conjunction with signal control. In the case, the UUT plus signalized control increases the capacity by 25% to 26.02%, decreases vehicle delay by 50.5% to 55.8%, and reduces number of stops by 69.5%, compared with the traditional DLT.

Driving with hemianopia: IV. Head scanning and detection at intersections in a simulator.

PubMed

Bowers, Alex R; Ananyev, Egor; Mandel, Aaron J; Goldstein, Robert B; Peli, Eli

2014-03-13

Using a driving simulator, we examined the effects of homonymous hemianopia (HH) on head scanning behaviors at intersections and evaluated the role of inadequate head scanning in detection failures. Fourteen people with complete HH and without cognitive decline or visual neglect and 12 normally sighted (NV) current drivers participated. They drove in an urban environment following predetermined routes, which included multiple intersections. Head scanning behaviors were quantified at T-intersections (n = 32) with a stop or yield sign. Participants also performed a pedestrian detection task. The relationship between head scanning and detection was examined at 10 intersections. For HH drivers, the first scan was more likely to be toward the blind than the seeing hemifield. They also made a greater proportion of head scans overall to the blind side than did the NV drivers to the corresponding side (P = 0.003). However, head scan magnitudes of HH drivers were smaller than those of the NV group (P < 0.001). Drivers with HH had impaired detection of blind-side pedestrians due either to not scanning in the direction of the pedestrian or to an insufficient scan magnitude (left HH detected only 46% and right HH 8% at the extreme left and right of the intersection, respectively). Drivers with HH demonstrated compensatory head scan patterns, but not scan magnitudes. Inadequate scanning resulted in blind-side detection failures, which might place HH drivers at increased risk for collisions at intersections. Scanning training tailored to specific problem areas identified in this study might be beneficial.

¿Somos iguales? Using a structural violence framework to understand gender and health inequities from an intersectional perspective in the Peruvian Amazon.

PubMed

Shannon, Geordan D; Motta, Angelica; Cáceres, Carlos F; Skordis-Worrall, Jolene; Bowie, Diana; Prost, Audrey

In the Peruvian Amazon, historical events of colonization and political marginalization intersect with identities of ethnicity, class and geography in the construction of gender and health inequities. Gender-based inequalities can manifest in poor health outcomes via discriminatory practices, healthcare system imbalances, inequities in health research, and differential exposures and vulnerabilities to diseases. Structural violence is a comprehensive framework to explain the mechanisms by which social forces such as poverty, racism and gender inequity become embodied as individual experiences and health outcomes, and thus may be a useful tool in structuring an intersectional analysis of gender and health inequities in Amazonian Peru. The aim of this paper is to explore the intersection of gender inequities with other social inequalities in the production of health and disease in Peru's Amazon using a structural violence approach. Exploratory qualitative research was performed in two Loreto settings - urban Iquitos and the rural Lower Napo River region - between March and November 2015. This included participant observation with prolonged stays in the community, 46 semi-structured individual interviews and three group discussions. Thematic analysis was performed to identify emerging themes related to gender inequalities in health and healthcare and how these intersect with layered social disadvantages in the reproduction of health and illness. We employed a structural violence approach to construct an intersectional analysis of gender and health inequities in Amazonian Peru. Our findings were arranged into five interrelated domains within a gender, structural violence and health model: gender as a symbolic institution, systemic gender-based violence, interpersonal violence, the social determinants of health, and other health outcomes. Each domain represents one aspect of the complex associations between gender, gender inequity and health. Through this model, we were able to explore: gender, health and intersectionality; structural violence; and to highlight particular local gender and health dynamics. Intersecting influences of poverty, ethnicity, geography and gender served as significant barriers to healthcare in both rural and urban settings.

Estimating rear-end accident probabilities at signalized intersections: a comparison study of intersections with and without green signal countdown devices.

PubMed

Ni, Ying; Li, Keping

2014-01-01

Rear-end accidents are the most common accident type at signalized intersections, because the diversity of actions taken increases due to signal change. Green signal countdown devices (GSCDs), which have been widely installed in Asia, are thought to have the potential of improving capacity and reducing accidents, but some negative effects on intersection safety have been observed in practice; for example, an increase in rear-end accidents. A microscopic modeling approach was applied to estimate rear-end accident probability during the phase transition interval in the study. The rear-end accident probability is determined by the following probabilities: (1) a leading vehicle makes a "stop" decision, which was formulated by using a binary logistic model, and (2) the following vehicle fails to stop in the available stopping distance, which is closely related to the critical deceleration used by the leading vehicle. Based on the field observation carried out at 2 GSCD intersections and 2 NGSCD intersections (i.e., intersections without GSCD devices) along an arterial in Suzhou, the rear-end probabilities at GSCD and NGSCD intersections were calculated using Monte Carlo simulation. The results suggested that, on the one hand, GSCDs caused significantly negative safety effects during the flashing green interval, especially for vehicles in a zone ranging from 15 to 70 m; on the other hand, GSCD devices were helpful in reducing rear-end accidents during the yellow interval, especially in a zone from 0 to 50 m. GSCDs helped shorten indecision zones and reduce rear-end collisions near the stop line during the yellow interval, but they easily resulted in risky car following behavior and much higher rear-end collision probabilities at indecision zones during both flashing green and yellow intervals. GSCDs are recommended to be cautiously installed and education on safe driving behavior should be available.

Multiphase flow in geometrically simple fracture intersections

USGS Publications Warehouse

Basagaoglu, H.; Meakin, P.; Green, C.T.; Mathew, M.; ,

2006-01-01

A two-dimensional lattice Boltzmann (LB) model with fluid-fluid and solid-fluid interaction potentials was used to study gravity-driven flow in geometrically simple fracture intersections. Simulated scenarios included fluid dripping from a fracture aperture, two-phase flow through intersecting fractures and thin-film flow on smooth and undulating solid surfaces. Qualitative comparisons with recently published experimental findings indicate that for these scenarios the LB model captured the underlying physics reasonably well.

UpSetR: an R package for the visualization of intersecting sets and their properties

PubMed Central

Conway, Jake R.; Lex, Alexander; Gehlenborg, Nils

2017-01-01

Abstract Motivation: Venn and Euler diagrams are a popular yet inadequate solution for quantitative visualization of set intersections. A scalable alternative to Venn and Euler diagrams for visualizing intersecting sets and their properties is needed. Results: We developed UpSetR, an open source R package that employs a scalable matrix-based visualization to show intersections of sets, their size, and other properties. Availability and implementation: UpSetR is available at https://github.com/hms-dbmi/UpSetR/ and released under the MIT License. A Shiny app is available at https://gehlenborglab.shinyapps.io/upsetr/. Contact: nils@hms.harvard.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:28645171

Matching shapes with self-intersections: application to leaf classification.

PubMed

Mokhtarian, Farzin; Abbasi, Sadegh

2004-05-01

We address the problem of two-dimensional (2-D) shape representation and matching in presence of self-intersection for large image databases. This may occur when part of an object is hidden behind another part and results in a darker section in the gray level image of the object. The boundary contour of the object must include the boundary of this part which is entirely inside the outline of the object. The Curvature Scale Space (CSS) image of a shape is a multiscale organization of its inflection points as it is smoothed. The CSS-based shape representation method has been selected for MPEG-7 standardization. We study the effects of contour self-intersection on the Curvature Scale Space image. When there is no self-intersection, the CSS image contains several arch shape contours, each related to a concavity or a convexity of the shape. Self intersections create contours with minima as well as maxima in the CSS image. An efficient shape representation method has been introduced in this paper which describes a shape using the maxima as well as the minima of its CSS contours. This is a natural generalization of the conventional method which only includes the maxima of the CSS image contours. The conventional matching algorithm has also been modified to accommodate the new information about the minima. The method has been successfully used in a real world application to find, for an unknown leaf, similar classes from a database of classified leaf images representing different varieties of chrysanthemum. For many classes of leaves, self-intersection is inevitable during the scanning of the image. Therefore the original contributions of this paper is the generalization of the Curvature Scale Space representation to the class of 2-D contours with self-intersection, and its application to the classification of Chrysanthemum leaves.

Influences of motorcycle rider and driver characteristics and road environment on red light running behavior at signalized intersections.

PubMed

Jensupakarn, Auearree; Kanitpong, Kunnawee

2018-04-01

In Thailand, red light running is considered as one of the most dangerous behaviors at intersection. Red light running (RLR) behavior is the failure to obey the traffic control signal. However, motorcycle riders and car drivers who are running through red lights could be influenced by human factors or road environment at intersection. RLR could be advertent or inadvertent behavior influenced by many factors. Little research study has been done to evaluate the contributing factors influencing the red-light violation behavior. This study aims to determine the factors influencing the red light running behavior including human characteristics, physical condition of intersection, traffic signal operation, and traffic condition. A total of 92 intersections were observed in Chiang Mai, Nakhon Ratchasima, and Chonburi, the major provinces in each region of Thailand. In addition, the socio-economic characteristics of red light runners were obtained from self-reported questionnaire survey. The Binary Logistic Regression and the Multiple Linear Regression models were used to determine the characteristics of red light runners and the factors influencing rates of red light running respectively. The results from this study can help to understand the characteristics of red light runners and factors affecting them to run red lights. For motorcycle riders and car drivers, age, gender, occupation, driving license, helmet/seatbelt use, and the probability to be penalized when running the red light significantly affect RLR behavior. In addition, the results indicated that vehicle travelling direction, time of day, existence of turning lane, number of lanes, lane width, intersection sight distance, type of traffic signal pole, type of traffic signal operation, length of yellow time interval, approaching speed, distance from intersection warning sign to stop line, and pavement roughness significantly affect RLR rates. Copyright © 2018 Elsevier Ltd. All rights reserved.

Intersectional health-related stigma in persons living with HIV and chronic pain: implications for depressive symptoms.

PubMed

Goodin, Burel R; Owens, Michael A; White, Dyan M; Strath, Larissa J; Gonzalez, Cesar; Rainey, Rachael L; Okunbor, Jennifer I; Heath, Sonya L; Turan, Janet M; Merlin, Jessica S

2018-05-30

"Intersectional health-related stigma" (IHRS) refers to stigma that arises at the convergence of multiple health conditions. People living with HIV (PLWH) and chronic pain have two highly stigmatized health conditions, and thus may be at especially high risk for internalizing these stigmas and consequently experiencing depression. This study examined the intersectionality of internalized HIV and chronic pain stigma in relation to depressive symptoms in a sample of PLWH and chronic pain. Sixty participants were recruited from an HIV clinic in the Southeastern United States. Chronic pain was defined as pain that has been present for at least three consecutive months, and that has been an ongoing problem for at least half the days in the past six months. All participants completed the HIV Stigma Mechanisms Scale, Internalized Stigma in Chronic Pain Scale, the Short-Form Brief Pain Inventory, and the Center for Epidemiological Studies - Depression Scale. Clinical data was collected from medical records. An intersectional HIV and chronic pain composite variable was created and participants were categorized as either high (28%), moderate (32%), or low (40%). Results revealed that intersectional HIV and chronic pain stigma was significantly associated with severity of depressive symptoms (p = .023). Pairwise contrasts revealed that participants with high (p = .009) and moderate (p = .033) intersectional stigma reported significantly greater mean depressive symptom severity than those with low intersectional stigma. Participants who reported the highest levels of internalized HIV and chronic pain stigma also reported the greatest severity of depressive symptoms. This suggests that the experience of both HIV and chronic pain stigma (i.e., IHRS) among PLWH and chronic pain may synergistically perpetuate negative mood in a more profound manner than experiencing either one stigma alone.

Long-Range Emergency Preemption of Traffic Lights

NASA Technical Reports Server (NTRS)

Bachelder, Aaron

2005-01-01

A forwarding system could prove beneficial as an addition to an electronic communication-and-control system that automatically modifies the switching of traffic lights to give priority to emergency vehicles. A system to which the forwarding system could be added could be any of a variety of emergency traffic-signal-preemption systems: these include systems now used in some municipalities as well as advanced developmental systems described in several NASA Tech Briefs articles in recent years. Because of a variety of physical and design limitations, emergency traffic-signal- preemption systems now in use are often limited in range to only one intersection at a time: in a typical system, only the next, closest intersection is preempted for an emergency vehicle. Simulations of gridlock have shown that such systems offer minimal advantages and can even cause additional delays. In analogy to what happens in fluid dynamics, the forwarding system insures that flow at a given location is sustained by guaranteeing downstream flow along the predicted route (typically a main artery) and intersecting routes (typically, side streets). In simplest terms, the forwarding system starts by taking note of any preemption issued by the preemption system to which it has been added. The forwarding system predicts which other intersections could be encountered by the emergency vehicle downstream of the newly preempted intersection. The system then forwards preemption triggers to those intersections. Beyond affording a right of way for the emergency vehicle at every intersection that lies ahead along any likely route from the current position of the vehicle, the forwarding system also affords the benefit of clearing congested roads far ahead of the vehicle. In a metropolitan environment with heavy road traffic, forwarding of preemption triggers could greatly enhance the performance of a pre-existing preemption system.

Intersection Monitor for Traffic-Light-Preemption System

NASA Technical Reports Server (NTRS)

Bachelder, Aaron; Foster, Conrad

2006-01-01

The figure shows an intersection monitor that is a key subsystem of an emergency traffic-light-preemption system that could be any of the systems described in the three immediately preceding articles and in Systems Would Preempt Traffic Lights for Emergency Vehicles (NPO-30573), NASA Tech Briefs, Vol. 28, No. 10 (October 2004), page 36. This unit is so named because it is installed at an intersection, where it monitors the phases (in the sense of timing) of the traffic lights. The mode of operation of this monitor is independent of the type of traffic-light-controller hardware or software in use at the intersection. Moreover, the design of the monitor is such that (1) the monitor does not, by itself, affect the operation of the traffic- light controller and (2) in the event of a failure of the monitor, the trafficlight controller continues to function normally (albeit without preemption). The monitor is installed in series with the traffic-light controller at an intersection. The control signals of interest are monitored by use of high-impedance taps on affected control lines. These taps are fully isolated and further protected by high-voltage diodes that prevent any voltages or short circuits that arise within the monitor from affecting the controller. The signals from the taps are processed digitally and cleaned up by use of high-speed logic gates, and the resulting data are passed on to other parts of the traffic-light-preemption intersection subsystem. The data are compared continuously with data from vehicles and used to calculate timing for reliable preemption of the traffic lights. The pedestrian crossing at the intersection is also monitored, and pedestrians are warned not to cross during preemption.

Time-series analysis to study the impact of an intersection on dispersion along a street canyon.

PubMed

Richmond-Bryant, Jennifer; Eisner, Alfred D; Hahn, Intaek; Fortune, Christopher R; Drake-Richman, Zora E; Brixey, Laurie A; Talih, M; Wiener, Russell W; Ellenson, William D

2009-12-01

This paper presents data analysis from the Brooklyn Traffic Real-Time Ambient Pollutant Penetration and Environmental Dispersion (B-TRAPPED) study to assess the transport of ultrafine particulate matter (PM) across urban intersections. Experiments were performed in a street canyon perpendicular to a highway in Brooklyn, NY, USA. Real-time ultrafine PM samplers were positioned on either side of an intersection at multiple locations along a street to collect time-series number concentration data. Meteorology equipment was positioned within the street canyon and at an upstream background site to measure wind speed and direction. Time-series analysis was performed on the PM data to compute a transport velocity along the direction of the street for the cases where background winds were parallel and perpendicular to the street. The data were analyzed for sampler pairs located (1) on opposite sides of the intersection and (2) on the same block. The time-series analysis demonstrated along-street transport, including across the intersection when background winds were parallel to the street canyon and there was minimal transport and no communication across the intersection when background winds were perpendicular to the street canyon. Low but significant values of the cross-correlation function (CCF) underscore the turbulent nature of plume transport along the street canyon. The low correlations suggest that flow switching around corners or traffic-induced turbulence at the intersection may have aided dilution of the PM plume from the highway. This observation supports similar findings in the literature. Furthermore, the time-series analysis methodology applied in this study is introduced as a technique for studying spatiotemporal variation in the urban microscale environment.

Influential factors of red-light running at signalized intersection and prediction using a rare events logistic regression model.

PubMed

Ren, Yilong; Wang, Yunpeng; Wu, Xinkai; Yu, Guizhen; Ding, Chuan

2016-10-01

Red light running (RLR) has become a major safety concern at signalized intersection. To prevent RLR related crashes, it is critical to identify the factors that significantly impact the drivers' behaviors of RLR, and to predict potential RLR in real time. In this research, 9-month's RLR events extracted from high-resolution traffic data collected by loop detectors from three signalized intersections were applied to identify the factors that significantly affect RLR behaviors. The data analysis indicated that occupancy time, time gap, used yellow time, time left to yellow start, whether the preceding vehicle runs through the intersection during yellow, and whether there is a vehicle passing through the intersection on the adjacent lane were significantly factors for RLR behaviors. Furthermore, due to the rare events nature of RLR, a modified rare events logistic regression model was developed for RLR prediction. The rare events logistic regression method has been applied in many fields for rare events studies and shows impressive performance, but so far none of previous research has applied this method to study RLR. The results showed that the rare events logistic regression model performed significantly better than the standard logistic regression model. More importantly, the proposed RLR prediction method is purely based on loop detector data collected from a single advance loop detector located 400 feet away from stop-bar. This brings great potential for future field applications of the proposed method since loops have been widely implemented in many intersections and can collect data in real time. This research is expected to contribute to the improvement of intersection safety significantly. Copyright © 2016 Elsevier Ltd. All rights reserved.

Platinum-group elements, S, Se and Cu in highly depleted abyssal peridotites from the Mid-Atlantic Ocean Ridge (ODP Hole 1274A): Influence of hydrothermal and magmatic processes

NASA Astrophysics Data System (ADS)

Marchesi, Claudio; Garrido, Carlos J.; Harvey, Jason; González-Jiménez, José María; Hidas, Károly; Lorand, Jean-Pierre; Gervilla, Fernando

2013-11-01

Highly depleted harzburgites and dunites were recovered from ODP Hole 1274A, near the intersection between the Mid-Atlantic Ocean Ridge and the 15°20'N Fracture Zone. In addition to high degrees of partial melting, these peridotites underwent multiple episodes of melt-rock reaction and intense serpentinization and seawater alteration close to the seafloor. Low concentrations of Se, Cu and platinum-group elements (PGE) in harzburgites drilled at around 35-85 m below seafloor are consistent with the consumption of mantle sulfides after high degrees (>15-20 %) of partial melting and redistribution of chalcophile and siderophile elements into PGE-rich residual microphases. Higher concentrations of Cu, Se, Ru, Rh and Pd in harzburgites from the uppermost and lowest cores testify to late reaction with a sulfide melt. Dunites were formed by percolation of silica- and sulfur-undersaturated melts into low-Se harzburgites. Platinum-group and chalcophile elements were not mobilized during dunite formation and mostly preserve the signature of precursor harzburgites, except for higher Ru and lower Pt contents caused by precipitation and removal of platinum-group minerals. During serpentinization at low temperature (<250 °C) and reducing conditions, mantle sulfides experienced desulfurization to S-poor sulfides (mainly heazlewoodite) and awaruite. Contrary to Se and Cu, sulfur does not record the magmatic evolution of peridotites but was mostly added in hydrothermal sulfides and sulfate from seawater. Platinum-group elements were unaffected by post-magmatic low-temperature processes, except Pt and Pd that may have been slightly remobilized during oxidative seawater alteration.

Helicopter rotor wake geometry and its influence in forward flight. Volume 2: Wake geometry charts

NASA Technical Reports Server (NTRS)

Egolf, T. A.; Landgrebe, A. J.

1983-01-01

Isometric and projection view plots, inflow ratio nomographs, undistorted axial displacement nomographs, undistorted longitudinal and lateral coordinates, generalized axial distortion nomographs, blade/vortex passage charts, blade/vortex intersection angle nomographs, and fore and aft wake boundary charts are discussed. Example condition, in flow ratio, undistorted axial location, longitudinal and lateral coordinates, axial coordinates distortions, blade/tip vortex intersections, angle of intersection, and fore and aft wake boundaries are also discussed.

Effects of countdown timers on driver behavior after the yellow onset at Chinese intersections.

PubMed

Long, Kejun; Han, Lee D; Yang, Qiang

2011-10-01

Few studies have focused on the effect of countdown timers at signalized intersections in China, where such timers are widely deployed for their perceived benefits of increased safety and capacity. This study examines the effect of countdown timers on driver behavior during the yellow interval. Signal phasing and traffic operations were videotaped at 4 comparable signalized intersections under normal conditions. Microscopic details were extracted manually at 25 Hz to yield 24 h of data on onset time of the yellow, onset time of the red, driver location and actions after the onset of the yellow, red light-running violations, etc. For comparable intersections with and without countdown timers, driver behavior measured by driver decision (stop or go) and vehicle entry time (when the vehicle crosses the stop line) were analyzed using binary logistical regression (BLR) and a nonparametric test, respectively. The results suggest that countdown timers can indeed influence driver behaviors, in terms of decisions to stop or cross the intersection as well as the distribution of vehicle entry times. There was a strong correlation between the presence of countdown timers and an increase in red light violations. Countdown timers may lead to increased entrance into the intersection during the later portions of the yellow and even the red. This alarming finding calls for further research as well as for serious consideration before the field deployment of countdown timers.

Inter-categorical intersectionality and leisure-based physical activity in Canada.

PubMed

Abichahine, Hayfa; Veenstra, Gerry

2017-08-01

Leisure-based physical activity is socially stratified in Canada. To date, inequalities in physical activity by race or ethnicity, gender, class or sexual orientation, in Canada and elsewhere, have largely been investigated as distinct, additive phenomena. Informed by intersectionality theory, this paper examines whether racial identity, gender, class and sexuality 'intersect' with one another to predict physical activity in data from Cycles 2.1 and 3.1 of the Canadian Community Health Survey (n= 149 574). In particular, we apply the intersectional principle of multiplicativity which suggests that people's experiences of their gender identities are raced, classed and sexualized; their racial experiences are gendered, classed and sexualized, and so forth. We find that the positive effect of income on being physically active is strong among visible minority men, of moderate strength among White men and women and weak to non-existent among visible minority women. We also find that a lesbian, gay or bisexual orientation corresponds with a higher likelihood of being physically active among women (especially among less educated women) but not among men. These multiplicative findings undermine additive approaches to investigating social inequalities in leisure-based physical activity and pave the way for future intersectional analyses of axes of inequality and their diverse, intersecting effects. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Driving simulator evaluation of drivers' response to intersections with dynamic use of exit-lanes for left-turn.

PubMed

Zhao, Jing; Yun, Meiping; Zhang, H Michael; Yang, Xiaoguang

2015-08-01

With the worsening of urban traffic congestion in large cities around the world, researchers have been looking for unconventional designs and/or controls to squeeze more capacity out of intersections, the most common bottlenecks of the road network. One of these innovative intersection designs, known as the exit-lanes for left-turn (EFL), opens up exit-lanes to be used by left-turn traffic with the help of an additional traffic light installed at the median opening (the pre-signal). This paper studies how drivers respond to EFL intersections with a series of driving simulator experiments. In our experiments, 64 drivers were recruited and divided into two groups. One group is trained to use the EFL while the other group is not. In addition, four scenarios were considered with different sign and marking designs and traffic conditions in the experiments. Results indicate that drivers show certain amount of confusion and hesitation when encountering an EFL intersection for the first time. They can be overcome, however, by increasing exposure through driver education or by cue provided from other vehicles. Moreover, drivers unfamiliar with EFL operation can make a left turn using the conventional left-turn lanes as usual. The EFL operation is not likely to pose any serious safety risk of the intersection in real life operations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Numerical simulation on pollutant dispersion from vehicle exhaust in street configurations.

PubMed

Yassin, Mohamed F; Kellnerová, R; Janour, Z

2009-09-01

The impact of the street configurations on pollutants dispersion from vehicles exhausts within urban canyons was numerically investigated using a computational fluid dynamics (CFD) model. Three-dimensional flow and dispersion of gaseous pollutants were modeled using standard kappa - epsilon turbulence model, which was numerically solved based on Reynolds-averaged Navier-Stokes equations by the commercial CFD code FLUENT. The concentration fields in the urban canyons were examined in three cases of street configurations: (1) a regular-shaped intersection, (2) a T-shaped intersection and (3) a Skew-shaped crossing intersection. Vehicle emissions were simulated as double line sources along the street. The numerical model was validated against wind tunnel results in order to optimize the turbulence model. Numerical predictions agreed reasonably well with wind tunnel results. The results obtained indicate that the mean horizontal velocity was very small in the center near the lower region of street canyon. The lowest turbulent kinetic energy was found at the separation and reattachment points associated with the corner of the down part of the upwind and downwind buildings in the street canyon. The pollutant concentration at the upwind side in the regular-shaped street intersection was higher than that in the T-shaped and Skew-shaped street intersections. Moreover, the results reveal that the street intersections are important factors to predict the flow patterns and pollutant dispersion in street canyon.

Multi-Party Privacy-Preserving Set Intersection with Quasi-Linear Complexity

NASA Astrophysics Data System (ADS)

Cheon, Jung Hee; Jarecki, Stanislaw; Seo, Jae Hong

Secure computation of the set intersection functionality allows n parties to find the intersection between their datasets without revealing anything else about them. An efficient protocol for such a task could have multiple potential applications in commerce, health care, and security. However, all currently known secure set intersection protocols for n>2 parties have computational costs that are quadratic in the (maximum) number of entries in the dataset contributed by each party, making secure computation of the set intersection only practical for small datasets. In this paper, we describe the first multi-party protocol for securely computing the set intersection functionality with both the communication and the computation costs that are quasi-linear in the size of the datasets. For a fixed security parameter, our protocols require O(n2k) bits of communication and Õ(n2k) group multiplications per player in the malicious adversary setting, where k is the size of each dataset. Our protocol follows the basic idea of the protocol proposed by Kissner and Song, but we gain efficiency by using different representations of the polynomials associated with users' datasets and careful employment of algorithms that interpolate or evaluate polynomials on multiple points more efficiently. Moreover, the proposed protocol is robust. This means that the protocol outputs the desired result even if some corrupted players leave during the execution of the protocol.

The diversity of gendered adaptation strategies to climate change of Indian farmers: A feminist intersectional approach.

PubMed

Ravera, Federica; Martín-López, Berta; Pascual, Unai; Drucker, Adam

2016-12-01

This paper examines climate change adaptation and gender issues through an application of a feminist intersectional approach. This approach permits the identification of diverse adaptation responses arising from the existence of multiple and fragmented dimensions of identity (including gender) that intersect with power relations to shape situation-specific interactions between farmers and ecosystems. Based on results from contrasting research cases in Bihar and Uttarakhand, India, this paper demonstrates, inter alia, that there are geographically determined gendered preferences and adoption strategies regarding adaptation options and that these are influenced by the socio-ecological context and institutional dynamics. Intersecting identities, such as caste, wealth, age and gender, influence decisions and reveal power dynamics and negotiation within the household and the community, as well as barriers to adaptation among groups. Overall, the findings suggest that a feminist intersectional approach does appear to be useful and worth further exploration in the context of climate change adaptation. In particular, future research could benefit from more emphasis on a nuanced analysis of the intra-gender differences that shape adaptive capacity to climate change.

Intersection-Controller Software Module

NASA Technical Reports Server (NTRS)

Bachelder, Aaron; Foster, Conrad

2005-01-01

An important part of the emergency-vehicle traffic-light-preemption system summarized in the preceding article is a software module executed by a microcontroller in each intersection controller. This module monitors the broadcasts from all nearby participating emergency vehicles and intersections. It gathers the broadcast data pertaining to the positions and velocities of the vehicles and the timing of traffic and pedestrian lights and processes the data into predictions of the future positions of the vehicles. Analyzing the predictions by a combination of proximity tests, map-matching techniques, and statistical calculations designed to minimize the adverse effects of uncertainties in vehicle positions and headings, the module decides whether to preempt and issues the appropriate commands to the traffic lights, pedestrian lights, and electronic warning signs at the intersection. The module also broadcasts its state to all nearby vehicles and intersections. The module is designed to mitigate the effects of missing data and of unpredictable delays in the system. It has been intensively tested and refined so that it fails to warn in very few cases and issues very few false warnings.

Problematizing Social Justice in Health Pedagogy and Youth Sport: Intersectionality of Race, Ethnicity, and Class.

PubMed

Dagkas, Symeon

2016-09-01

Social justice education recognizes the discrepancies in opportunities among disadvantaged groups in society. The purpose of the articles in this special topic on social justice is to (a) provide a critical reflection on issues of social justice within health pedagogy and youth sport of Black and ethnic-minority (BME) young people; (b) provide a framework for the importance of intersectionality research (mainly the intersection of social class, race, and ethnicity) in youth sport and health pedagogy for social justice; and (c) contextualize the complex intersection and interplay of social issues (i.e., race, ethnicity, social classes) and their influence in shaping physical culture among young people with a BME background. The article argues that there are several social identities in any given pedagogical terrain that need to be heard and legitimized to avoid neglect and "othering." This article suggests that a resurgence of interest in theoretical frameworks such as intersectionality can provide an effective platform to legitimize "non-normative bodies" (diverse bodies) in health pedagogy and physical education and sport by voicing positionalities on agency and practice.

Evaluation of the dispersion effect in through movement bicycles at signalized intersection via cellular automata simulation

NASA Astrophysics Data System (ADS)

Jiang, Hang; Ma, Yongjian; Jiang, Lin; Chen, Guozhou; Wang, Dongwei

2018-05-01

At signalized intersection areas, bicycle traffic presents a dispersion feature which may influence the movements of vehicles during peak period. The primary objective of this study is to simulate the dispersion effect in through-movement bicycle traffic at intersection areas and evaluate its influence on through-movement traffic. A cellular automata (CA) model is developed and validated to simulate the operations of through-movement bicycle traffic departing from two types of intersection approaches. Simulation results show that bicycles benefit from the dispersion effect when they depart from the approach with an exclusive right-turn vehicle lane. But when bicycles travel from the approach with a shared right-turn and through vehicle lane, the dispersion effect will result in friction interference and block interference on through-movement vehicles. Bicycle interferences reduce the vehicle speed and increase the delay of through-movement vehicles. The policy implications in regard to the dispersion effect from two types of approaches are discussed to improve the performance of through-movement traffic operations at signalized intersections.

Wind tunnel measurements of pollutant turbulent fluxes in urban intersections

NASA Astrophysics Data System (ADS)

Carpentieri, Matteo; Hayden, Paul; Robins, Alan G.

2012-01-01

Wind tunnel experiments have been carried out at the EnFlo laboratory to measure mean and turbulent tracer fluxes in geometries of real street canyon intersections. The work was part of the major DAPPLE project, focussing on the area surrounding the intersection between Marylebone Road and Gloucester Place in Central London, UK. Understanding flow and dispersion in urban streets is a very important issue for air quality management and planning, and turbulent mass exchange processes are important phenomena that are very often neglected in urban modelling studies. The adopted methodology involved the combined use of laser Doppler anemometry and tracer concentration measurements. This methodology was applied to quantify the mean and turbulent flow and dispersion fields within several street canyon intersections. Vertical profiles of turbulent tracer flux were also measured. The technique, despite a number of limitations, proved reliable and allowed tracer balance calculations to be undertaken in the selected street canyon intersections. The experience gained in this work will enable much more precise studies in the future as issues affecting the accuracy of the experimental technique have been identified and resolved.

Analytical solutions of the two-dimensional Dirac equation for a topological channel intersection

NASA Astrophysics Data System (ADS)

Anglin, J. R.; Schulz, A.

2017-01-01

Numerical simulations in a tight-binding model have shown that an intersection of topologically protected one-dimensional chiral channels can function as a beam splitter for noninteracting fermions on a two-dimensional lattice [Qiao, Jung, and MacDonald, Nano Lett. 11, 3453 (2011), 10.1021/nl201941f; Qiao et al., Phys. Rev. Lett. 112, 206601 (2014), 10.1103/PhysRevLett.112.206601]. Here we confirm this result analytically in the corresponding continuum k .p model, by solving the associated two-dimensional Dirac equation, in the presence of a "checkerboard" potential that provides a right-angled intersection between two zero-line modes. The method by which we obtain our analytical solutions is systematic and potentially generalizable to similar problems involving intersections of one-dimensional systems.

Cellular-based preemption system

NASA Technical Reports Server (NTRS)

Bachelder, Aaron D. (Inventor)

2011-01-01

A cellular-based preemption system that uses existing cellular infrastructure to transmit preemption related data to allow safe passage of emergency vehicles through one or more intersections. A cellular unit in an emergency vehicle is used to generate position reports that are transmitted to the one or more intersections during an emergency response. Based on this position data, the one or more intersections calculate an estimated time of arrival (ETA) of the emergency vehicle, and transmit preemption commands to traffic signals at the intersections based on the calculated ETA. Additional techniques may be used for refining the position reports, ETA calculations, and the like. Such techniques include, without limitation, statistical preemption, map-matching, dead-reckoning, augmented navigation, and/or preemption optimization techniques, all of which are described in further detail in the above-referenced patent applications.

Understanding Mental Illness Stigma Toward Persons With Multiple Stigmatized Conditions: Implications of Intersectionality Theory.

PubMed

Oexle, Nathalie; Corrigan, Patrick W

2018-05-01

People with mental illness are often members of multiple stigmatized social groups. Therefore, experienced disadvantage might not be determined solely by mental illness stigma. Nevertheless, most available research does not consider the effects and implications of membership in multiple stigmatized social groups among people with mental illness. Reflecting on intersectionality theory, the authors discuss two intersectional effects determining disadvantage among people with mental illness who are members of multiple stigmatized social groups, namely double disadvantage and prominence. To be effective, interventions to reduce disadvantage experienced by people with mental illness need to be flexible and targeted rather than universal in order to address the implications of intersectionality. Whereas education-based approaches usually assume homogeneity and use universal strategies, contact-based interventions consider diversity among people with mental illness.

Selective detection and characterization of nanoparticles from motor vehicles.

PubMed

Johnston, Murray V; Klems, Joseph P; Zordan, Christopher A; Pennington, M Ross; Smith, James N

2013-02-01

Numerous studies have shown that exposure to motor vehicle emissions increases the probability of heart attacks, asthma attacks, and hospital visits among at-risk individuals. However, while many studies have focused on measurements of ambient nanoparticles near highways, they have not focused on specific road-level domains, such as intersections near population centers. At these locations, very intense spikes in particle number concentration have been observed. These spikes have been linked to motor vehicle activity and have the potential to increase exposure dramatically. Characterizing both the contribution and composition of these spikes is critical in developing exposure models and abatement strategies. To determine the contribution of the particle spikes to the ambient number concentration, we implemented wavelet-based algorithms to isolate the particle spikes from measurements taken during the summer and winter of 2009 in Wilmington, Delaware, adjacent to a roadway intersection that approximately 28,000 vehicles pass through daily. These measurements included both number concentration and size distributions recorded once every second by a condensation particle counter (CPC*; TSI, Inc., St. Paul, MN) and a fast mobility particle sizer (FMPS). The high-frequency portion of the signal, consisting of a series of abrupt spikes in number concentration that varied in length from a few seconds to tens of seconds, accounted for 3% to 35% of the daily ambient number concentration, with spike contributions sometimes greater than 50% of hourly number concentrations. When the data were weighted by particle volume, this portion of the signal contributed an average of 10% to 20% to the daily concentration of particulate matter (PM) < or = 0.1 microm in aerodynamic diameter (PM0.1). The preferred locations for observing particle concentration spikes were those surrounding the measurement site at which motor vehicles accelerated after a red traffic light turned green. As the distance or transit time from emission to sampling increased, the size distribution shifted to a larger particle size, which confirmed the source assignments. To determine the distribution of emissions from individual vehicles, we correlated camera images with the spike contribution to particle number concentration at each time point. A small percentage of motor vehicles were found to emit a disproportionally large concentration of nanoparticles, and these high emitters included both spark-ignition (SI) and heavy-duty diesel (HDD) vehicles. In addition to characterizing the contribution of the spikes (local sources) to the ambient number concentration, we developed a method to determine the net contribution of motor vehicles (all sources) to the total mass concentration of ambient nanoparticles. To do this, we correlated the concentration of spikes with measurements of fast changes in the chemical composition of nanoparticles measured with the nano aerosol mass spectrometer (NAMS; built by the Johnston group). The NAMS irradiates individual, size-selected nanoparticles with a high-energy laser pulse to generate a mass spectrum consisting of multiply charged atomic ions. The elemental composition of each particle was determined from the ion signal intensities of each element. However, overlapping mass-to-charge ratios (m/z) at 4 m/z (O(+4) and C(+3)) and at 8 m/z (O(+2) and S(+4)) needed to be separated into their component ions to obtain a representative composition. To do this, we developed a method to deconvolute these ion signals using sucrose and ammonium sulfate [(NH4)2SO4] as calibration standards. With this approach, the differences between the expected and measured elemental mole fractions of carbon (C), oxygen (O), nitrogen (N), and sulfur (S) for a variety of test particles were generally much less than 10%. Ambient nanoparticles were found to consist mostly of C, O, N, and S. Many particles also contained silicon (Si). The elemental compositions were apportioned into molecular species that are commonly found in ambient aerosol: sulfate (SO4(2-)), nitrate (NO3-), ammonium (NH4+), carbonaceous matter, and when present, silicon dioxide (SiO2). Correlating NAMS chemical-composition measurements with spike contributions allowed for the development of a chemical profile representing motor vehicle emissions, which could be used to apportion their total contribution to the ambient nanoparticle mass. Particles originating from motor vehicles had compositions dominated by unoxidized carbonaceous matter, whereas non-motor vehicle particles consisted mostly of SO42-, NO3-, and oxidized carbonaceous matter. Motor vehicles were found to contribute up to 48% and 60% of the nanoparticle mass and number concentrations, respectively, in the winter measurement period, but only 16% and 49% of the nanoparticle mass and number concentrations, respectively, in the summer period. Chemical-composition profiles and contributions of SI versus HDD vehicles to the nanoparticle mass concentration were estimated by correlating still camera images, chemical composition, and spike contributions at each time point. The total mass contributions from SI and HDD vehicles were roughly equal, but the uncertainty in the split was large. The results of this study suggest that nanoparticle concentrations will be higher adjacent to an intersection than along the same roadway but further from an intersection. Possible ways to reduce the motor vehicle contribution to ambient nanoparticulate matter include minimizing stop-and-go activity at an intersection (i.e., vehicles accelerating after a red light turns green) and identifying the small fraction of motor vehicles that emit a disproportionally large number of nanoparticles.

Structural crashworthiness; International Symposium, 1st, University of Liverpool, Liverpool, England, September 14-16, 1983, Invited Lectures

NASA Astrophysics Data System (ADS)

Jones, N.; Wierzbicki, T.

The application of solid, structural, and experimental mechanics to predict the crumpling behavior and energy absorption of thin-walled structures under quasi-static compression and various dynamic crash loadings is examined in reviews of current research. Both fundamental aspects and specific problems in the design of crashworthy aircraft, automobiles, railroad cars, ships, and offshore installations are considered. Topics discussed include laterally compressed metal tubes as impact-energy absorbers, crushing behavior of plate intersections, axial crushing of fiber-reinforced composite tubes, finite-element analysis of structural crashworthiness in the automotive and aerospace industries, crash behavior of aircraft fuselage structures, aircraft crash analysis, ship collisions, and structural damage in airship and rolling-stock collisions. Photographs, graphs, drawings, and diagrams are provided.

Automatic contact in DYNA3D for vehicle crashworthiness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whirley, R.G.; Engelmann, B.E.

1993-07-15

This paper presents a new formulation for the automatic definition and treatment of mechanical contact in explicit nonlinear finite element analysis. Automatic contact offers the benefits of significantly reduced model construction time and fewer opportunities for user error, but faces significant challenges in reliability and computational costs. This paper discusses in detail a new four-step automatic contact algorithm. Key aspects of the proposed method include automatic identification of adjacent and opposite surfaces in the global search phase, and the use of a smoothly varying surface normal which allows a consistent treatment of shell intersection and corner contact conditions without ad-hocmore » rules. The paper concludes with three examples which illustrate the performance of the newly proposed algorithm in the public DYNA3D code.« less

Gamification: The Intersection between Behavior Analysis and Game Design Technologies.

PubMed

Morford, Zachary H; Witts, Benjamin N; Killingsworth, Kenneth J; Alavosius, Mark P

2014-05-01

Deterding et al. (Proceedings of the 15th International Academic MindTrek Conference: Envisioning Future Media Environments, USA 15: 9-15, 2011) report a recent rise in popularity of video game inspired software designed to address issues in a variety of areas, including health, energy conservation, education, and business. These applications have been based on the concept of gamification, which involves a process by which nongame activities are designed to be more like a game. We provide examples of how gamification has been used to increase health-related behavior, energy consumption, academic performance, and other socially-significant behavior. We argue that behavior analytic research and practice stands to benefit from incorporating successful elements of game design. Lastly, we provide suggestions for behavior analysts regarding applied and basic research related to gamification.

Transverse pumped laser amplifier architecture

DOEpatents

Bayramian, Andrew James; Manes, Kenneth R.; Deri, Robert; Erlandson, Alvin; Caird, John; Spaeth, Mary L.

2015-05-19

An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

Huygens-Fresnel Acoustic Interference and the Development of Robust Time-Averaged Patterns from Traveling Surface Acoustic Waves

NASA Astrophysics Data System (ADS)

Devendran, Citsabehsan; Collins, David J.; Ai, Ye; Neild, Adrian

2017-04-01

Periodic pattern generation using time-averaged acoustic forces conventionally requires the intersection of counterpropagating wave fields, where suspended micro-objects in a microfluidic system collect along force potential minimizing nodal or antinodal lines. Whereas this effect typically requires either multiple transducer elements or whole channel resonance, we report the generation of scalable periodic patterning positions without either of these conditions. A single propagating surface acoustic wave interacts with the proximal channel wall to produce a knife-edge effect according to the Huygens-Fresnel principle, where these cylindrically propagating waves interfere with classical wave fronts emanating from the substrate. We simulate these conditions and describe a model that accurately predicts the lateral spacing of these positions in a robust and novel approach to acoustic patterning.

Transverse pumped laser amplifier architecture

DOEpatents

Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

2013-07-09

An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

Optimal solar sail planetocentric trajectories

NASA Technical Reports Server (NTRS)

Sackett, L. L.

1977-01-01

The analysis of solar sail planetocentric optimal trajectory problem is described. A computer program was produced to calculate optimal trajectories for a limited performance analysis. A square sail model is included and some consideration is given to a heliogyro sail model. Orbit to a subescape point and orbit to orbit transfer are considered. Trajectories about the four inner planets can be calculated and shadowing, oblateness, and solar motion may be included. Equinoctial orbital elements are used to avoid the classical singularities, and the method of averaging is applied to increase computational speed. Solution of the two-point boundary value problem which arises from the application of optimization theory is accomplished with a Newton procedure. Time optimal trajectories are emphasized, but a penalty function has been considered to prevent trajectories which intersect a planet's surface.

Intersection of Southern Parkway and Southern Heights, looking toward the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Intersection of Southern Parkway and Southern Heights, looking toward the Beechmont Historic District, showing changes in landscaping, northeast - Southern Heights-Beechmont District Landscapes, Louisville, Jefferson County, KY

Improving Pedestrian Safety at Signalized Intersections

DOT National Transportation Integrated Search

2012-06-01

Our research investigated methods and technologies to make signalized intersections safer for pedestrians using the capabilities : of accessible pedestrian systems. Our research focused on three technologies: acoustic beaconing, passive pedestrian de...

Training strategies and materials.

DOT National Transportation Integrated Search

2008-08-01

TxDOT project 0-5840 Development of Left-Turn Operations Guidelines at Signalized Intersections has developed : guidelines for recommending the most appropriate left-turn phasing treatments at signalized intersections by investigating all : asp...

Method for Assessment of Changes in the Width of Cracks in Cement Composites with Use of Computer Image Processing and Analysis

NASA Astrophysics Data System (ADS)

Tomczak, Kamil; Jakubowski, Jacek; Fiołek, Przemysław

2017-06-01

Crack width measurement is an important element of research on the progress of self-healing cement composites. Due to the nature of this research, the method of measuring the width of cracks and their changes over time must meet specific requirements. The article presents a novel method of measuring crack width based on images from a scanner with an optical resolution of 6400 dpi, subject to initial image processing in the ImageJ development environment and further processing and analysis of results. After registering a series of images of the cracks at different times using SIFT conversion (Scale-Invariant Feature Transform), a dense network of line segments is created in all images, intersecting the cracks perpendicular to the local axes. Along these line segments, brightness profiles are extracted, which are the basis for determination of crack width. The distribution and rotation of the line of intersection in a regular layout, automation of transformations, management of images and profiles of brightness, and data analysis to determine the width of cracks and their changes over time are made automatically by own code in the ImageJ and VBA environment. The article describes the method, tests on its properties, sources of measurement uncertainty. It also presents an example of application of the method in research on autogenous self-healing of concrete, specifically the ability to reduce a sample crack width and its full closure within 28 days of the self-healing process.

Seismic Design of ITER Component Cooling Water System-1 Piping

NASA Astrophysics Data System (ADS)

Singh, Aditya P.; Jadhav, Mahesh; Sharma, Lalit K.; Gupta, Dinesh K.; Patel, Nirav; Ranjan, Rakesh; Gohil, Guman; Patel, Hiren; Dangi, Jinendra; Kumar, Mohit; Kumar, A. G. A.

2017-04-01

The successful performance of ITER machine very much depends upon the effective removal of heat from the in-vessel components and other auxiliary systems during Tokamak operation. This objective will be accomplished by the design of an effective Cooling Water System (CWS). The optimized piping layout design is an important element in CWS design and is one of the major design challenges owing to the factors of large thermal expansion and seismic accelerations; considering safety, accessibility and maintainability aspects. An important sub-system of ITER CWS, Component Cooling Water System-1 (CCWS-1) has very large diameter of pipes up to DN1600 with many intersections to fulfill the process flow requirements of clients for heat removal. Pipe intersection is the weakest link in the layout due to high stress intensification factor. CCWS-1 piping up to secondary confinement isolation valves as well as in-between these isolation valves need to survive a Seismic Level-2 (SL-2) earthquake during the Tokamak operation period to ensure structural stability of the system in the Safe Shutdown Earthquake (SSE) event. This paper presents the design, qualification and optimization of layout of ITER CCWS-1 loop to withstand SSE event combined with sustained and thermal loads as per the load combinations defined by ITER and allowable limits as per ASME B31.3, This paper also highlights the Modal and Response Spectrum Analyses done to find out the natural frequency and system behavior during the seismic event.

A method of plane geometry primitive presentation

NASA Astrophysics Data System (ADS)

Jiao, Anbo; Luo, Haibo; Chang, Zheng; Hui, Bin

2014-11-01

Point feature and line feature are basic elements in object feature sets, and they play an important role in object matching and recognition. On one hand, point feature is sensitive to noise; on the other hand, there are usually a huge number of point features in an image, which makes it complex for matching. Line feature includes straight line segment and curve. One difficulty in straight line segment matching is the uncertainty of endpoint location, the other is straight line segment fracture problem or short straight line segments joined to form long straight line segment. While for the curve, in addition to the above problems, there is another difficulty in how to quantitatively describe the shape difference between curves. Due to the problems of point feature and line feature, the robustness and accuracy of target description will be affected; in this case, a method of plane geometry primitive presentation is proposed to describe the significant structure of an object. Firstly, two types of primitives are constructed, they are intersecting line primitive and blob primitive. Secondly, a line segment detector (LSD) is applied to detect line segment, and then intersecting line primitive is extracted. Finally, robustness and accuracy of the plane geometry primitive presentation method is studied. This method has a good ability to obtain structural information of the object, even if there is rotation or scale change of the object in the image. Experimental results verify the robustness and accuracy of this method.

A human rights approach to the health implications of food and nutrition insecurity.

PubMed

Ayala, Ana; Meier, Benjamin Mason

2017-01-01

Food and nutrition insecurity continues to pose a serious global challenge, reflecting government shortcomings in meeting international obligations to ensure the availability, accessibility, and quality of food and to ensure the highest attainable standard of health of their peoples. With global drivers like climate change, urbanization, greater armed conflict, and the globalization of unhealthy diet, particularly in under-resourced countries, food insecurity is rapidly becoming an even greater challenge for those living in poverty. International human rights law can serve a critical role in guiding governments that are struggling to protect the health of their populations, particularly among the most susceptible groups, in responding to food and nutrition insecurity. This article explores and advocates for a human rights approach to food and nutrition security, specifically identifying legal mechanisms to "domesticate" relevant international human rights standards through national policy. Recognizing nutrition security as a determinant of public health, this article recognizes the important links between the four main elements of food security (i.e., availability, stability, utilization, and access) and the normative attributes of the right to health and the right to food (i.e., availability, accessibility, affordability, and quality). In drawing from the evolution of international human rights instruments, official documents issued by international human rights treaty bodies, as well as past scholarship at the intersection of the right to health and right to food, this article interprets and articulates the intersectional rights-based obligations of national governments in the face of food and nutrition insecurity.

Analysis on influencing factors and decision-making of pedestrian crossing at intersections

NASA Astrophysics Data System (ADS)

Liu, Likun; Wang, Ziyang

2017-10-01

The city signal intersection always has complex traffic flow and many traffic accidents. As vulnerable participants, the proportion of traffic accidents involving pedestrians remain high. And a lot of insecure crossing behavior seriously reduce the safety of the intersection. Therefore, it is necessary to carry out in-depth study on the traversing characteristics of pedestrians, reveal the inherent laws of pedestrian crossing, and then put forward targeted measures to improve pedestrian traffic environment, protect pedestrian crossing safety and improve traffic efficiency.

Matrix Models and A Proof of the Open Analog of Witten's Conjecture

NASA Astrophysics Data System (ADS)

Buryak, Alexandr; Tessler, Ran J.

2017-08-01

In a recent work, R. Pandharipande, J. P. Solomon and the second author have initiated a study of the intersection theory on the moduli space of Riemann surfaces with boundary. They conjectured that the generating series of the intersection numbers satisfies the open KdV equations. In this paper we prove this conjecture. Our proof goes through a matrix model and is based on a Kontsevich type combinatorial formula for the intersection numbers that was found by the second author.

Stress-strain state of a rock mass in the vicinity of the meeting point of intersecting and branching workings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konstantinova, S.A.; Spirkov, V.L.; Sokolov, V.Yu.

1987-07-01

The results of solving the problems of the stress-strain state of peripheral rock in the vicinity of the meeting point of two workings of intersection and branching type are presented. Values of the load coefficients are obtained, as well as values of the dimensions of the zone of influence of the meeting point and the conventional zone of inelastic deformations. Intersection and branching of workings at various angles are considered.

¿Somos iguales? Using a structural violence framework to understand gender and health inequities from an intersectional perspective in the Peruvian Amazon

PubMed Central

Shannon, Geordan D.; Motta, Angelica; Cáceres, Carlos F.; Skordis-Worrall, Jolene; Bowie, Diana; Prost, Audrey

2017-01-01

ABSTRACT Background: In the Peruvian Amazon, historical events of colonization and political marginalization intersect with identities of ethnicity, class and geography in the construction of gender and health inequities. Gender-based inequalities can manifest in poor health outcomes via discriminatory practices, healthcare system imbalances, inequities in health research, and differential exposures and vulnerabilities to diseases. Structural violence is a comprehensive framework to explain the mechanisms by which social forces such as poverty, racism and gender inequity become embodied as individual experiences and health outcomes, and thus may be a useful tool in structuring an intersectional analysis of gender and health inequities in Amazonian Peru. Objective: The aim of this paper is to explore the intersection of gender inequities with other social inequalities in the production of health and disease in Peru’s Amazon using a structural violence approach. Design: Exploratory qualitative research was performed in two Loreto settings – urban Iquitos and the rural Lower Napo River region – between March and November 2015. This included participant observation with prolonged stays in the community, 46 semi-structured individual interviews and three group discussions. Thematic analysis was performed to identify emerging themes related to gender inequalities in health and healthcare and how these intersect with layered social disadvantages in the reproduction of health and illness. We employed a structural violence approach to construct an intersectional analysis of gender and health inequities in Amazonian Peru. Results: Our findings were arranged into five interrelated domains within a gender, structural violence and health model: gender as a symbolic institution, systemic gender-based violence, interpersonal violence, the social determinants of health, and other health outcomes. Each domain represents one aspect of the complex associations between gender, gender inequity and health. Through this model, we were able to explore: gender, health and intersectionality; structural violence; and to highlight particular local gender and health dynamics. Intersecting influences of poverty, ethnicity, geography and gender served as significant barriers to healthcare in both rural and urban settings. PMID:28640664

Sources and controls of Arsenic contamination in groundwater of Rajnandgaon and Kanker District, Chattisgarh Central India

NASA Astrophysics Data System (ADS)

Shukla, Dericks Praise; Dubey, C. S.; Singh, Ningthoujam P.; Tajbakhsh, M.; Chaudhry, M.

2010-12-01

SummaryA high concentration of Arsenic (As) contamination in ground water has been reported in the village of Kaudikasa in Rajnandgaon district, wherein around 10% of the population is suffering from As-borne diseases. The region does not share any demographic or geological similarity with the sedimentary aquifers of the Bengal Delta Plain in Eastern India, but represents an igneous terrain with elevated As concentrations in groundwater. There is limited information about the source of As in groundwater and its mobility constraints. In this area, almost all the wells are located in the granitic terrain with pegmatitic intrusions. Most of these wells are characterized by As concentration above the World Health Organization ( WHO, 1999) and the BIS (Bureau of Indian Standards) standards, with the highest being found in a well with more than 250 μg/L of As. Here we report petrographic studies of the granitic host rock and X-ray diffraction results that indicate that altered realgar (α-As 4S 4), para realgar (AsS), and/or tennantite (Cu 12As 4S 13), are the main mineral that contain As. This element is leached during the weathering and water-rock interactions. Microprobe analysis of the altered realgar grains of in pegmatitic intrusions of the host granite indicate 23-27 wt.% As. Remote sensing is useful to delineate the source of this contaminant, which appears to lie at the intersection of a mineralized NW-SE and N-S lineaments associated with the Kotri rift zone. These lineaments are structurally controlled as rifting followed by thrusting and other types of faulting caused left-lateral displacement of N-S Kotri lineament along a NW-SE fault plane showing sinistral shearing. This process caused water drainage in the areas to flow along these highly mineralized weak zones. Thus, the water becomes highly contaminated due to leaching of minerals at the intersection of these lineaments, clearly visible at two areas of high contamination that lie very near to this intersection over granitic rock. The source of As affecting the Rajnandgaon district is located in granites that have pegmatitic intrusions likely generated by hydrothermal activity.

Thermo-optic microring resonator switching elements made of dielectric-loaded plasmonic waveguides

NASA Astrophysics Data System (ADS)

Tsilipakos, Odysseas; Kriezis, Emmanouil E.; Bozhevolnyi, Sergey I.

2011-04-01

Thermo-optic switching elements made of dielectric-loaded plasmonic (DLSPP) waveguides are theoretically investigated by utilizing the three-dimensional vector finite element method. The configurations considered employ microring resonators, whose resonant frequency is varied by means of thermal tuning. First, a classic add-drop filter with parallel access waveguides is examined. Such a component features very poor drop port extinction ratio (ER). We therefore extend the analysis to add-drop filters with perpendicular access waveguides, which are found to exhibit superior drop port ERs, due to interference effects associated with the drop port transmission. In the process, the performance of a DLSPP waveguide crossing is also assessed, since it is a building block of those filters whose bus waveguides intersect. An elliptic tapering scheme is proposed for minimizing cross talk and its effect on the filter performance is explored. The dual-resonator add-drop filter with perpendicular bus waveguides and an untreated waveguide crossing of Sec. V can act as an efficient 2×2 switching element (the single-resonator variant can only act as a 1×2 switch due to structure asymmetry), possessing two equivalent input ports and featuring high ERs for both output ports over a broad wavelength range. Specifically, an extinction ratio of at least 8 dB can be attained for both output ports over a wavelength range of 3.2 nm, accommodating four 100-GHz-spaced channels. Switching times are in the order of a few microseconds, rendering the aforementioned structure capable of handling real-world routing scenarios.

Perspective, environmental view looking from the intersection of West Lanvale ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Perspective, environmental view looking from the intersection of West Lanvale Street and North Carrollton Avenue - Reformed Episcopal Church of the Rock of Ages, 1210 West Lanvale Street, Baltimore, Independent City, MD

Optimum bus headway for preemption : a simulation approach

DOT National Transportation Integrated Search

1997-01-01

Preemption techniques are designed to provide preferential treatment for buses at signalized intersections. A preemption strategy, if properly designed, can provide continuous green phases for buses at successive intersections, thereby reducing trave...

32 CFR 636.25 - Right-of-way.

Code of Federal Regulations, 2012 CFR

2012-07-01

... of the vehicle on the left will yield right-of-way. When entering an intersection without traffic.... (b) Drivers turning left within an intersection will yield right-of-way to vehicles approaching from...

32 CFR 636.25 - Right-of-way.

Code of Federal Regulations, 2010 CFR

2010-07-01

... of the vehicle on the left will yield right-of-way. When entering an intersection without traffic.... (b) Drivers turning left within an intersection will yield right-of-way to vehicles approaching from...

32 CFR 636.25 - Right-of-way.

Code of Federal Regulations, 2011 CFR

2011-07-01

... of the vehicle on the left will yield right-of-way. When entering an intersection without traffic.... (b) Drivers turning left within an intersection will yield right-of-way to vehicles approaching from...

32 CFR 636.25 - Right-of-way.

Code of Federal Regulations, 2014 CFR

2014-07-01

... of the vehicle on the left will yield right-of-way. When entering an intersection without traffic.... (b) Drivers turning left within an intersection will yield right-of-way to vehicles approaching from...

4. NORTH SIDE, OBLIQUE VIEW, FROM INTERSECTION OF G AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. NORTH SIDE, OBLIQUE VIEW, FROM INTERSECTION OF G AND 5TH STREETS, LOOKING SOUTHEAST. - Oakland Naval Supply Center, Storehouse, Between G & H Streets, & Fifth & Sixth Streets, Oakland, Alameda County, CA

Intelligent Intersection Traffic Control Laboratory Fact Sheet

DOT National Transportation Integrated Search

2006-07-27

The Intelligent Intersection 11:affic Control Laboratory (IITCL) is an outdoor facility that supports the Federal Highway Administration's (FHWA) various research programs and research activities conducted by other U.S. Department of 11:ansportation ...

Drivers' evaluation of the diverging diamond interchange

DOT National Transportation Integrated Search

2007-01-01

In recent years, the Federal Highway Administration (FHWA) has been advocating novel intersection designs as a way to promote intersection safety while meeting the often conflicting demands for increasing capacity, decreasing congestion, and minimizi...