Multiscale geometric modeling of macromolecules II: Lagrangian representation

Science.gov (United States)

Feng, Xin; Xia, Kelin; Chen, Zhan; Tong, Yiying; Wei, Guo-Wei

2013-01-01

Geometric modeling of biomolecules plays an essential role in the conceptualization of biolmolecular structure, function, dynamics and transport. Qualitatively, geometric modeling offers a basis for molecular visualization, which is crucial for the understanding of molecular structure and interactions. Quantitatively, geometric modeling bridges the gap between molecular information, such as that from X-ray, NMR and cryo-EM, and theoretical/mathematical models, such as molecular dynamics, the Poisson-Boltzmann equation and the Nernst-Planck equation. In this work, we present a family of variational multiscale geometric models for macromolecular systems. Our models are able to combine multiresolution geometric modeling with multiscale electrostatic modeling in a unified variational framework. We discuss a suite of techniques for molecular surface generation, molecular surface meshing, molecular volumetric meshing, and the estimation of Hadwiger’s functionals. Emphasis is given to the multiresolution representations of biomolecules and the associated multiscale electrostatic analyses as well as multiresolution curvature characterizations. The resulting fine resolution representations of a biomolecular system enable the detailed analysis of solvent-solute interaction, and ion channel dynamics, while our coarse resolution representations highlight the compatibility of protein-ligand bindings and possibility of protein-protein interactions. PMID:23813599

SOME PROPERTIES OF GEOMETRIC DEA MODELS

Directory of Open Access Journals (Sweden)

Ozren Despić

2013-02-01

Full Text Available Some specific geometric data envelopment analysis (DEA models are well known to the researchers in DEA through so-called multiplicative or log-linear efficiency models. Valuable properties of these models were noted by several authors but the models still remain somewhat obscure and rarely used in practice. The purpose of this paper is to show from a mathematical perspective where the geometric DEA fits in relation to the classical DEA, and to provide a brief overview of some benefits in using geometric DEA in practice of decision making and/or efficiency measurement.

Research on Geometric Positioning Algorithm of License Plate in Multidimensional Parameter Space

Directory of Open Access Journals (Sweden)

Yinhua Huan

2014-05-01

Full Text Available Considering features of vehicle license plate location method which commonly used, in order to search a consistent location for reference images with license plates feature in multidimensional parameter space, a new algorithm of geometric location is proposed. Geometric location algorithm main include model training and real time search. Which not only adapt the gray-scale linearity and the gray non-linear changes, but also support changes of scale and angle. Compared with the mainstream locating software, numerical results shows under the same test conditions that the position deviation of geometric positioning algorithm is less than 0.5 pixel. Without taking into account the multidimensional parameter space, Geometric positioning algorithm position deviation is less than 1.0 pixel and angle deviation is less than 1.0 degree taking into account the multidimensional parameter space. This algorithm is robust, simple, practical and is better than the traditional method.

Transportation Options | Climate Neutral Research Campuses | NREL

Science.gov (United States)

Transportation Options Transportation Options Transportation to, from, and within a research campus from business travel often enlarge the footprint more than expected. To understand options for climate

Geometric group theory

CERN Document Server

Bestvina, Mladen; Vogtmann, Karen

2014-01-01

Geometric group theory refers to the study of discrete groups using tools from topology, geometry, dynamics and analysis. The field is evolving very rapidly and the present volume provides an introduction to and overview of various topics which have played critical roles in this evolution. The book contains lecture notes from courses given at the Park City Math Institute on Geometric Group Theory. The institute consists of a set of intensive short courses offered by leaders in the field, designed to introduce students to exciting, current research in mathematics. These lectures do not duplicate standard courses available elsewhere. The courses begin at an introductory level suitable for graduate students and lead up to currently active topics of research. The articles in this volume include introductions to CAT(0) cube complexes and groups, to modern small cancellation theory, to isometry groups of general CAT(0) spaces, and a discussion of nilpotent genus in the context of mapping class groups and CAT(0) gro...

Geometric methods in PDE’s

CERN Document Server

Manfredini, Maria; Morbidelli, Daniele; Polidoro, Sergio; Uguzzoni, Francesco

2015-01-01

The analysis of PDEs is a prominent discipline in mathematics research, both in terms of its theoretical aspects and its relevance in applications. In recent years, the geometric properties of linear and nonlinear second order PDEs of elliptic and parabolic type have been extensively studied by many outstanding researchers. This book collects contributions from a selected group of leading experts who took part in the INdAM meeting "Geometric methods in PDEs", on the occasion of the 70th birthday of Ermanno Lanconelli. They describe a number of new achievements and/or the state of the art in their discipline of research, providing readers an overview of recent progress and future research trends in PDEs. In particular, the volume collects significant results for sub-elliptic equations, potential theory and diffusion equations, with an emphasis on comparing different methodologies and on their implications for theory and applications. .

A numerical analysis of antithetic variates in Monte Carlo radiation transport with geometrical surface splitting

International Nuclear Information System (INIS)

Sarkar, P.K.; Prasad, M.A.

1989-01-01

A numerical study for effective implementation of the antithetic variates technique with geometric splitting/Russian roulette in Monte Carlo radiation transport calculations is presented. The study is based on the theory of Monte Carlo errors where a set of coupled integral equations are solved for the first and second moments of the score and for the expected number of flights per particle history. Numerical results are obtained for particle transmission through an infinite homogeneous slab shield composed of an isotropically scattering medium. Two types of antithetic transformations are considered. The results indicate that the antithetic transformations always lead to reduction in variance and increase in efficiency provided optimal antithetic parameters are chosen. A substantial gain in efficiency is obtained by incorporating antithetic transformations in rule of thumb splitting. The advantage gained for thick slabs (∼20 mfp) with low scattering probability (0.1-0.5) is attractively large . (author). 27 refs., 9 tabs

Geometric component of charge pumping current in nMOSFETs due to low-temperature irradiation

Science.gov (United States)

Witczak, S. C.; King, E. E.; Saks, N. S.; Lacoe, R. C.; Shaneyfelt, M. R.; Hash, G. L.; Hjalmarson, H. P.; Mayer, D. C.

2002-12-01

The geometric component of charge pumping current was examined in n-channel metal-oxide-silicon field effect transistors (MOSFETs) following low-temperature irradiation. In addition to the usual dependencies on channel length and gate bias transition time, the geometric component was found to increase with radiation-induced oxide-trapped charge density and decreasing temperature. A postirradiation injection of electrons into the gate oxide reduces the geometric component along with the density of oxide-trapped charge, which clearly demonstrates that the two are correlated. A fit of the injection data to a first-order model for trapping kinetics indicates that the electron trapping occurs predominantly at a single type of Coulomb-attractive trap site. The geometric component results primarily from the bulk recombination of channel electrons that fail to transport to the source or drain during the transition from inversion to accumulation. The radiation response of these transistors suggests that Coulomb scattering by oxide-trapped charge increases the bulk recombination at low temperatures by impeding electron transport. These results imply that the geometric component must be properly accounted for when charge pumping irradiated n-channel MOSFETs at low temperatures.

Geometrical properties of tension-induced fractures in granite

International Nuclear Information System (INIS)

Sato, Hisashi; Sawada, Atsushi; Yasuhara, Hideaki

2011-03-01

Considering a safe, long-term sequestration of energy byproducts such as high level radioactive wastes, it is of significant importance to well-constrain the hydraulic and transport behavior of targeted permeants within fractured rocks. Specifically, fluid flow within low-permeability crystalline rock masses (e.g., granite) is often dominated by transport in through-cutting fractures, and thus careful considerations are needed on the behavior. There are three planes along that granites fail most easily under tension, and those may be identified as the rift, grain, and hardway planes. This anisotropic fabric may be attributed to preferentially oriented microcrack sets contained within intact rock. In this research, geometrical properties of tension-induced fractures are evaluated as listed below; (1) Creation of tension-induced fractures considering the anisotropy clarified by elastic wave measurements. (2) Evaluation of geometrical properties in those fractures characterized by the anisotropy. In the item (1), the three planes of rift, grain and hardway were identified by measuring elastic wave. In the item (2), JRC, variogram, fractal dimension and distributions of elevations in the fracture surfaces were evaluated using digitized data of the fracture surfaces measured via a laser profilometry. Results show that rift planes are less rougher than the other planes of grain and hardway, and grain planes are generically rougher than the other planes of rift and hardway. It was also confirmed that the fracture shape anisotropy was correlated with the direction of the slit which constructed during tensile tests. On the other hand, the tendency peculiar to the direction of slit and granites fail about the estimated aperture distribution from fracture shape was not seen. (author)

Geometric phase effects in ultracold chemistry

Science.gov (United States)

Hazra, Jisha; Naduvalath, Balakrishnan; Kendrick, Brian K.

2016-05-01

In molecules, the geometric phase, also known as Berry's phase, originates from the adiabatic transport of the electronic wavefunction when the nuclei follow a closed path encircling a conical intersection between two electronic potential energy surfaces. It is demonstrated that the inclusion of the geometric phase has an important effect on ultracold chemical reaction rates. The effect appears in rotationally and vibrationally resolved integral cross sections as well as cross sections summed over all product quantum states. It arises from interference between scattering amplitudes of two reaction pathways: a direct path and a looping path that encircle the conical intersection between the two lowest adiabatic electronic potential energy surfaces. Illustrative results are presented for the O+ OH --> H+ O2 reaction and for hydrogen exchange in H+ H2 and D+HD reactions. It is also qualitatively demonstrated that the geometric phase effect can be modulated by applying an external electric field allowing the possibility of quantum control of chemical reactions in the ultracold regime. This work was supported in part by NSF Grant PHY-1505557 (N.B.) and ARO MURI Grant No. W911NF-12-1-0476 (N.B.).

Is Geometric Frustration-Induced Disorder a Recipe for High Ionic Conductivity?

Science.gov (United States)

Düvel, Andre; Heitjans, Paul; Fedorov, Pavel; Scholz, Gudrun; Cibin, Giannantonio; Chadwick, Alan V; Pickup, David M; Ramos, Silvia; Sayle, Lewis W L; Sayle, Emma K L; Sayle, Thi X T; Sayle, Dean C

2017-04-26

Ionic conductivity is ubiquitous to many industrially important applications such as fuel cells, batteries, sensors, and catalysis. Tunable conductivity in these systems is therefore key to their commercial viability. Here, we show that geometric frustration can be exploited as a vehicle for conductivity tuning. In particular, we imposed geometric frustration upon a prototypical system, CaF 2 , by ball milling it with BaF 2 , to create nanostructured Ba 1-x Ca x F 2 solid solutions and increased its ionic conductivity by over 5 orders of magnitude. By mirroring each experiment with MD simulation, including "simulating synthesis", we reveal that geometric frustration confers, on a system at ambient temperature, structural and dynamical attributes that are typically associated with heating a material above its superionic transition temperature. These include structural disorder, excess volume, pseudovacancy arrays, and collective transport mechanisms; we show that the excess volume correlates with ionic conductivity for the Ba 1-x Ca x F 2 system. We also present evidence that geometric frustration-induced conductivity is a general phenomenon, which may help explain the high ionic conductivity in doped fluorite-structured oxides such as ceria and zirconia, with application for solid oxide fuel cells. A review on geometric frustration [ Nature 2015 , 521 , 303 ] remarks that classical crystallography is inadequate to describe systems with correlated disorder, but that correlated disorder has clear crystallographic signatures. Here, we identify two possible crystallographic signatures of geometric frustration: excess volume and correlated "snake-like" ionic transport; the latter infers correlated disorder. In particular, as one ion in the chain moves, all the other (correlated) ions in the chain move simultaneously. Critically, our simulations reveal snake-like chains, over 40 Å in length, which indicates long-range correlation in our disordered systems. Similarly

Collaboration between physical activity researchers and transport planners

DEFF Research Database (Denmark)

Crist, Katie; Bolling, Khalisa; Schipperijn, Jasper

2018-01-01

Collaboration between physical activity (PA) researchers and transport planners is a recommended strategy to combat the physical inactivity epidemic. Data collected by PA researchers could be used to identify, implement and evaluate active transport (AT) projects. However, despite aligned interests......, researchers and transport planners rarely collaborate. This study utilized qualitative methods to 1) gain an in-depth understanding of the data utilized in AT planning, 2) explore the utility of Global Positioning Systems (GPS) and accelerometer data in supporting the planning process, 3) identify...... expertise in health or transport planning. A thematic analysis was conducted following structural coding by two researchers. The analysis revealed that geographic and physical activity data that are current, local, objective and specific to individual AT trips would improve upon currently available data...

Control of the spin geometric phase in semiconductor quantum rings.

Science.gov (United States)

Nagasawa, Fumiya; Frustaglia, Diego; Saarikoski, Henri; Richter, Klaus; Nitta, Junsaku

2013-01-01

Since the formulation of the geometric phase by Berry, its relevance has been demonstrated in a large variety of physical systems. However, a geometric phase of the most fundamental spin-1/2 system, the electron spin, has not been observed directly and controlled independently from dynamical phases. Here we report experimental evidence on the manipulation of an electron spin through a purely geometric effect in an InGaAs-based quantum ring with Rashba spin-orbit coupling. By applying an in-plane magnetic field, a phase shift of the Aharonov-Casher interference pattern towards the small spin-orbit-coupling regions is observed. A perturbation theory for a one-dimensional Rashba ring under small in-plane fields reveals that the phase shift originates exclusively from the modulation of a pure geometric-phase component of the electron spin beyond the adiabatic limit, independently from dynamical phases. The phase shift is well reproduced by implementing two independent approaches, that is, perturbation theory and non-perturbative transport simulations.

Research of z-axis geometric dose efficiency in multi-detector computed tomography

International Nuclear Information System (INIS)

Kim, You Hyun; Kim, Moon Chan

2006-01-01

With the recent prevalence of helical CT and multi-slice CT, which deliver higher radiation dose than conventional CT due to overbeaming effect in X-ray exposure and interpolation technique in image reconstruction. Although multi-detector and helical CT scanner provide a variety of opportunities for patient dose reduction, the potential risk for high radiation levels in CT examination can't be overemphasized in spite of acquiring more diagnostic information. So much more concerns is necessary about dose characteristics of CT scanner, especially dose efficient design as well as dose modulation software, because dose efficiency built into the scanner's design is probably the most important aspect of successful low dose clinical performance. This study was conducted to evaluate z-axis geometric dose efficiency in single detector CT and each level multi-detector CT, as well as to compare z-axis dose efficiency with change of technical scan parameters such as focal spot size of tube, beam collimation, detector combination, scan mode, pitch size, slice width and interval. The results obtained were as follows; 1. SDCT was most highest and 4 MDCT was most lowest in z-axis geometric dose efficiency among SDCT, 4, 8, 16, 64 slice MDCT made by GE manufacture. 2. Small focal spot was 0.67-13.62% higher than large focal spot in z-axis geometric dose efficiency at MDCT. 3. Large beam collimation was 3.13-51.52% higher than small beam collimation in z-axis geometric dose efficiency at MDCT. Z-axis geometric dose efficiency was same at 4 slice MDCT in all condition and 8 slice MDCT of large beam collimation with change of detector combination, but was changed irregularly at 8 slice MDCT of small beam collimation and 16 slice MDCT in all condition with change of detector combination. 5. There was no significant difference for z-axis geometric dose efficiency between conventional scan and helical scan, and with change of pitch factor, as well as change of slice width or interval for

Louisiana Transportation Research Center : Annual report, 2016-2017

Science.gov (United States)

2017-10-11

This publication is a report of the transportation research, technology transfer, education, and training activities of the Louisiana Transportation Research Center for July 1, 2016 - June 30, 2017. The center is sponsored jointly by the Louisiana De...

Geometric and Hydrodynamic Characteristics of Three-dimensional Saturated Prefractal Porous Media Determined with Lattice Boltzmann Modeling

Science.gov (United States)

Fractal and prefractal geometric models have substantial potential of contributing to the analysis of flow and transport in porous media such as soils and reservoir rocks. In this study, geometric and hydrodynamic parameters of saturated 3D mass and pore-solid prefractal porous media were characteri...

Transport research: Quo Vadis?

CSIR Research Space (South Africa)

Rust, FC

2008-07-01

Full Text Available the national R&D programme in transport became fragmented and consequently very little R&D has been done in the 2000s. This paper analyses the lessons learnt from six historic research programmes in both the public and private sector and in several project...

GeoBuilder: a geometric algorithm visualization and debugging system for 2D and 3D geometric computing.

Science.gov (United States)

Wei, Jyh-Da; Tsai, Ming-Hung; Lee, Gen-Cher; Huang, Jeng-Hung; Lee, Der-Tsai

2009-01-01

Algorithm visualization is a unique research topic that integrates engineering skills such as computer graphics, system programming, database management, computer networks, etc., to facilitate algorithmic researchers in testing their ideas, demonstrating new findings, and teaching algorithm design in the classroom. Within the broad applications of algorithm visualization, there still remain performance issues that deserve further research, e.g., system portability, collaboration capability, and animation effect in 3D environments. Using modern technologies of Java programming, we develop an algorithm visualization and debugging system, dubbed GeoBuilder, for geometric computing. The GeoBuilder system features Java's promising portability, engagement of collaboration in algorithm development, and automatic camera positioning for tracking 3D geometric objects. In this paper, we describe the design of the GeoBuilder system and demonstrate its applications.

Workshop on Topology and Geometric Group Theory

CERN Document Server

Fowler, James; Lafont, Jean-Francois; Leary, Ian

2016-01-01

This book presents articles at the interface of two active areas of research: classical topology and the relatively new field of geometric group theory. It includes two long survey articles, one on proofs of the Farrell–Jones conjectures, and the other on ends of spaces and groups. In 2010–2011, Ohio State University (OSU) hosted a special year in topology and geometric group theory. Over the course of the year, there were seminars, workshops, short weekend conferences, and a major conference out of which this book resulted. Four other research articles complement these surveys, making this book ideal for graduate students and established mathematicians interested in entering this area of research.

New developments in transportation for research reactors

Energy Technology Data Exchange (ETDEWEB)

Mondanel, J.L. [Transnucleaire, F-75008 Paris (France)

1998-07-01

For more than 30 years, Transnucleaire has been performing safely a large number of national and international transports of radioactive material. Transnucleaire has also designed and supplied numerous packagings for all types of nuclear fuel cycle radioactive materials: for front-end and back-end products and for power and research reactors. Since the last meeting held in Bruges, Transnucleaire has been continuously involved in transportation activities for fresh and irradiated materials for research reactors. We are pleased to take the opportunity in this meeting to share with reactor operators, official bodies and other partners, the on-going developments in transportation and associated services. Special attention will be paid to the starting of transports of MTR spent fuel elements to the La Hague reprocessing plant where COGEMA offers reprocessing services on a long-term basis to reactors operators. Detailed information is provided on regulatory issues, which may affect transport activities: evolution of the regulations, real experiences of recent transportation and development of new packaging designs. Options and solutions will be proposed by Transnucleaire to improve the situation for continuation of national and international transports at an acceptable price whilst maintaining an ultimate level of safety (author)

Latest Progress in Research on the SpaceLiner High-Speed Passenger Transportation Concept

OpenAIRE

Sippel, Martin; van Foreest, Arnold

2007-01-01

A vision aimed at revolutionizing ultra-long distance travel between different points on earth could be realized by a high-speed intercontinental passenger transport using rocket based, suborbital launchers. The paper gives an overview on the latest progress in conceptual design of the DLR SpaceLiner presenting geometrical size and mass data and describing results of trajectory simulations. The rockets are based on an advanced but technically conservative approach not relying on e...

Transport safety research abstracts. No. 1

International Nuclear Information System (INIS)

1991-07-01

The Transport Safety Research Abstracts is a collection of reports from Member States of the International Atomic Energy Agency, and other international organizations on research in progress or just completed in the area of safe transport of radioactive material. The main aim of TSRA is to draw attention to work that is about to be published, thus enabling interested parties to obtain further information through direct correspondence with the investigators. Information contained in this issue covers work being undertaken in 6 Member States and contracted by 1 international organization; it is hoped with succeeding issues that TSRA will be able to widen this base. TSRA is modelled after other IAEA publications describing work in progress in other programme areas, namely Health Physics Research Abstracts (No. 14 was published in 1989), Waste Management Research Abstracts (No. 20 was published in 1990), and Nuclear Safety Research Abstracts (No. 2 was published in 1990)

French experience in research reactor fuel transportation

International Nuclear Information System (INIS)

Raisonnier, Daniele

1996-01-01

Since 1963 Transnucleaire has safely performed a large number of national and international transports of radioactive material. Transnucleaire has also designed and supplied suitable packaging for all types of nuclear fuel cycle radioactive material from front-end and back-end products and for power or for research reactors. Transportation of spent fuel from power reactors are made on a regular and industrial basis, but this is not yet the case for the transport of spent fuel coming from research reactors. Each shipment is a permanent challenge and requires a reactive organization dealing with all the transportation issues. This presentation will explain the choices made by Transnucleaire and its associates to provide and optimize the corresponding services while remaining in full compliance with the applicable regulations and customer requirements. (author)

THE CONTRIBUTION OF PUBLIC INTEREST RESEARCH TO TRANSPORTATION POLICY

OpenAIRE

Makoto ITOH

2003-01-01

Established in 1995 with the basic philosophy of serving as a bridge between research and practice, the Institute for Transport Policy Studies conducts activities in support of transportation policy research in the public interest. This paper aims to describe the contribution of public interest research to transportation policy as seen in the Institute's activities. Touching first on the context and events leading to its establishment, the paper then describes the Institute's guiding principl...

Riemannian geometry and geometric analysis

CERN Document Server

Jost, Jürgen

2017-01-01

This established reference work continues to provide its readers with a gateway to some of the most interesting developments in contemporary geometry. It offers insight into a wide range of topics, including fundamental concepts of Riemannian geometry, such as geodesics, connections and curvature; the basic models and tools of geometric analysis, such as harmonic functions, forms, mappings, eigenvalues, the Dirac operator and the heat flow method; as well as the most important variational principles of theoretical physics, such as Yang-Mills, Ginzburg-Landau or the nonlinear sigma model of quantum field theory. The present volume connects all these topics in a systematic geometric framework. At the same time, it equips the reader with the working tools of the field and enables her or him to delve into geometric research.  The 7th edition has been systematically reorganized and updated. Almost no page has been left unchanged. It also includes new material, for instance on symplectic geometry, as well as the B...

Analysis of Geometric Thinking Students’ and Process-Guided Inquiry Learning Model

Science.gov (United States)

Hardianti, D.; Priatna, N.; Priatna, B. A.

2017-09-01

This research aims to analysis students’ geometric thinking ability and theoretically examine the process-oriented guided iquiry (POGIL) model. This study uses qualitative approach with descriptive method because this research was done without any treatment on subjects. Data were collected naturally. This study was conducted in one of the State Junior High School in Bandung. The population was second grade students and the sample was 32 students. Data of students’ geometric thinking ability were collected through geometric thinking test. These questions are made based on the characteristics of geometry thinking based on van hiele’s theory. Based on the results of the analysis and discussion, students’ geometric thinking ability is still low so it needs to be improved. Therefore, an effort is needed to overcome the problems related to students’ geometric thinking ability. One of the efforts that can be done by doing the learning that can facilitate the students to construct their own geometry concept, especially quadrilateral’s concepts so that students’ geometric thinking ability can enhance maximally. Based on study of the theory, one of the learning models that can enhance the students’ geometric thinking ability is POGIL model.

Geometric Series via Probability

Science.gov (United States)

Tesman, Barry

2012-01-01

Infinite series is a challenging topic in the undergraduate mathematics curriculum for many students. In fact, there is a vast literature in mathematics education research on convergence issues. One of the most important types of infinite series is the geometric series. Their beauty lies in the fact that they can be evaluated explicitly and that…

Stock price prediction using geometric Brownian motion

Science.gov (United States)

Farida Agustini, W.; Restu Affianti, Ika; Putri, Endah RM

2018-03-01

Geometric Brownian motion is a mathematical model for predicting the future price of stock. The phase that done before stock price prediction is determine stock expected price formulation and determine the confidence level of 95%. On stock price prediction using geometric Brownian Motion model, the algorithm starts from calculating the value of return, followed by estimating value of volatility and drift, obtain the stock price forecast, calculating the forecast MAPE, calculating the stock expected price and calculating the confidence level of 95%. Based on the research, the output analysis shows that geometric Brownian motion model is the prediction technique with high rate of accuracy. It is proven with forecast MAPE value ≤ 20%.

Colors and geometric forms in the work process information coding

Directory of Open Access Journals (Sweden)

Čizmić Svetlana

2006-01-01

Full Text Available The aim of the research was to establish the meaning of the colors and geometric shapes in transmitting information in the work process. The sample of 100 students connected 50 situations which could be associated with regular tasks in the work process with 12 colors and 4 geometric forms in previously chosen color. Based on chosen color-geometric shape-situation regulation, the idea of the research was to find out regularities in coding of information and to examine if those regularities can provide meaningful data assigned to each individual code and to explain which codes are better and applicable represents of examined situations.

A Geometric Fuzzy-Based Approach for Airport Clustering

Directory of Open Access Journals (Sweden)

Maria Nadia Postorino

2014-01-01

Full Text Available Airport classification is a common need in the air transport field due to several purposes—such as resource allocation, identification of crucial nodes, and real-time identification of substitute nodes—which also depend on the involved actors’ expectations. In this paper a fuzzy-based procedure has been proposed to cluster airports by using a fuzzy geometric point of view according to the concept of unit-hypercube. By representing each airport as a point in the given reference metric space, the geometric distance among airports—which corresponds to a measure of similarity—has in fact an intrinsic fuzzy nature due to the airport specific characteristics. The proposed procedure has been applied to a test case concerning the Italian airport network and the obtained results are in line with expectations.

Geometric interpretation of optimal iteration strategies

International Nuclear Information System (INIS)

Jones, R.B.

1977-01-01

The relationship between inner and outer iteration errors is extremely complex, and even formal description of total error behavior is difficult. Inner and outer iteration error propagation is analyzed in a variational formalism for a reactor model describing multidimensional, one-group theory. In a generalization the work of Akimov and Sabek, the number of inner iterations performed during each outer serial that minimizes the total computation time is determined. The generalized analysis admits a geometric interpretation of total error behavior. The results can be applied to both transport and diffusion theory computer methods. 1 figure

The research into development of passanger transport by land

Directory of Open Access Journals (Sweden)

J. Butkevičius

2004-10-01

Full Text Available This is the first scientific work in Lithuania carrying out a complex research into passenger transport by land, covering all problematic issues related to the field such as development, market planning, organization, management, competition, contractual relations, financing, development of transport technologies, implementation of new transport technologies elaborating the theoretical base for the development of passenger transport. The research shows the analysis of the movement of passenger transport volumes and determines the regularity of these changes. The forecast of passenger transport by land is based on a multiple analysis. The work determines the perspective markets of rail and road transport as well as elaborates the principles of the improvement of road and rail transport interaction.The author originates the principles of the development of passenger transport technologies and the principles of the implementation of advanced technologies. The author also founds the principles of planning, organization and management of land transport as well as the principles of security of equal conditions of competition and contractual relations between customers and haulers.

Visualizing the Geometric Series.

Science.gov (United States)

Bennett, Albert B., Jr.

1989-01-01

Mathematical proofs often leave students unconvinced or without understanding of what has been proved, because they provide no visual-geometric representation. Presented are geometric models for the finite geometric series when r is a whole number, and the infinite geometric series when r is the reciprocal of a whole number. (MNS)

CARONTE project: Creating an Agenda for Research on Transportation Security

Energy Technology Data Exchange (ETDEWEB)

Leon Bello, J.; Gonzalez Viosca, E.

2016-07-01

Europe’s prosperity relies on effective transport systems. Any attacks and disturbances to land freight and passenger transport would have significant impact on economic growth, territorial cohesion, social development and the environment. Unfortunately, there are weaknesses in the land transport security.The objective of CARONTE project is define a future research agenda for security in land transport that focuses on core gaps caused by emerging risks while avoiding any doubling-up of research elsewhere. Its research agenda will cover all threats, including cyber-crime, and security aspects across all modes of land transportation. At the same time, it will respect the fundamental human rights and privacy of European citizens. The step-by-step method of CARONTE’s consortium has analyzed the state of the art and emerging risks; has identified gaps, analyses and assessments of potential solutions; and has produced an overall research agenda for the future. CARONTE’s results will answer the following questions among others: Which existing research projects merit a follow up and extension? Where are the combinations or synergy effects to be attended? Which themes and topics should be elaborated in new research projects? Who should be involved and integrated in future research projects (stakeholders, authorities, etc.)? The CARONTE consortium includes universities and research institutes, companies, and end-users providing with experience in research and consultancy in transportation, logistics, infrastructure management, security and communications. ITENE - Instituto Tecnológico del Embalaje, Transporte y Logística-has been one of the Project partners among a total of 11 members from eight different countries in the European Union which have also been supported via a High Level Advisory Board. (Author)

On bivariate geometric distribution

Directory of Open Access Journals (Sweden)

K. Jayakumar

2013-05-01

Full Text Available Characterizations of bivariate geometric distribution using univariate and bivariate geometric compounding are obtained. Autoregressive models with marginals as bivariate geometric distribution are developed. Various bivariate geometric distributions analogous to important bivariate exponential distributions like, Marshall-Olkin’s bivariate exponential, Downton’s bivariate exponential and Hawkes’ bivariate exponential are presented.

Education in Transportation Systems Planning: Highway Research Record No. 462.

Science.gov (United States)

National Academy of Sciences - National Research Council, Washington, DC. Transportation Research Board.

The papers contained in the issue of Highway Research Record focus on current and emerging patterns of education and training related to transportation systems planning. The five papers are: Transportation Centers and Other Mechanisms to Encourage Interdisciplinary Research and Training Efforts in Transportation (Frederick J. Wegmann and Edward A.…

Overview of NASA's Next Generation Air Transportation System (NextGen) Research

Science.gov (United States)

Swenson, Harry N.

2009-01-01

This slide presentation is an overview of the research for the Next Generation Air Transportation System (NextGen). Included is a review of the current air transportation system and the challenges of air transportation research. Also included is a review of the current research highlights and significant accomplishments.

75 FR 24773 - Research and Innovative Technology Administration Advisory Council on Transportation Statistics...

Science.gov (United States)

2010-05-05

... DEPARTMENT OF TRANSPORTATION Bureau of Transportation Statistics Research and Innovative Technology Administration Advisory Council on Transportation Statistics; Notice of Meeting AGENCY: Research... Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, Attention...

4th Italian-Japanese workshop on Geometric Properties for Parabolic and Elliptic PDE’s

CERN Document Server

Ishige, Kazuhiro; Nitsch, Carlo; Salani, Paolo

2016-01-01

This book collects recent research papers by respected specialists in the field. It presents advances in the field of geometric properties for parabolic and elliptic partial differential equations, an area that has always attracted great attention. It settles the basic issues (existence, uniqueness, stability and regularity of solutions of initial/boundary value problems) before focusing on the topological and/or geometric aspects. These topics interact with many other areas of research and rely on a wide range of mathematical tools and techniques, both analytic and geometric. The Italian and Japanese mathematical schools have a long history of research on PDEs and have numerous active groups collaborating in the study of the geometric properties of their solutions. .

Geometrical parton

Energy Technology Data Exchange (ETDEWEB)

Ebata, T [Tohoku Univ., Sendai (Japan). Coll. of General Education

1976-06-01

The geometrical distribution inferred from the inelastic cross section is assumed to be proportional to the partial waves. The precocious scaling and the Q/sup 2/-dependence of various quantities are treated from the geometrical point of view. It is shown that the approximate conservation of the orbital angular momentum may be a very practical rule to understand the helicity structure of various hadronic and electromagnetic reactions. The rule can be applied to inclusive reactions as well. The model is also applied to large angle processes. Through the discussion, it is suggested that many peculiar properties of the quark-parton can be ascribed to the geometrical effects.

Transport safety research abstracts. No. 2. Information on research recently concluded and in progress

International Nuclear Information System (INIS)

1994-09-01

Transport Safety Research Abstracts (TSRA) was first published by the IAEA in 1991 as a means of disseminating information on research in radioactive material transport. This second edition utilizes International Nuclear Information System (INIS) protocol for data processing and report preparation for a research-in-progress database established by the IAEA's Division of Scientific and Technical Information. INIS subject categories and descriptors are included in the information about each project

Transport safety research abstracts. No. 2. Information on research recently concluded and in progress

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-09-01

Transport Safety Research Abstracts (TSRA) was first published by the IAEA in 1991 as a means of disseminating information on research in radioactive material transport. This second edition utilizes International Nuclear Information System (INIS) protocol for data processing and report preparation for a research-in-progress database established by the IAEA`s Division of Scientific and Technical Information. INIS subject categories and descriptors are included in the information about each project.

Research on geometric rectification of the Large FOV Linear Array Whiskbroom Image

Science.gov (United States)

Liu, Dia; Liu, Hui-tong; Dong, Hao; Liu, Xiao-bo

2015-08-01

To solve the geometric distortion problem of large FOV linear array whiskbroom image, a model of multi center central projection collinearity equation was founded considering its whiskbroom and linear CCD imaging feature, and the principle of distortion was analyzed. Based on the rectification method with POS, we introduced the angular position sensor data of the servo system, and restored the geometric imaging process exactly. An indirect rectification scheme aiming at linear array imaging with best scanline searching method was adopted, matrixes for calculating the exterior orientation elements was redesigned. We improved two iterative algorithms for this device, and did comparison and analysis. The rectification for the images of airborne imaging experiment showed ideal effect.

Dynamics in geometrical confinement

CERN Document Server

Kremer, Friedrich

2014-01-01

This book describes the dynamics of low molecular weight and polymeric molecules when they are constrained under conditions of geometrical confinement. It covers geometrical confinement in different dimensionalities: (i) in nanometer thin layers or self supporting films (1-dimensional confinement) (ii) in pores or tubes with nanometric diameters (2-dimensional confinement) (iii) as micelles embedded in matrices (3-dimensional) or as nanodroplets.The dynamics under such conditions have been a much discussed and central topic in the focus of intense worldwide research activities within the last two decades. The present book discusses how the resulting molecular mobility is influenced by the subtle counterbalance between surface effects (typically slowing down molecular dynamics through attractive guest/host interactions) and confinement effects (typically increasing the mobility). It also explains how these influences can be modified and tuned, e.g. through appropriate surface coatings, film thicknesses or pore...

Gravity, a geometrical course

CERN Document Server

Frè, Pietro Giuseppe

2013-01-01

‘Gravity, a Geometrical Course’ presents general relativity (GR) in a systematic and exhaustive way, covering three aspects that are homogenized into a single texture: i) the mathematical, geometrical foundations, exposed in a self consistent contemporary formalism, ii) the main physical, astrophysical and cosmological applications,  updated to the issues of contemporary research and observations, with glimpses on supergravity and superstring theory, iii) the historical development of scientific ideas underlying both the birth of general relativity and its subsequent evolution. The book is divided in two volumes.   Volume One is dedicated to the development of the theory and basic physical applications. It guides the reader from the foundation of special relativity to Einstein field equations, illustrating some basic applications in astrophysics. A detailed  account  of the historical and conceptual development of the theory is combined with the presentation of its mathematical foundations.  Differe...

Geometric modeling in probability and statistics

CERN Document Server

Calin, Ovidiu

2014-01-01

This book covers topics of Informational Geometry, a field which deals with the differential geometric study of the manifold probability density functions. This is a field that is increasingly attracting the interest of researchers from many different areas of science, including mathematics, statistics, geometry, computer science, signal processing, physics and neuroscience. It is the authors’ hope that the present book will be a valuable reference for researchers and graduate students in one of the aforementioned fields. This textbook is a unified presentation of differential geometry and probability theory, and constitutes a text for a course directed at graduate or advanced undergraduate students interested in applications of differential geometry in probability and statistics. The book contains over 100 proposed exercises meant to help students deepen their understanding, and it is accompanied by software that is able to provide numerical computations of several information geometric objects. The reader...

Geometrization of the Electromagnetic Field and Dark Matter

CERN Document Server

Pestov, I B

2005-01-01

A general concept of potential field is introduced. The potential field that one puts in correspondence with dark matter, has fundamental geometrical interpretation (parallel transport) and has intrinsically inherent local symmetry. The equations of dark matter field are derived that are invariant with respect to the local transformations. It is shown how to reduce these equations to the Maxwell equations. Thus, the dark matter field may be considered as generalized lectromagnetic field and a simple solution of the old problem is given to connect electromagnetic field with geometrical properties of the physical manifold itself. It is shown that gauge fixing renders generalized electromagnetic field effectively massive while the Maxwell electromagnetic field remains massless. To learn more about interactions between matter and dark matter on the microscopical level (and to recognize the fundamental role of internal symmetry) the general covariant Dirac equation is derived in the Minkowski space--time which des...

[TRANSPORT OF OXYGEN DURING GEOMETRICAL RECONSTRUCTION OF THE LEFT VENTRICLE IN CONJUNCTION WITH CORONARY ARTERY BYPASS GRAFTING AND USING OF HIGH THORACIC EPIDURAL ANESTHESIA AS A MAJOR COMPONENT OF GENERAL ANAESTHESIA].

Science.gov (United States)

Zatevahina, M V; Farzutdinov, A F; Rahimov, A A; Makrushin, I M; Kvachantiradze, G Y

2015-01-01

The purpose of the study is to examine the perioperative dynamics of strategic blood oxygen transport indicators: delivery (DO2), consumption (VO2), the coefficient of oxygen uptake (CUO2) and their composition, as well as the dynamics of blood lactate indicators in patients with ischaemic heart disease (IHD) who underwent surgery under cardiopulmonary bypass with high thoracic epidural anaesthesia (HTEA) as the main component of anesthesia. Research was conducted in 30 patients with a critical degree of operational risk, during the correction of post-infarction heart aneurysmn using the V. Dor method in combination with coronary artery bypass grafting. The strategic blood oxygen transport indicators (delivery, consumption and the oxygen uptake coefficient) showed a statistically significant decrease compared to the physiological norm and to the initial data at two points of the research: the intubation of the trachea and during cardiopulmonary bypass. The system components of oxygen were influenced at problematic stages by the dynamics of SvO2 (increase), AVD (decrease), hemodilution withe fall of the HIb- in the process of JR in the persence of superficial hypothermia. The maintenance of optimal CA in the context of HTEA, combined with a balanced volemic load and a minimized cardiotonic support ensured the stabilisation of strategic blood oxygen transport indicators aithe postperfusion stage and during the immediate postoperative period The article is dedicated to the study of strategic blood oxygen transport indicators and their components during the operation of geometric reconstruc-tion of the left ventricle combined with coronary artery-bypass using cardiopulmonary bypass and with high thoracic epidural anesthesia as the main component of general anaesthesia. The analysis has covered the stagewise delivery dynamics, consumption and the oxygen uptake coefficient at II stages of the operation and of the immediate postoperative period. The study has ident (fled

Fostering transport and logistics research in the Benelux countries

NARCIS (Netherlands)

Witlox, Frank; Dullaert, Wout; Jourquin, Bart

Promoting high quality research and education in the field of transport, within its region, is the main goal of the Benelux Interuniversity Association of Transport Economists - BIVEC-GIBET for short. Founded in 1978, the Association has evolved from a small group of transport economists into a

A practical guide to experimental geometrical optics

CERN Document Server

Garbovskiy, Yuriy A

2017-01-01

A concise, yet deep introduction to experimental, geometrical optics, this book begins with fundamental concepts and then develops the practical skills and research techniques routinely used in modern laboratories. Suitable for students, researchers and optical engineers, this accessible text teaches readers how to build their own optical laboratory and to design and perform optical experiments. It uses a hands-on approach which fills a gap between theory-based textbooks and laboratory manuals, allowing the reader to develop their practical skills in this interdisciplinary field, and also explores the ways in which this knowledge can be applied to the design and production of commercial optical devices. Including supplementary online resources to help readers track and evaluate their experimental results, this text is the ideal companion for anyone with a practical interest in experimental geometrical optics.

An Investigation into the Effect of Using Geometric and Non-Geometric Shapes on the Desirability of Human Character Stylization in Children’s Narrative Fiction Illustration

Directory of Open Access Journals (Sweden)

Hajar Salimi Namin

2017-12-01

Full Text Available This study aims to investigate the effect of teaching the using of geometric and non-geometric shapes on human character stylization created by undergraduate graphic design students with poor performance in illustration of children's narrative fiction. The research methodology includes an experimental research by pre- and post-testing with test group in the next stage. Statistical population of the study consists of female undergraduate sophomores of graphic design at Faculty of Arts, Al-Zahra University in 2017. The students were first subjected to pretesting, and then the training package was provided to them and they were again subjected to testing. 35 students are selected to conduct the research. The tools used in this study include files, materials in the books, articles and related sites, experiments and appraisal forms. The results show that there is a significant difference between the pre-test and post-test. The independent variable thus creates a significant difference in the test group and is able to improve the human character stylization implemented by undergraduate students of graphic design at the post-test stage. Therefore, it is suggested to employ using of geometric and non-geometric shapes in order to teach human character stylization to the students.

Morphing of geometric composites via residual swelling.

Science.gov (United States)

Pezzulla, Matteo; Shillig, Steven A; Nardinocchi, Paola; Holmes, Douglas P

2015-08-07

Understanding and controlling the shape of thin, soft objects has been the focus of significant research efforts among physicists, biologists, and engineers in the last decade. These studies aim to utilize advanced materials in novel, adaptive ways such as fabricating smart actuators or mimicking living tissues. Here, we present the controlled growth-like morphing of 2D sheets into 3D shapes by preparing geometric composite structures that deform by residual swelling. The morphing of these geometric composites is dictated by both swelling and geometry, with diffusion controlling the swelling-induced actuation, and geometric confinement dictating the structure's deformed shape. Building on a simple mechanical analog, we present an analytical model that quantitatively describes how the Gaussian and mean curvatures of a thin disk are affected by the interplay among geometry, mechanics, and swelling. This model is in excellent agreement with our experiments and numerics. We show that the dynamics of residual swelling is dictated by a competition between two characteristic diffusive length scales governed by geometry. Our results provide the first 2D analog of Timoshenko's classical formula for the thermal bending of bimetallic beams - our generalization explains how the Gaussian curvature of a 2D geometric composite is affected by geometry and elasticity. The understanding conferred by these results suggests that the controlled shaping of geometric composites may provide a simple complement to traditional manufacturing techniques.

Geometric information provider platform

Directory of Open Access Journals (Sweden)

Meisam Yousefzadeh

2015-07-01

Full Text Available Renovation of existing buildings is known as an essential stage in reduction of the energy loss. Considerable part of renovation process depends on geometric reconstruction of building based on semantic parameters. Following many research projects which were focused on parameterizing the energy usage, various energy modelling methods were developed during the last decade. On the other hand, by developing accurate measuring tools such as laser scanners, the interests of having accurate 3D building models are rapidly growing. But the automation of 3D building generation from laser point cloud or detection of specific objects in that is still a challenge.  The goal is designing a platform through which required geometric information can be efficiently produced to support energy simulation software. Developing a reliable procedure which extracts required information from measured data and delivers them to a standard energy modelling system is the main purpose of the project.

Subsurface transport with emphasis on hydrology: research needs. Subsurface Transport Program

International Nuclear Information System (INIS)

Zachara, J.M.; Wildung, R.E.

1982-03-01

A number of energy technologies presently in operation or under development generate solid wastes in large quantities as a major byproduct. These wastes will, for the most part, be disposed to the ground in landfills or inactive mine sites. Although the waste materials differ significantly among technologies, most contain residual, water-soluble chemical components which are of ecological and human health concern. Thus, in ground disposal may have a significant long-term impact on water supplies and human health if not properly conducted. With the growing magnitude of solid waste disposal operations, it becomes imperative to establish common ground between technologies such that research in this complex area can be efficiently managed to benefit a variety of users. This report develops the concept of multitechnology or generic research in subsurface transport with emphasis on hydrogeochemistry. Initially, a generic research approach was developed independent of waste characteristics. This approach both identified and prioritized the research information or experimentation and data management tools (models) required to resolve major technical concerns for in ground disposal. Waste characteristics were then evaluated to identify the common, cross-technology information needs. This evaluation indicated that solid wastes from energy producing technologies have physiocochemical properties in common which serve as a useful basis for identification of fundamental, generic research needs. Priority research projects are suggested for addressing contaminant identification, solubilization, transformation and transport. 38 references, 3 tables

Lessons learned from bacterial transport research at the South Oyster Site

Energy Technology Data Exchange (ETDEWEB)

Scheibe, T.; Hubbard, S.S.; Onstott, T.C.; DeFlaun, M.F.

2011-04-01

This paper provides a review of bacterial transport experiments conducted by a multi-investigator, multi-institution, multi-disciplinary team of researchers under the auspices of the U. S. Department of Energy (DOE). The experiments were conducted during the time period 1999-2001 at a field site near the town of Oyster, Virginia known as the South Oyster Site, and included four major experimental campaigns aimed at understanding and quantifying bacterial transport in the subsurface environment. Several key elements of the research are discussed here: (1) quantification of bacterial transport in physically, chemically and biologically heterogeneous aquifers, (2) evaluation of the efficacy of conventional colloid filtration theory, (3) scale effects in bacterial transport, (4) development of new methods for microbial enumeration and screening for low adhesion strains, (5) application of novel hydrogeophysical techniques for aquifer characterization, and (6) experiences regarding management of a large field research effort. Lessons learned are summarized in each of these areas. The body of literature resulting from South Oyster Site research has been widely cited and continues to influence research into the controls exerted by aquifer heterogeneity on reactive transport (including microbial transport). It also served as a model (and provided valuable experience) for subsequent and ongoing highly-instrumented field research efforts conducted by DOE-sponsored investigators.

Geometrization of the electromagnetic field and dark matter

International Nuclear Information System (INIS)

Pestov, I.B.

2005-01-01

A general concept of potential field is introduced. The potential field that one puts in correspondence with dark matter, has fundamental geometrical interpretation (parallel transport) and has intrinsically inherent local symmetry. The equations of dark matter field are derived that are invariant with respect to the local transformations. It is shown how to reduce these equations to the Maxwell equations. Thus, the dark matter field may be considered as generalized electromagnetic field and a simple solution of the old problem is given to connect electromagnetic field with geometrical properties of the physical manifold itself. It is shown that gauge fixing renders generalized electromagnetic field effectively massive while the Maxwell electromagnetic field remains massless. To learn more about interactions between matter and dark matter on the microscopical level (and to recognize the fundamental role of internal symmetry) the general covariant Dirac equation is derived in the Minkowski space-time which describes the interactions of spinor field with dark matter field

Geometrical tile design for complex neighborhoods.

Science.gov (United States)

Czeizler, Eugen; Kari, Lila

2009-01-01

Recent research has showed that tile systems are one of the most suitable theoretical frameworks for the spatial study and modeling of self-assembly processes, such as the formation of DNA and protein oligomeric structures. A Wang tile is a unit square, with glues on its edges, attaching to other tiles and forming larger and larger structures. Although quite intuitive, the idea of glues placed on the edges of a tile is not always natural for simulating the interactions occurring in some real systems. For example, when considering protein self-assembly, the shape of a protein is the main determinant of its functions and its interactions with other proteins. Our goal is to use geometric tiles, i.e., square tiles with geometrical protrusions on their edges, for simulating tiled paths (zippers) with complex neighborhoods, by ribbons of geometric tiles with simple, local neighborhoods. This paper is a step toward solving the general case of an arbitrary neighborhood, by proposing geometric tile designs that solve the case of a "tall" von Neumann neighborhood, the case of the f-shaped neighborhood, and the case of a 3 x 5 "filled" rectangular neighborhood. The techniques can be combined and generalized to solve the problem in the case of any neighborhood, centered at the tile of reference, and included in a 3 x (2k + 1) rectangle.

Sustainable Transportation Systems Research Group: Ongoing and Past Activities

OpenAIRE

Gkritza, Konstantina "Nadia"; Hurtado, Davis Chacon; Gkartzonikas, Christos; Ke, Yue; Losada, Lisa L

2017-01-01

This presentation describes the ongoing and past activities of the Sustainable Transportation Systems Research (STSR) group at Purdue University (https://engineering.purdue.edu/STSRG). The STSR group aims to achieve green, safe, efficient, and equitable transportation systems by studying and modeling transportation externalities, using state of the art statistical, econometric, and economic analysis tools.

Optical photon transport in powdered-phosphor scintillators. Part II. Calculation of single-scattering transport parameters

Energy Technology Data Exchange (ETDEWEB)

Poludniowski, Gavin G. [Joint Department of Physics, Division of Radiotherapy and Imaging, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT, United Kingdom and Centre for Vision Speech and Signal Processing (CVSSP), Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Evans, Philip M. [Centre for Vision Speech and Signal Processing (CVSSP), Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

2013-04-15

Purpose: Monte Carlo methods based on the Boltzmann transport equation (BTE) have previously been used to model light transport in powdered-phosphor scintillator screens. Physically motivated guesses or, alternatively, the complexities of Mie theory have been used by some authors to provide the necessary inputs of transport parameters. The purpose of Part II of this work is to: (i) validate predictions of modulation transform function (MTF) using the BTE and calculated values of transport parameters, against experimental data published for two Gd{sub 2}O{sub 2}S:Tb screens; (ii) investigate the impact of size-distribution and emission spectrum on Mie predictions of transport parameters; (iii) suggest simpler and novel geometrical optics-based models for these parameters and compare to the predictions of Mie theory. A computer code package called phsphr is made available that allows the MTF predictions for the screens modeled to be reproduced and novel screens to be simulated. Methods: The transport parameters of interest are the scattering efficiency (Q{sub sct}), absorption efficiency (Q{sub abs}), and the scatter anisotropy (g). Calculations of these parameters are made using the analytic method of Mie theory, for spherical grains of radii 0.1-5.0 {mu}m. The sensitivity of the transport parameters to emission wavelength is investigated using an emission spectrum representative of that of Gd{sub 2}O{sub 2}S:Tb. The impact of a grain-size distribution in the screen on the parameters is investigated using a Gaussian size-distribution ({sigma}= 1%, 5%, or 10% of mean radius). Two simple and novel alternative models to Mie theory are suggested: a geometrical optics and diffraction model (GODM) and an extension of this (GODM+). Comparisons to measured MTF are made for two commercial screens: Lanex Fast Back and Lanex Fast Front (Eastman Kodak Company, Inc.). Results: The Mie theory predictions of transport parameters were shown to be highly sensitive to both grain size

The effect of photometric and geometric context on photometric and geometric lightness effects.

Science.gov (United States)

Lee, Thomas Y; Brainard, David H

2014-01-24

We measured the lightness of probe tabs embedded at different orientations in various contextual images presented on a computer-controlled stereo display. Two background context planes met along a horizontal roof-like ridge. Each plane was a graphic rendering of a set of achromatic surfaces with the simulated illumination for each plane controlled independently. Photometric context was varied by changing the difference in simulated illumination intensity between the two background planes. Geometric context was varied by changing the angle between them. We parsed the data into separate photometric effects and geometric effects. For fixed geometry, varying photometric context led to linear changes in both the photometric and geometric effects. Varying geometric context did not produce a statistically reliable change in either the photometric or geometric effects.

Operations Research in PassengerRaiway Transportation

NARCIS (Netherlands)

D. Huisman (Dennis); L.G. Kroon (Leo); R.M. Lentink (Ramon); M.J.C.M. Vromans (Michiel)

2005-01-01

textabstractIn this paper we give an overview of state-of-the-art Operations Research models and techniques used in passenger railway transportation. For each planning phase (strategic, tactical and operational), we describe the planning problems arising there and discuss some models and algorithms

Geometric group theory

CERN Document Server

Druţu, Cornelia

2018-01-01

The key idea in geometric group theory is to study infinite groups by endowing them with a metric and treating them as geometric spaces. This applies to many groups naturally appearing in topology, geometry, and algebra, such as fundamental groups of manifolds, groups of matrices with integer coefficients, etc. The primary focus of this book is to cover the foundations of geometric group theory, including coarse topology, ultralimits and asymptotic cones, hyperbolic groups, isoperimetric inequalities, growth of groups, amenability, Kazhdan's Property (T) and the Haagerup property, as well as their characterizations in terms of group actions on median spaces and spaces with walls. The book contains proofs of several fundamental results of geometric group theory, such as Gromov's theorem on groups of polynomial growth, Tits's alternative, Stallings's theorem on ends of groups, Dunwoody's accessibility theorem, the Mostow Rigidity Theorem, and quasiisometric rigidity theorems of Tukia and Schwartz. This is the f...

Research on centrality of urban transport network nodes

Science.gov (United States)

Wang, Kui; Fu, Xiufen

2017-05-01

Based on the actual data of urban transport in Guangzhou, 19,150 bus stations in Guangzhou (as of 2014) are selected as nodes. Based on the theory of complex network, the network model of Guangzhou urban transport is constructed. By analyzing the degree centrality index, betweenness centrality index and closeness centrality index of nodes in the network, the level of centrality of each node in the network is studied. From a different point of view to determine the hub node of Guangzhou urban transport network, corresponding to the city's key sites and major transfer sites. The reliability of the network is determined by the stability of some key nodes (transport hub station). The research of network node centralization can provide a theoretical basis for the rational allocation of urban transport network sites and public transport system planning.

Lifting the geometric frustration through a monoclinic distortion in “114” YBaFe4O7.0: Magnetism and transport

International Nuclear Information System (INIS)

Duffort, V.; Sarkar, T.; Caignaert, V.; Pralong, V.; Raveau, B.; Avdeev, M.; Cervellino, A.; Waerenborgh, J.C.; Tsipis, E.V.

2013-01-01

The possibility to lift the geometric frustration in the “114” stoichiomeric tetragonal oxide YBaFe 4 O 7.0 by decreasing the temperature has been investigated using neutron and synchrotron powder diffraction techniques. Besides the structural transition from tetragonal to monoclinic symmetry that appears at T S =180 K, a magnetic transition is observed below T N =95 K. The latter corresponds to a lifting of the 3D geometric frustration toward an antiferromagnetic long range ordering, never observed to date in a cubic based “114’” oxide. The magnetic structure, characterized by the propagation vector k 1 =(0,0,½), shows that one iron Fe2 exhibits a larger magnetic moment than the three others, suggesting a possible charge ordering according to the formula YBaFe 3+ Fe 3 2+ O 7.0 . The magnetic M(T) and χ′(T) curves, in agreement with neutron data, confirm the structural and magnetic transitions and evidence the coexistence of residual magnetic frustration. Moreover, the transport measurements show a resistive transition from a thermally activated conduction mechanism to a variable range hopping mechanism at T S =180 K, with a significant increase of the dependence of the resistivity vs. temperature. Mössbauer spectroscopy clearly evidences a change in the electronic configuration of the iron framework at the structural transition as well as coexistence of several oxidation states. The role of barium underbonding in these transitions is discussed. - Graphical abstract: Atomic displacements at the tetragonal-monoclinic transition in YBaFe 4 O 7 . Display Omitted - Highlights: • The structural and magnetic phase transitions of YBaFe 4 O 7 were studied below room temperature. • The tetragonal to monoclinic transition, characterized by NPD and SXRD, was studied using mode crystallography approach. • Monoclinic distortion allows the lifting of the geometrical frustration on the iron sublattice, leading to AF order at T=95 K

The Creativity of Reflective and Impulsive Selected Students in Solving Geometric Problems

Science.gov (United States)

Shoimah, R. N.; Lukito, A.; Siswono, T. Y. E.

2018-01-01

This research purposed to describe the elementary students’ creativity with reflective and impulsive cognitive style in solving geometric problems. This research used qualitative research methods. The data was collected by written tests and task-based interviews. The subjects consisted of two 5th grade students that were measured by MFFT (Matching Familiar Figures Test). The data were analyzed based on the three main components of creativity; that is fluency, flexibility, and novelty. This results showed that subject with reflective cognitive style in solving geometric problems met all components of creativity (fluency; subject generated more than three different right-ideas in solving problems, flexibility; subject generated more than two different ways to get problem solved, and novelty; subject generated new ideas and new ways that original and has never been used before). While subject with impulsive cognitive style in solving geometric problems met two components of creativity (fluency; subject generated more than three different right-ideas in solving problems, flexibility; subject generated two different ways to get problem solved). Thus, it could be concluded that reflective students are more creative in solving geometric problems. The results of this research can also be used as a guideline in the future assessment of creativity based on cognitive style.

Development of the public transport research compendium portal

CSIR Research Space (South Africa)

Dimitrov, L

2009-07-01

Full Text Available research and development programme. The research compendium portal is a database providing access to information pertaining to public transport projects in the Republic of South Africa from 2003. The specific projects include regulatory, policy...

Geometrical foundations of continuum mechanics an application to first- and second-order elasticity and elasto-plasticity

CERN Document Server

Steinmann, Paul

2015-01-01

This book illustrates the deep roots of the geometrically nonlinear kinematics of generalized continuum mechanics in differential geometry. Besides applications to first- order elasticity and elasto-plasticity an appreciation thereof is particularly illuminating for generalized models of continuum mechanics such as second-order (gradient-type) elasticity and elasto-plasticity.   After a motivation that arises from considering geometrically linear first- and second- order crystal plasticity in Part I several concepts from differential geometry, relevant for what follows, such as connection, parallel transport, torsion, curvature, and metric for holonomic and anholonomic coordinate transformations are reiterated in Part II. Then, in Part III, the kinematics of geometrically nonlinear continuum mechanics are considered. There various concepts of differential geometry, in particular aspects related to compatibility, are generically applied to the kinematics of first- and second- order geometrically nonlinear con...

Geometric Transformations in Engineering Geometry

Directory of Open Access Journals (Sweden)

I. F. Borovikov

2015-01-01

Full Text Available Recently, for business purposes, in view of current trends and world experience in training engineers, research and faculty staff there has been a need to transform traditional courses of descriptive geometry into the course of engineering geometry in which the geometrical transformations have to become its main section. On the basis of critical analysis the paper gives suggestions to improve a presentation technique of this section both in the classroom and in academic literature, extend an application scope of geometrical transformations to solve the position and metric tasks and simulation of surfaces, as well as to design complex engineering configurations, which meet a number of pre-specified conditions.The article offers to make a number of considerable amendments to the terms and definitions used in the existing courses of descriptive geometry. It draws some conclusions and makes the appropriate proposals on feasibility of coordination in teaching the movement transformation in the courses of analytical and descriptive geometry. This will provide interdisciplinary team teaching and allow students to be convinced that a combination of analytical and graphic ways to solve geometric tasks is useful and reasonable.The traditional sections of learning courses need to be added with a theory of projective and bi-rational transformations. In terms of application simplicity and convenience it is enough to consider the central transformations when solving the applied tasks. These transformations contain a beam of sub-invariant (low-invariant straight lines on which the invariant curve induces non-involution and involution projectivities. The expediency of nonlinear transformations application is shown in the article by a specific example of geometric modeling of the interfacing surface "spar-blade".Implementation of these suggestions will contribute to a real transformation of a traditional course of descriptive geometry to the engineering geometry

On geometrized gravitation theories

International Nuclear Information System (INIS)

Logunov, A.A.; Folomeshkin, V.N.

1977-01-01

General properties of the geometrized gravitation theories have been considered. Geometrization of the theory is realized only to the extent that by necessity follows from an experiment (geometrization of the density of the matter Lagrangian only). Aor a general case the gravitation field equations and the equations of motion for matter are formulated in the different Riemann spaces. A covariant formulation of the energy-momentum conservation laws is given in an arbitrary geometrized theory. The noncovariant notion of ''pseudotensor'' is not required in formulating the conservation laws. It is shown that in the general case (i.e., when there is an explicit dependence of the matter Lagrangian density on the covariant derivatives) a symmetric energy-momentum tensor of the matter is explicitly dependent on the curvature tensor. There are enlisted different geometrized theories that describe a known set of the experimental facts. The properties of one of the versions of the quasilinear geometrized theory that describes the experimental facts are considered. In such a theory the fundamental static spherically symmetrical solution has a singularity only in the coordinate origin. The theory permits to create a satisfactory model of the homogeneous nonstationary Universe

Factorization of Transport Coefficients in Macroporous Media

DEFF Research Database (Denmark)

Shapiro, Alexander; Stenby, Erling Halfdan

2000-01-01

We prove the fundamental theorem about factorization of the phenomenological coefficients for transport in macroporous media. By factorization we mean the representation of the transport coefficients as products of geometric parameters of the porous medium and the parameters characteristic...

How Sensitive Are Transdermal Transport Predictions by Microscopic Stratum Corneum Models to Geometric and Transport Parameter Input?

Science.gov (United States)

Wen, Jessica; Koo, Soh Myoung; Lape, Nancy

2018-02-01

While predictive models of transdermal transport have the potential to reduce human and animal testing, microscopic stratum corneum (SC) model output is highly dependent on idealized SC geometry, transport pathway (transcellular vs. intercellular), and penetrant transport parameters (e.g., compound diffusivity in lipids). Most microscopic models are limited to a simple rectangular brick-and-mortar SC geometry and do not account for variability across delivery sites, hydration levels, and populations. In addition, these models rely on transport parameters obtained from pure theory, parameter fitting to match in vivo experiments, and time-intensive diffusion experiments for each compound. In this work, we develop a microscopic finite element model that allows us to probe model sensitivity to variations in geometry, transport pathway, and hydration level. Given the dearth of experimentally-validated transport data and the wide range in theoretically-predicted transport parameters, we examine the model's response to a variety of transport parameters reported in the literature. Results show that model predictions are strongly dependent on all aforementioned variations, resulting in order-of-magnitude differences in lag times and permeabilities for distinct structure, hydration, and parameter combinations. This work demonstrates that universally predictive models cannot fully succeed without employing experimentally verified transport parameters and individualized SC structures. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Geometric metamorphosis.

Science.gov (United States)

Niethammer, Marc; Hart, Gabriel L; Pace, Danielle F; Vespa, Paul M; Irimia, Andrei; Van Horn, John D; Aylward, Stephen R

2011-01-01

Standard image registration methods do not account for changes in image appearance. Hence, metamorphosis approaches have been developed which jointly estimate a space deformation and a change in image appearance to construct a spatio-temporal trajectory smoothly transforming a source to a target image. For standard metamorphosis, geometric changes are not explicitly modeled. We propose a geometric metamorphosis formulation, which explains changes in image appearance by a global deformation, a deformation of a geometric model, and an image composition model. This work is motivated by the clinical challenge of predicting the long-term effects of traumatic brain injuries based on time-series images. This work is also applicable to the quantification of tumor progression (e.g., estimating its infiltrating and displacing components) and predicting chronic blood perfusion changes after stroke. We demonstrate the utility of the method using simulated data as well as scans from a clinical traumatic brain injury patient.

CIME course on Ricci Flow and Geometric Applications

CERN Document Server

Mantegazza, Carlo

2016-01-01

Presenting some impressive recent achievements in differential geometry and topology, this volume focuses on results obtained using techniques based on Ricci flow. These ideas are at the core of the study of differentiable manifolds. Several very important open problems and conjectures come from this area and the techniques described herein are used to face and solve some of them. The book's four chapters are based on lectures given by leading researchers in the field of geometric analysis and low-dimensional geometry/topology, respectively offering an introduction to: the differentiable sphere theorem (G. Besson), the geometrization of 3-manifolds (M. Boileau), the singularities of 3-dimensional Ricci flows (C. Sinestrari), and Kahler-Ricci flow (G. Tian). The lectures will be particularly valuable to young researchers interested in differential manifolds.

Transportation research activities in support of nuclear waste management programs

International Nuclear Information System (INIS)

Allen, G.C. Jr.; Cashwell, J.W.; Jefferson, R.M.

1983-01-01

Transportation Technology Center has been conducting a wide range of technical research activities to assure the ability to transport radioactive materials in a safe, reliable manner. These activities include tasks in basic, analysis methodology and system research areas. Recently, the requirements of defense waste shipments have served as a focal point for development tasks with the expectation that they would serve as a precursor for commercial activities. The passage of the Nuclear Waste Policy Act has placed additional responsibility on the Department of Energy for concerns involving the shipments of civilian materials. The development of additional research responsibilities is expected to proceed concurrently with the evolution of the transportation mission plan for civilian spent fuel and high-level wastes

Experimental Study of Vibration Isolation Characteristics of a Geometric Anti-Spring Isolator

Directory of Open Access Journals (Sweden)

Lixun Yan

2017-07-01

Full Text Available In order to realize low-frequency vibration isolation, a novel geometric anti-spring isolator consisting of several cantilever blade springs are developed in this paper. The optimal design parameters of the geometric anti-spring isolator for different nonlinear geometric parameters are theoretically obtained. The transmissibility characteristic of the geometric anti-spring isolator is investigated through mathematical simulation. A geometric anti-spring isolator with a nonlinear geometric parameter of 0.92 is designed and its vibration isolation performance and nonlinearity characteristic is experimentally studied. The experiment results show that the designed isolator has good low-frequency vibration isolation performance, of which the initial isolation frequency is less than 3.6 Hz when the load weight is 21 kg. The jump phenomena of the response of the isolator under linear frequency sweep excitation are observed, and this result demonstrates that the geometric anti-spring isolator has a complex nonlinearity characteristics with the increment of excitation amplitude. This research work provides a theoretical and experimental basis for the application of the nonlinear geometric anti-spring low-frequency passive vibration isolation technology in engineering practice.

THEORETICAL RESEARCH ON HYDRODYNAMICS OF A GEOMETRIC SPAR IN FREQUENCY- AND TIME-DOMAINS

Institute of Scientific and Technical Information of China (English)

WANG Ying; YANG Jian-min; HU Zhi-qiang; XIAO Long-fei

2008-01-01

Considering the coupling effects of the vessel and its riser and mooring system, hydrodynamic analyses of a geometric spar were performed both in frequency- and time-domains. Based on the boundary element method, the 3-D panel model of the geometric spar and the related free water surface model were established, and the first-order and second-order difference-frequency wave loads and other hydrodynamic coefficients were calculated. Frequency domain analysis of the motion Response Amplitude Operators (RAO) and Quadratic Transfer Functions (QTF) and time domain analysis of the response series and spectra in an extreme wave condition were conducted for the coupled system with the mooring lines and risers involved. These analyses were further validated by the physical model test results.

Research on geometrical model and mechanism for metal deformation based on plastic flow

International Nuclear Information System (INIS)

An, H P; Li, X; Rui, Z Y

2015-01-01

Starting with general conditions of metal plastic deformation, it analyses the relation between the percentage spread and geometric parameters of a forming body with typical machining process are studied. A geometrical model of deforming metal is set up according to the characteristic of a flowing metal particle. Starting from experimental results, the effect of technological parameters and friction between workpiece and dies on plastic deformation of a material were studied and a slippage deformation model of mass points within the material was proposed. Finally, the computing methods for strain and deformation energy and temperature rise are derived from homogeneous deformation. The results can be used to select technical parameters and compute physical quantities such as strain, deformation energy, and temperature rise. (paper)

Evaluation of KFB-funded research on transport systems

Energy Technology Data Exchange (ETDEWEB)

Boyce, D.; Knudsen, T.; Wegener, M.

1999-09-01

This report presents an evaluation of two research projects on transport systems, which have been financed fully or partially by KFB. The projects are: l. Systems analysis of transport markets at the Division of Transport and Location Analysis in the Department of Infrastructure and Planning of the Royal Institute of Technology, Stockholm; and 2. Planning, analysis and management in traffic networks - optimization models and methods at the Division of Optimization in the Department of Mathematics at Linkoeping University. The evaluation seeks to examine the scientific quality of the research and its relevance to the academic world and society. The two project teams prepared a self-assessment of their research activities and submitted copies of relevant publications. The evaluation committee visited both institutions and engaged the teams in discussions of their results and methodology. These visits occurred on June 1 and 2, 1999. This report is based on the self-assessments of the teams, the materials submitted and the meetings with the project teams. The evaluation and recommendations presented in the report are those of the reviewers and do not necessarily represent the views of KFB

Image-Based Geometric Modeling and Mesh Generation

CERN Document Server

2013-01-01

As a new interdisciplinary research area, “image-based geometric modeling and mesh generation” integrates image processing, geometric modeling and mesh generation with finite element method (FEM) to solve problems in computational biomedicine, materials sciences and engineering. It is well known that FEM is currently well-developed and efficient, but mesh generation for complex geometries (e.g., the human body) still takes about 80% of the total analysis time and is the major obstacle to reduce the total computation time. It is mainly because none of the traditional approaches is sufficient to effectively construct finite element meshes for arbitrarily complicated domains, and generally a great deal of manual interaction is involved in mesh generation. This contributed volume, the first for such an interdisciplinary topic, collects the latest research by experts in this area. These papers cover a broad range of topics, including medical imaging, image alignment and segmentation, image-to-mesh conversion,...

Geometric approximation algorithms

CERN Document Server

Har-Peled, Sariel

2011-01-01

Exact algorithms for dealing with geometric objects are complicated, hard to implement in practice, and slow. Over the last 20 years a theory of geometric approximation algorithms has emerged. These algorithms tend to be simple, fast, and more robust than their exact counterparts. This book is the first to cover geometric approximation algorithms in detail. In addition, more traditional computational geometry techniques that are widely used in developing such algorithms, like sampling, linear programming, etc., are also surveyed. Other topics covered include approximate nearest-neighbor search, shape approximation, coresets, dimension reduction, and embeddings. The topics covered are relatively independent and are supplemented by exercises. Close to 200 color figures are included in the text to illustrate proofs and ideas.

Geometric Mixing, Peristalsis, and the Geometric Phase of the Stomach.

Science.gov (United States)

Arrieta, Jorge; Cartwright, Julyan H E; Gouillart, Emmanuelle; Piro, Nicolas; Piro, Oreste; Tuval, Idan

2015-01-01

Mixing fluid in a container at low Reynolds number--in an inertialess environment--is not a trivial task. Reciprocating motions merely lead to cycles of mixing and unmixing, so continuous rotation, as used in many technological applications, would appear to be necessary. However, there is another solution: movement of the walls in a cyclical fashion to introduce a geometric phase. We show using journal-bearing flow as a model that such geometric mixing is a general tool for using deformable boundaries that return to the same position to mix fluid at low Reynolds number. We then simulate a biological example: we show that mixing in the stomach functions because of the "belly phase," peristaltic movement of the walls in a cyclical fashion introduces a geometric phase that avoids unmixing.

Geometric Mixing, Peristalsis, and the Geometric Phase of the Stomach.

Directory of Open Access Journals (Sweden)

Jorge Arrieta

Full Text Available Mixing fluid in a container at low Reynolds number--in an inertialess environment--is not a trivial task. Reciprocating motions merely lead to cycles of mixing and unmixing, so continuous rotation, as used in many technological applications, would appear to be necessary. However, there is another solution: movement of the walls in a cyclical fashion to introduce a geometric phase. We show using journal-bearing flow as a model that such geometric mixing is a general tool for using deformable boundaries that return to the same position to mix fluid at low Reynolds number. We then simulate a biological example: we show that mixing in the stomach functions because of the "belly phase," peristaltic movement of the walls in a cyclical fashion introduces a geometric phase that avoids unmixing.

DOE's foreign research reactor transportation services contract: Perspective and experience

International Nuclear Information System (INIS)

Patterson, John

1997-01-01

DOE committed to low- and moderate-income countries participating in the foreign research reactor spent fuel returns program that the United States government would provide for the transportation of the spent fuel. In fulfillment of that commitment, DOE entered into transportation services contracts with qualified, private-sector firms. NAC will discuss its experience as a transportation services provider, including range of services available to the foreign reactors, advantages to DOE and to the foreign research reactors, access to contract services by high income countries and potential advantages, and experience with initial tasks performed under the contract. (author)

World-wide French experience in research reactor fuel cycle transportation

International Nuclear Information System (INIS)

Raisonnier, D.

1997-01-01

Since 1963 Transnucleaire has safely performed a large number of national and international transports of radioactive material. Transnucleaire has also designed and supplied suitable packagings for all types of nuclear fuel cycle radioactive material from front-end and back-end products and for power or for research reactors. Transportation of the nuclear fuel material for power reactors is made on a regular and industrial basis. The transportation of material for the research reactor fuel cycle is quite different due to the small quantities involved, the categorisation of material and the numerous places of delivery world-wide. Adapted solutions exist, which require a reactive organisation dealing with all the transportation issues for LEU and HEU products as metal, oxide, fresh fuel elements, spent fuel elements including supply of necessary transport packaging and equipment. This presentation will: - explain the choices made by Transnucleaire and its associates to provide and optimise the corresponding services, - demonstrate the capability to achieve, through reliable partnership, transport operations involving new routes, specific equipment and new political constraints while respecting sophisticated safety and security regulations. (author)

Geometric and numerical foundations of movements

CERN Document Server

Mansard, Nicolas; Lasserre, Jean-Bernard

2017-01-01

This book aims at gathering roboticists, control theorists, neuroscientists, and mathematicians, in order to promote a multidisciplinary research on movement analysis. It follows the workshop “ Geometric and Numerical Foundations of Movements ” held at LAAS-CNRS in Toulouse in November 2015[1]. Its objective is to lay the foundations for a mutual understanding that is essential for synergetic development in motion research. In particular, the book promotes applications to robotics --and control in general-- of new optimization techniques based on recent results from real algebraic geometry.

Kansas Department of Transportation research & technology news, vol. 6 #2, December 2013.

Science.gov (United States)

2013-12-01

Research & Technology News is a newsletter published by the Kansas Department of : Transportation, Bureau of Researchs Technology Transfer Section, in cooperation with : the Federal Highway Administration and the U.S. Department of Transportation.

Geometrical optical illusionists.

Science.gov (United States)

Wade, Nicholas J

2014-01-01

Geometrical optical illusions were given this title by Oppel in 1855. Variants on such small distortions of visual space were illustrated thereafter, many of which bear the names of those who first described them. Some original forms of the geometrical optical illusions are shown together with 'perceptual portraits' of those who described them. These include: Roget, Chevreul, Fick, Zöllner, Poggendorff, Hering, Kundt, Delboeuf Mach, Helmholtz, Hermann, von Bezold, Müller-Lyer, Lipps, Thiéry, Wundt, Münsterberg, Ebbinghaus, Titchener, Ponzo, Luckiesh, Sander, Ehrenstein, Gregory, Heard, White, Shepard, and. Lingelbach. The illusions are grouped under the headings of orientation, size, the combination of size and orientation, and contrast. Early theories of illusions, before geometrical optical illusions were so named, are mentioned briefly.

Field research program for unsaturated flow and transport experimentation

International Nuclear Information System (INIS)

Tidwell, V.C.; Rautman, C.A.; Glass, R.J.

1992-01-01

As part of the Yucca Mountain Site Characterization Project, a field research program has been developed to refine and validate models for flow and transport through unsaturated fractured rock. Validation of these models within the range of their application for performance assessment requires a more sophisticated understanding of the processes that govern flow and transport within fractured porous media than currently exists. In particular, our research is prioritized according to understanding and modeling processes that, if not accurately incorporated into performance assessment models, would adversely impact the project's ability to evaluate repository performance. For this reason, we have oriented our field program toward enhancing our understanding of scaling processes as they relate to effective media property modeling, as well as to the conceptual modeling of complex flow and transport phenomena

Charging and geometric effects on conduction through Anthracene molecular junctions

Science.gov (United States)

Kaur, Rupan Preet; Sawhney, Ravinder Singh; Engles, Derick

We studied the geometric effects on the charge transfer through the anthracenedithiol (ADT) molecular junction using density functional theory combined with the non-equilibrium Green’s function approach. Two major geometric aspects, bond length and bond angle, were moderated to optimize the electrical conduction. From the results established in this paper, we found that the electrical conduction can be tuned from 0.2 G0 to 0.9 G0 by varying the Au-S bond length, whereas the moderation of bonding angle assayed a minor change from 0.37 G0 to 0.47 G0. We attributed this escalating zero bias conductance to the increasing charge on the terminal sulfur atom of the ADT molecule, which increased the energy of the HOMO orbital towards Fermi level and exhibited a semi-metallic behaviour. Therefore, geometry plays a critical role in deciding the charge transport through the metal/molecule interface.

Geometric Constructions with the Computer.

Science.gov (United States)

Chuan, Jen-chung

The computer can be used as a tool to represent and communicate geometric knowledge. With the appropriate software, a geometric diagram can be manipulated through a series of animation that offers more than one particular snapshot as shown in a traditional mathematical text. Geometric constructions with the computer enable the learner to see and…

Alabama Department of Transportation : research and development 2011 peer exchange.

Science.gov (United States)

2011-05-01

Research and development are key to safe and efficient transportation systems in our country. They have played a vital role in the advancements that have led to our current transportation system. Federal regulation (23 CRF 420 Subpart B) establishes ...

Know-How Transfer and Training Issues for the Transport Research Professional

Directory of Open Access Journals (Sweden)

Prof. George A. Giannopoulos

2015-06-01

Other relevant actions could be taken within the existing collaborative Transport research programmes e.g. the Transport pillar of the “societal challenges” part of the H2020 programme and could consist of specific provisions, impeded in the research contracts, allowing funding for activities such as web-training short courses and workshops, formulation and provision of training materials, holding workshops with the involvement of senior research personnel or leading international academics, etc.

Passenger transport research

CSIR Research Space (South Africa)

Mokonyama, Mathetha T

2008-03-01

Full Text Available In South Africa, airport and airline services epitomise what many would like to see in everyday public transport. The CSIR investigates what it will take to provide a commercial public transport service in South Africa which resembles commercial air...

Center for Transportation Studies 24th annual transportation research conference, May 22-23, 2013, Saint Paul, Minnesota.

Science.gov (United States)

2013-05-01

The University of Minnesotas Center for Transportation : Studies is pleased to present its 24th Annual Transportation : Research Conference, May 22-23, 2013. The conference will : be held at the Saint Paul RiverCentre, 175 West Kellogg : Boulevard...

Transmuted Complementary Weibull Geometric Distribution

Directory of Open Access Journals (Sweden)

Ahmed Z. A…fify

2014-12-01

Full Text Available This paper provides a new generalization of the complementary Weibull geometric distribution that introduced by Tojeiro et al. (2014, using the quadratic rank transmutation map studied by Shaw and Buckley (2007. The new distribution is referred to as transmuted complementary Weibull geometric distribution (TCWGD. The TCWG distribution includes as special cases the complementary Weibull geometric distribution (CWGD, complementary exponential geometric distribution(CEGD,Weibull distribution (WD and exponential distribution (ED. Various structural properties of the new distribution including moments, quantiles, moment generating function and RØnyi entropy of the subject distribution are derived. We proposed the method of maximum likelihood for estimating the model parameters and obtain the observed information matrix. A real data set are used to compare the ‡exibility of the transmuted version versus the complementary Weibull geometric distribution.

Using geometrical, textural, and contextual information of land parcels for classification of detailed urban land use

Science.gov (United States)

Wu, S.-S.; Qiu, X.; Usery, E.L.; Wang, L.

2009-01-01

Detailed urban land use data are important to government officials, researchers, and businesspeople for a variety of purposes. This article presents an approach to classifying detailed urban land use based on geometrical, textural, and contextual information of land parcels. An area of 6 by 14 km in Austin, Texas, with land parcel boundaries delineated by the Travis Central Appraisal District of Travis County, Texas, is tested for the approach. We derive fifty parcel attributes from relevant geographic information system (GIS) and remote sensing data and use them to discriminate among nine urban land uses: single family, multifamily, commercial, office, industrial, civic, open space, transportation, and undeveloped. Half of the 33,025 parcels in the study area are used as training data for land use classification and the other half are used as testing data for accuracy assessment. The best result with a decision tree classification algorithm has an overall accuracy of 96 percent and a kappa coefficient of 0.78, and two naive, baseline models based on the majority rule and the spatial autocorrelation rule have overall accuracy of 89 percent and 79 percent, respectively. The algorithm is relatively good at classifying single-family, multifamily, commercial, open space, and undeveloped land uses and relatively poor at classifying office, industrial, civic, and transportation land uses. The most important attributes for land use classification are the geometrical attributes, particularly those related to building areas. Next are the contextual attributes, particularly those relevant to the spatial relationship between buildings, then the textural attributes, particularly the semivariance texture statistic from 0.61-m resolution images.

Intermodal safety research needs report of the sixth workshop on national transportation problems

Energy Technology Data Exchange (ETDEWEB)

Warshawer, A.J. (ed.)

1976-04-01

This conference brought together DOT policymakers, university principal investigators and other professionals to consider the intermodal safety research requirements of the Department of Transportation. The objectives of the conference were: (1) to highlight safety problems and needed transportation safety research identified by DOT modal safety managers and to stimulate university or university/industry teams to respond with research proposals which emphasize multi-modal applicability and a system view; and (2) to provide a forum for university research groups to inform DOT safety managers of promising new directions in transportation safety research and new tools with which to address safety related problems. The conference addressed the research requirements for safety as identified by the Statement of National Transportation Policy and by the modal safety managers in three principal contexts, each a workshop panel: I, Inter-Institutional Problems of Transportation Safety. Problems were described as: Federal-State, local; Federal-Industry; Federal-Public, Consumer groups. II, Goal Setting and Planning for Transportation Safety Programs. Issues were: modifying risk behavior, safety as a social value, and involving citizens in development of standards as a way of increasing probability of achieving program objectives. III, DOT Information, Management, and Evaluation Systems Requirements. Needs were: data requirements and analytic tools for management of safety programs.

Growing geometric reasoning in solving problems of analytical geometry through the mathematical communication problems to state Islamic university students

Science.gov (United States)

Mujiasih; Waluya, S. B.; Kartono; Mariani

2018-03-01

Skills in working on the geometry problems great needs of the competence of Geometric Reasoning. As a teacher candidate, State Islamic University (UIN) students need to have the competence of this Geometric Reasoning. When the geometric reasoning in solving of geometry problems has grown well, it is expected the students are able to write their ideas to be communicative for the reader. The ability of a student's mathematical communication is supposed to be used as a marker of the growth of their Geometric Reasoning. Thus, the search for the growth of geometric reasoning in solving of analytic geometry problems will be characterized by the growth of mathematical communication abilities whose work is complete, correct and sequential, especially in writing. Preceded with qualitative research, this article was the result of a study that explores the problem: Was the search for the growth of geometric reasoning in solving analytic geometry problems could be characterized by the growth of mathematical communication abilities? The main activities in this research were done through a series of activities: (1) Lecturer trains the students to work on analytic geometry problems that were not routine and algorithmic process but many problems that the process requires high reasoning and divergent/open ended. (2) Students were asked to do the problems independently, in detail, complete, order, and correct. (3) Student answers were then corrected each its stage. (4) Then taken 6 students as the subject of this research. (5) Research subjects were interviewed and researchers conducted triangulation. The results of this research, (1) Mathematics Education student of UIN Semarang, had adequate the mathematical communication ability, (2) the ability of this mathematical communication, could be a marker of the geometric reasoning in solving of problems, and (3) the geometric reasoning of UIN students had grown in a category that tends to be good.

Methods for teaching geometric modelling and computer graphics

Energy Technology Data Exchange (ETDEWEB)

Rotkov, S.I.; Faitel`son, Yu. Ts.

1992-05-01

This paper considers methods for teaching the methods and algorithms of geometric modelling and computer graphics to programmers, designers and users of CAD and computer-aided research systems. There is a bibliography that can be used to prepare lectures and practical classes. 37 refs., 1 tab.

Geometric modeling in the problem of ball bearing accuracy

Science.gov (United States)

Glukhov, V. I.; Pushkarev, V. V.; Khomchenko, V. G.

2017-06-01

The manufacturing quality of ball bearings is an urgent problem for machine-building industry. The aim of the research is to improve the geometric specifications accuracy of bearings based on evidence-based systematic approach and the method of adequate size, location and form deviations modeling of the rings and assembled ball bearings. The present work addressed the problem of bearing geometric specifications identification and the study of these specifications. The deviation from symmetric planar of rings and bearings assembly and mounting width are among these specifications. A systematic approach to geometric specifications values and ball bearings tolerances normalization in coordinate systems will improve the quality of bearings by optimizing and minimizing the number of specifications. The introduction of systematic approach to the international standards on rolling bearings is a guarantee of a significant increase in accuracy of bearings and the quality of products where they are applied.

Geometric phases in discrete dynamical systems

Energy Technology Data Exchange (ETDEWEB)

Cartwright, Julyan H.E., E-mail: julyan.cartwright@csic.es [Instituto Andaluz de Ciencias de la Tierra, CSIC–Universidad de Granada, E-18100 Armilla, Granada (Spain); Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, E-18071 Granada (Spain); Piro, Nicolas, E-mail: nicolas.piro@epfl.ch [École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland); Piro, Oreste, E-mail: piro@imedea.uib-csic.es [Departamento de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Tuval, Idan, E-mail: ituval@imedea.uib-csic.es [Mediterranean Institute for Advanced Studies, CSIC–Universitat de les Illes Balears, E-07190 Mallorca (Spain)

2016-10-14

In order to study the behaviour of discrete dynamical systems under adiabatic cyclic variations of their parameters, we consider discrete versions of adiabatically-rotated rotators. Parallelling the studies in continuous systems, we generalize the concept of geometric phase to discrete dynamics and investigate its presence in these rotators. For the rotated sine circle map, we demonstrate an analytical relationship between the geometric phase and the rotation number of the system. For the discrete version of the rotated rotator considered by Berry, the rotated standard map, we further explore this connection as well as the role of the geometric phase at the onset of chaos. Further into the chaotic regime, we show that the geometric phase is also related to the diffusive behaviour of the dynamical variables and the Lyapunov exponent. - Highlights: • We extend the concept of geometric phase to maps. • For the rotated sine circle map, we demonstrate an analytical relationship between the geometric phase and the rotation number. • For the rotated standard map, we explore the role of the geometric phase at the onset of chaos. • We show that the geometric phase is related to the diffusive behaviour of the dynamical variables and the Lyapunov exponent.

Blind Forensics of Successive Geometric Transformations in Digital Images Using Spectral Method: Theory and Applications.

Science.gov (United States)

Chen, Chenglong; Ni, Jiangqun; Shen, Zhaoyi; Shi, Yun Qing

2017-06-01

Geometric transformations, such as resizing and rotation, are almost always needed when two or more images are spliced together to create convincing image forgeries. In recent years, researchers have developed many digital forensic techniques to identify these operations. Most previous works in this area focus on the analysis of images that have undergone single geometric transformations, e.g., resizing or rotation. In several recent works, researchers have addressed yet another practical and realistic situation: successive geometric transformations, e.g., repeated resizing, resizing-rotation, rotation-resizing, and repeated rotation. We will also concentrate on this topic in this paper. Specifically, we present an in-depth analysis in the frequency domain of the second-order statistics of the geometrically transformed images. We give an exact formulation of how the parameters of the first and second geometric transformations influence the appearance of periodic artifacts. The expected positions of characteristic resampling peaks are analytically derived. The theory developed here helps to address the gap left by previous works on this topic and is useful for image security and authentication, in particular, the forensics of geometric transformations in digital images. As an application of the developed theory, we present an effective method that allows one to distinguish between the aforementioned four different processing chains. The proposed method can further estimate all the geometric transformation parameters. This may provide useful clues for image forgery detection.

SIAM Conference on Geometric Design and Computing. Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

None

2002-03-11

The SIAM Conference on Geometric Design and Computing attracted 164 domestic and international researchers, from academia, industry, and government. It provided a stimulating forum in which to learn about the latest developments, to discuss exciting new research directions, and to forge stronger ties between theory and applications. Final Report

Simulation of Tracer Transport in Porous Media: Application to Bentonites; Simulacion del Transporte de Trazadores en Medios Porosos: Aplicacion al Caso de Arcillas

Energy Technology Data Exchange (ETDEWEB)

Bru, A; Casero, D [CIEMAT, Madrid (Spain)

2001-07-01

We present a formal framework to describe tracer transport in heterogeneous media, such as porous media like bentonites. In these media, mean field approximation is not valid because there exist some geometrical constraints and the transport is anomalous. (Author)

Two-dimensional fast marching for geometrical optics.

Science.gov (United States)

Capozzoli, Amedeo; Curcio, Claudio; Liseno, Angelo; Savarese, Salvatore

2014-11-03

We develop an approach for the fast and accurate determination of geometrical optics solutions to Maxwell's equations in inhomogeneous 2D media and for TM polarized electric fields. The eikonal equation is solved by the fast marching method. Particular attention is paid to consistently discretizing the scatterers' boundaries and matching the discretization to that of the computational domain. The ray tracing is performed, in a direct and inverse way, by using a technique introduced in computer graphics for the fast and accurate generation of textured images from vector fields. The transport equation is solved by resorting only to its integral form, the transport of polarization being trivial for the considered geometry and polarization. Numerical results for the plane wave scattering of two perfectly conducting circular cylinders and for a Luneburg lens prove the accuracy of the algorithm. In particular, it is shown how the approach is capable of properly accounting for the multiple scattering occurring between the two metallic cylinders and how inverse ray tracing should be preferred to direct ray tracing in the case of the Luneburg lens.

Porous media geometry and transports

CERN Document Server

Adler, Pierre

1992-01-01

The goal of ""Porous Media: Geometry and Transports"" is to provide the basis of a rational and modern approach to porous media. This book emphasizes several geometrical structures (spatially periodic, fractal, and random to reconstructed) and the three major single-phase transports (diffusion, convection, and Taylor dispersion).""Porous Media"" serves various purposes. For students it introduces basic information on structure and transports. Engineers will find this book useful as a readily accessible assemblage of al the major experimental results pertaining to single-phase tr

Towards a theory of geometric graphs

CERN Document Server

Pach, Janos

2004-01-01

The early development of graph theory was heavily motivated and influenced by topological and geometric themes, such as the Konigsberg Bridge Problem, Euler's Polyhedral Formula, or Kuratowski's characterization of planar graphs. In 1936, when Denes Konig published his classical Theory of Finite and Infinite Graphs, the first book ever written on the subject, he stressed this connection by adding the subtitle Combinatorial Topology of Systems of Segments. He wanted to emphasize that the subject of his investigations was very concrete: planar figures consisting of points connected by straight-line segments. However, in the second half of the twentieth century, graph theoretical research took an interesting turn. In the most popular and most rapidly growing areas (the theory of random graphs, Ramsey theory, extremal graph theory, algebraic graph theory, etc.), graphs were considered as abstract binary relations rather than geometric objects. Many of the powerful techniques developed in these fields have been su...

Characteristic signatures of quantum criticality driven by geometrical frustration.

Science.gov (United States)

Tokiwa, Yoshifumi; Stingl, Christian; Kim, Moo-Sung; Takabatake, Toshiro; Gegenwart, Philipp

2015-04-01

Geometrical frustration describes situations where interactions are incompatible with the lattice geometry and stabilizes exotic phases such as spin liquids. Whether geometrical frustration of magnetic interactions in metals can induce unconventional quantum critical points is an active area of research. We focus on the hexagonal heavy fermion metal CeRhSn, where the Kondo ions are located on distorted kagome planes stacked along the c axis. Low-temperature specific heat, thermal expansion, and magnetic Grüneisen parameter measurements prove a zero-field quantum critical point. The linear thermal expansion, which measures the initial uniaxial pressure derivative of the entropy, displays a striking anisotropy. Critical and noncritical behaviors along and perpendicular to the kagome planes, respectively, prove that quantum criticality is driven be geometrical frustration. We also discovered a spin flop-type metamagnetic crossover. This excludes an itinerant scenario and suggests that quantum criticality is related to local moments in a spin liquid-like state.

Modelization of physical phenomena in research reactors with the help of new developments in transport methods, and methodology validation with experimental data

International Nuclear Information System (INIS)

Rauck, St.

2000-10-01

The aim of this work is to develop a scheme for experimental reactors, based on transport equations. This type of reactors is characterized by a small core, a complex, very heterogeneous geometry and a large leakage. The possible insertion of neutron beams in the reflector and the presence of absorbers in the core increase the difficulty of the 3D-geometrical description and the physical modeling of the component parameters of the reactor. The Orphee reactor has been chosen for our study. Physical models (homogenization, collapsing cross section in few groups, albedo multigroup condition) have been developed in the APOLLO2 and CRONOS2 codes to calculate flux and power maps in a 3D-geometry, with different burnup and through transport equations. Comparisons with experimental measurements have shown the interest of taking into account anisotropy, steep flux gradients by using Sn methods, and on the other hand using a 12-group cross section library. The modeling of neutron beams has been done outside the core modeling through Monte Carlo calculations and with the total geometry, including a large thickness of heavy water. Thanks to this calculations, one can evaluate the neutron beams anti-reactivity and determinate the core cycle. We assure these methods more accurate than usual transport-diffusion calculations will be used for the conception of new research reactors. (author)

Transportation-Related Consumer Preference Data | Transportation Research |

Science.gov (United States)

NREL Transportation-Related Consumer Preference Data Transportation-Related Consumer Preference Data Photo of reporters test driving Toyota prototype electric and fuel cell vehicles. Consumer for the development and implementation of these technologies. NREL collects, analyzes, and reports on

Transportation research activities in support of nuclear waste management programs

International Nuclear Information System (INIS)

Allen, G.C.; Luna, R.E.; Jefferson, R.M.; Wowak, W.E.

1983-01-01

The Transportation Technology Center has been conducting a wide range of technical and non-technical research activities to assure the ability to transport radioactive materials in a safe, reliable, and publicly acceptable manner. These activities include tasks in Information and Intergovernmental issues, Safety Assessment and Environmental Analysis and Technology Development. Until recently, the requirements of defense waste shipments have served as a focal point for development tasks with the expectation that they would serve as a precursor for commercial activities. The passage of the Nuclear Waste Policy Act has placed additional responsibility on DOE for concerns involving the shipments of civilian materials. The development of additional research responsibilities is expected to proceed concurrently with the evolution of the transportation mission plan for civilian spent fuel and high-level wastes

Project-oriented management of industrial production of fire and rescue equipment by means of geometric modelling

OpenAIRE

Rak, Iu; Bondarenko, V.

2013-01-01

Objective: The objective of the research is to develop a method based on the geometric modelling for the purpose of improving the effectiveness of fire protection project management in industrial production of fire protection technology systems. Methods: The theoretical inheritance mode of effective management in project-organizational structure of fire protection and specialized technical equipment production using geometric modelling. Results: Mathematical and geometric models of project ma...

The Geometric Phase in Quantum Systems

International Nuclear Information System (INIS)

Pascazio, S

2003-01-01

The discovery of the geometric phase is one of the most interesting and intriguing findings of the last few decades. It led to a deeper understanding of the concept of phase in quantum mechanics and motivated a surge of interest in fundamental quantum mechanical issues, disclosing unexpected applications in very diverse fields of physics. Although the key ideas underlying the existence of a purely geometrical phase had already been proposed in 1956 by Pancharatnam, it was Michael Berry who revived this issue 30 years later. The clarity of Berry's seminal paper, in 1984, was extraordinary. Research on the topic flourished at such a pace that it became difficult for non-experts to follow the many different theoretical ideas and experimental proposals which ensued. Diverse concepts in independent areas of mathematics, physics and chemistry were being applied, for what was (and can still be considered) a nascent arena for theory, experiments and technology. Although collections of papers by different authors appeared in the literature, sometimes with ample introductions, surprisingly, to the best of my knowledge, no specific and exhaustive book has ever been written on this subject. The Geometric Phase in Quantum Systems is the first thorough book on geometric phases and fills an important gap in the physical literature. Other books on the subject will undoubtedly follow. But it will take a fairly long time before other authors can cover that same variety of concepts in such a comprehensive manner. The book is enjoyable. The choice of topics presented is well balanced and appropriate. The appendices are well written, understandable and exhaustive - three rare qualities. I also find it praiseworthy that the authors decided to explicitly carry out most of the calculations, avoiding, as much as possible, the use of the joke 'after a straightforward calculation, one finds...' This was one of the sentences I used to dislike most during my undergraduate studies. A student is

Geochemical, hydrological and biological cycling of energy residuals. Research plan: subsurface transport program

International Nuclear Information System (INIS)

Wobber, F.J.

1985-09-01

Because natural processes associated with the release and the transport of organic compounds, trace metals, and radionuclides are incompletely understood, research in this area is critical if the long term scientific uncertainties about contaminant transport are to be resolved. The processes that control mobilization and attenuation of energy residuals in soils and geological strata, their hydrological transport to and within ground water regimes, and their accumulation in biological systems require research attention. A summary of DOE's core research program is described. It is designed to provide a base of fundamental scientific information so that the geochemical hydrological, and biophysical mechanics that contribute to the transport and long term fate of energy related contaminants in natural systems can be understood

Geometrical model of multiple production

International Nuclear Information System (INIS)

Chikovani, Z.E.; Jenkovszky, L.L.; Kvaratshelia, T.M.; Struminskij, B.V.

1988-01-01

The relation between geometrical and KNO-scaling and their violation is studied in a geometrical model of multiple production of hadrons. Predictions concerning the behaviour of correlation coefficients at future accelerators are given

Pragmatic geometric model evaluation

Science.gov (United States)

Pamer, Robert

2015-04-01

Quantification of subsurface model reliability is mathematically and technically demanding as there are many different sources of uncertainty and some of the factors can be assessed merely in a subjective way. For many practical applications in industry or risk assessment (e. g. geothermal drilling) a quantitative estimation of possible geometric variations in depth unit is preferred over relative numbers because of cost calculations for different scenarios. The talk gives an overview of several factors that affect the geometry of structural subsurface models that are based upon typical geological survey organization (GSO) data like geological maps, borehole data and conceptually driven construction of subsurface elements (e. g. fault network). Within the context of the trans-European project "GeoMol" uncertainty analysis has to be very pragmatic also because of different data rights, data policies and modelling software between the project partners. In a case study a two-step evaluation methodology for geometric subsurface model uncertainty is being developed. In a first step several models of the same volume of interest have been calculated by omitting successively more and more input data types (seismic constraints, fault network, outcrop data). The positions of the various horizon surfaces are then compared. The procedure is equivalent to comparing data of various levels of detail and therefore structural complexity. This gives a measure of the structural significance of each data set in space and as a consequence areas of geometric complexity are identified. These areas are usually very data sensitive hence geometric variability in between individual data points in these areas is higher than in areas of low structural complexity. Instead of calculating a multitude of different models by varying some input data or parameters as it is done by Monte-Carlo-simulations, the aim of the second step of the evaluation procedure (which is part of the ongoing work) is to

Simulation of Tracer Transport in Porous Media: Application to Bentonites

International Nuclear Information System (INIS)

Bru, A.; Casero, D.

2001-01-01

We present a formal framework to describe tracer transport in heterogeneous media, such as porous media like bentonites. In these media, mean field approximation is not valid because there exist some geometrical constraints and the transport is anomalous. (Author)

Analyses of the transportation of spent research reactor fuel in the United States

International Nuclear Information System (INIS)

Cashwell, J.W.; Neuhauser, K.S.

1989-01-01

The Transportation Technology Center at Sandia National Laboratories has analyzed the impacts of transportation of research reactor spent fuel from US and foreign reactors for the US Department of Energy (DOE) Office of Defense Programs. This effort represents the first comprehensive analytical evaluation of the risks of transporting high-, medium-, and low-enriched uranium spent research reactor fuel by both sea and land. Two separate shipment programs have been analyzed: the shipment of research reactor spent fuel from Taiwan to the US (Fuel Movement Program), and the return of research reactor spent fuels of US origin from foreign and domestic reactors (Research Reactor Fuel Return Program). In order to perform these analyses, a comprehensive methodology for analyzing the probabilities and consequences of transportation in coastal waters and port facilities, handling at the port, and shipment by truck to reprocessing facilities was developed. The Taiwanese fuel consists of low-burnup aluminum-clad metallic uranium research reactor spent fuel; the other fuels are primarily aluminum-clad oxide fuels. The Fuel Movement Program is ongoing, while the Fuel Return Program addresses future shipments over a ten-year period. The operational aspects of the Taiwanese shipments have been uniform, but several possible shipping configurations are possible for the Fuel Return Program shipments. Comprehensive assessments, which bound the impacts of spent fuel transport, demonstrate that when shipments are made in compliance with applicable regulations, the risks for all such transport are low. For comparison with previously licensed transport activities and to provide continuity with earlier analyses, the results for shipment of 150-day-old commercial pressurized water reactor (PWR) spent fuel are presented as part of this study

Radial transport with perturbed magnetic field

Energy Technology Data Exchange (ETDEWEB)

Hazeltine, R. D. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

2015-05-15

It is pointed out that the viscosity coefficient describing radial transport of toroidal angular momentum is proportional to the second power of the gyro-radius—like the corresponding coefficients for particle and heat transport—regardless of any geometrical symmetry. The observation is widely appreciated, but worth emphasizing because some literature gives the misleading impression that asymmetry can allow radial moment transport in first-order.

Radial transport with perturbed magnetic field

International Nuclear Information System (INIS)

Hazeltine, R. D.

2015-01-01

It is pointed out that the viscosity coefficient describing radial transport of toroidal angular momentum is proportional to the second power of the gyro-radius—like the corresponding coefficients for particle and heat transport—regardless of any geometrical symmetry. The observation is widely appreciated, but worth emphasizing because some literature gives the misleading impression that asymmetry can allow radial moment transport in first-order

Graphene geometric diodes for terahertz rectennas

International Nuclear Information System (INIS)

Zhu Zixu; Joshi, Saumil; Grover, Sachit; Moddel, Garret

2013-01-01

We demonstrate a new thin-film graphene diode called a geometric diode that relies on geometric asymmetry to provide rectification at 28 THz. The geometric diode is coupled to an optical antenna to form a rectenna that rectifies incoming radiation. This is the first reported graphene-based antenna-coupled diode working at 28 THz, and potentially at optical frequencies. The planar structure of the geometric diode provides a low RC time constant, on the order of 10 −15 s, required for operation at optical frequencies, and a low impedance for efficient power transfer from the antenna. Fabricated geometric diodes show asymmetric current–voltage characteristics consistent with Monte Carlo simulations for the devices. Rectennas employing the geometric diode coupled to metal and graphene antennas rectify 10.6 µm radiation, corresponding to an operating frequency of 28 THz. The graphene bowtie antenna is the first demonstrated functional antenna made using graphene. Its response indicates that graphene is a suitable terahertz resonator material. Applications for this terahertz diode include terahertz-wave and optical detection, ultra-high-speed electronics and optical power conversion. (paper)

Geometric Computing for Freeform Architecture

KAUST Repository

Wallner, J.

2011-06-03

Geometric computing has recently found a new field of applications, namely the various geometric problems which lie at the heart of rationalization and construction-aware design processes of freeform architecture. We report on our work in this area, dealing with meshes with planar faces and meshes which allow multilayer constructions (which is related to discrete surfaces and their curvatures), triangles meshes with circle-packing properties (which is related to conformal uniformization), and with the paneling problem. We emphasize the combination of numerical optimization and geometric knowledge.

Center for Transportation Research | The University of Tennessee, Knoxville

Science.gov (United States)

IRIS WEB ACCOUNTS PASSWORDS Libraries UNIVERSITY LIBRARIES AGRICULTURE & VET MED LAW MEDICAL MUSIC transportation research, service, and training needs of state and local government, business, and industry in

Geometric solitons of Hamiltonian flows on manifolds

Energy Technology Data Exchange (ETDEWEB)

Song, Chong, E-mail: songchong@xmu.edu.cn [School of Mathematical Sciences, Xiamen University, Xiamen 361005 (China); Sun, Xiaowei, E-mail: sunxw@cufe.edu.cn [School of Applied Mathematics, Central University of Finance and Economics, Beijing 100081 (China); Wang, Youde, E-mail: wyd@math.ac.cn [Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China)

2013-12-15

It is well-known that the LIE (Locally Induction Equation) admit soliton-type solutions and same soliton solutions arise from different and apparently irrelevant physical models. By comparing the solitons of LIE and Killing magnetic geodesics, we observe that these solitons are essentially decided by two families of isometries of the domain and the target space, respectively. With this insight, we propose the new concept of geometric solitons of Hamiltonian flows on manifolds, such as geometric Schrödinger flows and KdV flows for maps. Moreover, we give several examples of geometric solitons of the Schrödinger flow and geometric KdV flow, including magnetic curves as geometric Schrödinger solitons and explicit geometric KdV solitons on surfaces of revolution.

Geometric Computing for Freeform Architecture

KAUST Repository

Wallner, J.; Pottmann, Helmut

2011-01-01

Geometric computing has recently found a new field of applications, namely the various geometric problems which lie at the heart of rationalization and construction-aware design processes of freeform architecture. We report on our work in this area

A new geometrical gravitational theory

International Nuclear Information System (INIS)

Obata, T.; Chiba, J.; Oshima, H.

1981-01-01

A geometrical gravitational theory is developed. The field equations are uniquely determined apart from one unknown dimensionless parameter ω 2 . It is based on an extension of the Weyl geometry, and by the extension the gravitational coupling constant and the gravitational mass are made to be dynamical and geometrical. The fundamental geometrical objects in the theory are a metric gsub(μν) and two gauge scalars phi and psi. The theory satisfies the weak equivalence principle, but breaks the strong one generally. u(phi, psi) = phi is found out on the assumption that the strong one keeps holding good at least for bosons of low spins. Thus there is the simple correspondence between the geometrical objects and the gravitational objects. Since the theory satisfies the weak one, the inertial mass is also dynamical and geometrical in the same way as is the gravitational mass. Moreover, the cosmological term in the theory is a coscalar of power -4 algebraically made of psi and u(phi, psi), so it is dynamical, too. Finally spherically symmetric exact solutions are given. The permissible range of the unknown parameter ω 2 is experimentally determined by applying the solutions to the solar system. (author)

Mobile Watermarking against Geometrical Distortions

Directory of Open Access Journals (Sweden)

Jing Zhang

2015-08-01

Full Text Available Mobile watermarking robust to geometrical distortions is still a great challenge. In mobile watermarking, efficient computation is necessary because mobile devices have very limited resources due to power consumption. In this paper, we propose a low-complexity geometrically resilient watermarking approach based on the optimal tradeoff circular harmonic function (OTCHF correlation filter and the minimum average correlation energy Mellin radial harmonic (MACE-MRH correlation filter. By the rotation, translation and scale tolerance properties of the two kinds of filter, the proposed watermark detector can be robust to geometrical attacks. The embedded watermark is weighted by a perceptual mask which matches very well with the properties of the human visual system. Before correlation, a whitening process is utilized to improve watermark detection reliability. Experimental results demonstrate that the proposed watermarking approach is computationally efficient and robust to geometrical distortions.

Ballistic transport and electronic structure

NARCIS (Netherlands)

Schep, Kees M.; Kelly, Paul J.; Bauer, Gerrit E.W.

1998-01-01

The role of the electronic structure in determining the transport properties of ballistic point contacts is studied. The conductance in the ballistic regime is related to simple geometrical projections of the Fermi surface. The essential physics is first clarified for simple models. For real

University of Tennessee Center for Space Transportation and Applied Research (CSTAR)

Science.gov (United States)

1995-10-01

The Center for Space Transportation and Applied Research had projects with space applications in six major areas: laser materials processing, artificial intelligence/expert systems, space transportation, computational methods, chemical propulsion, and electric propulsion. The closeout status of all these projects is addressed.

University of Tennessee Center for Space Transportation and Applied Research (CSTAR)

Science.gov (United States)

1995-01-01

The Center for Space Transportation and Applied Research had projects with space applications in six major areas: laser materials processing, artificial intelligence/expert systems, space transportation, computational methods, chemical propulsion, and electric propulsion. The closeout status of all these projects is addressed.

Evaluating department of transportation's research program : a methodology and case study.

Science.gov (United States)

2012-06-01

An effective research program within a transportation organization can be a valuable asset to accomplish the goals of the overall : mission. Determining whether a research program is pursuing relevant research projects and obtaining results for the s...

Operational geometric phase for mixed quantum states

International Nuclear Information System (INIS)

Andersson, O; Heydari, H

2013-01-01

The geometric phase has found a broad spectrum of applications in both classical and quantum physics, such as condensed matter and quantum computation. In this paper, we introduce an operational geometric phase for mixed quantum states, based on spectral weighted traces of holonomies, and we prove that it generalizes the standard definition of the geometric phase for mixed states, which is based on quantum interferometry. We also introduce higher order geometric phases, and prove that under a fairly weak, generically satisfied, requirement, there is always a well-defined geometric phase of some order. Our approach applies to general unitary evolutions of both non-degenerate and degenerate mixed states. Moreover, since we provide an explicit formula for the geometric phase that can be easily implemented, it is particularly well suited for computations in quantum physics. (paper)

Iris-based medical analysis by geometric deformation features.

Science.gov (United States)

Ma, Lin; Zhang, D; Li, Naimin; Cai, Yan; Zuo, Wangmeng; Wang, Kuanguan

2013-01-01

Iris analysis studies the relationship between human health and changes in the anatomy of the iris. Apart from the fact that iris recognition focuses on modeling the overall structure of the iris, iris diagnosis emphasizes the detecting and analyzing of local variations in the characteristics of irises. This paper focuses on studying the geometrical structure changes in irises that are caused by gastrointestinal diseases, and on measuring the observable deformations in the geometrical structures of irises that are related to roundness, diameter and other geometric forms of the pupil and the collarette. Pupil and collarette based features are defined and extracted. A series of experiments are implemented on our experimental pathological iris database, including manual clustering of both normal and pathological iris images, manual classification by non-specialists, manual classification by individuals with a medical background, classification ability verification for the proposed features, and disease recognition by applying the proposed features. The results prove the effectiveness and clinical diagnostic significance of the proposed features and a reliable recognition performance for automatic disease diagnosis. Our research results offer a novel systematic perspective for iridology studies and promote the progress of both theoretical and practical work in iris diagnosis.

Transportation of failed or damaged foreign research reactor spent nuclear fuel

International Nuclear Information System (INIS)

Messick, C.E.; Mustin, T.P.; Massey, C.D.

1998-01-01

Since resuming the Foreign Research Reactor Spent Nuclear Fuel (FRR SNF) Acceptance Program in 1996, the Program has had to deal with difficult issues associated with the transportation of failed or damaged spent fuel. In several instances, problems with failed or damaged fuel have prevented the acceptance of the fuel at considerable cost to both the Department of Energy (DOE) and research reactor operators. In response to the problems faced by the Acceptance Program, DOE has undertaken significant steps to better define the spent fuel acceptance criteria. DOE has worked closely with the U.S. Nuclear Regulatory Commission to address failed or damaged research reactor spent fuel and to identify cask certificate issues which must be resolved by cask owners and foreign regulatory authorities. The specific issues associated with the transport of Materials Testing Reactor (MTR)-type FRR SNF will be discussed. The information presented will include U.S. Nuclear Regulatory Commission regulatory issues, cask certificate issues, technical constraints, and lessons learned. Specific information will also be provided on the latest efforts to revise DOE's Appendix B, Transport Package (Cask) Acceptance Criteria. The information presented in this paper will be important to foreign research reactor operators, shippers, and cask vendors, so that appropriate amendments to the Certificate of Compliance for spent fuel casks can be submitted in a timely manner to facilitate the safe and scheduled transport of FRR SNF

Geometrical factors in the perception of sacredness

DEFF Research Database (Denmark)

Costa, Marco; Bonetti, Leonardo

2016-01-01

Geometrical and environmental factors in the perception of sacredness, dominance, and attractiveness were assessed by 137 participants in five tests. In the first test, a two-alternative forced-choice paradigm was used to test the perception of sacredness, dominance, and attractiveness in geometr......Geometrical and environmental factors in the perception of sacredness, dominance, and attractiveness were assessed by 137 participants in five tests. In the first test, a two-alternative forced-choice paradigm was used to test the perception of sacredness, dominance, and attractiveness...... in geometrical figures differing in shape, verticality, size, and symmetry. Verticality, symmetry, and convexity were found to be important factors in the perception of sacredness. In the second test, participants had to mark the point inside geometrical surfaces that was perceived as most sacred, dominant....... Geometrical factors in the perception of sacredness, dominance, and attractiveness were largely overlapping....

Development of a transport cask for spent fuel elements of research reactors

International Nuclear Information System (INIS)

Quintana, F.; Saliba, R.O.; Furnari, J.C.; Mourao, R.P; Leite da Silva, L.; Novara, O.; Alexandre Miranda, C.; Mattar Neto, M.

2012-01-01

This article presents an overview of the development of a research reactor spent fuel transport cask. Through a project funded by the IAEA, Argentina, Brazil and Chile have collaborated to enhance regional capacity in the management of spent fuel elements from research reactors operated in the region. A packaging for the transport of research reactors spent fuel was developed. It was designed by a team of researchers from the countries mentioned and a 1:2 scale model for MTR type fuel was constructed in Argentina and subsequently tested in CDTN facilities in Belo Horizonte, Brazil. There were three test sequences to test the cask for normal transport and hypothetical accident conditions. It has successfully passed the tests and the overall performance was considered satisfactory. As part of the licensing process, a test sequence with the presence of regulatory authorities is scheduled for December, 2012 (author)

Asymptotic and geometrical quantization

International Nuclear Information System (INIS)

Karasev, M.V.; Maslov, V.P.

1984-01-01

The main ideas of geometric-, deformation- and asymptotic quantizations are compared. It is shown that, on the one hand, the asymptotic approach is a direct generalization of exact geometric quantization, on the other hand, it generates deformation in multiplication of symbols and Poisson brackets. Besides investigating the general quantization diagram, its applications to the calculation of asymptotics of a series of eigenvalues of operators possessing symmetry groups are considered

Geometric inequalities for black holes

International Nuclear Information System (INIS)

Dain, Sergio

2013-01-01

Full text: A geometric inequality in General Relativity relates quantities that have both a physical interpretation and a geometrical definition. It is well known that the parameters that characterize the Kerr-Newman black hole satisfy several important geometric inequalities. Remarkably enough, some of these inequalities also hold for dynamical black holes. This kind of inequalities, which are valid in the dynamical and strong field regime, play an important role in the characterization of the gravitational collapse. They are closed related with the cosmic censorship conjecture. In this talk I will review recent results in this subject. (author)

Optical traps with geometric aberrations

International Nuclear Information System (INIS)

Roichman, Yael; Waldron, Alex; Gardel, Emily; Grier, David G.

2006-01-01

We assess the influence of geometric aberrations on the in-plane performance of optical traps by studying the dynamics of trapped colloidal spheres in deliberately distorted holographic optical tweezers. The lateral stiffness of the traps turns out to be insensitive to moderate amounts of coma, astigmatism, and spherical aberration. Moreover holographic aberration correction enables us to compensate inherent shortcomings in the optical train, thereby adaptively improving its performance. We also demonstrate the effects of geometric aberrations on the intensity profiles of optical vortices, whose readily measured deformations suggest a method for rapidly estimating and correcting geometric aberrations in holographic trapping systems

Geometric inequalities for black holes

Energy Technology Data Exchange (ETDEWEB)

Dain, Sergio [Universidad Nacional de Cordoba (Argentina)

2013-07-01

Full text: A geometric inequality in General Relativity relates quantities that have both a physical interpretation and a geometrical definition. It is well known that the parameters that characterize the Kerr-Newman black hole satisfy several important geometric inequalities. Remarkably enough, some of these inequalities also hold for dynamical black holes. This kind of inequalities, which are valid in the dynamical and strong field regime, play an important role in the characterization of the gravitational collapse. They are closed related with the cosmic censorship conjecture. In this talk I will review recent results in this subject. (author)

Medical complications of intra-hospital patient transports: implications for architectural design and research.

Science.gov (United States)

Ulrich, Roger S; Zhu, Xuemei

2007-01-01

Literature on healthcare architecture and evidence-based design has rarely considered explicitly that patient outcomes may be worsened by intra-hospital transport (IHT), which is defined as transport of patients within the hospital. The article focuses on the effects of IHTs on patient complications and outcomes, and the implications of such impacts for designing safer, better hospitals. A review of 22 scientific studies indicates that IHTs are subject to a wide range of complications, many of which occur frequently and have distinctly detrimental effects on patient stability and outcomes. The research suggests that higher patient acuity and longer transport durations are associated with more frequent and serious IHT-related complications and outcome effects. It appears no rigorous research has compared different hospital designs and layouts with respect to having possibly differential effects on transport-related complications and worsened outcomes. Nonetheless, certain design implications can be extracted from the existing research literature, including the importance of minimizing transport delays due to restricted space and congestion, and creating layouts that shorten IHT times for high-acuity patients. Limited evidence raises the possibility that elevator-dependent vertical building layouts may increase susceptibility to transport delays that worsen complications. The strong evidence indicating that IHTs trigger complications and worsen outcomes suggests a powerful justification for adopting acuity-adaptable rooms and care models that substantially reduce transports. A program of studies is outlined to address gaps in knowledge.Key WordsPatient transports, transports within hospitals, patient safety, evidence-based design, hospital design, healthcare architecture, intra-hospital transport complications, acuity-adaptable care, elevators, outcomes.

A geometric framework for evaluating rare variant tests of association.

Science.gov (United States)

Liu, Keli; Fast, Shannon; Zawistowski, Matthew; Tintle, Nathan L

2013-05-01

The wave of next-generation sequencing data has arrived. However, many questions still remain about how to best analyze sequence data, particularly the contribution of rare genetic variants to human disease. Numerous statistical methods have been proposed to aggregate association signals across multiple rare variant sites in an effort to increase statistical power; however, the precise relation between the tests is often not well understood. We present a geometric representation for rare variant data in which rare allele counts in case and control samples are treated as vectors in Euclidean space. The geometric framework facilitates a rigorous classification of existing rare variant tests into two broad categories: tests for a difference in the lengths of the case and control vectors, and joint tests for a difference in either the lengths or angles of the two vectors. We demonstrate that genetic architecture of a trait, including the number and frequency of risk alleles, directly relates to the behavior of the length and joint tests. Hence, the geometric framework allows prediction of which tests will perform best under different disease models. Furthermore, the structure of the geometric framework immediately suggests additional classes and types of rare variant tests. We consider two general classes of tests which show robustness to noncausal and protective variants. The geometric framework introduces a novel and unique method to assess current rare variant methodology and provides guidelines for both applied and theoretical researchers. © 2013 Wiley Periodicals, Inc.

Role of R&D (research and development) in transport infrastructure in South Africa

CSIR Research Space (South Africa)

Rust, FC

2008-07-01

Full Text Available ) expenditure must be increased to a minimum of one per cent of GDP, there is currently a lack of focus in the national R&D agenda and in in government departments on transport-related research. A list of potential focus areas for future transport research...

The potential of statistical shape modelling for geometric morphometric analysis of human teeth in archaeological research.

Science.gov (United States)

Woods, Christopher; Fernee, Christianne; Browne, Martin; Zakrzewski, Sonia; Dickinson, Alexander

2017-01-01

This paper introduces statistical shape modelling (SSM) for use in osteoarchaeology research. SSM is a full field, multi-material analytical technique, and is presented as a supplementary geometric morphometric (GM) tool. Lower mandibular canines from two archaeological populations and one modern population were sampled, digitised using micro-CT, aligned, registered to a baseline and statistically modelled using principal component analysis (PCA). Sample material properties were incorporated as a binary enamel/dentin parameter. Results were assessed qualitatively and quantitatively using anatomical landmarks. Finally, the technique's application was demonstrated for inter-sample comparison through analysis of the principal component (PC) weights. It was found that SSM could provide high detail qualitative and quantitative insight with respect to archaeological inter- and intra-sample variability. This technique has value for archaeological, biomechanical and forensic applications including identification, finite element analysis (FEA) and reconstruction from partial datasets.

Spatial non-adiabatic passage using geometric phases

Energy Technology Data Exchange (ETDEWEB)

Benseny, Albert; Busch, Thomas [Okinawa Institute of Science and Technology Graduate University, Quantum Systems Unit, Okinawa (Japan); Kiely, Anthony; Ruschhaupt, Andreas [University College Cork, Department of Physics, Cork (Ireland); Zhang, Yongping [Okinawa Institute of Science and Technology Graduate University, Quantum Systems Unit, Okinawa (Japan); Shanghai University, Department of Physics, Shanghai (China)

2017-12-15

Quantum technologies based on adiabatic techniques can be highly effective, but often at the cost of being very slow. Here we introduce a set of experimentally realistic, non-adiabatic protocols for spatial state preparation, which yield the same fidelity as their adiabatic counterparts, but on fast timescales. In particular, we consider a charged particle in a system of three tunnel-coupled quantum wells, where the presence of a magnetic field can induce a geometric phase during the tunnelling processes. We show that this leads to the appearance of complex tunnelling amplitudes and allows for the implementation of spatial non-adiabatic passage. We demonstrate the ability of such a system to transport a particle between two different wells and to generate a delocalised superposition between the three traps with high fidelity in short times. (orig.)

Geometric Topology and Shape Theory

CERN Document Server

Segal, Jack

1987-01-01

The aim of this international conference the third of its type was to survey recent developments in Geometric Topology and Shape Theory with an emphasis on their interaction. The volume contains original research papers and carefully selected survey of currently active areas. The main topics and themes represented by the papers of this volume include decomposition theory, cell-like mappings and CE-equivalent compacta, covering dimension versus cohomological dimension, ANR's and LCn-compacta, homology manifolds, embeddings of continua into manifolds, complement theorems in shape theory, approximate fibrations and shape fibrations, fibered shape, exact homologies and strong shape theory.

Analyses of the transportation of spent research reactor fuel in the United States

International Nuclear Information System (INIS)

Cashwell, J.W.; Neuhauser, K.S.

1989-01-01

We analyzed the impacts of transportation of research reactor spent fuel from US and foreign reactors for the US Department of Energy's (DOE) Office of Defense Programs. Two separate shipment programs were analyzed. The shipment of research reactor spent fuel from Taiwan to the US (Fuel Movement Program), and the return of research reactor spent fuels of US origin from foreign and domestic reactors (Research Reactor Fuel Return Program). To perform these analyses, a comprehensive methodology for analyzing the probabilities and consequences of transportation in coastal waters and port facilities, handling at the port, and shipment by truck to reprocessing facilities was developed. The Taiwanese fuel consists of low-burnup aluminum-clad metallic uranium research reactor spent fuel; the other fuels are primarily aluminum-clad oxide fuels. The Fuel Movement Program is ongoing, while the Fuel Return Program addresses future shipments over a ten-year period. The operational aspects of the Taiwanese shipments have been uniform, but several possible shipping configurations are possible for the Fuel Return Program shipments. The risks of transporting spent nuclear fuel and other radioactive materials by all modes have been analyzed extensively. Comprehensive assessments, which bound the impacts of spent fuel transport, demonstrate that when shipments are made in compliance with applicable regulations, the risks for all such transport are low. For comparison with previously licensed transport activities and to provide continuity with earlier analyses, the results for shipment of 150-day-old commercial pressurized water reactor (PWR) spent fuel are presented as part of this study

Geometric phases for nonlinear coherent and squeezed states

International Nuclear Information System (INIS)

Yang Dabao; Chen Ying; Chen Jingling; Zhang Fulin

2011-01-01

The geometric phases for standard coherent states which are widely used in quantum optics have attracted considerable attention. Nevertheless, few physicists consider the counterparts of nonlinear coherent states, which are useful in the description of the motion of a trapped ion. In this paper, the non-unitary and non-cyclic geometric phases for two nonlinear coherent and one squeezed states are formulated, respectively. Moreover, some of their common properties are discussed, such as gauge invariance, non-locality and nonlinear effects. The nonlinear functions have dramatic impacts on the evolution of the corresponding geometric phases. They speed the evolution up or down. So this property may have an application in controlling or measuring geometric phase. For the squeezed case, when the squeezed parameter r → ∞, the limiting value of the geometric phase is also determined by a nonlinear function at a given time and angular velocity. In addition, the geometric phases for standard coherent and squeezed states are obtained under a particular condition. When the time evolution undergoes a period, their corresponding cyclic geometric phases are achieved as well. And the distinction between the geometric phases of the two coherent states may be regarded as a geometric criterion.

Center for Space Transportation and Applied Research Fifth Annual Technical Symposium Proceedings

Science.gov (United States)

1993-01-01

This Fifth Annual Technical Symposium, sponsored by the UT-Calspan Center for Space Transportation and Applied Research (CSTAR), is organized to provide an overview of the technical accomplishments of the Center's five Research and Technology focus areas during the past year. These areas include chemical propulsion, electric propulsion, commerical space transportation, computational methods, and laser materials processing. Papers in the area of artificial intelligence/expert systems are also presented.

Neoclassical transport in toroidal systems

International Nuclear Information System (INIS)

Wobig, H.

1992-01-01

The neoclassical theory of general toroidal equilibria is reformulated. The toroidal equilibrium of tokamaks and stellarators are described in Hamada coordinates. The relevant geometrical parameters are identified and it is shown how the reduction of Pfirsch-Schluter currents affects neoclassical transport and bootstrap effects. General flux-friction relations between thermodynamic forces and fluxes are derived. In drift-kinetic approximation the neoclassical transport coefficients are Onsager symmetric. Since a toroidal loop voltage is included, the theory is valid for all toroidal systems. (Author)

Space Transportation Technology Workshop: Propulsion Research and Technology

Science.gov (United States)

2000-01-01

This viewgraph presentation gives an overview of the Space Transportation Technology Workshop topics, including Propulsion Research and Technology (PR&T) project level organization, FY 2001 - 2006 project roadmap, points of contact, foundation technologies, auxiliary propulsion technology, PR&T Low Cost Turbo Rocket, and PR&T advanced reusable technologies RBCC test bed.

INFLUENCE OF MUSICAL TONES, IN THE CLASSICAL CONDITIONING OF PREFERENCE OF GEOMETRICAL FIGURES

Directory of Open Access Journals (Sweden)

WILSON LÓPEZ

2004-07-01

Full Text Available This research intended to create preferences on geometric figures using a classical conditioning procedurewhere 2 specific variations of musical structure were used -mayor and dissonant tones- as unconditionedstimulus. 24 university students with an age average of 23 years were exposed to stimular conditionswhere 2 geometric figures (CS+, were matched with mayor tones (UCS+ and other 2 (CS- withdissonant (UCS-; subsequently the figures were rated on a scale (where +10 = very pleasant and -10 =very unpleasant. According with the formulated hypothesis and the previous discoveries in both basicand applied research, three of the four conditions tested showed significant values using the Wilcoxonsign ranks test.

A Summary of Research on Energy Saving and Emission Reduction of Transportation

Science.gov (United States)

Cheng, Dongxiang; Wu, Lufen

2017-12-01

Road transport is an important part of transportation, and road in the field of energy-saving emission reduction is a very important industry. According to the existing problems of road energy saving and emission reduction, this paper elaborates the domestic and international research on energy saving and emission reduction from three aspects: road network optimization, pavement material and pavement maintenance. Road network optimization may be overlooked, and the research content is still relatively preliminary; pavement materials mainly from the asphalt pavement temperature mixed asphalt technology research; pavement maintenance technology development is relatively comprehensive.

Transportation of failed or damaged foreign research reactor spent nuclear fuel

International Nuclear Information System (INIS)

Messick, Charles E.; Mustin, Tracy P.; Massey, Charles D.

1999-01-01

Since initiating the Foreign Research Reactor Spent Nuclear Fuel (FRR SNF) Acceptance Program in 1996, the Program has had to deal with difficult issues associated with the transportation of failed or damaged spent fuel. In several instances, problems with failed or damaged fuel have prevented the acceptance of the fuel at considerable cost to both the Department of Energy and research reactor operators. In response to the problems faced by the Acceptance Program, DOE has undertaken significant steps to better define the spent fuel acceptance criteria. DOE has worked closely with the U.S. Nuclear Regulatory Commission to address failed or damaged research reactor spent fuel causing a degradation of the fuel assembly exposing fuel meat and to identify cask certificate issues which must be resolved by cask owners and foreign regulatory authorities. The specific issues and implementation challenges associated with the transport of MTR type FRR SNF will be discussed. The information presented will include U.S. Nuclear Regulatory Commission regulatory issues, cask certificate issues, technical constraints, implementation status, and lessons learned. Specific information will also be provided on the latest efforts to revise DOE's Appendix B, Transport Package (Cask) Acceptance Criteria. The information presented in this paper will be of interest to foreign research reactor operators, shippers, and cask vendors in evaluating the condition of their fuel to ensure it can be transported in accordance with appropriate cask certificate requirements. (author)

The geometric Hopf invariant and surgery theory

CERN Document Server

Crabb, Michael

2017-01-01

Written by leading experts in the field, this monograph provides homotopy theoretic foundations for surgery theory on higher-dimensional manifolds. Presenting classical ideas in a modern framework, the authors carefully highlight how their results relate to (and generalize) existing results in the literature. The central result of the book expresses algebraic surgery theory in terms of the geometric Hopf invariant, a construction in stable homotopy theory which captures the double points of immersions. Many illustrative examples and applications of the abstract results are included in the book, making it of wide interest to topologists. Serving as a valuable reference, this work is aimed at graduate students and researchers interested in understanding how the algebraic and geometric topology fit together in the surgery theory of manifolds. It is the only book providing such a wide-ranging historical approach to the Hopf invariant, double points and surgery theory, with many results old and new. .

Accessible Transportation Technologies Research Initiative (ATTRI) : User Needs Assessment: Stakeholder Engagement Report.

Science.gov (United States)

2016-05-01

The Accessible Transportation Technologies Research Initiative (ATTRI) is a joint U.S. Department of Transportation (U.S. DOT) initiative that is co-led by the Federal Highway Administration (FHWA) and the Federal Transit Administration (FTA). ATTRI ...

Squaring the Circle: Geometric Skewness and Symmetry Breaking for Passive Scalar Transport in Ducts and Pipes.

Science.gov (United States)

Aminian, Manuchehr; Bernardi, Francesca; Camassa, Roberto; McLaughlin, Richard M

2015-10-09

We study the role geometry plays in the emergence of asymmetries in diffusing passive scalars advected by pressure-driven flows in ducts and pipes of different aspect ratios. We uncover nonintuitive, multi-time-scale behavior gauged by a new statistic, which we term "geometric skewness" S^{G}, which measures instantaneously forming asymmetries at short times due to flow geometry. This signature distinguishes elliptical pipes of any aspect ratio, for which S^{G}=0, from rectangular ducts whose S^{G} is generically nonzero, and, interestingly, shows that a special duct of aspect ratio ≈0.53335 behaves like a circular pipe as its geometric skewness vanishes. Using a combination of exact solutions, novel short-time asymptotics, and Monte Carlo simulations, we establish the relevant time scales for plateaus and extrema in the evolution of the skewness and kurtosis for our class of geometries. For ducts limiting to channel geometries, we present new exact, single-series formulas for the first four moments on slices used to benchmark Monte Carlo simulations.

Regular Polygons and Geometric Series.

Science.gov (United States)

Jarrett, Joscelyn A.

1982-01-01

Examples of some geometric illustrations of limits are presented. It is believed the limit concept is among the most important topics in mathematics, yet many students do not have good intuitive feelings for the concept, since it is often taught very abstractly. Geometric examples are suggested as meaningful tools. (MP)

Using operations research to plan improvement of the transport of critically ill patients.

Science.gov (United States)

Chen, Jing; Awasthi, Anjali; Shechter, Steven; Atkins, Derek; Lemke, Linda; Fisher, Les; Dodek, Peter

2013-01-01

Operations research is the application of mathematical modeling, statistical analysis, and mathematical optimization to understand and improve processes in organizations. The objective of this study was to illustrate how the methods of operations research can be used to identify opportunities to reduce the absolute value and variability of interfacility transport intervals for critically ill patients. After linking data from two patient transport organizations in British Columbia, Canada, for all critical care transports during the calendar year 2006, the steps for transfer of critically ill patients were tabulated into a series of time intervals. Statistical modeling, root-cause analysis, Monte Carlo simulation, and sensitivity analysis were used to test the effect of changes in component intervals on overall duration and variation of transport times. Based on quality improvement principles, we focused on reducing the 75th percentile and standard deviation of these intervals. We analyzed a total of 3808 ground and air transports. Constraining time spent by transport personnel at sending and receiving hospitals was projected to reduce the total time taken by 33 minutes with as much as a 20% reduction in standard deviation of these transport intervals in 75% of ground transfers. Enforcing a policy of requiring acceptance of patients who have life- or limb-threatening conditions or organ failure was projected to reduce the standard deviation of air transport time by 63 minutes and the standard deviation of ground transport time by 68 minutes. Based on findings from our analyses, we developed recommendations for technology renovation, personnel training, system improvement, and policy enforcement. Use of the tools of operations research identifies opportunities for improvement in a complex system of critical care transport.

Geometric Invariants and Object Recognition.

Science.gov (United States)

1992-08-01

University of Chicago Press. Maybank , S.J. [1992], "The Projection of Two Non-coplanar Conics", in Geometric Invariance in Machine Vision, eds. J.L...J.L. Mundy and A. Zisserman, MIT Press, Cambridge, MA. Mundy, J.L., Kapur, .. , Maybank , S.J., and Quan, L. [1992a] "Geometric Inter- pretation of

Logical and Geometrical Distance in Polyhedral Aristotelian Diagrams in Knowledge Representation

Directory of Open Access Journals (Sweden)

Lorenz Demey

2017-09-01

Full Text Available Aristotelian diagrams visualize the logical relations among a finite set of objects. These diagrams originated in philosophy, but recently, they have also been used extensively in artificial intelligence, in order to study (connections between various knowledge representation formalisms. In this paper, we develop the idea that Aristotelian diagrams can be fruitfully studied as geometrical entities. In particular, we focus on four polyhedral Aristotelian diagrams for the Boolean algebra B 4 , viz. the rhombic dodecahedron, the tetrakis hexahedron, the tetraicosahedron and the nested tetrahedron. After an in-depth investigation of the geometrical properties and interrelationships of these polyhedral diagrams, we analyze the correlation (or lack thereof between logical (Hamming and geometrical (Euclidean distance in each of these diagrams. The outcome of this analysis is that the Aristotelian rhombic dodecahedron and tetrakis hexahedron exhibit the strongest degree of correlation between logical and geometrical distance; the tetraicosahedron performs worse; and the nested tetrahedron has the lowest degree of correlation. Finally, these results are used to shed new light on the relative strengths and weaknesses of these polyhedral Aristotelian diagrams, by appealing to the congruence principle from cognitive research on diagram design.

Investigation of Roadway Geometric and Traffic Flow Factors for Vehicle Crashes Using Spatiotemporal Interaction

Science.gov (United States)

Gill, G.; Sakrani, T.; Cheng, W.; Zhou, J.

2017-09-01

Traffic safety is a major concern in the transportation industry due to immense monetary and emotional burden caused by crashes of various severity levels, especially the injury and fatality ones. To reduce such crashes on all public roads, the safety management processes are commonly implemented which include network screening, problem diagnosis, countermeasure identification, and project prioritization. The selection of countermeasures for potential mitigation of crashes is governed by the influential factors which impact roadway crashes. Crash prediction model is the tool widely adopted by safety practitioners or researchers to link various influential factors to crash occurrences. Many different approaches have been used in the past studies to develop better fitting models which also exhibit prediction accuracy. In this study, a crash prediction model is developed to investigate the vehicular crashes occurring at roadway segments. The spatial and temporal nature of crash data is exploited to form a spatiotemporal model which accounts for the different types of heterogeneities among crash data and geometric or traffic flow variables. This study utilizes the Poisson lognormal model with random effects, which can accommodate the yearly variations in explanatory variables and the spatial correlations among segments. The dependency of different factors linked with roadway geometric, traffic flow, and road surface type on vehicular crashes occurring at segments was established as the width of lanes, posted speed limit, nature of pavement, and AADT were found to be correlated with vehicle crashes.

INVESTIGATION OF ROADWAY GEOMETRIC AND TRAFFIC FLOW FACTORS FOR VEHICLE CRASHES USING SPATIOTEMPORAL INTERACTION

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G. Gill

2017-09-01

Full Text Available Traffic safety is a major concern in the transportation industry due to immense monetary and emotional burden caused by crashes of various severity levels, especially the injury and fatality ones. To reduce such crashes on all public roads, the safety management processes are commonly implemented which include network screening, problem diagnosis, countermeasure identification, and project prioritization. The selection of countermeasures for potential mitigation of crashes is governed by the influential factors which impact roadway crashes. Crash prediction model is the tool widely adopted by safety practitioners or researchers to link various influential factors to crash occurrences. Many different approaches have been used in the past studies to develop better fitting models which also exhibit prediction accuracy. In this study, a crash prediction model is developed to investigate the vehicular crashes occurring at roadway segments. The spatial and temporal nature of crash data is exploited to form a spatiotemporal model which accounts for the different types of heterogeneities among crash data and geometric or traffic flow variables. This study utilizes the Poisson lognormal model with random effects, which can accommodate the yearly variations in explanatory variables and the spatial correlations among segments. The dependency of different factors linked with roadway geometric, traffic flow, and road surface type on vehicular crashes occurring at segments was established as the width of lanes, posted speed limit, nature of pavement, and AADT were found to be correlated with vehicle crashes.

The potential of statistical shape modelling for geometric morphometric analysis of human teeth in archaeological research.

Directory of Open Access Journals (Sweden)

Christopher Woods

Full Text Available This paper introduces statistical shape modelling (SSM for use in osteoarchaeology research. SSM is a full field, multi-material analytical technique, and is presented as a supplementary geometric morphometric (GM tool. Lower mandibular canines from two archaeological populations and one modern population were sampled, digitised using micro-CT, aligned, registered to a baseline and statistically modelled using principal component analysis (PCA. Sample material properties were incorporated as a binary enamel/dentin parameter. Results were assessed qualitatively and quantitatively using anatomical landmarks. Finally, the technique's application was demonstrated for inter-sample comparison through analysis of the principal component (PC weights. It was found that SSM could provide high detail qualitative and quantitative insight with respect to archaeological inter- and intra-sample variability. This technique has value for archaeological, biomechanical and forensic applications including identification, finite element analysis (FEA and reconstruction from partial datasets.

Geometric Methods in Physics XXXV

CERN Document Server

Odzijewicz, Anatol; Previato, Emma

2018-01-01

This book features a selection of articles based on the XXXV Białowieża Workshop on Geometric Methods in Physics, 2016. The series of Białowieża workshops, attended by a community of experts at the crossroads of mathematics and physics, is a major annual event in the field. The works in this book, based on presentations given at the workshop, are previously unpublished, at the cutting edge of current research, typically grounded in geometry and analysis, and with applications to classical and quantum physics. In 2016 the special session "Integrability and Geometry" in particular attracted pioneers and leading specialists in the field. Traditionally, the Białowieża Workshop is followed by a School on Geometry and Physics, for advanced graduate students and early-career researchers, and the book also includes extended abstracts of the lecture series.

Geometric phases and quantum computation

International Nuclear Information System (INIS)

Vedral, V.

2005-01-01

Full text: In my lectures I will talk about the notion of the geometric phase and explain its relevance for both fundamental quantum mechanics as well as quantum computation. The phase will be at first introduced via the idea of Pancharatnam which involves interference of three or more light beams. This notion will then be generalized to the evolving quantum systems. I will discuss both pure and mixed states as well as unitary and non-unitary evolutions. I will also show how the concept of the vacuum induced geometric phase arises in quantum optics. A simple measurement scheme involving a Mach Zehnder interferometer will be presented and will be used to illustrate all the concepts in the lecture. Finally, I will expose a simple generalization of the geometric phase to evolving degenerate states. This will be seen to lead to the possibility of universal quantum computation using geometric effects only. Moreover, this contains a promise of intrinsically fault tolerant quantum information processing, whose prospects will be outlined at the end of the lecture. (author)

Guide to Geometric Algebra in Practice

CERN Document Server

Dorst, Leo

2011-01-01

This highly practical "Guide to Geometric Algebra in Practice" reviews algebraic techniques for geometrical problems in computer science and engineering, and the relationships between them. The topics covered range from powerful new theoretical developments, to successful applications, and the development of new software and hardware tools. This title: provides hands-on review exercises throughout the book, together with helpful chapter summaries; presents a concise introductory tutorial to conformal geometric algebra (CGA) in the appendices; examines the application of CGA for the d

Research reactor fuel transport in the U.K

Energy Technology Data Exchange (ETDEWEB)

Panter, R [U.K. Atomic Energy Authority, Harwell (United Kingdom)

1983-09-01

This paper describes the containers currently used for transport of fresh or spent fuel elements for Research and Materials Test Reactors in the U.K., their status, operating procedures and some of the practical difficulties. In the U.K., MTR fuel cycle work is almost entirely the responsibility of the U.K. Atomic Energy Authority.

Geometric Phases for Mixed States in Trapped Ions

International Nuclear Information System (INIS)

Lu Hongxia

2006-01-01

The generalization of geometric phase from the pure states to the mixed states may have potential applications in constructing geometric quantum gates. We here investigate the mixed state geometric phases and visibilities of the trapped ion system in both non-degenerate and degenerate cases. In the proposed quantum system, the geometric phases are determined by the evolution time, the initial states of trapped ions, and the initial states of photons. Moreover, special periods are gained under which the geometric phases do not change with the initial states changing of photon parts in both non-degenerate and degenerate cases. The high detection efficiency in the ion trap system implies that the mixed state geometric phases proposed here can be easily tested.

STUDENTS’ GEOMETRIC THINKING BASED ON VAN HIELE’S THEORY

Directory of Open Access Journals (Sweden)

Harina Fitriyani

2018-02-01

Full Text Available The current study aims to identify the development level of students’ geometric thinking in mathematics education department, Universitas Ahmad Dahlan based on van Hiele’s theory. This is a descriptive qualitative research with the respondents as many as 129 students. In addition to researchers, the instrument used in this study is a test consisting of 25 items multiple choice questions. The data is analyzed by using Milles and Huberman model. The result shows that there were 30,65% of students in pre-visualization level, 21,51% of students in visualizes level, and 29,03% of students in analyze level, 16,67% of students in informal deduction level, 2,15% of students in deduction level, and 0,00% of student in rigor level. Furthermore, findings indicated a transition level among development levels of geometric thinking in pre-analyze, pre-informal deduction, pre-deduction, and pre-rigor that were 20%; 13,44%; 6,45%; 1,08% respectively. The other findings were 40,32% of students were difficult to determine and 4,3% of students cannot be identified.

Eigenvector centrality for geometric and topological characterization of porous media

Science.gov (United States)

Jimenez-Martinez, Joaquin; Negre, Christian F. A.

2017-07-01

Solving flow and transport through complex geometries such as porous media is computationally difficult. Such calculations usually involve the solution of a system of discretized differential equations, which could lead to extreme computational cost depending on the size of the domain and the accuracy of the model. Geometric simplifications like pore networks, where the pores are represented by nodes and the pore throats by edges connecting pores, have been proposed. These models, despite their ability to preserve the connectivity of the medium, have difficulties capturing preferential paths (high velocity) and stagnation zones (low velocity), as they do not consider the specific relations between nodes. Nonetheless, network theory approaches, where a complex network is a graph, can help to simplify and better understand fluid dynamics and transport in porous media. Here we present an alternative method to address these issues based on eigenvector centrality, which has been corrected to overcome the centralization problem and modified to introduce a bias in the centrality distribution along a particular direction to address the flow and transport anisotropy in porous media. We compare the model predictions with millifluidic transport experiments, which shows that, albeit simple, this technique is computationally efficient and has potential for predicting preferential paths and stagnation zones for flow and transport in porous media. We propose to use the eigenvector centrality probability distribution to compute the entropy as an indicator of the "mixing capacity" of the system.

Exact Solutions for Einstein's Hyperbolic Geometric Flow

International Nuclear Information System (INIS)

He Chunlei

2008-01-01

In this paper we investigate the Einstein's hyperbolic geometric flow and obtain some interesting exact solutions for this kind of flow. Many interesting properties of these exact solutions have also been analyzed and we believe that these properties of Einstein's hyperbolic geometric flow are very helpful to understanding the Einstein equations and the hyperbolic geometric flow

Geometric control theory and sub-Riemannian geometry

CERN Document Server

Boscain, Ugo; Gauthier, Jean-Paul; Sarychev, Andrey; Sigalotti, Mario

2014-01-01

This volume presents recent advances in the interaction between Geometric Control Theory and sub-Riemannian geometry. On the one hand, Geometric Control Theory used the differential geometric and Lie algebraic language for studying controllability, motion planning, stabilizability and optimality for control systems. The geometric approach turned out to be fruitful in applications to robotics, vision modeling, mathematical physics etc. On the other hand, Riemannian geometry and its generalizations, such as  sub-Riemannian, Finslerian  geometry etc., have been actively adopting methods developed in the scope of geometric control. Application of these methods  has led to important results regarding geometry of sub-Riemannian spaces, regularity of sub-Riemannian distances, properties of the group  of diffeomorphisms of sub-Riemannian manifolds, local geometry and equivalence of distributions and sub-Riemannian structures, regularity of the Hausdorff volume.

Towards a Common Research Strategic Roadmap for the Transportation Sector in Europe and beyond

Directory of Open Access Journals (Sweden)

Evangelos Bekiaris

2013-08-01

Full Text Available DETRA (Developing a European Transport Research Alliance is a 7th Framework project, whose concept derived from the so-called Lyon Declaration and concerns the deepening of the European Research Area objectives in transport in order to address the Grand Challenges. Key priorities of this Alliance is to examine the strengths, weaknesses, opportunities and threats (SWOT in the domain and develop common understanding and approaches to reducing fragmentation and overcoming barriers. The DETRA project aimed to meet and exceed the requirements and objectives of the call for an Analysis of the state of ERA development within the transport domain and to develop recommendations for the EC, member states and other stakeholders as well as for the DETRA partner organizations themselves. In this study, particular emphasis is given to the part of DETRA concerning the development of a single trans- European research program, which can be used as a compass for the future research activities of the whole transportation area.

A geometrical interpretation of renormalisation group flow

International Nuclear Information System (INIS)

Dolan, B.P.

1993-05-01

The renormalisation group (RG) equation in D-dimensional Euclidean space, R D , is analysed from a geometrical point of view. A general form of the RG equation is derived which is applicable to composite operators as well tensor operators (on R D ) which may depend on the Euclidean metric. It is argued that physical N-point amplitudes should be interpreted as rank N co-variant tensors on the space of couplings, G, and that the RG equation can be viewed as an equation for Lie transport on G with respect to the vector field generated by the β-functions of the theory. In one sense it is nothing more than the definition of a Lie derivative. The source of the anomalous dimensions can be interpreted as being due to the change of the basis vectors on G under Lie transport. The RG equation acts as a bridge between Euclidean space and coupling constant space in that the effect on amplitudes of a diffeomorphism of R D (that of dilations) is completely equivalent to a diffeomorphism of G generated by the β-functions of the theory. A form of the RG equation for operators is also given. These ideas are developed in detail for the example of massive λΦ 4 theory in 4 dimensions. (orig.)

Geometric correction of APEX hyperspectral data

Directory of Open Access Journals (Sweden)

Vreys Kristin

2016-03-01

Full Text Available Hyperspectral imagery originating from airborne sensors is nowadays widely used for the detailed characterization of land surface. The correct mapping of the pixel positions to ground locations largely contributes to the success of the applications. Accurate geometric correction, also referred to as “orthorectification”, is thus an important prerequisite which must be performed prior to using airborne imagery for evaluations like change detection, or mapping or overlaying the imagery with existing data sets or maps. A so-called “ortho-image” provides an accurate representation of the earth’s surface, having been adjusted for lens distortions, camera tilt and topographic relief. In this paper, we describe the different steps in the geometric correction process of APEX hyperspectral data, as applied in the Central Data Processing Center (CDPC at the Flemish Institute for Technological Research (VITO, Mol, Belgium. APEX ortho-images are generated through direct georeferencing of the raw images, thereby making use of sensor interior and exterior orientation data, boresight calibration data and elevation data. They can be referenced to any userspecified output projection system and can be resampled to any output pixel size.

Body shape shifting during growth permits tests that distinguish between competing geometric theories of metabolic scaling

DEFF Research Database (Denmark)

Hirst, Andrew G.; Glazier, Douglas S.; Atkinson, David

2014-01-01

Metabolism fuels all of life’s activities, from biochemical reactions to ecological interactions. According to two intensely debated theories, body size affects metabolism via geometrical influences on the transport of resources and wastes. However, these theories differ crucially in whether...... the size dependence of metabolism is derived from material transport across external surfaces, or through internal resource-transport networks. We show that when body shape changes during growth, these models make opposing predictions. These models are tested using pelagic invertebrates, because...... these animals exhibit highly variable intraspecific scaling relationships for metabolic rate and body shape. Metabolic scaling slopes of diverse integument-breathing species were significantly positively correlated with degree of body flattening or elongation during ontogeny, as expected from surface area...

Lectures on geometrical properties of nuclei

International Nuclear Information System (INIS)

Myers, W.D.

1975-11-01

Material concerning the geometrical properties of nuclei is drawn from a number of different sources. The leptodermous nature of nuclear density distributions and potential wells is used to draw together the various geometrical properties of these systems and to provide a unified means for their description. Extensive use is made of expansions of radial properties in terms of the surface diffuseness. A strong case is made for the use of convolution as a geometrical ansatz for generating diffuse surface distributions because of the number of simplifications that arise which are of practical importance. 7 figures

Coupled electron-photon radiation transport

International Nuclear Information System (INIS)

Lorence, L.; Kensek, R.P.; Valdez, G.D.; Drumm, C.R.; Fan, W.C.; Powell, J.L.

2000-01-01

Massively-parallel computers allow detailed 3D radiation transport simulations to be performed to analyze the response of complex systems to radiation. This has been recently been demonstrated with the coupled electron-photon Monte Carlo code, ITS. To enable such calculations, the combinatorial geometry capability of ITS was improved. For greater geometrical flexibility, a version of ITS is under development that can track particles in CAD geometries. Deterministic radiation transport codes that utilize an unstructured spatial mesh are also being devised. For electron transport, the authors are investigating second-order forms of the transport equations which, when discretized, yield symmetric positive definite matrices. A novel parallelization strategy, simultaneously solving for spatial and angular unknowns, has been applied to the even- and odd-parity forms of the transport equation on a 2D unstructured spatial mesh. Another second-order form, the self-adjoint angular flux transport equation, also shows promise for electron transport

Charge as the Stereographic Projection of Geometric Precession on Pseudospheres

CERN Document Server

Binder, B

2002-01-01

In this paper geometric phases (Berry and Aharonov-Bohm) are generalized to nonlinear topological phase fields on pseudospheres, where the coordinate vector field is parallel transported along the signal/soliton vector field with Levi--Civita connection. Projective $PSL(2,{\\Bbb R})$ symmetry describes the relativistic self-interacting bosonic sine-Gordon field. A Coulomb potential can be induced as the stereographic projection of a harmonic oscillator potential mapping angles or phases to distances and vice versa resulting in mutual coupling with a generalized coupling constant given by a nonlinear iteration. With single-valuedness requirement in 137-gonal symmetry it fits within a few ppb uncertainty to the Sommerfeld fine structure constant.

Making Tracks 1.0: Action Researching an Active Transportation Education Program

Science.gov (United States)

Robinson, Daniel; Foran, Andrew; Robinson, Ingrid

2014-01-01

This paper reports on the results of the first cycle of an action research project. The objective of this action research was to examine the implementation of a school-based active transportation education program (Making Tracks). A two-cycle action research design was employed in which elementary school students' (ages 7-9), middle school…

GEOMETRIC AND RADIOMETRIC EVALUATION OF RASAT IMAGES

Directory of Open Access Journals (Sweden)

A. Cam

2016-06-01

Full Text Available RASAT, the second remote sensing satellite of Turkey, was designed and assembled, and also is being operated by TÜBİTAK Uzay (Space Technologies Research Institute (Ankara. RASAT images in various levels are available free-of-charge via Gezgin portal for Turkish citizens. In this paper, the images in panchromatic (7.5 m GSD and RGB (15 m GSD bands in various levels were investigated with respect to its geometric and radiometric characteristics. The first geometric analysis is the estimation of the effective GSD as less than 1 pixel for radiometrically processed level (L1R of both panchromatic and RGB images. Secondly, 2D georeferencing accuracy is estimated by various non-physical transformation models (similarity, 2D affine, polynomial, affine projection, projective, DLT and GCP based RFM reaching sub-pixel accuracy using minimum 39 and maximum 52 GCPs. The radiometric characteristics are also investigated for 8 bits, estimating SNR between 21.8-42.2, and noise 0.0-3.5 for panchromatic and MS images for L1R when the sea is masked to obtain the results for land areas. The analysis show that RASAT images satisfies requirements for various applications. The research is carried out in Zonguldak test site which is mountainous and partly covered by dense forest and urban areas.

Impact of microstructure evolution on the difference between geometric and reactive surface areas in natural chalk

Science.gov (United States)

Yang, Y.; Bruns, S.; Stipp, S. L. S.; Sørensen, H. O.

2018-05-01

The coupling between flow and mineral dissolution drives the evolution of many natural and engineered flow systems. Pore surface changes as microstructure evolves but this transient behaviour has traditionally been difficult to model. We combined a reactor network model with experimental, greyscale tomography data to establish the morphological grounds for differences among geometric, reactive and apparent surface areas in dissolving chalk. This approach allowed us to study the effects of initial geometry and macroscopic flow rate independently. The simulations showed that geometric surface, which represents a form of local transport heterogeneity, increases in an imposed flow field, even when the porous structure is chemically homogeneous. Hence, the fluid-reaction coupling leads to solid channelisation, which further results in fluid focusing and an increase in geometric surface area. Fluid focusing decreases the area of reactive surface and the residence time of reactant, both contribute to the over-normalisation of reaction rate. In addition, the growing and merging of microchannels, near the fluid entrance, contribute to the macroscopic, fast initial dissolution rate of rocks.

Power Generation and Transportation Systems Research Department: 1992 annual status report (Gas Research Institute)

International Nuclear Information System (INIS)

Benedict, A.

1992-09-01

Activities of Gas Research Institute's Power Generation and Transportation Systems subprogram for the period between October 1, 1991 and September 30, 1992 are summarized. The particular project areas covered in the report are Cogeneration and Power Systems, Engine Technology and Component Development, Natural Gas Vehicles Research, and Electric Power Generation. For each project area a separate chapter is provided. Each chapter includes a rationale for funding the research effort, the goals and objectives to be achieved, a general statement on research accomplishments, and the strategy employed in the project area. Each chapter also contains a series of summary reports on the status of each contract

Geometric Semantic Genetic Programming Algorithm and Slump Prediction

OpenAIRE

Xu, Juncai; Shen, Zhenzhong; Ren, Qingwen; Xie, Xin; Yang, Zhengyu

2017-01-01

Research on the performance of recycled concrete as building material in the current world is an important subject. Given the complex composition of recycled concrete, conventional methods for forecasting slump scarcely obtain satisfactory results. Based on theory of nonlinear prediction method, we propose a recycled concrete slump prediction model based on geometric semantic genetic programming (GSGP) and combined it with recycled concrete features. Tests show that the model can accurately p...

Transport on river networks: A dynamical approach

OpenAIRE

Zaliapin, I; Foufoula-Georgiou, E; Ghil, M

2017-01-01

This study is motivated by problems related to environmental transport on river networks. We establish statistical properties of a flow along a directed branching network and suggest its compact parameterization. The downstream network transport is treated as a particular case of nearest-neighbor hierarchical aggregation with respect to the metric induced by the branching structure of the river network. We describe the static geometric structure of a drainage network by a tree, referred to as...

Undergraduate research internships to support exploratory research in transportation engineering : project final report, Sept. 2008.

Science.gov (United States)

2008-09-01

The Case Western Reserve University Department of Civil Engineering is in the process of expanding its teaching and research activities, Transportation Engineering as part of its initiative in the overall area of Infrastructure Performance and Reliab...

Geometrical optics and the diffraction phenomenon

International Nuclear Information System (INIS)

Timofeev, Aleksandr V

2005-01-01

This note outlines the principles of the geometrical optics of inhomogeneous waves whose description necessitates the use of complex values of the wave vector. Generalizing geometrical optics to inhomogeneous waves permits including in its scope the analysis of the diffraction phenomenon. (methodological notes)

Geometric U-folds in four dimensions

Science.gov (United States)

Lazaroiu, C. I.; Shahbazi, C. S.

2018-01-01

We describe a general construction of geometric U-folds compatible with a non-trivial extension of the global formulation of four-dimensional extended supergravity on a differentiable spin manifold. The topology of geometric U-folds depends on certain flat fiber bundles which encode how supergravity fields are globally glued together. We show that smooth non-trivial U-folds of this type can exist only in theories where both the scalar and space-time manifolds have non-trivial fundamental group and in addition the scalar map of the solution is homotopically non-trivial. Consistency with string theory requires smooth geometric U-folds to be glued using subgroups of the effective discrete U-duality group, implying that the fundamental group of the scalar manifold of such solutions must be a subgroup of the latter. We construct simple examples of geometric U-folds in a generalization of the axion-dilaton model of \

Enhanced Magnetoresistance in Molecular Junctions by Geometrical Optimization of Spin-Selective Orbital Hybridization.

Science.gov (United States)

Rakhmilevitch, David; Sarkar, Soumyajit; Bitton, Ora; Kronik, Leeor; Tal, Oren

2016-03-09

Molecular junctions based on ferromagnetic electrodes allow the study of electronic spin transport near the limit of spintronics miniaturization. However, these junctions reveal moderate magnetoresistance that is sensitive to the orbital structure at their ferromagnet-molecule interfaces. The key structural parameters that should be controlled in order to gain high magnetoresistance have not been established, despite their importance for efficient manipulation of spin transport at the nanoscale. Here, we show that single-molecule junctions based on nickel electrodes and benzene molecules can yield a significant anisotropic magnetoresistance of up to ∼200% near the conductance quantum G0. The measured magnetoresistance is mechanically tuned by changing the distance between the electrodes, revealing a nonmonotonic response to junction elongation. These findings are ascribed with the aid of first-principles calculations to variations in the metal-molecule orientation that can be adjusted to obtain highly spin-selective orbital hybridization. Our results demonstrate the important role of geometrical considerations in determining the spin transport properties of metal-molecule interfaces.

Forward error correction based on algebraic-geometric theory

CERN Document Server

A Alzubi, Jafar; M Chen, Thomas

2014-01-01

This book covers the design, construction, and implementation of algebraic-geometric codes from Hermitian curves. Matlab simulations of algebraic-geometric codes and Reed-Solomon codes compare their bit error rate using different modulation schemes over additive white Gaussian noise channel model. Simulation results of Algebraic-geometric codes bit error rate performance using quadrature amplitude modulation (16QAM and 64QAM) are presented for the first time and shown to outperform Reed-Solomon codes at various code rates and channel models. The book proposes algebraic-geometric block turbo codes. It also presents simulation results that show an improved bit error rate performance at the cost of high system complexity due to using algebraic-geometric codes and Chase-Pyndiah’s algorithm simultaneously. The book proposes algebraic-geometric irregular block turbo codes (AG-IBTC) to reduce system complexity. Simulation results for AG-IBTCs are presented for the first time.

Geometric screening of core/shell hydrogel microcapsules using a tapered microchannel with interdigitated electrodes.

Science.gov (United States)

Niu, Ye; Qi, Lin; Zhang, Fen; Zhao, Yi

2018-07-30

Core/shell hydrogel microcapsules attract increasing research attention due to their potentials in tissue engineering, food engineering, and drug delivery. Current approaches for generating core/shell hydrogel microcapsules suffer from large geometric variations. Geometrically defective core/shell microcapsules need to be removed before further use. High-throughput geometric characterization of such core/shell microcapsules is therefore necessary. In this work, a continuous-flow device was developed to measure the geometric properties of microcapsules with a hydrogel shell and an aqueous core. The microcapsules were pumped through a tapered microchannel patterned with an array of interdigitated microelectrodes. The geometric parameters (the shell thickness and the diameter) were derived from the displacement profiles of the microcapsules. The results show that this approach can successfully distinguish all unencapsulated microparticles. The geometric properties of core/shell microcapsules can be determined with high accuracy. The efficacy of this method was demonstrated through a drug releasing experiment where the optimization of the electrospray process based on geometric screening can lead to controlled and extended drug releasing profiles. This method does not require high-speed optical systems, simplifying the system configuration and making it an indeed miniaturized device. The throughput of up to 584 microcapsules per minute was achieved. This study provides a powerful tool for screening core/shell hydrogel microcapsules and is expected to facilitate the applications of these microcapsules in various fields. Copyright © 2018 Elsevier B.V. All rights reserved.

Refined geometric transition and qq-characters

Science.gov (United States)

Kimura, Taro; Mori, Hironori; Sugimoto, Yuji

2018-01-01

We show the refinement of the prescription for the geometric transition in the refined topological string theory and, as its application, discuss a possibility to describe qq-characters from the string theory point of view. Though the suggested way to operate the refined geometric transition has passed through several checks, it is additionally found in this paper that the presence of the preferred direction brings a nontrivial effect. We provide the modified formula involving this point. We then apply our prescription of the refined geometric transition to proposing the stringy description of doubly quantized Seiberg-Witten curves called qq-characters in certain cases.

Savannah River Laboratory environmental transport and effects research. Annual report, 1978

Energy Technology Data Exchange (ETDEWEB)

Crawford, T.V. (comp.)

1979-11-01

Research in the environmental sciences by the Savannah River Laboratory during 1978 is described in 43 articles. These articles are in the fields of terrestrial ecology, geologic studies, aquatic transport, aquatic ecology, atmospheric transport, emergency response, computer methods development, ocean program, and fuel cycle program. Thirty-seven of the articles were abstracted individually for ERA/EDB; those in scope were also included in INIS.

Testing of a transport cask for research reactor spent fuel

International Nuclear Information System (INIS)

Mourao, Rogerio P.; Silva, Luiz Leite da; Miranda, Carlos A.; Mattar Neto, Miguel; Quintana, Jose F.A.; Saliba, Roberto O.; Novara, Oscar E.

2011-01-01

Since the beginning of the last decade three Latin American countries which operate research reactors - Argentina, Brazil and Chile - have been joining efforts to improve the regional capability in the management of spent fuel elements from the reactors operated in the region. As a step in this direction, a packaging for the transport of irradiated fuel from research reactors was designed by a tri-national team and a half-scale model for MTR fuel constructed in Argentina and tested in Brazil. Two test campaigns have been carried out so far, covering both normal conditions of transportation and hypothetical accident conditions. Although the specimen has not successfully performed the tests, its overall performance was considered very satisfactory, and improvements are being introduced to the design. A third test sequence is planned for 2011. (author)

Optimal control for mathematical models of cancer therapies an application of geometric methods

CERN Document Server

Schättler, Heinz

2015-01-01

This book presents applications of geometric optimal control to real life biomedical problems with an emphasis on cancer treatments. A number of mathematical models for both classical and novel cancer treatments are presented as optimal control problems with the goal of constructing optimal protocols. The power of geometric methods is illustrated with fully worked out complete global solutions to these mathematically challenging problems. Elaborate constructions of optimal controls and corresponding system responses provide great examples of applications of the tools of geometric optimal control and the outcomes aid the design of simpler, practically realizable suboptimal protocols. The book blends mathematical rigor with practically important topics in an easily readable tutorial style. Graduate students and researchers in science and engineering, particularly biomathematics and more mathematical aspects of biomedical engineering, would find this book particularly useful.

The perception of geometrical structure from congruence

Science.gov (United States)

Lappin, Joseph S.; Wason, Thomas D.

1989-01-01

The principle function of vision is to measure the environment. As demonstrated by the coordination of motor actions with the positions and trajectories of moving objects in cluttered environments and by rapid recognition of solid objects in varying contexts from changing perspectives, vision provides real-time information about the geometrical structure and location of environmental objects and events. The geometric information provided by 2-D spatial displays is examined. It is proposed that the geometry of this information is best understood not within the traditional framework of perspective trigonometry, but in terms of the structure of qualitative relations defined by congruences among intrinsic geometric relations in images of surfaces. The basic concepts of this geometrical theory are outlined.

From the geometric quantization to conformal field theory

International Nuclear Information System (INIS)

Alekseev, A.; Shatashvili, S.

1990-01-01

Investigation of 2d conformal field theory in terms of geometric quantization is given. We quantize the so-called model space of the compact Lie group, Virasoro group and Kac-Moody group. In particular, we give a geometrical interpretation of the Virasoro discrete series and explain that this type of geometric quantization reproduces the chiral part of CFT (minimal models, 2d-gravity, WZNW theory). In the appendix we discuss the relation between classical (constant) r-matrices and this geometrical approach. (orig.)

Geometric inequalities methods of proving

CERN Document Server

Sedrakyan, Hayk

2017-01-01

This unique collection of new and classical problems provides full coverage of geometric inequalities. Many of the 1,000 exercises are presented with detailed author-prepared-solutions, developing creativity and an arsenal of new approaches for solving mathematical problems. This book can serve teachers, high-school students, and mathematical competitors. It may also be used as supplemental reading, providing readers with new and classical methods for proving geometric inequalities. .

Methods, measures and indicators for evaluating benefits of transportation research

CSIR Research Space (South Africa)

Du Plessis, Louw

2016-04-01

Full Text Available The purpose of this article is to provide updated information by identifying and discussing methods, measures and indicators for evaluating benefits appropriate for transportation-related research facilities/programmes. The information has been...

Geometry and transport in a model of two coupled quadratic nonlinear waveguides

DEFF Research Database (Denmark)

Stirling, James R.; Bang, Ole; Christiansen, Peter Leth

2008-01-01

This paper applies geometric methods developed to understand chaos and transport in Hamiltonian systems to the study of power distribution in nonlinear waveguide arrays. The specific case of two linearly coupled X(2) waveguides is modeled and analyzed in terms of transport and geometry in the pha...

Feature Extraction of Weld Defectology in Digital Image of Radiographic Film Using Geometric Invariant Moment and Statistical Texture

International Nuclear Information System (INIS)

Muhtadan

2009-01-01

The purpose of this research is to perform feature extraction in weld defect of digital image of radiographic film using geometric invariant moment and statistical texture method. Feature extraction values can be use as values that used to classify and pattern recognition on interpretation of weld defect in digital image of radiographic film by computer automatically. Weld defectology type that used in this research are longitudinal crack, transversal crack, distributed porosity, clustered porosity, wormhole, and no defect. Research methodology on this research are program development to read digital image, then performing image cropping to localize weld position, and then applying geometric invariant moment and statistical texture formulas to find feature values. The result of this research are feature extraction values that have tested with RST (rotation, scale, transformation) treatment and yield moment values that more invariant there are ϕ 3 , ϕ 4 , ϕ 5 from geometric invariant moment method. Feature values from statistical texture that are average intensity, average contrast, smoothness, 3 rd moment, uniformity, and entropy, they used as feature extraction values. (author)

Light transport and general aviation aircraft icing research requirements

Science.gov (United States)

Breeze, R. K.; Clark, G. M.

1981-01-01

A short term and a long term icing research and technology program plan was drafted for NASA LeRC based on 33 separate research items. The specific items listed resulted from a comprehensive literature search, organized and assisted by a computer management file and an industry/Government agency survey. Assessment of the current facilities and icing technology was accomplished by presenting summaries of ice sensitive components and protection methods; and assessments of penalty evaluation, the experimental data base, ice accretion prediction methods, research facilities, new protection methods, ice protection requirements, and icing instrumentation. The intent of the research plan was to determine what icing research NASA LeRC must do or sponsor to ultimately provide for increased utilization and safety of light transport and general aviation aircraft.

TRANSPORTATION RESEARCH IMPLEMENTATION MANAGEMENT : DEVELOPMENT OF PERFORMANCE BASED PROCESSES, METRICS, AND TOOLS

Science.gov (United States)

2018-02-02

The objective of this study is to develop an evidencebased research implementation database and tool to support research implementation at the Georgia Department of Transportation (GDOT).A review was conducted drawing from the (1) implementati...

Visualisation, imagery, and the development of geometrical reasoning

OpenAIRE

Jones, Keith; Bills, Chris

1998-01-01

This report focuses on some aspects of the nature and role of visualisation and imagery in the teaching and learning of mathematics, particularly as a component in the development of geometrical reasoning. Issues briefly addressed include the relationship between imagery and perception, imagery and memory, the nature of dynamic images, and the interaction between imagery and concept development. The report concludes with a series of questions that may provide a suitable programme for research...

Impulse propagation in the nocturnal boundary layer: analysis of the geometric component.

Science.gov (United States)

Blom, Philip; Waxler, Roger

2012-05-01

On clear dry nights over flat land, a temperature inversion and stable nocturnal wind jet lead to an acoustic duct in the lowest few hundred meters of the atmosphere. An impulsive signal propagating in such a duct is received at long ranges from the source as an extended wave train consisting of a series of weakly dispersed distinct arrivals followed by a strongly dispersed low-frequency tail. The leading distinct arrivals have been previously shown to be well modeled by geometric acoustics. In this paper, the geometric acoustics approximation for the leading arrivals is investigated. Using the solutions of the eikonal and transport equations, travel times, amplitudes, and caustic structures of the distinct arrivals have been determined. The time delay between and relative amplitudes of the direct-refracted and single ground reflection arrivals have been investigated as parameters for an inversion scheme. A two parameter quadratic approximation to the effective sound speed profile has been fit and found to be in strong agreement with meteorological measurements from the time of propagation.

Standalone visualization tool for three-dimensional DRAGON geometrical models

International Nuclear Information System (INIS)

Lukomski, A.; McIntee, B.; Moule, D.; Nichita, E.

2008-01-01

DRAGON is a neutron transport and depletion code able to solve one-, two- and three-dimensional problems. To date DRAGON provides two visualization modules, able to represent respectively two- and three-dimensional geometries. The two-dimensional visualization module generates a postscript file, while the three dimensional visualization module generates a MATLAB M-file with instructions for drawing the tracks in the DRAGON TRACKING data structure, which implicitly provide a representation of the geometry. The current work introduces a new, standalone, tool based on the open-source Visualization Toolkit (VTK) software package which allows the visualization of three-dimensional geometrical models by reading the DRAGON GEOMETRY data structure and generating an axonometric image which can be manipulated interactively by the user. (author)

Geometric group theory an introduction

CERN Document Server

Löh, Clara

2017-01-01

Inspired by classical geometry, geometric group theory has in turn provided a variety of applications to geometry, topology, group theory, number theory and graph theory. This carefully written textbook provides a rigorous introduction to this rapidly evolving field whose methods have proven to be powerful tools in neighbouring fields such as geometric topology. Geometric group theory is the study of finitely generated groups via the geometry of their associated Cayley graphs. It turns out that the essence of the geometry of such groups is captured in the key notion of quasi-isometry, a large-scale version of isometry whose invariants include growth types, curvature conditions, boundary constructions, and amenability. This book covers the foundations of quasi-geometry of groups at an advanced undergraduate level. The subject is illustrated by many elementary examples, outlooks on applications, as well as an extensive collection of exercises.

Geometric procedures for civil engineers

CERN Document Server

Tonias, Elias C

2016-01-01

This book provides a multitude of geometric constructions usually encountered in civil engineering and surveying practice.  A detailed geometric solution is provided to each construction as well as a step-by-step set of programming instructions for incorporation into a computing system. The volume is comprised of 12 chapters and appendices that may be grouped in three major parts: the first is intended for those who love geometry for its own sake and its evolution through the ages, in general, and, more specifically, with the introduction of the computer. The second section addresses geometric features used in the book and provides support procedures used by the constructions presented. The remaining chapters and the appendices contain the various constructions. The volume is ideal for engineering practitioners in civil and construction engineering and allied areas.

Recent Cooperative Research Activities of HDD and Flexible Media Transport Technologies in Japan

Science.gov (United States)

Ono, Kyosuke

This paper presents the recent status of industry-university cooperative research activities in Japan on the mechatronics of information storage and input/output equipment. There are three research committees for promoting information exchange on technical problems and research topics of head-disk interface in hard disk drives (HDD), flexible media transport and image printing processes which are supported by the Japan Society of Mechanical Engineering (JSME), the Japanese Society of Tribologists (JAST) and the Japan Society of Precision Engineering (JSPE). For hard disk drive technology, the Storage Research Consortium (SRC) is supporting more than 40 research groups in various different universities to perform basic research for future HDD technology. The past and present statuses of these activities are introduced, particularly focusing on HDD and flexible media transport mechanisms.

BOOK REVIEW: The Geometric Phase in Quantum Systems

Science.gov (United States)

Pascazio, S.

2003-12-01

The discovery of the geometric phase is one of the most interesting and intriguing findings of the last few decades. It led to a deeper understanding of the concept of phase in quantum mechanics and motivated a surge of interest in fundamental quantum mechanical issues, disclosing unexpected applications in very diverse fields of physics. Although the key ideas underlying the existence of a purely geometrical phase had already been proposed in 1956 by Pancharatnam, it was Michael Berry who revived this issue 30 years later. The clarity of Berry's seminal paper, in 1984, was extraordinary. Research on the topic flourished at such a pace that it became difficult for non-experts to follow the many different theoretical ideas and experimental proposals which ensued. Diverse concepts in independent areas of mathematics, physics and chemistry were being applied, for what was (and can still be considered) a nascent arena for theory, experiments and technology. Although collections of papers by different authors appeared in the literature, sometimes with ample introductions, surprisingly, to the best of my knowledge, no specific and exhaustive book has ever been written on this subject. The Geometric Phase in Quantum Systems is the first thorough book on geometric phases and fills an important gap in the physical literature. Other books on the subject will undoubtedly follow. But it will take a fairly long time before other authors can cover that same variety of concepts in such a comprehensive manner. The book is enjoyable. The choice of topics presented is well balanced and appropriate. The appendices are well written, understandable and exhaustive - three rare qualities. I also find it praiseworthy that the authors decided to explicitly carry out most of the calculations, avoiding, as much as possible, the use of the joke `after a straightforward calculation, one finds...' This was one of the sentences I used to dislike most during my undergraduate studies. A student is

Study of identification of geometrically shaped solids using colour and range information

International Nuclear Information System (INIS)

Ebihara, Kenichi

1997-05-01

This report is the revision of the Technical Report (MECSE 1996-7) of Monash University in Melbourne, Australia which has been distributed to the Department Library in this University. The main work which is described in this report was carried out at Intelligent Robotics Research Center (IRRC) in the Department of Electrical and Computer Systems Engineering of Monash University from March in 1995 to March in 1996 and was be supported by a grant from Research Development Corporation of Japan (JRDC). This report describes the study of identification of geometrically shaped solids with unique colour using colour and range information. This study aims at recognition of equipment in nuclear plants. For this purpose, it is hypothesized that equipment in nuclear plants can be represented by combination of geometrically shaped solids with unique colour, such as a sphere, an ellipsoid, a cone, a cylinder, a rectangular solid and a pyramid. In this report, the colour image of geometrically shaped solids could be segmented comparatively easily and effectively into regions of each solid by using colour and range information. The range data of each solid was extracted using the segmented colour image. Thus the extracted range data could be classified into a plane surface or a curved surface by checking its spatial distribution. (author)

BNFL's experience in the sea transport of irradiated research reactor fuel to the USA

International Nuclear Information System (INIS)

Hudson, I.A.; Porter, I.

2000-01-01

BNFL provides worldwide transport for a wide range of nuclear materials. BNFL Transport manages an unique fleet of vessels, designed, built, and operated to the highest safety standards, including the highest rating within the INF Code recommended by the International Maritime Organisation. The company has some 20 years of experience of transporting irradiated research reactor fuel in support of the United States' programme for returning US obligated fuel from around the world. Between 1977 and 1988 BNFL performed 11 shipments of irradiated research reactor fuel from the Japan Atomic Energy Research Institute to the US. Since 1997, a further 3 shipments have been performed as part of an ongoing programme for Japanese research reactor operators. Where possible, shipments of fuel from European countries such as Sweden and Spain have been combined with those from Japan for delivery to the US. (author)

5th Dagstuhl Seminar on Geometric Modelling

CERN Document Server

Brunnett, Guido; Farin, Gerald; Goldman, Ron

2004-01-01

In 19 articles presented by leading experts in the field of geometric modelling the state-of-the-art on representing, modeling, and analyzing curves, surfaces as well as other 3-dimensional geometry is given. The range of applications include CAD/CAM-systems, computer graphics, scientific visualization, virtual reality, simulation and medical imaging. The content of this book is based on selected lectures given at a workshop held at IBFI Schloss Dagstuhl, Germany. Topics treated are: – curve and surface modelling – non-manifold modelling in CAD – multiresolution analysis of complex geometric models – surface reconstruction – variational design – computational geometry of curves and surfaces – 3D meshing – geometric modelling for scientific visualization – geometric models for biomedical applications

Geometric photovoltaics applied to amorphous silicon thin film solar cells

Science.gov (United States)

Kirkpatrick, Timothy

Geometrically generalized analytical expressions for device transport are derived from first principles for a photovoltaic junction. Subsequently, conventional planar and unconventional coaxial and hemispherical photovoltaic architectures are applied to detail the device physics of the junction based on their respective geometry. For the conventional planar cell, the one-dimensional transport equations governing carrier dynamics are recovered. For the unconventional coaxial and hemispherical junction designs, new multi-dimensional transport equations are revealed. Physical effects such as carrier generation and recombination are compared for each cell architecture, providing insight as to how non-planar junctions may potentially enable greater energy conversion efficiencies. Numerical simulations are performed for arrays of vertically aligned, nanostructured coaxial and hemispherical amorphous silicon solar cells and results are compared to those from simulations performed for the standard planar junction. Results indicate that fundamental physical changes in the spatial dependence of the energy band profile across the intrinsic region of an amorphous silicon p-i-n junction manifest as an increase in recombination current for non-planar photovoltaic architectures. Despite an increase in recombination current, however, the coaxial architecture still appears to be able to surpass the efficiency predicted for the planar geometry, due to the geometry of the junction leading to a decoupling of optics and electronics.

Geometrical scaling, furry branching and minijets

International Nuclear Information System (INIS)

Hwa, R.C.

1988-01-01

Scaling properties and their violations in hadronic collisions are discussed in the framework of the geometrical branching model. Geometrical scaling supplemented by Furry branching characterizes the soft component, while the production of jets specifies the hard component. Many features of multiparticle production processes are well described by this model. 21 refs

Geometric Hyperplanes of the Near Hexagon L-3 x GQ(2,2)

Czech Academy of Sciences Publication Activity Database

Saniga, M.; Levay, P.; Planat, M.; Pracna, Petr

2010-01-01

Roč. 91, č. 1 (2010), s. 93-104 ISSN 0377-9017 Institutional research plan: CEZ:AV0Z40400503 Keywords : near hexagons * geometric hyperplanes * Veldkamp spaces Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.842, year: 2010

Stochastic transport through complex comb structures

International Nuclear Information System (INIS)

Zaburdaev, V. Yu.; Popov, P. V.; Romanov, A. S.; Chukbar, K. V.

2008-01-01

A unified rigorous approach is used to derive fractional differential equations describing subdiffusive transport through comb structures of various geometrical complexity. A general nontrivial effect of the initial particle distribution on the subsequent evolution is exposed. Solutions having qualitative features of practical importance are given for joined structures with widely different fractional exponents

Geometric Methods in Physics : XXXIII Workshop

CERN Document Server

Bieliavsky, Pierre; Odzijewicz, Anatol; Schlichenmaier, Martin; Voronov, Theodore

2015-01-01

This book presents a selection of papers based on the XXXIII Białowieża Workshop on Geometric Methods in Physics, 2014. The Białowieża Workshops are among the most important meetings in the field and attract researchers from both mathematics and physics. The articles gathered here are mathematically rigorous and have important physical implications, addressing the application of geometry in classical and quantum physics. Despite their long tradition, the workshops remain at the cutting edge of ongoing research. For the last several years, each Białowieża Workshop has been followed by a School on Geometry and Physics, where advanced lectures for graduate students and young researchers are presented; some of the lectures are reproduced here. The unique atmosphere of the workshop and school is enhanced by its venue, framed by the natural beauty of the Białowieża forest in eastern Poland. The volume will be of interest to researchers and graduate students in mathematical physics, theoretical physics and m...

Geometric programming facilities of EusLisp and assembly goal planner

International Nuclear Information System (INIS)

Matsui, Toshihiro; Sakane, Shigeyuki; Hirukawa, Hirohisa

1994-01-01

For robots in power plants to accomplish intelligent tasks such as maintenance, inspection, and assembly, the robots must have planning capabilities based on shape models of the environment. Such shape models are defined and manipulated by a program called a geometric modeler or a solid modeler. Although there are commercial solid modelers in the market, they are not always suitable for robotics research, since it is hard to integrate higher level planning functions which frequently access internal model representation. In order to accelerate advanced robotics research, we need a generic, extensible, efficient, and integration-oriented geometric modeler. After reviewing available modelers, we concluded that the object-oriented Lisp can be the best implementation language for solid modeling. The next section introduces the programming language, 'EusLisp', tuned for implementing a solid modeler for intelligent robot programming. The design philosophy and the structure and functions of EusLisp are stated. In the following sections, EusLisp's applications, i.e., viewpoint and light-source location planning, derivation of motion constraint, and assembly goal planning, are discussed. (J.P.N.)

Air Transport versus High-Speed Rail: An Overview and Research Agenda

Directory of Open Access Journals (Sweden)

Xiaoqian Sun

2017-01-01

Full Text Available The development of high-speed rail (HSR services throughout the last decades has gradually blurred the concept of competition and cooperation with air transportation. There is a wide range of studies on this subject, with a particular focus on single lines or smaller regions. This article synthesizes and discusses recently published studies in this area, while aiming to identify commonalities and deviations among different regions throughout the world, covering services from Europe, Asia, and North America. Our meta-analysis reveals that the literature is highly controversial and the results vary substantially from one region to another, and a generalization is difficult, given route-specific characteristics, such as demand distribution, network structure, and evolution of transportation modes. As a major contribution, we propose a list of five challenges as a future research agenda on HSR/air transport competition and cooperation. Among others, we see a need for the construction of an open-source dataset for large-scale multimodal transport systems, the comprehensive assessment of new emerging transport modes, and also taking into account the resilience of multimodal transport systems under disruption.

Geometric Bioinspired Networks for Recognition of 2-D and 3-D Low-Level Structures and Transformations.

Science.gov (United States)

Bayro-Corrochano, Eduardo; Vazquez-Santacruz, Eduardo; Moya-Sanchez, Eduardo; Castillo-Munis, Efrain

2016-10-01

This paper presents the design of radial basis function geometric bioinspired networks and their applications. Until now, the design of neural networks has been inspired by the biological models of neural networks but mostly using vector calculus and linear algebra. However, these designs have never shown the role of geometric computing. The question is how biological neural networks handle complex geometric representations involving Lie group operations like rotations. Even though the actual artificial neural networks are biologically inspired, they are just models which cannot reproduce a plausible biological process. Until now researchers have not shown how, using these models, one can incorporate them into the processing of geometric computing. Here, for the first time in the artificial neural networks domain, we address this issue by designing a kind of geometric RBF using the geometric algebra framework. As a result, using our artificial networks, we show how geometric computing can be carried out by the artificial neural networks. Such geometric neural networks have a great potential in robot vision. This is the most important aspect of this contribution to propose artificial geometric neural networks for challenging tasks in perception and action. In our experimental analysis, we show the applicability of our geometric designs, and present interesting experiments using 2-D data of real images and 3-D screw axis data. In general, our models should be used to process different types of inputs, such as visual cues, touch (texture, elasticity, temperature), taste, and sound. One important task of a perception-action system is to fuse a variety of cues coming from the environment and relate them via a sensor-motor manifold with motor modules to carry out diverse reasoned actions.

Geometric integrator for simulations in the canonical ensemble

Energy Technology Data Exchange (ETDEWEB)

Tapias, Diego, E-mail: diego.tapias@nucleares.unam.mx [Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México 04510 (Mexico); Sanders, David P., E-mail: dpsanders@ciencias.unam.mx [Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México 04510 (Mexico); Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Bravetti, Alessandro, E-mail: alessandro.bravetti@iimas.unam.mx [Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México 04510 (Mexico)

2016-08-28

We introduce a geometric integrator for molecular dynamics simulations of physical systems in the canonical ensemble that preserves the invariant distribution in equations arising from the density dynamics algorithm, with any possible type of thermostat. Our integrator thus constitutes a unified framework that allows the study and comparison of different thermostats and of their influence on the equilibrium and non-equilibrium (thermo-)dynamic properties of a system. To show the validity and the generality of the integrator, we implement it with a second-order, time-reversible method and apply it to the simulation of a Lennard-Jones system with three different thermostats, obtaining good conservation of the geometrical properties and recovering the expected thermodynamic results. Moreover, to show the advantage of our geometric integrator over a non-geometric one, we compare the results with those obtained by using the non-geometric Gear integrator, which is frequently used to perform simulations in the canonical ensemble. The non-geometric integrator induces a drift in the invariant quantity, while our integrator has no such drift, thus ensuring that the system is effectively sampling the correct ensemble.

Geometric integrator for simulations in the canonical ensemble

International Nuclear Information System (INIS)

Tapias, Diego; Sanders, David P.; Bravetti, Alessandro

2016-01-01

We introduce a geometric integrator for molecular dynamics simulations of physical systems in the canonical ensemble that preserves the invariant distribution in equations arising from the density dynamics algorithm, with any possible type of thermostat. Our integrator thus constitutes a unified framework that allows the study and comparison of different thermostats and of their influence on the equilibrium and non-equilibrium (thermo-)dynamic properties of a system. To show the validity and the generality of the integrator, we implement it with a second-order, time-reversible method and apply it to the simulation of a Lennard-Jones system with three different thermostats, obtaining good conservation of the geometrical properties and recovering the expected thermodynamic results. Moreover, to show the advantage of our geometric integrator over a non-geometric one, we compare the results with those obtained by using the non-geometric Gear integrator, which is frequently used to perform simulations in the canonical ensemble. The non-geometric integrator induces a drift in the invariant quantity, while our integrator has no such drift, thus ensuring that the system is effectively sampling the correct ensemble.

Research on crude oil storage and transportation based on optimization algorithm

Science.gov (United States)

Yuan, Xuhua

2018-04-01

At present, the optimization theory and method have been widely used in the optimization scheduling and optimal operation scheme of complex production systems. Based on C++Builder 6 program development platform, the theoretical research results are implemented by computer. The simulation and intelligent decision system of crude oil storage and transportation inventory scheduling are designed. The system includes modules of project management, data management, graphics processing, simulation of oil depot operation scheme. It can realize the optimization of the scheduling scheme of crude oil storage and transportation system. A multi-point temperature measuring system for monitoring the temperature field of floating roof oil storage tank is developed. The results show that by optimizing operating parameters such as tank operating mode and temperature, the total transportation scheduling costs of the storage and transportation system can be reduced by 9.1%. Therefore, this method can realize safe and stable operation of crude oil storage and transportation system.

Unsaturated flow and transport research questions and priorities

International Nuclear Information System (INIS)

Chery, D.L.

1993-01-01

A little over two years ago, a similar meeting (Workshop IV - Flow and Transport through Unsaturated Fractured Rock; Related to High-Level Radioactive Waste Disposal) was held her in Tucson, Arizona, to discuss the same issues discussed here the past 4 days. This presentation revisits what was said 2 years ago, reviews research needs that have been articulated by the licensing staff of the Division of High-Level Waste Management, Nuclear Regulatory Commission, and presents some of the thoughts on research needs resulting from the deliberations of a special committee of the National Research Council. After considering these aspects the questions of what has been accomplished in the past 2 years and where attention and energies should be focused in the coming few years, can be asked. 3 refs

The Symposium Proceedings of the 1998 Air Transport Research Group (ATRG). Volume 2

Science.gov (United States)

Reynolds-Feighan, Aisling (Editor); Bowen, Brent D. (Editor)

1998-01-01

The Air Transport Research Group of the World Conference on Transportation Research (WCTR) Society was formally launched as a special interest group at the 7th Triennial WCTR in Sydney, Australia in 1995. Since then, our membership base has expanded rapidly, and now includes over 400 active transportation researchers, policy-makers, industry executives, major corporations and research institutes from 28 countries. It became a tradition that the ATRG would hold an international conference at least once a year. In 1998, the ATRG organized a consecutive stream of 14 aviation sessions at the 8th Triennial WCTR Conference (July 12-17: Antwerp). Again, on 19-21 July, 1998, the ATRG Symposium was organized and executed very successfully by Dr. Aisling Reynolds-Feighan of the University College of Dublin. The Aviation Institute at the University of Nebraska at Omaha has published the Proceedings of the 1998 ATRG Dublin Symposium (being co-edited by Dr. Aisling Reynolds-Feighan and Professor Brent Bowen), and the Proceedings of the 1998 WCTR-ATRG Conference (being co-edited by Professors Tae H. Oum and Brent Bowen).

Geometrical charged-particle optics

CERN Document Server

Rose, Harald

2012-01-01

This second edition is an extended version of the first edition of Geometrical Charged-Particle Optics. The updated reference monograph is intended as a guide for researchers and graduate students who are seeking a comprehensive treatment of the design of instruments and beam-guiding systems of charged particles and their propagation in electromagnetic fields. Wave aspects are included in this edition for explaining electron holography, the Aharanov-Bohm effect and the resolution of electron microscopes limited by diffraction. Several methods for calculating the electromagnetic field are presented and procedures are outlined for calculating the properties of systems with arbitrarily curved axis. Detailed methods are presented for designing and optimizing special components such as aberration correctors, spectrometers, energy filters monochromators, ion traps, electron mirrors and cathode lenses. In particular, the optics of rotationally symmetric lenses, quadrupoles, and systems composed of these elements are...

Geometric Liouville gravity

International Nuclear Information System (INIS)

La, H.

1992-01-01

A new geometric formulation of Liouville gravity based on the area preserving diffeo-morphism is given and a possible alternative to reinterpret Liouville gravity is suggested, namely, a scalar field coupled to two-dimensional gravity with a curvature constraint

Geometric phase topology in weak measurement

Science.gov (United States)

Samlan, C. T.; Viswanathan, Nirmal K.

2017-12-01

The geometric phase visualization proposed by Bhandari (R Bhandari 1997 Phys. Rep. 281 1-64) in the ellipticity-ellipse orientation basis of the polarization ellipse of light is implemented to understand the geometric aspects of weak measurement. The weak interaction of a pre-selected state, acheived via spin-Hall effect of light (SHEL), results in a spread in the polarization ellipticity (η) or ellipse orientation (χ) depending on the resulting spatial or angular shift, respectively. The post-selection leads to the projection of the η spread in the complementary χ basis results in the appearance of a geometric phase with helical phase topology in the η - χ parameter space. By representing the weak measurement on the Poincaré sphere and using Jones calculus, the complex weak value and the geometric phase topology are obtained. This deeper understanding of the weak measurement process enabled us to explore the techniques’ capabilities maximally, as demonstrated via SHEL in two examples—external reflection at glass-air interface and transmission through a tilted half-wave plate.

Solute carrier transporters: Pharmacogenomics research ...

African Journals Online (AJOL)

Aghogho

2010-12-27

Dec 27, 2010 ... This paper reviews the solute carrier transporters and highlights the fact that there is much to be learnt from .... transporters, drug targets, effect or proteins and meta- ... basolateral or apical plasma membrane of polarized cells,.

Non-Reciprocal Geometric Wave Diode by Engineering Asymmetric Shapes of Nonlinear Materials

Energy Technology Data Exchange (ETDEWEB)

Ren, Jie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Li, Nianbei [Tongji Univ., Shanghai Shi (China)

2014-02-18

Unidirectional nonreciprocal transport is at the heart of many fundamental problems and applications in both science and technology. Here we study how to design the novel wave diode devices to realize the non-reciprocal wave propagations. Analytical results reveal that such non-reciprocal wave propagation can be purely induced by asymmetric geometry in nonlinear materials. The detailed numerical simulations are performed for a more realistic geometric wave diode model with typical asymmetric shape, where good non-reciprocal wave diode effect has been demonstrated. The results open a way for making wave diodes efficiently simply through shape engineering.

Geometric statistical inference

International Nuclear Information System (INIS)

Periwal, Vipul

1999-01-01

A reparametrization-covariant formulation of the inverse problem of probability is explicitly solved for finite sample sizes. The inferred distribution is explicitly continuous for finite sample size. A geometric solution of the statistical inference problem in higher dimensions is outlined

Reduced Gravity Studies of Soret Transport Effects in Liquid Fuel Combustion

Science.gov (United States)

Shaw, Benjamin D.

2004-01-01

Soret transport, which is mass transport driven by thermal gradients, can be important in practical flames as well as laboratory flames by influencing transport of low molecular weight species (e.g., monatomic and diatomic hydrogen). In addition, gas-phase Soret transport of high molecular weight fuel species that are present in practical liquid fuels (e.g., octane or methanol) can be significant in practical flames (Rosner et al., 2000; Dakhlia et al., 2002) and in high pressure droplet evaporation (Curtis and Farrell, 1992), and it has also been shown that Soret transport effects can be important in determining oxygen diffusion rates in certain classes of microgravity droplet combustion experiments (Aharon and Shaw, 1998). It is thus useful to obtain information on flames under conditions where Soret effects can be clearly observed. This research is concerned with investigating effects of Soret transport on combustion of liquid fuels, in particular liquid fuel droplets. Reduced-gravity is employed to provide an ideal (spherically-symmetrical) experimental model with which to investigate effects of Soret transport on combustion. The research will involve performing reduced-gravity experiments on combustion of liquid fuel droplets in environments where Soret effects significantly influence transport of fuel and oxygen to flame zones. Experiments will also be performed where Soret effects are not expected to be important. Droplets initially in the 0.5 to 1 mm size range will be burned. Data will be obtained on influences of Soret transport on combustion characteristics (e.g., droplet burning rates, droplet lifetimes, gas-phase extinction, and transient flame behaviors) under simplified geometrical conditions that are most amenable to theoretical modeling (i.e., spherical symmetry). The experiments will be compared with existing theoretical models as well as new models that will be developed. Normal gravity experiments will also be performed.

The representations of Lie groups and geometric quantizations

International Nuclear Information System (INIS)

Zhao Qiang

1998-01-01

In this paper we discuss the relation between representations of Lie groups and geometric quantizations. A series of representations of Lie groups are constructed by geometric quantization of coadjoint orbits. Particularly, all representations of compact Lie groups, holomorphic discrete series of representations and spherical representations of reductive Lie groups are constructed by geometric quantizations of elliptic and hyperbolic coadjoint orbits. (orig.)

Nonadiabatic geometrical quantum gates in semiconductor quantum dots

International Nuclear Information System (INIS)

Solinas, Paolo; Zanghi, Nino; Zanardi, Paolo; Rossi, Fausto

2003-01-01

In this paper, we study the implementation of nonadiabatic geometrical quantum gates with in semiconductor quantum dots. Different quantum information enconding (manipulation) schemes exploiting excitonic degrees of freedom are discussed. By means of the Aharanov-Anandan geometrical phase, one can avoid the limitations of adiabatic schemes relying on adiabatic Berry phase; fast geometrical quantum gates can be, in principle, implemented

Identifying and Fostering Higher Levels of Geometric Thinking

Science.gov (United States)

Škrbec, Maja; Cadež, Tatjana Hodnik

2015-01-01

Pierre M. Van Hiele created five levels of geometric thinking. We decided to identify the level of geometric thinking in the students in Slovenia, aged 9 to 11 years. The majority of students (60.7%) are at the transition between the zero (visual) level and the first (descriptive) level of geometric thinking. Nearly a third (31.7%) of students is…

Research Algorithm on Building Intelligent Transportation System based on RFID Technology

Directory of Open Access Journals (Sweden)

Chuanqi Chen

2013-05-01

Full Text Available Intelligent transportation system to all aspects of organic integration of human, vehicle, road and environment of the transport system, so that the operation of functional integration and intelligent vehicle, road. Intelligent transportation system (ITS to improve the efficiency of traffic system by increasing the effective use and management of traffic information is mainly composed of information collection and input, output, control strategy, implementation of the subsystems of data transmission and communication subsystem. The RFID reader to wireless communication through the antenna and RFID tag can achieve a write operation on the tag identification codes and memory read data. The paper proposes research on building intelligent transportation system based on RFID technology. Experimental results show that ITS system can effectively improve the traffic situation, improve the utilization rate of the existing road resource and save social cost.

Optimal wall spacing for heat transport in thermal convection

Energy Technology Data Exchange (ETDEWEB)

Shishkina, Olga [Max Planck Institute for Dynamics and Self-Organization, Goettingen (Germany)

2016-11-01

The simulation of RB flow for Ra up to 1 x 10{sup 10} is computationally expensive in terms of computing power and hard disk storage. Thus, we gratefully acknowledge the computational resources supported by Leibniz-Rechenzentrum Munich. Compared to Γ=1 situation, a new physical picture of heat transport is identified here at Γ{sub opt} for any explored Ra. Therefore, a detailed comparison between Γ=1 and Γ=Γ{sub opt} is valuable for our further research, for example, their vertical temperature and velocity profiles. Additionally, we plan to compare the fluid with different Pr under geometrical confinement, which are computationally expensive for the situations of Pr<<1 and Pr>>1.

Mathematical and information-geometrical entropy for phenomenological Fourier and non-Fourier heat conduction

Science.gov (United States)

Li, Shu-Nan; Cao, Bing-Yang

2017-09-01

The second law of thermodynamics governs the direction of heat transport, which provides the foundational definition of thermodynamic Clausius entropy. The definitions of entropy are further generalized for the phenomenological heat transport models in the frameworks of classical irreversible thermodynamics and extended irreversible thermodynamics (EIT). In this work, entropic functions from mathematics are combined with phenomenological heat conduction models and connected to several information-geometrical conceptions. The long-time behaviors of these mathematical entropies exhibit a wide diversity and physical pictures in phenomenological heat conductions, including the tendency to thermal equilibrium, and exponential decay of nonequilibrium and asymptotics, which build a bridge between the macroscopic and microscopic modelings. In contrast with the EIT entropies, the mathematical entropies expressed in terms of the internal energy function can avoid singularity paired with nonpositive local absolute temperature caused by non-Fourier heat conduction models.

Geometric effects of 90-degree vertical elbows on local two-phase flow parameters

International Nuclear Information System (INIS)

Yadav, M.; Worosz, T.; Kim, S.

2011-01-01

This study presents the geometric effects of 90-degree vertical elbows on the development of the local two-phase flow parameters. A multi-sensor conductivity probe is used to measure local two-phase flow parameters. It is found that immediately downstream of the vertical-upward elbow, the bubbles have a bimodal distribution along the horizontal radius of the pipe cross-section causing a dual-peak in the profiles of local void fraction and local interfacial area concentration. Immediately downstream of the vertical-downward elbow it is observed that the bubbles tend to migrate towards the inside of the elbow's curvature. The axial transport of void fraction and interfacial area concentration indicates that the elbows promote bubble disintegration. Preliminary predictions are obtained from group-one interfacial area transport equation (IATE) model for vertical-upward and vertical-downward two-phase flow. (author)

Marketing Research on Passenger Satisfaction With Public Transport Service in the City of Belgrade

Directory of Open Access Journals (Sweden)

Branislav Radnović

2015-03-01

Full Text Available The aim of this paper is to determine, based on conducted marketing research, the level of passenger satisfaction with public transport services for the purpose of making better marketing decisions in the example of the City of Belgrade. The main task is to test the hypothesis on the existence of significant influence of factors, such as quality service, attitude and behaviour of employees (e.g. driver, adequate informing, quality of vehicles, line routes and timetable, on passenger satisfaction. Correlation coefficient and regression analysis were used for interpreting the obtained results and examining the formulated hypothesis. Empirical research has shown that there is a significant correlation between the aforementioned factors and passenger satisfaction with public transport services. The obtained results provided recommendations and guidelines for improving and increasing the quality of public transport services. The research results also provide the basis for future research that could examine the relationship between passenger satisfaction with services and sub-groups within the analyzed factors.

Transportable Hydrogen Research Plant Based on Renewable Energy

International Nuclear Information System (INIS)

Mikel Fernandez; Carlos Madina; Asier Gil de Muro; Jose Angel Alzolab; Iker Marino; Javier Garcia-Tejedor; Juan Carlos Mugica; Inaki Azkkrate; Jose Angel Alzola

2006-01-01

Efficiency and cost are nowadays the most important barriers for the penetration of systems based on hydrogen and renewable energies. According to this background, TECNALIA Corporation has started in 2004 the HIDROTEC project: 'Hydrogen Technologies for Renewable Energy Applications'. The ultimate aim of this project is the implementation of a multipurpose demonstration and research plant in order to explore diverse options for sustainable energetic solutions based on hydrogen. The plant is conceived as an independent system that can be easily transported and assembled. Research and demonstration activities can thus be carried out at very different locations, including commercial renewable facilities. Modularity and scalability have also been taken into account for an optimised exploitation. (authors)

The Young-Laplace equation links capillarity with geometrical optics

International Nuclear Information System (INIS)

Rodriguez-Valverde, M A; Cabrerizo-Vilchez, M A; Hidalgo-Alvarez, R

2003-01-01

Analogies in physics are unusual coincidences that can be very useful to solve problems and to clarify some theoretical concepts. Apart from their own curiosity, analogies are attractive tools because they reduce the abstraction of some complex phenomena in such a way that these can be understood by means of other phenomena closer to daily experience. Usually, two analogous systems share a common aspect, like the movement of particles or transport of matter. On account of this, the analogy presented is exceptional since the involved phenomena are a priori disjoined. The most important equation of capillarity, the Young-Laplace equation, has the same structure as the Gullstrand equation of geometrical optics, which relates the optic power of a thick lens to its geometry and the properties of the media

An introduction to geometrical physics

CERN Document Server

Aldrovandi, R

1995-01-01

This book stresses the unifying power of the geometrical framework in bringing together concepts from the different areas of physics. Common underpinnings of optics, elasticity, gravitation, relativistic fields, particle mechanics and other subjects are underlined. It attempts to extricate the notion of space currently in the physical literature from the metric connotation.The book's goal is to present mathematical ideas associated with geometrical physics in a rather introductory language. Included are many examples from elementary physics and also, for those wishing to reach a higher level o

Geometric leaf placement strategies

International Nuclear Information System (INIS)

Fenwick, J D; Temple, S W P; Clements, R W; Lawrence, G P; Mayles, H M O; Mayles, W P M

2004-01-01

Geometric leaf placement strategies for multileaf collimators (MLCs) typically involve the expansion of the beam's-eye-view contour of a target by a uniform MLC margin, followed by movement of the leaves until some point on each leaf end touches the expanded contour. Film-based dose-distribution measurements have been made to determine appropriate MLC margins-characterized through an index d 90 -for multileaves set using one particular strategy to straight lines lying at various angles to the direction of leaf travel. Simple trigonometric relationships exist between different geometric leaf placement strategies and are used to generalize the results of the film work into d 90 values for several different strategies. Measured d 90 values vary both with angle and leaf placement strategy. A model has been derived that explains and describes quite well the observed variations of d 90 with angle. The d 90 angular variations of the strategies studied differ substantially, and geometric and dosimetric reasoning suggests that the best strategy is the one with the least angular variation. Using this criterion, the best straightforwardly implementable strategy studied is a 'touch circle' approach for which semicircles are imagined to be inscribed within leaf ends, the leaves being moved until the semicircles just touch the expanded target outline

Modelization of physical phenomena in research reactors with the help of new developments in transport methods, and methodology validation with experimental data; Modelisation des phenomenes physiques dans les reacteurs de recherche a l'aide de developpements realises dans les methodes de transport et qualification

Energy Technology Data Exchange (ETDEWEB)

Rauck, St

2000-10-01

The aim of this work is to develop a scheme for experimental reactors, based on transport equations. This type of reactors is characterized by a small core, a complex, very heterogeneous geometry and a large leakage. The possible insertion of neutron beams in the reflector and the presence of absorbers in the core increase the difficulty of the 3D-geometrical description and the physical modeling of the component parameters of the reactor. The Orphee reactor has been chosen for our study. Physical models (homogenization, collapsing cross section in few groups, albedo multigroup condition) have been developed in the APOLLO2 and CRONOS2 codes to calculate flux and power maps in a 3D-geometry, with different burnup and through transport equations. Comparisons with experimental measurements have shown the interest of taking into account anisotropy, steep flux gradients by using Sn methods, and on the other hand using a 12-group cross section library. The modeling of neutron beams has been done outside the core modeling through Monte Carlo calculations and with the total geometry, including a large thickness of heavy water. Thanks to this calculations, one can evaluate the neutron beams anti-reactivity and determinate the core cycle. We assure these methods more accurate than usual transport-diffusion calculations will be used for the conception of new research reactors. (author)

Gauge field governing parallel transport along mixed states

International Nuclear Information System (INIS)

Uhlmann, A.

1990-01-01

At first a short account is given of some basic notations and results on parallel transport along mixed states. A new connection form (gauge field) is introduced to give a geometric meaning to the concept of parallelity in the theory of density operators. (Author) 11 refs

Research and technology strategy to help overcome the environmental problems in relation to transport

International Nuclear Information System (INIS)

Gwilliam, K.M.; Geerlings, H.

1992-04-01

This report has been prepared for the Strategic Analysis in Science and Technology Unit (SAST) of the Directorate-General for Science, Research and Development of the Commission of the European Communities. The background of the project to which this report contributes is a recognition of the growing impact of transportation on the environment, both as a function of growth in trade and as a leisure activity. The project is directed towards the elucidation of the many interactions between technology, transport and environment, in order to provide the Commission with (a) recommendations on the priorities for Community research and development in transport technology and other related areas of technology, and (b) an understanding of the implications of technological change on policy options, within the Community with regard to transport and environment and other related areas, such as energy and regional planning

Implementation and display of Computer Aided Design (CAD) models in Monte Carlo radiation transport and shielding applications

International Nuclear Information System (INIS)

Burns, T.J.

1994-01-01

An Xwindow application capable of importing geometric information directly from two Computer Aided Design (CAD) based formats for use in radiation transport and shielding analyses is being developed at ORNL. The application permits the user to graphically view the geometric models imported from the two formats for verification and debugging. Previous models, specifically formatted for the radiation transport and shielding codes can also be imported. Required extensions to the existing combinatorial geometry analysis routines are discussed. Examples illustrating the various options and features which will be implemented in the application are presented. The use of the application as a visualization tool for the output of the radiation transport codes is also discussed

Percolation, statistical topography, and transport in random media

International Nuclear Information System (INIS)

Isichenko, M.B.

1992-01-01

A review of classical percolation theory is presented, with an emphasis on novel applications to statistical topography, turbulent diffusion, and heterogeneous media. Statistical topography involves the geometrical properties of the isosets (contour lines or surfaces) of a random potential ψ(x). For rapidly decaying correlations of ψ, the isopotentials fall into the same universality class as the perimeters of percolation clusters. The topography of long-range correlated potentials involves many length scales and is associated either with the correlated percolation problem or with Mandelbrot's fractional Brownian reliefs. In all cases, the concept of fractal dimension is particularly fruitful in characterizing the geometry of random fields. The physical applications of statistical topography include diffusion in random velocity fields, heat and particle transport in turbulent plasmas, quantum Hall effect, magnetoresistance in inhomogeneous conductors with the classical Hall effect, and many others where random isopotentials are relevant. A geometrical approach to studying transport in random media, which captures essential qualitative features of the described phenomena, is advocated

Field tracer transport experiments at the site of Canada's underground research laboratory

International Nuclear Information System (INIS)

Frost, L.H.; Davison, C.C.; Vandergraaf, T.T.; Scheier, N.W.; Kozak, E.T.

1997-01-01

To gain a better understanding of the processes affecting solute transport in fractured crystalline rock, groundwater tracer experiments are being performed within natural fracture domains and excavation damage zones at various scales at the site of AECL's Underground Research Laboratory (URL). The main objective of these experiments is to develop and demonstrate methods for characterizing the solute transport properties within fractured crystalline rock. Estimates of these properties are in turn being used in AECL's conceptual and numerical models of groundwater flow and solute transport through the geosphere surrounding a nuclear fuel waste disposal vault in plutonic rock of the Canadian Shield. (author)

Geometric scaling as traveling waves

International Nuclear Information System (INIS)

Munier, S.; Peschanski, R.

2003-01-01

We show the relevance of the nonlinear Fisher and Kolmogorov-Petrovsky-Piscounov (KPP) equation to the problem of high energy evolution of the QCD amplitudes. We explain how the traveling wave solutions of this equation are related to geometric scaling, a phenomenon observed in deep-inelastic scattering experiments. Geometric scaling is for the first time shown to result from an exact solution of nonlinear QCD evolution equations. Using general results on the KPP equation, we compute the velocity of the wave front, which gives the full high energy dependence of the saturation scale

Geometrical spin symmetry and spin

International Nuclear Information System (INIS)

Pestov, I. B.

2011-01-01

Unification of General Theory of Relativity and Quantum Mechanics leads to General Quantum Mechanics which includes into itself spindynamics as a theory of spin phenomena. The key concepts of spindynamics are geometrical spin symmetry and the spin field (space of defining representation of spin symmetry). The essence of spin is the bipolar structure of geometrical spin symmetry induced by the gravitational potential. The bipolar structure provides a natural derivation of the equations of spindynamics. Spindynamics involves all phenomena connected with spin and provides new understanding of the strong interaction.

Asymptotic geometric analysis, part I

CERN Document Server

Artstein-Avidan, Shiri

2015-01-01

The authors present the theory of asymptotic geometric analysis, a field which lies on the border between geometry and functional analysis. In this field, isometric problems that are typical for geometry in low dimensions are substituted by an "isomorphic" point of view, and an asymptotic approach (as dimension tends to infinity) is introduced. Geometry and analysis meet here in a non-trivial way. Basic examples of geometric inequalities in isomorphic form which are encountered in the book are the "isomorphic isoperimetric inequalities" which led to the discovery of the "concentration phenomen

Geometrical analysis of the interacting boson model

International Nuclear Information System (INIS)

Dieperink, A.E.L.

1983-01-01

The Interacting Boson Model is considered, in relation with geometrical models and the application of mean field techniques to algebraic models, in three lectures. In the first, several methods are reviewed to establish a connection between the algebraic formulation of collective nuclear properties in terms of the group SU(6) and the geometric approach. In the second lecture the geometric interpretation of new degrees of freedom that arise in the neutron-proton IBA is discussed, and in the third one some further applications of algebraic techniques to the calculation of static and dynamic collective properties are presented. (U.K.)

A Geometrical View of Higgs Effective Theory

CERN Multimedia

CERN. Geneva

2016-01-01

A geometric formulation of Higgs Effective Field Theory (HEFT) is presented. Experimental observables are given in terms of geometric invariants of the scalar sigma model sector such as the curvature of the scalar field manifold M. We show how the curvature can be measured experimentally via Higgs cross-sections, W_L scattering, and the S parameter. The one-loop action of HEFT is given in terms of geometric invariants of M. The distinction between the Standard Model (SM) and HEFT is whether M is flat or curved, with the curvature a signal of the scale of new physics.

Geometric phases and hidden local gauge symmetry

International Nuclear Information System (INIS)

Fujikawa, Kazuo

2005-01-01

The analysis of geometric phases associated with level crossing is reduced to the familiar diagonalization of the Hamiltonian in the second quantized formulation. A hidden local gauge symmetry, which is associated with the arbitrariness of the phase choice of a complete orthonormal basis set, becomes explicit in this formulation (in particular, in the adiabatic approximation) and specifies physical observables. The choice of a basis set which specifies the coordinate in the functional space is arbitrary in the second quantization, and a subclass of coordinate transformations, which keeps the form of the action invariant, is recognized as the gauge symmetry. We discuss the implications of this hidden local gauge symmetry in detail by analyzing geometric phases for cyclic and noncyclic evolutions. It is shown that the hidden local symmetry provides a basic concept alternative to the notion of holonomy to analyze geometric phases and that the analysis based on the hidden local gauge symmetry leads to results consistent with the general prescription of Pancharatnam. We however note an important difference between the geometric phases for cyclic and noncyclic evolutions. We also explain a basic difference between our hidden local gauge symmetry and a gauge symmetry (or equivalence class) used by Aharonov and Anandan in their definition of generalized geometric phases

Evaluation of the Montana Department of Transportation's research project solicitation, prioritization, and selection process

Science.gov (United States)

2008-05-01

The Montana Department of Transportation (MDT) contracted the Bureau of Business and Economic Research at the University of Montana Missoula to conduct research to determine how other states solicit, prioritize, and select research problem statem...

Urbanisation and 3d Spatial - a Geometric Approach

Science.gov (United States)

Duncan, E. E.; Rahman, A. Abdul

2013-09-01

Urbanisation creates immense competition for space, this may be attributed to an increase in population owing to domestic and external tourism. Most cities are constantly exploring all avenues in maximising its limited space. Hence, urban or city authorities need to plan, expand and use such three dimensional (3D) space above, on and below the city space. Thus, difficulties in property ownership and the geometric representation of the 3D city space is a major challenge. This research, investigates the concept of representing a geometric topological 3D spatial model capable of representing 3D volume parcels for man-made constructions above and below the 3D surface volume parcel. A review of spatial data models suggests that the 3D TIN (TEN) model is significant and can be used as a unified model. The concepts, logical and physical models of 3D TIN for 3D volumes using tetrahedrons as the base geometry is presented and implemented to show man-made constructions above and below the surface parcel within a user friendly graphical interface. Concepts for 3D topology and 3D analysis are discussed. Simulations of this model for 3D cadastre are implemented. This model can be adopted by most countries to enhance and streamline geometric 3D property ownership for urban centres. 3D TIN concept for spatial modelling can be adopted for the LA_Spatial part of the Land Administration Domain Model (LADM) (ISO/TC211, 2012), this satisfies the concept of 3D volumes.

Non-Markovian effect on the geometric phase of a dissipative qubit

International Nuclear Information System (INIS)

Chen Juanjuan; Tong Qingjun; An Junhong; Luo Honggang; Oh, C. H.

2010-01-01

We studied the geometric phase of a two-level atom coupled to an environment with Lorentzian spectral density. The non-Markovian effect on the geometric phase is explored analytically and numerically. In the weak coupling limit, the lowest order correction to the geometric phase is derived analytically and the general case is calculated numerically. It was found that the correction to the geometric phase is significantly large if the spectral width is small, and in this case the non-Markovian dynamics has a significant impact on the geometric phase. When the spectral width increases, the correction to the geometric phase becomes negligible, which shows the robustness of the geometric phase to the environmental white noises. The result is significant to the quantum information processing based on the geometric phase.

Monte Carlo methods for flux expansion solutions of transport problems

International Nuclear Information System (INIS)

Spanier, J.

1999-01-01

Adaptive Monte Carlo methods, based on the use of either correlated sampling or importance sampling, to obtain global solutions to certain transport problems have recently been described. The resulting learning algorithms are capable of achieving geometric convergence when applied to the estimation of a finite number of coefficients in a flux expansion representation of the global solution. However, because of the nonphysical nature of the random walk simulations needed to perform importance sampling, conventional transport estimators and source sampling techniques require modification to be used successfully in conjunction with such flux expansion methods. It is shown how these problems can be overcome. First, the traditional path length estimators in wide use in particle transport simulations are generalized to include rather general detector functions (which, in this application, are the individual basis functions chosen for the flus expansion). Second, it is shown how to sample from the signed probabilities that arise as source density functions in these applications, without destroying the zero variance property needed to ensure geometric convergence to zero error

Research of transport and deposition of aerosol in human airway replica

Science.gov (United States)

Lizal, Frantisek; Jedelsky, Jan; Elcner, Jakub; Durdina, Lukas; Halasova, Tereza; Mravec, Filip; Jicha, Miroslav

2012-04-01

Growing concern about knowledge of aerosol transport in human lungs is caused by great potential of use of inhaled pharmaceuticals. Second substantial motive for the research is an effort to minimize adverse effects of particular matter emitted by traffic and industry on human health. We created model geometry of human lungs to 7th generation of branching. This model geometry was used for fabrication of two physical models. The first one is made from thin walled transparent silicone and it allows a measurement of velocity and size of aerosol particles by Phase Doppler Anemometry (PDA). The second one is fabricated by stereolithographic method and it is designed for aerosol deposition measurements. We provided a series of measurements of aerosol transport in the transparent model and we ascertained remarkable phenomena linked with lung flow. The results are presented in brief. To gather how this phenomena affects aerosol deposition in human lungs we used the second model and we developed a technique for deposition fraction and deposition efficiency assessment. The results confirmed that non-symmetric and complicated shape of human airways essentially affects transport and deposition of aerosol. The research will now focus on deeper insight in aerosol deposition.

Research on Evaluation of resource allocation efficiency of transportation system based on DEA

Science.gov (United States)

Zhang, Zhehui; Du, Linan

2017-06-01

In this paper, we select the time series data onto 1985-2015 years, construct the land (shoreline) resources, capital and labor as inputs. The index system of the output is freight volume and passenger volume, we use Quantitative analysis based on DEA method evaluated the resource allocation efficiency of railway, highway, water transport and civil aviation in China. Research shows that the resource allocation efficiency of various modes of transport has obvious difference, and the impact on scale efficiency is more significant. The most important two ways to optimize the allocation of resources to improve the efficiency of the combination of various modes of transport is promoting the co-ordination of various modes of transport and constructing integrated transportation system.

Some Hermite–Hadamard Type Inequalities for Geometrically Quasi ...

Indian Academy of Sciences (India)

Abstract. In the paper, we introduce a new concept 'geometrically quasi-convex function' and establish some Hermite–Hadamard type inequalities for functions whose derivatives are of geometric quasi-convexity.

Research on the Importance of Language Culture for Transport Experts

Directory of Open Access Journals (Sweden)

Angelika Petrėtienė

2014-06-01

Full Text Available The article analyses the importance of language culture for transport experts. The analysis has been conducted on a questionnaire basis. Pursuant to the questionnaire, the obtained data were aimed at establishing if the use of a correct language might increase employment possibilities, if service suppliers talking correctly were stronger preferred, what sources designated for language culture were used in order to revise the accuracy of the employed terminol- ogy (or word, etc. The questionnaire also presents terms more relevant to transport staff and investigates the frequency of the used terminology both correct and incorrect. The researched data have been systemized and presented in the form of charts.

Constructing Geometric Properties of Rectangle, Square, and Triangle in the Third Grade of Indonesian Primary Schools

Directory of Open Access Journals (Sweden)

Ilham Rizkianto

2013-07-01

Full Text Available Previous studies have provided that when learning shapes for the first time, young children tend to use the prototype as the reference point for comparisons, but often fail when doing so since they do not yet think about the defining attributes or the geometric properties of the shapes. Most of the time, elementary students learn geometric properties of shapes only as empty verbal statements to be memorized, without any chance to experience the contepts meaningfully. In the light of it, a sequence of instructional activities along with computer manipulative was designed to support Indonesian third graders in constructing geometric properties of square, rectangle, and triangle. The aim of the present study is to develop a loval instructional theory to support third graders in constructing geometric properties of rectangle, square, and triangle. Thirty seven students of one third grade classes in SD Pupuk Sriwijaya Palembang, along with their class teacher, were involved in the study. Our findings suggest that the combination of computer and non-computer activities suppots third graders in constructing geometric properties of square, rectangle, and triangle in that it provides opportunities to the students to experience and to develop the concepts meaningfully while using their real experiences as the bases to attain a higher geometric thinking level.Key concepts: Geometric properties, rectangle, square, triangle, design research, realistic mathematics education DOI: http://dx.doi.org/10.22342/jme.4.2.414.160-171

Anterior, posterior, left anterior oblique, and geometric mean views in gastric emptying studies using a glucose solution

Energy Technology Data Exchange (ETDEWEB)

Phillips, W.T. [Dept. of Radiology, Univ. of Texas Health Science Center, San Antonio, TX (United States); McMahan, C.A. [Dept. of Pathology, Univ. of Texas Health Science Center, San Antonio, TX (United States); Lasher, J.C. [Dept. of Radiology, Univ. of Texas Health Science Center, San Antonio, TX (United States); Blumhardt, M.R. [Dept. of Pathology, Univ. of Texas Health Science Center, San Antonio, TX (United States); Schwartz, J.G. [Dept. of Pathology, Univ. of Texas Health Science Center, San Antonio, TX (United States)

1995-02-01

Previous research has shown that the single anterior view of the stomach overestimates the gastric half-emptying time of a solid meal compared to the geometric mean of the anterior and posterior views. Little research has been performed comparing the various views of gastric emptying of a glucose solution. After an overnight fast, 49 nondiabetic subjects were given a 450 ml solution containing 50 g of glucose and 200 {mu}Ci of technetium-99m sulfur colloid. Sequential 1-min anterior, posterior, and left anterior oblique views were obtained every 15 min. The mean percent solution remaining in the stomach for all three views differed from the geometric mean by 1.9% or less at all time points. Average gastric half-emptying times were: geometric mean, 62.7{+-}3.3 min; anterior, 61.9{+-}3.2 min; posterior, 63.5{+-}3.5 min; and left anterior oblique, 61.6{+-}3.3 min. These half-emptying times were not statistically different. For individual patients, differences between all three views and the geometric mean were not clinically important. Approximately 95% of all patients are expected to have gastric half-emptying times measured by any of the three single views within 17 min of the gastric half-emptying time obtained using the geometric mean. The imaging of gastric emptying using glucose solutions can be performed using a convenient single view which allows continuous dynamic imaging. (orig.)

Summary of the working group on high current transport and final focus lenses

International Nuclear Information System (INIS)

Garren, A.A.

1978-01-01

Transverse instabilities of intense beams in periodic transport lines are reviewed. Chromatic aberrations in the final beam transport lines and geometric aberrations due to quadrupole fringe fields are discussed and corrections to reduce them are evaluated. The implications for four reference designs are evaluated by comparing the tune depression, momentum spread, and emittance

Geometric Hypergraph Learning for Visual Tracking

OpenAIRE

Du, Dawei; Qi, Honggang; Wen, Longyin; Tian, Qi; Huang, Qingming; Lyu, Siwei

2016-01-01

Graph based representation is widely used in visual tracking field by finding correct correspondences between target parts in consecutive frames. However, most graph based trackers consider pairwise geometric relations between local parts. They do not make full use of the target's intrinsic structure, thereby making the representation easily disturbed by errors in pairwise affinities when large deformation and occlusion occur. In this paper, we propose a geometric hypergraph learning based tr...

Sparse geometric graphs with small dilation

NARCIS (Netherlands)

Aronov, B.; Berg, de M.; Cheong, O.; Gudmundsson, J.; Haverkort, H.J.; Vigneron, A.; Deng, X.; Du, D.

2005-01-01

Given a set S of n points in the plane, and an integer k such that 0 = k geometric graph with vertex set S, at most n – 1 + k edges, and dilation O(n / (k + 1)) can be computed in time O(n log n). We also construct n–point sets for which any geometric graph with n – 1 + k edges

Geometric ghosts and unitarity

International Nuclear Information System (INIS)

Ne'eman, Y.

1980-09-01

A review is given of the geometrical identification of the renormalization ghosts and the resulting derivation of Unitarity equations (BRST) for various gauges: Yang-Mills, Kalb-Ramond, and Soft-Group-Manifold

A Color Image Watermarking Scheme Resistant against Geometrical Attacks

Directory of Open Access Journals (Sweden)

Y. Xing

2010-04-01

Full Text Available The geometrical attacks are still a problem for many digital watermarking algorithms at present. In this paper, we propose a watermarking algorithm for color images resistant to geometrical distortions (rotation and scaling. The singular value decomposition is used for watermark embedding and extraction. The log-polar map- ping (LPM and phase correlation method are used to register the position of geometrical distortion suffered by the watermarked image. Experiments with different kinds of color images and watermarks demonstrate that the watermarking algorithm is robust to common image processing attacks, especially geometrical attacks.

Modeling of solar transmission through multilayer glazing facade using shading blinds with arbitrary geometrical and surface optical properties

International Nuclear Information System (INIS)

Luo, Yongqiang; Zhang, Ling; Wu, Jing; Wang, Xiliang; Liu, Zhongbing; Wu, Zhenghong

2017-01-01

A system model that can accurately simulate the instantaneous solar transmittance through multilayer glazing façade (MGF) and shading device can provide a solid foundation for the thermal and daylighting performance calculation of MGF as well as indoor visual comfort evaluation. Traditional optical models for venetian blind and glazing façade meet with their limitations to analyze new prototype of shading blind like photovoltaic (PV) blind which has quite different surface optical properties compared with conventional venetian blind. The present study proposed a new system model for MGF using shading blind with arbitrary geometrical and optical features which is suitable for a wide range of applications. Three major calculation types for modeling of shading blinds cover all the possible situations in application. Guess Integer-Valued Function is adopted for delivering a general description on direct radiation transport. The direct-direct, direct-diffuse and diffuse-diffuse radiation transports are separately considered. A series of experiments were carried out to validate the model under various parameter settings and different weather conditions. Parametric study revealed some new findings in the evaluations of influence of ambient radiation situations, geometrical and optical features of blind space on both solar transmittance and solar absorption by blind layer. - Highlights: • Solar transport through glazing façades with PV blind with arbitrary geometry is simulated. • Ray-tracing and radiosity method are coupled in calculation. • Guess Integer-Valued Function is used in calculation of direct radiation transport. • Experiment and simulated data are compared for model validation. • Parametric study is conducted for evaluating the impact of different factors on the system.

Solving Absolute Value Equations Algebraically and Geometrically

Science.gov (United States)

Shiyuan, Wei

2005-01-01

The way in which students can improve their comprehension by understanding the geometrical meaning of algebraic equations or solving algebraic equation geometrically is described. Students can experiment with the conditions of the absolute value equation presented, for an interesting way to form an overall understanding of the concept.

Quasirandom geometric networks from low-discrepancy sequences

Science.gov (United States)

Estrada, Ernesto

2017-08-01

We define quasirandom geometric networks using low-discrepancy sequences, such as Halton, Sobol, and Niederreiter. The networks are built in d dimensions by considering the d -tuples of digits generated by these sequences as the coordinates of the vertices of the networks in a d -dimensional Id unit hypercube. Then, two vertices are connected by an edge if they are at a distance smaller than a connection radius. We investigate computationally 11 network-theoretic properties of two-dimensional quasirandom networks and compare them with analogous random geometric networks. We also study their degree distribution and their spectral density distributions. We conclude from this intensive computational study that in terms of the uniformity of the distribution of the vertices in the unit square, the quasirandom networks look more random than the random geometric networks. We include an analysis of potential strategies for generating higher-dimensional quasirandom networks, where it is know that some of the low-discrepancy sequences are highly correlated. In this respect, we conclude that up to dimension 20, the use of scrambling, skipping and leaping strategies generate quasirandom networks with the desired properties of uniformity. Finally, we consider a diffusive process taking place on the nodes and edges of the quasirandom and random geometric graphs. We show that the diffusion time is shorter in the quasirandom graphs as a consequence of their larger structural homogeneity. In the random geometric graphs the diffusion produces clusters of concentration that make the process more slow. Such clusters are a direct consequence of the heterogeneous and irregular distribution of the nodes in the unit square in which the generation of random geometric graphs is based on.

Geometric convergence of some two-point Pade approximations

International Nuclear Information System (INIS)

Nemeth, G.

1983-01-01

The geometric convergences of some two-point Pade approximations are investigated on the real positive axis and on certain infinite sets of the complex plane. Some theorems concerning the geometric convergence of Pade approximations are proved, and bounds on geometric convergence rates are given. The results may be interesting considering the applications both in numerical computations and in approximation theory. As a specific case, the numerical calculations connected with the plasma dispersion function may be performed. (D.Gy.)

Geometric quantization and general relativity

International Nuclear Information System (INIS)

Souriau, J.-M.

1977-01-01

The purpose of geometric quantization is to give a rigorous mathematical content to the 'correspondence principle' between classical and quantum mechanics. The main tools are borrowed on one hand from differential geometry and topology (differential manifolds, differential forms, fiber bundles, homology and cohomology, homotopy), on the other hand from analysis (functions of positive type, infinite dimensional group representations, pseudo-differential operators). Some satisfactory results have been obtained in the study of dynamical systems, but some fundamental questions are still waiting for an answer. The 'geometric quantization of fields', where some further well known difficulties arise, is still in a preliminary stage. In particular, the geometric quantization on the gravitational field is still a mere project. The situation is even more uncertain due to the fact that there is no experimental evidence of any quantum gravitational effect which could give us a hint towards what we are supposed to look for. The first level of both Quantum Theory, and General Relativity describes passive matter: influence by the field without being a source of it (first quantization and equivalence principle respectively). In both cases this is only an approximation (matter is always a source). But this approximation turns out to be the least uncertain part of the description, because on one hand the first quantization avoids the problems of renormalization and on the other hand the equivalence principle does not imply any choice of field equations (it is known that one can modify Einstein equations at short distances without changing their geometrical properties). (Auth.)

Auto-focusing accelerating hyper-geometric laser beams

International Nuclear Information System (INIS)

Kovalev, A A; Kotlyar, V V; Porfirev, A P

2016-01-01

We derive a new solution to the paraxial wave equation that defines a two-parameter family of three-dimensional structurally stable vortex annular auto-focusing hyper-geometric (AH) beams, with their complex amplitude expressed via a degenerate hyper-geometric function. The AH beams are found to carry an orbital angular momentum and be auto-focusing, propagating on an accelerating path toward a focus, where the annular intensity pattern is ‘sharply’ reduced in diameter. An explicit expression for the complex amplitude of vortex annular auto-focusing hyper-geometric-Gaussian beams is derived. The experiment has been shown to be in good agreement with theory. (paper)

Studies in geometric quantization

International Nuclear Information System (INIS)

Tuynman, G.M.

1988-01-01

This thesis contains five chapters, of which the first, entitled 'What is prequantization, and what is geometric quantization?', is meant as an introduction to geometric quantization for the non-specialist. The second chapter, entitled 'Central extensions and physics' deals with the notion of central extensions of manifolds and elaborates and proves the statements made in the first chapter. Central extensions of manifolds occur in physics as the freedom of a phase factor in the quantum mechanical state vector, as the phase factor in the prequantization process of classical mechanics and it appears in mathematics when studying central extension of Lie groups. In this chapter the connection between these central extensions is investigated and a remarkable similarity between classical and quantum mechanics is shown. In chapter three a classical model is given for the hydrogen atom including spin-orbit and spin-spin interaction. The method of geometric quantization is applied to this model and the results are discussed. In the final chapters (4 and 5) an explicit method to calculate the operators corresponding to classical observables is given when the phase space is a Kaehler manifold. The obtained formula are then used to quantise symplectic manifolds which are irreducible hermitian symmetric spaces and the results are compared with other quantization procedures applied to these manifolds (in particular to Berezin's quantization). 91 refs.; 3 tabs

Understanding geometric algebra for electromagnetic theory

CERN Document Server

Arthur, John W

2011-01-01

"This book aims to disseminate geometric algebra as a straightforward mathematical tool set for working with and understanding classical electromagnetic theory. It's target readership is anyone who has some knowledge of electromagnetic theory, predominantly ordinary scientists and engineers who use it in the course of their work, or postgraduate students and senior undergraduates who are seeking to broaden their knowledge and increase their understanding of the subject. It is assumed that the reader is not a mathematical specialist and is neither familiar with geometric algebra or its application to electromagnetic theory. The modern approach, geometric algebra, is the mathematical tool set we should all have started out with and once the reader has a grasp of the subject, he or she cannot fail to realize that traditional vector analysis is really awkward and even misleading by comparison"--Provided by publisher.

The Eisenhart lift: a didactical introduction of modern geometrical concepts from Hamiltonian dynamics

International Nuclear Information System (INIS)

Cariglia, Marco; Alves, Filipe Kelmer

2015-01-01

This work originates from part of a final year undergraduate research project on the Eisenhart lift for Hamiltonian systems. The Eisenhart lift is a procedure to describe trajectories of a classical natural Hamiltonian system as geodesics in an enlarged space. We point out that it can be easily obtained from basic principles of Hamiltonian dynamics, and as such it represents a useful didactical way to introduce graduate students to several modern concepts of geometry applied to physics: curved spaces, both Riemannian and Lorentzian, conformal transformations, geometrization of interactions and extra dimensions, and geometrization of dynamical symmetries. For all these concepts the Eisenhart lift can be used as a theoretical tool that provides easily achievable examples, with the added benefit of also being a topic of current research with several applications, among which are included the study of dynamical systems and non-relativistic holography. (paper)

Lattice degeneracies of geometric fermions

International Nuclear Information System (INIS)

Raszillier, H.

1983-05-01

We give the minimal numbers of degrees of freedom carried by geometric fermions on all lattices of maximal symmetries in d = 2, 3, and 4 dimensions. These numbers are lattice dependent, but in the (free) continuum limit, part of the degrees of freedom have to escape to infinity by a Wilson mechanism built in, and 2sup(d) survive for any lattice. On self-reciprocal lattices we compare the minimal numbers of degrees of freedom of geometric fermions with the minimal numbers of naive fermions on these lattices and argue that these numbers are equal. (orig.)

Research on the effects of geometrical and material uncertainties on the band gap of the undulated beam

Science.gov (United States)

Li, Yi; Xu, Yanlong

2017-09-01

Considering uncertain geometrical and material parameters, the lower and upper bounds of the band gap of an undulated beam with periodically arched shape are studied by the Monte Carlo Simulation (MCS) and interval analysis based on the Taylor series. Given the random variations of the overall uncertain variables, scatter plots from the MCS are used to analyze the qualitative sensitivities of the band gap respect to these uncertainties. We find that the influence of uncertainty of the geometrical parameter on the band gap of the undulated beam is stronger than that of the material parameter. And this conclusion is also proved by the interval analysis based on the Taylor series. Our methodology can give a strategy to reduce the errors between the design and practical values of the band gaps by improving the accuracy of the specially selected uncertain design variables of the periodical structures.

Japanese perspectives and research on packaging, transport and storage of spent fuel

International Nuclear Information System (INIS)

Saegusa, T.; Ito, C.; Yamakawa, H.; Shirai, K.

2004-01-01

The Japanese policy on spent fuel is reprocessing. Until, reprocessed, spent fuel shall be stored properly. This paper overviews current status of transport and storage of spent fuel with related research in Japan. The research was partly carried out under a contract of Ministry of Economy, Trade and Industry of the Japanese government

Thomas Young's contributions to geometrical optics.

Science.gov (United States)

Atchison, David A; Charman, W Neil

2011-07-01

In addition to his work on physical optics, Thomas Young (1773-1829) made several contributions to geometrical optics, most of which received little recognition in his time or since. We describe and assess some of these contributions: Young's construction (the basis for much of his geometric work), paraxial refraction equations, oblique astigmatism and field curvature, and gradient-index optics. © 2011 The Authors. Clinical and Experimental Optometry © 2011 Optometrists Association Australia.

Geometric and computer-aided spline hob modeling

Science.gov (United States)

Brailov, I. G.; Myasoedova, T. M.; Panchuk, K. L.; Krysova, I. V.; Rogoza, YU A.

2018-03-01

The paper considers acquiring the spline hob geometric model. The objective of the research is the development of a mathematical model of spline hob for spline shaft machining. The structure of the spline hob is described taking into consideration the motion in parameters of the machine tool system of cutting edge positioning and orientation. Computer-aided study is performed with the use of CAD and on the basis of 3D modeling methods. Vector representation of cutting edge geometry is accepted as the principal method of spline hob mathematical model development. The paper defines the correlations described by parametric vector functions representing helical cutting edges designed for spline shaft machining with consideration for helical movement in two dimensions. An application for acquiring the 3D model of spline hob is developed on the basis of AutoLISP for AutoCAD environment. The application presents the opportunity for the use of the acquired model for milling process imitation. An example of evaluation, analytical representation and computer modeling of the proposed geometrical model is reviewed. In the mentioned example, a calculation of key spline hob parameters assuring the capability of hobbing a spline shaft of standard design is performed. The polygonal and solid spline hob 3D models are acquired by the use of imitational computer modeling.

An Introduction to Geometric Algebra with some Preliminary Thoughts on the Geometric Meaning of Quantum Mechanics

International Nuclear Information System (INIS)

Horn, Martin Erik

2014-01-01

It is still a great riddle to me why Wolfgang Pauli and P.A.M. Dirac had not fully grasped the meaning of their own mathematical constructions. They invented magnificent, fantastic and very important mathematical features of modern physics, but they only delivered half of the interpretations of their own inventions. Of course, Pauli matrices and Dirac matrices represent operators, which Pauli and Dirac discussed in length. But this is only part of the true meaning behind them, as the non-commutative ideas of Grassmann, Clifford, Hamilton and Cartan allow a second, very far reaching interpretation of Pauli and Dirac matrices. An introduction to this alternative interpretation will be discussed. Some applications of this view on Pauli and Dirac matrices are given, e.g. a geometric algebra picture of the plane wave solution of the Maxwell equation, a geometric algebra picture of special relativity, a toy model of SU(3) symmetry, and some only very preliminary thoughts about a possible geometric meaning of quantum mechanics

Geometric integrators for stochastic rigid body dynamics

KAUST Repository

Tretyakov, Mikhail

2016-01-05

Geometric integrators play an important role in simulating dynamical systems on long time intervals with high accuracy. We will illustrate geometric integration ideas within the stochastic context, mostly on examples of stochastic thermostats for rigid body dynamics. The talk will be mainly based on joint recent work with Rusland Davidchak and Tom Ouldridge.

Geometric integrators for stochastic rigid body dynamics

KAUST Repository

Tretyakov, Mikhail

2016-01-01

Geometric integrators play an important role in simulating dynamical systems on long time intervals with high accuracy. We will illustrate geometric integration ideas within the stochastic context, mostly on examples of stochastic thermostats for rigid body dynamics. The talk will be mainly based on joint recent work with Rusland Davidchak and Tom Ouldridge.

IAEA mode-related research in the safe transport of radioactive material

Energy Technology Data Exchange (ETDEWEB)

Blalock, L.G.; Rawl, R.R. [International Atomic Energy Agency, IAEA, Vienna (Austria)

1998-07-01

The International Atomic Energy Agency sponsors Co-ordinated Research Programmes (CRP) in the safe transport of radioactive material. The CRPs are intended to encourage research by Member States in identified areas and to facilitate co-ordination of exchange of information and resources to reach a common understanding of the problem and alternative solutions. Two of these programmes are: Accident Severity at Sea During the Transport of Radioactive Material and Accident Severity During the Air Transport of Radioactive Material. This paper will discuss these two programmes and their relationship to the continuing regulatory revision process and interfaces with the International Maritime Organization (IMO) and the International Civil Aviation Organization (ICAO). Some Member States and non-governmental organizations in IMO meetings expressed concerns that accidents on board ships may be more severe than the IAEA regulatory tests account for, and that package failure with subsequent release of radioactive material may occur. The CRP on accident severity at sea was established to develop further quantitative information on potential accident severities during the transport of radioactive material by ships. The primary objective of this programme is to collect and evaluate statistical data of marine accidents, perform analyses of potential accident conditions and evaluate the risks resulting from such shipments. The CRP on air transport was established to make a major international effort to collect relevant frequency and severity data and to analyze it so the accident forces to which a packages of radioactive material might be subjected to in a severe air accident can be more confidently quantified. Several countries have ongoing data collection activities related to aircraft accidents and severity and other sources of statistics for in-flight aircraft accidents will be explored. The International Civil Aviation Organization informed the IAEA of their plans to improve

IAEA mode-related research in the safe transport of radioactive material

International Nuclear Information System (INIS)

Blalock, L.G.; Rawl, R.R.

1998-01-01

The International Atomic Energy Agency sponsors Co-ordinated Research Programmes (CRP) in the safe transport of radioactive material. The CRPs are intended to encourage research by Member States in identified areas and to facilitate co-ordination of exchange of information and resources to reach a common understanding of the problem and alternative solutions. Two of these programmes are: Accident Severity at Sea During the Transport of Radioactive Material and Accident Severity During the Air Transport of Radioactive Material. This paper will discuss these two programmes and their relationship to the continuing regulatory revision process and interfaces with the International Maritime Organization (IMO) and the International Civil Aviation Organization (ICAO). Some Member States and non-governmental organizations in IMO meetings expressed concerns that accidents on board ships may be more severe than the IAEA regulatory tests account for, and that package failure with subsequent release of radioactive material may occur. The CRP on accident severity at sea was established to develop further quantitative information on potential accident severities during the transport of radioactive material by ships. The primary objective of this programme is to collect and evaluate statistical data of marine accidents, perform analyses of potential accident conditions and evaluate the risks resulting from such shipments. The CRP on air transport was established to make a major international effort to collect relevant frequency and severity data and to analyze it so the accident forces to which a packages of radioactive material might be subjected to in a severe air accident can be more confidently quantified. Several countries have ongoing data collection activities related to aircraft accidents and severity and other sources of statistics for in-flight aircraft accidents will be explored. The International Civil Aviation Organization informed the IAEA of their plans to improve

Challenges in Governing the Digital Transportation Ecosystem in Jakarta: A Research Direction in Smart City Frameworks

Directory of Open Access Journals (Sweden)

Iqbal Yulizar Mukti

2018-03-01

Full Text Available Mobility is one of the most difficult domains of the smart city to face. In fact, most large cities in the world are still facing urban mobility problems, especially traffic congestion. Particularly, in Jakarta, Indonesia, traffic congestion is a major issue that negatively affects productivity and the overall living quality of the citizens. Along with the development of the information communication and technology (ICT, the transportation domain in Jakarta has formed a digital transportation ecosystem, shown by the emergence of innovative digital-based transportation services. In line with this current condition, this paper hopes to contribute to the improvement of urban traffic in Jakarta by proposing research directions to govern the digital transportation ecosystem within a smart city framework. The significance of the research directions is reviewed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA methodology in a systematic review of previous studies. Ultimately, the research directions proposed in this paper lead to the necessity for an architectural perspective and relevant big data analytical tools to improve the digital transportation ecosystem in Jakarta.

The Analysis of Geometrical Reasoning Ability Viewed from Self-Efficacy on Connected Mathematic Project (CMP Learning Etnomathematics-Based

Directory of Open Access Journals (Sweden)

Desi Dwi Damaryanti

2017-11-01

Full Text Available The purpose of this research was to know the geometrical reasoning ability of the students viewed from the self-efficacy through the learning of  Connected Mathematic Project (CMP ethnomathematic-based. The type of this research was qualitative which was descriptive. To obtained the validity of the qualitative data, the checking technique used in this research was sources triangulation, which had been done by comparing the suitability of the obtained data from the results of the interview and the test. Population of this research was the students of grade VIII at SMP Negeri 1 Sidoharjo and the sample was the students from VIII A Class. At the final, 12 research subjects were chosen to represent the group of level 1 self-efficacy, level 2 self-efficacy, level 3 self-efficacy, level 4 self efficacy, level 5 self-efficacy, and level 6 self-efficacy. In this research, there was a finding which shows us that the students with high self-efficacy had low ability to finish the geometrical reasoning ability test, while the students with low self-efficacy had the ability to finish the geometrical reasoning ability test. The factors which affected the finding were the motivations and the interest of learning mathematics which was affecting the attitude of the students in the classroom.

A geometric view on learning Bayesian network structures

Czech Academy of Sciences Publication Activity Database

Studený, Milan; Vomlel, Jiří; Hemmecke, R.

2010-01-01

Roč. 51, č. 5 (2010), s. 578-586 ISSN 0888-613X. [PGM 2008] R&D Projects: GA AV ČR(CZ) IAA100750603; GA MŠk(CZ) 1M0572; GA ČR GA201/08/0539 Grant - others:GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : learning Bayesian networks * standard imset * inclusion neighborhood * geometric neighborhood * GES algorithm Subject RIV: BA - General Mathematics Impact factor: 1.679, year: 2010 http://library.utia.cas.cz/separaty/2010/MTR/studeny-0342804. pdf

Modeling cotton (Gossypium spp) leaves and canopy using computer aided geometric design (CAGD)

Science.gov (United States)

The goal of this research is to develop a geometrically accurate model of cotton crop canopies for exploring changes in canopy microenvironment and physiological function with leaf structure. We develop an accurate representation of the leaves, including changes in three-dimensional folding and orie...

Geometric reconstruction methods for electron tomography

DEFF Research Database (Denmark)

Alpers, Andreas; Gardner, Richard J.; König, Stefan

2013-01-01

Electron tomography is becoming an increasingly important tool in materials science for studying the three-dimensional morphologies and chemical compositions of nanostructures. The image quality obtained by many current algorithms is seriously affected by the problems of missing wedge artefacts...... and discuss several algorithms from the mathematical fields of geometric and discrete tomography. The algorithms incorporate geometric prior knowledge (mainly convexity and homogeneity), which also in principle considerably reduces the number of tilt angles required. Results are discussed...

Geometrical formulation of the conformal Ward identity

International Nuclear Information System (INIS)

Kachkachi, M.

2002-08-01

In this paper we use deep ideas in complex geometry that proved to be very powerful in unveiling the Polyakov measure on the moduli space of Riemann surfaces and lead to obtain the partition function of perturbative string theory for 2, 3, 4 loops. Indeed, a geometrical interpretation of the conformal Ward identity in two dimensional conformal field theory is proposed: the conformal anomaly is interpreted as a deformation of the complex structure of the basic Riemann surface. This point of view is in line with the modern trend of geometric quantizations that are based on deformations of classical structures. Then, we solve the conformal Ward identity by using this geometrical formalism. (author)

Normed algebras and the geometric series test

Directory of Open Access Journals (Sweden)

Robert Kantrowitz

2017-11-01

Full Text Available The purpose of this article is to survey a class of normed algebras that share many central features of Banach algebras, save for completeness. The likeness of these algebras to Banach algebras derives from the fact that the geometric series test is valid, whereas the lack of completeness points to the failure of the absolute convergence test for series in the algebra. Our main result is a compendium of conditions that are all equivalent to the validity of the geometric series test for commutative unital normed algebras. Several examples in the final section showcase some incomplete normed algebras for which the geometric series test is valid, and still others for which it is not.

Initial singularity and pure geometric field theories

Science.gov (United States)

Wanas, M. I.; Kamal, Mona M.; Dabash, Tahia F.

2018-01-01

In the present article we use a modified version of the geodesic equation, together with a modified version of the Raychaudhuri equation, to study initial singularities. These modified equations are used to account for the effect of the spin-torsion interaction on the existence of initial singularities in cosmological models. Such models are the results of solutions of the field equations of a class of field theories termed pure geometric. The geometric structure used in this study is an absolute parallelism structure satisfying the cosmological principle. It is shown that the existence of initial singularities is subject to some mathematical (geometric) conditions. The scheme suggested for this study can be easily generalized.

Geometric optimization and sums of algebraic functions

KAUST Repository

Vigneron, Antoine E.

2014-01-01

We present a new optimization technique that yields the first FPTAS for several geometric problems. These problems reduce to optimizing a sum of nonnegative, constant description complexity algebraic functions. We first give an FPTAS for optimizing such a sum of algebraic functions, and then we apply it to several geometric optimization problems. We obtain the first FPTAS for two fundamental geometric shape-matching problems in fixed dimension: maximizing the volume of overlap of two polyhedra under rigid motions and minimizing their symmetric difference. We obtain the first FPTAS for other problems in fixed dimension, such as computing an optimal ray in a weighted subdivision, finding the largest axially symmetric subset of a polyhedron, and computing minimum-area hulls.

The Geometric Phase of Stock Trading.

Science.gov (United States)

Altafini, Claudio

2016-01-01

Geometric phases describe how in a continuous-time dynamical system the displacement of a variable (called phase variable) can be related to other variables (shape variables) undergoing a cyclic motion, according to an area rule. The aim of this paper is to show that geometric phases can exist also for discrete-time systems, and even when the cycles in shape space have zero area. A context in which this principle can be applied is stock trading. A zero-area cycle in shape space represents the type of trading operations normally carried out by high-frequency traders (entering and exiting a position on a fast time-scale), while the phase variable represents the cash balance of a trader. Under the assumption that trading impacts stock prices, even zero-area cyclic trading operations can induce geometric phases, i.e., profits or losses, without affecting the stock quote.

Can EPR non-locality be geometrical?

International Nuclear Information System (INIS)

Ne'eman, Y.

1995-01-01

The presence in Quantum Mechanics of non-local correlations is one of the two fundamentally non-intuitive features of that theory. The non-local correlations themselves fall into two classes: EPR and Geometrical. The non-local characteristics of the geometrical type are well-understood and are not suspected of possibly generating acausal features, such as faster-than-light propagation of information. This has especially become true since the emergence of a geometrical treatment for the relevant gauge theories, i.e. Fiber Bundle geometry, in which the quantum non-localities are seen to correspond to pure homotopy considerations. This aspect is reviewed in section 2. Contrary-wise, from its very conception, the EPR situation was felt to be paradoxical. It has been suggested that the non-local features of EPR might also derive from geometrical considerations, like all other non-local characteristics of QM. In[7], one of the authors was able to point out several plausibility arguments for this thesis, emphasizing in particular similarities between the non-local correlations provided by any gauge field theory and those required by the preservation of the quantum numbers of the original EPR state-vector, throughout its spatially-extended mode. The derivation was, however, somewhat incomplete, especially because of the apparent difference between, on the one hand, the closed spatial loops arising in the analysis of the geometrical non-localities, from Aharonov-Bohm and Berry phases to magnetic monopoles and instantons, and on the other hand, in the EPR case, the open line drawn by the positions of the two moving decay products of the disintegrating particle. In what follows, the authors endeavor to remove this obstacle and show that as in all other QM non-localities, EPR is somehow related to closed loops, almost involving homotopy considerations. They develop this view in section 3

Geometrical modulus of a casting and its influence on solidification process

Directory of Open Access Journals (Sweden)

F. Havlicek

2011-10-01

Full Text Available Object: The work analyses the importance of the known criterion for evaluating the controlled solidification of castings, so called geometrical modulus defined by N. Chvorinov as the first one. Geometrical modulus influences the solidification process. The modulus has such specificity that during the process of casting formation it is not a constant but its initial value decreases with the solidification progress because the remaining melt volume can decrease faster than its cooling surface.Methodology: The modulus is determined by a simple calculation from the ratio of the casting volume after pouring the metal in the mould to the cooled mould surface. The solidified metal volume and the cooled surface too are changed during solidification. That calculation is much more complicated. Results were checked up experimentally by measuring the temperatures in the cross-section of heavy steel castings during cooling them.Results: The given experimental results have completed the original theoretical calculations by Chvorinov and recent researches done with use of numerical calculations. The contribution explains how the geometrical modulus together with the thermal process in the casting causes the higher solidification rate in the axial part of the casting cross-section and shortening of solidification time. Practical implications: Change of the geometrical modulus negatively affects the casting internal quality. Melt feeding by capillary filtration in the dendritic network in the casting central part decreases and in such a way the shrinkage porosity volume increases. State of stress character in the casting is changed too and it increases.

Research of transport and deposition of aerosol in human airway replica

Directory of Open Access Journals (Sweden)

Mravec Filip

2012-04-01

Full Text Available Growing concern about knowledge of aerosol transport in human lungs is caused by great potential of use of inhaled pharmaceuticals. Second substantial motive for the research is an effort to minimize adverse effects of particular matter emitted by traffic and industry on human health. We created model geometry of human lungs to 7th generation of branching. This model geometry was used for fabrication of two physical models. The first one is made from thin walled transparent silicone and it allows a measurement of velocity and size of aerosol particles by Phase Doppler Anemometry (PDA. The second one is fabricated by stereolithographic method and it is designed for aerosol deposition measurements. We provided a series of measurements of aerosol transport in the transparent model and we ascertained remarkable phenomena linked with lung flow. The results are presented in brief. To gather how this phenomena affects aerosol deposition in human lungs we used the second model and we developed a technique for deposition fraction and deposition efficiency assessment. The results confirmed that non-symmetric and complicated shape of human airways essentially affects transport and deposition of aerosol. The research will now focus on deeper insight in aerosol deposition.

Automatic braking system modification for the Advanced Transport Operating Systems (ATOPS) Transportation Systems Research Vehicle (TSRV)

Science.gov (United States)

Coogan, J. J.

1986-01-01

Modifications were designed for the B-737-100 Research Aircraft autobrake system hardware of the Advanced Transport Operating Systems (ATOPS) Program at Langley Research Center. These modifications will allow the on-board flight control computer to control the aircraft deceleration after landing to a continuously variable level for the purpose of executing automatic high speed turn-offs from the runway. A bread board version of the proposed modifications was built and tested in simulated stopping conditions. Test results, for various aircraft weights, turnoff speed, winds, and runway conditions show that the turnoff speeds are achieved generally with errors less than 1 ft/sec.

FAA/NASA Joint University Program for Air Transportation Research 1994-1995

Science.gov (United States)

Remer, J. H.

1998-01-01

The Joint University Program for Air Transportation Research (JUP) is a coordinated set of three grants co-sponsored by the Federal Aviation Administration (FAA) and the National Aeronautics and Space Administration (NASA). Under JUP, three institutions: the Massachusetts Institute of Technology, Princeton, and Ohio Universities receive research grants and collaborate with FAA and NASA in defining and performing civil aeronautics research in a multitude of areas. Some of these disciplines are artificial intelligence, control theory, atmospheric hazards, navigation, avionics, human factors, flight dynamics, air traffic management, and electronic communications.

The high speed civil transport and NASA's High Speed Research (HSR) program

Science.gov (United States)

Shaw, Robert J.

1994-01-01

Ongoing studies being conducted not only in this country but in Europe and Asia suggest that a second generation supersonic transport, or High-Speed Civil Transport (HSCT), could become an important part of the 21st century international air transportation system. However, major environmental compatibility and economic viability issues must be resolved if the HSCT is to become a reality. This talk will overview the NASA High-Speed Research (HSR) program which is aimed at providing the U.S. industry with a technology base to allow them to consider launching an HSCT program early in the next century. The talk will also discuss some of the comparable activities going on within Europe and Japan.

Geometric integration for particle accelerators

Science.gov (United States)

Forest, Étienne

2006-05-01

This paper is a very personal view of the field of geometric integration in accelerator physics—a field where often work of the highest quality is buried in lost technical notes or even not published; one has only to think of Simon van der Meer Nobel prize work on stochastic cooling—unpublished in any refereed journal. So I reconstructed the relevant history of geometrical integration in accelerator physics as much as I could by talking to collaborators and using my own understanding of the field. The reader should not be too surprised if this account is somewhere between history, science and perhaps even fiction.

Geometric integration for particle accelerators

International Nuclear Information System (INIS)

Forest, Etienne

2006-01-01

This paper is a very personal view of the field of geometric integration in accelerator physics-a field where often work of the highest quality is buried in lost technical notes or even not published; one has only to think of Simon van der Meer Nobel prize work on stochastic cooling-unpublished in any refereed journal. So I reconstructed the relevant history of geometrical integration in accelerator physics as much as I could by talking to collaborators and using my own understanding of the field. The reader should not be too surprised if this account is somewhere between history, science and perhaps even fiction

Observation of the geometric phase using photon echoes

International Nuclear Information System (INIS)

Tian, Mingzhen; Reibel, Randy R.; Barber, Zeb W.; Fischer, Joe A.; Babbitt, Wm. Randall

2003-01-01

The geometric phase of an atomic system has been observed in V-type three-level barium atoms using photon echoes. The geometric phase results from a cyclic evolution of a two-level subsystem driven by a laser pulse. The phase change is observed on the echo field produced on a different subsystem that is coupled via the ground state to the driven subsystem. The measured geometric phase was half of the solid angle subtended by the Bloch vector along the driven evolution circuit. This evolution has the potential to form universal operations of quantum bits

Savannah River Laboratory environmental transport and effects research. Annual report, 1974

International Nuclear Information System (INIS)

Crawford, T.V.

1975-06-01

The principal objective of environmental transport research at the Savannah River Laboratory (SRL) is to develop, apply, adapt, use, test, and verify models that predict the directions and magnitude of ecosystem processes. Since an ecosystem is understood to be a complex ecological unit composed of physical, chemical, and biotic components interacting in the cycling and transport of matter and the flow of energy, the understanding of ecosystem processes demands integrated study by scientists of differing disciplines. Data are included from studies on factors that affect the atmospheric transport and dispersion of radionuclides and chemical effluents; surface and groundwater transport of various pollutants following release to the soil surface or a flowing stream; the uptake and retention of tritium oxide by pine trees; calculations of the radiation dose commitment for human populations from 14 C released by the nuclear industry; the effects of thermal effluents on aquatic organisms, including plankton productivity, the population dynamics of freshwater snails, and the growth and respiration rates of the sand-burrowing mayfly (Dolania americana). Data are included from a survey of seismic activity in South Carolina. (CH)

Geometric and engineering drawing

CERN Document Server

Morling, K

2010-01-01

The new edition of this successful text describes all the geometric instructions and engineering drawing information that are likely to be needed by anyone preparing or interpreting drawings or designs with plenty of exercises to practice these principles.

PHITS: Particle and heavy ion transport code system, version 2.23

International Nuclear Information System (INIS)

Niita, Koji; Matsuda, Norihiro; Iwamoto, Yosuke; Sato, Tatsuhiko; Nakashima, Hiroshi; Sakamoto, Yukio; Iwase, Hiroshi; Sihver, Lembit

2010-10-01

A Particle and Heavy-Ion Transport code System PHITS has been developed under the collaboration of JAEA (Japan Atomic Energy Agency), RIST (Research Organization for Information Science and Technology) and KEK (High Energy Accelerator Research Organization). PHITS can deal with the transport of all particles (nucleons, nuclei, mesons, photons, and electrons) over wide energy ranges, using several nuclear reaction models and nuclear data libraries. Geometrical configuration of the simulation can be set with GG (General Geometry) or CG (Combinatorial Geometry). Various quantities such as heat deposition, track length and production yields can be deduced from the simulation, using implemented estimator functions called 'tally'. The code also has a function to draw 2D and 3D figures of the calculated results as well as the setup geometries, using a code ANGEL. Because of these features, PHITS has been widely used for various purposes such as designs of accelerator shielding, radiation therapy and space exploration. Recently PHITS introduces an event generator for particle transport parts in the low energy region. Thus, PHITS was completely rewritten for the introduction of the event generator for neutron-induced reactions in energy region less than 20 MeV. Furthermore, several new tallis were incorporated for estimation of the relative biological effects. This document provides a manual of the new PHITS. (author)

Transportable Heavy Duty Emissions Testing Laboratory and Research Program

Energy Technology Data Exchange (ETDEWEB)

David Lyons

2008-03-31

The objective of this program was to quantify the emissions from heavy-duty vehicles operating on alternative fuels or advanced fuel blends, often with novel engine technology or aftertreatment. In the first year of the program West Virginia University (WVU) researchers determined that a transportable chassis dynamometer emissions measurement approach was required so that fleets of trucks and buses did not need to be ferried across the nation to a fixed facility. A Transportable Heavy-Duty Vehicle Emissions Testing Laboratory (Translab) was designed, constructed and verified. This laboratory consisted of a chassis dynamometer semi-trailer and an analytic trailer housing a full scale exhaust dilution tunnel and sampling system which mimicked closely the system described in the Code of Federal Regulations for engine certification. The Translab was first used to quantify emissions from natural gas and methanol fueled transit buses, and a second Translab unit was constructed to satisfy research demand. Subsequent emissions measurement was performed on trucks and buses using ethanol, Fischer-Tropsch fuel, and biodiesel. A medium-duty chassis dynamometer was also designed and constructed to facilitate research on delivery vehicles in the 10,000 to 20,000lb range. The Translab participated in major programs to evaluate low-sulfur diesel in conjunction with passively regenerating exhaust particulate filtration technology, and substantial reductions in particulate matter were recorded. The researchers also participated in programs to evaluate emissions from advanced natural gas engines with closed loop feedback control. These natural gas engines showed substantially reduced levels of oxides of nitrogen. For all of the trucks and buses characterized, the levels of carbon monoxide, oxides of nitrogen, hydrocarbons, carbon dioxide and particulate matter were quantified, and in many cases non-regulated species such as aldehydes were also sampled. Particle size was also

Study into Point Cloud Geometric Rigidity and Accuracy of TLS-Based Identification of Geometric Bodies

Science.gov (United States)

Klapa, Przemyslaw; Mitka, Bartosz; Zygmunt, Mariusz

2017-12-01

Capability of obtaining a multimillion point cloud in a very short time has made the Terrestrial Laser Scanning (TLS) a widely used tool in many fields of science and technology. The TLS accuracy matches traditional devices used in land surveying (tacheometry, GNSS - RTK), but like any measurement it is burdened with error which affects the precise identification of objects based on their image in the form of a point cloud. The point’s coordinates are determined indirectly by means of measuring the angles and calculating the time of travel of the electromagnetic wave. Each such component has a measurement error which is translated into the final result. The XYZ coordinates of a measuring point are determined with some uncertainty and the very accuracy of determining these coordinates is reduced as the distance to the instrument increases. The paper presents the results of examination of geometrical stability of a point cloud obtained by means terrestrial laser scanner and accuracy evaluation of solids determined using the cloud. Leica P40 scanner and two different settings of measuring points were used in the tests. The first concept involved placing a few balls in the field and then scanning them from various sides at similar distances. The second part of measurement involved placing balls and scanning them a few times from one side but at varying distances from the instrument to the object. Each measurement encompassed a scan of the object with automatic determination of its position and geometry. The desk studies involved a semiautomatic fitting of solids and measurement of their geometrical elements, and comparison of parameters that determine their geometry and location in space. The differences of measures of geometrical elements of balls and translations vectors of the solids centres indicate the geometrical changes of the point cloud depending on the scanning distance and parameters. The results indicate the changes in the geometry of scanned objects

Degenerated shell element for geometrically nonlinear analysis of thin-walled piezoelectric active structures

International Nuclear Information System (INIS)

Marinković, D; Köppe, H; Gabbert, U

2008-01-01

Active piezoelectric thin-walled structures, especially those with a notably higher membrane than bending stiffness, are susceptible to large rotations and transverse deflections. Recent investigations conducted by a number of researchers have shown that the predicted behavior of piezoelectric structures can be significantly influenced by the assumption of large displacements and rotations of the structure, thus demanding a geometrically nonlinear formulation in order to investigate it. This paper offers a degenerated shell element and a simplified formulation that relies on small incremental steps for the geometrically nonlinear analysis of piezoelectric composite structures. A set of purely mechanical static cases is followed by a set of piezoelectric coupled static cases, both demonstrating the applicability of the proposed formulation

An approach for the design of closure bolts of spent fuel elements transportation packages

International Nuclear Information System (INIS)

Mattar Neto, Miguel; Miranda, Carlos A.J.; Fainer, Gerson

2009-01-01

The spent fuel elements transportation packages must be designed for severe conditions including significant fire and impact loads corresponding to hypothetical accident conditions. In general, these packages have large flat lids connected to cylindrical bodies by closure bolts that can be the weak link in the containment system. The bolted closure design depends on the geometrical characteristics of the flat lid and the cylindrical body, including their flanges, on the type of the gaskets and their dimensions, and on the number, strength, and tightness of the bolts. There are well established procedures for the closure bolts design used in pressure vessels and piping. They can not be used directly in the bolts design applied to transportation packages. Prior to the use of these procedures, it is necessary consider the differences in the main loads (pressure for the pressure vessels and piping and impact loads for the transportation packages) and in the geometry (large flat lids are not used in pressure vessels and piping). So, this paper presents an approach for the design of the closure bolts of spent fuel elements transportation packages considering the impact loads and the typical geometrical configuration of the transportation packages. (author)

Exploring the relationship between structurally defined geometrical parameters of reinforced concrete beams and the thermal comfort on indoor environment

DEFF Research Database (Denmark)

Lee, Daniel Sang-Hoon; Naboni, Emanuele

2017-01-01

mass effect (and the implication on thermal comfort) and the given geometrical parameters of exposed soffit reinforced concrete beams are explored. The geometrical parameters of the beams are initially defined in means of structural optimisation. The beams consist of flange and web in likeness of T...... the resultant heat exchange behaviour, and the implication on thermal comfort indoor environment. However, the current paper presents the thermal mass characteristics of one geometrical type. The study is based on results derived from computational fluid dynamics (CFD) analysis, where Rhino 3D is used......The paper presents a research exploring the thermal mass effect of reinforced concrete beams with structurally optimised geometrical forms. Fully exposed concrete soffits in architectural contexts create more than just visual impacts on the indoor climate through their possible interferences...

Geometric inequalities for axially symmetric black holes

International Nuclear Information System (INIS)

Dain, Sergio

2012-01-01

A geometric inequality in general relativity relates quantities that have both a physical interpretation and a geometrical definition. It is well known that the parameters that characterize the Kerr-Newman black hole satisfy several important geometric inequalities. Remarkably enough, some of these inequalities also hold for dynamical black holes. This kind of inequalities play an important role in the characterization of the gravitational collapse; they are closely related with the cosmic censorship conjecture. Axially symmetric black holes are the natural candidates to study these inequalities because the quasi-local angular momentum is well defined for them. We review recent results in this subject and we also describe the main ideas behind the proofs. Finally, a list of relevant open problems is presented. (topical review)

EARLY HISTORY OF GEOMETRIC PROBABILITY AND STEREOLOGY

Directory of Open Access Journals (Sweden)

Magdalena Hykšová

2012-03-01

Full Text Available The paper provides an account of the history of geometric probability and stereology from the time of Newton to the early 20th century. It depicts the development of two parallel ways: on one hand, the theory of geometric probability was formed with minor attention paid to other applications than those concerning spatial chance games. On the other hand, practical rules of the estimation of area or volume fraction and other characteristics, easily deducible from geometric probability theory, were proposed without the knowledge of this branch. A special attention is paid to the paper of J.-É. Barbier published in 1860, which contained the fundamental stereological formulas, but remained almost unnoticed both by mathematicians and practicians.

Optimal Mass Transport for Statistical Estimation, Image Analysis, Information Geometry, and Control

Science.gov (United States)

2017-01-10

advances on formulating and solving optimal transport problems on discrete spaces (networks) while ensuring robustness of the transportation plan. This...Metric Uncertainty for Spectral Estimation based on Nevanlinna-Pick Interpolation, (with J. Karlsson) Intern. Symp. on the Math . Theory of Networks and...Systems, Melbourne 2012. 22. Geometric tools for the estimation of structured covariances, (with L. Ning, X. Jiang) Intern. Symposium on the Math . Theory

BOT3P - Bologna Transport Analysis Pre-Post-Processors Version 3.0

International Nuclear Information System (INIS)

Orsi, Roberto

2004-01-01

BOT3P is a set of standard FORTRAN 77 language programs developed at the ENEA-Bologna Nuclear Data Centre. BOT3P Version 1.0 was originally conceived to give the users of the DORT and TORT deterministic transport codes some useful diagnostic tools to prepare and to check their input data files. BOT3P Version 3.0 contains some important additions in the input geometrical model description, such as 'rod' and 'hexagonal' geometrical objects, respecting the exact cross-sectional area value and very suitable to describe a reactor lattice in detail. Moreover, it has extended the possibility to produce the geometrical, material distribution, and fixed neutron source data for the deterministic transport codes TWODANT and THREEDANT of the DANTSYS system and for the PARTISN code too, starting from the same input to BOT3P. When users require X-Y-Z TORT/THREEDANT/PARTISN mesh grids to be generated, BOT3P Version 3.0 produces a geometrical input for the MCNP Monte Carlo transport code also, where the MCNP cells correspond to the X-Y-Z bodies created for TORT.BOT3P Version 3.0 lets users specify areas/volumes of the model where the zone/material distribution can be defined not only by a combinatorial geometry but also by an external source, such as one originated from computerized tomography scan data (only for three-dimensional applications) and from one or more external DORT/TORT input files. BOT3P was developed on a DIGITAL UNIX ALPHA 500/333 workstation and successfully used in some complex neutron shielding and criticality benchmarks. It was also tested on Red Hat Linux 7.1 and is designed to run on most UNIX platforms. All BOT3P versions are publicly available from the Organisation for Economic Co-operation and Development/Nuclear Energy Agency Data Bank (NEA-1627, NEA-1678)

Size and mobility of lipid domains tuned by geometrical constraints.

Science.gov (United States)

Schütte, Ole M; Mey, Ingo; Enderlein, Jörg; Savić, Filip; Geil, Burkhard; Janshoff, Andreas; Steinem, Claudia

2017-07-25

In the plasma membrane of eukaryotic cells, proteins and lipids are organized in clusters, the latter ones often called lipid domains or "lipid rafts." Recent findings highlight the dynamic nature of such domains and the key role of membrane geometry and spatial boundaries. In this study, we used porous substrates with different pore radii to address precisely the extent of the geometric constraint, permitting us to modulate and investigate the size and mobility of lipid domains in phase-separated continuous pore-spanning membranes (PSMs). Fluorescence video microscopy revealed two types of liquid-ordered ( l o ) domains in the freestanding parts of the PSMs: ( i ) immobile domains that were attached to the pore rims and ( ii ) mobile, round-shaped l o domains within the center of the PSMs. Analysis of the diffusion of the mobile l o domains by video microscopy and particle tracking showed that the domains' mobility is slowed down by orders of magnitude compared with the unrestricted case. We attribute the reduced mobility to the geometric confinement of the PSM, because the drag force is increased substantially due to hydrodynamic effects generated by the presence of these boundaries. Our system can serve as an experimental test bed for diffusion of 2D objects in confined geometry. The impact of hydrodynamics on the mobility of enclosed lipid domains can have great implications for the formation and lateral transport of signaling platforms.

Research showcase, winter 2014 : reducing traffic noise impacts, university transportation centers, advanced prismatic sheeting.

Science.gov (United States)

2014-01-01

This issue of Research Showcase features articles on two successful research efforts, one on quiet : pavements and the other on the bene ts of prismatic sign sheeting, and an article on university : transportation center participation in Florida.

The Spacetime Memory of Geometric Phases and Quantum Computing

CERN Document Server

Binder, B

2002-01-01

Spacetime memory is defined with a holonomic approach to information processing, where multi-state stability is introduced by a non-linear phase-locked loop. Geometric phases serve as the carrier of physical information and geometric memory (of orientation) given by a path integral measure of curvature that is periodically refreshed. Regarding the resulting spin-orbit coupling and gauge field, the geometric nature of spacetime memory suggests to assign intrinsic computational properties to the electromagnetic field.

Development of interfacial area transport equation

International Nuclear Information System (INIS)

Kim, Seung Jin; Ishii, Mamoru; Kelly, Joseph

2005-01-01

The interfacial area transport equation dynamically models the changes in interfacial structures along the flow field by mechanistically modeling the creation and destruction of dispersed phase. Hence, when employed in the numerical thermal-hydraulic system analysis codes, it eliminates artificial bifurcations stemming from the use of the static flow regime transition criteria. Accounting for the substantial differences in the transport mechanism for various sizes of bubbles, the transport equation is formulated for two characteristic groups of bubbles. The group 1 equation describes the transport of small-dispersed bubbles, whereas the group 2 equation describes the transport of large cap, slug or churn-turbulent bubbles. To evaluate the feasibility and reliability of interfacial area transport equation available at present, it is benchmarked by an extensive database established in various two-phase flow configurations spanning from bubbly to churn-turbulent flow regimes. The geometrical effect in interfacial area transport is examined by the data acquired in vertical air-water two-phase flow through round pipes of various sizes and a confined flow duct, and by those acquired in vertical co-current downward air-water two-phase flow through round pipes of two different sizes

The geometric semantics of algebraic quantum mechanics.

Science.gov (United States)

Cruz Morales, John Alexander; Zilber, Boris

2015-08-06

In this paper, we will present an ongoing project that aims to use model theory as a suitable mathematical setting for studying the formalism of quantum mechanics. We argue that this approach provides a geometric semantics for such a formalism by means of establishing a (non-commutative) duality between certain algebraic and geometric objects. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Research and development of electric vehicles for clean transportation.

Science.gov (United States)

Wada, Masayoshi

2009-01-01

This article presents the research and development of an electric vehicle (EV) in Department of Human-Robotics Saitama Institute of Technology, Japan. Electric mobile systems developed in our laboratory include a converted electric automobile, electric wheelchair and personal mobile robot. These mobile systems contribute to realize clean transportation since energy sources and devices from all vehicles, i.e., batteries and electric motors, does not deteriorate the environment. To drive motors for vehicle traveling, robotic technologies were applied.

Discrete geometric structures for architecture

KAUST Repository

Pottmann, Helmut

2010-06-13

The emergence of freeform structures in contemporary architecture raises numerous challenging research problems, most of which are related to the actual fabrication and are a rich source of research topics in geometry and geometric computing. The talk will provide an overview of recent progress in this field, with a particular focus on discrete geometric structures. Most of these result from practical requirements on segmenting a freeform shape into planar panels and on the physical realization of supporting beams and nodes. A study of quadrilateral meshes with planar faces reveals beautiful relations to discrete differential geometry. In particular, we discuss meshes which discretize the network of principal curvature lines. Conical meshes are among these meshes; they possess conical offset meshes at a constant face/face distance, which in turn leads to a supporting beam layout with so-called torsion free nodes. This work can be generalized to a variety of multilayer structures and laid the ground for an adapted curvature theory for these meshes. There are also efforts on segmenting surfaces into planar hexagonal panels. Though these are less constrained than planar quadrilateral panels, this problem is still waiting for an elegant solution. Inspired by freeform designs in architecture which involve circles and spheres, we present a new kind of triangle mesh whose faces\\' in-circles form a packing, i.e., the in-circles of two triangles with a common edge have the same contact point on that edge. These "circle packing (CP) meshes" exhibit an aesthetic balance of shape and size of their faces. They are closely tied to sphere packings on surfaces and to various remarkable structures and patterns which are of interest in art, architecture, and design. CP meshes constitute a new link between architectural freeform design and computational conformal geometry. Recently, certain timber structures motivated us to study discrete patterns of geodesics on surfaces. This

Administrative mechanics of research fuel transportation

International Nuclear Information System (INIS)

Harmon, Diane W.

1983-01-01

This presentation contains the discussion on the multitude of administrative mechanics that have to be meshed for the successful completion of a shipment of spent fuel, HEU or LEU in the research reactors fuel cycle. The costs associated with transportation may be the equivalent of 'a black hole', so an overview of cost factors is given. At the end one could find that this black hole factor in the budget is actually a bargain. The first step is the quotation phase. The cost variables in the quotation contain the cost of packaging i.e. containers; the complete routing of the packages and the materials. Factors that are of outmost importance are the routing restrictions and regulations, physical security regulations. All of this effort is just to provide a valid quotation not to accomplish the goal of completing a shipment. Public relations cannot be omitted either

Administrative mechanics of research fuel transportation

Energy Technology Data Exchange (ETDEWEB)

Harmon, Diane W [Edlow International Company, Washington, DC (United States)

1983-09-01

This presentation contains the discussion on the multitude of administrative mechanics that have to be meshed for the successful completion of a shipment of spent fuel, HEU or LEU in the research reactors fuel cycle. The costs associated with transportation may be the equivalent of 'a black hole', so an overview of cost factors is given. At the end one could find that this black hole factor in the budget is actually a bargain. The first step is the quotation phase. The cost variables in the quotation contain the cost of packaging i.e. containers; the complete routing of the packages and the materials. Factors that are of outmost importance are the routing restrictions and regulations, physical security regulations. All of this effort is just to provide a valid quotation not to accomplish the goal of completing a shipment. Public relations cannot be omitted either.

Domain wall magnetoresistance in nanowires: Dependence on geometrical factors and material parameters

International Nuclear Information System (INIS)

Allende, S.; Retamal, J.C.; Altbir, D.; D'Albuquerque e Castro, J.

2014-01-01

The magnetoresistance associated with the presence of domain walls in metallic nanowires is investigated as a function of geometrical parameters, corresponding to the wall thickness and the nanowire width, as well as of material parameters, such as the band filling and the exchange interaction. Transport across the structure is described within Landauer formalism. Both cases of saturated and non-saturated ferromagnets are considered, and in all of them the contributions from spin-flip and non-spin-flip are separately analyzed. It has been found that for certain range of parameters deviations in the normalized magnetoresistance as high as 20% may be achieved. In addition, it has been shown that the spin-flip process is dependent on the wall thickness. - Highlights: • We identify thickness regions within which transport across the wall is dominated by either spin-flip or non-spin-flip process. • We analyze the dependence of the magnetoresistance on both the material's band filling and strength of the exchange interaction. • We identify parameter ranges within which magnetoresistance ratios as high as 20% or even more might be achieved

Domain wall magnetoresistance in nanowires: Dependence on geometrical factors and material parameters

Energy Technology Data Exchange (ETDEWEB)

Allende, S.; Retamal, J.C. [Departamento de Física, CEDENNA, Universidad de Santiago de Chile, USACH, Avenida Ecuador 3493, 917-0124 Santiago (Chile); Altbir, D., E-mail: dora.altbir@usach.cl [Departamento de Física, CEDENNA, Universidad de Santiago de Chile, USACH, Avenida Ecuador 3493, 917-0124 Santiago (Chile); D' Albuquerque e Castro, J. [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro 21941-972 (Brazil)

2014-04-15

The magnetoresistance associated with the presence of domain walls in metallic nanowires is investigated as a function of geometrical parameters, corresponding to the wall thickness and the nanowire width, as well as of material parameters, such as the band filling and the exchange interaction. Transport across the structure is described within Landauer formalism. Both cases of saturated and non-saturated ferromagnets are considered, and in all of them the contributions from spin-flip and non-spin-flip are separately analyzed. It has been found that for certain range of parameters deviations in the normalized magnetoresistance as high as 20% may be achieved. In addition, it has been shown that the spin-flip process is dependent on the wall thickness. - Highlights: • We identify thickness regions within which transport across the wall is dominated by either spin-flip or non-spin-flip process. • We analyze the dependence of the magnetoresistance on both the material's band filling and strength of the exchange interaction. • We identify parameter ranges within which magnetoresistance ratios as high as 20% or even more might be achieved.

Exponentiated Lomax Geometric Distribution: Properties and Applications

Directory of Open Access Journals (Sweden)

Amal Soliman Hassan

2017-09-01

Full Text Available In this paper, a new four-parameter lifetime distribution, called the exponentiated Lomax geometric (ELG is introduced. The new lifetime distribution contains the Lomax geometric and exponentiated Pareto geometric as new sub-models. Explicit algebraic formulas of probability density function, survival and hazard functions are derived. Various structural properties of the new model are derived including; quantile function, Re'nyi entropy, moments, probability weighted moments, order statistic, Lorenz and Bonferroni curves. The estimation of the model parameters is performed by maximum likelihood method and inference for a large sample is discussed. The flexibility and potentiality of the new model in comparison with some other distributions are shown via an application to a real data set. We hope that the new model will be an adequate model for applications in various studies.

BOT3P: a mesh generation software package for the transport analysis codes Dort, Tort, Twodant, Threedant and MCNP

International Nuclear Information System (INIS)

Orsi, R.

2003-01-01

Bot3p consists of a set of standard Fortran 77 language programs that gives the users of the deterministic transport codes Dort and Tort some useful diagnostic tools to prepare and check the geometry of their input data files for both Cartesian and cylindrical geometries including graphical display modules. Bot3p produces at the same time the geometrical and material distribution data for the deterministic transport codes Twodant and Threedant and, only in three-dimensional (3D) Cartesian geometry, for the Monte Carlo Transport Code MCNP. This makes it possible to compare directly for the same geometry the effects stemming from the use of different data libraries and solution approaches on transport analysis results. Through the use of Bot3p, radiation transport problems with complex 3D geometrical structures can be modelled easily, as a relatively small amount of engineer-time is required and refinement is achieved by changing few parameters. This tool is useful for solving very large challenging problems. (author)

Sudan-decoding generalized geometric Goppa codes

DEFF Research Database (Denmark)

Heydtmann, Agnes Eileen

2003-01-01

Generalized geometric Goppa codes are vector spaces of n-tuples with entries from different extension fields of a ground field. They are derived from evaluating functions similar to conventional geometric Goppa codes, but allowing evaluation in places of arbitrary degree. A decoding scheme...... for these codes based on Sudan's improved algorithm is presented and its error-correcting capacity is analyzed. For the implementation of the algorithm it is necessary that the so-called increasing zero bases of certain spaces of functions are available. A method to obtain such bases is developed....

Human behavior research and the design of sustainable transport systems

Science.gov (United States)

Schauer, James J.

2011-09-01

reduced carbon emissions are central to the design and optimization of future low carbon transport systems. Gaker et al (2011) suggest a framework, and provide insight into the willingness of transport consumers to pay for emission reductions of carbon dioxide from their personal transport choices within the context of other attributes of transport variables. The results of this study, although limited to a small demographic segment of the US population, demonstrate that people can integrate information on greenhouse gas emissions with other transport attributes including cost and time. Likewise, the research shows that the study group was willing to pay for reduction in greenhouse gas emissions associated with their transport choices. The study examined auto purchase choice, transport mode choice and transport route choice, which represent key decisions associated with transport that impact greenhouse gas emissions. Interestingly, they found that the study group was willing to pay for reductions in greenhouse gas emissions at a relatively consistent price across these transport choices. Clearly, the study results may not broadly apply to all demographics of users of transport, even in the study domain, due to the small demographic segment that was examined and the fact that the study was conducted in the laboratory. However, the methods used by Gaker et al (2011) are cause for optimism that future studies can obtain much needed mapping of transport preferences and willingness to pay for greenhouse gas emission reductions associated with personal transport choices. Although the Gaker et al (2011) study is directed at understanding the promotion of low carbon transport in the context of existing infrastructures, the ability of these studies to elucidate human behavior and preferences within the trade-offs of transport are critical to the design of future transport systems that seek to meet transport demand with constrained greenhouse gas emissions. Additional studies of

Electronic transport properties of copper and gold at atomic scale

Energy Technology Data Exchange (ETDEWEB)

Mohammadzadeh, Saeideh

2010-11-23

The factors governing electronic transport properties of copper and gold atomic-size contacts are theoretically examined in the present work. A two-terminal conductor using crystalline electrodes is adopted. The non-equilibrium Green's function combined with the density functional tight-binding method is employed via gDFTB simulation tool to calculate the transport at both equilibrium and non-equilibrium conditions. The crystalline orientation, length, and arrangement of electrodes have very weak influence on the electronic characteristics of the considered atomic wires. The wire width is found to be the most effective geometric aspect determining the number of conduction channels. The obtained conductance oscillation and linear current-voltage curves are interpreted. To analyze the conduction mechanism in detail, the transmission channels and their decomposition to the atomic orbitals are calculated in copper and gold single point contacts. The presented results offer a possible explanation for the relation between conduction and geometric structure. Furthermore, the results are in good agreement with available experimental and theoretical studies. (orig.)

Geometrical intuition and the learning and teaching of geometry

OpenAIRE

Fujita, Taro; Jones, Keith; Yamamoto, Shinya

2004-01-01

Intuition is often regarded as essential in the learning of geometry, but how such skills might be effectively developed in students remains an open question. This paper reviews the role and importance of geometrical intuition and suggests it involves the skills to create and manipulate geometrical figures in the mind, to see geometrical properties, to relate images to concepts and theorems in geometry, and decide where and how to start when solving problems in geometry. Based on these theore...

Geometric picture of quantum discord for two-qubit quantum states

International Nuclear Information System (INIS)

Shi Mingjun; Jiang Fengjian; Sun Chunxiao; Du Jiangfeng

2011-01-01

Among various definitions of quantum correlations, quantum discord has attracted considerable attention. To find an analytical expression for quantum discord is an intractable task. Exact results are known only for very special states, namely two-qubit X-shaped states. We present in this paper a geometric viewpoint, from which two-qubit quantum discord can be described clearly. The known results on X state discord are restated in the directly perceivable geometric language. As a consequence, the dynamics of classical correlations and quantum discord for an X state in the presence of decoherence is endowed with geometric interpretation. More importantly, we extend the geometric method to the case of more general states, for which numerical as well as analytical results on quantum discord have not yet been obtained. Based on the support of numerical computations, some conjectures are proposed to help us establish the geometric picture. We find that the geometric picture for these states has an intimate relationship with that for X states. Thereby, in some cases, analytical expressions for classical correlations and quantum discord can be obtained.

Sustainable Mobility Initiative | Transportation Research | NREL

Science.gov (United States)

travel behavior and consumer choice leading to the adoption of more fuel-efficient vehicles and more behavior in response to real-time feedback and incentives. By pairing transportation modeling with behavior . Schroeder, Y. Zhang, P. Chipman, and S. Johnson (2015) Consumer Views on Transportation and Advanced Vehicle

FAA/NASA Joint University Program for Air Transportation Research, 1992-1993

Science.gov (United States)

Morrell, Frederick R. (Compiler)

1994-01-01

The research conducted during the academic year 1992-1993 under the FAA/NASA sponsored Joint University Program for Air Transportation Research is summarized. The year end review was held at Ohio University, Athens, Ohio, 17-18 June 1993. The Joint University Program is a coordinated set of three grants sponsored by the Federal Aviation Administration and NASA Langley Research Center, one each with the Massachusetts Institute of Technology, Ohio University, and Princeton University. Completed works, status reports, and annotated bibliographies are presented for research topics, which include navigation, guidance, and control theory and practice, aircraft performance, human factors and air traffic management. An overview of the year's activities for each university is also presented.

Today's research development on the application of the superconductivity transport system in Japan

Science.gov (United States)

Kyotani, Yoshihiro

1995-01-01

At the Miyazaki test track today, the new test vehicle, MLU002N, is under test run to obtain necessary data for Yamanashi test track where the construction is underway, the test vehicle has been ordered and the first tunnel was completed in December 1993. Superconducting magnetohydrodynamic drive ship, MHDS, 'Yamato 1' has completed its experiment in 1992 and it is now under preparation to exhibit to the public in___1994. Furthermore, to promote the research development of MHDS, the detailed discussion is underway on the magnetohydrodynamic drive equipment as well as the research on the future scheme. Neither an automobile nor railway but a new transport system called EQUOS LIM CAR(ELC) has been proposed. By using the rotating magnetic field, it will levitate on the aluminum like reaction plate. On the normal road, it will run by rolling the wheels like an electric car but on the highway, it will levitate on the guideway resulting to less noise, less vibration and pollution free drive. To understand the concept of the ELC, the model was built and experimented by using permanent magnet. The same model was donated to the MUSEUM OF SCIENCE AND INDUSTRY in Chicago and was displayed to the public. Today, the trial superconducting magnet has been made and the research development of the subsystem is underway. Research development of superconducting elevator, equipment for the launching of spaceship, tube transportation system and others are in progress for the superconducting applied transportation system.

Research and Development Program for transportation packagings at Sandia National Laboratories

International Nuclear Information System (INIS)

Hohnstreiter, G.F.; Sorenson, K.B.

1995-01-01

This document contains information about the research and development programs dealing with waste transport at Sandia National Laboratories. This paper discusses topics such as: Why new packaging is needed; analytical methodologies and design codes;evaluation of packaging components; materials characterization; creative packaging concepts; packaging engineering and analysis; testing; and certification support

Geometric Methods in Physics : XXXII Workshop

CERN Document Server

Bieliavsky, Pierre; Odesskii, Alexander; Odzijewicz, Anatol; Schlichenmaier, Martin; Voronov, Theodore; Geometric Methods in Physics

2014-01-01

The Białowieża Workshops on Geometric Methods in Physics, which are hosted in the unique setting of the Białowieża natural forest in Poland, are among the most important meetings in the field. Every year some 80 to 100 participants from both the mathematics and physics world join to discuss new developments and to exchange ideas. The current volume was produced on the occasion of the 32nd meeting in 2013. It is now becoming a tradition that the Workshop is followed by a School on Geometry and Physics, which consists of advanced lectures for graduate students and young researchers. Selected speakers at the 2013 Workshop were asked to contribute to this book, and their work was supplemented by additional review articles. The selection shows that, despite its now long tradition, the workshop remains at the cutting edge of research. The 2013 Workshop also celebrated the 75th birthday of Daniel Sternheimer, and on this occasion the discussion mainly focused on his contributions to mathematical physics such as ...

Implementation and efficiency of two geometric stiffening approaches

International Nuclear Information System (INIS)

Lugris, Urbano; Naya, Miguel A.; Perez, Jose A.; Cuadrado, Javier

2008-01-01

When the modeling of flexible bodies is required in multibody systems, the floating frame of reference formulations are probably the most efficient methods available. In the case of beams undergoing high speed rotations, the geometric stiffening effect can appear due to geometric nonlinearities, and it is often not captured by the aforementioned methods, since it is common to linearize the elastic forces assuming small deformations. The present work discusses the implementation of different existing methods developed to consider such geometric nonlinearities within a floating frame of reference formulation in natural coordinates, making emphasis on the relation between efficiency and accuracy of the resulting algorithms, seeking to provide practical criteria of use

Geometric transitions, flops and non-Kahler manifolds: I

International Nuclear Information System (INIS)

Becker, Melanie; Dasgupta, Keshav; Knauf, Anke; Tatar, Radu

2004-01-01

We construct a duality cycle which provides a complete supergravity description of geometric transitions in type II theories via a flop in M-theory. This cycle connects the different supergravity descriptions before and after the geometric transitions. Our construction reproduces many of the known phenomena studied earlier in the literature and allows us to describe some new and interesting aspects in a simple and elegant fashion. A precise supergravity description of new torsional manifolds that appear on the type IIA side with branes and fluxes and the corresponding geometric transition are obtained. A local description of new G2 manifolds that are circle fibrations over non-Kahler manifolds is presented

Active Learning Environment with Lenses in Geometric Optics

Science.gov (United States)

Tural, Güner

2015-01-01

Geometric optics is one of the difficult topics for students within physics discipline. Students learn better via student-centered active learning environments than the teacher-centered learning environments. So this study aimed to present a guide for middle school teachers to teach lenses in geometric optics via active learning environment…

Additional transport channel of carbon ions for biological research at the Nuclotron of JINR

International Nuclear Information System (INIS)

Yudin, I.P.; Panasik, V.A.; Tyutyunnikov, S.I.

2011-01-01

The paper deals with the construction of the 12 C +6 beam transport line for biomedical research at the Nuclotron accelerator complex, JINR. We have studied the scheme and modes of magneto-optical elements of the channel. The results of calculations of the investigated beam transport of carbon ions are presented. The algorithms to control the carbon ion beam in the transportation system are discussed. The choice of the magneto-optical system is motivated. The graphs of the beam envelopes in the channel are given. The scanning control beam functions are considered

Additional transport channel of carbon ions for biological research at the Nuclotron of JINR

International Nuclear Information System (INIS)

Yudin, I.P.; Panasik, V.A.; Tyutyunnikov, S.I.

2012-01-01

The paper deals with the construction of the beam 12 C +6 transport line for biomedical research at the Nuclotron accelerator complex, JINR. We have studied the scheme and modes of magneto-optical elements of the channel. The results of calculations of the investigated beam transport of carbon ions are presented. The algorithms to control the carbon ion beam in the transportation system are discussed. The choice of the magneto-optical system is motivated. The graphs of the beam envelopes in the channel are given. The scanning control beam functions are considered

Geometric Representations of Condition Queries on Three-Dimensional Vector Fields

Science.gov (United States)

Henze, Chris

1999-01-01

Condition queries on distributed data ask where particular conditions are satisfied. It is possible to represent condition queries as geometric objects by plotting field data in various spaces derived from the data, and by selecting loci within these derived spaces which signify the desired conditions. Rather simple geometric partitions of derived spaces can represent complex condition queries because much complexity can be encapsulated in the derived space mapping itself A geometric view of condition queries provides a useful conceptual unification, allowing one to intuitively understand many existing vector field feature detection algorithms -- and to design new ones -- as variations on a common theme. A geometric representation of condition queries also provides a simple and coherent basis for computer implementation, reducing a wide variety of existing and potential vector field feature detection techniques to a few simple geometric operations.

Edit propagation using geometric relationship functions

KAUST Repository

Guerrero, Paul; Jeschke, Stefan; Wimmer, Michael; Wonka, Peter

2014-01-01

We propose a method for propagating edit operations in 2D vector graphics, based on geometric relationship functions. These functions quantify the geometric relationship of a point to a polygon, such as the distance to the boundary or the direction to the closest corner vertex. The level sets of the relationship functions describe points with the same relationship to a polygon. For a given query point, we first determine a set of relationships to local features, construct all level sets for these relationships, and accumulate them. The maxima of the resulting distribution are points with similar geometric relationships. We show extensions to handle mirror symmetries, and discuss the use of relationship functions as local coordinate systems. Our method can be applied, for example, to interactive floorplan editing, and it is especially useful for large layouts, where individual edits would be cumbersome. We demonstrate populating 2D layouts with tens to hundreds of objects by propagating relatively few edit operations. © 2014 ACM 0730-0301/2014/03- ART15 $15.00.

Edit propagation using geometric relationship functions

KAUST Repository

Guerrero, Paul

2014-04-15

We propose a method for propagating edit operations in 2D vector graphics, based on geometric relationship functions. These functions quantify the geometric relationship of a point to a polygon, such as the distance to the boundary or the direction to the closest corner vertex. The level sets of the relationship functions describe points with the same relationship to a polygon. For a given query point, we first determine a set of relationships to local features, construct all level sets for these relationships, and accumulate them. The maxima of the resulting distribution are points with similar geometric relationships. We show extensions to handle mirror symmetries, and discuss the use of relationship functions as local coordinate systems. Our method can be applied, for example, to interactive floorplan editing, and it is especially useful for large layouts, where individual edits would be cumbersome. We demonstrate populating 2D layouts with tens to hundreds of objects by propagating relatively few edit operations. © 2014 ACM 0730-0301/2014/03- ART15 $15.00.

A GEOMETRICAL HEIGHT SCALE FOR SUNSPOT PENUMBRAE

International Nuclear Information System (INIS)

Puschmann, K. G.; Ruiz Cobo, B.; MartInez Pillet, V.

2010-01-01

Inversions of spectropolarimetric observations of penumbral filaments deliver the stratification of different physical quantities in an optical depth scale. However, without establishing a geometrical height scale, their three-dimensional geometrical structure cannot be derived. This is crucial in understanding the correct spatial variation of physical properties in the penumbral atmosphere and to provide insights into the mechanism capable of explaining the observed penumbral brightness. The aim of this work is to determine a global geometrical height scale in the penumbra by minimizing the divergence of the magnetic field vector and the deviations from static equilibrium as imposed by a force balance equation that includes pressure gradients, gravity, and the Lorentz force. Optical depth models are derived from the inversion of spectropolarimetric data of an active region observed with the Solar Optical Telescope on board the Hinode satellite. We use a genetic algorithm to determine the boundary condition for the inference of geometrical heights. The retrieved geometrical height scale permits the evaluation of the Wilson depression at each pixel and the correlation of physical quantities at each height. Our results fit into the uncombed penumbral scenario, i.e., a penumbra composed of flux tubes with channeled mass flow and with a weaker and more horizontal magnetic field as compared with the background field. The ascending material is hotter and denser than their surroundings. We do not find evidence of overturning convection or field-free regions in the inner penumbral area analyzed. The penumbral brightness can be explained by the energy transfer of the ascending mass carried by the Evershed flow, if the physical quantities below z = -75 km are extrapolated from the results of the inversion.

Lectures in geometric combinatorics

CERN Document Server

Thomas, Rekha R

2006-01-01

This book presents a course in the geometry of convex polytopes in arbitrary dimension, suitable for an advanced undergraduate or beginning graduate student. The book starts with the basics of polytope theory. Schlegel and Gale diagrams are introduced as geometric tools to visualize polytopes in high dimension and to unearth bizarre phenomena in polytopes. The heart of the book is a treatment of the secondary polytope of a point configuration and its connections to the state polytope of the toric ideal defined by the configuration. These polytopes are relatively recent constructs with numerous connections to discrete geometry, classical algebraic geometry, symplectic geometry, and combinatorics. The connections rely on Gr�bner bases of toric ideals and other methods from commutative algebra. The book is self-contained and does not require any background beyond basic linear algebra. With numerous figures and exercises, it can be used as a textbook for courses on geometric, combinatorial, and computational as...

Geometric calibration between PET scanner and structured light scanner

DEFF Research Database (Denmark)

Kjer, Hans Martin; Olesen, Oline Vinter; Paulsen, Rasmus Reinhold

2011-01-01

Head movements degrade the image quality of high resolution Positron Emission Tomography (PET) brain studies through blurring and artifacts. Manny image reconstruction methods allows for motion correction if the head position is tracked continuously during the study. Our method for motion tracking...... is a structured light scanner placed just above the patient tunnel on the High Resolution Research Tomograph (HRRT, Siemens). It continuously registers point clouds of a part of the patient's face. The relative motion is estimated as the rigid transformation between frames. A geometric calibration between...

Effect of varying geometrical parameters of trapezoidal corrugated-core sandwich structure

Directory of Open Access Journals (Sweden)

Zaid N.Z.M.

2017-01-01

Full Text Available Sandwich structure is an attractive alternative that increasingly used in the transportation and aerospace industry. Corrugated-core with trapezoidal shape allows enhancing the damage resistance to the sandwich structure, but on the other hand, it changes the structural response of the sandwich structure. The aim of this paper is to study the effect of varying geometrical parameters of trapezoidal corrugated-core sandwich structure under compression loading. The corrugated-core specimen was fabricated using press technique, following the shape of trapezoidal shape. Two different materials were used in the study, glass fibre reinforced plastic (GFRP and carbon fibre reinforced plastic (CFRP. The result shows that the mechanical properties of the core in compression loading are sensitive to the variation of a number of unit cells and the core thickness.

Geometric universality of currents in an open network of interacting particles

International Nuclear Information System (INIS)

Sinitsyn, Nikolai A.; Chernyak, Vladimir Y.; Chertkov, Michael

2010-01-01

We discuss a non-equilibrium statistical system on a graph or network. Identical particles are injected, interact with each other, traverse, and leave the graph in a stochastic manner described in terms of Poisson rates, possibly dependent on time and instantaneous occupation numbers at the nodes of the graph. We show that under the assumption of the relative rates constancy, the system demonstrates a profound statistical symmetry, resulting in geometric universality of the particle currents statistics. The phenomenon applies broadly to many man-made and natural open stochastic systems, such as queuing of packages over internet, transport of electrons and quasi-particles in mesoscopic systems, and chains of reactions in bio-chemical networks. We illustrate the utility of the general approach using two enabling examples from the two latter disciplines.

Geometric nonlinear effects on the planar dynamics of a pivoted flexible beam encountering a point-surface impact

International Nuclear Information System (INIS)

Li Qing; Wang Tianshu; Ma Xingrui

2009-01-01

Flexible-body modeling with geometric nonlinearities remains a hot topic of research by applications in multibody system dynamics undergoing large overall motions. However, the geometric nonlinear effects on the impact dynamics of flexible multibody systems have attracted significantly less attention. In this paper, a point-surface impact problem between a rigid ball and a pivoted flexible beam is investigated. The Hertzian contact law is used to describe the impact process, and the dynamic equations are formulated in the floating frame of reference using the assumed mode method. The two important geometric nonlinear effects of the flexible beam are taken into account, i.e., the longitudinal foreshortening effect due to the transverse deformation, and the stress stiffness effect due to the axial force. The simulation results show that good consistency can be obtained with the nonlinear finite element program ABAQUS/Explicit if proper geometric nonlinearities are included in the floating frame formulation. Specifically, only the foreshortening effect should be considered in a pure transverse impact for efficiency, while the stress stiffness effect should be further considered in an oblique case with much more computational effort. It also implies that the geometric nonlinear effects should be considered properly in the impact dynamic analysis of more general flexible multibody systems

Geometrical methods for power network analysis

Energy Technology Data Exchange (ETDEWEB)

Bellucci, Stefano; Tiwari, Bhupendra Nath [Istituto Nazioneale di Fisica Nucleare, Frascati, Rome (Italy). Lab. Nazionali di Frascati; Gupta, Neeraj [Indian Institute of Technology, Kanpur (India). Dept. of Electrical Engineering

2013-02-01

Uses advanced geometrical methods to analyse power networks. Provides a self-contained and tutorial introduction. Includes a fully worked-out example for the IEEE 5 bus system. This book is a short introduction to power system planning and operation using advanced geometrical methods. The approach is based on well-known insights and techniques developed in theoretical physics in the context of Riemannian manifolds. The proof of principle and robustness of this approach is examined in the context of the IEEE 5 bus system. This work addresses applied mathematicians, theoretical physicists and power engineers interested in novel mathematical approaches to power network theory.

Geometric modular action and transformation groups

International Nuclear Information System (INIS)

Summers, S.J.

1996-01-01

We study a weak form of geometric modular action, which is naturally associated with transformation groups of partially ordered sets and which provides these groups with projective representations. Under suitable conditions it is shown that these groups are implemented by point transformations of topological spaces serving as models for space-times, leading to groups which may be interpreted as symmetry groups of the space-times. As concrete examples, it is shown that the Poincare group and the de Sitter group can be derived from this condition of geometric modular action. Further consequences and examples are discussed. (orig.)

Effect analysis of geometric parameters of floating raft on isolation performance

Directory of Open Access Journals (Sweden)

LI Shangda

2017-12-01

Full Text Available [Objectives] This paper focuses on the effects of the geometric parameters of a floating raft on isolation performance.[Methods] Based on the idea that the weight of a floating raft remains constant, a parametric finite element model is established using geometric parameters, and the effects of the geometric parameters when isolation performance is measured by vibration level difference are discussed.[Results] The effects of the geometric parameters of a floating raft on isolation performance are mainly reflected in the middle and high frequency areas. The most important geometric parameters which have an impact on isolation performance are the raft's height, length to width ratio and number of ribs. Adjusting the geometric parameters of the raft is one effective way to avoid the vibration frequency of mechanical equipment.[Conclusions] This paper has some practical value for the engineering design of floating raft isolation systems.

Multiscale geometric modeling of macromolecules I: Cartesian representation

Science.gov (United States)

Xia, Kelin; Feng, Xin; Chen, Zhan; Tong, Yiying; Wei, Guo-Wei

2014-01-01

This paper focuses on the geometric modeling and computational algorithm development of biomolecular structures from two data sources: Protein Data Bank (PDB) and Electron Microscopy Data Bank (EMDB) in the Eulerian (or Cartesian) representation. Molecular surface (MS) contains non-smooth geometric singularities, such as cusps, tips and self-intersecting facets, which often lead to computational instabilities in molecular simulations, and violate the physical principle of surface free energy minimization. Variational multiscale surface definitions are proposed based on geometric flows and solvation analysis of biomolecular systems. Our approach leads to geometric and potential driven Laplace-Beltrami flows for biomolecular surface evolution and formation. The resulting surfaces are free of geometric singularities and minimize the total free energy of the biomolecular system. High order partial differential equation (PDE)-based nonlinear filters are employed for EMDB data processing. We show the efficacy of this approach in feature-preserving noise reduction. After the construction of protein multiresolution surfaces, we explore the analysis and characterization of surface morphology by using a variety of curvature definitions. Apart from the classical Gaussian curvature and mean curvature, maximum curvature, minimum curvature, shape index, and curvedness are also applied to macromolecular surface analysis for the first time. Our curvature analysis is uniquely coupled to the analysis of electrostatic surface potential, which is a by-product of our variational multiscale solvation models. As an expository investigation, we particularly emphasize the numerical algorithms and computational protocols for practical applications of the above multiscale geometric models. Such information may otherwise be scattered over the vast literature on this topic. Based on the curvature and electrostatic analysis from our multiresolution surfaces, we introduce a new concept, the

Multiscale geometric modeling of macromolecules I: Cartesian representation

Energy Technology Data Exchange (ETDEWEB)

Xia, Kelin [Department of Mathematics, Michigan State University, MI 48824 (United States); Feng, Xin [Department of Computer Science and Engineering, Michigan State University, MI 48824 (United States); Chen, Zhan [Department of Mathematics, Michigan State University, MI 48824 (United States); Tong, Yiying [Department of Computer Science and Engineering, Michigan State University, MI 48824 (United States); Wei, Guo-Wei, E-mail: wei@math.msu.edu [Department of Mathematics, Michigan State University, MI 48824 (United States); Department of Biochemistry and Molecular Biology, Michigan State University, MI 48824 (United States)

2014-01-15

This paper focuses on the geometric modeling and computational algorithm development of biomolecular structures from two data sources: Protein Data Bank (PDB) and Electron Microscopy Data Bank (EMDB) in the Eulerian (or Cartesian) representation. Molecular surface (MS) contains non-smooth geometric singularities, such as cusps, tips and self-intersecting facets, which often lead to computational instabilities in molecular simulations, and violate the physical principle of surface free energy minimization. Variational multiscale surface definitions are proposed based on geometric flows and solvation analysis of biomolecular systems. Our approach leads to geometric and potential driven Laplace–Beltrami flows for biomolecular surface evolution and formation. The resulting surfaces are free of geometric singularities and minimize the total free energy of the biomolecular system. High order partial differential equation (PDE)-based nonlinear filters are employed for EMDB data processing. We show the efficacy of this approach in feature-preserving noise reduction. After the construction of protein multiresolution surfaces, we explore the analysis and characterization of surface morphology by using a variety of curvature definitions. Apart from the classical Gaussian curvature and mean curvature, maximum curvature, minimum curvature, shape index, and curvedness are also applied to macromolecular surface analysis for the first time. Our curvature analysis is uniquely coupled to the analysis of electrostatic surface potential, which is a by-product of our variational multiscale solvation models. As an expository investigation, we particularly emphasize the numerical algorithms and computational protocols for practical applications of the above multiscale geometric models. Such information may otherwise be scattered over the vast literature on this topic. Based on the curvature and electrostatic analysis from our multiresolution surfaces, we introduce a new concept, the

Geometric Aspects of Quantum Mechanics and Quantum Entanglement

International Nuclear Information System (INIS)

Chruscinski, Dariusz

2006-01-01

It is shown that the standard non-relativistic Quantum Mechanics gives rise to elegant and rich geometrical structures. The space of quantum states is endowed with nontrivial Fubini-Study metric which is responsible for the 'peculiarities' of the quantum world. We show that there is also intricate connection between geometrical structures and quantum entanglement

Geometric Analysis of Vein Fracture Networks From the Awibengkok Core, Indonesia

Science.gov (United States)

Khatwa, A.; Bruhn, R. L.; Brown, S. R.

2003-12-01

Fracture network systems within rocks are important features for the transportation and remediation of hazardous waste, oil and gas production, geothermal energy extraction and the formation of vein fillings and ore deposits. A variety of methods, including computational and laboratory modeling have been employed to further understand the dynamic nature of fractures and fracture systems (e.g. Ebel and Brown, this session). To substantiate these studies, it is also necessary to analyze the characteristics and morphology of naturally occurring vein systems. The Awibengkok core from a geothermal system in West Java, Indonesia provided an excellent opportunity to study geometric and petrologic characteristics of vein systems in volcanic rock. Vein minerals included chlorite, calcite, quartz, zeolites and sulphides. To obtain geometric data on the veins, we employed a neural net image processing technique to analyze high-resolution digital photography of the veins. We trained a neural net processor to map the extent of the vein using RGB pixel training classes. The resulting classification image was then converted to a binary image file and processed through a MatLab program that we designed to calculate vein geometric statistics, including aperture and roughness. We also performed detailed petrographic and microscopic geometric analysis on the veins to determine the history of mineralization and fracturing. We found that multi-phase mineralization due to chemical dissolution and re-precipitation as well as mechanical fracturing was a common feature in many of the veins and that it had a significant role for interpreting vein tortuosity and history of permeability. We used our micro- and macro-scale observations to construct four hypothetical permeability models that compliment the numerical and laboratory modeled data reported by Ebel and Brown. In each model, permeability changes, and in most cases fluctuates, differently over time as the tortuosity and aperture of

A report on the on-going researches on safe transport of radioactive materials as collected by the IAEA in 1980

International Nuclear Information System (INIS)

1981-01-01

Presented are brief reports made by Member States on research in progress in the area of safe transport of radioactive materials. Most of the research reported deals with some aspect of packaging or container design. The research contracts within the IAEA's coordinated research programme on safe transport are also outlined

Testing of a Transport Cask for Research Reactor Spent Fuel - 13003

International Nuclear Information System (INIS)

Mourao, Rogerio P.; Leite da Silva, Luiz; Miranda, Carlos A.; Mattar Neto, Miguel; Quintana, Jose F.A.; Saliba, Roberto O.; Novara, Oscar E.

2013-01-01

Since the beginning of the last decade three Latin American countries that operate research reactors - Argentina, Brazil and Chile - have been joining efforts to improve the regional capability in the management of spent fuel elements from the TRIGA and MTR reactors operated in the region. A main drive in this initiative, sponsored by the International Atomic Energy Agency, is the fact that no definite solution regarding the back end of the research reactor fuel cycle has been taken by any of the participating country. However, any long-term solution - either disposition in a repository or storage away from reactor - will involve at some stage the transportation of the spent fuel through public roads. Therefore, a licensed cask that provides adequate shielding, assurance of subcriticality, and conformance to internationally accepted safety, security and safeguards regimes is considered a strategic part of any future solution to be adopted at a regional level. As a step in this direction, a packaging for the transport of irradiated fuel for MTR and TRIGA research reactors was designed by the tri-national team and a half-scale model equipped with the MTR version of the internal basket was constructed in Argentina and Brazil and tested in Brazil. Three test campaigns have been carried out so far, covering both normal conditions of transportation and hypothetical accident conditions. After failing the tests in the first two test series, the specimen successfully underwent the last test sequence. A second specimen, incorporating the structural improvements in view of the previous tests results, will be tested in the near future. Numerical simulations of the free drop and thermal tests are being carried out in parallel, in order to validate the computational modeling that is going to be used as a support for the package certification. (authors)

Geometric mean for subspace selection.

Science.gov (United States)

Tao, Dacheng; Li, Xuelong; Wu, Xindong; Maybank, Stephen J

2009-02-01

Subspace selection approaches are powerful tools in pattern classification and data visualization. One of the most important subspace approaches is the linear dimensionality reduction step in the Fisher's linear discriminant analysis (FLDA), which has been successfully employed in many fields such as biometrics, bioinformatics, and multimedia information management. However, the linear dimensionality reduction step in FLDA has a critical drawback: for a classification task with c classes, if the dimension of the projected subspace is strictly lower than c - 1, the projection to a subspace tends to merge those classes, which are close together in the original feature space. If separate classes are sampled from Gaussian distributions, all with identical covariance matrices, then the linear dimensionality reduction step in FLDA maximizes the mean value of the Kullback-Leibler (KL) divergences between different classes. Based on this viewpoint, the geometric mean for subspace selection is studied in this paper. Three criteria are analyzed: 1) maximization of the geometric mean of the KL divergences, 2) maximization of the geometric mean of the normalized KL divergences, and 3) the combination of 1 and 2. Preliminary experimental results based on synthetic data, UCI Machine Learning Repository, and handwriting digits show that the third criterion is a potential discriminative subspace selection method, which significantly reduces the class separation problem in comparing with the linear dimensionality reduction step in FLDA and its several representative extensions.

Experimental realization of universal geometric quantum gates with solid-state spins.

Science.gov (United States)

Zu, C; Wang, W-B; He, L; Zhang, W-G; Dai, C-Y; Wang, F; Duan, L-M

2014-10-02

Experimental realization of a universal set of quantum logic gates is the central requirement for the implementation of a quantum computer. In an 'all-geometric' approach to quantum computation, the quantum gates are implemented using Berry phases and their non-Abelian extensions, holonomies, from geometric transformation of quantum states in the Hilbert space. Apart from its fundamental interest and rich mathematical structure, the geometric approach has some built-in noise-resilience features. On the experimental side, geometric phases and holonomies have been observed in thermal ensembles of liquid molecules using nuclear magnetic resonance; however, such systems are known to be non-scalable for the purposes of quantum computing. There are proposals to implement geometric quantum computation in scalable experimental platforms such as trapped ions, superconducting quantum bits and quantum dots, and a recent experiment has realized geometric single-bit gates in a superconducting system. Here we report the experimental realization of a universal set of geometric quantum gates using the solid-state spins of diamond nitrogen-vacancy centres. These diamond defects provide a scalable experimental platform with the potential for room-temperature quantum computing, which has attracted strong interest in recent years. Our experiment shows that all-geometric and potentially robust quantum computation can be realized with solid-state spin quantum bits, making use of recent advances in the coherent control of this system.

An information geometric approach to least squares minimization

Science.gov (United States)

Transtrum, Mark; Machta, Benjamin; Sethna, James

2009-03-01

Parameter estimation by nonlinear least squares minimization is a ubiquitous problem that has an elegant geometric interpretation: all possible parameter values induce a manifold embedded within the space of data. The minimization problem is then to find the point on the manifold closest to the origin. The standard algorithm for minimizing sums of squares, the Levenberg-Marquardt algorithm, also has geometric meaning. When the standard algorithm fails to efficiently find accurate fits to the data, geometric considerations suggest improvements. Problems involving large numbers of parameters, such as often arise in biological contexts, are notoriously difficult. We suggest an algorithm based on geodesic motion that may offer improvements over the standard algorithm for a certain class of problems.

Uhlmann's geometric phase in presence of isotropic decoherence

International Nuclear Information System (INIS)

Tidstroem, Jonas; Sjoeqvist, Erik

2003-01-01

Uhlmann's mixed state geometric phase [Rep. Math. Phys. 24, 229 (1986)] is analyzed in the case of a qubit affected by isotropic decoherence treated in the Markovian approximation. It is demonstrated that this phase decreases rapidly with increasing decoherence rate and that it is most fragile to weak decoherence for pure or nearly pure initial states. In the unitary case, we compare Uhlmann's geometric phase for mixed states with that occurring in standard Mach-Zehnder interferometry [Phys. Rev. Lett. 85, 2845 (2000)] and show that the latter is more robust to reduction in the length of the Bloch vector. We also describe how Uhlmann's geometric phase in the present case could in principle be realized experimentally

Comparison between stellarator and tokamak divertor transport

International Nuclear Information System (INIS)

Feng, Y.; Lunt, T.; Kobayashi, M.; Reiter, D.

2010-11-01

The paper compares the essential divertor transport features of the poloidal divertor, which is well-developed for tokamaks, and the non-axisymmetric divertors currently investigated on helical devices. It aims at surveying the fundamental similarities and differences in divertor concept and geometry, and their consequences for how the divertor functions. In particular, the importance of various transport terms governing axisymmetric and helical scrape-off-layers (SOLs) is examined, with special attention being paid to energy, momentum and impurity transport. Tokamak and stellarator SOLs are compared by identifying key geometric parameters through which the governing physics can be illustrated by simple models and estimates. More quantitative assessments rely nevertheless on the modeling using EMC3-EIRENE code. Most of the theoretical results are discussed in conjunction with experimental observations. (author)

Geometrical optics in general relativity

OpenAIRE

Loinger, A.

2006-01-01

General relativity includes geometrical optics. This basic fact has relevant consequences that concern the physical meaning of the discontinuity surfaces propagated in the gravitational field - as it was first emphasized by Levi-Civita.

A new approach to estimate the geometrical factors, solid angle approximation, geometrical efficiency and their use in basic interaction cross section measurements

CERN Document Server

Rao, D V; Brunetti, A; Gigante, G E; Takeda, T; Itai, Y; Akatsuka, T

2002-01-01

A new approach is developed to estimate the geometrical factors, solid angle approximation and geometrical efficiency for a system with experimental arrangements using X-ray tube and secondary target as an excitation source in order to produce the nearly monoenergetic K alpha radiation to excite the sample. The variation of the solid angle is studied by changing the radius and length of the collimators towards and away from the source and sample. From these values the variation of the total solid angle and geometrical efficiency is deduced and the optimum value is used for the experimental work. (authors)

A new approach to estimate the geometrical factors, solid angle approximation, geometrical efficiency and their use in basic interaction cross section measurements

Energy Technology Data Exchange (ETDEWEB)

Rao, D.V.; Cesareo, R.; Brunetti, A. [Sassari University, Istituto di Matematica e Fisica (Italy); Gigante, G.E. [Roma Universita, Dipt. di Fisica (Italy); Takeda, T.; Itai, Y. [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine; Akatsuka, T. [Yamagata Univ., Yonezawa (Japan). Faculty of Engineering

2002-10-01

A new approach is developed to estimate the geometrical factors, solid angle approximation and geometrical efficiency for a system with experimental arrangements using X-ray tube and secondary target as an excitation source in order to produce the nearly monoenergetic K{alpha} radiation to excite the sample. The variation of the solid angle is studied by changing the radius and length of the collimators towards and away from the source and sample. From these values the variation of the total solid angle and geometrical efficiency is deduced and the optimum value is used for the experimental work. (authors)

A new approach to estimate the geometrical factors, solid angle approximation, geometrical efficiency and their use in basic interaction cross section measurements

Science.gov (United States)

Rao, D. V.; Cesareo, R.; Brunetti, A.; Gigante, G. E.; Takeda, T.; Itai, Y.; Akatsuka, T.

2002-10-01

A new approach is developed to estimate the geometrical factors, solid angle approximation and geometrical efficiency for a system with experimental arrangements using X-ray tube and secondary target as an excitation source in order to produce the nearly monoenergetic Kα radiation to excite the sample. The variation of the solid angle is studied by changing the radius and length of the collimators towards and away from the source and sample. From these values the variation of the total solid angle and geometrical efficiency is deduced and the optimum value is used for the experimental work.

The use of modern information technology in research on transport accessibility

Directory of Open Access Journals (Sweden)

Bartosz BARTOSIEWICZ

2015-09-01

Full Text Available Transport accessibility can be analyzed using a number of different methods. The problem with each of them is the difficulty of obtaining data to measure this phenomenon The focus of this article and its main goal are to present methods and tools for gathering data on road traffic; thanks to modern information technology, it is possible to collect real data without the need for large-scale and highly capital-intensive measurements. The application of modern information technology (IT presented in the article, such as computer programs and applications like Google Maps Traffic Overlay and TomTom Live Traffic, enable research to be conducted on a scale that has thus far been unattainable, and allows information to be collected on such criteria as traffic volume, flow, average traffic speed, and actual journey time. Such innovative means of gathering data on automobile traffic open up new perspectives for assessing transport accessibility in terms of automobile traffic by providing high-quality data that meet the requirements for use in primary research.

TRIDENT-CTR: a two-dimensional transport code for CTR applications

International Nuclear Information System (INIS)

Seed, T.J.

1978-01-01

TRIDENT-CTR is a two-dimensional x-y and r-z geometry multigroup neutral transport code developed at Los Alamos for toroidal calculations. The use of triangular finite elements gives it the geometric flexibility to cope with the nonorthogonal shapes of many toroidal designs of current interest in the CTR community

Extraction of Coal and Gangue Geometric Features with Multifractal Detrending Fluctuation Analysis

Directory of Open Access Journals (Sweden)

Kai Liu

2018-03-01

Full Text Available The separation of coal and gangue is an important process of the coal preparation technology. The conventional way of manual selection and separation of gangue from the raw coal can be replaced by computer vision technology. In the literature, research on image recognition and classification of coal and gangue is mainly based on the grayscale and texture features of the coal and gangue. However, there are few studies on characteristics of coal and gangue from the perspective of their outline differences. Therefore, the multifractal detrended fluctuation analysis (MFDFA method is introduced in this paper to extract the geometric features of coal and gangue. Firstly, the outline curves of coal and gangue in polar coordinates are detected and achieved along the centroid, thereby the multifractal characteristics of the series are analyzed and compared. Subsequently, the modified local singular spectrum widths Δ h of the outline curve series are extracted as the characteristic variables of the coal and gangue for pattern recognition. Finally, the extracted geometric features by MFDFA combined with the grayscale and texture features of the images are compared with other methods, indicating that the recognition rate of coal gangue images can be increased by introducing the geometric features.

A new Weyl-like tensor of geometric origin

Science.gov (United States)

Vishwakarma, Ram Gopal

2018-04-01

A set of new tensors of purely geometric origin have been investigated, which form a hierarchy. A tensor of a lower rank plays the role of the potential for the tensor of one rank higher. The tensors have interesting mathematical and physical properties. The highest rank tensor of the hierarchy possesses all the geometrical properties of the Weyl tensor.

Study on Multi-Depot Collaborative Transportation Problem of Milk-Run Pattern

Directory of Open Access Journals (Sweden)

Lou Zhenkai

2016-01-01

Full Text Available Analyze the relevance between Milk Run mode and collaborative transportation problem, put forward collaborative transportation problem of multiple-depot on Milk Run mode under the supply and demand separate nodes, consider the value of transport and transport costs, introduce the concept of node - arc flow, by comparing the size of traffic flow determine nodes collection, and then constructed multi-transport model of the problem. Considering one-way pickup and delivery closed, construct two-stage algorithm model, use dynamic programming recursive solution to determine the best route to pick up, and then solving delivery routing problem with different start and return point based on geometric method of Cosine. Finally use a numerical example illustrates the effectiveness of the algorithm and reasonable model.

TRANSPORTATION RESEARCH CONTRIBUTIONS TO SOCIETY BY UNIVERSITY TRANSPORTATION CENTERS

Directory of Open Access Journals (Sweden)

Robert C. JOHNS

2003-01-01

Full Text Available This paper discusses the importance of knowledge in the global economy and reviews the process in which knowledge is applied to develop innovations. It confirms the importance of innovation as a key factor for success in today's competitive environment. The paper discusses the contributions a university can make to the innovation process in the field of transportation, and offers a vision of how a university center can enhance and facilitate these contributions. It then describes the efforts of one center, including three examples of innovations facilitated by the center in traffic detection, regional planning, and pavement management. The paper concludes with suggestions that would strengthen the societal contributions of university transportation centers.

MM Algorithms for Geometric and Signomial Programming.

Science.gov (United States)

Lange, Kenneth; Zhou, Hua

2014-02-01

This paper derives new algorithms for signomial programming, a generalization of geometric programming. The algorithms are based on a generic principle for optimization called the MM algorithm. In this setting, one can apply the geometric-arithmetic mean inequality and a supporting hyperplane inequality to create a surrogate function with parameters separated. Thus, unconstrained signomial programming reduces to a sequence of one-dimensional minimization problems. Simple examples demonstrate that the MM algorithm derived can converge to a boundary point or to one point of a continuum of minimum points. Conditions under which the minimum point is unique or occurs in the interior of parameter space are proved for geometric programming. Convergence to an interior point occurs at a linear rate. Finally, the MM framework easily accommodates equality and inequality constraints of signomial type. For the most important special case, constrained quadratic programming, the MM algorithm involves very simple updates.

Demystifying the memory effect: A geometrical approach to understanding speckle correlations

Science.gov (United States)

Prunty, Aaron C.; Snieder, Roel K.

2017-05-01

The memory effect has seen a surge of research into its fundamental properties and applications since its discovery by Feng et al. [Phys. Rev. Lett. 61, 834 (1988)]. While the wave trajectories for which the memory effect holds are hidden implicitly in the diffusion probability function [Phys. Rev. B 40, 737 (1989)], the physical intuition of why these trajectories satisfy the memory effect has often been masked by the derivation of the memory correlation function itself. In this paper, we explicitly derive the specific trajectories through a random medium for which the memory effect holds. Our approach shows that the memory effect follows from a simple conservation argument, which imposes geometrical constraints on the random trajectories that contribute to the memory effect. We illustrate the time-domain effects of these geometrical constraints with numerical simulations of pulse transmission through a random medium. The results of our derivation and numerical simulations are consistent with established theory and experimentation.

Lie group model neuromorphic geometric engine for real-time terrain reconstruction from stereoscopic aerial photos

Science.gov (United States)

Tsao, Thomas R.; Tsao, Doris

1997-04-01

In the 1980's, neurobiologist suggested a simple mechanism in primate visual cortex for maintaining a stable and invariant representation of a moving object. The receptive field of visual neurons has real-time transforms in response to motion, to maintain a stable representation. When the visual stimulus is changed due to motion, the geometric transform of the stimulus triggers a dual transform of the receptive field. This dual transform in the receptive fields compensates geometric variation in the stimulus. This process can be modelled using a Lie group method. The massive array of affine parameter sensing circuits will function as a smart sensor tightly coupled to the passive imaging sensor (retina). Neural geometric engine is a neuromorphic computing device simulating our Lie group model of spatial perception of primate's primal visual cortex. We have developed the computer simulation and experimented on realistic and synthetic image data, and performed a preliminary research of using analog VLSI technology for implementation of the neural geometric engine. We have benchmark tested on DMA's terrain data with their result and have built an analog integrated circuit to verify the computational structure of the engine. When fully implemented on ANALOG VLSI chip, we will be able to accurately reconstruct a 3D terrain surface in real-time from stereoscopic imagery.

Separation of plastic waste via the hydraulic separator Multidune under different geometric configurations.

Science.gov (United States)

La Marca, Floriana; Moroni, Monica; Cherubini, Lorenzo; Lupo, Emanuela; Cenedese, Antonio

2012-07-01

The recovery of high-quality plastic materials is becoming an increasingly challenging issue for the recycling sector. Technologies for plastic recycling have to guarantee high-quality secondary raw material, complying with specific standards, for use in industrial applications. The variability in waste plastics does not always correspond to evident differences in physical characteristics, making traditional methodologies ineffective for plastic separation. The Multidune separator is a hydraulic channel allowing the sorting of solid particles on the basis of differential transport mechanisms by generating particular fluid dynamic conditions due to its geometric configuration and operational settings. In this paper, the fluid dynamic conditions were investigated by an image analysis technique, allowing the reconstruction of velocity fields generated inside the Multidune, considering two different geometric configurations of the device, Configuration A and Configuration B. Furthermore, tests on mono- and bi-material samples were completed with varying operational conditions under both configurations. In both series of experiments, the bi-material samples were composed of differing proportions (85% vs. 15%) to simulate real conditions in an industrial plant for the purifying of a useful fraction from a contaminating fraction. The separation results were evaluated in terms of grade and recovery of the useful fraction. Copyright © 2012 Elsevier Ltd. All rights reserved.

Geometric Rationalization for Freeform Architecture

KAUST Repository

Jiang, Caigui

2016-01-01

The emergence of freeform architecture provides interesting geometric challenges with regards to the design and manufacturing of large-scale structures. To design these architectural structures, we have to consider two types of constraints. First

Geometrical approach to tumor growth.

Science.gov (United States)

Escudero, Carlos

2006-08-01

Tumor growth has a number of features in common with a physical process known as molecular beam epitaxy. Both growth processes are characterized by the constraint of growth development to the body border, and surface diffusion of cells and particles at the growing edge. However, tumor growth implies an approximate spherical symmetry that makes necessary a geometrical treatment of the growth equations. The basic model was introduced in a former paper [C. Escudero, Phys. Rev. E 73, 020902(R) (2006)], and in the present work we extend our analysis and try to shed light on the possible geometrical principles that drive tumor growth. We present two-dimensional models that reproduce the experimental observations, and analyze the unexplored three-dimensional case, for which interesting conclusions on tumor growth are derived.

Development of instrumentation in the transport phenomena research in thermal equipment

International Nuclear Information System (INIS)

Carvalho Tofani, P. de; Ladeira, L.C.D.

1983-11-01

The results obtained from the effort on the acquisition of know-how in experimental reactor thermal during the last years, through the approach of relevant aspects of basic research on transport phenomena applicable to nuclear reactor analysis and conventional thermal equipment based in the simultaneous development of instrumentation and experimental methods are presented. (E.G.) [pt

Flow modelling and radionuclide transport research and development in saturated and unsaturated soils

International Nuclear Information System (INIS)

Carvalho Filho, Carlos Alberto de; Branco, Otavio Eurico de Aquino; Loureiro, Celso de Oliveira

1996-01-01

The Engenho Nogueira Hydrogeological Project, PROHBEN, was idealized with the goal of implementing an Experimental Hydrogeological basin within its limits, in order to permit the development of hydrogeological studies and techniques, mainly in the modeling of flow and transport of contaminants (radionuclides) in the saturated and unsaturated porous media. The PROHBEN is located in Belo Horizonte, Minas Gerais, amounting a 5 km 2 area. The local porous-granular, heterogeneous and anisotropic, water-table aquifer reaches 40 meters of thickness, and is compound mainly by alluvial deposits and alteration rocks products, with a sandy texture. The flow and transport modeling are being done using the Modflow and MT3D codes. Three master degree researches are being done in the PROHBEN area and one expects is that more researchers come to use this experimental site. (author)

Geometric transitions on non-Kaehler manifolds

International Nuclear Information System (INIS)

Knauf, A.

2007-01-01

We study geometric transitions on the supergravity level using the basic idea of an earlier paper (M. Becker et al., 2004), where a pair of non-Kaehler backgrounds was constructed, which are related by a geometric transition. Here we embed this idea into an orientifold setup. The non-Kaehler backgrounds we obtain in type IIA are non-trivially fibered due to their construction from IIB via T-duality with Neveu-Schwarz flux. We demonstrate that these non-Kaehler manifolds are not half-flat and show that a symplectic structure exists on them at least locally. We also review the construction of new non-Kaehler backgrounds in type I and heterotic theory. They are found by a series of T- and S-duality and can be argued to be related by geometric transitions as well. A local toy model is provided that fulfills the flux equations of motion in IIB and the torsional relation in heterotic theory, and that is consistent with the U-duality relating both theories. For the heterotic theory we also propose a global solution that fulfills the torsional relation because it is similar to the Maldacena-Nunez background. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Mechanical transport in two-dimensional networks of fractures

International Nuclear Information System (INIS)

Endo, H.K.

1984-04-01

The objectives of this research are to evaluate directional mechanical transport parameters for anisotropic fracture systems, and to determine if fracture systems behave like equivalent porous media. The tracer experiments used to measure directional tortuosity, longitudinal geometric dispersivity, and hydraulic effective porosity are conducted with a uniform flow field and measurements are made from the fluid flowing within a test section where linear length of travel is constant. Since fluid flow and mechanical transport are coupled processes, the directional variations of specific discharge and hydraulic effective porosity are measured in regions with constant hydraulic gradients to evaluate porous medium equivalence for the two processes, respectively. If the fracture region behaves like an equivalent porous medium, the system has the following stable properties: (1) specific discharge is uniform in any direction and can be predicted from a permeability tensor; and (2) hydraulic effective porosity is directionally stable. Fracture systems with two parallel sets of continuous fractures satisfy criterion 1. However, in these systems hydraulic effective porosity is directionally dependent, and thus, criterion 2 is violated. Thus, for some fracture systems, fluid flow can be predicted using porous media assumptions, but it may not be possible to predict transport using porous media assumptions. Two discontinuous fracture systems were studied which satisfied both criteria. Hydraulic effective porosity for both systems has a value between rock effective porosity and total porosity. A length-density analysis (LDS) of Canadian fracture data shows that porous media equivalence for fluid flow and transport is likely when systems have narrow aperture distributions. 54 references, 90 figures, 7 tables

The geometric phase in quantum physics

International Nuclear Information System (INIS)

Bohm, A.

1993-03-01

After an explanatory introduction, a quantum system in a classical time-dependent environment is discussed; an example is a magnetic moment in a classical magnetic field. At first, the general abelian case is discussed in the adiabatic approximation. Then the geometric phase for nonadiabatic change of the environment (Anandan--Aharonov phase) is introduced, and after that general cyclic (nonadiabatic) evolution is discussed. The mathematics of fiber bundles is introduced, and some of its results are used to describe the relation between the adiabatic Berry phase and the geometric phase for general cyclic evolution of a pure state. The discussion is restricted to the abelian, U(1) phase

Field Usage of Alternative Deicers for Snow and Ice Control : Transportation Research Synthesis.

Science.gov (United States)

2017-09-01

This Transportation Research Synthesis (TRS) summarizes non-chloride based deicers available on the market at this time, including acetate, formate, glycol, and succinate based deicing products. This report explores their feasibility for use as alter...

Spherical projections and liftings in geometric tomography

DEFF Research Database (Denmark)

Goodey, Paul; Kiderlen, Markus; Weil, Wolfgang

2011-01-01

We consider a variety of integral transforms arising in Geometric Tomography. It will be shown that these can be put into a common framework using spherical projection and lifting operators. These operators will be applied to support functions and surface area measures of convex bodies and to rad......We consider a variety of integral transforms arising in Geometric Tomography. It will be shown that these can be put into a common framework using spherical projection and lifting operators. These operators will be applied to support functions and surface area measures of convex bodies...... and to radial functions of star bodies. We then investigate averages of lifted projections and show that they correspond to self-adjoint intertwining operators. We obtain formulas for the eigenvalues of these operators and use them to ascertain circumstances under which tomographic measurements determine...... the original bodies. This approach via mean lifted projections leads us to some unexpected relationships between seemingly disparate geometric constructions....

Competences Evaluation of Transport Management Specialists in Baltic States: Research of Students’ Opinion

Directory of Open Access Journals (Sweden)

Kristina Ledauskaitė

2011-03-01

Full Text Available To develop knowledge, advanced technology and skilled labor-based economy in Lithuania, it is necessary to make an effective business interaction and practical training, and preparation of specialists to ensure the ability to compete in European labor markets, and general capacity building. Common started training for professionals is to consider raising questions as to develop people in constantly changing global context. Several years of the research done in Lithuania, Latvia and Estonia transport sectors, has allowed the evaluating of the general competencies of these area specialists, and showed that specialists working in transport/logistics area are faced with lack of practical skills. The eliminating of these lacks requires close cooperation between the educational institutions and transport and/or logistics sector cooperation.Article in Lithuanian

A Geometric Dissection Problem

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 7. A Geometric Dissection Problem. M N Deshpande. Think It Over Volume 7 Issue 7 July 2002 pp 91-91. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/007/07/0091-0091. Author Affiliations.

FAA/NASA Joint University Program for Air Transportation Research: 1993-1994

Science.gov (United States)

Hueschen, Richard M. (Compiler)

1995-01-01

This report summarizes the research conducted during the academic year 1993-1994 under the NASA/FAA sponsored Joint University Program for Air Transportation Research. The year end review was held at Ohio University, Athens, Ohio, July 14-15, 1994. The Joint University Program is a coordinated set of three grants sponsored by NASA Langley Research Center and the Federal Aviation Administration, one each with the Massachusetts Institute of Technology (NGL-22-009-640), Ohio University (NGR-36-009-017), and Princeton University (NGL-31-001-252). Completed works, status reports, and annotated bibliographies are presented for research topics which include navigation, guidance and control theory and practice, aircraft performance, human factors, and expert systems concepts applied to aircraft and airport operations. An overview of the year's activities for each university is also presented.

Geometric phases in astigmatic optical modes of arbitrary order

International Nuclear Information System (INIS)

Habraken, Steven J. M.; Nienhuis, Gerard

2010-01-01

The transverse spatial structure of a paraxial beam of light is fully characterized by a set of parameters that vary only slowly under free propagation. They specify bosonic ladder operators that connect modes of different orders, in analogy to the ladder operators connecting harmonic-oscillator wave functions. The parameter spaces underlying sets of higher-order modes are isomorphic to the parameter space of the ladder operators. We study the geometry of this space and the geometric phase that arises from it. This phase constitutes the ultimate generalization of the Gouy phase in paraxial wave optics. It reduces to the ordinary Gouy phase and the geometric phase of nonastigmatic optical modes with orbital angular momentum in limiting cases. We briefly discuss the well-known analogy between geometric phases and the Aharonov-Bohm effect, which provides some complementary insights into the geometric nature and origin of the generalized Gouy phase shift. Our method also applies to the quantum-mechanical description of wave packets. It allows for obtaining complete sets of normalized solutions of the Schroedinger equation. Cyclic transformations of such wave packets give rise to a phase shift, which has a geometric interpretation in terms of the other degrees of freedom involved.

Workshop to review problem-behavior research programs : pedestrian, bicycle, and pupil transportation safety

Science.gov (United States)

1981-09-01

This report presents the proceedings of a workshop on pedestrian, bicycle, and pupil transportation safety. The purpose of this workshop was to develop specific recommendations for the planning and implementation of NHTSA research, development, and d...

Light ion beam transport research at NRL

International Nuclear Information System (INIS)

Hinshelwood, D.D.; Boller, J.R.; Cooperstein, G.

1996-01-01

Transport of light ion beams through low-pressure background gas is under investigation at NRL in support of the light-ion ICF program at Sandia National Laboratories. Scaling experiments and the field solver/orbit code ATHETA have been used to design and construct a focusing, extraction applied-B diode for transport experiments. An active anode source has been developed to provide a high proton fraction in the ion beam and a fast ion turn-on time. A very sensitive Zeeman diagnostic is being developed to determine the net current distribution in the beam/transport system. Both analytical and numerical techniques using several codes are being applied to transport modeling, leading to the capability of full system studies. (author). 1 tab., 5 figs., 10 refs

Light ion beam transport research at NRL

Energy Technology Data Exchange (ETDEWEB)

Hinshelwood, D D; Boller, J R; Cooperstein, G [Naval Research Lab., Washington, DC (United States). Plasma Physics Div.; and others

1997-12-31

Transport of light ion beams through low-pressure background gas is under investigation at NRL in support of the light-ion ICF program at Sandia National Laboratories. Scaling experiments and the field solver/orbit code ATHETA have been used to design and construct a focusing, extraction applied-B diode for transport experiments. An active anode source has been developed to provide a high proton fraction in the ion beam and a fast ion turn-on time. A very sensitive Zeeman diagnostic is being developed to determine the net current distribution in the beam/transport system. Both analytical and numerical techniques using several codes are being applied to transport modeling, leading to the capability of full system studies. (author). 1 tab., 5 figs., 10 refs.

Geometric Mechanics Reveals Optimal Complex Terrestrial Undulation Patterns

Science.gov (United States)

Gong, Chaohui; Astley, Henry; Schiebel, Perrin; Dai, Jin; Travers, Matthew; Goldman, Daniel; Choset, Howie; CMU Team; GT Team

Geometric mechanics offers useful tools for intuitively analyzing biological and robotic locomotion. However, utility of these tools were previously restricted to systems that have only two internal degrees of freedom and in uniform media. We show kinematics of complex locomotors that make intermittent contacts with substrates can be approximated as a linear combination of two shape bases, and can be represented using two variables. Therefore, the tools of geometric mechanics can be used to analyze motions of locomotors with many degrees of freedom. To demonstrate the proposed technique, we present studies on two different types of snake gaits which utilize combinations of waves in the horizontal and vertical planes: sidewinding (in the sidewinder rattlesnake C. cerastes) and lateral undulation (in the desert specialist snake C. occipitalis). C. cerastes moves by generating posteriorly traveling body waves in the horizontal and vertical directions, with a relative phase offset equal to +/-π/2 while C. occipitalismaintains a π/2 offset of a frequency doubled vertical wave. Geometric analysis reveals these coordination patterns enable optimal movement in the two different styles of undulatory terrestrial locomotion. More broadly, these examples demonstrate the utility of geometric mechanics in analyzing realistic biological and robotic locomotion.

Guide to federal intelligent transportation system (ITS) research.

Science.gov (United States)

2013-01-01

The U.S. Department of Transportations (USDOT) Intelligent Transportation System (ITS) Program aims to bring connectivity to transportation through the use of advanced wireless technologies powerful technologies that enable transformative chan...

A case for inherent geometric and geodetic accuracy in remotely sensed VNIR and SWIR imaging products

Science.gov (United States)

Driver, J. M.

1982-01-01

Significant aberrations can occur in acquired images which, unless compensated on board the spacecraft, can seriously impair throughput and timeliness for typical Earth observation missions. Conceptual compensations options are advanced to enable acquisition of images with inherent geometric and geodetic accuracy. Research needs are identified which, when implemented, can provide inherently accurate images. Agressive pursuit of these research needs is recommended.

A 3D transport-based core analysis code for research reactors with unstructured geometry

International Nuclear Information System (INIS)

Zhang, Tengfei; Wu, Hongchun; Zheng, Youqi; Cao, Liangzhi; Li, Yunzhao

2013-01-01

Highlights: • A core analysis code package based on 3D neutron transport calculation in complex geometry is developed. • The fine considerations on flux mapping, control rod effects and isotope depletion are modeled. • The code is proved to be with high accuracy and capable of handling flexible operational cases for research reactors. - Abstract: As an effort to enhance the accuracy in simulating the operations of research reactors, a 3D transport core analysis code system named REFT was developed. HELIOS is employed due to the flexibility of describing complex geometry. A 3D triangular nodal S N method transport solver, DNTR, endows the package the capability of modeling cores with unstructured geometry assemblies. A series of dedicated methods were introduced to meet the requirements of research reactor simulations. Afterwards, to make it more user friendly, a graphical user interface was also developed for REFT. In order to validate the developed code system, the calculated results were compared with the experimental results. Both the numerical and experimental results are in close agreement with each other, with the relative errors of k eff being less than 0.5%. Results for depletion calculations were also verified by comparing them with the experimental data and acceptable consistency was observed in results

The Effect of Origami-Based Instruction on Spatial Visualization, Geometry Achievement, and Geometric Reasoning

Science.gov (United States)

Arici, Sevil; Aslan-Tutak, Fatma

2015-01-01

This research study examined the effect of origami-based geometry instruction on spatial visualization, geometry achievement, and geometric reasoning of tenth-grade students in Turkey. The sample ("n" = 184) was chosen from a tenth-grade population of a public high school in Turkey. It was a quasi-experimental pretest/posttest design. A…

Ion Transport in Organic Electrolyte Solution through the Pore Channels of Anodic Nanoporous Alumina Membranes

International Nuclear Information System (INIS)

Fukutsuka, Tomokazu; Koyamada, Kohei; Maruyama, Shohei; Miyazaki, Kohei; Abe, Takeshi

2016-01-01

Highlights: • Ion transport in organic electrolyte solution in macro- and meso-pores was focused. • Anodic nanoporous alumina membrane was used as a porous material. • The specific ion conductivities drastically decreased in macro- and meso-pores. - Abstract: For the development of high energy density lithium-ion batteries with the high rate performance, the enhancement of the ion transport in the electrolyte solutions impregnated in the porous electrodes is a key. To study the ion transport in porous electrodes, anodic nanoporous alumina (APA) self-standing membranes with macro- or meso-pores were used as model porous materials. These membranes had nearly spherical pore channels of discrete 20–68 nm in diameters. By using the geometric shape of the pores, we attempted to evaluate the specific ion conductivities of the organic electrolyte solution dissolving lithium salt simply. AC impedance spectroscopy measurement of a four-electrode cell with membranes showed one depressed semi-circle in the Nyquist plots and this semi-circle can be assigned as the ion transport resistance in the pores. The specific ion conductivities evaluated from the ion transport resistances and the geometric parameters showed very small values, even in the macro-pores, as compared with that of the bulk electrolyte solution.

A computational study of the effect of capillary network anastomoses and tortuosity on oxygen transport.

Science.gov (United States)

Goldman, D; Popel, A S

2000-09-21

The objective of this study was to investigate the effects of capillary network anastomoses and tortuosity on oxygen transport in skeletal muscle, as well as the importance of muscle fibers in determining the arrangement of parallel capillaries. Countercurrent flow and random capillary blockage (e.g. by white blood cells) were also studied. A general computational model was constructed to simulate oxygen transport from a network of blood vessels within a rectangular volume of tissue. A geometric model of the capillary network structure, based on hexagonally packed muscle fibers, was constructed to produce networks of straight unbranched capillaries, capillaries with anastomoses, and capillaries with tortuosity, in order to examine the effects of these geometric properties. Quantities examined included the tissue oxygen tension and the capillary oxyhemoglobin saturation. The computational model included a two-phase simulation of blood flow. Appropriate parameters were chosen for working hamster cheek-pouch retractor muscle. Our calculations showed that the muscle-fiber geometry was important in reducing oxygen transport heterogeneity, as was countercurrent flow. Tortuosity was found to increase tissue oxygenation, especially when combined with anastomoses. In the absence of tortuosity, anastomoses had little effect on oxygen transport under normal conditions, but significantly improved transport when vessel blockages were present. Copyright 2000 Academic Press.

On chromatic and geometrical calibration

DEFF Research Database (Denmark)

Folm-Hansen, Jørgen

1999-01-01

The main subject of the present thesis is different methods for the geometrical and chromatic calibration of cameras in various environments. For the monochromatic issues of the calibration we present the acquisition of monochrome images, the classic monochrome aberrations and the various sources...... the correct interpolation method is described. For the chromatic issues of calibration we present the acquisition of colour and multi-spectral images, the chromatic aberrations and the various lens/camera based non-uniformities of the illumination of the image plane. It is described how the monochromatic...... to design calibration targets for both geometrical and chromatic calibration are described. We present some possible systematical errors on the detection of the objects in the calibration targets, if viewed in a non orthogonal angle, if the intensities are uneven or if the image blurring is uneven. Finally...

Calculation of the geometrical intensity on an image surface

International Nuclear Information System (INIS)

Seppala, L.G.

1975-01-01

Laser fusion experiments involve the focusing of high power laser beams onto fuel pellets. The geometrical intensity is of interest in the cases where the laser is focused to the center of the pellet. Analytic expressions and ray trace methods for evaluating the geometrical intensity are presented

Transport and spin effects in homogeneous magnetic superlattice

International Nuclear Information System (INIS)

Cardoso, J.L.; Pereyra, P.; Anzaldo-Meneses, A.

2000-09-01

Homogeneous semiconductors under spacially periodic external magnetic fields exhibit spin-band splitting and displacements, more clearly defined than in diluted magnetic semiconductor superlattices. We study the influence of the geometrical parameters and the spin-field interaction on the electronic transport properties. We show that by varying the external magnetic field, one can easily block the transmission of either the spin-up or the spin-down electrons. (author)

A geometric renormalization group in discrete quantum space-time

International Nuclear Information System (INIS)

Requardt, Manfred

2003-01-01

We model quantum space-time on the Planck scale as dynamical networks of elementary relations or time dependent random graphs, the time dependence being an effect of the underlying dynamical network laws. We formulate a kind of geometric renormalization group on these (random) networks leading to a hierarchy of increasingly coarse-grained networks of overlapping lumps. We provide arguments that this process may generate a fixed limit phase, representing our continuous space-time on a mesoscopic or macroscopic scale, provided that the underlying discrete geometry is critical in a specific sense (geometric long range order). Our point of view is corroborated by a series of analytic and numerical results, which allow us to keep track of the geometric changes, taking place on the various scales of the resolution of space-time. Of particular conceptual importance are the notions of dimension of such random systems on the various scales and the notion of geometric criticality

Inverse Kinematics for Industrial Robots using Conformal Geometric Algebra

Directory of Open Access Journals (Sweden)

Adam L. Kleppe

2016-01-01

Full Text Available This paper shows how the recently developed formulation of conformal geometric algebra can be used for analytic inverse kinematics of two six-link industrial manipulators with revolute joints. The paper demonstrates that the solution of the inverse kinematics in this framework relies on the intersection of geometric objects like lines, circles, planes and spheres, which provides the developer with valuable geometric intuition about the problem. It is believed that this will be very useful for new robot geometries and other mechanisms like cranes and topside drilling equipment. The paper extends previous results on inverse kinematics using conformal geometric algebra by providing consistent solutions for the joint angles for the different configurations depending on shoulder left or right, elbow up or down, and wrist flipped or not. Moreover, it is shown how to relate the solution to the Denavit-Hartenberg parameters of the robot. The solutions have been successfully implemented and tested extensively over the whole workspace of the manipulators.

Monomial geometric programming with an arbitrary fuzzy relational inequality

Directory of Open Access Journals (Sweden)

E. Shivanian

2015-11-01

Full Text Available In this paper, an optimization model with geometric objective function is presented. Geometric programming is widely used; many objective functions in optimization problems can be analyzed by geometric programming. We often encounter these in resource allocation and structure optimization and technology management, etc. On the other hand, fuzzy relation equalities and inequalities are also used in many areas. We here present a geometric programming model with a monomial objective function subject to the fuzzy relation inequality constraints with an arbitrary function. The feasible solution set is determined and compared with some common results in the literature. A necessary and sufficient condition and three other necessary conditions are presented to conceptualize the feasibility of the problem. In general a lower bound is always attainable for the optimal objective value by removing the components having no effect on the solution process. By separating problem to non-decreasing and non-increasing function to prove the optimal solution, we simplify operations to accelerate the resolution of the problem.

An integrated introduction to computer graphics and geometric modeling

CERN Document Server

Goldman, Ronald

2009-01-01

… this book may be the first book on geometric modelling that also covers computer graphics. In addition, it may be the first book on computer graphics that integrates a thorough introduction to 'freedom' curves and surfaces and to the mathematical foundations for computer graphics. … the book is well suited for an undergraduate course. … The entire book is very well presented and obviously written by a distinguished and creative researcher and educator. It certainly is a textbook I would recommend. …-Computer-Aided Design, 42, 2010… Many books concentrate on computer programming and soon beco

The Effects of Computer-assisted and Distance Learning of Geometric Modeling

Directory of Open Access Journals (Sweden)

Omer Faruk Sozcu

2013-01-01

Full Text Available The effects of computer-assisted and distance learning of geometric modeling and computer aided geometric design are studied. It was shown that computer algebra systems and dynamic geometric environments can be considered as excellent tools for teaching mathematical concepts of mentioned areas, and distance education technologies would be indispensable for consolidation of successfully passed topics

Estimation of geometrically undistorted B0 inhomogeneity maps

International Nuclear Information System (INIS)

Matakos, A; Balter, J; Cao, Y

2014-01-01

Geometric accuracy of MRI is one of the main concerns for its use as a sole image modality in precision radiation therapy (RT) planning. In a state-of-the-art scanner, system level geometric distortions are within acceptable levels for precision RT. However, subject-induced B 0 inhomogeneity may vary substantially, especially in air-tissue interfaces. Recent studies have shown distortion levels of more than 2 mm near the sinus and ear canal are possible due to subject-induced field inhomogeneity. These distortions can be corrected with the use of accurate B 0 inhomogeneity field maps. Most existing methods estimate these field maps from dual gradient-echo (GRE) images acquired at two different echo-times under the assumption that the GRE images are practically undistorted. However distortion that may exist in the GRE images can result in estimated field maps that are distorted in both geometry and intensity, leading to inaccurate correction of clinical images. This work proposes a method for estimating undistorted field maps from GRE acquisitions using an iterative joint estimation technique. The proposed method yields geometrically corrected GRE images and undistorted field maps that can also be used for the correction of images acquired by other sequences. The proposed method is validated through simulation, phantom experiments and applied to patient data. Our simulation results show that our method reduces the root-mean-squared error of the estimated field map from the ground truth by ten-fold compared to the distorted field map. Both the geometric distortion and the intensity corruption (artifact) in the images caused by the B 0 field inhomogeneity are corrected almost completely. Our phantom experiment showed improvement in the geometric correction of approximately 1 mm at an air-water interface using the undistorted field map compared to using a distorted field map. The proposed method for undistorted field map estimation can lead to improved geometric

Estimation of geometrically undistorted B0 inhomogeneity maps

Science.gov (United States)

Matakos, A.; Balter, J.; Cao, Y.

2014-09-01

Geometric accuracy of MRI is one of the main concerns for its use as a sole image modality in precision radiation therapy (RT) planning. In a state-of-the-art scanner, system level geometric distortions are within acceptable levels for precision RT. However, subject-induced B0 inhomogeneity may vary substantially, especially in air-tissue interfaces. Recent studies have shown distortion levels of more than 2 mm near the sinus and ear canal are possible due to subject-induced field inhomogeneity. These distortions can be corrected with the use of accurate B0 inhomogeneity field maps. Most existing methods estimate these field maps from dual gradient-echo (GRE) images acquired at two different echo-times under the assumption that the GRE images are practically undistorted. However distortion that may exist in the GRE images can result in estimated field maps that are distorted in both geometry and intensity, leading to inaccurate correction of clinical images. This work proposes a method for estimating undistorted field maps from GRE acquisitions using an iterative joint estimation technique. The proposed method yields geometrically corrected GRE images and undistorted field maps that can also be used for the correction of images acquired by other sequences. The proposed method is validated through simulation, phantom experiments and applied to patient data. Our simulation results show that our method reduces the root-mean-squared error of the estimated field map from the ground truth by ten-fold compared to the distorted field map. Both the geometric distortion and the intensity corruption (artifact) in the images caused by the B0 field inhomogeneity are corrected almost completely. Our phantom experiment showed improvement in the geometric correction of approximately 1 mm at an air-water interface using the undistorted field map compared to using a distorted field map. The proposed method for undistorted field map estimation can lead to improved geometric

Special Semester titled Geometric mechanics : variational and stochastic methods : CIB, Lausanne, Switzerland, January-June 2015

CERN Document Server

Cruzeiro, Ana; Holm, Darryl

2017-01-01

Collecting together contributed lectures and mini-courses, this book details the research presented in a special semester titled “Geometric mechanics – variational and stochastic methods” run in the first half of 2015 at the Centre Interfacultaire Bernoulli (CIB) of the Ecole Polytechnique Fédérale de Lausanne. The aim of the semester was to develop a common language needed to handle the wide variety of problems and phenomena occurring in stochastic geometric mechanics. It gathered mathematicians and scientists from several different areas of mathematics (from analysis, probability, numerical analysis and statistics, to algebra, geometry, topology, representation theory, and dynamical systems theory) and also areas of mathematical physics, control theory, robotics, and the life sciences, with the aim of developing the new research area in a concentrated joint effort, both from the theoretical and applied points of view. The lectures were given by leading specialists in different areas of mathematics a...

Geometric singular perturbation analysis of systems with friction

DEFF Research Database (Denmark)

Bossolini, Elena

This thesis is concerned with the application of geometric singular perturbation theory to mechanical systems with friction. The mathematical background on geometric singular perturbation theory, on the blow-up method, on non-smooth dynamical systems and on regularization is presented. Thereafter......, two mechanical problems with two different formulations of the friction force are introduced and analysed. The first mechanical problem is a one-dimensional spring-block model describing earthquake faulting. The dynamics of earthquakes is naturally a multiple timescale problem: the timescale...... scales. The action of friction is generally explained as the loss and restoration of linkages between the surface asperities at the molecular scale. However, the consequences of friction are noticeable at much larger scales, like hundreds of kilometers. By using geometric singular perturbation theory...

Aspects of random geometric graphs : Pursuit-evasion and treewidth

NARCIS (Netherlands)

Li, A.

2015-01-01

In this thesis, we studied two aspects of random geometric graphs: pursuit-evasion and treewidth. We first studied one pursuit-evasion game: Cops and Robbers. This game, which dates back to 1970s, are studied extensively in recent years. We investigate this game on random geometric graphs, and get

Relativistic transport theory for cosmic-rays

International Nuclear Information System (INIS)

Webb, G.M.

1985-01-01

Various aspects of the transport of cosmic-rays in a relativistically moving magnetized plasma supporting a spectrum of hydromagnetic waves that scatter the cosmic-rays are presented. A local Lorentz frame moving with the waves or turbulence scattering the cosmic-rays is used to specify the individual particle momentum. The comoving frame is in general a noninertial frame in which the observer's volume element is expanding and shearing, geometric energy change terms appear in the cosmic-ray transport equation which consist of the relativistic generalization of the adiabatic deceleration term and a further term involving the acceleration vector of the scatterers. A relativistic version of the pitch angle evolution equation, including the effects of adiabatic focussing, pitch angle scattering, and energy changes is presented

Discrete geometric structures for architecture

KAUST Repository

Pottmann, Helmut

2010-01-01

. The talk will provide an overview of recent progress in this field, with a particular focus on discrete geometric structures. Most of these result from practical requirements on segmenting a freeform shape into planar panels and on the physical realization

Quantum renormalization group approach to geometric phases in spin chains

International Nuclear Information System (INIS)

Jafari, R.

2013-01-01

A relation between geometric phases and criticality of spin chains are studied using the quantum renormalization-group approach. I have shown how the geometric phase evolve as the size of the system becomes large, i.e., the finite size scaling is obtained. The renormalization scheme demonstrates how the first derivative of the geometric phase with respect to the field strength diverges at the critical point and maximum value of the first derivative, and its position, scales with the exponent of the system size

Geometric measures of multipartite entanglement in finite-size spin chains

Energy Technology Data Exchange (ETDEWEB)

Blasone, M; Dell' Anno, F; De Siena, S; Giampaolo, S M; Illuminati, F, E-mail: illuminati@sa.infn.i [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy)

2010-09-01

We investigate the behaviour of multipartite entanglement in finite-size quantum spin systems, resorting to a hierarchy of geometric measures of multipartite entanglement recently introduced in the literature. In particular, we investigate the ground-state entanglement in the XY model defined on finite chains of N sites with periodic boundary conditions. We analyse the behaviour of the geometric measures of (N- 1)-partite and (N/2)-partite entanglement and compare them with the Wei-Goldbart geometric measure of global entanglement.

Geometric measures of multipartite entanglement in finite-size spin chains

International Nuclear Information System (INIS)

Blasone, M; Dell'Anno, F; De Siena, S; Giampaolo, S M; Illuminati, F

2010-01-01

We investigate the behaviour of multipartite entanglement in finite-size quantum spin systems, resorting to a hierarchy of geometric measures of multipartite entanglement recently introduced in the literature. In particular, we investigate the ground-state entanglement in the XY model defined on finite chains of N sites with periodic boundary conditions. We analyse the behaviour of the geometric measures of (N- 1)-partite and (N/2)-partite entanglement and compare them with the Wei-Goldbart geometric measure of global entanglement.

Aspects of the geometrical approach to supermanifolds

International Nuclear Information System (INIS)

Rogers, A.

1984-01-01

Various topics in the theory and application of the geometrical approach to supermanifolds are discussed. The construction of the superspace used in supergravity over an arbitrary spacetime manifold is described. Super Lie groups and their relation to graded Lie algebras (and more general structures referred to as 'graded Lie modules') are discussed, with examples. Certain supermanifolds, allowed in the geometric approach (using the fine topology), but having no analogue in the algebraic approach, are discussed. Finally lattice supersymmetry, and its relation to the differential geometry of supermanifolds, is discussed. (orig.)

Chromatic correction for the final transport system

International Nuclear Information System (INIS)

Brown, K.L.; Peterson, J.M.

1980-01-01

The final transport and focusing of the heavy-ion beam onto the fusion pellet in vacuum is complicated by several non-linear effects - namely, chromatic (momentum dependent) effects, geometric aberrations, and space-charge forces. This paper gives an example of how the chromatic effects can be nullified, at least to second order. Whether third- or higher-order terms are important is not yet clear. Space-charge effects are important but are not considered here

GEOMETRIZATION OF NONHOLONOMIC MECHANICAL SYSTEMS AND THEIR SOLVABILITY

Institute of Scientific and Technical Information of China (English)

慕小武; 郭仲衡

1990-01-01

A new geometrization approach to nonholonomic mechanical systems is proposed and a series of solvability conditions under the proposed geometric frame are given. The proposed frame differs essentially from Hermann’s. The limitations of Hermann’s frame are also discussed. It is shown that a system under Hermann’s frame is solvable only if its constraints are given by natural conservation laws of the corresponding constraint-free system.

Ideal versus real: simulated annealing of experimentally derived and geometric platinum nanoparticles

Science.gov (United States)

Ellaby, Tom; Aarons, Jolyon; Varambhia, Aakash; Jones, Lewys; Nellist, Peter; Ozkaya, Dogan; Sarwar, Misbah; Thompsett, David; Skylaris, Chris-Kriton

2018-04-01

Platinum nanoparticles find significant use as catalysts in industrial applications such as fuel cells. Research into their design has focussed heavily on nanoparticle size and shape as they greatly influence activity. Using high throughput, high precision electron microscopy, the structures of commercially available Pt catalysts have been determined, and we have used classical and quantum atomistic simulations to examine and compare them with geometric cuboctahedral and truncated octahedral structures. A simulated annealing procedure was used both to explore the potential energy surface at different temperatures, and also to assess the effect on catalytic activity that annealing would have on nanoparticles with different geometries and sizes. The differences in response to annealing between the real and geometric nanoparticles are discussed in terms of thermal stability, coordination number and the proportion of optimal binding sites on the surface of the nanoparticles. We find that annealing both experimental and geometric nanoparticles results in structures that appear similar in shape and predicted activity, using oxygen adsorption as a measure. Annealing is predicted to increase the catalytic activity in all cases except the truncated octahedra, where it has the opposite effect. As our simulations have been performed with a classical force field, we also assess its suitability to describe the potential energy of such nanoparticles by comparing with large scale density functional theory calculations.

Geometric measure theory

CERN Document Server

Waerden, B

1996-01-01

From the reviews: "... Federer's timely and beautiful book indeed fills the need for a comprehensive treatise on geometric measure theory, and his detailed exposition leads from the foundations of the theory to the most recent discoveries. ... The author writes with a distinctive style which is both natural and powerfully economical in treating a complicated subject. This book is a major treatise in mathematics and is essential in the working library of the modern analyst." Bulletin of the London Mathematical Society.

Geometric homology revisited

OpenAIRE

Ruffino, Fabio Ferrari

2013-01-01

Given a cohomology theory, there is a well-known abstract way to define the dual homology theory using the theory of spectra. In [4] the author provides a more geometric construction of the homology theory, using a generalization of the bordism groups. Such a generalization involves in its definition the vector bundle modification, which is a particular case of the Gysin map. In this paper we provide a more natural variant of that construction, which replaces the vector bundle modification wi...

Developing geometrical reasoning

OpenAIRE

Brown, Margaret; Jones, Keith; Taylor, Ron; Hirst, Ann

2004-01-01

This paper summarises a report (Brown, Jones & Taylor, 2003) to the UK Qualifications and Curriculum Authority of the work of one geometry group. The group was charged with developing and reporting on teaching ideas that focus on the development of geometrical reasoning at the secondary school level. The group was encouraged to explore what is possible both within and beyond the current requirements of the UK National Curriculum and the Key Stage 3 strategy, and to consider the whole atta...

Plasma geometric optics analysis and computation

International Nuclear Information System (INIS)

Smith, T.M.

1983-01-01

Important practical applications in the generation, manipulation, and diagnosis of laboratory thermonuclear plasmas have created a need for elaborate computational capabilities in the study of high frequency wave propagation in plasmas. A reduced description of such waves suitable for digital computation is provided by the theory of plasma geometric optics. The existing theory is beset by a variety of special cases in which the straightforward analytical approach fails, and has been formulated with little attention to problems of numerical implementation of that analysis. The standard field equations are derived for the first time from kinetic theory. A discussion of certain terms previously, and erroneously, omitted from the expansion of the plasma constitutive relation is given. A powerful but little known computational prescription for determining the geometric optics field in the neighborhood of caustic singularities is rigorously developed, and a boundary layer analysis for the asymptotic matching of the plasma geometric optics field across caustic singularities is performed for the first time with considerable generality. A proper treatment of birefringence is detailed, wherein a breakdown of the fundamental perturbation theory is identified and circumvented. A general ray tracing computer code suitable for applications to radiation heating and diagnostic problems is presented and described

Geometric Rationalization for Freeform Architecture

KAUST Repository

Jiang, Caigui

2016-06-20

The emergence of freeform architecture provides interesting geometric challenges with regards to the design and manufacturing of large-scale structures. To design these architectural structures, we have to consider two types of constraints. First, aesthetic constraints are important because the buildings have to be visually impressive. Sec- ond, functional constraints are important for the performance of a building and its e cient construction. This thesis contributes to the area of architectural geometry. Specifically, we are interested in the geometric rationalization of freeform architec- ture with the goal of combining aesthetic and functional constraints and construction requirements. Aesthetic requirements typically come from designers and architects. To obtain visually pleasing structures, they favor smoothness of the building shape, but also smoothness of the visible patterns on the surface. Functional requirements typically come from the engineers involved in the construction process. For exam- ple, covering freeform structures using planar panels is much cheaper than using non-planar ones. Further, constructed buildings have to be stable and should not collapse. In this thesis, we explore the geometric rationalization of freeform archi- tecture using four specific example problems inspired by real life applications. We achieve our results by developing optimization algorithms and a theoretical study of the underlying geometrical structure of the problems. The four example problems are the following: (1) The design of shading and lighting systems which are torsion-free structures with planar beams based on quad meshes. They satisfy the functionality requirements of preventing light from going inside a building as shad- ing systems or reflecting light into a building as lighting systems. (2) The Design of freeform honeycomb structures that are constructed based on hex-dominant meshes with a planar beam mounted along each edge. The beams intersect without

Direct Simulation of Transport Properties from Three-Dimensional (3D) Reconstructed Solid-Oxide Fuel-Cell (SOFC) Electrode Microstructures

International Nuclear Information System (INIS)

Gunda, Naga Siva Kumar; Mitra, Sushanta K

2012-01-01

A well-known approach to develop a high efficiency solid-oxide fuel-cell (SOFC) consists of extracting the microstructure and transport properties such as volume fractions, internal surface area, geometric connectivity, effective gas diffusivity, effective electronic conductivity and geometric tortuosities from three-dimensional (3D) microstructure of the SOFC electrodes; thereafter, performing the SOFC efficiency calculations using previously mentioned quantities. In the present work, dual-beam focused ion beam - scanning electron microscopy (FIB-SEM) is applied on one of the SOFC cathodes, a lanthanum strontium manganite (LSM) electrode, to estimate the aforementioned properties. A framework for calculating transport properties is presented in this work. 3D microstructures of LSM electrode are reconstructed from a series of two-dimensional (2D) cross-sectional FIB-SEM images. Volume percentages of connected, isolated and dead-ends networks of pore and LSM phases are estimated. Different networks of pore and LSM phases are discretized with tetrahedral elements. Finally, the finite element method (FEM) is applied to calculate effective gas diffusivity and electronic conductivity of pore and LSM phases, respectively. Geometric tortuosities are estimated from the porosity and effective transport properties. The results obtained using FEM are compared with the finite volume method (FVM) results obtained by Gunda et al. [J. Power Sources, 196(7), 35929(2011)] and other numerical results obtained on randomly generated porous medium. Effect of consideration of dead-ends and isolated-ends networks on calculation of effective transport properties is studied.

Air medical transport personnel experiences with and opinions about research.

Science.gov (United States)

Fox, Jolene; Thomas, Frank; Carpenter, Judi; Handrahan, Diana

2010-01-01

This study examined air medical transport (AMT) personnel's experiences with and opinions about prehospital and AMT research. A Web-based questionnaire was sent to eight randomly selected AMT programs from each of six Association of Air Medical Services (AAMS) regions. Responders were defined by university association (UA) and AMT professional role. Forty-eight of 54 (89%) contacted programs and 536 of 1,282 (42%) individuals responded. Non-UA responders (74%) had significantly more work experience in emergency medical services (EMS) (13.5 +/- 8.5 vs. 10.8 +/- 8.3 years, P = .002) and AMT (8.3 +/- 6.3 vs. 6.8 +/- 5.7 years, P = .008), whereas UA responders (26%) had more research training (51% vs. 37%, P = .006), experience (79% vs. 59%, P < .001), and grants (7% vs. 2%, P = .006). By AMT role, administrators had the most work experience, and physicians had the most research experience. Research productivity of responders was low, with only 9% having presented and 10% having published research; and UA made no difference in productivity. A majority of responders advocated research: EMS (66%) and AMT (68%), program (53%). Willingness to participate in research was high for both EMS research (87%) and AMT research (92%). Although AMT personnel were strong advocates of and willing to participate in research, few had research knowledge. For AMT personnel, disparity exists between advocating for and producing research. Copyright 2010 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

Geometric Approaches to Quadratic Equations from Other Times and Places.

Science.gov (United States)

Allaire, Patricia R.; Bradley, Robert E.

2001-01-01

Focuses on geometric solutions of quadratic problems. Presents a collection of geometric techniques from ancient Babylonia, classical Greece, medieval Arabia, and early modern Europe to enhance the quadratic equation portion of an algebra course. (KHR)

The Conference Proceedings of the 1998 Air Transport Research Group (ATRG) of the WCTR Society. Volume 3

Science.gov (United States)

Oum, Tae Hoon (Editor); Bowen, Brent D. (Editor)

1998-01-01

Thirteen papers (presentations) from the 8th World Conference on Transportation Research are presented. Topics include European Airline competition, cost analyses, performance evaluations, deregulation; aviation policy in Southeast Asia; corporate involvement in European business transportation; and cycles in the airline industry.

Influence of plasma shape on transport in the TCV tokamak

International Nuclear Information System (INIS)

Moret, J.M.; Franke, S.; Weisen, H.

1996-11-01

The energy confinement time of TCV ohmic, L-mode plasmas is observed to depend on the shape, improving slightly with elongation and degrading strongly with positive triangularity. This dependence can be explained by combination of geometrical effects on the temperature gradient and power degradation, without invoking a shape dependence of the transport coefficients. (author) 5 figs., 8 refs

Islamic geometric patterns their historical development and traditional methods of construction

CERN Document Server

Bonner, Jay

2017-01-01

The main focus of this unique book is an in-depth examination of the polygonal technique; the primary method used by master artists of the past in creating Islamic geometric patterns. The author details the design methodology responsible for this all-but-lost art form and presents evidence for its use from the historical record, both of which are vital contributions to the understanding of this ornamental tradition. Additionally, the author examines the historical development of Islamic geometric patterns, the significance of geometric design within the broader context of Islamic ornament as a whole, the formative role that geometry plays throughout the Islamic ornamental arts (including calligraphy, the floral idiom, dome decoration, geometric patterns, and more), and the underexamined question of pattern classification. Featuring over 600 beautiful color images, Islamic Geometric Patterns: Their Historical Development and Traditional Methods of Construction is a valuable addition to the literature of Islam...

Geometric calculus: a new computational tool for Riemannian geometry

International Nuclear Information System (INIS)

Moussiaux, A.; Tombal, P.

1988-01-01

We compare geometric calculus applied to Riemannian geometry with Cartan's exterior calculus method. The correspondence between the two methods is clearly established. The results obtained by a package written in an algebraic language and doing general manipulations on multivectors are compared. We see that the geometric calculus is as powerful as exterior calculus

Unstructured 3D core calculations with the descartes system application to the JHR research reactor

International Nuclear Information System (INIS)

Baudron, A. M.; Doderlein, C.; Guerin, P.; Lautard, J. J.; Moreau, F.

2007-01-01

Recent developments in the DESCARTES system enable neutronics calculations dealing with very complex unstructured geometrical configurations. The discretization can be made either by using a very fine Cartesian mesh and the fast simplified transport (SPN) solver MINOS, or a discretization based on triangles and the SP1 solver MINARET. In order to perform parallel calculations dealing with a very fine mesh in 3D, a domain decomposition with non overlapping domains has been implemented. To illustrate these capabilities, we present an application on the future European research reactor JHR dedicated to technological irradiations. (authors)

The differential-geometric aspects of integrable dynamical systems

International Nuclear Information System (INIS)

Prykarpatsky, Y.A.; Samoilenko, A.M.; Prykarpatsky, A.K.; Bogolubov, N.N. Jr.; Blackmore, D.L.

2007-05-01

The canonical reduction method on canonically symplectic manifolds is analyzed in detail, and the relationships with the geometric properties of associated principal fiber bundles endowed with connection structures are described. Some results devoted to studying geometrical properties of nonabelian Yang-Mills type gauge field equations are presented. A symplectic theory approach is developed for partially solving the problem of algebraic-analytical construction of integral submanifold embeddings for integrable (via the abelian and nonabelian Liouville-Arnold theorems) Hamiltonian systems on canonically symplectic phase spaces. The fundamental role of the so-called Picard-Fuchs type equations is revealed, and their differential-geometric and algebraic properties are studied in detail. Some interesting examples of integrable Hamiltonian systems are are studied in detail in order to demonstrate the ease of implementation and effectiveness of the procedure for investigating the integral submanifold embedding mapping. (author)

Geometric model from microscopic theory for nuclear absorption

International Nuclear Information System (INIS)

John, S.; Townsend, L.W.; Wilson, J.W.; Tripathi, R.K.

1993-07-01

A parameter-free geometric model for nuclear absorption is derived herein from microscopic theory. The expression for the absorption cross section in the eikonal approximation, taken in integral form, is separated into a geometric contribution that is described by an energy-dependent effective radius and two surface terms that cancel in an asymptotic series expansion. For collisions of light nuclei, an expression for the effective radius is derived from harmonic oscillator nuclear density functions. A direct extension to heavy nuclei with Woods-Saxon densities is made by identifying the equivalent half-density radius for the harmonic oscillator functions. Coulomb corrections are incorporated, and a simplified geometric form of the Bradt-Peters type is obtained. Results spanning the energy range from 1 MeV/nucleon to 1 GeV/nucleon are presented. Good agreement with experimental results is obtained

Geometric model for nuclear absorption from microscopic theory

International Nuclear Information System (INIS)

John, S.; Townsend, L.W.; Wilson, J.W.; Tripathi, R.K.

1993-01-01

A parameter-free geometric model for nuclear absorption is derived from microscopic theory. The expression for the absorption cross section in the eikonal approximation taken in integral form is separated into a geometric contribution, described by an energy-dependent effective radius, and two surface terms which are shown to cancel in an asymptotic series expansion. For collisions of light nuclei, an expression for the effective radius is derived using harmonic-oscillator nuclear density functions. A direct extension to heavy nuclei with Woods-Saxon densities is made by identifying the equivalent half density radius for the harmonic-oscillator functions. Coulomb corrections are incorporated and a simplified geometric form of the Bradt-Peters type obtained. Results spanning the energy range of 1 MeV/nucleon to 1 GeV/nucleon are presented. Good agreement with experimental results is obtained

Stress measurement in thin films by geometrical optics

Science.gov (United States)

Rossnagel, S. M.; Gilstrap, P.; Rujkorakarn, R.

1982-01-01

A variation of Newton's rings experiment is proposed for measuring film stress. The procedure described, the geometrical optics method, is used to measure radii of curvature for a series of film depositions with Ta, Al, and Mo films. The method has a sensitivity of 1 x 10 to the 9th dyn/sq cm, corresponding to the practical radius limit of about 50 m, and a repeatability usually within five percent. For the purposes of comparison, radii are also measured by Newton's rings method and the Talysurf method; all results are found to be in general agreement. Measurement times are also compared: the geometrical optics method requires only 1/2-1 minute. It is concluded that the geometrical optics method provides an inexpensive, fast, and a reasonably correct technique with which to measure stresses in film.

Electric Vehicle Grid Integration | Transportation Research | NREL

Science.gov (United States)

Electric Vehicle Grid Integration Electric Vehicle Grid Integration Illustration of a house with a in the garage, is connected via a power cord to a household outlet. A sustainable transportation sustainable transportation technologies to increase the capacity, efficiency, and stability of the grid

Ricci flow and geometrization of 3-manifolds

CERN Document Server

Morgan, John W

2010-01-01

This book is based on lectures given at Stanford University in 2009. The purpose of the lectures and of the book is to give an introductory overview of how to use Ricci flow and Ricci flow with surgery to establish the Poincar� Conjecture and the more general Geometrization Conjecture for 3-dimensional manifolds. Most of the material is geometric and analytic in nature; a crucial ingredient is understanding singularity development for 3-dimensional Ricci flows and for 3-dimensional Ricci flows with surgery. This understanding is crucial for extending Ricci flows with surgery so that they are defined for all positive time. Once this result is in place, one must study the nature of the time-slices as the time goes to infinity in order to deduce the topological consequences. The goal of the authors is to present the major geometric and analytic results and themes of the subject without weighing down the presentation with too many details. This book can be read as an introduction to more complete treatments of ...

The Conference Proceedings of the 1997 Air Transport Research Group (ATRG) of the WCTR Society. Volume 1

Science.gov (United States)

Oum, Tae Hoon (Editor); Bowen, Brent D. (Editor)

1997-01-01

The UNO Aviation Institute has published the 1997 Proceedings of the Air Transport Research Group of the World Conference on Transportation Research (WCTR) Society. Items published in this three volume, seven monograph series were presented at the triennial ATRG Conference held at the University of British Columbia, June 25-27, 1997. A wide variety of policy issues are discussed including the following: open- skies agreements, liberalization, globalization, airline competition, airport performance, pricing, hubs, and safety, among others.

Calibration and verification of thermographic cameras for geometric measurements

Science.gov (United States)

Lagüela, S.; González-Jorge, H.; Armesto, J.; Arias, P.

2011-03-01

Infrared thermography is a technique with an increasing degree of development and applications. Quality assessment in the measurements performed with the thermal cameras should be achieved through metrology calibration and verification. Infrared cameras acquire temperature and geometric information, although calibration and verification procedures are only usual for thermal data. Black bodies are used for these purposes. Moreover, the geometric information is important for many fields as architecture, civil engineering and industry. This work presents a calibration procedure that allows the photogrammetric restitution and a portable artefact to verify the geometric accuracy, repeatability and drift of thermographic cameras. These results allow the incorporation of this information into the quality control processes of the companies. A grid based on burning lamps is used for the geometric calibration of thermographic cameras. The artefact designed for the geometric verification consists of five delrin spheres and seven cubes of different sizes. Metrology traceability for the artefact is obtained from a coordinate measuring machine. Two sets of targets with different reflectivity are fixed to the spheres and cubes to make data processing and photogrammetric restitution possible. Reflectivity was the chosen material propriety due to the thermographic and visual cameras ability to detect it. Two thermographic cameras from Flir and Nec manufacturers, and one visible camera from Jai are calibrated, verified and compared using calibration grids and the standard artefact. The calibration system based on burning lamps shows its capability to perform the internal orientation of the thermal cameras. Verification results show repeatability better than 1 mm for all cases, being better than 0.5 mm for the visible one. As it must be expected, also accuracy appears higher in the visible camera, and the geometric comparison between thermographic cameras shows slightly better

Height and Tilt Geometric Texture

DEFF Research Database (Denmark)

Andersen, Vedrana; Desbrun, Mathieu; Bærentzen, Jakob Andreas

2009-01-01

compromise between functionality and simplicity: it can efficiently handle and process geometric texture too complex to be represented as a height field, without having recourse to full blown mesh editing algorithms. The height-and-tilt representation proposed here is fully intrinsic to the mesh, making...

Cartan's geometrical structure of supergravity

International Nuclear Information System (INIS)

Baaklini, N.S.

1977-06-01

The geometrical partnership of the vierbein and the spin-3/2 field in the structure of the supergravity Lagrangian is emphasized. Both fields are introduced as component of the same matrix differential form. The only local symmetry of the theory is SL(2,C)

Harmonic measure geometric and analytic points of view

CERN Document Server

Capogna, Luca; Lanzani, Loredana

2005-01-01

Recent developments in geometric measure theory and harmonic analysis have led to new and deep results concerning the regularity of the support of measures which behave "asymptotically" (for balls of small radius) as the Euclidean volume. A striking feature of these results is that they actually characterize flatness of the support in terms of the asymptotic behavior of the measure. Such characterizations have led to important new progress in the study of harmonic measure for non-smooth domains. This volume provides an up-to-date overview and an introduction to the research literature in this area. The presentation follows a series of five lectures given by Carlos Kenig at the 2000 Arkansas Spring Lecture Series. The original lectures have been expanded and updated to reflect the rapid progress in this field. A chapter on the planar case has been added to provide a historical perspective. Additional background has been included to make the material accessible to advanced graduate students and researchers in h...

XXXIV Bialowieza Workshop on Geometric Methods in Physics

CERN Document Server

Ali, S; Bieliavsky, Pierre; Odzijewicz, Anatol; Schlichenmaier, Martin; Voronov, Theodore

2016-01-01

This book features a selection of articles based on the XXXIV Białowieża Workshop on Geometric Methods in Physics, 2015. The articles presented are mathematically rigorous, include important physical implications and address the application of geometry in classical and quantum physics. Special attention deserves the session devoted to discussions of Gerard Emch's most important and lasting achievements in mathematical physics. The Białowieża workshops are among the most important meetings in the field and gather participants from mathematics and physics alike. Despite their long tradition, the Workshops remain at the cutting edge of ongoing research. For the past several years, the Białowieża Workshop has been followed by a School on Geometry and Physics, where advanced lectures for graduate students and young researchers are presented. The unique atmosphere of the Workshop and School is enhanced by the venue, framed by the natural beauty of the Białowieża forest in eastern Poland.

Non-stoquastic Hamiltonians in quantum annealing via geometric phases

Science.gov (United States)

Vinci, Walter; Lidar, Daniel A.

2017-09-01

We argue that a complete description of quantum annealing implemented with continuous variables must take into account the non-adiabatic Aharonov-Anandan geometric phase that arises when the system Hamiltonian changes during the anneal. We show that this geometric effect leads to the appearance of non-stoquasticity in the effective quantum Ising Hamiltonians that are typically used to describe quantum annealing with flux qubits. We explicitly demonstrate the effect of this geometric non-stoquasticity when quantum annealing is performed with a system of one and two coupled flux qubits. The realization of non-stoquastic Hamiltonians has important implications from a computational complexity perspective, since it is believed that in many cases quantum annealing with stoquastic Hamiltonians can be efficiently simulated via classical algorithms such as Quantum Monte Carlo. It is well known that the direct implementation of non-stoquastic Hamiltonians with flux qubits is particularly challenging. Our results suggest an alternative path for the implementation of non-stoquasticity via geometric phases that can be exploited for computational purposes.

Time space domain decomposition methods for reactive transport - Application to CO2 geological storage

International Nuclear Information System (INIS)

Haeberlein, F.

2011-01-01

Reactive transport modelling is a basic tool to model chemical reactions and flow processes in porous media. A totally reduced multi-species reactive transport model including kinetic and equilibrium reactions is presented. A structured numerical formulation is developed and different numerical approaches are proposed. Domain decomposition methods offer the possibility to split large problems into smaller subproblems that can be treated in parallel. The class of Schwarz-type domain decomposition methods that have proved to be high-performing algorithms in many fields of applications is presented with a special emphasis on the geometrical viewpoint. Numerical issues for the realisation of geometrical domain decomposition methods and transmission conditions in the context of finite volumes are discussed. We propose and validate numerically a hybrid finite volume scheme for advection-diffusion processes that is particularly well-suited for the use in a domain decomposition context. Optimised Schwarz waveform relaxation methods are studied in detail on a theoretical and numerical level for a two species coupled reactive transport system with linear and nonlinear coupling terms. Well-posedness and convergence results are developed and the influence of the coupling term on the convergence behaviour of the Schwarz algorithm is studied. Finally, we apply a Schwarz waveform relaxation method on the presented multi-species reactive transport system. (author)

Geometric phase of neutrinos: Differences between Dirac and Majorana neutrinos

Science.gov (United States)

Capolupo, A.; Giampaolo, S. M.; Hiesmayr, B. C.; Vitiello, G.

2018-05-01

We analyze the non-cyclic geometric phase for neutrinos. We find that the geometric phase and the total phase associated to the mixing phenomenon provide a theoretical tool to distinguish between Dirac and Majorana neutrinos. Our results hold for neutrinos propagating in vacuum and through the matter. We feed the values of the experimental parameters in our formulas in order to make contact with experiments. Although it remains an open question how the geometric phase of neutrinos could be detected, our theoretical results may open new scenarios in the investigation of the neutrino nature.

Geometric Algebra Computing

CERN Document Server

Corrochano, Eduardo Bayro

2010-01-01

This book presents contributions from a global selection of experts in the field. This useful text offers new insights and solutions for the development of theorems, algorithms and advanced methods for real-time applications across a range of disciplines. Written in an accessible style, the discussion of all applications is enhanced by the inclusion of numerous examples, figures and experimental analysis. Features: provides a thorough discussion of several tasks for image processing, pattern recognition, computer vision, robotics and computer graphics using the geometric algebra framework; int

Enhancement of geometric phase by frustration of decoherence: A Parrondo-like effect

Science.gov (United States)

Banerjee, Subhashish; Chandrashekar, C. M.; Pati, Arun K.

2013-04-01

Geometric phase plays an important role in evolution of pure or mixed quantum states. However, when a system undergoes decoherence the development of geometric phase may be inhibited. Here we show that when a quantum system interacts with two competing environments there can be enhancement of geometric phase. This effect is akin to a Parrondo-like effect on the geometric phase which results from quantum frustration of decoherence. Our result suggests that the mechanism of two competing decoherence can be useful in fault-tolerant holonomic quantum computation.

Heuristic geometric ''eigenvalue universality'' in a one-dimensional neutron transport problem with anisotropic scattering

International Nuclear Information System (INIS)

Goncalves, G.A.; Vilhena, M.T. de; Bodmann, B.E.J.

2010-01-01

In the present work we propose a heuristic construction of a transport equation for neutrons with anisotropic scattering considering only the radial cylinder dimension. The eigenvalues of the solutions of the equation correspond to the positive values for the one dimensional case. The central idea of the procedure is the application of the S N method for the discretisation of the angular variable followed by the application of the zero order Hankel transformation. The basis the construction of the scattering terms in form of an integro-differential equation for stationary transport resides in the hypothesis that the eigenvalues that compose the elementary solutions are independent of geometry for a homogeneous medium. We compare the solutions for the cartesian one dimensional problem for an infinite cylinder with azimuthal symmetry and linear anisotropic scattering for two cases. (orig.)

Geometric methods for estimating representative sidewalk widths applied to Vienna's streetscape surfaces database

Science.gov (United States)

Brezina, Tadej; Graser, Anita; Leth, Ulrich

2017-04-01

Space, and in particular public space for movement and leisure, is a valuable and scarce resource, especially in today's growing urban centres. The distribution and absolute amount of urban space—especially the provision of sufficient pedestrian areas, such as sidewalks—is considered crucial for shaping living and mobility options as well as transport choices. Ubiquitous urban data collection and today's IT capabilities offer new possibilities for providing a relation-preserving overview and for keeping track of infrastructure changes. This paper presents three novel methods for estimating representative sidewalk widths and applies them to the official Viennese streetscape surface database. The first two methods use individual pedestrian area polygons and their geometrical representations of minimum circumscribing and maximum inscribing circles to derive a representative width of these individual surfaces. The third method utilizes aggregated pedestrian areas within the buffered street axis and results in a representative width for the corresponding road axis segment. Results are displayed as city-wide means in a 500 by 500 m grid and spatial autocorrelation based on Moran's I is studied. We also compare the results between methods as well as to previous research, existing databases and guideline requirements on sidewalk widths. Finally, we discuss possible applications of these methods for monitoring and regression analysis and suggest future methodological improvements for increased accuracy.

Animal Transports

Directory of Open Access Journals (Sweden)

Diana Ludrovcová

2016-08-01

Full Text Available Purpose and Originality: The research is aimed to the animal transports issue, from two points of view – first is the animal cruelty and second is the policy and economic consideration. The goal is to acquaint the readers with the transports risks and its cruelty and evaluation of the economic, political aspects for he involved countries. The study is oriented on more points of view, what is rare in works with a similar theme. Method: This paper examines many issues and examinations from different authors and subsequently summarized the findings with authors own knowledge to one expanded unit. Results: Results proves, that livestock transports have negative impact on animal´s health, environment. Number of transported animals is rising every year. Society: Research familiarize the society with the animal transports, cruelty against animals during them, and influence of transports on some countries, their economy, policy. People get better informed and can form their own opinion on this topic. They may start acting, undertaking some steps to improve the present situation, what could help a lot to animals and environment. Limitations / further research: Future research could show progress and improvement of transports, quality of food supply and economics.