WorldWideScience

Sample records for maximum commutative group

  1. Opechowski's theorem and commutator groups

    International Nuclear Information System (INIS)

    Caride, A.O.; Zanette, S.I.

    1985-01-01

    It is shown that the conditions of application of Opechowski's theorem for double groups of subgroups of O(3) are directly associated to the structure of their commutator groups. Some characteristics of the structure of classes are also discussed. (Author) [pt

  2. Commutativity theorems for rings and groups with constraints on commutators

    Directory of Open Access Journals (Sweden)

    Evagelos Psomopoulos

    1984-01-01

    Full Text Available Let n>1, m, t, s be any positive integers, and let R be an associative ring with identity. Suppose xt[xn,y]=[x,ym]ys for all x, y in R. If, further, R is n-torsion free, then R is commutativite. If n-torsion freeness of R is replaced by “m, n are relatively prime,” then R is still commutative. Moreover, example is given to show that the group theoretic analogue of this theorem is not true in general. However, it is true when t=s=0 and m=n+1.

  3. Power Maps and Commutativity of Groups

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 7. Power Maps and Commutativity of Groups. Ashok Singh. Classroom Volume 9 Issue 7 July 2004 pp 70-73. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/009/07/0070-0073. Keywords. Abelian ...

  4. DSR Theories, Conformal Group and Generalized Commutation Relation

    International Nuclear Information System (INIS)

    Leiva, Carlos

    2006-01-01

    In this paper the relationship of DSR theories and Conformal Group is reviewed. On the other hand, the relation between DSR Magueijo Smolin generators and generalized commutation relations is also shown

  5. Non-commutative representation for quantum systems on Lie groups

    Energy Technology Data Exchange (ETDEWEB)

    Raasakka, Matti Tapio

    2014-01-27

    The topic of this thesis is a new representation for quantum systems on weakly exponential Lie groups in terms of a non-commutative algebra of functions, the associated non-commutative harmonic analysis, and some of its applications to specific physical systems. In the first part of the thesis, after a review of the necessary mathematical background, we introduce a {sup *}-algebra that is interpreted as the quantization of the canonical Poisson structure of the cotangent bundle over a Lie group. From the physics point of view, this represents the algebra of quantum observables of a physical system, whose configuration space is a Lie group. We then show that this quantum algebra can be represented either as operators acting on functions on the group, the usual group representation, or (under suitable conditions) as elements of a completion of the universal enveloping algebra of the Lie group, the algebra representation. We further apply the methods of deformation quantization to obtain a representation of the same algebra in terms of a non-commutative algebra of functions on a Euclidean space, which we call the non-commutative representation of the original quantum algebra. The non-commutative space that arises from the construction may be interpreted as the quantum momentum space of the physical system. We derive the transform between the group representation and the non-commutative representation that generalizes in a natural way the usual Fourier transform, and discuss key properties of this new non-commutative harmonic analysis. Finally, we exhibit the explicit forms of the non-commutative Fourier transform for three elementary Lie groups: R{sup d}, U(1) and SU(2). In the second part of the thesis, we consider application of the non-commutative representation and harmonic analysis to physics. First, we apply the formalism to quantum mechanics of a point particle on a Lie group. We define the dual non-commutative momentum representation, and derive the phase

  6. Non-commutative representation for quantum systems on Lie groups

    International Nuclear Information System (INIS)

    Raasakka, Matti Tapio

    2014-01-01

    The topic of this thesis is a new representation for quantum systems on weakly exponential Lie groups in terms of a non-commutative algebra of functions, the associated non-commutative harmonic analysis, and some of its applications to specific physical systems. In the first part of the thesis, after a review of the necessary mathematical background, we introduce a * -algebra that is interpreted as the quantization of the canonical Poisson structure of the cotangent bundle over a Lie group. From the physics point of view, this represents the algebra of quantum observables of a physical system, whose configuration space is a Lie group. We then show that this quantum algebra can be represented either as operators acting on functions on the group, the usual group representation, or (under suitable conditions) as elements of a completion of the universal enveloping algebra of the Lie group, the algebra representation. We further apply the methods of deformation quantization to obtain a representation of the same algebra in terms of a non-commutative algebra of functions on a Euclidean space, which we call the non-commutative representation of the original quantum algebra. The non-commutative space that arises from the construction may be interpreted as the quantum momentum space of the physical system. We derive the transform between the group representation and the non-commutative representation that generalizes in a natural way the usual Fourier transform, and discuss key properties of this new non-commutative harmonic analysis. Finally, we exhibit the explicit forms of the non-commutative Fourier transform for three elementary Lie groups: R d , U(1) and SU(2). In the second part of the thesis, we consider application of the non-commutative representation and harmonic analysis to physics. First, we apply the formalism to quantum mechanics of a point particle on a Lie group. We define the dual non-commutative momentum representation, and derive the phase space path

  7. Limits of commutative triangular systems on locally compact groups

    Indian Academy of Sciences (India)

    Commutative triangular systems of probability measures on locally compact groups have been studied extensively and ... in [S3,S4], we extend our earlier result to some particular triangular systems on algebraic groups. We also discuss ..... Now G can be embedded as a closed subgroup in. G2 ¼ G1=D and G0. 2 ¼ ًG0 آ ...

  8. Quantum groups, non-commutative differential geometry and applications

    International Nuclear Information System (INIS)

    Schupp, P.; California Univ., Berkeley, CA

    1993-01-01

    The topic of this thesis is the development of a versatile and geometrically motivated differential calculus on non-commutative or quantum spaces, providing powerful but easy-to-use mathematical tools for applications in physics and related sciences. A generalization of unitary time evolution is proposed and studied for a simple 2-level system, leading to non-conservation of microscopic entropy, a phenomenon new to quantum mechanics. A Cartan calculus that combines functions, forms, Lie derivatives and inner derivations along general vector fields into one big algebra is constructed for quantum groups and then extended to quantum planes. The construction of a tangent bundle on a quantum group manifold and an BRST type approach to quantum group gauge theory are given as further examples of applications. The material is organized in two parts: Part I studies vector fields on quantum groups, emphasizing Hopf algebraic structures, but also introducing a ''quantum geometric'' construction. Using a generalized semi-direct product construction we combine the dual Hopf algebras A of functions and U of left-invariant vector fields into one fully bicovariant algebra of differential operators. The pure braid group is introduced as the commutant of Δ(U). It provides invariant maps A → U and thereby bicovariant vector fields, casimirs and metrics. This construction allows the translation of undeformed matrix expressions into their less obvious quantum algebraic counter parts. We study this in detail for quasitriangular Hopf algebras, giving the determinant and orthogonality relation for the ''reflection'' matrix. Part II considers the additional structures of differential forms and finitely generated quantum Lie algebras -- it is devoted to the construction of the Cartan calculus, based on an undeformed Cartan identity

  9. Fundamental Investigations on the Unit Groups of Commutative Group Algebras in Bulgaria

    OpenAIRE

    Mollov, Todor

    2010-01-01

    In this paper we give the first investigations and also some basic results on the unit groups of commutative group algebras in Bulgaria. These investigations continue some classical results. Namely, it is supposed that the cardinality of the starting group is arbitrary.

  10. Groups of automorphisms of the canonical commutation and anticommutation relations

    International Nuclear Information System (INIS)

    Grosse, H.; Pittner, L.

    1987-01-01

    Observables of supersymmetric quantum mechanics are coded by taking the antisymmetric tensor product with anticommuting parameters. Next we define superunitary transformations, which mix bosonic and fermionic degrees of freedom, in order to construct automorphisms of the canonical (anti-) commutation relations. Conversely, every automorphism of the C(A)CR is implemented by an essentially unique superunitary transformation. 12 refs. (Author)

  11. On Subgroups of Non-Commutative General Rhotrix Group ...

    African Journals Online (AJOL)

    This paper considers the pair (GRn(F),o) consisting of the set of all invertible rhotrices of size n over an arbitrary field F; and together with the binary operation of row-column based method for rhotrix multiplication; 'o' , in order to introduce it as the concept of “non commutative general rhotrix group”. We identify a number of ...

  12. EnviroAtlas - Commute Time to Work by Census Block Group for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset portrays the commute time of workers to their workplace for each Census Block Group (CBG) during 2008-2012. Data were compiled from the...

  13. An introduction to quantum groups and non-commutative differential calculus

    International Nuclear Information System (INIS)

    Azcarraga, J.A. de; Rodenas, F.

    1995-01-01

    An introduction to quantum groups and quantum spaces is presented, and the non-commutative calculus on them is discussed. The case of q-Minkowski space is presented as an illustrative example. A set of useful expressions and formulae are collected in an appendix. 45 refs

  14. Non commutative geometry methods for group C*-algebras

    International Nuclear Information System (INIS)

    Do Ngoc Diep.

    1996-09-01

    This book is intended to provide a quick introduction to the subject. The exposition is scheduled in the sequence, as possible for more understanding for beginners. The author exposed a K-theoretic approach to study group C * -algebras: started in the elementary part, with one example of description of the structure of C * -algebra of the group of affine transformations of the real straight line, continued then for some special classes of solvable and nilpotent Lie groups. In the second advanced part, he introduced the main tools of the theory. In particular, the conception of multidimensional geometric quantization and the index of group C * -algebras were created and developed. (author). Refs

  15. Non commutative geometry methods for group C{sup *}-algebras

    Energy Technology Data Exchange (ETDEWEB)

    Diep, Do Ngoc

    1996-09-01

    This book is intended to provide a quick introduction to the subject. The exposition is scheduled in the sequence, as possible for more understanding for beginners. The author exposed a K-theoretic approach to study group C{sup *}-algebras: started in the elementary part, with one example of description of the structure of C{sup *}-algebra of the group of affine transformations of the real straight line, continued then for some special classes of solvable and nilpotent Lie groups. In the second advanced part, he introduced the main tools of the theory. In particular, the conception of multidimensional geometric quantization and the index of group C{sup *}-algebras were created and developed. (author). Refs.

  16. Topological and homological properties of the orbit space of a compact linear Lie group with commutative connected component

    OpenAIRE

    Styrt, O. G.

    2016-01-01

    The problem in question is whether the quotient space of a compact linear group is a topological manifold and whether it is a homological manifold. In the paper, the case of an infinite group with commutative connected component is considered.

  17. EnviroAtlas - Commute Modes and Working from Home by Block Group for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset portrays the percent of workers who commute to work using various modes, and the percent who work from home within each Census Block Group...

  18. Non-commutative cryptography and complexity of group-theoretic problems

    CERN Document Server

    Myasnikov, Alexei; Ushakov, Alexander

    2011-01-01

    This book is about relations between three different areas of mathematics and theoretical computer science: combinatorial group theory, cryptography, and complexity theory. It explores how non-commutative (infinite) groups, which are typically studied in combinatorial group theory, can be used in public-key cryptography. It also shows that there is remarkable feedback from cryptography to combinatorial group theory because some of the problems motivated by cryptography appear to be new to group theory, and they open many interesting research avenues within group theory. In particular, a lot of emphasis in the book is put on studying search problems, as compared to decision problems traditionally studied in combinatorial group theory. Then, complexity theory, notably generic-case complexity of algorithms, is employed for cryptanalysis of various cryptographic protocols based on infinite groups, and the ideas and machinery from the theory of generic-case complexity are used to study asymptotically dominant prop...

  19. Minimal deformation of the commutative algebra and the linear group GL(n)

    International Nuclear Information System (INIS)

    Zupnik, B.M.

    1993-01-01

    We consider the relations of generalized commutativity in the algebra of formal series M q (x i ), which conserve a tensor I q -graduation and depend on parameters q(i,k). We choose the I q -invariant version of differential calculus on M q . A new construction of the symmetrized tensor product for M q -type algebras and the corresponding definition of minimally deformed linear group QGL(n) and Lie algebra qgl(n) are proposed. We study the connection of QGL(n) and qgl(n) with the special matrix algebra Mat(n, Q) containing matrices with noncommutative elements. A definition of the deformed determinant in the algebra Mat(n, Q) is given. The exponential parametrization in the algebra Mat(n, Q) is considered on the basis of Campbell-Hausdorf formula

  20. Anomalous commutator of gauge group generators in a non-Abelian chiral theory

    International Nuclear Information System (INIS)

    Jo, S.

    1985-01-01

    This paper discusses commutators among non-Abelian fermion currents that are calculated using the BJL limit. It is observed that the gauge dependence of the fermion current with fixed canonical variables should be different from the covariant seagull in order to have correct anomalous commutators

  1. Group size and dispersal ploys: an analysis of commuting behaviour of the pond bat (Myotis dasycneme)

    NARCIS (Netherlands)

    Haarsma, A.J.; Siepel, H.

    2014-01-01

    Like most bat species, the pond bat (Myotis dasycneme (Boie, 1825)) lives in roosts more or less in the centre of their foraging habitat and are considered central-place foragers. Commuting routes, or flyways, between roosts and hunting areas have an essential ecological function for bats. We

  2. Distribution of phytoplankton groups within the deep chlorophyll maximum

    KAUST Repository

    Latasa, Mikel; Cabello, Ana Marí a; Moran, Xose Anxelu G.; Massana, Ramon; Scharek, Renate

    2016-01-01

    and optical and FISH microscopy. All groups presented minimum abundances at the surface and a maximum in the DCM layer. The cell distribution was not vertically symmetrical around the DCM peak and cells tended to accumulate in the upper part of the DCM layer

  3. Distribution of phytoplankton groups within the deep chlorophyll maximum

    KAUST Repository

    Latasa, Mikel

    2016-11-01

    The fine vertical distribution of phytoplankton groups within the deep chlorophyll maximum (DCM) was studied in the NE Atlantic during summer stratification. A simple but unconventional sampling strategy allowed examining the vertical structure with ca. 2 m resolution. The distribution of Prochlorococcus, Synechococcus, chlorophytes, pelagophytes, small prymnesiophytes, coccolithophores, diatoms, and dinoflagellates was investigated with a combination of pigment-markers, flow cytometry and optical and FISH microscopy. All groups presented minimum abundances at the surface and a maximum in the DCM layer. The cell distribution was not vertically symmetrical around the DCM peak and cells tended to accumulate in the upper part of the DCM layer. The more symmetrical distribution of chlorophyll than cells around the DCM peak was due to the increase of pigment per cell with depth. We found a vertical alignment of phytoplankton groups within the DCM layer indicating preferences for different ecological niches in a layer with strong gradients of light and nutrients. Prochlorococcus occupied the shallowest and diatoms the deepest layers. Dinoflagellates, Synechococcus and small prymnesiophytes preferred shallow DCM layers, and coccolithophores, chlorophytes and pelagophytes showed a preference for deep layers. Cell size within groups changed with depth in a pattern related to their mean size: the cell volume of the smallest group increased the most with depth while the cell volume of the largest group decreased the most. The vertical alignment of phytoplankton groups confirms that the DCM is not a homogeneous entity and indicates groups’ preferences for different ecological niches within this layer.

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

    Science.gov (United States)

    Bernardara, M.; Tabuada, G.

    2016-06-01

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

  5. Non-commutative analysis

    CERN Document Server

    Jorgensen, Palle

    2017-01-01

    The book features new directions in analysis, with an emphasis on Hilbert space, mathematical physics, and stochastic processes. We interpret 'non-commutative analysis' broadly to include representations of non-Abelian groups, and non-Abelian algebras; emphasis on Lie groups and operator algebras (C* algebras and von Neumann algebras.)A second theme is commutative and non-commutative harmonic analysis, spectral theory, operator theory and their applications. The list of topics includes shift invariant spaces, group action in differential geometry, and frame theory (over-complete bases) and their applications to engineering (signal processing and multiplexing), projective multi-resolutions, and free probability algebras.The book serves as an accessible introduction, offering a timeless presentation, attractive and accessible to students, both in mathematics and in neighboring fields.

  6. A commutator

    Energy Technology Data Exchange (ETDEWEB)

    Matsukura, K.

    1981-06-18

    The synchronous, electric micromotor of a time commutator, by means of a three staged cylindrical gear drive rotates a disk with a semirounded segmented notch, which, in turn, drives a Maltese cross. The gear drum, linked with the Maltese cross rotates a disk with an indicator, equipped with radial, spherical grooves, equidistant from each other. Radially projecting catches, which are used with rotation of the disk to accomplish elastic movement of a vertical shaft under the effect of a three beam, asymmetrical star, are mounted in the disk's grooves by means of spring loaded locking devices, in accordance with the required time technological program. There are driving and locking cams located on the lower end of the shaft. The first is of pear shaped section and provides drive to the microswitch, which commutates the output electrical circuit of the apparatus.

  7. Enveloping algebra-valued gauge transformations for non-abelian gauge groups on non-commutative spaces

    Science.gov (United States)

    Jurco, B.; Schraml, S.; Schupp, P.; Wess, J.

    2000-11-01

    An enveloping algebra-valued gauge field is constructed, its components are functions of the Lie algebra-valued gauge field and can be constructed with the Seiberg-Witten map. This allows the formulation of a dynamics for a finite number of gauge field components on non-commutative spaces.

  8. Enveloping algebra-valued gauge transformations for non-abelian gauge groups on non-commutative spaces

    International Nuclear Information System (INIS)

    Jurco, B.; Schraml, S.; Wess, J.; Schupp, P.

    2000-01-01

    An enveloping algebra-valued gauge field is constructed, its components are functions of the Lie algebra-valued gauge field and can be constructed with the Seiberg-Witten map. This allows the formulation of a dynamics for a finite number of gauge field components on non-commutative spaces. (orig.)

  9. Enveloping algebra-valued gauge transformations for non-abelian gauge groups on non-commutative spaces

    Energy Technology Data Exchange (ETDEWEB)

    Jurco, B. [Max-Planck-Institut fuer Mathematik, Bonn (Germany); Schraml, S.; Wess, J. [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany); Sektion Physik, Universitaet Muenchen, Theresienstrasse 37, 80333 Muenchen (Germany); Schupp, P. [Sektion Physik, Universitaet Muenchen, Theresienstrasse 37, 80333 Muenchen (Germany)

    2000-11-01

    An enveloping algebra-valued gauge field is constructed, its components are functions of the Lie algebra-valued gauge field and can be constructed with the Seiberg-Witten map. This allows the formulation of a dynamics for a finite number of gauge field components on non-commutative spaces. (orig.)

  10. Commuting, Life-Satisfaction and Internet Addiction

    Science.gov (United States)

    Lachmann, Bernd; Sariyska, Rayna; Kannen, Christopher; Stavrou, Maria

    2017-01-01

    The focus of the present work was on the association between commuting (business and private), life satisfaction, stress, and (over-) use of the Internet. Considering that digital devices are omnipresent in buses and trains, no study has yet investigated if commuting contributes to the development of Internet addiction. Overall, N = 5039 participants (N = 3477 females, age M = 26.79, SD = 10.68) took part in an online survey providing information regarding their commuting behavior, Internet addiction, personality, life satisfaction, and stress perception. Our findings are as follows: Personality seems to be less suitable to differentiate between commuter and non-commuter groups, which is possibly due to commuters often not having a choice but simply must accept offered job opportunities at distant locations. Second, the highest levels of satisfaction were found with income and lodging in the group commuting for business purposes. This might be related to the fact that commuting results in higher salaries (hence also better and more expensive housing style) due to having a job in another city which might exceed job opportunities at one’s own living location. Third, within the business-commuters as well as in the private-commuter groups, females had significantly higher levels of stress than males. This association was not present in the non-commuter group. For females, commuting seems to be a higher burden and more stressful than for males, regardless of whether they commute for business or private reasons. Finally, we observed an association between higher stress perception (more negative attitude towards commuting) and Internet addiction. This finding suggests that some commuters try to compensate their perceived stress with increased Internet use. PMID:28981452

  11. Commuting, Life-Satisfaction and Internet Addiction

    Directory of Open Access Journals (Sweden)

    Bernd Lachmann

    2017-10-01

    Full Text Available The focus of the present work was on the association between commuting (business and private, life satisfaction, stress, and (over- use of the Internet. Considering that digital devices are omnipresent in buses and trains, no study has yet investigated if commuting contributes to the development of Internet addiction. Overall, N = 5039 participants (N = 3477 females, age M = 26.79, SD = 10.68 took part in an online survey providing information regarding their commuting behavior, Internet addiction, personality, life satisfaction, and stress perception. Our findings are as follows: Personality seems to be less suitable to differentiate between commuter and non-commuter groups, which is possibly due to commuters often not having a choice but simply must accept offered job opportunities at distant locations. Second, the highest levels of satisfaction were found with income and lodging in the group commuting for business purposes. This might be related to the fact that commuting results in higher salaries (hence also better and more expensive housing style due to having a job in another city which might exceed job opportunities at one’s own living location. Third, within the business-commuters as well as in the private-commuter groups, females had significantly higher levels of stress than males. This association was not present in the non-commuter group. For females, commuting seems to be a higher burden and more stressful than for males, regardless of whether they commute for business or private reasons. Finally, we observed an association between higher stress perception (more negative attitude towards commuting and Internet addiction. This finding suggests that some commuters try to compensate their perceived stress with increased Internet use.

  12. Commuting, Life-Satisfaction and Internet Addiction.

    Science.gov (United States)

    Lachmann, Bernd; Sariyska, Rayna; Kannen, Christopher; Stavrou, Maria; Montag, Christian

    2017-10-05

    The focus of the present work was on the association between commuting (business and private), life satisfaction, stress, and (over-) use of the Internet. Considering that digital devices are omnipresent in buses and trains, no study has yet investigated if commuting contributes to the development of Internet addiction. Overall, N = 5039 participants (N = 3477 females, age M = 26.79, SD = 10.68) took part in an online survey providing information regarding their commuting behavior, Internet addiction, personality, life satisfaction, and stress perception. Our findings are as follows: Personality seems to be less suitable to differentiate between commuter and non-commuter groups, which is possibly due to commuters often not having a choice but simply must accept offered job opportunities at distant locations. Second, the highest levels of satisfaction were found with income and lodging in the group commuting for business purposes. This might be related to the fact that commuting results in higher salaries (hence also better and more expensive housing style) due to having a job in another city which might exceed job opportunities at one's own living location. Third, within the business-commuters as well as in the private-commuter groups, females had significantly higher levels of stress than males. This association was not present in the non-commuter group. For females, commuting seems to be a higher burden and more stressful than for males, regardless of whether they commute for business or private reasons. Finally, we observed an association between higher stress perception (more negative attitude towards commuting) and Internet addiction. This finding suggests that some commuters try to compensate their perceived stress with increased Internet use.

  13. On θ-commutators and the corresponding non-commuting graphs

    Directory of Open Access Journals (Sweden)

    Shalchi S.

    2017-12-01

    Full Text Available The θ-commutators of elements of a group with respect to an automorphism are introduced and their properties are investigated. Also, corresponding to θ-commutators, we define the θ-non-commuting graphs of groups and study their correlations with other notions. Furthermore, we study independent sets in θ-non-commuting graphs, which enable us to evaluate the chromatic number of such graphs.

  14. Commuting in the settlement system of Serbia

    Directory of Open Access Journals (Sweden)

    Lukić Vesna

    2011-01-01

    Full Text Available Territorial organization of settlement system is the framework for internal migration flows. The purpose of this paper is to consider the relation between commuting and the settlement structure. Commuting patterns and characteristics of commuters in Serbia are relatively unknown and insufficiently researched, and as such, can not be adequately used in creation of development strategies and public policies which would include commuters' issues. It has been emphasized the importance of research of commuting ties between different settlements and also pointed out in which way commuting flows could be researched and analyzed by using existing sources, due to better understanding of connections between migrations and settlements. Commuting patterns of workers in Serbia and interrelations between the scope and the structure of commuting flows, as well as the type and population size of settlements in Serbia have been examined. Apart from territorial dimension of commuting phenomenon, socio-economic component of commuting population has also been considered. The use of costumised tabulations from 2002 Census have enabled us to examine all types of commuting and emphasise dominant directions of commuting flows of economically active population according to gender, level of education and sector of economic activity, within the settlement hierarchy. Workers have been classified into seven groups according to place of residence and place of work. The findings reveal there is a clear connection between the hierarchy structure and commuting patterns in Serbia. Further, we find some evidence that only 9,5% of workers - commuters have been working in the settlement of the same population size and type such as their residing settlement. Commuting flows within Serbia’s settlement system point out to certain variations when looking at individual categories of population, but it can be concluded that there is general trend of commuting "upwards" within the

  15. Groups of homeomorphisms of the line. Criteria for the existence of invariant and projectively invariant measures in terms of the commutator subgroup

    Energy Technology Data Exchange (ETDEWEB)

    Beklaryan, L A [Central Economics and Mathematics Institute, RAS, Moscow (Russian Federation)

    2014-12-31

    Existence criteria for invariant and projectively invariant measures are obtained for a group G of homeomorphisms of the line. These criteria are formulated in terms of the commutator subgroup [G,G]. For the special (but very important) case of groups of homeomorphisms of the line containing a freely acting element we obtain a criterion for the existence of a projectively invariant measure in the form of the absence of a special subgroup with two generators in which one of the generating elements is a freely acting element. Bibliography: 20 titles.

  16. A commutator

    Energy Technology Data Exchange (ETDEWEB)

    Siokhara, T.; Khibino, Y.; Tiaki, K.; Vatanabe, K.

    1981-06-22

    Switching of a microswitch, which switches the output electrical circuits of a unit, which supports control of industrial processes in time, is accomplished by a two arm rocking lever. The lever is driven by a cam mechanism, linked with a complex, multistage mechanical drive, which includes cylindrical gear drives and cam couplings for linkage, rotated by a synchronous electric micromotor. The unit is equipped with two subassemblies for establishment of process control: in functions of conditional time and functions of the times of day. The dials of the subassemblies for time establishment, located on the facial panel of the instrument, are equipped with arrows for the assigners with illumination and signal lamps. The lights control the mode of electric power for the instrument and the modes of the output circuits of the commutating subassembly.

  17. Application of Maximum Entropy Distribution to the Statistical Properties of Wave Groups

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The new distributions of the statistics of wave groups based on the maximum entropy principle are presented. The maximum entropy distributions appear to be superior to conventional distributions when applied to a limited amount of information. Its applications to the wave group properties show the effectiveness of the maximum entropy distribution. FFT filtering method is employed to obtain the wave envelope fast and efficiently. Comparisons of both the maximum entropy distribution and the distribution of Longuet-Higgins (1984) with the laboratory wind-wave data show that the former gives a better fit.

  18. Inductive energy storage commutator

    International Nuclear Information System (INIS)

    Gavrilov, I.M.

    1987-01-01

    An inductive energy storage commutator is described. The value of commutated current is up to 800 A, the voltage amplitude in the load is up to 50 kV, the working frequency is equal to 1-50 Hz, the commutated power is up to 40 MW. The commutating device comprises of the first stage commutator having two in-series connected modules of the BTSV - 800/235 high-voltage thyristor unit, the second stage commutator containing three GMI-43A parallel connected powerful pulsed triodes, a commutating capacitor, an induction coil, two supplementary high-voltage thyristor keys (20 in-series connected thyristors T2-300 (13 class)), load, control pulse shapers, thyristor keys, power supply

  19. Commuting patterns of workers in a village of Barddhaman district, West Bengal

    Directory of Open Access Journals (Sweden)

    Bhaswati Mondal

    2015-06-01

    Full Text Available Commuting helps to keep balance between residence and workplace of workers. With growing accessibility and connectivity, the importance of commuting is increasing all over the world. It is becoming a major substitute to migration. In commute-studies, commute-pattern is an important chapter. It highlights commuters’ directions of movement, distance they cover, modes of transport they use, the time they take to commute, etc. Unlike the urban-based commute pattern, commute pattern in rural areas are relatively an under-researched issue. In fact, traditionally rural people are thought to carry a sedentary lifestyle. Using primary data, this study aims to explore the commute patterns of rural workers located in the village of Gandharbapur of Barddhaman district of West Bengal, India. All the commuters were found to be engaged in non-farm work. Commuters stem from two major groups. One group of commuters is accumulated farm-income induced. They possess sufficient agricultural land. Investing their surplus farm-income, they have established non-farm works. The second group of commuters is poverty-driven. They are landless poor or are marginal farmers and to escape poverty, they have slipped into these works. Located beyond the suburban area (Memari being the nearest town, most commuters commute to nearby rural areas. Due to non-availability of public transport, women commute less than men do. Regular-paid government employees commute longer than other workers commute. The article concludes with a summary of findings and recommendations for further research.

  20. Wages and commuting

    DEFF Research Database (Denmark)

    Mulalic, Ismir; Ommeren, Jos N. van; Pilegaard, Ninette

    2011-01-01

    We examine the causal effect of commuting distance on workers' wages in a quasi-natural experiments setting using information on all workers in Denmark. We account for endogeneity of distance by using changes in distance that are due to firms’ relocations. For the range of commuting distances where...... income tax reductions associated with commuting do not apply, one kilometre increase in commuting distance induces a wage increase of about 0.42%, suggesting an hourly compensation of about half of the hourly net wage. Our findings are consistent with wage bargaining theory and suggest a bargaining power...

  1. Analysis of Pairwise Interactions in a Maximum Likelihood Sense to Identify Leaders in a Group

    Directory of Open Access Journals (Sweden)

    Violet Mwaffo

    2017-07-01

    Full Text Available Collective motion in animal groups manifests itself in the form of highly coordinated maneuvers determined by local interactions among individuals. A particularly critical question in understanding the mechanisms behind such interactions is to detect and classify leader–follower relationships within the group. In the technical literature of coupled dynamical systems, several methods have been proposed to reconstruct interaction networks, including linear correlation analysis, transfer entropy, and event synchronization. While these analyses have been helpful in reconstructing network models from neuroscience to public health, rules on the most appropriate method to use for a specific dataset are lacking. Here, we demonstrate the possibility of detecting leaders in a group from raw positional data in a model-free approach that combines multiple methods in a maximum likelihood sense. We test our framework on synthetic data of groups of self-propelled Vicsek particles, where a single agent acts as a leader and both the size of the interaction region and the level of inherent noise are systematically varied. To assess the feasibility of detecting leaders in real-world applications, we study a synthetic dataset of fish shoaling, generated by using a recent data-driven model for social behavior, and an experimental dataset of pharmacologically treated zebrafish. Not only does our approach offer a robust strategy to detect leaders in synthetic data but it also allows for exploring the role of psychoactive compounds on leader–follower relationships.

  2. Weak KAM for commuting Hamiltonians

    International Nuclear Information System (INIS)

    Zavidovique, M

    2010-01-01

    For two commuting Tonelli Hamiltonians, we recover the commutation of the Lax–Oleinik semi-groups, a result of Barles and Tourin (2001 Indiana Univ. Math. J. 50 1523–44), using a direct geometrical method (Stoke's theorem). We also obtain a 'generalization' of a theorem of Maderna (2002 Bull. Soc. Math. France 130 493–506). More precisely, we prove that if the phase space is the cotangent of a compact manifold then the weak KAM solutions (or viscosity solutions of the critical stationary Hamilton–Jacobi equation) for G and for H are the same. As a corollary we obtain the equality of the Aubry sets and of the Peierls barrier. This is also related to works of Sorrentino (2009 On the Integrability of Tonelli Hamiltonians Preprint) and Bernard (2007 Duke Math. J. 136 401–20)

  3. Non-commutative standard model: model building

    CERN Document Server

    Chaichian, Masud; Presnajder, P

    2003-01-01

    A non-commutative version of the usual electro-weak theory is constructed. We discuss how to overcome the two major problems: (1) although we can have non-commutative U(n) (which we denote by U sub * (n)) gauge theory we cannot have non-commutative SU(n) and (2) the charges in non-commutative QED are quantized to just 0,+-1. We show how the latter problem with charge quantization, as well as with the gauge group, can be resolved by taking the U sub * (3) x U sub * (2) x U sub * (1) gauge group and reducing the extra U(1) factors in an appropriate way. Then we proceed with building the non-commutative version of the standard model by specifying the proper representations for the entire particle content of the theory, the gauge bosons, the fermions and Higgs. We also present the full action for the non-commutative standard model (NCSM). In addition, among several peculiar features of our model, we address the inherentCP violation and new neutrino interactions. (orig.)

  4. Commutation and Darboux transformation

    Indian Academy of Sciences (India)

    1College of Military Engineering, Pune 411 031, India. 2Department of ... Liouville equation is a particular application of the commutation method. Darboux ... transformation of a differential operator L, then there exists a differential operator A of.

  5. Commuter Survey-2014

    Data.gov (United States)

    US Agency for International Development — This dataset is the USAID portion of a larger dataset developed by OMB to better understand and to quanity the carbon footprint of the daily commute of government...

  6. Commuting graphs of matrix algebras

    International Nuclear Information System (INIS)

    Akbari, S.; Bidkhori, H.; Mohammadian, A.

    2006-08-01

    The commuting graph of a ring R, denoted by Γ(R), is a graph whose vertices are all non- central elements of R and two distinct vertices x and y are adjacent if and only if xy = yx. The commuting graph of a group G, denoted by Γ(G), is similarly defined. In this paper we investigate some graph theoretic properties of Γ(M n (F)), where F is a field and n ≥ 2. Also we study the commuting graphs of some classical groups such as GL n (F) and SL n (F). We show that Γ(M n (F)) is a connected graph if and only if every field extension of F of degree n contains a proper intermediate field. We prove that apart from finitely many fields, a similar result is true for Γ(GL n (F)) and Γ(SL n (F)). Also we show that for two fields E and F and integers m, n ≥> 2, if Γ(M m (E)) ≅ Γ(M n (F)), then m = n and vertical bar E vertical bar = vertical bar F vertical bar. (author)

  7. RELIABILITY OF THE ONE-REPETITION MAXIMUM TEST BASED ON MUSCLE GROUP AND GENDER

    Directory of Open Access Journals (Sweden)

    Dong-il Seo

    2012-06-01

    Full Text Available The purpose of the present study was to examine the influence of muscle group location and gender on the reliability of assessing the one-repetition maximum (1RM test. Thirty healthy males (n = 15 and females (n = 15 who experienced at least 3 months of continuous resistance training during the last 2 years aged 18-35 years volunteered to participate in the study. The 1RM for the biceps curl, lat pull down, bench press, leg curl, hip flexion, triceps extension, shoulder press, low row, leg extension, hip extension, leg press and squat were measured twice by a trained professional using a standard published protocol. Biceps curl, lat pull down, bench press, leg curl, hip flexion, and squat 1RM's were measured on the first visit, then 48 hours later, subjects returned for their second visit. During their second visit, 1RM of triceps extension, shoulder press, low row, leg extension, hip extension, and leg press were measured. One week from the second visit, participants completed the 1 RM testing as previously done during the first and second visits. The third and fourth visits were separated by 48 hours as well. All four visits to the laboratory were at the same time of day. A high intraclass correlation coefficient (ICC > 0.91 was found for all exercises, independent of gender and muscle group size or location, however there was a significant interaction for muscle group location (upper body vs. lower body in females (p < 0.027. In conclusion, a standardized 1RM testing protocol with a short warm-up and familiarization period is a reliable measurement to assess muscle strength changes regardless of muscle group location or gender

  8. Computational commutative and non-commutative algebraic geometry

    CERN Document Server

    Cojocaru, S; Ufnarovski, V

    2005-01-01

    This publication gives a good insight in the interplay between commutative and non-commutative algebraic geometry. The theoretical and computational aspects are the central theme in this study. The topic is looked at from different perspectives in over 20 lecture reports. It emphasizes the current trends in commutative and non-commutative algebraic geometry and algebra. The contributors to this publication present the most recent and state-of-the-art progresses which reflect the topic discussed in this publication. Both researchers and graduate students will find this book a good source of information on commutative and non-commutative algebraic geometry.

  9. Differential Galois obstructions for non-commutative integrability

    Energy Technology Data Exchange (ETDEWEB)

    Maciejewski, Andrzej J. [Institute of Astronomy, University of Zielona Gora, Podgorna 50, PL-65-246 Zielona Gora (Poland)], E-mail: maciejka@astro.ia.uz.zgora.pl; Przybylska, Maria [Torun Centre for Astronomy, N. Copernicus University, Gagarina 11, PL-87-100 Torun (Poland)], E-mail: mprzyb@astri.uni.torun.pl

    2008-08-11

    We show that if a holomorphic Hamiltonian system is holomorphically integrable in the non-commutative sense in a neighbourhood of a non-equilibrium phase curve which is located at a regular level of the first integrals, then the identity component of the differential Galois group of the variational equations along the phase curve is Abelian. Thus necessary conditions for the commutative and non-commutative integrability given by the differential Galois approach are the same.

  10. Maximum-likelihood estimation of the hyperbolic parameters from grouped observations

    DEFF Research Database (Denmark)

    Jensen, Jens Ledet

    1988-01-01

    a least-squares problem. The second procedure Hypesti first approaches the maximum-likelihood estimate by iterating in the profile-log likelihood function for the scale parameter. Close to the maximum of the likelihood function, the estimation is brought to an end by iteration, using all four parameters...

  11. Commuting, Exercise and Sport

    DEFF Research Database (Denmark)

    Larsen, Jonas

    2018-01-01

    The uniqueness of this article is that it deals with long-distance bike commuting in pro-cycling Copenhagen and its environs. Informed by practice theory and sensuous studies of urban and sport practices, I discuss the ‘things and environments’, ‘meanings’ and ‘competences and biological bodies......’ that typify long-distance commuter cycling. This article develops cycling literature and the ‘mobilities paradigm’ in the following ways: by outlining a practice approach to cycling; challenging the idea that commuter cycling is only for short distances; undermining the distinction between utility and sport...... cycling; and lastly by connecting the ‘mobilities paradigm’ with literature on active travel and sport studies....

  12. Combinatorial commutative algebra

    CERN Document Server

    Miller, Ezra

    2005-01-01

    Offers an introduction to combinatorial commutative algebra, focusing on combinatorial techniques for multigraded polynomial rings, semigroup algebras, and determined rings. The chapters in this work cover topics ranging from homological invariants of monomial ideals and their polyhedral resolutions, to tools for studying algebraic varieties.

  13. Commutative algebra constructive methods finite projective modules

    CERN Document Server

    Lombardi, Henri

    2015-01-01

    Translated from the popular French edition, this book offers a detailed introduction to various basic concepts, methods, principles, and results of commutative algebra. It takes a constructive viewpoint in commutative algebra and studies algorithmic approaches alongside several abstract classical theories. Indeed, it revisits these traditional topics with a new and simplifying manner, making the subject both accessible and innovative. The algorithmic aspects of such naturally abstract topics as Galois theory, Dedekind rings, Prüfer rings, finitely generated projective modules, dimension theory of commutative rings, and others in the current treatise, are all analysed in the spirit of the great developers of constructive algebra in the nineteenth century. This updated and revised edition contains over 350 well-arranged exercises, together with their helpful hints for solution. A basic knowledge of linear algebra, group theory, elementary number theory as well as the fundamentals of ring and module theory is r...

  14. Point-splitting analysis of commutator anomalies in non-abelian chiral gauge theories

    International Nuclear Information System (INIS)

    Ghosh, S.; Banerjee, R.

    1988-01-01

    A gauge covariant point-splitting regularisation is employed to calculate different anomalous commutators in four dimensional chiral gauge theories. For an external gauge field the fixed time anomalous commutator of the gauge group generators is seen to violate the Jacobi identity. The cohomological prediction can be confirmed provided the electric fields do not commute. Other commutators like the current-current and current-electric field are consistent with the Bjorken-Johnson-Low (BJL) derivation. (orig.)

  15. Categories and Commutative Algebra

    CERN Document Server

    Salmon, P

    2011-01-01

    L. Badescu: Sur certaines singularites des varietes algebriques.- D.A. Buchsbaum: Homological and commutative algebra.- S. Greco: Anelli Henseliani.- C. Lair: Morphismes et structures algebriques.- B.A. Mitchell: Introduction to category theory and homological algebra.- R. Rivet: Anneaux de series formelles et anneaux henseliens.- P. Salmon: Applicazioni della K-teoria all'algebra commutativa.- M. Tierney: Axiomatic sheaf theory: some constructions and applications.- C.B. Winters: An elementary lecture on algebraic spaces.

  16. Perfect commuting-operator strategies for linear system games

    Science.gov (United States)

    Cleve, Richard; Liu, Li; Slofstra, William

    2017-01-01

    Linear system games are a generalization of Mermin's magic square game introduced by Cleve and Mittal. They show that perfect strategies for linear system games in the tensor-product model of entanglement correspond to finite-dimensional operator solutions of a certain set of non-commutative equations. We investigate linear system games in the commuting-operator model of entanglement, where Alice and Bob's measurement operators act on a joint Hilbert space, and Alice's operators must commute with Bob's operators. We show that perfect strategies in this model correspond to possibly infinite-dimensional operator solutions of the non-commutative equations. The proof is based around a finitely presented group associated with the linear system which arises from the non-commutative equations.

  17. Associations between long commutes and subjective health complaints among railway workers in Norway

    Directory of Open Access Journals (Sweden)

    Terhi Urhonen

    2016-12-01

    Full Text Available Commuting is an important aspect of daily life for many employees, but there is little knowledge of how this affects individual commuters' health and well-being. The authors investigated the relationship between commuting and subjective health complaints, using data from a web-based questionnaire. In a sample of 2126 railway employees, 644 (30.3% had long commute times. A 29-item inventory was used to measure the number and degree of the subjective health complaints. Those who commuted 60 min or more each way were characterized by significantly higher numbers and degrees of subjective health complaints compared with their peers with short commutes. The mean number of complaints was 7.5 among the former group and 6.4 for the latter group (p = 0.009. In a regression model, in which the authors controlled for age, gender, education, self-rated health, and coping, the employees with long commutes reported more complaints than those with short commutes. Significant associations were found between those with long commutes and the number and degree of incidences of self-reported musculoskeletal pain, pseudo-neurologic complaints, and gastrointestinal problems. Commuters who had had long commutes for more than 10 years reported more gastrointestinal and musculoskeletal complaints than those with long commutes for less than 2 years. Also, commuters with long commutes spent less time with their families and leisure activities compared with those with short commutes. The authors conclude that the association between long commute times and higher levels of subjective health complaints should attract the attention of transport planners, employers, and public health policymaker.

  18. Word posets, with applications to Coxeter groups

    Directory of Open Access Journals (Sweden)

    Matthew J. Samuel

    2011-08-01

    Full Text Available We discuss the theory of certain partially ordered sets that capture the structure of commutation classes of words in monoids. As a first application, it follows readily that counting words in commutation classes is #P-complete. We then apply the partially ordered sets to Coxeter groups. Some results are a proof that enumerating the reduced words of elements of Coxeter groups is #P-complete, a recursive formula for computing the number of commutation classes of reduced words, as well as stronger bounds on the maximum number of commutation classes than were previously known. This also allows us to improve the known bounds on the number of primitive sorting networks.

  19. Radar channel balancing with commutation

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2014-02-01

    When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

  20. What interventions increase commuter cycling? A systematic review.

    Science.gov (United States)

    Stewart, Glenn; Anokye, Nana Kwame; Pokhrel, Subhash

    2015-08-14

    To identify interventions that will increase commuter cycling. All settings where commuter cycling might take place. Adults (aged 18+) in any country. Individual, group or environmental interventions including policies and infrastructure. A wide range of 'changes in commuter cycling' indicators, including frequency of cycling, change in workforce commuting mode, change in commuting population transport mode, use of infrastructure by defined populations and population modal shift. 12 studies from 6 countries (6 from the UK, 2 from Australia, 1 each from Sweden, Ireland, New Zealand and the USA) met the inclusion criteria. Of those, 2 studies were randomised control trials and the remainder preintervention and postintervention studies. The majority of studies (n=7) evaluated individual-based or group-based interventions and the rest environmental interventions. Individual-based or group-based interventions in 6/7 studies were found to increase commuter cycling of which the effect was significant in only 3/6 studies. Environmental interventions, however, had small but positive effects in much larger but more difficult to define populations. Almost all studies had substantial loss to follow-up. Despite commuter cycling prevalence varying widely between countries, robust evidence of what interventions will increase commuter cycling in low cycling prevalence nations is sparse. Wider environmental interventions that make cycling conducive appear to reach out to hard to define but larger populations. This could mean that environmental interventions, despite their small positive effects, have greater public health significance than individual-based or group-based measures because those interventions encourage a larger number of people to integrate physical activity into their everyday lives. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. Non-Commutative Mechanics in Mathematical & in Condensed Matter Physics

    Directory of Open Access Journals (Sweden)

    Peter A. Horváthy

    2006-12-01

    Full Text Available Non-commutative structures were introduced, independently and around the same time, in mathematical and in condensed matter physics (see Table 1. Souriau's construction applied to the two-parameter central extension of the planar Galilei group leads to the ''exotic'' particle, which has non-commuting position coordinates. A Berry-phase argument applied to the Bloch electron yields in turn a semiclassical model that has been used to explain the anomalous/spin/optical Hall effects. The non-commutative parameter is momentum-dependent in this case, and can take the form of a monopole in momentum space.

  2. Testing Non-commutative QED, Constructing Non-commutative MHD

    OpenAIRE

    Guralnik, Z.; Jackiw, R.; Pi, S. Y.; Polychronakos, A. P.

    2001-01-01

    The effect of non-commutativity on electromagnetic waves violates Lorentz invariance: in the presence of a background magnetic induction field b, the velocity for propagation transverse to b differs from c, while propagation along b is unchanged. In principle, this allows a test by the Michelson-Morley interference method. We also study non-commutativity in another context, by constructing the theory describing a charged fluid in a strong magnetic field, which forces the fluid particles into ...

  3. Commutative and Non-commutative Parallelogram Geometry: an Experimental Approach

    OpenAIRE

    Bertram, Wolfgang

    2013-01-01

    By "parallelogram geometry" we mean the elementary, "commutative", geometry corresponding to vector addition, and by "trapezoid geometry" a certain "non-commutative deformation" of the former. This text presents an elementary approach via exercises using dynamical software (such as geogebra), hopefully accessible to a wide mathematical audience, from undergraduate students and high school teachers to researchers, proceeding in three steps: (1) experimental geometry, (2) algebra (linear algebr...

  4. On the Lie groups with the commutation relations of the type [Hsub(i), Hsub(j)]=rsub(ij)Hsub(i)(i

    International Nuclear Information System (INIS)

    Lebedenko, V.M.

    1976-01-01

    The class of PR-groups, i.e., the class of all connected and simply-connected groups of the type mentioned in the title, has been described. A number of properties has been studied and the linear realizations of arbitrary PR-groups have been considered. All the PR-groups are shown to be exponential. It follows from this fact a simple sufficient condition of applicability of the Kirillov orbit method to the construction of the harmonic analysis on concrete groups. Examples of the PR-groups are given which have been already used in theoretical physics

  5. The standard model on non-commutative space-time

    International Nuclear Information System (INIS)

    Calmet, X.; Jurco, B.; Schupp, P.; Wohlgenannt, M.; Wess, J.

    2002-01-01

    We consider the standard model on a non-commutative space and expand the action in the non-commutativity parameter θ μν . No new particles are introduced; the structure group is SU(3) x SU(2) x U(1). We derive the leading order action. At zeroth order the action coincides with the ordinary standard model. At leading order in θ μν we find new vertices which are absent in the standard model on commutative space-time. The most striking features are couplings between quarks, gluons and electroweak bosons and many new vertices in the charged and neutral currents. We find that parity is violated in non-commutative QCD. The Higgs mechanism can be applied. QED is not deformed in the minimal version of the NCSM to the order considered. (orig.)

  6. The standard model on non-commutative space-time

    Energy Technology Data Exchange (ETDEWEB)

    Calmet, X.; Jurco, B.; Schupp, P.; Wohlgenannt, M. [Sektion Physik, Universitaet Muenchen (Germany); Wess, J. [Sektion Physik, Universitaet Muenchen (Germany); Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2002-03-01

    We consider the standard model on a non-commutative space and expand the action in the non-commutativity parameter {theta}{sup {mu}}{sup {nu}}. No new particles are introduced; the structure group is SU(3) x SU(2) x U(1). We derive the leading order action. At zeroth order the action coincides with the ordinary standard model. At leading order in {theta}{sup {mu}}{sup {nu}} we find new vertices which are absent in the standard model on commutative space-time. The most striking features are couplings between quarks, gluons and electroweak bosons and many new vertices in the charged and neutral currents. We find that parity is violated in non-commutative QCD. The Higgs mechanism can be applied. QED is not deformed in the minimal version of the NCSM to the order considered. (orig.)

  7. MIT employee commuter behavior trial.

    Science.gov (United States)

    2013-04-01

    The objectives of the project included the following: : To evaluate the potential impact (in terms of commuter mode shifts) from the introduction of : disruptive technologies at the Massachusetts Institute of Technology in Cambridge, MA, includin...

  8. Computational linear and commutative algebra

    CERN Document Server

    Kreuzer, Martin

    2016-01-01

    This book combines, in a novel and general way, an extensive development of the theory of families of commuting matrices with applications to zero-dimensional commutative rings, primary decompositions and polynomial system solving. It integrates the Linear Algebra of the Third Millennium, developed exclusively here, with classical algorithmic and algebraic techniques. Even the experienced reader will be pleasantly surprised to discover new and unexpected aspects in a variety of subjects including eigenvalues and eigenspaces of linear maps, joint eigenspaces of commuting families of endomorphisms, multiplication maps of zero-dimensional affine algebras, computation of primary decompositions and maximal ideals, and solution of polynomial systems. This book completes a trilogy initiated by the uncharacteristically witty books Computational Commutative Algebra 1 and 2 by the same authors. The material treated here is not available in book form, and much of it is not available at all. The authors continue to prese...

  9. Determinants of long-duration commuting and long-duration commuters' perceptions and attitudes toward commuting time: Evidence from Kunming, China

    Directory of Open Access Journals (Sweden)

    Mingwei He

    2017-04-01

    Full Text Available Understanding the commuting patterns of long-duration commuters and the possible changes in these patterns can help policymakers adopt the more reasonable land use and transportation policies. With Kunming in China as a case study, the determinants of long-duration commuting trips were identified based on logistic regression model. The results indicated that age, education level, number of workers, presence of retirees, and residential location have a significant impact on the occurrence of long-duration commuting trips. The ideal commuting times and tolerance thresholds of commuting time of long-duration commuters were also investigated. The statistical results revealed the distributions of ideal commuting times and tolerance thresholds of commuting time of both short- and long-duration commuters. The average tolerance threshold of commuting time and the average ideal commuting time of long-duration commuters were greater than those of short-duration commuters. For 97.2% of the long-duration commuters, their actual commuting time was longer than the ideal commuting time; this finding indicates that most long-duration commuters are dissatisfied with their commuting time. The actual commuting time of 40.1% long-duration commuters exceeded their tolerance thresholds; these commuters are eager to reduce their commuting time.

  10. Electron commutator on integrated circuits

    International Nuclear Information System (INIS)

    Demidenko, V.V.

    1975-01-01

    The scheme and the parameters of an electron 16-channel contactless commutator based entirely on integrated circuits are described. The device consists of a unit of analog keys based on field-controlled metal-insulator-semiconductor (m.i.s.) transistors, operation amplifier comparators controlling these keys, and a level distributor. The distributor is based on a ''matrix'' scheme and comprises two ring-shaped shift registers plugged in series and a decoder base on two-input logical elements I-NE. The principal dynamical parameters of the circuit are as follows: the control signal delay in the distributor. 50 nsec; the total channel switch-over time, 500-600 nsec. The commutator transmits both constant signals and pulses whose duration reaches tens of nsec. The commutator can be used in data acquisition and processing systems, for shaping complicated signals (for example), (otherwise signals), for simultaneous oscillographing of several signals, and so forth [ru

  11. P-commutative topological *-algebras

    International Nuclear Information System (INIS)

    Mohammad, N.; Thaheem, A.B.

    1991-07-01

    If P(A) denotes the set of all continuous positive functionals on a unital complete Imc *-algebra and S(A) the extreme points of P(A), and if the spectrum of an element χ Ε A coincides with the set {f(χ): f Ε S(A)}, then A is shown to be P-commutative. Moreover, if A is unital symmetric Frechet Q Imc *-algebra, then this spectral condition is, in fact, necessary. Also, an isomorphism theorem between symmetric Frechet P-commutative Imc *-algebras is established. (author). 12 refs

  12. Active Commuting: Workplace Health Promotion for Improved Employee Well-Being and Organizational Behavior.

    Science.gov (United States)

    Page, Nadine C; Nilsson, Viktor O

    2016-01-01

    Objective: This paper describes a behavior change intervention that encourages active commuting using electrically assisted bikes (e-bikes) for health promotion in the workplace. This paper presents the preliminary findings of the intervention's impact on improving employee well-being and organizational behavior, as an indicator of potential business success. Method: Employees of a UK-based organization participated in a workplace travel behavior change intervention and used e-bikes as an active commuting mode; this was a change to their usual passive commuting behavior. The purpose of the intervention was to develop employee well-being and organizational behavior for improved business success. We explored the personal benefits and organizational co-benefits of active commuting and compared these to a travel-as-usual group of employees who did not change their behavior and continued taking non-active commutes. Results: Employees who changed their behavior to active commuting reported more positive affect, better physical health and more productive organizational behavior outcomes compared with passive commuters. In addition, there was an interactive effect of commuting mode and commuting distance: a more frequent active commute was positively associated with more productive organizational behavior and stronger overall positive employee well-being whereas a longer passive commute was associated with poorer well-being, although there was no impact on organizational behavior. Conclusion: This research provides emerging evidence of the value of an innovative workplace health promotion initiative focused on active commuting in protecting and improving employee well-being and organizational behavior for stronger business performance. It considers the significant opportunities for organizations pursuing improved workforce well-being, both in terms of employee health, and for improved organizational behavior and business success.

  13. Non-commutative and commutative vacua effects in a scalar torsion scenario

    Energy Technology Data Exchange (ETDEWEB)

    Sheikhahmadi, Haidar, E-mail: h.sh.ahmadi@gmail.com [Department of Physics, Faculty of Science, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Aghamohammadi, Ali, E-mail: a.aghamohamadi@iausdj.ac.ir [Sanandaj Branch, Islamic Azad University, Sanandaj (Iran, Islamic Republic of); Saaidi, Khaled, E-mail: ksaaidi@uok.ac.ir [Department of Physics, Faculty of Science, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2015-10-07

    In this work, the effects of non-commutative and commutative vacua on the phase space generated by a scalar field in a scalar torsion scenario are investigated. For both classical and quantum regimes, the commutative and non-commutative cases are compared. To take account the effects of non-commutativity, two well known non-commutative parameters, θ and β, are introduced. It should be emphasized, the effects of β which is related to momentum sector has more key role in comparison to θ which is related to space sector. Also the different boundary conditions and mathematical interpretations of non-commutativity are explored.

  14. Non-commutative and commutative vacua effects in a scalar torsion scenario

    International Nuclear Information System (INIS)

    Sheikhahmadi, Haidar; Aghamohammadi, Ali; Saaidi, Khaled

    2015-01-01

    In this work, the effects of non-commutative and commutative vacua on the phase space generated by a scalar field in a scalar torsion scenario are investigated. For both classical and quantum regimes, the commutative and non-commutative cases are compared. To take account the effects of non-commutativity, two well known non-commutative parameters, θ and β, are introduced. It should be emphasized, the effects of β which is related to momentum sector has more key role in comparison to θ which is related to space sector. Also the different boundary conditions and mathematical interpretations of non-commutativity are explored.

  15. Non-commutative and commutative vacua effects in a scalar torsion scenario

    Directory of Open Access Journals (Sweden)

    Haidar Sheikhahmadi

    2015-10-01

    Full Text Available In this work, the effects of non-commutative and commutative vacua on the phase space generated by a scalar field in a scalar torsion scenario are investigated. For both classical and quantum regimes, the commutative and non-commutative cases are compared. To take account the effects of non-commutativity, two well known non-commutative parameters, θ and β, are introduced. It should be emphasized, the effects of β which is related to momentum sector has more key role in comparison to θ which is related to space sector. Also the different boundary conditions and mathematical interpretations of non-commutativity are explored.

  16. 8 CFR 211.5 - Alien commuters.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent residence.... An alien commuter engaged in seasonal work will be presumed to have taken up residence in the United...

  17. Commutation relations for functions of operators

    International Nuclear Information System (INIS)

    Transtrum, Mark K.; Van Huele, Jean-Francois S.

    2005-01-01

    We derive an expression for the commutator of functions of operators with constant commutations relations in terms of the partial derivatives of these functions. This result extends the well-known commutation relation between one operator and a function of another operator. We discuss the range of applicability of the formula with examples in quantum mechanics

  18. Covariant Gauss law commutator anomaly

    International Nuclear Information System (INIS)

    Dunne, G.V.; Trugenberger, C.A.; Massachusetts Inst. of Tech., Cambridge

    1990-01-01

    Using a (fixed-time) hamiltonian formalism we derive a covariant form for the anomaly in the commutator algebra of Gauss law generators for chiral fermions interacting with a dynamical non-abelian gauge field in 3+1 dimensions. (orig.)

  19. Workers' marginal costs of commuting

    DEFF Research Database (Denmark)

    van Ommeren, Jos; Fosgerau, Mogens

    2009-01-01

    This paper applies a dynamic search model to estimate workers' marginal costs of commuting, including monetary and time costs. Using data on workers' job search activity as well as moving behaviour, for the Netherlands, we provide evidence that, on average, workers' marginal costs of one hour...

  20. On commuting operator exponentials, II

    Indian Academy of Sciences (India)

    where N is an unbounded normal operator and M is a bounded normal operator in the. Hilbert space. Keywords. Self-adjoint and normal operator; commuting normal operator exponent- ials; Borel functional calculus. 1. Introduction. Let E be a complex Hilbert space and let B(E) be the algebra of bounded linear operators.

  1. On CNC Commuting Contractive Tuples

    Indian Academy of Sciences (India)

    The characteristic function has been an important tool for studying completely non-unitary contractions on Hilbert spaces. In this note, we consider completely non-coisometric contractive tuples of commuting operators on a Hilbert space H . We show that the characteristic function, which is now an operator-valued analytic ...

  2. Fractional charge and anomalous commutators

    International Nuclear Information System (INIS)

    Frishman, Y.; Gepner, D.

    1983-06-01

    Non-integer charges on topological objects in the presence of fermions are further investigated. The connection with anomalous commutators is discussed. The reason for the identical results in two-dimensional solutions and four-dimensional monopoles is pointed out. (author)

  3. On commutativity theorems for rings

    Directory of Open Access Journals (Sweden)

    H. A. S. Abujabal

    1990-01-01

    Full Text Available Let R be an associative ring with unity. It is proved that if R satisfies the polynomial identity [xny−ymxn,x]=0(m>1,n≥1, then R is commutative. Two or more related results are also obtained.

  4. Summable Family in a Commutative Group

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2015-12-01

    Full Text Available Hölzl et al. showed that it was possible to build “a generic theory of limits based on filters” in Isabelle/HOL [22], [7]. In this paper we present our formalization of this theory in Mizar [6].

  5. Non-commutative flux representation for loop quantum gravity

    Science.gov (United States)

    Baratin, A.; Dittrich, B.; Oriti, D.; Tambornino, J.

    2011-09-01

    The Hilbert space of loop quantum gravity is usually described in terms of cylindrical functionals of the gauge connection, the electric fluxes acting as non-commuting derivation operators. It has long been believed that this non-commutativity prevents a dual flux (or triad) representation of loop quantum gravity to exist. We show here, instead, that such a representation can be explicitly defined, by means of a non-commutative Fourier transform defined on the loop gravity state space. In this dual representation, flux operators act by sstarf-multiplication and holonomy operators act by translation. We describe the gauge invariant dual states and discuss their geometrical meaning. Finally, we apply the construction to the simpler case of a U(1) gauge group and compare the resulting flux representation with the triad representation used in loop quantum cosmology.

  6. Non-commutativity in polar coordinates

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, James P. [Universidad Michoacana de San Nicolas de Hidalgo, Ciudad Universitaria, Instituto de Fisica y Matematicas, Morelia, Michoacan (Mexico)

    2017-05-15

    We reconsider the fundamental commutation relations for non-commutative R{sup 2} described in polar coordinates with non-commutativity parameter θ. Previous analysis found that the natural transition from Cartesian coordinates to the traditional polar system led to a representation of [r, φ] as an everywhere diverging series. In this article we compute the Borel resummation of this series, showing that it can subsequently be extended throughout parameter space and hence provide an interpretation of this commutator. Our analysis provides a complete solution for arbitrary r and θ that reproduces the earlier calculations at lowest order and benefits from being generally applicable to problems in a two-dimensional non-commutative space. We compare our results to previous literature in the (pseudo-)commuting limit, finding a surprising spatial dependence for the coordinate commutator when θ >> r{sup 2}. Finally, we raise some questions for future study in light of this progress. (orig.)

  7. Non-commutative covering spaces and their symmetries

    DEFF Research Database (Denmark)

    Canlubo, Clarisson

    dened and its corresponding Galois theory. Using this and basic concepts from algebraic geometryand spectral theory, we will give a full description of the general structure of non-centralcoverings. Examples of coverings of the rational and irrational non-commutative tori will alsobe studied. Using...... will explain this and relate it to bi-Galois theory.Using the OZ-transform, we will show that non-commutative covering spaces come in pairs.Several categories of covering spaces will be dened and studied. Appealing to Tannaka duality,we will explain how this lead to a notion of an etale fundamental group...

  8. Predicting the start and maximum amplitude of solar cycle 24 using similar phases and a cycle grouping

    International Nuclear Information System (INIS)

    Wang Jialong; Zong Weiguo; Le Guiming; Zhao Haijuan; Tang Yunqiu; Zhang Yang

    2009-01-01

    We find that the solar cycles 9, 11, and 20 are similar to cycle 23 in their respective descending phases. Using this similarity and the observed data of smoothed monthly mean sunspot numbers (SMSNs) available for the descending phase of cycle 23, we make a date calibration for the average time sequence made of the three descending phases of the three cycles, and predict the start of March or April 2008 for cycle 24. For the three cycles, we also find a linear correlation of the length of the descending phase of a cycle with the difference between the maximum epoch of this cycle and that of its next cycle. Using this relationship along with the known relationship between the rise-time and the maximum amplitude of a slowly rising solar cycle, we predict the maximum SMSN of cycle 24 of 100.2 ± 7.5 to appear during the period from May to October 2012. (letters)

  9. A note on maximal commutators and commutators of maximal functions

    Czech Academy of Sciences Publication Activity Database

    Agcayazi, M.; Gogatishvili, Amiran; Koca, K.; Mustafayev, R.

    2015-01-01

    Roč. 67, č. 2 (2015), s. 581-593 ISSN 0025-5645 R&D Projects: GA ČR GA13-14743S; GA ČR GA201/08/0383 Institutional support: RVO:67985840 Keywords : macimal operator * commutator * BMO Subject RIV: BA - General Mathematics Impact factor: 0.524, year: 2015 http://projecteuclid.org/euclid.jmsj/1429624595

  10. Non-commutative Nash inequalities

    International Nuclear Information System (INIS)

    Kastoryano, Michael; Temme, Kristan

    2016-01-01

    A set of functional inequalities—called Nash inequalities—are introduced and analyzed in the context of quantum Markov process mixing. The basic theory of Nash inequalities is extended to the setting of non-commutative L p spaces, where their relationship to Poincaré and log-Sobolev inequalities is fleshed out. We prove Nash inequalities for a number of unital reversible semigroups

  11. Analysis of Subway Interior Noise at Peak Commuter Time.

    Science.gov (United States)

    Lee, Donguk; Kim, Gibbeum; Han, Woojae

    2017-07-01

    Although mass transit systems are convenient and efficient for urban people, little attention has been paid to the potential hearing hazard from their noise. The purpose of the current study was to measure and analyze levels of subway interior noise at peak commuter times and to provide information about commuters' daily dose of noise exposure. To measure the subway interior noise, nine subway lines inside Seoul (i.e., lines 1-9) and six lines surrounding the capital city area (i.e., Central, Bundang, Sinbundang, Incheon, Gyeongui, and Gyeongchun) were chosen. The noise was measured and recorded by a sound level meter for two-hour periods in the morning and evening. 1) In the LZeq analysis, the average noise level of all 15 lines was 72.78 dB; the maximum and minimum noise levels were 78.34 and 62.46 dB, respectively. The average noise level of the nine lines inside Seoul was 73.45 dB, which was 1.68-dB louder than that of the six lines surrounding the capital city area. 2) Based on the LZeq analysis of 33 measured frequencies, 12.5 Hz was the highest frequency and 20,000 Hz was the lowest. 3) There was no remarkable difference in the level of subway interior noise between morning and evening peak commuter times. We concluded that the level of subway interior noise was not loud enough for commuters to incur noise-induced hearing loss. Regardless, environmental noise control efforts in the subway system might be needed for commuters who take a subway every day.

  12. When is Commuting Desirable to the Individual?

    OpenAIRE

    Ory, David T.; Mokhtarian, Patricia L.; Redmond, Lothlorien S.; Collantes, Gustavo O.; Choo, Sangho

    2004-01-01

    Commuting is popularly viewed as a stressful, costly, time-wasting experience from the individual perspective, with the attendant congestion imposing major social costs as well. However, several authors have noted that commuting can also offer benefits to the individual, serving as a valued transition between the home and work realms of personal life. Using survey data collected from about 1,300 commuting workers in three San Francisco Bay Area neighborhoods, empirical models are developed fo...

  13. When is Commuting Desirable to the Individual?

    OpenAIRE

    Ory, D T; Mokhtarian, Patricia L; Redmond, Lothlorien; Salomon, Ilan; Collantes, G O; Choo, Sangho

    2004-01-01

    Commuting is popularly viewed as a stressful, costly, time-wasting experience from the individual perspective, with the attendant congestion imposing major social costs as well. However, several authors have noted that commuting can also offer benefits to the individual, serving as a valued transition between the home and work realms of personal life. Using survey data collected from about 1,300 commuting workers in three San Francisco Bay Area neighborhoods, we develop empirical models for f...

  14. Non-commutative tomography and signal processing

    International Nuclear Information System (INIS)

    Mendes, R Vilela

    2015-01-01

    Non-commutative tomography is a technique originally developed and extensively used by Professors M A Man’ko and V I Man’ko in quantum mechanics. Because signal processing deals with operators that, in general, do not commute with time, the same technique has a natural extension to this domain. Here, a review is presented of the theory and some applications of non-commutative tomography for time series as well as some new results on signal processing on graphs. (paper)

  15. The consequences of a reduction in the administratively applied maximum annual dose equivalent level for an individual in a group of occupationally exposed workers

    International Nuclear Information System (INIS)

    Harrison, N.T.

    1980-02-01

    An analysis is described for predicting the consequences of a reduction in the administratively applied maximum dose equivalent level to individuals in a group of workers occupationally exposed to ionising radiations, for the situation in which no changes are made to the working environment. This limitation of the maximum individual dose equivalent is accommodated by allowing the number of individuals in the working group to increase. The derivation of the analysis is given, together with worked examples, which highlight the important assumptions that have been made and the conclusions that can be drawn. The results are obtained in the form of the capacity of the particular working environment to accommodate the limitation of the maximum individual dose equivalent, the increase in the number of workers required to carry out the productive work and any consequent increase in the occupational collective dose equivalent. (author)

  16. Commutation circuit for an HVDC circuit breaker

    Science.gov (United States)

    Premerlani, William J.

    1981-01-01

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components.

  17. Commutated automatic gain control system

    Science.gov (United States)

    Yost, S. R.

    1982-01-01

    A commutated automatic gain control (AGC) system was designed and built for a prototype Loran C receiver. The receiver uses a microcomputer to control a memory aided phase-locked loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The circuit designed for the AGC is described, and bench and flight test results are presented. The AGC circuit described actually samples starting at a point 40 microseconds after a zero crossing determined by the software lock pulse ultimately generated by a 30 microsecond delay and add network in the receiver front end envelope detector.

  18. Active commuting and sociodemographic factors among university students in Spain.

    Science.gov (United States)

    Molina-García, Javier; Sallis, James F; Castillo, Isabel

    2014-02-01

    Commuting to university represents an opportunity to incorporate physical activity (walking or biking) into students' daily routines. There are few studies that analyze patterns of transport in university populations. This cross-sectional study estimated energy expenditure from active commuting to university (ACU) and examined sociodemographic differences in findings. The sample included 518 students with a mean age of 22.4 years (59.7% female) from 2 urban universities in Valencia, Spain. Time spent in each mode of transport to university and sociodemographic factors was assessed by self-report. Nearly 35% of the students reported walking or biking as their main mode of transport. ACU (min/wk) were highest for walkers (168) and cyclists (137) and lowest for motorbike riders (0.0) and car drivers (16). Public transport users, younger students, low socioeconomic status students, and those living ≤ 2 km from the university had higher energy expenditure from active commuting than comparison groups. Biking was highest among those living 2-5 km from the university. Our findings suggest that active commuting and public transit use generated substantial weekly energy expenditure, contributed to meeting physical activity recommendations, and may aid in obesity prevention.

  19. Bonding in Heavier Group 14 Zero-Valent Complexes-A Combined Maximum Probability Domain and Valence Bond Theory Approach.

    Science.gov (United States)

    Turek, Jan; Braïda, Benoît; De Proft, Frank

    2017-10-17

    The bonding in heavier Group 14 zero-valent complexes of a general formula L 2 E (E=Si-Pb; L=phosphine, N-heterocyclic and acyclic carbene, cyclic tetrylene and carbon monoxide) is probed by combining valence bond (VB) theory and maximum probability domain (MPD) approaches. All studied complexes are initially evaluated on the basis of the structural parameters and the shape of frontier orbitals revealing a bent structural motif and the presence of two lone pairs at the central E atom. For the VB calculations three resonance structures are suggested, representing the "ylidone", "ylidene" and "bent allene" structures, respectively. The influence of both ligands and central atoms on the bonding situation is clearly expressed in different weights of the resonance structures for the particular complexes. In general, the bonding in the studied E 0 compounds, the tetrylones, is best described as a resonating combination of "ylidone" and "ylidene" structures with a minor contribution of the "bent allene" structure. Moreover, the VB calculations allow for a straightforward assessment of the π-backbonding (E→L) stabilization energy. The validity of the suggested resonance model is further confirmed by the complementary MPD calculations focusing on the E lone pair region as well as the E-L bonding region. Likewise, the MPD method reveals a strong influence of the σ-donating and π-accepting properties of the ligand. In particular, either one single domain or two symmetrical domains are found in the lone pair region of the central atom, supporting the predominance of either the "ylidene" or "ylidone" structures having one or two lone pairs at the central atom, respectively. Furthermore, the calculated average populations in the lone pair MPDs correlate very well with the natural bond orbital (NBO) populations, and can be related to the average number of electrons that is backdonated to the ligands. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Factors affecting commuter rail energy efficiency.

    Science.gov (United States)

    2016-02-17

    The objective of this study is to develop a planninglevel model of commuter rail energy efficiency. The : environmental benefits of commuter rail are often cited as one of the key benefits and motivators for its rapid development as a public trans...

  1. Active commuting: prevalence, barriers, and associated variables.

    Science.gov (United States)

    Silva, Kelly Samara; Vasques, Daniel Giordani; Martins, Caroline de Oliveira; Williams, Laura Ashley; Lopes, Adair S

    2011-08-01

    Research has demonstrated that adolescents who actively commute have higher levels of physical activity (PA), which have declined precipitously over the past 30 years. The purpose of this study was to describe the prevalence of active commuting to school; and to identify barriers associated with active commuting. A cross-sectional study was conducted with 1672 students (46.8% boys and 53.2% girls) from 11 to 17 years of age in Caxias do Sul/RS, Brazil. The students were asked to answer questionnaires about active transport, PA, and sedentary behaviors. They also completed a cardiovascular fitness test and body composition measurements. The study used a multivariate Poisson regression analysis. A total of 62.5% of students were observed to actively commute and the prevalence ratio (PR) of not actively commuting was associated with the type of school (Private: 2.41; 1.47, 3.95) and the time spent on commuting (>20 min: 1.93; 1.23, 3.03). The associated barriers to passive commuting were distance (3.02; 1.95, 4.71), crime/danger (2.65; 1.82, 3.85), and traffic (1.75; 1.19, 2.58). This study showed that environmental variables were strongly associated with active commuting. However, no alterations in body composition or other behavioral variables were observed after adjustment.

  2. Commuting quantum traces for quadratic algebras

    International Nuclear Information System (INIS)

    Nagy, Zoltan; Avan, Jean; Doikou, Anastasia; Rollet, Genevieve

    2005-01-01

    Consistent tensor products on auxiliary spaces, hereafter denoted 'fusion procedures', and commuting transfer matrices are defined for general quadratic algebras, nondynamical and dynamical, inspired by results on reflection algebras. Applications of these procedures then yield integer-indexed families of commuting Hamiltonians

  3. Prime alternative algebras that are nearly commutative

    International Nuclear Information System (INIS)

    Pchelintsev, S V

    2004-01-01

    We prove that by deforming the multiplication in a prime commutative alternative algebra using a C-operation we obtain a prime non-commutative alternative algebra. Under certain restrictions on non-commutative algebras this relation between algebras is reversible. Isotopes are special cases of deformations. We introduce and study a linear space generated by the Bruck C-operations. We prove that the Bruck space is generated by operations of rank 1 and 2 and that 'general' Bruck operations of rank 2 are independent in the following sense: a sum of n operations of rank 2 cannot be written as a linear combination of (n-1) operations of rank 2 and an arbitrary operation of rank 1. We describe infinite series of non-isomorphic prime non-commutative algebras of bounded degree that are deformations of a concrete prime commutative algebra

  4. Causality, spin, and equal-time commutators

    International Nuclear Information System (INIS)

    Abdel-Rahman, A.M.

    1975-01-01

    We study the causality constraints on the structure of the Lorentz-antisymmetric component of the commutator of two conserved isovector currents between fermion states of equal momenta. We discuss the sum rules that follow from causality and scaling, using the recently introduced refined infinite-momentum technique. The complete set of sum rules is found to include the spin-dependent fixed-mass sum rules obtained from light-cone commutators. The causality and scaling restrictions on the structure of the electromagnetic equal-time commutators are discussed, and it is found, in particular, that causality requires the spin-dependent part of the matrix element for the time-space electromagnetic equal-time commutator to vanish identically. It is also shown, in comparison with the electromagnetic case, that the corresponding matrix element for the time-space isovector current equal-time commutator is required, by causality, to have isospin-antisymmetric tensor and scalar operator Schwinger terms

  5. NYPA/TH!NK Clean Commute Program Final Report - Inception through December 2004

    Energy Technology Data Exchange (ETDEWEB)

    James Francfort; Don Karner

    2005-11-01

    The Clean Commute Program uses TH!NK city electric vehicles from Ford Motor Company’s electric vehicle group, TH!NK Mobility, to demonstrate the feasibility of using electric transportation in urban applications. Suburban New York City railroad commuters use the TH!NK city vehicles to commute from their private residences to railroad stations, where they catch commuter trains into New York City. Electric vehicle charging infrastructure for the TH!NK city vehicles is located at the commuters’ private residences as well as seven train stations. Ford leased at total of 97 TH!NK city electric vehicles to commuters from Westchester, Putnam, Rockland, Queens, Nassau, and Suffolk counties for $199 per month. First Clean Commute Program vehicle deliveries occurred late in 2001, with data collection commencing in February 2002. Through May, 2004, 24 of the lessees have returned their vehicles to Ford and no longer participate in the Clean Commute Program. Reasons given for leaving the Program include relocation out of the Program area, change in employment status, change in commuting status, and, in a few cases, dissatisfaction with the vehicle. Additionally, 13 vehicles were returned to Ford when the lease was completed. In August 2002, Ford announced that it was ceasing production of the TH!NK city and would not extend any TH!NK city leases. Mileage accumulation dropped in the last quarter of the program as vehicle leases were returned to Ford. The impact of the program overall was significant as participants in the Clean Commute Program drove their vehicles over 406,074 miles, avoiding the use of over 18,887 gallons of gasoline. During the active portion of the program, the TH!NK city vehicles were driven an average of between 180 and 230 miles per month. Over 95% of all trips taken with the TH!NK city vehicles replaced trips previously taken in gasoline vehicles. This report covers the period from Program inception through December 2004.

  6. NYPA/TH!NK Clean Commute Program Report – Inception Through May 2004

    Energy Technology Data Exchange (ETDEWEB)

    Don Karner; James Francfort; Randall Solomon

    2004-11-01

    The Clean Commute Program uses TH!NK city electric vehicles from Ford Motor Company’s electric vehicle group, TH!NK Mobility, to demonstrate the feasibility of using electric vehicles for transportation in urban applications. Suburban New York City railroad commuters use the TH!NK city vehicles to commute from their private residences to railroad stations, where they catch commuter trains into New York City. Electric vehicle charging infrastructure for the TH!NK city vehicles is located at the commuters’ private residences as well as seven train stations. Ford leased 97 TH!NK city electric vehicles to commuters from Westchester, Putnam, Rockland, Queens, Nassau, and Suffolk counties for $199 per month per vehicle. The first Clean Commute Program vehicle deliveries occurred late in 2001, with data collection commencing in February 2002. Through May 2004, 24 of the lessees have returned their vehicles to Ford and no longer participate in the Clean Commute Program. Reasons given for returning the vehicles include relocation out of the Program area, change in employment status, change in commuting status, and, in a few cases, dissatisfaction with the vehicle. Additionally, 13 vehicles have been returned to Ford as their leases have completed. In August 2002, Ford announced that it was ceasing production of the TH!NK city and would not extend any TH!NK city leases. Through May 2004, participants in the Clean Commute Program have driven their vehicles over 370,000 miles, avoiding the use of over 17,000 gallons of gasoline. The TH!NK city vehicles are driven an average of between 180 and 230 miles per month, and over 95% of all trips taken with the TH!NK city vehicles replace trips previously taken in gasoline vehicles. This report covers the period from Program inception through May 2004.

  7. Commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi.

    Science.gov (United States)

    Kumar, Pramod; Gupta, N C

    2016-01-15

    A public health concern is to understand the linkages between specific pollution sources and adverse health impacts. Commuting can be viewed as one of the significant-exposure activity in high-vehicle density areas. This paper investigates the commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi, India. Air pollution levels are significantly contributed by automobile exhaust and also in-vehicle exposure can be higher sometime than ambient levels. Motorcycle, auto rickshaw, car and bus were selected to study particles concentration along two routes in Delhi between Kashmere Gate and Dwarka. The bus and auto rickshaw were running on compressed natural gas (CNG) while the car and motorcycle were operated on gasoline fuel. Aerosol spectrometer was employed to measure inhalable, thoracic and alveolic particles during morning and evening rush hours for five weekdays. From the study, we observed that the concentration levels of these particles were greatly influenced by transportation modes. Concentrations of inhalable particles were found higher during morning in auto rickshaw (332.81 ± 90.97 μg/m(3)) while the commuter of bus exhibited higher exposure of thoracic particles (292.23 ± 110.45 μg/m(3)) and car commuters were exposed to maximum concentrations of alveolic particles (222.37 ± 26.56 μg/m(3)). We observed that in evening car commuters experienced maximum concentrations of all sizes of particles among the four commuting modes. Interestingly, motorcycle commuters were exposed to lower levels of inhalable and thoracic particles during morning and evening hours as compared to other modes of transport. The mean values were found greater than the median values for all the modes of transport suggesting that positive skewed distributions are characteristics of naturally occurring phenomenon. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. The theory of finitely generated commutative semigroups

    CERN Document Server

    Rédei, L; Stark, M; Gravett, K A H

    1966-01-01

    The Theory of Finitely Generated Commutative Semigroups describes a theory of finitely generated commutative semigroups which is founded essentially on a single """"fundamental theorem"""" and exhibits resemblance in many respects to the algebraic theory of numbers. The theory primarily involves the investigation of the F-congruences (F is the the free semimodule of the rank n, where n is a given natural number). As applications, several important special cases are given. This volume is comprised of five chapters and begins with preliminaries on finitely generated commutative semigroups before

  9. Multiplication modules over non-commutative rings

    International Nuclear Information System (INIS)

    Tuganbaev, A A

    2003-01-01

    It is proved that each submodule of a multiplication module over a regular ring is a multiplicative module. If A is a ring with commutative multiplication of right ideals, then each projective right ideal is a multiplicative module, and a finitely generated A-module M is a multiplicative module if and only if all its localizations with respect to maximal right ideals of A are cyclic modules over the corresponding localizations of A. In addition, several known results on multiplication modules over commutative rings are extended to modules over not necessarily commutative rings

  10. On the interrelations between migration and commuting

    Directory of Open Access Journals (Sweden)

    Lukić Vesna

    2013-01-01

    Full Text Available In this paper, we emphasise the significance of studying the interrelations between commuting and migration. The aim of the paper is to point out the factors which affect these interrelations (demographic and socio-economic characteristics of migrants and commuters, labour market, real estate market, information, life style, etc., with the special emphasis on the role of commuting distance onto the chosen mobility type. Besides theorethical frameworks and results of the selected foreign researches up to date, the overview of research of interrelations between migration and commuting in Serbia has also been presented. While earlier studies conducted by Gawryszenski (1978, Termote (1980 and Reitsma&Vergoossen (1987 pointed to the replacement of migration types between each other within country, in recent literature the interaction between migration and commuting has been studied in a trans-boundary context of the contemporary EU. Modern trend of long distance commuting instead of migration and the concept of substitution/replacement regarding migration and commuting have also been discussed. In Serbia, there is a positive correlation between commuting outflows and immigration in rural settlements of Vojvodina province. Namely, commuting and migration are complement, which is the characteristic of both processes sub-urbanisation and ex-urbanisation (Lukić, 2012. In addition to ownership of real estate and previous migration experience, marital status influenced the chosen mobility type in Serbia as well. Adjustment to changes of Serbian labour market is mostly conducted via migration (Miletić, Lukić, Miljanović, 2011. Interrelations between migration and commuting are very significant due to the tendency of transformation of some commuters into migrants. This process has its consequences, both on demographic as well as the overall socio-economic development of the area of commuters’ origin and destination. However, even though the surveys

  11. Two-dimensional black holes and non-commutative spaces

    International Nuclear Information System (INIS)

    Sadeghi, J.

    2008-01-01

    We study the effects of non-commutative spaces on two-dimensional black hole. The event horizon of two-dimensional black hole is obtained in non-commutative space up to second order of perturbative calculations. A lower limit for the non-commutativity parameter is also obtained. The observer in that limit in contrast to commutative case see two horizon

  12. Commuter Shopping : A study in understanding commuting in the context of shopping

    OpenAIRE

    Andersson, Åsa; Skoog, Sara; Svensson, Johanna

    2014-01-01

    Background For ages people have commuted to work, or to other activities, located outside their home municipality. Statements found indicate that the basic decision for commuting are based on utility maximisation and no matter what the character of the benefit is; it should be higher than what can be found closer to the home location. This thesis aims to investigate if people are also commuting with the purpose of obtaining benefits from shopping. The shopping location will in this thesis be ...

  13. Application of commutator theorems to the integration of representations of Lie algebras and commutation relations

    International Nuclear Information System (INIS)

    Froehlich, J.

    1977-01-01

    Sufficient conditions on unbounded, symmetric operators A and B which imply that exp(itA)exp(isB)exp(-itA) satisfies the well known 'multiple commutator' formula are derived. This formula is then applied to prove new necessary and sufficient conditions for the integrability of representations of Lie algebras and canonical commutation relations and the commutativity of the spectral projections of two commuting, unbounded, self-adjoint operators. A classic theorem of Nelson's is obtained as a corollary. Our results are useful in relativistic quantum field theory. (orig.) [de

  14. Foundations of commutative rings and their modules

    CERN Document Server

    Wang, Fanggui

    2016-01-01

    This book provides an introduction to the basics and recent developments of commutative algebra. A glance at the contents of the first five chapters shows that the topics covered are ones that usually are included in any commutative algebra text. However, the contents of this book differ significantly from most commutative algebra texts: namely, its treatment of the Dedekind–Mertens formula, the (small) finitistic dimension of a ring, Gorenstein rings, valuation overrings and the valuative dimension, and Nagata rings. Going further, Chapter 6 presents w-modules over commutative rings as they can be most commonly used by torsion theory and multiplicative ideal theory. Chapter 7 deals with multiplicative ideal theory over integral domains. Chapter 8 collects various results of the pullbacks, especially Milnor squares and D+M constructions, which are probably the most important example-generating machines. In Chapter 9, coherent rings with finite weak global dimensions are probed, and the local ring of weak gl...

  15. Reversal thyristor-relay direct current commutator

    International Nuclear Information System (INIS)

    Ivanenko, A.I.

    1982-01-01

    A thyristor-relay commutator used for alteration of the leading magnetic field direction in experiments with polarized neutrons is described. The commutator flowsheet is presented. Thyristors, connected so as to allow the relay trigger operation mode, are used as controllable electronic relay. Two connected in series coils with the total inductance of the order of 0.28 H serve as the electronic relay load. The arc-free current commutation is effected at the moment of the minimal current across the load terminals, which allows to easily reverse the current up to 10 A at a volatage, v <= 150 V. The experience gained within a year of operation has shown that the commutator meets the requirements of reliability and tuning

  16. Covariant non-commutative space–time

    Directory of Open Access Journals (Sweden)

    Jonathan J. Heckman

    2015-05-01

    Full Text Available We introduce a covariant non-commutative deformation of 3+1-dimensional conformal field theory. The deformation introduces a short-distance scale ℓp, and thus breaks scale invariance, but preserves all space–time isometries. The non-commutative algebra is defined on space–times with non-zero constant curvature, i.e. dS4 or AdS4. The construction makes essential use of the representation of CFT tensor operators as polynomials in an auxiliary polarization tensor. The polarization tensor takes active part in the non-commutative algebra, which for dS4 takes the form of so(5,1, while for AdS4 it assembles into so(4,2. The structure of the non-commutative correlation functions hints that the deformed theory contains gravitational interactions and a Regge-like trajectory of higher spin excitations.

  17. Euler Polynomials and Identities for Non-Commutative Operators

    OpenAIRE

    De Angelis, V.; Vignat, C.

    2015-01-01

    Three kinds of identities involving non-commutating operators and Euler and Bernoulli polynomials are studied. The first identity, as given by Bender and Bettencourt, expresses the nested commutator of the Hamiltonian and momentum operators as the commutator of the momentum and the shifted Euler polynomial of the Hamiltonian. The second one, due to J.-C. Pain, links the commutators and anti-commutators of the monomials of the position and momentum operators. The third appears in a work by Fig...

  18. Extreme commutative quantum observables are sharp

    International Nuclear Information System (INIS)

    Heinosaari, Teiko; Pellonpaeae, Juha-Pekka

    2011-01-01

    It is well known that, in the description of quantum observables, positive operator valued measures (POVMs) generalize projection valued measures (PVMs) and they also turn out be more optimal in many tasks. We show that a commutative POVM is an extreme point in the convex set of all POVMs if and only if it is a PVM. This results implies that non-commutativity is a necessary ingredient to overcome the limitations of PVMs.

  19. How do motorways shape commuting patterns?

    DEFF Research Database (Denmark)

    Hovgesen, Henrik Harder; Nielsen, Thomas Alexander Sick

    2004-01-01

    on urbanization and spatial interaction patterns in the last 20 years. This paper presents results on how the building of the motorway network has shaped spatial interactions patterns in Denmark over a ten year period. The question asked is how travel time reductions and changing motorway access is related...... to change in the commute pattern. And whether the relations between these factors and commuting are a new course of development or a continuation of past trends....

  20. Daily commuting to work is not associated with variables of health.

    Science.gov (United States)

    Mauss, Daniel; Jarczok, Marc N; Fischer, Joachim E

    2016-01-01

    Commuting to work is thought to have a negative impact on employee health. We tested the association of work commute and different variables of health in German industrial employees. Self-rated variables of an industrial cohort (n = 3805; 78.9 % male) including absenteeism, presenteeism and indices reflecting stress and well-being were assessed by a questionnaire. Fasting blood samples, heart-rate variability and anthropometric data were collected. Commuting was grouped into one of four categories: 0-19.9, 20-44.9, 45-59.9, ≥60 min travelling one way to work. Bivariate associations between commuting and all variables under study were calculated. Linear regression models tested this association further, controlling for potential confounders. Commuting was positively correlated with waist circumference and inversely with triglycerides. These associations did not remain statistically significant in linear regression models controlling for age, gender, marital status, and shiftwork. No other association with variables of physical, psychological, or mental health and well-being could be found. The results indicate that commuting to work has no significant impact on well-being and health of German industrial employees.

  1. Determinants of self-employment among commuters and non-commuters

    DEFF Research Database (Denmark)

    Backman, M.; Karlsson, C.

    2016-01-01

    We analyse the determinants of self-employment and focus on the contextual environment. By distinguishing between commuters and non-commuters we are able to analyse the influence from the work and home environment, respectively. Our results indicate a significant difference between non...

  2. Migration Dilemmas of Islanders: Commuting Leading to Migration or Remaining at Home

    Directory of Open Access Journals (Sweden)

    Ivan Lajić

    2001-09-01

    Full Text Available The paper presents and discusses the results of an empirical survey carried out in April 2000 on the islands Prvić, Zlarin and Krapanj in the Šibenik coastal area. These islands are part of a group of islands marked by the highest rates of depopulation, in which even recently daily commuting was one of the most expressed forms of mechanical population development. Daily commuting is seen as an initial state leading to permanent migration, i.e. to out-migration. Potential migrants become familiar with the social, economic, cultural and other traits of their future destination area, which makes it easier for them to leave their places of origin. Thus, for the purposes of the research, the survey selected a population of daily commuters, mainly young people of working age who usually constitute the segment of the population most Iikely to migrate. The survey used both a questionnaire and interviews. Respondents belonged to two relevant groups of the island population: employees commuting each day to work and pupils commuting daily to school. Even though the sample included practically the entire island population with the given migrational and socio-demographic characteristics, the total number of respondents was still too small for the application of standard methods of statistical analysis. In order to gain better insight into the pre-migrational situation on the islands, a few adult islander commuters were added to the group of commuting employees. The goal of the research was to gain an understanding of commuting phenomena in the island micro-society, especially of the migration dilemmas of young islanders. The most frequent variables in the survey were: island/settlement, gender and school. Commuting between the island and mainland is the dominant form of spatial mobility among islanders and constitutes an essential part of their daily life. The most frequent reasons for commuting among islanders are school attendance, going to work, going

  3. Opinions of the commuters to receive oral health messages in South central railway zone India: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    P Parthasarathi Reddy

    2015-01-01

    Full Text Available Introduction: The railroads of India are the fourth most heavily used system in the world. Railways are one of the main modes of transport and millions of people travel by train daily. Aim: To know the opinions of commuters in receiving oral health messages in railways station through various methods and also their knowledge and practice regarding oral hygiene. Materials and Methods: Using convenient sampling method data from the commuters was obtained by a pretested questionnaire through interview method from 14 railway stations of South Central Railway zone. Pearson Chi-square test was used to compare the opinions of commuters based on their gender to receive oral health messages. Results: A total of 596 (97.3% responded to the survey; a maximum of 297 (49.8% subjects strongly agreed to the statement that railway platforms should have informative posters on oral health. A maximum of 188 (31.5% commuters strongly agreed that prerecorded messages on oral health if played before the announcement of arrival and departure of train will be helpful to spread oral health awareness. Majority of 43% commuters (255 preferred to receive oral hygiene instructions printed on back side of the ticket followed by messages on television and through posters. Conclusion: Majority of the commuters preferred to receive oral health information in railways stations. Hence, efforts can be directed in spreading oral health information among public through railways.

  4. Survey of how staff commute to work

    CERN Multimedia

    2014-01-01

    A survey was initiated by the Canton of Geneva (Direction Générale des Transports) and the Swiss Permanent Mission to the United Nations, and is aimed at better understanding how staff in International Organisations commute to/from work so as to better plan future works (road access, public transport, etc.). The ILO, WHO, UNAIDs, Global Fund, IFRC, CERN and UNOG are taking part in this important survey.   People living in Switzerland or France are invited to respond to this survey. The purpose of this survey is to better understand: - your commuting habits, - your willingness to explore alternative commuting options, - your expectations and needs. All data provided to this external company (www.mobilidee.ch) will be kept confidential and will only be used for this particular study. CERN has received all guarantees of confidentiality from this company. Many thanks for your collaboration! GS Department

  5. Commutability of food microbiology proficiency testing samples.

    Science.gov (United States)

    Abdelmassih, M; Polet, M; Goffaux, M-J; Planchon, V; Dierick, K; Mahillon, J

    2014-03-01

    Food microbiology proficiency testing (PT) is a useful tool to assess the analytical performances among laboratories. PT items should be close to routine samples to accurately evaluate the acceptability of the methods. However, most PT providers distribute exclusively artificial samples such as reference materials or irradiated foods. This raises the issue of the suitability of these samples because the equivalence-or 'commutability'-between results obtained on artificial vs. authentic food samples has not been demonstrated. In the clinical field, the use of noncommutable PT samples has led to erroneous evaluation of the performances when different analytical methods were used. This study aimed to provide a first assessment of the commutability of samples distributed in food microbiology PT. REQUASUD and IPH organized 13 food microbiology PTs including 10-28 participants. Three types of PT items were used: genuine food samples, sterile food samples and reference materials. The commutability of the artificial samples (reference material or sterile samples) was assessed by plotting the distribution of the results on natural and artificial PT samples. This comparison highlighted matrix-correlated issues when nonfood matrices, such as reference materials, were used. Artificially inoculated food samples, on the other hand, raised only isolated commutability issues. In the organization of a PT-scheme, authentic or artificially inoculated food samples are necessary to accurately evaluate the analytical performances. Reference materials, used as PT items because of their convenience, may present commutability issues leading to inaccurate penalizing conclusions for methods that would have provided accurate results on food samples. For the first time, the commutability of food microbiology PT samples was investigated. The nature of the samples provided by the organizer turned out to be an important factor because matrix effects can impact on the analytical results. © 2013

  6. Commuting quantum traces: the case of reflection algebras

    Energy Technology Data Exchange (ETDEWEB)

    Avan, Jean [Laboratory of Theoretical Physics and Modelization, University of Cergy, 5 mail Gay-Lussac, Neuville-sur-Oise, F-95031, Cergy-Pontoise Cedex (France); Doikou, Anastasia [Theoretical Physics Laboratory of Annecy-Le-Vieux, LAPTH, BP 110, Annecy-Le-Vieux, F-74941 (France)

    2004-02-06

    We formulate a systematic construction of commuting quantum traces for reflection algebras. This is achieved by introducing two dual sets of generalized reflection equations with associated consistent fusion procedures. Products of their respective solutions yield commuting quantum traces.

  7. Job-induced Commuting between Two Residences – Characteristics of a Multilocational Living Arrangement in the Late Modernity

    Directory of Open Access Journals (Sweden)

    Darja Reuschke

    2010-09-01

    Full Text Available Against the background of the ongoing flexibilisation of labour markets and a rising labour force participation of (highly qualified women, job-related commuting between a main and secondary residence has become more important in Western capitalist countries as is the case in contemporary Germany. The limited number of recent empirical studies on this kind of multilocational living arrangement almost entirely focuses on commuters in couple/family households. The main objective of this article is, firstly, to provide data about the characteristics and formation contexts of job-related multilocational household organisations as a whole, in order to make a contribution to the discussion of the forms and causes of this currently important phenomenon. Secondly, by means of comparison analyses, the multilocational form of living is compared to the group of long-distance movers, in order to provide insights into who prefers commuting to migration with the complete household under which circumstances. The article draws on data of a field research study, which have been obtained from an individual based random sample from official registers of inhabitants of four metropolises in Germany. The sample was restricted to individuals with specific characteristics (in-movers, age 25 to 59. The fully structured postal interviews were complemented by qualitative telephone interviews with selected commuters. The results show that commuters are a heterogeneous group. Living in a partnership and the social connections established thereby play a prominent role for multilocational household organisations. Among male commuters, one can distinguish between those who are young, never married and predominantly childless, on the one hand, and a group of older married commuters with children in the household, on the other. The vast majority of female commuters, however, live childless. As men commute between two residences even if they live with a family, they significantly

  8. Commute Scheduling and Congestion in a Monocentric City

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Kim, Jinwon; Ranjan, Abhishek

    2017-01-01

    to the CBD, residents choose their commute departure time jointly with residential location and housing consumption. Commuters arrive at the bottleneck in sequence sorted by residential location, so that more distant residents arrive later. The socially optimal toll makes central residents commute earlier...

  9. Commuter partnerships : balancing home, family, and distant work

    NARCIS (Netherlands)

    van der Klis, M.

    2009-01-01

    This study is about commuter partnerships. The commuter partnership is a particular non-standard household arrangement in which, for part of the time, one partner lives near his or her work and away from the communal family home, because the commuting distance is too great to travel on a daily

  10. Commutating Permanent-Magnet Motors At Low Speed

    Science.gov (United States)

    Dolland, C.

    1985-01-01

    Circuit provides forced commutation during starting. Forced commutation circuit diverts current from inverter SCR's and turns SCR's off during commutation intervals. Silicon controlled rectifier in circuit unnecessary when switch S10 replaced by high-current, high-voltage transistor. At present, high-current, low-voltage device must suffice.

  11. 2D Toda chain and associated commutator identity

    OpenAIRE

    Pogrebkov, A. K.

    2007-01-01

    Developing observation made in \\cite{commut} we show that simple identity of the commutator type on an associative algebra is in one-to-one correspondence to 2D (infinite) Toda chain. We introduce representation of elements of associative algebra that, under some generic conditions, enables derivation of the Toda chain equation and its Lax pair from the given commutator identity.

  12. Commutator identities on associative algebras and integrability of nonlinear pde's

    OpenAIRE

    Pogrebkov, A. K.

    2007-01-01

    It is shown that commutator identities on associative algebras generate solutions of linearized integrable equations. Next, a special kind of the dressing procedure is suggested that in a special class of integral operators enables to associate to such commutator identity both nonlinear equation and its Lax pair. Thus problem of construction of new integrable pde's reduces to construction of commutator identities on associative algebras.

  13. Happiness and Satisfaction with Work Commute

    NARCIS (Netherlands)

    Olsson, L.E.; Gärling, T.; Ettema, D.F.; Friman, M.; Fujii, S.

    2012-01-01

    Research suggests that for many people happiness is being able to make the routines of everyday life work, such that positive feelings dominate over negative feelings resulting from daily hassles. In line with this, a survey of work commuters in the three largest urban areas of Sweden show that

  14. Discrete choice models for commuting interactions

    DEFF Research Database (Denmark)

    Rouwendal, Jan; Mulalic, Ismir; Levkovich, Or

    An emerging quantitative spatial economics literature models commuting interactions by a gravity equation that is mathematically equivalent to a multinomial logit model. This model is widely viewed as restrictive because of the independence of irrelevant alternatives (IIA) property that links sub...

  15. A syntactic commutativity format for SOS

    NARCIS (Netherlands)

    Mousavi, M.R.; Reniers, M.A.; Groote, J.F.

    2005-01-01

    Considering operators defined using Structural Operational Semantics (SOS), commutativity axioms are intuitive properties that hold for many of them. Proving this intuition is usually a laborious task, requiring several pages of boring and standard proof. To save this effort, we propose a syntactic

  16. Star products from commutative string theory

    Indian Academy of Sciences (India)

    in commutative open-string theory performed in [2], and an impressive ... formed to all orders in the derivative expansion, but keeping only terms of order(F 2) ... nonlogarithmic finite parts [2] and come from propagators for which there is no self-.

  17. Quantum Gibbs Samplers: The Commuting Case

    Science.gov (United States)

    Kastoryano, Michael J.; Brandão, Fernando G. S. L.

    2016-06-01

    We analyze the problem of preparing quantum Gibbs states of lattice spin Hamiltonians with local and commuting terms on a quantum computer and in nature. Our central result is an equivalence between the behavior of correlations in the Gibbs state and the mixing time of the semigroup which drives the system to thermal equilibrium (the Gibbs sampler). We introduce a framework for analyzing the correlation and mixing properties of quantum Gibbs states and quantum Gibbs samplers, which is rooted in the theory of non-commutative {mathbb{L}_p} spaces. We consider two distinct classes of Gibbs samplers, one of them being the well-studied Davies generator modelling the dynamics of a system due to weak-coupling with a large Markovian environment. We show that their spectral gap is independent of system size if, and only if, a certain strong form of clustering of correlations holds in the Gibbs state. Therefore every Gibbs state of a commuting Hamiltonian that satisfies clustering of correlations in this strong sense can be prepared efficiently on a quantum computer. As concrete applications of our formalism, we show that for every one-dimensional lattice system, or for systems in lattices of any dimension at temperatures above a certain threshold, the Gibbs samplers of commuting Hamiltonians are always gapped, giving an efficient way of preparing the associated Gibbs states on a quantum computer.

  18. Commutative monads as a theory of distributions

    DEFF Research Database (Denmark)

    Kock, Anders

    2012-01-01

    It is shown how the theory of commutative monads provides an axiomatic framework for several aspects of distribution theory in a broad sense, including probability distributions, physical extensive quantities, and Schwartz distributions of compact support. Among the particular aspects considered...... here are the notions of convolution, density, expectation, and conditional probability....

  19. Non-commutative arithmetic circuits with division

    Czech Academy of Sciences Publication Activity Database

    Hrubeš, Pavel; Wigderson, A.

    2015-01-01

    Roč. 11, Article 14 (2015), s. 357-393 ISSN 1557-2862 EU Projects: European Commission(XE) 339691 - FEALORA Institutional support: RVO:67985840 Keywords : arithmetic circuits * non-commutative rational function * skew field Subject RIV: BA - General Mathematics http://theoryofcomputing.org/articles/v011a014/

  20. Non-commutative geometry and supersymmetry 2

    International Nuclear Information System (INIS)

    Hussain, F.; Thompson, G.

    1991-05-01

    Following the general construction of supersymmetric models, the model based on the idea of non-commutative geometry is formulated as a Yang-Mills theory of the graded Lie algebra U(2/1) over a graded space-time manifold. 4 refs

  1. Hermiticity of quantum observables versus commutation relations

    International Nuclear Information System (INIS)

    Shirokov, M.I.

    2002-01-01

    In order to obtain sum rules and spectral representations the Hermiticity property = of observables is used. It is shown that for certain Ψ and Φ the property turn out to be inconsistent with the commutation relations that contain Α. The known Schwinger paradox is explained by this inconsistency

  2. Distances in zero-divisor and total graphs from commutative rings–A survey

    Directory of Open Access Journals (Sweden)

    T. Tamizh Chelvam

    2016-12-01

    Full Text Available There are so many ways to construct graphs from algebraic structures. Most popular constructions are Cayley graphs, commuting graphs and non-commuting graphs from finite groups and zero-divisor graphs and total graphs from commutative rings. For a commutative ring R with non-zero identity, we denote the set of zero-divisors and unit elements of R by Z(R and U(R, respectively. One of the associated graphs to a ring R is the zero-divisor graph; it is a simple graph with vertex set Z(R∖{0}, and two vertices x and y are adjacent if and only if xy=0. This graph was first introduced by Beck, where all the elements of R are considered as the vertices. Anderson and Badawi, introduced the total graph of R, as the simple graph with all elements of R as vertices, and two distinct vertices x and y are adjacent if and only if x+y∈Z(R. For a given graph G, the concept of connectedness, diameter and girth are always of great interest. Several authors extensively studied about the zero-divisor and total graphs from commutative rings. In this paper, we present a survey of results obtained with regard to distances in zero-divisor and total graphs.

  3. Upper bound for the length of commutative algebras

    International Nuclear Information System (INIS)

    Markova, Ol'ga V

    2009-01-01

    By the length of a finite system of generators for a finite-dimensional associative algebra over an arbitrary field one means the least positive integer k such that the words of length not exceeding k span this algebra (as a vector space). The maximum length for the systems of generators of an algebra is referred to as the length of the algebra. In the present paper, an upper bound for the length of a commutative algebra in terms of a function of two invariants of the algebra, the dimension and the maximal degree of the minimal polynomial for the elements of the algebra, is obtained. As a corollary, a formula for the length of the algebra of diagonal matrices over an arbitrary field is obtained. Bibliography: 8 titles.

  4. Non-Commutative Integration, Zeta Functions and the Haar State for SU{sub q}(2)

    Energy Technology Data Exchange (ETDEWEB)

    Matassa, Marco, E-mail: marco.matassa@gmail.com [SISSA (Italy)

    2015-12-15

    We study a notion of non-commutative integration, in the spirit of modular spectral triples, for the quantum group SU{sub q}(2). In particular we define the non-commutative integral as the residue at the spectral dimension of a zeta function, which is constructed using a Dirac operator and a weight. We consider the Dirac operator introduced by Kaad and Senior and a family of weights depending on two parameters, which are related to the diagonal automorphisms of SU{sub q}(2). We show that, after fixing one of the parameters, the non-commutative integral coincides with the Haar state of SU{sub q}(2). Moreover we can impose an additional condition on the zeta function, which also fixes the second parameter. For this unique choice the spectral dimension coincides with the classical dimension.

  5. Almost-commutative geometries beyond the standard model II: new colours

    International Nuclear Information System (INIS)

    Stephan, Christoph A

    2007-01-01

    We will present an extension of the standard model of particle physics in its almost-commutative formulation. This extension is guided by the minimal approach to almost-commutative geometries employed by Iochum et al (2004 J. Math. Phys. 45 5003 (Preprint hep-th/0312276)), Jureit and Stephan (2005 J. Math. Phys. 46 043512 (Preprint hep-th/0501134)), Schuecker (2005 Preprint hep-th/0501181), Jureit et al (2005 J. Math. Phys. 46 072303 (Preprint hep-th/0503190)) and Jureit and Stephan (2006 Preprint hep-th/0610040), although the model presented here is not minimal itself. The corresponding almost-commutative geometry leads to a Yang-Mills-Higgs model which consists of the standard model and two new fermions of opposite electromagnetic charge which may possess a new colour-like gauge group. As a new phenomenon, grand unification is no longer required by the spectral action

  6. Non-Commutative Integration, Zeta Functions and the Haar State for SUq(2)

    International Nuclear Information System (INIS)

    Matassa, Marco

    2015-01-01

    We study a notion of non-commutative integration, in the spirit of modular spectral triples, for the quantum group SU q (2). In particular we define the non-commutative integral as the residue at the spectral dimension of a zeta function, which is constructed using a Dirac operator and a weight. We consider the Dirac operator introduced by Kaad and Senior and a family of weights depending on two parameters, which are related to the diagonal automorphisms of SU q (2). We show that, after fixing one of the parameters, the non-commutative integral coincides with the Haar state of SU q (2). Moreover we can impose an additional condition on the zeta function, which also fixes the second parameter. For this unique choice the spectral dimension coincides with the classical dimension

  7. Area-preserving diffeomorphisms in gauge theory on a non-commutative plane. A lattice study

    International Nuclear Information System (INIS)

    Bietenholz, W.; Bigarini, A.; INFN, Sezione di Perugia; Humboldt-Universitaet, Berlin; Torrielli, A.

    2007-06-01

    We consider Yang-Mills theory with the U(1) gauge group on a non-commutative plane. Perturbatively it was observed that the invariance of this theory under area-preserving diffeomorphisms (APDs) breaks down to a rigid subgroup SL(2,R). Here we present explicit results for the APD symmetry breaking at finite gauge coupling and finite non-commutativity. They are based on lattice simulations and measurements of Wilson loops with the same area but with a variety of different shapes. Our results confirm the expected loss of invariance under APDs. Moreover, they strongly suggest that non-perturbatively the SL(2,R) symmetry does not persist either. (orig.)

  8. Maximum power demand cost

    International Nuclear Information System (INIS)

    Biondi, L.

    1998-01-01

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

  9. Carbon monoxide levels in popular passenger commuting modes traversing major commuting routes in Hong Kong

    International Nuclear Information System (INIS)

    Chan, L.Y.; Liu, Y.M.

    2001-01-01

    Vehicle exhaust is a major source of air pollution in metropolitan cities. Commuters are exposed to high traffic-related pollutant concentrations. Public transportation is the most popular commuting mode in Hong Kong and there are about 10.8 million passenger trips every day. Two-thirds of them are road commuters. An extensive survey was conducted to measure carbon monoxide in three popular passenger commuting modes, bus, minibus, and taxi, which served, respectively, 3.91 million, 1.76 million and 1.31 million passenger trips per day in 1998. Three types of commuting microenvironments were selected: urban-urban, urban-suburban and urban-rural. Results indicated that in-vehicle CO level increased in the following order: bus, minibus and taxi. The overall average in-vehicle CO level in air-conditioned bus, minibus and taxi were 1.8, 2.9 and 3.3ppm, respectively. The average concentration level between air-conditioned buses (1.8ppm) and non-air-conditioned buses (1.9ppm) was insignificant. The fluctuation of in-vehicle CO level of non-air-conditioned vehicle followed the variation of out-vehicle CO concentration. Our result also showed that even in air-conditioned vehicles, the in-vehicle CO concentration was affected by the out-vehicle CO concentration although there exists a smoothing out effect. The in-vehicle CO level was the highest in urban-suburban commuting routes and was followed by urban-urban routes. The in-vehicle CO level in urban-rural routes was the lowest. The highest CO level was recorded after the vehicle traversed through tunnel.. The average CO exposure level of public road transportation commuters in Honk Kong was lower than most other cities. Factors governing the CO levels were also discussed. (Author)

  10. Quantifying commuter exposures to volatile organic compounds

    Science.gov (United States)

    Kayne, Ashleigh

    Motor-vehicles can be a predominant source of air pollution in cities. Traffic-related air pollution is often unavoidable for people who live in populous areas. Commuters may have high exposures to traffic-related air pollution as they are close to vehicle tailpipes. Volatile organic compounds (VOCs) are one class of air pollutants of concern because exposure to VOCs carries risk for adverse health effects. Specific VOCs of interest for this work include benzene, toluene, ethylbenzene, and xylenes (BTEX), which are often found in gasoline and combustion products. Although methods exist to measure time-integrated personal exposures to BTEX, there are few practical methods to measure a commuter's time-resolved BTEX exposure which could identify peak exposures that could be concealed with a time-integrated measurement. This study evaluated the ability of a photoionization detector (PID) to measure commuters' exposure to BTEX using Tenax TA samples as a reference and quantified the difference in BTEX exposure between cyclists and drivers with windows open and closed. To determine the suitability of two measurement methods (PID and Tenax TA) for use in this study, the precision, linearity, and limits of detection (LODs) for both the PID and Tenax TA measurement methods were determined in the laboratory with standard BTEX calibration gases. Volunteers commuted from their homes to their work places by cycling or driving while wearing a personal exposure backpack containing a collocated PID and Tenax TA sampler. Volunteers completed a survey and indicated if the windows in their vehicle were open or closed. Comparing pairs of exposure data from the Tenax TA and PID sampling methods determined the suitability of the PID to measure the BTEX exposures of commuters. The difference between BTEX exposures of cyclists and drivers with windows open and closed in Fort Collins was determined. Both the PID and Tenax TA measurement methods were precise and linear when evaluated in the

  11. Social Involvement and Commuter Students: The First-Year Student Voice

    Science.gov (United States)

    Krause, Kerri-Lee D.

    2007-01-01

    This qualitative study explores the nature of undergraduate commuter students' social involvement with peers during the transitional first six months of their university experience. Focus group interviews with 46 participants provided a student perspective of the role of social interactions in students' transition to university life. Findings…

  12. Matrix models as non-commutative field theories on R3

    International Nuclear Information System (INIS)

    Livine, Etera R

    2009-01-01

    In the context of spin foam models for quantum gravity, group field theories are a useful tool allowing on the one hand a non-perturbative formulation of the partition function and on the other hand admitting an interpretation as generalized matrix models. Focusing on 2d group field theories, we review their explicit relation to matrix models and show their link to a class of non-commutative field theories invariant under a quantum-deformed 3d Poincare symmetry. This provides a simple relation between matrix models and non-commutative geometry. Moreover, we review the derivation of effective 2d group field theories with non-trivial propagators from Boulatov's group field theory for 3d quantum gravity. Besides the fact that this gives a simple and direct derivation of non-commutative field theories for the matter dynamics coupled to (3d) quantum gravity, these effective field theories can be expressed as multi-matrix models with a non-trivial coupling between matrices of different sizes. It should be interesting to analyze this new class of theories, both from the point of view of matrix models as integrable systems and for the study of non-commutative field theories.

  13. Gravity models to classify commuting vs. resident workers. An application to the analysis of residential risk in a contaminated area

    Science.gov (United States)

    2011-01-01

    Background The analysis of risk for the population residing and/or working in contaminated areas raises the topic of commuting. In fact, especially in contaminated areas, commuting groups are likely to be subject to lower exposure than residents. Only very recently environmental epidemiology has started considering the role of commuting as a differential source of exposure in contaminated areas. In order to improve the categorization of groups, this paper applies a gravitational model to the analysis of residential risk for workers in the Gela petrochemical complex, which began life in the early 60s in the municipality of Gela (Sicily, Italy) and is the main source of industrial pollution in the local area. Results A logistic regression model is implemented to measure the capacity of Gela "central location" to attract commuting flows from other sites. Drawing from gravity models, the proposed methodology: a) defines the probability of finding commuters from municipalities outside Gela as a function of the origin's "economic mass" and of its distance from each destination; b) establishes "commuting thresholds" relative to the origin's mass. The analysis includes 367 out of the 390 Sicilian municipalities. Results are applied to define "commuters" and "residents" within the cohort of petrochemical workers. The study population is composed of 5,627 workers. Different categories of residence in Gela are compared calculating Mortality Rate Ratios for lung cancer through a Poisson regression model, controlling for age and calendar period. The mobility model correctly classifies almost 90% of observations. Its application to the mortality analysis confirms a major risk for lung cancer associated with residence in Gela. Conclusions Commuting is a critical aspect of the health-environment relationship in contaminated areas. The proposed methodology can be replicated to different contexts when residential information is lacking or unreliable; however, a careful consideration

  14. Gravity models to classify commuting vs. resident workers. An application to the analysis of residential risk in a contaminated area

    Directory of Open Access Journals (Sweden)

    La Rocca Marina

    2011-01-01

    Full Text Available Abstract Background The analysis of risk for the population residing and/or working in contaminated areas raises the topic of commuting. In fact, especially in contaminated areas, commuting groups are likely to be subject to lower exposure than residents. Only very recently environmental epidemiology has started considering the role of commuting as a differential source of exposure in contaminated areas. In order to improve the categorization of groups, this paper applies a gravitational model to the analysis of residential risk for workers in the Gela petrochemical complex, which began life in the early 60s in the municipality of Gela (Sicily, Italy and is the main source of industrial pollution in the local area. Results A logistic regression model is implemented to measure the capacity of Gela "central location" to attract commuting flows from other sites. Drawing from gravity models, the proposed methodology: a defines the probability of finding commuters from municipalities outside Gela as a function of the origin's "economic mass" and of its distance from each destination; b establishes "commuting thresholds" relative to the origin's mass. The analysis includes 367 out of the 390 Sicilian municipalities. Results are applied to define "commuters" and "residents" within the cohort of petrochemical workers. The study population is composed of 5,627 workers. Different categories of residence in Gela are compared calculating Mortality Rate Ratios for lung cancer through a Poisson regression model, controlling for age and calendar period. The mobility model correctly classifies almost 90% of observations. Its application to the mortality analysis confirms a major risk for lung cancer associated with residence in Gela. Conclusions Commuting is a critical aspect of the health-environment relationship in contaminated areas. The proposed methodology can be replicated to different contexts when residential information is lacking or unreliable

  15. Strong commutativity preserving generalized derivations on ...

    African Journals Online (AJOL)

    Let R be a non-commutative prime ring of characteristic different from 2, with right Utumi quotient ring U and extended centroid C and let F and G be generalized derivations of R such that F(x)G(y)-F(y)G(x) = [x; y], for all x; y ∈ S, where S is a subset of R. Here we will discuss the following cases: (a) S = [R;R];. b) S = L, where ...

  16. Classical mechanics in non-commutative phase space

    International Nuclear Information System (INIS)

    Wei Gaofeng; Long Chaoyun; Long Zhengwen; Qin Shuijie

    2008-01-01

    In this paper the laws of motion of classical particles have been investigated in a non-commutative phase space. The corresponding non-commutative relations contain not only spatial non-commutativity but also momentum non-commutativity. First, new Poisson brackets have been defined in non-commutative phase space. They contain corrections due to the non-commutativity of coordinates and momenta. On the basis of this new Poisson brackets, a new modified second law of Newton has been obtained. For two cases, the free particle and the harmonic oscillator, the equations of motion are derived on basis of the modified second law of Newton and the linear transformation (Phys. Rev. D, 2005, 72: 025010). The consistency between both methods is demonstrated. It is shown that a free particle in commutative space is not a free particle with zero-acceleration in the non-commutative phase space, but it remains a free particle with zero-acceleration in non-commutative space if only the coordinates are non-commutative. (authors)

  17. FET commutated current-FED inverter

    Science.gov (United States)

    Rippel, Wally E. (Inventor); Edwards, Dean B. (Inventor)

    1983-01-01

    A shunt switch comprised of a field-effect transistor (Q.sub.1) is employed to commutate a current-fed inverter (10) using thyristors (SCR1, SCR2) or bijunction transistors (Q.sub.2, Q.sub.3) in a full bridge (1, 2, 3, 4) or half bridge (5, 6) and transformer (T.sub.1) configuration. In the case of thyristors, a tapped inverter (12) is employed to couple the inverter to a dc source to back bias the thyristors during commutation. Alternatively, a commutation power supply (20) may be employed for that purpse. Diodes (D.sub.1, D.sub.2) in series with some voltage dropping element (resistor R.sub.12 or resistors R.sub.1, R.sub.2 or Zener diodes D.sub.4, D.sub.5) are connected in parallel with the thyristors in the half bridge and transformer configuration to assure sharing the back bias voltage. A clamp circuit comprised of a winding (18) negatively coupled to the inductor and a diode (D.sub.3) return stored energy from the inductor to the power supply for efficient operation with buck or boost mode.

  18. The Influence of Urban Land-Use and Public Transport Facilities on Active Commuting in Wellington, New Zealand: Active Transport Forecasting Using the WILUTE Model

    Directory of Open Access Journals (Sweden)

    Joreintje Dingena Mackenbach

    2016-03-01

    Full Text Available Physical activity has numerous physical and mental health benefits, and active commuting (walking or cycling to work can help meet physical activity recommendations. This study investigated socioeconomic differences in active commuting, and assessed the impact of urban land-use and public transport policies on active commuting in the Wellington region in New Zealand. We combined data from the New Zealand Household Travel Survey and GIS data on land-use and public transport facilities with the Wellington Integrated Land-Use, Transportation and Environment (WILUTE model, and forecasted changes in active commuter trips associated with changes in the built environment. Results indicated high income individuals were more likely to commute actively than individuals on low income. Several land-use and transportation factors were associated with active commuting and results from the modelling showed a potential increase in active commuting following an increase in bus frequency and parking fees. In conclusion, regional level policies stimulating environmental factors that directly or indirectly affect active commuting may be a promising strategy to increase population level physical activity. Access to, and frequency of, public transport in the neighbourhood can act as a facilitator for a more active lifestyle among its residents without negatively affecting disadvantaged groups.

  19. Commuting Pattern with Park-and-Ride Option for Heterogeneous Commuters

    Directory of Open Access Journals (Sweden)

    Chengjuan Zhu

    2013-01-01

    Full Text Available We study the effect of the parking on heterogeneous commuters' travel choice in a competitive transportation system which consists of a subway and a parallel road with a bottleneck of limited service capacity. Every morning, commuters either use their private cars only or drive their cars to the bottleneck, park there, and then take the subway to the destination. Considering the effects caused by body congestion in carriage and the parking fees, we developed a bottleneck model to describe the commuters' travel choice. There exist several types of equilibrium that corresponds to user equilibrium. We investigated the influence of the capacity of the bottleneck and the total travel demand on the travel behaviors and on the total social cost. It is shown that there exists a scheme with suitable subway fare and parking fees to implement the minimum total social cost.

  20. Reducing drag of a commuter train, using engine exhaust momentum

    Science.gov (United States)

    Ha, Dong Keun

    The objective of this thesis was to perform numerical investigations of two different methods of injecting fluid momentum into the air flow above a commuter train to reduce its drag. Based on previous aerodynamic modifications of heavy duty trucks in improving fuel efficiency, two structural modifications were designed and applied to a Metrolink Services commuter train in the Los Angeles (LA) County area to reduce its drag and subsequently improve fuel efficiency. The first modification was an L-shaped channel, added to the exhaust cooling fan above the locomotive roof to divert and align the exhaust gases in the axial direction. The second modification was adding an airfoil shaped lid over the L-shape channel, to minimize the drag of the perturbed structure, and thus reduce the overall drag. The computational fluid dynamic (CFD) software CCM+ from CD-Adapco with the ?-? turbulence model was used for the simulations. A single train set which consists of three vehicles: one locomotive, one trailer car and one cab car were used. All the vehicles were modeled based on the standard Metrolink fleet train size. The wind speed was at 90 miles per hour (mph), which is the maximum speed for the Orange County Metrolink line. Air was used as the exhaust gas in the simulation. The temperature of the exhausting air emitting out of the cooling fan on the roof was 150 F and the average fan speed was 120 mph. Results showed that with the addition of the lid, momentum injection results in reduced flow separation and pressure recovery behind the locomotive, which reduces the overall drag by at least 30%.

  1. Fuzzy commutative algebra and its application in mechanical engineering

    International Nuclear Information System (INIS)

    Han, J.; Song, H.

    1996-01-01

    Based on literature data, this paper discusses the whole mathematical structure about point-fuzzy number set F(R). By introducing some new operations about addition, subtraction, multiplication, division and scalar multiplication, we prove that F(R) can form fuzzy linear space, fuzzy commutative ring, fuzzy commutative algebra in order. Furthermore, we get that A is fuzzy commutative algebra for any fuzzy subset. At last, we give an application of point-fuzzy number to mechanical engineering

  2. Geometry, commutation relations and the quantum fictitious force

    DEFF Research Database (Denmark)

    Botero, J.; Cirone, M.A.; Dahl, Jens Peder

    2003-01-01

    We express the commutation relation between the operators of the momentum and the radial unit vectors in D dimensions in differential and integral form. We connect this commutator with the quantum fictitious potential emerging in the radial Schrodinger equation of an s-wave.......We express the commutation relation between the operators of the momentum and the radial unit vectors in D dimensions in differential and integral form. We connect this commutator with the quantum fictitious potential emerging in the radial Schrodinger equation of an s-wave....

  3. Can non-commutativity resolve the big-bang singularity?

    Energy Technology Data Exchange (ETDEWEB)

    Maceda, M.; Madore, J. [Laboratoire de Physique Theorique, Universite de Paris-Sud, Batiment 211, 91405, Orsay (France); Manousselis, P. [Department of Engineering Sciences, University of Patras, 26110, Patras (Greece); Physics Department, National Technical University, Zografou Campus, 157 80, Zografou, Athens (Greece); Zoupanos, G. [Physics Department, National Technical University, Zografou Campus, 157 80, Zografou, Athens (Greece); Theory Division, CERN, 1211, Geneva 23 (Switzerland)

    2004-08-01

    A possible way to resolve the singularities of general relativity is proposed based on the assumption that the description of space-time using commuting coordinates is not valid above a certain fundamental scale. Beyond that scale it is assumed that the space-time has non-commutative structure leading in turn to a resolution of the singularity. As a first attempt towards realizing the above programme a modification of the Kasner metric is constructed which is commutative only at large time scales. At small time scales, near the singularity, the commutation relations among the space coordinates diverge. We interpret this result as meaning that the singularity has been completely delocalized. (orig.)

  4. Rectifier transformer saturation on commutation failure

    International Nuclear Information System (INIS)

    Lu, E.; Bronner, G.

    1989-01-01

    The rectifier transformer's service differs from the power transformer's service because of the rectifier load. Under certain fault conditions, such as a commutation failure, d.c. magnetization may be introduced into the rectifier transformer cores, resulting in possible saturation of the magnetic circuit, thus in degradation of the performance of the transformer. It is the purpose of this paper to present an approach for evaluating the electromagnetic transient process under such a fault condition. The studies were made on the operating 1000MVA converter system at the Princeton Plasma Physics Laboratory

  5. Non-commutative tools for topological insulators

    International Nuclear Information System (INIS)

    Prodan, Emil

    2010-01-01

    This paper reviews several analytic tools for the field of topological insulators, developed with the aid of non-commutative calculus and geometry. The set of tools includes bulk topological invariants defined directly in the thermodynamic limit and in the presence of disorder, whose robustness is shown to have nontrivial physical consequences for the bulk states. The set of tools also includes a general relation between the current of an observable and its edge index, a relation that can be used to investigate the robustness of the edge states against disorder. The paper focuses on the motivations behind creating such tools and on how to use them.

  6. Electronically commutated DC motor. Elektronisch kommutierter Gleichstrommotor

    Energy Technology Data Exchange (ETDEWEB)

    Gruenleitner, H; Schalk, K; Koegler, G

    1981-08-13

    The purpose of the invention is to create a controlled and electronically commutated DC motor, so that the braking current regulator does not act with the frequency motor current regulator, where an additional switch is not required to decouple the braking current transistor while running, and where the reference value of braking current need not be greater than the reference value of motor current. According to the invention, this problem is solved by a connection, by which, while running, the braking current regulator is interlocked out by means of the output signal of the motor current regulator. A cheap diode and the associated wiring are all that is required for the interlock.

  7. Geometry of time-spaces non-commutative algebraic geometry, applied to quantum theory

    CERN Document Server

    Landau, Olav Arnfinn

    2011-01-01

    This is a monograph about non-commutative algebraic geometry, and its application to physics. The main mathematical inputs are the non-commutative deformation theory, moduli theory of representations of associative algebras, a new non-commutative theory o

  8. Non commutative geometry and super Yang-Mills theory

    International Nuclear Information System (INIS)

    Bigatti, D.

    1999-01-01

    We aim to connect the non commutative geometry 'quotient space' viewpoint with the standard super Yang Mills theory approach in the spirit of Connes-Douglas-Schwartz and Douglas-Hull description of application of noncommutative geometry to matrix theory. This will result in a relation between the parameters of a rational foliation of the torus and the dimension of the group U(N). Namely, we will be provided with a prescription which allows to study a noncommutative geometry with rational parameter p/N by means of a U(N) gauge theory on a torus of size Σ/N with the boundary conditions given by a system with p units of magnetic flux. The transition to irrational parameter can be obtained by letting N and p tend to infinity with fixed ratio. The precise meaning of the limiting process will presumably allow better clarification. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  9. Home Here, Home There: The lives and Landscape within High-tech Trans-Pacific Commuter Culture

    Directory of Open Access Journals (Sweden)

    Shenglin Chang

    2004-12-01

    Full Text Available Within the last two decades the issue of 'home identity' (how a home reflects a person's identity has been an emerging topic within contemporary intellectual discourse in fields as diverse as Asian-American studies, anthropology, cultural geography, cultural studies, literary criticism and landscape architecture. In this article, I focus on the transnational experiences of members of a newly emerging trans-Pacific commuter culture, and give special attention to describing how individual members of this group construct the relationship between self and landscape. This article reveals the complex process in which members of a newly emerging trans-Pacific commuter culture have developed new non-traditional ways of constructing the landscape/home relationship - ways that call for challenging essentialist versions of home within a rapidly changing information age. I examine how Taiwanese-born, high-tech computer engineers who relocated to Silicon Valley engage in a struggle between their old identities and their newly forming American identities. These engineers and their families - members of the 'trans-Pacific home phenomenon' that emerged in the late 1990s - have a lifestyle in which they regularly commute between their American and Taiwanese homes. The ease of global travel and instant worldwide communication that became available in the 1990s afforded the trans-Pacific commuter group ease of travel, simultaneous ownership of two homes, and led to the reinvention of the relationship between global and local within the construction of self and home. This article explores how members of the trans-Pacific commuter culture struggle to make sense between the here-and-there homes across the Pacific Rim. With evidence from 80 interviews conducted in Silicon Valley (USA, Hsinchu (Taiwan, and Shanghai and Beijing (China, I focus on the ways in which members of the global-commuter group invented new, non-essentialist ways of constructing their home

  10. Reducing employee travelling time through smart commuting

    International Nuclear Information System (INIS)

    Rahman, A N N A; Yusoff, Z M; Aziz, I S; Omar, D

    2014-01-01

    Extremely congested roads will definitely delay the arrival time of each trip.This certainly impacted the journey of employees. Tardiness at the workplace has become a perturbing issue for companies where traffic jams are the most common worker excuses. A depressing consequence on daily life and productivity of the employee occurs. The issues of commuting distance between workplace and resident area become the core point of this research. This research will emphasize the use of Geographical Information System (GIS) technique to explore the distance parameter to the employment area and will focus on the accessibility pattern of low-cost housing. The research methodology consists of interview sessions and a questionnaire to residents of low-cost housing areas in Melaka Tengah District in Malaysia. The combination of these processes will show the criteria from the selected parameter for each respondent from their resident area to the employment area. This will further help in the recommendation of several options for a better commute or improvement to the existing routes and public transportations system. Thus enhancing quality of life for employees and helping to reduce stress, decrease lateness, absenteeism and improving productivity in workplace

  11. BEHAVIORAL INTENTION PENUMPANG KRL COMMUTER LINE JABODETABEK

    Directory of Open Access Journals (Sweden)

    Ronald Sukwadi

    2015-06-01

    Full Text Available Behavioral intention dipandang sebagai penentu utama kinerja penyedia transportasi umum. Penelitian ini menekankan pada hubungan antara behavioral intention dan variabel-variabel yang mempengaruhinya seperti kualitas layanan, nilai yang dirasakan, keterlibatan, dan kepuasan penumpang. Dengan melakukan survei penumpang Kereta Rel Listrik (KRL Commuter Line Jabodetabek, teknik model persamaan struktural menggunakan software AMOS 22.0 digunakan untuk menganalisis hubungan antar variabel dalam model konseptual. Hasil penelitian mengungkapkan bahwa kualitas layanan memiliki dampak positif terhadap nilai yang dirasakan. Nilai yang dirasakan dan kepuasan penumpang mempunyai dampak positif terhadap keterlibatan. Kualitas layanan dan keterlibatan memiliki dampak positif terhadap behavioral intention.     Abstract   The behavioral intention of public transportation passengers is seen as a crucial determinant of public transportation provider performance. This research highlights the relationships between passenger behavioral intention and the various variables that affect it such as service quality, perceived value, involvement, and satisfaction of public transportation services. By using passenger survey data from the Kereta Rel Listrik (KRL Commuter Line Jabodetabek, the structural equation modeling technique AMOS 22.0 is applied to analyze the conceptualized relationship model. The findings reveal that service quality has positive effect to perceived value. Perceived value and customer satisfaction have positive effect to involvement. Service quality and involvement have positive effect to behavioral intention.

  12. Reducing employee travelling time through smart commuting

    Science.gov (United States)

    Rahman, A. N. N. A.; Yusoff, Z. M.; Aziz, I. S.; Omar, D.

    2014-02-01

    Extremely congested roads will definitely delay the arrival time of each trip.This certainly impacted the journey of employees. Tardiness at the workplace has become a perturbing issue for companies where traffic jams are the most common worker excuses. A depressing consequence on daily life and productivity of the employee occurs. The issues of commuting distance between workplace and resident area become the core point of this research. This research will emphasize the use of Geographical Information System (GIS) technique to explore the distance parameter to the employment area and will focus on the accessibility pattern of low-cost housing. The research methodology consists of interview sessions and a questionnaire to residents of low-cost housing areas in Melaka Tengah District in Malaysia. The combination of these processes will show the criteria from the selected parameter for each respondent from their resident area to the employment area. This will further help in the recommendation of several options for a better commute or improvement to the existing routes and public transportations system. Thus enhancing quality of life for employees and helping to reduce stress, decrease lateness, absenteeism and improving productivity in workplace.

  13. On tea, donuts and non-commutative geometry

    Directory of Open Access Journals (Sweden)

    Igor V. Nikolaev

    2018-03-01

    Full Text Available As many will agree, it feels good to complement a cup of tea by a donut or two. This sweet relationship is also a guiding principle of non-commutative geometry known as Serre Theorem. We explain the algebra behind this theorem and prove that elliptic curves are complementary to the so-called non-commutative tori.

  14. Commutators of Integral Operators with Variable Kernels on Hardy ...

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 115; Issue 4. Commutators of Integral Operators with Variable Kernels on Hardy Spaces. Pu Zhang Kai Zhao. Volume 115 Issue 4 November 2005 pp 399-410 ... Keywords. Singular and fractional integrals; variable kernel; commutator; Hardy space.

  15. 75 FR 13680 - Commutation of Sentence: Technical Change

    Science.gov (United States)

    2010-03-23

    ... Sentence: Technical Change AGENCY: Bureau of Prisons, Justice. ACTION: Interim rule. SUMMARY: This document makes a minor technical change to the Bureau of Prisons (Bureau) regulations on sentence commutation to.... Commutation of Sentence: Technical Change This document makes a minor technical change to the Bureau...

  16. 26 CFR 1.46-11 - Commuter highway vehicles.

    Science.gov (United States)

    2010-04-01

    ... Rules for Computing Credit for Investment in Certain Depreciable Property § 1.46-11 Commuter highway... investment under section 46(c)(1) for a qualifying commuter highway vehicle is 100 percent. A qualifying... meets the following requirements: (1) The vehicle is section 38 property in the hands of the taxpayer...

  17. Newton's second law in a non-commutative space

    International Nuclear Information System (INIS)

    Romero, Juan M.; Santiago, J.A.; Vergara, J. David

    2003-01-01

    In this Letter we show that corrections to Newton's second law appear if we assume a symplectic structure consistent with the commutation rules of the non-commutative quantum mechanics. For central field we find that the correction term breaks the rotational symmetry. For the Kepler problem, this term is similar to a Coriolis force

  18. Commutators with idempotent values on multilinear polynomials in ...

    Indian Academy of Sciences (India)

    Introduction and statements of the result. In mid-forties, after the development of the general structure theory for rings, a great deal of work was done that showed that under certain types of hypothesis, rings had to be commutative or almost commutative. A classical result of ring theory established by Jacobson generalizes at ...

  19. Soft commutated direct current motor [summary of proposed paper

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, John S.

    1998-10-22

    A novel soft commutated direct current (DC) motor is introduced. The current of the commutated coil is intentionally drained before the brush disconnects the coil. This prevents the spark generation that normally occurs in conventional DC motors. A similar principle can be applied for DC generators.

  20. The university workers' willingness to pay for commuting

    NARCIS (Netherlands)

    Russo, G.; van Ommeren, J.N.; Rietveld, P.

    2012-01-01

    Using a dynamic approach, employing data on job mobility, we demonstrate that university workers' marginal willingness to pay for reducing commuting distance is about €0. 25 per kilometre travelled. This corresponds to a marginal willingness to pay for reducing commuting time of about 75 % of the

  1. Modelling the relation between income and commuting distance

    DEFF Research Database (Denmark)

    Carra, Giulia; Mulalic, Ismir; Fosgerau, Mogens

    2016-01-01

    We discuss the distribution of commuting distances and its relation to income. Using data from Denmark, the UK and the USA, we show that the commuting distance is (i) broadly distributed with a slow decaying tail that can be fitted by a power law with exponent γ ≈ 3 and (ii) an average growing...

  2. Linearization of non-commuting operators in the partition function

    International Nuclear Information System (INIS)

    Ahmed, M.

    1983-06-01

    A generalization of the Stratonovich-Hubbard scheme for evaluating the grand canonical partition function is given. The scheme involves linearization of products of non-commuting operators using the functional integral method. The non-commutivity of the operators leads to an additional term which can be absorbed in the single-particle Hamiltonian. (author)

  3. Homogeneous Buchberger algorithms and Sullivant's computational commutative algebra challenge

    DEFF Research Database (Denmark)

    Lauritzen, Niels

    2005-01-01

    We give a variant of the homogeneous Buchberger algorithm for positively graded lattice ideals. Using this algorithm we solve the Sullivant computational commutative algebra challenge.......We give a variant of the homogeneous Buchberger algorithm for positively graded lattice ideals. Using this algorithm we solve the Sullivant computational commutative algebra challenge....

  4. Non-commutative geometry on quantum phase-space

    International Nuclear Information System (INIS)

    Reuter, M.

    1995-06-01

    A non-commutative analogue of the classical differential forms is constructed on the phase-space of an arbitrary quantum system. The non-commutative forms are universal and are related to the quantum mechanical dynamics in the same way as the classical forms are related to classical dynamics. They are constructed by applying the Weyl-Wigner symbol map to the differential envelope of the linear operators on the quantum mechanical Hilbert space. This leads to a representation of the non-commutative forms considered by A. Connes in terms of multiscalar functions on the classical phase-space. In an appropriate coincidence limit they define a quantum deformation of the classical tensor fields and both commutative and non-commutative forms can be studied in a unified framework. We interprete the quantum differential forms in physical terms and comment on possible applications. (orig.)

  5. Euler polynomials and identities for non-commutative operators

    Science.gov (United States)

    De Angelis, Valerio; Vignat, Christophe

    2015-12-01

    Three kinds of identities involving non-commutating operators and Euler and Bernoulli polynomials are studied. The first identity, as given by Bender and Bettencourt [Phys. Rev. D 54(12), 7710-7723 (1996)], expresses the nested commutator of the Hamiltonian and momentum operators as the commutator of the momentum and the shifted Euler polynomial of the Hamiltonian. The second one, by Pain [J. Phys. A: Math. Theor. 46, 035304 (2013)], links the commutators and anti-commutators of the monomials of the position and momentum operators. The third appears in a work by Figuieira de Morisson and Fring [J. Phys. A: Math. Gen. 39, 9269 (2006)] in the context of non-Hermitian Hamiltonian systems. In each case, we provide several proofs and extensions of these identities that highlight the role of Euler and Bernoulli polynomials.

  6. Feasible Histories, Maximum Entropy

    International Nuclear Information System (INIS)

    Pitowsky, I.

    1999-01-01

    We consider the broadest possible consistency condition for a family of histories, which extends all previous proposals. A family that satisfies this condition is called feasible. On each feasible family of histories we choose a probability measure by maximizing entropy, while keeping the probabilities of commuting histories to their quantum mechanical values. This procedure is justified by the assumption that decoherence increases entropy. Finally, a criterion for identifying the nearly classical families is proposed

  7. Neighborhood educational disparities in active commuting among women: the effect of distance between the place of residence and the place of work/study (an ACTI-Cités study).

    Science.gov (United States)

    Perchoux, Camille; Nazare, Julie-Anne; Benmarhnia, Tarik; Salze, Paul; Feuillet, Thierry; Hercberg, Serge; Hess, Franck; Menai, Mehdi; Weber, Christiane; Charreire, Hélène; Enaux, Christophe; Oppert, Jean-Michel; Simon, Chantal

    2017-06-12

    Active transportation has been associated with favorable health outcomes. Previous research highlighted the influence of neighborhood educational level on active transportation. However, little is known regarding the effect of commuting distance on social disparities in active commuting. In this regard, women have been poorly studied. The objective of this paper was to evaluate the relationship between neighborhood educational level and active commuting, and to assess whether the commuting distance modifies this relationship in adult women. This cross-sectional study is based on a subsample of women from the Nutrinet-Santé web-cohort (N = 1169). Binomial, log-binomial and negative binomial regressions were used to assess the associations between neighborhood education level and (i) the likelihood of reporting any active commuting time, and (ii) the share of commuting time made by active transportation modes. Potential effect measure modification of distance to work on the previous associations was assessed both on the additive and the multiplicative scales. Neighborhood education level was positively associated with the probability of reporting any active commuting time (relative risk = 1.774; p education was greater at long distances to work for both outcomes. Our results suggest that neighborhood educational disparities in active commuting tend to increase with commuting distance among women. Further research is needed to provide geographically driven guidance for health promotion intervention aiming at reducing disparities in active transportation among socioeconomic groups.

  8. Effects of a school-based intervention on active commuting to school and health-related fitness

    Directory of Open Access Journals (Sweden)

    Emilio Villa-González

    2017-01-01

    Full Text Available Abstract Background Active commuting to school has declined over time, and interventions are needed to reverse this trend. The main objective was to investigate the effects of a school-based intervention on active commuting to school and health-related fitness in school-age children of Southern Spain. Methods A total of 494 children aged 8 to 11 years were invited to participate in the study. The schools were non-randomly allocated (i.e., school level allocation into the experimental group (EG or the control group (CG. The EG received an intervention program for 6 months (a monthly activity focused on increasing the level of active commuting to school and mainly targeting children’s perceptions and attitudes. Active commuting to school and health-related fitness (i.e., cardiorespiratory fitness, muscular fitness and speed-agility, were measured at baseline and at the end of the intervention. Children with valid data on commuting to school at baseline and follow-up, sex, age and distance from home to school were included in the final analysis (n = 251. Data was analyzed through a factorial ANOVA and the Bonferroni post-hoc test. Results At follow up, the EG had higher rates of cycling to school than CG for boys only (p = 0.04, but not for walking to school for boys or girls. The EG avoided increases in the rates of passive commuting at follow up, which increased in the CG among girls for car (MD = 1.77; SE = 0.714; p = 0.010 and bus (MD = 1.77; SE = 0.714; p = 0.010 modes. Moreover, we observed significant interactions and main effects between independent variables (study group, sex and assessment time point on health-related fitness (p < 0.05 over the 6-month period between groups, with higher values in the control group (mainly in boys. Conclusion A school-based intervention focused on increasing active commuting to school was associated with increases in rates of cycling to school among boys, but not for

  9. Integrated seismic analysis of the Chalk Group in eastern Denmark—Implications for estimates of maximum palaeo-burial in southwest Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Lars; Boldreel, Lars Ole; Hansen, Thomas Mejer

    2011-01-01

    Group. The sonic velocities are consistent with the overall seismic layering, although they show additional fine-scale layering. Integration of gamma and sonic log with porosity data shows that seismic velocity is sensitive to clay content. In intervals near boundaries of the refraction model, moderate......The origin of the topography of southwest Scandinavia is subject to discussion. Analysis of borehole seismic velocity has formed the basis for interpretation of several hundred metres of Neogene uplift in parts of Denmark.Here, refraction seismic data constrain a 7.5km long P-wave velocity model...... of the Chalk Group below the Stevns peninsula, eastern part of the Danish Basin. The model contains four layers in the ~860m thick Chalk Group with mean velocities of 2.2km/s, 2.4km/s, 3.1km/s, and 3.9–4.3km/s. Sonic and gamma wireline log data from two cored boreholes represent the upper ~450m of the Chalk...

  10. Electronically commutated dc motors for electric vehicles

    Science.gov (United States)

    Maslowski, E. A.

    1981-01-01

    A motor development program to explore the feasibility of electronically commutated dc motors (also known as brushless) for electric cars is described. Two different design concepts and a number of design variations based on these concepts are discussed. One design concept is based on a permanent magnet, medium speed, machine rated at 7000 to 9000 rpm, and powered via a transistor inverter power conditioner. The other concept is based on a permanent magnet, high speed, machine rated at 22,000 to 26,000 rpm, and powered via a thyristor inverter power conditioner. Test results are presented for a medium speed motor and a high speed motor each of which have been fabricated using samarium cobalt permanent magnet material.

  11. Active commuting to school in Portuguese adolescents

    DEFF Research Database (Denmark)

    Pizarro, Andreia Nogueira; Schipperijn, Jasper; Andersen, Henriette Bondo

    2016-01-01

    Abstract The declining levels of physical activity (PA) have led to active commuting to school (ACS) being seen as a key strategy to increase PA levels in school-aged children. In Portugal, no data exists on the patterns of this behavior, an essential step for developing evidence......-based and effective interventions. The purpose of this study is to explore the travel to school behavior using an objective methodology. Methods 155 adolescents (mean age 15.9±1.1 years) wore an accelerometer and a GPS for 7 consecutive days. Home and school addresses were geocoded to identify home-school trips....... The web-based tool PALMS was used to combine GPS and accelerometer data, categorize Moderate to Vigorous Physical Activity (MVPA) and classify trip mode of home-school trips into: walking, bicycling or vehicle. Results 609 trips were identified as home-school trips. Walking was the most frequent trip mode...

  12. Electronically commutated motors for vehicle applications

    Science.gov (United States)

    Echolds, E. F.

    1980-02-01

    Two permanent magnet electronically commutated motors for electric vehicle traction are discussed. One, based on existing technology, produces 23 kW (peak) at 26,000 rpm, and 11 kW continuous at 18,000 rpm. The motor has a conventional design: a four-pole permanent magnet rotor and a three-phase stator similar to those used on ordinary induction motors. The other, advanced technology motor, is rated at 27 kW (peak) at 14,000 rpm, and 11 kW continuous at 10,500 rpm. The machine employs a permanent magnet rotor and a novel ironless stator design in an axial air gap, homopolar configuration. Comparison of the new motors with conventional brush type machines indicates potential for substantial cost savings.

  13. The use of ultraproducts in commutative algebra

    CERN Document Server

    Schoutens, Hans

    2010-01-01

    In spite of some recent applications of ultraproducts in algebra, they remain largely unknown to commutative algebraists, in part because they do not preserve basic properties such as Noetherianity. This work wants to make a strong case against these prejudices. More precisely, it studies ultraproducts of Noetherian local rings from a purely algebraic perspective, as well as how they can be used to transfer results between the positive and zero characteristics, to derive uniform bounds, to define tight closure in characteristic zero, and to prove asymptotic versions of homological conjectures in mixed characteristic. Some of these results are obtained using variants called chromatic products, which are often even Noetherian. This book, neither assuming nor using any logical formalism, is intended for algebraists and geometers, in the hope of popularizing ultraproducts and their applications in algebra.

  14. Calculation of atomic integrals using commutation relations

    International Nuclear Information System (INIS)

    Zamastil, J.; Vinette, F.; Simanek, M.

    2007-01-01

    In this paper, a numerically stable method of calculating atomic integrals is suggested. The commutation relations among the components of the angular momentum and the Runge-Lenz vector are used to deduce recurrence relations for the Sturmian radial functions. The radial part of the one- and two-electron integrals is evaluated by means of these recurrence relations. The product of two radial functions is written as a linear combination of the radial functions. This enables us to write the integrals over four radial functions as a linear combination of the integrals over two radial functions. The recurrence relations for the functions are used to derive the recursion relations for the coefficients of the linear combination and for the integrals over two functions

  15. A lightweight electronically commutated dc motor for electric passenger vehicles

    Science.gov (United States)

    Echolds, E. F.; Walla, P. S.

    1982-01-01

    A functional model breadboard converter and a rare-earth-cobalt, permanent magnet motor; as well as an engineering model converter and PM motor suitable for vehicle installations were developed and tested. The converter and motor achieved an 88% peak efficiency, a maximum output of 26 kW at 26,000 rpm, and a continuous rating of 15 kW. The system also generated power to the source during braking, with a demonstrated peak power available at the converter terminals of approximately 26 kW at 88% efficiency. Major conclusions include: (1) the SAE J227a(D) driving cycle efficiency for the converter/motor is 86% to 88% when energy available for recovery at the converter terminals is included; (2) the converter initial cost is approximately five times that of the permanent magnet motor, but can be reduced by means of LSI logic and integrated liquid cooled semiconductor packages; and (3) an electronically commutated motor with a liquid cooled converter will operate reliably without service or maintenance for the life of a passenger vehicle.

  16. A lightweight electronically commutated dc motor for electric passenger vehicles

    Science.gov (United States)

    Echolds, E. F.; Walla, P. S.

    1982-09-01

    A functional model breadboard converter and a rare-earth-cobalt, permanent magnet motor; as well as an engineering model converter and PM motor suitable for vehicle installations were developed and tested. The converter and motor achieved an 88% peak efficiency, a maximum output of 26 kW at 26,000 rpm, and a continuous rating of 15 kW. The system also generated power to the source during braking, with a demonstrated peak power available at the converter terminals of approximately 26 kW at 88% efficiency. Major conclusions include: (1) the SAE J227a(D) driving cycle efficiency for the converter/motor is 86% to 88% when energy available for recovery at the converter terminals is included; (2) the converter initial cost is approximately five times that of the permanent magnet motor, but can be reduced by means of LSI logic and integrated liquid cooled semiconductor packages; and (3) an electronically commutated motor with a liquid cooled converter will operate reliably without service or maintenance for the life of a passenger vehicle.

  17. Commuting behavior of western U.S. residents

    Energy Technology Data Exchange (ETDEWEB)

    Caviglia, J. [Tennessee Univ., Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States)

    1996-06-01

    Estimation and interpretation of commutes to work has been studied extensively with respect to gender, race, and income. While the literature is extensive in these areas, there has been little research on regional differences between US states and territories. Since data which reports the commute to work is in average minutes, the distance traveled is estimated using estimates of the distance between home and work county centroids. The models differ in estimation of in-county commutes. The first assumes that the commute is equal to the radius of the county and the second estimates the commute as a weighted distance based on place location. Two data sets are compared, US National Guard data and US census data. Goal of this paper is to make conclusions about the commuting behavior of western residents through the use of these estimates, and therefore to provide a estimation method for distance commutes which can be used in further research. It is concluded that the radius method of estimation may be an over estimation, in particular in the western states. Since the non-western states are generally more homogeneously populated, this overestimation is not observed. It is recommended that the place location method be used for similar research, in particular studies dealing with western states. Suggestions are made for further research and recommendations are made for the US Army National Guard in regards to recruiting.

  18. Introduction to Dubois-Violette's non-commutative differential geometry

    International Nuclear Information System (INIS)

    Djemai, A.E.F.

    1994-07-01

    In this work, one presents a detailed review of Dubois-Violette et al. approach to non-commutative differential calculus. The non-commutative differential geometry of matrix algebras and the non-commutative Poisson structures are treated in some details. We also present the analog of the Maxwell's theory and the new models of Yang-Mills-Higgs theories that can be constructed in this framework. In particular, some simple models are compared with the standard model. Finally, we discuss some perspectives and open questions. (author). 32 refs

  19. Non-commutative field theory with twistor-like coordinates

    International Nuclear Information System (INIS)

    Taylor, Tomasz R.

    2007-01-01

    We consider quantum field theory in four-dimensional Minkowski spacetime, with the position coordinates represented by twistors instead of the usual world-vectors. Upon imposing canonical commutation relations between twistors and dual twistors, quantum theory of fields described by non-holomorphic functions of twistor variables becomes manifestly non-commutative, with Lorentz symmetry broken by a time-like vector. We discuss the free field propagation and its impact on the short- and long-distance behavior of physical amplitudes in perturbation theory. In the ultraviolet limit, quantum field theories in twistor space are generically less divergent than their commutative counterparts. Furthermore, there is no infrared-ultraviolet mixing problem

  20. Note on Ideal Based Zero-Divisor Graph of a Commutative Ring

    Directory of Open Access Journals (Sweden)

    Mallika A.

    2017-12-01

    Full Text Available In this paper, we consider the ideal based zero divisor graph ΓI(R of a commutative ring R. We discuss some graph theoretical properties of ΓI(R in relation with zero divisor graph. We also relate certain parameters like vertex chromatic number, maximum degree and minimum degree for the graph ΓI(R with that of Γ(R/I . Further we determine a necessary and sufficient condition for the graph to be Eulerian and regular.

  1. Respiratory effects of commuters' exposure to air pollution in traffic.

    Science.gov (United States)

    Zuurbier, Moniek; Hoek, Gerard; Oldenwening, Marieke; Meliefste, Kees; van den Hazel, Peter; Brunekreef, Bert

    2011-03-01

    Much time is spent in traffic, especially during rush hours, when air pollution concentrations on roads are relatively high. Controlled exposure studies have shown acute respiratory effects of short, high exposures to air pollution from motor vehicles. Acute health effects of lower real-life exposures in traffic are unclear. Exposures of 34 healthy, nonsmoking adult volunteers were repeatedly measured while commuting for 2 hours by bus, car, or bicycle. Particle number (PN), particulate matter (PM2.5 and PM10), and soot exposures were measured. Lung function and airway resistance were measured directly before, directly following, and 6 hours after exposure. Exhaled nitric oxide (NO) was measured directly before and 6 hours after exposure. Inhaled doses were estimated based on monitored heart rates. Mixed models were used to analyze effects of exposure on changes in health parameters after exposure compared with before. PN, PM10, and soot were associated with decreased peak expiratory flow directly following but not 6 hours after exposure. PN doses were associated with decreases in maximum midexpiratory flow and forced expiratory flow (FEV1) 6 hours after exposure, whereas PN and soot exposures were associated with increased maximum midexpiratory flow and FEV1 directly after exposure. PN and soot were associated with increased exhaled NO after car and bus but not bicycle trips. PN was also associated with an increase in airway resistance directly following exposure but not 6 hours later. We found modest effects of 2-hour in-traffic exposure to air pollutants on peak flow, exhaled NO, and airway resistance.

  2. Electronic fare collection options for commuter railroads : final report

    Science.gov (United States)

    2009-09-01

    This research is designed to support FTA in its efforts to disseminate knowledge of new technologies within the transit community, in this case focusing on issues associated with automated fare collection (AFC) for commuter rail. By identifying le...

  3. Exploring characteristics and motives of long distance commuter cyclists

    DEFF Research Database (Denmark)

    Hansen, Karsten Bruun; Nielsen, Thomas Alexander Sick

    2014-01-01

    are very positive about their commute - pointing to positive experiences, better mood, and stress relief as experiences related to their cycle trip to work. Policy support should devote attention to unlocking the potential that may be embedded in individuals combining their exercise and travel time......, commuter cyclists (>5 km from home to work) have more mobility options, higher incomes, and a longer education than other commuter cyclists. The main motive for longer distance cycling is physical exercise, followed by reduced costs and time used for traveling. The long distance commuter cyclists surveyed......, budgets to promote active travel to work as well as the role of psychological benefits as a factor in promoting and sustaining cycling practices....

  4. Interactions Between Representation Ttheory, Algebraic Topology and Commutative Algebra

    CERN Document Server

    Pitsch, Wolfgang; Zarzuela, Santiago

    2016-01-01

    This book includes 33 expanded abstracts of selected talks given at the two workshops "Homological Bonds Between Commutative Algebra and Representation Theory" and "Brave New Algebra: Opening Perspectives," and the conference "Opening Perspectives in Algebra, Representations, and Topology," held at the Centre de Recerca Matemàtica (CRM) in Barcelona between January and June 2015. These activities were part of the one-semester intensive research program "Interactions Between Representation Theory, Algebraic Topology and Commutative Algebra (IRTATCA)." Most of the abstracts present preliminary versions of not-yet published results and cover a large number of topics (including commutative and non commutative algebra, algebraic topology, singularity theory, triangulated categories, representation theory) overlapping with homological methods. This comprehensive book is a valuable resource for the community of researchers interested in homological algebra in a broad sense, and those curious to learn the latest dev...

  5. Minimal length uncertainty and generalized non-commutative geometry

    International Nuclear Information System (INIS)

    Farmany, A.; Abbasi, S.; Darvishi, M.T.; Khani, F.; Naghipour, A.

    2009-01-01

    A generalized formulation of non-commutative geometry for the Bargmann-Fock space of quantum field theory is presented. The analysis is related to the symmetry of the simplistic space and a minimal length uncertainty.

  6. 7 CFR 354.2 - Administrative instructions prescribing commuted traveltime.

    Science.gov (United States)

    2010-01-01

    ... period of overtime and holiday duty, as defined in § 354.1 shall, in addition, include a commuted... Undesignated ports St. Albans 3 Virgin Islands: Alexander Hamilton Airport, St. Croix 1 Charlotte Amalie, St...

  7. Vectors and covectors in non-commutative setting

    OpenAIRE

    Parfionov, G. N.; Romashev, Yu. A.; Zapatrine, R. R.

    1995-01-01

    Following the guidelines of classical differential geometry the `building material' for the tensor calculus in non-commutative geometry is suggested. The algebraic account of moduli of vectors and covectors is carried out.

  8. The shear viscosity of the non-commutative plasma

    International Nuclear Information System (INIS)

    Landsteiner, Karl; Mas, Javier

    2007-01-01

    We compute the shear viscosity of the non-commutative N = 4 super Yang-Mills quantum field theory at strong coupling using the dual supergravity background. Special interest derives from the fact that the background presents an intrinsic anisotropy in space through the distinction of commutative and non-commutative directions. Despite this anisotropy the analysis exhibits the ubiquitous result η/s = 1/4π for two different shear channels. In order to derive this result, we show that the boundary energy momentum tensor must couple to the open string metric. As a byproduct we compute the renormalised holographic energy momentum tensor and show that it coincides with one in the commutative theory

  9. Will urban commuting time affect housing prices and vehicle emissions?

    Science.gov (United States)

    2016-03-01

    The transportation cost is an essential factor that impacts land and house values in urban areas. In a classical monocentric city model, residents who work in the Central Business District (CBD) are facing a tradeoff between rent and commuting dis...

  10. Commutative curvature operators over four-dimensional generalized symmetric

    Directory of Open Access Journals (Sweden)

    Ali Haji-Badali

    2014-12-01

    Full Text Available Commutative properties of four-dimensional generalized symmetric pseudo-Riemannian manifolds were considered. Specially, in this paper, we studied Skew-Tsankov and Jacobi-Tsankov conditions in 4-dimensional pseudo-Riemannian generalized symmetric manifolds.

  11. Commutative algebra with a view toward algebraic geometry

    CERN Document Server

    Eisenbud, David

    1995-01-01

    Commutative Algebra is best understood with knowledge of the geometric ideas that have played a great role in its formation, in short, with a view towards algebraic geometry. The author presents a comprehensive view of commutative algebra, from basics, such as localization and primary decomposition, through dimension theory, differentials, homological methods, free resolutions and duality, emphasizing the origins of the ideas and their connections with other parts of mathematics. Many exercises illustrate and sharpen the theory and extended exercises give the reader an active part in complementing the material presented in the text. One novel feature is a chapter devoted to a quick but thorough treatment of Grobner basis theory and the constructive methods in commutative algebra and algebraic geometry that flow from it. Applications of the theory and even suggestions for computer algebra projects are included. This book will appeal to readers from beginners to advanced students of commutative algebra or algeb...

  12. Kohn condition and exotic Newton-Hooke symmetry in the non-commutative Landau problem

    International Nuclear Information System (INIS)

    Zhang, P.-M.; Horvathy, P.A.

    2012-01-01

    N “exotic” [alias non-commutative] particles with masses m a , charges e a and non-commutative parameters θ a , moving in a uniform magnetic field B, separate into center-of-mass and internal motions if Kohn's condition e a /m a =const is supplemented with e a θ a =const. Then the center-of-mass behaves as a single exotic particle carrying the total mass and charge of the system, M and e, and a suitably defined non-commutative parameter Θ. For vanishing electric field off the critical case eΘB≠1, the particles perform the usual cyclotronic motion with modified but equal frequency. The system is symmetric under suitable time-dependent translations which span a (4+2)-parameter centrally-extended subgroup of the “exotic” [i.e., two-parameter centrally-extended] Newton–Hooke group. In the critical case B=B c =(eΘ) −1 the system is frozen into a static “crystal” configuration. Adding a constant electric field, all particles perform, collectively, a cyclotronic motion combined with a drift perpendicular to the electric field when eΘB≠1. For B=B c the cyclotronic motion is eliminated and all particles move, collectively, following the Hall law. Our time-dependent symmetries are reduced to the (2+1)-parameter Heisenberg group of centrally-extended translations.

  13. Electronically commutated serial-parallel switching for motor windings

    Science.gov (United States)

    Hsu, John S [Oak Ridge, TN

    2012-03-27

    A method and a circuit for controlling an ac machine comprises controlling a full bridge network of commutation switches which are connected between a multiphase voltage source and the phase windings to switch the phase windings between a parallel connection and a series connection while providing commutation discharge paths for electrical current resulting from inductance in the phase windings. This provides extra torque for starting a vehicle from lower battery current.

  14. An improved 4-step commutation method application for matrix converter

    DEFF Research Database (Denmark)

    Guo, Yu; Guo, Yougui; Deng, Wenlang

    2014-01-01

    A novel four-step commutation method is proposed for matrix converter cell, 3 phase inputs to 1 phase output in this paper, which is obtained on the analysis of published commutation methods for matrix converter. The first and fourth step can be shorter than the second or third one. The discussed...... method here is implemented by programming in VHDL language. Finally, the novel method in this paper is verified by experiments....

  15. On commutativity of one-sided s-unital rings

    Directory of Open Access Journals (Sweden)

    H. A. S. Abujabal

    1992-01-01

    Full Text Available The following theorem is proved: Let r=r(y>1, s, and t be non-negative integers. If R is a left s-unital ring satisfies the polynomial identity [xy−xsyrxt,x]=0 for every x,y∈R, then R is commutative. The commutativity of a right s-unital ring satisfying the polynomial identity [xy−yrxt,x]=0 for all x,y∈R, is also proved.

  16. Translation invariance, commutation relations and ultraviolet/infrared mixing

    International Nuclear Information System (INIS)

    Galluccio, Salvatore; Lizzi, Fedele; Vitale, Patrizia

    2009-01-01

    We show that the Ultraviolet/Infrared mixing of noncommutative field theories with the Groenewold-Moyal product, whereby some (but not all) ultraviolet divergences become infrared, is a generic feature of translationally invariant associative products. We find, with an explicit calculation that the phase appearing in the nonplanar diagrams is the one given by the commutator of the coordinates, the semiclassical Poisson structure of the non commutative spacetime. We do this with an explicit calculation for represented generic products.

  17. Associations between active commuting and physical and mental wellbeing.

    Science.gov (United States)

    Humphreys, David K; Goodman, Anna; Ogilvie, David

    2013-08-01

    To examine whether a relationship exists between active commuting and physical and mental wellbeing. In 2009, cross-sectional postal questionnaire data were collected from a sample of working adults (aged 16 and over) in the Commuting and Health in Cambridge study. Travel behaviour and physical activity were ascertained using the Recent Physical Activity Questionnaire (RPAQ) and a seven-day travel-to-work recall instrument from which weekly time spent in active commuting (walking and cycling) was derived. Physical and mental wellbeing were assessed using the Medical Outcomes Study Short Form survey (SF-8). Associations were tested using multivariable linear regression. An association was observed between physical wellbeing (PCS-8) score and time spent in active commuting after adjustment for other physical activity (adjusted regression coefficients 0.48, 0.79 and 1.21 for 30-149 min/week, 150-224 min/week and ≥ 225 min/week respectively versus mental wellbeing (MCS-8) (p=0.52). Greater time spent actively commuting is associated with higher levels of physical wellbeing. Longitudinal studies should examine the contribution of changing levels of active commuting and other forms of physical activity to overall health and wellbeing. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Trace Dynamics and a non-commutative special relativity

    International Nuclear Information System (INIS)

    Lochan, Kinjalk; Singh, T.P.

    2011-01-01

    Trace Dynamics is a classical dynamical theory of non-commuting matrices in which cyclic permutation inside a trace is used to define the derivative with respect to an operator. We use the methods of Trace Dynamics to construct a non-commutative special relativity. We define a line-element using the Trace over space-time coordinates which are assumed to be operators. The line-element is shown to be invariant under standard Lorentz transformations, and is used to construct a non-commutative relativistic dynamics. The eventual motivation for constructing such a non-commutative relativity is to relate the statistical thermodynamics of this classical theory to quantum mechanics. -- Highlights: → Classical time is external to quantum mechanics. → This implies need for a formulation of quantum theory without classical time. → A starting point could be a non-commutative special relativity. → Such a relativity is developed here using the theory of Trace Dynamics. → A line-element is defined using the Trace over non-commuting space-time operators.

  19. Massive neutrinos in almost-commutative geometry

    International Nuclear Information System (INIS)

    Stephan, Christoph A.

    2007-01-01

    In the noncommutative formulation of the standard model of particle physics by Chamseddine and Connes [Commun. Math. Phys. 182, 155 (1996), e-print hep-th/9606001], one of the three generations of fermions has to possess a massless neutrino. [C. P. Martin et al., Phys. Rep. 29, 363 (1998), e-print hep-th-9605001]. This formulation is consistent with neutrino oscillation experiments and the known bounds of the Pontecorvo-Maki-Nakagawa-Sakata matrix (PMNS matrix). But future experiments which may be able to detect neutrino masses directly and high-precision measurements of the PMNS matrix might need massive neutrinos in all three generations. In this paper we present an almost-commutative geometry which allows for a standard model with massive neutrinos in all three generations. This model does not follow in a straightforward way from the version of Chamseddine and Connes since it requires an internal algebra with four summands of matrix algebras, instead of three summands for the model with one massless neutrino

  20. On commutators and semicommutators of Toeplitz operators

    International Nuclear Information System (INIS)

    Berkani, M.

    1994-04-01

    Let φ and ψ be two essentially bounded functions on the unit circle T. This paper is devoted to the study of the semicommutator T φψ -T φ T ψ of the Toeplitz operators T φ and T ψ . We prove that if φ is inner and P+(ψφ-bar) is an element of B 1/p p then the semicommutator T φψ -T φ T ψ is in the Schatten-Von-Neumann class σ p , p>0. Here B 1/p p denote the Besov class, P + is the orthogonal projection from L 2 onto the Hardy space H 2 . Moreover if φ is also continuous, then T φψ -T φ T ψ is of finite rank. An example based on the Hardy-Littelwood series shows that the result fails if we suppose φ only continuous. We also give some sufficient conditions on the Fourier coefficients of the symbols φ and ψ which implies that the commutator [T φ ,T ψ ] belongs to σ p , p>0. (author). 14 refs

  1. On commutators and semicommutators of Toeplitz operators

    International Nuclear Information System (INIS)

    Berkani, M.

    1996-08-01

    Let φ and ψ be two essentially bounded functions on the unit circle T. This paper is devoted to the study of the semicommutator T φψ - T φ T ψ of the Toeplitz operators T φ and T ψ . We prove that if φ is inner and P + (ψφ-bar) is an element of B 1/p p then the semicommutator T φψ - T φ T ψ is in the Schatten-Von-Neumann class σ p , p > 0. Here B 1/p p denote the Besov class, P + is the orthogonal projection from L 2 onto the Hardy space H 2 . Moreover if φ is also continuous, then T φψ - T φ T ψ is of finite rank. An example based on the Hardy-Littlewood series shows that the result fails if we suppose φ only continuous. We also give some sufficient conditions on the Fourier coefficients of the symbols φ and ψ which implies that the commutator [T φ , T ψ ] belongs to σ p , p > 0. (author). 14 refs

  2. Pion--nucleon sigma-commutator

    International Nuclear Information System (INIS)

    Banerjee, M.K.; Cammarata, J.B.

    1977-07-01

    The reasons for the large discrepancies in the magnitude of the πN sigma-commutator, sigma(πN), obtained by several authors are discussed using dynamic theory of the πN scattering amplitude. With sigma(πN) approximately 25 MeV this theory reproduces reasonably well both the experimental S-wave phase shifts at low energies and the amplitudes C approximately/sup(+)/(ν=0,t less than or equal to 0) determined by Langbein. In the method of Cheng and Dashen the value of sigma(πN) is obtained from these amplitudes by extrapolation to t = 2m 2 /sub π/. A study of the experimental D-wave ''scattering lengths'' implies that the coefficient of the term quadratic in t in the Hoehler expansion of C approximately/sup(+)/(0,t) is negative. Adding such a term to the results of the S-wave theory will tend to improve the agreement for C approximately/sup (+)/(0,t less than or equal to 0). These results suggest that the large ''world value'' sigma(πN) = 65 +- 5 MeV obtained using the Cheng-Dashen method is a consequence of errors in the extrapolation of amplitudes to the unphysical point ν = 0, t = 2m 2 /sub π/. Only the smaller value sigma(πN) approximately 25 MeV appears to be consistent with the experimental data and theoretical constraints

  3. Children who commute to school unaccompanied have greater autonomy and perceptions of safety.

    Science.gov (United States)

    Herrador-Colmenero, Manuel; Villa-González, Emilio; Chillón, Palma

    2017-12-01

    We explored the rates of children who actively commuted to school, both accompanied and unaccompanied, and identified their safety perceptions. This cross-sectional study focused on 745 children, aged 6-12 years, from public schools in the Spanish Granada region. They completed a questionnaire, providing personal data, their school grade, safety perceptions, whether they were accompanied to school and how they travelled to school. We analysed how active commuters were accompanied to school by age group and assessed the associations between safety perceptions and whether or not they were accompanied. Children aged 10-12 years were more likely to travel to school unaccompanied, more likely to travel actively and had better safety perceptions than younger children. We also found differences in how active commuters between 10 and 12 years and children aged 6-7 and 8-9 years (all p safety issues than accompanied children (p safety perceptions than other children in this sample of children aged 6-12. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  4. Non-commutative solitons and strong-weak duality

    Energy Technology Data Exchange (ETDEWEB)

    Blas, Harold [Departamento de Matematica - ICET, Universidade Federal de Mato Grosso, Av. Fernando Correa, s/n, Coxipo, 78060-900, Cuiaba - MT (Brazil)]. E-mail: blas@cpd.ufmt.br; Carrion, Hector L. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21941-972 Rio de Janeiro (Brazil); Rojas, Moises [Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud, 150 CEP 22290-180, Rio de Janeiro-RJ (Brazil)

    2005-03-01

    Some properties of the non-commutative versions of the sine-Gordon model (NCSG) and the corresponding massive Thirring theories (NCMT) are studied. Our method relies on the NC extension of integrable models and the master Lagrangian approach to deal with dual theories. The master lagrangians turn out to be the NC versions of the so-called affine Toda model coupled to matter fields (NCATM) associated to the group GL(2), in which the Toda field belongs to certain representations of either U(1)xU(1) or U(1){sub C} corresponding to the Lechtenfeld et al. (NCSG{sub 1}) or Grisaru-Penati (NCSG{sub 2}) proposals for the NC versions of the sine-Gordon model, respectively. Besides, the relevant NCMT{sub 1,2} models are written for two (four) types of Dirac fields corresponding to the Moyal product extension of one (two) copy(ies) of the ordinary massive Thirring model. The NCATM{sub 1,2} models share the same one-soliton (real Toda field sector of model 2) exact solutions, which are found without expansion in the NC parameter {theta} for the corresponding Toda and matter fields describing the strong-weak phases, respectively. The correspondence NCSG{sub 1} {r_reversible} NCMT{sub 1} is promising since it is expected to hold on the quantum level. (author)

  5. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

  6. Active commuting to school: How far is too far?

    LENUS (Irish Health Repository)

    Nelson, Norah M

    2008-01-01

    ABSTRACT: BACKGROUND: Walking and cycling to school provide a convenient opportunity to incorporate physical activity into an adolescent\\'s daily routine. School proximity to residential homes has been identified as an important determinant of active commuting among children. The purpose of this study is to identify if distance is a barrier to active commuting among adolescents, and if there is a criterion distance above which adolescents choose not to walk or cycle. METHODS: Data was collected in 2003-05 from a cross-sectional cohort of 15-17 yr old adolescents in 61 post primary schools in Ireland. Participants self-reported distance, mode of transport to school and barriers to active commuting. Trained researchers took physical measurements of height and weight. The relation between mode of transport, gender and population density was examined. Distance was entered into a bivariate logistic regression model to predict mode choice, controlling for gender, population density socio-economic status and school clusters. RESULTS: Of the 4013 adolescents who participated (48.1% female, mean age 16.02 +\\/- 0.661), one third walked or cycled to school. A higher proportion of males than females commuted actively (41.0 vs. 33.8%, chi2 (1) = 22.21, p < 0.001, r = -0.074). Adolescents living in more densely populated areas had greater odds of active commuting than those in the most sparsely populated areas (chi2 (df = 3) = 839.64, p < 0.001). In each density category, active commuters travelled shorter distances to school. After controlling for gender and population density, a 1-mile increase in distance decreased the odds of active commuting by 71% (chi2 (df = 1) = 2591.86, p < 0.001). The majority of walkers lived within 1.5 miles and cyclists within 2.5 miles. Over 90% of adolescents who perceived distance as a barrier to active commuting lived further than 2.5 miles from school. CONCLUSION: Distance is an important perceived barrier to active commuting and a predictor

  7. Fitness, Fatness and Active School Commuting among Liverpool Schoolchildren

    Directory of Open Access Journals (Sweden)

    Robert J. Noonan

    2017-08-01

    Full Text Available This study investigated differences in health outcomes between active and passive school commuters, and examined associations between parent perceptions of the neighborhood environment and active school commuting (ASC. One hundred-ninety-four children (107 girls, aged 9–10 years from ten primary schools in Liverpool, England, participated in this cross-sectional study. Measures of stature, body mass, waist circumference and cardiorespiratory fitness (CRF were taken. School commute mode (active/passive was self-reported and parents completed the neighborhood environment walkability scale for youth. Fifty-three percent of children commuted to school actively. Schoolchildren who lived in more deprived neighborhoods perceived by parents as being highly connected, unaesthetic and having mixed land-use were more likely to commute to school actively (p < 0.05. These children were at greatest risk of being obese and aerobically unfit(p < 0.01. Our results suggest that deprivation may explain the counterintuitive relationship between obesity, CRF and ASC in Liverpool schoolchildren. These findings encourage researchers and policy makers to be equally mindful of the social determinants of health when advocating behavioral and environmental health interventions. Further research exploring contextual factors to ASC, and examining the concurrent effect of ASC and diet on weight status by deprivation is needed.

  8. Bias Assessment of General Chemistry Analytes using Commutable Samples.

    Science.gov (United States)

    Koerbin, Gus; Tate, Jillian R; Ryan, Julie; Jones, Graham Rd; Sikaris, Ken A; Kanowski, David; Reed, Maxine; Gill, Janice; Koumantakis, George; Yen, Tina; St John, Andrew; Hickman, Peter E; Simpson, Aaron; Graham, Peter

    2014-11-01

    Harmonisation of reference intervals for routine general chemistry analytes has been a goal for many years. Analytical bias may prevent this harmonisation. To determine if analytical bias is present when comparing methods, the use of commutable samples, or samples that have the same properties as the clinical samples routinely analysed, should be used as reference samples to eliminate the possibility of matrix effect. The use of commutable samples has improved the identification of unacceptable analytical performance in the Netherlands and Spain. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has undertaken a pilot study using commutable samples in an attempt to determine not only country specific reference intervals but to make them comparable between countries. Australia and New Zealand, through the Australasian Association of Clinical Biochemists (AACB), have also undertaken an assessment of analytical bias using commutable samples and determined that of the 27 general chemistry analytes studied, 19 showed sufficiently small between method biases as to not prevent harmonisation of reference intervals. Application of evidence based approaches including the determination of analytical bias using commutable material is necessary when seeking to harmonise reference intervals.

  9. Noncommutative conformally coupled scalar field cosmology and its commutative counterpart

    International Nuclear Information System (INIS)

    Barbosa, G.D.

    2005-01-01

    We study the implications of a noncommutative geometry of the minisuperspace variables for the Friedmann-Robertson-Walker universe with a conformally coupled scalar field. The investigation is carried out by means of a comparative study of the universe evolution in four different scenarios: classical commutative, classical noncommutative, quantum commutative, and quantum noncommutative, the last two employing the Bohmian formalism of quantum trajectories. The role of noncommutativity is discussed by drawing a parallel between its realizations in two possible frameworks for physical interpretation: the NC frame, where it is manifest in the universe degrees of freedom, and in the C frame, where it is manifest through θ-dependent terms in the Hamiltonian. As a result of our comparative analysis, we find that noncommutative geometry can remove singularities in the classical context for sufficiently large values of θ. Moreover, under special conditions, the classical noncommutative model can admit bouncing solutions characteristic of the commutative quantum Friedmann-Robertson-Walker universe. In the quantum context, we find nonsingular universe solutions containing bounces or being periodic in the quantum commutative model. When noncommutativity effects are turned on in the quantum scenario, they can introduce significant modifications that change the singular behavior of the universe solutions or that render them dynamical whenever they are static in the commutative case. The effects of noncommutativity are completely specified only when one of the frames for its realization is adopted as the physical one. Nonsingular solutions in the NC frame can be mapped into singular ones in the C frame

  10. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

  11. K-groups of reciprocity functors

    OpenAIRE

    Ivorra, Florian; Rülling, Kay

    2012-01-01

    In this work we introduce reciprocity functors, construct the associated K-group of a family of reciprocity functors, which itself is a reciprocity functor, and compute it in several different cases. It may be seen as a first attempt to get close to the notion of reciprocity sheaves imagined by B. Kahn. Commutative algebraic groups, homotopy invariant Nisnevich sheaves with transfers, cycle modules or K\\"ahler differentials are examples of reciprocity functors. As commutative algebraic groups...

  12. Estimating commute-travel implications of telecommuting by female employees in Kuala Lumpur, Malaysia

    Directory of Open Access Journals (Sweden)

    Mootaz M. Jaff

    2018-04-01

    Full Text Available A number of Malaysian cities are experiencing severe traffic congestion resulting from rapidly increasing vehicle ownership and usage, and the insufficient supply and inferior quality of public transport. The trend of congestion, frequent traffic accidents and air pollution is nowhere more prevalent in Kuala Lumpur where telecommuting is increasingly being perceived as a viable travel demand management strategy. Due to a number of unique travel characteristics of female commuters and the relatively large participation rate of women in the Malaysian work force, telecommuting by female employees seems a more relevant and potentially more crucial means of alleviating rush hour traffic in the Kuala Lumpur metropolitan area. The aim of this study is to estimate both the potential and actual travel implications of telecommuting by female employees. Therefore, this study is exploratory in nature as it mainly aims to explore the influence of the propagation of a phenomenon (i.e., telecommuting among female employees in Kuala Lumpur on travel demand, and is thus mainly a quantitative research. The travel implications estimated in this paper include the reduction in commute trips, with a particular emphasis on the reduction in single occupancy vehicles (SOVs entering the city of Kuala Lumpur during peak hours; vehicle and passenger-kilometers forgone; and time savings as a result of the elimination of the daily commute. The findings clearly show the potential of substantial reduction in vehicle and passenger-kilometers travelled, as well as potential time savings of more than 7000 employee-hours/day under an optimal adoption scenario. Furthermore, telecommuting by female employees could potentially result in a daily reduction of up to 7.8% of all SOVs entering Kuala Lumpur in 2019; however, there is a large gap between that potential reduction and the maximum actual reduction of 0.96%. Keywords: Travel implications, Telecommuting, Female employees, Single

  13. Impact of Distance on Mode of Active Commuting in Chilean Children and Adolescents

    Directory of Open Access Journals (Sweden)

    Fernando Rodríguez-Rodríguez

    2017-11-01

    Full Text Available Active commuting could contribute to increasing physical activity. The objective of this study was to characterise patterns of active commuting to and from schools in children and adolescents in Chile. A total of 453 Chilean children and adolescents aged between 10 and 18 years were included in this study. Data regarding modes of commuting and commuting distance was collected using a validated questionnaire. Commuting mode was classified as active commuting (walking and/or cycling or non-active commuting (car, motorcycle and/or bus. Commuting distance expressed in kilometres was categorised into six subgroups (0 to 0.5, 0.6 to 1, 1.1 to 2, 2.1 to 3, 3.1 to 5 and >5 km. Car commuting was the main mode for children (to school 64.9%; from school 51.2% and adolescents (to school 50.2%; from school 24.7%. Whereas public bus commuting was the main transport used by adolescents to return from school. Only 11.0% and 24.8% of children and adolescents, respectively, walk to school. The proportion of children and adolescents who engage in active commuting was lower in those covering longer distances compared to a short distance. Adolescents walked to and from school more frequently than children. These findings show that non-active commuting was the most common mode of transport and that journey distances may influence commuting modes in children and adolescents.

  14. Modes and Moods of Mobility: Tourists and Commuters

    Directory of Open Access Journals (Sweden)

    Orvar Löfgren

    2015-06-01

    Full Text Available What can we learn from comparing different modes and moods of travel, among, for example, tourists and commuters? This paper contrasts these two very different kinds of mobility, and the ways in which they organise both motion and emotion. It is not only a question about how people interact with various systems of transport, but also how materialities and affects work together. An important topic is the question of how people acquire travelling skills. How do they learn to be a tourist or a commuter, to handle a train ride, navigate a transit space, or interact with strangers? A good reason to contrast commuters and tourists is also because they have often been studied within very different research paradigms. How can these different research traditions be put into a dialogue with each other, and help to develop methods for capturing the often elusive ways in which motion and emotion work together?

  15. QPFT operator algebras and commutative exterior differential calculus

    International Nuclear Information System (INIS)

    Yur'ev, D.V.

    1993-01-01

    The reduction of the structure theory of the operator algebras of quantum projective (sl(2, C)-invariant) field theory (QPFT operator algebras) to a commutative exterior differential calculus by means of the operation of renormalization of a pointwise product of operator fields is described. In the first section, the author introduces the concept of the operator algebra of quantum field theory and describes the operation of the renormalization of a pointwise product of operator fields. The second section is devoted to a brief exposition of the fundamentals of the structure theory of QPT operator algebras. The third section is devoted to commutative exterior differential calculus. In the fourth section, the author establishes the connection between the renormalized pointwise product of operator fields in QPFT operator algebras and the commutative exterior differential calculus. 5 refs

  16. Optimization of polynomials in non-commuting variables

    CERN Document Server

    Burgdorf, Sabine; Povh, Janez

    2016-01-01

    This book presents recent results on positivity and optimization of polynomials in non-commuting variables. Researchers in non-commutative algebraic geometry, control theory, system engineering, optimization, quantum physics and information science will find the unified notation and mixture of algebraic geometry and mathematical programming useful. Theoretical results are matched with algorithmic considerations; several examples and information on how to use NCSOStools open source package to obtain the results provided. Results are presented on detecting the eigenvalue and trace positivity of polynomials in non-commuting variables using Newton chip method and Newton cyclic chip method, relaxations for constrained and unconstrained optimization problems, semidefinite programming formulations of the relaxations and finite convergence of the hierarchies of these relaxations, and the practical efficiency of algorithms.

  17. Some commutativity theorems for a certain class of rings

    International Nuclear Information System (INIS)

    Khan, M.A.

    1994-08-01

    In the present paper we first establish the commutativity theorem for semiprime ring satisfying the polynomial identity [x n ,y]x r = ±y s [x,y m ]y t for all x,y in R, where m,n,r,s and t are fixed nonnegative integers, and further, we investigate commutativity of rings with unity under some additional hypothesis. Moreover, it is also shown that the above result is true for s-unital. Also, we provide some counter examples which show that the hypothesis of our theorems are not altogether superfluous. The results of this paper generalize some of the well-known commutativity theorems for rings which are right s-unital. (author). 21 refs

  18. Emergent classicality via commuting position and momentum operators

    Energy Technology Data Exchange (ETDEWEB)

    Halliwell, J J, E-mail: j.halliwell@ic.ac.u [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)

    2009-06-01

    Any account of the emergence of classicality from quantum theory must address the fact that the quantum operators representing positions and momenta do not commute, whereas their classical counterparts suffer no such restrictions. To address this, we revive an old idea of von Neumann, and seek a pair of commuting operators X, P which are, in a specific sense, 'close' to the canonical non-commuting position and momentum operators, x,p. The construction of such operators is related to the problem of finding complete sets of orthonormal phase space localized states, a problem severely limited by the Balian-Low theorem. Here these limitations are avoided by restricting attention to situations in which the density matrix is reasonably decohered (i.e., spread out in phase space).

  19. A Study on The Marriage Phenomenolgy of Commuter Marriage Spouse

    Directory of Open Access Journals (Sweden)

    B’tari Sekar Nastiti

    2017-08-01

    Full Text Available In general, the marriage is lived by a spouse who lives together and cooperates with each other to shape the family. Recently, many couples do not live together, but in a distant city, and are called a long-distance marriage or a commuter marriage. From many reasons that create the long distance marriage, one of which is the job. The aim of this study is to find out the condition of the marriage life in commuter marriage and the dynamics on perceived marital satisfaction. This research method uses the qualitative method. Subjects in this study are 3 pairs of husband and wife practicing commuter marriage, which has a minimum marriage age of 5 years and has at least one child. The research result has shown that wives tend to experience dissatisfaction in the marriage, while the husbands feel quite happy in the marriage.

  20. Cyclists' Behaviour: identification of factors on commuting by bicycle

    Directory of Open Access Journals (Sweden)

    Kátia Andrade

    2013-12-01

    Full Text Available In Japan, cycling is a widely accepted transportation mode and often used for commuting or other purposes. Accordingly, this paper focuses on the reasons that motivate people to cycle, even though the Japanese transportation policies towards cycling are somewhat limited when compared to other countries with high cycling levels. Behavioural and statistical analyses are presented with a focus on unimodal commuting trips. In the behavioural analysis, commuters’ views on cycling are presented. In the statistical analysis, Nested Logit models are estimated to assess factors with strong influence on cycling. This paper contributes to further understanding the behaviour of active cyclists.

  1. Modular Theory, Non-Commutative Geometry and Quantum Gravity

    Directory of Open Access Journals (Sweden)

    Wicharn Lewkeeratiyutkul

    2010-08-01

    Full Text Available This paper contains the first written exposition of some ideas (announced in a previous survey on an approach to quantum gravity based on Tomita-Takesaki modular theory and A. Connes non-commutative geometry aiming at the reconstruction of spectral geometries from an operational formalism of states and categories of observables in a covariant theory. Care has been taken to provide a coverage of the relevant background on modular theory, its applications in non-commutative geometry and physics and to the detailed discussion of the main foundational issues raised by the proposal.

  2. Seasonal and socio-demographic determinants of school commuting

    DEFF Research Database (Denmark)

    Bjørkelund Børrestad, Line Anita; Andersen, Lars Bo; Bere, Elling

    2011-01-01

    OBJECTIVE: To report prevalence of commuting to school in Norway with regard to season, gender, parental education level, ethnicity and distance to school. METHODS: Cross-sectional questionnaire data from the Fruits and Vegetables Make the Marks project collected in 2008, including 1,339 ten...... to twelve-year-old children from 27 schools. The participants were categorized according to main mode of commuting to school in the three different school seasons (fall, winter and spring) and for the full school year if more than 50% of all trips were conducted by one specific mode. RESULTS: Most pupils...

  3. Decreasing the commutation failure frequency in HVDC transmission systems

    DEFF Research Database (Denmark)

    Hansen (retired June, 2000), Arne; Havemann (retired June, 2000), Henrik

    2000-01-01

    In this paper we show how a fairly large proportion of those commutation failures that are due to single-phased short circuits to earth can be avoided. In a control circuit based on a digital signal processor (DSP) it is possible, with instantaneous results, to switch from a normal control strategy...... with equidistant firing pulses to a strategy that takes into consideration the potentially dangerous voltage changes on the supply lines, If the supply voltages are monitored continuously, it is possible to calculate the necessity of advancing the firing pulses to avoid commutation failures. In the paper...

  4. Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes

    Directory of Open Access Journals (Sweden)

    Dirba J.

    2017-04-01

    Full Text Available The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force or angle ε (angle between rotor direct axis and armature magnetomotive force axis is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.

  5. Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes

    Science.gov (United States)

    Dirba, J.; Lavrinovicha, L.; Dobriyan, R.

    2017-04-01

    The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force) or angle ɛ (angle between rotor direct axis and armature magnetomotive force axis) is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.

  6. Analyses of commuting distances and times in the household context: The case of Berlin

    OpenAIRE

    Beige, Sigrun

    2012-01-01

    Commuting is the consequence of a spatial discrepancy between the residential and occupational locations. Commuting distance and time are changed either by residential or occupational mobility. Residential locations are by their very nature chosen at the household level. These joint decisions determine commuting distances and times of each employed household member, leading to a sort of commuting collaboration between the spouses. Multiple-earner households have to adapt their residential loc...

  7. MRI-related magnetic field exposures and risk of commuting accidents - A cross-sectional survey among Dutch imaging technicians.

    Science.gov (United States)

    Huss, Anke; Schaap, Kristel; Kromhout, Hans

    2017-07-01

    Imaging technicians working with magnetic resonance imaging (MRI) may experience acute effects such as vertigo or dizziness when being exposed. A previous study also reported an increased risk of accidents in MRI exposed staff. We aimed at evaluating commuting accident risk in Dutch imaging technicians. Of invited imaging technicians, 490 (29%) filled in a questionnaire pertaining to (near) accidents when driving or riding a bike, health, lifestyle and work practices. We used logistic regression to evaluate the association between exposure to MRI-related electromagnetic fields and risk of commuting (near) accidents in the year prior to the survey, adjusted for a range of potential confounders. Our cross-sectional study indicated an increased risk of (near) accidents if imaging technicians had worked with MRI in the year prior to the survey (odds ratio OR 2.13, 95%CI 1.23-3.69). Risks were higher in persons who worked with MRI more often (OR 2.32, 95%CI 1.25-4.31) compared to persons who worked sometimes with MRI (OR 1.91, 95%CI 0.98-3.72), and higher in those who had likely experienced higher peak exposures to static and time-varying magnetic fields (OR 2.18, 95%CI 1.06-4.48). The effect was seen on commuting accidents that had occurred on the commute from home to work as well as accidents from work to home or elsewhere. Imaging technicians working with MRI scanners may be at an increased risk of commuting (near) accidents. This result needs confirmation and potential risks for other groups (volunteers, patients) should be investigated. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Are workers with a long commute less productive? An empirical analysis of absenteeism

    NARCIS (Netherlands)

    van Ommeren, J.N.; Gutierrez Puigarnau, E.

    2011-01-01

    We hypothesise, and test for, a negative effect of the length of the worker's commute on worker's productivity, by examining whether the commute has a positive effect on worker's absenteeism. We identify this effect using employer-induced changes in commuting distance. Our estimates for Germany

  9. Impacts of urban sprawl and commuting: A modelling study for Italy

    NARCIS (Netherlands)

    Travisi, C.M.; Camagni, R.; Nijkamp, P.

    2010-01-01

    This paper aims to analyse empirically the intricate relationship between urban sprawl and commuting, a process that started a few decades ago in Italy. Using a mobility impact index based on commuting data for 1981 and 1991, we quantify the impact of commuting for seven major Italian urban areas,

  10. 20 CFR 704.102 - Commutation of payments to aliens and nonresidents.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Commutation of payments to aliens and... LHWCA EXTENSIONS Defense Base Act § 704.102 Commutation of payments to aliens and nonresidents. Authority to commute payments to aliens and nonnationals who are not residents of the United States and...

  11. The commuter family as a geographical adaptive strategy for the work-family balance

    NARCIS (Netherlands)

    van der Klis, M.; Karsten, L.

    2009-01-01

    In this paper we raise the question of how commuter families create a work-family balance in a situation of incongruity of the geographical scales of work and family. Commuter families combine the work location of a commuting parent on the (inter)national scale, with the home-based parent's work

  12. The impact of rural hospital closures on equity of commuting time for haemodialysis patients: simulation analysis using the capacity-distance model.

    Science.gov (United States)

    Matsumoto, Masatoshi; Ogawa, Takahiko; Kashima, Saori; Takeuchi, Keisuke

    2012-07-23

    Frequent and long-term commuting is a requirement for dialysis patients. Accessibility thus affects their quality of lives. In this paper, a new model for accessibility measurement is proposed in which both geographic distance and facility capacity are taken into account. Simulation of closure of rural facilities and that of capacity transfer between urban and rural facilities are conducted to evaluate the impacts of these phenomena on equity of accessibility among dialysis patients. Post code information as of August 2011 of all the 7,374 patients certified by municipalities of Hiroshima prefecture as having first or third grade renal disability were collected. Information on post code and the maximum number of outpatients (capacity) of all the 98 dialysis facilities were also collected. Using geographic information systems, patient commuting times were calculated in two models: one that takes into account road distance (distance model), and the other that takes into account both the road distance and facility capacity (capacity-distance model). Simulations of closures of rural and urban facilities were then conducted. The median commuting time among rural patients was more than twice as long as that among urban patients (15 versus 7 minutes, psimulation, when five rural public facilitiess were closed, Gini coefficient of commuting times among the patients increased by 16%, indicating a substantial worsening of equity, and the number of patients with commuting times longer than 90 minutes increased by 72 times. In contrast, closure of four urban public facilities with similar capacities did not affect these values. Closures of dialysis facilities in rural areas have a substantially larger impact on equity of commuting times among dialysis patients than closures of urban facilities. The accessibility simulations using the capacity-distance model will provide an analytic framework upon which rational resource distribution policies might be planned.

  13. On some classes of unbounded commutants of unbounded operator families

    International Nuclear Information System (INIS)

    Shabani, J.

    1985-08-01

    We consider some classes of unbounded commutants and bicommutants and we investigate their behaviour with respect to the quasi weak* topology which seems to play here the role of the weak topology for bounded operators. In particular we give some sufficient conditions in order that the bicommutants be the quasi weak* closure of the original set of operators. (author)

  14. The M5-brane and non-commutative open strings

    NARCIS (Netherlands)

    Bergshoeff, E.; Berman, D.S.; Schaar, J.P. van der; Sundell, P.

    2001-01-01

    The M-theory origin of non-commutative open-string theory is examined by investigating the M-theory 5-brane at near critical field strength. In particular, it is argued that the open-membrane metric provides the appropriate moduli when calculating the duality relations between M and II

  15. Notes on algebraic invariants for non-commutative dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    Longo, R [Rome Univ. (Italy). Istituto di Matematica

    1979-11-01

    We consider an algebraic invariant for non-commutative dynamical systems naturally arising as the spectrum of the modular operator associated to an invariant state, provided certain conditions of mixing type are present. This invariant turns out to be exactly the annihilator of the invariant T of Connes. Further comments are included, in particular on the type of certain algebras of local observables

  16. A generalization of zero divisor graphs associated to commutative ...

    Indian Academy of Sciences (India)

    M. Afkhami

    2018-03-19

    Mar 19, 2018 ... R . We also determine all isomorphic classes of finite commutative rings whose generalized zero divisor graphs have genus at most three. Keywords. Zero divisor graph; lower triangular matrix; genus; complete graph. 2010 Mathematics Subject Classification. 15B33, 05C10, 05C25, 05C45. 1. Introduction.

  17. African Women Commuter Traders in Nairobi in the First Decade ...

    African Journals Online (AJOL)

    This article investigates African women commuter trading activities in Nairobi in the first decade after World War One. Its findings derive mainly from a research project carried out in 1989-1996. The major source of data for the study was oral interviews with the women who traded in Nairobi during the years under study, ...

  18. Exploratory mapping of commuter flows in England and Wales

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick; Hovgesen, Henrik Harder; Lassen, Claus

    2005-01-01

    The availability of representative and disaggregate interaction data allows for a new range of “realistic” analysis with geographical information systems and spatial statistics. The paper uses the origin-destination commute data published from Census 2001 to analyse interaction patterns generally...

  19. Commutative $C^*$-algebras and $\\sigma$-normal morphisms

    OpenAIRE

    de Jeu, Marcel

    2003-01-01

    We prove in an elementary fashion that the image of a commutative monotone $\\sigma$-complete $C^*$-algebra under a $\\sigma$-normal morphism is again monotone $\\sigma$-complete and give an application of this result in spectral theory.

  20. Commuter Effects on Local Labour Markets: A German Modelling Study

    NARCIS (Netherlands)

    Russo, G.; Tedeschi, F.; Reggiani, A.; Nijkamp, P.

    2014-01-01

    This paper offers an exploratory investigation of the effects of inbound commuter flows on employment in regional labour markets in Germany. For this purpose, the paper distinguishes three main channels that may transmit the effects concerned: a crowding-out mechanism and two labour demand

  1. Limit algebras of differential forms in non-commutative geometry

    Indian Academy of Sciences (India)

    The holomorphic functional calculus closure of Connes' non- commutative de Rham algebra. ∗. D. (p. 549 of [C]) leads to a couple of operator algebras which are briefly discussed in this section. In §5, which contains the main contributions of the paper, quantized integrals are constructed on ∞A by using Dixmier trace ...

  2. Regenerative Snubber For GTO-Commutated SCR Inverter

    Science.gov (United States)

    Rippel, Wally E.; Edwards, Dean B.

    1992-01-01

    Proposed regenerative snubbing circuit substituted for dissipative snubbing circuit in inverter based on silicon controlled rectifiers (SCR's) commutated by gate-turn-off thyristor (GTO). Intended to reduce loss of power that occurs in dissipative snubber. Principal criteria in design: low cost, simplicity, and reliability.

  3. A new method of converter transformer protection without commutation failure

    Science.gov (United States)

    Zhang, Jiayu; Kong, Bo; Liu, Mingchang; Zhang, Jun; Guo, Jianhong; Jing, Xu

    2018-01-01

    With the development of AC / DC hybrid transmission technology, converter transformer as nodes of AC and DC conversion of HVDC transmission technology, its reliable safe and stable operation plays an important role in the DC transmission. As a common problem of DC transmission, commutation failure poses a serious threat to the safe and stable operation of power grid. According to the commutation relation between the AC bus voltage of converter station and the output DC voltage of converter, the generalized transformation ratio is defined, and a new method of converter transformer protection based on generalized transformation ratio is put forward. The method uses generalized ratio to realize the on-line monitoring of the fault or abnormal commutation components, and the use of valve side of converter transformer bushing CT current characteristics of converter transformer fault accurately, and is not influenced by the presence of commutation failure. Through the fault analysis and EMTDC/PSCAD simulation, the protection can be operated correctly under the condition of various faults of the converter.

  4. quasi hyperrigidity and weak peak points for non-commutative ...

    Indian Academy of Sciences (India)

    7

    Abstract. In this article, we introduce the notions of weak boundary repre- sentation, quasi hyperrigidity and weak peak points in the non-commutative setting for operator systems in C∗-algebras. An analogue of Saskin's theorem relating quasi hyperrigidity and weak Choquet boundary for particular classes of C∗-algebras is ...

  5. On W algebras commuting with a set of screenings

    Energy Technology Data Exchange (ETDEWEB)

    Litvinov, Alexey [Landau Institute for Theoretical Physics,Akademika Semenova av., 1-A , Chernogolovka (Russian Federation); Kharkevich Institute for Information Transmission Problems,Bolshoy Karetny per. 19-1, Moscow, 127051 (Russian Federation); Spodyneiko, Lev [Landau Institute for Theoretical Physics,Akademika Semenova av., 1-A , Chernogolovka (Russian Federation); California Institute of Technology, Department of Physics,1200 East California Boulevard, Pasadena, 91125 (United States)

    2016-11-22

    We consider the problem of classification of all W algebras which commute with a set of exponential screening operators. Assuming that the W algebra has a nontrivial current of spin 3, we find equations satisfied by the screening operators and classify their solutions.

  6. Local commutativity versus Bell inequality violation for entangled states and versus non-violation for separable states

    International Nuclear Information System (INIS)

    Seevinck, Michael; Uffink, Jos

    2007-01-01

    By introducing a quantitative 'degree of commutativity' in terms of the angle between spin observables we present two tight quantitative trade-off relations in the case of two qubits. First, for entangled states, between the degree of commutativity of local observables and the maximal amount of violation of the Bell inequality: if both local angles increase from zero to π/2 (i.e., the degree of local commutativity decreases), the maximum violation of the Bell inequality increases. Secondly, a converse trade-off relation holds for separable states: if both local angles approach π/2 the maximal value obtainable for the correlations in the Bell inequality decreases and thus the non-violation increases. As expected, the extremes of these relations are found in the case of anticommuting local observables where, respectively, the bounds of 2√(2) and √(2) hold for the expectation value of the Bell operator. The trade-off relations show that noncommmutativity gives ''a more than classical result'' for entangled states, whereas ''a less than classical result'' is obtained for separable states. The experimental relevance of the trade-off relation for separable states is that it provides an experimental test for two qubit entanglement. Its advantages are twofold: in comparison to violations of Bell inequalities it is a stronger criterion and in comparison to entanglement witnesses it needs to make less strong assumptions about the observables implemented in the experiment

  7. Local environment and social factors in primary school children's afterschool commute in China

    Directory of Open Access Journals (Sweden)

    John Zacharias

    2017-09-01

    Full Text Available The rapid decline in young children's active commutes to and from school has prompted investigations into ways to raise activity levels. The period after school is recognized as very important in the daily activity regime of primary school children. In this study, we examine the relative effects of local environmental factors and socio-economic status on children's after-school commute mode choice. Environmental factors are pedestrian priority streets, street intersection density, motorways, shops, and play spaces. Property values are used as a proxy for income. Twenty-four school districts are selected using intersection density and motorway length as criteria. All children's exit behaviors were film-recorded on October weekdays and extracted as four choices–alone, in a group of children, on foot with a parent or guardian, on e-bike driven by an adult. A multinomial logistic regression reveals that gated communities, higher priced housing, motorways and bus stops are associated with children accompanied by adults. The presence of pedestrian streets is associated with children travelling alone and in groups. Greater travel distance is also associated with parents accompanying children on foot or on e-bike. The amount of play space is associated with children leaving school in groups. Overall, social and environmental factors are influential in the independent travel of primary school children after the school day ends in south China.

  8. Longitudinal associations of active commuting with wellbeing and sickness absence.

    Science.gov (United States)

    Mytton, Oliver Tristan; Panter, Jenna; Ogilvie, David

    2016-03-01

    Our aim was to explore longitudinal associations of active commuting (cycling to work and walking to work) with physical wellbeing (PCS-8), mental wellbeing (MCS-8) and sickness absence. We used data from the Commuting and Health in Cambridge study (2009 to 2012; n=801) to test associations between: a) maintenance of cycling (or walking) to work over a one year period and indices of wellbeing at the end of that one year period; and b) associations between change in cycling (or walking) to work and change in indices of wellbeing. Linear regression was used for testing associations with PCS-8 and MCS-8, and negative binomial regression for sickness absence. After adjusting for sociodemographic variables, physical activity and physical limitation, those who maintained cycle commuting reported lower sickness absence (0.46, 95% CI: 0.14-0.80; equivalent to one less day per year) and higher MCS-8 scores (1.50, 0.10-2.10) than those who did not cycle to work. The association for sickness absence persisted after adjustment for baseline sickness absence. No significant associations were observed for PCS-8. Associations between change in cycle commuting and change in indices of wellbeing were not significant. No significant associations were observed for walking. This work provides some evidence of the value of cycle commuting in improving or maintaining the health and wellbeing of adults of working age. This may be important in engaging employers in the promotion of active travel and communicating the benefits of active travel to employees. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Active commuting to school: How far is too far?

    Directory of Open Access Journals (Sweden)

    Moyna Niall M

    2008-01-01

    Full Text Available Abstract Background Walking and cycling to school provide a convenient opportunity to incorporate physical activity into an adolescent's daily routine. School proximity to residential homes has been identified as an important determinant of active commuting among children. The purpose of this study is to identify if distance is a barrier to active commuting among adolescents, and if there is a criterion distance above which adolescents choose not to walk or cycle. Methods Data was collected in 2003–05 from a cross-sectional cohort of 15–17 yr old adolescents in 61 post primary schools in Ireland. Participants self-reported distance, mode of transport to school and barriers to active commuting. Trained researchers took physical measurements of height and weight. The relation between mode of transport, gender and population density was examined. Distance was entered into a bivariate logistic regression model to predict mode choice, controlling for gender, population density socio-economic status and school clusters. Results Of the 4013 adolescents who participated (48.1% female, mean age 16.02 ± 0.661, one third walked or cycled to school. A higher proportion of males than females commuted actively (41.0 vs. 33.8%, χ2 (1 = 22.21, p 2 (df = 3 = 839.64, p 2 (df = 1 = 2591.86, p Conclusion Distance is an important perceived barrier to active commuting and a predictor of mode choice among adolescents. Distances within 2.5 miles are achievable for adolescent walkers and cyclists. Alternative strategies for increasing physical activity are required for individuals living outside of this criterion.

  10. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  11. Commuting behaviour and urban form: a longitudinal study of a polycentric urban region in Denmark

    DEFF Research Database (Denmark)

    Grunfelder, Julien; Nielsen, Thomas Alexander Sick

    2012-01-01

    is a polycentric urban region in Denmark. Data from the National Transport Survey of Denmark were used for this quantitative analysis and two time periods were selected to highlight any potential changes over time. Empirical findings indicate that urban form and location variables help to explain the three......This paper is an empirical investigation of the relation between urban form and commuting behaviour in a polycentric urban region. It explores to what extent urban form and location variables help to explain commuting time, distance and mode based on an empirical case, East Jutland, which...... selected aspects of commuting. However, urban form variables have greater explanatory power in explaining commuting modes than commuting time and commuting distance. No general trends in commuting were detectable from the data. Finally, the empirical findings revealed specificities of the case study...

  12. The equationally-defined commutator a study in equational logic and algebra

    CERN Document Server

    Czelakowski, Janusz

    2015-01-01

    This monograph introduces and explores the notions of a commutator equation and the equationally-defined commutator from the perspective of abstract algebraic logic.  An account of the commutator operation associated with equational deductive systems is presented, with an emphasis placed on logical aspects of the commutator for equational systems determined by quasivarieties of algebras.  The author discusses the general properties of the equationally-defined commutator, various centralization relations for relative congruences, the additivity and correspondence properties of the equationally-defined commutator, and its behavior in finitely generated quasivarieties. Presenting new and original research not yet considered in the mathematical literature, The Equationally-Defined Commutator will be of interest to professional algebraists and logicians, as well as graduate students and other researchers interested in problems of modern algebraic logic.

  13. Maximum Quantum Entropy Method

    OpenAIRE

    Sim, Jae-Hoon; Han, Myung Joon

    2018-01-01

    Maximum entropy method for analytic continuation is extended by introducing quantum relative entropy. This new method is formulated in terms of matrix-valued functions and therefore invariant under arbitrary unitary transformation of input matrix. As a result, the continuation of off-diagonal elements becomes straightforward. Without introducing any further ambiguity, the Bayesian probabilistic interpretation is maintained just as in the conventional maximum entropy method. The applications o...

  14. The impact of rural hospital closures on equity of commuting time for haemodialysis patients: simulation analysis using the capacity-distance model

    Directory of Open Access Journals (Sweden)

    Matsumoto Masatoshi

    2012-07-01

    Full Text Available Abstract Background Frequent and long-term commuting is a requirement for dialysis patients. Accessibility thus affects their quality of lives. In this paper, a new model for accessibility measurement is proposed in which both geographic distance and facility capacity are taken into account. Simulation of closure of rural facilities and that of capacity transfer between urban and rural facilities are conducted to evaluate the impacts of these phenomena on equity of accessibility among dialysis patients. Methods Post code information as of August 2011 of all the 7,374 patients certified by municipalities of Hiroshima prefecture as having first or third grade renal disability were collected. Information on post code and the maximum number of outpatients (capacity of all the 98 dialysis facilities were also collected. Using geographic information systems, patient commuting times were calculated in two models: one that takes into account road distance (distance model, and the other that takes into account both the road distance and facility capacity (capacity-distance model. Simulations of closures of rural and urban facilities were then conducted. Results The median commuting time among rural patients was more than twice as long as that among urban patients (15 versus 7 minutes, p  Conclusions Closures of dialysis facilities in rural areas have a substantially larger impact on equity of commuting times among dialysis patients than closures of urban facilities. The accessibility simulations using thecapacity-distance model will provide an analytic framework upon which rational resource distribution policies might be planned.

  15. Essay on physics and non-commutative geometry

    International Nuclear Information System (INIS)

    Connes, A.

    1990-01-01

    Our aim, in this article, is to try to discover what physics would be like if the space in which it took place was not a set of points, but a non-commutative space. We shall not go very far in this direction, and the consequences of this investigation are for the moment either mathematical or only applied to a commutative space-time. It is clear, however, that a tool as remarkable as the Dixmier trace for analyzing logarithmic divergences should be useful to physicists. Moreover we have been able to show that a small modification of our picture of space-time gives a conceptual explanation of the Higgs fields and of the way they appear in the Weinberg-Salam model. This should allow us to make at the classical level explicit predictions of the Higgs mass: a very crude one is discussed. (author)

  16. Some Thoughts on Commutation Relations and Measurement Accuracy

    International Nuclear Information System (INIS)

    Noyes, H. Pierre

    1999-01-01

    We show that measuring the trajectories of charged particles to finite accuracy leads to the commutation relations needed for the derivation of the free space Maxwell equations using the discrete ordered calculus (DOC). We note that the finite step length derivation of the discrete difference version of the single particle Dirac equation implies the discrete version of the p, q commutation relations for a free particle. We speculate that a careful operational analysis of the change in momenta occurring in a step-wise continuous solution of the discrete Dirac equation could supply the missing source-sink terms in the DOC derivation of the Maxwell equations, and lead to a finite and discrete (''renormalized'') quantum electrodynamics (QED)

  17. Commuting periodic operators and the periodic Wigner function

    International Nuclear Information System (INIS)

    Zak, J

    2004-01-01

    Commuting periodic operators (CPO) depending on the coordinate x-hat and the momentum p-hat operators are defined. The CPO are functions of the two basic commuting operators exp(i x-hat 2π/a) and exp(i/h p-hat a), with a being an arbitrary constant. A periodic Wigner function (PWF) w(x, p) is defined and it is shown that it is applicable in a normal expectation value calculation to the CPO, as done in the original Wigner paper. Moreover, this PWF is non-negative everywhere, and it can therefore be interpreted as an actual probability distribution. The PWF w(x, p) is shown to be given as an expectation value of the periodic Dirac delta function in the phase plane. (letter to the editor)

  18. Almost-commutative geometries beyond the standard model

    International Nuclear Information System (INIS)

    Stephan, Christoph A

    2006-01-01

    In Iochum et al (2004 J. Math. Phys. 45 5003), Jureit and Stephan (2005 J. Math. Phys. 46 043512), Schuecker T (2005 Preprint hep-th/0501181) and Jureit et al (2005 J. Math. Phys. 46 072303), a conjecture is presented that almost-commutative geometries, with respect to sensible physical constraints, allow only the standard model of particle physics and electro-strong models as Yang-Mills-Higgs theories. In this paper, a counter-example will be given. The corresponding almost-commutative geometry leads to a Yang-Mills-Higgs model which consists of the standard model of particle physics and two new fermions of opposite electro-magnetic charge. This is the second Yang-Mills-Higgs model within noncommutative geometry, after the standard model, which could be compatible with experiments. Combined to a hydrogen-like composite particle, these new particles provide a novel dark matter candidate

  19. Route Choice Model Based on Game Theory for Commuters

    Directory of Open Access Journals (Sweden)

    Licai Yang

    2016-06-01

    Full Text Available The traffic behaviours of commuters may cause traffic congestion during peak hours. Advanced Traffic Information System can provide dynamic information to travellers. Due to the lack of timeliness and comprehensiveness, the provided information cannot satisfy the travellers’ needs. Since the assumptions of traditional route choice model based on Expected Utility Theory conflict with the actual situation, a route choice model based on Game Theory is proposed to provide reliable route choice to commuters in actual situation in this paper. The proposed model treats the alternative routes as game players and utilizes the precision of predicted information and familiarity of traffic condition to build a game. The optimal route can be generated considering Nash Equilibrium by solving the route choice game. Simulations and experimental analysis show that the proposed model can describe the commuters’ routine route choice decisionexactly and the provided route is reliable.

  20. Space/time non-commutative field theories and causality

    International Nuclear Information System (INIS)

    Bozkaya, H.; Fischer, P.; Pitschmann, M.; Schweda, M.; Grosse, H.; Putz, V.; Wulkenhaar, R.

    2003-01-01

    As argued previously, amplitudes of quantum field theories on non-commutative space and time cannot be computed using naive path integral Feynman rules. One of the proposals is to use the Gell-Mann-Low formula with time-ordering applied before performing the integrations. We point out that the previously given prescription should rather be regarded as an interaction-point time-ordering. Causality is explicitly violated inside the region of interaction. It is nevertheless a consistent procedure, which seems to be related to the interaction picture of quantum mechanics. In this framework we compute the one-loop self-energy for a space/time non-commutative φ 4 theory. Although in all intermediate steps only three-momenta play a role, the final result is manifestly Lorentz covariant and agrees with the naive calculation. Deriving the Feynman rules for general graphs, we show, however, that such a picture holds for tadpole lines only. (orig.)

  1. Stability of a non-commutative Jackiw-Teitelboim gravity

    Energy Technology Data Exchange (ETDEWEB)

    Vassilevich, D.V. [Universitaet Leipzig, Institut fuer Theoretische Physik, Postfach 100 920, Leipzig (Germany); St. Petersburg University, V.A. Fock Institute of Physics, St. Petersburg (Russian Federation); Fresneda, R.; Gitman, D.M. [Sao Paulo Univ. (Brazil). Inst. de Fisica

    2006-07-15

    We start with a non-commutative version of the Jackiw-Teitelboim gravity in two dimensions which has a linear potential for the dilaton fields. We study whether it is possible to deform this model by adding quadratic terms to the potential but preserving the number of gauge symmetries. We find that no such deformation exists (provided one does not twist the gauge symmetries). (orig.)

  2. Semiclassical and quantum motions on the non-commutative plane

    International Nuclear Information System (INIS)

    Baldiotti, M.C.; Gazeau, J.P.; Gitman, D.M.

    2009-01-01

    We study the canonical and the coherent state quantizations of a particle moving in a magnetic field on the non-commutative plane. Using a θ-modified action, we perform the canonical quantization and analyze the gauge dependence of the theory. We compare coherent states quantizations obtained through Malkin-Man'ko states and circular squeezed states. The relation between these states and the 'classical' trajectories is investigated, and we present numerical explorations of some semiclassical quantities.

  3. Semiclassical and quantum motions on the non-commutative plane

    Energy Technology Data Exchange (ETDEWEB)

    Baldiotti, M.C., E-mail: baldiott@fma.if.usp.b [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318-CEP, 05315-970 Sao Paulo, S.P. (Brazil); Gazeau, J.P., E-mail: gazeau@apc.univ-paris7.f [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318-CEP, 05315-970 Sao Paulo, S.P. (Brazil); Gitman, D.M., E-mail: gitman@dfn.if.usp.b [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318-CEP, 05315-970 Sao Paulo, S.P. (Brazil)

    2009-10-19

    We study the canonical and the coherent state quantizations of a particle moving in a magnetic field on the non-commutative plane. Using a theta-modified action, we perform the canonical quantization and analyze the gauge dependence of the theory. We compare coherent states quantizations obtained through Malkin-Man'ko states and circular squeezed states. The relation between these states and the 'classical' trajectories is investigated, and we present numerical explorations of some semiclassical quantities.

  4. Parallel resonant converter with LLC-type commutation

    Science.gov (United States)

    Lee, C. Q.; Liu, Rui; Batarseh, Issa

    1989-11-01

    It is shown that by using a proper transformation of state variables, the third-order system of the parallel resonant converter (PRC) with LLC-type commutation can be analyzed by means of a two-dimensional state-plane diagram. A set of characteristic curves which can be used for the converter design is derived from the analysis. It is shown from these curves that the converter possesses more desirable features than the conventional PRC.

  5. Particle exposure and inhaled dose during commuting in Singapore

    Science.gov (United States)

    Tan, Sok Huang; Roth, Matthias; Velasco, Erik

    2017-12-01

    Exposure concentration and inhaled dose of particles during door-to-door trips walking and using motorized transport modes (subway, bus, taxi) are evaluated along a selected route in a commercial district of Singapore. Concentrations of particles smaller than 2.5 μm in size (PM2.5), black carbon, particle-bound polycyclic aromatic hydrocarbons, number of particles, active surface area and carbon monoxide have been measured in-situ using portable instruments. Simultaneous measurements were conducted at a nearby park to capture the background concentrations. The heart rate of the participants was monitored during the measurements as a proxy of the inhalation rate used to calculate the inhaled dose of particles. All measured metrics were highest and well above background levels during walking. No significant difference was observed in the exposure concentration of PM2.5 for the three motorized transport modes, unlike for the metrics associated with ultrafine particles (UFP). The concentration of these freshly emitted particles was significantly lower on subway trips. The absence of combustion sources, use of air conditioning and screen doors at station platforms are effective measures to protect passengers' health. For other transport modes, sections of trips close to accelerating and idling vehicles, such as bus stops, traffic junctions and taxi stands, represent hotspots of particles. Reducing the waiting time at such locations will lower pollutants exposure and inhaled dose during a commute. After taking into account the effect of inhalation and travel duration when calculating dose, the health benefit of commuting by subway for this particular district of Singapore became even more evident. For example, pedestrians breathe in 2.6 and 3.2 times more PM2.5 and UFP, respectively than subway commuters. Public buses were the second best alternative. Walking emerged as the worst commuting mode in terms of particle exposure and inhaled dose.

  6. A study on mobility improvement for intellectually disabled student commuters

    Directory of Open Access Journals (Sweden)

    Fumihiko Nakamura

    2017-07-01

    Overall, our findings suggested that to actually implement mobility support in school commuting environments in a way that will improve the mobility of intellectually disabled people requires not only the cooperation of schools, but also contributions from transport operators, road administrators, and traffic administrators. Because the contributions of these entities are essential, awareness-raising activities and a system for promoting common understanding among them are vital.

  7. On (m, n)-absorbing ideals of commutative rings

    Indian Academy of Sciences (India)

    with respect to various ring theoretic constructions and study (m, n)-absorbing ideals in several commutative rings. For example, in a Bézout ring or a Boolean ring, an ideal is an (m, n)-absorbing ideal if and only if it is an n-absorbing ideal, and in an almost. Dedekind domain every (m, n)-absorbing ideal is a product of at ...

  8. a generalization of zero divisor graphs associated to commutative

    Indian Academy of Sciences (India)

    8

    R is isomorphic to the zero divisor graph Γ(R), and so Γn. R is a generalization of Γ(R) which is called a generalized zero divisor graph of R. In this paper, we study some basic properties of Γn. R. We also determine all isomorphic classes of finite commutative rings whose generalized zero divisor graphs have genus at most ...

  9. AC system stabilization via phase shift transformer with thyristor commutation

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Jose Carlos de; Guimaraes, Geraldo Caixeta; Moraes, Adelio Jose [Uberlandia Univ., MG (Brazil); Abreu, Jose Policarpo G. de [Escola Federal de Engenharia de Itajuba, MG (Brazil); Oliveira, Edimar Jose de [Juiz de Fora Univ., MG (Brazil)

    1994-12-31

    This article aims to present initially the constructive and operative forms of a phase-shift autotransformer which provides both magnitude and phase angle change through thyristor commutation, including a technic to reduce the number of thyristors. Following, it is proposed a control system to make such equipment an efficient AC system stabilizing tool. It is presented some simulation results to show the operation of this transformer in an electrical system. (author) 3 refs., 11 figs., 3 tabs.

  10. New relativistic generalization of the Heisenberg commutation relations

    International Nuclear Information System (INIS)

    Bohm, A.; Loewe, M.; Magnollay, P.; Tarlini, M.; Aldinger, R.R.; Kielanowski, P.

    1984-01-01

    A relativistic generalization of the Heisenberg commutation relations is suggested which is different from the conventional ones used for the intrinsic coordinates and momenta in the relativistic oscillator model and the relativistic string. This new quantum relativistic oscillator model is determined by the requirement that it gives a unified description of relativistic vibrations and rotations and contracts in the nonrelativistic limit c -1 →0 into the usual nonrelativistic harmonic oscillator

  11. Investigating Proenvironmental Behavior: The Case of Commuting Mode Choice

    Science.gov (United States)

    Trinh, Tu Anh; Phuong Linh Le, Thi

    2018-04-01

    The central aim of this article is to investigate mode choice behavior among commuters in Ho Chi Minh City using disaggregate mode choice model and norm activation theory. A better understanding of commuters’ choice of transport mode provide an opportunity to obtain valuable information on their travel behaviors which help to build a basic for proffering solutions stimulating commuters to switch to public transport, which in turn contribute to deal with traffic problems and environmental issues. Binary logistic regression was employed under disaggregate choice method. Key findings indicated that Demographic factors including Age (-0.308), Married (-9.089), Weather (-8.272); Trip factors including Travel cost (0.437), Travel distance (0.252), and Norm activation theory (Awareness of consequences: AC2 (-1.699), AC4 (2.951), AC6 (-3.523), AC7 (-2.092), AC9 (-3.045), AC11 (+ 2.939), and Personal norms: PN2 (-2.695)) had strong impact on the commuters’ mode choice. Although motorcycle was the major transport mode among commuters, they presented their willingness to switch to bus transport if it had less negative impacts on the environment and their daily living environment.

  12. Marginal Consistency: Upper-Bounding Partition Functions over Commutative Semirings.

    Science.gov (United States)

    Werner, Tomás

    2015-07-01

    Many inference tasks in pattern recognition and artificial intelligence lead to partition functions in which addition and multiplication are abstract binary operations forming a commutative semiring. By generalizing max-sum diffusion (one of convergent message passing algorithms for approximate MAP inference in graphical models), we propose an iterative algorithm to upper bound such partition functions over commutative semirings. The iteration of the algorithm is remarkably simple: change any two factors of the partition function such that their product remains the same and their overlapping marginals become equal. In many commutative semirings, repeating this iteration for different pairs of factors converges to a fixed point when the overlapping marginals of every pair of factors coincide. We call this state marginal consistency. During that, an upper bound on the partition function monotonically decreases. This abstract algorithm unifies several existing algorithms, including max-sum diffusion and basic constraint propagation (or local consistency) algorithms in constraint programming. We further construct a hierarchy of marginal consistencies of increasingly higher levels and show than any such level can be enforced by adding identity factors of higher arity (order). Finally, we discuss instances of the framework for several semirings, including the distributive lattice and the max-sum and sum-product semirings.

  13. Take part in the Commute-Another-Way Challenge!

    CERN Multimedia

    CERN Bulletin

    2015-01-01

    Ring the changes on Thursday, 4 June by commuting another way! CERN has signed up for the 5th “challenge mobilité Rhône-Alpes”, the aim of which is to encourage people to use modes of transport other than their car to get to work. Are you up for the challenge?   Join in the challenge! Sign up using the dedicated CERN form. "Commute another way!" is an initiative launched by the Rhône-Alpes regional authorities and the French environment agency ADEME (l’Agence de l’environnement et de la maîtrise de l’énergie française) to promote alternative ways of travelling to work than the car (excluding carpooling), in private and public-sector organisations across the region. We love this idea and CERN has been signed up to a similar scheme - Bike to Work - for several years. That’s why we’ve decided that CERN should join the Commute-A...

  14. Non-topological non-commutativity in string theory

    International Nuclear Information System (INIS)

    Guttenberg, S.; Herbst, M.; Kreuzer, M.; Rashkov, R.

    2008-01-01

    Quantization of coordinates leads to the non-commutative product of deformation quantization, but is also at the roots of string theory, for which space-time coordinates become the dynamical fields of a two-dimensional conformal quantum field theory. Appositely, open string diagrams provided the inspiration for Kontsevich's solution of the long-standing problem of quantization of Poisson geometry by virtue of his formality theorem. In the context of D-brane physics non-commutativity is not limited, however, to the topological sector. We show that non-commutative effective actions still make sense when associativity is lost and establish a generalized Connes-Flato-Sternheimer condition through second order in a derivative expansion. The measure in general curved backgrounds is naturally provided by the Born-Infeld action and reduces to the symplectic measure in the topological limit, but remains non-singular even for degenerate Poisson structures. Analogous superspace deformations by RR-fields are also discussed. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  15. Individual Public Transportation Accessibility is Positively Associated with Self-Reported Active Commuting.

    Science.gov (United States)

    Djurhuus, Sune; Hansen, Henning Sten; Aadahl, Mette; Glümer, Charlotte

    2014-01-01

    Active commuters have lower risk of chronic disease. Understanding which of the, to some extent, modifiable characteristics of public transportation that facilitate its use is thus important in a public health perspective. The aim of the study was to examine the association between individual public transportation accessibility and self-reported active commuting, and whether the associations varied with commute distance, age, and gender. Twenty-eight thousand nine hundred twenty-eight commuters in The Capital Region of Denmark reported self-reported time spent either walking or cycling to work or study each day and the distance to work or study. Data were obtained from the Danish National Health Survey collected in February to April 2010. Individual accessibility by public transportation was calculated using a multi-modal network in a GIS. Multilevel logistic regression was used to analyze the association between accessibility, expressed as access area, and being an active commuter. Public transport accessibility area based on all stops within walking and cycling distance was positively associated with being an active commuter. Distance to work, age, and gender modified the associations. Residing within 10 km commute distance and in areas of high accessibility was associated with being an active commuter and meeting the recommendations of physical activity. For the respondents above 29 years, individual public transportation accessibility was positively associated with being an active commuter. Women having high accessibility had significantly higher odds of being an active commuter compared to having a low accessibility. For men, the associations were insignificant. This study extends the knowledge about the driving forces of using public transportation for commuting by examining the individual public transportation accessibility. Findings suggest that transportation accessibility supports active commuting and planning of improved public transit accessibility

  16. Active commuting of the inhabitants of Liberec city in low and high walkability areas

    Directory of Open Access Journals (Sweden)

    Lukáš Rubín

    2015-12-01

    Full Text Available Background: Active commuting in terms of everyday transport to school or work can have a significant effect on physical activity. Active commuting can be influenced by the environment, and examples from abroad show that current environmental changes tend mostly to promote passive forms of commuting. A similar situation of decreasing active commuting might be expected in the Czech Republic. However, little information has been published to date about the issue of active commuting among the inhabitants of our country. Objective: The main objective of the present study is to describe the active commuting patterns of the inhabitants of Liberec city in low and high walkability areas. Methods: A total of 23,621 economically active inhabitants or students of Liberec city aged 6-87 years (34.77 ± 14.39 participated in the study. The data about commuting were retrieved from the national Population and Housing Census of 2011. Geographic information systems were used to objectively analyze the built environment and to calculate the walkability index. Results: Active commuting to/from school or work is used by 17.41% of inhabitants. Active commuting is dominated by walking (16.60% as opposed to cycling (0.81%. Inhabitants who lived in high walkability areas were more likely to actively commute than those living in low walkability areas (OR = 1.54; 95% CI [1.41, 1.68]. Conclusions: This study confirmed the findings of international studies about the effect of the built environment on active commuting among Liberec inhabitants. Active commuters are often those living near or in the city center, which is characterized by high walkability. In Liberec city, walking as a means of active commuting significantly prevails over cycling. One of the reasons might be the diverse topography of the city and the insufficiently developed cycling network.

  17. Economic, social, energy and environmental assessment of inter-municipality commuting: The case of Portugal

    International Nuclear Information System (INIS)

    Ferreira, João-Pedro; Barata, Eduardo; Ramos, Pedro Nogueira; Cruz, Luis

    2014-01-01

    Commuting is one of the main contributors to the high energy consumption patterns in modern economies. The need to reduce the energy spent in commuting has attracted the attention of academics and policy makers. The main goal of this research is to improve knowledge of the economic, social, energy and environmental opportunity costs of inter-municipality commuting and to support policy-oriented strategies that explicitly take them into account. For this, we use hypothetical assumptions based on the baseline scenario that Portuguese households do not travel between municipalities for commuting purposes coupled with the expected changes in private final consumption. Accordingly, the direct, indirect and induced opportunity costs of inter-municipality commuting are assessed using an input–output model. The significance of the estimated virtual net benefits of commuting is analyzed according to their macroeconomic (GVA, taxes, international imports and employment), energy (primary energy consumption) and environmental (CO 2 emissions) dimensions. The results obtained empirically indicate that inter-municipality commuting has significant opportunity costs in the GVA and GDP as well as in primary energy consumption and CO 2 emissions. The results also indicate that commuters in metropolitan regions and long-distance commuters are responsible for a major share of these opportunity costs. - Highlights: • This paper provides an insight into the magnitude of opportunity costs of commuting. • Input–output modeling is valuable to assess changes in final consumption patterns. • About 25% of household's fuel consumption is due to inter-municipality commuting. • Inter-municipality commuting has net negative effects on GDP, GVA and employment. • The main opportunity costs come from metropolitan and long distance commuting

  18. Maximum likely scale estimation

    DEFF Research Database (Denmark)

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

    2005-01-01

    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  19. Robust Maximum Association Estimators

    NARCIS (Netherlands)

    A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

    2017-01-01

    textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

  20. Leisure-time exercise, physical activity during work and commuting, and risk of metabolic syndrome.

    Science.gov (United States)

    Kuwahara, Keisuke; Honda, Toru; Nakagawa, Tohru; Yamamoto, Shuichiro; Akter, Shamima; Hayashi, Takeshi; Mizoue, Tetsuya

    2016-09-01

    Data are limited regarding effect of intensity of leisure-time physical activity on metabolic syndrome. Furthermore, no prospective data are available regarding effect of occupational and commuting physical activity on metabolic syndrome. We compared metabolic syndrome risk by intensity level of leisure-time exercise and by occupational and commuting physical activity in Japanese workers. We followed 22,383 participants, aged 30-64 years, without metabolic syndrome until 2014 March (maximum, 5 years of follow-up). Physical activity was self-reported. Metabolic syndrome was defined by the Joint Statement criteria. We used Cox regression models to estimate the hazard ratios (HRs) and 95 % confidence intervals (CIs) of metabolic syndrome. During a mean follow-up of 4.1 years, 5361 workers developed metabolic syndrome. After adjustment for covariates, compared with engaging in no exercise, the HRs (95 % CIs) for metabolic equivalent hours of exercise per week were 0.99 (0.90, 1.08), 0.99 (0.90, 1.10), and 0.95 (0.83, 1.08), respectively, among individuals engaging in moderate-intensity exercise alone; 0.93 (0.75, 1.14), 0.81 (0.64, 1.02), and 0.84 (0.66, 1.06), among individuals engaging in vigorous-intensity exercise alone; and 0.90 (0.70, 1.17), 0.74 (0.62, 0.89), and 0.81 (0.69, 0.96) among individuals engaging in the two intensities. Higher occupational physical activity was weakly but significantly associated with lower risk of metabolic syndrome. Walking to and from work was not associated with metabolic syndrome. Vigorous-intensity exercise alone or vigorous-intensity combined with moderate-intensity exercise and worksite intervention for physical activity may help prevent metabolic syndrome for Japanese workers.

  1. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  2. Income, Wealth and Consumption of Cross-Border Commuters to Luxembourg

    OpenAIRE

    Thomas Y. Mathä; Alessandro Porpiglia; Michael Ziegelmeyer

    2012-01-01

    Exceeding 40% of domestic employment cross-border commuters are extremely important to Luxembourg's economy and labour market in general. This paper presents unique information on their income, wealth and consumption using representative survey data from cross-border commuter households to Luxembourg. The estimated average total net wealth of cross-border commuter households is about EUR 240,000, which falls substantially short of comparable estimates for Luxembourg resident households exceed...

  3. One-loop beta functions for the orientable non-commutative Gross Neveu model TH1"-->

    Science.gov (United States)

    Lakhoua, A.; Vignes-Tourneret, F.; Wallet, J.-C.

    2007-11-01

    We compute at the one-loop order the β-functions for a renormalisable non-commutative analog of the Gross Neveu model defined on the Moyal plane. The calculation is performed within the so called x-space formalism. We find that this non-commutative field theory exhibits asymptotic freedom for any number of colors. The β-function for the non-commutative counterpart of the Thirring model is found to be non vanishing.

  4. A new non-commutative representation of the Wiener and Poisson processes

    International Nuclear Information System (INIS)

    Privault, N.

    1996-01-01

    Using two different constructions of the chaotic and variational calculus on Poisson space, we show that the Wiener and Poisson processes have a non-commutative representation which is different from the one obtained by transfer of the Fock space creation and annihilation operators. We obtain in this way an extension of the non-commutative It calculus. The associated commutation relations show a link between the geometric and exponential distributions. (author). 11 refs

  5. Trade-offs between commuting time and health-related activities.

    Science.gov (United States)

    Christian, Thomas J

    2012-10-01

    To further understand documented associations between obesity and urban sprawl, this research describes individuals' trade-offs between health-related activities and commuting time. A cross-section of 24,861 working-age individuals employed full-time and residing in urban counties is constructed from the American Time Use Survey (2003-2010). Data are analyzed using seemingly unrelated regressions to quantify health-related activity decreases in response to additional time spent commuting. Outcomes are total daily minutes spent in physical activity at a moderate or greater intensity, preparing food, eating meals with family, and sleeping. Commuting time is measured as all travel time between home and work and vice versa. The mean commuting time is 62 min daily, the median is 55 min, and 10.1% of workers commute 120 min or more. Spending an additional 60 min daily commuting above average is associated with a 6% decrease in aggregate health-related activities and spending an additional 120 min is associated with a 12% decrease. The greatest percentage of commuting time comes from sleeping time reductions (28-35%). Additionally, larger proportions of commuting time are taken from physical activity and food preparation relative to the mean commuting length: of 60 min spent commuting, 16.1% is taken from physical activity and 4.1% is taken from food preparation; of 120 min commuting, 20.3% is taken from physical activity and 5.6% is taken from food preparation. The results indicate that longer commutes are associated with behavioral patterns which over time may contribute to obesity and other poor health outcomes. These findings will assist both urban planners and researchers wishing to understand time constraints' impacts on health.

  6. The role of the commutator equations in integration methods in tetrad formalisms in general relativity

    International Nuclear Information System (INIS)

    Edgar, S.B.

    1990-01-01

    The structures of the N.P. and G.H.P formalisms are reviewed in order to understand and demonstrate the important role played by the commutator equations in the associated integration procedures. Particular attention is focused on how the commutator equations are to be satisfied, or checked for consistency. It is shown that Held's integration method will only guarantee genuine solutions of Einstein's equations when all the commutator equations are correctly and completely satisfied. (authors)

  7. Potential health impact of switching from car to public transportation when commuting to work.

    Science.gov (United States)

    Morabia, Alfredo; Mirer, Franklin E; Amstislavski, Tashia M; Eisl, Holger M; Werbe-Fuentes, Jordan; Gorczynski, John; Goranson, Chris; Wolff, Mary S; Markowitz, Steven B

    2010-12-01

    We assessed humidity-corrected particulate matter (PM(2.5)) exposure and physical activity (using global positioning system monitors and diaries) among 18 people who commuted by car to Queens College, New York, New York, for 5 days, and then switched to commuting for the next 5 days via public transportation. The PM(2.5) differed little between car and public transportation commutes (1.41 μg/M(3)·min; P = .226). Commuting by public transportation rather than by car increased energy expenditure (+124 kcal/day; P < .001) equivalent to the loss of 1 pound of body fat per 6 weeks.

  8. Commutative discrete filtering on unstructured grids based on least-squares techniques

    International Nuclear Information System (INIS)

    Haselbacher, Andreas; Vasilyev, Oleg V.

    2003-01-01

    The present work is concerned with the development of commutative discrete filters for unstructured grids and contains two main contributions. First, building on the work of Marsden et al. [J. Comp. Phys. 175 (2002) 584], a new commutative discrete filter based on least-squares techniques is constructed. Second, a new analysis of the discrete commutation error is carried out. The analysis indicates that the discrete commutation error is not only dependent on the number of vanishing moments of the filter weights, but also on the order of accuracy of the discrete gradient operator. The results of the analysis are confirmed by grid-refinement studies

  9. High Speed Rail commuting: Efficiency analysis of the Spanish HSR links

    Energy Technology Data Exchange (ETDEWEB)

    Moyano, A.

    2016-07-01

    This paper is centred on the analysis of the commuting High Speed Rail (HSR) links that are possible nowadays in the Spanish network. The large development of the network multiplies the possibilities of travelling for commuting. However, not only the feasibility but also the characteristics of the trip, in terms of ticket cost and time spent on the travel, become essential factors when considering HSR commuting links. This paper presents a person-based methodology focused on travellers’ needs and working schedules constraints, which allow differentiating among connections and identifying those intervals of time spent and costs that are affordable for commuting. (Author)

  10. Sporadic simple groups and quotient singularities

    International Nuclear Information System (INIS)

    Cheltsov, I A; Shramov, C A

    2013-01-01

    We show that if a faithful irreducible representation of a central extension of a sporadic simple group with centre contained in the commutator subgroup gives rise to an exceptional (resp. weakly exceptional but not exceptional) quotient singularity, then that simple group is the Hall-Janko group (resp. the Suzuki group)

  11. Maximum entropy methods

    International Nuclear Information System (INIS)

    Ponman, T.J.

    1984-01-01

    For some years now two different expressions have been in use for maximum entropy image restoration and there has been some controversy over which one is appropriate for a given problem. Here two further entropies are presented and it is argued that there is no single correct algorithm. The properties of the four different methods are compared using simple 1D simulations with a view to showing how they can be used together to gain as much information as possible about the original object. (orig.)

  12. The last glacial maximum

    Science.gov (United States)

    Clark, P.U.; Dyke, A.S.; Shakun, J.D.; Carlson, A.E.; Clark, J.; Wohlfarth, B.; Mitrovica, J.X.; Hostetler, S.W.; McCabe, A.M.

    2009-01-01

    We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Nearly all ice sheets were at their LGM positions from 26.5 ka to 19 to 20 ka, corresponding to minima in these forcings. The onset of Northern Hemisphere deglaciation 19 to 20 ka was induced by an increase in northern summer insolation, providing the source for an abrupt rise in sea level. The onset of deglaciation of the West Antarctic Ice Sheet occurred between 14 and 15 ka, consistent with evidence that this was the primary source for an abrupt rise in sea level ???14.5 ka.

  13. Optimization of performance and energy efficiency for series hybrid commuter-car; Series hybrid hoshiki no commuter car ni okeru doryoku seino to energy koritsu ni kansuru kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Hayashida, M; Narusawa, K [Traffic Safety and Nuisance Research Institute, Tokyo (Japan)

    1997-10-01

    The purpose of this study is to reveal a proper power system for a miniature vehicle called as `Commuter-car` for short trips in urban areas. Two types of simulated series hybrid commuter-cars were set on bench test systems. In order to have sufficient performance and energy saving, combination of electric motor and reduction gear. regenerative break efficiency and generator power supplying were considered by transient driving experiments. Further, estimation of primary energy consumption of the commuter-car was tried. 7 refs., 13 figs., 2 tabs.

  14. Topological field theories and quantum mechanics on commutative space

    International Nuclear Information System (INIS)

    Lefrancois, M.

    2005-12-01

    In particle physics, the Standard Model describes the interactions between fundamental particles. However, it was not able till now to unify quantum field theory and general relativity. This thesis focuses on two different unification approaches, though they might show some compatibility: topological field theories and quantum mechanics on non-commutative space. Topological field theories have been introduced some twenty years ago and have a very strong link to mathematics: their observables are topological invariants of the manifold they are defined on. In this thesis, we first give interest to topological Yang-Mills. We develop a superspace formalism and give a systematic method for the determination of the observables. This approach allows, once projected on a particular super gauge (of Wess-Zumino type), to recover the existing results but it also gives a generalisation to the case of an unspecified super-gauge. We have then be able to show that the up-to-now known observables correspond to the most general form of the solutions. This superspace formalism can be applied to more complex models; the case of topological gravity is given here in example. Quantum mechanics on noncommutative space provides an extension of the Heisenberg algebra of ordinary quantum mechanics. What differs here is that the components of the position or momentum operators do not commute with each other anymore. This implies to introduce a fundamental length. The second part of this thesis focuses on the description of the commutation algebra. Applications are made to low-dimensional quantum systems (Landau system, harmonic oscillator...) and to supersymmetric systems. (author)

  15. Exposure to hydrocarbon concentrations while commuting or exercising in Dublin.

    Science.gov (United States)

    O'Donoghue, R T; Gill, L W; McKevitt, R J; Broderick, B

    2007-01-01

    In Ireland, several studies have monitored the air pollution due to traffic in both urban and rural environments. However, few studies have attempted to quantify the relative exposure to traffic derived HC pollutants between different modes of commuter transport. In this study, the difference in pollution exposure between bus and cycling commuters on a route in Dublin was compared by sampling for five vehicle related hydrocarbons: benzene, 1,3-butadiene, acetylene, ethane and ethylene. Samples were collected during both morning and afternoon rush hour periods using a fixed speed pump to gain representative concentrations across the whole journey. Journey times were also measured, as were typical breathing rates in order to calculate the overall dose of pollutant inhaled on the journey. Results clearly picked up significantly higher pollutant concentrations in the bus compared to cycling and also revealed elevated concentrations on the congested side of the road compared to the side moving against the traffic. However, when respiration rates and travel times were taken into account to reveal the mass of pollutants inhaled over the course of a journey, the pattern was reversed, showing slightly enhanced levels of hydrocarbons for the cyclist compared to the bus passenger. In addition, the concentrations of these compounds (excluding ethane), were ascertained at playing pitches in the vicinity of a heavily trafficked suburban motorway and in Dublin city centre. Although the concentrations were relatively low at all sites, when breathing rates were taken into consideration, the average inhaled weights of pollutants were, on occasion, higher than those average values observed for both bus and bicycle commuters.

  16. Central extensions of some Abelian finite gauge groups

    International Nuclear Information System (INIS)

    Combe, Ph.; Rodriguez, R.; Sirugue, M.; Sirugue-Collin, M.

    1981-01-01

    The authors describe central extensions of Abelian finite gauge groups on lattices which are permutation invariant. Moreover some remarks are made on the gauge models on lattice associated with these non-commutative central extensions. (Auth.)

  17. Number-to-voltage converter on commutated condensers

    International Nuclear Information System (INIS)

    Grekhov, Yu.N.

    1975-01-01

    A code-voltage converter using precision voltage dividers based on commutated capacitors [1] is described which is distinguished by the absence of precision elements. Each digit includes eight field-effect transistors in two 1KT682 microcircuit assemblies and three microcapacitors with a conventional unstable capacitance 6200 pF +- 50%. The converter has a speed of response that is not inferior to that of converters based on R-2R matrices, while in time stability of the characteristics, low interference level, and low output impedance it is superior to such converters

  18. Promoting health and safety for traveling and commuting employees.

    Science.gov (United States)

    Pochat-Debroux, Sophia

    2008-09-01

    In a society that relies on a growing market economy and free enterprise, Americans spend inordinate time commuting and traveling for work. Aircraft and private vehicles are the two primary modes of work-related travel, with each having its own inherit risks and hazards. Although much has been written about international travel health, little has been published about protecting the health and safety of workers during domestic business travel. The intent of this article is to highlight the statistics associated with domestic business travel and present sound rationale for an inclusive and comprehensive domestic travel health and safety program for employees.

  19. Operating limits on commutator dc machines used as electromechanical capacitors

    International Nuclear Information System (INIS)

    Thullen, P.

    1981-01-01

    This paper presents data gathered in testing 28 rebuilt motors and discusses the impact of possible variation of characteristics among the machines of the operation of the facility. It also discusses commutation limits and their relationship to the economics and reliability of the system. When installed, the system will consist of 30 motors and will have a rating of 50 kA, 1.68 kV corresponding to 84 MVA at a peak power of 42 MW. The cost of this supply will be near $6/kVA which continues to compare favorably with the present $30/kVA cost of alternators

  20. Using a micromachined magnetostatic relay in commutating a DC motor

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Wright, John A. (Inventor); Lilienthal, Gerald (Inventor)

    2004-01-01

    A DC motor is commutated by rotating a magnetic rotor to induce a magnetic field in at least one magnetostatic relay in the motor. Each relay is activated in response to the magnetic field to deliver power to at least one corresponding winding connected to the relay. In some cases, each relay delivers power first through a corresponding primary winding and then through a corresponding secondary winding to a common node. Specific examples include a four-pole, three-phase motor in which each relay is activated four times during one rotation of the magnetic rotor.

  1. Note on the Tableau Technique for Commutative Transition Systems

    DEFF Research Database (Denmark)

    Srba, Jirí

    2002-01-01

    We define a class of transition systems called effective commutative transition systems (ECTS) and show, by generalising a tableau-based proof for BPP, that strong bisimilarity between any two states of such a transition system is decidable. It gives a general technique for extending decidability...... borders of strong bisimilarity for a wide class of infinite-state transition systems. This is demonstrated for several process formalisms, namely BPP process algebra, lossy BPP processes, BPP systems with interrupt and timed-arc BPP nets....

  2. Canonical commutation relations - historical aspect and new results

    International Nuclear Information System (INIS)

    Mnatsakanova, M.N.; Vernov, Yu.S.

    1997-01-01

    The aim of the paper is to describe the historical aspects of the canonical commutation relations (CCR) and to analyse the new results. The CCR are the algebraic structure (Heisenberg algebra) on the basis of quantum mechanics and quantum field theory. The following results are discussed: the Weyl form of CCR, Von Neumann's uniqueness theorem, regularity conditions, CCR representation in standard and Weyl forms, CCR in an indefinite metric space, class of CCR regular representations and CCR in the case of infinite number of degrees of freedom [ru

  3. Non-commutative geometry inspired charged black holes

    International Nuclear Information System (INIS)

    Ansoldi, Stefano; Nicolini, Piero; Smailagic, Anais; Spallucci, Euro

    2007-01-01

    We find a new, non-commutative geometry inspired, solution of the coupled Einstein-Maxwell field equations describing a variety of charged, self-gravitating objects, including extremal and non-extremal black holes. The metric smoothly interpolates between de Sitter geometry, at short distance, and Reissner-Nordstrom geometry far away from the origin. Contrary to the ordinary Reissner-Nordstrom spacetime there is no curvature singularity in the origin neither 'naked' nor shielded by horizons. We investigate both Hawking process and pair creation in this new scenario

  4. Commutators method for boson mapping in the seniority scheme

    International Nuclear Information System (INIS)

    Bonatsos, D.; Klein, A.; Ching-Teh Li

    1984-01-01

    A new approximate method for carrying out the boson mapping in the seniority scheme is described, in which the boson expansions of the pair and multipole operators are determined by satisfying the commutation relations for the associated Lie algebra. The method is illustrated for the single-j shell-model algebra SO(2(2j + 1)). The calculation is successively carried out to lowest and to next-higher order, the latter exhibiting the necessity of including g-bosons in the calculation in order to reach algebraic consistency. Agreement with the exact result of Ginocchio for j = 3/2 is established to the order considered. (orig.)

  5. Model-independent study of light cone current commutators

    International Nuclear Information System (INIS)

    Gautam, S.R.; Dicus, D.A.

    1974-01-01

    An attempt is made to extract information on the nature of light cone current commutators (L. C. C.) in a model independent manner. Using simple assumptions on the validity of the DGS representation for the structure functions of deep inelastic scattering and using the Bjorken--Johnston--Low theorem it is shown that in principle the L. C. C. may be constructed knowing the experimental electron--proton scattering data. On the other hand the scaling behavior of the structure functions is utilized to study the consistency of a vanishing value for various L. C. C. under mild assumptions on the behavior of the DGS spectral moments. (U.S.)

  6. Family of commuting operators for the totally asymmetric exclusion process

    International Nuclear Information System (INIS)

    Golinelli, O; Mallick, K

    2007-01-01

    The algebraic structure underlying the totally asymmetric exclusion process is studied by using the Bethe Ansatz technique. From the properties of the algebra generated by the local jump operators, we explicitly construct the hierarchy of operators (called generalized Hamiltonians) that commute with the Markov operator. The transfer matrix, which is the generating function of these operators, is shown to represent a discrete Markov process with long-range jumps. We give a general combinatorial formula for the connected Hamiltonians obtained by taking the logarithm of the transfer matrix. This formula is proved using a symbolic calculation program for the first ten connected operators

  7. Maximum Gene-Support Tree

    Directory of Open Access Journals (Sweden)

    Yunfeng Shan

    2008-01-01

    Full Text Available Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP, minimum evolution (ME, maximum likelihood (ML, and neighbor-joining (NJ—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one, in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1 The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2 There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3 The maximum gene-support tree reflects the phylogenetic relationship among species in comparison.

  8. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  9. Strong coupling effects in non-commutative spaces from OM theory and supergravity

    International Nuclear Information System (INIS)

    Russo, J.G.; Sheikh-Jabbari, M.M.

    2000-11-01

    We show that a four-parameter class of 3+1 dimensional NCOS theories can be obtained by dimensional reduction on a general 2-torus from OM theory. Compactifying two spatial directions of NCOS theory on a 2-torus, we study the transformation properties under the SO(2,2; Z) T-duality group. We then discuss non-perturbative configurations of non-commutative super Yang-Mills theory. In particular, we calculate the tension for magnetic monopoles and (p,q) dyons and exhibit their six-dimensional origin, and construct a supergravity solution representing an instanton in the gauge theory. We also compute the potential for a monopole-antimonopole in the supergravity approximation. (author)

  10. Towards a differentiated understanding of active travel behaviour: using social theory to explore everyday commuting.

    Science.gov (United States)

    Guell, C; Panter, J; Jones, N R; Ogilvie, D

    2012-07-01

    Fostering physical activity is an established public health priority for the primary prevention of a variety of chronic diseases. One promising population approach is to seek to embed physical activity in everyday lives by promoting walking and cycling to and from work ('active commuting') as an alternative to driving. Predominantly quantitative epidemiological studies have investigated travel behaviours, their determinants and how they may be changed towards more active choices. This study aimed to depart from narrow behavioural approaches to travel and investigate the social context of commuting with qualitative social research methods. Within a social practice theory framework, we explored how people describe their commuting experiences and make commuting decisions, and how travel behaviour is embedded in and shaped by commuters' complex social worlds. Forty-nine semi-structured interviews and eighteen photo-elicitation interviews with accompanying field notes were conducted with a subset of the Commuting and Health in Cambridge study cohort, based in the UK. The findings are discussed in terms of three particularly pertinent facets of the commuting experience. Firstly, choice and decisions are shaped by the constantly changing and fluid nature of commuters' social worlds. Secondly, participants express ambiguities in relation to their reasoning, ambitions and identities as commuters. Finally, commuting needs to be understood as an embodied and emotional practice. With this in mind, we suggest that everyday decision-making in commuting requires the tactical negotiation of these complexities. This study can help to explain the limitations of more quantitative and static models and frameworks in predicting travel behaviour and identify future research directions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Probable maximum flood control

    International Nuclear Information System (INIS)

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility

  12. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1988-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. We review the need for such methods in data analysis and show, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. We conclude with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  13. Solar maximum observatory

    International Nuclear Information System (INIS)

    Rust, D.M.

    1984-01-01

    The successful retrieval and repair of the Solar Maximum Mission (SMM) satellite by Shuttle astronauts in April 1984 permitted continuance of solar flare observations that began in 1980. The SMM carries a soft X ray polychromator, gamma ray, UV and hard X ray imaging spectrometers, a coronagraph/polarimeter and particle counters. The data gathered thus far indicated that electrical potentials of 25 MeV develop in flares within 2 sec of onset. X ray data show that flares are composed of compressed magnetic loops that have come too close together. Other data have been taken on mass ejection, impacts of electron beams and conduction fronts with the chromosphere and changes in the solar radiant flux due to sunspots. 13 references

  14. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1989-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. The author reviews the need for such methods in data analysis and shows, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. He concludes with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  15. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    MAF outperforms the functional PCA in concentrating the interesting' spectra/shape variation in one end of the eigenvalue spectrum and allows for easier interpretation of effects. Conclusions. Functional MAF analysis is a useful methods for extracting low dimensional models of temporally or spatially......Purpose. We aim at data where samples of an underlying function are observed in a spatial or temporal layout. Examples of underlying functions are reflectance spectra and biological shapes. We apply functional models based on smoothing splines and generalize the functional PCA in......\\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  16. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

    2015-01-01

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  17. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  18. Non-commutative multiple-valued logic algebras

    CERN Document Server

    Ciungu, Lavinia Corina

    2014-01-01

    This monograph provides a self-contained and easy-to-read introduction to non-commutative multiple-valued logic algebras; a subject which has attracted much interest in the past few years because of its impact on information science, artificial intelligence and other subjects.   A study of the newest results in the field, the monograph includes treatment of pseudo-BCK algebras, pseudo-hoops, residuated lattices, bounded divisible residuated lattices, pseudo-MTL algebras, pseudo-BL algebras and pseudo-MV algebras. It provides a fresh perspective on new trends in logic and algebras in that algebraic structures can be developed into fuzzy logics which connect quantum mechanics, mathematical logic, probability theory, algebra and soft computing.   Written in a clear, concise and direct manner, Non-Commutative Multiple-Valued Logic Algebras will be of interest to masters and PhD students, as well as researchers in mathematical logic and theoretical computer science.

  19. Numerical simulation of nonlinear dynamical systems driven by commutative noise

    International Nuclear Information System (INIS)

    Carbonell, F.; Biscay, R.J.; Jimenez, J.C.; Cruz, H. de la

    2007-01-01

    The local linearization (LL) approach has become an effective technique for the numerical integration of ordinary, random and stochastic differential equations. One of the reasons for this success is that the LL method achieves a convenient trade-off between numerical stability and computational cost. Besides, the LL method reproduces well the dynamics of nonlinear equations for which other classical methods fail. However, in the stochastic case, most of the reported works has been focused in Stochastic Differential Equations (SDE) driven by additive noise. This limits the applicability of the LL method since there is a number of interesting dynamics observed in equations with multiplicative noise. On the other hand, recent results show that commutative noise SDEs can be transformed into a random differential equation (RDE) by means of a random diffeomorfism (conjugacy). This paper takes advantages of such conjugacy property and the LL approach for defining a LL scheme for SDEs driven by commutative noise. The performance of the proposed method is illustrated by means of numerical simulations

  20. Examining the Link Between Public Transit Use and Active Commuting

    Directory of Open Access Journals (Sweden)

    Melissa Bopp

    2015-04-01

    Full Text Available Background: An established relationship exists between public transportation (PT use and physical activity. However, there is limited literature that examines the link between PT use and active commuting (AC behavior. This study examines this link to determine if PT users commute more by active modes. Methods: A volunteer, convenience sample of adults (n = 748 completed an online survey about AC/PT patterns, demographic, psychosocial, community and environmental factors. t-test compared differences between PT riders and non-PT riders. Binary logistic regression analyses examined the effect of multiple factors on AC and a full logistic regression model was conducted to examine AC. Results: Non-PT riders (n = 596 reported less AC than PT riders. There were several significant relationships with AC for demographic, interpersonal, worksite, community and environmental factors when considering PT use. The logistic multivariate analysis for included age, number of children and perceived distance to work as negative predictors and PT use, feelings of bad weather and lack of on-street bike lanes as a barrier to AC, perceived behavioral control and spouse AC were positive predictors. Conclusions: This study revealed the complex relationship between AC and PT use. Further research should investigate how AC and public transit use are related.

  1. Bootstrapping non-commutative gauge theories from L∞ algebras

    Science.gov (United States)

    Blumenhagen, Ralph; Brunner, Ilka; Kupriyanov, Vladislav; Lüst, Dieter

    2018-05-01

    Non-commutative gauge theories with a non-constant NC-parameter are investigated. As a novel approach, we propose that such theories should admit an underlying L∞ algebra, that governs not only the action of the symmetries but also the dynamics of the theory. Our approach is well motivated from string theory. We recall that such field theories arise in the context of branes in WZW models and briefly comment on its appearance for integrable deformations of AdS5 sigma models. For the SU(2) WZW model, we show that the earlier proposed matrix valued gauge theory on the fuzzy 2-sphere can be bootstrapped via an L∞ algebra. We then apply this approach to the construction of non-commutative Chern-Simons and Yang-Mills theories on flat and curved backgrounds with non-constant NC-structure. More concretely, up to the second order, we demonstrate how derivative and curvature corrections to the equations of motion can be bootstrapped in an algebraic way from the L∞ algebra. The appearance of a non-trivial A∞ algebra is discussed, as well.

  2. Assessment of noise exposure during commuting in the Madrid subway.

    Science.gov (United States)

    Tabacchi, M; Pavón, I; Ausejo, M; Asensio, C; Recuero, M

    2011-09-01

    Because noise-induced hearing impairment is the result not only of occupational noise exposure but also of total daily noise exposure, it is important to take the non-occupational exposure of individuals (during commuting to and from their jobs, at home, and during recreational activities) into account. Mass transit is one of the main contributors to non-occupational noise exposure. We developed a new methodology to estimate a representative commuting noise exposure. The methodology was put into practice for the Madrid subway because of all Spanish subway systems it covers the highest percentage of worker journeys (22.6%). The results of the application highlight that, for Madrid subway passengers, noise exposure level normalized to a nominal 8 hr (L(Ex,8h-cj) ) depends strongly on the type of train, the presence of squealing noise, and the public address audio system, ranging from 68.6 dBA to 72.8 dBA. These values play an important role in a more complete evaluation of a relationship between noise dose and worker health response.

  3. Commuter exposure to aerosol pollution on public transport in Singapore

    Science.gov (United States)

    Tan, S.; Velasco, E.; Roth, M.; Norford, L.

    2013-12-01

    Personal exposure to aerosol pollutants in the transport microenvironment of Singapore has not been well documented. Studies from many cities suggest that brief periods of exposure to high concentrations of airborne pollutants may have significant health impacts. Thus, a large proportion of aerosol exposure may be experienced during daily commuting trips due to the proximity to traffic. A better understanding of the variability across transport modes is therefore needed to design transport policies that minimize commuters' exposure. In light of this, personal exposure measurements of PM10 and PM2.5, particle number (PN), black carbon (BC), carbon monoxide (CO), particle-bound polycyclic aromatic hydrocarbons (pPAH), and active surface area (SA) were conducted on a selected route in downtown Singapore. Portable and real-time monitoring instruments were carried onto three different modes of public transport (bus, taxi, subway) and by foot. Simultaneous measurements were taken at a nearby park to capture the background concentrations. Large variability was observed amongst the various transport modes investigated. For example, the particle number concentration was on average 1.5, 1.6, 0.8, and 2.2 times higher inside buses, taxis, subway and by foot, respectively, than at the background site. Based on the results, it is possible to come up with a ranking of the 'cleanest' transport mode for Singapore.

  4. Getting to High School in Baltimore: Student Commuting and Public Transportation

    Science.gov (United States)

    Stein, Marc L.; Grigg, Jeffrey; Cronister, Curt; Chavis, Celeste; Connolly, Faith

    2017-01-01

    This report is the first publication of a multi-year project examining the relationship between student commutes using public transportation and on-time arrival and absenteeism. This report begins to develop a basic understanding of how students commute to high school in Baltimore with a focus on those using public transportation. The report is…

  5. 77 FR 45715 - Application of Key Lime Air Corporation for Commuter Authority

    Science.gov (United States)

    2012-08-01

    ... DEPARTMENT OF TRANSPORTATION Office of the Secretary [Docket DOT-OST-2009-0116] Application of Key Lime Air Corporation for Commuter Authority AGENCY: Department of Transportation. ACTION: Notice of... Lime Air Corporation fit, willing, and able, and awarding it a Commuter Air Carrier Authorization...

  6. 20 CFR 725.521 - Commutation of payments; lump sum awards.

    Science.gov (United States)

    2010-04-01

    ... present value of future benefit payments commuted, computed at 4 percent true discount compounded annually... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Commutation of payments; lump sum awards. 725.521 Section 725.521 Employees' Benefits EMPLOYMENT STANDARDS ADMINISTRATION, DEPARTMENT OF LABOR...

  7. New PWM method and commutation strategy for HF-link converters for fuel cells and photovoltaics

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a new PWM method and commutation strategy for HF-link converters, which leads to safe commutation of the load current in the output bidirectional bridge. The proposed implementation is independent of the particular HF-link converter topology and bidirectional switch selection ...

  8. 77 FR 4326 - Announcement of Requirements and Registration for “Health Innovations in Commuting Challenge”

    Science.gov (United States)

    2012-01-27

    ... known about the health of workers during commutes beyond population studies on general health impact... innovative development. 3. Understanding of effects of automobile commutes on health outcomes. Additional... DEPARTMENT OF HEALTH AND HUMAN SERVICES Announcement of Requirements and Registration for ``Health...

  9. Commuting and happiness: What ways feel best for what kinds of people?

    NARCIS (Netherlands)

    Lancee, S; M.J. Burger (Martijn); R. Veenhoven (Ruut)

    2018-01-01

    textabstractQuestion: How happy we are, depends partly on how we live our life and part of our way of life is how we commute between home and work. In that context, we are faced with the question of how much time spent on commuting is optimal happiness wise and with what means of transportation we

  10. Wages and commuting: quasi-natural experiments' evidence from firms that relocate

    NARCIS (Netherlands)

    Mulalic, I.; van Ommeren, J.N.; Pilegaard, N.

    2014-01-01

    We examine individual-level compensating differentials for commuting distance in a quasi-natural experiment setting by examining how wages respond to changes in commuting distance induced by firm relocations. This set-up enables us to test for the relevance of job search frictions within labour

  11. Modeling commuter preferences for the proposed bus rapid transit in Dar-es-Salaam

    NARCIS (Netherlands)

    Nkurunziza, A.; Zuidgeest, M.H.P.; Brussel, M.J.G.; van Maarseveen, M.F.A.M.

    2012-01-01

    The paper analyzes individual commuter preferences towards the proposed bus rapid transit (BRT) system in Dar-es-Salaam, Tanzania. The objective of the survey was to identify how commuters perceive and value the proposed BRT service quality attributes. A stated preference survey of potential users

  12. A Good $\\lambda$ Estimate for Multilinear Commutator of Singular Integral on Spaces of Homogeneous Type

    Directory of Open Access Journals (Sweden)

    Zhang Qian

    2011-04-01

    Full Text Available In this paper, a good $\\lambda$ estimate for the multilinear commutator associated to the singular integral operator on the spaces of homogeneous type is obtained. Under this result, we get the$(L^p(X,L^q(X$-boundedness of the multilinear commutator.

  13. The relationship between urban neighbourhood type and commuting distance in Gauteng City region, South Africa. A preliminary analysis

    CSIR Research Space (South Africa)

    Moselakgomo, M

    2013-07-01

    Full Text Available This paper uses the 2001 and 2013 Gauteng household travel survey datasets to investigate the nature of change in commuting distances of commuters from different neighbourhood types in the Gauteng City Region, in South Africa. The investigation...

  14. The Finite Lamplighter Groups: A Guided Tour

    Science.gov (United States)

    Siehler, Jacob A.

    2012-01-01

    In this article, we present a family of finite groups, which provide excellent examples of the basic concepts of group theory. To work out the center, conjuagacy classes, and commutators of these groups, all that's required is a bit of linear algebra.

  15. Novel theory of the human brain: information-commutation basis of architecture and principles of operation

    Directory of Open Access Journals (Sweden)

    Bryukhovetskiy AS

    2015-02-01

    Full Text Available Andrey S Bryukhovetskiy Center for Biomedical Technologies, Federal Research and Clinical Center for Specialized Types of Medical Assistance and Medical Technologies of the Federal Medical Biological Agency, NeuroVita Clinic of Interventional and Restorative Neurology and Therapy, Moscow, Russia Abstract: Based on the methodology of the informational approach and research of the genome, proteome, and complete transcriptome profiles of different cells in the nervous tissue of the human brain, the author proposes a new theory of information-commutation organization and architecture of the human brain which is an alternative to the conventional systemic connective morphofunctional paradigm of the brain framework. Informational principles of brain operation are defined: the modular principle, holographic principle, principle of systematicity of vertical commutative connection and complexity of horizontal commutative connection, regulatory principle, relay principle, modulation principle, “illumination” principle, principle of personalized memory and intellect, and principle of low energy consumption. The author demonstrates that the cortex functions only as a switchboard and router of information, while information is processed outside the nervous tissue of the brain in the intermeningeal space. The main structural element of information-commutation in the brain is not the neuron, but information-commutation modules that are subdivided into receiver modules, transmitter modules, and subscriber modules, forming a vertical architecture of nervous tissue in the brain as information lines and information channels, and a horizontal architecture as central, intermediate, and peripheral information-commutation platforms. Information in information-commutation modules is transferred by means of the carriers that are characteristic to the specific information level from inductome to genome, transcriptome, proteome, metabolome, secretome, and magnetome

  16. Solar maximum mission

    International Nuclear Information System (INIS)

    Ryan, J.

    1981-01-01

    By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

  17. Conference on Recent Advances in Commutative Ring and Module Theory & Conference on Rings and Polynomials

    CERN Document Server

    Frisch, Sophie; Glaz, Sarah; Tartarone, Francesca; Zanardo, Paolo

    2017-01-01

    This volume presents a collection of articles highlighting recent developments in commutative algebra and related non-commutative generalizations. It also includes an extensive bibliography and lists a substantial number of open problems that point to future directions of research in the represented subfields. The contributions cover areas in commutative algebra that have flourished in the last few decades and are not yet well represented in book form. Highlighted topics and research methods include Noetherian and non-Noetherian ring theory, module theory and integer-valued polynomials along with connections to algebraic number theory, algebraic geometry, topology and homological algebra. Most of the eighteen contributions are authored by attendees of the two conferences in commutative algebra that were held in the summer of 2016: “Recent Advances in Commutative Ring and Module Theory,” Bressanone, Italy; “Conference on Rings and Polynomials”  Graz, Austria. There is also a small collection of invite...

  18. Commuter exposure to PM2.5, BC, and UFP in six common transport microenvironments in Sacramento, California

    Science.gov (United States)

    Ham, Walter; Vijayan, Abhilash; Schulte, Nico; Herner, Jorn D.

    2017-10-01

    This study was designed to estimate and compare the air pollution exposures experienced by commuters in six common transportation modes utilized by California residents, and to evaluate the impact of practical exposure mitigation strategies in reducing commute exposures. We measured concentrations of fine particle matter (PM2.5), black carbon (BC), and ultrafine particles (UFP) for 161 commutes between April 2014 and November 2015 in Sacramento, CA. We collected measurements for six modes including single occupancy vehicles, high occupancy vehicles (multiple occupants), buses, light rail, train, and bicycling. The largest average concentrations for most pollutants were measured during train commutes and the lowest average concentrations were observed during light-rail commutes. Mitigation options were explored for personal vehicles, bicycling, and train commute modes. We found that ventilation settings of personal vehicles can reduce in-vehicle PM2.5, BC, and UFP concentrations by up to 75%. Similarly, bicycle route choice can reduce exposures by 15-75% with the lowest concentrations observed during commutes on dedicated bicycle paths away from traffic sources. Train commuters experienced UFP concentrations an order of magnitude greater when the locomotive engine was pulling the rail cars versus pushing the rail cars. We found that UFP concentrations during bus, bicycling, and train commutes were 1.6-5.3 times greater than personal vehicle commutes, while light rail commutes had 30% lower UFP concentrations than personal vehicle commutes. The largest exposure per mile occurred during bicycle commutes with PM2.5, BC, and UFP exposures of 1.312 μg/mile, 0.097 μg/mile, and 3.0 × 109 particles/mile, respectively. Train commutes experienced the largest exposure per mile of all of the combustion-derived transportation commute modes. BC accounted for 5-20% of total PM mass across all commute modes with an average fraction of ∼7% of PM2.5.

  19. Impact of the Mexican Alien Commuter on the Apparel Industry of El Paso, Texas--A Case Study. Final Report.

    Science.gov (United States)

    Rungeling, Brian Scott

    This study analyzed what effect commuters had on wage levels, employment, and industrial locations, and the relative importance of the commuter as part of the work force. A questionnaire was administered to 190 workers and to their 20 employers in the apparel industry of El Paso, Texas. The questionnaires revealed that the commuters were paid the…

  20. The relationship between bicycle commuting and perceived stress: a cross-sectional study.

    Science.gov (United States)

    Avila-Palencia, Ione; de Nazelle, Audrey; Cole-Hunter, Tom; Donaire-Gonzalez, David; Jerrett, Michael; Rodriguez, Daniel A; Nieuwenhuijsen, Mark J

    2017-06-23

    Active commuting - walking and bicycling for travel to and/or from work or educational addresses - may facilitate daily, routine physical activity. Several studies have investigated the relationship between active commuting and commuting stress; however, there are no studies examining the relationship between solely bicycle commuting and perceived stress, or studies that account for environmental determinants of bicycle commuting and stress. The current study evaluated the relationship between bicycle commuting, among working or studying adults in a dense urban setting, and perceived stress. A cross-sectional study was performed with 788 adults who regularly travelled to work or study locations (excluding those who only commuted on foot) in Barcelona, Spain. Participants responded to a comprehensive telephone survey concerning their travel behaviour from June 2011 through to May 2012. Participants were categorised as either bicycle commuters or non-bicycle commuters, and (based on the Perceived Stress Scale, PSS-4) as either stressed or non-stressed. Multivariate Poisson regression with robust variance models of stress status based on exposures with bicycle commuting were estimated and adjusted for potential confounders. Bicycle commuters had significantly lower risk of being stressed than non-bicycle commuters (Relative Risk; RR (95% CI)=0.73 (0.60 to 0.89), p=0.001). Bicycle commuters who bicycled 4 days per week (RR (95% CI)=0.42 (0.24 to 0.73), p=0.002) and those who bicycled 5 or more days per week (RR (95% CI)=0.57 (0.42 to 0.77), pstressed than those who bicycled less than 4 days. This relationship remained statistically significant after adjusting for individual and environmental confounders and when using different cut-offs of perceived stress. Stress reduction may be an important consequence of routine bicycle use and should be considered by decision makers as another potential benefit of its promotion. © Article author(s) (or their employer

  1. Geodesics in hypercomplex number systems. Application to commutative quaternions

    International Nuclear Information System (INIS)

    Catoni, Francesco; Zampetti, Paolo; Cannata, Roberto; Bordoni, Luciana

    1997-10-01

    The functions of hypercomplex variable can be related to the physical fields. Following the Einstein's ideas, by which the Theory of General Relativity was developed, they want to verify if a generalisation is possible, in order to described the motion of a body in a gravitational field, by the geodesics in spaces ''deformed'' by functional transformations of hypercomplex variables. These number systems introduce new space symmetries. This paper is just a first step in the more extended study. As a first application they consider the ''commutative quaternions'' system that may be considered as a composition of complex and hyperbolic numbers. By using in this system the same functional transformations valid for the two dimensional case, elliptical geodesics are obtained, with the eccentricity related to the angle between the orbit plane and a reference plane. These geodesics do not describe the Kepler orbits, but they show a space anisotropy that might be related to planet orbits of the solar system

  2. Commutative deformations of general relativity: nonlocality, causality, and dark matter

    Energy Technology Data Exchange (ETDEWEB)

    De Vegvar, P.G.N. [SWK Research, Bellingham, WA (United States)

    2017-01-15

    Hopf algebra methods are applied to study Drinfeld twists of (3+1)-diffeomorphisms and deformed general relativity on commutative manifolds. A classical nonlocality length scale is produced above which microcausality emerges. Matter fields are utilized to generate self-consistent Abelian Drinfeld twists in a background independent manner and their continuous and discrete symmetries are examined. There is negligible experimental effect on the standard model of particles. While baryonic twist producing matter would begin to behave acausally for rest masses above ∝1-10 TeV, other possibilities are viable dark matter candidates or a right-handed neutrino. First order deformed Maxwell equations are derived and yield immeasurably small cosmological dispersion and produce a propagation horizon only for photons at or above Planck energies. This model incorporates dark matter without any appeal to extra dimensions, supersymmetry, strings, grand unified theories, mirror worlds, or modifications of Newtonian dynamics. (orig.)

  3. Non-commuting variations in mathematics and physics a survey

    CERN Document Server

    Preston, Serge

    2016-01-01

    This text presents and studies the method of so –called noncommuting variations in Variational Calculus. This method was pioneered by Vito Volterra who noticed that the conventional Euler-Lagrange (EL-) equations are not applicable in Non-Holonomic Mechanics and suggested to modify the basic rule used in Variational Calculus. This book presents a survey of Variational Calculus with non-commutative variations and shows that most basic properties of conventional Euler-Lagrange Equations are, with some modifications, preserved for EL-equations with K-twisted (defined by K)-variations. Most of the book can be understood by readers without strong mathematical preparation (some knowledge of Differential Geometry is necessary). In order to make the text more accessible the definitions and several necessary results in Geometry are presented separately in Appendices I and II Furthermore in Appendix III a short presentation of the Noether Theorem describing the relation between the symmetries of the differential equa...

  4. Stress-tensor commutators and Schwinger terms in singleton theories

    International Nuclear Information System (INIS)

    Bergshoeff, E.; Sezgin, E.; Tanii, Y.

    1989-06-01

    We compute the commutators of the regularized quantum stress-tensor of singleton theories formulated on the boundary of a (p + 2)-dimensional anti de Sitter space (AdS p+2 ). (These are superconformal field theories on S p x S 1 ). We find that the algebra is not closed except in the case of AdS 3 . It does contain, however, the finite dimensional AdS p+2 algebra SO(p + 1,2). We also find divergent, field dependent as well as field independent Schwinger terms (i.e. the central extensions), which, however, do not lead to anomalies in the algebra of the AdS charges. We also give a simple derivation of the two-point functions for bosonic and fermionic singletons. (author). 15 refs

  5. On a question of Herstein concerning commutators in division rings

    International Nuclear Information System (INIS)

    Mahdavi Hezavehi, M.; Akbari Feyzaabaadi, S.

    1995-05-01

    Let D be a division ring with centre Z in which for all x not = 0 and y not = 0 in D, (xyx -1 y -1 ) p(x,y) is an element of Z, for some integer p(x,y) ≥ 1, depending on x and y. Given a is an element of D such that a s is an element of Z for some s ≥ 1, it is shown that the minimal polynomial of a over Z is of the form t k - r, where (k,6) = 1. Using this result, it is proved that if p(x,y) is of the form 2 n(x,y) , then D is commutative. (author). 7 refs

  6. Ceramic high temperature superconductor levitating motor with laser commutator

    International Nuclear Information System (INIS)

    Roslan Abd Shukor; Lee Keng Heong

    1996-01-01

    The design of a magnetically levitating motor using a ceramic high temperature superconductor with laser commutator is discussed. A YBa sub 2 Cu sub 3 O sub 7-δ high temperature superconductor with 25 mm diameter and 6 mm thickness is used to levitate a Nd-Fe-B magnet (19.0 mm diameter and 4.8 mm thickness) which is attached symmetrically to a 150 mm long graphite rod. A smaller magnet (5.5 mm diameter and 2.0 mm thickness) is attached at each end of the rod with the appropriate poles arrangements. A suitable laser beam chopper is used to optically drive a solenoid which repels the smaller magnets thus driving the motor. A simple and efficient liquid nitrogen supply system is designed to cool the superconductor. The stability of the bearing is provided by the flux pinning in this type-II superconductor. Some characteristics of the motor are discussed

  7. Baryon number violation and novel canonical anti-commutation relations

    Science.gov (United States)

    Fujikawa, Kazuo; Tureanu, Anca

    2018-02-01

    The possible neutron-antineutron oscillation is described by an effective quadratic Lagrangian analogous to the BCS theory. It is shown that the conventional equal-time anti-commutation relations of the neutron variable n (t , x →) are modified by the baryon number violating terms. This is established by the Bjorken-Johnson-Low prescription and also by the canonical quantization combined with equations of motion. This novel canonical behavior can give rise to an important physical effect, which is illustrated by analyzing the Lagrangian that violates the baryon number but gives rise to the degenerate effective Majorana fermions and thus no neutron-antineutron oscillation. Technically, this model is neatly treated using a relativistic analogue of the Bogoliubov transformation.

  8. Silicon controlled rectifier polyphase bridge inverter commutated with gate-turn-off thyristor

    Science.gov (United States)

    Edwards, Dean B. (Inventor); Rippel, Wally E. (Inventor)

    1986-01-01

    A polyphase SCR inverter (10) having N switching poles, each comprised of two SCR switches (1A, 1B; 2A, 2B . . . NA, NB) and two diodes (D1B; D1B; D2A, D2B . . . DNA, DNB) in series opposition with saturable reactors (L1A, L1B; L2A, L2B . . . LNA, LNB) connecting the junctions between the SCR switches and diodes to an output terminal (1, 2 . . . 3) is commutated with only one GTO thyristor (16) connected between the common negative terminal of a dc source and a tap of a series inductor (14) connected to the positive terminal of the dc source. A clamp winding (22) and diode (24) are provided, as is a snubber (18) which may have its capacitance (c) sized for maximum load current divided into a plurality of capacitors (C.sub.1, C.sub.2 . . . C.sub.N), each in series with an SCR switch S.sub.1, S.sub.2 . . . S.sub.N). The total capacitance may be selected by activating selected switches as a function of load current. A resistor 28 and SCR switch 26 shunt reverse current when the load acts as a generator, such as a motor while braking.

  9. Non(anti)commutative gauge theories in harmonic superspace

    International Nuclear Information System (INIS)

    Quevedo Z., L.E.

    2006-01-01

    In this work we study the properties of non-singlet Q-deformed N=2 supersymmetric gauge theories, from a field-theoretical point of view. Starting from the supersymmetry breaking pattern induced by a general deformation matrix, we embark on the construction of the non-singlet deformed gauge transformation laws for all vector multiplet fields and their corresponding minimal Seiberg-Witten map. Several deformes super-Yang-Mills actions in components corresponding to different choices of the non-singlet deformation tensor are built. For a particular decomposition ansats of such tensor, we obtain exact actions describing the bosonic sector of the deformed N=(1,0) and the full action for enhances N=(1,1/2) residual supersymmetry. A tuned supersymmetry breaking of this enhanced action down to the N=(1,0) case is found by weakly restoring some discarded degrees of freedom of the deformation. Finally we find the associated residual supersymmetry transformations for the cases studied. The first part of this work, gives an overview of noncommutativity in quantum field theory and of harmonic superspace as needed to define noncommutative generalizations of extended gauge field theories. A study of general properties of non(anti)commutative structures in N=2 euclidean superspace and the (super)symmetry breaking pattern induced by Q-deformations follows. in addition, singlet-deformed super-Yang-Mills is given as an example. The second part deals with non-singlet Q-deformations of gauge theories. We introduce a decomposition ansatz for the deformation matrix, allowing an exact study of the deformed gauge transformations, and develop a general algorithm to solve the harmonic equations associated to this decomposition. A close expression for the gauge transformations of component fields is derived, along with the corresponding minimal Seiberg-Witten map to an equivalent commutative gauge theory. Finally we build deformed super-Yang-Mills actions and their corresponding

  10. What Factors Explain Bicycling and Walking for Commuting by ELSA-Brasil Participants?

    Science.gov (United States)

    de Matos, Sheila Maria Alvim; Pitanga, Francisco José Gondim; Almeida, Maria da Conceição C; Queiroz, Ciro Oliveira; Dos Santos, Clarice Alves; de Almeida, Rogerio Tosta; da Silva, Ianne Tayrine Martins; Griep, Rosane Harter; Amorim, Leila Denise Alves Ferreira; Patrão, Ana Luísa; Aquino, Estela M L

    2018-03-01

    To analyze the factors associated with commuting by bicycling and walking in adult participants from ELSA-Brasil (Longitudinal Study of Adult Health). Cross-sectional. Six teaching/research institutions throughout Brazil. A total of 15 105 civil servants. Commuting by bicycling and walking was analyzed using the long-form International Physical Activity Questionnaire. A hierarchical model containing possible factors associated with commuting by bicycling and walking was constructed. Crude and adjusted odds ratios were calculated using multinomial logistic regression. Considering the 2 forms of commuting, 66% of the participants were being considered inactive or insufficiently active. In women, being "heavier," feeling unsafe practicing physical activity, and being a former smoker were factors negatively associated with commuting by bicycling and walking. In men, active commuting was less common among those who were overweight or had abdominal obesity, those with a negative perception of safety, and those reporting that there was nowhere suitable in the neighborhood to practice physical activity. Obesity and negative perceptions in the neighborhood are associated with inactive or insufficiently active commuting. The relevance of this finding for public health is reinforce developing policies aimed at promoting health in Brazil and in other countries with similar characteristics.

  11. The association between access to public transportation and self-reported active commuting.

    Science.gov (United States)

    Djurhuus, Sune; Hansen, Henning S; Aadahl, Mette; Glümer, Charlotte

    2014-12-05

    Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928). Access to public transportation measures were computed by combining GIS-based road network distances from home address to public transit stops an integrating their service level. Multilevel logistic regression was used to examine the association between access to public transportation measures and active commuting. Distance to bus stop, density of bus stops, and number of transport modes were all positively associated with being an active commuter and with meeting recommendations of physical activity. No significant association was found between bus services at the nearest stop and active commuting. The results highlight the importance of including detailed measurements of access to public transit in order to identify the characteristics that facilitate the use of public transportation and active commuting.

  12. Is the environment near school associated with active commuting to school among preschoolers?

    Directory of Open Access Journals (Sweden)

    Jose Cazuza Farias Junior

    2013-05-01

    Full Text Available Available studies show that environmental factors may influence how parentes choose to commute their children from home to school. Thus, the aim of this study was to analyze the association between the characteristics of the physical and social environment near school and active commuting to school among preschool children. A school-based cross-sectional study with a sample of children aged 3to 5 years (n=914 was undertaken. Participants were selected by a single-stage cluster sampling process. To obtain data on commuting to school and demographicand socioeconomic variables, a previously validated questionnaire was used while an audit tool was used to assess the environment near school. Binarylogistic regression was used to analyze the association and results were presented as Odds Ratio values. Results showed that 28.3% (95%CI 25.5-31.3 ofthe children were active commuters from home to school. A positive association was found between public transportation (p=0.002 and social environment(p=0.004 domains and active commuting. However, this association was foundonly among children from families that did not have a car. The likelihood of achild being an active commuter was higher among those who are enrolled in schools with better environmental surroundings (OR=1.88; 95%CI 1.31-2.70. It was concluded that there was a positive association between some of the environmental factors near school and active commuting to school among children from families that did not have a car.

  13. Simulation of Population-Based Commuter Exposure to NO2 Using Different Air Pollution Models

    Directory of Open Access Journals (Sweden)

    Martina S. Ragettli

    2014-05-01

    Full Text Available We simulated commuter routes and long-term exposure to traffic-related air pollution during commute in a representative population sample in Basel (Switzerland, and evaluated three air pollution models with different spatial resolution for estimating commute exposures to nitrogen dioxide (NO2 as a marker of long-term exposure to traffic-related air pollution. Our approach includes spatially and temporally resolved data on actual commuter routes, travel modes and three air pollution models. Annual mean NO2 commuter exposures were similar between models. However, we found more within-city and within-subject variability in annual mean (±SD NO2 commuter exposure with a high resolution dispersion model (40 ± 7 µg m−3, range: 21–61 than with a dispersion model with a lower resolution (39 ± 5 µg m−3; range: 24–51, and a land use regression model (41 ± 5 µg m−3; range: 24–54. Highest median cumulative exposures were calculated along motorized transport and bicycle routes, and the lowest for walking. For estimating commuter exposure within a city and being interested also in small-scale variability between roads, a model with a high resolution is recommended. For larger scale epidemiological health assessment studies, models with a coarser spatial resolution are likely sufficient, especially when study areas include suburban and rural areas.

  14. The Association between Access to Public Transportation and Self-Reported Active Commuting

    Directory of Open Access Journals (Sweden)

    Sune Djurhuus

    2014-12-01

    Full Text Available Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928. Access to public transportation measures were computed by combining GIS-based road network distances from home address to public transit stops an integrating their service level. Multilevel logistic regression was used to examine the association between access to public transportation measures and active commuting. Distance to bus stop, density of bus stops, and number of transport modes were all positively associated with being an active commuter and with meeting recommendations of physical activity. No significant association was found between bus services at the nearest stop and active commuting. The results highlight the importance of including detailed measurements of access to public transit in order to identify the characteristics that facilitate the use of public transportation and active commuting.

  15. On the generalization of linear least mean squares estimation to quantum systems with non-commutative outputs

    Energy Technology Data Exchange (ETDEWEB)

    Amini, Nina H. [Stanford University, Edward L. Ginzton Laboratory, Stanford, CA (United States); CNRS, Laboratoire des Signaux et Systemes (L2S) CentraleSupelec, Gif-sur-Yvette (France); Miao, Zibo; Pan, Yu; James, Matthew R. [Australian National University, ARC Centre for Quantum Computation and Communication Technology, Research School of Engineering, Canberra, ACT (Australia); Mabuchi, Hideo [Stanford University, Edward L. Ginzton Laboratory, Stanford, CA (United States)

    2015-12-15

    The purpose of this paper is to study the problem of generalizing the Belavkin-Kalman filter to the case where the classical measurement signal is replaced by a fully quantum non-commutative output signal. We formulate a least mean squares estimation problem that involves a non-commutative system as the filter processing the non-commutative output signal. We solve this estimation problem within the framework of non-commutative probability. Also, we find the necessary and sufficient conditions which make these non-commutative estimators physically realizable. These conditions are restrictive in practice. (orig.)

  16. Commuting--a further stress factor for working people: evidence from the European Community. II. An empirical study.

    Science.gov (United States)

    Costa, G; Pickup, L; Di Martino, V

    1988-01-01

    This report summarizes the main results of research promoted by the European Foundation for the Improvement of Living and Working Conditions, concerning the impact of commuting on the health and safety of workers. An empirical study, carried out among 1167 industrial Italian workers, shows that "commuters" (workers whose journey from home to work usually does not take less than 45 min in each direction) experienced a more stressed life-style than did "non commuters" (whose journey does not take more than 20 min). Commuting appears for many workers to be a necessity which is imposed by external factors, such as the housing market and job opportunities. Commuting is shown to interfere with patterns of everyday life by restricting free-time and reducing sleeping time. A majority of commuters use public transport mainly because of cost. Public transport commuters have problems due to more changes between modes, idle waiting times and delays leading to late arrival at work. Inside transport modes, commuters suffered discomfort as a result of overcrowding, microclimatic conditions, noise and vibrations. Commuters also reported higher psychological stress scores, more health complaints, essentially of psychosomatic nature, and greater absenteeism from work due to sickness. Commuting, in addition to shiftwork, further increases sleep problems, psychosomatic complaints and difficulties with family and social life. Women commuters were at a greater disadvantage than men, having more family difficulties, more travelling complaints and higher absenteeism.

  17. Wages and commuting: quasi-natural experiments' evidence from firms that relocate

    DEFF Research Database (Denmark)

    Mulalic, Ismir; N. Van Ommeren, Jos; Pilegaard, Ninette

    We examine workers' compensating differentials for commuting distance in a quasi-natural experiment setting by examining how wages of workers belonging to the same firm respond to changes in commuting distance induced by firm relocations. This setup enables us to test for the relevance of non...... explanations. We focus on wage changes in the year after, as well as three years after, the firm relocation. We demonstrate that a one km increase in commuting distance induces a wage increase of only 0.06 percent in the year after the relocation, but a more substantial wage increase of about 0.2 percent three...

  18. WAGES AND COMMUTING: QUASI-NATURAL EXPERIMENTS’ EVIDENCE FROM FIRMS THAT RELOCATE

    DEFF Research Database (Denmark)

    Mulalic, Ismir; N. Van Ommeren, Jos; Pilegaard, Ninette

    2014-01-01

    We examine individual-level compensating differentials for commuting distance in a quasi-natural experiment setting by examining how wages respond to changes in commuting distance induced by firm relocations. This set-up enables us to test for the relevance of job search frictions within labour...... market models. Due to the quasi-experimental set-up, we are able to avoid a range of endogeneity issues. We demonstrate that a 1 km increase in commuting distance induces an almost negligible wage increase in the year after the relocation but a more substantial wage increase of about 0.15% three years...

  19. Wages and commuting: quasi-natural experiments' evidence from firms that relocate

    DEFF Research Database (Denmark)

    Mulalic, Ismir; N. Van Ommeren, Jos; Pilegaard, Ninette

    2014-01-01

    We examine individual-level compensating differentials for commuting distance in a quasi-natural experiment setting by examining how wages respond to changes in commuting distance induced by firm relocations. This set-up enables us to test for the relevance of job search frictions within labour...... market models. Due to the quasi-experimental set-up, we are able to avoid a range of endogeneity issues. We demonstrate that a 1 km increase in commuting distance induces an almost negligible wage increase in the year after the relocation but a more substantial wage increase of about 0.15% three years...

  20. Wages and commuting: quasi-natural experiments' evidence from firms that relocate

    DEFF Research Database (Denmark)

    Mulalic, Ismir; Pilegaard, Ninette; van Ommeren, Jos N.

    We examine the causal effect of commuting distance on workers' wages in a quasi-natural experiments setting using information on all workers in Denmark. We account for endogeneity of distance by using changes in distance that are due to firms’ relocations. A one kilometre increase in commuting...... distance induces a wage increase of about 0.42%, suggesting an hourly commuting time compensation of 49% of the hourly net wage. Our findings are consistent with wage bargaining theory and due to the experimental setup we are able to exclude many competing explanations of the wage-distance relationship....

  1. A non-commutative formula for the isotropic magneto-electric response

    International Nuclear Information System (INIS)

    Leung, Bryan; Prodan, Emil

    2013-01-01

    A non-commutative formula for the isotropic magneto-electric response of disordered insulators under magnetic fields is derived using the methods of non-commutative geometry. Our result follows from an explicit evaluation of the Ito derivative with respect to the magnetic field of the non-commutative formula for the electric polarization reported in Schulz-Baldes and Teufel (2012 arXiv:1201.4812v1). The quantization, topological invariance and connection to a second Chern number of the magneto-electric response are discussed in the context of three-dimensional, disordered, time-reversal or inversion symmetric topological insulators. (paper)

  2. On the classical dynamics of charges in non-commutative QED

    International Nuclear Information System (INIS)

    Fatollahi, A.H.; Mohammadzadeh, H.

    2004-01-01

    Following Wong's approach to formulating the classical dynamics of charged particles in non-Abelian gauge theories, we derive the classical equations of motion of a charged particle in U(1) gauge theory on non-commutative space, the so-called non-commutative QED. In the present use of the procedure, it is observed that the definition of the mechanical momenta should be modified. The derived equations of motion manifest the previous statement about the dipole behavior of the charges in non-commutative space. (orig.)

  3. ANALISIS FAKTOR-FAKTOR YANG MEMPENGARUHI KEPUTUSAN MIGRASI COMMUTER DI KABUPATEN DEMAK

    Directory of Open Access Journals (Sweden)

    Ahmad Shidiq

    2017-06-01

    Full Text Available Fenomena migrasi sangat mewarnai di beberapa negara berkembang, termasuk di berbagai daerah di Indonesia. Di Indonesia terutama banyak tenaga kerja yang berasal dari daerah pedesaan mengalir ke daerah perkotaan, Salah satunya dari Kabupaten Demak. Penelitian ini bertujuan untuk mengetahui faktor-faktor yang mempengaruhi keputusan migrasi commuter di Kecamatan Karangtengah Kabupaten Demak antara lain adalah pendapatan pendidikan, pekerjaan daerah asal, jumlah tanggungan serta status perkawinan. Dalam penelitian ini menggunakan data primer melalui instrumen kuesioner terhadap sampel yaitu sebanyak 89 responden, dan menggunakan data sekunder yaitu data dari instansi-instansi terkait serta literatur buku. Penelitian ini dilakukan di Kecamatan Karangtengah Kabupaten Demak. Analisi yang digunakan dalam penelitian ini adalah binary logistic regression. Hasil penelitian menunjukkan bahwa pendapatan berpengaruh negatif dan signifikan terhadap keputusan migrasi commuter, pendidikan berpengaruh positif dan tidak signifikan terhadap keputusan migrasi commuter, pekerjaan di daerah asal berpengaruh positif dan tidak signifikan terhadap keputusan migrasi commuter, jumlah tanggungan daerah asal berpengaruh negatif dan tidak signifikan terhadap keputusan migrasi commuter, status perkawinan berpengaruh positif dan signifikan terhadap keputusan migrasi commuter. The phenomenon of migration is very coloring in some developing countries , including in the various regions in Indonesia . In Indonesia especially many workers coming from rural regions flowed into the urban area, One of Demak District. This study aims to determine the factors that influence the decision of commuter migration in Sub Karangtengah Demak district include the earnings of education, employment areas of origin, number of dependents and marital status. In this research, using primary data through a questionnaire on the sample of 89 respondents, and using secondary data is data from relevant

  4. Loop calculations for the non-commutative U*(1) gauge field model with oscillator term

    International Nuclear Information System (INIS)

    Blaschke, Daniel N.; Grosse, Harald; Kronberger, Erwin; Schweda, Manfred; Wohlgenannt, Michael

    2010-01-01

    Motivated by the success of the non-commutative scalar Grosse-Wulkenhaar model, a non-commutative U * (1) gauge field theory including an oscillator-like term in the action has been put forward in (Blaschke et al. in Europhys. Lett. 79:61002, 2007). The aim of the current work is to analyze whether that action can lead to a fully renormalizable gauge model on non-commutative Euclidean space. In a first step, explicit one-loop graph computations are hence presented, and their results as well as necessary modifications of the action are successively discussed. (orig.)

  5. Associations between Recreational and Commuter Cycling, Changes in Cycling, and Type 2 Diabetes Risk

    DEFF Research Database (Denmark)

    Rasmussen, Martin G; Grøntved, Anders; Blond, Kim

    2016-01-01

    BACKGROUND: Cycling is a recreational activity and mode of commuting with substantial potential to improve public health in many countries around the world. The aim of this study was to examine prospective associations between recreational and commuter cycling, changes in cycling habits, and risk.......83 (0.69, 1.00), and 0.70 (0.57, 0.85) (p for trend = 150 min/wk to work, respectively. The main limitation of the current study is the use of self-reported physical activity. CONCLUSIONS: Commuter and recreational cycling was consistently associated with lower...

  6. Commuting and happiness: What ways feel best for what kinds of people?

    OpenAIRE

    Lancee, S; Burger, Martijn; Veenhoven, Ruut

    2018-01-01

    textabstractQuestion: How happy we are, depends partly on how we live our life and part of our way of life is how we commute between home and work. In that context, we are faced with the question of how much time spent on commuting is optimal happiness wise and with what means of transportation we will feel best. Decisions about commuting are typically made as a side issue in job choice and there are indications that we are bad in predicting how such decisions will work out on our happiness i...

  7. Healthy travel and the socio-economic structure of car commuting in Cambridge, UK: a mixed-methods analysis.

    Science.gov (United States)

    Goodman, Anna; Guell, Cornelia; Panter, Jenna; Jones, Natalia R; Ogilvie, David

    2012-06-01

    Car use is associated with substantial health and environmental costs but research in deprived populations indicates that car access may also promote psychosocial well-being within car-oriented environments. This mixed-method (quantitative and qualitative) study examined this issue in a more affluent setting, investigating the socio-economic structure of car commuting in Cambridge, UK. Our analyses involved integrating self-reported questionnaire data from 1142 participants in the Commuting and Health in Cambridge study (collected in 2009) and in-depth interviews with 50 participants (collected 2009-2010). Even in Britain's leading 'cycling city', cars were a key resource in bridging the gap between individuals' desires and their circumstances. This applied both to long-term life goals such as home ownership and to shorter-term challenges such as illness. Yet car commuting was also subject to constraints, with rush hour traffic pushing drivers to start work earlier and with restrictions on, or charges for, workplace parking pushing drivers towards multimodal journeys (e.g. driving to a 'park-and-ride' site then walking). These patterns of car commuting were socio-economically structured in several ways. First, the gradient of housing costs made living near Cambridge more expensive, affecting who could 'afford' to cycle and perhaps making cycling the more salient local marker of Bourdieu's class distinction. Nevertheless, cars were generally affordable in this relatively affluent, highly-educated population, reducing the barrier which distance posed to labour-force participation. Finally, having the option of starting work early required flexible hours, a form of job control which in Britain is more common among higher occupational classes. Following a social model of disability, we conclude that socio-economic advantage can make car-oriented environments less disabling via both greater affluence and greater job control, and in ways manifested across the full socio

  8. Maximum neutron flux in thermal reactors

    International Nuclear Information System (INIS)

    Strugar, P.V.

    1968-12-01

    Direct approach to the problem is to calculate spatial distribution of fuel concentration if the reactor core directly using the condition of maximum neutron flux and comply with thermal limitations. This paper proved that the problem can be solved by applying the variational calculus, i.e. by using the maximum principle of Pontryagin. Mathematical model of reactor core is based on the two-group neutron diffusion theory with some simplifications which make it appropriate from maximum principle point of view. Here applied theory of maximum principle are suitable for application. The solution of optimum distribution of fuel concentration in the reactor core is obtained in explicit analytical form. The reactor critical dimensions are roots of a system of nonlinear equations and verification of optimum conditions can be done only for specific examples

  9. The association of leisure-time physical activity and active commuting with measures of socioeconomic position in a multiethnic population living in the Netherlands: results from the cross-sectional SUNSET study

    NARCIS (Netherlands)

    de Munter, Jeroen S. L.; Agyemang, Charles; Brewster, Lizzy M.; Stronks, Karien; van Valkengoed, Irene G. M.

    2012-01-01

    Background: In most European origin populations measures of socioeconomic position are positively associated with leisure time physical activity (LTPA), this is unclear for active commuting. In addition, these associations have scarcely been studied in ethnic minority groups, who often have a high

  10. Individual public transportation accessibility is positively associated with self-reported active commuting

    DEFF Research Database (Denmark)

    Djurhuus, Sune; Hansen, Henning Sten; Aadahl, Mette

    2014-01-01

    BACKGROUND: Active commuters have lower risk of chronic disease. Understanding which of the, to some extent, modifiable characteristics of public transportation that facilitate its use is thus important in a public health perspective. The aim of the study was to examine the association between...... individual public transportation accessibility and self-reported active commuting, and whether the associations varied with commute distance, age, and gender. METHODS: Twenty-eight thousand nine hundred twenty-eight commuters in The Capital Region of Denmark reported self-reported time spent either walking...... or cycling to work or study each day and the distance to work or study. Data were obtained from the Danish National Health Survey collected in February to April 2010. Individual accessibility by public transportation was calculated using a multi-modal network in a GIS. Multilevel logistic regression was used...

  11. INdAM Meeting on Homological and Computational Methods in Commutative Algebra

    CERN Document Server

    Gubeladze, Joseph; Römer, Tim

    2017-01-01

    This volume collects contributions by leading experts in the area of commutative algebra related to the  INdAM meeting “Homological and Computational Methods in Commutative Algebra” held in Cortona (Italy) from May 30 to  June 3, 2016 . The conference and this volume are dedicated to Winfried Bruns on the occasion of his 70th birthday. In particular, the topics of this book strongly reflect the variety of Winfried Bruns’ research interests and his great impact on commutative algebra as well as its applications to related fields. The authors discuss recent and relevant developments in algebraic geometry, commutative algebra, computational algebra, discrete geometry and homological algebra. The book offers a unique resource, both for young and more experienced researchers seeking comprehensive overviews and extensive bibliographic references.

  12. (Non-)commutative closed string on T-dual toroidal backgrounds

    CERN Document Server

    Andriot, David; Lust, Dieter; Patalong, Peter

    2013-01-01

    In this paper we investigate the connection between (non-)geometry and (non-)commutativity of the closed string. To this end, we solve the classical string on three T-dual toroidal backgrounds: a torus with H-flux, a twisted torus and a non-geometric background with Q-flux. In all three situations we work under the assumption of a dilute flux and consider quantities to linear order in the flux density. Furthermore, we perform the first steps of a canonical quantization for the twisted torus, to derive commutators of the string expansion modes. We use them as well as T-duality to determine, in the non-geometric background, a commutator of two string coordinates, which turns out to be non-vanishing. We relate this non-commutativity to the closed string boundary conditions, and the non-geometric Q-flux.

  13. Potential to increase active commuting level in university area (Case study: Universitas Gadjah Mada)

    Science.gov (United States)

    Devi, M. K.

    2017-06-01

    In order to alleviate the negative impacts of motorized vehicle use as well as create sustainable environment within campus area, it is pivotal to encourage mode shifting among university students. Active transport modes such as walking, cycling, and using public transport can be considered as alternative modes. This paper tried to identify the potential to increase active commuting in UGM by understanding student’s travel behavior. ANOVA test was employed to identify the perceptions between students across residential zones toward motivators and barriers to actively commute. The findings were used to propose strategies for increasing active commuting level in UGM, which are: reducing barriers to actively commute, improving public transport services, improving walking and cycling facilities, and introducing programs to discourage motorized vehicle use.

  14. 11. PO Ngesa African Women Commuter Traders in Nairobi in the ...

    African Journals Online (AJOL)

    REGINALDS

    Thought and Practice: A Journal of the Philosophical Association of Kenya (PAK) .... The history of women commuter traders in present day Nairobi goes back to pre- ... The African market became a focal point in the continuing women's trade,.

  15. Non(anti)commutative N = (1,1/2) supersymmetric U(1) gauge theory

    International Nuclear Information System (INIS)

    Araki, Takeo; Ito, Katsushi; Ohtsuka, Akihisa

    2005-01-01

    We study a reduction of deformation parameters in non(anti)commutative N = 2 harmonic superspace to those in non(anti)commutative N = 1 superspace. By this reduction we obtain the exact gauge and supersymmetry transformations in the Wess-Zumino gauge of non(anti)commutative N = 2 supersymmetric U(1) gauge theory defined in the deformed harmonic superspace. We also find that the action with the first order correction in the deformation parameter reduces to the one in the N = 1 superspace by some field redefinition. We construct deformed N = (1,1/2) supersymmetry in N = 2 supersymmetric U(1) gauge theory in non(anti)commutative N = 1 superspace

  16. Associations between active commuting to school and objectively measured physical activity

    DEFF Research Database (Denmark)

    Børrestad L, Anita Bjørkelund; Ostergaard, Lars; Andersen, Lars Bo

    2013-01-01

    , b) compare moderate vigorous physical activity (MVPA) among children cycling vs. walking to school, and c) thus calculate possible underestimated MVPA, when using accelerometers to measure commuter cycling. Methods: A total of 78 children, average age 11.4 (SD = 0.5), participated in the study....... Physical activity was measured with cycle computers and accelerometers for 4 days. Mode of commuting and demographic information was self-reported in a questionnaire. Results: Children who reported to cycle to school spent significantly more time cycling than those who walked to school, 53.6 (SD = ± 33......Background: To provide more accurate assessment of commuting behavior and potential health effect, it is important to have accurate methods. Therefore, the current study aimed to a) compare questionnaire reported mode of commuting with objectively measured data from accelerometer and cycle computer...

  17. Assessing importance and satisfaction judgments of intermodal work commuters with electronic survey methodology.

    Science.gov (United States)

    2013-09-01

    Recent advances in multivariate methodology provide an opportunity to further the assessment of service offerings in public transportation for work commuting. We offer methodologies that are alternative to direct rating scale and have advantages in t...

  18. Eléments de mathématique algèbre commutative

    CERN Document Server

    Bourbaki, Nicolas

    Les élements de mathématique de Nicolas Bourbaki ont pour objet une présentation rigoureuse, systématique et sans prérequis des mathématiques depuis leurs fondements. Ce premier volume du Livre d'Algèbre commutative, septième Livre du traité, est consacré aux concepts fondamentaux de l'algèbre commutative.

  19. A Departure Time Choice for Morning Commute Considering Train Capacity of a Rail Transit Line

    OpenAIRE

    Jia Feng; Baohua Mao; Zhijie Chen; Yun Bai; Minggao Li

    2013-01-01

    Every commuter utilizing urban rail transit decides the departure time from home to a station according to individual judgment for the biggest possibility to board a train as soon as possible after the arrival. Therefore, the departure time choice behavior of the commuters is complicated especially when the transport capacity of this transit line cannot meet the travel demands of its users in rush hour. This research first develops a travel cost function mainly considering the travel time to ...

  20. K\\"{a}hler structure in the commutative limit of matrix geometry

    OpenAIRE

    Ishiki, Goro; Matsumoto, Takaki; Muraki, Hisayoshi

    2016-01-01

    We consider the commutative limit of matrix geometry described by a large-$N$ sequence of some Hermitian matrices. Under some assumptions, we show that the commutative geometry possesses a K\\"{a}hler structure. We find an explicit relation between the K\\"{a}hler structure and the matrix configurations which define the matrix geometry. We also find a relation between the matrix configurations and those obtained from the geometric quantization.

  1. Objective physical activity of filipino youth stratified for commuting mode to school.

    Science.gov (United States)

    Tudor-Locke, Catrine; Ainsworth, Barbara E; Adair, Linda S; Popkin, Barry M

    2003-03-01

    The Cebu Longitudinal Health and Nutrition Survey included self-report measures and objective measures (Caltrac accelerometer) of Filipino adolescent (ages 14-16) physical activity (PA) in 1998-99. The purpose of this subanalysis was to compare objectively monitored PA of adolescents who differed by their self-reported habitual commuting mode to school, specifically commuting by walking, motorized transport, or a combination of the two. Descriptive analysis included the proportion of adolescents who reported commuting to school by the different modes, participating in sport/exercise during or after school, or currently working. ANCOVA was used to estimate and compare adjusted mean Caltrac-derived energy expenditure (kcal.d ) by commuting mode for each gender. Covariates were age, weight, and height. The analysis sample of 1518 Filipino adolescents included 691 male (BMI = 18.5 +/- 2.5) and 827 female subjects (BMI = 18.7 +/- 2.3). A total of 323 male subjects (46.8% of all male subjects) walked to school, 160 (23.2%) took motorized transport, and 208 (30.0%) used a combination of the two modes. The corresponding values for female subjects were 303 (36.6%), 177 (21.4%), and 347 (42.0%). The absolute difference in Caltrac-derived energy expenditure that appeared to be due to active commuting was 44.2 kcal.d for Filipino male adolescents and 33.2 kcal.d for female adolescents. These differences between commuting modes could not be explained by participation in sport/exercise or by current employment. Assuming 200 school days in a year, the difference in energy expended due to active commuting translates to a 8840 kcal and 6640 kcal in male and female subjects, respectively. For those youth who commute to school by motorized transport a yearly positive energy balance (i.e., weight gain) of 2-3 lb would be anticipated, all other things being held constant.

  2. Credal Networks under Maximum Entropy

    OpenAIRE

    Lukasiewicz, Thomas

    2013-01-01

    We apply the principle of maximum entropy to select a unique joint probability distribution from the set of all joint probability distributions specified by a credal network. In detail, we start by showing that the unique joint distribution of a Bayesian tree coincides with the maximum entropy model of its conditional distributions. This result, however, does not hold anymore for general Bayesian networks. We thus present a new kind of maximum entropy models, which are computed sequentially. ...

  3. Decolonisation of fractional calculus rules: Breaking commutativity and associativity to capture more natural phenomena

    Science.gov (United States)

    Atangana, Abdon; Gómez-Aguilar, J. F.

    2018-04-01

    To answer some issues raised about the concept of fractional differentiation and integration based on the exponential and Mittag-Leffler laws, we present, in this paper, fundamental differences between the power law, exponential decay, Mittag-Leffler law and their possible applications in nature. We demonstrate the failure of the semi-group principle in modeling real-world problems. We use natural phenomena to illustrate the importance of non-commutative and non-associative operators under which the Caputo-Fabrizio and Atangana-Baleanu fractional operators fall. We present statistical properties of generator for each fractional derivative, including Riemann-Liouville, Caputo-Fabrizio and Atangana-Baleanu ones. The Atangana-Baleanu and Caputo-Fabrizio fractional derivatives show crossover properties for the mean-square displacement, while the Riemann-Liouville is scale invariant. Their probability distributions are also a Gaussian to non-Gaussian crossover, with the difference that the Caputo Fabrizio kernel has a steady state between the transition. Only the Atangana-Baleanu kernel is a crossover for the waiting time distribution from stretched exponential to power law. A new criterion was suggested, namely the Atangana-Gómez fractional bracket, that helps describe the energy needed by a fractional derivative to characterize a 2-pletic manifold. Based on these properties, we classified fractional derivatives in three categories: weak, mild and strong fractional differential and integral operators. We presented some applications of fractional differential operators to describe real-world problems and we proved, with numerical simulations, that the Riemann-Liouville power-law derivative provides a description of real-world problems with much additional information, that can be seen as noise or error due to specific memory properties of its power-law kernel. The Caputo-Fabrizio derivative is less noisy while the Atangana-Baleanu fractional derivative provides an

  4. Mitigation of commutation failures in LCC–HVDC systems based on superconducting fault current limiters

    International Nuclear Information System (INIS)

    Lee, Jong-Geon; Khan, Umer Amir; Lee, Ho-Yun; Lim, Sung-Woo; Lee, Bang-Wook

    2016-01-01

    Commutation failure in line commutated converter based HVDC systems cause severe damages on the entire power grid system. For LCC–HVDC, thyristor valves are turned on by a firing signal but turn off control is governed by the external applied AC voltage from surrounding network. When the fault occurs in AC system, turn-off control of thyristor valves is unavailable due to the voltage collapse of point of common coupling (PCC), which causes the commutation failure in LCC–HVDC link. Due to the commutation failure, the power transfer interruption, dc voltage drop and severe voltage fluctuation in the AC system could be occurred. In a severe situation, it might cause the protection system to block the valves. In this paper, as a solution to prevent the voltage collapse on PCC and to limit the fault current, the application study of resistive superconducting fault current limiter (SFCL) on LCC–HVDC grid system was performed with mathematical and simulation analyses. The simulation model was designed by Matlab/Simulink considering Haenam-Jeju HVDC power grid in Korea which includes conventional AC system and onshore wind farm and resistive SFCL model. From the result, it was observed that the application of SFCL on LCC–HVDC system is an effective solution to mitigate the commutation failure. And then the process to determine optimum quench resistance of SFCL which enables the recovery of commutation failure was deeply investigated.

  5. Transport priorities, risk perception and worry associated with mode use and preferences among Norwegian commuters.

    Science.gov (United States)

    Nordfjærn, Trond; Simşekoğlu, Özlem; Lind, Hans Brende; Jørgensen, Stig Halvard; Rundmo, Torbjørn

    2014-11-01

    There is currently scant research on the role of transport priorities, risk perception and worry for travel mode use and preferences. The present study aims to examine these factors in relation to mode use and preferences among Norwegian commuters. A web-based survey was conducted in a randomly obtained representative sample of daily commuters in the extended greater Oslo area (n=690). The results showed that those who prioritized efficiency and flexibility tended to commute by car, while those who prioritized safety and comfort used public (e.g. metro, tram, and train) or active (e.g. walking and cycling) transport. In a free choice scenario, the respondents who prioritized flexibility reported a preference for using a car, whereas those who prioritized safety and comfort preferred public and active transport for their commuter travels. Risk perception of high impact events, such as terrorism and major accidents, as well as risk perception related to personal impact risks (theft, violence etc.) were related to car use on commuter travels. Transport-related worry exerted weak influences on mode use and preferences. Increased speed on rail transport and more frequent departures may be effective in reducing car use on commuter travels. Risk communication should focus on highlighting the low risk of experiencing security and safety issues in the public transport sector, and this message should be complemented by efforts to reduce the probability of negative events affecting public transport. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Do driving restriction policies effectively motivate commuters to use public transportation?

    International Nuclear Information System (INIS)

    Liu, Yunxia; Hong, Zaisheng; Liu, Yong

    2016-01-01

    Driving restriction policies have been implemented in some large Chinese cities to cope with severe urban smog pollution. We explored the roles of policy acceptance and other factors in commuters' transport mode decisions, based on the Theory of Planned Behavior. A questionnaire survey was conducted in Tianjin, China. A structural equation model was developed to test eight hypotheses, two of which were rejected. The results indicate that a driving restriction policy alone cannot effectively motivate commuters to use public transport if the policymakers fail to improve public transport, enhance commuters' awareness of consequences, increase commuters' perceived behavior control, and encourage car owners to change driving behavior. Comparisons between car owners and non-owners indicated that car owners view driving restriction policy and public transport more negatively. These negative views could be a barrier for the promotion of public transport among car owners. In addition, attitude toward public transport was found to have positive correlation with commuting time. - Highlights: • Attitude towards public transport has an impact on policy acceptance. • Driving habit indirectly affects policy acceptance and perceived behavior control. • Driving restriction policy and public transport are not popular among car owners. • Attitude towards public transport correlates positively with commuting time.

  7. Mitigation of commutation failures in LCC–HVDC systems based on superconducting fault current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong-Geon; Khan, Umer Amir; Lee, Ho-Yun; Lim, Sung-Woo; Lee, Bang-Wook, E-mail: bangwook@hanyang.ac.kr

    2016-11-15

    Commutation failure in line commutated converter based HVDC systems cause severe damages on the entire power grid system. For LCC–HVDC, thyristor valves are turned on by a firing signal but turn off control is governed by the external applied AC voltage from surrounding network. When the fault occurs in AC system, turn-off control of thyristor valves is unavailable due to the voltage collapse of point of common coupling (PCC), which causes the commutation failure in LCC–HVDC link. Due to the commutation failure, the power transfer interruption, dc voltage drop and severe voltage fluctuation in the AC system could be occurred. In a severe situation, it might cause the protection system to block the valves. In this paper, as a solution to prevent the voltage collapse on PCC and to limit the fault current, the application study of resistive superconducting fault current limiter (SFCL) on LCC–HVDC grid system was performed with mathematical and simulation analyses. The simulation model was designed by Matlab/Simulink considering Haenam-Jeju HVDC power grid in Korea which includes conventional AC system and onshore wind farm and resistive SFCL model. From the result, it was observed that the application of SFCL on LCC–HVDC system is an effective solution to mitigate the commutation failure. And then the process to determine optimum quench resistance of SFCL which enables the recovery of commutation failure was deeply investigated.

  8. Regular Routes: Deep Mapping a Performative Counterpractice for the Daily Commute 1

    Directory of Open Access Journals (Sweden)

    Laura Bissell

    2015-09-01

    Full Text Available This article offers a textual “deep map” of a series of experimental commutes undertaken in the west of Scotland in 2014. Recent developments in the field of transport studies have reconceived travel time as a far richer cultural experience than in previously utilitarian and economic approaches to the “problem” of commuting. Understanding their own commutes in these terms—as spaces of creativity, productivity and transformation—the authors trace the development of a performative “counterpractice” for their daily journeys between home and work. Deep mapping—as a form of “theory-informed story-telling”—is employed as a productive strategy to document this reimagination of ostensibly quotidian and functional travel. Importantly, this particular stage of the project is not presented as an end-point. Striving to develop an ongoing creative engagement with landscape, the authors continue this exploratory mobile research by connecting to other commuters’ journeys, and proposing a series of “strategies” for reimagining the daily commute; a list of prompts for future action within the routines and spaces of commuting. A range of alternative approaches to commuting are offered here to anyone who regularly travels to and from work to employ or develop as they wish, extending the mapping process to other routes and contexts.

  9. Mitigation of commutation failures in LCC-HVDC systems based on superconducting fault current limiters

    Science.gov (United States)

    Lee, Jong-Geon; Khan, Umer Amir; Lee, Ho-Yun; Lim, Sung-Woo; Lee, Bang-Wook

    2016-11-01

    Commutation failure in line commutated converter based HVDC systems cause severe damages on the entire power grid system. For LCC-HVDC, thyristor valves are turned on by a firing signal but turn off control is governed by the external applied AC voltage from surrounding network. When the fault occurs in AC system, turn-off control of thyristor valves is unavailable due to the voltage collapse of point of common coupling (PCC), which causes the commutation failure in LCC-HVDC link. Due to the commutation failure, the power transfer interruption, dc voltage drop and severe voltage fluctuation in the AC system could be occurred. In a severe situation, it might cause the protection system to block the valves. In this paper, as a solution to prevent the voltage collapse on PCC and to limit the fault current, the application study of resistive superconducting fault current limiter (SFCL) on LCC-HVDC grid system was performed with mathematical and simulation analyses. The simulation model was designed by Matlab/Simulink considering Haenam-Jeju HVDC power grid in Korea which includes conventional AC system and onshore wind farm and resistive SFCL model. From the result, it was observed that the application of SFCL on LCC-HVDC system is an effective solution to mitigate the commutation failure. And then the process to determine optimum quench resistance of SFCL which enables the recovery of commutation failure was deeply investigated.

  10. Maximum entropy and Bayesian methods

    International Nuclear Information System (INIS)

    Smith, C.R.; Erickson, G.J.; Neudorfer, P.O.

    1992-01-01

    Bayesian probability theory and Maximum Entropy methods are at the core of a new view of scientific inference. These 'new' ideas, along with the revolution in computational methods afforded by modern computers allow astronomers, electrical engineers, image processors of any type, NMR chemists and physicists, and anyone at all who has to deal with incomplete and noisy data, to take advantage of methods that, in the past, have been applied only in some areas of theoretical physics. The title workshops have been the focus of a group of researchers from many different fields, and this diversity is evident in this book. There are tutorial and theoretical papers, and applications in a very wide variety of fields. Almost any instance of dealing with incomplete and noisy data can be usefully treated by these methods, and many areas of theoretical research are being enhanced by the thoughtful application of Bayes' theorem. Contributions contained in this volume present a state-of-the-art overview that will be influential and useful for many years to come

  11. Fast Katz and commuters : efficient estimation of social relatedness.

    Energy Technology Data Exchange (ETDEWEB)

    On, Byung-Won; Lakshmanan, Laks V. S.; Esfandiar, Pooya; Bonchi, Francesco; Grief, Chen; Gleich, David F.

    2010-12-01

    Motivated by social network data mining problems such as link prediction and collaborative filtering, significant research effort has been devoted to computing topological measures including the Katz score and the commute time. Existing approaches typically approximate all pairwise relationships simultaneously. In this paper, we are interested in computing: the score for a single pair of nodes, and the top-k nodes with the best scores from a given source node. For the pairwise problem, we apply an iterative algorithm that computes upper and lower bounds for the measures we seek. This algorithm exploits a relationship between the Lanczos process and a quadrature rule. For the top-k problem, we propose an algorithm that only accesses a small portion of the graph and is related to techniques used in personalized PageRank computing. To test the scalability and accuracy of our algorithms we experiment with three real-world networks and find that these algorithms run in milliseconds to seconds without any preprocessing.

  12. Commuting quantum circuits and complexity of Ising partition functions

    International Nuclear Information System (INIS)

    Fujii, Keisuke; Morimae, Tomoyuki

    2017-01-01

    Instantaneous quantum polynomial-time (IQP) computation is a class of quantum computation consisting only of commuting two-qubit gates and is not universal. Nevertheless, it has been shown that if there is a classical algorithm that can simulate IQP efficiently, the polynomial hierarchy collapses to the third level, which is highly implausible. However, the origin of the classical intractability is still less understood. Here we establish a relationship between IQP and computational complexity of calculating the imaginary-valued partition functions of Ising models. We apply the established relationship in two opposite directions. One direction is to find subclasses of IQP that are classically efficiently simulatable by using exact solvability of certain types of Ising models. Another direction is applying quantum computational complexity of IQP to investigate (im)possibility of efficient classical approximations of Ising partition functions with imaginary coupling constants. Specifically, we show that a multiplicative approximation of Ising partition functions is #P-hard for almost all imaginary coupling constants even on planar lattices of a bounded degree. (paper)

  13. Fully controlled 5-phase, 10-pulse, line commutated rectifier

    Directory of Open Access Journals (Sweden)

    Mahmoud I. Masoud

    2015-12-01

    Full Text Available The development and production of multiphase machines either generators or motors, specially five-phase, offers improved performance compared to three-phase counterpart. Five phase generators could generate power in applications such as, but not limited to, wind power generation, electric vehicles, aerospace, and oil and gas. The five-phase generator output requires converter system such as ac–dc converters. In this paper, a fully controlled 10-pulse line commutated rectifier, suitable to be engaged with wind energy applications, fed from five-phase source is introduced. A shunt active power filter (APF is used to improve power factor and supply current total harmonic distortion (THD. Compared to three-phase converters, 6-pulse or 12-pulse rectifiers, the 10-pulse rectifier engaged with 5-phase source alleviate their drawbacks such as high dc ripples and no need for electric gear or phase shifting transformer. MATLAB/SIMULINK platform is used as a simulation tool to investigate the performance of the proposed rectifier.

  14. Analyzing multiday route choice behavior of commuters using GPS data

    Directory of Open Access Journals (Sweden)

    Wenyun Tang

    2016-02-01

    Full Text Available In this study, accurate global position system and geographic information system data were employed to reveal multiday routes people used and to study multiday route choice behavior for the same origin–destination trips, from home to work. A new way of thinking about route choice modeling is provided in this study. Travelers are classified into three kinds based on the deviation between actual routes and the shortest travel time paths. Based on the classification, a two-stage route choice process is proposed, in which the first step is to classify the travelers and the second one is to model route choice behavior. After analyzing the characteristics of different types of travelers, an artificial neural network was adopted to classify travelers and model route choice behavior. An empirical study using global position systems data collected in Minneapolis–St Paul metropolitan area was carried out. It finds that most travelers follow the same route during commute trips on successive days. And different types of travelers have a significant difference in route choice property. The modeling results indicate that neural network framework can classify travelers and model route choice well.

  15. Weinberg-Salam theory in non-commutative geometry

    International Nuclear Information System (INIS)

    Morita, Katsusada; Okumura, Yoshitaka.

    1994-01-01

    Ordinary differential calculus on smooth manifold is generalized so as to construct gauge theory coupled to fermions on discrete space M 4 xZ 2 which is an underlying space-time in the non-commutative geometry for the standard model. We can reproduce not only the bosonic sector but also the fermionic sector of the Weinberg-Salam theory without recourse to the Dirac operator at the outset. Treatment of the fermionic sector is based on the generalized spinor one-forms from which the Dirac lagrangian is derived through taking the inner product. Two model constructions are presented using our formalism, both giving the classical mass relation m H = √2m w . The first model leaves the Weinberg angle arbitrary as usual, while the second one predicts sin 2 θ w = 1/4 in the tree level. This prediction is the same as that of Connes but we obtain it from correct hypercharge assignment of 2x2 matrix-valued Higgs field and from vanishing photon mass, thereby dispensing with Connes' 0-trace condition or the equivalent. (author)

  16. Study of advanced rotary combustion engines for commuter aircraft

    Science.gov (United States)

    Berkowitz, M.; Jones, C.; Myers, D.

    1983-01-01

    Performance, weight, size, and maintenance data for advanced rotary aircraft engines suitable for comparative commuter aircraft system evaluation studies of alternate engine candidates are provided. These are turbocharged, turbocompounded, direct injected, stratified charge rotary engines. Hypothetical engines were defined (an RC4-74 at 895 kW and an RC6-87 at 1490 kW) based on the technologies and design approaches used in the highly advanced engine of a study of advanced general aviation rotary engines. The data covers the size range of shaft power from 597 kW (800 hp) to 1865 kW (2500 hp) and is in the form of drawings, tables, curves and written text. These include data on internal geometry and configuration, installation information, turbocharging and turbocompounding arrangements, design features and technologies, engine cooling, fuels, scaling for weight size BSFC and heat rejection for varying horsepower, engine operating and performance data, and TBO and maintenance requirements. The basic combustion system was developed and demonstrated; however the projected power densities and performance efficiencies require increases in engine internal pressures, thermal loading, and rotative speed.

  17. Problem of quantifying quantum correlations with non-commutative discord

    Science.gov (United States)

    Majtey, A. P.; Bussandri, D. G.; Osán, T. M.; Lamberti, P. W.; Valdés-Hernández, A.

    2017-09-01

    In this work we analyze a non-commutativity measure of quantum correlations recently proposed by Guo (Sci Rep 6:25241, 2016). By resorting to a systematic survey of a two-qubit system, we detected an undesirable behavior of such a measure related to its representation-dependence. In the case of pure states, this dependence manifests as a non-satisfactory entanglement measure whenever a representation other than the Schmidt's is used. In order to avoid this basis-dependence feature, we argue that a minimization procedure over the set of all possible representations of the quantum state is required. In the case of pure states, this minimization can be analytically performed and the optimal basis turns out to be that of Schmidt's. In addition, the resulting measure inherits the main properties of Guo's measure and, unlike the latter, it reduces to a legitimate entanglement measure in the case of pure states. Some examples involving general mixed states are also analyzed considering such an optimization. The results show that, in most cases of interest, the use of Guo's measure can result in an overestimation of quantum correlations. However, since Guo's measure has the advantage of being easily computable, it might be used as a qualitative estimator of the presence of quantum correlations.

  18. Remarks on the application of group extensions to quantization

    International Nuclear Information System (INIS)

    Mozrzymas, J.; Rzewuski, J.

    1976-01-01

    Quantization is described in the language of the theory of group extensions. Under the assumption of analyticity the most general form of factor of the extension is derived. A realization of the extended group in terms of functionals is described in the case of quantum field theory. The homomorphism of the extended group with the Weyl group of canonical commutation relations is demonstrated. (author)

  19. On orbits and admissible subalgebras for the PR groups

    International Nuclear Information System (INIS)

    Lebedenko, V.M.

    1977-01-01

    The PR-groups (Lie groups with commutation relations of [Hsub(i),Hsub(0)] = rsub(ij)Hsub(i) (i< j)-type) are investigated within the Kirillov orbit method. Orbits for all the PR-groups are constructed in a general form. For some classes of PR-groups orbits and admissible subalgebras are obtained in an explicit form

  20. Bikeability and methodological issues using the active commuting route environment scale (ACRES in a metropolitan setting

    Directory of Open Access Journals (Sweden)

    Schantz Peter

    2011-01-01

    Full Text Available Abstract Background Route environments can positively influence people's active commuting and thereby contribute to public health. The Active Commuting Route Environment Scale (ACRES was developed to study active commuters' perceptions of their route environments. However, bicycle commuters represent a small portion of the population in many cities and thus are difficult to study using population-based material. Therefore, the aim of this study is to expand the state of knowledge concerning the criterion-related validity of the ACRES and the representativity using an advertisement-recruited sample. Furthermore, by comparing commuting route environment profiles of inner urban and suburban areas, we provide a novel basis for understanding the relationship between environment and bikeability. Methods Bicycle commuters from Greater Stockholm, Sweden, advertisement- (n = 1379 and street-recruited (n = 93, responded to the ACRES. Traffic planning and environmental experts from the Municipality of Stockholm (n = 24 responded to a modified version of the ACRES. The criterion-related validity assessments were based on whether or not differences between the inner urban and the suburban route environments, as indicated by the experts and by four existing objective measurements, were reflected by differences in perceptions of these environments. Comparisons of ratings between advertisement- and street-recruited participants were used for the assessments of representativity. Finally, ratings of inner urban and suburban route environments were used to evaluate commuting route environment profiles. Results Differences in ratings of the inner urban and suburban route environments by the advertisement-recruited participants were in accord with the existing objective measurements and corresponded reasonably well with those of the experts. Overall, there was a reasonably good correspondence between the advertisement- and street-recruited participants' ratings

  1. Bikeability and methodological issues using the active commuting route environment scale (ACRES) in a metropolitan setting.

    Science.gov (United States)

    Wahlgren, Lina; Schantz, Peter

    2011-01-17

    Route environments can positively influence people's active commuting and thereby contribute to public health. The Active Commuting Route Environment Scale (ACRES) was developed to study active commuters' perceptions of their route environments. However, bicycle commuters represent a small portion of the population in many cities and thus are difficult to study using population-based material. Therefore, the aim of this study is to expand the state of knowledge concerning the criterion-related validity of the ACRES and the representativity using an advertisement-recruited sample. Furthermore, by comparing commuting route environment profiles of inner urban and suburban areas, we provide a novel basis for understanding the relationship between environment and bikeability. Bicycle commuters from Greater Stockholm, Sweden, advertisement- (n = 1379) and street-recruited (n = 93), responded to the ACRES. Traffic planning and environmental experts from the Municipality of Stockholm (n = 24) responded to a modified version of the ACRES. The criterion-related validity assessments were based on whether or not differences between the inner urban and the suburban route environments, as indicated by the experts and by four existing objective measurements, were reflected by differences in perceptions of these environments. Comparisons of ratings between advertisement- and street-recruited participants were used for the assessments of representativity. Finally, ratings of inner urban and suburban route environments were used to evaluate commuting route environment profiles. Differences in ratings of the inner urban and suburban route environments by the advertisement-recruited participants were in accord with the existing objective measurements and corresponded reasonably well with those of the experts. Overall, there was a reasonably good correspondence between the advertisement- and street-recruited participants' ratings. Distinct differences in commuting route environment

  2. Noncommutative phase spaces on Aristotle group

    Directory of Open Access Journals (Sweden)

    Ancille Ngendakumana

    2012-03-01

    Full Text Available We realize noncommutative phase spaces as coadjoint orbits of extensions of the Aristotle group in a two dimensional space. Through these constructions the momenta of the phase spaces do not commute due to the presence of a naturally introduced magnetic eld. These cases correspond to the minimal coupling of the momentum with a magnetic potential.

  3. Abelian varieties and p-divisible groups

    NARCIS (Netherlands)

    Oort, F.

    2005-01-01

    Yuri Manin’s Emeritierung Conference 24 – 26 February 2005 It is nice to give a talk at this event on the influential paper: [M] Yu. I. Manin – The theory of commutative formal groups over fields of finite characteristic. Usp. Math. 18 (1963), 3-90; Russ. Math. Surveys 18 (1963), 1-80.

  4. Shower maximum detector for SDC calorimetry

    International Nuclear Information System (INIS)

    Ernwein, J.

    1994-01-01

    A prototype for the SDC end-cap (EM) calorimeter complete with a pre-shower and a shower maximum detector was tested in beams of electrons and Π's at CERN by an SDC subsystem group. The prototype was manufactured from scintillator tiles and strips read out with 1 mm diameter wave-length shifting fibers. The design and construction of the shower maximum detector is described, and results of laboratory tests on light yield and performance of the scintillator-fiber system are given. Preliminary results on energy and position measurements with the shower max detector in the test beam are shown. (authors). 4 refs., 5 figs

  5. On the subgroups of PR groups

    International Nuclear Information System (INIS)

    Lebedenko, V.M.

    1979-01-01

    The subgroups of PR-groups are being studied, i.e., the subgroups of connected and simply connected nonabelian Lie groups, their Lie algebras being defined by the commuting relations of the type [Hsub(i), Hsub(j)] = rsub(ij)Hsub(i) (i 1 of PR-group G there exists such complementary subgroup G 2 and that group G is expanded in semidirect product G = G 1 xG 2 [ru

  6. Reconstruction of the spontaneously broken gauge theory in non-commutative geometry

    International Nuclear Information System (INIS)

    Okumura, Y.; Morita, K.

    1996-01-01

    The scheme previously proposed by the present authors is modified to incorporate the strong interaction by affording the direct product internal symmetry. The authors do not need to prepare the extra discrete space for the colour gauge group responsible for the strong interaction to reconstruct the standard model and the left-right symmetric gauge model (LRSM). The approach based on non-commutative geometry leads us to present many attractive points such as the unified picture of the gauge and Higgs field as the generalized connection on the discrete space M 4 x Z N . This approach leads to unified picture of gauge and Higgs fields as the generalized connection. The standard model needs N=2 discrete space for reconstruction in this formalism. LRSM is still alive as a model with the intermediate symmetry of the spontaneously broken SO(10) grand unified theory (GUT). N=3 discrete space is needed for the reconstruction of LRSM to include two Higgs φ and ξ bosons usual transformed as (2, 2 * , 0) and (1, 3, -2) under SU(2) L x SU(2) R x U(1) Y , respectively. ξ is responsible to make v R Majorana fermion and so well explains the seesaw mechanism. Up and down quarks have different masses through the vacuum expectation value of φ

  7. The socio-economic and environmental impact of school commuting : a case study of the Johannesburg Inner City

    OpenAIRE

    2014-01-01

    M.Sc. (Environmental Management) This study explores the school-commuting phenomenon that occurs across the city of Johannesburg, with specific reference to inner city private schools. It was hypothesized that the school commute, much of which has its origins in spatial apartheid, is financially and socially unsustainable. As spatial apartheid continues to dominate the urban landscape in Johannesburg, it is posited that overall, the school commute hinders the City of Johannesburg’s progres...

  8. Modification of Traffic-related Respiratory Response by Asthma Control in a Population of Car Commuters

    Science.gov (United States)

    Mirabelli, Maria C.; Golan, Rachel; Greenwald, Roby; Raysoni, Amit U.; Holguin, Fernando; Kewada, Priya; Winquist, Andrea; Flanders, W. Dana; Sarnat, Jeremy A.

    2015-01-01

    Background Effects of traffic-related exposures on respiratory health are well documented, but little information is available about whether asthma control influences individual susceptibility. We analyzed data from the Atlanta Commuter Exposure study to evaluate modification of associations between rush-hour commuting, in-vehicle air pollution, and selected respiratory health outcomes by asthma control status. Methods Between 2009 and 2011, 39 adults participated in Atlanta Commuter Exposure, and each conducted two scripted rush-hour highway commutes. In-vehicle particulate components were measured during all commutes. Among adults with asthma, we evaluated asthma control by questionnaire and spirometry. Exhaled nitric oxide, forced expiratory volume in 1 second (FEV1), and other metrics of respiratory health were measured precommute and 0, 1, 2, and 3 hours postcommute. We used mixed effects linear regression to evaluate associations between commute-related exposures and postcommute changes in metrics of respiratory health by level of asthma control. Results We observed increased exhaled nitric oxide across all levels of asthma control compared with precommute measurements, with largest postcommute increases observed among participants with below-median asthma control (2 hours postcommute: 14.6% [95% confidence interval {CI} = 5.7, 24.2]; 3 hours postcommute: 19.5% [95% CI = 7.8, 32.5]). No associations between in-vehicle pollutants and percent of predicted FEV1 were observed, although higher PM2.5 was associated with lower FEV1 % predicted among participants with below-median asthma control (3 hours postcommute: −7.2 [95% CI = −11.8, −2.7]). Conclusions Level of asthma control may influence respiratory response to in-vehicle exposures experienced during rush-hour commuting. PMID:25901844

  9. Commutability of possible external quality assessment materials for cardiac troponin measurement.

    Directory of Open Access Journals (Sweden)

    Shunli Zhang

    Full Text Available The measurement of cardiac troponin is crucial in the diagnosis of myocardial infarction. The performance of troponin measurement is most conveniently monitored by external quality assessment (EQA programs. The commutability of EQA samples is often unknown and the effectiveness of EQA programs is limited.Commutability of possible EQA materials was evaluated. Commercial control materials used in an EQA program, human serum pools prepared from patient samples, purified analyte preparations, swine sera from model animals and a set of patient samples were measured for cTnI with 4 assays including Abbott Architect, Beckman Access, Ortho Vitros and Siemens Centaur. The measurement results were logarithm-transformed, and the transformed data for patient samples were pairwise analyzed with Deming regression and 95% prediction intervals were calculated for each pair of assays. The commutability of the materials was evaluated by comparing the logarithmic results of the materials with the limits of the intervals. Matrix-related biases were estimated for noncommutable materials. The impact of matrix-related bias on EQA was analyzed and a possible correction for the bias was proposed.Human serum pools were commutable for all assays; purified analyte preparations were commutable for 2 of the 6 assay pairs; commercial control materials and swine sera were all noncommutable; swine sera showed no reactivity to Vitros assay. The matrix-related biases for noncommutable materials ranged from -83% to 944%. Matrix-related biases of the EQA materials caused major abnormal between-assay variations in the EQA program and correction of the biases normalized the variations.Commutability of materials has major impact on the effectiveness of EQA programs for cTnI measurement. Human serum pools prepared from patient samples are commutable and other materials are mostly noncommutable. EQA programs should include at least one human serum pool to allow proper interpretation of

  10. The association of leisure-time physical activity and active commuting with measures of socioeconomic position in a multiethnic population living in the Netherlands: results from the cross-sectional SUNSET study.

    Science.gov (United States)

    de Munter, Jeroen S L; Agyemang, Charles; Brewster, Lizzy M; Stronks, Karien; van Valkengoed, Irene G M

    2012-09-21

    In most European origin populations measures of socioeconomic position are positively associated with leisure time physical activity (LTPA), this is unclear for active commuting. In addition, these associations have scarcely been studied in ethnic minority groups, who often have a high cardiovascular disease risk. Because of the expected public health potential, we assessed the relationship of active commuting and LTPA with measures of socioeconomic position across two large ethnic minority groups in the Netherlands as compared to the European-Dutch population. We included South Asian-Surinamese (n = 370), African-Surinamese (n = 689), and European-Dutch (n = 567) from the cross-sectional population-based SUNSET study (2001-2003). Active commuting and LTPA were assessed by the SQUASH physical activity questionnaire and calculated in square-root-transformed metabolic equivalents of task-hours/week (SQRTMET). Socioeconomic position was indicated by level of education (low/high) and occupational class (low/high). We used age-adjusted linear regression models to assess the association between physical activity and socioeconomic position. Compared to the European-Dutch men, South Asian-Surinamese men engaged in lower levels of commuting activity and LTPA, and South Asian-Surinamese women engaged in lower levels of LTPA than their European-Dutch counterparts. Differences between the African Surinamese and the European-Dutch were small. We observed a positive gradient in active commuting activity for education in European-Dutch men (beta high education was 0.93, 95%CI: 0.45-1.40 SQRTMET higher versus low education), in South Asian-Surinamese men (beta: 0.56, 0.19-0.92), but not in African-Surinamese men (-0.06, -0.45-0.33, p for ethnicity-interaction = 0.002). In women we observed a positive gradient in active commuting activity and occupational class in European-Dutch women, and less strongly in South Asian-Surinamese and African-Surinamese women (p for

  11. Sociodemographic and environmental correlates of active commuting in rural America.

    Science.gov (United States)

    Fan, Jessie X; Wen, Ming; Kowaleski-Jones, Lori

    2015-01-01

    This research investigated participation rates in 3 modes of active commuting (AC) and their sociodemographic and physical environmental correlates in rural America. The 2000 Census supplemented with other data sets were used to analyze AC rates in percentage of workers walking, biking, and taking public transportation to work in 14,209 nonmetropolitan rural tracts identified by RUCA codes, including 4,067 small rural and 10,142 town-micropolitan rural tracts. Sociodemographic and physical environmental variables were correlated with 3 AC modes simultaneously using Seemingly Unrelated Regression for nonmetro rural, and for small rural and town-micropolitan rural separately. The average AC rates in rural tracts were 3.63%, 0.26%, and 0.56% for walking, biking, and public transportation to work, respectively, with small rural tracts having a higher rate of walking but lower rates of biking and public transportation to work than town-micropolitan tracts. In general, better economic well-being was negatively associated with AC but percentage of college-educated was a positive correlate. Population density was positively associated with AC but greenness and proximity to parks were negative correlates. However, significant differences existed for different AC modes, and between small rural and town-micropolitan rural tracts. Sociodemographic factors explained more variance in AC than physical environmental factors but the detailed relationships were complex, varying by AC mode and by degree of rurality. Any strategy to promote AC in rural America needs to be sensitive to the population size of the area and assessed in a comprehensive manner to avoid a "one size fits all" approach. © 2014 National Rural Health Association.

  12. Safe commuting factors from existing guidelines in Malaysia: a review for the construction sector

    Science.gov (United States)

    Sukor, E. S. A.; Suratkon, A.; Mohammad, H.; Yaman, S. K.

    2018-04-01

    The construction industry is a very active and dynamic industry, which proceeding as one of the significant industry that contributing to the country’s economy. Unfortunately, the construction industry has also earned the reputation of being the riskiest industry because of the higher rates of accidents and fatalities. Nevertheless, overwhelming focus by many on the accident in the workplace has shaded the alarming issue of the construction-related commuting accident. As reported by the Malaysia’s Social Security Organisation (SOCSO) in 2016, the number of commuting accidents and the compensations paid is increasing each year, and it is including the construction sector. Aware of the importance of safe commuting, several Malaysian agencies have developed their guidelines specifically for the improvement of such issue. Regrettably, the number of guidelines published does not exemplify the improvement of such issue when the number of commuting accidents is on the rise, especially for the construction sector. Therefore, this preliminary research was conducted to identify the safe commuting factors from the existing guidelines through manual document analysis. The finding shows that there are four (4) major categories namely; (1) driver/human factor, (2) vehicle factor, (3) environment factor, and (4) others. Hence, the research posits for subsequent exploration to ensure strategic implementation of those factors that will benefit the Malaysia’s construction sector.

  13. Gambaran Keharmonisan Commuter Family Pada Anggota Brigade Mobile Kepolisian Daerah Sumatera Utara

    Directory of Open Access Journals (Sweden)

    Marhisar Simatupang

    2017-08-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui gambaran keharmonisan commuter family pada anggota BRIMOB, untuk mengetahui faktor-faktor yang menyebabkan terjadinya keharmonisan commuter family, dan untuk mengetahui strategi dan tahapan pada keluarga commuter family. Penelitian ini dilakukan pada keluarga anggota BRIMOB di Medan. Waktu penelitian dilaksanakan pada Desember 2016 sampai Maret 2017. Teknik pengambil sampel menggunakan teknik snowball sampling. Subjek penelitian berjumlah 2 keluarga anggota BRIMOB yang mengalami penikahan commuter family karena mendapatkan bawah kendali operas (BKO.  Metode penelitian yang digunakan yaitu metode penelitian kualitatif pendekatan deskriptif. Teknik pengumpulan data menggunakan wawancara, observasi dan dokumentasi. Analisis data yang digunakan adalah analisis pada tingkat awal, pada saat pengumpulan data dan setelah selesai pengumpulan data. Hasil dari penelitian ini yaitu kedua keluarga mengaku pertama kali berjauhan dengan keluarga timbul rasa kesepian dan kesedihan. Selain itu istri harus mampu menjalani dua peran sekaligus bagi anak-anaknya yaitu sebagai ayah dan ibu, saat suami melaksanakan tugas. Rasa jenuh dan takut sering dirasakan oleh kedua keluarga. Pada tahap awal mengalami commuter family, kedua keluarga mengaku mengalami ketidak percayaan pada pasangan sehingga menimbulkan masalah dalam keluarga. Masalah yang ada diselesaikan melalui dialog keluarga yang baik. Mendekatkan diri kepada Tuhan menjadi salah satu faktor mempertahankan keharmonisan keluarga. Kunci utama menjaga keharmonisan pada kedua keluarga ini, sehingga tetap bertahan adalah dengan selalu berkomunikasi, saling pengertian, kerja sama, dan membangun rasa kasih sayang. Tidak melakukan hal-hal di luar batas, dan memegang komitmen pernikahan.

  14. Maximum Entropy in Drug Discovery

    Directory of Open Access Journals (Sweden)

    Chih-Yuan Tseng

    2014-07-01

    Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

  15. The Association between Access to Public Transportation and Self-Reported Active Commuting

    DEFF Research Database (Denmark)

    Djurhuus, Sune; Hansen, Henning S; Aadahl, Mette

    2014-01-01

    Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate...... more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation...... and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928). Access to public transportation measures were computed by combining GIS...

  16. Effectiveness and implementation of interventions to increase commuter cycling to school

    DEFF Research Database (Denmark)

    Østergaard, Lars; Støckel, Jan Toftegaard; Andersen, Lars Bo

    2015-01-01

    BACKGROUND: Active transportation to school has been positively associated with various health parameters whereas only sparse evidence exists on risk of injury while commuting to school. This study investigated the overall effectiveness of cycling promotion combined with structural changes...... on cycling to school. METHODS: Interventions at public schools in three different regions in Denmark were based on planned infrastructural changes near schools (e.g. road surface and traffic regulation) and school-motivation for promoting commuter cycling. Participants were pupils from control schools (n...... = 12) or intervention schools (n = 13). All children (n = 2415) from the 4(th) and 5(th) grade were measured at baseline during spring 2010 and at follow-up one year later. RESULTS: No significant differences in commuter cycling were detected in the adjusted analyses comparing the intervention...

  17. Late time acceleration in a non-commutative model of modified cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Malekolkalami, B., E-mail: b.malakolkalami@uok.ac.ir [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of); Atazadeh, K., E-mail: atazadeh@azaruniv.ac.ir [Department of Physics, Azarbaijan Shahid Madani University, 53714-161, Tabriz (Iran, Islamic Republic of); Vakili, B., E-mail: b-vakili@iauc.ac.ir [Department of Physics, Central Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2014-12-12

    We investigate the effects of non-commutativity between the position–position, position–momentum and momentum–momentum of a phase space corresponding to a modified cosmological model. We show that the existence of such non-commutativity results in a Moyal Poisson algebra between the phase space variables in which the product law between the functions is of the kind of an α-deformed product. We then transform the variables in such a way that the Poisson brackets between the dynamical variables take the form of a usual Poisson bracket but this time with a noncommutative structure. For a power law expression for the function of the Ricci scalar with which the action of the gravity model is modified, the exact solutions in the commutative and noncommutative cases are presented and compared. In terms of these solutions we address the issue of the late time acceleration in cosmic evolution.

  18. Bus commuters' coping strategies and anxiety from terrorism: an example of the Israeli experience.

    Science.gov (United States)

    Gidron, Y; Gal, R; Zahavi, S

    1999-01-01

    This study examined the use of three coping strategies: (1) emotion-focused coping (calming-distraction); (2) problem-focused coping (checking-behavior); and (3) denial (reduced perceived vulnerability), and their relationship to anxiety from terrorism among 50 Israeli bus commuters. Their mean age was 31 years (60% females). Commuting frequency was negatively correlated, and problem-focused coping was positively correlated with anxiety from terrorism. Ratios of problem-focused coping/denial and of problem-focused/emotion-focused coping were each positively correlated with anxiety from terrorism. Coping ratios accounted for 15% of the variance in anxiety from terrorism, after considering commuting frequency. Combining minimal problem-focused preventative acts with distraction and reduced perceived vulnerability may be beneficial.

  19. Almost commuting self-adjoint matrices: The real and self-dual cases

    Science.gov (United States)

    Loring, Terry A.; Sørensen, Adam P. W.

    2016-08-01

    We show that a pair of almost commuting self-adjoint, symmetric matrices is close to a pair of commuting self-adjoint, symmetric matrices (in a uniform way). Moreover, we prove that the same holds with self-dual in place of symmetric and also for paths of self-adjoint matrices. Since a symmetric, self-adjoint matrix is real, we get a real version of Huaxin Lin’s famous theorem on almost commuting matrices. Similarly, the self-dual case gives a version for matrices over the quaternions. To prove these results, we develop a theory of semiprojectivity for real C*-algebras and also examine various definitions of low-rank for real C*-algebras.

  20. Anisotropic harmonic oscillator, non-commutative Landau problem and exotic Newton-Hooke symmetry

    International Nuclear Information System (INIS)

    Alvarez, Pedro D.; Gomis, Joaquim; Kamimura, Kiyoshi; Plyushchay, Mikhail S.

    2008-01-01

    We investigate the planar anisotropic harmonic oscillator with explicit rotational symmetry as a particle model with non-commutative coordinates. It includes the exotic Newton-Hooke particle and the non-commutative Landau problem as special, isotropic and maximally anisotropic, cases. The system is described by the same (2+1)-dimensional exotic Newton-Hooke symmetry as in the isotropic case, and develops three different phases depending on the values of the two central charges. The special cases of the exotic Newton-Hooke particle and non-commutative Landau problem are shown to be characterized by additional, so(3) or so(2,1) Lie symmetry, which reflects their peculiar spectral properties

  1. Regional differences in commuting activities of inhabitants in the Tokyo metropolitan suburb

    Directory of Open Access Journals (Sweden)

    Masaki Kawase

    2004-12-01

    Full Text Available The purpose of this study is to elucidate gender differences and regional differences of co-mmuting activities by inhabitants in Japanese metropolitan suburbs. I found the different parts by districts in the metropolitan suburb. Regional factors cause gender differences in commuting activities and result in regional differences: In residential areas, inhabitants who work in metropolitan centers occupy much of the population. In older built-up areas, there are many “local” persons. In rural areas, motorization is progressing because access to rail-roads has been inconvenient. These regional factors influence the behavioral characteristics of commuting by married men, married women, never married men and never married women.

  2. Late time acceleration in a non-commutative model of modified cosmology

    International Nuclear Information System (INIS)

    Malekolkalami, B.; Atazadeh, K.; Vakili, B.

    2014-01-01

    We investigate the effects of non-commutativity between the position–position, position–momentum and momentum–momentum of a phase space corresponding to a modified cosmological model. We show that the existence of such non-commutativity results in a Moyal Poisson algebra between the phase space variables in which the product law between the functions is of the kind of an α-deformed product. We then transform the variables in such a way that the Poisson brackets between the dynamical variables take the form of a usual Poisson bracket but this time with a noncommutative structure. For a power law expression for the function of the Ricci scalar with which the action of the gravity model is modified, the exact solutions in the commutative and noncommutative cases are presented and compared. In terms of these solutions we address the issue of the late time acceleration in cosmic evolution

  3. A cost analysis for the implementation of commonality in the family of commuter airplanes, revised

    Science.gov (United States)

    Creighton, Tom; Haddad, Rafael; Hendrich, Louis; Hensley, Doug; Morgan, Louise; Russell, Mark; Swift, Jerry

    1987-01-01

    The acquisition costs determined for the NASA family of commute airplanes are presented. The costs of the baseline designs are presented along with the calculated savings due to the commonality in the family. A sensitivity study is also presented to show the major drivers in the acquisition cost calculations. The baseline costs are calculated with the Nicolai method. A comparison is presented of the estimated costs for the commuter family with the actual price for existing commuters. The cost calculations for the engines and counter-rotating propellers are reported. The effects of commonality on acquisition costs are calculated. The sensitivity calculations of the cost to various costing parameters are shown. The calculations for the direct operating costs, with and without commonality are presented.

  4. An algebraic scheme associated with the non-commutative KP hierarchy and some of its extensions

    International Nuclear Information System (INIS)

    Dimakis, Aristophanes; Mueller-Hoissen, Folkert

    2005-01-01

    A well-known ansatz ('trace method') for soliton solutions turns the equations of the (non-commutative) KP hierarchy, and those of certain extensions, into families of algebraic sum identities. We develop an algebraic formalism, in particular involving a (mixable) shuffle product, to explore their structure. More precisely, we show that the equations of the non-commutative KP hierarchy and its extension (xncKP) in the case of a Moyal-deformed product, as derived in previous work, correspond to identities in this algebra. Furthermore, the Moyal product is replaced by a more general associative product. This leads to a new even more general extension of the non-commutative KP hierarchy. Relations with Rota-Baxter algebras are established

  5. Commuting to work: RN travel time to employment in rural and urban areas.

    Science.gov (United States)

    Rosenberg, Marie-Claire; Corcoran, Sean P; Kovner, Christine; Brewer, Carol

    2011-02-01

    To investigate the variation in average daily travel time to work among registered nurses (RNs) living in urban, suburban, and rural areas. We examine how travel time varies across RN characteristics, job setting, and availability of local employment opportunities. Descriptive statistics and linear regression using a 5% sample from the 2000 Census and a longitudinal survey of newly licensed RNs (NLRN). Travel time for NLRN respondents was estimated using geographic information systems (GIS) software. In the NLRN, rural nurses and those living in small towns had significantly longer average commute times. Young married RNs and RNs with children also tended to have longer commute times, as did RNs employed by hospitals. The findings indicate that travel time to work varies significantly across locale types. Further research is needed to understand whether and to what extent lengthy commute times impact RN workforce needs in rural and urban areas.

  6. Linear deformations of discrete groups and constructions of multivalued groups

    International Nuclear Information System (INIS)

    Yagodovskii, Petr V

    2000-01-01

    We construct deformations of discrete multivalued groups described as special deformations of their group algebras in the class of finite-dimensional associative algebras. We show that the deformations of ordinary groups producing multivalued groups are defined by cocycles with coefficients in the group algebra of the original group and obtain classification theorems on these deformations. We indicate a connection between the linear deformations of discrete groups introduced in this paper and the well-known constructions of multivalued groups. We describe the manifold of three-dimensional associative commutative algebras with identity element, fixed basis, and a constant number of values. The group algebras of n-valued groups of order three (three-dimensional n-group algebras) form a discrete set in this manifold

  7. Motivations for active commuting: a qualitative investigation of the period of home or work relocation.

    Science.gov (United States)

    Jones, Caroline H D; Ogilvie, David

    2012-09-11

    Promoting walking or cycling to work (active commuting) could help to increase population physical activity levels. According to the habit discontinuity and residential self-selection hypotheses, moving home or workplace is a period when people (re)assess, and may be more likely to change, their travel behavior. Research in this area is dominated by the use of quantitative research methods, but qualitative approaches can provide in-depth insight into the experiences and processes of travel behavior change. This qualitative study aimed to explore experiences and motivations regarding travel behavior around the period of relocation, in an effort to understand how active commuting might be promoted more effectively. Participants were recruited from the Commuting and Health in Cambridge study cohort in the UK. Commuters who had moved home, workplace or both between 2009 and 2010 were identified, and a purposive sample was invited to participate in semi-structured interviews regarding their experiences of, and travel behavior before and after, relocating. A grounded theory approach was taken to analysis. Twenty-six commuters participated. Participants were motivated by convenience, speed, cost and reliability when selecting modes of travel for commuting. Physical activity was not a primary motivation, but incidental increases in physical activity were described and valued in association with active commuting, the use of public transport and the use of park-and-ride facilities. Emphasizing and improving the relative convenience, cost, speed and reliability of active commuting may be a more promising approach to promoting its uptake than emphasizing the health benefits, at least around the time of relocation. Providing good quality public transport and free car parking within walking or cycling distance of major employment sites may encourage the inclusion of active travel in the journey to work, particularly for people who live too far from work to walk or cycle the

  8. Evaluating In-Car Movements in the Design of Mindful Commute Interventions: Exploratory Study.

    Science.gov (United States)

    Paredes, Pablo Enrique; Hamdan, Nur Al-Huda; Clark, Dav; Cai, Carrie; Ju, Wendy; Landay, James A

    2017-12-04

    The daily commute could be a right moment to teach drivers to use movement or breath towards improving their mental health. Long commutes, the relevance of transitioning from home to work, and vice versa and the privacy of commuting by car make the commute an ideal scenario and time to perform mindful exercises safely. Whereas driving safety is paramount, mindful exercises might help commuters decrease their daily stress while staying alert. Increasing vehicle automation may present new opportunities but also new challenges. This study aimed to explore the design space for movement-based mindful interventions for commuters. We used qualitative analysis of simulated driving experiences in combination with simple movements to obtain key design insights. We performed a semistructured viability assessment in 2 parts. First, a think-aloud technique was used to obtain information about a driving task. Drivers (N=12) were given simple instructions to complete movements (configural or breath-based) while engaged in either simple (highway) or complex (city) simulated urban driving tasks using autonomous and manual driving modes. Then, we performed a matching exercise where participants could experience vibrotactile patterns from the back of the car seat and map them to the prior movements. We report a summary of individual perceptions concerning different movements and vibrotactile patterns. Beside describing situations within a drive when it may be more likely to perform movement-based interventions, we also describe movements that may interfere with driving and those that may complement it well. Furthermore, we identify movements that could be conducive to a more relaxing commute and describe vibrotactile patterns that could guide such movements and exercises. We discuss implications for design such as the influence of driving modality on the adoption of movement, need for personal customization, the influence that social perception has on participants, and the potential

  9. Implications of an arithmetical symmetry of the commutant for modular invariants

    International Nuclear Information System (INIS)

    Ruelle, P.; Thiran, E.; Weyers, J.

    1993-01-01

    We point out the existence of an arithmetical symmetry for the commutant of the modular matrices S and T. This symmetry holds for all affine simple Lie algebras at all levels and implies the equality of certain coefficients in any modular invariant. Particularizing to SU(3) k , we classify the modular invariant partition functions when k+3 is an integer coprime with 6 and when it is a power of either 2 or 3. Our results imply that no detailed knowledge of the commutant is needed to undertake a classification of all modular invariants. (orig.)

  10. Non-commutative phase space and its space-time symmetry

    International Nuclear Information System (INIS)

    Li Kang; Dulat Sayipjamal

    2010-01-01

    First a description of 2+1 dimensional non-commutative (NC) phase space is presented, and then we find that in this formulation the generalized Bopp's shift has a symmetric representation and one can easily and straightforwardly define the star product on NC phase space. Then we define non-commutative Lorentz transformations both on NC space and NC phase space. We also discuss the Poincare symmetry. Finally we point out that our NC phase space formulation and the NC Lorentz transformations are applicable to any even dimensional NC space and NC phase space. (authors)

  11. Some homological properties of skew PBW extensions arising in non-commutative algebraic geometry

    Directory of Open Access Journals (Sweden)

    Lezama Oswaldo

    2017-06-01

    Full Text Available In this short paper we study for the skew PBW (Poincar-Birkhoff-Witt extensions some homological properties arising in non-commutative algebraic geometry, namely, Auslander-Gorenstein regularity, Cohen-Macaulayness and strongly noetherianity. Skew PBW extensions include a considerable number of non-commutative rings of polynomial type such that classical PBW extensions, quantum polynomial rings, multiplicative analogue of the Weyl algebra, some Sklyanin algebras, operator algebras, diffusion algebras, quadratic algebras in 3 variables, among many others. Parametrization of the point modules of some examples is also presented.

  12. On the necessity and sufficiency of local commutativity for causality in quantum mechanics

    International Nuclear Information System (INIS)

    Muynck, W.M. de.

    1984-01-01

    This thesis contributes to the resolution of the question whether quantum mechanics admits an objectivistic interpretation if the description is restricted to the phenomenalistic domain of the quantum mechanical observables. Without touching the realism-phenomenalism dichotomy, this thesis investigates the possibility to disregard the influence of the measurement interaction on the qm measuring results. In the first part, the measuring process is studied and its influence on the objectivity of measuring results. The measurement of a local observable is interpreted as a local operation. Its local commutativity is a necessary condition for macrocausality. In the second part the converse question is studied, viz. Whether local commutativity is sufficient for macrocausality. (Auth.)

  13. Silicon-controlled-rectifier square-wave inverter with protection against commutation failure

    Science.gov (United States)

    Birchenough, A. G.

    1971-01-01

    The square-wave SCR inverter that was designed, built, and tested includes a circuit to turn off the inverter in case of commutation failure. The basic power stage is a complementary impulse-commutated parallel inverter consisting of only six components. The 400-watt breadboard was tested while operating at + or - 28 volts, and it had a peak efficiency of 95.5 percent at 60 hertz and 91.7 percent at 400 hertz. The voltage regulation for a fixed input was 3 percent at 60 hertz. An analysis of the operation and design information is included.

  14. A new inverter topology using GTO commutation. [Gate Turn Off thyristor

    Science.gov (United States)

    Rippel, W. E.

    1983-01-01

    A new N-phase, forced commutated bridge inverter topology has been developed wherein a single Gate Turn Off Thyristor (GTO) is used to commutate each of 2N main Thyristors (SCRs). Since, for most applications, the primary loss mechanism is the SCR forward drop, very high efficiencies are possible. Compared with conventional pure SCR and pure GTO inverters, cost per kW is lower - in the former case due to the large cost differential between GTOs and SCRs. Other advantages of the new inverter include high power density, low switching losses and stresses, modulation flexibility and amenability to high voltage and high frequency operation.

  15. On the linearization of nonlinear supersymmetry based on the commutator algebra

    Energy Technology Data Exchange (ETDEWEB)

    Tsuda, Motomu, E-mail: tsuda@sit.ac.jp

    2017-01-10

    We discuss a linearization procedure of nonlinear supersymmetry (NLSUSY) based on the closure of the commutator algebra for variations of functionals of Nambu–Goldstone fermions and their derivative terms under NLSUSY transformations in Volkov–Akulov NLSUSY theory. In the case of a set of bosonic and fermionic functionals, which leads to (massless) vector linear supermultiplets, we explicitly show that general linear SUSY transformations of basic components defined from those functionals are uniquely determined by examining the commutation relation in the NLSUSY theory.

  16. Existence and density theorems for stochastic maps on commutative C*-algebras

    International Nuclear Information System (INIS)

    Alberti, P.M.; Uhlmann, A.

    1979-06-01

    Theorems are presented on the structure of stochastic and normalized positive linear maps over commutative C*-algebras. It is shown how strongly the solution of the n-tupel problem for stochastic maps relates to the fact that stochastic maps of finite rank are weakly dense within stochastic maps in case of a commutative C*-algebra. A new proof of the density theorem is given and (besides the solution of the n-tupel problem) results are derived concerning the extremal maps of certain convex subsets which are weakly dense. All stated facts suggest application in statistical physics (algebraic approach), especially concerning questions around evolution of classical systems. (author)

  17. Commuter Air Carrier Symposium (2nd) January 15-16, 1981 .

    Science.gov (United States)

    1981-01-16

    AJAN B1 UNCLASSIFIED FAA-ASF-300-81-b NL J , E EEEIEEEI mIhIhhEIhEEEI EEIhIhEIhEEIhE IIIIIIIIIIIIIu IIIEII~lElI Second ot Denrpotmn A Fodeol~(ntiorpom...Kathryn B. Creedy AVMARK, Inc. Commuter Air 1120 19th St., N.W. 4827 Rugby Ave. Washington, D.C. 20002 Bethesda, MD 20008 J. Keith Carter Albert J...Commuter Air Piper Aircraft Corp. 4823 Rugby Rd. 3000 Medulla Rd. Bethesda, MD 20014 Lakeland, Florida 33803 -Calvin Davison ’ Crowell & Moring 1100

  18. Motivations for active commuting: a qualitative investigation of the period of home or work relocation

    Directory of Open Access Journals (Sweden)

    Jones Caroline HD

    2012-09-01

    Full Text Available Abstract Background Promoting walking or cycling to work (active commuting could help to increase population physical activity levels. According to the habit discontinuity and residential self-selection hypotheses, moving home or workplace is a period when people (reassess, and may be more likely to change, their travel behavior. Research in this area is dominated by the use of quantitative research methods, but qualitative approaches can provide in-depth insight into the experiences and processes of travel behavior change. This qualitative study aimed to explore experiences and motivations regarding travel behavior around the period of relocation, in an effort to understand how active commuting might be promoted more effectively. Methods Participants were recruited from the Commuting and Health in Cambridge study cohort in the UK. Commuters who had moved home, workplace or both between 2009 and 2010 were identified, and a purposive sample was invited to participate in semi-structured interviews regarding their experiences of, and travel behavior before and after, relocating. A grounded theory approach was taken to analysis. Results Twenty-six commuters participated. Participants were motivated by convenience, speed, cost and reliability when selecting modes of travel for commuting. Physical activity was not a primary motivation, but incidental increases in physical activity were described and valued in association with active commuting, the use of public transport and the use of park-and-ride facilities. Conclusions Emphasizing and improving the relative convenience, cost, speed and reliability of active commuting may be a more promising approach to promoting its uptake than emphasizing the health benefits, at least around the time of relocation. Providing good quality public transport and free car parking within walking or cycling distance of major employment sites may encourage the inclusion of active travel in the journey to work

  19. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    60, No. 3. — journal of. March 2003 physics pp. 415–422. Maximum stellar iron core mass. F W GIACOBBE. Chicago Research Center/American Air Liquide ... iron core compression due to the weight of non-ferrous matter overlying the iron cores within large .... thermal equilibrium velocities will tend to be non-relativistic.

  20. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore. 11 refs., 4 figs

  1. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore

  2. A portable storage maximum thermometer

    International Nuclear Information System (INIS)

    Fayart, Gerard.

    1976-01-01

    A clinical thermometer storing the voltage corresponding to the maximum temperature in an analog memory is described. End of the measurement is shown by a lamp switch out. The measurement time is shortened by means of a low thermal inertia platinum probe. This portable thermometer is fitted with cell test and calibration system [fr

  3. Rush hour commuting in the Netherlands : Gender-specific household activities and personal attitudes towards responsibility sharing.

    NARCIS (Netherlands)

    Oakil, A.T.; Nijland, E.W.L.

    2016-01-01

    Apart from work-hour commitments, rush hour commuting is dependent on household activities and responsibilities. It can also be gender specific when gender differences in performing household activities prevail. To that end, this study investigates gender differences in rush hour commuting in

  4. Rush hour commuting in the Netherlands: Gender-specific household activities and personal attitudes towards responsibility sharing

    NARCIS (Netherlands)

    Oakil, A.T.M.; Nijland, E.W.L.; Dijst, M.

    2016-01-01

    Apart from work-hour commitments, rush hour commuting is dependent on household activities and responsibilities. It can also be gender specific when gender differences in performing household activities prevail. To that end, this study investigates gender differences in rush hour commuting in

  5. Covariantisation of the Boulware-Deger representation for equal-time commutators of the energy-momentum tensor

    International Nuclear Information System (INIS)

    Indukaev, C.V.; Shirokov, Yu.M.

    1975-01-01

    A complete set of restrictions on equal-time commutators of the energy-momentum tensor is derived. The restrictions obtained represent the consequences of the conditions of relativistic covariance and spectality. The technoloque developed is exemplified on a simple system of energy-momentum tensor equal-time commutators

  6. 76 FR 65769 - Application of Friendship Airways, Inc. d/b/a Yellow Air Taxi for Commuter Authority

    Science.gov (United States)

    2011-10-24

    ... DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Friendship Airways, Inc. d/b/a Yellow Air Taxi for Commuter Authority AGENCY: Department of Transportation. ACTION: Notice of Order to... issued to Friendship Airways, Inc. d/b/a Yellow Air Taxi and deny its application to resume commuter...

  7. The Impact of Employer Attitude to Green Commuting Plans on Reducing Car Driving: A Mixed Method Analysis

    Directory of Open Access Journals (Sweden)

    Chuan Ding

    2014-04-01

    Full Text Available Reducing car trips and promoting green commuting modes are generally considered important solutions to reduce the increase of energy consumption and transportation CO2 emissions. One potential solution for alleviating transportation CO2 emissions has been to identify a role for the employer through green commuter programs. This paper offers an approach to assess the effects of employer attitudes towards green commuting plans on commuter mode choice and the intermediary role car ownership plays in the mode choice decision process. A mixed method which extends the traditional discrete choice model by incorporating latent variables and mediating variables with a structure equation model was used to better understand the commuter mode choice behaviour. The empirical data were selected from Washington-Baltimore Regional Household Travel Survey in 2007-2008, including all the trips from home to workplace during the morning hours. The model parameters were estimated using the simultaneous estimation approach and the integrated model turns out to be superior to the traditional multinomial logit (MNL model accounting for the impact of employer attitudes towards green commuting. The direct and indirect effects of socio-demographic attributes and employer attitudes towards green commuting were estimated. Through the structural equation modelling with mediating variable, this approach confirmed the intermediary nature of car ownership in the choice process. The results found in this paper provide helpful information for transportation and planning policymakers to test the transportation and planning policies effects and encourage green commuting reducing transportation CO2 emissions.

  8. Mood during commute in the Netherlands : What way of travel feels best for what kind of people?

    NARCIS (Netherlands)

    S. Lancée (Sascha); R. Veenhoven (Ruut); M.J. Burger (Martijn)

    2017-01-01

    markdownabstractQuestion How happy we are depends partly on how we live our life and part of our way of life is the commute between home and work. In this context we are faced with the question of how much time spent on commuting is optimal happiness wise, and what means of transportation. Since

  9. Substitution between Working at Home and Out-of-Home: The Role of ICT and Commuting Costs

    NARCIS (Netherlands)

    de Graaff, T.; Rietveld, P.

    2007-01-01

    This paper analyzes the trade-off between working at home and out-of-home, ICT and commuting time. To this end, we develop a microeconomic demand system, which explicitly incorporates both time and income constraints. Commuting time is considered as the price to be paid for working out-of-home and a

  10. Neutron spectra unfolding with maximum entropy and maximum likelihood

    International Nuclear Information System (INIS)

    Itoh, Shikoh; Tsunoda, Toshiharu

    1989-01-01

    A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

  11. Quantum E(2) group and and its Pontryagin dual

    International Nuclear Information System (INIS)

    Woronowicz, S.L.

    1991-01-01

    The quantum deformation of the group of motions of the plane and its Pontryagin dual are described in detail. It is shown that the Pontryagin dual is a quantum deformation of the group of transformations of the plane generated by translations and dilations. An explicit expression for the unitary bicharacter describing the Pontryagin duality is found. The Heisenberg commutation relations are written down. (orig.)

  12. The probability that a pair of group elements is autoconjugate

    Indian Academy of Sciences (India)

    [1] Alghamdi A M and Russo F G, A generalization of the probability that the commutator of two group elements is equal to a given element, Bull. Iranian Math. Soc. 38 (2012). 973–986. [2] Blackburn S R, Britnell J R and Wildon M, The probability that a pair of elements of a finite group are conjugate, J. London Math. Soc.

  13. On Maximum Entropy and Inference

    Directory of Open Access Journals (Sweden)

    Luigi Gresele

    2017-11-01

    Full Text Available Maximum entropy is a powerful concept that entails a sharp separation between relevant and irrelevant variables. It is typically invoked in inference, once an assumption is made on what the relevant variables are, in order to estimate a model from data, that affords predictions on all other (dependent variables. Conversely, maximum entropy can be invoked to retrieve the relevant variables (sufficient statistics directly from the data, once a model is identified by Bayesian model selection. We explore this approach in the case of spin models with interactions of arbitrary order, and we discuss how relevant interactions can be inferred. In this perspective, the dimensionality of the inference problem is not set by the number of parameters in the model, but by the frequency distribution of the data. We illustrate the method showing its ability to recover the correct model in a few prototype cases and discuss its application on a real dataset.

  14. 41 CFR 302-7.14 - Are there any disadvantages to using the commuted rate method for transporting HHG, PBP&E and...

    Science.gov (United States)

    2010-07-01

    ... disadvantages to using the commuted rate method for transporting HHG, PBP&E and temporary storage? 302-7.14... disadvantages to using the commuted rate method for transporting HHG, PBP&E and temporary storage? Yes. The disadvantages to using the commuted rate method for transporting HHG, PBP&E and temporary storage are that the...

  15. Maximum Water Hammer Sensitivity Analysis

    OpenAIRE

    Jalil Emadi; Abbas Solemani

    2011-01-01

    Pressure waves and Water Hammer occur in a pumping system when valves are closed or opened suddenly or in the case of sudden failure of pumps. Determination of maximum water hammer is considered one of the most important technical and economical items of which engineers and designers of pumping stations and conveyance pipelines should take care. Hammer Software is a recent application used to simulate water hammer. The present study focuses on determining significance of ...

  16. Homological functor of a torsion free crystallographic group of dimension five with a nonabelian point group

    Science.gov (United States)

    Ting, Tan Yee; Idrus, Nor'ashiqin Mohd.; Masri, Rohaidah; Sarmin, Nor Haniza; Hassim, Hazzirah Izzati Mat

    2014-06-01

    Torsion free crystallographic groups, called Bieberbach groups, appear as fundamental groups of compact, connected, flat Riemannian manifolds and have many interesting properties. New properties of the group can be obtained by, not limited to, exploring the groups and by computing their homological functors such as nonabelian tensor squares, the central subgroup of nonabelian tensor squares, the kernel of the mapping of nonabelian tensor squares of a group to the group and many more. In this paper, the homological functor, J(G) of a centerless torsion free crystallographic group of dimension five with a nonabelian point group which is a dihedral point group is computed using commutator calculus.

  17. LCLS Maximum Credible Beam Power

    International Nuclear Information System (INIS)

    Clendenin, J.

    2005-01-01

    The maximum credible beam power is defined as the highest credible average beam power that the accelerator can deliver to the point in question, given the laws of physics, the beam line design, and assuming all protection devices have failed. For a new accelerator project, the official maximum credible beam power is determined by project staff in consultation with the Radiation Physics Department, after examining the arguments and evidence presented by the appropriate accelerator physicist(s) and beam line engineers. The definitive parameter becomes part of the project's safety envelope. This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5 the beam through the matching section and injected into Linac-1 is discussed

  18. Zipf's law, power laws and maximum entropy

    International Nuclear Information System (INIS)

    Visser, Matt

    2013-01-01

    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines—from astronomy to demographics to software structure to economics to linguistics to zoology, and even warfare. A recent model of random group formation (RGF) attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present paper I argue that the specific cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified. (paper)

  19. Kornwell-Norton moments and electromagnetic current commutator expansion on light cone

    International Nuclear Information System (INIS)

    Vitsorek, Eh.; Motts, G.

    1975-01-01

    Relations have been obtained between the asymptotic behaviour of moments and the commutator of electromagnetic currents on the light cone. The existence of the operator decomposition on the light cone and the applicability of Fourier transformation to it has not been assumed

  20. GreenCommute: the Nortel Networks Transportation Demand Management (TDM) Program

    Energy Technology Data Exchange (ETDEWEB)

    Lewinson, S [Transport Canada, Ottawa, ON (Canada)

    2001-07-01

    The structural elements and the environmental benefits to the employer, the employees and the community of the 'GreenCommute' program, designed by Nortel Networks and negotiated with the City of Ottawa, the National Capital Commission, and OC Transpo (the regional transportation authority), are described. The program is designed to mitigate congestion, minimize infrastructure requirements, minimize parking area requirements and to act as a pilot program for the region. The Program was designed after extensive consultation with employees. Some 87 per cent of those who responded (40 per cent response rate) expressed willingness to try a commuting alternative, including walking, cycling and car-pooling. A program is complete with a comprehensive 'GreenCoummute' website for up-to-date information, an efficient ride-matching system based on postal code, highly visible support for alternative commuting including lighted signage for all walking, cycling, transit and car-pooling information at the main entrance to the Nortel Campus, and a one-month free pass for transit riders from OC Transpo. Mid-year 2000 results indicated that the GreenCommute program was well on its way to achieve targeted objectives for 2000. Experience to-date indicate that the program is well appreciated by employees, but there is an ongoing need to market the program by varied promotion and positive messaging.

  1. Gravitational amplitudes in black hole evaporation: the effect of non-commutative geometry

    International Nuclear Information System (INIS)

    Grezia, Elisabetta Di; Esposito, Giampiero; Miele, Gennaro

    2006-01-01

    Recent work in the literature has studied the quantum-mechanical decay of a Schwarzschild-like black hole, formed by gravitational collapse, into almost-flat spacetime and weak radiation at a very late time. The relevant quantum amplitudes have been evaluated for bosonic and fermionic fields, showing that no information is lost in collapse to a black hole. On the other hand, recent developments in non-commutative geometry have shown that, in general relativity, the effects of non-commutativity can be taken into account by keeping the standard form of the Einstein tensor on the left-hand side of the field equations and introducing a modified energy-momentum tensor as a source on the right-hand side. The present paper, relying on the recently obtained non-commutativity effect on a static, spherically symmetric metric, considers from a new perspective the quantum amplitudes in black hole evaporation. The general relativity analysis of spin-2 amplitudes is shown to be modified by a multiplicative factor F depending on a constant non-commutativity parameter and on the upper limit R of the radial coordinate. Limiting forms of F are derived which are compatible with the adiabatic approximation here exploited. Approximate formulae for the particle emission rate are also obtained within this framework

  2. Charge and/or spin limits for black holes at a non-commutative scale

    Indian Academy of Sciences (India)

    Biplab Paik

    2017-07-12

    Jul 12, 2017 ... momentum (J) of a generalized black hole of mass M to be bounded by the condition Q2 + (J/M)2 ≤ M2, whereas ... in the classical commutative space–time background is ... scale of the Standard Model of particle physics and.

  3. A Note on UV/IR Mixing and Non-Commutative Instanton Calculus

    CERN Document Server

    Bichl, A A

    2003-01-01

    We estimate the instanton-induced vacuum energy in non-commutative U(1) Yang-Mills theory in four dimensions. In the dilute gas approximation, it is found to be plagued by infrared divergences, as a result of UV/IR mixing.

  4. Covariance of time-ordered products implies local commutativity of fields

    International Nuclear Information System (INIS)

    Greenberg, O.W.

    2006-01-01

    We formulate Lorentz covariance of a quantum field theory in terms of covariance of time-ordered products (or other Green's functions). This formulation of Lorentz covariance implies spacelike local commutativity or anticommutativity of fields, sometimes called microscopic causality or microcausality. With this formulation microcausality does not have to be taken as a separate assumption

  5. Tertiary Student Attitudes to Bicycle Commuting in a Regional Australian University

    Science.gov (United States)

    Whannell, Patricia; Whannell, Robert; White, Richard

    2012-01-01

    Purpose: The purpose of this paper is to provide executive management at a regional university with empirical data to justify, or otherwise, a substantial outlay of funds to support bicycle commuting as a viable strategy for the reduction of traffic congestion. Design/methodology/approach: A custom designed questionnaire was completed by 270…

  6. A dynamic parking charge optimal control model under perspective of commuters' evolutionary game behavior

    Science.gov (United States)

    Lin, XuXun; Yuan, PengCheng

    2018-01-01

    In this research we consider commuters' dynamic learning effect by modeling the trip mode choice behavior from a new perspective of dynamic evolutionary game theory. We explore the behavior pattern of different types of commuters and study the evolution path and equilibrium properties under different traffic conditions. We further establish a dynamic parking charge optimal control (referred to as DPCOC) model to alter commuters' trip mode choice while minimizing the total social cost. Numerical tests show. (1) Under fixed parking fee policy, the evolutionary results are completely decided by the travel time and the only method for public transit induction is to increase the parking charge price. (2) Compared with fixed parking fee policy, DPCOC policy proposed in this research has several advantages. Firstly, it can effectively turn the evolutionary path and evolutionary stable strategy to a better situation while minimizing the total social cost. Secondly, it can reduce the sensitivity of trip mode choice behavior to traffic congestion and improve the ability to resist interferences and emergencies. Thirdly, it is able to control the private car proportion to a stable state and make the trip behavior more predictable for the transportation management department. The research results can provide theoretical basis and decision-making references for commuters' mode choice prediction, dynamic setting of urban parking charge prices and public transit induction.

  7. Multicenter evaluation of the commutability of a potential reference material for harmonization of enzyme activities

    NARCIS (Netherlands)

    Scharnhorst, V.; Apperloo, J.J.; Baadenhuijsen, H.; Vader, H.L.

    2014-01-01

    Standardization of laboratory results allows for the use of common reference intervals and can be achieved via calibration of field methods with secondary reference materials. These harmonization materials should be commutable, i.e., they produce identical numerical results independent of assay

  8. A geography of moral hazard: sources and sinks of motor-vehicle commuting externalities.

    Science.gov (United States)

    Yiannakoulias, Niko; Bland, Widmer; Scott, Darren M

    2014-09-01

    Motor-vehicles are responsible for harms to health that are not directly experienced by individual drivers - such as air pollution and risk of injury to pedestrians. In addition to their direct effects on health, these harms also represent a moral hazard since drivers are not required to consider their effects as part of their decision to drive. We describe an approach for estimating sources of motor-vehicle commuter externalities as a means of understanding the geography of moral hazard, and in particular, the spatial displacement of negative health externalities associated with motor-vehicle commuting. This approach models motor-vehicle commuter traffic flow by trip origin for small geographic areas within the City of Toronto, Ontario. We find that most health-related externalities associated with motor-vehicle commuters are not locally generated, with a large share coming from outside Toronto. Low income is associated with externalities originating outside the municipal boundary, but not with locally sourced externalities. We discuss the impact of geographical moral hazard on the agency of citizens as well as policy options aimed at addressing motor-vehicle externalities. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Network Analysis of Commuting Flows: A Comparative Static Approach to German Data

    NARCIS (Netherlands)

    Patuelli, R.; Reggiani, A.; Nijkamp, P.; Bade, F-J

    2007-01-01

    The analysis of complex networks has recently received considerable attention. The work by Albert and Barabási presented a research challenge to network analysis, that is, growth of the network. The present paper offers a network analysis of the spatial commuting network in Germany. First, we study

  10. Changes to urban form and commuting patterns: trends in two Danish city regions

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick

    2015-01-01

    This paper compares indicators of polycentricity in a monocentric (MUR) and a polycentric urban region (PUR) in Denmark at two points in time (1982 and 2002). It describes how population, jobs and commuting indicators of polycentricity develop and interact over time. Both the MUR and the PUR tend...

  11. Self-Commutators of Composition Operators with Monomial Symbols on the Dirichlet Space

    Directory of Open Access Journals (Sweden)

    A. Abdollahi

    2011-01-01

    Full Text Available Let (=,∈, for some positive integer and the composition operator on the Dirichlet space induced by . In this paper, we completely determine the point spectrum, spectrum, essential spectrum, and essential norm of the operators ∗,∗ and self-commutators of , which expose that the spectrum and point spectrum coincide. We also find the eigenfunctions of the operators.

  12. An Analysis of the Relationship between Distance from Campus and GPA of Commuter Students

    Science.gov (United States)

    Nelson, Danielle; Misra, Kaustav; Sype, Gail E.; Mackie, Wayne

    2016-01-01

    A variety of factors influence a student's ability to succeed in college and complete a degree program. Students who live on-campus, at least during their freshman year, have been shown to be more likely to complete their degrees than are students who live off-campus. Students who are commuters may have more demands on their time and may have…

  13. What affects commute mode choice: Physical neighborhood structure or preferences toward neighborhoods?

    NARCIS (Netherlands)

    Schwanen, T.; Mokhtarian, P.L.

    2005-01-01

    The academic literature on the impact of urban form on travel behavior has increasingly recognized that residential location choice and travel choices may be interconnected. We contribute to the understanding of this interrelation by studying to what extent commute mode choice differs by

  14. Influence of Water and Mineral Oil on the Leaks in Satellite Motor Commutation Unit Clearances

    Directory of Open Access Journals (Sweden)

    Śliwiński Paweł

    2017-09-01

    Full Text Available The article describes the flow rates of mineral oil and water flowing, as working media, through the commutation unit of a hydraulic satellite motor. It is demonstrated that geometrical dimensions of commutation unit clearances change as a function of the machine shaft rotation angle. Methods for measuring the rate of this flow and the pressure in the working chamber are presented. The results of pressure measurements in the working chamber during the transition from the filling cycle to the emptying cycle are included. The pressure in the motor’s working chamber changes linearly as a function of the shaft rotation angle, which has a significant effect on the leakage in the commutation unit clearances. The paper presents new mathematical formulas in the form: Q=f(Δpγ to calculate the flow rate of water and mineral oil in the commutation unit clearances. The γ factor is described as a function of fluid viscosity and clearance length (the motor shaft rotation angle. The coefficients used in these formulas were determined based on the results of laboratory tests of a motor supplied with water and mineral oil.

  15. On generalized co-Cohen-Macaulay and co-Buchsbaum modules over commutative rings

    International Nuclear Information System (INIS)

    Nguyen Tu Cuong; Nguyen Thi Dung; Le Thanh Nhan

    2004-07-01

    We study two classes of Artinian modules over commutative Noetherian rings called co-Buchsbaum modules and generalized co-Cohen-Macaulay modules. Some properties on q-weak co-sequences, co-standard sequences, multiplicity, local homology modules, localization, etc, of these modules are presented. (author)

  16. Commutator dc machines used as mechanical capacitors in a series resonant ohmic-heating circuit simulation

    International Nuclear Information System (INIS)

    Thullen, P.; Weldon, D.M.

    1979-01-01

    Rotating electrical machines, and in particular commutator dc machines can serve as a high-power energy-source for testing large, pulsed magnets. This paper describes a pulsed power supply based on traction motors which will be used to test the LASL prototype 20-MJ superconducting tokamak induction coil

  17. On Some Isomorphisms between Bounded Linear Maps and Non-Commutative Lp-Spaces

    Directory of Open Access Journals (Sweden)

    E. J. Atto

    2014-04-01

    Full Text Available We define a particular space of bounded linear maps using a Von Neumann algebra and some operator spaces. By this, we prove some isomorphisms, and using interpolation in some particular cases, we get analogue of non-commutative Lp spaces.

  18. Solar-to-vehicle (S2V) systems for powering commuters of the future

    Science.gov (United States)

    Birnie, Dunbar P.

    Hybrid electric vehicles are growing in popularity and significance in our marketplace as gasoline prices continue to rise. Consumers are also increasingly aware of their carbon "footprint" and seek ways of lowering their carbon dioxide output. Plug-in hybrid and electric vehicles appear to be the next wave in helping transition from a gasoline-based transportation infrastructure to an electric-grid-sourced mode, though most plug-in scenarios ultimately rely on having the electric utilities converted from fossil sources to renewable generation in the long run. At present, one of the key advantages of plug-in hybrid/electric vehicles is that they can be charged at home, at night, when lower off-peak rates could apply. The present analysis considers a further advancement: the impact of daytime recharging using solar arrays located at commuters' work sites. This would convert large parking areas into solar recharge stations for commuters. The solar power would be large enough to supply many commuters' needs. The implications for electric car design in relation to commuter range are discussed in detail.

  19. Localisation in commutative rings at a prime ideal p - (0), (2) | Apine ...

    African Journals Online (AJOL)

    This paper discuses localization, one of the most important concepts in commutative algebra. A process by which new rings are constructed. The nature of the resulting new ring depends on that of a multiplicative subset of the given ring. This paper also focuses on the extension of the ring of integers Z to that of rational ...

  20. Particulates and noise exposure during bicycle, bus and car commuting: A study in three European cities

    NARCIS (Netherlands)

    Okokon, E.O.; Yli-Tuomi, T.; Turunen, A.W.; Taimisto, P.; Pennanen, A.; Vouitsis, I.; Samaras, Z.; Voogt, M.; Keuken, M.; Lanki, T.

    2017-01-01

    Background: In order to curb traffic-related air pollution and its impact on the physical environment, contemporary city commuters are encouraged to shift from private car use to active or public transport modes. However, personal exposures to particulate matter (PM), black carbon and noise during