Laser Theory for Optomechanics: Limit Cycles in the Quantum Regime

Directory of Open Access Journals (Sweden)

Niels Lörch

2014-01-01

Full Text Available Optomechanical systems can exhibit self-sustained limit cycles where the quantum state of the mechanical resonator possesses nonclassical characteristics such as a strongly negative Wigner density, as was shown recently in a numerical study by Qian et al. [Phys. Rev. Lett. 109, 253601 (2012]. Here, we derive a Fokker-Planck equation describing mechanical limit cycles in the quantum regime that correctly reproduces the numerically observed nonclassical features. The derivation starts from the standard optomechanical master equation and is based on techniques borrowed from the laser theory due to Haake and Lewenstein. We compare our analytical model with numerical solutions of the master equation based on Monte Carlo simulations and find very good agreement over a wide and so far unexplored regime of system parameters. As one main conclusion, we predict negative Wigner functions to be observable even for surprisingly classical parameters, i.e., outside the single-photon strong-coupling regime, for strong cavity drive and rather large limit-cycle amplitudes. The approach taken here provides a natural starting point for further studies of quantum effects in optomechanics.

Advancing urban sustainability theory and action: Challenges and opportunities

Science.gov (United States)

Daniel L. Childers; Steward T.A. Pickett; J. Morgan Grove; Laura Ogden; Alison. Whitmer

2014-01-01

Urban ecology and its theories are increasingly poised to contribute to urban sustainability, through both basic understanding and action. We present a conceptual framework that expands the Industrial → Sanitary → Sustainable City transition to include non-sanitary cities, "new cities", and various permutations of transition options for...

Analytic theory of alternate multilayer gratings operating in single-order regime.

Science.gov (United States)

Yang, Xiaowei; Kozhevnikov, Igor V; Huang, Qiushi; Wang, Hongchang; Hand, Matthew; Sawhney, Kawal; Wang, Zhanshan

2017-07-10

Using the coupled wave approach (CWA), we introduce the analytical theory for alternate multilayer grating (AMG) operating in the single-order regime, in which only one diffraction order is excited. Differing from previous study analogizing AMG to crystals, we conclude that symmetrical structure, or equal thickness of the two multilayer materials, is not the optimal design for AMG and may result in significant reduction in diffraction efficiency. The peculiarities of AMG compared with other multilayer gratings are analyzed. An influence of multilayer structure materials on diffraction efficiency is considered. The validity conditions of analytical theory are also discussed.

Quantum fields in the non-perturbative regime. Yang-Mills theory and gravity

International Nuclear Information System (INIS)

Eichhorn, Astrid

2011-01-01

In this thesis we study candidates for fundamental quantum field theories, namely non-Abelian gauge theories and asymptotically safe quantum gravity. Whereas the first ones have a stronglyinteracting low-energy limit, the second one enters a non-perturbative regime at high energies. Thus, we apply a tool suited to the study of quantum field theories beyond the perturbative regime, namely the Functional Renormalisation Group. In a first part, we concentrate on the physical properties of non-Abelian gauge theories at low energies. Focussing on the vacuum properties of the theory, we present an evaluation of the full effective potential for the field strength invariant F μν F μν from non-perturbative gauge correlation functions and find a non-trivial minimum corresponding to the existence of a dimension four gluon condensate in the vacuum. We also relate the infrared asymptotic form of the β function of the running background-gauge coupling to the asymptotic behavior of Landau-gauge gluon and ghost propagators and derive an upper bound on their scaling exponents. We then consider the theory at finite temperature and study the nature of the confinement phase transition in d = 3+1 dimensions in various non-Abelian gauge theories. For SU(N) with N= 3,..,12 and Sp(2) we find a first-order phase transition in agreement with general expectations. Moreover our study suggests that the phase transition in E(7) Yang-Mills theory also is of first order. Our studies shed light on the question which property of a gauge group determines the order of the phase transition. In a second part we consider asymptotically safe quantum gravity. Here, we focus on the Faddeev-Popov ghost sector of the theory, to study its properties in the context of an interacting UV regime. We investigate several truncations, which all lend support to the conjecture that gravity may be asymptotically safe. In a first truncation, we study the ghost anomalous dimension which we find to be negative at the

Social Theories of Urban Violence in the Global South: Towards ...

International Development Research Centre (IDRC) Digital Library (Canada)

2018-04-25

Apr 25, 2018 ... Yet, social theory, largely developed and tested in the Global North, ... 15-project research programme, Social Theories of Urban Violence in the ... adapt existing theoretical and conceptual frameworks, others develop and test ...

Effects of Urbanization on the Flow Regimes of Semi-Arid Southern California Streams

Science.gov (United States)

Hawley, R. J.; Bledsoe, B. P.; Stein, E. D.

2010-12-01

Stream channel erosion and associated habitat degradation are pervasive in streams draining urban areas in the southwestern US. The prevalence of these impacts results from the inherent sensitivity of streams in semi-arid climates to changes in flow and sediment regimes, and past inattention to management of geomorphically effective flows. Addressing this issue is difficult due to the lack of data linking ranges of flow (from small to large runoff events) to geomorphic channel response. Forty-three U. S. Geological Survey gages with record lengths greater than ~15 yrs and watershed areas less than ~250 square kilometers were used to empirically model the effects of urbanization on streams in southern California. The watersheds spanned a gradient of urban development and ranged from 0 to 23% total impervious area in 2001. With little flow control at the subdivision scale to date, most impervious area in the region is relatively well-connected to surface-drainage networks. Consequently, total impervious area was an effective surrogate for urbanization, and emerged as a significant (p approach expands on previous scaling procedures to produce histogram-style cumulative flow duration graphs for ungaged sites based on urbanization extent and other watershed descriptors. Urbanization resulted in proportionally-longer durations of all geomorphically-effective flows, with a more pronounced effect on the durations of moderate flows. For example, an average watershed from the study domain with ~20% imperviousness could experience five times as many days of mean daily flows on the order of 100 cfs (3 cubic meters per second) and approximately three times as many days on the order of 1,000 cfs (30 cubic meters per second) relative to the undeveloped setting. Increased duration of sediment-transporting flows is a primary driver of accelerated changes in channel form that are often concurrent with urbanization throughout southern California, particularly in unconfined, fine

A Theory on Urban Resilience to Floods - A Basis for Alternative Planning Practices

Directory of Open Access Journals (Sweden)

Kuei-Hsien Liao

2012-12-01

Full Text Available River cities require a management approach based on resilience to floods rather than on resistance. Resisting floods by means of levees, dams, and channelization neglects inherent uncertainties arising from human-nature couplings and fails to address the extreme events that are expected to increase with climate change, and is thereby not a reliable approach to long-term flood safety. By applying resilience theory to address system persistence through changes, I develop a theory on "urban resilience to floods" as an alternative framework for urban flood hazard management. Urban resilience to floods is defined as a city's capacity to tolerate flooding and to reorganize should physical damage and socioeconomic disruption occur, so as to prevent deaths and injuries and maintain current socioeconomic identity. It derives from living with periodic floods as learning opportunities to prepare the city for extreme ones. The theory of urban resilience to floods challenges the conventional wisdom that cities cannot live without flood control, which in effect erodes resilience. To operationalize the theory for planning practice, a surrogate measure - the percent floodable area - is developed for assessing urban resilience to floods. To enable natural floodplain functions to build urban resilience to floods, flood adaptation is advocated in order to replace flood control for mitigating flood hazards.

Understanding urban inequality: a model based on existing theories and an empirical illustration.

NARCIS (Netherlands)

Musterd, S.; Burgers, J.

2002-01-01

In the debate on urban inequality, Sassen's theory on social polarization and Wilson's theory on spatial mismatch have received much attention. Where Sassen highlights the decline of the middle classes, Wilson focuses on the upgrading of urban labour markets. In this article we argue that both

United theory of planet formation (i): Tandem regime

Science.gov (United States)

Ebisuzaki, Toshikazu; Imaeda, Yusuke

2017-07-01

The present paper is the first one of a series of papers that present the new united theory of planet formation, which includes magneto-rotational instability and porous aggregation of solid particles in an consistent way. We here describe the ;tandem; planet formation regime, in which a solar system like planetary systems are likely to be produced. We have obtained a steady-state, 1-D model of the accretion disk of a protostar taking into account the magneto-rotational instability (MRI) and and porous aggregation of solid particles. We find that the disk is divided into an outer turbulent region (OTR), a MRI suppressed region (MSR), and an inner turbulent region (ITR). The outer turbulent region is fully turbulent because of MRI. However, in the range, rout(= 8 - 60 AU) from the central star, MRI is suppressed around the midplane of the gas disk and a quiet area without turbulence appears, because the degree of ionization of gas becomes low enough. The disk becomes fully turbulent again in the range rin(= 0.2 - 1 AU), which is called the inner turbulent region, because the midplane temperature become high enough (>1000 K) due to gravitational energy release. Planetesimals are formed through gravitational instability at the outer and inner MRI fronts (the boundaries between the MRI suppressed region (MSR) and the outer and inner turbuent regions) without particle enhancement in the original nebula composition, because of the radial concentration of the solid particles. At the outer MRI front, icy particles grow through low-velocity collisions into porous aggregates with low densities (down to ∼10-5 gcm-3). They eventually undergo gravitational instability to form icy planetesimals. On the other hand, rocky particles accumulate at the inner MRI front, since their drift velocities turn outward due to the local maximum in gas pressure. They undergo gravitational instability in a sub-disk of pebbles to form rocky planetesimals at the inner MRI front. They are likely

A multidimensional theory for electron trapping by a plasma wake generated in the bubble regime

International Nuclear Information System (INIS)

Kostyukov, I; Nerush, E; Pukhov, A; Seredov, V

2010-01-01

We present a theory for electron self-injection in nonlinear, multidimensional plasma waves excited by a short laser pulse in the bubble regime or by a short electron beam in the blowout regime. In these regimes, which are typical for electron acceleration in the last impressive experiments, the laser radiation pressure or the electron beam charge pushes out plasma electrons from some region, forming a plasma cavity or a bubble with a huge ion charge. The plasma electrons can be trapped in the bubble and accelerated by the plasma wakefields up to a very high energy. We derive the condition of the electron trapping in the bubble. The developed theory predicts the trapping cross section in terms of the bubble radius and the bubble velocity. It is found that the dynamic bubble deformations observed in the three-dimensional (3D) particle-in-cell (PIC) simulations influence the trapping process significantly. The bubble elongation reduces the gamma-factor of the bubble, thereby strongly enhancing self-injection. The obtained analytical results are in good agreement with the 3D PIC simulations.

The epsilon regime of chiral perturbation theory with Wilson-type fermions

Energy Technology Data Exchange (ETDEWEB)

Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Shindler, A. [Liverpool Univ. (United Kingdom). Theoretical Physics Division

2009-11-15

In this proceeding contribution we report on the ongoing effort to simulate Wilson-type fermions in the so called epsilon regime of chiral perturbation theory (cPT).We present results for the chiral condensate and the pseudoscalar decay constant obtained with Wilson twisted mass fermions employing two lattice spacings, two different physical volumes and several quark masses. With this set of simulations we make a first attempt to estimate the systematic uncertainties. (orig.)

The epsilon regime of chiral perturbation theory with Wilson-type fermions

International Nuclear Information System (INIS)

Jansen, K.; Shindler, A.

2009-11-01

In this proceeding contribution we report on the ongoing effort to simulate Wilson-type fermions in the so called epsilon regime of chiral perturbation theory (cPT).We present results for the chiral condensate and the pseudoscalar decay constant obtained with Wilson twisted mass fermions employing two lattice spacings, two different physical volumes and several quark masses. With this set of simulations we make a first attempt to estimate the systematic uncertainties. (orig.)

Quantum fields in the non-perturbative regime. Yang-Mills theory and gravity

Energy Technology Data Exchange (ETDEWEB)

Eichhorn, Astrid

2011-09-06

In this thesis we study candidates for fundamental quantum field theories, namely non-Abelian gauge theories and asymptotically safe quantum gravity. Whereas the first ones have a stronglyinteracting low-energy limit, the second one enters a non-perturbative regime at high energies. Thus, we apply a tool suited to the study of quantum field theories beyond the perturbative regime, namely the Functional Renormalisation Group. In a first part, we concentrate on the physical properties of non-Abelian gauge theories at low energies. Focussing on the vacuum properties of the theory, we present an evaluation of the full effective potential for the field strength invariant F{sub {mu}}{sub {nu}}F{sup {mu}}{sup {nu}} from non-perturbative gauge correlation functions and find a non-trivial minimum corresponding to the existence of a dimension four gluon condensate in the vacuum. We also relate the infrared asymptotic form of the {beta} function of the running background-gauge coupling to the asymptotic behavior of Landau-gauge gluon and ghost propagators and derive an upper bound on their scaling exponents. We then consider the theory at finite temperature and study the nature of the confinement phase transition in d = 3+1 dimensions in various non-Abelian gauge theories. For SU(N) with N= 3,..,12 and Sp(2) we find a first-order phase transition in agreement with general expectations. Moreover our study suggests that the phase transition in E(7) Yang-Mills theory also is of first order. Our studies shed light on the question which property of a gauge group determines the order of the phase transition. In a second part we consider asymptotically safe quantum gravity. Here, we focus on the Faddeev-Popov ghost sector of the theory, to study its properties in the context of an interacting UV regime. We investigate several truncations, which all lend support to the conjecture that gravity may be asymptotically safe. In a first truncation, we study the ghost anomalous dimension

Urban land takeup and the potential for a crisis in the real estate regime

Directory of Open Access Journals (Sweden)

Mariana Giaretto

2010-07-01

Full Text Available Urban land takeups have become one of the main problems in Latin American cities within the last twenty years. From a social and critical perspective, the task at hand is double: to discredit common sense views considering take ups are crime offences and fostering poverty criminalization and, at the same time, to critically analyze the relations between the State and the individuals involved in land take ups, so that we may understand the complexity of this problem.By analysing some interviews to individuals involved in social conflicts in the framework of urban land take ups —both by grassroots sectors and municipal officers, and by secondary sources—, to review varied concrete experiences in the city of Cipolletti (Argentina is proposed, focusing in State intervention forms and discussing whether they are or they are not the sign of a structural crisis within the capitalist property regime under new accumulation conditions.

Diurnal cycling of urban aerosols under different weather regimes

Science.gov (United States)

Gregorič, Asta; Drinovec, Luka; Močnik, Griša; Remškar, Maja; Vaupotič, Janja; Stanič, Samo

2016-04-01

A one month measurement campaign was performed in summer 2014 in Ljubljana, the capital of Slovenia (population 280,000), aiming to study temporal and spatial distribution of urban aerosols and the mixing state of primary and secondary aerosols. Two background locations were chosen for this purpose, the first one in the city center (urban background - KIS) and the second one in the suburban background (Brezovica). Simultaneous measurements of black carbon (BC) and particle number size distribution of submicron aerosols (PM1) were conducted at both locations. In the summer season emission from traffic related sources is expected to be the main local contribution to BC concentration. Concentrations of aerosol species and gaseous pollutants within the planetary boundary layer are controlled by the balance between emission sources of primary aerosols and gases, production of secondary aerosols, chemical reactions of precursor gases under solar radiation and the rate of dilution by mixing within the planetary boundary layer (PBL) as well as with tropospheric air. Only local emission sources contribute to BC concentration during the stable PBL with low mixing layer height, whereas during the time of fully mixed PBL, regionally transported BC and other aerosols can contribute to the surface measurements. The study describes the diurnal behaviour of the submicron aerosol at the urban and suburban background location under different weather regimes. Particles in three size modes - nucleation (humidity, wind speed and direction), diurnal profile differs for sunny, cloudy and rainy days. Nucleation mode particles were found to be subjected to lower daily variation and only slightly influenced by weather, as opposed to Aitken and accumulation mode particles. The highest correlation between BC and particle number concentration is observed during stable atmospheric conditions in the night and morning hours and is attributed to different particle size modes, depending on the

Does proximity to urban centres affect the dietary regime of marine benthic filter feeders?

Science.gov (United States)

Puccinelli, Eleonora; Noyon, Margaux; McQuaid, Christopher D.

2016-02-01

Threats to marine ecosystems include habitat destruction and degradation of water quality, resulting from land- and ocean-based human activities. Anthropogenic input causing modification of water quality, can affect primary productivity and thus food availability and quality for higher trophic levels. This is especially important for sedentary benthic intertidal communities, which rely on local food availability. We investigated the effect of urbanization on the dietary regime of four species of intertidal filter feeders (three barnacles and one mussel) at sites close to high-density cities and at sites far from heavily urbanized areas using fatty acid and stable isotope techniques. δ15N was significantly higher at urbanized sites compared to their corresponding control sites for all species with few exceptions, while no effect on δ13C was recorded. Barnacle fatty acid profiles were not affected by cities, while mussels from sites close to cities had fatty acid signatures with a higher proportion of polyunsaturated fatty acids (PUFA). We suggest that the enrichment in δ15N at urbanised sites reflects the influence of anthropogenically derived nitrogen directly linked to wastewater input from domestic and industrial sewage. Linked to this, the high proportion of PUFA in mussels at urbanized sites may reflect the influence of increased nitrogen concentrations on primary production and enhanced growth of large phytoplankton cells. The results indicate that anthropogenic effects can strongly influence the diets of benthic organisms, but these effects differ among taxa. Changes in the diet of such habitat forming species can affect their fitness and survival with potential effects on the populations associated with them.

[Medical theories and urban management: Fortaleza's 1877-79 drought].

Science.gov (United States)

Costa, Maria Clélia Lustosa

2004-01-01

Down through the nineteenth century, new medical theories on the origin of disease influenced the norms and regulations that controlled the population's behavior and the urban space. The present study discusses the ideas, medical practices , and administrative initiatives adopted during the 1877-79 drought in Fortaleza, capital of Ceará province. The drought was accompanied by a smallpox epidemic, along with the increased migration of sertão dwellers to the capitol. The city lacked a public service network capable of meeting the needs of this new population, which took up lodgings on the city and periphery. The municipal administration endeavored to implement the recommendations of physicians based on modern principles of hygienization. Through an analysis of reports by the provincial presidents and by public health inspectors, the study intends to show how these medical theories influenced the practices of urban reorganization at a moment of public emergency.

Transition from weak wave turbulence regime to solitonic regime

Science.gov (United States)

Hassani, Roumaissa; Mordant, Nicolas

2017-11-01

The Weak Turbulence Theory (WTT) is a statistical theory describing the interaction of a large ensemble of random waves characterized by very different length scales. For both weak non-linearity and weak dispersion a different regime is predicted where solitons propagate while keeping their shape unchanged. The question under investigation here is which regime between weak turbulence or soliton gas does the system choose ? We report an experimental investigation of wave turbulence at the surface of finite depth water in the gravity-capillary range. We tune the wave dispersion and the level of nonlinearity by modifying the depth of water and the forcing respectively. We use space-time resolved profilometry to reconstruct the deformed surface of water. When decreasing the water depth, we observe a drastic transition between weak turbulence at the weakest forcing and a solitonic regime at stronger forcing. We characterize the transition between both states by studying their Fourier Spectra. We also study the efficiency of energy transfer in the weak turbulence regime. We report a loss of efficiency of angular transfer as the dispersion of the wave is reduced until the system bifurcates into the solitonic regime. This project has recieved funding from the European Research Council (ERC, Grant Agreement No. 647018-WATU).

Social Theories of Urban Violence in the Global South | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

2018-04-25

Apr 25, 2018 ... Book cover: Social Theories of Urban Violence in the Global South ... Call for new OWSD Fellowships for Early Career Women Scientists now open ... adaptive water management: Innovative solutions from the Global South”.

Semiempirical theory of level spacing distribution beyond the Berry-Robnik regime: modeling the localization and the tunneling effects

International Nuclear Information System (INIS)

Batistic, Benjamin; Robnik, Marko

2010-01-01

In this work we study the level spacing distribution in the classically mixed-type quantum systems (which are generic), exhibiting regular motion on invariant tori for some initial conditions and chaotic motion for the complementary initial conditions. In the asymptotic regime of the sufficiently deep semiclassical limit (sufficiently small effective Planck constant) the Berry and Robnik (1984 J. Phys. A: Math. Gen. 17 2413) picture applies, which is very well established. We present a new quasi-universal semiempirical theory of the level spacing distribution in a regime away from the Berry-Robnik regime (the near semiclassical limit), by describing both the dynamical localization effects of chaotic eigenstates, and the tunneling effects which couple regular and chaotic eigenstates. The theory works extremely well in the 2D mixed-type billiard system introduced by Robnik (1983 J. Phys. A: Math. Gen. 16 3971) and is also tested in other systems (mushroom billiard and Prosen billiard).

Sustainable urban development and the multi-level transition perspective

DEFF Research Database (Denmark)

Næss, Petter; Vogel, Nina

2012-01-01

This article discusses some challenges and possible adaptations of transition theory as a framework for analyzing the prospects for environmentally more sustainable development of urban land use and transport infrastructure. Rather than depending first and foremost on niche innovations......, a transition toward sustainable urban development is a matter of changing the composition of existing multisegmented land use and transportation regimes. Those well-experienced forms of built environment and transport infrastructure that are in line with sustainability objectives should be strengthened while...... those that are not should be actively constrained and reduced. Urban development in a Danish provincial city is used as a case to illustrate some of the points made in the theoretical part of the article. Due to the wide gap between present conditions and those required to realize a sustainable urban...

Behavior of the S parameter in the crossover region between walking and QCD-like regimes of an SU(N) gauge theory

International Nuclear Information System (INIS)

Kurachi, Masafumi; Shrock, Robert

2006-01-01

We consider a vectorial, confining SU(N) gauge theory with a variable number, N f , of massless fermions transforming according to the fundamental representation. Using the Schwinger-Dyson and Bethe-Salpeter equations, we calculate the S parameter in terms of the current-current correlation functions. We focus on values of N f such that the theory is in the crossover region between the regimes of walking behavior and QCD-like (nonwalking) behavior. Our calculations indicate that the contribution to S from a given fermion decreases as one moves from the QCD-like to the walking regimes. The implications of this result for technicolor theories are discussed

The theory and simulation of relativistic electron beam transport in the ion-focused regime

International Nuclear Information System (INIS)

Swanekamp, S.B.; Holloway, J.P.; Kammash, T.; Gilgenbach, R.M.

1992-01-01

Several recent experiments involving relativistic electron beam (REB) transport in plasma channels show two density regimes for efficient transport; a low-density regime known as the ion-focused regime (IFR) and a high-pressure regime. The results obtained in this paper use three separate models to explain the dependency of REB transport efficiency on the plasma density in the IFR. Conditions for efficient beam transport are determined by examining equilibrium solutions of the Vlasov--Maxwell equations under conditions relevant to IFR transport. The dynamic force balance required for efficient IFR transport is studied using the particle-in-cell (PIC) method. These simulations provide new insight into the transient beam front physics as well as the dynamic approach to IFR equilibrium. Nonlinear solutions to the beam envelope are constructed to explain oscillations in the beam envelope observed in the PIC simulations but not contained in the Vlasov equilibrium analysis. A test particle analysis is also developed as a method to visualize equilibrium solutions of the Vlasov equation. This not only provides further insight into the transport mechanism but also illustrates the connections between the three theories used to describe IFR transport. Separately these models provide valuable information about transverse beam confinement; together they provide a clear physical understanding of REB transport in the IFR

Coulomb drag in the mesoscopic regime

DEFF Research Database (Denmark)

Mortensen, N. Asger; Flensberg, Karsten; Jauho, Antti-Pekka

2002-01-01

We present a theory for Coulomb drug between two mesoscopic systems which expresses the drag in terms of scattering matrices and wave functions. The formalism can be applied to both ballistic and disordered systems and the consequences can be studied either by numerical simulations or analytic...... means such as perturbation theory or random matrix theory. The physics of Coulomb drag in the mesoscopic regime is very different from Coulomb drag between extended electron systems. In the mesoscopic regime we in general find fluctuations of the drag comparable to the mean value. Examples are vanishing...

Coulomb drag in the mesoscopic regime

DEFF Research Database (Denmark)

Mortensen, N.A.; Flensberg, Karsten; Jauho, Antti-Pekka

2002-01-01

We present a theory for Coulomb drag between two mesoscopic systems which expresses the drag in terms of scattering matrices and wave functions. The formalism can be applied to both ballistic and disordered systems and the consequences can be studied either by numerical simulations or analytic...... means such as perturbation theory or random matrix theory. The physics of Coulomb drag in the mesoscopic regime is very different from Coulomb drag between extended electron systems. In the mesoscopic regime we in general find fluctuations of the drag comparable to the mean value. Examples are vanishing...

Quantum resource theory of non-stabilizer states in the one-shot regime

Science.gov (United States)

Ahmadi, Mehdi; Dang, Hoan; Gour, Gilad; Sanders, Barry

Universal quantum computing is known to be impossible using only stabilizer states and stabilizer operations. However, addition of non-stabilizer states (also known as magic states) to quantum circuits enables us to achieve universality. The resource theory of non-stablizer states aims at quantifying the usefulness of non-stabilizer states. Here, we focus on a fundamental question in this resource theory in the so called single-shot regime: Given two resource states, is there a free quantum channel that will (approximately or exactly) convert one to the other?. To provide an answer, we phrase the question as a semidefinite program with constraints on the Choi matrix of the corresponding channel. Then, we use the semidefinite version of the Farkas lemma to derive the necessary and sufficient conditions for the conversion between two arbitrary resource states via a free quantum channel. BCS appreciates financial support from Alberta Innovates, NSERC, China's 1000 Talent Plan and the Institute for Quantum Information and Matter.

URBAN POLITICS: KEY APPROACHES

Directory of Open Access Journals (Sweden)

Ledyaeva Ol'ga Mikhaylovna

2012-10-01

Full Text Available Several approaches that underlie urban politics are discussed in the paper. They include neo-liberalism, political economy discourse, elitist/pluralist debates, and postmodernism. The neoliberal approach focuses on the limited role of the state and individual responsibility. The legal framework protects both the rights and responsibilities of individuals and regulates the operation of the market. It is the market that fosters individual choices and provides goods and services by virtue of the processes which are flexible, efficient and transparent. The political economy approaches (regulation theory, public choice theory, neo-Marxism explain urban politics via the analysis of national and international economic processes and changes in contemporary capitalism. Changes in national and international economies determine what solutions are possible. The discourse has been influenced by the debate on globalization of capital and labour markets. Modern elitism and neopluralism are represented by theories of "growth machines" and "urban regimes". The former focuses on bargaining alliances between political and business leaders in order to manage the urban system and to promote its growth. The latter develops neopluralist explanations of power within local communities with an emphasis on the fragmented nature of the government where local authorities lack comprehensive governing powers. Postmodernism views the city as the site of the crisis of late capitalism which leads to segregation of neighbourhoods onto prosperous areas and ghettoes. In contrast to the modern city, the postmodern city is not defined by its industrial base; rather, it is determined by its consumerist environment of malls and museums, characterized by revivalist architecture. At the same time, the suburban shopping mall and a motorway network make nonsense of the idea of the city as a unique and well-defined space. These and other approaches encompass a wide spectrum of possibilities

Urban ecology in a developing world: why advanced socioecological theory needs Africa

OpenAIRE

McHale, Melissa R; Bunn, David N; Pickett, Steward TA; Twine, Wayne

2013-01-01

Socioecological theory, developed through the study of urban environments, has recently led to a proliferation of research focusing on comparative analyses of cities. This research emphasis has been concentrated in the more developed countries of the Northern Hemisphere (often referred to as the “Global North”), yet urbanization is now occurring mostly in the developing world, with the fastest rates of growth in sub-Saharan Africa. Countries like South Africa are experiencing a variety of lan...

Urban ecology in a developing world: why advanced socioecological theory needs Africa.

Science.gov (United States)

McHale, Melissa R; Bunn, David N; Pickett, Steward Ta; Twine, Wayne

2013-12-01

Socioecological theory, developed through the study of urban environments, has recently led to a proliferation of research focusing on comparative analyses of cities. This research emphasis has been concentrated in the more developed countries of the Northern Hemisphere (often referred to as the "Global North"), yet urbanization is now occurring mostly in the developing world, with the fastest rates of growth in sub-Saharan Africa. Countries like South Africa are experiencing a variety of land-cover changes that may challenge current assumptions about the differences between urban and rural environments and about the connectivity of these dynamic socioecological systems. Furthermore, questions concerning ecosystem services, landscape preferences, and conservation - when analyzed through rural livelihood frameworks - may provide insights into the social and ecological resilience of human settlements. Increasing research on urban development processes occurring in Africa, and on patterns of kinship and migration in the less developed countries of the "Global South", will advance a more comprehensive worldview of how future urbanization will influence the progress of sustainable societies.

Planning for a sustainable Oslo: the challenge of turning urban theory into practice

OpenAIRE

Andersen, Bengt; Skrede, Joar

2016-01-01

Many cities today face challenges related to urban growth. This is also the case in Oslo, currently one of the fastest growing capitals in Europe. In order to prepare for the population growth, a new municipal master plan has been prepared. In this, sustainable development is a prominent concept, and the urban district is going to be densified as part of the strategy. This paper examines some obstacles of turning planning theory into practice. There is a lack of coherence between municipal...

Adiabatic perturbation theory for atoms and molecules in the low-frequency regime.

Science.gov (United States)

Martiskainen, Hanna; Moiseyev, Nimrod

2017-12-14

There is an increasing interest in the photoinduced dynamics in the low frequency, ω, regime. The multiphoton absorptions by molecules in strong laser fields depend on the polarization of the laser and on the molecular structure. The unique properties of the interaction of atoms and molecules with lasers in the low-frequency regime imply new concepts and directions in strong-field light-matter interactions. Here we represent a perturbational approach for the calculations of the quasi-energy spectrum in the low-frequency regime, which avoids the construction of the Floquet operator with extremely large number of Floquet channels. The zero-order Hamiltonian in our perturbational approach is the adiabatic Hamiltonian where the atoms/molecules are exposed to a dc electric field rather than to ac-field. This is in the spirit of the first step in the Corkum three-step model. The second-order perturbation correction terms are obtained when iℏω∂∂τ serves as a perturbation and τ is a dimensionless variable. The second-order adiabatic perturbation scheme is found to be an excellent approach for calculating the ac-field Floquet solutions in our test case studies of a simple one-dimensional time-periodic model Hamiltonian. It is straightforward to implement the perturbation approach presented here for calculating atomic and molecular energy shifts (positions) due to the interaction with low-frequency ac-fields using high-level electronic structure methods. This is enabled since standard quantum chemistry packages allow the calculations of atomic and molecular energy shifts due to the interaction with dc-fields. In addition to the shift of the energy positions, the energy widths (inverse lifetimes) can be obtained at the same level of theory. These energy shifts are functions of the laser parameters (low frequency, intensity, and polarization).

Urbanization and human rights

NARCIS (Netherlands)

Mihr, A.

Urban governance on the basis of human rights can help to set up problem solving mechanisms to guarantee social peace, economic growth and political participation.If states both integrate more in international or regional human rights regime and give more autonomy to urban governments and local

Exploring complex causal pathways between urban renewal, health and health inequality using a theory-driven realist approach.

Science.gov (United States)

Mehdipanah, Roshanak; Manzano, Ana; Borrell, Carme; Malmusi, Davide; Rodriguez-Sanz, Maica; Greenhalgh, Joanne; Muntaner, Carles; Pawson, Ray

2015-01-01

Urban populations are growing and to accommodate these numbers, cities are becoming more involved in urban renewal programs to improve the physical, social and economic conditions in different areas. This paper explores some of the complexities surrounding the link between urban renewal, health and health inequalities using a theory-driven approach. We focus on an urban renewal initiative implemented in Barcelona, the Neighbourhoods Law, targeting Barcelona's (Spain) most deprived neighbourhoods. We present evidence from two studies on the health evaluation of the Neighbourhoods Law, while drawing from recent urban renewal literature, to follow a four-step process to develop a program theory. We then use two specific urban renewal interventions, the construction of a large central plaza and the repair of streets and sidewalks, to further examine this link. In order for urban renewal programs to affect health and health inequality, neighbours must use and adapt to the changes produced by the intervention. However, there exist barriers that can result in negative outcomes including factors such as accessibility, safety and security. This paper provides a different perspective to the field that is largely dominated by traditional quantitative studies that are not always able to address the complexities such interventions provide. Furthermore, the framework and discussions serve as a guide for future research, policy development and evaluation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Urbanism and Racial Attitudes: A Test of Some Urban Theories.

Science.gov (United States)

Wilson, Thomas C.

1984-01-01

National survey data are used to test the relationship between urbanism and racial attitudes among Whites, and a liberalizing effect of urbanism is found. It appears that urbanism liberalizes racial attitudes by increasing equal-status, cooperative, and relatively personal contact between members of racial subcultures. (Author/RDN)

Transforming Water Supply Regimes in India: Do Public-Private Partnerships Have a Role to Play?

Directory of Open Access Journals (Sweden)

Govind Gopakumar

2010-10-01

Full Text Available Public-private partnerships (PPP are an important governance strategy that has recently emerged as a solution to enhance the access of marginalised residents to urban infrastructures. With the inception of neo-liberal economic reforms in India, in Indian cities too PPP has emerged as an innovative approach to expand coverage of water supply and sanitation infrastructures. However, there has been little study of the dynamics of partnership efforts in different urban contexts: What role do they play in transforming existing infrastructure regimes? Do reform strategies such as partnerships result in increased privatisation or do they make the governance of infrastructures more participative? Reviewing some of the recent literature on urban political analysis, this article develops the concept of water supply regime to describe the context of water provision in three metropolitan cities in India. To further our understanding of the role of PPP within regimes, this article sketches five cases of water supply and sanitation partnerships located within these three metropolitan cities. From these empirical studies, the article arrives at the conclusion that while PPP are always products of the regime-context they are inserted within, quite often strategic actors in the partnership use the PPP to further their interests by initiating a shift in the regime pathway. This leads us to conclude that PPPs do play a role in making water supply regimes more participative but that depends on the nature of the regime as well as the actions of partners.

Towards a green urban economy? Unravelling urban sustainability transitions from a regime perspective

NARCIS (Netherlands)

Mans, U.; Meerow, S.

2012-01-01

The current debate about sustainability transitions has embraced the multi-level perspective as a useful methodological tool for assessing the dynamics that are at play between landscape, regime and niche. As a consequence, the thinking about socio-technical transitions has gradually shifted in

Transport regimes spanning magnetization-coupling phase space

Science.gov (United States)

Baalrud, Scott D.; Daligault, Jérôme

2017-10-01

The manner in which transport properties vary over the entire parameter-space of coupling and magnetization strength is explored. Four regimes are identified based on the relative size of the gyroradius compared to other fundamental length scales: the collision mean free path, Debye length, distance of closest approach, and interparticle spacing. Molecular dynamics simulations of self-diffusion and temperature anisotropy relaxation spanning the parameter space are found to agree well with the predicted boundaries. Comparison with existing theories reveals regimes where they succeed, where they fail, and where no theory has yet been developed.

Simulation and assessment of urbanization impacts on runoff metrics

DEFF Research Database (Denmark)

Zhang, Yongyong; Xia, Jun; Yu, Jingjie

2018-01-01

changes. The Qing River catchment as a peri-urban catchment in the Beijing metropolitan area is selected as our study region. Results show that: (1) the dryland agriculture is decreased from 13.9% to 1.5% of the total catchment area in the years 2000–2015, while the percentages of impervious surface...... information for urban planning such as Sponge City design.......Urbanization-induced landuse changes alter runoff regimes in complex ways. In this study, a detailed investigation of the urbanization impacts on runoff regimes is provided by using multiple runoff metrics and with consideration of landuse dynamics. A catchment hydrological model is modified...

Governance in urban development crisis situations

Directory of Open Access Journals (Sweden)

Jörg Rober

2008-01-01

Full Text Available Urban shrinking processes are increasingly recognized as a phenomenon for research in urban politics, encompassing entire cities or parts of it as well as metropolitan areas that are experiencing a fundamental decline in both their economic and social bases.Cities are facing complex social problems like aging processes within the resident population and simultaneously running shrinking processes. Observable side effects of these transformation processes are higher vacancy rates and under-utilization of infrastructure facilities. Therefore cities are no longer able to cope alone with this growing complexity, hence a demand for cooperation evolves. The ongoing reforms of internal structure of local government connected with the devolution of resources and competences, as well as the changing external relationships between the business community, local public bodies, individual bureaucrats and local politicians, increase institutional fragmentation. Thus internal and external reform processes generate an extended network of policy actors involved in local decision making. Schools of thought in urban politics accentuate the changing role of local governments in decision making processes. Regime theory, corporatism, regulation theory or civic governance concepts differ in their emphasis on the importance of specific actors participating in local decision making. The paper reviews the competing theoretical assumptions for the importance of specific actors in local decision making. This addresses the question to what extent specific governance modes adopted in reaction to shrinking processes are an expression of a changing relationship between local governments and civil society or business actors in an international comparative context. Is there a trend to more convergence with respect to the adopted governance modes?

Fixing extensions to general relativity in the nonlinear regime

Science.gov (United States)

Cayuso, Juan; Ortiz, Néstor; Lehner, Luis

2017-10-01

The question of what gravitational theory could supersede General Relativity has been central in theoretical physics for decades. Many disparate alternatives have been proposed motivated by cosmology, quantum gravity and phenomenological angles, and have been subjected to tests derived from cosmological, solar system and pulsar observations typically restricted to linearized regimes. Gravitational waves from compact binaries provide new opportunities to probe these theories in the strongly gravitating/highly dynamical regimes. To this end however, a reliable understanding of the dynamics in such a regime is required. Unfortunately, most of these theories fail to define well posed initial value problems, which prevents at face value from meeting such challenge. In this work, we introduce a consistent program able to remedy this situation. This program is inspired in the approach to "fixing" viscous relativistic hydrodynamics introduced by Israel and Stewart in the late 70's. We illustrate how to implement this approach to control undesirable effects of higher order derivatives in gravity theories and argue how the modified system still captures the true dynamics of the putative underlying theories in 3 +1 dimensions. We sketch the implementation of this idea in a couple of effective theories of gravity, one in the context of Noncommutative Geometry, and one in the context of Chern-Simons modified General Relativity.

Transport processes in magnetically confined plasmas in the nonlinear regime.

Science.gov (United States)

Sonnino, Giorgio

2006-06-01

A field theory approach to transport phenomena in magnetically confined plasmas is presented. The thermodynamic field theory (TFT), previously developed for treating the generic thermodynamic system out of equilibrium, is applied to plasmas physics. Transport phenomena are treated here as the effect of the field linking the thermodynamic forces with their conjugate flows combined with statistical mechanics. In particular, the Classical and the Pfirsch-Schluter regimes are analyzed by solving the thermodynamic field equations of the TFT in the weak-field approximation. We found that, the TFT does not correct the expressions of the ionic heat fluxes evaluated by the neoclassical theory in these two regimes. On the other hand, the fluxes of matter and electronic energy (heat flow) is further enhanced in the nonlinear Classical and Pfirsch-Schluter regimes. These results seem to be in line with the experimental observations. The complete set of the electronic and ionic transport equations in the nonlinear Banana regime, is also reported. A paper showing the comparison between our theoretic results and the experimental observations in the JET machine is currently in preparation.

Scaling electron acceleration in the bubble regime for upcoming lasers

International Nuclear Information System (INIS)

Jansen, O.; Tueckmantel, T.; Pukhov, A.

2014-01-01

Electron acceleration in the laser-plasma bubble appeared to be the most successful regime of laser wake field acceleration in the last decade. The laser technology became mature enough to generate short and relativistically intense pulses required to reach the bubble regime naturally delivering quasi-monoenergetic bunches of relativistic electrons. The upcoming laser technology projects are promising short pulses with many times more energy than the existing ones. The natural question is how will the bubble regime scale with the available laser energy. We present here a parametric study of laser-plasma acceleration in the bubble regime using full three dimensional particle-in-cell simulations and compare numerical results with the analytical scalings from the relativistic laser-plasma similarity theory. Our simulations and the theory match almost perfectly for spot sizes above R = 2λ and laser amplitudes above a 0 = 4. We also studied the emission of synchrotron radiation by the accelerated electrons. Both classical and a QED model were applied. We found borders, at which theory and simulations stopped matching. With small spot radii (R < 2λ) we almost never observed the formation of a bubble structure or any form of mono-energetic acceleration. Low laser amplitudes lead to higher energies than predicted by the theory

The new urban politics as a politics of carbon control.

Science.gov (United States)

Jonas, Andrew E G; Gibbs, David; While, Aidan

2011-01-01

The new urban politics (NUP) literature has helped to draw attention to a new generation of entrepreneurial urban regimes involved in the competition to attract investment to cities. Interurban competition often had negative environmental consequences for the urban living place. Yet knowledge of the environment was not very central to understanding the NUP. Entrepreneurial urban regimes today are struggling to deal with climate change and reductions in greenhouse gas emissions. Carbon reduction strategies could have profound implications for interurban competition and the politics of urban development. This paper explores the rise of a distinctive low-carbon urban polity—carbon control—and examines its potential ramifications for a new environmental politics of urban development (NEPUD). The NEPUD signals the growing centrality of carbon control in discourses, strategies and struggles around urban development. Using examples from cities in the US and Europe, the paper examines how these new environmental policy considerations are being mainstreamed in urban development politics. Alongside competitiveness, the management of carbon emissions represents a new yet at the same time contestable mode of calculation in urban governance.

Multiscale and Multitemporal Urban Remote Sensing

Science.gov (United States)

Mesev, V.

2012-07-01

The remote sensing of urban areas has received much attention from scientists conducting studies on measuring sprawl, congestion, pollution, poverty, and environmental encroachment. Yet much of the research is case and data-specific where results are greatly influenced by prevailing local conditions. There seems to be a lack of epistemological links between remote sensing and conventional theoretical urban geography; in other words, an oversight for the appreciation of how urban theory fuels urban change and how urban change is measured by remotely sensed data. This paper explores basic urban theories such as centrality, mobility, materiality, nature, public space, consumption, segregation and exclusion, and how they can be measured by remote sensing sources. In particular, the link between structure (tangible objects) and function (intangible or immaterial behavior) is addressed as the theory that supports the wellknow contrast between land cover and land use classification from remotely sensed data. The paper then couches these urban theories and contributions from urban remote sensing within two analytical fields. The first is the search for an "appropriate" spatial scale of analysis, which is conveniently divided between micro and macro urban remote sensing for measuring urban structure, understanding urban processes, and perhaps contributions to urban theory at a variety of scales of analysis. The second is on the existence of a temporal lag between materiality of urban objects and the planning process that approved their construction, specifically how time-dependence in urban structural-functional models produce temporal lags that alter the causal links between societal and political functional demands and structural ramifications.

Picturing Urban Green Attachments

DEFF Research Database (Denmark)

Blok, Anders; Meilvang, Marie Leth

2015-01-01

In this article, we explore the cultural-political tensions and ambiguities of urban ecology, by way of following how activists move and translate between ‘familiar’ and ‘public’ engagements in the green city. Empirically, we locate our exploration in and around Nordhavnen (The North Harbor......), a large-scale sustainable urban development project in Copenhagen. Invoking Laurent Thévenot’s pragmatic sociology of ‘regimes of engagement’, we sketch a culturally sensitive approach to urban ecological activism, highlighting the critical moral capacities involved in building new forms of ‘commonality...

THE ARABIC ORIGINS OF ENGLISH AND INDO-EUROPEAN "URBAN TERMS": A RADICAL LINGUISTIC THEORY APPROACH

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Zaidan Ali Jassem

2015-06-01

Full Text Available This paper traces the Arabic origins of English, German, French, Latin, Greek, and Sanskrit "urban terms" from a radical linguistic (or lexical root theory perspective. The data comprises 130 such terms like abide, building, city, construction, courtyard, hotel, house, live, mansion, mason, palace, metropolis, residence, road, rural, sedentary, sojourn, stay, structure, tent, town, urban, villa, village, zoo, and so on. The results clearly show that all such words have true Arabic cognates with the same or similar forms and meanings, whose differences are due to natural and plausible causes and different routes of linguistic change. Moreover, the results support the adequacy of the radical linguistic theory according to which, unlike the Comparative Method and/or Family Tree Model, Arabic, English, German, French, Latin, Greek, and Sanskrit are dialects of the same language or family, renamed Eurabian or Urban family, with Arabic being their origin all for sharing the whole cognates with them and for its huge phonetic, morphological, grammatical, and lexical variety and wealth. Also, they indicate that there is a radical language from which all human languages stemmed and which has been preserved almost intact in Arabic as the most conservative and productive language, without which it is impossible to interpret its linguistic richness and versatility on all levels.

Urban interventions

DEFF Research Database (Denmark)

Pinder, David

2008-01-01

Challenging perspectives on the urban question have arisen in recent years from beyond academic realms through the work of artists and cultural practitioners. Often in dialogue with urban theory and political activism, and employing a range of tactical practices, they have engaged critically......, relationships and situations. Such interventionist practices may rarely be seen as part of the traditional purview of urban studies. Yet in asserting their significance here, this essay argues that growing dialogues across and between urban and spatial theory, and artistic and cultural practice, have...... considerable potential for inspiring and developing critical approaches to cities. The essay highlights a number of specific challenges thrown up by such interconnections that are of political and pedagogical significance and in need of further debate....

Fire Regime Characteristics along Environmental Gradients in Spain

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María Vanesa Moreno

2016-11-01

Full Text Available Concern regarding global change has increased the need to understand the relationship between fire regime characteristics and the environment. Pyrogeographical theory suggests that fire regimes are constrained by climate, vegetation and fire ignition processes, but it is not obvious how fire regime characteristics are related to those factors. We used a three-matrix approach with a multivariate statistical methodology that combined an ordination method and fourth-corner analysis for hypothesis testing to investigate the relationship between fire regime characteristics and environmental gradients across Spain. Our results suggest that fire regime characteristics (i.e., density and seasonality of fire activity are constrained primarily by direct gradients based on climate, population, and resource gradients based on forest potential productivity. Our results can be used to establish a predictive model for how fire regimes emerge in order to support fire management, particularly as global environmental changes impact fire regime characteristics.

Hydrological impacts of urbanization at the catchment scale

Science.gov (United States)

Oudin, Ludovic; Salavati, Bahar; Furusho-Percot, Carina; Ribstein, Pierre; Saadi, Mohamed

2018-04-01

The impacts of urbanization on floods, droughts and the overall river regime have been largely investigated in the past few decades, but the quantification and the prediction of such impacts still remain a challenge in hydrology. We gathered a sample of 142 catchments that have a documented increase in urban areas over the hydrometeorological record period in the United States. The changes in river flow regimes due to urban spread were differentiated from climate variability using the GR4J conceptual hydrological model. High, low and mean flows were impacted at a threshold of a 10% total impervious area. Moreover, the historical evolution of urban landscape spatial patterns was used to further detail the urbanization process in terms of extent and fragmentation of urban areas throughout the catchment and to help interpret the divergent impacts observed in streamflow behaviors. Regression analysis pointed out the importance of major wastewater treatment facilities that might overpass the effects of imperviousness, and therefore further research should either take them explicitly into account or select a wastewater facility-free catchment sample to clearly evaluate the impacts of urban landscape on low flows.

INFLUENCE OF REGIME SWITCHING TO RISK IN PORT-MODERN PORTFOLIO MANAGEMENT

OpenAIRE

Cristina Geambaşu; Liviu Geambaşu; Iulia Jianu

2013-01-01

The present financial crises determines an increase in analysing the application of regime switching over portfolio investments. We applied the switching regimes to measurement of risk as presented in post-modern portfolio management theory. Post-modern portfolio theory include investor’s tendency to measure risk as the chance to obtain from the investment performed a return lower than the minimum expected by him. The investor, as presented by behavioural finance, is more concerned about his ...

Rethinking Sustainable Sanitation for the Urban Domain

OpenAIRE

Norström, A; Mcconville, Jennifer; Lüthi, C; Panesar, Arne

2010-01-01

Climate change, diminishing natural resources and rural-urban demographic trends will have profound impacts on future urban infrastructure delivery in both developed and developing countries. These challenges will however, leverage new opportunities for circular urban economies in which productive sanitation will play an important role in both the North and South. In the developed world, the challenge is to initiate a transition from disposal oriented, water-based infrastructure regimes towar...

Build Artifacts in Sustainable Urban Projects

DEFF Research Database (Denmark)

Pinheiro-Croisel, Rebecca; Hernes, Tor

2015-01-01

This paper explores innovation and social behaviourist theory in relation to sustainable urban projects in the highly institutionalized public sector (towns). Using empirical data from France, we examine the dynamics of a design process in which unexpected practices generated innovative urban...... into a movement of collective action, which presupposed the acquisition of a new identity. Ultimately, our objective is to combine social behaviourist theory and innovation theory and to facilitate innovative design in urban projects....

Urban base flow with low impact development

Science.gov (United States)

Bhaskar, Aditi; Hogan, Dianna M.; Archfield, Stacey A.

2016-01-01

A novel form of urbanization, low impact development (LID), aims to engineer systems that replicate natural hydrologic functioning, in part by infiltrating stormwater close to the impervious surfaces that generate it. We sought to statistically evaluate changes in a base flow regime because of urbanization with LID, specifically changes in base flow magnitude, seasonality, and rate of change. We used a case study watershed in Clarksburg, Maryland, in which streamflow was monitored during whole-watershed urbanization from forest and agricultural to suburban residential development using LID. The 1.11-km2 watershed contains 73 infiltration-focused stormwater facilities, including bioretention facilities, dry wells, and dry swales. We examined annual and monthly flow during and after urbanization (2004–2014) and compared alterations to nearby forested and urban control watersheds. We show that total streamflow and base flow increased in the LID watershed during urbanization as compared with control watersheds. The LID watershed had more gradual storm recessions after urbanization and attenuated seasonality in base flow. These flow regime changes may be because of a reduction in evapotranspiration because of the overall decrease in vegetative cover with urbanization and the increase in point sources of recharge. Precipitation that may once have infiltrated soil, been stored in soil moisture to be eventually transpired in a forested landscape, may now be recharged and become base flow. The transfer of evapotranspiration to base flow is an unintended consequence to the water balance of LID.

Anti-Weak Localization Measurements in the Ballistic Regime

Science.gov (United States)

Jayathilaka, Dilhani; Dedigama, Aruna; Murphy, Sheena; Edirisooriya, Madhavie; Goel, Niti; Mishima, Tetsuya; Santos, Michael; Mullen, Kieran

2007-03-01

Anti-weak localization dominates at low fields in systems in which spin-orbit coupling is strong. The experimental results are well described by theory [1] in low mobility systems in which the magnetic length (lB) is greater than the mean free path; however high mobility systems with strong spin-orbit interactions, such the InSb based two dimensional systems (2DESs) examined here, are not in this diffusive regime. A recently developed theory [2] addresses both the diffusive and ballistic regimes taking into account both the backscattered and non-backscattered contributions to the conductivity. We will discuss the agreement of the new theory to measurements of InSb 2DESs prepared with both strong Dresselhaus and Rashba effects. [1] S.V. Iordanskii, Yu B. Lyanda-Geller, and G.E. Pikus, JETP Lett. 60, 206 (1994). [2] L.E. Golub, Phys. Rev. B. 71, 235310 (2005).

The Geography of Solar Photovoltaics (PV and a New Low Carbon Urban Transition Theory

Directory of Open Access Journals (Sweden)

Peter Newton

2013-06-01

Full Text Available This paper examines the early phases of a 21st century energy transition that involves distributed generation technologies employing low or zero carbon emission power sources and their take-up within Australia, with particular reference to the major cities and solar photovoltaics (PV. This transition is occurring in a nation with significant path dependency to overcome in relation to fossil fuel use. Tracking the diffusion of solar PV technology within Australia over the past decade provides a basis for assessing those factors underpinning its exponential growth and its associated geography of diffusion. Positive evidence that there are pathways for cities to decarbonise is apparent but there appear to be different pathways for different city forms with lower density suburban areas showing the biggest take-up of household-based energy technologies. This suggests a model for the low carbon urban transition involving combinations of simple technological changes and harder structural changes, depending upon which parts of the urban fabric are in focus. This is being called a New Low Carbon Urban Transition Theory.

The nutrition/excretion system of urban areas: socioecological regimes and transitions.

OpenAIRE

Esculier , Fabien

2018-01-01

Nutrition and excretion are fundamental physiological needs for all human beings. Analysis of their materiality, from the cellular scale up to the great planetary-scale biogeochemical cycles, shows that nutrition and excretion form a system. The focus of our study is the sustainability of the nutrition/excretion systems of urban areas, which we have sought to assess by analysing substance flows.The most relevant of these substances seems to be nitrogen, so by assessing urban nitrogen flows we...

Rural-urban migration and child survival in urban Bangladesh: are the urban migrants and poor disadvantaged?

Science.gov (United States)

Islam, M Mazharul; Azad, Kazi Md Abul Kalam

2008-01-01

This paper analyses the levels and trends of childhood mortality in urban Bangladesh, and examines whether children's survival chances are poorer among the urban migrants and urban poor. It also examines the determinants of child survival in urban Bangladesh. Data come from the 1999-2000 Bangladesh Demographic and Health Survey. The results indicate that, although the indices of infant and child mortality are consistently better in urban areas, the urban-rural differentials in childhood mortality have diminished in recent years. The study identifies two distinct child morality regimes in urban Bangladesh: one for urban natives and one for rural-urban migrants. Under-five mortality is higher among children born to urban migrants compared with children born to life-long urban natives (102 and 62 per 1000 live births, respectively). The migrant-native mortality differentials more-or-less correspond with the differences in socioeconomic status. Like childhood mortality rates, rural-urban migrants seem to be moderately disadvantaged by economic status compared with their urban native counterparts. Within the urban areas, the child survival status is even worse among the migrant poor than among the average urban poor, especially recent migrants. This poor-non-poor differential in childhood mortality is higher in urban areas than in rural areas. The study findings indicate that rapid growth of the urban population in recent years due to rural-to-urban migration, coupled with higher risk of mortality among migrant's children, may be considered as one of the major explanations for slower decline in under-five mortality in urban Bangladesh, thus diminishing urban-rural differentials in childhood mortality in Bangladesh. The study demonstrates that housing conditions and access to safe drinking water and hygienic toilet facilities are the most critical determinants of child survival in urban areas, even after controlling for migration status. The findings of the study may

Stormwater infiltration and the 'urban karst' - A review

Science.gov (United States)

Bonneau, Jeremie; Fletcher, Tim D.; Costelloe, Justin F.; Burns, Matthew J.

2017-09-01

The covering of native soils with impervious surfaces (e.g. roofs, roads, and pavement) prevents infiltration of rainfall into the ground, resulting in increased surface runoff and decreased groundwater recharge. When this excess water is managed using stormwater drainage systems, flow and water quality regimes of urban streams are severely altered, leading to the degradation of their ecosystems. Urban streams restoration requires alternative approaches towards stormwater management, which aim to restore the flow regime towards pre-development conditions. The practice of stormwater infiltration-achieved using a range of stormwater source-control measures (SCMs)-is central to restoring baseflow. Despite this, little is known about what happens to the infiltrated water. Current knowledge about the impact of stormwater infiltration on flow regimes was reviewed. Infiltration systems were found to be efficient at attenuating high-flow hydrology (reducing peak magnitudes and frequencies) at a range of scales (parcel, streetscape, catchment). Several modelling studies predict a positive impact of stormwater infiltration on baseflow, and empirical evidence is emerging, but the fate of infiltrated stormwater remains unclear. It is not known how infiltrated water travels along the subsurface pathways that characterise the urban environment, in particular the 'urban karst', which results from networks of human-made subsurface pathways, e.g. stormwater and sanitary sewer pipes and associated high permeability trenches. Seepage of groundwater into and around such pipes is possible, meaning some infiltrated stormwater could travel along artificial pathways. The catchment-scale ability of infiltration systems to restore groundwater recharge and baseflow is thus ambiguous. Further understanding of the fate of infiltrated stormwater is required to ensure infiltration systems deliver optimal outcomes for waterway flow regimes.

Flocking regimes in a simple lattice model.

Science.gov (United States)

Raymond, J R; Evans, M R

2006-03-01

We study a one-dimensional lattice flocking model incorporating all three of the flocking criteria proposed by Reynolds [Computer Graphics 21, 4 (1987)]: alignment, centering, and separation. The model generalizes that introduced by O. J. O'Loan and M. R. Evans [J. Phys. A. 32, L99 (1999)]. We motivate the dynamical rules by microscopic sampling considerations. The model exhibits various flocking regimes: the alternating flock, the homogeneous flock, and dipole structures. We investigate these regimes numerically and within a continuum mean-field theory.

Clustering impact regime with shocks in freely evolving granular gas

Science.gov (United States)

Isobe, Masaharu

2017-06-01

A freely cooling granular gas without any external force evolves from the initial homogeneous state to the inhomogeneous clustering state, at which the energy decay deviates from the Haff's law. The asymptotic behavior of energy in the inelastic hard sphere model have been predicted by several theories, which are based on the mode coupling theory or extension of inelastic hard rods gas. In this study, we revisited the clustering regime of freely evolving granular gas via large-scale molecular dynamics simulation with up to 16.7 million inelastic hard disks. We found novel regime regarding on collisions between "clusters" spontaneously appearing after clustering regime, which can only be identified more than a few million particles system. The volumetric dilatation pattern of semicircular shape originated from density shock propagation are well characterized on the appearing of "cluster impact" during the aggregation process of clusters.

Viscous conformal gauge theories

DEFF Research Database (Denmark)

Toniato, Arianna; Sannino, Francesco; Rischke, Dirk H.

2017-01-01

We present the conformal behavior of the shear viscosity-to-entropy density ratio and the fermion-number diffusion coefficient within the perturbative regime of the conformal window for gauge-fermion theories.......We present the conformal behavior of the shear viscosity-to-entropy density ratio and the fermion-number diffusion coefficient within the perturbative regime of the conformal window for gauge-fermion theories....

Soils in urban and industrial environments

International Nuclear Information System (INIS)

Burghardt, W.

1994-01-01

Urban areas are expanding rapidly. Therefore the interest in soil science activities on urban and industrial sites grows. The paper gives an overview of the research and mapping activities in Germany. A model of soils in urban ecosystems shows the relationships of development of soils and soil quality to land use. The water regime of soils is influenced by the characteristics of urban landscape and sealing. Of special interest are the typical substrates. Some properties of soils which develop on tipped substrates of natural material are discussed. Of importance are technological substrates as rubble, ash, slag, waste material and sludges in urban environments. Proposals of classification of urban and industrial soils are presented. For proper use by the municipal authorities availability and application of information on urban soils must be a part of research. (orig.) [de

Pollutant Plume Dispersion in the Atmospheric Boundary Layer over Idealized Urban Roughness

Science.gov (United States)

Wong, Colman C. C.; Liu, Chun-Ho

2013-05-01

The Gaussian model of plume dispersion is commonly used for pollutant concentration estimates. However, its major parameters, dispersion coefficients, barely account for terrain configuration and surface roughness. Large-scale roughness elements (e.g. buildings in urban areas) can substantially modify the ground features together with the pollutant transport in the atmospheric boundary layer over urban roughness (also known as the urban boundary layer, UBL). This study is thus conceived to investigate how urban roughness affects the flow structure and vertical dispersion coefficient in the UBL. Large-eddy simulation (LES) is carried out to examine the plume dispersion from a ground-level pollutant (area) source over idealized street canyons for cross flows in neutral stratification. A range of building-height-to-street-width (aspect) ratios, covering the regimes of skimming flow, wake interference, and isolated roughness, is employed to control the surface roughness. Apart from the widely used aerodynamic resistance or roughness function, the friction factor is another suitable parameter that measures the drag imposed by urban roughness quantitatively. Previous results from laboratory experiments and mathematical modelling also support the aforementioned approach for both two- and three-dimensional roughness elements. Comparing the UBL plume behaviour, the LES results show that the pollutant dispersion strongly depends on the friction factor. Empirical studies reveal that the vertical dispersion coefficient increases with increasing friction factor in the skimming flow regime (lower resistance) but is more uniform in the regimes of wake interference and isolated roughness (higher resistance). Hence, it is proposed that the friction factor and flow regimes could be adopted concurrently for pollutant concentration estimate in the UBL over urban street canyons of different roughness.

Exchange Rate Regimes – A periodical overview and a critical analysis of exchange rate regimes in Kosovo

Directory of Open Access Journals (Sweden)

Flamur Bunjaku

2015-03-01

Full Text Available Exchange rate regimes and the monetary policy are the key instruments governments use to achieve their economic and financial objectives. Moreover, due to global financial crisis the latter instruments get more importance. Empirical evidences show that exchange rate regimes in Kosovo and its monetary policy throughout their development were mainly influenced by different political and historical developments. In regard of Euroisation of monetary system in Kosovo it was found that this action generated macro - financial stability in terms of inflation and price fluctuation. However, in terms of microeconomic aspects, the unilateral adaptation of Euro as the official currency of Kosovo failed to provide microeconomic advantages such as to export stimulation, and so forth. The main exchange rate regime systems were discussed focusing in their advantages and disadvantages, and it was concluded that there is no commonly accepted theory regarding the optimality of exchange rate regimes. In addition, the global financial crisis impact in the financial system of Kosovo is also discussed and it was found that negative impacts of global financial crisis were moderate and indirect.

Urban Sound Interfaces

DEFF Research Database (Denmark)

Breinbjerg, Morten

2012-01-01

This paper draws on the theories of Michel de Certeau and Gaston Bachelard to discuss how media architecture, in the form of urban sound interfaces, can help us perceive the complexity of the spaces we inhabit, by exploring the history and the narratives of the places in which we live. In this pa......This paper draws on the theories of Michel de Certeau and Gaston Bachelard to discuss how media architecture, in the form of urban sound interfaces, can help us perceive the complexity of the spaces we inhabit, by exploring the history and the narratives of the places in which we live....... In this paper, three sound works are discussed in relation to the iPod, which is considered as a more private way to explore urban environments, and as a way to control the individual perception of urban spaces....

Optimization of hydrometric monitoring network in urban drainage systems using information theory.

Science.gov (United States)

Yazdi, J

2017-10-01

Regular and continuous monitoring of urban runoff in both quality and quantity aspects is of great importance for controlling and managing surface runoff. Due to the considerable costs of establishing new gauges, optimization of the monitoring network is essential. This research proposes an approach for site selection of new discharge stations in urban areas, based on entropy theory in conjunction with multi-objective optimization tools and numerical models. The modeling framework provides an optimal trade-off between the maximum possible information content and the minimum shared information among stations. This approach was applied to the main surface-water collection system in Tehran to determine new optimal monitoring points under the cost considerations. Experimental results on this drainage network show that the obtained cost-effective designs noticeably outperform the consulting engineers' proposal in terms of both information contents and shared information. The research also determined the highly frequent sites at the Pareto front which might be important for decision makers to give a priority for gauge installation on those locations of the network.

STAR POLYMERS IN GOOD SOLVENTS FROM DILUTE TO CONCENTRATED REGIMES: CROSSOVER APPROACH

Directory of Open Access Journals (Sweden)

S.B.Kiselev

2002-01-01

Full Text Available An introduction is given to the crossover theory of the conformational and thermodynamic properties of star polymers in good solvents. The crossover theory is tested against Monte Carlo simulation data for the structure and thermodynamics of model star polymers. In good solvent conditions, star polymers approach a "universal" limit as N → ∞, however, there are two types of approach towards this limit. In the dilute regime, a critical degree of polymerization N* is found to play a similar role as the Ginzburg number in the crossover theory for critical phenomena in simple fluids. A rescaled penetration function is found to control the free energy of star polymer solutions in the dilute and semidilute regions. This equation of state captures the scaling behaviour of polymer solutions in the dilute/semidilute regimes and also performs well in the concentrated regimes, where the details of the monomer-monomer interactions become important.

Sedimentological regimes for turbidity currents: Depth-averaged theory

Science.gov (United States)

Halsey, Thomas C.; Kumar, Amit; Perillo, Mauricio M.

2017-07-01

Turbidity currents are one of the most significant means by which sediment is moved from the continents into the deep ocean; their properties are interesting both as elements of the global sediment cycle and due to their role in contributing to the formation of deep water oil and gas reservoirs. One of the simplest models of the dynamics of turbidity current flow was introduced three decades ago, and is based on depth-averaging of the fluid mechanical equations governing the turbulent gravity-driven flow of relatively dilute turbidity currents. We examine the sedimentological regimes of a simplified version of this model, focusing on the role of the Richardson number Ri [dimensionless inertia] and Rouse number Ro [dimensionless sedimentation velocity] in determining whether a current is net depositional or net erosional. We find that for large Rouse numbers, the currents are strongly net depositional due to the disappearance of local equilibria between erosion and deposition. At lower Rouse numbers, the Richardson number also plays a role in determining the degree of erosion versus deposition. The currents become more erosive at lower values of the product Ro × Ri, due to the effect of clear water entrainment. At higher values of this product, the turbulence becomes insufficient to maintain the sediment in suspension, as first pointed out by Knapp and Bagnold. We speculate on the potential for two-layer solutions in this insufficiently turbulent regime, which would comprise substantial bedload flow with an overlying turbidity current.

Urban Is Floating Face down in the Mainstream: Using Hip-Hop-Based Education Research to Resurrect "The Urban" in Urban Education

Science.gov (United States)

Irby, Decoteau J.

2015-01-01

Throughout this article, I argue that within the mainstream field of urban education, "the urban" is floating face down, lifeless, and devoid of significant meaning. "City" and "urban" function as taken-for-granted variables that stand in the rightful place of rich explanations, based in theory and evidence, of the…

Computational characterization of ignition regimes in a syngas/air mixture with temperature fluctuations

KAUST Repository

Pal, Pinaki; Valorani, Mauro; Arias, Paul G.; Im, Hong G.; Wooldridge, Margaret S.; Ciottoli, Pietro P.; Galassi, Riccardo M.

2016-01-01

) was applied to characterize the auto-ignition phenomena. All results supported that the observed ignition behaviors were consistent with the expected ignition regimes predicted by the theory of the regime diagram. This work provides new high-fidelity data

Detecting spatial regimes in ecosystems | Science Inventory ...

Science.gov (United States)

Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory based method, on both terrestrial and aquatic animal data (US Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps, and multivariate analysis such as nMDS (non-metric Multidimensional Scaling) and cluster analysis. We successfully detect spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change. Use an information theory based method to identify ecological boundaries and compare our results to traditional early warning

Effects of temperature anisotropy on neoclassical transport in the plateau and banana-plateau regimes

International Nuclear Information System (INIS)

Taguchi, Masayoshi

1999-01-01

The neoclassical transport theory in a presence of temperature anisotropy is investigated in the low to the intermediate collision frequency regimes for a large aspect-ratio tokamak plasma. The standard procedure for an isotropic plasma in the plateau regime is extended to an anisotropic plasma, and the neoclassical transport coefficients in this regime are explicitly calculated. By interpolating the results in the plateau regime and the previously obtained ones in the banana regime, the expressions for the neoclassical transport coefficients which are continuously valid from the banana to the plateau regimes are presented. (author)

Nonlinear transport processes in tokamak plasmas. I. The collisional regimes

International Nuclear Information System (INIS)

Sonnino, Giorgio; Peeters, Philippe

2008-01-01

An application of the thermodynamic field theory (TFT) to transport processes in L-mode tokamak plasmas is presented. The nonlinear corrections to the linear ('Onsager') transport coefficients in the collisional regimes are derived. A quite encouraging result is the appearance of an asymmetry between the Pfirsch-Schlueter (P-S) ion and electron transport coefficients: the latter presents a nonlinear correction, which is absent for the ions, and makes the radial electron coefficients much larger than the former. Explicit calculations and comparisons between the neoclassical results and the TFT predictions for Joint European Torus (JET) plasmas are also reported. It is found that the nonlinear electron P-S transport coefficients exceed the values provided by neoclassical theory by a factor that may be of the order 10 2 . The nonlinear classical coefficients exceed the neoclassical ones by a factor that may be of order 2. For JET, the discrepancy between experimental and theoretical results for the electron losses is therefore significantly reduced by a factor 10 2 when the nonlinear contributions are duly taken into account but, there is still a factor of 10 2 to be explained. This is most likely due to turbulence. The expressions of the ion transport coefficients, determined by the neoclassical theory in these two regimes, remain unaltered. The low-collisional regimes, i.e., the plateau and the banana regimes, are analyzed in the second part of this work

Understanding energy-related regimes: A participatory approach from central Australia

International Nuclear Information System (INIS)

Foran, Tira; Fleming, David; Spandonide, Bruno; Williams, Rachel; Race, Digby

2016-01-01

For a particular community, what energy-related innovations constitute no-regrets strategies? We present a methodology to understand how alternative energy consuming activities and policy regimes impact on current and future liveability of socio-culturally diverse communities facing climate change. Our methodology augments the energy policy literature by harnessing three concepts (collaborative governance, innovation and political economic regime of provisioning) to support dialogue around changing energy-related activities. We convened workshops in Alice Springs, Australia to build capability to identify no-regrets energy-related housing or transport activities and strategies. In preparation, we interviewed policy actors and constructed three new housing-related future scenarios. After discussing the scenarios, policy and research actors prioritised five socio-technical activities or strategies. Evaluations indicate participants enjoyed opportunities given by the methodology to have focussed discussions about activities and innovation, while requesting more socially nuanced scenario storylines. We discuss implications for theory and technique development. - Highlights: •Energy-related activities and regimes frustrate pro-sustainability action. •Participatory workshops increased understanding of activities and regimes. •Workshops used a novel combination of governance and social theories. •Results justify inclusive dialogue around building energy standards and transport options.

QCD in the {delta}-regime

Energy Technology Data Exchange (ETDEWEB)

Bietenholz, W. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Ciencias Nucleares; Cundy, N. [Seoul National Univ. (Korea, Republic of). Lattice Gauge Theory Research Center; Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Horsley, R.; Zanotti, J.M. [Edinburgh Univ. (United Kingdom). School of Physics; Nakamura, Y. [Tsukuba Univ., Ibaraki (Japan). Center for Computational Sciences; Pleiter, D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Schierholz, G. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2011-03-15

The {delta}-regime of QCD is characterised by light quarks in a small spatial box, but a large extent in (Euclidean) time. In this setting a specific variant of chiral perturbation theory - the {delta}-expansion - applies, based on a quantum mechanical treatment of the quasi onedimensional system. In particular, for vanishing quark masses one obtains a residual pion mass M{sup R}{sub {pi}}, which has been computed to the third order in the {delta}-expansion. A comparison with numerical measurements of this residual mass allows for a new determination of some Low Energy Constants, which appear in the chiral Lagrangian. We first review the attempts to simulate 2-flavour QCD directly in the {delta}-regime. This is very tedious, but results compatible with the predictions for M{sup R}{sub {pi}} have been obtained. Then we show that an extrapolation of pion masses measured in a larger volume towards the {delta}-regime leads to good agreement with the theoretical predictions. From those results, we also extract a value for the (controversial) sub-leading Low Energy Constant anti l{sub 3}. (orig.)

QCD in the δ-regime

International Nuclear Information System (INIS)

Bietenholz, W.; Rakow, P.E.L.

2011-03-01

The δ-regime of QCD is characterised by light quarks in a small spatial box, but a large extent in (Euclidean) time. In this setting a specific variant of chiral perturbation theory - the δ-expansion - applies, based on a quantum mechanical treatment of the quasi onedimensional system. In particular, for vanishing quark masses one obtains a residual pion mass M R π , which has been computed to the third order in the δ-expansion. A comparison with numerical measurements of this residual mass allows for a new determination of some Low Energy Constants, which appear in the chiral Lagrangian. We first review the attempts to simulate 2-flavour QCD directly in the δ-regime. This is very tedious, but results compatible with the predictions for M R π have been obtained. Then we show that an extrapolation of pion masses measured in a larger volume towards the δ-regime leads to good agreement with the theoretical predictions. From those results, we also extract a value for the (controversial) sub-leading Low Energy Constant anti l 3 . (orig.)

Electron acceleration in the bubble regime

Energy Technology Data Exchange (ETDEWEB)

Jansen, Oliver

2014-02-03

The bubble regime of laser-wakefield acceleration has been studied over the recent years as an important alternative to classical accelerators. Several models and theories have been published, in particular a theory which provides scaling laws for acceleration parameters such as energy gain and acceleration length. This thesis deals with numerical simulations within the bubble regime, their comparison to these scaling laws and data obtained from experiments, as well as some specific phenomenona. With a comparison of the scaling laws with numerical results a parameter scan was able to show a large parameter space in which simulation and theory agree. An investigation of the limits of this parameter space revealed boundaries to other regimes, especially at very high (a{sub 0} > 100) and very low laser amplitudes (a{sub 0} < 4). Comparing simulation data with data from experiments concerning laser pulse development and electron energies, it was found that experimental results can be adequately reproduced using the Virtual-Laser-Plasma-Laboratory code. In collaboration with the Institut fuer Optik und Quantenelektronik at the Friedrich-Schiller University Jena synchrotron radiation emitted from the inside of the bubble was investigated. A simulation of the movement of the electrons inside the bubble together with time dependent histograms of the emitted radiation helped to prove that the majority of radiation created during a bubble acceleration originates from the inside of the bubble. This radiation can be used to diagnose the amplitude of oscillation of the trapped electrons. During a further study it was proven that the polarisation of synchrotron radiation from a bubble contains information about the exact oscillation direction. This oscillation was successfully controlled by using either a laser pulse with a tilted pulse front or an asymmetric laser pulse. First results of ongoing studies concerning injecting electrons into an existing bubble and a scheme called

Power counting regime of chiral extrapolation and beyond

International Nuclear Information System (INIS)

Derek Leinweber; Anthony Thomas; Ross Young

2005-01-01

Finite-range regularized chiral effective field theory is presented in the context of approximation schemes ubiquitous in modern lattice QCD calculations. Using FRR techniques, the power-counting regime (PCR) of chiral perturbation theory can be estimated. To fourth-order in the expansion at the 1% tolerance level, we find 0 (le) m π (le) 180 MeV for the PCR, extending only a small distance beyond the physical pion mass

Study of the Higgs-Yukawa theory in the strong-Yukawa coupling regime

International Nuclear Information System (INIS)

Bulava, John; Gerhold, Philipp; Nagy, Attila; Deutsches Elektronen-Synchrotron; Hou, George W.S.; Smigielski, Brian; Jansen, Karl; Knippschild, Bastian; Univ. of Mainz; Lin, David C.J.; National Centre of Theoretical Sciences, Hsinchu; Nagai, Kei-Ichi; Ogawa, Kenji

2011-12-01

In this article, we present an ongoing lattice study of the Higgs-Yukawa model, in the regime of strong-Yukawa coupling, using overlap fermions. We investigated the phase structure in this regime by computing the Higgs vacuum expectation value, and by exploring the finite-size scaling behaviour of the susceptibility corresponding to the magnetisation. Our preliminary results indicate the existence of a second-order phase transition when the Yukawa coupling becomes large enough, at which the Higgs vacuum expectation value vanishes and the susceptibility diverges. (orig.)

Renormalization Group Theory

International Nuclear Information System (INIS)

Stephens, C. R.

2006-01-01

In this article I give a brief account of the development of research in the Renormalization Group in Mexico, paying particular attention to novel conceptual and technical developments associated with the tool itself, rather than applications of standard Renormalization Group techniques. Some highlights include the development of new methods for understanding and analysing two extreme regimes of great interest in quantum field theory -- the ''high temperature'' regime and the Regge regime

CONSIDERATIONS ON URBAN SOILS

Directory of Open Access Journals (Sweden)

Radu Lacatusu

2005-10-01

Full Text Available Urban soil is an material that has been manipulated, disturbed or transported by man’s activities in the urban environment and is used as a medium for plant growth and for constructions. The physical, chemical, and biological properties are generally less favorable as a rooting medium than soil found on the natural landscape. The main characteristics of urban soils are: great vertical and spatial variability; modified soil structure leading to compaction; presence of a surface crust; modified soil reaction, usually elevated; restricted aeration and water drainage; modified abundance of chemical elements, interrupted nutrient cycling and soil organism activity; presence of anthropic materials contaminants and pollutants; modified soil temperature regime. The urbic horizon is designated as U (always capital letter and for indication of processes are used different small letters. It is necessary elaboration a new classification of urban soils for our country.

Rural-Urban Migration and Unemployment: Theory and Policy Implications

OpenAIRE

Zenou, Yves

2010-01-01

We develop a regional model where, in the city, unemployment prevails because of too high (efficiency) wages, while, in the rural area, workers are paid at their marginal productivity. We characterize the steady-state equilibrium and show that it is unique. We then consider two policies: decreasing urban unemployment benefits and subsidizing urban employment. We find that decreasing the unemployment benefit in the city creates urban jobs and reduces rural-urban migration since new migrants ha...

Effective theory of bosonic superfluids

International Nuclear Information System (INIS)

Schakel, A.M.J.

1994-01-01

The authors discuss the effective theory of a bosonic superfluid whose microscopic behavior is described by a nonrelativistic, weak-coupling φ 4 theory in the phase with broken particle number symmetry, both at zero temperature and in the vicinity of the phase transition. In the zero-temperature regime, the theory is governed by the gapless Goldstone mode resulting from the broken symmetry. Although this mode is gapless, the effective theory turns out to be Gallilei invariant. The regime just below the critical temperature is approached in a high-temperature expansion which is shown to be consistent with the weak-coupling assumption of the theory. The authors calculate the critical temperature, the coefficients of the Landau theory, and the finite-temperature sound velocity. A comparison with BCS theory is given

Bridging Theory and Practice: Using Hip-Hop Pedagogy As A Culturally Relevant Approach In The Urban Science Classroom

Science.gov (United States)

Adjapong, Edmund S.

This dissertation explores the context of urban science education as it relates to the achievement and engagement of urban youth. This study provides a framework for Hip-Hop Pedagogy, an approach to teaching and learning anchored in the creative elements of Hip-Hop culture, in STEM as an innovative approach to teaching and learning demonstrates the effect that Hip-Hop Pedagogy, as a culturally relevant approach to teaching has on teaching and learning in an urban science classroom. This study establishes practical tools and approaches, which were formed from by theory and research that transcend the traditional monolithic approaches to teaching science. Participants in this study are middle school students who attend an urban school in one of the largest school systems in the country. This research showed that as result of utilizing Hip-Hop pedagogical practices, students reported that they developed a deeper understanding of science content, students were more likely to identify as scientists, and students were provided a space and opportunities to deconstruct traditional classroom spaces and structures.

Detecting spatial regimes in ecosystems

Science.gov (United States)

Sundstrom, Shana M.; Eason, Tarsha; Nelson, R. John; Angeler, David G.; Barichievy, Chris; Garmestani, Ahjond S.; Graham, Nicholas A.J.; Granholm, Dean; Gunderson, Lance; Knutson, Melinda; Nash, Kirsty L.; Spanbauer, Trisha; Stow, Craig A.; Allen, Craig R.

2017-01-01

Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory-based method, on both terrestrial and aquatic animal data (U.S. Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps and multivariate analyses such as nMDS and cluster analysis. We successfully detected spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change.

High-electric-field quantum transport theory for semiconductor superlattices

International Nuclear Information System (INIS)

Nguyen Hong Shon; Nazareno, H.N.

1995-12-01

Based on the Baym-Kadanoff-Keldysh nonequilibrium Green's functions technique, a quantum transport theory for semiconductor superlattices under high-electric field is developed. This theory is capable of considering collisional broadening, intra-collisional field effects and band transport and hopping regimes simultaneously. Numerical calculations for narrow-miniband superlattices in high electric field, when the hopping regime dominates are in reasonable agreement with experimental results and show a significant deviation from the Boltzmann theory. A semiphenomenological formula for current density in hopping regime is proposed. (author). 60 refs, 4 figs

The structuration of socio-technical regimes - Conceptual foundations from institutional theory

NARCIS (Netherlands)

Fuenfschilling, Lea; Truffer, Bernhard|info:eu-repo/dai/nl/6603148005

2014-01-01

In recent years, socio-technical transitions literature has gained importance in addressing long-term, transformative change in various industries. In order to account for the inertia and path-dependency experienced in these sectors, the concept of the socio-technical regime has been formulated.

Hydroperiod regime controls the organization of plant species in wetlands

OpenAIRE

Foti, R.; del Jesus, M.; Rinaldo, A.; Rodriguez-Iturbe, I.

2012-01-01

With urban, agricultural, and industrial needs growing throughout the past decades, wetland ecosystems have experienced profound changes. Most critically, the biodiversity of wetlands is intimately linked to its hydrologic dynamics, which in turn are being drastically altered by ongoing climate changes. Hydroperiod regimes, e.g., percentage of time a site is inundated, exert critical control in the creation of niches for different plant species in wetlands. However, the spatial signatures of ...

From "Ethnocracity" to Urban Apartheid: A View from Jerusalem\\al-Quds

Directory of Open Access Journals (Sweden)

Haim Yacobi

2016-11-01

Full Text Available In the core of this article stands an argument that while ethnocracy was a relevant analytical framework for understanding the urban dynamics of Jerusalem\\al-Quds up until two decades ago, this is no longer the case. As this article demonstrates, ver the past twenty years or so, the city’s geopolitical balance and its means of demographic control, as well as an intensifying militarization and a growing use of state violence, have transformed the city from an ethnocracity into an urban apartheid.  Theoretically, this article aims to go beyond the specific analogy with South African apartheid, the most notorious case of such a regime. Rather I would suggest that in our current market-driven, neo-liberal era, an apartheid city should be taken as a distinct urban regime based on urban trends such as privatization of space, gentrification, urban design, infrastructure development and touristic planning. I would propose that these practices substitute for explicit apartheid legislation (of a sort introduced in the South African case, bringing to the fore new participants in the apartheidization of the city, such as real estate developers and various interest groups.

Enforcing the climate regime: Game theory and the Marrakesh Accords

International Nuclear Information System (INIS)

Hovi, Jon

2002-01-01

The article reviews basic insights about compliance and ''hard'' enforcement that can be derived from various non-cooperative equilibrium concepts and evaluates the Marrakesh Accords in light of these insights. Five different notions of equilibrium are considered - the Nash equilibrium, the sub game perfect equilibrium, the re negotiation proof equilibrium, the coalition proof equilibrium and the perfect Bayesian equilibrium. These various types of equilibrium have number of implications for effective enforcement: 1. Consequences of non-compliance should be more than proportionate. 2. To be credible punishment needs to take place in the Pareto frontier, rather than by reversion to some suboptimal state. 3. An effective enforcement system must be able to curb collective as well as individual incentives to cheat. 4. A fully transparent enforcement regime could in fact turn out to be detrimental for compliance levels. It is concluded that constructing an effective system for ''hard'' enforcement of the Kyoto Protocol is a formidable task that has only partially been accomplished by the Marrakesh Accords. A possible explanation is that the design of a compliance system for the climate regime involved a careful balancing of the desire to minimise non-compliance against other important considerations. (Author)

What Do We Know about Hybrid Regimes after Two Decades of Scholarship?

Directory of Open Access Journals (Sweden)

Mariam Mufti

2018-06-01

Full Text Available In two decades of scholarship on hybrid regimes two significant advancements have been made. First, scholars have emphasized that the hybrid regimes that emerged in the post-Cold War era should not be treated as diminished sub-types of democracy, and second, regime type is a multi-dimensional concept. This review essay further contends that losing the lexicon of hybridity and focusing on a single dimension of regime type—flawed electoral competition—has prevented an examination of extra-electoral factors that are necessary for understanding how regimes are differently hybrid, why there is such immense variation in the outcome of elections and why these regimes are constantly in flux. Therefore, a key recommendation emerging from this review of the scholarship is that to achieve a more thorough, multi-dimensional assessment of hybrid regimes, further research ought to be driven by nested research designs in which qualitative and quantitative approaches can be used to advance mid-range theory building.

Urban hydrogeology in Indonesia: A highlight from Jakarta

Science.gov (United States)

Lubis, R. F.

2018-02-01

In many cities in the developing countries, groundwater is an important source of public water supply. The interaction between groundwater systems and urban environments has become an urgent challenge for many developing cities in the world, Indonesia included. Contributing factors are, but not limited to, the continuous horizontal and vertical expansion of cities, population growth, climate change, water scarcity and groundwater quality degradation. Jakarta as the capital city of Indonesia becomes a good example to study and implement urban hydrogeology. Urban hydrogeology is a science for investigating groundwater at the hydrological cycle and its change, water regime and quality within the urbanized landscape and zones of its impact. The present paper provides a review of urban groundwater studies in Jakarta in the context of urban water management, advances in hydrogeological investigation, monitoring and modelling since the city was established. The whole study emphasizes the necessity of an integrated urban groundwater management and development supporting hydrogeological techniques for urban areas.

Changes in Latitudes, Changes in Attitudes: Narrating a Regime Change

Science.gov (United States)

2015-03-01

portrayal of Guatemala to be counter to what was being reported and challenged the narrative. Bernays continued the media assault on Guatemala by convincing...strategic narrative designed to elicit domestic and international support. Drawing from the tenets of social movement theory, this thesis examines the...other special warfare operation. 14. SUBJECT TERMS MISO, PSYOP, social movement theory, regime change, influence 17. SECURITY 18. SECURITY

Large N field theories, string theory and gravity

Energy Technology Data Exchange (ETDEWEB)

Maldacena, J [Lyman Laboratory of Physics, Harvard University, Cambridge (United States)

2002-05-15

We describe the holographic correspondence between field theories and string/M theory, focusing on the relation between compactifications of string/ M theory on Anti-de Sitter spaces and conformal field theories. We review the background for this correspondence and discuss its motivations and the evidence for its correctness. We describe the main results that have been derived from the correspondence in the regime that the field theory is approximated by classical or semiclassical gravity. We focus on the case of the N = 4 supersymmetric gauge theory in four dimensions. These lecture notes are based on the Review written by O. Aharony, S. Gubser, J. Maldacena, H. Ooguri and Y. Oz. (author)

A non-linear theory for the bubble regime of plasma wake fields in tailored plasma channels

CERN Document Server

Thomas, Johannes

2016-01-01

We introduce a first full analytical bubble and blow-out model for a radially inhomogeneous plasma in a quasi-static approximation. For both cases we calculate the accelerating and the focusing fields. In our model we also assume a thin electron layer that surrounds the wake field and calculate the field configuration within. Our theory holds for arbitrary radial density profiles and reduces to known models in the limit of a homogeneous plasma. From a previous study of hollow plasma channels with smooth boundaries for laser-driven electron acceleration in the bubble regime we know that pancake-like laser pulses lead to highest electron energies [Pukhov et al, PRL 113, 245003 (2014)]. As it was shown, the bubble fields can be adjusted to balance the laser depletion and dephasing lengths by varying the plasma density profile inside a deep channel. Now we show why the radial fields in the vacuum part of a channel become defocussing.

An Ethology of Urban Fabric(s)

DEFF Research Database (Denmark)

Fritsch, Jonas; Thomsen, Bodil Marie Stavning

2014-01-01

The article explores a non-metaphorical understanding of urban fabric(s), shifting the attention from a bird’s eye perspective to the actual, textural manifestations of a variety of urban fabric(s) to be studied in their real, processual, ecological and ethological complexity within urban life. We...... effectuate this move by bringing into resonance a range of intersecting fields that all deal with urban fabric(s) in complementary ways (interaction design and urban design activism, fashion, cultural theory, philosophy, urban computing)....

Urban Green Network Design: Defining green network from an urban planning perspective

OpenAIRE

Andrea Tulisi

2017-01-01

From the theoretical context of Smart City various studies have emerged that adopt an analytical approach and description of urban phenomena based on the principles of “network design”; this line of research uses the network systems theory to define the principles that regulate the relationships among the various elements of urban sub-systems in order to optimize their functionality. From the same theoretical basis, urban greenspaces have also been studied as networks, by means of the creatio...

Modeling whistler wave generation regimes in magnetospheric cyclotron maser

Directory of Open Access Journals (Sweden)

D. L. Pasmanik

2004-11-01

Full Text Available Numerical analysis of the model for cyclotron instability in the Earth's magnetosphere is performed. This model, based on the self-consistent set of equations of quasi-linear plasma theory, describes different regimes of wave generation and related energetic particle precipitation. As the source of free energy the injection of energetic electrons with transverse anisotropic distribution function to the interaction region is considered. A parametric study of the model is performed. The main attention is paid to the analysis of generation regimes for different characteristics of energetic electron source, such as the shape of pitch angle distributions and its intensity. Two mechanisms of removal of energetic electrons from a generation region are considered, one is due to the particle precipitation through the loss cone and another one is related to the magnetic drift of energetic particles.

It was confirmed that two main regimes occur in this system in the presence of a constant particle source, in the case of precipitation losses. At small source intensity relaxation oscillations were found, whose parameters are in good agreement with simplified analytical theory developed earlier. At a larger source intensity, transition to a periodic generation occurs. In the case of drift losses the regime of self-sustained periodic generation regime is realized for source intensity higher than some threshold. The dependencies of repetition period and dynamic spectrum shape on the source parameters were studied in detail. In addition to simple periodic regimes, those with more complex spectral forms were found. In particular, alteration of spikes with different spectral shape can take place. It was also shown that quasi-stationary generation at the low-frequency band can coexist with periodic modulation at higher frequencies.

On the basis of the results obtained, the model for explanation of

A Living Story of Parks : Urban History Research of Stockholmsskolan

OpenAIRE

Wang, Pengfei; Wang, Jiayi

2016-01-01

Our thesis started with a continuous discovery of theory and observation. As a group work of landscape architect and architect, during the study of our Urbanism program, we were both curious about the urbanism theories within Europe. Among them, partly in terms of the landscape background, we were particularly interested in the theory of landscape urbanism and its practices in Europe. Spontaneously, this became our original thesis topic.   However, after reading and collecting, we realized la...

Autonomia e relevância dos regimes The autonomy and relevance of regimes

Directory of Open Access Journals (Sweden)

Gustavo Seignemartin de Carvalho

2005-12-01

Full Text Available Teorias institucionalistas na disciplina de relações internacionais usualmente definem regimes como um conjunto de normas e regras formais ou informais que permitem a convergência de expectativas ou a padronização do comportamento de seus participantes em uma determinada área de interesses com o objetivo de resolver problemas de coordenação que tenderiam a resultados não pareto-eficientes. Como estas definições baseadas meramente na "eficiência" dos regimes não parecem suficientes para explicar sua efetividade, o presente artigo propõe uma definição diferente para regimes: a de arranjos políticos que permitem a redistribuição dos ganhos da cooperação pelos participantes em uma determinada área de interesses em um contexto de interdependência. Regimes possuiriam efetividade pela sua autonomia e relevância, ou seja, por possuírem existência objetiva autônoma da de seus participantes e por influenciarem seu comportamento e expectativas de maneiras que não podem ser reduzidas à ação individual de nenhum deles. O artigo inicia-se com uma breve discussão sobre as dificuldades terminológicas associadas ao estudo de regimes e a definição dos conceitos de autonomia e relevância. Em seguida, classifica os diversos autores participantes do debate em duas perspectivas distintas, uma que nega (não-autonomistas e outra que atribui (autonomistas aos regimes autonomia e relevância, e faz uma breve análise dos autores e tradições mais significativos para o debate, aprofundando-se nos autonomistas e nos argumentos que reforçam a hipótese aqui apresentada. Ao final, o artigo propõe uma decomposição analítica dos regimes nos quatro elementos principais que lhes propiciam autonomia e relevância: normatividade, atores, especificidade da área de interesses e interdependência complexa com o contexto.Regimes are defined by institutionalist theories in the discipline of International Relations as formal or informal sets

Urban transitions: on urban resilience and human-dominated ecosystems.

Science.gov (United States)

Ernstson, Henrik; van der Leeuw, Sander E; Redman, Charles L; Meffert, Douglas J; Davis, George; Alfsen, Christine; Elmqvist, Thomas

2010-12-01

Urbanization is a global multidimensional process paired with increasing uncertainty due to climate change, migration of people, and changes in the capacity to sustain ecosystem services. This article lays a foundation for discussing transitions in urban governance, which enable cities to navigate change, build capacity to withstand shocks, and use experimentation and innovation in face of uncertainty. Using the three concrete case cities--New Orleans, Cape Town, and Phoenix--the article analyzes thresholds and cross-scale interactions, and expands the scale at which urban resilience has been discussed by integrating the idea from geography that cities form part of "system of cities" (i.e., they cannot be seen as single entities). Based on this, the article argues that urban governance need to harness social networks of urban innovation to sustain ecosystem services, while nurturing discourses that situate the city as part of regional ecosystems. The article broadens the discussion on urban resilience while challenging resilience theory when addressing human-dominated ecosystems. Practical examples of harnessing urban innovation are presented, paired with an agenda for research and policy.

Transition from the constant ion mobility regime to the ion-atom charge-exchange regime for bounded collisional plasmas

International Nuclear Information System (INIS)

Poggie, Jonathan; Sternberg, Natalia

2005-01-01

A numerical and analytical study of a planar, collisional, direct-current, plasma-wall problem is presented. The fluid model for the problem is first validated by comparing numerical solutions with experimental data for low-pressure (∼0.1 Pa) electrode sheaths with wall potentials on the order of -100 V. For electric potential, ion number density, and ion velocity, good agreement was found between theory and experiment from within the sheath out to the bulk plasma. The frictional drag resulting from ion-neutral collisions is described by a model incorporating both linear and quadratic velocity terms. In order to study the transition from the constant ion mobility regime (linear friction) to the ion-atom charge-exchange collision regime (quadratic friction), the theoretical model was examined numerically for a range of ion temperatures and ion-neutral collision rates. It was found that the solution profiles in the quasineutral plasma depend on the ion temperature. For low ion temperatures they are governed mainly by the ion-atom charge-exchange regime, whereas for high temperatures they are governed by the constant ion mobility regime. Quasineutral plasma models corresponding to these two limiting cases were solved analytically. In particular, an analytical plasma solution is given for the ion-atom charge exchange regime that includes the effects of ion inertia. In contrast to the quasineutral plasma, the sheath is always governed for low to moderate collision rates by the ion-atom charge-exchange regime, independent of the ion temperature. Varying the collision rate, it was shown that when the wall potential is sufficiently high, the sheath cannot be considered collisionless, even if the collision rate is quite small

Enforcing the climate regime: Game theory and the Marrakesh Accords

Energy Technology Data Exchange (ETDEWEB)

Hovi, Jon

2002-07-01

The article reviews basic insights about compliance and ''hard'' enforcement that can be derived from various non-cooperative equilibrium concepts and evaluates the Marrakesh Accords in light of these insights. Five different notions of equilibrium are considered - the Nash equilibrium, the sub game perfect equilibrium, the re negotiation proof equilibrium, the coalition proof equilibrium and the perfect Bayesian equilibrium. These various types of equilibrium have number of implications for effective enforcement: 1. Consequences of non-compliance should be more than proportionate. 2. To be credible punishment needs to take place in the Pareto frontier, rather than by reversion to some suboptimal state. 3. An effective enforcement system must be able to curb collective as well as individual incentives to cheat. 4. A fully transparent enforcement regime could in fact turn out to be detrimental for compliance levels. It is concluded that constructing an effective system for ''hard'' enforcement of the Kyoto Protocol is a formidable task that has only partially been accomplished by the Marrakesh Accords. A possible explanation is that the design of a compliance system for the climate regime involved a careful balancing of the desire to minimise non-compliance against other important considerations. (Author)

Pulsar timing arrays and gravity tests in the radiative regime

Science.gov (United States)

Lee, K. J.

2013-11-01

In this paper, we focus on testing gravity theories in the radiative regime using pulsar timing array observations. After reviewing current techniques to measure the dispersion and alternative polarization of gravitational waves, we extend the framework to the most general situations, where the combinations of a massive graviton and alternative polarization modes are considered. The atlas of the Hellings-Downs functions is completed by the new calculations for these dispersive alternative polarization modes. We find that each mode and corresponding graviton mass introduce characteristic features in the Hellings-Downs function. Thus, in principal, we can not only detect each polarization mode, measure the corresponding graviton mass, but also discriminate the different scenarios. In this way, we can test gravity theories in the radiative regime in a generalized fashion, and such method is a direct experiment, where one can address the gauge symmetry of the gravity theories in their linearized limits. Although current pulsar timing still lacks enough stable pulsars and sensitivity for such practices, we expect that future telescopes with larger collecting areas could make such experiments feasible.

Regime switching model for financial data: Empirical risk analysis

Science.gov (United States)

Salhi, Khaled; Deaconu, Madalina; Lejay, Antoine; Champagnat, Nicolas; Navet, Nicolas

2016-11-01

This paper constructs a regime switching model for the univariate Value-at-Risk estimation. Extreme value theory (EVT) and hidden Markov models (HMM) are combined to estimate a hybrid model that takes volatility clustering into account. In the first stage, HMM is used to classify data in crisis and steady periods, while in the second stage, EVT is applied to the previously classified data to rub out the delay between regime switching and their detection. This new model is applied to prices of numerous stocks exchanged on NYSE Euronext Paris over the period 2001-2011. We focus on daily returns for which calibration has to be done on a small dataset. The relative performance of the regime switching model is benchmarked against other well-known modeling techniques, such as stable, power laws and GARCH models. The empirical results show that the regime switching model increases predictive performance of financial forecasting according to the number of violations and tail-loss tests. This suggests that the regime switching model is a robust forecasting variant of power laws model while remaining practical to implement the VaR measurement.

Scaling Theory of Polyelectrolyte Nanogels

International Nuclear Information System (INIS)

Qu Li-Jian

2017-01-01

The present paper develops the scaling theory of polyelectrolyte nanogels in dilute and semidilute solutions. The dependencies of the nanogel dimension on branching topology, charge fraction, subchain length, segment number, solution concentration are obtained. For a single polyelectrolyte nanogel in salt free solution, the nanogel may be swelled by the Coulombic repulsion (the so-called polyelectrolyte regime) or the osmotic counterion pressure (the so-called osmotic regime). Characteristics and boundaries between different regimes of a single polyelectrolyte nanogel are summarized. In dilute solution, the nanogels in polyelectrolyte regime will distribute orderly with the increase of concentration. While the nanogels in osmotic regime will always distribute randomly. Different concentration dependencies of the size of a nanogel in polyelectrolyte regime and in osmotic regime are also explored. (paper)

STAKEHOLDER THEORY DAN KARYA KESELAMATAN SCHINDLER

Directory of Open Access Journals (Sweden)

Edward Nicodemus Lontah

2015-04-01

Donaldson and Peterson studies have shown that stakeholder theory has a more solid foundation than the epistemology of shareholder theory to analyze the performance of business ethics and moral duty of a company. This article discussed the business activities of Oskar Schindler, an industrialist war-profiteer during World War II. Schindler's business which was originally run by the government under the Nazi regime, eventually opposed the mission of economic and legal liability imposed by the regime. Schindler's transformation of vision and business mission in this article demonstrate the characteristics and connection of layers in descriptive, instrumental and normative stakeholder theory in the concept of "normative, instrumental and descriptive stakeholder theory" according to Donaldson and Peterson.

Dynamical theory of anomalous particle transport

International Nuclear Information System (INIS)

Meiss, J.D.; Cary, J.R.; Escande, D.F.; MacKay, R.S.; Percival, I.C.; Tennyson, J.L.

1985-01-01

The quasi-linear theory of transport applies only in a restricted parameter range, which does not necessarily correspond to experimental conditions. Theories are developed which extend transport calculations to the regimes of marginal stochasticity and strong turbulence. Near the stochastic threshold the description of transport involves the leakage through destroyed invariant surfaces, and the dynamical scaling theory is used to obtain a universal form for transport coefficients. In the strong-turbulence regime, there is an adiabatic invariant which is preserved except near separatrices. Breakdown of this invariant leads to a new form for the diffusion coefficient. (author)

Urbanization and Third World stability

Energy Technology Data Exchange (ETDEWEB)

Bienen, H

1984-07-01

This essay reviews images of urbanization that have been held by academics and activists, including revolutionary leaders. It examines the methodology and findings of case studies in Nigeria, Mexico, Peru, Brazil, Kenya, Turkey, Malaysia and other countries with the aim of determining how well suited are the data and theories for assessing the relationship between urbanization and political stability. The review examines the following topics: migration; political participaton and the urban poor; radical parties and urban violence; the over-urbanization thesis; class and ethnicity. It especially evaluates the role of so-called urban marginals in urban political life and concludes that the evidence is overwhelming that there is no widespread culture of poverty or culture of apathy among the urban poor in developing countries. 119 references.

Governance Regime Factors Conducive to Innovation Uptake in Urban Water Management: Experiences from Europe

Directory of Open Access Journals (Sweden)

Josselin Rouillard

2016-10-01

Full Text Available Innovative ways to manage the urban water cycle are required to deal with an ageing drinking and waste water infrastructure and new societal imperatives. This paper examines the influence of water governance in enabling transformations and technological innovation uptake in urban water management. A governance assessment framework is developed and applied in three case-studies, examining different scales and types of innovations used to tackle challenges in European urban water management. The methodology combines documentary analysis and interviews to reconstruct historical storylines of the shift in the water governance of urban water management for each site. The research provides detailed empirical observations on the factors conducive to innovation uptake at the local level. Critical governance factors such as commitment to compromise, the necessity to build political support, and the role of “entrepreneurs” and coalitions are highlighted. The paper also explores the role of discursive strategies and partnership design, as well as that of regulative, economic and communicative instruments, in creating barriers and opportunities to initiate and secure change. A number of recommendations targeted at innovators and water managers are presented in the conclusion.

Urban Water Innovation Network (UWIN): Transitioning Toward Sustainbale Urban Water Systems

Science.gov (United States)

Arabi, M.

2015-12-01

City water systems are at risk of disruption from global social and environmental hazards, which could have deleterious effects on human health, property, and loss of critical infrastructure. The Urban Water Innovation Network (UWIN), a consortium of 14 academic institutions and other key partners across the U.S., is working to address challenges that threaten urban water systems across the nation. UWIN's mission is to create technological, institutional and management solutions to help communities increase the resilience of their water systems and enhance their preparedness for responding to water crisis. The network seeks solutions that achieve widespread adoption consistent with inclusive, equitable and sustainable urban development. The integrative and adaptive analysis framework of UWIN is presented. The framework identifies a toolbox of sustainable solutions by simultaneously minimizing pressures, enhancing resilience to extreme events, and maximizing cobenefits. The benefits of sustainable urban water solutions for linked urban ecosystems, economies, and arrangements for environmental justice and social equity, will be discussed. The network encompasses six U.S. regions with varying ecohydrologic and climatic regimes ranging from the coastal moist mid-latitude climates of the Mid-Atlantic to the subtropical semi-arid deserts of the Southwest. These regions also represent a wide spectrum of demographic, cultural, and policy settings. The opportunities for cross-site assessments that facilitate the exploration of locally appropriate solutions across regions undergoing various development trajectories will be discussed.

International regime formation: Ozone depletion and global climate change

International Nuclear Information System (INIS)

Busmann, N.E.

1994-03-01

Two theoretical perspectives, neorealism and neoliberal institutionalism, dominate in international relations. An assessment is made of whether these perspectives provide compelling explanations of why a regime with specific targets and timetables was formed for ozone depletion, while a regime with such specificity was not formed for global climate change. In so doing, the assumptions underlying neorealism and neoliberal institutionalism are examined. A preliminary assessment is offered of the policymaking and institutional bargaining process. Patterns of interstate behavior are evolving toward broader forms of cooperation, at least with regard to global environmental issues, although this process is both slow and cautious. State coalitions on specific issues are not yet powerful enough to create a strong community of states in which states are willing to devolve power to international institutions. It is shown that regime analysis is a useful analytic framework, but it should not be mistaken for theory. Regime analysis provides an organizational framework offering a set of questions regarding the principles and norms that govern cooperation and conflict in an issue area, and whether forces independent of states exist which affect the scope of state behavior. An examination of both neorealism and neoliberal institutionalism, embodied by four approaches to regime formation, demonstrates that neither has sufficient scope to account for contextual dynamics in either the ozone depletion or global climate change regime formation processes. 261 refs

Re-thinking urban flood management

DEFF Research Database (Denmark)

Sörensen, Johanna; Persson, Andreas; Sternudd, Catharina

2016-01-01

-term flood risk and harm the riverine ecosystems in urban as well as rural areas. In the present paper, we depart from resilience theory and suggest a concept to improve urban flood resilience. We identify areas where contemporary challenges call for improved collaborative urban flood management. The concept...... emphasizes resiliency and achieved synergy between increased capacity to handle stormwater runoff and improved experiential and functional quality of the urban environments. We identify research needs as well as experiments for improved sustainable and resilient stormwater management namely, flexibility...

Regimes internacionais e o contencioso das patentes para medicamentos: estratégias para países em desenvolvimento International regimes and the medical patent dispute: strategies for developing countries

Directory of Open Access Journals (Sweden)

Gabriel Cepaluni

2005-06-01

Full Text Available Este artigo mostra que não existe apenas uma única teoria sobre regimes internacionais, mas um conjunto de estudos teóricos e empíricos que, isoladamente ou em conjunto, não constituem uma "teoria geral" das relações internacionais. Três abordagens resumem os principais debates sobre os regimes: o realismo-estrutural, o neoliberalismo e o cognitivismo. A primeira perspectiva - a realista - considera que o poder é o principal conceito para explicar os regimes internacionais. O neoliberalismo considera que o interesse é a principal noção analítica para entender a criação e a manutenção dos regimes. Finalmente, o cognitivismo coloca as idéias e os valores no centro de suas explicações. Feitas essas considerações, analisa-se o contencioso das patentes farmacêuticas entre o Brasil e os Estados Unidos (1988-2001 utilizando insights fornecidos pelos estudos de regimes internacionais - privilegiando-se a abordagem neoliberal. A partir do conflito entre o Brasil e os Estados Unidos, também são desenhadas algumas estratégias que podem ser utilizadas pelos países em desenvolvimento para maximizar seus ganhos no cenário internacional.This article demonstrates that there is not one international regime theory, but a set of theoretical and empirical studies that, alone or together, do not constitute a "general theory" of International Relations. Three approaches summarise the main debates on regimes: structural realism, neoliberalism, and cognitivism. The first perspective - the realist - considers power as the main concept for explaining international regimes. Neoliberalism considers interest as the main analytical tool to understand the creation and maintenance of regimes. Finally, cognitivism places ideas and values at the center of its explanations. After establishing these perspectives, the pharmaceutical patents dispute between Brazil and the United States (1988-2001 is analyzed, utilizing insights gained by the study of

Towards a Theory of Urban Fragmentation: A Cross-Cultural Analysis of Fear, Privatization, and the State

Directory of Open Access Journals (Sweden)

Setha Low

2006-10-01

Full Text Available This paper employs a cross-cultural analysis to explore regional and national variations in residential gating and enclosure as a first step in developing an integrated theory of urban fragmentation. Utilizing data from the urban and suburban United States, Latin America and China, a series of dimensions are compared: 1 domestic architecture, 2 urban/suburban settlement pattern, 3 the role of the state, 4 governance, 5 citizenship, 6 cultural meaning, 7 identity, 8 provision of goods and services, 9 taxation, 10 degree of privatization, 11 cultural pattern of social sanction, and 12 fear of crime and others. This comparative analysis locates culturally meaningful and theoretically significant distinctions among the regions and provides data for the development of explanatory models in which each region varies along a dimensional continuum.  At the macro-level of analysis, the impact of globalization and flexible accumulation with increased local heterogeneity, increases in inequality and changes in perceived crime rate emerge as the major underlying factors in the fear of crime and others found in all three regions.  At a micro-level, differences in cultural meanings are explained by local social and political contexts, while provision of goods and services and governance depend on club realm economic explanations.  

Going beyond The three worlds of welfare capitalism: regime theory and public health research.

Science.gov (United States)

Bambra, C

2007-12-01

International research on the social determinants of health has increasingly started to integrate a welfare state regimes perspective. Although this is to be welcomed, to date there has been an over-reliance on Esping-Andersen's The three worlds of welfare capitalism typology (1990). This is despite the fact that it has been subjected to extensive criticism and that there are in fact a number of competing welfare state typologies within the comparative social policy literature. The purpose of this paper is to provide public health researchers with an up-to-date overview of the welfare state regime literature so that it can be reflected more accurately in future research. It outlines The three worlds of welfare capitalism typology, and it presents the criticisms it received and an overview of alternative welfare state typologies. It concludes by suggesting new avenues of study in public health that could be explored by drawing upon this broader welfare state regimes literature.

Qualifying Urban Landscapes

DEFF Research Database (Denmark)

Clemmensen, Thomas Juel; Nielsen, Tom; Daugaard, Morten

2010-01-01

The article presents an attempt to develop alternatives to the dominant planning and design principles used in building and rebuilding the contemporary urban landscape. The basic idea is that the ‘forces of modernisation’ driving current development might result in a broader and more interesting...... for contemporary urban landscape design practice....... to the task of constructing and improving things. With this goal, a set of objectives based in important insights from recent urban theory are formulated constituting the normative spine of the analysis of a number of found situations as basis for formulating eight generic concepts of qualification...

Tree agency and urban forest governance

DEFF Research Database (Denmark)

Konijnendijk, Cecil Cornelis

2016-01-01

governance also involving businesses and civic society. However, governance theory usually does not consider the role of non-human agency, which can be considered problematic due to, for example, the important role of urban trees in place making. The purpose of this paper is to provide further insight...... into the importance of considering tree agency in governance. Design/methodology/approach – Taking an environmental governance and actor network theory perspective, the paper presents a critical view of current urban forest governance, extending the perspective to include not only a wide range of human actors......, but also trees as important non-human actors. Findings – Urban forest governance has become more complex and involves a greater range of actors and actor networks. However, the agency of trees in urban forest governance is seldom well developed. Trees, in close association with local residents, create...

From Ephemeral Planning to Permanent Urbanism: An Urban Planning Theory of Mega-Events

Directory of Open Access Journals (Sweden)

Eva Kassens-Noor

2016-03-01

Full Text Available Mega-events like the Olympic Games are powerful forces that shape cities. In the wake of mega-events, a variety of positive and negative legacies have remained in host cities. In order to bring some theoretical clarity to debates about legacy creation, I introduce the concepts of the mega-event utopia, dystopia and heterotopia. A mega-event utopia is ideal and imaginary urbanism embracing abstract concepts about economies, socio-political systems, spaces, and societies in the host during events. The mega-event utopia (in contrast to other utopian visions other stakeholders may hold is dictated by the desires of the mega-event owners irrespective of the realities in the event host. In short, a mega-event utopia is the perfect event host from the owner’s perspective. Mega-event utopias are suggested as a theoretical model for the systematic transformation of their host cities. As large-scale events progress as ever more powerful transformers into this century, mega-event dystopias have emerged as negatives of these idealistic utopias. As hybrid post-event landscapes, mega-event heterotopias manifest the temporary mega-event utopia as legacy imprints into the long-term realities in hosting cities. Using the Olympic utopia as an example of a mega-event utopia, I theorize utopian visions around four urban traits: economy, image, infrastructure and society. Through the concept of the mega-event legacy utopia, I also provide some insight toward the operationalization of the four urban traits for a city’s economic development, local place marketing, urban development, and public participation.

Urban Land Expansion and Spatial Dynamics in Globalizing Shanghai

Directory of Open Access Journals (Sweden)

Han Li

2014-12-01

Full Text Available Urban land expansion in China has attracted considerable scholarly attention. However, more work is needed to apply spatial modeling to understanding the mechanisms of urban growth from both institutional and physical perspectives. This paper analyzes urban expansion in Shanghai and its development zones (DZs. We find that, as nodes of global-local interface, the DZs are the most significant components of urban growth in Shanghai, and major spatial patterns of urban expansion in Shanghai are infilling and edge expansion. We apply logistic regression, geographically weighted logistic regression (GWLR and spatial regime regression to investigate the determinants of urban land expansion including physical conditions, state policy and land development. Regressions reveal that, though the market has been an important driving force in urban growth, the state has played a predominant role through the implementation of urban planning and the establishment of DZs to fully capitalize on globalization. We also find that differences in urban growth dynamics exist between the areas inside and outside of the DZs. Finally, this paper discusses policies to promote sustainable development in Shanghai.

Evaluation of a new method for assessing resilience in urban aquatic social-ecological systems

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Jonathan P. Moores

2017-12-01

Full Text Available Urban aquatic social-ecological systems (SESs comprise socio-technical elements, the built environment and its management, and natural elements (water bodies that provide ecosystem services. Changed hydrology, poor stormwater quality, and the modification of water bodies associated with urban development brings challenges for maintaining ecosystem services provision in an urban aquatic SES. Water sensitive urban design (WSUD has emerged as a form of development that aims to better support the provision of ecosystem services. Resilience concepts provide a basis for discriminating between WSUD and conventional development approaches. Building on an existing decision support system, a new, preliminary method for assessing resilience based on the combination of the socio-technical capacity (STC and natural capacity (NC of urban aquatic SESs has been developed. The STC score reflects a multicriteria assessment of the characteristics of stormwater infrastructure and management. The NC score reflects an assessment of the state and trajectory of biophysical attributes of the system associated with the provision of ecosystem services. By modeling a series of future urban development scenarios in Auckland, New Zealand, the method has been shown to discriminate between scenario outcomes within constraints associated with the biophysical and built characteristics modeled. Results are consistent with key concepts of resilience theory: outcomes are grouped in regimes and exhibit hysteresis, with the ability of WSUD to improve the state of the system strongly influenced by the presence of legacy effects. The method provides a source of additional, valuable information that complements other indicators by providing a snapshot of the interaction of catchment management effort and outcomes and indicating the likely future state of the SES. Recognizing that the method is limited to providing a relative assessment of resilience and adopts certain simplistic

Flow regimes

International Nuclear Information System (INIS)

Kh'yuitt, G.

1980-01-01

An introduction into the problem of two-phase flows is presented. Flow regimes arizing in two-phase flows are described, and classification of these regimes is given. Structures of vertical and horizontal two-phase flows and a method of their identification using regime maps are considered. The limits of this method application are discussed. The flooding phenomena and phenomena of direction change (flow reversal) of the flow and interrelation of these phenomena as well as transitions from slug regime to churn one and from churn one to annular one in vertical flows are described. Problems of phase transitions and equilibrium are discussed. Flow regimes in tubes where evaporating liquid is running, are described [ru

Dynamic Financial Constraints: Distinguishing Mechanism Design from Exogenously Incomplete Regimes.

Science.gov (United States)

Karaivanov, Alexander; Townsend, Robert M

2014-05-01

We formulate and solve a range of dynamic models of constrained credit/insurance that allow for moral hazard and limited commitment. We compare them to full insurance and exogenously incomplete financial regimes (autarky, saving only, borrowing and lending in a single asset). We develop computational methods based on mechanism design, linear programming, and maximum likelihood to estimate, compare, and statistically test these alternative dynamic models with financial/information constraints. Our methods can use both cross-sectional and panel data and allow for measurement error and unobserved heterogeneity. We estimate the models using data on Thai households running small businesses from two separate samples. We find that in the rural sample, the exogenously incomplete saving only and borrowing regimes provide the best fit using data on consumption, business assets, investment, and income. Family and other networks help consumption smoothing there, as in a moral hazard constrained regime. In contrast, in urban areas, we find mechanism design financial/information regimes that are decidedly less constrained, with the moral hazard model fitting best combined business and consumption data. We perform numerous robustness checks in both the Thai data and in Monte Carlo simulations and compare our maximum likelihood criterion with results from other metrics and data not used in the estimation. A prototypical counterfactual policy evaluation exercise using the estimation results is also featured.

A Case for Intermediate Exchange-Rate Regimes

OpenAIRE

Agnès Bénassy-Quéré; Véronique Salins

2010-01-01

Despite increasing capital mobility and the subsequent difficulty in controlling exchange rates, intermediate exchange-rate regimes have remained widespread, especially in emerging and developing economies. This piece of evidence hardly fits the "impossible Trinity" theory arguing that it becomes difficult to control the exchange rate without a "hard" device when capital flows are freed. Calvo and Reinhart (2000) have suggested several explanations for such "fear of floating": exchange rate p...

Kohn-Sham density functional theory for quantum wires in arbitrary correlation regimes

NARCIS (Netherlands)

Malet, F.; Mirtschink, A.P.; Cremon, J. C.; Reimann, S. M.; Gori Giorgi, P.

2013-01-01

We use the exact strong-interaction limit of the Hohenberg-Kohn energy density functional to construct an approximation for the exchange-correlation term of the Kohn-Sham approach. The resulting exchange-correlation potential is able to capture the features of the strongly correlated regime without

Dune growth under multidirectional wind regimes

Science.gov (United States)

Gadal, C.; Rozier, O.; Claudin, P.; Courrech Du Pont, S.; Narteau, C.

2017-12-01

Under unidirectional wind regimes, flat sand beds become unstable to produce periodic linear dunes, commonly called transverse dunes because their main ridges are oriented perpendicular to the air flow. In areas of low sediment availability, the same interactions between flow, transport and topography produce barchan dunes, isolated sand-pile migrating over long distances with a characteristic crescentic shape. For the last fifteen years, barchan dunes and the instability at the origin of transverse dunes have been the subject of numerous studies that have identified a set of characteristic length and time scales with respect to the physical properties of both grains and fluid. This is not the case for dunes developing under multidirectional wind regimes. Under these conditions, dune orientation is measured with respect to the direction of the resultant sand flux. Depending on the wind regime, dunes do not always line up perpendicularly to the resultant sand flux, but can also be at an oblique angle or even parallel to it. These oblique and longitudinal dunes are ubiquitous in all deserts on Earth and planetary bodies because of the seasonal variability of wind orientation. They are however poorly constrained by observations and there is still no complete theoretical framework providing a description of their orientation and initial wavelength. Here, we extend the linear stability analysis of a flat sand of bed done in two dimensions for a unidirectional flow to three dimensions and multidirectional flow regimes. We are able to recover transitions from transverse to oblique or longitudinal dune patterns according to changes in wind regimes. We besides give a prediction for the initial dune wavelength. Our results compare well to previous theory of dune orientation and to field, experimental and numerical data.

Quantum interference magnetoconductance of polycrystalline germanium films in the variable-range hopping regime

Science.gov (United States)

Li, Zhaoguo; Peng, Liping; Zhang, Jicheng; Li, Jia; Zeng, Yong; Zhan, Zhiqiang; Wu, Weidong

2018-06-01

Direct evidence of quantum interference magnetotransport in polycrystalline germanium films in the variable-range hopping (VRH) regime is reported. The temperature dependence of the conductivity of germanium films fulfilled the Mott VRH mechanism with the form of ? in the low-temperature regime (?). For the magnetotransport behaviour of our germanium films in the VRH regime, a crossover, from negative magnetoconductance at the low-field to positive magnetoconductance at the high-field, is observed while the zero-field conductivity is higher than the critical value (?). In the regime of ?, the magnetoconductance is positive and quadratic in the field for some germanium films. These features are in agreement with the VRH magnetotransport theory based on the quantum interference effect among random paths in the hopping process.

Thermal Characteristics of Urban Landscapes

Science.gov (United States)

Luvall, Jeffrey C.; Quattrochi, Dale A.

1998-01-01

Although satellite data are very useful for analysis of the urban heat island effect at a coarse scale, they do not lend themselves to developing a better understanding of which surfaces across the city contribute or drive the development of the urban heat island effect. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., less than 15 m) to adequately resolve these surfaces and their attendant thermal energy regimes. Additionally, very fine scale spatial resolution thermal infrared data, such as that obtained from aircraft, are very useful for demonstrating to planning officials, policy makers, and the general populace the benefits of the urban forest. These benefits include mitigating the urban heat island effect, making cities more aesthetically pleasing and more habitable environments, and aid in overall cooling of the community. High spatial resolution thermal data are required to quantify how artificial surfaces within the city contribute to an increase in urban heating and the benefit of cool surfaces (e.g., surface coatings that reflect much of the incoming solar radiation as opposed to absorbing it thereby lowering urban temperatures). The TRN (thermal response number) is a technique using aircraft remotely sensed surface temperatures to quantify the thermal response of urban surfaces. The TRN was used to quantify the thermal response of various urban surface types ranging from completely vegetated surfaces to asphalt and concrete parking lots for Huntsville, AL.

Re-thinking the politics of migration. On the uses and challenges of regime perspectives for migration research

NARCIS (Netherlands)

Horvath, Kenneth; Amelinaz, Anna; Peters, Karin

2017-01-01

The aim of this special issue is to critically assess the potential of regime theory for migration research. Against the background of contemporary political dynamics, regime terminology has become rather popular in migration studies. There has, however, been little debate on the foundations and

Developing a stochastic conflict resolution model for urban runoff quality management: Application of info-gap and bargaining theories

Science.gov (United States)

Ghodsi, Seyed Hamed; Kerachian, Reza; Estalaki, Siamak Malakpour; Nikoo, Mohammad Reza; Zahmatkesh, Zahra

2016-02-01

In this paper, two deterministic and stochastic multilateral, multi-issue, non-cooperative bargaining methodologies are proposed for urban runoff quality management. In the proposed methodologies, a calibrated Storm Water Management Model (SWMM) is used to simulate stormwater runoff quantity and quality for different urban stormwater runoff management scenarios, which have been defined considering several Low Impact Development (LID) techniques. In the deterministic methodology, the best management scenario, representing location and area of LID controls, is identified using the bargaining model. In the stochastic methodology, uncertainties of some key parameters of SWMM are analyzed using the info-gap theory. For each water quality management scenario, robustness and opportuneness criteria are determined based on utility functions of different stakeholders. Then, to find the best solution, the bargaining model is performed considering a combination of robustness and opportuneness criteria for each scenario based on utility function of each stakeholder. The results of applying the proposed methodology in the Velenjak urban watershed located in the northeastern part of Tehran, the capital city of Iran, illustrate its practical utility for conflict resolution in urban water quantity and quality management. It is shown that the solution obtained using the deterministic model cannot outperform the result of the stochastic model considering the robustness and opportuneness criteria. Therefore, it can be concluded that the stochastic model, which incorporates the main uncertainties, could provide more reliable results.

TYPES OF POLITICAL REGIMES IN THE IRKUTSK REGION

Directory of Open Access Journals (Sweden)

И В Орлова

2017-12-01

Full Text Available The authors consider contemporary western and Russian classifications of regional political regimes and their applicability for Russia. Based on the analysis of political theories, the authors chose the traditional typology of regional political regimes focusing on the minimalist interpretation of democracy (electoral competition and methods for identifying regional scenarios introduced by V.Ya. Gelman. The authors study the case of the Irkutsk Region as a region with conflicting elites, in which in a short period several regional heads were replaced. Based on the contemporary political history, the authors analyze the regional political regime using the following criteria: democracy/autocracy, consolidation/oligo-poly, compromise/conflict relations within the ruling elite. The results of the analysis prove the existence of checks and balances in the political system of the Irkutsk Region. Such a system restrains strong politicians attempts to monopolize the political power in the region. When any political player gains too much influence, other centers of power unite against him and together return the situation to the status quo. The political regime of the Irkutsk Region ensures a relatively high level of political competition, at the same time it is a part of the uncompetitive political regime of the Russian Federation, therefore it is a ‘hybrid democracy’. The authors’ analysis of intra-elite relations in the region revealed a high predisposition to conflicts with the dominant scenario of ‘war of all against all’.

Climate conscious citizenship in a digital urban setting

DEFF Research Database (Denmark)

Andersen, Sophie Esmann; Nielsen, Anne Ellerup

2011-01-01

Climate change has challenged urban life, and as an omnipresent force, Nature sets the agenda for urban living. Using stakeholder theory to conceptualise urban life, we approach Nature as both an omnipresent stakeholder and an issue to be continuously addressed and related to. Adapting the stakeh......Climate change has challenged urban life, and as an omnipresent force, Nature sets the agenda for urban living. Using stakeholder theory to conceptualise urban life, we approach Nature as both an omnipresent stakeholder and an issue to be continuously addressed and related to. Adapting...... explore how the citizen is framed and invited to enact his/her responsibilities to the natural environment in an urban setting and how the digital mediation facilitates various forms of relations and climate conscious positions, incorporating both narcissistic desires, universal anxiety, moral obligations......, ethical virtue and image performance. Statements from the actual confessors/committers exemplify this. Thus, the paper provides insight into understanding the complexity of climate-conscious citizenship as a complex configuration of paradoxical, co-existing ethics and arguments....

Scaling Theory of Polyelectrolyte Nanogels

Science.gov (United States)

Qu, Li-Jian

2017-08-01

The present paper develops the scaling theory of polyelectrolyte nanogels in dilute and semidilute solutions. The dependencies of the nanogel dimension on branching topology, charge fraction, subchain length, segment number, solution concentration are obtained. For a single polyelectrolyte nanogel in salt free solution, the nanogel may be swelled by the Coulombic repulsion (the so-called polyelectrolyte regime) or the osmotic counterion pressure (the so-called osmotic regime). Characteristics and boundaries between different regimes of a single polyelectrolyte nanogel are summarized. In dilute solution, the nanogels in polyelectrolyte regime will distribute orderly with the increase of concentration. While the nanogels in osmotic regime will always distribute randomly. Different concentration dependencies of the size of a nanogel in polyelectrolyte regime and in osmotic regime are also explored. Supported by China Earthquake Administration under Grant No. 20150112 and National Natural Science Foundation of China under Grant No. 21504014

Climate change and future fire regimes: Examples from California

Science.gov (United States)

Keeley, Jon E.; Syphard, Alexandra D.

2016-01-01

Climate and weather have long been noted as playing key roles in wildfire activity, and global warming is expected to exacerbate fire impacts on natural and urban ecosystems. Predicting future fire regimes requires an understanding of how temperature and precipitation interact to control fire activity. Inevitably this requires historical analyses that relate annual burning to climate variation. Fuel structure plays a critical role in determining which climatic parameters are most influential on fire activity, and here, by focusing on the diversity of ecosystems in California, we illustrate some principles that need to be recognized in predicting future fire regimes. Spatial scale of analysis is important in that large heterogeneous landscapes may not fully capture accurate relationships between climate and fires. Within climatically homogeneous subregions, montane forested landscapes show strong relationships between annual fluctuations in temperature and precipitation with area burned; however, this is strongly seasonal dependent; e.g., winter temperatures have very little or no effect but spring and summer temperatures are critical. Climate models that predict future seasonal temperature changes are needed to improve fire regime projections. Climate does not appear to be a major determinant of fire activity on all landscapes. Lower elevations and lower latitudes show little or no increase in fire activity with hotter and drier conditions. On these landscapes climate is not usually limiting to fires but these vegetation types are ignition-limited. Moreover, because they are closely juxtaposed with human habitations, fire regimes are more strongly controlled by other direct anthropogenic impacts. Predicting future fire regimes is not rocket science; it is far more complicated than that. Climate change is not relevant to some landscapes, but where climate is relevant, the relationship will change due to direct climate effects on vegetation trajectories, as well as

Climate Change and Future Fire Regimes: Examples from California

Directory of Open Access Journals (Sweden)

Jon E. Keeley

2016-08-01

Full Text Available Climate and weather have long been noted as playing key roles in wildfire activity, and global warming is expected to exacerbate fire impacts on natural and urban ecosystems. Predicting future fire regimes requires an understanding of how temperature and precipitation interact to control fire activity. Inevitably this requires historical analyses that relate annual burning to climate variation. Fuel structure plays a critical role in determining which climatic parameters are most influential on fire activity, and here, by focusing on the diversity of ecosystems in California, we illustrate some principles that need to be recognized in predicting future fire regimes. Spatial scale of analysis is important in that large heterogeneous landscapes may not fully capture accurate relationships between climate and fires. Within climatically homogeneous subregions, montane forested landscapes show strong relationships between annual fluctuations in temperature and precipitation with area burned; however, this is strongly seasonal dependent; e.g., winter temperatures have very little or no effect but spring and summer temperatures are critical. Climate models that predict future seasonal temperature changes are needed to improve fire regime projections. Climate does not appear to be a major determinant of fire activity on all landscapes. Lower elevations and lower latitudes show little or no increase in fire activity with hotter and drier conditions. On these landscapes climate is not usually limiting to fires but these vegetation types are ignition-limited. Moreover, because they are closely juxtaposed with human habitations, fire regimes are more strongly controlled by other direct anthropogenic impacts. Predicting future fire regimes is not rocket science; it is far more complicated than that. Climate change is not relevant to some landscapes, but where climate is relevant, the relationship will change due to direct climate effects on vegetation

Alternative approaches to food: Community supported agriculture in urban China

OpenAIRE

Krul, K.; Ho, P.P.S.

2017-01-01

One of the most remarkable features of China's development path is its large-scale and fast-paced urbanization. As cities already accommodate more than half of China's population, new challenges to urban food systems have emerged concurrently. Concerns over environmental degradation and food safety have provoked growing dissatisfaction with China's food regime. Amidst these concerns, the aim of this paper is to study the role of new and alternative approaches to food, focusing in on the quest...

Inflation from Asymptotically Safe Theories

DEFF Research Database (Denmark)

Nielsen, Niklas Grønlund; Sannino, Francesco; Svendsen, Ole

2015-01-01

for inflation. In the minimal coupling case the theory requires large non-perturbative quantum corrections to the quantum potential for the theory to agree with data, while in the non- minimal coupling case the perturbative regime in the couplings of the theory is preferred. Requiring the theory to reproduce...... the observed amplitude of density perturbations constrain the geometric data of the theory such as the number of colors and flavors for generic values of the non-minimal coupling....

Fluid Mechanics of Urban Environments

Science.gov (United States)

Fernando, Harindra J.

2008-11-01

The rapid urbanization of the Earth has led to highly populated cities that act as concentrated centers of anthropogenic stressors on the natural environment. The degradation of environmental quality due to such stressors, in turn, greatly impacts human behavior. Anthropogenic stressors largely originate as a result of coupling between man-made urban elements (i.e., networks of engineering and socio-economic infrastructures) and the environment, for which surrounding fluid motions play a key role. In recent years, research efforts have been directed at the understanding and modeling of fluid motions in urban areas, infrastructure dynamics and interactions thereof, with the hope of identifying environmental impacts of urbanization and complex outcomes (or ``emergent properties'') of nominally simple interactions between infrastructures and environment. Such consequences play an important role in determining the ``resilience'' of cities under anthropogenic stressors, defined as maintaining the structure and essential functions of an urbanity without regime shifts. Holistic integrated models that meld the dynamics of infrastructures and environment as well as ``quality of life'' attributes are becoming powerful decision-making tools with regard to sustainability of urban areas (continuance or even enhancement of socio-economic activities in harmony with the environment). The rudimentary forms of integrated models are beginning to take shape, augmented by comprehensive field studies and advanced measurement platforms to validate them. This presentation deals with the challenges of modeling urban atmosphere, subject to anthropogenic forcing. An important emergent property, the Urban Heat Island, and its role in determining resilience and sustainability of cities will be discussed based on the prediction of a coupled model.

Participatory Design in an Urban Context

DEFF Research Database (Denmark)

Gøtze, John

of the conditions necessary for estab-lishing urban social networks, and different methodologies for doing so are examined. As part of this, a study is done on electronic democracy, i.e., different forms of information and communi-cation technologies (IT/ICT, Internet) that are actually and potentially applicable...... to innovative urban community development. The project combines theories of communication, dialogue and innovation with theories of systems, information, media and decision making. The project involves a comparative study of selected projects in the capital regions of Den-mark (Copenhagen) and Japan (Tokyo...

Neoclassical kinetic theory near an X point: Plateau regime

International Nuclear Information System (INIS)

Solano, E.R.; Hazeltine, R.D.

1994-01-01

Traditionally, neoclassical transport calculations ignore poloidal variation of the poloidal magnetic field. Near an X point of the confining field of a diverted plasma, the poloidal field is small, causing guiding centers to linger at that poloidal position. A study of how neoclassical transport is affected by this differential shaping is presented. The problem is solved in general in the plateau regime, and a model poloidal flux function with an X point is utilized as an analytic example to show that the plateau diffusion coefficient can change considerably (factor of 2 reduction). Ion poloidal rotation is proportional to the local value of B pol but otherwise it is not strongly affected by shaping. The usual favorable scaling of neoclassical confinement time with plasma current is unaffected by the X point

On the ontological emergence from quantum regime

Energy Technology Data Exchange (ETDEWEB)

Luty, Damian [Adam Mickiewicz University, Poznan (Poland)

2014-07-01

There are several views on the relation between quantum physics and theory of relativity (especially General Relativity, GR). A popular perspective is this: GR with its macroscopic gravitational effects will turn out to be a limit of a more fundamental theory which should consider discrete physics and not deal with continuity (like theory of relativity). Thus, GR will emerge from a more basic theory, which should be quantum-like. One could call this an epistemic emergence view towards fundamental theories. The question is, given that scientific realism is valid: should emergence be a fundamental notion in our ontological view about the evolving, physical Universe? Is there an ontological emergence fully compatible with the notion of fundamentality? I argue that if we want to defend ontological emergence (from quantum to macroscopic regime) as something fundamental, we will arrive at the position of metaphysics of dispositions (and I argue, why this is undesirable), or conclude, that we cannot square fully fundamental ontology with the notion of emergence, and that we have to accept an ontological pluralism relativised to a certain scale. I defend the latter proposition, showing, that epistemic emergence doesn't entail (logically) ontological emergence.

Urban Regeneration Partnerships: A Figurational Critique of Governmentality Theory

OpenAIRE

Lever, John

2011-01-01

This article provides a critique of governmentally inspired accounts of urban regeneration and partnership working. Drawing on the work of Norbert Elias and prominent figurational sociologists, it discusses the changes taking place within and through the many partnerships set up by New Labour around the notion of ‘community safety’. Although recognizing the important insights provided by accounts of urban regeneration emerging through studies of governmentality, the article argues that such a...

Beyond urban legends: an emerging framework of urban ecology, as illustrated by the Baltimore Ecosystem Study

Science.gov (United States)

Steward T.A. Pickett; Mary L. Cadenasso; J. Morgan Grove; Peter M. Groffman; Lawrence E. Band; Christopher G. Boone; William R., Jr. Burch; Susan B. Grimmond; John Hom; Jennifer C. Jenkins; Neely L. Law; Charles H. Nilon; Richard V. Pouyat; Katalin Szlavecz; Paige S. Warren; Matthew A. Wilson

2008-01-01

The emerging discipline of urban ecology is shifting focus from ecological processes embedded within cities to integrative studies of large urban areas as biophysical-social complexes. Yet this discipline lacks a theory. Results from the Baltimore Ecosystem Study, part of the Long Term Ecological Research Network, expose new assumptions and test existing assumptions...

Scale Mismatches in Management of Urban Landscapes

Directory of Open Access Journals (Sweden)

Sara T. Borgström

2006-12-01

Full Text Available Urban landscapes constitute the future environment for most of the world's human population. An increased understanding of the urbanization process and of the effects of urbanization at multiple scales is, therefore, key to ensuring human well-being. In many conventional natural resource management regimes, incomplete knowledge of ecosystem dynamics and institutional constraints often leads to institutional management frameworks that do not match the scale of ecological patterns and processes. In this paper, we argue that scale mismatches are particularly pronounced in urban landscapes. Urban green spaces provide numerous important ecosystem services to urban citizens, and the management of these urban green spaces, including recognition of scales, is crucial to the well-being of the citizens. From a qualitative study of the current management practices in five urban green spaces within the Greater Stockholm Metropolitan Area, Sweden, we found that 1 several spatial, temporal, and functional scales are recognized, but the cross-scale interactions are often neglected, and 2 spatial and temporal meso-scales are seldom given priority. One potential effect of the neglect of ecological cross-scale interactions in these highly fragmented landscapes is a gradual reduction in the capacity of the ecosystems to provide ecosystem services. Two important strategies for overcoming urban scale mismatches are suggested: 1 development of an integrative view of the whole urban social-ecological landscape, and 2 creation of adaptive governance systems to support practical management.

Quantum theory of acoustoelectric interaction

DEFF Research Database (Denmark)

Mosekilde, Erik

1974-01-01

term, significant in the classical-collision-dominated regime only, the dielectric response function and the acoustic gain factor for a piezoelectrically active sound wave are obtained for the quantum and semiclassical-microscopic regimes. The manner in which the theory can be extended to the collision......-dominated regime is discussed. For a collision-free electron gas, the requirements of energy and momentum conservation in individual electron-phonon interactions lead to a cutoff in the acoustoelectric coupling when the acoustic wave number exceeds the characteristic electron wave number. The broadening...

State Response to Contemporary Urban Movements in Turkey : A Critical Overview of State Entrepreneurialism and Authoritarian Interventions

NARCIS (Netherlands)

Eraydin, A.; Tasa-Kok, T.

2013-01-01

This paper grapples with the state's response to contemporary urban movements. In light of recent debates on the changing nature of urban movements, it presents an overview of the responses of states in different modes of regulation, ranging from a Keynesian regime to sequential stages of

Critical slowing down associated with regime shifts in the US housing market

Science.gov (United States)

Tan, James Peng Lung; Cheong, Siew Siew Ann

2014-02-01

Complex systems are described by a large number of variables with strong and nonlinear interactions. Such systems frequently undergo regime shifts. Combining insights from bifurcation theory in nonlinear dynamics and the theory of critical transitions in statistical physics, we know that critical slowing down and critical fluctuations occur close to such regime shifts. In this paper, we show how universal precursors expected from such critical transitions can be used to forecast regime shifts in the US housing market. In the housing permit, volume of homes sold and percentage of homes sold for gain data, we detected strong early warning signals associated with a sequence of coupled regime shifts, starting from a Subprime Mortgage Loans transition in 2003-2004 and ending with the Subprime Crisis in 2007-2008. Weaker signals of critical slowing down were also detected in the US housing market data during the 1997-1998 Asian Financial Crisis and the 2000-2001 Technology Bubble Crisis. Backed by various macroeconomic data, we propose a scenario whereby hot money flowing back into the US during the Asian Financial Crisis fueled the Technology Bubble. When the Technology Bubble collapsed in 2000-2001, the hot money then flowed into the US housing market, triggering the Subprime Mortgage Loans transition in 2003-2004 and an ensuing sequence of transitions. We showed how this sequence of couple transitions unfolded in space and in time over the whole of US.

Socioeconomic inequalities in oral health in different European welfare state regimes.

Science.gov (United States)

Guarnizo-Herreño, Carol C; Watt, Richard G; Pikhart, Hynek; Sheiham, Aubrey; Tsakos, Georgios

2013-09-01

There is very little information about the relationship between welfare regimes and oral health inequalities. We compared socioeconomic inequalities in adults' oral health in five European welfare-state regimes: Scandinavian, Anglo-Saxon, Bismarckian, Southern and Eastern. Using data from the oral health module of the Eurobarometer 72.3 survey, we assessed inequalities in two self-reported oral health measures: no functional dentition (less than 20 natural teeth) and edentulousness (no natural teeth). Occupational social class, education and subjective social status (SSS) were included as socioeconomic position indicators. We estimated age-standardised prevalence rates, ORs, the Relative Index of Inequality (RII) and the Slope Index of Inequality (SII). The Scandinavian regime showed the lowest prevalence rates of the two oral health measures while the Eastern showed the highest. In all welfare regimes there was a general pattern of social gradients by occupational social class and education. Relative educational inequalities in no functional dentition were largest in the Scandinavian welfare regime (RII=3.81; 95% CI 2.68 to 5.42). The Scandinavian and Southern regimes showed the largest relative inequalities in edentulousness by occupation and education, respectively. There were larger absolute inequalities in no functional dentition in the Eastern regime by occupation (SII=42.16; 95% CI 31.42 to 52.89) and in the Southern by SSS (SII=27.92; 95% CI 17.36 to 38.47). Oral health inequalities in adults exist in all welfare-state regimes, but contrary to what may be expected from theory, they are not smaller in the Scandinavian regime. Future work should examine the potential mechanisms linking welfare provision and oral health inequalities.

Modeling Whistler Wave Generation Regimes In Magnetospheric Cyclotron Maser

Science.gov (United States)

Pasmanik, D. L.; Demekhov, A. G.; Trakhtengerts, V. Y.; Parrot, M.

Numerical analysis of the model for cyclotron instability development in the Earth magnetosphere is made.This model, based on the self-consistent set of equations of quasi-linear plasma theory, describes different regimes of wave generation and related energetic particle precipitation. As the source of free energy the injection of energetic electrons with transverse anisotropic distribution function to the interaction region is considered. Two different mechanisms of energetic electron loss from the interaction region are discussed. The first one is precipitation of energetic particles via the loss cone. The other mechanism is drift of particles away from the interaction region across the mag- netic field line. In the case of interaction in plasmasphere or rather large areas of cold plasma density enhancement the loss cone precipitation are dominant. For interaction in a subauroral duct losses due to drift are most effective. A parametric study of the model for both mechanisms of particle losses is made. The main attention is paid to the analysis of generation regimes for different characteristics of energetic electron source, such as the shape of pitch-angle distributions and elec- tron density. We show that in addition to the well-known stationary generation and periodic regime with successive spikes of similar shape, more complex forms of wave spectrum exist. In particular, we found a periodic regime, in which a single period in- cludes two separate spikes with different spectral shapes. In another regime, periodic generation of spikes at higher frequencies together with quasi-stationary generation at lower frequencies occurs. Quasi-periodic regime with spike overlapping, i.e. when generation of a new spike begins before the previous one is over is also found. Results obtained are compared with experimental data on quasi-periodic regimes of whistler wave generation.

Photoabsorption spectra in the perturbative regime for atoms in crossed electric and magnetic fields

International Nuclear Information System (INIS)

Marxer, H.; Moser, I.; O'Mahony, P.F.; Mota-Furtado, F.

1994-01-01

We calculate photoabsorption spectra of atoms in crossed electric and magnetic fields using a truncated basis of Coulomb eigenfunctions. The method yields spectra in the regime where inter-n-mixing is not dominant and allows for the treatment of non-hydrogenic atoms via a simple recourse to quantum defects. We compare results for hydrogen to those obtained in second order perturbation theory where the residual degeneracy left in first order perturbation theory is completely lifted and we show that only a very small basis size is needed to achieve convergence to within the accuracy of second order perturbation theory. In the case of lithium the coupling of an incomplete hydrogen-like manifold to states with non-negligible quantum defects substantially modifies the spectra obtained in comparison to the purely hydrogenic spectra. In the inter-n-mixing regime we also compare our convoluted results directly with an experimental spectrum for hydrogen and find good agreement below the saddle point. (Author)

Analysis of the Two-Regime Method on Square Meshes

KAUST Repository

Flegg, Mark B.

2014-01-01

The two-regime method (TRM) has been recently developed for optimizing stochastic reaction-diffusion simulations [M. Flegg, J. Chapman, and R. Erban, J. Roy. Soc. Interface, 9 (2012), pp. 859-868]. It is a multiscale (hybrid) algorithm which uses stochastic reaction-diffusion models with different levels of detail in different parts of the computational domain. The coupling condition on the interface between different modeling regimes of the TRM was previously derived for onedimensional models. In this paper, the TRM is generalized to higher dimensional reaction-diffusion systems. Coupling Brownian dynamics models with compartment-based models on regular (square) two-dimensional lattices is studied in detail. In this case, the interface between different modeling regimes contains either flat parts or right-angle corners. Both cases are studied in the paper. For flat interfaces, it is shown that the one-dimensional theory can be used along the line perpendicular to the TRM interface. In the direction tangential to the interface, two choices of the TRM parameters are presented. Their applicability depends on the compartment size and the time step used in the molecular-based regime. The two-dimensional generalization of the TRM is also discussed in the case of corners. © 2014 Society for Industrial and Applied Mathematics.

Research on application of intelligent computation based LUCC model in urbanization process

Science.gov (United States)

Chen, Zemin

2007-06-01

Global change study is an interdisciplinary and comprehensive research activity with international cooperation, arising in 1980s, with the largest scopes. The interaction between land use and cover change, as a research field with the crossing of natural science and social science, has become one of core subjects of global change study as well as the front edge and hot point of it. It is necessary to develop research on land use and cover change in urbanization process and build an analog model of urbanization to carry out description, simulation and analysis on dynamic behaviors in urban development change as well as to understand basic characteristics and rules of urbanization process. This has positive practical and theoretical significance for formulating urban and regional sustainable development strategy. The effect of urbanization on land use and cover change is mainly embodied in the change of quantity structure and space structure of urban space, and LUCC model in urbanization process has been an important research subject of urban geography and urban planning. In this paper, based upon previous research achievements, the writer systematically analyzes the research on land use/cover change in urbanization process with the theories of complexity science research and intelligent computation; builds a model for simulating and forecasting dynamic evolution of urban land use and cover change, on the basis of cellular automation model of complexity science research method and multi-agent theory; expands Markov model, traditional CA model and Agent model, introduces complexity science research theory and intelligent computation theory into LUCC research model to build intelligent computation-based LUCC model for analog research on land use and cover change in urbanization research, and performs case research. The concrete contents are as follows: 1. Complexity of LUCC research in urbanization process. Analyze urbanization process in combination with the contents

Measuring the Complexity of Urban Form and Design

OpenAIRE

Boeing, Geoff

2017-01-01

Complex systems have become a popular lens for conceptualizing cities, and complexity has substantial implications for urban performance and resilience. This paper develops a typology of methods and measures for assessing the complexity of the built form at the scale of urban design. It extends quantitative methods from urban planning, network science, ecosystems studies, fractal geometry, and information theory to the physical urban form and the analysis of qualitative human experience. Metr...

Urbancontext: A Management Model For Pervasive Environments In User-Oriented Urban Computing

Directory of Open Access Journals (Sweden)

Claudia L. Zuniga-Canon

2014-01-01

Full Text Available Nowadays, urban computing has gained a lot of interest for guiding the evolution of citiesinto intelligent environments. These environments are appropriated for individuals’ inter-actions changing in their behaviors. These changes require new approaches that allow theunderstanding of how urban computing systems should be modeled.In this work we present UrbanContext, a new model for designing of urban computingplatforms that applies the theory of roles to manage the individual’s context in urban envi-ronments. The theory of roles helps to understand the individual’s behavior within a socialenvironment, allowing to model urban computing systems able to adapt to individuals statesand their needs.UrbanContext collects data in urban atmospheres and classifies individuals’ behaviorsaccording to their change of roles, to optimize social interaction and offer secure services.Likewise, UrbanContext serves as a generic model to provide interoperability, and to facilitatethe design, implementation and expansion of urban computing systems.

Social development in cities and the impact of the Nordic welfare regime

DEFF Research Database (Denmark)

Christensen, Anders Bøggild; Rasmussen, Tove Valborg; Rasinkangas, Jarkko

The ongoing globalisation and urbanisation in most Western societies points at the cities and urban regions as especially interesting in order to discover new trends in the societal development and the welfare regimes ability to deal with these trends. In the literature about social polarisation...... it is mostly the so called global cities - and further capital cities - which are in focus of the analysis {{81 Sassen,Saskia 2001; 366 Sassen, Saskia 2000; 85 Castells,Manuel 1991; 86 Mollenkopf,John Hull 1991; 57 Marcuse,Peter 2000; 94 Hamnett,Chris 2003; 409 Andersen,Hans Thor 2005; 410 Wessel, Terje; 411...... Vaattovaara, Mari and Matti Kortteinen 2003}}. Following central thesis of trends in the distributional and spatial development in cities and discussions about the role of the welfare regime, we shall compare two middle sized cities in two Nordic countries: Aarhus, Denmark (approx 300.000 inhabitants...

Emergent nested systems a theory of understanding and influencing complex systems as well as case studies in urban systems

CERN Document Server

Walloth, Christian

2016-01-01

This book presents a theory as well as methods to understand and to purposively influence complex systems. It suggests a theory of complex systems as nested systems, i. e. systems that enclose other systems and that are simultaneously enclosed by even other systems. According to the theory presented, each enclosing system emerges through time from the generative activities of the systems they enclose. Systems are nested and often emerge unplanned, and every system of high dynamics is enclosed by a system of slower dynamics. An understanding of systems with faster dynamics, which are always guided by systems of slower dynamics, opens up not only new ways to understanding systems, but also to effectively influence them. The aim and subject of this book is to lay out these thoughts and explain their relevance to the purposive development of complex systems, which are exemplified in case studies from an urban system. The interested reader, who is not required to be familiar with system-theoretical concepts or wit...

Interface between urban and rural

DEFF Research Database (Denmark)

Brandt, Jesper

2007-01-01

  Counterurbanisation combined with recent trends in agricultural technology has resulted in a ‘multifunctional countryside regime', raising new questions on the relation between nature and land use in rural areas and between very different values and interests developing in these areas. Indicators...... for new trends in rural landscapes have been related to a model for urban pressure on rural areas in Denmark however without any convincing results. A model for the historical development of a typical Danish village has been made, to see if the socially differentiated process of counterurbanisation can...... be related to the differentiation in the development of different types of village developments. Such a model can elucidate the potentials of a multifunctional landscape as a basis for a varied and and attractive fulfilment of human needs in an urban-rural continuum....

Strategic urban governance of transition in household practices

DEFF Research Database (Denmark)

Quitzau, Maj-Britt; Hoffmann, Birgitte; Hansen, Trine Bang

2013-01-01

Several studies have indicated that urban governance is in different ways intertwined with transitions in socio-technical systems (see e.g. Bulkeley et al. 2011). For example, some local authorities attempt to gain degrees of influence and control over regimes in order to achieve territorial...... priorities (Hodson and Marvin 2010). It has been argued that such governance initiatives do seldom represent transition paths in themselves, due to the delimited focus on the urban scale (Geels 2011). However, these governance initiatives still represent important transition activities that need...... based on the work by Shove and Walker (2010), who note that practitioners are actively involved in making and reproducing socio-technical systems. We especially wish to put forward this point in relation to discussions about what role urban governance initiatives may play in transitions in socio...

Urbanization as Socioenvironmental Succession: The Case of Hazardous Industrial Site Accumulation.

Science.gov (United States)

Elliott, James R; Frickel, Scott

2015-05-01

This study rehabilitates concepts from classical human ecology and synthesizes them with contemporary urban and environmental sociology to advance a theory of urbanization as socioenvironmental succession. The theory illuminates how social and biophysical phenomena interact endogenously at the local level to situate urban land use patterns recursively and reciprocally in place. To demonstrate this theory we conduct a historical-comparative analysis of hazardous industrial site accumulation in four U.S. cities, using a relational database that was assembled for more than 11,000 facilities that operated during the past half century--most of which remain unacknowledged in government reports. Results show how three iterative processes--hazardous industrial churning, residential churning, and risk containment--intersect to produce successive socioenvironmental changes that are highly relevant to but often missed by research on urban growth machines, environmental inequality, and systemic risk.

Discrete and mesoscopic regimes of finite-size wave turbulence

International Nuclear Information System (INIS)

L'vov, V. S.; Nazarenko, S.

2010-01-01

Bounding volume results in discreteness of eigenmodes in wave systems. This leads to a depletion or complete loss of wave resonances (three-wave, four-wave, etc.), which has a strong effect on wave turbulence (WT) i.e., on the statistical behavior of broadband sets of weakly nonlinear waves. This paper describes three different regimes of WT realizable for different levels of the wave excitations: discrete, mesoscopic and kinetic WT. Discrete WT comprises chaotic dynamics of interacting wave 'clusters' consisting of discrete (often finite) number of connected resonant wave triads (or quarters). Kinetic WT refers to the infinite-box theory, described by well-known wave-kinetic equations. Mesoscopic WT is a regime in which either the discrete and the kinetic evolutions alternate or when none of these two types is purely realized. We argue that in mesoscopic systems the wave spectrum experiences a sandpile behavior. Importantly, the mesoscopic regime is realized for a broad range of wave amplitudes which typically spans over several orders on magnitude, and not just for a particular intermediate level.

Heptagon amplitude in the multi-Regge regime

International Nuclear Information System (INIS)

Bartels, J.

2014-05-01

As we have shown in previous work, the high energy limit of scattering amplitudes in N=4 supersymmetric Yang-Mills theory corresponds to the infrared limit of the 1-dimensional quantum integrable system that solves minimal area problems in AdS 5 . This insight can be developed into a systematic algorithm to compute the strong coupling limit of amplitudes in the multi-Regge regime through the solution of auxiliary Bethe Ansatz equations. We apply this procedure to compute the scattering amplitude for n=7 external gluons in different multi-Regge regions at infinite 't Hooft coupling. Our formulas are remarkably consistent with the expected form of 7-gluon Regge cut contributions in perturbative gauge theory. A full description of the general algorithm and a derivation of results is given in a forthcoming paper.

Institutional property rights structure, common pool resource (CPR), tragedy of the urban commons: A Review

Science.gov (United States)

Ling, G.; Ho, C. S.; Ali, H. M.

2014-02-01

There have been a plethora of researches on the significance of public open space (POS) in contributing to societies' sustainability. However, by virtue of identified maladaptive policy-based-property rights structure, such a shared good becomes vulnerable to tragedy of the urban commons (overexploitation) that subsequently leads to burgeoning number of mismanaged POS e.g., degraded and unkempt urban public spaces. By scrutinising the literatures within property rights domain and commons resources, an objective is highlighted in this paper which is to insightfully discourse institutional property rights structure pertaining to the mechanism, roles and interrelationship between property-rights regimes, bundle of property rights and resource domains; types of goods on how they act upon and tie in the POS with the social quandary. In summary, urban POS tragedy can potentially be triggered by the institutional structure especially if the ownership is left under open-access resource regime and ill-defined property rights which both successively constitute the natures of Common Pool Resource (CPR) within the commons, POS. Therefore, this paper sparks an idea to policy makers that property rights structure is a determinant in sustainably governing the POS in which adaptive assignment of property regimes and property rights are impelled.

Institutional property rights structure, common pool resource (CPR), tragedy of the urban commons: A Review

International Nuclear Information System (INIS)

Ling, G; Ho, C S; Ali, H M

2014-01-01

There have been a plethora of researches on the significance of public open space (POS) in contributing to societies' sustainability. However, by virtue of identified maladaptive policy-based-property rights structure, such a shared good becomes vulnerable to tragedy of the urban commons (overexploitation) that subsequently leads to burgeoning number of mismanaged POS e.g., degraded and unkempt urban public spaces. By scrutinising the literatures within property rights domain and commons resources, an objective is highlighted in this paper which is to insightfully discourse institutional property rights structure pertaining to the mechanism, roles and interrelationship between property-rights regimes, bundle of property rights and resource domains; types of goods on how they act upon and tie in the POS with the social quandary. In summary, urban POS tragedy can potentially be triggered by the institutional structure especially if the ownership is left under open-access resource regime and ill-defined property rights which both successively constitute the natures of Common Pool Resource (CPR) within the commons, POS. Therefore, this paper sparks an idea to policy makers that property rights structure is a determinant in sustainably governing the POS in which adaptive assignment of property regimes and property rights are impelled

Multidimensional Plasma Wake Excitation in the Non-linear Blowout Regime

CERN Document Server

Vieira, J.; Silva, L.O.

2016-01-01

Plasma accelerators can sustain very high acceleration gradients. They are promising candidates for future generations of particle accelerators for sev- eral scientific, medical and technological applications. Current plasma based acceleration experiments operate in the relativistic regime, where the plasma response is strongly non-linear. We outline some of the key properties of wake- field excitation in these regimes. We outline a multidimensional theory for the excitation of plasma wakefields in connection with current experiments. We then use these results and provide design guidelines for the choice of laser and plasma parameters ensuring a stable laser wakefield accelerator that maximizes the quality of the accelerated electrons. We also mention some of the future challenges associated with this technology.

Principles of urban quality of life for a neighborhood

Directory of Open Access Journals (Sweden)

Hamam Serag El Din

2013-04-01

Full Text Available Urban quality of life is a notion that has been discussed recently in various studies as a response to many problems facing the new towns all over the world as well as in Egypt. The purpose of this paper is to decompose the term urban quality of life into other more precise terms such as quality, quality of life and urban/urban planning. The paper also aims to address the notion of sustainable development and tries to understand its relationship with the notion of quality of life. Further, it deduces urban quality of life definition and dimensions. On the other hand this paper discusses contemporary urban planning theories and approaches raised in the late of twentieth century in order to provide a high and sustainable quality of life and protect the natural environment. Finally, a matrix concluding the relationship between the principles of these contemporary urban planning theories and approaches and urban quality of life dimensions is developed, in order to achieve a set of principles that address environmental, physical, mobility, social, psychological, economical and political concerns called urban quality of life principles. These principles represent a guide useful for participants of the design process and for policy makers.

Urban greening: environmentalism or marketable aesthetics

Directory of Open Access Journals (Sweden)

Dominic Bowd

2015-11-01

Full Text Available In recent decades, urban greening has been conceptualized, and subsequently marketed, as a way of making cities more sustainable. Urban greening has been actualized in large global cities, regional centers, and also in many cities in the Global South, where it has been touted as a potential solution to the urban heat island (UHI effect and as a way of reducing carbon dioxide (CO2 emissions. This involves planting street trees and installing curbside gardens, bioswales, green walls, green roofs, and the redevelopment of former industrial zones into urban parklands. This paper questions the assumption that this “greening” of the city must necessarily lead to positive environmental impacts. While such infrastructure itself might be constructed with environmental principles in mind, wider questions concerning the production of such landscapes, and the consumption-orientated lifestyles of those who inhabit these urban landscapes, are seldom considered. Moreover, green aesthetics and environmental sustainability are not always as mutually inclusive as the concepts might suggest, as aesthetics are often a dominating influence in the process of planning green urban environments. This review reorients the focus on the way in which the UHI effect and CO2 emissions have been framed by utilizing Foucault's (1980 “regimes of truth,” where environmental issues are contextualized within the “colonised lifeworld” of free-market forces. This review suggests that for sustainability to be achieved in urban contexts, the process of urban greening must move beyond quick techno-fixes through engagement in the co-production of knowledge.

Flow regimes

International Nuclear Information System (INIS)

Liles, D.R.

1982-01-01

Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced

Dynamics of SU(N) supersymmetric gauge theory

Energy Technology Data Exchange (ETDEWEB)

Douglas, M R [Rutgers - the State Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy; Shenker, S H [Rutgers - the State Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy

1995-08-07

We study the physics of the Seiberg-Witten and Argyres-Faraggi-Klemm-Lerche-Theisen-Yankielowicz solutions of D=4, N=2 and N=1 SU(N) supersymmetric gauge theory. The N=1 theory is confining and its effective Lagrangian is a spontaneously broken U(1){sup N-1} abelian gauge theory. We identify some features of its physics which see this internal structure, including a spectrum of different string tensions. We discuss the limit N{yields}{infinity}, identify a scaling regime in which instanton and monopole effects survive, and give exact results for the crossover from weak to strong coupling along a scaling trajectory. We find a large hierarchy of mass scales in the scaling regime, including very light W bosons, and the absence of weak coupling. The light W`s leave a novel imprint on the effective dual magnetic theory. The effective Lagrangian appears to be inadequate to understand the conventional large N limit of the confining N=1 theory. (orig.).

Using Remotely Sensed Data to Map Urban Vulnerability to Heat

Science.gov (United States)

Stefanov, William L.

2010-01-01

This slide presentation defines remote sensing, and presents examples of remote sensing and astronaut photography, which has been a part of many space missions. The presentation then reviews the project aimed at analyzing urban vulnerability to climate change, which is to test the hypotheses that Exposure to excessively warm weather threatens human health in all types of climate regimes; Heat kills and sickens multitudes of people around the globe every year -- directly and indirectly, and Climate change, coupled with urban development, will impact human health. Using Multiple Endmember Spectral Mixing Analysis (MESMA), and the Phoenix urban area as the example, the Normalized Difference Vegetation Index (NDVI) is calculated, a change detection analysis is shown, and surface temperature is shown.

Urban Green Network Design: Defining green network from an urban planning perspective

Directory of Open Access Journals (Sweden)

Andrea Tulisi

2017-08-01

Full Text Available From the theoretical context of Smart City various studies have emerged that adopt an analytical approach and description of urban phenomena based on the principles of “network design”; this line of research uses the network systems theory to define the principles that regulate the relationships among the various elements of urban sub-systems in order to optimize their functionality. From the same theoretical basis, urban greenspaces have also been studied as networks, by means of the creation of models capable of measuring the performance of the system in its entirety, posing the basis of a new multy-disciplinary research field called green network. This paper presents the results of research aimed at clarifying the meaning of green network from an urban planning perspective through a lexical analysis applied to a textual corpus of more than 300 abstracts of research papers that have dealt with this topic over the last twenty years. The results show that the concept of green network appears still fuzzy and unclear, due to the different meaning given to the term “green” and to an incorrect use of the term “network”, often referred to as a generic set of natural areas present in a city, without any reference to the network system theory or to the basic rules linking these elements together. For this reason, the paper proposes a unique definition of green network from an urban planning perspective that takes into account the contribution of other research areas to effective green infrastructure planning. This is the concept of “urban green network design” defined as “an urban planning practice, supported by decision support tools able to model green infrastructure as network, composed by natural and semi-natural areas, whose connections are modelled according to specific variables, in order to deliver an equal distribution of public services for enhancing the quality of life as well as a wide range of ecosystem services”.

Toward an integrated theory of spatial morphology and resilient urban systems

Directory of Open Access Journals (Sweden)

Lars Marcus

2014-12-01

Full Text Available We take the first step in the development of a new field of research with the aim of merging spatial morphology and resilience science. This involves a revisiting and reunderstanding of the meaning of sustainable urban form. We briefly describe the fields of resilience science and spatial morphology. Drawing on a selected set of propositions in both fields, we put urban form in the context of the adaptive renewal cycle, a dynamic framework model used in resilience science to capture the dynamics of complex adaptive systems, of which urban systems are prime examples. We discuss the insights generated in this endeavor, dealing with some key morphological aspects in relation to four key attributes of resilience, i.e., "change," "diversity," "self-organization," and "learning." We discuss and relate these to urban form and other social variables, with special attention paid to the "backloop phase" of the adaptive renewal cycle. We conclude by postulating ways in which resilience thinking could contribute to the development of a new research frontier for addressing designs for resilient urban social-ecological systems, and end by proposing three strategic areas of research in such a field.

δ expansion for a quantum field theory in the nonperturbative regime

International Nuclear Information System (INIS)

Bender, C.M.; Milton, K.A.; Pinsky, S.S.; Simmons, L.M. Jr.

1990-01-01

The δ expansion, a recently proposed nonperturbative technique in quantum field theory, is used to calculate the dimensionless renormalized coupling constant of a λ(var-phi 2 ) 1+δ quantum field theory in d-dimensional space-time at the critical point defined by λ→∞ with the renormalized mass held fixed. The calculation is performed to leading order in δ and compared with previous lattice strong-coupling calculations. The numerical results are good and provide new evidence that the theory in four dimensions is free for all δ

Primordial black holes in linear and non-linear regimes

Energy Technology Data Exchange (ETDEWEB)

Allahyari, Alireza; Abolhasani, Ali Akbar [Department of Physics, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Firouzjaee, Javad T., E-mail: allahyari@physics.sharif.edu, E-mail: j.taghizadeh.f@ipm.ir [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

2017-06-01

We revisit the formation of primordial black holes (PBHs) in the radiation-dominated era for both linear and non-linear regimes, elaborating on the concept of an apparent horizon. Contrary to the expectation from vacuum models, we argue that in a cosmological setting a density fluctuation with a high density does not always collapse to a black hole. To this end, we first elaborate on the perturbation theory for spherically symmetric space times in the linear regime. Thereby, we introduce two gauges. This allows to introduce a well defined gauge-invariant quantity for the expansion of null geodesics. Using this quantity, we argue that PBHs do not form in the linear regime irrespective of the density of the background. Finally, we consider the formation of PBHs in non-linear regimes, adopting the spherical collapse picture. In this picture, over-densities are modeled by closed FRW models in the radiation-dominated era. The difference of our approach is that we start by finding an exact solution for a closed radiation-dominated universe. This yields exact results for turn-around time and radius. It is important that we take the initial conditions from the linear perturbation theory. Additionally, instead of using uniform Hubble gauge condition, both density and velocity perturbations are admitted in this approach. Thereby, the matching condition will impose an important constraint on the initial velocity perturbations δ {sup h} {sub 0} = −δ{sub 0}/2. This can be extended to higher orders. Using this constraint, we find that the apparent horizon of a PBH forms when δ > 3 at turn-around time. The corrections also appear from the third order. Moreover, a PBH forms when its apparent horizon is outside the sound horizon at the re-entry time. Applying this condition, we infer that the threshold value of the density perturbations at horizon re-entry should be larger than δ {sub th} > 0.7.

The single reflection regime of X-rays travelling into a monocapillary

International Nuclear Information System (INIS)

Dabagov, S.B.; Marcelli, A.

1999-01-01

In this manuscript an analysis of the transmission of x-rays through a single monocapillary under the single reflection regime is presented and discussed. Because ray tracing does not allow to explain the experimental data, a first qualitative interpretation of the observed behavior is given in the framework of the wave theory

Land expropriation in urbanizing China

DEFF Research Database (Denmark)

Wang, Hui; Zhu, Pengyu; Chen, Xiao Qing

2017-01-01

A driving force of urban development is “accumulation by dispossession” which occurs through expropriation, privatization, and commodification of land. While the macro theory is now well refined, there is still much we do not know about how the underlying processes occur and how they shape economic...... development and urbanization. In this study, we analyze 2009 survey data of land expropriation cases across 12 Chinese cities, and find that expropriation takes different forms leading to specific outcomes. In half the cases, local governments followed central government policies requiring them to pay...... undermines urban development leading to social instability....

Measurement of the internal bremsstrahlung spectrum of a 89Sr beta emitter in the 1–100 keV photon energy regime

International Nuclear Information System (INIS)

Singh, Amrit; Dhaliwal, A.S.

2015-01-01

The internal bremsstrahlung (IB) spectrum of 89 Sr, which is a unique first forbidden beta emitter, is studied in the 1–100 keV photon energy regime. The IB spectrum is experimentally measured using a Si(Li) detector, which is efficient in this photon energy regime, and is compared with the IB distributions that are predicted by the Knipp, Uhlenbeck and Bloch (KUB), Nilsson, and Lewis and Ford theories. In the soft energy regime up to 15 keV, the measured results are in agreement with all the aforementioned theories. However, from 16–30 keV, the experimental results are in agreement with the Lewis and Ford theory, which applies to forbidden transitions, and at higher photon energies, the Nilsson theory best describes the measured results. The differences among the different theories also increase with the photon energy. The effect of the electrostatic Coulomb field on the IB process for beta emitters with different end-point energies is investigated by comparing the ratio of the IB probabilities predicted using the KUB and Nilsson theories for 35 S and 89 Sr, i.e., soft and hard beta emitters, respectively. The Coulomb effect is shown to be significant in the high photon energy regime and for beta emitters with low end-point energies. - Highlights: • Internal bremsstrahlung spectrum of 89 Sr, a unique first forbidden beta emitter, is studied. • The measurements are taken in the photon energy regions of 1–100 keV with Si(Li) detector. • The measured results are deviating from Lewis and Ford theory and are close to the Nilsson theory. • The effect of Coulomb field on the IB process for different end point energy sources is investigated. • Effect of Coulomb field is more for low energy beta emitter towards the high energy end

Interdisciplinary Pathways for Urban Metabolism Research

Science.gov (United States)

Newell, J. P.

2011-12-01

With its rapid rise as a metaphor to express coupled natural-human systems in cities, the concept of urban metabolism is evolving into a series of relatively distinct research frameworks amongst various disciplines, with varying definitions, theories, models, and emphases. In industrial ecology, housed primarily within the disciplinary domain of engineering, urban metabolism research has focused on quantifying material and energy flows into, within, and out of cities, using methodologies such as material flow analysis and life cycle assessment. In the field of urban ecology, which is strongly influenced by ecology and urban planning, research focus has been placed on understanding and modeling the complex patterns and processes of human-ecological systems within urban areas. Finally, in political ecology, closely aligned with human geography and anthropology, scholars theorize about the interwoven knots of social and natural processes, material flows, and spatial structures that form the urban metabolism. This paper offers three potential interdisciplinary urban metabolism research tracks that might integrate elements of these three "ecologies," thereby bridging engineering and the social and physical sciences. First, it presents the idea of infrastructure ecology, which explores the complex, emergent interdependencies between gray (water and wastewater, transportation, etc) and green (e.g. parks, greenways) infrastructure systems, as nested within a broader socio-economic context. For cities to be sustainable and resilient over time-space, the theory follows, these is a need to understand and redesign these infrastructure linkages. Second, there is the concept of an urban-scale carbon metabolism model which integrates consumption-based material flow analysis (including goods, water, and materials), with the carbon sink and source dynamics of the built environment (e.g. buildings, etc) and urban ecosystems. Finally, there is the political ecology of the material

Institutional change to support regime transformation: Lessons from Australia's water sector

Science.gov (United States)

Werbeloff, Lara; Brown, Rebekah; Cocklin, Chris

2017-07-01

Institutional change is fundamental to regime transformation, and a necessary part of moving toward integrated water management. However, insight into the role of institutional change processes in such transitions is currently limited. A more nuanced understanding of institutional frameworks is necessary, both to advance understanding of institutional change in the context of transitions toward improved water management and to inform strategies for guiding such processes. To this end, we examine two contemporary cases of transformative change in Australia's urban water sector, exploring the evolution of institutional change in each city. This paper offers insights into regime transformation, providing guidance on types of institutional structures and the ways structure-change initiatives can be sequenced to support a transition. The results reveal the importance of regulation in embedding regime change and suggest that engagement with structural frameworks should begin early in transition processes to ensure the timely introduction of supporting regulation. Our findings also highlight the inextricable link between culture-based and structure-based change initiatives, and the importance of using a diverse range of institutional change mechanisms in a mutually reinforcing way to provide a strong foundation for change. These findings provide a foundation for further scholarly examination of institutional change mechanisms, while also serving to inform the strategic activities of transition-oriented organizations and actors.

Trends in Urbanization and Implications for Peri-Urban Livelihoods in Accra, Ghana

Science.gov (United States)

Adom, Cynthia

-growth neighborhoods as a result of increasing urbanization have disproportionately benefited male-headed households compared to female-headed households. Although study findings do not match some of the prior thinking about impacts of urbanization on livelihoods, it corroborates recent urban theory that asserts that urbanization does not necessarily result in the perpetuation of urban poverty.

Effective actions for F-theory compactifications and tensor theories

International Nuclear Information System (INIS)

Bonetti, Federico

2014-01-01

In this thesis we study the low-energy effective dynamics emerging from a class of F-theory compactifications in four and six dimensions. We also investigate six-dimensional supersymmetric quantum field theories with self-dual tensors, motivated by the problem of describing the long-wavelength regime of a stack of M5-branes in M-theory. These setups share interesting common features. They both constitute examples of intrinsically non-perturbative physics. On the one hand, in the context of F-theory the non-perturbative character is encoded in the geometric formulation of this class of string vacua, which allows the complexified string coupling to vary in space. On the other hand, the dynamics of a stack of multiple M5-branes flows in the infrared to a novel kind of superconformal field theories in six dimensions - commonly referred to as (2,0) theories - that are expected to possess no perturbative weakly coupled regime and have resisted a complete understanding so far. In particular, no Lagrangian description is known for these models. The strategy we employ to address these two problems is also analogous. A recurring Leitmotif of our work is a transdimensional treatment of the system under examination: in order to extract information about dynamics in d dimensions we consider a (d-1)-dimensional setup. As far as F-theory compactifications are concerned, this is a consequence of the duality between M-theory and F-theory, which constitutes our main tool in the derivation of the effective action of F-theory compactifications. We apply it to six-dimensional F-theory vacua, obtained by taking the internal space to be an elliptically fibered Calabi-Yau threefold, but we also employ it to explore a novel kind of F-theory constructions in four dimensions based on manifolds with Spin(7) holonomy. With reference to six-dimensional (2,0) theories, the transdimensional character of our approach relies in the idea of studying these theories in five dimensions. Indeed, we

Urban Displacement: Fruits of a History of Collusion.

Science.gov (United States)

Thomas, June Manning

1979-01-01

Examines evidence supporting the theory that urban displacement is an example of the link between social injustice and economic interests. Considers federal policies regarding public housing, urban renewal, and highway construction and demonstrates how they have resulted in perpetuating discrimination against poorer citizens. (Author/WP)

The ecological foundations of transmission potential and vector-borne disease in urban landscapes.

Science.gov (United States)

LaDeau, Shannon L; Allan, Brian F; Leisnham, Paul T; Levy, Michael Z

2015-07-01

Urban transmission of arthropod-vectored disease has increased in recent decades. Understanding and managing transmission potential in urban landscapes requires integration of sociological and ecological processes that regulate vector population dynamics, feeding behavior, and vector-pathogen interactions in these unique ecosystems. Vectorial capacity is a key metric for generating predictive understanding about transmission potential in systems with obligate vector transmission. This review evaluates how urban conditions, specifically habitat suitability and local temperature regimes, and the heterogeneity of urban landscapes can influence the biologically-relevant parameters that define vectorial capacity: vector density, survivorship, biting rate, extrinsic incubation period, and vector competence.Urban landscapes represent unique mosaics of habitat. Incidence of vector-borne disease in urban host populations is rarely, if ever, evenly distributed across an urban area. The persistence and quality of vector habitat can vary significantly across socio-economic boundaries to influence vector species composition and abundance, often generating socio-economically distinct gradients of transmission potential across neighborhoods.Urban regions often experience unique temperature regimes, broadly termed urban heat islands (UHI). Arthropod vectors are ectothermic organisms and their growth, survival, and behavior are highly sensitive to environmental temperatures. Vector response to UHI conditions is dependent on regional temperature profiles relative to the vector's thermal performance range. In temperate climates UHI can facilitate increased vector development rates while having countervailing influence on survival and feeding behavior. Understanding how urban heat island (UHI) conditions alter thermal and moisture constraints across the vector life cycle to influence transmission processes is an important direction for both empirical and modeling research.There remain

Is sprawl associated with a widening urban-suburban mortality gap?

Science.gov (United States)

Fan, Yingling; Song, Yan

2009-09-01

This paper examines whether sprawl, featured by low development density, segregated land uses, lack of significant centers, and poor street connectivity, contributes to a widening mortality gap between urban and suburban residents. We employ two mortality datasets, including a national cross-sectional dataset examining the impact of metropolitan-level sprawl on urban-suburban mortality gaps and a longitudinal dataset from Portland examining changes in urban-suburban mortality gaps over time. The national and Portland studies provide the only evidence to date that (1) across metropolitan areas, the size of urban-suburban mortality gaps varies by the extent of sprawl: in sprawling metropolitan areas, urban residents have significant excess mortality risks than suburban residents, while in compact metropolitan areas, urbanicity-related excess mortality becomes insignificant; (2) the Portland metropolitan area not only experienced net decreases in mortality rates but also a narrowing urban-suburban mortality gap since its adoption of smart growth regime in the past decade; and (3) the existence of excess mortality among urban residents in US sprawling metropolitan areas, as well as the net mortality decreases and narrowing urban-suburban mortality gap in the Portland metropolitan area, is not attributable to sociodemographic variations. These findings suggest that health threats imposed by sprawl affect urban residents disproportionately compared to suburban residents and that efforts curbing sprawl may mitigate urban-suburban health disparities.

Optically levitating dielectrics in the quantum regime: Theory and protocols

International Nuclear Information System (INIS)

Romero-Isart, O.; Pflanzer, A. C.; Cirac, J. I.; Juan, M. L.; Quidant, R.; Kiesel, N.; Aspelmeyer, M.

2011-01-01

We provide a general quantum theory to describe the coupling of light with the motion of a dielectric object inside a high-finesse optical cavity. In particular, we derive the total Hamiltonian of the system as well as a master equation describing the state of the center-of-mass mode of the dielectric and the cavity-field mode. In addition, a quantum theory of elasticity is used to study the coupling of the center-of-mass motion with internal vibrational excitations of the dielectric. This general theory is applied to the recent proposal of using an optically levitating nanodielectric as a cavity optomechanical system [see Romero-Isart et al., New J. Phys. 12, 033015 (2010); Chang et al., Proc. Natl. Acad. Sci. USA 107, 1005 (2010)]. On this basis, we also design a light-mechanics interface to prepare non-Gaussian states of the mechanical motion, such as quantum superpositions of Fock states. Finally, we introduce a direct mechanical tomography scheme to probe these genuine quantum states by time-of- flight experiments.

Computational characterization of ignition regimes in a syngas/air mixture with temperature fluctuations

KAUST Repository

Pal, Pinaki

2016-07-27

Auto-ignition characteristics of compositionally homogeneous reactant mixtures in the presence of thermal non-uniformities and turbulent velocity fluctuations were computationally investigated. The main objectives were to quantify the observed ignition characteristics and numerically validate the theory of the turbulent ignition regime diagram recently proposed by Im et al. 2015 [29] that provides a framework to predict ignition behavior . a priori based on the thermo-chemical properties of the reactant mixture and initial flow and scalar field conditions. Ignition regimes were classified into three categories: . weak (where deflagration is the dominant mode of fuel consumption), . reaction-dominant strong, and . mixing-dominant strong (where volumetric ignition is the dominant mode of fuel consumption). Two-dimensional (2D) direct numerical simulations (DNS) of auto-ignition in a lean syngas/air mixture with uniform mixture composition at high-pressure, low-temperature conditions were performed in a fixed volume. The initial conditions considered two-dimensional isotropic velocity spectrums, temperature fluctuations and localized thermal hot spots. A number of parametric test cases, by varying the characteristic turbulent Damköhler and Reynolds numbers, were investigated. The evolution of the auto-ignition phenomena, pressure rise, and heat release rate were analyzed. In addition, combustion mode analysis based on front propagation speed and computational singular perturbation (CSP) was applied to characterize the auto-ignition phenomena. All results supported that the observed ignition behaviors were consistent with the expected ignition regimes predicted by the theory of the regime diagram. This work provides new high-fidelity data on syngas ignition characteristics over a broad range of conditions and demonstrates that the regime diagram serves as a predictive guidance in the understanding of various physical and chemical mechanisms controlling auto

Self-organized criticality and urban development

Directory of Open Access Journals (Sweden)

Michael Batty

1999-01-01

Full Text Available Urban society is undergoing as profound a spatial transformation as that associated with the emergence of the industrial city two centuries ago. To describe and measure this transition, we introduce a new theory based on the concept that large-scale, complex systems composed of many interacting elements, show a surprising degree of resilience to change, holding themselves at critical levels for long periods until conditions emerge which move the system, often abruptly, to a new threshold. This theory is called ‘self-organized criticality’; it is consistent with systems in which global patterns emerge from local action which is the hallmark of self-organization, and it is consistent with developments in system dynamics and their morphology which find expression in fractal geometry and weak chaos theory. We illustrate the theory using a unique space–time series of urban development for Buffalo, Western New York, which contains the locations of over one quarter of a million sites coded by their year of construction and dating back to 1773, some 60 years before the city began to develop. We measure the emergence and growth of the city using urban density functions from which measures of fractal dimension are used to construct growth paths of the way the city has grown to fill its region. These phase portraits suggest the existence of transitions between the frontier, the settled agricultural region, the centralized industrial city and the decentralized postindustrial city, and our analysis reveals that Buffalo has maintained itself at a critical threshold since the emergence of the automobile city some 70 years ago. Our implied speculation is: how long will this kind of urban form be maintained in the face of seemingly unstoppable technological change?

Identifying hydrological regime and eco-flow threshold of small and medium flood of the Xiaoqing River in Jinan city

Science.gov (United States)

Liu, Yang; Cao, Sheng-Le

2017-06-01

It was known that hydrological regime was the main influencing factor of river ecosystem, but the regime of different flow rates of urban rivers was poorly understood. We collected daily inflows at the Huangtai station of the Xiaoqing River from 1960 to 2014 and divided the data into three periods. Then we calculated hydrological parameters by the method of EFCs (Environmental Flow Components) and analyzed the tendency and change rates of each component respectively in the three periods. Combined with the ecological significance of environmental flow components, we identified the small and medium flood had the greatest impact on the river regime and ecosystem. And then we used the hydraulic parameters in the good ecosystem period as control conditions, to calculate the ecological threshold of the flow component under the current situation. This study could provide technical support for restoring and improving hydrological regime and ecological environment of the Xiaoqing River in Jinan city.

RF SQUID in the nonhysteretic regime with k2Ql>1

International Nuclear Information System (INIS)

Dmitrenko, I.M.; Tsoi, G.M.; Shnyrkov, V.I.; Kartsovnik, V.V.

1982-01-01

Experimental measurements of current-voltage, current-phase, amplitude-frequency, phase-frequency, and signal characteristics of an rf SQUID operating at a frequency of 30 MHz in the nonhysteretic regime (1 = 2πL 0 I 0 /phi/sub o/ 2 Ql>1. Here I 0 is the critical current of the weak link, L 0 is the SQUID ring inductance, k is the coefficient of coupling of the SQUID ring to a resonant tank circuit of quality Q, and phi 0 is the magnetic flux quantum. A numerical analysis of the above characteristics for all relevant parameter values close to those occurring under experimental conditions was performed for qualitative comparison with theory. The main difference from the traditional nonhysteretic regime of SQUID operation (k 2 Q1 12 V/Wb for the single-valued region of the signal characteristics. The results suggest that considerable improvement of rf SQUID resolution is possible in the regime k 2 Ql>1

Galilean Yang-Mills theory

Energy Technology Data Exchange (ETDEWEB)

Bagchi, Arjun [Center for Theoretical Physics, Massachusetts Institute of Technology,77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Basu, Rudranil [Saha Institute of Nuclear Physics,Block AF, Sector 1, Bidhannagar, Kolkata 700068 (India); Kakkar, Ashish [Indian Institute of Science Education and Research,Dr Homi Bhabha Road, Pashan. Pune 411008 (India); Mehra, Aditya [Indian Institute of Science Education and Research,Dr Homi Bhabha Road, Pashan. Pune 411008 (India); Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)

2016-04-11

We investigate the symmetry structure of the non-relativistic limit of Yang-Mills theories. Generalising previous results in the Galilean limit of electrodynamics, we discover that for Yang-Mills theories there are a variety of limits inside the Galilean regime. We first explicitly work with the SU(2) theory and then generalise to SU(N) for all N, systematising our notation and analysis. We discover that the whole family of limits lead to different sectors of Galilean Yang-Mills theories and the equations of motion in each sector exhibit hitherto undiscovered infinite dimensional symmetries, viz. infinite Galilean Conformal symmetries in D=4. These provide the first examples of interacting Galilean Conformal Field Theories (GCFTs) in D>2.

Galilean Yang-Mills theory

International Nuclear Information System (INIS)

Bagchi, Arjun; Basu, Rudranil; Kakkar, Ashish; Mehra, Aditya

2016-01-01

We investigate the symmetry structure of the non-relativistic limit of Yang-Mills theories. Generalising previous results in the Galilean limit of electrodynamics, we discover that for Yang-Mills theories there are a variety of limits inside the Galilean regime. We first explicitly work with the SU(2) theory and then generalise to SU(N) for all N, systematising our notation and analysis. We discover that the whole family of limits lead to different sectors of Galilean Yang-Mills theories and the equations of motion in each sector exhibit hitherto undiscovered infinite dimensional symmetries, viz. infinite Galilean Conformal symmetries in D=4. These provide the first examples of interacting Galilean Conformal Field Theories (GCFTs) in D>2.

Low-Carbon Transportation Oriented Urban Spatial Structure: Theory, Model and Case Study

Directory of Open Access Journals (Sweden)

Yuyao Ye

2017-12-01

Full Text Available Optimising the spatial structure of cities to promote low-carbon travel is a primary goal of urban planning and construction innovation in the low-carbon era. There is a need for basic research on the structural characteristics that help to reduce motor traffic, thereby promoting energy conservation. We first review the existing literature on the influence of urban spatial structure on transport carbon dioxide emissions and summarise the influence mechanisms. We then present two low-carbon transportation oriented patterns of urban spatial structure including the traditional walking city and the modern transit metropolis, illustrated by case studies. Furthermore, we propose an improved model Green Transportation System Oriented Development (GTOD, which is an extension of traditional transit-oriented development (TOD and includes the additional features of a walking city and an emphasis on the integration of land use with a green transportation system, consisting of the public transportation and non-auto travel system. A compact urban form, effective mix of land use and appropriate scale of block are the basic structural features of a low-carbon transportation city. However, these features are only effective at promoting low-carbon transportation when integrated with the green traffic systems. Proper integration of the urban structural system with the green space system is also required. The optimal land use/transportation integration strategy is to divide traffic corridors with wedge-shaped green spaces and limit development along the transit corridors. This strategy forms the basis of the proposed urban structural model to promote low-carbon transportation and sustainable urban growth management.

Turbulent transport regimes and the SOL heat flux width

Science.gov (United States)

Myra, J. R.; D'Ippolito, D. A.; Russell, D. A.

2014-10-01

Understanding the responsible mechanisms and resulting scaling of the scrape-off layer (SOL) heat flux width is important for predicting viable operating regimes in future tokamaks, and for seeking possible mitigation schemes. Simulation and theory results using reduced edge/SOL turbulence models have produced SOL widths and scalings in reasonable accord with experiments in many cases. In this work, we attempt to qualitatively and conceptually understand various regimes of edge/SOL turbulence and the role of turbulent transport in establishing the SOL heat flux width. Relevant considerations include the type and spectral characteristics of underlying instabilities, the location of the gradient drive relative to the SOL, the nonlinear saturation mechanism, and the parallel heat transport regime. Recent SOLT turbulence code results are employed to understand the roles of these considerations and to develop analytical scalings. We find a heat flux width scaling with major radius R that is generally positive, consistent with older results reviewed in. The possible relationship of turbulence mechanisms to the heuristic drift mechanism is considered, together with implications for future experiments. Work supported by US DOE grant DE-FG02-97ER54392.

Relic dark energy from the trans-Planckian regime

International Nuclear Information System (INIS)

Mersini, Laura; Bastero-Gil, Mar; Kanti, Panagiota

2001-01-01

As yet, there is no underlying fundamental theory for the trans-Planckian regime. There is a need to address the issue of how the observables in our present Universe are affected by processes that may have occurred at super-Planckian energies (referred to as the trans-Planckian regime). Specifically, we focus on the impact the trans-Planckian regime has on two observables: namely, dark energy and the cosmic microwave background radiation (CMBR) spectrum. We model the trans-Planckian regime by introducing a 1-parameter family of smooth non-linear dispersion relations which modify the frequencies at very short distances. A particular feature of the family of dispersion functions chosen is the production of ultralow frequencies at very high momenta k (for k>M P ). We name the range of the ultralow energy modes (of very short distances) that have frequencies equal to or less than the current Hubble rate H 0 as the tail modes. These modes are still frozen today due to the expansion of the Universe. We calculate their energy today and show that the tail provides a strong candidate for the dark energy of the Universe. During inflation, their energy is about 122 to 123 orders of magnitude smaller than the total energy, for any random value of the free parameter in the family of dispersion relations. For this family of dispersions, we present the exact solutions and show that the CMBR spectrum is that of a (nearly) blackbody, and that the adiabatic vacuum is the only choice for the initial conditions

A comparative gradient approach as a tool for understanding and managing urban ecosystems

Science.gov (United States)

Christopher G. Boone; Elizabeth Cook; Sharon J. Hall; Marcia L. Nation; Nancy B. Grimm; Carol B. Raish; Deborah M. Finch; Abigail M. York

2012-01-01

To meet the grand challenges of the urban century - such as climate change, biodiversity loss, and persistent poverty - urban and ecological theory must contribute to integrated frameworks that treat social and ecological dynamics as interdependent. A socioecological framework that encapsulates theory from the social and ecological sciences will improve understanding...

Streams in the urban heat island: spatial and temporal variability in temperature

Science.gov (United States)

Somers, Kayleigh A.; Bernhardt, Emily S.; Grace, James B.; Hassett, Brooke A.; Sudduth, Elizabeth B.; Wang, Siyi; Urban, Dean L.

2013-01-01

Streams draining urban heat islands tend to be hotter than rural and forested streams at baseflow because of warmer urban air and ground temperatures, paved surfaces, and decreased riparian canopy. Urban infrastructure efficiently routes runoff over hot impervious surfaces and through storm drains directly into streams and can lead to rapid, dramatic increases in temperature. Thermal regimes affect habitat quality and biogeochemical processes, and changes can be lethal if temperatures exceed upper tolerance limits of aquatic fauna. In summer 2009, we collected continuous (10-min interval) temperature data in 60 streams spanning a range of development intensity in the Piedmont of North Carolina, USA. The 5 most urbanized streams averaged 21.1°C at baseflow, compared to 19.5°C in the 5 most forested streams. Temperatures in urban streams rose as much as 4°C during a small regional storm, whereas the same storm led to extremely small to no changes in temperature in forested streams. Over a kilometer of stream length, baseflow temperature varied by as much as 10°C in an urban stream and as little as 2°C in a forested stream. We used structural equation modeling to explore how reach- and catchment-scale attributes interact to explain maximum temperatures and magnitudes of storm-flow temperature surges. The best predictive model of baseflow temperatures (R2  =  0.461) included moderately strong pathways directly (extent of development and road density) and indirectly, as mediated by reach-scale factors (canopy closure and stream width), from catchment-scale factors. The strongest influence on storm-flow temperature surges appeared to be % development in the catchment. Reach-scale factors, such as the extent of riparian forest and stream width, had little mitigating influence (R2  =  0.448). Stream temperature is an essential, but overlooked, aspect of the urban stream syndrome and is affected by reach-scale habitat variables, catchment-scale urbanization

Remnants of semiclassical bistability in the few-photon regime of cavity QED.

Science.gov (United States)

Kerckhoff, Joseph; Armen, Michael A; Mabuchi, Hideo

2011-11-21

Broadband homodyne detection of the light transmitted by a Fabry-Perot cavity containing a strongly-coupled (133)Cs atom is used to probe the dynamic optical response in a regime where semiclassical theory predicts bistability but strong quantum corrections should apply. While quantum fluctuations destabilize true equilibrium bistability, our observations confirm the existence of metastable states with finite lifetimes and a hysteretic response is apparent when the optical drive is modulated on comparable timescales. Our experiment elucidates remnant semiclassical behavior in the attojoule (~10 photon) regime of single-atom cavity QED, of potential significance for ultra-low power photonic signal processing. © 2011 Optical Society of America

Assessment of Urban Ecosystem Health Based on Entropy Weight Extension Decision Model in Urban Agglomeration

Directory of Open Access Journals (Sweden)

Qian Yang

2016-08-01

Full Text Available Urban ecosystem health evaluation can assist in sustainable ecological management at a regional level. This study examined urban agglomeration ecosystem health in the middle reaches of the Yangtze River with entropy weight and extension theories. The model overcomes information omissions and subjectivity problems in the evaluation process of urban ecosystem health. Results showed that human capital and education, economic development level as well as urban infrastructure have a significant effect on the health states of urban agglomerations. The health status of the urban agglomeration’s ecosystem was not optimistic in 2013. The majority of the cities were unhealthy or verging on unhealthy, accounting for 64.52% of the total number of cities in the urban agglomeration. The regional differences of the 31 cities’ ecosystem health are significant. The cause originated from an imbalance in economic development and the policy guidance of city development. It is necessary to speed up the integration process to promote coordinated regional development. The present study will aid us in understanding and advancing the health situation of the urban ecosystem in the middle reaches of the Yangtze River and will provide an efficient urban ecosystem health evaluation method that can be used in other areas.

Nonperturbative theory of weak pre- and post-selected measurements

Energy Technology Data Exchange (ETDEWEB)

Kofman, Abraham G., E-mail: kofmana@gmail.com; Ashhab, Sahel; Nori, Franco

2012-11-01

This paper starts with a brief review of the topic of strong and weak pre- and post-selected (PPS) quantum measurements, as well as weak values, and afterwards presents original work. In particular, we develop a nonperturbative theory of weak PPS measurements of an arbitrary system with an arbitrary meter, for arbitrary initial states of the system and the meter. New and simple analytical formulas are obtained for the average and the distribution of the meter pointer variable. These formulas hold to all orders in the weak value. In the case of a mixed preselected state, in addition to the standard weak value, an associated weak value is required to describe weak PPS measurements. In the linear regime, the theory provides the generalized Aharonov–Albert–Vaidman formula. Moreover, we reveal two new regimes of weak PPS measurements: the strongly-nonlinear regime and the inverted region (the regime with a very large weak value), where the system-dependent contribution to the pointer deflection decreases with increasing the measurement strength. The optimal conditions for weak PPS measurements are obtained in the strongly-nonlinear regime, where the magnitude of the average pointer deflection is equal or close to the maximum. This maximum is independent of the measurement strength, being typically of the order of the pointer uncertainty. In the optimal regime, the small parameter of the theory is comparable to the overlap of the pre- and post-selected states. We show that the amplification coefficient in the weak PPS measurements is generally a product of two qualitatively different factors. The effects of the free system and meter Hamiltonians are discussed. We also estimate the size of the ensemble required for a measurement and identify optimal and efficient meters for weak measurements. Exact solutions are obtained for a certain class of the measured observables. These solutions are used for numerical calculations, the results of which agree with the theory

Nonperturbative theory of weak pre- and post-selected measurements

International Nuclear Information System (INIS)

Kofman, Abraham G.; Ashhab, Sahel; Nori, Franco

2012-01-01

This paper starts with a brief review of the topic of strong and weak pre- and post-selected (PPS) quantum measurements, as well as weak values, and afterwards presents original work. In particular, we develop a nonperturbative theory of weak PPS measurements of an arbitrary system with an arbitrary meter, for arbitrary initial states of the system and the meter. New and simple analytical formulas are obtained for the average and the distribution of the meter pointer variable. These formulas hold to all orders in the weak value. In the case of a mixed preselected state, in addition to the standard weak value, an associated weak value is required to describe weak PPS measurements. In the linear regime, the theory provides the generalized Aharonov–Albert–Vaidman formula. Moreover, we reveal two new regimes of weak PPS measurements: the strongly-nonlinear regime and the inverted region (the regime with a very large weak value), where the system-dependent contribution to the pointer deflection decreases with increasing the measurement strength. The optimal conditions for weak PPS measurements are obtained in the strongly-nonlinear regime, where the magnitude of the average pointer deflection is equal or close to the maximum. This maximum is independent of the measurement strength, being typically of the order of the pointer uncertainty. In the optimal regime, the small parameter of the theory is comparable to the overlap of the pre- and post-selected states. We show that the amplification coefficient in the weak PPS measurements is generally a product of two qualitatively different factors. The effects of the free system and meter Hamiltonians are discussed. We also estimate the size of the ensemble required for a measurement and identify optimal and efficient meters for weak measurements. Exact solutions are obtained for a certain class of the measured observables. These solutions are used for numerical calculations, the results of which agree with the theory

Three novel tokamak plasma regimes in TFTR

International Nuclear Information System (INIS)

Furth, H.P.

1985-10-01

Aside from extending ''standard'' ohmic and neutral beam heating studies to advanced plasma parameters, TFTR has encountered a number of special plasma regimes that have the potential to shed new light on the physics of tokamak confinement and the optimal design of future D-T facilities: (1) High-powered, neutral beam heating at low plasma densities can maintain a highly reactive hot-ion population (with quasi-steady-state beam fueling and current drive) in a tokamak configuration of modest bulk-plasma confinement requirements. (2) Plasma displacement away from limiter contact lends itself to clarification of the role of edge-plasma recycling and radiation cooling within the overall pattern of tokamak heat flow. (3) Noncentral auxiliary heating (with a ''hollow'' power-deposition profile) should serve to raise the central tokamak plasma temperature without deterioration of central region confinement, thus facilitating the study of alpha-heating effects in TFTR. The experimental results of regime (3) support the theory that tokamak profile consistency is related to resistive kink stability and that the global energy confinement time is determined by transport properties of the plasma edge region

Mapping Theory

DEFF Research Database (Denmark)

Smith, Shelley

This paper came about within the context of a 13-month research project, Focus Area 1 - Method and Theory, at the Center for Public Space Research at the Royal Academy of the Arts School of Architecture in Copenhagen, Denmark. This project has been funded by RealDania. The goals of the research...... project, Focus Area 1 - Method and Theory, which forms the framework for this working paper, are: * To provide a basis from which to discuss the concept of public space in a contemporary architectural and urban context - specifically relating to theory and method * To broaden the discussion of the concept...

A law & economics approach to the study of integrated management regimes of estuaries

NARCIS (Netherlands)

van de Griendt, W.E.

2004-01-01

In this paper it is proposed to analyse legal regimes for integrated management of estuaries with the help of institutional legal theory and the Schlager & Ostrom framework for types of ownership. Estuaries are highly valued and valuable and therefore need protection. The problem is that they

Computer vision uncovers predictors of physical urban change.

Science.gov (United States)

Naik, Nikhil; Kominers, Scott Duke; Raskar, Ramesh; Glaeser, Edward L; Hidalgo, César A

2017-07-18

Which neighborhoods experience physical improvements? In this paper, we introduce a computer vision method to measure changes in the physical appearances of neighborhoods from time-series street-level imagery. We connect changes in the physical appearance of five US cities with economic and demographic data and find three factors that predict neighborhood improvement. First, neighborhoods that are densely populated by college-educated adults are more likely to experience physical improvements-an observation that is compatible with the economic literature linking human capital and local success. Second, neighborhoods with better initial appearances experience, on average, larger positive improvements-an observation that is consistent with "tipping" theories of urban change. Third, neighborhood improvement correlates positively with physical proximity to the central business district and to other physically attractive neighborhoods-an observation that is consistent with the "invasion" theories of urban sociology. Together, our results provide support for three classical theories of urban change and illustrate the value of using computer vision methods and street-level imagery to understand the physical dynamics of cities.

Quantifying the benefits of urban forest systems as a component of the green infrastructure stormwater treatment network

Science.gov (United States)

Eric Kuehler; Jon Hathaway; Andrew Tirpak

2017-01-01

The use of green infrastructure for reducing stormwater runoff is increasingly common. One under‐studied component of the green infrastructure network is the urban forest system. Trees can play an important role as the “first line of defense” for restoring more natural hydrologic regimes in urban watersheds by intercepting rainfall, delaying runoff, infiltrating, and...

Vulnerability and adaptation to climate-related fire impacts in rural and urban interior Alaska

Science.gov (United States)

Trainor, Sarah F.; Calef, Monika; Natcher, David; Chapin, F. Stuart; McGuire, A. David; Huntington, Orville; Duffy, Paul A.; Rupp, T. Scott; DeWilde, La'Ona; Kwart, Mary; Fresco, Nancy; Lovecraft, Amy Lauren

2009-01-01

This paper explores whether fundamental differences exist between urban and rural vulnerability to climate-induced changes in the fire regime of interior Alaska. We further examine how communities and fire managers have responded to these changes and what additional adaptations could be put in place. We engage a variety of social science methods, including demographic analysis, semi-structured interviews, surveys, workshops and observations of public meetings. This work is part of an interdisciplinary study of feedback and interactions between climate, vegetation, fire and human components of the Boreal forest social–ecological system of interior Alaska. We have learned that although urban and rural communities in interior Alaska face similar increased exposure to wildfire as a result of climate change, important differences exist in their sensitivity to these biophysical, climate-induced changes. In particular, reliance on wild foods, delayed suppression response, financial resources and institutional connections vary between urban and rural communities. These differences depend largely on social, economic and institutional factors, and are not necessarily related to biophysical climate impacts per se. Fire management and suppression action motivated by political, economic or other pressures can serve as unintentional or indirect adaptation to climate change. However, this indirect response alone may not sufficiently reduce vulnerability to a changing fire regime. More deliberate and strategic responses may be required, given the magnitude of the expected climate change and the likelihood of an intensification of the fire regime in interior Alaska.

A New Era for Urban Modelling

OpenAIRE

Pumain , Denise

1994-01-01

International audience; In the last two decades, several interesting innovations have appeared in the field of urban research. New paradigms such as the dynamics of open systems, self-organization, synergetics, chaos, evolution, were recognized as conveying fruitful analogies for urban theory. New types of modeling were investigated, as sets of non-linear differential equations for spatial systems, cellular automata, multi-agents models, fractal growth, neural networks, evolutionary models… H...

Improving Urban Freight Governance and Stakeholder Management

DEFF Research Database (Denmark)

Gammelgaard, Britta; Bech Godskesen Andersen, Christina; Figueroa, Maria J.

2017-01-01

Urban freight transport is a complex field characterised by many actors and stakeholders and thus many rationalities are at stake. This paper contributes to literature on urban freight governance by approaching the field with social system theory combined with the concepts of relationship platforms...... and value co-creation. This approach facilitates an improved process to foster implementation of innovative urban freight solutions that is illustrated by means of an analysis of the Copenhagen Citylogistik-kbh demonstration project. The results of this analysis indicate that attaining a shared sense...... of value creation among stakeholders through this process is key to implementation of new urban freight solutions....

Measuring Thermal Characteristics of Urban Landscapes

Science.gov (United States)

Luvall, Jeffrey C.; Quattrochi, Dale A.; Rickman, Doug L.

1999-01-01

The additional heating of the air over the city is the result of the replacement of naturally vegetated surfaces with those composed of asphalt, concrete, rooftops and other man-made materials. The temperatures of these artificial surfaces can be 20 to 40 C higher than vegetated surfaces. Materials such as asphalt store much of the sun's energy and remains hot long after sunset. This produces a dome of elevated air temperatures 5 to 8 C greater over the city, compared to the air temperatures over adjacent rural areas. This effect is called the "urban heat island". Urban landscapes are a complex mixture of vegetated and nonvegetated surfaces. It is difficult to take enough temperature measurements over a large city area to characterize the complexity of urban radiant surface temperature variability. However, the use of remotely sensed thermal data from airborne scanners are ideal for the task. In a study funded by NASA, a series of flights over Huntsville, Alabama were performed in September 1994 and over Atlanta, Georgia in May 1997. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., energy regimes. Additionally, very fine scale spatial resolution thermal infrared data, such as that obtained from aircraft, are very useful for demonstrating to planning officials, policy makers, and the general populace, what the benefits are of the urban forest in both mitigating the urban heat island effect, in making cities more aesthetically pleasing and more habitable environments, and in overall cooling of the community. In this presentation we will examine the techniques of analyzing remotely sensed data for measuring the effect of various urban surfaces on their contribution to the urban heat island effect.

An Applied Mereology of the City: Unifying Science and Philosophy for Urban Planning.

Science.gov (United States)

Epting, Shane

2016-10-01

Based on their research showing that growing cities follow basic principles, two theoretical physicists, Luis Bettencourt and Geoffrey West, call for researchers and professionals to contribute to a grand theory of urban sustainability. In their research, they develop a 'science of the city' to help urban planners address problems that arise from population increases. Although they provide valuable insights for understanding urban sustainability issues, they do not give planners a manageable way to approach such problems. I argue that developing an applied mereology to understand the concept of 'city identity' gives planners a theoretical device for addressing urban affairs, including ethical concerns. In turn, I devise a model of city identity to show how a 'philosophy of the city' contributes to a grand theory of urban sustainability.

Teaching Urban Anthropology: An Experiential Approach.

Science.gov (United States)

Miracle, Andrew W., Jr.

1981-01-01

Discusses the curriculum design and instructional goals of an undergraduate urban anthropology service course with a heterogeneous student composition. Compares the pedagogical techniques used with Bruner's theory of instruction. (CJM)

Catchment Dispersion Mechanisms in an Urban Context

Science.gov (United States)

Gironas, J. A.; Mejia, A.; Rossel, F.; Rinaldo, A.; Rodriguez, F.

2014-12-01

Dispersion mechanisms have been examined in-depth in natural catchments in previous studies. However, these dispersion mechanisms have been studied little in urban catchments, where artificial transport elements and morphological arrangements are expected to modify travel times and mobilize excess rainfall from spatially distributed impervious sites. Thus, these features can modify the variance of the catchment's travel times and hence the total dispersion. This work quantifies the dispersion mechanisms in an urban catchment using the theory of transport by travel times as represented by the Urban Morpho-climatic Instantaneous Unit Hydrograph (U-McIUH) model. This model computes travel times based on kinematic wave theory and accounts explicitly for the path heterogeneities and altered connectivity patterns characteristic of an urban drainage network. The analysis is illustrated using the Aubinière urban catchment (France) as a case study. We found that kinematic dispersion is dominant for small rainfall intensities, whereas geomorphologic dispersion becomes more dominant for larger intensities. The total dispersion scales with the drainage area in a power law fashion. The kinematic dispersion is dominant across spatial scales up to a threshold of approximately 2-3 km2, after which the geomorphologic dispersion becomes more dominant. Overall, overland flow is responsible for most of the dispersion, while conduits tend to counteract the increase of the geomorphologic dispersion with a negative kinematic dispersion. Further studies with other catchments are needed to assess whether the latter is a general feature of urban drainage networks.

Mathematical foundations of transport theory

International Nuclear Information System (INIS)

Ershov, Yu.I.; Shikhov, S.B.

1985-01-01

Main items of application of the operator equations analyzing method in transport theory problems are considered. The mathematical theory of a reactor critical state is presented. Theorems of existence of positive solutions of non-linear non-stationary equations taking into account the temperature and xenon feedbacks are proved. Conditions for stability and asymptotic stability of steady-state regimes for different distributed models of a nuclear reactor are obtained on the basis of the modern operator perturbation theory, certain problems on control using an absorber are considered

An hybrid and non-modern approach to urban studies

Directory of Open Access Journals (Sweden)

Marc Grau i Solés

2012-03-01

Full Text Available This article draws upon the so-called Forat de la Vergonya urban controversy and the urban transformation process of a neighborhood in Barcelona: el Casc Antic. Drawing on inputs from Actor-Network Theory (ANT, the city is explored as a multiple urban assemblage. Besides, we analyze the dichotomous nature of the modern notion of politics. Especially, the role of object-subject dichotomy is explored. Through the analysis of citizen participation opportunities we propose a new hybrid notion of citizen participation and urban policy.

Regime change?

International Nuclear Information System (INIS)

Pilat, Joseph F.; Budlong-Sylvester, K.W.

2004-01-01

Following the 1998 nuclear tests in South Asia and later reinforced by revelations about North Korean and Iraqi nuclear activities, there has been growing concern about increasing proliferation dangers. At the same time, the prospects of radiological/nuclear terrorism are seen to be rising - since 9/11, concern over a proliferation/terrorism nexus has never been higher. In the face of this growing danger, there are urgent calls for stronger measures to strengthen the current international nuclear nonproliferation regime, including recommendations to place civilian processing of weapon-useable material under multinational control. As well, there are calls for entirely new tools, including military options. As proliferation and terrorism concerns grow, the regime is under pressure and there is a temptation to consider fundamental changes to the regime. In this context, this paper will address the following: Do we need to change the regime centered on the Treaty on the Nonproliferation of Nuclear Weapons (NPT) and the International Atomic Energy Agency (IAEA)? What improvements could ensure it will be the foundation for the proliferation resistance and physical protection needed if nuclear power grows? What will make it a viable centerpiece of future nonproliferation and counterterrorism approaches?

The Impact of Mentoring Programs on Teachers in Urban Middle Schools

Science.gov (United States)

Wider, Beyonka Shantel

2012-01-01

Retaining teachers is a pressing issue facing many urban middle schools in the southern US. Urban middle schools continually face increased teacher turnover rates in spite of state mandated induction and mentoring programs. Drawing from Maslow's hierarchy of needs theory, the purpose of the qualitative case study was to examine urban middle…

Concept of ‘Good Urban Governance’ and Its Application in Sustainable Urban Planning

Science.gov (United States)

Badach, Joanna; Dymnicka, Małgorzata

2017-10-01

Contemporary urban theory and practice in the post-industrial era is increasingly often turning towards an approach based on sustainable development. That concept bearing the traits of a paradigm has grown on the ground of broad quest for an alternative to the existing development model of the industrial civilisation. It has gained wide social acceptance and is the basis for many development and environmental programmes at the level of national and local government. It puts in a new light the socio-cultural, ecological and energy-related aspects of space as well as its value and aesthetics. A model of governing the city called ‘good urban governance’ is in a very close relation with the concept of sustainable development. It is based on the principles of inclusiveness, citizenship, accountability, processuality and effectiveness. Although this approach is not entirely novel, it stays valid and open to new challenges connected with satisfying human needs in the urban built environment on the basis of new contemporary conceptualisations such as ‘smart governance’, ‘governing the smart city’, ‘network governance’ and ‘governance networks’. The advantages of this approach based on the assumption of multidimensionality and subjectivity, matching the various and seemingly contradicting interests with a sense of responsibility for the quality of life in the urban environment are often underlined both in literature and in academic debate. The aim of this article is an attempt to present selected practices in spatial planning which employ the principles of the idea of co-governance. It will include various methodological assumptions and criteria applied in ‘good urban governance’. The intention will be to show its new research and application possibilities in countries like Poland where the idea of governance and sustainable development remains a matter of theory.

Fire-regime variability impacts forest carbon dynamics for centuries to millennia

Science.gov (United States)

Hudiburg, Tara W.; Higuera, Philip E.; Hicke, Jeffrey A.

2017-08-01

Wildfire is a dominant disturbance agent in forest ecosystems, shaping important biogeochemical processes including net carbon (C) balance. Long-term monitoring and chronosequence studies highlight a resilience of biogeochemical properties to large, stand-replacing, high-severity fire events. In contrast, the consequences of repeated fires or temporal variability in a fire regime (e.g., the characteristic timing or severity of fire) are largely unknown, yet theory suggests that such variability could strongly influence forest C trajectories (i.e., future states or directions) for millennia. Here we combine a 4500-year paleoecological record of fire activity with ecosystem modeling to investigate how fire-regime variability impacts soil C and net ecosystem carbon balance. We found that C trajectories in a paleo-informed scenario differed significantly from an equilibrium scenario (with a constant fire return interval), largely due to variability in the timing and severity of past fires. Paleo-informed scenarios contained multi-century periods of positive and negative net ecosystem C balance, with magnitudes significantly larger than observed under the equilibrium scenario. Further, this variability created legacies in soil C trajectories that lasted for millennia. Our results imply that fire-regime variability is a major driver of C trajectories in stand-replacing fire regimes. Predicting carbon balance in these systems, therefore, will depend strongly on the ability of ecosystem models to represent a realistic range of fire-regime variability over the past several centuries to millennia.

Unrenormalizable theories can be predictive

CERN Document Server

Kubo, J

2003-01-01

Unrenormalizable theories contain infinitely many free parameters. Considering these theories in terms of the Wilsonian renormalization group (RG), we suggest a method for removing this large ambiguity. Our basic assumption is the existence of a maximal ultraviolet cutoff in a cutoff theory, and we require that the theory be so fine tuned as to reach the maximal cutoff. The theory so obtained behaves as a local continuum theory to the shortest distance. In concrete examples of the scalar theory we find that at least in a certain approximation to the Wilsonian RG, this requirement enables us to make unique predictions in the infrared regime in terms of a finite number of independent parameters. Therefore, this method might provide a way for calculating quantum corrections in a low-energy effective theory of quantum gravity. (orig.)

Visualization of differences across port state control regimes by means of correspondence analysis

NARCIS (Netherlands)

S. Knapp (Sabine); M. van de Velden (Michel)

2007-01-01

textabstractThis article is based on a combined dataset of 183,819 port state control (PSC) inspections from various port state control regimes around the world. In theory, there should be no differences in treatments of inspections to determine if a vessel is substandard or not no matter where the

An extension of the Theory of Planned Behavior to predict willingness to pay for the conservation of an urban park.

Science.gov (United States)

López-Mosquera, Natalia; García, Teresa; Barrena, Ramo

2014-03-15

This paper relates the concept of moral obligation and the components of the Theory of Planned Behavior to determine their influence on the willingness to pay of visitors for park conservation. The sample consists of 190 visitors to an urban Spanish park. The mean willingness to pay estimated was 12.67€ per year. The results also indicated that moral norm was the major factor in predicting behavioral intention, followed by attitudes. The new relations established between the components of the Theory of Planned Behavior show that social norms significantly determine the attitudes, moral norms and perceived behavioral control of individuals. The proportion of explained variance shows that the inclusion of moral norms improves the explanatory power of the original model of the Theory of Planned Behavior (32-40%). Community-based social marketing and local campaigns are the main strategies that should be followed by land managers with the objective of promoting responsible, pro-environmental attitudes as well as a greater willingness to pay for this type of goods. Copyright © 2014 Elsevier Ltd. All rights reserved.

Linguistic Justice for which Demos? The Democratic Legitimacy of Language Regime Choices

Directory of Open Access Journals (Sweden)

Garcia Núria

2016-10-01

Full Text Available In the European Union language regime debate, theorists of multiculturalism and cosmopolitanism have framed their arguments in reference to different theories of justice and democracy. Philippe Van Parijs advocates the diffusion of a lingua franca, namely English, as means of changing the scale of the justificatory community to the European level and allowing the creation of a transnational demos. Paradoxically, one key dimension of democracy has hardly been addressed in this discussion: the question of the democratic legitimacy of language regime choices and citizens’ preferences on the different language regime scenarios. Addressing the question of the congruence of language policy choices operated by national and European elites and ordinary citizens’ preferences, this paper argues first that the dimension of democratic legitimacy is crucial and needs to be taken into account in discussions around linguistic justice. Criticizing the assumption of a direct correspondence between individuals’ language learning choices and citizens’ language regime preferences made by different authors, the analysis shows the ambivalence of citizens’ preferences measured by survey data. The article secondly raises the question of the boundaries of the political community at which the expression of citizens’ preferences should be measured and demonstrates that the outcome and the fairness of territorial linguistic regimes may vary significantly according to the level at which this democratic legitimacy is taken into account.

Multiparton interactions. Theory and experimental findings

Energy Technology Data Exchange (ETDEWEB)

Diehl, Markus

2013-06-15

I give an introduction to multiparton interactions in proton-proton collisions, with a focus on the perturbative regime. Recent experimental results are discussed, as well as progress and open questions in theory.

MARKET AND GOVERNMENT FAILURES RELATED TO THE INTRODUCTION OF TAX INCENTIVES REGIME

Directory of Open Access Journals (Sweden)

Olena SOKOLOVSKA

2015-12-01

Full Text Available The paper deals with problem of effectiveness of tax incentive regimes. The main purpose of this paper is to define causes, factors and measures aimed to prevent and neutralize failures of introduction of tax incentives. In order to examine the behavior of economic agents we used game theory tools, notably the “principal-agent” model, similar to the Allingham-Sandmo model. To solve a problem of inefficient interaction, when investors unreasonably pretend on tax incentives and government ignore that by granting them incentives, we proposed to use Nash-equilibrium in pure strategies. Finally we defined factors of improvement of efficiency of tax incentive regimes, particularly mechanisms of their implementation and termination.

Dispossessing Urbanization: Urban Marxism in the Face of the Problem of Primitive Accumulation

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Piotr Juskowiak

2015-04-01

Full Text Available The article is a complex attempt to present the achievements of the broadly understood urban Marxism in the field of reinterpretation of the classic concept from the cards of Capital – “primitive accumulation”. Drawing on theories of such scholars as David Harvey (“accumulation by dispossession” or Saskia Sassen (“expulsions”, the author points to the possible ways to operationalize the concept of “dispossessing urbanization”. Inspired by the theorizations of autonomist Marxists (Antonio Negri, Sandro Mezzadra, Massimo De Angelis, he proposes to see it as a relatively new and increasingly important dispostif that allows not only to improve traditional methods of enclosures and construct entirely new ones, but also to instrumentalize urban cultures which seems unlikely for the historical versions of primitive accumulation. This theoretical inspiration leads him also to highlight another gap in the accumulation by dispossession theory, namely the lack of sufficient reflection on the production of subjectivity processes which seem constitutive for the broad set of dispossessing practices.

Marketing everything and theming sameness: Urban destination marketing in contemporary Europe

Directory of Open Access Journals (Sweden)

Heeley John

2014-01-01

Full Text Available This paper reviews the academic and practitioner literature on urban destination marketing, suggesting that it contains within it a dominant paradigm which the author characterises as 'the theory of marketing competitive advantage'. As such, this theory requires towns and cities to differentiate themselves through the provision of unique products, based on which they subsequently undertake branding, market positioning, distribution and other activities through bespoke destination marketing organisations (DMOs. Practice is then contrasted with theory by reference to a discordant strad of the literature as well as the actual destination marketing currently being undertaken in 60 European towns and cities. The theory of marketing competitive advantage is shown to be an ideal which rarely translates into practice. Irrespective of whether or not a town or city possesses competitive advantage, DMO destination marketing gravitates almost inexorably towards a 'marketing of everything'. Such an approach, in turn, reduces to a bland and monolithic 'theming of urban sameness', all of which is diametrically opposite to what one would expect to be the case as per the theory of marketing competitive advantage. The author contends that this gap between theory and practice matters, necessitating a rethinking of how academics and practitioners should in future seek to explain or otherwise account for urban destination marketing.

Civic ecology practices: insights from practice theory

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Marianne E. Krasny

2015-06-01

Full Text Available Our aim was to explore the use of practice theory as an approach to studying urban environmental stewardship. Urban environmental stewardship, or civic ecology practice, contributes to ecosystem services and community well-being and has been studied using social-ecological systems resilience, property rights, communities of practice, and governance frameworks. Practice theory, which previously has been applied in studies of consumer behaviors, adds a new perspective to urban stewardship research, focusing on how elements of a practice, such as competencies, meanings, and physical resource, together define the practice. We applied practice theory to eight different civic ecology practices, including oyster gardening in New York City, a civil society group engaged in litter cleanup in Iran, and village grove restoration in South Korea. Our analysis suggests that in applying practice theory to the civic ecology context, consideration should be given to social and communication competencies, how meanings can motivate volunteers and sustain practice, and the nature of the resource that is being stewarded. Future studies may want to focus on how practice elements interact within and vary across practices and may be used to more systematically analyze and share ideas among diverse civic ecology practices.

Urban Landscape Architecture in the Reshaping of the Contemporary Cityscape

Science.gov (United States)

Ananiadou-Tzimopoulou, Maria; Bourlidou, Anastasia

2017-10-01

The contemporary urban landscape is the evolving image of dynamic social, economic and ecological changes and heterogeneity. It constitutes the mirror of history, natural and cultural, urban processes, as well as locations of hybrid character, such as degraded and fragmented spaces within the urban fabric or in the city boundaries -areas in between, infrastructures, post-industrial and waterfront sites, but also potential grounds for urban development. Along with the awakening of the global ecological awareness and the ongoing discussion on sustainability issues, the cityscape with its new attributes, constitutes a challenging field of research and planning for various disciplines, further more than landscape architecture, such as architecture, planning, ecology, environment and engineering. This paper focuses on the role of urban landscape architecture, via its theory and practice, in the reshaping of the city territory. It aspires to broaden the discussion concerning the upgrading of the contemporary cities, aiming firstly at the determination of a wider vocabulary for the urban landscape and its design, and secondly at the highlighting of landscape architecture’s contribution to the sustainable perspective of urban design and planning. The methodology is based on a comparative research implemented both on a theoretical level and on a level of applied work. Urban landscape architecture is described through theory and practice, along with correlative approaches deriving mainly from landscape urbanism and secondarily from the field of architecture. Urban landscape is approached as a socio-ecological and perceptual legible, a territory of culture, process and production; operating as an entity of ecological, infrastructural systems and planning needs, it is also regarded as a precedent for urban development. Furthermore, the research is supported by selected European and International urban landscape projects, presented in a cohesive multiscalar approach, from the

Arctic circulation regimes.

Science.gov (United States)

Proshutinsky, Andrey; Dukhovskoy, Dmitry; Timmermans, Mary-Louise; Krishfield, Richard; Bamber, Jonathan L

2015-10-13

Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic and anticyclonic alternating at 5 to 7 year intervals. During cyclonic regimes, low sea-level atmospheric pressure (SLP) dominated over the Arctic Ocean driving sea ice and the upper ocean counterclockwise; the Arctic atmosphere was relatively warm and humid, and freshwater flux from the Arctic Ocean towards the subarctic seas was intensified. By contrast, during anticylonic circulation regimes, high SLP dominated driving sea ice and the upper ocean clockwise. Meanwhile, the atmosphere was cold and dry and the freshwater flux from the Arctic to the subarctic seas was reduced. Since 1997, however, the Arctic system has been under the influence of an anticyclonic circulation regime (17 years) with a set of environmental parameters that are atypical for this regime. We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from the Arctic Ocean and Greenland impact environmental conditions and interrupt their decadal variability. © 2015 The Authors.

Causas estruturais e consequências dos regimes internacionais: regimes como variáveis intervenientes

Directory of Open Access Journals (Sweden)

Stephen D. Krasner

2012-06-01

Full Text Available Os regimes internacionais são definidos como princípios, normas, regras e procedimentos de tomada de decisões ao redor dos quais as expectativas dos atores convergem em uma dada área-tema. Como ponto de partida, os regimes são conceituados como variáveis intervenientes, estando entre fatores causais básicos e os resultados e comportamentos relacionados. Há três visões a respeito da importância dos regimes: as orientações estruturais convencionais desvalorizam os regimes como sendo, na melhor das hipóteses, ineficazes; as orientações grocianas vêem os regimes como componentes íntimos do sistema internacional; as perspectivas estruturalistas modificadas vêem os regimes como significativos somente em certas condições restritas. Para os argumentos grociano e estruturalista modificado - que concordam com a visão de que os regimes podem influenciar resultados e comportamentos - , o desenvolvimento de regimes é visto como uma função de cinco variáveis causais básicas: auto-interesse egoísta; poder político; normas e princípios difusos; usos e costumes; conhecimento.

The urban informal economy in Ethiopia: theory and empirical ...

African Journals Online (AJOL)

Eastern Africa Social Science Research Review ... data to explore the roles and characteristics of the informal sector in urban centers of Ethiopia, ... informal sources, 4) the level of income per person varied sharply among the various sectors.

Ultrafast photoionization dynamics at high laser intensities in the xuv regime

Energy Technology Data Exchange (ETDEWEB)

Kaiser, B.; Vagov, A.; Axt, V. M.; Pietsch, U. [Institut fuer Theoretische Physik III, Universitaet Bayreuth, D-95440 Bayreuth (Germany); Institut fuer Festkoerperphysik, Universitaet Siegen, D-57068 Siegen (Germany)

2011-10-15

We study the ionization dynamics in the soft-x-ray regime for high intensities and short pulses for excitations near the ionization threshold. Using a one-dimensional helium atom model, we compare exact numerical solutions with time-dependent Hartree-Fock results in order to identify the role of electron-electron correlations. At moderate intensities but still in the x-ray and short-pulse regime, we find that the Hartree-Fock theory reproduces well the dynamics of the ground-state occupation, while at high intensities strong correlation effects occur for excitations close to the threshold. From their characteristic momentum distributions, we can identify contributions to the double ionization from sequential three-photon and nonsequential or sequential two-photon processes. At elevated intensities these contributions deviate from their usual intensity scaling due to saturation effects, even though the total double-ionization probability stays below 10%. Furthermore, analysis of the time evolution of the momentum distribution reveals signatures of the energy-time uncertainty which indicate a coherent regime of the dynamics.

Hydroperiod regime controls the organization of plant species in wetlands.

Science.gov (United States)

Foti, Romano; del Jesus, Manuel; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio

2012-11-27

With urban, agricultural, and industrial needs growing throughout the past decades, wetland ecosystems have experienced profound changes. Most critically, the biodiversity of wetlands is intimately linked to its hydrologic dynamics, which in turn are being drastically altered by ongoing climate changes. Hydroperiod regimes, e.g., percentage of time a site is inundated, exert critical control in the creation of niches for different plant species in wetlands. However, the spatial signatures of the organization of plant species in wetlands and how the different drivers interact to yield such signatures are unknown. Focusing on Everglades National Park (ENP) in Florida, we show here that cluster sizes of each species follow a power law probability distribution and that such clusters have well-defined fractal characteristics. Moreover, we individuate and model those signatures via the interplay between global forcings arising from the hydroperiod regime and local controls exerted by neighboring vegetation. With power law clustering often associated with systems near critical transitions, our findings are highly relevant for the management of wetland ecosystems. In addition, our results show that changes in climate and land management have a quantifiable predictable impact on the type of vegetation and its spatial organization in wetlands.

Urban transportation projects conceptualised:

DEFF Research Database (Denmark)

Pineda, Andres Felipe Valderrama

is straightforward: transportation projects transform cities. The paradoxical reality thus is that a problem that has been traditionally conceptualized in technical terms (transportation engineering, transportation economics, planning theory, traffic engineering, urban planning, etc.), has tremendous consequences...... operation when discussing transportation projects in big cities. The tradition of Science and Technology Studies might have provided some clues. In the following paper we discuss the most prominent aspects of some theories in STS in order to understand and conceptualize the cases of Bogotá and Copenhagen...

Inflation, Growth and Exchange Rate Regimes in Small Open Economies

OpenAIRE

Hernandez-Verme, Paula

2002-01-01

Summary. This is an extended working paper version of the paper that appeared in Economic Theory. It paper compares the merits of alternative exchange rate regimes in small open economies where financial intermediaries perform a real allocative function, there are multiple reserve requirements, and credit market frictions may or may not cause credit rationing. Under floating exchange rates, raising domestic inflation can increase production if credit is rationed. However, there exist infla...

Rethinking immigration policy theory beyond 'Western liberal democracies'.

Science.gov (United States)

Natter, Katharina

2018-01-01

How do political systems shape immigration policy-making? Explicitly or implicitly, comparative politics and migration policy theories suggest a 'regime effect' that links specific dynamics of immigration policy to liberal democracy. The literature's dominant focus on so-called 'Western liberal democracies', however, has left the 'regime effect' largely untested and research on variations and similarities in immigration policymaking across political systems strikingly undertheorized. This paper challenges the theoretical usefulness of essentialist, dichotomous categories such as Western/non-Western or democratic/autocratic and calls for a more nuanced theorizing of immigration policy-making. It proposes a two-dimensional classification of immigration policy theories, distinguishing between 'issue-specific' theories that capture immigration policy processes regardless of the political system in place and 'regime-specific' theories whose insights are tied to the characteristics of a political system. The paper also advances the 'illiberal paradox' hypothesis to explain why illiberal, autocratic states may enact liberal immigration policies. This theoretical expansion beyond the 'Western' and 'liberal' bubble is illustrated by an analysis of immigration policy-making in 21st century Morocco and Tunisia. Showing how domestic and international institutions, interests, and ideas shape immigration policy-making in Morocco's monarchy and Tunisia's democratic transition, the paper investigates the broader role of political systems in immigration politics and herewith seeks to contribute to a more general and global theorization of immigration policies.

Efficacy of theory-based HIV behavioral prevention among rural-to-urban migrants in China: a randomized controlled trial.

Science.gov (United States)

Li, Xiaoming; Lin, Danhua; Wang, Bo; Du, Hongfei; Tam, Cheuk Chi; Stanton, Bonita

2014-08-01

Our objective was to evaluate the efficacy of a cultural adaptation of a social cognitive theory-based HIV behavioral prevention program among young rural-to-urban migrants in China. The intervention design and assessment were guided by the Protection Motivation Theory (PMT). The intervention was evaluated through a randomized controlled trial with 6-month and 12-month follow-ups. The primary behavioral outcome was the use of condoms. Other outcome measures include HIV knowledge, condom use knowledge, HIV-related perceptions (PMT constructs), and intention to use condom. The mixed-effects regression models for condom use with regular partners indicated that overall frequency of condom use, condom use in last three sexual acts and proper condom use increased over time for the participants but the increases were significantly greater among the intervention group than the control group at 6-month and 12-month follow-ups. The mixed-effects models for HIV-related perceptions indicated that extrinsic rewards, intrinsic rewards, and response costs decreased while vulnerability, severity, response efficacy, and self-efficacy increased over time for the intervention group. The increases in HIV knowledge, condom use knowledge, and intention to use condom were also significantly greater among the intervention group than the control group. The data in the current study suggested efficacy of a social cognitive theory-based behavioral intervention in increasing condom use among young migrants in China. The intervention also increased protective perceptions and decreased risk perception posited by the theory (i.e., PMT).

Onset of the nonlinear regime in unified dark matter models

International Nuclear Information System (INIS)

Avelino, P.P.; Beca, L.M.G.; Carvalho, J.P.M. de; Martins, C.J.A.P.; Copeland, E.J.

2004-01-01

We discuss the onset of the nonlinear regime in the context of unified dark matter models involving a generalized Chaplygin gas. We show that the transition from dark-matter-like to dark-energy-like behavior will never be smooth. In some regions of space the transition will never take place while in others it may happen sooner or later than naively expected. As a result the linear theory used in previous studies may break down late in the matter dominated era even on large cosmological scales. We study the importance of this effect showing that its magnitude depends on the exact form of the equation of state in the low density regime. We expect that our results will be relevant for other unified dark matter scenarios, particularly those where the quartessence candidate is a perfect fluid

On possibility of vibrational stabilization in nuclear instable stationary regimes in nuclear reactors

International Nuclear Information System (INIS)

Trakhtenberg, A.M.

1987-01-01

A principle possibility of applying the vibrational stabilization method to nuclear reactors is studied. The problem of securing the stability of nuclear reactor operation steady-state regimes is one of the central ones in dynamics theory and nuclear reaction operation experience. In particular, the problem of xenon oscillation suppressing in a reactor, occuring as a result of steady-state regime instability is urgent. Investigation is conducted using the simpliest reactor model, repesenting it as a non-linear object with concentrated parameters. It is proved that vibrational stabilization is achieved by periodic fluctuations of the control rod positions in the reactor core and boric acid concentration in the coolant with period 1s 4 s. In practice stabilization is effective, when the steady-state regime is located near the stability boundary, which appears to be dangerous, i.e. self-oscillations with inadmissibly high amplitude occure in the reactor

Status and future of lattice gauge theory

International Nuclear Information System (INIS)

Hoek, J.

1989-07-01

The current status of lattice Quantum Chromo Dynamics (QCD) calculations, the computer requirements to obtain physical results and the direction computing is taking are described. First of all, there is a lot of evidence that QCD is the correct theory of strong interactions. Since it is an asymptotically free theory we can use perturbation theory to solve it in the regime of very hard collisions. However even in the case of very hard parton collisions the end-results of the collisions are bound states of quarks and perturbation theory is not sufficient to calculate these final stages. The way to solve the theory in this regime was opened by Wilson. He contemplated replacing the space-time continuum by a discrete lattice, with a lattice spacing a. Continuum physics is then recovered in the limit where the correlation length of the theory, say ξ. is large with respect to the lattice spacing. This will be true if the lattice spacing becomes very small, which for asymptotically free theories also implies that the coupling g becomes small. The lattice approach to QCD is in many respects analogous to the use of finite element methods to solve classical field theories. These finite element methods are easy to apply in 2-dimensional simulations but are computationally demanding in the 3-dimensional case. Therefore it is not unexpected that the 4-dimensional simulations needed for lattice gauge theories have led to an explosion in demand for computing power by theorists. (author)

The Homogeneity Research of Urban Rail Transit Network Performance

Directory of Open Access Journals (Sweden)

Wang Fu-jian

2016-01-01

Full Text Available Urban Rail Transit is an important part of the public transit, it is necessary to carry out the corresponding network function analysis. Previous studies mainly about network performance analysis of a single city rail transit, lacking of horizontal comparison between the multi-city, it is difficult to find inner unity of different Urban Rail Transit network functions. Taking into account the Urban Rail Transit network is a typical complex networks, so this paper proposes the application of complex network theory to research the homogeneity of Urban Rail Transit network performance. This paper selects rail networks of Beijing, Shanghai, Guangzhou as calculation case, gave them a complex network mapping through the L, P Space method and had a static topological analysis using complex network theory, Network characteristics in three cities were calculated and analyzed form node degree distribution and node connection preference. Finally, this paper studied the network efficiency changes of Urban Rail Transit system under different attack mode. The results showed that, although rail transport network size, model construction and construction planning of the three cities are different, but their network performance in many aspects showed high homogeneity.

The Power of Micro Urban Structures, Theory of EEPGC - the Micro Urban Energy Distribution Model as a Planning Tool for Sustainable City Development

Directory of Open Access Journals (Sweden)

Tkáč Štefan

2015-11-01

Full Text Available To achieve the smart growth and equitable development in the region, urban planners should consider also lateral energies represented by the energy urban models like further proposed EEPGC focused on energy distribution via connections among micro-urban structures, their onsite renewable resources and the perception of micro-urban structures as decentralized energy carriers based on pre industrialized era. These structures are still variously bound when part of greater patterns. After the industrial revolution the main traded goods became energy in its various forms. The EEPGC is focused on sustainable energy transportation distances between the villages and the city, described by the virtual “energy circles”. This more human scale urbanization, boost the economy in micro-urban areas, rising along with clean energy available in situ that surely gives a different perspective to human quality of life in contrast to overcrowded multicultural mega-urban structures facing generations of problems and struggling to survive as a whole.

The Power of Micro Urban Structures, Theory of EEPGC - the Micro Urban Energy Distribution Model as a Planning Tool for Sustainable City Development

Science.gov (United States)

Tkáč, Štefan

2015-11-01

To achieve the smart growth and equitable development in the region, urban planners should consider also lateral energies represented by the energy urban models like further proposed EEPGC focused on energy distribution via connections among micro-urban structures, their onsite renewable resources and the perception of micro-urban structures as decentralized energy carriers based on pre industrialized era. These structures are still variously bound when part of greater patterns. After the industrial revolution the main traded goods became energy in its various forms. The EEPGC is focused on sustainable energy transportation distances between the villages and the city, described by the virtual "energy circles". This more human scale urbanization, boost the economy in micro-urban areas, rising along with clean energy available in situ that surely gives a different perspective to human quality of life in contrast to overcrowded multicultural mega-urban structures facing generations of problems and struggling to survive as a whole.

Classical tokamak transport theory

International Nuclear Information System (INIS)

Nocentini, Aldo

1982-01-01

A qualitative treatment of the classical transport theory of a magnetically confined, toroidal, axisymmetric, two-species plasma is presented. The 'weakly collisional' ('banana' and 'plateau') and 'collision dominated' ('Pfirsch-Schlueter' and 'highly collisional') regimes, as well as the Ware effect are discussed. The method used to evaluate the diffusion coffieicnts of particles and heat in the weakly collisional regime is based on stochastic argument, that requires an analysis of the characteristic collision frequencies and lengths for particles moving in a tokamak-like magnetic field. The same method is used to evaluate the Ware effect. In the collision dominated regime on the other hand, the particle and heat fluxes across the magnetic field lines are dominated by macroscopic effects so that, although it is possible to present them as diffusion (in fact, the fluxes turn out to be proportional to the density and temperature gradients), a macroscopic treatment is more appropriate. Hence, fluid equations are used to inveatigate the collision dominated regime, to which particular attention is devoted, having been shown relatively recently that it is more complicated than the usual Pfirsch-Schlueter regime. The whole analysis presented here is qualitative, aiming to point out the relevant physical mechanisms involved in the various regimes more than to develop a rigorous mathematical derivation of the diffusion coefficients, for which appropriate references are given. (author)

Alien plants as mediators of ecosystem services and disservices in urban systems: a global review

CSIR Research Space (South Africa)

Potgieter, LJ

2017-12-01

Full Text Available by human activities and their floras comprise a high proportion of alien plant species, many of which were intentionally introduced to provide, augment or restore ES. Urban environments also have novel disturbance regimes and provide colonization sites...

Can one tell Einstein's unimodular theory from Einstein's general relativity?

OpenAIRE

Alvarez, Enrique

2005-01-01

The so called unimodular theory of gravitation is compared with general relativity in the quadratic (Fierz-Pauli) regime, using a quite broad framework, and it is argued that quantum effects allow in principle to discriminate between both theories.

Weak turbulence theory of Langmuir waves: A reconsideration of validity of quasilinear theory

International Nuclear Information System (INIS)

Liang, Y.M.; Diamond, P.H.

1991-01-01

The weak turbulence theory of Langmuir waves in a one-dimensional, one-species plasma is discussed. Analytical calculations using the theory of two-point correlation functions show that in the weak turbulence regime τ ac much-lt min[τ tr , γ k -1 ], the nonlinear enhancement of the mode growth rate relative to the linear Landau mode growth rate γ k L is rather weak, and quasilinear theory is reproduced at the lowest order. Hence this work also proves the validity of the quasilinear theory. Here τ ac ∼ (kΔv ph ) -1 is the phase-mixing time or the auto-correlation time, and τ tr ∼ (k 2 D ql ) -1/3 is the particle decorrelation time or the turbulence trapping time. In particular, the lowest order nonlinear correction to γ k L in the regime τ ac much-lt τ tr much-lt γ k -1 is proportional to (1/ω k τ tr )γ k L . Both corrections are additive, not multiplicative, and are of higher order in the weak turbulence expansion. The smallness of the corrections is due to the fact that the only mechanism for the relaxation of the plasma distribution function in a one-dimensional, one-species plasma is momentum exchange between waves and particles, which is exactly the interaction considered in the quasilinear theory. No like-like particle momentum exchange is allowed due to momentum conservation constraints. Similar calculations are also done for the traveling wave tube, which can be used to test this theory experimentally, especially for the case of bump-on-tail instability. A comparison of theoretical predictions with experimental results is presented. 3 refs

Non local theory of excitations applied to the Hubbard model

International Nuclear Information System (INIS)

Kakehashi, Y; Nakamura, T; Fulde, P

2010-01-01

We propose a nonlocal theory of single-particle excitations. It is based on an off-diagonal effective medium and the projection operator method for treating the retarded Green function. The theory determines the nonlocal effective medium matrix elements by requiring that they are consistent with those of the self-energy of the Green function. This arrows for a description of long-range intersite correlations with high resolution in momentum space. Numerical study for the half-filled Hubbard model on the simple cubic lattice demonstrates that the theory is applicable to the strong correlation regime as well as the intermediate regime of Coulomb interaction strength. Furthermore the results show that nonlocal excitations cause sub-bands in the strong Coulomb interaction regime due to strong antiferromagnetic correlations, decrease the quasi-particle peak on the Fermi level with increasing Coulomb interaction, and shift the critical Coulomb interaction U C2 for the divergence of effective mass towards higher energies at least by a factor of two as compared with that in the single-site approximation.

Toward an integrated theory of spatial morphology and resilient urban systems

OpenAIRE

Lars Marcus; Johan Colding

2014-01-01

We take the first step in the development of a new field of research with the aim of merging spatial morphology and resilience science. This involves a revisiting and reunderstanding of the meaning of sustainable urban form. We briefly describe the fields of resilience science and spatial morphology. Drawing on a selected set of propositions in both fields, we put urban form in the context of the adaptive renewal cycle, a dynamic framework model used in resilience science to capture the dynam...

Moment equation approach to neoclassical transport theory

International Nuclear Information System (INIS)

Hirshman, S.P.

1978-01-01

The neoclassical cross-field fluxes for a toroidally confined, axisymmetric plasma are calculated in terms of the thermodynamic forces from the fluid continuity and momentum balance equations. This macroscopic formulation of neoclassical transport theory unifies the numerous complex expressions for the transport coefficients, previously obtained by solving the Fokker--Planck equation, and elucidates their physical basis. In the large aspect ratio limit, the continuous transition in the scaling of the diffusion coefficient throughout various collisionality regimes is shown to depend on the ratio of parallel viscosity coefficients of the plasma species. Comparison of the present results with the kinetic theory expressions for the neoclassical fluxes determines the parallel viscosity coefficients for a multispecies plasma in the long-mean-free-path regime

Transparent electrodes in the terahertz regime – a new approach

DEFF Research Database (Denmark)

Malureanu, Radu; Song, Z.; Zalkovskij, Maksim

We suggest a new possibility for obtaining a transparent metallic film, thus allowing for completely transparent electrodes. By placing a complementary composite layer on top of the electrode, we can cancel the back-scattering of the latter thus obtaining a perfectly transparent structure. For ea...... of fabrication, we performed the first experiments in the THz regime, but the concept is applicable to the entire electromagnetic waves spectrum. We show that the experiments and theory match each other perfectly....

Laser Frequency Noise in Coherent Optical Systems: Spectral Regimes and Impairments.

Science.gov (United States)

Kakkar, Aditya; Rodrigo Navarro, Jaime; Schatz, Richard; Pang, Xiaodan; Ozolins, Oskars; Udalcovs, Aleksejs; Louchet, Hadrien; Popov, Sergei; Jacobsen, Gunnar

2017-04-12

Coherent communication networks are based on the ability to use multiple dimensions of the lightwave together with electrical domain compensation of transmission impairments. Electrical-domain dispersion compensation (EDC) provides many advantages such as network flexibility and enhanced fiber nonlinearity tolerance, but makes the system more susceptible to laser frequency noise (FN), e.g. to the local oscillator FN in systems with post-reception EDC. Although this problem has been extensively studied, statistically, for links assuming lasers with white-FN, many questions remain unanswered. Particularly, the influence of a realistic non-white FN-spectrum due to e.g., the presence of 1/f-flicker and carrier induced noise remains elusive and a statistical analysis becomes insufficient. Here we provide an experimentally validated theory for coherent optical links with lasers having general non-white FN-spectrum and EDC. The fundamental reason of the increased susceptibility is shown to be FN-induced symbol displacement that causes timing jitter and/or inter/intra symbol interference. We establish that different regimes of the laser FN-spectrum cause a different set of impairments. The influence of the impairments due to some regimes can be reduced by optimizing the corresponding mitigation algorithms, while other regimes cause irretrievable impairments. Theoretical boundaries of these regimes and corresponding criteria applicable to system/laser design are provided.

Exchange rate regimes and monetary arrangements

Directory of Open Access Journals (Sweden)

Ivan Ribnikar

2005-06-01

Full Text Available There is a close relationship between a country’s exchange rate regime and monetary arrangement and if we are to examine monetary arrangements then exchange rate regimes must first be analysed. Within the conventional and most widely used classification of exchange rate regimes into rigid and flexible or into polar regimes (hard peg and float on one side, and intermediate regimes on the other there, is a much greater variety among intermediate regimes. A more precise and, as will be seen, more useful classification of exchange rate regimes is the first topic of the paper. The second topic is how exchange rate regimes influence or determine monetary arrangements and monetary policy or monetary policy regimes: monetary autonomy versus monetary nonautonomy and discretion in monetary policy versus commitment in monetary policy. Both topics are important for countries on their path to the EU and the euro area

The theory of ionizing shock waves in a magnetic field

International Nuclear Information System (INIS)

Liberman, M.A.; Velikovich, A.L.

1981-01-01

The general theory of ionizing shock waves in a magnetic field is constructed. The theory takes into account precursor ionization of a neutral gas ahead of the shock wave front, caused by photo-ionization, as well as by the impact ionization with electrons accelerated by a transverse electric field induced by the shock front in the incident flow of a neutral gas. The concept of shock wave ionization stability, being basic in the theory of ionizing shock waves in a magnetic field, is introduced. The ionizing shock wave structures are shown to transform from the GD regime at a low shock velocity to the MHD regime at an enhanced intensity of the shock wave. The abruptness of such a transition is determined by precursor photo-ionization. (author)

Semi adiabatic theory of seasonal Markov processes

Energy Technology Data Exchange (ETDEWEB)

Talkner, P [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

The dynamics of many natural and technical systems are essentially influenced by a periodic forcing. Analytic solutions of the equations of motion for periodically driven systems are generally not known. Simulations, numerical solutions or in some limiting cases approximate analytic solutions represent the known approaches to study the dynamics of such systems. Besides the regime of weak periodic forces where linear response theory works, the limit of a slow driving force can often be treated analytically using an adiabatic approximation. For this approximation to hold all intrinsic processes must be fast on the time-scale of a period of the external driving force. We developed a perturbation theory for periodically driven Markovian systems that covers the adiabatic regime but also works if the system has a single slow mode that may even be slower than the driving force. We call it the semi adiabatic approximation. Some results of this approximation for a system exhibiting stochastic resonance which usually takes place within the semi adiabatic regime are indicated. (author) 1 fig., 8 refs.

Land use context and natural soil controls on plant community and soil nitrogen and carbon dynamics in urban and rural forests

Science.gov (United States)

Peter M. Groffman; Richard V. Pouyat; Mary L. Cadenasso; Wayne C. Zipperer; Katalin Szlavecz; Ian D. Yesilonis; Lawrence E. Band; Grace S. Brush

2006-01-01

Forests embedded in an urban matrix are a useful venue for investigating the effects of multiple factors such as climate change, altered disturbance regimes and species invasions on forest ecosystems. Urban forests also represent a significant land area, with potentially important effects on landscape and regional scale nitrogen (N) and carbon (C) storage and flux. We...

A dynamic model for firm-response to non-credible incentive regulation regimes

International Nuclear Information System (INIS)

Agrell, Per J.; Grifell-Tatjé, Emili

2016-01-01

Economic network regulation increasingly use quantitative performance models (from econometrics and engineering) to set revenues. In theory, high-powered incentive regulation, such as revenue-caps, induces firms to cost-efficient behavior independent of underlying model. However, anecdotal evidence shows regulated firms occasionally maintaining cost-inefficiency under incentive regulation even under slumping profitability. We present a model for firm-level efficiency under a regime with a probability of failure explaining this phenomenon. The model is based on the hypothesis that the regulatory choice of method can be associated with intrinsic flaws leading to judicial repeal and replacement of it by a low-powered regime. The results show that the cost efficiency policy is proportional to the type of firm (cost of effort), value of time (discount factor) and the credibility of the method (risk of failure). A panel data set for 2000–2006 for 128 electricity distributors in Sweden is used to validate the model predictions (radical productivity slowdown, failing profitability and efficiency) at the launch and demise of a non-credible regulation method. The work highlights the fallacy of viewing incentive regulation as a method-independent instrument, a result applicable in any infrastructure regulation. - Highlights: • Incentive regulation relies on fixed revenue for operators. • In existing theory the efficiency-inducing effect is model-independent. • A dynamic game exposes the firm to a regulation that may fail. • One optimal policy is to pad cost and wait for the failure. • The Swedish DSOs show this policy 2003–2006, when the regime failed.

Urban Gardening in the Crisis Conjuncture

Directory of Open Access Journals (Sweden)

Christopher Maughan

2016-10-01

Full Text Available Urban gardening finds itself at a juncture – not only are crises caused and exacerbated by the industrial food system urgently demonstrating the need for more localised, sustainable, and democratically-determined food systems, but alternative food movements are increasingly negotiating crises of their own. Critical Foodscapes was a one-day conference part-funded by Warwick’s Institute of Advanced Study (IAS and the Food GRP. The conference was put together with the intention of bringing a ‘critical studies’ approach to the emerging research area of urban community food growing; namely, to put critical – but constructive – pressure on some of the assumptions which underlie current theory and practice of the various forms of urban food growing. This article offers some reflections on the conference itself as well as on the prospects for urban gardening more generally.

Urbanization and the more-individuals hypothesis.

Science.gov (United States)

Chiari, Claudia; Dinetti, Marco; Licciardello, Cinzia; Licitra, Gaetano; Pautasso, Marco

2010-03-01

1. Urbanization is a landscape process affecting biodiversity world-wide. Despite many urban-rural studies of bird assemblages, it is still unclear whether more species-rich communities have more individuals, regardless of the level of urbanization. The more-individuals hypothesis assumes that species-rich communities have larger populations, thus reducing the chance of local extinctions. 2. Using newly collated avian distribution data for 1 km(2) grid cells across Florence, Italy, we show a significantly positive relationship between species richness and assemblage abundance for the whole urban area. This richness-abundance relationship persists for the 1 km(2) grid cells with less than 50% of urbanized territory, as well as for the remaining grid cells, with no significant difference in the slope of the relationship. These results support the more-individuals hypothesis as an explanation of patterns in species richness, also in human modified and fragmented habitats. 3. However, the intercept of the species richness-abundance relationship is significantly lower for highly urbanized grid cells. Our study confirms that urban communities have lower species richness but counters the common notion that assemblages in densely urbanized ecosystems have more individuals. In Florence, highly inhabited areas show fewer species and lower assemblage abundance. 4. Urbanized ecosystems are an ongoing large-scale natural experiment which can be used to test ecological theories empirically.

La scuola svedese e la teoria macroeconomica: riflessioni su una piccola economia aperta operante in regime di cambi flessibiliThe Swedish School and macroeconomic theory: Reflections on a small open economy operating within a regime of flexible exchanges

Directory of Open Access Journals (Sweden)

D. TROPEANO

2013-10-01

Full Text Available The Swedish School, with its representatives Ohlin, Hammarskjöld and Lindahl, madeimportant contributions to the economic theory of the open economy, even if such contributions have never been at the centre of attention of economists, probably due to their dark language style. In particular, it had a vision of the operating of an open economy that was completely different from post-war Keynesian orthodoxy. The exchange rate regime does not isolate a small economy from the repercussions of events that occur in financial markets and from goods at the international level. The other major assumption of open economy macroeconomics was the independence of monetary policy. The Keynesian models in the 1950s included only external money. On the contrary, the Swedes considered the credit system and the working of international banks.JEL: F41

Nonlinear Plasma Response to Resonant Magnetic Perturbation in Rutherford Regime

Science.gov (United States)

Zhu, Ping; Yan, Xingting; Huang, Wenlong

2017-10-01

Recently a common analytic relation for both the locked mode and the nonlinear plasma response in the Rutherford regime has been developed based on the steady-state solution to the coupled dynamic system of magnetic island evolution and torque balance equations. The analytic relation predicts the threshold and the island size for the full penetration of resonant magnetic perturbation (RMP). It also rigorously proves a screening effect of the equilibrium toroidal flow. In this work, we test the theory by solving for the nonlinear plasma response to a single-helicity RMP of a circular-shaped limiter tokamak equilibrium with a constant toroidal flow, using the initial-value, full MHD simulation code NIMROD. Time evolution of the parallel flow or ``slip frequency'' profile and its asymptotic approach to steady state obtained from the NIMROD simulations qualitatively agree with the theory predictions. Further comparisons are carried out for the saturated island size, the threshold for full mode penetration, as well as the screening effects of equilibrium toroidal flow in order to understand the physics of nonlinear plasma response in the Rutherford regime. Supported by National Magnetic Confinement Fusion Science Program of China Grants 2014GB124002 and 2015GB101004, the 100 Talent Program of the Chinese Academy of Sciences, and U.S. Department of Energy Grants DE-FG02-86ER53218 and DE-FC02-08ER54975.

Assessing the ammonium nitrate formation regime in the Paris megacity and its representation in the CHIMERE model

Directory of Open Access Journals (Sweden)

H. Petetin

2016-08-01

Full Text Available Secondary inorganic compounds represent a major fraction of fine aerosol in the Paris megacity. The thermodynamics behind their formation is now relatively well constrained but, due to sparse direct measurements of their precursors (in particular NH3 and HNO3, uncertainties remain on their concentrations and variability as well as the formation regime of ammonium nitrate (in terms of limited species among NH3 and HNO3 in urban environments such as Paris. This study presents the first urban background measurements of both inorganic aerosol compounds and their gaseous precursors during several months within the city of Paris. Intense agriculture-related NH3 episodes are observed in spring/summer while HNO3 concentrations remain relatively low, even during summer, which leads to a NH3-rich regime in Paris. The local formation of ammonium nitrate within the city appears low, despite high NOx emissions. The data set also allows evaluating the CHIMERE chemistry-transport model (CTM. Interestingly, the rather good results obtained on ammonium nitrates hide significant errors on gaseous precursors (e.g., mean bias of −75 and +195 % for NH3 and HNO3, respectively. This leads to a misrepresentation of the nitrate formation regime through a highly underestimated gas ratio metric (introduced by Ansari and Pandis, 1998 and a much higher sensitivity of nitrate concentrations to ammonia changes. Several uncertainty sources are investigated, pointing out the importance of better assessing both NH3 agricultural emissions and OH concentrations in the future. These results remind us of the caution required when using of CTMs for emission scenario analysis, highlighting the importance of prior diagnostic and dynamic evaluations.

Causas estruturais e consequências dos regimes internacionais: regimes como variáveis intervenientes

OpenAIRE

Krasner, Stephen D.

2012-01-01

Os regimes internacionais são definidos como princípios, normas, regras e procedimentos de tomada de decisões ao redor dos quais as expectativas dos atores convergem em uma dada área-tema. Como ponto de partida, os regimes são conceituados como variáveis intervenientes, estando entre fatores causais básicos e os resultados e comportamentos relacionados. Há três visões a respeito da importância dos regimes: as orientações estruturais convencionais desvalorizam os regimes como sendo, na melhor ...

The Metacity: A Conceptual Framework for Integrating Ecology and Urban Design

Directory of Open Access Journals (Sweden)

S. T. A. Pickett

2011-10-01

Full Text Available We introduce the term metacity as a conceptual framework that can be shared by ecologists and designers and applied across the wide variety of urban habitats found around the world. While the term metacity was introduced by UN-HABITAT to designate hyper cities of over twenty million people, for us it is not limited to large urban agglomerations, but rather refers to the proliferation of new forms of urbanization, each with distinct ecological and social attributes. These various urban configurations when combined with new digital sensing, communication and social networking technologies constitute a virtual meta-infrastructure, present in all cities today. This new metacity has the potential to integrate new activist forms of ecological and urban design research and practice in making the transition from sanitary to sustainable city models globally. The city of Baltimore, Maryland will be used both as a site to illustrate these recent urban trends, and also as an example of the integration of ecology and urban design pursued by the two authors over the past seven years [1,2]. Metacity theory is drawn from both an architectural analysis of contemporary forms of urbanism, new forms of digital monitoring and communication technologies, as well as metapopulation and metacommunity theories in ecology. We seek to provide tools and lessons from our experiences for realizing an integrated metacity approach to achieving social sustainability and ecological resilience on an increasingly urbanized planet.

Characterisation of urban catchment suspended particulate matter (Auckland region, New Zealand); a comparison with non-urban SPM

International Nuclear Information System (INIS)

Bibby, Rebecca L.; Webster-Brown, Jenny G.

2005-01-01

Suspended particulate matter (SPM) is an important transport agent for metal contaminants in streams, particularly during high flow periods such as storm events. For highly contaminated urban catchments in the greater Auckland (New Zealand) area, trace metal partitioning between the dissolved phase and SPM was determined, and SPM characterised in terms of its Si, Al, Fe, Mn, Zn, Cu, Pb, TOC, TON and PO 4 concentrations, as well as particle size, abundance, type and surface area. This data was compared to similar data from representative non-urban catchments in the Auckland region, the Kaipara River and Waikato River catchments, to identify any significant differences in the SPM and its potential trace metal adsorption capacity. Trace metal partitioning was assessed by way of a distribution coefficient: K D =[Me SPM ]/[Me DISS ]. Auckland urban SPM comprises quartz, feldspars and clay minerals, with Fe-oxides and minor Mn-oxides. No particles of anthropogenic origin, other than glass shards, were observed. No change in urban SPM particle size or SSA was observed with seasonal change in temperature, but the nature of the SPM was observed to change with flow regime. The abundance of finer particles, SSA and Al content of the SPM increased under moderate flow conditions; however, Si/Al ratios remained constant, confirming the importance of aluminosilicate detrital minerals in surface run-off. The SPM Fe content was observed to decrease with increased flow and was attributed to dilution of SPM Fe-oxide of groundwater origin. The Kaipara River SPM was found to be mineralogically, chemically and biologically similar to the urban SPM. However, major differences between urban catchment SPM and SPM from the much larger (non-urban) Waikato River were observed, and attributed to a higher abundance of diatoms. The Fe content of the Waikato River SPM was consistently lower (<5%), and the Si/Al ratio and Mn content was higher. Such differences observed between urban and non-urban

The Pedagogical Benefits of "SimCity" in Urban Geography Education

Science.gov (United States)

Kim, Minsung; Shin, Jungyeop

2016-01-01

This article investigated the pedagogical potential of the "SimCity" simulation game in an urban geography course. University students used "SimCity" to build their own cities and applied a wide range of theories to support their urban structures. Moreover, the students critically evaluated the logic and functioning of the…

Holographic effective field theories

Energy Technology Data Exchange (ETDEWEB)

Martucci, Luca [Dipartimento di Fisica ed Astronomia “Galileo Galilei' , Università di Padova,and INFN - Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Zaffaroni, Alberto [Dipartimento di Fisica, Università di Milano-Bicocca,and INFN - Sezione di Milano-Bicocca, I-20126 Milano (Italy)

2016-06-28

We derive the four-dimensional low-energy effective field theory governing the moduli space of strongly coupled superconformal quiver gauge theories associated with D3-branes at Calabi-Yau conical singularities in the holographic regime of validity. We use the dual supergravity description provided by warped resolved conical geometries with mobile D3-branes. Information on the baryonic directions of the moduli space is also obtained by using wrapped Euclidean D3-branes. We illustrate our general results by discussing in detail their application to the Klebanov-Witten model.

Sensitivity to spatial and temporal scale and fire regime inputs in deriving fire regime condition class

Science.gov (United States)

Linda Tedrow; Wendel J. Hann

2015-01-01

The Fire Regime Condition Class (FRCC) is a composite departure measure that compares current vegetation structure and fire regime to historical reference conditions. FRCC is computed as the average of: 1) Vegetation departure (VDEP) and 2) Regime (frequency and severity) departure (RDEP). In addition to the FRCC rating, the Vegetation Condition Class (VCC) and Regime...

Effect of the shaft on the aerodynamic performance of urban vertical axis wind turbines

NARCIS (Netherlands)

Rezaeiha, A.; Kalkman, I.; Montazeri, H.; Blocken, B.J.E.

2017-01-01

The central shaft is an inseparable part of a vertical axis wind turbine (VAWT). For small turbines such as those typically used in urban environments, the shaft could operate in the subcritical regime, resulting in large drag and considerable aerodynamic power loss. The current study aims to (i)

Quantifying urban growth patterns in Hanoi using landscape expansion modes and time series spatial metrics

Science.gov (United States)

Lepczyk, Christopher A.; Miura, Tomoaki; Fox, Jefferson M.

2018-01-01

Urbanization has been driven by various social, economic, and political factors around the world for centuries. Because urbanization continues unabated in many places, it is crucial to understand patterns of urbanization and their potential ecological and environmental impacts. Given this need, the objectives of our study were to quantify urban growth rates, growth modes, and resultant changes in the landscape pattern of urbanization in Hanoi, Vietnam from 1993 to 2010 and to evaluate the extent to which the process of urban growth in Hanoi conformed to the diffusion-coalescence theory. We analyzed the spatiotemporal patterns and dynamics of the built-up land in Hanoi using landscape expansion modes, spatial metrics, and a gradient approach. Urbanization was most pronounced in the periods of 2001–2006 and 2006–2010 at a distance of 10 to 35 km around the urban center. Over the 17 year period urban expansion in Hanoi was dominated by infilling and edge expansion growth modes. Our findings support the diffusion-coalescence theory of urbanization. The shift of the urban growth areas over time and the dynamic nature of the spatial metrics revealed important information about our understanding of the urban growth process and cycle. Furthermore, our findings can be used to evaluate urban planning policies and aid in urbanization issues in rapidly urbanizing countries. PMID:29734346

Quantifying urban growth patterns in Hanoi using landscape expansion modes and time series spatial metrics.

Science.gov (United States)

Nong, Duong H; Lepczyk, Christopher A; Miura, Tomoaki; Fox, Jefferson M

2018-01-01

Urbanization has been driven by various social, economic, and political factors around the world for centuries. Because urbanization continues unabated in many places, it is crucial to understand patterns of urbanization and their potential ecological and environmental impacts. Given this need, the objectives of our study were to quantify urban growth rates, growth modes, and resultant changes in the landscape pattern of urbanization in Hanoi, Vietnam from 1993 to 2010 and to evaluate the extent to which the process of urban growth in Hanoi conformed to the diffusion-coalescence theory. We analyzed the spatiotemporal patterns and dynamics of the built-up land in Hanoi using landscape expansion modes, spatial metrics, and a gradient approach. Urbanization was most pronounced in the periods of 2001-2006 and 2006-2010 at a distance of 10 to 35 km around the urban center. Over the 17 year period urban expansion in Hanoi was dominated by infilling and edge expansion growth modes. Our findings support the diffusion-coalescence theory of urbanization. The shift of the urban growth areas over time and the dynamic nature of the spatial metrics revealed important information about our understanding of the urban growth process and cycle. Furthermore, our findings can be used to evaluate urban planning policies and aid in urbanization issues in rapidly urbanizing countries.

Interactions in 2D electron and hole systems in the intermediate and ballistic regimes

International Nuclear Information System (INIS)

Proskuryakov, Y Y; Savchenko, A K; Safonov, S S; Li, L; Pepper, M; Simmons, M Y; Ritchie, D A; Linfield, E H; Kvon, Z D

2003-01-01

In different 2D semiconductor systems we study the interaction correction to the Drude conductivity in the intermediate and ballistic regimes, where the parameter k B Tτ/ h-bar changes from 0.1 to 10 (τ is momentum relaxation time). The temperature dependence of the resistance and magnetoresistance in parallel and perpendicular magnetic fields is analysed in terms of the recent theories of electron-electron interactions in systems with different degree of disorder and different character of the fluctuation potential. Generally, good agreement is found between the experiments and the theories

Modelling atmospheric deposition flux of Cadmium and Lead in urban areas

International Nuclear Information System (INIS)

Cherin, Nicolas

2017-01-01

According to WHO, air pollution is responsible for more than 3.7 million premature deaths each year (OMS, 2014). Moreover, among these deaths, more than 70 within urban areas. Consequently, the health and environmental impacts of pollutants within these urban areas are of great concern in air quality studies. The deposition fluxes of air pollutants, which can be significant near sources of pollution, have rarely been modeled within urban areas. Historically, atmospheric deposition studies have focused mostly on remote areas to assess the potential impacts on ecosystems of acid deposition and nitrogen loading. Therefore, current atmospheric deposition models may not be suitable to simulate deposition fluxes in urban areas, which include complex surface geometries and diverse land use types. Atmospheric dry deposition is typically modeled using an average roughness length, which depends on land use. This classical roughness-length approach cannot account for the spatial variability of dry deposition in complex settings such as urban areas. Urban canopy models have been developed to parameterize momentum and heat transfer. We extend this approach here to mass transfer, and a new dry deposition model based on the urban canyon concept is presented. It uses a local mixing-length parameterization of turbulence within the canopy, and a description of the urban canopy via key parameters to provide spatially distributed dry deposition fluxes. This approach provides spatially distributed dry deposition fluxes depending on surfaces (streets, walls, roofs) and flow regimes (recirculation and ventilation) within the urban area. (author) [fr

[Effect of antecedent dry weather period on urban storm runoff pollution load].

Science.gov (United States)

Li, Li-qing; Yin, Cheng-qing; Kong, Ling-li; He, Qing-ci

2007-10-01

Twelve storm events were surveyed at Shilipu catchment in Wuhan City through three-year monitoring regime. The flow discharges, total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in runoff were measured to study the mechanism of urban stormwater runoff pollution. The relationship between the event pollution load and the antecedent dry weather period was identified to discuss the influence of the urban surface sanitation management, operation of sewer pipe maintenance and rainfall characteristics on the urban stormwater runoff pollution. It was found that the antecedent dry weather period and runoff amount were the important determining factors in the generation of urban stormwater runoff pollution. The event pollution load was positively correlated to the antecedent dry weather period between two rainfall events (R2 = 0.95, p pollution loads. The best regression equation to estimate pollution load for storm events was developed based on the antecedent dry weather period and runoff depth. Source control including improving urban street sweeping activities and operation of sewer pipe maintenance should be made to reduce the amount of available pollutant over the dry days. It is important alternative to control urban stormwater runoff pollution for Hanyang District.

Conserving Biodiversity in Urbanizing Areas: Nontraditional Views from a Bird’s Perspective

Directory of Open Access Journals (Sweden)

Amanda D. Rodewald

2008-01-01

Full Text Available We review common population and community-level responses of wildlife to urbanization, and discuss how: (1 the amount and configuration of land cover and land use, and (2 the alteration of resources (e.g., type of vegetation, presence of food and water and processes (e.g., natural disturbance regimes, species interactions, intensity of human recreation within built environments influence animals, with special emphasis on birds. Although each landscape presents unique opportunities and constraints, we suggest that all urban areas have the potential to contribute to the conservation of biodiversity. The ecological value of urban areas may be promoted if planners, managers, and homeowners consider ways to (1 encourage retention and protection of natural habitats within urbanizing landscapes, (2 plan explicitly for open spaces and natural habitats within new subdivisions, (3 use a variety of arrangements of built and open space within developments, (4 enhance and restore habitat within open spaces, (5 improve quality of developed lands (i.e., the urban matrix rather than directing management efforts only towards parks, reserves, and open areas, and (6 celebrate urban biological diversity to foster connections between people and their natural heritage.

HIV/STD risk behaviors and perceptions among rural-to-urban migrants in China.

Science.gov (United States)

Li, Xiaoming; Fang, Xiaoyi; Lin, Danhua; Mao, Rong; Wang, Jing; Cottrell, Lesley; Harris, Carole; Stanton, Bonita

2004-12-01

Data from 2,153 sexually active rural-to-urban migrants in China were analyzed to examine the relationship between the movement of rural-to-urban migration and increased HIV/STD (sexually transmitted disease) risk and the applicability of constructs of a Western-based theory of behavioral change to the study population. Measurements included migrant mobility, sexual risk, and the seven constructs of the protection motivation theory (PMT). Data in the current study suggest that high mobility among rural-to-urban migrants was associated with increased sexual risk. The PMT constructs are applicable in identifying perceptions and attitudes associated with sexual risk behaviors in this culturally distinct population. Increased sexual risk was associated with increased perceptions of extrinsic rewards, intrinsic rewards, and response cost. Also consistent with PMT, increased sexual risk was associated with perceptions of decreased severity, vulnerability, response efficacy, and self-efficacy. After controlling for a number of key confounding factors, all seven PMT constructs were associated with sexual risk in the manner posited by the theory. The association between mobility and sexual risk underscores the importance of effective HIV/STD prevention efforts among this vulnerable population. The social cognitive theories including the PMT may form a logical base for prevention intervention programs targeting rural-to-urban migrants in China.

Gauge theories, black hole evaporation and cosmic censorship

International Nuclear Information System (INIS)

Davies, P.C.W.

1981-01-01

Recent work of Linde, which suggests that gauge theories modify the effective gravitational constant, are applied to the theory of black hole evaporation. Considerable modification of the late stages of evaporation are predicted. Contrary to expectations, the black hole never attains a sufficient temperature to enter the antigravity regime, which would represent a failure of cosmic censorship. (orig.)

Delineating Urban Fringe Area by Land Cover Information Entropy—An Empirical Study of Guangzhou-Foshan Metropolitan Area, China

Directory of Open Access Journals (Sweden)

Junyi Huang

2016-05-01

Full Text Available Rapid urbanization has caused many environmental problems, such as the heat island effect, intensifying air pollution, pollution from runoff, loss of wildlife habitat, etc. Accurate evaluations of these problems demand an accurate delineation of the spatial extent of the urban fringe. Conceptual and analytical ambiguity of the urban fringe and a general lack of consensus among researchers have made its measurement very difficult. This study reports a compound and reliable method to delineate the urban fringe area using a case study. Based on the 'fringe effect' theory in landscape ecology, the existing land cover information entropy model for defining the urban fringe is renewed by incorporating scale theory, cartography and urban geography theory. Results show that the urban fringe area of Guangzhou and Foshan metropolitan area covers an area of 2031 km2, and it occupies over 31% of the total study area. Result evaluation by industry structure data shows satisfactory correspondence with different land cover types. This paper reports the method and outcome of an attempt to provide an objective, repeatable and generally applicable method for mapping its spatial extent from remote sensing imageries, and could be beneficial to relevant urban studies and urban fringe management projects.

Generalized extended Navier-Stokes theory

DEFF Research Database (Denmark)

Hansen, J. S.; Daivis, Peter J.; Dyre, Jeppe C.

2013-01-01

in molecular fluids. To discuss these phenomena in detail, molecular dynamics simulations of molecular chlorine are performed for three different state points. In general, the theory captures the behavior for small wavevector and frequencies as expected. For example, in the hydrodynamic regime......The extended Navier-Stokes theory accounts for the coupling between the translational and rotational molecular degrees of freedom. In this paper, we generalize this theory to non-zero frequencies and wavevectors, which enables a new study of spatio-temporal correlation phenomena present...... and for molecular fluids with small moment of inertia like chlorine, the theory predicts that the longitudinal and transverse intrinsic angular velocity correlation functions are almost identical, which is also seen in the molecular dynamics simulations. However, the theory fails at large wavevector and frequencies...

Quantum Field Theory at non zero temperature

International Nuclear Information System (INIS)

Alvarez-Estrada, R.

1989-01-01

The formulations of the Φ 4 Quantum Field Theory and of Quantum Electrodynamics in I+d dimensions (d spatial dimensions) at non-zero temperature are reviewed. The behaviours of all those theories in the regime of large distances and high temperatures are surveyed. Only results are reported, all technicalities being omitted. The leading high-temperature contributions to correlation functions, to all perturbative orders, in those theories turn out to be also given by simpler theories, having much milder (superrenormalizable) ultraviolet behaviour and special mass renormalizations. In particular, the triviality/non-triviality issue for the Φ 4 theory in 1+3 dimensions is discussed briefly. (Author)

Significant and Basic Innovations in Urban Planning

Science.gov (United States)

Kolyasnikov, V. A.

2017-11-01

The article considers the development features of the innovative urban planning in the USSR and Russia in XVIII - XX centuries. Innovative urban planning is defined as an activity on innovations creation and their implementation to obtain a socio-economic, political, environmental or other effect. In the course of urban development history this activity represents a cyclic wave process in which there are phases of rise and fall. The study of cyclic waves in the development of innovative urban planning uses the concept of basic and epochal innovations selection. This concept was developed by scientists for the study of cyclic wave processes in economics. Its adaptation to the conditions of innovative urban planning development allows one to introduce the concept of “basic innovation” and “significant innovation” in the theory and practice of settlement formation and their systems as well as to identify opportunities to highlight these innovations in the history of Russian urban planning. From these positions, six innovation waves committed to the urban development over the past 300 years are being investigated. The observed basic innovations in the domestic urban area show that urban development is a vital area for ensuring the country’s geopolitical security. Basic innovations are translated in time and modernized under new conditions of urban planning development. In this regard, we can predict the development of four basic innovations in post-Soviet Russia.

Transport through semiconductor nanowire quantum dots in the Kondo regime

Energy Technology Data Exchange (ETDEWEB)

Schmaus, Stefan; Koerting, Verena; Woelfle, Peter [Institut fuer Theorie der Kondensierten Materie, Universitaet Karlsruhe, Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe (Germany)

2008-07-01

Recent experiments on quantum dots made of semiconductor nanowires in the Coulomb blockade regime have shown the influence of several approximately equidistant levels on the conductance. We study a model with three levels occupied by three electrons. At finite bias voltage charge energy conserving excitations into several higher lying states occur leading to features in the differential conductance. We restrict our study to the six lowest lying states by performing a Schrieffer-Wolff type projection onto this subspace. The emerging effective Kondo Hamiltonian is treated in non-equilibrium perturbation theory in the coupling to the leads. For convenience we use a pseudoparticle representation and an exact projection method. The voltage-dependence of the occupation numbers is discussed. The density matrix on the dot turns out to be off-diagonal in the dot eigenstate Hilbert space in certain parameter regimes. The dependence of the differential conductance on magnetic field and temperature is calculated in lowest order in the dot-lead coupling and the results are compared with experiment.

Sharp transition between thermal and quantum tunneling regimes in magnetization relaxation processes

Science.gov (United States)

Tejada, J.; Zhang, X. X.; Barbara, B.

1993-03-01

In this paper we describe experiments involving measurements of the dependence on time of the thermoremanence magnetization of 2-dimensional random magnets. The low temperature values for the magnetic viscosity agree well with both current theories of tunneling of the magnetization vector (Chudnovsky et al.) and the work of Grabert et al. who predicted that the transition from classical to quantum regime is rather sharp for undamped systems.

Kinetic theory of tearing instabilities

International Nuclear Information System (INIS)

Drake, J.F.; Lee, Y.C.

1977-01-01

The transition of the tearing instability from the collisional to the collisionless regime is investigated kinetically using a Fokker--Planck collision operator to represent electron-ion collisions. As a function of the collisionality of the plasma, the tearing instability falls into three regions, which are referred to as collisionless, semi-collisional, and collisional. The width Δ of the singular layer around kxB 0 =0 is limited by electron thermal motion along B 0 in the collisional and semi-collisional regimes and is typically smaller than rho/sub i/, the ion Larmor radius. Previously accepted theories, which are based on the assumption Δvery-much-greater-thanrho/sub i/, are found to be valid only in the collisional regime. The effects of density and temperature gradients on the instabilities are also studied. The tearing instability is only driven by the temperature gradient in the collisional and semi-collisional regimes. Numerical calculations indicate that the semi-collisional tearing instability is particularly relevant to present day high temperature tokamak discharges

Urban sharing culture

DEFF Research Database (Denmark)

Fjalland, Emmy Laura Perez

of the structures of the networked urban mobilities and holds the potentials to change the future mobilities. References Bauman, Zygmunt. 2000. Liquid Modernity. Cambridge: Polity. Beck, Ulrich. 1992. Risk Society: Towards a New Modernity (Published in Association with Theory, Culture & Society). London: SAGE......In urban areas sharing cultures, services and economies are rising. People share, rent and recycle their homes, cars, bikes, rides, tools, cloths, working space, knowhow and so on. The sharing culture can be understood as mobilities (Kesselring and Vogl 2013) of goods, values and ideas reshaping...... problems and side effects from concentration of consumption and contamination; and due to the shift from ownership to access it change our basic social cultural norms (Sayer 2005; Sayer 2011) about the ‘good’ life and social status (Freudendal-Pedersen 2007), commons and individuality, responsibility...

GOVERNANCE, URBAN COMPETITIVENESS AND CRISIS IN SPAIN

Directory of Open Access Journals (Sweden)

Xosé SOMOZA MEDINA

2016-07-01

Full Text Available This article describes the rise of the term governance from its beginnings in the business world and the neoliberal economic thought through its application in urban renewal actions in the world’s major cities. Over the analysis, we argue that it was the theoretical discourse of urban governance and competitiveness that for decades enabled the private property sector to direct the urban regeneration processes of greatest added value. Changes in transport infrastructures and the abandonment of old industrial facilities left large central segments of the city available for redevelopment in line with the theories of post-Fordist capitalism. The global economic crisis has paralysed many of these projects, which had entailed the investment of large sums of public money and yielded low social returns. At the same time, criticism has been levelled against governance and strategic planning. Here, I examine the processes of governance and competitiveness as an urban objective and recent examples of urban renewal in Spanish cities.

Human Rights Promotion through Transnational Investment Regimes: An International Political Economy Approach

Directory of Open Access Journals (Sweden)

Claire Cutler

2013-05-01

Full Text Available International investment agreements are foundational instruments in a transnational investment regime that governs how states regulate the foreign-owned assets and the foreign investment activities of private actors. Over 3,000 investment agreements between states govern key governmental powers and form the basis for an emerging transnational investment regime. This transnational regime significantly decentralizes, denationalizes, and privatizes decision-making and policy choices over foreign investment. Investment agreements set limits to state action in a number of areas of vital public concern, including the protection of human and labour rights, the environment, and sustainable development. They determine the distribution of power between foreign investors and host states and their societies. However, the societies in which they operate seldom have any input into the terms or operation of these agreements, raising crucial questions of their democratic legitimacy as mechanisms of governance. This paper draws on political science and law to explore the political economy of international investment agreements and asks whether these agreements are potential vehicles for promoting international human rights. The analysis provides an historical account of the investment regime, while a review of the political economy of international investment agreements identifies what appears to be a paradox at the core of their operation. It then examines contract theory for insight into this apparent paradox and considers whether investment agreements are suitable mechanisms for advancing international human rights.

2010 World Expo and Urban Life Quality in Shanghai in Terms of Sustainable Development

Institute of Scientific and Technical Information of China (English)

Zhu Dajian; Peter P.Rogers

2006-01-01

Based on sustainable development theory and the UN's Human Development Index, this thesis puts forward what the quality of urban life implies,makes a study of the world Expo's potential influences on the urban life of Shanghai and advances the strategy and measures to strengthen the life-quality-facing urban management

Modeling of dialogue regimes of distance robot control

Science.gov (United States)

Larkin, E. V.; Privalov, A. N.

2017-02-01

Process of distance control of mobile robots is investigated. Petri-Markov net for modeling of dialogue regime is worked out. It is shown, that sequence of operations of next subjects: a human operator, a dialogue computer and an onboard computer may be simulated with use the theory of semi-Markov processes. From the semi-Markov process of the general form Markov process was obtained, which includes only states of transaction generation. It is shown, that a real transaction flow is the result of «concurrency» in states of Markov process. Iteration procedure for evaluation of transaction flow parameters, which takes into account effect of «concurrency», is proposed.

APPROACHES TO THE ANALYSIS AND EVALUATION OF URBAN TOURISM SYSTEM WITHIN URBAN DESTINATIONS

Directory of Open Access Journals (Sweden)

Amalia BĂDIŢĂ

2013-12-01

Full Text Available The city is an area that has a complex functionality which is based on the utility of its zones that imprint a quality of life and a specificity to the place, but it is also based on the architectural aesthetics which determines a local lifestyle and a potential which can be exploited through tourist activities. The study aims to identify the characteristics of the urban tourism and the elements of an urban tourism system, which will be approached by identifying the city-breaker profile, the relation between turisticity and urbanity to determine the quality of places. These elements will be applied as a case study in Craiova, a mixed industrial and services economical profile city, with a low tourism function. This type of city has an urban tourism system which starts to take shape, and according to the theory of "overlapping cities" although there are many forms of tourism in a city (cultural, business, shopping, sports tourism, visiting relatives and friends and recreational tourism, Craiova focuses on the typology of the city for festivals, business, leisure and sport, as a strategy for the tourism sector development and for entering the tourism market of Romania.

Strengthening the nuclear non-proliferation regime

International Nuclear Information System (INIS)

Carlson, J.

2003-01-01

Although the nuclear non-proliferation regime has enjoyed considerable success, today the regime has never been under greater threat. Three states have challenged the objectives of the NPT, and there is a technology challenge - the spread of centrifuge enrichment technology and know-how. A major issue confronting the international community is, how to deal with a determined proliferator? Despite this gloomy scenario, however, the non-proliferation regime has considerable strengths - many of which can be developed further. The regime comprises complex interacting and mutually reinforcing elements. At its centre is the NPT - with IAEA safeguards as the Treaty's verification mechanism. Important complementary elements include: restraint in the supply and the acquisition of sensitive technologies; multilateral regimes such as the CTBT and proposed FMCT; various regional and bilateral regimes; the range of security and arms control arrangements outside the nuclear area (including other WMD regimes); and the development of proliferation-resistant technologies. Especially important are political incentives and sanctions in support of non-proliferation objectives. This paper outlines some of the key issues facing the non-proliferation regime

Which transition comes first? Urban and demographic transitions in Belgium and Sweden

Directory of Open Access Journals (Sweden)

Philippe Bocquier

2015-12-01

Full Text Available Background: Several theories compete to explain the main drivers of urbanisation, past and present, in relation to both demographic transition and economic development. One hypothesis is that rural-to-urban migration is the driver of urbanisation; another is that urban mortality decline actually triggered urban transition. Objective: This paper reconsiders the relationship between demographic (vital migration and urban transitions by analysing the long-term contribution of natural and migratory movements to urban transition. The respective contributions of birth, death, and migration and their timing will indicate whether economic development, through labour force migration, or vital transition mainly determines urban transition. Methods: After examining the spatial dimension of the demographic transition theory, we use 19th and 20th century series on Sweden and Belgium to better identify the migration component of urban transition through the computation of growth difference between urban and rural areas, accounting for the often neglected reclassification effect. Results: In both Sweden and Belgium, migration is the direct or indirect (through reclassification engine of urban transition and its contribution precedes the onset of vital transition, while the vital transition has a secondary, unstable, and negative role in the urban transition. Conclusions: Changes in the economic sphere are reinstated as the underlying cause of population change, acting through the shift of human capital in space. Methodological consequences are then drawn for analysing vital and urban transitions in an increasingly interdependent world. Contribution: The paper contributes to the theoretical literature on urban and demographic transitions in relation to economic development. The proposed method evaluates migration contribution without having to measure it.

URBAN GROWTH AND WATER QUALITY IN THIMPHU, BHUTAN

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Nandu Giri

2013-01-01

Full Text Available Detailed study was undertaken in 2008 and 2009 on assessment of water quality of River Wang Chhu which flows through Thimphu urban area, the capital city of Bhutan. The water samples were examined at upstream of urban area, within the urban area and its downstream. The water quality was analyzed by studying the physico-chemical, biological and benthic macro-invertebrates. The water quality data obtained during present study are discussed in relation to land use/land cover changes (LULC and various ongoing human activities at upstream, within the each activity areas and it’s downstream. Analyses of satellite imagery of 1990 and 2008 using GIS revealed that over a period of eighteen years the forest, scrub and agricultural areas have decreased whereas urban area and road network have increased considerably. The forest cover, agriculture area and scrub decreased from 43.3% to 42.57%, 6.88% to 5.33% and 42.55% to 29.42%, respectively. The LULC changes effect water quality in many ways. The water temperature, pH, conductivity, total dissolved solids, turbidity, nitrate, phosphate, chloride, total coliform, and biological oxygen demand were lower at upstream and higher in urban area. On the other hand dissolved oxygen was found higher at upstream and lower in urban area. The pollution sensitive benthic macro- invertebrates population were dominant at upstream sampling sites whereas pollution tolerant benthic macro-invertebrates were found abundant in urban area and its immediate downstream. The rapid development of urban infrastructure in Thimphu city may be posing serious threats to water regime in terms of its quality. Though the deterioration of water quality is restricted to a few localized areas, the trend is serious and needs proper attention of policy planners and decision makers. Proper treatment of effluents from urban areas is urgently needed to reduce water pollution in such affected areas to check further deterioration of water quality

URBAN GROWTH AND WATER QUALITY IN THIMPHU, BHUTAN

Directory of Open Access Journals (Sweden)

Nandu Giri

2013-06-01

Full Text Available Detailed study was undertaken in 2008 and 2009 on assessment of water quality of River Wang Chhu which flows through Thimphu urban area, the capital city of Bhutan. The water samples were examined at upstream of urban area, within the urban area and its downstream. The water samples were analyzed by studying the physico-chemical, biological and benthic macro-invertebrates. The water quality data obtained during present study are discussed in relation to land use/land cover changes(LULC and various ongoing human activities at upstream, within the each activity areas and it’s downstream. Analyses of satellite imagery of 1990 and 2008 using GIS revealed that over a period of eighteen years the forest, scrub and agricultural areas have decreased whereas urban area and road network have increased considerably. The forest cover, agriculture area and scrub decreased from 43.3% to 42.57%, 6.88% to 5.33% and 42.55% to 29.42%, respectively. The LULC changes effect water quality in many ways. The water temperature, pH, conductivity, total dissolved solids, turbidity, nitrate, phosphate, chloride, total coliform, and biological oxygen demand were lower at upstream and higher in urban area. On the other hand dissolved oxygen was found higher at upstream and lower in urban area. The pollution sensitive benthic macro-invertebrates population were dominant at upstream sampling sites whereas pollution tolerant benthic macro-invertebrates were found abundant in urban area and its immediate downstream. The rapid development of urban infrastructure in Thimphu city may be posing serious threats to water regime in terms of its quality. Though the deterioration of water quality is restricted to a few localized areas, the trend is serious and needs proper attention of policy planners and decision makers. Proper treatment of effluents from urban areas is urgently needed to reduce water pollution in such affected areas to check further deterioration of water quality

OPTIMIZATION OF TAX REGIME USING THE INSTRUMENT OF GAME THEORY

Directory of Open Access Journals (Sweden)

Igor Yu. Pelevin

2014-01-01

Full Text Available The article is devoted to one of one possible mechanism of taxation optimization of agricultural enterprises where used the game theory. Use of this mechanism allows to apply the most optimal type of taxation that would benefit both a taxpayer and the government. In the article offered the definition of the tax storage and its possible applications.

The impacts of urbanisation and climate change on urban flooding and urban water quality: A review of the evidence concerning the United Kingdom

Directory of Open Access Journals (Sweden)

James D. Miller

2017-08-01

New hydrological insights: There is a lack of nationally research focused on the dual impacts of climate change and urbanisation on flooding and water quality in UK urban areas. This is despite there being a clear acceptance that flood risk is increasing, water quality is generally not meeting desirable levels, and that combined population and climate change projections pose a pressing challenge. The available evidence has been found to be of medium-high confidence that both pressures will result in (i an increase in pluvial and fluvial flood risk, and (ii further reduction in water quality caused by point source pollution and altered flow regimes. Evidence concerning urban groundwater flooding, diffuse pollution and water temperature was found to be more sparse and was ascribed a low-medium confidence that both pressures will further exacerbate existing issues. The confidence ascribed to evidence was also found to reflect the utility of current science for setting policy and urban planning. Recurring factors that limit the utility of evidence for managing the urban environment includes: (i climate change projection uncertainty and suitability, (ii lack of sub-daily projections for storm rainfall, (iii the complexity of managing and modelling the urban environment, and (iv lack of probable national-scale future urban land-use projections. Suitable climate products are increasingly being developed and their application in applied urban research is critical in the wake of a series of extreme flooding events across the UK and timely for providing state-of-the-art evidence on which to base possible future water quality legislation in a post Brexit-WFD era.

Operational resource theory of total quantum coherence

Science.gov (United States)

Yang, Si-ren; Yu, Chang-shui

2018-01-01

Quantum coherence is an essential feature of quantum mechanics and is an important physical resource in quantum information. Recently, the resource theory of quantum coherence has been established parallel with that of entanglement. In the resource theory, a resource can be well defined if given three ingredients: the free states, the resource, the (restricted) free operations. In this paper, we study the resource theory of coherence in a different light, that is, we consider the total coherence defined by the basis-free coherence maximized among all potential basis. We define the distillable total coherence and the total coherence cost and in both the asymptotic regime and the single-copy regime show the reversible transformation between a state with certain total coherence and the state with the unit reference total coherence. Extensively, we demonstrate that the total coherence can also be completely converted to the total correlation with the equal amount by the free operations. We also provide the alternative understanding of the total coherence, respectively, based on the entanglement and the total correlation in a different way.

Mapping Theory - a mapping of the theoretical territory related to a contemporary concept of public space

DEFF Research Database (Denmark)

Smith, Shelley

2008-01-01

This working paper maps the theoretical territory of public space - urban public space - in a contemporary urban context. By finding, selecting, registering and examining existing theoretical stand points, the paper founds a basis for the creation of theory in an architectural discourse and for t......This working paper maps the theoretical territory of public space - urban public space - in a contemporary urban context. By finding, selecting, registering and examining existing theoretical stand points, the paper founds a basis for the creation of theory in an architectural discourse...

Mathematical Analysis of Urban Spatial Networks

CERN Document Server

Blanchard, Philippe

2009-01-01

Cities can be considered to be among the largest and most complex artificial networks created by human beings. Due to the numerous and diverse human-driven activities, urban network topology and dynamics can differ quite substantially from that of natural networks and so call for an alternative method of analysis. The intent of the present monograph is to lay down the theoretical foundations for studying the topology of compact urban patterns, using methods from spectral graph theory and statistical physics. These methods are demonstrated as tools to investigate the structure of a number of real cities with widely differing properties: medieval German cities, the webs of city canals in Amsterdam and Venice, and a modern urban structure such as found in Manhattan. Last but not least, the book concludes by providing a brief overview of possible applications that will eventually lead to a useful body of knowledge for architects, urban planners and civil engineers.

Status of a minimal composite Higgs theory

Science.gov (United States)

Fodor, Zoltan; Holland, Kieran; Kuti, Julius; Mondal, Santanu; Nogradi, Daniel; Wong, Chik Him

2017-12-01

We analyze three sets of gauge ensembles in our extended physics program of a particularly important BSM gauge theory with a fermion doublet in the two-index symmetric (sextet) representation of the SU(3) BSM color gauge group. Our investigations include chiral symmetry breaking (χSB) in the p-regime and 𝜖-regime, the mass of the composite 0++ scalar, resonance spectroscopy, new physics from gauge anomaly constraints, and the role of stable sextet BSM baryons with Electroweak interactions in dark matter searches. Important new goals include studies of the 0++ scalar entangled with Goldstone dynamics in the p-regime and the 𝜖-regime, the resonance spectrum with particular attention to emerging LHC signals, like recent hints for diphoton excess at 750 GeV or diboson anomalies in the 2 TeV range. All results reported here are preliminary before journal publication including some post-conference material for the discussion.

Les Houches lectures on large N field theories and gravity

International Nuclear Information System (INIS)

Maldacena, J.

2002-01-01

We describe the holographic correspondence between field theories and string/M theory, focusing on the relation between compactifications of string/M theory on Anti-de Sitter spaces and conformal field theories. We review the background for this correspondence and discuss its motivations and the evidence for its correctness. We describe the main results that have been derived from the correspondence in the regime that the field theory is approximated by classical or semiclassical gravity. We focus on the case of the N = 4 supersymmetric gauge theory in four dimensions. (authors)

Static converters power supply: transient regimes; Alimentation par convertisseurs statiques: regimes transitoires

Energy Technology Data Exchange (ETDEWEB)

Pasqualini, G. [Ecole Superieure d`Electricite (France)

1997-08-01

Direct current motors, asynchronous and variable speed synchronous motors are generally supplied with static converters. Speed variation is obtained by voltage variation in DC motors and by frequency variation in AC motors. In these conditions, these motors are running continuously in transient regimes: the DC motors current is not direct and the AC motors current is not sinusoidal. This situation leads to pulsing couples in the shaft line and to an increase of Joule effect losses. The aim of this paper is to present the methods of study of the electric motors functioning using the shape of the power voltages given by converters and mathematical models of these machines. The synchronous machines are rapidly described while the asynchronous machines are studied using Ku`s transformation instead of Park`s transformation for simplification. For each type of machine, calculation methods allow to determine their current, additional losses and couple characteristics. The transient regimes considered are those remaining when the motor is running at a constant speed and defined regime (supply voltages are periodical functions of time). These transient regimes are identically reproducing with a frequency which is a multiple of the converters supply frequency. Transient regimes due to functioning changes of the motor, such as resisting couple or power supply frequency variations, are not considered in this study. (J.S.) 9 refs.

Spin-wave damping in ferromagnets in the ordered regime

International Nuclear Information System (INIS)

Reinecke, T.L.; Stinchcombe, R.B.

1978-01-01

Theoretical results based on a high-density approach are compared with experimental measurements for the damping of long-wavelength spin waves in the nearly isotropic ferromagnet for temperatures up to the critical regime. The theory, which has no adjustable parameters, is shown to account well for the overall magnitude of the spin-wave widths measured in recent neutron scattering experiments on EuO, and it is also in satisfactory agreement with the measured wave vector and temperature dependence of these widths. An estimate is also given for the contribution of dipolar coupling to the spin-wave widths

Forecasting urban growth across the United States-Mexico border

Science.gov (United States)

Norman, L.M.; Feller, M.; Phillip, Guertin D.

2009-01-01

The sister-city area of Nogales, Arizona, and Nogales, Sonora, Mexico, is known collectively as Ambos (both) Nogales. This area was historically one city and was administratively divided by the Gadsden Purchase in 1853. These arid-lands have limited and sensitive natural resources. Environmental planning can support sustainable development to accommodate the predicted influx of population. The objective of this research is to quantify the amount of predicted urban growth for the Ambos Nogales watershed to support future planning for sustainable development. Two modeling regimes are explored. Our goal is to identify possible growth patterns associated with the twin-city area as a whole and with the two cities modeled as separate entities. We analyzed the cross-border watershed using regression analysis from satellite images from 1975, 1983, 1996, and 2002 and created urban area classifications. We used these classifications as input to the urban growth model, SLEUTH, to simulate likely patterns of development and define projected conversion probabilities. Model results indicate that the two cities are undergoing very different patterns of change and identify locations of expected growth based on historical development. Growth in Nogales, Arizona is stagnant while the urban area in Nogales, Sonora is exploding. This paper demonstrates an application that portrays how future binational urban growth could develop and affect the environment. This research also provides locations of potential growth for use in city planning.

Center-stabilized Yang-Mills Theory:Confinement and Large N Volume Independence

International Nuclear Information System (INIS)

Unsal, Mithat; Yaffe, Laurence G.

2008-01-01

We examine a double trace deformation of SU(N) Yang-Mills theory which, for large N and large volume, is equivalent to unmodified Yang-Mills theory up to O(1/N 2 ) corrections. In contrast to the unmodified theory, large N volume independence is valid in the deformed theory down to arbitrarily small volumes. The double trace deformation prevents the spontaneous breaking of center symmetry which would otherwise disrupt large N volume independence in small volumes. For small values of N, if the theory is formulated on R 3 x S 1 with a sufficiently small compactification size L, then an analytic treatment of the non-perturbative dynamics of the deformed theory is possible. In this regime, we show that the deformed Yang-Mills theory has a mass gap and exhibits linear confinement. Increasing the circumference L or number of colors N decreases the separation of scales on which the analytic treatment relies. However, there are no order parameters which distinguish the small and large radius regimes. Consequently, for small N the deformed theory provides a novel example of a locally four-dimensional pure gauge theory in which one has analytic control over confinement, while for large N it provides a simple fully reduced model for Yang-Mills theory. The construction is easily generalized to QCD and other QCD-like theories

Center-stabilized Yang-Mills theory: Confinement and large N volume independence

International Nuclear Information System (INIS)

Uensal, Mithat; Yaffe, Laurence G.

2008-01-01

We examine a double trace deformation of SU(N) Yang-Mills theory which, for large N and large volume, is equivalent to unmodified Yang-Mills theory up to O(1/N 2 ) corrections. In contrast to the unmodified theory, large N volume independence is valid in the deformed theory down to arbitrarily small volumes. The double trace deformation prevents the spontaneous breaking of center symmetry which would otherwise disrupt large N volume independence in small volumes. For small values of N, if the theory is formulated on R 3 xS 1 with a sufficiently small compactification size L, then an analytic treatment of the nonperturbative dynamics of the deformed theory is possible. In this regime, we show that the deformed Yang-Mills theory has a mass gap and exhibits linear confinement. Increasing the circumference L or number of colors N decreases the separation of scales on which the analytic treatment relies. However, there are no order parameters which distinguish the small and large radius regimes. Consequently, for small N the deformed theory provides a novel example of a locally four-dimensional pure-gauge theory in which one has analytic control over confinement, while for large N it provides a simple fully reduced model for Yang-Mills theory. The construction is easily generalized to QCD and other QCD-like theories.

Contemporary Neighborhood Theories: Integration versus Romance and Reaction.

Science.gov (United States)

Stever, James A.

1978-01-01

This paper discusses the integrative, romantic, and reactive theories of neighborhood government within the context of the urban reform movement and argues that the integrative theory is the one best suited for an effective political relationship between the neighborhood and the greater metropolis. (EB)

Development of concepts for the management of thermal resources in urban areas - Assessment of transferability from the Basel (Switzerland) and Zaragoza (Spain) case studies

Science.gov (United States)

Epting, Jannis; García-Gil, Alejandro; Huggenberger, Peter; Vázquez-Suñe, Enric; Mueller, Matthias H.

2017-05-01

The shallow subsurface in urban areas is increasingly used by shallow geothermal energy systems as a renewable energy resource and as a cheap cooling medium, e.g. for building air conditioning. In combination with further anthropogenic activities, this results in altered thermal regimes in the subsurface and the so-called subsurface urban heat island effect. Successful thermal management of urban groundwater resources requires understanding the relative contributions of the different thermal parameters and boundary conditions that result in the "present thermal state" of individual urban groundwater bodies. To evaluate the "present thermal state" of urban groundwater bodies, good quality data are required to characterize the hydraulic and thermal aquifer parameters. This process also involved adequate monitoring systems which provide consistent subsurface temperature measurements and are the basis for parameterizing numerical heat-transport models. This study is based on previous work already published for two urban groundwater bodies in Basel (CH) and Zaragoza (ES), where comprehensive monitoring networks (hydraulics and temperature) as well as calibrated high-resolution numerical flow- and heat-transport models have been analyzed. The "present thermal state" and how it developed according to the different hydraulic and thermal boundary conditions is compared to a "potential natural state" in order to assess the anthropogenic thermal changes that have already occurred in the urban groundwater bodies we investigated. This comparison allows us to describe the various processes concerning groundwater flow and thermal regimes for the different urban settings. Furthermore, the results facilitate defining goals for specific aquifer regions, including future aquifer use and urbanization, as well as evaluating the thermal use potential for these regions. As one example for a more sustainable thermal use of subsurface water resources, we introduce the thermal management

Cities of light two centuries of urban illumination

CERN Document Server

Isenstadt, Sandy; Neumann, Dietrich

2014-01-01

Cities of Light is the first global overview of modern urban illumination, a development that allows human wakefulness to colonize the night, doubling the hours available for purposeful and industrious activities.　 Urban lighting is undergoing a revolution due to recent developments in lighting technology, and increased focus on sustainability and human-scaled environments. Cities of Light is expansive in coverage, spanning two centuries and touching on developments on six continents, without diluting its central focus on architectural and urban lighting.　 Covering history, geography, theory, and speculation in urban lighting, readers will have numerous points of entry into the book, finding it easy to navigate for a quick reference and or a coherent narrative if read straight through. With chapters written by respected scholars and highly-regarded contemporary practitioners, this book will delight students and practitioners of architectural and urban history, area and cultural studies, and lighting desig...

Study on the complex network characteristics of urban road system based on GIS

Science.gov (United States)

Gao, Zhonghua; Chen, Zhenjie; Liu, Yongxue; Huang, Kang

2007-06-01

Urban road system is the basic bone of urban transportation and one of the most important factors that influent and controls the urban configuration. In this paper, an approach of modeling, analyzing and optimizing urban road system is described based on complex network theory and GIS technology. The urban road system is studied on three focuses: building the urban road network, modeling the computational procedures based on urban road networks and analyzing the urban road system of Changzhou City as the study case. The conclusion is that the urban road network is a scale-free network with small-world characteristic, and there is still space for development of the whole network as a small-world network, also the key road crosses should be kept expedite.

Urban Innovation through Co-Design Scenarios

DEFF Research Database (Denmark)

Lissandrello, Enza; Morelli, Nicola; Schillaci, Domenico

2018-01-01

-2020), that addresses the issue of behavioral change towards (more) sustainable mobility lifestyle in EU cities. The paper frames the MUV method through the combination of theories on collaborative urban planning and participatory design with a background rooted on governance of public participation, as the interplay...

Seasonal Drivers of Dissolved Metal Transport During Infiltration of Road Runoff in an Urban Roadside Environment

Science.gov (United States)

Mullins, A.; Bain, D.

2017-12-01

Infiltration-based green infrastructure (GI) is being increasingly applied in urban areas, systems characterized by substantial legacy contamination and complicated hydrology. However, it is not clear how the application of green infrastructure changes the geochemistry of urban roadside environments. Most current research on GI focuses on small sets of chemical parameters (e.g. road salt, nitrogen and phosphorous species) over relatively short time periods, limiting comprehensive understanding of geochemical function. This work measures changes in groundwater infiltration rate and dissolved metal concentrations in two infiltration trenches in Pittsburgh, PA to evaluate function and measure dissolved metal transport from the system over time. Two distinct geochemical regimes seem to be driven by seasonality: road de-icer exchange and microbial driven summer reducing conditions. Interactions between these geochemical regimes and variability in infiltration rate control the flux of different metals, varying with metal chemistry. These findings suggest the adoption of infiltration based green infrastructure will likely create complicated patterns of legacy contamination transport to downstream receptors.

Study on the Delimitation of the Urban Development Boundary in a Special Economic Zone: A Case Study of the Central Urban Area of Doumen in Zhuhai, China

Directory of Open Access Journals (Sweden)

Biao Zheng

2018-03-01

Full Text Available Since it implemented open-door policies, China has become the fastest growing economy in the world, and its urbanization level has steadily improved. Taking a special economic zone as the object of study, this paper delineates the urban development boundary of the Central Urban Area of Doumen. Using multiple models and methods, the urban development rigid and elastic boundaries are delineated separately, with the rigid boundary serving as the premise and foundation for delineating the elastic boundary. The results are as follows. First, the scale of the urban development rigid boundary is 79.60 km². Moreover, the scales of the urban development elastic boundaries in 2020 and 2026 are 24.51 km² and 28.53 km², respectively. Second, by delimiting the urban development elastic boundary, the compactness of urban land will be improved. Third, the urban development boundary of this paper is reasonable in theory. This paper suggests that the urban development boundary can curb urban sprawl and guide rational urban development, which is conducive to optimizing an urban spatial layout.

Study of Yang–Mills–Chern–Simons theory in presence of the Gribov horizon

Energy Technology Data Exchange (ETDEWEB)

Canfora, Fabrizio, E-mail: canfora@cecs.cl [Centro de Estudios Cientificos (CECs), Valdivia (Chile); Universidad Andres Bello, Av. Republica 440, Santiago (Chile); Gomez, Arturo, E-mail: arturo.gomez@proyectos.uai.cl [Departamento de Ciencias, Facultad de Artes Liberales y Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar. (Chile); Sorella, Silvio Paolo, E-mail: sorella@uerj.br [UERJ, Universidade do Estado do Rio de Janeiro (UERJ), Instituto de Física Teórica, Rua São Francisco Xavier 524, 20550-013, Maracaná, Rio de Janeiro (Brazil); Vercauteren, David, E-mail: vercauteren.uerj@gmail.com [UERJ, Universidade do Estado do Rio de Janeiro (UERJ), Instituto de Física Teórica, Rua São Francisco Xavier 524, 20550-013, Maracaná, Rio de Janeiro (Brazil)

2014-06-15

The two-point gauge correlation function in Yang–Mills–Chern–Simons theory in three dimensional Euclidean space is analysed by taking into account the non-perturbative effects of the Gribov horizon. In this way, we are able to describe the confinement and de-confinement regimes, which naturally depend on the topological mass and on the gauge coupling constant of the theory. -- Highlights: •We implement the Gribov quantization to the Topologically massive Yang–Mills theory. •We find a modified propagator at strong coupling by the Gribov horizon. •The gauge propagator depends on the topological mass and the coupling constant. •By studying the gauge propagator we describe the confined–deconfined regimes.

Study of Yang–Mills–Chern–Simons theory in presence of the Gribov horizon

International Nuclear Information System (INIS)

Canfora, Fabrizio; Gomez, Arturo; Sorella, Silvio Paolo; Vercauteren, David

2014-01-01

The two-point gauge correlation function in Yang–Mills–Chern–Simons theory in three dimensional Euclidean space is analysed by taking into account the non-perturbative effects of the Gribov horizon. In this way, we are able to describe the confinement and de-confinement regimes, which naturally depend on the topological mass and on the gauge coupling constant of the theory. -- Highlights: •We implement the Gribov quantization to the Topologically massive Yang–Mills theory. •We find a modified propagator at strong coupling by the Gribov horizon. •The gauge propagator depends on the topological mass and the coupling constant. •By studying the gauge propagator we describe the confined–deconfined regimes

Sustainable urban development

DEFF Research Database (Denmark)

Jensen, Jesper Ole; Christensen, Toke Haunstrup; Gram-Hanssen, Kirsten

Sustainability in urban planning has a long history and it has been a widespread solution to build high and compact in order to minimise the need for transportation, land use and heating. Recent research, however, points towards the need for a supplementary approach which includes the consumer...... behaviour of the household. This approach necessarily has to work from below and include the citizens, as it is their daily practices that have to be challenged. This article reviews the literature of to what extent compact cities are the most sustainable and it use lifestyle interpretations of urbane forms...... to challenge the compact cities approach. As an alternative or supplementary approach the article introduce practice theory as a way to understand consumption and it gives examples on how this approach can be used to inspire local authorities to alternative and supplementary strategies of achieving sustainable...

Urban Scaling in Europe

Science.gov (United States)

2016-03-16

the structural funds for regional development and cohesion . Until recently, several systems of territorial units have coexisted in European...for European MAs versus population. See text and figures 1–7, electronic supplementary material, figures S1–S8 for additional details and electronic...scale as expected, although with wide confidence intervals (table 1). The urbanized area of Spanish cities appears superlinear, contrary to theory

Stability in quadratic torsion theories

Energy Technology Data Exchange (ETDEWEB)

Vasilev, Teodor Borislavov; Cembranos, Jose A.R.; Gigante Valcarcel, Jorge; Martin-Moruno, Prado [Universidad Complutense de Madrid, Departamento de Fisica Teorica I, Madrid (Spain)

2017-11-15

We revisit the definition and some of the characteristics of quadratic theories of gravity with torsion. We start from a Lagrangian density quadratic in the curvature and torsion tensors. By assuming that General Relativity should be recovered when the torsion vanishes and investigating the behaviour of the vector and pseudo-vector torsion fields in the weak-gravity regime, we present a set of necessary conditions for the stability of these theories. Moreover, we explicitly obtain the gravitational field equations using the Palatini variational principle with the metricity condition implemented via a Lagrange multiplier. (orig.)

Stability in quadratic torsion theories

International Nuclear Information System (INIS)

Vasilev, Teodor Borislavov; Cembranos, Jose A.R.; Gigante Valcarcel, Jorge; Martin-Moruno, Prado

2017-01-01

We revisit the definition and some of the characteristics of quadratic theories of gravity with torsion. We start from a Lagrangian density quadratic in the curvature and torsion tensors. By assuming that General Relativity should be recovered when the torsion vanishes and investigating the behaviour of the vector and pseudo-vector torsion fields in the weak-gravity regime, we present a set of necessary conditions for the stability of these theories. Moreover, we explicitly obtain the gravitational field equations using the Palatini variational principle with the metricity condition implemented via a Lagrange multiplier. (orig.)

Ecological resistance in urban streams: the role of natural and legacy attributes

Science.gov (United States)

Utz, Ryan M.; Hopkins, Kristina G.; Beesley, Leah; Booth, Derek B.; Hawley, Robert J.; Baker, Matthew E.; Freeman, Mary C.; Jones, Krista L.

2016-01-01

Urbanization substantially changes the physicochemical and biological characteristics of streams. The trajectory of negative effect is broadly similar around the world, but the nature and magnitude of ecological responses to urban growth differ among locations. Some heterogeneity in response arises from differences in the level of urban development and attributes of urban water management. However, the heterogeneity also may arise from variation in hydrologic, biological, and physicochemical templates that shaped stream ecosystems before urban development. We present a framework to develop hypotheses that predict how natural watershed and channel attributes in the pre-urban-development state may confer ecological resistance to urbanization. We present 6 testable hypotheses that explore the expression of such attributes under our framework: 1) greater water storage capacity mitigates hydrologic regime shifts, 2) coarse substrates and a balance between erosive forces and sediment supply buffer morphological changes, 3) naturally high ionic concentrations and pH pre-adapt biota to water-quality stress, 4) metapopulation connectivity results in retention of species richness, 5) high functional redundancy buffers trophic function from species loss, and 6) landuse history mutes or reverses the expected trajectory of eutrophication. Data from past comparative analyses support these hypotheses, but rigorous testing will require targeted investigations that account for confounding or interacting factors, such as diversity in urban infrastructure attributes. Improved understanding of the susceptibility or resistance of stream ecosystems could substantially strengthen conservation, management, and monitoring efforts in urban streams. We hope that these preliminary, conceptual hypotheses will encourage others to explore these ideas further and generate additional explanations for the heterogeneity observed in urban streams.

Populism versus IMF Conditionalities: Demand Management Policies in Present Regime of Globalization

Directory of Open Access Journals (Sweden)

Ayub Mehar

2018-01-01

Full Text Available The end of a bipolar regime after the collapse of the Soviet Union diverted the world economies to globalization regime, where economic freedom and liberalization were adopted as most powerful and popular philosophies of the economic welfare and development. The origination of a free trade regime, decentralization in public finance, and revival of the classical school of thought in economic policies are the natural outcomes of the global failure of centrally controlled economic planning experiences. Autonomy of the central banks, market-oriented exchange rates, convertibility of the currencies, privatization, deregulation, and free trade are the banners of classical economic thoughts in the present regime. Meanwhile, the International Monetary Fund (IMF came into force when the world was divided into left and right arms. The IMF conditionality and recommended measures are still based on demand management mechanism where most of the advices belong to exchange rate mechanism (devaluation, increase in interest rate, increase in tax revenue, reduction in subsidies, transfer payments, so on. The core objective of this study is to review the IMF policies and practices in the contemporary world where supply-side policies and classical theories are regaining their importance in post-Soviet regime. Before any recommendation and contemplating the role of the IMF in the contemporary world, it will be appropriate to review and analyze the current practices of the IMF by three dimensions: History and cause of the creation of the IMF, its governance and financial structure, and its role in global economy and lending activities. The study suggests the change in the IMF governance structure and the coordination between World Trade Organization (WTO, World Economic Forum (WEF, and IMF policies.

Quality Regimes in Agro-Food Industries

DEFF Research Database (Denmark)

Staricco, Juan Ignacio; Ponte, Stefano

2015-01-01

In this article, we examine the transformative potential of changing quality regimes in agro-food industries through the analysis of whether Fair Trade wine in Argentina provides a meaningful economic alternative that goes beyond the impact it has on direct beneficiaries. The wine sector has a long...... history in valorizing a variety of quality dimensions, and has developed one of the most complex and sophisticated quality infrastructures, making it an ideal terrain of analysis. Furthermore, it is going through a major process of restructuring in which the battle-lines are drawn along the application......, challenge and re-interpretation of different quality content. Through the lenses of a sector-adjusted version of regulation theory, we show that the Fair Trade wine sector does not substantially deviate from the conventional wine economy in Argentina. Instead of empowering the most vulnerable groups, those...

From Slum Clearance to Urban Policy

DEFF Research Database (Denmark)

Vagnby, Bo Hellisen; Jensen, Ole B.

2002-01-01

the physical and social living conditions in the cities, as well as discussing the actors and their interests behind these approaches. Thus the aim is to use the theory of planning dosctrine to investigate how Danish urban policy has changed historically, under different rationales and on behalf of different......The article explores the societal conditions under which the various approaches to Danish housing improvement and urban renewal have been exercised since the early part of the 20th century. In doing, so, the article analyses the specific approaches used by the Danish state in order to improve...... stakeholder interests and powers....

On the Validity of the Streaming Model for the Redshift-Space Correlation Function in the Linear Regime

Science.gov (United States)

Fisher, Karl B.

1995-08-01

The relation between the galaxy correlation functions in real-space and redshift-space is derived in the linear regime by an appropriate averaging of the joint probability distribution of density and velocity. The derivation recovers the familiar linear theory result on large scales but has the advantage of clearly revealing the dependence of the redshift distortions on the underlying peculiar velocity field; streaming motions give rise to distortions of θ(Ω0.6/b) while variations in the anisotropic velocity dispersion yield terms of order θ(Ω1.2/b2). This probabilistic derivation of the redshift-space correlation function is similar in spirit to the derivation of the commonly used "streaming" model, in which the distortions are given by a convolution of the real-space correlation function with a velocity distribution function. The streaming model is often used to model the redshift-space correlation function on small, highly nonlinear, scales. There have been claims in the literature, however, that the streaming model is not valid in the linear regime. Our analysis confirms this claim, but we show that the streaming model can be made consistent with linear theory provided that the model for the streaming has the functional form predicted by linear theory and that the velocity distribution is chosen to be a Gaussian with the correct linear theory dispersion.

‘Smart food city’: conceptual relations between smart city planning, urban food systems and innovation theory

OpenAIRE

Maye, Damian

2018-01-01

This paper develops a conceptual link between smart city planning and urban food systems research in terms of governance and innovation. The ‘smart city’ concept is linked to an urban research agenda which seeks to embed advances in technology and data collection into the infrastructures of urban environments. Through this neoliberal framework, market-led and technological solutions to city governance and development are prioritised. The urban food movement has a different trajectory compared...

International Food Regime

Directory of Open Access Journals (Sweden)

A. V. Malov

2018-01-01

Full Text Available The review article reveals the content of the concept of Food Regime, which is little-known in the Russian academic reference. The author monitored and codified the semantic dynamic of the terminological unit from its original interpretations to modern formulations based on the retrospective analysis. The rehabilitation of the academic merits of D. Puchala and R. Hopkins — authors who used the concept Food Regime for a few years before its universally recognized origin and official scientific debut, was accomplished with help of historical and comparative methods. The author implemented the method of ascension from the abstract to the concrete to demonstrating the classification of Food Regimes compiled on the basis of geopolitical interests in the sphere of international production, consumption, and distribution of foodstuffs. The characteristic features of historically formed Food Regime were described in the chronological order, as well as modern tendencies possessing reformist potential were identified. In particular, it has been established that the idea of Food Sovereignty (which is an alternative to the modern Corporate Food Regime is the subject for acute academic disputes. The discussion between P. McMichael P. and H. Bernstein devoted to the “peasant question” — mobilization frame of the Food Sovereignty strategy was analyzed using the secondary data processing method. Due to the critical analysis, the author comes to the conclusion that it is necessary to follow the principles of the Food Sovereignty strategy to prevent the catastrophic prospects associated with ecosystem degradation, accelerated erosion of soils, the complete disappearance of biodiversity and corporate autoc racy successfully. The author is convinced that the idea of Food Sovereignty can ward off energetic liberalization of nature, intensive privatization of life and rapid monetization of unconditioned human reflexes.

[Employment and urban growth; an application of Czamanski's model to the Mexican case].

Science.gov (United States)

Verduzco Chavez, B

1991-01-01

The author applies the 1964 model developed by Stanislaw Czamanski, based on theories of urban growth and industrial localization, to the analysis of urban growth in Mexico. "The advantages of this model in its application as a support instrument in the process of urban planning when the information available is incomplete are...discussed...." Census data for 44 cities in Mexico are used. (SUMMARY IN ENG) excerpt

Pricing Vulnerable Options with Market Prices of Common Jump Risks under Regime-Switching Models

Directory of Open Access Journals (Sweden)

Miao Han

2018-01-01

Full Text Available This paper investigates the valuation of vulnerable European options considering the market prices of common systematic jump risks under regime-switching jump-diffusion models. The way of regime-switching Esscher transform is adopted to identify an equivalent martingale measure for pricing vulnerable European options. Explicit analytical pricing formulae for vulnerable European options are derived by risk-neutral pricing theory. For comparison, the other two cases are also considered separately. The first case considers all jump risks as unsystematic risks while the second one assumes all jumps risks to be systematic risks. Numerical examples for the valuation of vulnerable European options are provided to illustrate our results and indicate the influence of the market prices of jump risks on the valuation of vulnerable European options.

'Affirmative resonances' in the city? Sound, imagination and urban space in early 1930s Germany

NARCIS (Netherlands)

Birdsall, C.; Mieszkowski, S.; Smith, J.; de Valck, M.

2007-01-01

This article focuses on the role of sound in producing urban space and reworking identity formations in the early years of the Nazi regime. I analyze a case study about the mythology created around the Nazi party martyr Albert Leo Schlageter in the German city of Düsseldorf. By tracing the cultural

Antecedents of Teachers Fostering Effort within Two Different Management Regimes: An Assessment-Based Accountability Regime and Regime without External Pressure on Results

Science.gov (United States)

Christophersen, Knut-Andreas; Elstad, Eyvind; Turmo, Are

2012-01-01

This article focuses on the comparison of organizational antecedents of teachers' fostering of students' effort in two quite different accountability regimes: one management regime with an external-accountability system and one with no external accountability devices. The methodology involves cross-sectional surveys from two different management…

When do Armed Revolts Succeed: Lessons from Lanchester Theory

Science.gov (United States)

2011-10-01

When do Armed Revolts Succeed: Lessons from Lanchester Theory Michael P. Atkinson 1, Alexander Gutfraind 2, Moshe Kress 1 Abstract Major revolts have...classic Lanchester theory of combat. The model accounts for the split in the population between those loyal to the regime and those favoring the...Lessons from Lanchester Theory 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f

Towards chaos criterion in quantum field theory

OpenAIRE

Kuvshinov, V. I.; Kuzmin, A. V.

2002-01-01

Chaos criterion for quantum field theory is proposed. Its correspondence with classical chaos criterion in semi-classical regime is shown. It is demonstrated for real scalar field that proposed chaos criterion can be used to investigate stability of classical solutions of field equations.

Testing QCD in the non-perturbative regime

Energy Technology Data Exchange (ETDEWEB)

A.W. Thomas

2007-01-01

This is an exciting time for strong interaction physics. We have a candidate for a fundamental theory, namely QCD, which has passed all the tests thrown at it in the perturbative regime. In the non-perturbative regime it has also produced some promising results and recently a few triumphs but the next decade will see enormous progress in our ability to unambiguously calculate the consequences of non-perturbative QCD and to test those predictions experimentally. Amongst the new experimental facilities being constructed, the hadronic machines at JPARC and GSI-FAIR and the 12 GeV Upgrade at Jefferson Lab, the major new electromagnetic facility worldwide, present a beautifully complementary network aimed at producing precise new measurements which will advance our knowledge of nuclear systems and push our ability to calculate the consequences of QCD to the limit. We will first outline the plans at Jefferson Lab for doubling the energy of CEBAF. The new facility presents some wonderful opportunities for discovery in strong interaction physics, as well as beyond the standard model. Then we turn to the theoretical developments aimed at extracting precise results for physical hadron properties from lattice QCD simulations. This discussion will begin with classical examples, such as the mass of the nucleon and ?, before dealing with a very recent and spectacular success involving information extracted from modern parity violating electron scattering.

Visões de um objeto incômodo: o regime militar brasileiro An undesirable subject: the Brazilian military regime

Directory of Open Access Journals (Sweden)

Angelo Del Vecchio

2007-05-01

Full Text Available O presente artigo visa a qualificação do regime político vigente no Brasil entre 1964-1985. Para tanto, desenvolvo o resgate do conceito de ditadura, especialmente a partir da obra de Carl Schimitt, e busco aferir a sua adequação à análise do período militar. Palavras-chave: Estado. Regime político. Ditadura. Regime militar. The present article tries to qualify the political regime in Brazil from 1964 to 1985, using the concept of dictatorship mainly developed by Carl Schimitt in his writings and tries to adequate this concept to the Brazilian military regime. Keywords: State. Political regime. Dictatorship. Military regime.

THE INFLUENCED FLOW REGIMES

Directory of Open Access Journals (Sweden)

Gavril PANDI

2011-03-01

Full Text Available The influenced flow regimes. The presence and activities ofhumanity influences the uniform environmental system, and in this context, therivers water resources. In concordance with this, the natural runoff regime suffersbigger and deeper changes. The nature of these changes depending on the type anddegree of water uses. The multitude of the use cause different types of influence,whit different quantitative aspects. In the same time, the influences havequalitative connotations, too, regarding to the modifications of the yearly watervolume runoff. So the natural runoff regime is modified. After analyzing thedistribution laws of the monthly runoff, there have been differenced four types ofinfluenced runoff regimes. In the excess type the influenced runoff is bigger thanthe natural, continuously in the whole year. The deficient type is characterized byinverse rapports like the first type, in the whole year. In the sinusoidal type, theinfluenced runoff is smaller than the natural in the period when the water isretained in the lake reservoirs, and in the depletion period the situation inverts. Atthe irregular type the ratio between influenced and natural runoff is changeable ina random meaner monthly. The recognition of the influenced regime and the gradeof influence are necessary in the evaluation and analysis of the usable hydrologicalriver resources, in the flood defence activities, in the complex scheme of thehydrographic basins, in the environment design and so on.

Analytic theory of soft x-ray diffraction by lamellar multilayer gratings

NARCIS (Netherlands)

Kozhevnikov, I.V.; van der Meer, R.; Bastiaens, Hubertus M.J.; Boller, Klaus J.; Bijkerk, Frederik

2011-01-01

An analytic theory describing soft x-ray diffraction by Lamellar Multilayer Gratings (LMG) has been developed. The theory is derived from a coupled waves approach for LMGs operating in the single-order regime, where an incident plane wave can only excite a single diffraction order. The results from

Development of a local-scale urban stream assessment method using benthic macroinvertebrates: An example from the Santa Clara Basin, California

Science.gov (United States)

Carter, J.L.; Purcell, A.H.; Fend, S.V.; Resh, V.H.

2009-01-01

Research that explores the biological response to urbanization on a site-specific scale is necessary for management of urban basins. Recent studies have proposed a method to characterize the biological response of benthic macroinvertebrates along an urban gradient for several climatic regions in the USA. Our study demonstrates how this general framework can be refined and applied on a smaller scale to an urbanized basin, the Santa Clara Basin (surrounding San Jose, California, USA). Eighty-four sampling sites on 14 streams in the Santa Clara Basin were used for assessing local stream conditions. First, an urban index composed of human population density, road density, and urban land cover was used to determine the extent of urbanization upstream from each sampling site. Second, a multimetric biological index was developed to characterize the response of macroinvertebrate assemblages along the urban gradient. The resulting biological index included metrics from 3 ecological categories: taxonomic composition ( Ephemeroptera, Plecoptera, and Trichoptera), functional feeding group (shredder richness), and habit ( clingers). The 90th-quantile regression line was used to define the best available biological conditions along the urban gradient, which we define as the predicted biological potential. This descriptor was then used to determine the relative condition of sites throughout the basin. Hierarchical partitioning of variance revealed that several site-specific variables (dissolved O2 and temperature) were significantly related to a site's deviation from its predicted biological potential. Spatial analysis of each site's deviation from its biological potential indicated geographic heterogeneity in the distribution of impaired sites. The presence and operation of local dams optimize water use, but modify natural flow regimes, which in turn influence stream habitat, dissolved O2, and temperature. Current dissolved O2 and temperature regimes deviate from natural

Urban Noise and Strategies of Sound Mapping

DEFF Research Database (Denmark)

Kreutzfeldt, Jacob

2012-01-01

project from the Copenhagen Munincipelity initiated in 2006, as a starting point to discuss the politics of urban sound. It points out an important challenge for the methodology of urban sonic environments: namely that sound as a senso-motoric register may be poorly evaluated through concepts of noise...... practices as a kind of social interaction – a method that may supplement the engineer’s quantitative sound measurements and the landscape architect’s qualitative descriptors this article outlines a few approaches to a theory of acoustic territoriality and suggests alternative ways of mapping, analyzing...

Comparision by Simulation of Different Approaches to the Urban Traffic Control

Czech Academy of Sciences Publication Activity Database

Přikryl, Jan; Tichý, T.; Bělinová, Z.; Kapitán, J.

2012-01-01

Roč. 5, č. 4 (2012), s. 26-30 ISSN 1899-8208 R&D Projects: GA TA ČR TA01030603 Institutional support: RVO:67985556 Keywords : traffic * ITS * telematics * urban traffic control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2012/AS/prikryl-comparision by simulation of different approaches to the urban traffic control.pdf

Caste, Class, and Urbanization: The Shaping of Religious Community in Contemporary India

Science.gov (United States)

Stroope, Samuel

2012-01-01

Building on the implications of qualitative work from India and urbanism theories, I aim to understand whether religious bonding social capital in contemporary India increases with greater urbanization and whether such increases are moderated by caste or social class position. Results from multinomial logistic regression on 1,417 Hindu respondents…

Flux scaling: Ultimate regime

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Flux scaling: Ultimate regime. With the Nusselt number and the mixing length scales, we get the Nusselt number and Reynolds number (w'd/ν) scalings: and or. and. scaling expected to occur at extremely high Ra Rayleigh-Benard convection. Get the ultimate regime ...

Spatial interaction creates period-doubling bifurcation and chaos of urbanization

International Nuclear Information System (INIS)

Chen Yanguang

2009-01-01

This paper provides a new way of looking at complicated dynamics of simple mathematical models. The complicated behavior of simple equations is one of the headstreams of chaos theory. However, a recent study based on dynamical equations of urbanization shows that there are still some undiscovered secrets behind the simple mathematical models such as logistic equation. The rural-urban interaction model can also display varied kinds of complicated dynamics, including period-doubling bifurcation and chaos. The two-dimension map of urbanization presents the same dynamics as that from the one-dimension logistic map. In theory, the logistic equation can be derived from the two-population interaction model. This seems to suggest that the complicated behavior of simple models results from interaction rather than pure intrinsic randomicity. In light of this idea, the classical predator-prey interaction model can be revised to explain the complex dynamics of logistic equation in physical and social sciences.

High resolution modelling of aerosol dispersion regimes during the CAPITOUL field experiment: from regional to local scale interactions

Directory of Open Access Journals (Sweden)

B. Aouizerats

2011-08-01

Full Text Available High resolution simulation of complex aerosol particle evolution and gaseous chemistry over an atmospheric urban area is of great interest for understanding air quality and processes. In this context, the CAPITOUL (Canopy and Aerosol Particle Interactions in the Toulouse Urban Layer field experiment aims at a better understanding of the interactions between the urban dynamics and the aerosol plumes. During a two-day Intensive Observational Period, a numerical model experiment was set up to reproduce the spatial distribution of specific particle pollutants, from the regional scales and the interactions between different cities, to the local scales with specific turbulent structures. Observations show that local dynamics depends on the day-regime, and may lead to different mesoscale dynamical structures. This study focuses on reproducing these fine scale dynamical structures, and investigate the impact on the aerosol plume dispersion. The 500-m resolution simulation manages to reproduce convective rolls at local scale, which concentrate most of the aerosol particles and can locally affect the pollutant dispersion and air quality.

Neighboring and Urbanism: Commonality versus Friendship.

Science.gov (United States)

Silverman, Carol J.

1986-01-01

Examines a dimension of neighboring that need not assume friendship as the role model. When the model assumes only a sense of connectedness as defining neighboring, then the residential correlation, shown in many studies between urbanism and neighboring, disappears. Theories of neighboring, study variables, methods, and analysis are discussed.…

: Urban design, urban project, urban art, urban composition ... a question of vocabulary?

OpenAIRE

Pinson , Daniel

2014-01-01

Actes à paraître; International audience; The term "urbanism" of Pierre Clerget (1910) put the mess in the practice and the formations in France. Urban planning is thus, on the academic level, a coexistence of disciplinary approaches, which does not help to a multidisciplinary urban training. Thinking about "urban design", after beautifull city, urban composition, or alongside the urban project and other territorial approaches can help to see more clearly in town planning.; Le terme « urbanis...

Collective identity and dance in modern urban Greece

Directory of Open Access Journals (Sweden)

Filippos Filippou

2016-02-01

Full Text Available The aim of this study is to trace the way some cultural groups demonstrate their identity through dance in the contemporary urban society. The survey follows revelry with folk music, singing and dancing organized by a local cultural troupe on the occasion of a feast day. The collection of the ethnographic data relied on long standing observation and the video recording of the revelries between 2000 and 2005. Further information was gathered with the means of a closed questionnaire and open question interviews. In the process of the material two theories were mainly employed: the performance theory and the theory of collective identity in postmodern culture. To sum up, we would say that dance as presented on the feast day reflects the local “multicultural” society’s characteristics. It retains its dynamic with its entity, function and content to be composed of agricultural and urban features. Dance continues to exist since it has the potential to adjust to each time social, economic and historical circumstances.

Increasing the availability of urban passenger transport on objective ...

African Journals Online (AJOL)

Increasing the availability of urban passenger transport on objective control data ... mathematical modeling, probability theory and mathematical statistics, expert ... intended for development of methods and means of operative management of ...

Abrupt climate-independent fire regime changes

Science.gov (United States)

Pausas, Juli G.; Keeley, Jon E.

2014-01-01

Wildfires have played a determining role in distribution, composition and structure of many ecosystems worldwide and climatic changes are widely considered to be a major driver of future fire regime changes. However, forecasting future climatic change induced impacts on fire regimes will require a clearer understanding of other drivers of abrupt fire regime changes. Here, we focus on evidence from different environmental and temporal settings of fire regimes changes that are not directly attributed to climatic changes. We review key cases of these abrupt fire regime changes at different spatial and temporal scales, including those directly driven (i) by fauna, (ii) by invasive plant species, and (iii) by socio-economic and policy changes. All these drivers might generate non-linear effects of landscape changes in fuel structure; that is, they generate fuel changes that can cross thresholds of landscape continuity, and thus drastically change fire activity. Although climatic changes might contribute to some of these changes, there are also many instances that are not primarily linked to climatic shifts. Understanding the mechanism driving fire regime changes should contribute to our ability to better assess future fire regimes.

Nanophotonic light-trapping theory for solar cells

Energy Technology Data Exchange (ETDEWEB)

Yu, Zongfu; Raman, Aaswath; Fan, Shanhui [Stanford University, Ginzton Lab, Stanford, CA (United States)

2011-11-15

Conventional light-trapping theory, based on a ray-optics approach, was developed for standard thick photovoltaic cells. The classical theory established an upper limit for possible absorption enhancement in this context and provided a design strategy for reaching this limit. This theory has become the foundation for light management in bulk silicon PV cells, and has had enormous influence on the optical design of solar cells in general. This theory, however, is not applicable in the nanophotonic regime. Here we develop a statistical temporal coupled-mode theory of light trapping based on a rigorous electromagnetic approach. Our theory reveals that the standard limit can be substantially surpassed when optical modes in the active layer are confined to deep-subwavelength scale, opening new avenues for highly efficient next-generation solar cells. (orig.)

Fano-Kondo and the Kondo box regimes crossover in a quantum dot coupled to a quantum box

Science.gov (United States)

Apel, Victor M.; Orellana, Pedro A.; Pacheco, Monica; Anda, Enrique V.

2013-12-01

In this work, we study the Kondo effect of a quantum dot (QD) connected to leads and to a discrete set of one-particle states provided by a quantum box represented by a quantum ring (QR) pierced by a magnetic flux side attached to the QD. The interplay between the bulk Kondo effect and the so-called Kondo box regime is studied. In this system the QR energies can be continuously modified by the application of the magnetic field. The crossover between these two regimes is analyzed by changing the connection of the QD to the QR from the weak to the strong coupling regime. In the weak coupling regime, the differential conductance develops a sequence of Fano-Kondo anti-resonances due to destructive interference between the discrete quantum ring levels and the conducting Kondo channel provided by the leads. In the strong coupling regime the differential conductance has very sharp resonances when one of the Kondo discrete sub-levels characterizing the Kondo box is tuned by the applied potential. The conductance, the current fluctuations and the Fano coefficient result as being the relevant physical magnitudes to be analyzed to reveal the physical properties of these two Kondo regimes and the crossover region between them. The results were obtained by using the slave boson mean field theory (SBMFT).

Strategic maneuvering in supporting the feasibility of political change: A pragma-dialectical analysis of Egyptian anti-regime columns

NARCIS (Netherlands)

Omar, A.A.A.M.H.

2016-01-01

Paving the way to the revolutionary uprising of 2011, Egyptian anti-regime columnists aimed at convincing their audiences that a political change towards democracy would not only be desirable but also feasible. The extended pragma-dialectical argumentation theory is used as a theoretical and

Research on centrality of urban transport network nodes

Science.gov (United States)

Wang, Kui; Fu, Xiufen

2017-05-01

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

Fire regimes and vegetation responses in two Mediterranean-climate regions

Science.gov (United States)

Montenegro, G.; Ginocchio, R.; Segura, A.; Keely, J.E.; Gomez, M.

2004-01-01

Wildfires resulting from thunderstorms are common in some Mediterranean-climate regions, such as southern California, and have played an important role in the ecology and evolution of the flora. Mediterranean-climate regions are major centers for human population and thus anthropogenic impacts on fire regimes may have important consequences on these plant formations. However, changes in fire regimes may have different impacts on Mediterranean type-ecosystems depending on the capability of plants to respond to such perturbations. Therefore, we compare here fire regimes and vegetation responses of two Mediterranean-climate regions which differ in wildfire regimes and history of human occupation, the central zone of Chile (matorral) and the southern area of California in United States (chaparral). In Chile almost all fires result from anthropogenic activities, whereas lightning fires resulting from thunderstorms are frequent in California. In both regions fires are more frequent in summer, due to high accumulation of dry plant biomass for ignition. Humans have markedly increased fires frequency both in the matorral and chaparral, but extent of burned areas has remained unaltered, probably due to better fire suppression actions and a decline in the built-up of dry plant fuel associated to increased landscape fragmentation with less flammable agricultural and urban developments. As expected, post-fire plant regeneration responses differs between the matorral and chaparral due to differences in the importance of wildfires as a natural evolutionary force in the system. Plants from the chaparral show a broader range of post-fire regeneration responses than the matorral, from basal resprouting, to lignotuber resprouting, and to fire-stimulated germination and flowering with fire-specific clues such as heat shock, chemicals from smoke or charred wood. Plants from the matorral have some resprouting capabilities after fire, but these probably evolved from other environmental

Neutrino-nucleus cross section in the impulse approximation regime

International Nuclear Information System (INIS)

Benhar, Omar; Farina, Nicola

2005-01-01

In the impulse approximation regime the nuclear response to a weakly interacting probe can be written in terms of the measured nucleon structure functions and the target spectral function, yielding the energy and momentum distribution of the constituent nucleons. We discuss a calculation of charged current neutrino-oxygen interactions in the quasielastic channel, carried out within nuclear many body theory. The proposed approach, extensively and successfully employed in the analysis of electron-nucleus scattering data, allows for a parameter free prediction of the neutrino-nucleus cross section, whose quantitative understanding will be critical to the analysis of the next generation of high precision neutrino oscillation experiments

Behavior Space Design and Expression by the Theories and Methods of Urban Design—The Yan Dao ancient town of design practice

Directory of Open Access Journals (Sweden)

Chen Wei

2015-01-01

Full Text Available In recent years, the ancient town of update and development has become a new hot spot, the study of old town renewal of concern is gradually warming. And again there are a lot of space in the middle of the old town renewal design and traditional style, space activities and use the contradiction between population, which becomes a problem urgently to be solved in design stage. The purpose of this study was to explore old town design space and behavior, traditional and modern conflict resolution methods, and to present the town development and design with a design concept. This paper’ uses three theories of urban design (The relationship between figure and ground, Contact theory and Place theory as a real-time monitoring, assessment, comparison of methods, to study Yan Dao Ancient Town, and the space for analysis. In the research, this paper based on the design theory of the three major city as a starting point, detailedly describes the different types in a certain area of difference in the behavior and the properties of space, and the ancient town of Hubei Shennongjia forest region salt path planning and design practice, the ancient town of updating the connotation of the historical context and space behavior of connection. The conclusion of this thesis put forward the method of that based on the space shape of ancient design method of its application in practice.

Large J expansion in ABJM theory revisited.

Science.gov (United States)

Dimov, H; Mladenov, S; Rashkov, R C

Recently there has been progress in the computation of the anomalous dimensions of gauge theory operators at strong coupling by making use of the AdS/CFT correspondence. On the string theory side they are given by dispersion relations in the semiclassical regime. We revisit the problem of a large-charge expansion of the dispersion relations for simple semiclassical strings in an [Formula: see text] background. We present the calculation of the corresponding anomalous dimensions of the gauge theory operators to an arbitrary order using three different methods. Although the results of the three methods look different, power series expansions show their consistency.

Large transverse momentum behavior of gauge theories

International Nuclear Information System (INIS)

Coquereaux, Robert; De Rafael, Eduardo.

1977-05-01

The large transverse momentum behavior of Compton scattering and Moeller scattering in Quantum Electrodynamics; and of elastic quark-quark scattering in Quantum Chromodynamics are examined in perturbation theory. The results strongly suggest that the large transverse momentum regime in gauge theories is governed by a differential equation of the Callan-Symanzik type with a suitable momentum dependent anomalous dimension term. An explicit solution for the quark-quark elastic scattering amplitude at large transverse momentum is given

Urban Quality Development & Management

DEFF Research Database (Denmark)

Lehmann, Martin; Fryd, Ole

2008-01-01

Purpose: The purpose of this article is to describe and discuss the development and the structure of a new international master on the subject of Urban Quality Development & Management, and explore the potential of the process and the outcome in serving as models adoptable by faculty at other......: Urban quality development and management is dependent on human resource development, institutionalised networks and confident exchange of knowledge, and must identify and incorporate multiple environmental, social, economic and cultural aspects. The authors find that at the core of innovative societies......, an interlinkage exists between practice (business, civil society, governance) and theory (research, education). The case illustrates how a new curriculum takes time to develop and implement and how it relies on confidence and trust between partners, in this case cities and universities, before being able to plant...

Urban Climate Risk Communities

DEFF Research Database (Denmark)

Blok, Anders

2016-01-01

of Beck’s forward-looking agenda for a post-Euro-centric social science, outlines the contours of such an urban-cosmopolitan ‘realpolitik’ of climate risks, as this is presently unfolding across East Asian world cities. Much more than a theory-building endeavour, the essay suggests, Beck’s sociology......Ulrich Beck’s cosmopolitan sociology affords a much-needed rethinking of the transnational politics of climate change, not least in pointing to an emerging inter-urban geography of world cities as a potential new source of community, change and solidarity. This short essay, written in honour...... provides a standing invitation for further transnational dialogue and collaborative empirical work, in East Asia and beyond, on what are, arguably, the defining challenges for the 21st century world of global risks....

The trade regime and the climate regime. Institutional evolution and adaptation

International Nuclear Information System (INIS)

Brewer, Thomas L.

2003-01-01

This article addresses concerns that the multilateral trade regime centered in the WTO and the emerging climate regime may conflict in ways that could be damaging to either or both. The article discusses the institutional and diplomatic context of these concerns, and it identifies the kinds of issues that are in question. The analysis suggests that there are opportunities for win-win outcomes in the interactions of the two regimes, for instance in the possibility of reducing fossil fuel subsidies. However, there are also problematic areas where they intersect. A core issue-and as yet an unresolved one-is whether and how emission credit trading and other activities envisioned by the Kyoto Protocol would be subject to WTO rules. The resolution of this issue will affect many other issues as well. Additional specific issues about the interactions of particular provisions in WTO agreements and the Kyoto Protocol are analyzed in a subsequent companion article in Climate Policy

Surface hopping, transition state theory and decoherence. I. Scattering theory and time-reversibility.

Science.gov (United States)

Jain, Amber; Herman, Michael F; Ouyang, Wenjun; Subotnik, Joseph E

2015-10-07

We provide an in-depth investigation of transmission coefficients as computed using the augmented-fewest switches surface hopping algorithm in the low energy regime. Empirically, microscopic reversibility is shown to hold approximately. Furthermore, we show that, in some circumstances, including decoherence on top of surface hopping calculations can help recover (as opposed to destroy) oscillations in the transmission coefficient as a function of energy; these oscillations can be studied analytically with semiclassical scattering theory. Finally, in the spirit of transition state theory, we also show that transmission coefficients can be calculated rather accurately starting from the curve crossing point and running trajectories forwards and backwards.

Synergies between nonproliferation regimes: A pragmatic approach

International Nuclear Information System (INIS)

Findlay, Trevor; Meier, Oliver

2001-01-01

Full text: With the recent progress in establishing international nonproliferation regimes, the question of synergies between different verification and monitoring regimes is becoming more acute. Three multilateral and universal nonproliferation organisations covering safeguards on civil nuclear materials, nuclear testing, and chemical weapons are up and running. A regime on biological weapons is under negotiation. Several regional organisations concerned with monitoring nonproliferation commitments in the nuclear field are in place; others are being established. Past discussions on synergies between these regimes have suffered from being too far-reaching. These discussions often have not reflected adequately the political difficulties of cooperation between regimes with different membership, scope and institutional set-up. This paper takes a pragmatic look at exploiting synergies and identifies some potential and real overlaps in the work between different verification regimes. It argues for a bottom-up approach and identifies building blocks for collaboration between verification regimes. By realising such, more limited potential for cooperation, the ground could be prepared for exploiting other synergies between these regimes. (author)

De Facto Regimes in International Law

Directory of Open Access Journals (Sweden)

Jonte van Essen

2012-02-01

Full Text Available The ambiguous position of de facto regimes in international law has long been the subject of scholarly debate and a source of political conflict. An assessment of the current standing of these regimes in international law and the consequences of actions by international actors on this status has, however, been long overdue. The manner in which de facto regimes are regarded internationally has serious consequences for the individuals under the influence of this legal grey area. Therefore, the study into this problem and possible solutions is of great significance. The 2011 developments in Northern Africa underline the need of contemporary research into this area. This essay aims to clarify the position of de facto regimes in international law and the influence on their status by actions of international actors. The author first argues that de facto regimes have rights and obligations under international law, which provide them with (some form of international legal personality. He then pleads for a reconsideration of the contemporary legal treatment of these regimes. The author argues against the current system of government recognition and proposes a system that better addresses the needs of both de facto regimes and the international community. 

Spatial characterization of catchment dispersion mechanisms in an urban context

Science.gov (United States)

Rossel, Florian; Gironás, Jorge; Mejía, Alfonso; Rinaldo, Andrea; Rodriguez, Fabrice

2014-12-01

Previous studies have examined in-depth the dispersion mechanisms in natural catchments. In contrast, these dispersion mechanisms have been studied little in urban catchments, where artificial transport elements and morphological arrangements are expected to modify travel times and mobilize excess rainfall from spatially distributed impervious sites. This has the ability to modify the variance of the catchment's travel times and hence the total dispersion. This work quantifies the dispersion mechanisms in an urban catchment using the theory of transport by travel times as represented by the Urban Morpho-climatic Instantaneous Unit Hydrograph (U-McIUH) model. The U-McIUH computes travel times based on kinematic wave theory and accounts explicitly for the path heterogeneities and altered connectivity patterns characteristic of an urban drainage network. The analysis is illustrated using the Aubinière urban catchment in France as a case study. We found that kinematic dispersion is dominant for small rainfall intensities, whereas geomorphologic dispersion becomes more dominant for larger intensities. The total dispersion scales with the drainage area in a power law fashion. The kinematic dispersion is dominant across spatial scales up to a threshold of approximately 2-3 km2, after which the geomorphologic dispersion becomes more dominant. Overall, overland flow is responsible for most of the dispersion in the catchment, while conduits tend to counteract the increase of the geomorphologic dispersion with a negative kinematic dispersion. Further study with other catchments is needed to asses if the latter is a general feature of urban drainage networks.

Neoliberal policies and urban reconfigurations. Victoria, San Fernando, province of Buenos Aires, a city understood from theory

Directory of Open Access Journals (Sweden)

Laura Ester Donadío

2016-07-01

Full Text Available This article aims to explain from a theoretical conceptual approach the particularities that exist in Victoria, San Fernando, Buenos Aires, from its urban production. Through a series of field works, semi-structured interviews and observations, it was possible to perceive that in this locality, there are three logics of city production, market, state and necessity, according to Abramo, P. (2002. The post-development cities of Latin America, a space in which constant tensions are generated that alter the harmonious development of daily life and the interaction of those who inhabit the area. On the other hand, it is also perceived that the inhabitants naturalize that way of life, their spatial disposition, the progressive privatization of public areas and the proliferation of closed housing estates. Here is a quote that we have heard repeatedly in interviews with the neighbors: "No one in Victoria gives a ball to anyone." At the moment of understanding Victoria from the theory, we take into account such concepts as the "heterotopy" of Foucault M. (1967 - understood as the juxtaposition of spaces that would be incompatible -the term "com-fusa city" (Abramo P. - as an urban structure that interweaves two traditional models (the Mediterranean compact and the Anglo-Saxon diffused, the notion of "privatopia" by I.Rodriguez Chumillas (2005 and E. Mckenzie (1994 as private spatial consolidation, and finally the concepts: informative and dual cities of R Castells (1995 terms that emerge from the process of globalization, which may be useful to think about the reality of Victoria .

Pitch angle scattering of relativistic electrons from stationary magnetic waves: Continuous Markov process and quasilinear theory

International Nuclear Information System (INIS)

Lemons, Don S.

2012-01-01

We develop a Markov process theory of charged particle scattering from stationary, transverse, magnetic waves. We examine approximations that lead to quasilinear theory, in particular the resonant diffusion approximation. We find that, when appropriate, the resonant diffusion approximation simplifies the result of the weak turbulence approximation without significant further restricting the regime of applicability. We also explore a theory generated by expanding drift and diffusion rates in terms of a presumed small correlation time. This small correlation time expansion leads to results valid for relatively small pitch angle and large wave energy density - a regime that may govern pitch angle scattering of high-energy electrons into the geomagnetic loss cone.

Simulation and assessment of urbanization impacts on runoff metrics: insights from landuse changes

Science.gov (United States)

Zhang, Yongyong; Xia, Jun; Yu, Jingjie; Randall, Mark; Zhang, Yichi; Zhao, Tongtiegang; Pan, Xingyao; Zhai, Xiaoyan; Shao, Quanxi

2018-05-01

Urbanization-induced landuse changes alter runoff regimes in complex ways. In this study, a detailed investigation of the urbanization impacts on runoff regimes is provided by using multiple runoff metrics and with consideration of landuse dynamics. A catchment hydrological model is modified by coupling a simplified flow routing module of the urban drainage system and landuse dynamics to improve long-term urban runoff simulations. Moreover, multivariate statistical approach is adopted to mine the spatial variations of runoff metrics so as to further identify critical impact factors of landuse changes. The Qing River catchment as a peri-urban catchment in the Beijing metropolitan area is selected as our study region. Results show that: (1) the dryland agriculture is decreased from 13.9% to 1.5% of the total catchment area in the years 2000-2015, while the percentages of impervious surface, forest and grass are increased from 63.5% to 72.4%, 13.5% to 16.6% and 5.1% to 6.5%, respectively. The most dramatic landuse changes occur in the middle and downstream regions; (2) The combined landuse changes do not alter the average flow metrics obviously at the catchment outlet, but slightly increase the high flow metrics, particularly the extreme high flows; (3) The impacts on runoff metrics in the sub-catchments are more obvious than those at the catchment outlet. For the average flow metrics, the most impacted metric is the runoff depth in the dry season (October ∼ May) with a relative change from -10.9% to 11.6%, and the critical impact factors are the impervious surface and grass. For the high flow metrics, the extreme high flow depth is increased most significantly with a relative change from -0.6% to 10.5%, and the critical impact factors are the impervious surface and dryland agriculture; (4) The runoff depth metrics in the sub-catchments are increased because of the landuse changes from dryland agriculture to impervious surface, but are decreased because of the

Analytical theory of Doppler reflectometry in slab plasma model

Energy Technology Data Exchange (ETDEWEB)

Gusakov, E.Z.; Surkov, A.V. [Ioffe Institute, Politekhnicheskaya 26, St. Petersburg (Russian Federation)

2004-07-01

Doppler reflectometry is considered in slab plasma model in the frameworks of analytical theory. The diagnostics locality is analyzed for both regimes: linear and nonlinear in turbulence amplitude. The toroidal antenna focusing of probing beam to the cut-off is proposed and discussed as a method to increase diagnostics spatial resolution. It is shown that even in the case of nonlinear regime of multiple scattering, the diagnostics can be used for an estimation (with certain accuracy) of plasma poloidal rotation profile. (authors)

Perturbation theory with non-diagonal propagators and its use in the intermediate-coupling regime

International Nuclear Information System (INIS)

Znojil, M.

1998-01-01

An innovated method of construction of the Rayleigh-Schroedinger perturbation series in a seemingly nonperturbative regime is offered. Designed for the needs of condensed matter physics, nuclear physics and quantum chemistry, the flexibility of our new formalism is based on a nonstandard Lanczosean construction of unperturbed basis. With an asymmetric choice of the model space the recipe becomes recurrent not only order-by- order in a small parameter (as usual) but also projection-by-projection in the Hilbert space. Its idea and efficiency are illustrated on a few schematic examples. (Copyright (1998) World Scientific Publishing Co. Pte. Ltd)

Effects of diversity and procrastination in priority queuing theory: The different power law regimes

Science.gov (United States)

Saichev, A.; Sornette, D.

2010-01-01

Empirical analyses show that after the update of a browser, or the publication of the vulnerability of a software, or the discovery of a cyber worm, the fraction of computers still using the older browser or software version, or not yet patched, or exhibiting worm activity decays as a power law ˜1/tα with 0procrastination,” defined as the situation in which the target task may be postponed or delayed even after the individual has solved all other pending tasks. This regime provides an explanation for even slower apparent decay and longer persistence.

Theory of relativistic radiation reflection from plasmas

Science.gov (United States)

Gonoskov, Arkady

2018-01-01

We consider the reflection of relativistically strong radiation from plasma and identify the physical origin of the electrons' tendency to form a thin sheet, which maintains its localisation throughout its motion. Thereby, we justify the principle of relativistic electronic spring (RES) proposed in [Gonoskov et al., Phys. Rev. E 84, 046403 (2011)]. Using the RES principle, we derive a closed set of differential equations that describe the reflection of radiation with arbitrary variation of polarization and intensity from plasma with an arbitrary density profile for an arbitrary angle of incidence. We confirm with ab initio PIC simulations that the developed theory accurately describes laser-plasma interactions in the regime where the reflection of relativistically strong radiation is accompanied by significant, repeated relocation of plasma electrons. In particular, the theory can be applied for the studies of plasma heating and coherent and incoherent emissions in the RES regime of high-intensity laser-plasma interaction.

Entrepreneurship within Urban and Rural Areas

DEFF Research Database (Denmark)

Freire-Gibb, L. Carlos; Nielsen, Kristian

2014-01-01

The entrepreneurial dynamics of urban and rural areas are different, and this paper explores creativity and social networks factors in both places. The probabilities of becoming an entrepreneur and of surviving are analyzed. The results are based on longitudinal data combined with a questionnaire......, common entrepreneurship beliefs can be questioned and entrepreneurship theory benefited....

Capacity of Fading Channels in the Low Power Regime

KAUST Repository

Benkhelifa, Fatma

2013-01-01

The low power regime has attracted various researchers in the information theory and communication communities to understand the performance limits of wireless systems. Indeed, the energy consumption is becoming one of the major limiting factors in wireless systems. As such, energy-efficient wireless systems are of major importance to the next generation wireless systems designers. The capacity is a metric that measures the performance limit of a wireless system. The study of the ergodic capacity of some fading channels in the low power regime is the main subject of this thesis. In our study, we consider that the receiver has always a full knowledge of the channel state information. However, we assume that the transmitter has possibly imperfect knowledge of the channel state information, i.e. he knows either perfectly the channel or only an estimated version of the channel. Both radio frequency and free space optical communication channel models are considered. The main contribution of this work is the explicit characterization of how the capacity scales as function of the signal-to-noise ratio in the low power regime. This allows us to characterize the gain due to the perfect knowledge compared to no knowledge of the channel state information at the transmitter. In particular, we show that the gain increases logarithmically for radio frequency communication. However, the gain increases as log2(Pavg) or log4(Pavg) for free-space optical communication, where Pavg is the average power constraint imposed to the input. Furthermore, we characterize the capacity of cascaded fading channels and we applied the result to Rayleigh-product fading channel and to a free-space optical link over gamma-gamma atmospheric turbulence in the presence of pointing errors. Finally, we study the capacity of Nakagami-m fading channel under quality of service constraints, namely the effective capacity. We have shown that the effective capacity converges to Shannon capacity in the very low

Impacts and adaptation for climate change in urban forests

Energy Technology Data Exchange (ETDEWEB)

Johnston, M. [Saskatchewan Research Council, Saskatoon, SK (Canada)

2006-07-01

Changes to urban trees as a result of climate change were reviewed in order to aid urban forest managers in the development of adaptive climate change strategies. Various climate change models have predicted that winter and spring temperatures will increase. Higher amounts of precipitation are also anticipated. Higher temperatures will results in evapotranspiration, which will cause soil moisture levels to decline. Climatologists have also suggested that very hot days, winter storms and high rainfall events will increase in frequency. In addition, higher levels of atmospheric carbon dioxide (CO{sub 2}) will affect photosynthesis, with associated impacts on urban tree growth. Higher temperatures and longer growing seasons will allow insect populations to build up to higher levels, and warmer and dryer summers are likely to bring longer fire seasons and more severe fires. Urban trees under stress from drought and higher temperatures will be increasingly vulnerable to existing urban stressors such as air pollution and soil compaction. However, the ecological services provided by trees will become more valuable under future climate change regimes, particularly for shading and space cooling, as well as soil aeration and stabilization and the uptake of storm water. It was suggested that future tree growth may be enhanced on sites with adequate water and nutrients, but will probably decline in areas that are already marginal. It was recommended that urban forest managers assess the present vulnerability of trees to climate-related events in order to prepare for future change. Managers should also assess their capacity to implement various strategies through municipal and provincial partnerships. It was observed that decisions taken now about forest management will play out over several decades. It was concluded that maintaining a flexible and resilient urban forest management system is the best defence, as specific climate change impacts cannot be predicted. 18 refs., 4

Achieving Flourishing City Schools and Communities--Corporate Reform, Neoliberal Urbanism, and the Right to the City

Science.gov (United States)

Means, Alexander

2014-01-01

This essay critiques the ideological assertions of corporate school reform and discusses how these logics perpetuate failure in urban education. Drawing on theories of neoliberal urbanism, the right to the city, and the commons, the essay argues that educational researchers and advocates need to reframe the values of urban education in line with a…

Urban Elementary Single-Sex Math Classrooms: Mitigating Stereotype Threat for African American Girls

Science.gov (United States)

Bowe, Anica G.; Desjardins, Christopher D.; Covington Clarkson, Lesa M.; Lawrenz, Frances

2017-01-01

This study utilized a mixed-methods approach to holistically examine single-sex and coeducational urban elementary mathematics classes through situated cognitive theory. Participants came from two urban low-income Midwestern elementary schools with a high representation of minority students (n = 77 sixth graders, n = 4 teachers, n = 2 principals).…

POLITICAL REGIME, COMPETITIVENESS, AND FOREIGN INVESTMENT: AN EVIDENCE OF THE EURO AREAS’ FDI POLICIES TO SOUTHEAST ASIAN COUNTRIES

Directory of Open Access Journals (Sweden)

Ari Warokka

2011-01-01

Full Text Available Theory and previous evidences provide conflicting predictions concerning the growth effects of foreign direct investment (FDI. The mainstream ideas support FDI as an engine of employment, technological progress, productivity improvements, and ultimately economic growth. Because of these significant benefits, attracting FDI has become one of the integral parts of economic development strategies in many countries. There are two schools of thought that hypothesize the FDI determinants: economic factors and political factors. For the latter school of thought, the central questions are directed to determine whether political regime affect country’s trade policy or not. In the advanced industrial countries where labour tends to be scarce, are left political regimes more protectionist than right ones, which represent capital owners? Prior evidence had demonstrated an association between the type of political regimes and trade policies (FDI policies.

MILLIHERTZ QUASI-PERIODIC OSCILLATIONS AND THERMONUCLEAR BURSTS FROM TERZAN 5: A SHOWCASE OF BURNING REGIMES

Energy Technology Data Exchange (ETDEWEB)

Linares, M.; Chakrabarty, D. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States); Altamirano, D. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam and Center for High-Energy Astrophysics, P.O. BOX 94249, 1090 GE Amsterdam (Netherlands); Cumming, A. [Department of Physics, McGill University, 3600 Rue University, Montreal, QC H3A 2T8 (Canada); Keek, L. [School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

2012-04-01

We present a comprehensive study of the thermonuclear bursts and millihertz quasi-periodic oscillations (mHz QPOs) from the neutron star (NS) transient and 11 Hz X-ray pulsar IGR J17480-2446, located in the globular cluster Terzan 5. The increase in burst rate that we found during its 2010 outburst, when persistent luminosity rose from 0.1 to 0.5 times the Eddington limit, is in qualitative agreement with thermonuclear burning theory yet contrary to all previous observations of thermonuclear bursts. Thermonuclear bursts gradually evolved into a mHz QPO when the accretion rate increased, and vice versa. The mHz QPOs from IGR J17480-2446 resemble those previously observed in other accreting NSs, yet they feature lower frequencies (by a factor {approx}3) and occur when the persistent luminosity is higher (by a factor 4-25). We find four distinct bursting regimes and a steep (close to inverse cubic) decrease of the burst recurrence time with increasing persistent luminosity. We compare these findings to nuclear burning models and find evidence for a transition between the pure helium and mixed hydrogen/helium ignition regimes when the persistent luminosity was about 0.3 times the Eddington limit. We also point out important discrepancies between the observed bursts and theory, which predicts brighter and less frequent bursts, and suggest that an additional source of heat in the NS envelope is required to reconcile the observed and expected burst properties. We discuss the impact of NS magnetic field and spin on the expected nuclear burning regimes, in the context of this particular pulsar.

Projected coupled cluster theory.

Science.gov (United States)

Qiu, Yiheng; Henderson, Thomas M; Zhao, Jinmo; Scuseria, Gustavo E

2017-08-14

Coupled cluster theory is the method of choice for weakly correlated systems. But in the strongly correlated regime, it faces a symmetry dilemma, where it either completely fails to describe the system or has to artificially break certain symmetries. On the other hand, projected Hartree-Fock theory captures the essential physics of many kinds of strong correlations via symmetry breaking and restoration. In this work, we combine and try to retain the merits of these two methods by applying symmetry projection to broken symmetry coupled cluster wave functions. The non-orthogonal nature of states resulting from the application of symmetry projection operators furnishes particle-hole excitations to all orders, thus creating an obstacle for the exact evaluation of overlaps. Here we provide a solution via a disentanglement framework theory that can be approximated rigorously and systematically. Results of projected coupled cluster theory are presented for molecules and the Hubbard model, showing that spin projection significantly improves unrestricted coupled cluster theory while restoring good quantum numbers. The energy of projected coupled cluster theory reduces to the unprojected one in the thermodynamic limit, albeit at a much slower rate than projected Hartree-Fock.

Phase structure of three- and four-dimensional φ4 field theory

International Nuclear Information System (INIS)

Efimov, G.V.

1991-01-01

Strong coupling regime of gφ theory in space-time R d for d=3,4 is investigated by the methods of canonical transformations and renormalization group. Comparison with the case d=2 shows a crucial influence of the renormalization structure of the theory of its phase structure. 19 refs.; 7 figs.; 1 tab

Impediments to integrated urban stormwater management: the need for institutional reform.

Science.gov (United States)

Brown, Rebekah R

2005-09-01

It is now well established that the traditional practice of urban stormwater management contributes to the degradation of receiving waterways, and this practice was more recently critiqued for facilitating the wastage of a valuable water resource. However, despite significant advances in alternative "integrated urban stormwater management" techniques and processes over the last 20 years, wide-scale implementation has been limited. This problem is indicative of broader institutional impediments that are beyond current concerns of strengthening technological and planning process expertise. Presented here is an analysis of the institutionalization of urban stormwater management across Sydney with the objective of scoping institutional impediments to more sustainable management approaches. The analysis reveals that the inertia with the public administration of urban stormwater inherently privileges and perpetuates traditional stormwater management practices at implementation. This inertia is characterized by historically entrained forms of technocratic institutional power and expertise, values and leadership, and structure and jurisdiction posing significant impediments to change and the realization of integrated urban stormwater management. These insights strongly point to the need for institutional change specifically directed at fostering horizontal integration of the various functions of the existing administrative regime. This would need to be underpinned with capacity-building interventions targeted at enabling a learning culture that values integration and participatory decision making. These insights also provide guideposts for assessing the institutional and capacity development needs for improving urban water management practices in other contexts.

Assessment of a transitional boundary layer theory at low hypersonic Mach numbers

Science.gov (United States)

Shamroth, S. J.; Mcdonald, H.

1972-01-01

An investigation was carried out to assess the accuracy of a transitional boundary layer theory in the low hypersonic Mach number regime. The theory is based upon the simultaneous numerical solution of the boundary layer partial differential equations for the mean motion and an integral form of the turbulence kinetic energy equation which controls the magnitude and development of the Reynolds stress. Comparisions with experimental data show the theory is capable of accurately predicting heat transfer and velocity profiles through the transitional regime and correctly predicts the effects of Mach number and wall cooling on transition Reynolds number. The procedure shows promise of predicting the initiation of transition for given free stream disturbance levels. The effects on transition predictions of the pressure dilitation term and of direct absorption of acoustic energy by the boundary layer were evaluated.

Spinodal decomposition in a food colloid-biopolymer mixture: evidence for a linear regime

Energy Technology Data Exchange (ETDEWEB)

Bhat, Suresh [Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, 1700 Fribourg (Switzerland); Tuinier, Remco [Forschungszentrum Juelich, Institut fuer Festkoerperforschung, 52425 Juelich (Germany); Schurtenberger, Peter [Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, 1700 Fribourg (Switzerland)

2006-07-05

We investigate phase separation and structural evolution in a complex food colloid (casein micelles) and biopolymer (xanthan) mixture using small-angle light scattering. We demonstrate that phase separation is induced by a depletion mechanism, and that the resulting coexistence curve can be described by osmotic equilibrium theory for mixtures of colloids and polymer chains in a background solvent, taking into account interactions between the polymer chains in the excluded volume limit. We show that the light scattering pattern of an unstable mixture exhibits the typical behaviour of spinodal decomposition, and we are able to confirm the validity of dynamic similarity scaling. We find three distinct regimes (initial or linear, intermediate and transition stage) for the decomposition kinetics that differ in the time dependence of the peak position of the structure factor. In particular we find clear evidence for the existence of an initial linear regime, where the peak position remains constant and the amplitude grows. The existence of spinodal-like decomposition and the validity of universal scaling in the intermediate and transition stages have been found in previous studies of phase separation in attractive colloidal suspensions. However, to our knowledge the initial linear regime has never been observed in colloidal suspensions, and we attribute this at least partly to the effect of hydrodynamic interactions which are efficiently screened in our system due to the fact that the measurements were performed at high polymer concentrations, i.e. in the semi-dilute regime. (letter to the editor)

Is science the driving force in the operation of environmental regimes? : A case study of the Mediterranean Action Plan

NARCIS (Netherlands)

Frantzi, Sofia; Lovett, Jonathan Cranidge

2008-01-01

This study examines the role of science in the operation of environmental regimes using the Barcelona Convention/Mediterranean Action Plan (MAP) as a case study. The ‘epistemic communities’ theory suggests that emergence of the Mediterranean Action Plan was largely driven by scientific experts. In

Is science the driving force in the operation of environmental regimes? A case study of the Mediterranean Action Plan

NARCIS (Netherlands)

Frantzi, Sofia; Lovett, Jonathan Cranidge

2008-01-01

This study examines the role of science in the operation of environmental regimes using the Barcelona Convention/Mediterranean Action Plan (MAP) as a case study. The ‘epistemic communities’ theory suggests that emergence of the Mediterranean Action Plan was largely driven by scientific experts. In

Is science the driving force in the operation of environmental regimes? A case study of the Mediterranean Action Plan

NARCIS (Netherlands)

Frantzi, S.; Lovett, J.C.

2008-01-01

This study examines the role of science in the operation of environmental regimes using the Barcelona Convention/Mediterranean Action Plan (MAP) as a case study. The 'epistemic communities' theory suggests that emergence of the Mediterranean Action Plan was largely driven by scientific experts. In

Chiral perturbation theory for lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Baer, Oliver

2010-07-21

The formulation of chiral perturbation theory (ChPT) for lattice Quantum Chromodynamics (QCD) is reviewed. We start with brief summaries of ChPT for continuum QCD as well as the Symanzik effective theory for lattice QCD. We then review the formulation of ChPT for lattice QCD. After an additional chapter on partial quenching and mixed action theories various concrete applications are discussed: Wilson ChPT, staggered ChPT and Wilson ChPT with a twisted mass term. The remaining chapters deal with the epsilon regime with Wilson fermions and selected results in mixed action ChPT. Finally, the formulation of heavy vector meson ChPT with Wilson fermions is discussed. (orig.)

Chiral perturbation theory for lattice QCD

International Nuclear Information System (INIS)

Baer, Oliver

2010-01-01

The formulation of chiral perturbation theory (ChPT) for lattice Quantum Chromodynamics (QCD) is reviewed. We start with brief summaries of ChPT for continuum QCD as well as the Symanzik effective theory for lattice QCD. We then review the formulation of ChPT for lattice QCD. After an additional chapter on partial quenching and mixed action theories various concrete applications are discussed: Wilson ChPT, staggered ChPT and Wilson ChPT with a twisted mass term. The remaining chapters deal with the epsilon regime with Wilson fermions and selected results in mixed action ChPT. Finally, the formulation of heavy vector meson ChPT with Wilson fermions is discussed. (orig.)

Tourism Labor, Embodied Suffering, and the Deportation Regime in the Dominican Republic.

Science.gov (United States)

Padilla, Mark; Colón-Burgos, José Félix; Varas-Díaz, Nelson; Matiz-Reyes, Armando; Parker, Caroline Mary

2018-04-17

In this article, we use syndemic theory to examine socio-structural factors that result in heightened vulnerability to HIV infection and drug addiction among Dominican deportees who survive post-deportation through informal tourism labor. Through an ongoing NIDA-funded ethnographic study of the syndemic of HIV and problematic drug use among men involved in tourism labor in the Dominican Republic, we argue that the legal and political-economic context of the global deportation regime contributes to structural vulnerabilities among deportees in the Dominican Republic, most of whom are men with histories of incarceration in the United States and/or Puerto Rico. While Dominican laws and institutional practices work conjointly with foreign policies to reconfigure non-criminal deportees as hardened criminals unworthy of full citizenship rights, the informal tourism economy provides one of the few absorption points for male deportee labor, linking the deportation regime directly to the Caribbean tourism industry. © 2018 by the American Anthropological Association.

Measuring the effectiveness of international environmental regimes

Energy Technology Data Exchange (ETDEWEB)

Helm, C.; Sprinz, D.F.

1999-05-01

While past research has emphasized the importance of international regimes for international governance, systematic assessments of regime effects are missing. This article derives a standardized measurement concept for the effectiveness of international environmental regimes by developing an operational rational choice calculus to evaluate actual policy simultaneously against a non-regime counterfactual and a collective optimum. Subsequently, the empirical feasibility of the measurement instrument is demonstrated by way of two international treaties regulating transboundary air pollution in Europe. The results demonstrate that the regimes indeed show positive effects - but fall substantially short of the collective optima. (orig.)

Urbanization and the Carbon Cycle: Synthesis of Ongoing Research

Science.gov (United States)

Gurney, K. R.; Duren, R. M.; Hutyra, L.; Ehleringer, J. R.; Patarasuk, R.; Song, Y.; Huang, J.; Davis, K.; Kort, E. A.; Shepson, P. B.; Turnbull, J. C.; Lauvaux, T.; Rao, P.; Eldering, A.; Miller, C. E.; Wofsy, S.; McKain, K.; Mendoza, D. L.; Lin, J. C.; Sweeney, C.; Miles, N. L.; Richardson, S.; Cambaliza, M. O. L.

2015-12-01

Given the explosive growth in urbanization and its dominant role in current and future global greenhouse gas emissions, urban areas have received increasing research attention from the carbon cycle science community. The emerging focus is driven by the increasingly dense atmospheric observing capabilities - ground and space-based - in addition to the rising profile of cities within international climate change policymaking. Dominated by anthropogenic emissions, urban carbon cycle research requires a cross-disciplinary perspective with contributions from disciplines such as engineering, economics, social theory, and atmospheric science. We review the recent results from a sample of the active urban carbon research efforts including the INFLUX experiment (Indianapolis), the Megacity carbon project (Los Angeles), Salt Lake City, and Boston. Each of these efforts represent unique approaches in pursuit of different scientific and policy questions and assist in setting priorities for future research. From top-down atmospheric measurement systems to bottom-up estimation, these research efforts offer a view of the challenges and opportunities in urban carbon cycle research.

Realistic control considerations for electromagnetically levitated urban transit vehicles

Energy Technology Data Exchange (ETDEWEB)

Billing, J R

1976-04-01

A discussion is given of realistic control considerations of suspension dynamics and vehicle/guideway interaction for electromagnetically-levitated urban transit vehicles in the context of revenue applications. The emphasis is on safety, reliability, and maintainability rather than performance. An example urban transit system is described, and the following considerations of dynamics and control are examined: stability, magnet force requirements, magnet airgap requirements, vehicle ride, and component failures. It is shown that it is a formidable problem to ensure suspension stability under all conditions; that operation on curves is a critical magnet and control system design case; that operation of the magnets in the non-linear regime is unavoidable and that component failures will be a major problem. However, good vehicle ride is to be expected. It is concluded that magnetic levitation suspension technology requires substantial development effort before it can be considered suitable for revenue operation.

Accommodating human values in the climate regime

Directory of Open Access Journals (Sweden)

Rosalind Cook

2008-12-01

Full Text Available The climate regime addresses one of the most important challenges facing humankind today. However, while the environmental and economic sides of the problem are well represented, it lacks the inclusion of social and human aspects. The human rights regime, in contrast, is a regime which has been established precisely to implement human values. This article ex-plains the problems of climate change in terms of human values and argues that some proce-dures from the human rights regime offer possibilities for improvement. It is submitted that through the inclusion of human rights instruments, such as individual communication, pro-gressive realisation and authoritative interpretation, the inclusion of human values into the climate regime will be facilitated. This article presents these instruments and discusses their potential for inclusion in the climate regime.

Human impacts on river ice regime in the Carpathian Basin

Science.gov (United States)

Takács, Katalin; Nagy, Balázs; Kern, Zoltán

2014-05-01

examples from the Carpathian Basin represent some of the most common human impacts (engineering regulation, hydropower usage, water pollution), disturbing natural river ice regimes of mid-latitude rivers with densely populated or dynamically growing urban areas along their courses. In addition simple tests are also introduced to detect not only the climatic, but also the effect of anthropogenic impacts on river ice regime. As a result of river regulation on River Danube at Budapest a vanishing trend in river ice phenomena could be detected in the Danube records. The average ice-affected season shortened from 40 to 27 days, the average ice-covered season reduced greatly, from 27 to 7 days. In historical times the ice jams on the River Danube caused many times ice floods. The relative frequency of the break-up jam also decreased; moreover no ice flood occurred over the past 50 years. The changes due to hydropower usage are different upstream and downstream to the damming along the river. On Raba River upstream of the Nick dam at Ragyogóhíd, the ice-affected and ice-covered seasons were lengthened by 4 and 9 days, in contrast, downstream of the dam, the length of the ice-covered season was shortened by 7 days, and the number of ice-affected days decreased by 8 days at Árpás. During the observation period at Budapest on Danube River, the temperature requirements for river ice phenomena occurrence changed. Nowadays, much lower temperatures are needed to create the same ice phenomena compared to the start of the observations. For ice appearance, the mean winter air temperature requirements decreased from +2.39 °C to +1.71 °C. This investigation focused on anthropogenic effects on river ice regime, eliminating the impact of climatic conditions. Different forms of anthropogenic effects cause in most cases, a shorter length of ice-affected seasons and decreasing frequency of ice phenomena occurrence. Rising winter temperatures result the same changes in river ice regime

THE CALCULATION OF THE ENERGY RECOVERY ELECTRIFIED URBAN TRANSPORT DURING THE INSTALLATION DRIVE FOR TRACTION SUBSTATION

Directory of Open Access Journals (Sweden)

A. A. Sulim

2014-01-01

Full Text Available At present a great attention is paid to increasing of energy efficiency at operated electrified urban transport. Perspective direction for increasing energy efficiency at that type of transport is the application of regenerative braking. For additional increasing of energy efficiency there were suggested the use of capacitive drive on tires of traction substation. One of the main task is the analysis of energy recovery application  with drive and without it.These analysis demonstrated that the calculation algorithms don’t allow in the full volume to carry out calculations of amount and cost of energy recovery without drive and with it. That is why we see the current interest to this topic. The purpose of work is to create methods of algorithms calculation for definite amount and cost of consumed, redundant and recovery energy of electrified urban transport due to definite regime of motion on wayside. There is algorithm developed, which allow to calculate amount and cost of consumed, redundant and recovery energy of electrified urban transport on wayside during the installation capacitive drive at traction substation. On the basis of developed algorithm for the definite regime of wagon motion of subway there were fulfilled the example of energy recovery amount and its cost calculation, among them with limited energy intensity drive, when there are 4 trains on wayside simultaneously.

Boomerang RG flows in M-theory with intermediate scaling

Science.gov (United States)

Donos, Aristomenis; Gauntlett, Jerome P.; Rosen, Christopher; Sosa-Rodriguez, Omar

2017-07-01

We construct novel RG flows of D=11 supergravity that asymptotically approach AdS 4 × S 7 in the UV with deformations that break spatial translations in the dual field theory. In the IR the solutions return to exactly the same AdS 4 × S 7 vacuum, with a renormalisation of relative length scales, and hence we refer to the flows as `boomerang RG flows'. For sufficiently large deformations, on the way to the IR the solutions also approach two distinct intermediate scaling regimes, each with hyperscaling violation. The first regime is Lorentz invariant with dynamical exponent z = 1 while the second has z = 5/2. Neither ofthe two intermediatescaling regimesare associatedwith exact hyperscaling violation solutions of D = 11 supergravity. The RG flow solutions are constructed using the four dimensional N = 2 STU gauged supergravity theory with vanishing gauge fields, but non-vanishing scalar and pseudoscalar fields. In the ABJM dual field theory the flows are driven by spatially modulated deformation parameters for scalar and fermion bilinear operators.

Econometric studies of urban population density: a survey.

Science.gov (United States)

Mcdonald, J F

1989-01-01

This paper presents the 1st reasonably comprehensive survey of empirical research of urban population densities since the publication of the book by Edmonston in 1975. The survey summarizes contributions to empirical knowledge that have been made since 1975 and points toward possible areas for additional research. The paper also provides a brief interpretative intellectual history of the topic. It begins with a personal overview of research in the field. The next section discusses econometric issues that arise in the estimation of population density functions in which density is a function only of a distance to the central business district of the urban area. Section 4 summarizes the studies of a single urban area that went beyond the estimation of simple distance-density functions, and Section 5 discusses studies that sought to explain the variations across urban areas in population density patterns. McDonald refers to the standard theory of urban population density throughout the paper. This basic model is presented in the textbook by Mills and Hamilton and it is assumed that the reader is familiar with the model.

Managing Disagreement: A Defense of "Regime Bias"

Science.gov (United States)

Sabl, Andrew

2011-02-01

Stein Ringen's theory of democratic purpose cannot do the work expected of it. Ringen's own criteria oscillate between being too vague to be useful (i.e. "freedom") or, when specified more fully, conflicting, so that almost all democracies will seem to be potentially at cross-purposes with themselves rather than their purposes or sub-purposes being mutually reinforcing. This reflects a bigger and more theoretical problem. Disagreement about the purpose of democracy is built into democracy itself. The whole point of many (perhaps all) of our democratic institutions is to arrive at conditionally legitimate decisions in spite of such disagreement. So-called regime bias, i.e. the tendency to assess democracies according to the form and stability of their institutions rather than their results or their ability to serve certain purposes, does not in fact arise from bias. It arises on the contrary from a determination to avoid the bias inherent in giving some-inevitably partisan-ideals of what democracies should do pride of place over others in a scheme of measurement or evaluation. And even a regime-based definition of democracy must itself make simplifying assumptions that elide possible normative controversies over how the democratic game is best played. Vindicating one's preferred set of democratic ideals against alternatives is a completely legitimate enterprise and lends richness to debates within and across democracies. But it is an inherently ideological and political enterprise, not a neutral or scholarly one.

Characterizing multistationarity regimes in biochemical reaction networks.

Directory of Open Access Journals (Sweden)

Irene Otero-Muras

Full Text Available Switch like responses appear as common strategies in the regulation of cellular systems. Here we present a method to characterize bistable regimes in biochemical reaction networks that can be of use to both direct and reverse engineering of biological switches. In the design of a synthetic biological switch, it is important to study the capability for bistability of the underlying biochemical network structure. Chemical Reaction Network Theory (CRNT may help at this level to decide whether a given network has the capacity for multiple positive equilibria, based on their structural properties. However, in order to build a working switch, we also need to ensure that the bistability property is robust, by studying the conditions leading to the existence of two different steady states. In the reverse engineering of biological switches, knowledge collected about the bistable regimes of the underlying potential model structures can contribute at the model identification stage to a drastic reduction of the feasible region in the parameter space of search. In this work, we make use and extend previous results of the CRNT, aiming not only to discriminate whether a biochemical reaction network can exhibit multiple steady states, but also to determine the regions within the whole space of parameters capable of producing multistationarity. To that purpose we present and justify a condition on the parameters of biochemical networks for the appearance of multistationarity, and propose an efficient and reliable computational method to check its satisfaction through the parameter space.

Integrated approaches to long-term studies of urban ecological systems

Science.gov (United States)

Nancy B. Grimm; J. Morgan Grove; Steward T.A. Pickett; Charles L. Redman

2000-01-01

Urban ecological systems present multiple challenges to ecologists—pervasive human impact and extreme heterogeneity of cities, and the need to integrate social and ecological approaches, concepts, and theory.

State Structure and Political Regime Structure

Directory of Open Access Journals (Sweden)

Paul – Iulian Nedelcu

2012-05-01

Full Text Available The political regime is the concrete form of organization and functioning of political system andtherefore, the regime means the concrete way of organize, institutionalize and function a political systemand of the exercise of political power by a social-political force in a social community or global socialistem. The political regime is not limited to institutions and state bodies, but it covers the entire politicalsystem. Form of expression in social practice plan is the result of balance of forces between classes ofcitizens, organizations, between them and civil society and politics.Designates the concrete form ofgovernment formation and organization, of state bodies, in aspect of their characteristics and principles, therelations between them and other state bodies, and also as the relationship between them and otherinstitutionalized forms of political systems. Instead, the political regime is an explicit realization ofaxiological operations, a specific hierarchy of values, in general and political values, in particular. Even ifsome elements of the political regime overlap to some extent and in some respects, those of form orstructure of guvernamnt state, thus they dissolve his identity, distinct quality of being specific traits of thepolitical regime.

Analytic theory of the gyrotron

International Nuclear Information System (INIS)

Lentini, P.J.

1989-06-01

An analytic theory is derived for a gyrotron operating in the linear gain regime. The gyrotron is a coherent source of microwave and millimeter wave radiation based on an electron beam emitting at cyclotron resonance Ω in a strong, uniform magnetic field. Relativistic equations of motion and first order perturbation theory are used. Results are obtained in both laboratory and normalized variables. An expression for cavity threshold gain is derived in the linear regime. An analytic expression for the electron phase angle in momentum space shows that the effect of the RF field is to form bunches that are equal to the unperturbed transit phase plus a correction term which varies as the sine of the input phase angle. The expression for the phase angle is plotted and bunching effects in and out of phase (0 and -π) with respect to the RF field are evident for detunings leading to gain and absorption, respectively. For exact resonance, field frequency ω = Ω, a bunch also forms at a phase of -π/2. This beam yields the same energy exchange with the RF field as an unbunched, (nonrelativistic) beam. 6 refs., 10 figs

Military Authoritarian Regimes and Economic Development: The ROK’s Economic Take-Off Under Park Chung Hee

Science.gov (United States)

2008-12-01

and the Personalization of Power in Malaysia ," Comparative Politics 36, no. 1 (Oct. 2003), 81-101. 2 Talcott Parsons, Theories of Society...BAIR (bureaucratic-authoritarian industrializing regime).21 The annual growth rate of HPAEs eight countries (Hong Kong, Indonesia, Japan, Malaysia ...industries, and finally Samsung Electronics, POSCO, Daewoo shipbuilding, Hyundai Heavy were developed.58

Planificarea urbană între coerența unității și gestionarea diferențelor

Directory of Open Access Journals (Sweden)

Elena Maria MINEA

2007-12-01

Full Text Available City plans are grounded in analysis of local condition and contain a vision of an urban future that the citizens, local elected officials, planning staff and consultants consider desirable. Urban plans vary greatly in approach, content, sophistication, comprehensiveness, time frame and format. In the first half of the twentieth century, urban planning was elitist and paid little attention to implementation. Planning theory was focused on how to create stable cities, geared to a static world and based on a similar system of rules. During this period the planners were free from political interference. Planners actually work with neighborhood residents, local elected officials, interest groups and private developers. Planners negotiate, mediate, resolve conflicts and serve like diplomats. We must accept and study an approach to urban planning that recognizes that different groups compete in the planning process. What makes urban planning so fascinating is the variety of issues planning theory and practice must confront. Issues of aesthetics, design, economic feasibility, decision-making theory, conflict resolution and sustainability are just some of the core concerns which planning must confront in the twenty-first century.

Totalitäre Regimes

OpenAIRE

Merkel, Wolfgang

2004-01-01

"The development of the term and the analytical concept of totalitarianism have gone through several stages since the 1920s. However, even in its most sophisticated form, the version seen in Friedrich/ Brzezinski, the concept exhibits substantial systematic classification problems and analytical weaknesses. This article attempts to frame the type of totalitarian regime within a general typology of political regimes. Special attention is dedicated to the problem of distinguishing autocra...

Mass corrections in string theory and lattice field theory

International Nuclear Information System (INIS)

Del Debbio, Luigi; Kerrane, Eoin; Russo, Rodolfo

2009-01-01

Kaluza-Klein (KK) compactifications of higher-dimensional Yang-Mills theories contain a number of 4-dimensional scalars corresponding to the internal components of the gauge field. While at tree level the scalar zero modes are massless, it is well known that quantum corrections make them massive. We compute these radiative corrections at 1 loop in an effective field theory framework, using the background field method and proper Schwinger-time regularization. In order to clarify the proper treatment of the sum over KK modes in the effective field theory approach, we consider the same problem in two different UV completions of Yang-Mills: string theory and lattice field theory. In both cases, when the compactification radius R is much bigger than the scale of the UV completion (R>>√(α ' ), a), we recover a mass renormalization that is independent of the UV scale and agrees with the one derived in the effective field theory approach. These results support the idea that the value of the mass corrections is, in this regime, universal for any UV completion that respects locality and gauge invariance. The string analysis suggests that this property holds also at higher loops. The lattice analysis suggests that the mass of the adjoint scalars appearing in N=2, 4 super Yang-Mills is highly suppressed, even if the lattice regularization breaks all supersymmetries explicitly. This is due to an interplay between the higher-dimensional gauge invariance and the degeneracy of bosonic and fermionic degrees of freedom.

'CANDLE' burnup regime after LWR regime

International Nuclear Information System (INIS)

Sekimoto, Hiroshi; Nagata, Akito

2008-01-01

CANDLE (Constant Axial shape of Neutron flux, nuclide densities and power shape During Life of Energy producing reactor) burnup strategy can derive many merits. From safety point of view, the change of excess reactivity along burnup is theoretically zero, and the core characteristics, such as power feedback coefficients and power peaking factor, are not changed along burnup. Application of this burnup strategy to neutron rich fast reactors makes excellent performances. Only natural or depleted uranium is required for the replacing fuels. About 40% of natural or depleted uranium undergoes fission without the conventional reprocessing and enrichment. If the LWR produced energy of X Joules, the CANDLE reactor can produce about 50X Joules from the depleted uranium left at the enrichment facility for the LWR fuel. If we can say LWRs have produced energy sufficient for full 20 years, we can produce the energy for 1000 years by using the CANDLE reactors with depleted uranium. We need not mine any uranium ore, and do not need reprocessing facility. The burnup of spent fuel becomes 10 times. Therefore, the spent fuel amount per produced energy is also reduced to one-tenth. The details of the scenario of CANDLE burnup regime after LWR regime will be presented at the symposium. (author)

Urban lifestyle and urban biodiversity

DEFF Research Database (Denmark)

Petersen, L. K.; Lyytimäki, J.; Normander, B.

2007-01-01

This report is concerned with the relations between lifestyles of urban populations on one hand and protection of biodiversity in urban areas on the other. Urban areas are of importance for the general protection of biodiversity. In the surroundings of cities and within urban sprawls there can...... biodiversity, recreational, educational and other needs. However, uncovered and unsealed space is constantly under pressure for building and infrastructure development in the urban landscape, and the design and usages of urban green structure is a matter of differing interests and expectations. Integrating...... the green needs of urban lifestyle in the planning process does not come by itself. Nor does finding the synergies between urban lifestyle and urban biodiversity. Careful planning including stakeholder involvement is required. In this process various mapping techniques and use of indicators can be most...

Babinet's principle in the Fresnel regime studied using ultrasound

Science.gov (United States)

Hitachi, Akira; Takata, Momo

2010-07-01

The diffraction of ultrasound by a circular disk and an aperture of the same size has been investigated as a demonstration of Babinet's principle in the Fresnel regime. The amplitude and the phase of the diffracted ultrasonic waves are measured and a graphical treatment of the results is performed by drawing vectors in the complex plane. The results verify Babinet's principle. It is also found that the incident wave is π /2 behind the phase of the wave passing through on the central axis of a circular aperture. Because both waves travel the same path and the same distance, they should be in phase. This paradox has previously been regarded as a defect of Fresnel's theory.

Behind School Doors: The Impact of Hostile Racial Climates on Urban Teachers of Color

Science.gov (United States)

Kohli, Rita

2018-01-01

Despite recruitment efforts, teachers of Color are underrepresented and leaving the teaching force at faster rates than their White counterparts. Using Critical Race Theory to analyze and present representative qualitative narratives from 218 racial justice-oriented, urban teachers of color, this article affirms that urban schools--despite serving…

Is Urban Planning in Australia Hindered by Poor Metropolitan Governance?

Directory of Open Access Journals (Sweden)

Paul Burton

2017-11-01

Full Text Available There are many calls for urban planning in Australia to be reformed, although often in contradictory ways. For example, some argue it should be capable of delivering greater certainty to developers while others call for more flexibility in processes of urban development regulation; some would like to roll back its regulatory impact while others argue for a renewal of planning’s commitment to promoting social and spatial justice. The Australian planning system is also held to be hindered by a comparative lack of planning at and for the metropolitan scale. This is connected to the absence of well-developed structures of metropolitan governance in what is a three-tier federal system, with most power over planning concentrated at the State and Territory government scale. The paper explores this putative hindrance by considering three important issues in Australian urban policy debates about the efficacy of contemporary multi-level governance arrangements: spatial scale; identity and legitimacy; and efficiency and effectiveness. It includes some analysis of the case made for a more explicit and rigorous national urban policy and how this might relate to lower level planning regimes. The paper focuses on recent urban policy and planning initiatives in South East Queensland, one of Australia’s fastest growing metropolitan regions, and concludes that while incremental but nonetheless significant improvements in planning policy and practice are possible, these are unlikely to satisfy those calling for more radical changes to improve the Australian planning system.

Urban niche dynamics of Kaifeng city%开封市的城市生态位变化分析

Institute of Scientific and Technical Information of China (English)

丁圣彦; 李志恒

2007-01-01

Niche theory is one of the most important ecological theories. It is widely applied to analyzing such phenomena as competition among, and evolution of, urban ecosystem functional modules. This paper describes a study concerningdifferent functional modules of Kaifeng city urban ecosystem. Niche theory and techniques were used to analyze the changes of these functional modules in the period 1994-2003. The results showed that, in the period 1994-2003: (1) Niche value of the atmospheric environment and urban virescence modules increased, while niche value of the water environment and sound environment modules decreased; (2) niche value of the tertiary industry module increased, niche value of the secondary industry module decreased, while niche value of the primary industry module showed little change; and (3) niche value of the infrastructure, resource distribution, and production & social security modules increased, while niche value of the population module decreased. This study may contribute to macroscopic planning of urban functional modules,economic development, and environmental protection.

Supply regimes in fisheries

DEFF Research Database (Denmark)

Nielsen, Max

2006-01-01

Supply in fisheries is traditionally known for its backward bending nature, owing to externalities in production. Such a supply regime, however, exist only for pure open access fisheries. Since most fisheries worldwide are neither pure open access, nor optimally managed, rather between the extremes......, the traditional understanding of supply regimes in fisheries needs modification. This paper identifies through a case study of the East Baltic cod fishery supply regimes in fisheries, taking alternative fisheries management schemes and mesh size limitations into account. An age-structured Beverton-Holt based bio......-economic supply model with mesh sizes is developed. It is found that in the presence of realistic management schemes, the supply curves are close to vertical in the relevant range. Also, the supply curve under open access with mesh size limitations is almost vertical in the relevant range, owing to constant...

Can additional urban development have major impacts on streamflow of a peri-urban catchment? A case study from Portugal

Science.gov (United States)

Ferreira, Carla; Walsh, Rory; Nunes, João; Steenhuis, Tammo; de Lima, João; Coelho, Celeste; Ferreira, António

2016-04-01

- and post- additional urban development periods. Response time to rainfall reduced from 60-75 minutes to 40 minutes and recession time fell from 21.3-29.5 h to 7.4-8.7 h, respectively. The relatively low runoff and storm runoff coefficients given the extent of urban land-use is due to the dispersed urban pattern and movement of at least part of the overland flow from impervious surfaces into pervious soils (within urban areas and/or downslope woodland and abandoned fields). High soil permeability, linked to the sandstone and limestone bedrock, favours the establishment of water sinks. The additional extension of observed urban development during the study period, however, also included partial routing of overland flow from additional impervious surfaces into the stream network, enhancing flow connectivity, thus, increasing storm runoff and providing quicker hydrologic response. Urban planning should consider the landscape mosaic of peri-urban areas in order to maximize water infiltration and minimize the impacts on streamflow regime and urban flooding.

URBAN REVITALIZATION AND SEATTLE CRIME, 1982-2000.

Science.gov (United States)

Kreager, Derek A; Lyons, Christopher J; Hays, Zachary R

2011-11-01

This study examines the relationship between crime and processes of urban revitalization, or gentrification. Drawing on recent urban demography research, we hypothesize that gentrification progressed rapidly in many American cities over the last decade of the 20 th century, and that these changes had implications for area crime rates. Criminological theories hold competing hypotheses for the connections between gentrification and crime, and quantitative studies of this link remain infrequent and limited. Using two measures of gentrification and longitudinal tract-level demographic and crime data for the city of Seattle, we find that many of Seattle's downtown tracts underwent rapid revitalization during the 1990's, and that these areas 1) saw reductions in crime relative to similar tracts that did not gentrify, and 2) were areas with higher-than-average crime at the beginning of the decade. Moreover, using a within-tract longitudinal design, we find that yearly housing investments in the 1980's showed a modest positive association with crime change, while yearly investments in the 1990's showed the opposite pattern. Our findings suggest a curvilinear gentrification-crime relationship, whereby gentrification in its earlier stages is associated with small increases in crime, but gentrification in its more consolidated form is associated with modest crime declines. Implications of these results for criminological theory, urban development, and broader crime patterns are discussed.

Particle linear theory on a self-gravitating perturbed cubic Bravais lattice

International Nuclear Information System (INIS)

Marcos, B.

2008-01-01

Discreteness effects are a source of uncontrolled systematic errors of N-body simulations, which are used to compute the evolution of a self-gravitating fluid. We have already developed the so-called ''particle linear theory''(PLT), which describes the evolution of the position of self-gravitating particles located on a perturbed simple cubic lattice. It is the discrete analogue of the well-known (Lagrangian) linear theory of a self-gravitating fluid. Comparing both theories permits us to quantify precisely discreteness effects in the linear regime. It is useful to develop the PLT also for other perturbed lattices because they represent different discretizations of the same continuous system. In this paper we detail how to implement the PLT for perturbed cubic Bravais lattices (simple, body, and face-centered) in a cubic simulation box. As an application, we will study the discreteness effects--in the linear regime--of N-body simulations for which initial conditions have been set up using these different lattices.

Stochastic dynamical models for ecological regime shifts

DEFF Research Database (Denmark)

Møller, Jan Kloppenborg; Carstensen, Jacob; Madsen, Henrik

the physical and biological knowledge of the system, and nonlinearities introduced here can generate regime shifts or enhance the probability of regime shifts in the case of stochastic models, typically characterized by a threshold value for the known driver. A simple model for light competition between...... definition and stability of regimes become less subtle. Ecological regime shifts and their modeling must be viewed in a probabilistic manner, particularly if such model results are to be used in ecosystem management....

Dispossessing Urbanization: Urban Marxism in the Face of the Problem of Primitive Accumulation

OpenAIRE

Piotr Juskowiak

2015-01-01

The article is a complex attempt to present the achievements of the broadly understood urban Marxism in the field of reinterpretation of the classic concept from the cards of Capital – “primitive accumulation”. Drawing on theories of such scholars as David Harvey (“accumulation by dispossession”) or Saskia Sassen (“expulsions”), the author points to the possible ways to operationalize the concept of “dispossessing urbanization”. Inspired by the theorizations of autonomist Marxists (Antonio Ne...

From the theory to practice: Five years of urban regeneration workshops

Directory of Open Access Journals (Sweden)

Raimundo Bambó-Naya

2018-05-01

Full Text Available The aim of this communication is to present the experience of four academic courses in the subject of Integrated Urban and Landscape Design, taught in the framework of the Master in Architecture of the School of Engineering and Architecture of the University of Zaragoza. It addresses urban regeneration interventions in vulnerable areas of the consolidated city with approaches to teaching innovation in the academic field and in the topic of user participation. The workshop methodology is explained in detail, paying more attention to the process followed than to the specific results of the workshop. The different stages of the process are presented: previous phase and selection of the study area, phase of analysis and diagnosis, phase of proposals, where a joint work is carried out with vision of action in the whole of the neighbourhood, and phase of presentation of the results to the Neighbours. Finally, some future challenges of this workshop are outlined.

The Colour of Skill: Contesting a Racialised Regime of Skill from the Experience of Recent Immigrants in Canada

Science.gov (United States)

Guo, Shibao

2015-01-01

This article contests a racialised skills regime in Canada. Canadian studies of the labour market transitions of skilled immigrants are analysed through the lens of critical race theory. The analysis shows that knowledge and skills of recent immigrants in Canada are racialised and materialised on the basis of ethnic and national origins. Skin…

Abelian Duality, Confinement, and Chiral-Symmetry Breaking in a SU(2) QCD-Like Theory

International Nuclear Information System (INIS)

Uensal, Mithat

2008-01-01

We analyze the vacuum structure of SU(2) QCD with multiple massless adjoint representation fermions formulated on a small spatial S 1 xR 3 . The absence of thermal fluctuations, and the fact that quantum fluctuations favor the vacuum with unbroken center symmetry in a weakly coupled regime, renders the interesting dynamics of these theories analytically calculable. Confinement and the generation of the mass gap in the gluonic sector are shown analytically. In this regime, theory exhibits confinement without continuous chiral-symmetry breaking. However, a flavor singlet chiral condensate (which breaks a discrete chiral symmetry) persists at arbitrarily small S 1 . Under certain reasonable assumptions, we show that the theory exhibits a zero temperature chiral phase transition in the absence of any change in spatial center symmetry realizations

Time varying moments, regime switch, and crisis warning: The birth-death process with changing transition probability

Science.gov (United States)

Tang, Yinan; Chen, Ping

2014-06-01

The sub-prime crisis in the U.S. reveals the limitation of diversification strategy based on mean-variance analysis. A regime switch and a turning point can be observed using a high moment representation and time-dependent transition probability. Up-down price movements are induced by interactions among agents, which can be described by the birth-death (BD) process. Financial instability is visible by dramatically increasing 3rd to 5th moments one-quarter before and during the crisis. The sudden rising high moments provide effective warning signals of a regime-switch or a coming crisis. The critical condition of a market breakdown can be identified from nonlinear stochastic dynamics. The master equation approach of population dynamics provides a unified theory of a calm and turbulent market.

School Vision of Learning: Urban Setting

Science.gov (United States)

Guy, Tiffany A.

2010-01-01

In this paper, the author develops her school vision of learning. She explains the theories she used to help develop the vision. The author then goes into detail on the methods she will use to make her vision for a school that prepares urban students for a successful life after high school. She takes into account all the stakeholders and how they…

Theory of Self-pulsing in Photonic Crystal Fano Lasers

DEFF Research Database (Denmark)

Rasmussen, Thorsten Svend; Yu, Yi; Mørk, Jesper

2017-01-01

-dispersive Fano mirror, the laser frequency and the threshold gain. The model is based upon a combination of conventional laser rate equations and coupled-mode theory. The dynamical model is used to demonstrate how the laser has two regimes of operation, continuous-wave output and self-pulsing, and these regimes......Laser self-pulsing was a phenomenon exclusive to macroscopic lasers until recently, where self-starting laser pulsation in a microscopic photonic crystal Fano laser was reported. In this paper a theoretical model is developed to describe the Fano laser, including descriptions of the highly...

Summary of the working group on FEL theory

International Nuclear Information System (INIS)

Pellegrini, C.

1984-01-01

The working group on FEL theory dedicated most of its discussions to topics relevant to the high gain regime in a free electron laser. In addition the area of interest was mainly restricted to FELs for the production of XUV radiation (<1000 A). A list of the topics that were felt to be relevant is: (1) characterization of the FEL high gain regime; (2) the amplified spontaneous emission mode of operation (ASE); (3) superradiance in FELs; (4) diffraction effects for high gain FELs; (5) noise and start-up; (6) coherence properties of the radiation for the ASE and superradiant FELS. 9 references

Summary of the working group on FEL theory

Energy Technology Data Exchange (ETDEWEB)

Pellegrini, C.

1984-01-01

The working group on FEL theory dedicated most of its discussions to topics relevant to the high gain regime in a free electron laser. In addition the area of interest was mainly restricted to FELs for the production of XUV radiation (<1000 A). A list of the topics that were felt to be relevant is: (1) characterization of the FEL high gain regime; (2) the amplified spontaneous emission mode of operation (ASE); (3) superradiance in FELs; (4) diffraction effects for high gain FELs; (5) noise and start-up; (6) coherence properties of the radiation for the ASE and superradiant FELS. 9 references.

Loschmidt echo for local perturbations: non-monotonic cross-over from the Fermi-golden-rule to the escape-rate regime

International Nuclear Information System (INIS)

Goussev, Arseni; Waltner, Daniel; Richter, Klaus; Jalabert, Rodolfo A

2008-01-01

We address the sensitivity of quantum mechanical time evolution by considering the time decay of the Loschmidt echo (LE) (or fidelity) for local perturbations of the Hamiltonian. Within a semiclassical approach, we derive analytical expressions for the LE decay for chaotic systems for the whole range from weak to strong local perturbations and identify different decay regimes which complement those known for the case of global perturbations. For weak perturbations, a Fermi-golden-rule (FGR)-type behavior is recovered. For strong perturbations, the escape-rate regime is reached, where the LE decays exponentially with a rate independent of the perturbation strength. The transition between the FGR regime and the escape-rate regime is non-monotonic, i.e. the rate of the exponential time-decay of the LE oscillates as a function of the perturbation strength. We further perform extensive quantum mechanical calculations of the LE based on numerical wave packet evolution, which strongly support our semiclassical theory. Finally, we discuss in some detail possible experimental realizations for observing the predicted behavior of the LE

Multi-Criteria Sustainability Assessment of Urban Sludge Treatment Technologies

DEFF Research Database (Denmark)

An, Da; Xi, Beidou; Ren, Jingzheng

2017-01-01

to determine the weights of the criteria for sustainability assessment, and extension theory was used to prioritize the alternative technologies for the treatment of urban sewage sludge and grade their sustainability performances. An illustrative case including three technologies (compositing, incineration...

Basic formation and realization problems of urban policy

Directory of Open Access Journals (Sweden)

Skiba Alisa Anatol’evna

2014-04-01

Full Text Available The article focuses on the problems that arise in the process of urban development of areas planning, their solutions (improvement and transformation of settlement system, in which case we should base on the new geopolitical situation in the country, the development and modernization of transport and communication infrastructure, where it is necessary to consider both the internal needs of the state and external ones in order to think about possible ways of problem solutions in major cities, as well as the main directions of urban development reforms. The main objectives of the urban development policy are the development of social and economic level of small towns, activities for the conservation of historical, cultural and natural heritage of Russia, the use of modern theories of urban planning, the development of research in this area (both abstract and applied, conducting statistical base of urban development activities. The authors describe the schemes of entry into long-term ownership of land under the current system of urban regulation and the system based on zoning, which acts in real estate market conditions. Among other things, the article offers an idea of the method of socio-controlled planning, which supposes the development plans of the city's buildings and areas, different urban systems (based on the analysis of the existing problems and the needs that must be met.

Admittance measurements in the quantum Hall effect regime

Energy Technology Data Exchange (ETDEWEB)

Hernández, C., E-mail: carlos.hernandezr@unimilitar.edu.co [Departamento de Física, Universidad Militar Nueva Granada, Carrera 11 # 101-80, Bogotá D.C. (Colombia); Laboratorio de Magnetismo, Departamento de Física, Universidad de los Andes, A.A. 4976, Bogotá D.C. (Colombia); Consejo, C.; Chaubet, C. [Laboratoire Charles Coulomb L2C, Université Montpellier II, Pl. E. Bataillon, 34095 Montpellier Cedex 5 (France)

2014-11-15

In this work we present an admittance study of a two-dimensional electron gas (2DEG) in the quantum Hall effect (QHE) regime. We have studied several Hall bars in different contacts configurations in the frequency range 100 Hz–1 MHz. Our interpretation is based on the Landauer–Büttiker theory and takes into account both the capacitance and the topology of the coaxial cables which are connected to the sample holder. We show that we always observe losses through the capacitive impedance of the coaxial cables, except in the two contacts configuration in which the cable capacitance does not influence the admittance measurement of the sample. In this case, we measure the electrochemical capacitance of the 2DEG and show its dependence with the filling factor ν.

A numerical assessment of rough surface scattering theories. I - Horizontal polarization. II - Vertical polarization

Science.gov (United States)

Rodriguez, Ernesto; Kim, Yunjin; Durden, Stephen L.

1992-01-01

A numerical evaluation is presented of the regime of validity for various rough surface scattering theories against numerical results obtained by employing the method of moments. The contribution of each theory is considered up to second order in the perturbation expansion for the surface current. Considering both vertical and horizontal polarizations, the unified perturbation method provides best results among all theories weighed.

Language development in rural and urban Russian-speaking children with and without developmental language disorder.

Science.gov (United States)

Kornilov, Sergey A; Lebedeva, Tatiana V; Zhukova, Marina A; Prikhoda, Natalia A; Korotaeva, Irina V; Koposov, Roman A; Hart, Lesley; Reich, Jodi; Grigorenko, Elena L