Modeling of Reverberation Effects for Radio Localization and Communications
DEFF Research Database (Denmark)
Steinböck, Gerhard
2013-01-01
a recently proposed approach, we transcribe these models to electromagnetics and validate them experimentally following a systematic procedure. These transcribed models provide accurate predictions of the delay power spectrum in a typical office environment. Furthermore, they can predict changes...... into a distance dependent model of the delay power spectrum, which we then validate experimentally. From this model we derive secondary models that predict the received power, the mean delay, the rms delay spread and the kurtosis versus distance. The behavior of the diffuse component versus distance in indoor...... environment is linked to reverberation effects analog to reverberation effects observed in room acoustics and electromagnetic reverberation chambers. Reverberation models of room acoustics relate the decay rate of the diffuse component to the room geometry and an average absorption coefficient. Following...
Modeling the effects of local climate change on crop acreage
Directory of Open Access Journals (Sweden)
Hyunok Lee
2016-01-01
Full Text Available The impacts of climate change on agriculture depend on local conditions and crops grown. For instance, warmer winter temperatures in a given area would reduce chill hours, potentially cutting yields for some crops but extending the growing season for others. Using a century of climate data and six decades of acreage data, we established quantitative economic relationships between the evolution of local climate and acreage of 12 important crops in Yolo County. We then used the historical trend in climate change to project future crop acreages in the county. Only marginal changes in acreage in 2050 were projected for tree and vine crops there, in part because chill hours, although lower, remained above critical values. Walnuts were the most vulnerable tree crop, and the projections indicated some cultivars might be marginal in years with particularly warm winters. Processing tomato acreage might increase, due to a longer growing season, and also alfalfa acreage, if water availability and other factors remain constant.
Commuter Effects on Local Labour Markets: A German Modelling Study
Russo, G.; Tedeschi, F.; Reggiani, A.; Nijkamp, P.
2014-01-01
This paper offers an exploratory investigation of the effects of inbound commuter flows on employment in regional labour markets in Germany. For this purpose, the paper distinguishes three main channels that may transmit the effects concerned: a crowding-out mechanism and two labour demand
International Nuclear Information System (INIS)
Vasconcelos Dos Santos, R.J.; Coutinho, S.
1995-01-01
The effect of a local field acting on decorating classical D-vector bond spins of an antiferromagnetic Ising model on the square lattice is studied for both the annealed isotropic and the axial decorated cases. In both models the effect on the phase diagrams of the transversal and the longitudinal components of the local field acting on the decorating spins are fully analyzed and discussed
Directory of Open Access Journals (Sweden)
Henk van Arkel
2007-10-01
Full Text Available In poor regions, lack of local monetary circulation is one of the key elements causing underdevelopment. The more incoming money is passed from hand to hand, the more the local economy will be stimulated. However, in most poor areas money is spent outside the community before circulating locally, reducing the effectiveness of money inflow dramatically.Development programs would increase their effectiveness if knowledge was available on how spending money could lead to optimized and prolonged local circulation. To gain this knowledge a simulation tool will be created, which is able to analyze financial flows, to evaluate the potency of specific actions aimed on local development, and to monitor a development scheme during the execution phase.The basic model will be developed through a multi-agent approach, where each agent represents one (or more family/households belonging to one of several socio-economic groups. A Social Accounting Matrix (SAM of the local economy will be used as a basis to set up a spendings matrix for each agent, defining its spending priorities. Artificial Intelligence techniques will be used to give the agent the possibility to make decisions on how to satisfy these spending priorities. Also, social dynamics, the simulation of strategic planning behavior, learning, and exchange in limited networks will be addressed.The simulation application will consist of a common user interface allowing the user to “play” the simulation. This user interface layer will be “pluggable” with the underlying programming layer responsible for the calculations on the simulation, so that different plug-ins may be used for different simulation techniques.
Lee, Duncan; Rushworth, Alastair; Sahu, Sujit K
2014-06-01
Estimation of the long-term health effects of air pollution is a challenging task, especially when modeling spatial small-area disease incidence data in an ecological study design. The challenge comes from the unobserved underlying spatial autocorrelation structure in these data, which is accounted for using random effects modeled by a globally smooth conditional autoregressive model. These smooth random effects confound the effects of air pollution, which are also globally smooth. To avoid this collinearity a Bayesian localized conditional autoregressive model is developed for the random effects. This localized model is flexible spatially, in the sense that it is not only able to model areas of spatial smoothness, but also it is able to capture step changes in the random effects surface. This methodological development allows us to improve the estimation performance of the covariate effects, compared to using traditional conditional auto-regressive models. These results are established using a simulation study, and are then illustrated with our motivating study on air pollution and respiratory ill health in Greater Glasgow, Scotland in 2011. The model shows substantial health effects of particulate matter air pollution and nitrogen dioxide, whose effects have been consistently attenuated by the currently available globally smooth models. © 2014, The Authors Biometrics published by Wiley Periodicals, Inc. on behalf of International Biometric Society.
DEFF Research Database (Denmark)
Ruban, Andrei; Simak, S.I.; Shallcross, S.
2003-01-01
We present a simple effective tetrahedron model for local lattice relaxation effects in random metallic alloys on simple primitive lattices. A comparison with direct ab initio calculations for supercells representing random Ni0.50Pt0.50 and Cu0.25Au0.75 alloys as well as the dilute limit of Au-ri......-rich CuAu alloys shows that the model yields a quantitatively accurate description of the relaxtion energies in these systems. Finally, we discuss the bond length distribution in random alloys....
Brown, Jeremy M. C.; Currell, Fred J.
2017-01-01
A local effect model (LEM)-based framework capable of interpolating nanoparticle-enhanced photon-irradiated clonogenic cell survival fraction measurements as a function of nanoparticle concentration was developed and experimentally benchmarked for gold nanoparticle (AuNP)-doped bovine aortic endothelial cells (BAECs) under superficial kilovoltage X-ray irradiation. For three different superficial kilovoltage X-ray spectra, the BAEC survival fraction response was predicted for two different Au...
Size effects and strain localization in atomic-scale cleavage modeling
International Nuclear Information System (INIS)
Elsner, B A M; Müller, S
2015-01-01
In this work, we study the adhesion and decohesion of Cu(1 0 0) surfaces using density functional theory (DFT) calculations. An upper stress to surface decohesion is obtained via the universal binding energy relation (UBER), but the model is limited to rigid separation of bulk-terminated surfaces. When structural relaxations are included, an unphysical size effect arises if decohesion is considered to occur as soon as the strain energy equals the energy of the newly formed surfaces. We employ the nudged elastic band (NEB) method to show that this size effect is opposed by a size-dependency of the energy barriers involved in the transition. Further, we find that the transition occurs via a localization of bond strain in the vicinity of the cleavage plane, which resembles the strain localization at the tip of a sharp crack that is predicted by linear elastic fracture mechanics. (paper)
Empowering Effective STEM Role Models to Promote STEM Equity in Local Communities
Harte, T.; Taylor, J.
2017-12-01
Empowering Effective STEM Role Models, a three-hour training developed and successfully implemented by NASA Langley Research Center's Science Directorate, is an effort to encourage STEM professionals to serve as role models within their community. The training is designed to help participants reflect on their identity as a role model and provide research-based strategies to effectively engage youth, particularly girls, in STEM (science, technology, engineering, and mathematics). Research shows that even though girls and boys do not demonstrate a significant difference in their ability to be successful in mathematics and science, there is a significant difference in their confidence level when participating in STEM subject matter and pursuing STEM careers. The Langley training model prepares professionals to disrupt this pattern and take on the habits and skills of effective role models. The training model is based on other successful models and resources for role modeling in STEM including SciGirls; the National Girls Collaborative; and publications by the American Association of University Women and the National Academies. It includes a significant reflection component, and participants walk through situation-based scenarios to practice a focused suite of research-based strategies. These strategies can be implemented in a variety of situations and adapted to the needs of groups that are underrepresented in STEM fields. Underpinning the training and the discussions is the fostering of a growth mindset and promoting perseverance. "The Power of Yet" becomes a means whereby role models encourage students to believe in themselves, working toward reaching their goals and dreams in the area of STEM. To provide additional support, NASA Langley role model trainers are available to work with a champion at other organizations to facilitate the training. This champion helps recruit participants, seeks leadership buy-in, and helps provide valuable insights for needs and
Directory of Open Access Journals (Sweden)
Sayyed Mohammad Ali Alamolhodaei
2015-03-01
Full Text Available The internationalization of small and medium size businesses is regarded as one of the most leading general policies in many of the world’s countries. The reason is that it is often the small and medium size companies which have a vital role in industrial innovation and gain profit for their societies through economic development. This research has investigated and identified the effective factors (organizational factors and business etiquette in Islam on entering into international markets by presenting local Islamic model in the companies of incubator of Science and Technology Park. The statistical population of the research includes the existing companies of Incubator of Mashhad Science and Technology Park. The statistical sample was investigated through simple random sampling from managers of active companies in export in Science and Technology Park. AMOS and SPSS software were applied for data analysis to identify the effects among variables survey research methodology and questionnaire tools were used.
Elsässer, Thilo
Exposure to radiation of high-energy and highly charged ions (HZE) causes a major risk to human beings, since in long term space explorations about 10 protons per month and about one HZE particle per month hit each cell nucleus (1). Despite the larger number of light ions, the high ionisation power of HZE particles and its corresponding more complex damage represents a major hazard for astronauts. Therefore, in order to get a reasonable risk estimate, it is necessary to take into account the entire mixed radiation field. Frequently, neoplastic cell transformation serves as an indicator for the oncogenic potential of radiation exposure. It can be measured for a small number of ion and energy combinations. However, due to the complexity of the radiation field it is necessary to know the contribution to the radiation damage of each ion species for the entire range of energies. Therefore, a model is required which transfers the few experimental data to other particles with different LETs. We use the Local Effect Model (LEM) (2) with its cluster extension (3) to calculate the relative biological effectiveness (RBE) of neoplastic transformation. It was originally developed in the framework of hadrontherapy and is applicable for a large range of ions and energies. The input parameters for the model include the linear-quadratic parameters for the induction of lethal events as well as for the induction of transformation events per surviving cell. Both processes of cell inactivation and neoplastic transformation per viable cell are combined to eventually yield the RBE for cell transformation. We show that the Local Effect Model is capable of predicting the RBE of neoplastic cell transformation for a broad range of ions and energies. The comparison of experimental data (4) with model calculations shows a reasonable agreement. We find that the cluster extension results in a better representation of the measured RBE values. With this model it should be possible to better
The effect of local/topical analgesics on incisional pain in a pig model
Directory of Open Access Journals (Sweden)
Castel D
2017-09-01
Full Text Available David Castel,1 Itai Sabbag,2 Sigal Meilin3 1The Neufeld Cardiac Research Institute, Sheba Medical Centre, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, 2Lahav Research Institute, Kibutz Lahav, Negev, 3Neurology R&D Division, MD Biosciences, Nes-Ziona, Israel Abstract: Interest in the development of new topical/local drug administration for blocking pain at peripheral sites, with maximum drug activity and minimal systemic effects, is on the rise. In the review article by Kopsky and Stahl, four critical barriers in the process of research and development of topical analgesics were indicated. The active pharmaceutical ingredient (API and the formulation are among the major challenges. The road to the development of such drugs passes through preclinical studies. These studies, if planned correctly, should serve as guidance for choosing the right API and formulation. Although rodent models for pain continue to provide valuable data on the mechanisms driving pain, their use in developing topical and localized treatment approaches is limited for technical (intraplate injection area is small as well as mechanical reasons (non-similarity to human skin and innervation. It has been previously shown that pigs are comparable to humans in ways that make them a better choice for evaluating topical and local analgesics. The aim of this study was to summarize several experiments that used pigs for testing postoperative pain in an incisional pain model (skin incision [SI] and skin and muscle incision [SMI]. At the end of the surgery, the animals were treated with different doses of bupivacaine solution (Marcaine®, bupivacaine liposomal formulation (Exparel® or ropivacaine solution (Naropin. Von Frey testing demonstrated a decrease in the animals’ sensitivity to mechanical stimulation expressed as an increase in the withdrawal force following local treatment. These changes reflect the clinical condition in the level as well as in the duration of
Modeling of liquid–gas meniscus for textured surfaces: effects of curvature and local slip length
International Nuclear Information System (INIS)
Gaddam, Anvesh; Garg, Mayank; Agrawal, Amit; Joshi, Suhas S
2015-01-01
Surface texturing at the micro/nanolevel allows air to be trapped in sufficiently small cavities, thereby reducing the flow resistance over the surface in the laminar regime. The nature of the liquid–gas meniscus plays an important role in defining the boundary condition and it depends on the flow conditions and geometrical properties of textures. In the present work, we employ the unsteady volume of fluid model to investigate the behavior of the liquid–gas meniscus for ridges arranged normal to the flow direction to substantiate the frictional resistance of flow in a microchannel. It is found that the assumption of ‘zero shear stress’ at the liquid–gas interface grossly overpredicts the effective slip length with meniscus curvature and local partial slip length playing the dominant role. Numerical simulations performed in the laminar regime (20 < Re < 120) over single layered ridges normal to the flow direction revealed the effect of texture geometry on the reduction in pressure drop. In single layered structures, lotus-like geometries exhibited a greater reduction in drag (more than 30%) when compared to all other texture geometries. It is recognized that the flow experiences expansion and contraction cycles as it flows over the transverse ridges increasing the frictional resistance. Our findings will help to modify the boundary condition at the liquid–gas meniscus for accurate modeling in the laminar regime and to optimize the texture geometry to improve drag reduction. (paper)
Reich, Felix A.; Rickert, Wilhelm; Müller, Wolfgang H.
2018-03-01
This study investigates the implications of various electromagnetic force models in macroscopic situations. There is an ongoing academic discussion which model is "correct," i.e., generally applicable. Often, gedankenexperiments with light waves or photons are used in order to motivate certain models. In this work, three problems with bodies at the macroscopic scale are used for computing theoretical model-dependent predictions. Two aspects are considered, total forces between bodies and local deformations. By comparing with experimental data, insight is gained regarding the applicability of the models. First, the total force between two cylindrical magnets is computed. Then a spherical magnetostriction problem is considered to show different deformation predictions. As a third example focusing on local deformations, a droplet of silicone oil in castor oil is considered, placed in a homogeneous electric field. By using experimental data, some conclusions are drawn and further work is motivated.
Scholz, M; The Physics of Quantum Electronics
2004-01-01
The physical and biological basis of our model to calculate the biological effects of charged particles, termed local effect model (LEM), has been recently questioned in a commentary by R. Katz. Major objections were related to the definition of the target size and the use of the term cross section. Here we show that the objections raised against our approach are unjustified and largely based on serious misunderstandings of the conceptual basis of the local effect model. Furthermore, we show that the approach developed by Katz and coworkers itself suffers from exactly those deficiencies, for which Katz criticises our model. The essential conceptual differences between the two models are discussed by means of some illustrative examples, based on a comparison with experimental data. For these examples, the predictions of the LEM model are fully consistent with the experimental data. Contrarily, e.g. for very heavy ions there are significant discrepancies observed for the Katz approach. These discrepancies can b...
The effects of local insulin application to lumbar spinal fusions in a rat model.
Koerner, John D; Yalamanchili, Praveen; Munoz, William; Uko, Linda; Chaudhary, Saad B; Lin, Sheldon S; Vives, Michael J
2013-01-01
The rates of pseudoarthrosis after a single-level spinal fusion have been reported up to 35%, and the agents that increase the rate of fusion have an important role in decreasing pseudoarthrosis after spinal fusion. Previous studies have analyzed the effects of local insulin application to an autograft in a rat segmental defect model. Defects treated with a time-released insulin implant had significantly more new bone formation and greater quality of bone compared with controls based on histology and histomorphometry. A time-released insulin implant may have similar effects when applied in a lumbar spinal fusion model. This study analyzes the effects of a local time-released insulin implant applied to the fusion bed in a rat posterolateral lumbar spinal fusion model. Our hypothesis was twofold: first, a time-released insulin implant applied to the autograft bed in a rat posterolateral lumbar fusion will increase the rate of successful fusion and second, will alter the local environment of the fusion site by increasing the levels of local growth factors. Animal model (Institutional Animal Care and Use Committee approved) using 40 adult male Sprague-Dawley rats. Forty skeletally mature Sprague-Dawley rats weighing approximately 500 g each underwent posterolateral intertransverse lumbar fusions with iliac crest autograft from L4 to L5 using a Wiltse-type approach. After exposure of the transverse processes and high-speed burr decortication, a Linplant (Linshin Canada, Inc., ON, Canada) consisting of 95% microrecrystalized palmitic acid and 5% bovine insulin (experimental group) or a sham implant consisting of only palmitic acid (control group) was implanted on the fusion bed with iliac crest autograft. As per the manufacturer, the Linplant has a release rate of 2 U/day for a minimum of 40 days. The transverse processes and autograft beds of 10 animals from the experimental and 10 from the control group were harvested at Day 4 and analyzed for growth factors. The
Alleman, Coleman N.; Foulk, James W.; Mota, Alejandro; Lim, Hojun; Littlewood, David J.
2018-02-01
The heterogeneity in mechanical fields introduced by microstructure plays a critical role in the localization of deformation. To resolve this incipient stage of failure, it is therefore necessary to incorporate microstructure with sufficient resolution. On the other hand, computational limitations make it infeasible to represent the microstructure in the entire domain at the component scale. In this study, the authors demonstrate the use of concurrent multiscale modeling to incorporate explicit, finely resolved microstructure in a critical region while resolving the smoother mechanical fields outside this region with a coarser discretization to limit computational cost. The microstructural physics is modeled with a high-fidelity model that incorporates anisotropic crystal elasticity and rate-dependent crystal plasticity to simulate the behavior of a stainless steel alloy. The component-scale material behavior is treated with a lower fidelity model incorporating isotropic linear elasticity and rate-independent J2 plasticity. The microstructural and component scale subdomains are modeled concurrently, with coupling via the Schwarz alternating method, which solves boundary-value problems in each subdomain separately and transfers solution information between subdomains via Dirichlet boundary conditions. In this study, the framework is applied to model incipient localization in tensile specimens during necking.
Czech Academy of Sciences Publication Activity Database
Kafka, Vratislav
2011-01-01
Roč. 56, č. 4 (2011), s. 343-358 ISSN 0001-7043 R&D Projects: GA ČR(CZ) GA103/09/2101 Institutional research plan: CEZ:AV0Z20710524 Keywords : crack propagation * nonlocal effect * deviatoric local effect * isotropic nonlocal Subject RIV: BM - Solid Matter Physics ; Magnetism
Construction of exact constants of motion and effective models for many-body localized systems
Goihl, M.; Gluza, M.; Krumnow, C.; Eisert, J.
2018-04-01
One of the defining features of many-body localization is the presence of many quasilocal conserved quantities. These constants of motion constitute a cornerstone to an intuitive understanding of much of the phenomenology of many-body localized systems arising from effective Hamiltonians. They may be seen as local magnetization operators smeared out by a quasilocal unitary. However, accurately identifying such constants of motion remains a challenging problem. Current numerical constructions often capture the conserved operators only approximately, thus restricting a conclusive understanding of many-body localization. In this work, we use methods from the theory of quantum many-body systems out of equilibrium to establish an alternative approach for finding a complete set of exact constants of motion which are in addition guaranteed to represent Pauli-z operators. By this we are able to construct and investigate the proposed effective Hamiltonian using exact diagonalization. Hence, our work provides an important tool expected to further boost inquiries into the breakdown of transport due to quenched disorder.
Directory of Open Access Journals (Sweden)
Pichai Aree
2005-07-01
Full Text Available The transfer-function block-diagram model of single-machine infinite-bus power system has been a popular analytical tool amongst power engineers for explaining and assessing synchronous generator dynamic behaviors. In previous studies, the effects of local load together with damper circuit on generator damping have not yet been addressed because neither of them was integrated into this model. Since the model only accounts for the generator main field circuit, it may not always yield a realistic damping assessment due to lack of damper circuit representation. This paper presents an extended transfer-function block-diagram model, which includes one of the q-axis damper circuits as well as local load. This allows a more realistic investigation of the local load effect on the generator damping. The extended model is applied to assess thegenerator dynamic performance. The results show that the damping power components mostly derived from the q-axis damper and the field circuits can be improved according to the local load. The frequency response method is employed to carry out the fundamental analysis.
A simple model for localized-itinerant magnetic systems: crystal field effects
International Nuclear Information System (INIS)
Iannarella, L.; Silva, X.A. da; Guimarares, A.P.
1989-01-01
The magnetic behavior of a system consisting of localized electrons coupled to conduction electrons and submitted to an axial crystral field at T=0 K is ivestigated within the framework of the molecular field approximation. An analytical ionic magnetic state equation is deduced; it shows how the magnetization depends on the model parameters (exchange, crystal field, band occupation) and external magnetic field. A condition for the onset of spontaneous magnetic order is obtained and the ferro - and paramagnetic phases are studied. This study displays several features of real magnetic systems, including quenching or total suppression of the magnetic moments (depending on the relative value of the crystal field parameter) and exchange enhacement. The relevance of such model for the description of rare-earth intermetallic compounds is discussed. (author) [pt
Quantifying the effects of LUCCs on local temperatures, precipitation, and wind using the WRF model.
Lian, Lishu; Li, Baofu; Chen, Yaning; Chu, Cuicui; Qin, Yanhua
2017-09-11
Land use/cover changes (LUCCs) are an important cause of regional climate changes, but the contribution of LUCCs to regional climate changes is not clear. In this study, the Weather Research and Forecasting (WRF) model and statistical methods were used to investigate changes in meteorologic variables in January, April, July, and October 2013 due to local LUCCs from 1990 to 2010 in southern Shandong province, China. The results indicate that the WRF model simulates temperatures in the region well, with high correlation coefficients (0.86-0.97, p wind speed and direction substantially during these four months: average wind speeds increased by 0.02 and 0.01 m/s in January and October, respectively, and decreased by 0.02 and 0.05 m/s in April and July, respectively. Overall, The LUCCs affected spring temperatures the least and summer precipitation the most.
MODELING OF THERMOELECTRIC SYSTEM FOR LOCAL THERMAL EFFECTS ON HUMAN FOREARM ZONE
Directory of Open Access Journals (Sweden)
T. A. Ismailov
2013-01-01
Full Text Available In this paper we consider a model of the thermoelectric system for the thermal effect on the human forearm. The model is implemented on the basis of numerical solution of differentialequations of heat conduction for bodies of complex configuration. Two-dimensional and onedimensional graphs of the temperature change in different zones of the object of exposure aregiven.
Pauley, Penelope; Matthews, Brya G; Wang, Liping; Dyment, Nathaniel A; Matic, Igor; Rowe, David W; Kalajzic, Ivo
2014-09-01
Osteogenesis imperfecta is a serious genetic disorder that results from improper type I collagen production. We aimed to evaluate whether bone marrow stromal cells (BMSC) delivered locally into femurs were able to engraft, differentiate into osteoblasts, and contribute to formation of normal bone matrix in the osteogenesis imperfect murine (oim) model. Donor BMSCs from bone-specific reporter mice (Col2.3GFP) were expanded in vitro and transplanted into the femoral intramedullary cavity of oim mice. Engraftment was evaluated after four weeks. We detected differentiation of donor BMSCs into Col2.3GFP+ osteoblasts and osteocytes in cortical and trabecular bone of transplanted oim femurs. New bone formation was detected by deposition of dynamic label in the proximity to the Col2.3GFP+ osteoblasts, and new bone showed more organized collagen structure and expression of type I α2 collagen. Col2.3GFP cells were not found in the contralateral femur indicating that transplanted osteogenic cells did not disseminate by circulation. No osteogenic engraftment was observed following intravenous transplantation of BMSCs. BMSC cultures derived from transplanted femurs showed numerous Col2.3GFP+ colonies, indicating the presence of donor progenitor cells. Secondary transplantation of cells recovered from recipient femurs and expanded in vitro also showed Col2.3GFP+ osteoblasts and osteocytes confirming the persistence of donor stem/progenitor cells. We show that BMSCs delivered locally in oim femurs are able to engraft, differentiate into osteoblasts and osteocytes and maintain their progenitor potential in vivo. This suggests that local delivery is a promising approach for introduction of autologous MSC in which mutations have been corrected.
A simple localized-itinerant model for PrAl3: crystal field and exchange effects
International Nuclear Information System (INIS)
Ranke, P.J. von; Palermo, L.
1990-01-01
We present a simple magnetic model for PrAl sub(3). The effects of crystal field are treated using a reduced set of levels and the corresponding wave functions are extracted from the actual crystal field levels of Pr sup(+3) in a hexagonal symmetry. The exchange between 4f- and conduction electrons are dealt within a molecular field approximation. An analytical magnetic state equation is derived and the magnetic behaviour discussed. The parameters of the model are estimated from a fitting of the inverse susceptibility of PrAl sub(3) given in the literature. (author)
Numerical aspects of the modelling of the local effects of a high level waste repository
International Nuclear Information System (INIS)
Ferreri, J.C.; Ventura, M.A.
1985-01-01
The numerical approximations adapted for the development of the computational models for the prediction of the effects of the emplacement of a high level waste repository are reviewed. The problems considered include: the thermal history of the rocky mass constituting the burial media, the flow of underground water and the associated migration of radionuclides in the same media. Results associated with verification of the implemented codes are presented. Their limitations and advantages are discussed. (Author) [es
Badde, Stephanie; Heed, Tobias; Röder, Brigitte
2016-04-01
To act upon a tactile stimulus its original skin-based, anatomical spatial code has to be transformed into an external, posture-dependent reference frame, a process known as tactile remapping. When the limbs are crossed, anatomical and external location codes are in conflict, leading to a decline in tactile localization accuracy. It is unknown whether this impairment originates from the integration of the resulting external localization response with the original, anatomical one or from a failure of tactile remapping in crossed postures. We fitted probabilistic models based on these diverging accounts to the data from three tactile localization experiments. Hand crossing disturbed tactile left-right location choices in all experiments. Furthermore, the size of these crossing effects was modulated by stimulus configuration and task instructions. The best model accounted for these results by integration of the external response mapping with the original, anatomical one, while applying identical integration weights for uncrossed and crossed postures. Thus, the model explained the data without assuming failures of remapping. Moreover, performance differences across tasks were accounted for by non-individual parameter adjustments, indicating that individual participants' task adaptation results from one common functional mechanism. These results suggest that remapping is an automatic and accurate process, and that the observed localization impairments in touch result from a cognitively controlled integration process that combines anatomically and externally coded responses.
International Nuclear Information System (INIS)
Kijanka, P; Radecki, R; Packo, P; Staszewski, W J; Uhl, T
2013-01-01
Temperature has a significant effect on Lamb wave propagation. It is important to compensate for this effect when the method is considered for structural damage detection. The paper explores a newly proposed, very efficient numerical simulation tool for Lamb wave propagation modelling in aluminum plates exposed to temperature changes. A local interaction approach implemented with a parallel computing architecture and graphics cards is used for these numerical simulations. The numerical results are compared with the experimental data. The results demonstrate that the proposed approach could be used efficiently to produce a large database required for the development of various temperature compensation procedures in structural health monitoring applications. (paper)
High-fidelity Modeling of Local Effects of Damage for Derated Offshore Wind Turbines
International Nuclear Information System (INIS)
Richards, Phillip W; Griffith, D Todd; Hodges, Dewey H
2014-01-01
Offshore wind power production is an attractive clean energy option, but the difficulty of access can lead to expensive and rare opportunities for maintenance. As part of the Structural Health and Prognostics Management (SHPM) project at Sandia National Laboratories, smart loads management (controls) are investigated for their potential to increase the fatigue life of offshore wind turbine rotor blades. Derating refers to altering the rotor angular speed and blade pitch to limit power production and loads on the rotor blades. High- fidelity analysis techniques like 3D finite element modeling (FEM) should be used alongside beam models of wind turbine blades to characterize these control strategies in terms of their effect to mitigate fatigue damage and extend life of turbine blades. This study will consider a commonly encountered damage type for wind turbine blades, the trailing edge disbond, and show how FEM can be used to quantify the effect of operations and control strategies designed to extend the fatigue life of damaged blades. The Virtual Crack Closure Technique (VCCT) will be used to post-process the displacement and stress results to provide estimates of damage severity/criticality and provide a means to estimate the fatigue life under a given operations and control strategy
High-fidelity Modeling of Local Effects of Damage for Derated Offshore Wind Turbines
Richards, Phillip W.; Griffith, D. Todd; Hodges, Dewey H.
2014-06-01
Offshore wind power production is an attractive clean energy option, but the difficulty of access can lead to expensive and rare opportunities for maintenance. As part of the Structural Health and Prognostics Management (SHPM) project at Sandia National Laboratories, smart loads management (controls) are investigated for their potential to increase the fatigue life of offshore wind turbine rotor blades. Derating refers to altering the rotor angular speed and blade pitch to limit power production and loads on the rotor blades. High- fidelity analysis techniques like 3D finite element modeling (FEM) should be used alongside beam models of wind turbine blades to characterize these control strategies in terms of their effect to mitigate fatigue damage and extend life of turbine blades. This study will consider a commonly encountered damage type for wind turbine blades, the trailing edge disbond, and show how FEM can be used to quantify the effect of operations and control strategies designed to extend the fatigue life of damaged blades. The Virtual Crack Closure Technique (VCCT) will be used to post-process the displacement and stress results to provide estimates of damage severity/criticality and provide a means to estimate the fatigue life under a given operations and control strategy.
New model. Local financing for local energy
International Nuclear Information System (INIS)
Detroy, Florent
2015-01-01
While evoking the case of the VMH Energies company in the Poitou-Charentes region, and indicating the difference between France and Germany in terms of wind and photovoltaic energy production potential, of number of existing local companies, and of citizen-based funding, this article shows that renewable energies could put the energy production financing in France into question again, with a more important participation of local communities and of their inhabitants. The author describes how the law on energy transition makes this possible, notably with the strengthening of citizen participation. The author evokes some French local experiments and the case of Germany where this participation is already very much developed
International Nuclear Information System (INIS)
Scott, B.R.
1995-01-01
Individuals who work at nuclear reactor facilities can be at risk for deterministic effects in the skin from exposure to discrete Β- and γ-emitting (ΒγE) sources (e.g., ΒγE hot particles) on the skin or clothing. Deterministic effects are non-cancer effects that have a threshold and increase in severity as dose increases (e.g., ulcer in skin). Hot ΒγE particles are 60 Co- or nuclear fuel-derived particles with diameters > 10 μm and < 3 mm and contain at least 3.7 kBq (0.1 μCi) of radioactivity. For such ΒγE sources on the skin, it is the beta component of the dose that is most important. To develop exposure limitation systems that adequately control exposure of workers to discrete ΒγE sources, models are needed for systems that adequately control exposure of workers to discrete ΒγE sources, models are needed for evaluating the risk of deterministic effects of localized Β irradiation of the skin. The purpose of this study was to develop dose-rate and irradiated-area dependent, response-surface models for evaluating risks of significant deterministic effects of localized irradiation of the skin by discrete ΒγE sources and to use modeling results to recommend approaches to limiting occupational exposure to such sources. The significance of the research results as follows: (1) response-surface models are now available for evaluating the risk of specific deterministic effects of localized irradiation of the skin; (2) modeling results have been used to recommend approaches to limiting occupational exposure of workers to Β radiation from ΒγE sources on the skin or on clothing; and (3) the generic irradiated-volume, weighting-factor approach to limiting exposure can be applied to other organs including the eye, the ear, and organs of the respiratory or gastrointestinal tract and can be used for both deterministic and stochastic effects
Energy Technology Data Exchange (ETDEWEB)
Scott, B.R.
1995-12-01
Individuals who work at nuclear reactor facilities can be at risk for deterministic effects in the skin from exposure to discrete {Beta}- and {gamma}-emitting ({Beta}{gamma}E) sources (e.g., {Beta}{gamma}E hot particles) on the skin or clothing. Deterministic effects are non-cancer effects that have a threshold and increase in severity as dose increases (e.g., ulcer in skin). Hot {Beta}{gamma}E particles are {sup 60}Co- or nuclear fuel-derived particles with diameters > 10 {mu}m and < 3 mm and contain at least 3.7 kBq (0.1 {mu}Ci) of radioactivity. For such {Beta}{gamma}E sources on the skin, it is the beta component of the dose that is most important. To develop exposure limitation systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for evaluating the risk of deterministic effects of localized {Beta} irradiation of the skin. The purpose of this study was to develop dose-rate and irradiated-area dependent, response-surface models for evaluating risks of significant deterministic effects of localized irradiation of the skin by discrete {Beta}{gamma}E sources and to use modeling results to recommend approaches to limiting occupational exposure to such sources. The significance of the research results as follows: (1) response-surface models are now available for evaluating the risk of specific deterministic effects of localized irradiation of the skin; (2) modeling results have been used to recommend approaches to limiting occupational exposure of workers to {Beta} radiation from {Beta}{gamma}E sources on the skin or on clothing; and (3) the generic irradiated-volume, weighting-factor approach to limiting exposure can be applied to other organs including the eye, the ear, and organs of the respiratory or gastrointestinal tract and can be used for both deterministic and stochastic effects.
International Nuclear Information System (INIS)
Sartori, E.; Schuler, W.
1992-01-01
Software and data for nuclear energy applications are acquired, tested and distributed by several information centres; in particular, relevant computer codes are distributed internationally by the OECD/NEA Data Bank (France) and by ESTSC and EPIC/RSIC (United States). This activity is coordinated among the centres and is extended outside the OECD area through an arrangement with the IAEA. This article proposes more specifically a scheme for acquiring, storing and distributing atmospheric tracer experiment data (ATE) required for verification of atmospheric dispersion models especially the most advanced ones including topographic effects and specific to the local and meso-scale. These well documented data sets will form a valuable complement to the set of atmospheric dispersion computer codes distributed internationally. Modellers will be able to gain confidence in the predictive power of their models or to verify their modelling skills. (au)
Malanotte-Rizzoli, Paola; Young, Roberta E.
1995-12-01
The primary objective of this paper is to assess the relative effectiveness of data sets with different space coverage and time resolution when they are assimilated into an ocean circulation model. We focus on obtaining realistic numerical simulations of the Gulf Stream system typically of the order of 3-month duration by constructing a "synthetic" ocean simultaneously consistent with the model dynamics and the observations. The model used is the Semispectral Primitive Equation Model. The data sets are the "global" Optimal Thermal Interpolation Scheme (OTIS) 3 of the Fleet Numerical Oceanography Center providing temperature and salinity fields with global coverage and with bi-weekly frequency, and the localized measurements, mostly of current velocities, from the central and eastern array moorings of the Synoptic Ocean Prediction (SYNOP) program, with daily frequency but with a very small spatial coverage. We use a suboptimal assimilation technique ("nudging"). Even though this technique has already been used in idealized data assimilation studies, to our knowledge this is the first study in which the effectiveness of nudging is tested by assimilating real observations of the interior temperature and salinity fields. This is also the first work in which a systematic assimilation is carried out of the localized, high-quality SYNOP data sets in numerical experiments longer than 1-2 weeks, that is, not aimed to forecasting. We assimilate (1) the global OTIS 3 alone, (2) the local SYNOP observations alone, and (3) both OTIS 3 and SYNOP observations. We assess the success of the assimilations with quantitative measures of performance, both on the global and local scale. The results can be summarized as follows. The intermittent assimilation of the global OTIS 3 is necessary to keep the model "on track" over 3-month simulations on the global scale. As OTIS 3 is assimilated at every model grid point, a "gentle" weight must be prescribed to it so as not to overconstrain
Efficient Iris Localization via Optimization Model
Directory of Open Access Journals (Sweden)
Qi Wang
2017-01-01
Full Text Available Iris localization is one of the most important processes in iris recognition. Because of different kinds of noises in iris image, the localization result may be wrong. Besides this, localization process is time-consuming. To solve these problems, this paper develops an efficient iris localization algorithm via optimization model. Firstly, the localization problem is modeled by an optimization model. Then SIFT feature is selected to represent the characteristic information of iris outer boundary and eyelid for localization. And SDM (Supervised Descent Method algorithm is employed to solve the final points of outer boundary and eyelids. Finally, IRLS (Iterative Reweighted Least-Square is used to obtain the parameters of outer boundary and upper and lower eyelids. Experimental result indicates that the proposed algorithm is efficient and effective.
Energy Technology Data Exchange (ETDEWEB)
Villani, Mattia, E-mail: villani@fi.infn.it [Sezione INFN di Firenze, Polo Scientifico Via Sansone 1, 50019, Sesto Fiorentino (Italy)
2014-06-01
We consider the Goode-Wainwright representation of the Szekeres cosmological models and calculate the Taylor expansion of the luminosity distance in order to study the effects of the inhomogeneities on cosmographic parameters. Without making a particular choice for the arbitrary functions defining the metric, we Taylor expand up to the second order in redshift for Family I and up to the third order for Family II Szekeres metrics under the hypotesis, based on observation, that local structure formation is over. In a conservative fashion, we also allow for the existence of a non null cosmological constant.
The local effects of ovarian diathermy in an ovine model of polycystic ovary syndrome.
Connolly, Fiona; Rae, Michael T; Butler, Mairead; Klibanov, Alexander L; Sboros, Vassilis; McNeilly, Alan S; Duncan, W Colin
2014-01-01
In order to develop a medical alternative to surgical ovarian diathermy (OD) in polycystic ovary syndrome (PCOS) more mechanistic information is required about OD. We therefore studied the cellular, molecular and vascular effects of diathermy on the ovary using an established ovine model of PCOS. Pregnant sheep were treated twice weekly with testosterone propionate (100 mg) from day 30-100 gestation. Their female offspring (n = 12) were studied during their second breeding season when the PCOS-like phenotype, with anovulation, is fully manifest. In one group (n = 4) one ovary underwent diathermy and it was collected and compared to the contralateral ovary after 24 hours. In another group a treatment PCOS cohort underwent diathermy (n = 4) and the ovaries were collected and compared to the control PCOS cohort (n = 4) after 5 weeks. Ovarian vascular indices were measured using contrast-enhanced ultrasound and colour Doppler before, immediately after, 24 hours and five weeks after diathermy. Antral follicles were assessed by immunohistochemistry and ovarian stromal gene expression by quantitative RT-PCR 24 hours and 5 weeks after diathermy. Diathermy increased follicular atresia (Povarian microvasculature (P = 0.05) but this was not seen at 24 hours. However 24 hours after diathermy there was a reduction in the stromal Doppler blood flow signal (Povarian resistance index (Povarian stromal blood flow with an increased ovarian artery resistance index associated with atresia of antral follicles.
The local effects of ovarian diathermy in an ovine model of polycystic ovary syndrome.
Directory of Open Access Journals (Sweden)
Fiona Connolly
Full Text Available In order to develop a medical alternative to surgical ovarian diathermy (OD in polycystic ovary syndrome (PCOS more mechanistic information is required about OD. We therefore studied the cellular, molecular and vascular effects of diathermy on the ovary using an established ovine model of PCOS. Pregnant sheep were treated twice weekly with testosterone propionate (100 mg from day 30-100 gestation. Their female offspring (n = 12 were studied during their second breeding season when the PCOS-like phenotype, with anovulation, is fully manifest. In one group (n = 4 one ovary underwent diathermy and it was collected and compared to the contralateral ovary after 24 hours. In another group a treatment PCOS cohort underwent diathermy (n = 4 and the ovaries were collected and compared to the control PCOS cohort (n = 4 after 5 weeks. Ovarian vascular indices were measured using contrast-enhanced ultrasound and colour Doppler before, immediately after, 24 hours and five weeks after diathermy. Antral follicles were assessed by immunohistochemistry and ovarian stromal gene expression by quantitative RT-PCR 24 hours and 5 weeks after diathermy. Diathermy increased follicular atresia (P<0.05 and reduced antral follicle numbers after 5 weeks (P<0.05. There was an increase in stromal CCL2 expression 24 hours after diathermy (P<0.01 but no alteration in inflammatory indices at 5 weeks. Immediately after diathermy there was increased microbubble transit time in the ovarian microvasculature (P = 0.05 but this was not seen at 24 hours. However 24 hours after diathermy there was a reduction in the stromal Doppler blood flow signal (P<0.05 and an increased ovarian resistance index (P<0.05 both of which persisted at 5 weeks (P<0.01; P<0.05. In the ovine model of PCOS, OD causes a sustained reduction in ovarian stromal blood flow with an increased ovarian artery resistance index associated with atresia of antral follicles.
Gauging Non-local Quark Models
International Nuclear Information System (INIS)
Broniowski, W.
1999-09-01
The gauge effective quark model with non-local interactions is considered. It is shown how this approach regularize the theory in such a way that the anomalies are preserved and charges are properly quantized. With non-local interactions the effective action is finite to all orders in the loop expansion and there is no need to introduce the quark momentum cut-off parameter
Local models of astrophysical discs
Latter, Henrik N.; Papaloizou, John
2017-12-01
Local models of gaseous accretion discs have been successfully employed for decades to describe an assortment of small-scale phenomena, from instabilities and turbulence, to dust dynamics and planet formation. For the most part, they have been derived in a physically motivated but essentially ad hoc fashion, with some of the mathematical assumptions never made explicit nor checked for consistency. This approach is susceptible to error, and it is easy to derive local models that support spurious instabilities or fail to conserve key quantities. In this paper we present rigorous derivations, based on an asympototic ordering, and formulate a hierarchy of local models (incompressible, Boussinesq and compressible), making clear which is best suited for a particular flow or phenomenon, while spelling out explicitly the assumptions and approximations of each. We also discuss the merits of the anelastic approximation, emphasizing that anelastic systems struggle to conserve energy unless strong restrictions are imposed on the flow. The problems encountered by the anelastic approximation are exacerbated by the disc's differential rotation, but also attend non-rotating systems such as stellar interiors. We conclude with a defence of local models and their continued utility in astrophysical research.
Treyssède, Fabien
2018-01-01
Understanding thermal effects on the vibration of local (cable-dominant) modes in multi-cable structures is a complicated task. The main difficulty lies in the modification by temperature change of cable tensions, which are then undetermined. This paper applies a finite element procedure to investigate the effects of thermal loads on the linear dynamics of prestressed self-weighted multi-cable structures. Provided that boundary conditions are carefully handled, the discretization of cables with nonlinear curved beam elements can properly represent the thermoelastic behavior of cables as well as their linearized dynamics. A three-step procedure that aims to replace applied pretension forces with displacement continuity conditions is used. Despite an increase in the computational cost related to beam rotational degrees of freedom, such an approach has several advantages. Nonlinear beam finite elements are usually available in commercial codes. The overall method follows a thermoelastic geometrically non-linear analysis and hereby includes the main sources of non-linearities in multi-cable structures. The effects of cable bending stiffness, which can be significant, are also naturally accounted for. The accuracy of the numerical approach is assessed thanks to an analytical model for the vibration of a single inclined cable under temperature change. Then, the effects of thermal loads are investigated for two cable bridges, highlighting how natural frequencies can be affected by temperature. Although counterintuitive, a reverse relative change of natural frequency may occur for certain local modes. This phenomenon can be explained by two distinct mechanisms, one related to the physics intrinsic to cables and the other related to the thermal deflection of the superstructure. Numerical results show that cables cannot be isolated from the rest of the structure and the importance of modeling the whole structure for a quantitative analysis of temperature effects on the
Gauge threshold corrections for local string models
International Nuclear Information System (INIS)
Conlon, Joseph P.
2009-01-01
We study gauge threshold corrections for local brane models embedded in a large compact space. A large bulk volume gives important contributions to the Konishi and super-Weyl anomalies and the effective field theory analysis implies the unification scale should be enhanced in a model-independent way from M s to RM s . For local D3/D3 models this result is supported by the explicit string computations. In this case the scale RM s comes from the necessity of global cancellation of RR tadpoles sourced by the local model. We also study D3/D7 models and discuss discrepancies with the effective field theory analysis. We comment on phenomenological implications for gauge coupling unification and for the GUT scale.
Non-local crystal plasticity model with intrinsic SSD and GND effects
Evers, L.P.; Brekelmans, W.A.M.; Geers, M.G.D.
2004-01-01
A strain gradient-dependent crystal plasticity approach is presented to model the constitutive behaviour of polycrystal FCC metals under large plastic deformation. In order to be capable of predicting scale dependence, the heterogeneous deformation-induced evolution and distribution of geometrically
Modeling the Effects of the Local Environment on a Received GNSS Signal
2012-12-18
fIF + fDm(t)) t+ φm) (3.5) rIF(t) ∈ C is now restated using a complex exponential instead of sine and cosine functions: rIF(t) = M(t)∑ m=0 Am(t)D(t− τm... Portugal , 2010, pp. 1480-1485. 35. F. Caron, E. Duflos, M. Davy, P. Vanheeghe, “Particle Filtering for Multipath Effects Reduction in Land Vehicule...GNSS Re- ceivers,” M.S. thesis, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Lisbon, Portugal , 2008. 45. J. Soubielle, I. Fijalkow, P
Energy Technology Data Exchange (ETDEWEB)
Mairani, A [University of Pavia, Department of Nuclear and Theoretical Physics, and INFN, via Bassi 6, 27100 Pavia (Italy); Brons, S; Parodi, K [Heidelberg Ion Beam Therapy Center and Department of Radiation Oncology, Im Neuenheimer Feld 450, 69120 Heidelberg (Germany); Cerutti, F; Ferrari, A; Sommerer, F [CERN, 1211 Geneva 23 (Switzerland); Fasso, A [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Kraemer, M; Scholz, M, E-mail: Andrea.Mairani@mi.infn.i [GSI Biophysik, Planck-Str. 1, D-64291 Darmstadt (Germany)
2010-08-07
Clinical Monte Carlo (MC) calculations for carbon ion therapy have to provide absorbed and RBE-weighted dose. The latter is defined as the product of the dose and the relative biological effectiveness (RBE). At the GSI Helmholtzzentrum fuer Schwerionenforschung as well as at the Heidelberg Ion Therapy Center (HIT), the RBE values are calculated according to the local effect model (LEM). In this paper, we describe the approach followed for coupling the FLUKA MC code with the LEM and its application to dose and RBE-weighted dose calculations for a superimposition of two opposed {sup 12}C ion fields as applied in therapeutic irradiations. The obtained results are compared with the available experimental data of CHO (Chinese hamster ovary) cell survival and the outcomes of the GSI analytical treatment planning code TRiP98. Some discrepancies have been observed between the analytical and MC calculations of absorbed physical dose profiles, which can be explained by the differences between the laterally integrated depth-dose distributions in water used as input basic data in TRiP98 and the FLUKA recalculated ones. On the other hand, taking into account the differences in the physical beam modeling, the FLUKA-based biological calculations of the CHO cell survival profiles are found in good agreement with the experimental data as well with the TRiP98 predictions. The developed approach that combines the MC transport/interaction capability with the same biological model as in the treatment planning system (TPS) will be used at HIT to support validation/improvement of both dose and RBE-weighted dose calculations performed by the analytical TPS.
Mairani, A; Kraemer, M; Sommerer, F; Parodi, K; Scholz, M; Cerutti, F; Ferrari, A; Fasso, A
2010-01-01
Clinical Monte Carlo (MC) calculations for carbon ion therapy have to provide absorbed and RBE-weighted dose. The latter is defined as the product of the dose and the relative biological effectiveness (RBE). At the GSI Helmholtzzentrum fur Schwerionenforschung as well as at the Heidelberg Ion Therapy Center (HIT), the RBE values are calculated according to the local effect model (LEM). In this paper, we describe the approach followed for coupling the FLUKA MC code with the LEM and its application to dose and RBE-weighted dose calculations for a superimposition of two opposed C-12 ion fields as applied in therapeutic irradiations. The obtained results are compared with the available experimental data of CHO (Chinese hamster ovary) cell survival and the outcomes of the GSI analytical treatment planning code TRiP98. Some discrepancies have been observed between the analytical and MC calculations of absorbed physical dose profiles, which can be explained by the differences between the laterally integrated depth-d...
Inference for local autocorrelations in locally stationary models.
Zhao, Zhibiao
2015-04-01
For non-stationary processes, the time-varying correlation structure provides useful insights into the underlying model dynamics. We study estimation and inferences for local autocorrelation process in locally stationary time series. Our constructed simultaneous confidence band can be used to address important hypothesis testing problems, such as whether the local autocorrelation process is indeed time-varying and whether the local autocorrelation is zero. In particular, our result provides an important generalization of the R function acf() to locally stationary Gaussian processes. Simulation studies and two empirical applications are developed. For the global temperature series, we find that the local autocorrelations are time-varying and have a "V" shape during 1910-1960. For the S&P 500 index, we conclude that the returns satisfy the efficient-market hypothesis whereas the magnitudes of returns show significant local autocorrelations.
International Nuclear Information System (INIS)
Boman, C.
1997-01-01
The decided phasing out of nuclear power and the goal of reducing CO 2 emissions from fossil fuels causes a substantial estimated increase in the use of biomass fuels for energy production. Thus, a significant shift from small scale heating generated by electricity or fuel oil to biomass fuels is desirable. If a drastic deterioration of the local air quality is to be avoided, a reduction of today's emission limits is necessary. The objective of this report was therefore to describe the use of biomass fuels and small scale pellet fuel combustion, to make a theoretical study of the effects of increased pellets heating on the air quality in a residential area, and to discuss necessary emission limits for small biomass fuel plants. The general description is based on literature studies. In the theoretical study, several different dispersion model calculations were performed using the computer program Dispersion 1.1.0. The contents of tar and total hydrocarbons (THC) in the air were calculated for different scenarios with conversion from electricity to pellets and with different pellet plant performance. A sensitivity analysis was performed with additional variables and dispersion calculations according to an underlying statistical experimental design. The modeling and design computer program MODDE was used to facilitate design, evaluation and illustration of the calculated results. The results show that a substantial increase in the use of small scale pellets heating with worst calculated plant performance, will lead to a drastic increase of the content of hydrocarbons in the air. Thus, with best available performance, the content only increases marginally. Conversion from electricity to pellets, plant performance and time of year were the most influential variables. Also conversion from wood to pellets showed a significant effect, despite the small number of wood heated houses within the studied area. If a significant deterioration of the air quality is to be avoided
Population genetics models of local ancestry.
Gravel, Simon
2012-06-01
Migrations have played an important role in shaping the genetic diversity of human populations. Understanding genomic data thus requires careful modeling of historical gene flow. Here we consider the effect of relatively recent population structure and gene flow and interpret genomes of individuals that have ancestry from multiple source populations as mosaics of segments originating from each population. This article describes general and tractable models for local ancestry patterns with a focus on the length distribution of continuous ancestry tracts and the variance in total ancestry proportions among individuals. The models offer improved agreement with Wright-Fisher simulation data when compared to the state-of-the art and can be used to infer time-dependent migration rates from multiple populations. Considering HapMap African-American (ASW) data, we find that a model with two distinct phases of "European" gene flow significantly improves the modeling of both tract lengths and ancestry variances.
Spencer, Kevin C; Sy, Jay C; Falcón-Banchs, Roberto; Cima, Michael J
2017-02-28
Glial scar formation remains a significant barrier to the long term success of neural probes. Micromotion coupled with mechanical mismatch between the probe and tissue is believed to be a key driver of the inflammatory response. In vitro glial scar models present an intermediate step prior to conventional in vivo histology experiments as they enable cell-device interactions to be tested on a shorter timescale, with the ability to conduct broader biochemical assays. No established in vitro models have incorporated methods to assess device performance with respect to mechanical factors. In this study, we describe an in vitro glial scar model that combines high-precision linear actuators to simulate axial micromotion around neural implants with a 3D primary neural cell culture in a collagen gel. Strain field measurements were conducted to visualize the local displacement within the gel in response to micromotion. Primary brain cell cultures were found to be mechanically responsive to micromotion after one week in culture. Astrocytes, as determined by immunohistochemical staining, were found to have significantly increased in cell areas and perimeters in response to micromotion compared to static control wells. These results demonstrate the importance of micromotion when considering the chronic response to neural implants. Going forward, this model provides advantages over existing in vitro models as it will enable critical mechanical design factors of neural implants to be evaluated prior to in vivo testing.
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).
Business Models for Local Foods
DEFF Research Database (Denmark)
Esbjerg, Lars; Pedersen, Maja; Pederson, Robert
2014-01-01
sales of food products (and vice versa) and therefore have to develop alternative marketing channels. The purpose of this paper is to investigate the practices of different small and medium-sized Danish producers of locally grown and/or processed foods in relation to developing marketing channels...
Zwolak, Pawel; Farei-Campagna, Jan; Jentzsch, Thorsten; von Rechenberg, Brigitte; Werner, Clément M
2018-01-01
Posterolateral spinal fusion is a common orthopaedic surgery performed to treat degenerative and traumatic deformities of the spinal column. In posteriolateral spinal fusion, different osteoinductive demineralized bone matrix products have been previously investigated. We evaluated the effect of locally applied zoledronic acid in combination with commercially available demineralized bone matrix putty on new bone formation in posterolateral spinal fusion in a murine in vivo model. A posterolateral sacral spine fusion in murine model was used to evaluate the new bone formation. We used the sacral spine fusion model to model the clinical situation in which a bone graft or demineralized bone matrix is applied after dorsal instrumentation of the spine. In our study, group 1 received decortications only (n = 10), group 2 received decortication, and absorbable collagen sponge carrier, group 3 received decortication and absorbable collagen sponge carrier with zoledronic acid in dose 10 µg, group 4 received demineralized bone matrix putty (DBM putty) plus decortication (n = 10), and group 5 received DBM putty, decortication and locally applied zoledronic acid in dose 10 µg. Imaging was performed using MicroCT for new bone formation assessment. Also, murine spines were harvested for histopathological analysis 10 weeks after surgery. The surgery performed through midline posterior approach was reproducible. In group with decortication alone there was no new bone formation. Application of demineralized bone matrix putty alone produced new bone formation which bridged the S1-S4 laminae. Local application of zoledronic acid to demineralized bone matrix putty resulted in significant increase of new bone formation as compared to demineralized bone matrix putty group alone. A single local application of zoledronic acid with DBM putty during posterolateral fusion in sacral murine spine model increased significantly new bone formation in situ in our model. Therefore, our
Local environment effects in disordered alloys
International Nuclear Information System (INIS)
Cable, J.W.
1978-01-01
The magnetic moment of an atom in a ferromagnetic disordered alloy depends on the local environment of that atom. This is particularly true for Ni and Pd based alloys for which neutron diffuse scattering measurements of the range and magnitude of the moment disturbances indicate that both magnetic and chemical environment are important in determining the moment distribution. In this paper we review recent neutron studies of local environment effects in Ni based alloys. These are discussed in terms of a phenomenological model that allows a separation of the total moment disturbance at a Ni site into its chemical and magnetic components
Energy Technology Data Exchange (ETDEWEB)
Mello, Alberto W.; Nicolas, Andrea [School of Aeronautics and Astronautics, Purdue University, 701 W. Stadium Ave, West Lafayette, IN 47907-2045 (United States); Lebensohn, Ricardo A. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Sangid, Michael D., E-mail: msangid@purdue.edu [School of Aeronautics and Astronautics, Purdue University, 701 W. Stadium Ave, West Lafayette, IN 47907-2045 (United States)
2016-04-20
Microstructure attributes are responsible for heterogeneous deformation and strain localization. In this study, the relation between residual strain fields and microstructure is examined and assessed by means of experiments and crystal plasticity modeling. The microstructure of rolled aluminum alloys (AA) in the 7050-T7451 condition was experimentally obtained with electron backscatter diffraction (EBSD) analysis along the rolling direction (L-T orientation), across the rolling direction (T-L orientation), and transverse to the rolling direction (T-S orientation). Each of these sections was also patterned using a novel microstamping procedure, to allow for strain mapping by digital image correlation (DIC). The measured microstructures were in turn used as input of an elasto-viscoplastic crystal plasticity formulation based on fast Fourier transforms (EVP-FFT). Comparisons between the strain maps obtained experimentally by the concurrent DIC-EBSD method and the EVP-FFT simulations were made for the three sections, corresponding to the initial textures. The comparisons showed that the predicted levels of strain concentration were reasonable for all three specimens from a statistical perspective, which is important to properly describe and predict the strains within an ensemble of components; however the spatial match with the actual strain fields needs improvement.
Directory of Open Access Journals (Sweden)
M Mozafari
2016-10-01
Full Text Available Introduction: Alzheimer’s disease is one of the most prevalent brain neurodegenerative diseases and the most common cognitive deficits are memory dysfunction and spatial perception impairment. Progesterone has a neorostroid action in hippocampal neurogenesis, synaptic stability and spatial learning and memory and has antioxidant effect. Since oxidative stress is involved in the pathogenesis of Alzheimer's disease, and conflicting results were reported about the effects of progesterone on therefore in Alzheimer’s, the present study investigated the effect of microinjection of three doses of progesterone on the process of spatial memory and lipid peroxidation and total peroxidation in the hippocampus in the experimental model of AD. Methods: 42 adult male Wistar rats weighting 250±50 g were randomly divided into six main groups (n=7: control group, sham group, Alzheimer’s model (intracerebroventricular injection of streptozotocin, Alzheimer model + progesterone (0.5, 1.5, 2µg/kg. 2 weeks after injection of streptozotocin (3 mg/kg, Alzheimer's was induced then progesterone injected in different doses. After termination of behavioral testing days, the hippocampus was removed to measure the levels of oxidative stress parameter to measure levels of oxidative stress parameters. Statistical analysis was performed using analysis of variance (ANOVA. Results: Results showed that intraventricular injection of STZ decreased spatial memory in comparison to control group (P<0.001. Administration progesterone significantly improved spatial memory in experimental models of Alzheimer's rats (P<0.001. MDA and SOD in all doses of progesterone showed a significant reduction compared to the AD animals (P<0.001. Conclusion: Progesterone can prevent a decrease in spatial learning and memory by reducing oxidative stress in the hippocampus of rats with Alzheimer's.
Energy Technology Data Exchange (ETDEWEB)
Schmitt, Nikolai [Inria, 2004 Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France); Technische Universitaet Darmstadt, Institut fuer Theorie Elektromagnetischer Felder (TEMF), Schlossgartenstr. 8, 64289 Darmstadt (Germany); Scheid, Claire [Inria, 2004 Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France); University of Nice – Sophia Antipolis, Mathematics laboratory, Parc Valrose, 06108 Nice, Cedex 02 (France); Lanteri, Stéphane, E-mail: Stephane.Lanteri@inria.fr [Inria, 2004 Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France); Moreau, Antoine [Institut Pascal, Université Blaise Pascal, 24, avenue des Landais, 63171 Aubière Cedex (France); Viquerat, Jonathan [Inria, 2004 Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France)
2016-07-01
The interaction of light with metallic nanostructures is increasingly attracting interest because of numerous potential applications. Sub-wavelength metallic structures, when illuminated with a frequency close to the plasma frequency of the metal, present resonances that cause extreme local field enhancements. Exploiting the latter in applications of interest requires a detailed knowledge about the occurring fields which can actually not be obtained analytically. For the latter mentioned reason, numerical tools are thus an absolute necessity. The insight they provide is very often the only way to get a deep enough understanding of the very rich physics at play. For the numerical modeling of light-structure interaction on the nanoscale, the choice of an appropriate material model is a crucial point. Approaches that are adopted in a first instance are based on local (i.e. with no interaction between electrons) dispersive models, e.g. Drude or Drude–Lorentz models. From the mathematical point of view, when a time-domain modeling is considered, these models lead to an additional system of ordinary differential equations coupled to Maxwell's equations. However, recent experiments have shown that the repulsive interaction between electrons inside the metal makes the response of metals intrinsically non-local and that this effect cannot generally be overlooked. Technological achievements have enabled the consideration of metallic structures in a regime where such non-localities have a significant influence on the structures' optical response. This leads to an additional, in general non-linear, system of partial differential equations which is, when coupled to Maxwell's equations, significantly more difficult to treat. Nevertheless, dealing with a linearized non-local dispersion model already opens the route to numerous practical applications of plasmonics. In this work, we present a Discontinuous Galerkin Time-Domain (DGTD) method able to solve the system
Crowley, D Max; Greenberg, Mark T; Feinberg, Mark E; Spoth, Richard L; Redmond, Cleve R
2012-02-01
A substantial challenge in improving public health is how to facilitate the local adoption of evidence-based interventions (EBIs). To do so, an important step is to build local stakeholders' knowledge and decision-making skills regarding the adoption and implementation of EBIs. One EBI delivery system, called PROSPER (PROmoting School-community-university Partnerships to Enhance Resilience), has effectively mobilized community prevention efforts, implemented prevention programming with quality, and consequently decreased youth substance abuse. While these results are encouraging, another objective is to increase local stakeholder knowledge of best practices for adoption, implementation and evaluation of EBIs. Using a mixed methods approach, we assessed local stakeholder knowledge of these best practices over 5 years, in 28 intervention and control communities. Results indicated that the PROSPER partnership model led to significant increases in expert knowledge regarding the selection, implementation, and evaluation of evidence-based interventions. Findings illustrate the limited programming knowledge possessed by members of local prevention efforts, the difficulty of complete knowledge transfer, and highlight one method for cultivating that knowledge.
Directory of Open Access Journals (Sweden)
Dong S
2013-10-01
Full Text Available Shengli Dong,1 Qibin Tang,2 Miaoyun Long,3 Jian Guan,4 Lu Ye,5 Gaopeng Li6 1Department of General Surgery, The Second Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi Province, 2Department of Hepatobiliopancreatic Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 3Department of Thyroid and Vascular Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 4Department of Radiology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 5Infection Department, Guangzhou No 8 Hospital, Guangzhou, Guangdong Province, 6Department of Ultrasound, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, People's Republic of China Background/aim: A local nanotherapy (LNT combining the therapeutic efficacy of trans-arterial embolization, nanoparticles, and p53 gene therapy has been previously presented. The study presented here aimed to further improve the incomplete tumor eradication and limited survival enhancement and to elucidate the molecular mechanism of the LNT. Methods: In a tumor-targeting manner, recombinant expressing plasmids harboring wild-type p53 and Rb were either co-transferred or transferred separately to rabbit hepatic VX2 tumors in a poly-L-lysine-modified hydroxyapatite nanoparticle nanoplex and Lipiodol® (Guerbet, Villepinte, France emulsion via the hepatic artery. Subsequent co-expression of p53 and Rb proteins within the treated tumors was investigated by Western blotting and in situ analysis by laser-scanning confocal microscopy. The therapeutic effect was evaluated by the tumor growth velocity, apoptosis and necrosis rates, their sensitivity to Adriamycin® (ADM, mitomycin C, and fluorouracil, the microvessel density of tumor tissue, and the survival time of animals. Eventually, real-time polymerase chain reaction and enhanced chemiluminescence Western blotting
Radioprotective effect of local hypothermia
International Nuclear Information System (INIS)
Hong, Seong-Su; Ogawa, Yoshihiro; Higano, Shuichi; Nakamura, Mamoru; Hoshino, Fumihiko
1985-01-01
We attempted local hypothermia to prevent radiation dermatitis and stomatitis. With regard to parasternal skin reactions postoperatively irradiated breast cancer, dry and moist desquamation, which occasionally occurred with conventional irradiation was not observed in combination with local cooling. As for head and neck tumors, patients who complained of stomatitis decreased with the local cooling, and no one wanted a pause in irradiation before 40 Gy. As local hypothermia is free from danger and does not require special equipment, it was considered to be widely applicable. (author)
Local discrete symmetries from superstring derived models
International Nuclear Information System (INIS)
Faraggi, A.E.
1996-10-01
Discrete and global symmetries play an essential role in many extensions of the Standard Model, for example, to preserve the proton lifetime, to prevent flavor changing neutral currents, etc. An important question is how can such symmetries survive in a theory of quantum gravity, like superstring theory. In a specific string model the author illustrates how local discrete symmetries may arise in string models and play an important role in preventing fast proton decay and flavor changing neutral currents. The local discrete symmetry arises due to the breaking of the non-Abelian gauge symmetries by Wilson lines in the superstring models and forbids, for example dimension five operators which mediate rapid proton decay, to all orders of nonrenormalizable terms. In the context of models of unification of the gauge and gravitational interactions, it is precisely this type of local discrete symmetries that must be found in order to insure that a given model is not in conflict with experimental observations
Ueberham, Maximilian; Hertel, Daniel; Schlink, Uwe
2017-04-01
Deeper knowledge about urban climate conditions is getting more important in the context of climate change, urban population growth, urban compaction and continued surface sealing. Especially the urban heat island effect (UHI) is one of the most significant human induced alterations of Earth's surface climate. According to this the appearance frequency of heat waves in cities will increase with deep impacts on personal thermal comfort, human health and local residential quality of citizens. UHI can be very heterogenic within a city and research needs to focus more on the neighborhood scale perspective to get further insights about the heat burden of individuals. However, up to now, few is known about local thermal environmental variances and personal exposure loads. To monitor these processes and the impact on individuals, improved monitoring approaches are crucial, complementing data recorded at conventional fixed stations. Therefore we emphasize the importance of micro-meteorological modelling and mobile measurements to shed new light on the nexus of urban human-climate interactions. Contributing to this research we jointly present the approaches of our two PhD-projects. Firstly we illustrate on the basis of an example site, how local thermal conditions in an urban district can be simulated and predicted by a micro-meteorological model. Secondly we highlight the potentials of personal exposure measurements based on an evaluation of mobile micro-sensing devices (MSDs) and analyze and explain differences between model predictions and mobile records. For the examination of local thermal conditions we calculated ENVI-met simulations within the "Bayerischer Bahnhof" quarter in Leipzig (Saxony, Germany; 51°20', 12°22'). To accomplish the maximum temperature contrasts within the diverse built-up structures we chose a hot summer day (25 Aug 2016) under autochthonous weather conditions. From these simulations we analyzed a UHI effect between the model core (urban area
Relativistic effects in local inertial frames including PPN effects
International Nuclear Information System (INIS)
Shahid-Saless, B.
1986-01-01
In this dissertation they use the concept of a generalized Fermi frame to describe the relativistic effects on a body placed in a local inertial frame of reference due to local and distant sources of gravitation. They have considered, in particular, a model, consisted of two spherically symmetric gravitating sources, moving in circular orbits around a common barycenter where one of the bodies is chosen to be the local and the other the distant one. This has been done in the Parametrized-Post-Newtonian formalism using the slow motion, weak field approximation. The PPN parameters used are γ, β, zeta 1 and zeta 2 . They show that the main relativistic effect on a local satellite is described by the Schwarzchild field of the local body and the nonlinear term corresponding to the self-interaction of the local source itself. There are also much smaller terms that are proportional to the product of the potentials of local and distant bodies and distant body's self interactions. The spatial axis of the local frame undergoes Geodetic precession. Effects involving the parameters zeta 1 and zeta 2 seem to be slightly too small to be observable at the present time. In addition they have found accelerations that vanish in the general relativity limit
Quark model and equivalent local potential
International Nuclear Information System (INIS)
Takeuchi, Sachiko; Shimizu, Kiyotaka
2002-01-01
In this paper, we investigate the short-range repulsion given by the quark cluster model employing an inverse scattering problem. We find that the local potential which reproduces the same phase shifts as those given by the quark cluster model has a strong repulsion at short distances in the NN 1 S 0 channel. There, however, appears an attractive pocket at very short distances due to a rather weak repulsive behavior at very high energy. This repulsion-attractive-pocket structure becomes more manifest in the channel which has an almost forbidden state, ΣN(T=3/2) 3 S 1 . In order to see what kinds of effects are important to reproduce the short-range repulsion in the quark cluster model, we investigate the contribution coming from the one-gluon-exchange potential and the normalization separately. It is clarified that the gluon exchange constructs the short-range repulsion in the NN 1 S 0 while the quark Pauli-blocking effect governs the feature of the repulsive behavior in the ΣN(T=3/2) 3 S 1 channel
Operating cost model for local service airlines
Anderson, J. L.; Andrastek, D. A.
1976-01-01
Several mathematical models now exist which determine the operating economics for a United States trunk airline. These models are valuable in assessing the impact of new aircraft into an airline's fleet. The use of a trunk airline cost model for the local service airline does not result in representative operating costs. A new model is presented which is representative of the operating conditions and resultant costs for the local service airline. The calculated annual direct and indirect operating costs for two multiequipment airlines are compared with their actual operating experience.
Local business models for district heat production; Kaukolaemmoen paikalliset liiketoimintamallit
Energy Technology Data Exchange (ETDEWEB)
Hakala, L.; Pesola, A.; Vanhanen, J.
2012-12-15
Local district heating business, outside large urban centers, is a profitable business in Finland, which can be practiced with several different business models. In addition to the traditional, local district heating business, local district heat production can be also based on franchising business model, on integrated service model or on different types of cooperation models, either between a local district heat producer and industrial site providing surplus heat or between a local district heat producer and a larger district heating company. Locally available wood energy is currently utilized effectively in the traditional district heating business model, in which a local entrepreneur produces heat to consumers in the local area. The franchising model is a more advanced version of the traditional district heating entrepreneurship. In this model, franchisor funds part of the investments, as well as offers centralized maintenance and fuel supply, for example. In the integrated service model, the local district heat producer offers also energy efficiency services and other value-added services, which are based on either the local district heat suppliers or his partner's expertise. In the cooperation model with industrial site, the local district heating business is based on the utilization of the surplus heat from the industrial site. In some cases, profitable operating model approach may be a district heating company outsourcing operations of one or more heating plants to a local entrepreneur. It can be concluded that all business models for district heat production (traditional district heat business model, franchising, integrated service model, cooperative model) discussed in this report can be profitable in Finnish conditions, as well for the local heat producer as for the municipality - and, above all, they produce cost-competitive heat for the end-user. All the models were seen as viable and interesting and having possibilities for expansion Finland
A NEW COMBINED LOCAL AND NON-LOCAL PBL MODEL FOR METEOROLOGY AND AIR QUALITY MODELING
A new version of the Asymmetric Convective Model (ACM) has been developed to describe sub-grid vertical turbulent transport in both meteorology models and air quality models. The new version (ACM2) combines the non-local convective mixing of the original ACM with local eddy diff...
Region effects influence local tree species diversity.
Ricklefs, Robert E; He, Fangliang
2016-01-19
Global patterns of biodiversity reflect both regional and local processes, but the relative importance of local ecological limits to species coexistence, as influenced by the physical environment, in contrast to regional processes including species production, dispersal, and extinction, is poorly understood. Failure to distinguish regional influences from local effects has been due, in part, to sampling limitations at small scales, environmental heterogeneity within local or regional samples, and incomplete geographic sampling of species. Here, we use a global dataset comprising 47 forest plots to demonstrate significant region effects on diversity, beyond the influence of local climate, which together explain more than 92% of the global variation in local forest tree species richness. Significant region effects imply that large-scale processes shaping the regional diversity of forest trees exert influence down to the local scale, where they interact with local processes to determine the number of coexisting species.
Locally Simple Models Construction: Methodology and Practice
Directory of Open Access Journals (Sweden)
I. A. Kazakov
2017-12-01
Full Text Available One of the most notable trends associated with the Fourth industrial revolution is a significant strengthening of the role played by semantic methods. They are engaged in artificial intelligence means, knowledge mining in huge flows of big data, robotization, and in the internet of things. Smart contracts also can be mentioned here, although the ’intelligence’ of smart contracts still needs to be seriously elaborated. These trends should inevitably lead to an increased role of logical methods working with semantics, and significantly expand the scope of their application in practice. However, there are a number of problems that hinder this process. We are developing an approach, which makes the application of logical modeling efficient in some important areas. The approach is based on the concept of locally simple models and is primarily focused on solving tasks in the management of enterprises, organizations, governing bodies. The most important feature of locally simple models is their ability to replace software systems. Replacement of programming by modeling gives huge advantages, for instance, it dramatically reduces development and support costs. Modeling, unlike programming, preserves the explicit semantics of models allowing integration with artificial intelligence and robots. In addition, models are much more understandable to general people than programs. In this paper we propose the implementation of the concept of locally simple modeling on the basis of so-called document models, which has been developed by us earlier. It is shown that locally simple modeling is realized through document models with finite submodel coverages. In the second part of the paper an example of using document models for solving a management problem of real complexity is demonstrated.
Rúa-Uribe, Guillermo L; Suárez-Acosta, Carolina; Chauca, José; Ventosilla, Palmira; Almanza, Rita
2013-09-01
Dengue fever is a major impact on public health vector-borne disease, and its transmission is influenced by entomological, sociocultural and economic factors. Additionally, climate variability plays an important role in the transmission dynamics. A large scientific consensus has indicated that the strong association between climatic variables and disease could be used to develop models to explain the incidence of the disease. To develop a model that provides a better understanding of dengue transmission dynamics in Medellin and predicts increases in the incidence of the disease. The incidence of dengue fever was used as dependent variable, and weekly climatic factors (maximum, mean and minimum temperature, relative humidity and precipitation) as independent variables. Expert Modeler was used to develop a model to better explain the behavior of the disease. Climatic variables with significant association to the dependent variable were selected through ARIMA models. The model explains 34% of observed variability. Precipitation was the climatic variable showing statistically significant association with the incidence of dengue fever, but with a 20 weeks delay. In Medellin, the transmission of dengue fever was influenced by climate variability, especially precipitation. The strong association dengue fever/precipitation allowed the construction of a model to help understand dengue transmission dynamics. This information will be useful to develop appropriate and timely strategies for dengue control.
International Nuclear Information System (INIS)
Gordon, J; Snyder, K; Zhong, H; Chetty, I
2014-01-01
Purpose: Dose-response models that can reliably predict radiation pneumonitis (RP) to guide radiation therapy (RT) for lung cancer presently do not exist. A model is proposed that incorporates non-local radiationinduced bystander effect (RIBE). Methods: A single sigmoid response function, derived from published data for whole lung irradiation, relates RP probability to cumulative lung damage, regardless of fractionation scheme. Lung damage is assumed to be caused by direct local radiation damage, quantified via the linear-quadratic (LQ) model, and RIBE. Based on published data, RIBE is assumed to be activated when per-fraction dose rises above ∼0.6 Gy, but is constant with dose above that threshold. Integral RIBE damage is assumed proportional to lung volume irradiated above ∼0.6 Gy per fraction. Key model parameters include LQ α and β, and two RIBE parameters: the single-fraction probability δ of damage, and a proportionality parameter κ that relates the potential for RIBE damage to irradiated lung volume. All parameters are tentatively fitted from published data, the RIBE parameters from published RP rates for conventionally fractionated RT (CFRT) and stereotactic body RT (SBRT). Results: The model predicts dose-response curves that are consistent with clinical experience. It provides a tentative explanation for why V20 (33 fractions), V13 (20 fractions) and V5 (<10 fractions) are observed to be correlated with RP. It also provides a plausible explanation for the success of SBRT — RIBE damage increases with the number of fractions, so penalizes CFRT relative to SBRT. Conclusion: The proposed model is relatively simple, extrapolates from published data, plausibly explains several clinical observations, and produces dose-response curves that are consistent with clinical experience. While capable of elaboration, its ability to explain doseresponse experience with different fractionation schemes using a small number of assumptions and parameters is an
Energy Technology Data Exchange (ETDEWEB)
Gordon, J; Snyder, K; Zhong, H; Chetty, I [Henry Ford Health System, Dept. Radiation Oncology, Detroit, MI (United States)
2014-06-01
Purpose: Dose-response models that can reliably predict radiation pneumonitis (RP) to guide radiation therapy (RT) for lung cancer presently do not exist. A model is proposed that incorporates non-local radiationinduced bystander effect (RIBE). Methods: A single sigmoid response function, derived from published data for whole lung irradiation, relates RP probability to cumulative lung damage, regardless of fractionation scheme. Lung damage is assumed to be caused by direct local radiation damage, quantified via the linear-quadratic (LQ) model, and RIBE. Based on published data, RIBE is assumed to be activated when per-fraction dose rises above ∼0.6 Gy, but is constant with dose above that threshold. Integral RIBE damage is assumed proportional to lung volume irradiated above ∼0.6 Gy per fraction. Key model parameters include LQ α and β, and two RIBE parameters: the single-fraction probability δ of damage, and a proportionality parameter κ that relates the potential for RIBE damage to irradiated lung volume. All parameters are tentatively fitted from published data, the RIBE parameters from published RP rates for conventionally fractionated RT (CFRT) and stereotactic body RT (SBRT). Results: The model predicts dose-response curves that are consistent with clinical experience. It provides a tentative explanation for why V20 (33 fractions), V13 (20 fractions) and V5 (<10 fractions) are observed to be correlated with RP. It also provides a plausible explanation for the success of SBRT — RIBE damage increases with the number of fractions, so penalizes CFRT relative to SBRT. Conclusion: The proposed model is relatively simple, extrapolates from published data, plausibly explains several clinical observations, and produces dose-response curves that are consistent with clinical experience. While capable of elaboration, its ability to explain doseresponse experience with different fractionation schemes using a small number of assumptions and parameters is an
Dissipative Continuous Spontaneous Localization (CSL) model.
Smirne, Andrea; Bassi, Angelo
2015-08-05
Collapse models explain the absence of quantum superpositions at the macroscopic scale, while giving practically the same predictions as quantum mechanics for microscopic systems. The Continuous Spontaneous Localization (CSL) model is the most refined and studied among collapse models. A well-known problem of this model, and of similar ones, is the steady and unlimited increase of the energy induced by the collapse noise. Here we present the dissipative version of the CSL model, which guarantees a finite energy during the entire system's evolution, thus making a crucial step toward a realistic energy-conserving collapse model. This is achieved by introducing a non-linear stochastic modification of the Schrödinger equation, which represents the action of a dissipative finite-temperature collapse noise. The possibility to introduce dissipation within collapse models in a consistent way will have relevant impact on the experimental investigations of the CSL model, and therefore also on the testability of the quantum superposition principle.
Local galactic kinematics: an isothermal model
International Nuclear Information System (INIS)
Nunez, J.
1983-01-01
The kinematical parameters of galactic rotation in the solar neighborhood and the corrections to the precession have been calculated. For this purpose, an isothermal model for the solar neighborhood has been used together with the high order momenta of the local stellar velocity distribution and the Ogorodnikov-Milne model. Both have been calculated using some samples of the ''512 Distant FK4/FK4 Sup. Stars'' of Fricke (1977) and of Gliese's Gatalogue. (author)
Global and local level density models
International Nuclear Information System (INIS)
Koning, A.J.; Hilaire, S.; Goriely, S.
2008-01-01
Four different level density models, three phenomenological and one microscopic, are consistently parameterized using the same set of experimental observables. For each of the phenomenological models, the Constant Temperature Model, the Back-shifted Fermi gas Model and the Generalized Superfluid Model, a version without and with explicit collective enhancement is considered. Moreover, a recently published microscopic combinatorial model is compared with the phenomenological approaches and with the same set of experimental data. For each nuclide for which sufficient experimental data exists, a local level density parameterization is constructed for each model. Next, these local models have helped to construct global level density prescriptions, to be used for cases for which no experimental data exists. Altogether, this yields a collection of level density formulae and parameters that can be used with confidence in nuclear model calculations. To demonstrate this, a large-scale validation with experimental discrete level schemes and experimental cross sections and neutron emission spectra for various different reaction channels has been performed
Localized endomorphisms of the chiral Ising model
International Nuclear Information System (INIS)
Boeckenhauer, J.
1994-07-01
In the frame of the treatment of the chiral Ising model by Mack and Schomerus, examples of localized endomorphisms ρ 1 loc and ρ 1/2 loc are presented. It is shown that they lead to the same superselection sectors as the global ones in the sense that π 0 oρ 1 log ≅π 1 and π 0 pρ 1/2 loc ≅π 1/2 holds. For proving the latter unitary equivalence, Arakis formalism of the selfdual CAR algebra is used. Further it is shown that the localized endomorphisms obey the Ising fusion rules. (orig.)
Modelling Danish local CHP on market conditions
DEFF Research Database (Denmark)
Ravn, Hans V.; Riisom, Jannik; Schaumburg-Müller, Camilla
2004-01-01
with the liberalisation process of the energy sectors of the EU countries, it is however anticipated that Danish local CHP are to begin operating on market conditions within the year 2005. This means that the income that the local CHPs previously gained from selling electricity at the feed-in tariff is replaced in part...... the consequences of acting in a liberalised market for a given CHP plant, based on the abovementioned bottom-up model. The key assumption determining the bottom line is the electricity spot price. The formation of the spot price in the Nordic area depends heavily upon the state of the water reservoirs in Norway...
Estimation and prediction under local volatility jump-diffusion model
Kim, Namhyoung; Lee, Younhee
2018-02-01
Volatility is an important factor in operating a company and managing risk. In the portfolio optimization and risk hedging using the option, the value of the option is evaluated using the volatility model. Various attempts have been made to predict option value. Recent studies have shown that stochastic volatility models and jump-diffusion models reflect stock price movements accurately. However, these models have practical limitations. Combining them with the local volatility model, which is widely used among practitioners, may lead to better performance. In this study, we propose a more effective and efficient method of estimating option prices by combining the local volatility model with the jump-diffusion model and apply it using both artificial and actual market data to evaluate its performance. The calibration process for estimating the jump parameters and local volatility surfaces is divided into three stages. We apply the local volatility model, stochastic volatility model, and local volatility jump-diffusion model estimated by the proposed method to KOSPI 200 index option pricing. The proposed method displays good estimation and prediction performance.
Davies, Julie; Sampson, Mark; Beesley, Frank; Smith, Debra; Baldwin, Victoria
2014-05-01
5 Boroughs Partnership NHS Foundation Trust, in the Northwest of England, has trained over 500 staff in the Knowledge and Understanding Framework, level 1 personality disorder awareness training. This is a 3-day nationally devised training programme delivered via an innovative co-production model (i.e. co-delivery and partnership working with service users who have lived experience). This paper provides quantitative and qualitative information on the effectiveness of training delivery and also serves to provide some insight into the impact of service-user involvement via such a co-production model. Information on 162 participants using the Knowledge and Understanding Framework bespoke questionnaire (Personality Disorder Knowledge, Attitudes and Skills Questionnaire) suggests that the training can be effectively delivered by and within a local NHS Mental Health Trust. Results immediately post-training suggest an improvement in levels of understanding and capability efficacy and a reduction in negative emotional reactions. Indications from a 3-month follow-up suggest that while understanding and emotional reaction remain improved, capability efficacy regresses back to pre-training levels, suggesting the need for ongoing supervision and/or support to consolidate skills. Discussion includes guidelines for the implementation of a truly integrated co-production model of training provision, as well as advice relating to the maximization of long-term benefits. Copyright © 2014 John Wiley & Sons, Ltd.
More about the comparison of local and non-local NN interaction models
International Nuclear Information System (INIS)
Amghar, A.; Desplanques, B.
2003-01-01
The effect of non-locality in the NN interaction with an off-energy shell character has been studied in the past in relation with the possibility that some models could be approximately phase-shifts equivalent. This work is extended to a non-locality implying terms that involve an anticommutator with the operator p 2 . It includes both scalar and tensor components. The most recent 'high accuracy' models are considered in the analysis. After studying the deuteron wave functions, electromagnetic properties of various models are compared with the idea that these ones differ by their non-locality but are equivalent up to a unitary transformation. It is found that the extra non-local tensor interaction considered in this work tends to re-enforce the role of the term considered in previous works, allowing one to explain almost completely the difference in the deuteron D-state probabilities evidenced by the comparison of the Bonn-QB and Paris models for instance. Conclusions for the effect of the non-local scalar interaction are not so clear. In many cases, it was found that these terms could explain part of the differences that the comparison of predictions for various models evidences but cases where they could not were also found. Some of these last ones have been analyzed in order to pointing out the origin of the failure
A local-world evolving hypernetwork model
International Nuclear Information System (INIS)
Yang Guang-Yong; Liu Jian-Guo
2014-01-01
Complex hypernetworks are ubiquitous in the real system. It is very important to investigate the evolution mechanisms. In this paper, we present a local-world evolving hypernetwork model by taking into account the hyperedge growth and local-world hyperedge preferential attachment mechanisms. At each time step, a newly added hyperedge encircles a new coming node and a number of nodes from a randomly selected local world. The number of the selected nodes from the local world obeys the uniform distribution and its mean value is m. The analytical and simulation results show that the hyperdegree approximately obeys the power-law form and the exponent of hyperdegree distribution is γ = 2 + 1/m. Furthermore, we numerically investigate the node degree, hyperedge degree, clustering coefficient, as well as the average distance, and find that the hypernetwork model shares the scale-free and small-world properties, which shed some light for deeply understanding the evolution mechanism of the real systems. (interdisciplinary physics and related areas of science and technology)
Localization effects in heavy ion collisions
International Nuclear Information System (INIS)
Donangelo, R.J.
1984-01-01
Radial and angular localization in heavy ion reactions on deformed nuclei is discussed. A theoretical method appropriate to study these localization effects is briefly described and then applied to the determination of deformed heavy ion potentials from inclastic scattering data. It is argued that one-and two-nucleon transfer reactions on deformed nuclei can provide a probe of nuclear structure in high angular momentum states and be at least qualitatively analyzed in the light of these localization concepts. (Author) [pt
Local effects of living windbreaks
International Nuclear Information System (INIS)
Souto, L.F.M.A.R.; Meneses, J.F.
2004-01-01
The primary purpose of living windbreaks is the reduction of the wind speed. Changes in the velocity and direction of airflow lead to changes in the microclimate. Microclimate is the result of various interacting factors, most of which can be affected by shelter at detectable levels. The effectiveness of windbreaks depends upon their internal and external structure. The most important structural feature is porosity. Maximum wind reductions are closely related to low porosity. However, barriers with low porosity generate more turbulence to leeward then medium or high ones. The horizontal extent of windbreak effects is proportional to windbreak height (h). Wind reductions are detectable on the windward side of the barrier from 2 h to 5 h, and extend to leeward about 20 h, if significant reductions of the normal wind speed (10% - 30%) occur. The principal effects of natural windbreaks on microclimate are reviewed. These are: wind speed, turbulence and their dependence on the porosity and height of the barrier; solar and thermal radiation around the windbreak; air temperature during the day and at night; humidity and snow deposition. Complementary effects of windbreaks are discussed, such as wind and hydraulic erosion, crop protection and plant growth, livestock protection of buildings and people. Disadvantages of windbreaks result from tree-crop competition and pests. Windbreaks allow the practice of agriculture in many regions of the world, namely on island and coastal areas, which are particularly sensitive due to the high wind speeds and salt content of the wind. Windbreaks contribute to sustainable agricultural systems by maintaining biological diversity and improving the aesthetic value of the landscape. A better understanding of their dynamics will certainly contribute to the improvement of sheltered areas and to the establishment of more efficient windbreaks, with less negative impacts to the countryside
The Thick Market Effect on Local Unemployment Rate Fluctuations
Li Gan; Qinghua Zhang
2005-01-01
This paper studies how the thick market effect influences local unemployment rate fluctuations. The paper presents a model to demonstrate that the average matching quality improves as the number of workers and firms increases. Unemployed workers accumulate in a city until the local labor market reaches a critical minimum size, which leads to cyclical fluctuations in the local unemployment rates. Since larger cities attain the critical market size more frequently, they have shorter unemploymen...
Aerosol numerical modelling at local scale
International Nuclear Information System (INIS)
Albriet, Bastien
2007-01-01
At local scale and in urban areas, an important part of particulate pollution is due to traffic. It contributes largely to the high number concentrations observed. Two aerosol sources are mainly linked to traffic. Primary emission of soot particles and secondary nanoparticle formation by nucleation. The emissions and mechanisms leading to the formation of such bimodal distribution are still badly understood nowadays. In this thesis, we try to provide an answer to this problematic by numerical modelling. The Modal Aerosol Model MAM is used, coupled with two 3D-codes: a CFD (Mercure Saturne) and a CTM (Polair3D). A sensitivity analysis is performed, at the border of a road but also in the first meters of an exhaust plume, to identify the role of each process involved and the sensitivity of different parameters used in the modelling. (author) [fr
Non-local modeling of materials
DEFF Research Database (Denmark)
Niordson, Christian Frithiof
2002-01-01
Numerical studies of non-local plasticity effects on different materials and problems are carried out. Two different theories are used. One is of lower order in that it retains the structure of a conventional plasticity boundary value problem, while the other is of higher order and employs higher...... order stresses as work conjugates to higher order strains and uses higher order boundary conditions. The influence of internal material length parameters is studied, and the effects of higher order boundary conditions are analyzed. The focus of the thesis is on metal-matrix composites, and non...
International Nuclear Information System (INIS)
Krossnes, Baard Kronen; Mella, Olav; Dahl, Olav
1996-01-01
.3 and 0.4 deg. C higher during SNP infusion in the MFF and pentobarbital group, respectively. Conclusion: We have developed a small animal model in inbred rats feasible for exploring the influence of a stable blood pressure reduction induced by SNP, on the effect of HT given alone or in combination with other treatment modalities to a transplantable tumor. The greatly increased cytotoxic effect of local waterbath HT in the present tumor response experiments is probably a consequence of increased tumor temperature during SNP infusion
Modelling and inversion of local magnetic anomalies
International Nuclear Information System (INIS)
Quesnel, Y; Langlais, B; Sotin, C; Galdéano, A
2008-01-01
We present a method—named as MILMA for modelling and inversion of local magnetic anomalies—that combines forward and inverse modelling of aeromagnetic data to characterize both magnetization properties and location of unconstrained local sources. Parameters of simple-shape magnetized bodies (cylinder, prism or sphere) are first adjusted by trial and error to predict the signal. Their parameters provide a priori information for inversion of the measurements. Here, a generalized nonlinear approach with a least-squares criterion is adopted to seek the best parameters of the sphere (dipole). This inversion step allows the model to be more objectively adjusted to fit the magnetic signal. The validity of the MILMA method is demonstrated through synthetic and real cases using aeromagnetic measurements. Tests with synthetic data reveal accurate results in terms of depth source, whatever be the number of sources. The MILMA method is then used with real measurements to constrain the properties of the magnetized units of the Champtoceaux complex (France). The resulting parameters correlate with the crustal structure and properties revealed by other geological and geophysical surveys in the same area. The MILMA method can therefore be used to investigate the properties of poorly constrained lithospheric magnetized sources
Analytical model for local scour prediction around hydrokinetic turbine foundations
Musa, M.; Heisel, M.; Hill, C.; Guala, M.
2017-12-01
Marine and Hydrokinetic renewable energy is an emerging sustainable and secure technology which produces clean energy harnessing water currents from mostly tidal and fluvial waterways. Hydrokinetic turbines are typically anchored at the bottom of the channel, which can be erodible or non-erodible. Recent experiments demonstrated the interactions between operating turbines and an erodible surface with sediment transport, resulting in a remarkable localized erosion-deposition pattern significantly larger than those observed by static in-river construction such as bridge piers, etc. Predicting local scour geometry at the base of hydrokinetic devices is extremely important during foundation design, installation, operation, and maintenance (IO&M), and long-term structural integrity. An analytical modeling framework is proposed applying the phenomenological theory of turbulence to the flow structures that promote the scouring process at the base of a turbine. The evolution of scour is directly linked to device operating conditions through the turbine drag force, which is inferred to locally dictate the energy dissipation rate in the scour region. The predictive model is validated using experimental data obtained at the University of Minnesota's St. Anthony Falls Laboratory (SAFL), covering two sediment mobility regimes (clear water and live bed), different turbine designs, hydraulic parameters, grain size distribution and bedform types. The model is applied to a potential prototype scale deployment in the lower Mississippi River, demonstrating its practical relevance and endorsing the feasibility of hydrokinetic energy power plants in large sandy rivers. Multi-turbine deployments are further studied experimentally by monitoring both local and non-local geomorphic effects introduced by a twelve turbine staggered array model installed in a wide channel at SAFL. Local scour behind each turbine is well captured by the theoretical predictive model. However, multi
Relative-locality effects in Snyder spacetime
International Nuclear Information System (INIS)
Mignemi, S.; Samsarov, A.
2017-01-01
Most models of noncommutative geometry and doubly special relativity suggest that the principle of absolute locality should be replaced by the milder notion of relative locality. In particular, they predict the occurrence of a delay in the time of arrival of massless particle of different energies emitted by a distant observer. In this letter, we show that this is not the case with Snyder spacetime, essentially because the Lorentz invariance is not deformed in this case. Distant observers may however measure different times of flight for massive particles. - Highlights: • We discuss the dynamics of the Snyder model from the point of view of relative locality. • We show that no time delay is present for particles emitted by distant observers. • We ascribe this fact to the Lorentz invariance of the model. • Distant observers may however measure different times of flight for massive particle.
Relative-locality effects in Snyder spacetime
Energy Technology Data Exchange (ETDEWEB)
Mignemi, S., E-mail: smignemi@unica.it [Dipartimento di Matematica e Informatica, Università di Cagliari, viale Merello 92, 09123 Cagliari (Italy); INFN, Sezione di Cagliari, Cittadella Universitaria, 09042 Monserrato (Italy); Samsarov, A., E-mail: andjelo.samsarov@irb.hr [Rudjer Bošković Institute, Bijenička cesta 54, 10002 Zagreb (Croatia)
2017-05-18
Most models of noncommutative geometry and doubly special relativity suggest that the principle of absolute locality should be replaced by the milder notion of relative locality. In particular, they predict the occurrence of a delay in the time of arrival of massless particle of different energies emitted by a distant observer. In this letter, we show that this is not the case with Snyder spacetime, essentially because the Lorentz invariance is not deformed in this case. Distant observers may however measure different times of flight for massive particles. - Highlights: • We discuss the dynamics of the Snyder model from the point of view of relative locality. • We show that no time delay is present for particles emitted by distant observers. • We ascribe this fact to the Lorentz invariance of the model. • Distant observers may however measure different times of flight for massive particle.
Modelling of ductile and cleavage fracture by local approach
International Nuclear Information System (INIS)
Samal, M.K.; Dutta, B.K.; Kushwaha, H.S.
2000-08-01
This report describes the modelling of ductile and cleavage fracture processes by local approach. It is now well known that the conventional fracture mechanics method based on single parameter criteria is not adequate to model the fracture processes. It is because of the existence of effect of size and geometry of flaw, loading type and rate on the fracture resistance behaviour of any structure. Hence, it is questionable to use same fracture resistance curves as determined from standard tests in the analysis of real life components because of existence of all the above effects. So, there is need to have a method in which the parameters used for the analysis will be true material properties, i.e. independent of geometry and size. One of the solutions to the above problem is the use of local approaches. These approaches have been extensively studied and applied to different materials (including SA33 Gr.6) in this report. Each method has been studied and reported in a separate section. This report has been divided into five sections. Section-I gives a brief review of the fundamentals of fracture process. Section-II deals with modelling of ductile fracture by locally uncoupled type of models. In this section, the critical cavity growth parameters of the different models have been determined for the primary heat transport (PHT) piping material of Indian pressurised heavy water reactor (PHWR). A comparative study has been done among different models. The dependency of the critical parameters on stress triaxiality factor has also been studied. It is observed that Rice and Tracey's model is the most suitable one. But, its parameters are not fully independent of triaxiality factor. For this purpose, a modification to Rice and Tracery's model is suggested in Section-III. Section-IV deals with modelling of ductile fracture process by locally coupled type of models. Section-V deals with the modelling of cleavage fracture process by Beremins model, which is based on Weibulls
Field, L. A.; Sholtz, A.; Chetty, S.; Manzara, A.; Johnson, D.; Christodoulou, E.; Decca, R.; Walter, P.; Katuri, K.; Bhattacharyya, S.; Ivanova, D.; Mlaker, V.; Perovich, D. K.
2017-12-01
This work uses ecologically benign surface treatment of silica-based materials in carefully selected, limited areas to reduce polar ice melt by reflecting energy from summertime polar sun to attempt to slow ice loss due to the Ice-Albedo Feedback Effect. Application of Ice911's materials can be accomplished within a season, at a comparatively low cost, and with far less secondary environmental impact than many other proposed geo-engineering solutions. Field testing, instrumentation, safety testing, data-handling and modeling results will be presented. The albedo modification has been tested over a number of melt seasons with an evolving array of instrumentation, at multiple sites and on progressively larger scales, most recently in a small artificial pond in Minnesota and in a lake in Barrow, Alaska's BEO (Barrow Experimental Observatory) area. The test data show that the glass bubbles can provide an effective material for increasing albedo, significantly reducing the melting rate of ice. Using NCAR's CESM package the environmental impact of the approach of surface albedo modification was studied. During two separate runs, region-wide Arctic albedo modification as well as more targeted localized treatments were modeled and compared. The parameters of a surface snow layer are used as a proxy to simulate Ice911's high-albedo materials, and the modification is started in January over selected ice/snow regions in the Arctic. Preliminary results show promising possibilities of enhancements in surface albedo, sea ice area and sea-ice concentration, as well as temperature reductions of .5 to 3 degree Kelvin in the Arctic, and global average temperature reductions of .5 to 1 degrees.
Wheeler, David C.; Hickson, DeMarc A.; Waller, Lance A.
2010-01-01
Many diagnostic tools and goodness-of-fit measures, such as the Akaike information criterion (AIC) and the Bayesian deviance information criterion (DIC), are available to evaluate the overall adequacy of linear regression models. In addition, visually assessing adequacy in models has become an essential part of any regression analysis. In this paper, we focus on a spatial consideration of the local DIC measure for model selection and goodness-of-fit evaluation. We use a partitioning of the DIC into the local DIC, leverage, and deviance residuals to assess local model fit and influence for both individual observations and groups of observations in a Bayesian framework. We use visualization of the local DIC and differences in local DIC between models to assist in model selection and to visualize the global and local impacts of adding covariates or model parameters. We demonstrate the utility of the local DIC in assessing model adequacy using HIV prevalence data from pregnant women in the Butare province of Rwanda during 1989-1993 using a range of linear model specifications, from global effects only to spatially varying coefficient models, and a set of covariates related to sexual behavior. Results of applying the diagnostic visualization approach include more refined model selection and greater understanding of the models as applied to the data. PMID:21243121
Local load-sharing fiber bundle model in higher dimensions.
Sinha, Santanu; Kjellstadli, Jonas T; Hansen, Alex
2015-08-01
We consider the local load-sharing fiber bundle model in one to five dimensions. Depending on the breaking threshold distribution of the fibers, there is a transition where the fracture process becomes localized. In the localized phase, the model behaves as the invasion percolation model. The difference between the local load-sharing fiber bundle model and the equal load-sharing fiber bundle model vanishes with increasing dimensionality with the characteristics of a power law.
Directory of Open Access Journals (Sweden)
R. Ghobadian
2016-10-01
Full Text Available Introduction: Flow and sediment transport has an important role in entrance deformation of open channel junctions. As water moved through a drainage network, it forced to converge at confluence. Due to increasing of water discharge and collision of converging flows, a complex three-dimensional and most highly turbulent location were occurred in the vicinity of the junction. Therefore a deep scour hole and point bar has developed in this area that caused the change in rivers morphology. Despite the large amount of research carried out on flow patterns in river confluences, only a few researches have focused on sediment transport. Materials and methods: In this research three dimensional model (SSIIM1 was used to study of flow pattern and sediment and erosion pattern at 60 degree Junction .the Navier-Stockes equation of turbulent flow in a general three-dimensional geometry are solved to obtain the water velocity: , (1 Where U is average velocity, ρ is density of water, is pressure, the Kronecker delta, which is 1 if i is equal to j and 0 otherwise and general space dimension. The last term is Reynolds stress, often modeled with the following equation: (2 Where and k are eddy viscosity and turbulent kinetic energy respectively. Van Rijn's relations were used to calculate sediment suspended and bed load transport. Dirichlet and zero gradients boundary conditions were used at inflow and outflow boundary respectively. fixed-lid approach was used to computed free surface by using zero gradient for all variables. The wall law for rough boundaries was also used as a boundary condition for bed and wall. In equilibrium situation, The sediment concentration for the cell closet to the bed was specified as the bed boundary condition. Specified value was used for sediment concentration of other boundary conditions at upstream boundary and zero gradients for the water surface, outlet, and the sides. the only simulation of local scouring and sedimentation at
Development of local TDC model in core thermal hydraulic analysis
International Nuclear Information System (INIS)
Kwon, H.S.; Park, J.R.; Hwang, D.H.; Lee, S.K.
2004-01-01
The local TDC model consisting of natural mixing and forced mixing part was developed to obtain more realistic local fluid properties in the core subchannel analysis. To evaluate the performance of local TDC model, the CHF prediction capability was tested with the various CHF correlations and local fluid properties at CHF location which are based on the local TDC model. The results show that the standard deviation of measured to predicted CHF ratio (M/P) based on local TDC model can be reduced by about 7% compared to those based on global TDC model when the CHF correlation has no term to account for distance from the spacer grid. (author)
Model reduction of systems with localized nonlinearities.
Energy Technology Data Exchange (ETDEWEB)
Segalman, Daniel Joseph
2006-03-01
An LDRD funded approach to development of reduced order models for systems with local nonlinearities is presented. This method is particularly useful for problems of structural dynamics, but has potential application in other fields. The key elements of this approach are (1) employment of eigen modes of a reference linear system, (2) incorporation of basis functions with an appropriate discontinuity at the location of the nonlinearity. Galerkin solution using the above combination of basis functions appears to capture the dynamics of the system with a small basis set. For problems involving small amplitude dynamics, the addition of discontinuous (joint) modes appears to capture the nonlinear mechanics correctly while preserving the modal form of the predictions. For problems involving large amplitude dynamics of realistic joint models (macro-slip), the use of appropriate joint modes along with sufficient basis eigen modes to capture the frequencies of the system greatly enhances convergence, though the modal nature the result is lost. Also observed is that when joint modes are used in conjunction with a small number of elastic eigen modes in problems of macro-slip of realistic joint models, the resulting predictions are very similar to those of the full solution when seen through a low pass filter. This has significance both in terms of greatly reducing the number of degrees of freedom of the problem and in terms of facilitating the use of much larger time steps.
Geng, Xiwen; Wang, Xuenan; Xie, Jinlu; Zhang, Xiao; Wang, Xiusong; Hou, Yabing; Lei, Chengdong; Li, Min; Han, Hongyu; Yao, Xiaomeng; Zhang, Qun; Wang, Min
2016-12-15
Levodopa (l-DOPA) has been proved to reverse the pathologic neuron activities in many brain regions related to Parkinson's disease (PD). But little is known about the effect of l-DOPA on the altered electrophysiological coherent activities between pedunculopontine nucleus (PPN) and motor cortex. To investigate this, local field potentials (LFPs) of PPN and primary motor cortex (M1) were recorded simultaneously in control, 6-hydroxydopamine lesioned and lesioned rats with l-DOPA chronic treatment. The results revealed that in resting state, chronic l-DOPA treatment could correct the suppressed power of LFPs in PPN and M1 in low-frequency band (1-7Hz) and the enhanced power in high-frequency band (7-70Hz in PPN and 12-70Hz in M1) of lesioned rats. In locomotor state, l-DOPA treatment could correct the alterations in most of frequency bands except the δ band in PPN and α band in M1. Moreover, l-DOPA could also reverse the altered coherent relationships caused by dopamine depletion in resting state between PPN and M1 in β band. And in locomotor state, l-DOPA had therapeutic effect on the alterations in δ and β bands but not in the α band. These findings provide evidence that l-DOPA can reverse the altered LFP activities in PPN and M1 and their relationships in a rat model of PD, which contributes to better understanding the electrophysiological mechanisms of the pathophysiology and therapy of PD. Copyright © 2016. Published by Elsevier B.V.
Non-local model analysis of heat pulse propagation
International Nuclear Information System (INIS)
Iwasaki, Takuya; Itoh, Sanae-I.; Yagi, Masatoshi
1998-01-01
A new theoretical model equation which includes the non-local effect in the heat flux is proposed to study the transient transport phenomena. A non-local heat flux, which is expressed in terms of the integral equation, is superimposed on the conventional form of the heat flux. This model is applied to describe the experimental results from the power switching [Stroth U, et al 1996 Plasma Phys. Control. Fusion 38 1087] and the power modulation experiments [Giannone L, et al 1992 Nucl. Fusion 32 1985] in the W7-AS stellarator. A small fraction of non-local component in the heat flux is found to be very effective in modifying the response against an external modulation. The transient feature of the transport property, which are observed in the response of heat pulse propagation, are qualitatively reproduced by the transport simulations based on this model. A possibility is discussed to determine the correlation length of the non-local effect experimentally by use of the results of transport simulations. (author)
Combined discriminative global and generative local models for visual tracking
Zhao, Liujun; Zhao, Qingjie; Chen, Yanming; Lv, Peng
2016-03-01
It is a challenging task to develop an effective visual tracking algorithm due to factors such as pose variation, rotation, and so on. Combined discriminative global and generative local appearance models are proposed to address this problem. Specifically, we develop a compact global object representation by extracting the low-frequency coefficients of the color and texture of the object based on two-dimensional discrete cosine transform. Then, with the global appearance representation, we learn a discriminative metric classifier in an online fashion to differentiate the target object from its background, which is very important to robustly indicate the changes in appearance. Second, we develop a new generative local model that exploits the scale invariant feature transform and its spatial geometric information. To make use of the advantages of the global discriminative model and the generative local model, we incorporate them into Bayesian inference framework. In this framework, the complementary models help the tracker locate the target more accurately. Furthermore, we use different mechanisms to update global and local templates to capture appearance changes. The experimental results demonstrate that the proposed approach performs favorably against state-of-the-art methods in terms of accuracy.
Islands Climatology at Local Scale. Downscaling with CIELO model
Azevedo, Eduardo; Reis, Francisco; Tomé, Ricardo; Rodrigues, Conceição
2016-04-01
Islands with horizontal scales of the order of tens of km, as is the case of the Atlantic Islands of Macaronesia, are subscale orographic features for Global Climate Models (GCMs) since the horizontal scales of these models are too coarse to give a detailed representation of the islands' topography. Even the Regional Climate Models (RCMs) reveals limitations when they are forced to reproduce the climate of small islands mainly by the way they flat and lowers the elevation of the islands, reducing the capacity of the model to reproduce important local mechanisms that lead to a very deep local climate differentiation. Important local thermodynamics mechanisms like Foehn effect, or the influence of topography on radiation balance, have a prominent role in the climatic spatial differentiation. Advective transport of air - and the consequent induced adiabatic cooling due to orography - lead to transformations of the state parameters of the air that leads to the spatial configuration of the fields of pressure, temperature and humidity. The same mechanism is in the origin of the orographic clouds cover that, besides the direct role as water source by the reinforcement of precipitation, act like a filter to direct solar radiation and as a source of long-wave radiation that affect the local balance of energy. Also, the saturation (or near saturation) conditions that they provide constitute a barrier to water vapour diffusion in the mechanisms of evapotranspiration. Topographic factors like slope, aspect and orographic mask have also significant importance in the local energy balance. Therefore, the simulation of the local scale climate (past, present and future) in these archipelagos requires the use of downscaling techniques to adjust locally outputs obtained at upper scales. This presentation will discuss and analyse the evolution of the CIELO model (acronym for Clima Insular à Escala LOcal) a statistical/dynamical technique developed at the University of the Azores
Pan, Yuanjie; Nitin, N
2015-11-01
Oxidation of encapsulated bioactives in emulsions is one of the key challenges that limit shelf-life of many emulsion containing products. This study seeks to quantify the role of layer-by-layer coatings and localization of antioxidant molecules at the emulsion interface in influencing oxidation of the encapsulated bioactives. Oxidative barrier properties of the emulsions were simulated by measuring the rate of reaction of peroxyl radicals generated in the aqueous phase with the encapsulated radical sensitive dye in the lipid core of the emulsions. The results of peroxyl radical permeation were compared to the stability of encapsulated retinol (model bioactive) in emulsions. To evaluate the role of layer-by-layer coatings in influencing oxidative barrier properties, radical permeation rates and retinol stability were evaluated in emulsion formulations of SDS emulsion and SDS emulsion with one or two layers of polymers (ϵ-polylysine and dextran sulfate) coated at the interface. To localize antioxidant molecules to the interface, gallic acid (GA) was chemically conjugated with ϵ-polylysine and subsequently deposited on SDS emulsion based on electrostatic interactions. Emulsion formulations with localized GA molecules at the interface were compared with SDS emulsion with GA molecules in the bulk aqueous phase. The results of this study demonstrate the advantage of localization of antioxidant at the interface and the limited impact of short chain polymer coatings at the interface of emulsions in reducing permeation of radicals and oxidation of a model encapsulated bioactive in oil-in-water emulsions. Copyright © 2015 Elsevier B.V. All rights reserved.
Macroscopic local-field effects on photoabsorption processes
International Nuclear Information System (INIS)
Ma Xiaoguang; Gong Yubing; Wang Meishan; Wang Dehua
2008-01-01
The influence of the local-field effect on the photoabsorption cross sections of the atoms which are embedded in the macroscopic medium has been studied by a set of alternative expressions in detail. Some notes on the validity of some different local-field models used to study the photoabsorption cross sections of atoms in condensed matter have been given for the first time. Our results indicate that the local fields can have substantial and different influence on the photoabsorption cross section of atoms in condensed matter for different models. Clausius-Mossotti model and Onsager model have proved to be more reasonable to describe the local field in gas, liquid, or even some simple solid, while Glauber-Lewenstein model probably is wrong in these conditions except for the ideal gas. A procedure which can avoid the errors introduced by Kramers-Kronig transformation has been implemented in this work. This procedure can guarantee that the theoretical studies on the local field effects will not be influenced by the integral instability of the Kramers-Kronig transformation
Energy Technology Data Exchange (ETDEWEB)
Gillmann, Clarissa, E-mail: clarissa.gillmann@med.uni-heidelberg.de [Department of Radiation Oncology and Radiation Therapy, Heidelberg University Hospital, Heidelberg (Germany); Jäkel, Oliver [Department of Radiation Oncology and Radiation Therapy, Heidelberg University Hospital, Heidelberg (Germany); Heidelberg Ion Beam Therapy Center (HIT), Heidelberg (Germany); Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg (Germany); Schlampp, Ingmar [Department of Radiation Oncology and Radiation Therapy, Heidelberg University Hospital, Heidelberg (Germany); Karger, Christian P. [Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg (Germany)
2014-04-01
Purpose: To compare the relative biological effectiveness (RBE)–weighted tolerance doses for temporal lobe reactions after carbon ion radiation therapy using 2 different versions of the local effect model (LEM I vs LEM IV) for the same patient collective under identical conditions. Methods and Materials: In a previous study, 59 patients were investigated, of whom 10 experienced temporal lobe reactions (TLR) after carbon ion radiation therapy for low-grade skull-base chordoma and chondrosarcoma at Helmholtzzentrum für Schwerionenforschung (GSI) in Darmstadt, Germany in 2002 and 2003. TLR were detected as visible contrast enhancements on T1-weighted MRI images within a median follow-up time of 2.5 years. Although the derived RBE-weighted temporal lobe doses were based on the clinically applied LEM I, we have now recalculated the RBE-weighted dose distributions using LEM IV and derived dose-response curves with Dmax,V-1 cm³ (the RBE-weighted maximum dose in the remaining temporal lobe volume, excluding the volume of 1 cm³ with the highest dose) as an independent dosimetric variable. The resulting RBE-weighted tolerance doses were compared with those of the previous study to assess the clinical impact of LEM IV relative to LEM I. Results: The dose-response curve of LEM IV is shifted toward higher values compared to that of LEM I. The RBE-weighted tolerance dose for a 5% complication probability (TD{sub 5}) increases from 68.8 ± 3.3 to 78.3 ± 4.3 Gy (RBE) for LEM IV as compared to LEM I. Conclusions: LEM IV predicts a clinically significant increase of the RBE-weighted tolerance doses for the temporal lobe as compared to the currently applied LEM I. The limited available photon data do not allow a final conclusion as to whether RBE predictions of LEM I or LEM IV better fit better clinical experience in photon therapy. The decision about a future clinical application of LEM IV therefore requires additional analysis of temporal lobe reactions in a
Coupling of nonlocal and local continuum models by the Arlequinapproach
Han, Fei
2011-08-09
The objective of this work is to develop and apply the Arlequin framework to couple nonlocal and local continuum mechanical models. A mechanically-based model of nonlocal elasticity, which involves both contact and long-range forces, is used for the \\'fine scale\\' description in which nonlocal interactions are considered to have non-negligible effects. Classical continuum mechanics only involving local contact forces is introduced for the rest of the structure where these nonlocal effects can be neglected. Both models overlap in a coupling subdomain called the \\'gluing area\\' in which the total energy is separated into nonlocal and local contributions by complementary weight functions. A weak compatibility is ensured between kinematics of both models using Lagrange multipliers over the gluing area. The discrete formulation of this specific Arlequin coupling framework is derived and fully described. The validity and limits of the technique are demonstrated through two-dimensional numerical applications and results are compared against those of the fully nonlocal elasticity method. © 2011 John Wiley & Sons, Ltd.
Local and Global Function Model of the Liver
Energy Technology Data Exchange (ETDEWEB)
Wang, Hesheng, E-mail: hesheng@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Jackson, Andrew [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Ten Haken, Randall K.; Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Cao, Yue [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan (United States)
2016-01-01
Purpose: To develop a local and global function model in the liver based on regional and organ function measurements to support individualized adaptive radiation therapy (RT). Methods and Materials: A local and global model for liver function was developed to include both functional volume and the effect of functional variation of subunits. Adopting the assumption of parallel architecture in the liver, the global function was composed of a sum of local function probabilities of subunits, varying between 0 and 1. The model was fit to 59 datasets of liver regional and organ function measures from 23 patients obtained before, during, and 1 month after RT. The local function probabilities of subunits were modeled by a sigmoid function in relating to MRI-derived portal venous perfusion values. The global function was fitted to a logarithm of an indocyanine green retention rate at 15 minutes (an overall liver function measure). Cross-validation was performed by leave-m-out tests. The model was further evaluated by fitting to the data divided according to whether the patients had hepatocellular carcinoma (HCC) or not. Results: The liver function model showed that (1) a perfusion value of 68.6 mL/(100 g · min) yielded a local function probability of 0.5; (2) the probability reached 0.9 at a perfusion value of 98 mL/(100 g · min); and (3) at a probability of 0.03 [corresponding perfusion of 38 mL/(100 g · min)] or lower, the contribution to global function was lost. Cross-validations showed that the model parameters were stable. The model fitted to the data from the patients with HCC indicated that the same amount of portal venous perfusion was translated into less local function probability than in the patients with non-HCC tumors. Conclusions: The developed liver function model could provide a means to better assess individual and regional dose-responses of hepatic functions, and provide guidance for individualized treatment planning of RT.
Local models and hidden nonlocality in Quantum Theory
Guerini, Leonardo
2014-01-01
This Master's thesis has two central subjects: the simulation of correlations generated by local measurements on entangled quantum states by local hidden-variables models and the revelation of hidden nonlocality. We present and detail the Werner's local model and the hidden nonlocality of some Werner states of dimension $d\\geq5$, the Gisin-Degorre's local model for a Werner state of dimension $d=2$ and the local model of Hirsch et al. for mixtures of the singlet state and noise, all of them f...
A non-local model analysis of heat pulse propagation
International Nuclear Information System (INIS)
Iwasaki, T.; Itoh, S.I.; Yagi, M.; Stroth, U.
1998-01-01
The anomalous transport in high temperature plasma has been studied for a long time, from the beginning of the fusion research. Since the electron channel in stellarators and tokamaks is clearly anomalous, it is of fundamental importance to investigate the electron heat diffusivity coefficient, χ e and to understand the physical mechanism. Recently, the experimental data for the transient transport of the heat pulse propagation in fusion plasma has been accumulated. An observation was reported on W7-AS which the heat flux changes faster than the change of the temperature profile, responding to the switching on off of the central heating power. The observation on the transient response has simulated the transport modeling, e.g., the critical marginality which implies the existence of a finite threshold in ∇T for the excitation of the turbulence, or the model in which the thermal conductivity is assumed to depend on the heating power. Extensive study is made by use of these models, and the critical marginally model seems to be insufficient to explain various transient transport. The rapid change of the plasma state and its hysteresis nature were successfully modeled by a heating-power-dependent model. The foundation of this model, however, is left for future work. The development of the transport modeling remains to be an urgent problem. In this paper, we investigate the role of the non-locality of the plasma transport in the study of the heat pulse propagation. For this purpose, a model equation is proposed, in which the non-local effect is taken into account in the heat flux. The properties of this model are investigated by performing a transport simulation. The organization of this paper is as follows: In Sec. II, the model equation is proposed and the properties of the model are explained. Using the model equation, the switching on off experiment is simulated in Sec. III. Summary and discussion are given in Sec. IV. (author)
LENUS (Irish Health Repository)
Gibbons, Aileen
2011-09-01
Inhaled recombinant Secretory Leukocyte Protease Inhibitor (rSLPI) has shown potential for treatment of inflammatory lung conditions. Rapid inactivation of rSLPI by cathepsin L (Cat L) and rapid clearance from the lungs have limited clinical efficacy. Encapsulation of rSLPI within 1,2-Dioleoyl-sn-Glycero-3-[Phospho-L-Serine]:Cholesterol liposomes (DOPS-rSLPI) protects rSLPI against Cat L inactivation in vitro. We aimed to determine the effect of liposomes on rSLPI pharmacokinetics and activity in vitro and after local delivery to the airways in vivo.
Effect of coulomb interaction on Anderson localization
International Nuclear Information System (INIS)
Waintal, X.
1999-01-01
We study the quantum mechanics of interacting particles in a disordered system, and in particular, what happens to Anderson localisation when interaction is taken into account. In the first part, one looks at the excited states of two particles in one dimension. For this model, it has been shown (Shepelyansky 1994) that a local repulsive interaction can partially destroy Anderson localisation. Here, we show that this model has similarities with the three-dimensional Anderson model at the metal-insulator transition. In particular, the maximum of rigidity obtained in the spectral statistics correspond to some intermediary statistics that cannot be described by random matrix theory neither by a Poisson statistics. The wave functions show a multifractal behaviour and the spreading of the center of mass of a wave packet is logarithmic in time. The second part deals with the ground state of a finite density of spinless fermions in two dimensions. After the scaling theory of localisation, it was commonly accepted that there was no metal in two dimensions. This idea has been challenged by the observation of a metal-insulator transition in low density electron gas (Kravchenko et al. 1994). We propose a scenario in which a metallic phase occurs between the Anderson insulator and the pinned Wigner crystal. This intermediate phase is characterized by an alignment of the local currents flowing in the system. (author)
Beyond local effective material properties for metamaterials
Mnasri, K.; Khrabustovskyi, A.; Stohrer, C.; Plum, M.; Rockstuhl, C.
2018-02-01
To discuss the properties of metamaterials on physical grounds and to consider them in applications, effective material parameters are usually introduced and assigned to a given metamaterial. In most cases, only weak spatial dispersion is considered. It allows to assign local material properties, e.g., a permittivity and a permeability. However, this turned out to be insufficient. To solve this problem, we study here the effective properties of metamaterials with constitutive relations beyond a local response and take strong spatial dispersion into account. This research requires two contributions. First, bulk properties in terms of eigenmodes need to be studied. We particularly investigate the isofrequency surfaces of their dispersion relation are investigated and compared to those of an actual metamaterial. The significant improvement to effectively describe it provides evidence for the necessity to use nonlocal material laws in the effective description of metamaterials. Second, to be able to capitalize on such constitutive relations, also interface conditions need to be known. They are derived in this contribution for our form of the nonlocality using a generalized (weak) formulation of Maxwell's equations. Based on such interface conditions, Fresnel expressions are obtained that predict the amplitude of the reflected and transmitted plane wave upon illuminating a slab of such a nonlocal metamaterial. This all together offers the necessary means for the in-depth analysis of metamaterials characterized by strong spatial dispersion. The general formulation we choose here renders our approach applicable to a wide class of metamaterials.
Local TEC Modelling and Forecasting using Neural Networks
Tebabal, A.; Radicella, S. M.; Nigussie, M.; Damtie, B.; Nava, B.; Yizengaw, E.
2017-12-01
Abstract Modelling the Earth's ionospheric characteristics is the focal task for the ionospheric community to mitigate its effect on the radio communication, satellite navigation and technologies. However, several aspects of modelling are still challenging, for example, the storm time characteristics. This paper presents modelling efforts of TEC taking into account solar and geomagnetic activity, time of the day and day of the year using neural networks (NNs) modelling technique. The NNs have been designed with GPS-TEC measured data from low and mid-latitude GPS stations. The training was conducted using the data obtained for the period from 2011 to 2014. The model prediction accuracy was evaluated using data of year 2015. The model results show that diurnal and seasonal trend of the GPS-TEC is well reproduced by the model for the two stations. The seasonal characteristics of GPS-TEC is compared with NN and NeQuick 2 models prediction when the latter one is driven by the monthly average value of solar flux. It is found that NN model performs better than the corresponding NeQuick 2 model for low latitude region. For the mid-latitude both NN and NeQuick 2 models reproduce the average characteristics of TEC variability quite successfully. An attempt of one day ahead forecast of TEC at the two locations has been made by introducing as driver previous day solar flux and geomagnetic index values. The results show that a reasonable day ahead forecast of local TEC can be achieved.
Directory of Open Access Journals (Sweden)
Min Luo
2017-08-01
Full Text Available The effects of global climate change threaten the availability of water resources worldwide and modify their tempo-spatial pattern. Properly quantifying the possible effects of climate change on water resources under different hydrological models is a great challenge in ungauged alpine regions. By using remote sensing data to support established models, this study aimed to reveal the effects of climate change using two models of hydrological processes including total water resources, peak flows, evapotranspiration, snowmelt and snow accumulation in the ungauged Hotan River Basin under future representative concentration pathway (RCP scenarios. The results revealed that stream flow was much more sensitive to temperature variation than precipitation change and increased by 0.9–10.0% according to MIKE SHE or 6.5–10.5% according to SWAT. Increased evapotranspiration was similar for both models with a range of 7.6–31.3%. The snow-covered area shrank from 32.5% to 11.9% between the elevations of 4200–6400 m, respectively, and snow accumulation increased when the elevation exceeded 6400 m above sea level (asl. The results also suggested that the fully distributed and semi-distributed structures of these two models strongly influenced the responses to climate change. The study proposes a practical approach to assess the climate change effect in ungauged regions.
International Nuclear Information System (INIS)
Cagnetti, P.; Ferrara, V.; Pellegrini, A.
1985-01-01
The aim of this contract is the characterization, from the thermal and anemological point of view, of the lower layers of the atmosphere at a coastal site, affected by breeze circulation. Data are utilized to set up diffusion models for accidental releases of airborne materials, both of short and prolonged duration. Five inland meteorological campaigns, starting from Jan. 82 (Jan., Apr., Jul., Oct. 1982, Jan. 1983), have been carried out; an appropriate extension of the contract allowed the execution of two more campaigns in the open sea (Apr., Jul. 1983), utilizing the oceanographic ship ''Bannock'' kindly supplied by CNR. The analysis of the data showed the development of a well defined IBL during on-shore flow only in Spring and Summer, while an inversion layer was detectable aloft independently of the season (provided that an anticyclonic situation was present). According to those relevant features a simple diffusion model has been developed for short duration releases at local scale. Finally, the analysis and elaboration of the data, collected on site by a meteorological automatic station, allowed the extension of the model to prolonged releases
Churn classification model for local telecommunication company ...
African Journals Online (AJOL)
... model based on the Rough Set Theory to classify customer churn. The results of the study show that the proposed Rough Set classification model outperforms the existing models and contributes to significant accuracy improvement. Keywords: customer churn; classification model; telecommunication industry; data mining;
Integration of Local Hydrology into Regional Hydrologic Simulation Model
Van Zee, R. J.; Lal, W. A.
2002-05-01
South Florida hydrology is dominated by the Central and South Florida (C&SF) Project that is managed to provide flood protection, water supply and environmental protection. A complex network of levees canals and structures provide these services to the individual drainage basins. The landscape varies widely across the C&SF system, with corresponding differences in the way water is managed within each basin. Agricultural areas are managed for optimal crop production. Urban areas maximize flood protection while maintaining minimum water levels to protect adjacent wetlands and local water supplies. "Natural" areas flood and dry out in response to the temporal distribution of rainfall. The evaluation of planning, regulation and operational issues require access to a simulation model that captures the effects of both regional and local hydrology. The Regional Simulation Model (RSM) uses a "pseudo-cell" approach to integrate local hydrology within the context of a regional hydrologic system. A 2-dimensional triangulated mesh is used to represent the regional surface and ground water systems and a 1-dimensional canal network is superimposed onto this mesh. The movement of water is simulated using a finite volume formulation with a diffusive wave approximation. Each cell in the triangulated mesh has a "pseudo-cell" counterpart, which represents the same area as the cell, but it is conceptualized such that it simulates the localized hydrologic conditions Protocols have been established to provide an interface between a cell and its pseudo-cell counterpart. . A number of pseudo-cell types have already been developed and tested in the simulation of Water Conservation Area 1 and several have been proposed to deal with specific local issues in the Southwest Florida Feasibility Study. This presentation will provide an overview of the overall RSM design, describe the relationship between cells and pseudo-cells, and illustrate how pseudo-cells are be used to simulate agriculture
Effect of altering local protein fluctuations using artificial intelligence
Nishiyama, Katsuhiko
2017-03-01
The fluctuations in Arg111, a significantly fluctuating residue in cathepsin K, were locally regulated by modifying Arg111 to Gly111. The binding properties of 15 dipeptides in the modified protein were analyzed by molecular simulations, and modeled as decision trees using artificial intelligence. The decision tree of the modified protein significantly differed from that of unmodified cathepsin K, and the Arg-to-Gly modification exerted a remarkable effect on the peptide binding properties. By locally regulating the fluctuations of a protein, we may greatly alter the original functions of the protein, enabling novel applications in several fields.
Effect of altering local protein fluctuations using artificial intelligence
Directory of Open Access Journals (Sweden)
Katsuhiko Nishiyama
2017-03-01
Full Text Available The fluctuations in Arg111, a significantly fluctuating residue in cathepsin K, were locally regulated by modifying Arg111 to Gly111. The binding properties of 15 dipeptides in the modified protein were analyzed by molecular simulations, and modeled as decision trees using artificial intelligence. The decision tree of the modified protein significantly differed from that of unmodified cathepsin K, and the Arg-to-Gly modification exerted a remarkable effect on the peptide binding properties. By locally regulating the fluctuations of a protein, we may greatly alter the original functions of the protein, enabling novel applications in several fields.
Mental models of women with breast implants : local complications
Byram, S.; Fischhoff, B.; Embrey, M.; Bruine de Bruin, W.J.A.; Thorne, S.
2001-01-01
Twenty-five women with breast implants participated in semistructured interviews designed to reveal their "mental models" of the processes potentially causing local (ie, nonsystemic) problems. The authors analyzed their responses in terms of an "expert model," circumscribing scientifically relevant
Local models of heterotic flux vacua: spacetime and worldsheet aspects
International Nuclear Information System (INIS)
Israel, D.; Carlevaro, L.
2011-01-01
We report on some recent progress in understanding heterotic flux compactifications, from a worldsheet perspective mainly. We consider local models consisting in torus fibration over warped Eguchi-Hanson space and non-Kaehler resolved conifold geometries. We analyze the supergravity solutions and define a double-scaling limit of the resolved singularities, defined such that the geometry is smooth and weakly coupled. We show that, remarkably, the heterotic solutions admit solvable worldsheet CFT descriptions in this limit. This allows in particular to understand the important role of worldsheet non-perturbative effects. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Assessment of Constraint Effects based on Local Approach
International Nuclear Information System (INIS)
Lee, Tae Rin; Chang, Yoon Suk; Choi, Jae Boong; Seok, Chang Sung; Kim, Young Jin
2005-01-01
Traditional fracture mechanics has been used to ensure a structural integrity, in which the geometry independence is assumed in crack tip deformation and fracture toughness. However, the assumption is applicable only within limited conditions. To address fracture covering a broad range of loading and crack geometries, two-parameter global approach and local approach have been proposed. The two-parameter global approach can quantify the load and crack geometry effects by adopting T-stress or Q-parameter but time-consuming and expensive since lots of experiments and finite element (FE) analyses are necessary. On the other hand, the local approach evaluates the load and crack geometry effects based on damage model. Once material specific fitting constants are determined from a few experiments and FE analyses, the fracture resistance characteristics can be obtained by numerical simulation. The purpose of this paper is to investigate constraint effects for compact tension (CT) specimens with different in-plane or out-of-plane size using local approach. Both modified GTN model and Rousselier model are adopted to examine the ductile fracture behavior of SA515 Gr.60 carbon steel at high temperature. The fracture resistance (J-R) curves are estimated through numerical analysis, compared with corresponding experimental results and, then, crack length, thickness and side-groove effects are evaluated
Local heterogeneity effects on small-sample worths
International Nuclear Information System (INIS)
Schaefer, R.W.
1986-01-01
One of the parameters usually measured in a fast reactor critical assembly is the reactivity associated with inserting a small sample of a material into the core (sample worth). Local heterogeneities introduced by the worth measurement techniques can have a significant effect on the sample worth. Unfortunately, the capability is lacking to model some of the heterogeneity effects associated with the experimental technique traditionally used at ANL (the radial tube technique). It has been suggested that these effects could account for a large portion of what remains of the longstanding central worth discrepancy. The purpose of this paper is to describe a large body of experimental data - most of which has never been reported - that shows the effect of radial tube-related local heterogeneities
Local fit evaluation of structural equation models using graphical criteria.
Thoemmes, Felix; Rosseel, Yves; Textor, Johannes
2018-03-01
Evaluation of model fit is critically important for every structural equation model (SEM), and sophisticated methods have been developed for this task. Among them are the χ² goodness-of-fit test, decomposition of the χ², derived measures like the popular root mean square error of approximation (RMSEA) or comparative fit index (CFI), or inspection of residuals or modification indices. Many of these methods provide a global approach to model fit evaluation: A single index is computed that quantifies the fit of the entire SEM to the data. In contrast, graphical criteria like d-separation or trek-separation allow derivation of implications that can be used for local fit evaluation, an approach that is hardly ever applied. We provide an overview of local fit evaluation from the viewpoint of SEM practitioners. In the presence of model misfit, local fit evaluation can potentially help in pinpointing where the problem with the model lies. For models that do fit the data, local tests can identify the parts of the model that are corroborated by the data. Local tests can also be conducted before a model is fitted at all, and they can be used even for models that are globally underidentified. We discuss appropriate statistical local tests, and provide applied examples. We also present novel software in R that automates this type of local fit evaluation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Directory of Open Access Journals (Sweden)
Diana Erazo
2016-11-01
Full Text Available Abstract Background Chagas disease is a major public health concern in Latin America and it is transmitted by insects of the subfamily Triatominae, including Rhodnius spp. Since palm trees are ubiquitous in Colombia and a habitat for Rhodnius spp., the presence of palms near villages could increase contact rates between vectors and humans. Therefore, knowing whether a relationship exists between the proximity of palms to villages and the abundance and distribution of vectors therein, may be critical for Chagas disease prevention programs. Adapting a mathematical model for R. prolixus population dynamics in a small village, we model the implications of changing distances between palms and dwellings, to the risk of Chagas disease infection. Methods We implemented a mathematical model that reflects R. prolixus population dynamics in a small village located in the department of Casanare (Colombia to study the role of palm-house proximity. We varied the distance between palms and houses by monitoring the network global efficiency metric. We constructed 1,000 hypothetical villages varying distances and each one was run 100 times. Results According to the model, as palm-house proximity increases, houses were more likely to be visited by triatomine bugs. The number of bugs per unit time increased progressively in a non-linear fashion with high variability. We stress the importance of village configuration on the model output. Conclusions From a theoretical perspective, palm-house proximity may have a positive effect on the incidence of Chagas disease. The model predicts a 1% increase in new human cases per year when houses and palms are brought closer by 75%.
Big infrastructures effects on local developments
Directory of Open Access Journals (Sweden)
Bruna Vendemmia
2011-10-01
articulation and of translation between different extensive layers of the multi-scaled urban ‘cake’“ (Read, 2007 it will not be astonishing to discover, in Naples Metropolitan Area, new peripheral commercial centralities on the trucks of an old roman street. This synergy, raised in some urban nodes, is the result of a slow bottom-up process. Meanwhile, as the opposite top-down development, and as a consequence of the industrial sector reorganization, faster global dynamics create “new centralities” producing effects at the local scale and increasing the fragmentation. Moreover, it must be taken into account that these layers and processes are not only restricted to physical networks but they are shaped also by economical and social interactions, and that a network is always global and local in all its points (Latour, Nous n'avons jamais été modernes. Essai d'anthropologie symétrique, 1991.From a methodological point of you, a first interpretation of the city growth has driven to the compilation of thematic maps and photographical reports. The information, learned through the graphical and photographical process, were supported by a theoretical approach about both urban development in general and Naples growth in particular.
Effective theory of rotationally faulted multilayer graphene - the local limit
International Nuclear Information System (INIS)
Kindermann, M; First, P N
2012-01-01
Interlayer coupling in rotationally faulted graphene multilayers breaks the local sublattice-symmetry of the individual layers. Earlier we have presented a theory of this mechanism, which reduces to an effective Dirac model with space-dependent mass in an important limit. It thus makes a wealth of existing knowledge available for the study of rotationally faulted graphene multilayers. Agreement of this theory with a recent experiment in a strong magnetic field was demonstrated. Here we explore some of the predictions of this theory for the system in zero magnetic field at large interlayer bias, when it becomes local in space. We use that theory to illuminate the physics of localization and velocity renormalization in twisted graphene layers. (paper)
The principle of locality: Effectiveness, fate, and challenges
International Nuclear Information System (INIS)
Doplicher, Sergio
2010-01-01
The special theory of relativity and quantum mechanics merge in the key principle of quantum field theory, the principle of locality. We review some examples of its 'unreasonable effectiveness' in giving rise to most of the conceptual and structural frame of quantum field theory, especially in the absence of massless particles. This effectiveness shows up best in the formulation of quantum field theory in terms of operator algebras of local observables; this formulation is successful in digging out the roots of global gauge invariance, through the analysis of superselection structure and statistics, in the structure of the local observable quantities alone, at least for purely massive theories; but so far it seems unfit to cope with the principle of local gauge invariance. This problem emerges also if one attempts to figure out the fate of the principle of locality in theories describing the gravitational forces between elementary particles as well. An approach based on the need to keep an operational meaning, in terms of localization of events, of the notion of space-time, shows that, in the small, the latter must loose any meaning as a classical pseudo-Riemannian manifold, locally based on Minkowski space, but should acquire a quantum structure at the Planck scale. We review the geometry of a basic model of quantum space-time and some attempts to formulate interaction of quantum fields on quantum space-time. The principle of locality is necessarily lost at the Planck scale, and it is a crucial open problem to unravel a replacement in such theories which is equally mathematically sharp, namely, a principle where the general theory of relativity and quantum mechanics merge, which reduces to the principle of locality at larger scales. Besides exploring its fate, many challenges for the principle of locality remain; among them, the analysis of superselection structure and statistics also in the presence of massless particles, and to give a precise mathematical
Analysis of Local Dependence and Multidimensionality in Graphical Loglinear Rasch Models
DEFF Research Database (Denmark)
Kreiner, Svend; Christensen, Karl Bang
2004-01-01
Local independence; Multidimensionality; Differential item functioning; Uniform local dependence and DIF; Graphical Rasch models; Loglinear Rasch model......Local independence; Multidimensionality; Differential item functioning; Uniform local dependence and DIF; Graphical Rasch models; Loglinear Rasch model...
International Nuclear Information System (INIS)
Palacios, Elias; Ferreri, J.C.
1985-01-01
Safety analyses assocciated with the elimination of radioactive wastes in rock masses assume, in all cases, the existance of wastes which will corrode the waste canisters producing the liberation of radionuclides in the rocky and their ultimate migration towards the biosphere. A conceptual discussion is presented which allows the specification to be met by the models for the prediction of the effects of the emplacement of a high level waste repository located at a depth of 500 m in a granitic rock. Furthermore, the radionuclides giving the largest contribution to the radiological impact are identified. (Author) [es
International Nuclear Information System (INIS)
Sanchez Zapata, J. D.; Martin-Serrano, C.
2013-01-01
Chemistry is one of the principal factors that takes part in IGSCC materials susceptibility. BWR industry has been applying different mitigation techniques against IGSCC: hydrogen injection and noble metals. Mitigation effectiveness is checked by studying chemical parameters: ECP (for hydrogen injection) and Molar Ratio (for noble metal application). There is a software from EPRI called BWRVIA that allows to modelize radiolysis influence in parameters variation and obtain them at different points in the vessel. Recently, this kind of studies have become very relevant within BWR industry because it is the previous step to implement BWRVIP-62-A guidelines in order to get longer inspection intervals at vessel location where mitigation effectiveness is justified, with the cost savings for plants that this means. (Author)
Modelling of local extinction and reignition of the flame
Energy Technology Data Exchange (ETDEWEB)
Brink, A.; Kilpinen, P.; Hupa, M. [Aabo Akademi, Turku (Finland); Kjaeldman, L. [VTT Energy, Espoo (Finland); Jaeaeskelaeinen, K. [Imatran Voima Oy, Helsinki (Finland)
1996-12-31
The influence of the relations between the chemical time scale and the turbulent time scale on local extinction in turbulent flames has been studied. The results from the numerical investigation of a non-swirling flame in a sudden-expansion combustor was compared with measurements and computations reported in the literature. The turbulence-chemistry interaction was modelled using the Eddy-Dissipation Concept (EDC). In the study, different turbulent time scales were used; the Kolmogorov related time scale proposed in the EDC model and two turbulent time scales related to k/{epsilon}. The chemical time scale has been obtained from a model based on calculations with a comprehensive chemical reaction scheme. The results indicate that the Kolmogorov related time scale of the EDC model is too short to be used as an extinction criterium. The two k/{epsilon} related time scales both resulted in a closer agreement between the numerically obtained and the measured results. The result indicates that the time scale used in the EDC model should be further investigated before confident results from modelling of flows with extinction effects can be obtained. (author)
Modelling of local extinction and reignition of the flame
Energy Technology Data Exchange (ETDEWEB)
Brink, A; Kilpinen, P; Hupa, M [Aabo Akademi, Turku (Finland); Kjaeldman, L [VTT Energy, Espoo (Finland); Jaeaeskelaeinen, K [Imatran Voima Oy, Helsinki (Finland)
1997-12-31
The influence of the relations between the chemical time scale and the turbulent time scale on local extinction in turbulent flames has been studied. The results from the numerical investigation of a non-swirling flame in a sudden-expansion combustor was compared with measurements and computations reported in the literature. The turbulence-chemistry interaction was modelled using the Eddy-Dissipation Concept (EDC). In the study, different turbulent time scales were used; the Kolmogorov related time scale proposed in the EDC model and two turbulent time scales related to k/{epsilon}. The chemical time scale has been obtained from a model based on calculations with a comprehensive chemical reaction scheme. The results indicate that the Kolmogorov related time scale of the EDC model is too short to be used as an extinction criterium. The two k/{epsilon} related time scales both resulted in a closer agreement between the numerically obtained and the measured results. The result indicates that the time scale used in the EDC model should be further investigated before confident results from modelling of flows with extinction effects can be obtained. (author)
Non-Local Effects in Kaonic Atoms
International Nuclear Information System (INIS)
Lutz, M.; Florkowski, W.
2000-01-01
Optical potentials with non-local (gradient) terms are used to describe the spectra of kaonic atoms. The strength of the non-local terms is determined from a many-body calculation of the kaon self energy in nuclear matter. We find that the non-local terms are quantitatively important and the results depend strongly on the way the gradient terms are arranged. Phenomenologically successful description is obtained for p-wave like optical potentials. It is suggested that the microscopic form of the non-local interaction terms is obtained systematically by means of a semi-classical expansion of the nucleus structure. (author)
Local lattice-gas model for immiscible fluids
International Nuclear Information System (INIS)
Chen, S.; Doolen, G.D.; Eggert, K.; Grunau, D.; Loh, E.Y.
1991-01-01
We present a lattice-gas model for two-dimensional immiscible fluid flows with surface tension that uses strictly local collision rules. Instead of using a local total color flux as Somers and Rem [Physica D 47, 39 (1991)], we use local colored holes to be the memory of particles of the same color. Interactions between walls and fluids are included that produce arbitrary contact angles
Coupling of nonlocal and local continuum models by the Arlequinapproach
Han, Fei; Lubineau, Gilles
2011-01-01
for the 'fine scale' description in which nonlocal interactions are considered to have non-negligible effects. Classical continuum mechanics only involving local contact forces is introduced for the rest of the structure where these nonlocal effects can
Strain gradient crystal plasticity effects on flow localization
DEFF Research Database (Denmark)
Borg, Ulrik
2007-01-01
for metals described by the reformulated Fleck-Hutchinson strain gradient plasticity theory. The theory is implemented numerically within a finite element framework using slip rate increments and displacement increments as state variables. The formulation reduces to the classical crystal plasticity theory...... in the absence of strain gradients. The model is used to study the effect of an internal material length scale on the localization of plastic flow in shear bands in a single crystal under plane strain tension. It is shown that the mesh sensitivity is removed when using the nonlocal material model considered...
A novel Monte Carlo approach to hybrid local volatility models
A.W. van der Stoep (Anton); L.A. Grzelak (Lech Aleksander); C.W. Oosterlee (Cornelis)
2017-01-01
textabstractWe present in a Monte Carlo simulation framework, a novel approach for the evaluation of hybrid local volatility [Risk, 1994, 7, 18–20], [Int. J. Theor. Appl. Finance, 1998, 1, 61–110] models. In particular, we consider the stochastic local volatility model—see e.g. Lipton et al. [Quant.
Non-local effects in kaonic atoms
International Nuclear Information System (INIS)
Lutz, M.; Florkowski, W.
2000-04-01
Optical potentials with non-local (gradient) terms are used to describe the spectra of kaonic atoms. The strength of the non-local terms is determined from a many-body calculation of the kaon self-energy in nuclear matter. The optical potentials show strong non-linearities in the nucleon density and sizeable non-local terms. We find that the non-local terms are quantitatively important and the results depend strongly on the way the gradient terms are arranged. Phenomenologically successful fits are obtained for p-wave like optical potentials. It is suggested that the microscopic form of the non-local interaction terms is obtained systematically by means of a semi-classical expansion of the nucleus structure. We conclude that a microscopic description of kaonic atom data requires further detailed studies of the microscopic K - nuclear dynamics. (orig.)
Extension of local front reconstruction method with controlled coalescence model
Rajkotwala, A. H.; Mirsandi, H.; Peters, E. A. J. F.; Baltussen, M. W.; van der Geld, C. W. M.; Kuerten, J. G. M.; Kuipers, J. A. M.
2018-02-01
The physics of droplet collisions involves a wide range of length scales. This poses a challenge to accurately simulate such flows with standard fixed grid methods due to their inability to resolve all relevant scales with an affordable number of computational grid cells. A solution is to couple a fixed grid method with subgrid models that account for microscale effects. In this paper, we improved and extended the Local Front Reconstruction Method (LFRM) with a film drainage model of Zang and Law [Phys. Fluids 23, 042102 (2011)]. The new framework is first validated by (near) head-on collision of two equal tetradecane droplets using experimental film drainage times. When the experimental film drainage times are used, the LFRM method is better in predicting the droplet collisions, especially at high velocity in comparison with other fixed grid methods (i.e., the front tracking method and the coupled level set and volume of fluid method). When the film drainage model is invoked, the method shows a good qualitative match with experiments, but a quantitative correspondence of the predicted film drainage time with the experimental drainage time is not obtained indicating that further development of film drainage model is required. However, it can be safely concluded that the LFRM coupled with film drainage models is much better in predicting the collision dynamics than the traditional methods.
Carvalho, Vanessa F M; Migotto, Amanda; Giacone, Daniela V; de Lemos, Débora P; Zanoni, Thalita B; Maria-Engler, Silvya S; Costa-Lotufo, Leticia V; Lopes, Luciana B
2017-11-15
Considering that tumor development is generally multifactorial, therapy with a combination of agents capable of potentiating cytotoxic effects is promising. In this study, we co-encapsulated C6 ceramide (0.35%) and paclitaxel (0.50%) in micro and nanoemulsions containing tributyrin (a butyric acid pro-drug included for potentiation of cytotoxicity), and compared their ability to co-localize the drugs in viable skin layers. The nanoemulsion delivered 2- and 2.4-fold more paclitaxel into viable skin layers of porcine skin in vitro at 4 and 8h post-application than the microemulsion, and 1.9-fold more C6 ceramide at 8h. The drugs were co-localized mainly in the epidermis, suggesting the nanoemulsion ability for a targeted delivery. Based on this result, the nanoemulsion was selected for evaluation of the nanocarrier-mediated cytotoxicity against cells in culture (2D model) and histological changes in a 3D melanoma model. Encapsulation of the drugs individually decreased the concentration necessary to reduce melanoma cells viability to 50% (EC 50 ) by approximately 4- (paclitaxel) and 13-fold (ceramide), demonstrating an improved nanoemulsion-mediated drug delivery. Co-encapsulation of paclitaxel and ceramide further decreased EC 50 by 2.5-4.5-fold, and calculation of the combination index indicated a synergistic effect. Nanoemulsion topical administration on 3D bioengineered melanoma models for 48h promoted marked epidermis destruction, with only few cells remaining in this layer. This result demonstrates the efficacy of the nanoemulsion, but also suggests non-selective cytotoxic effects, which highlights the importance of localizing the drugs within cutaneous layers where the lesions develop to avoid adverse effects. Copyright © 2017 Elsevier B.V. All rights reserved.
Bonissone CIDU Presentation: Design of Local Fuzzy Models
National Aeronautics and Space Administration — After reviewing key background concepts in fuzzy systems and evolutionary computing, we will focus on the use of local fuzzy models, which are related to both kernel...
Local models violating Bell's inequality by time delays
International Nuclear Information System (INIS)
Scalera, G.C.
1984-01-01
The performance of ensemble averages is neither a sufficient nor a necessary condition to avoid Bell's inequality violations characteristic of nonergodic systems. Slight modifications of a local nonergodic logical model violating Bell's inequality produce a stochastic model exactly fitting the quantum-mechanical correlation function. From these considerations is appears evident that the last experiments on the existence of local hidden variables are not conclusive
Bang-bang Model for Regulation of Local Blood Flow
Golub, Aleksander S.; Pittman, Roland N.
2013-01-01
The classical model of metabolic regulation of blood flow in muscle tissue implies the maintenance of basal tone in arterioles of resting muscle and their dilation in response to exercise and/or tissue hypoxia via the evoked production of vasodilator metabolites by myocytes. A century-long effort to identify specific metabolites responsible for explaining active and reactive hyperemia has not been successful. Furthermore, the metabolic theory is not compatible with new knowledge on the role of physiological radicals (e.g., nitric oxide, NO, and superoxide anion, O2−) in the regulation of microvascular tone. We propose a model of regulation in which muscle contraction and active hyperemia are considered the physiologically normal state. We employ the “bang-bang” or “on/off” regulatory model which makes use of a threshold and hysteresis; a float valve to control the water level in a tank is a common example of this type of regulation. Active bang-bang regulation comes into effect when the supply of oxygen and glucose exceeds the demand, leading to activation of membrane NADPH oxidase, release of O2− into the interstitial space and subsequent neutralization of the interstitial NO. Switching arterioles on/off when local blood flow crosses the threshold is realized by a local cell circuit with the properties of a bang-bang controller, determined by its threshold, hysteresis and dead-band. This model provides a clear and unambiguous interpretation of the mechanism to balance tissue demand with a sufficient supply of nutrients and oxygen. PMID:23441827
Synthesis of industrial applications of local approach to fracture models
International Nuclear Information System (INIS)
Eripret, C.
1993-03-01
This report gathers different applications of local approach to fracture models to various industrial configurations, such as nuclear pressure vessel steel, cast duplex stainless steels, or primary circuit welds such as bimetallic welds. As soon as models are developed on the basis of microstructural observations, damage mechanisms analyses, and fracture process, the local approach to fracture proves to solve problems where classical fracture mechanics concepts fail. Therefore, local approach appears to be a powerful tool, which completes the standard fracture criteria used in nuclear industry by exhibiting where and why those classical concepts become unvalid. (author). 1 tab., 18 figs., 25 refs
A model of optimization for local energy infrastructure development
International Nuclear Information System (INIS)
Juroszek, Zbigniew; Kudelko, Mariusz
2016-01-01
The authors present a non-linear, optimization model supporting the planning of local energy systems development. The model considers two forms of final energy – heat and electricity. The model reflects both private and external costs and is designed to show the social perspective. It considers the variability of the marginal costs attributed to local renewable resources. In order to demonstrate the capacity of the model, the authors present a case study by modelling the development of the energy infrastructure in a municipality located in the south of Poland. The ensuing results show that a swift and significant shift in the local energy policy of typical central European municipalities is needed. The modelling is done in two scenarios – with and without the internalization of external environmental costs. The results confirm that the internalization of the external costs of energy production on a local scale leads to a significant improvement in the allocation of resources. - Highlights: • A model for municipal energy system development in Central European environment has been developed. • The variability of marginal costs of local, renewable fuels is considered. • External, environmental costs are considered. • The model reflects both network and individual energy infrastructure (e.g. individual housing boilers). • A swift change in Central European municipal energy infrastructure is necessary.
Transorbital target localization in the porcine model
DeLisi, Michael P.; Mawn, Louise A.; Galloway, Robert L.
2013-03-01
Current pharmacological therapies for the treatment of chronic optic neuropathies such as glaucoma are often inadequate due to their inability to directly affect the optic nerve and prevent neuron death. While drugs that target the neurons have been developed, existing methods of administration are not capable of delivering an effective dose of medication along the entire length of the nerve. We have developed an image-guided system that utilizes a magnetically tracked flexible endoscope to navigate to the back of the eye and administer therapy directly to the optic nerve. We demonstrate the capabilities of this system with a series of targeted surgical interventions in the orbits of live pigs. Target objects consisted of NMR microspherical bulbs with a volume of 18 μL filled with either water or diluted gadolinium-based contrast, and prepared with either the presence or absence of a visible coloring agent. A total of 6 pigs were placed under general anesthesia and two microspheres of differing color and contrast content were blindly implanted in the fat tissue of each orbit. The pigs were scanned with T1-weighted MRI, image volumes were registered, and the microsphere containing gadolinium contrast was designated as the target. The surgeon was required to navigate the flexible endoscope to the target and identify it by color. For the last three pigs, a 2D/3D registration was performed such that the target's coordinates in the image volume was noted and its location on the video stream was displayed with a crosshair to aid in navigation. The surgeon was able to correctly identify the target by color, with an average intervention time of 20 minutes for the first three pigs and 3 minutes for the last three.
Local void and slip model used in BODYFIT-2PE
International Nuclear Information System (INIS)
Chen, B.C.J.; Chien, T.H.; Kim, J.H.; Lellouche, G.S.
1983-01-01
A local void and slip model has been proposed for a two-phase flow without the need of fitting any empirical parameters. This model is based on the assumption that all bubbles have reached their terminal rise velocities in the two-phase region. This simple model seems to provide reasonable calculational results when compared with the experimental data and other void and slip models. It provides a means to account for the void and slip of a two-phase flow on a local basis. This is particularly suitable for a fine mesh thermal-hydraulic computer program such as BODYFIT-2PE
McPhee, James; Mengual, Sebastian; MacDonell, Shelley
2017-04-01
Seasonal snowpack melt constitutes the main water source for large portions of extratropical South America, including central Chile and Western Argentina. The properties and distribution of snow in the Andes are threatened by rapid climate change, characterised by warming and drying. This study provides a first attempt at detailed description of the energy balance of the seasonal snowpack and its variability along a latitudinal gradient, which is also correlated with an elevation and precipitation gradient, in the Andes Cordillera. The Snowpack model was validated at semi-arid, Mediterranean and temperate humid sites, where meteorological and snowpack properties have been observed since year 2013. Site elevations decrease from north to south, whereas precipitation climatology increases with latitude. Results show that turbulent energy exchange becomes relatively more important in periods of low snow accumulation, with sensible heat fluxes having a greater effect in cooling the snowpack at the high-altitude, low latitude site. Likewise, daily melt-freeze cycles are important in maintaining positive cold contents throughout the accumulation season at this site, and contribute to extending the duration of snow cover despite low accumulation and high radiation loads. In contrast, the southernmost, lowest elevation site shows smaller daily temperature amplitude and a much more preponderant radiation component to the energy balance. This modelling exercise highlights the nonlinearities of snow dynamics at different geographical settings in a sparsely monitored mountain area of the world, as well as the need for further understanding in order to evaluate the sensitivity of snow-dominated watersheds to global warming and climate change.
Electrophysiological Data and the Biophysical Modelling of Local Cortical Circuits
Directory of Open Access Journals (Sweden)
Dimitris Pinotsis
2014-03-01
Full Text Available This paper shows how recordings of gamma oscillations – under different experimental conditions or from different subjects – can be combined with a class of population models called neural fields and dynamic causal modeling (DCM to distinguish among alternative hypotheses regarding cortical structure and function. This approach exploits inter-subject variability and trial-specific effects associated with modulations in the peak frequency of gamma oscillations. It draws on the computational power of Bayesian model inversion, when applied to neural field models of cortical dynamics. Bayesian model comparison allows one to adjudicate among different mechanistic hypotheses about cortical excitability, synaptic kinetics and the cardinal topographic features of local cortical circuits. It also provides optimal parameter estimates that quantify neuromodulation and the spatial dispersion of axonal connections or summation of receptive fields in the visual cortex. This paper provides an overview of a family of neural field models that have been recently implemented using the DCM toolbox of the academic freeware Statistical Parametric Mapping (SPM. The SPM software is a popular platform for analyzing neuroimaging data, used by several neuroscience communities worldwide. DCM allows for a formal (Bayesian statistical analysis of cortical network connectivity, based upon realistic biophysical models of brain responses. It is this particular feature of DCM – the unique combination of generative models with optimization techniques based upon (variational Bayesian principles – that furnishes a novel way to characterize functional brain architectures. In particular, it provides answers to questions about how the brain is wired and how it responds to different experimental manipulations. For a review of the general role of neural fields in SPM the reader can consult e.g. see [1]. Neural fields have a long and illustrious history in mathematical
Progress towards localization in the attractive Hubbard model
Morong, W.; Xu, W.; Demarco, B.
2017-04-01
The interplay between fermionic superfluidity and disorder is a topic of long-standing interest that has recently come within reach of ultracold gas experiments. Outstanding questions include the fate of Cooper pairs in a localized superfluid and the effect of disorder on the superfluid transition temperature. We report progress on tackling this problem using a realization of the Hubbard model with attractive interactions. Our system consists of two spin states of fermionic potassium-40 trapped in a cubic optical lattice. Disorder is introduced using an optical speckle potential, and interactions are controlled via a Feshbach resonance. We study the binding and unbinding of Cooper pairs in this system using rf spectroscopy, changes in Tc by measuring the condensate fraction, and transport properties by observing the response to an applied impulse. We will discuss progress towards these measurements.
Image contrast enhancement based on a local standard deviation model
International Nuclear Information System (INIS)
Chang, Dah-Chung; Wu, Wen-Rong
1996-01-01
The adaptive contrast enhancement (ACE) algorithm is a widely used image enhancement method, which needs a contrast gain to adjust high frequency components of an image. In the literature, the gain is usually inversely proportional to the local standard deviation (LSD) or is a constant. But these cause two problems in practical applications, i.e., noise overenhancement and ringing artifact. In this paper a new gain is developed based on Hunt's Gaussian image model to prevent the two defects. The new gain is a nonlinear function of LSD and has the desired characteristic emphasizing the LSD regions in which details are concentrated. We have applied the new ACE algorithm to chest x-ray images and the simulations show the effectiveness of the proposed algorithm
The small length scale effect for a non-local cantilever beam: a paradox solved.
Challamel, N; Wang, C M
2008-08-27
Non-local continuum mechanics allows one to account for the small length scale effect that becomes significant when dealing with microstructures or nanostructures. This paper presents some simplified non-local elastic beam models, for the bending analyses of small scale rods. Integral-type or gradient non-local models abandon the classical assumption of locality, and admit that stress depends not only on the strain value at that point but also on the strain values of all points on the body. There is a paradox still unresolved at this stage: some bending solutions of integral-based non-local elastic beams have been found to be identical to the classical (local) solution, i.e. the small scale effect is not present at all. One example is the Euler-Bernoulli cantilever nanobeam model with a point load which has application in microelectromechanical systems and nanoelectromechanical systems as an actuator. In this paper, it will be shown that this paradox may be overcome with a gradient elastic model as well as an integral non-local elastic model that is based on combining the local and the non-local curvatures in the constitutive elastic relation. The latter model comprises the classical gradient model and Eringen's integral model, and its application produces small length scale terms in the non-local elastic cantilever beam solution.
A knowledge representation of local pandemic influenza planning models.
Islam, Runa; Brandeau, Margaret L; Das, Amar K
2007-10-11
Planning for pandemic flu outbreak at the small-government level can be aided through the use of mathematical policy models. Formulating and analyzing policy models, however, can be a time- and expertise-expensive process. We believe that a knowledge-based system for facilitating the instantiation of locale- and problem-specific policy models can reduce some of these costs. In this work, we present the ontology we have developed for pandemic influenza policy models.
Anomalously suppressed localization in the two-channel Anderson model
International Nuclear Information System (INIS)
Nguyen, Ba Phi; Kim, Kihong
2012-01-01
We study numerically the localization properties of a two-channel quasi-one-dimensional Anderson model with uncorrelated diagonal disorder within the nearest-neighbor tight-binding approximation. We calculate and analyze the disorder-averaged transmittance and the Lyapunov exponent. We find that the localization of the entire system is enhanced by increasing the interchain hopping strength t-tilde. From the numerical investigation of the energy dependence of the Lyapunov exponent for many different interchain hopping strengths, we find that apart from the band center anomaly, which usually occurs in strictly one-dimensional disordered systems, additional anomalies appear at special spectral points. They are found to be associated with the interchain hopping strength and occur at E=± t-tilde/2 and ± t-tilde. We find that the anomalies at E=± t-tilde are associated with the π-coupling occurring within one energy band and those at E=± t-tilde/2 are associated with the π-coupling occurring between two different energy bands. Despite having a similar origin, these two anomalies have distinct characteristics in their dependence on the strength of disorder. We also show that for a suitable range of parameter values, effectively delocalized states are observed in finite-size systems. (paper)
A Local Composition Model for Paraffinic Solid Solutions
DEFF Research Database (Denmark)
Coutinho, A.P. João; Knudsen, Kim; Andersen, Simon Ivar
1996-01-01
The description of the solid-phase non-ideality remains the main obstacle in modelling the solid-liquid equilibrium of hydrocarbons. A theoretical model, based on the local composition concept, is developed for the orthorhombic phase of n-alkanes and tested against experimental data for binary sy...... systems. It is shown that it can adequately predict the experimental phase behaviour of paraffinic mixtures. This work extends the applicability of local composition models to the solid phase. Copyright (C) 1996 Elsevier Science Ltd....
Vortices, semi-local vortices in gauged linear sigma model
International Nuclear Information System (INIS)
Kim, Namkwon
1998-11-01
We consider the static (2+1)D gauged linear sigma model. By analyzing the governing system of partial differential equations, we investigate various aspects of the model. We show the existence of energy finite vortices under a partially broken symmetry on R 2 with the necessary condition suggested by Y. Yang. We also introduce generalized semi-local vortices and show the existence of energy finite semi-local vortices under a certain condition. The vacuum manifold for the semi-local vortices turns out to be graded. Besides, with a special choice of a representation, we show that the O(3) sigma model of which target space is nonlinear is a singular limit of the gauged linear sigma model of which target space is linear. (author)
Modeling of plastic localization in aluminum and Al–Cu alloys under shock loading
International Nuclear Information System (INIS)
Krasnikov, V.S.; Mayer, A.E.
2014-01-01
This paper focuses on the modeling of plastic deformation localization in pure aluminum and aluminum–copper alloys during the propagation of a plane shock wave. Modeling is carried out with the use of continual dislocation plasticity model in 2-D geometry. It is shown that the formation of localization bands occurs at an angle of 45° to the direction of propagation of the shock front. Effective initiators for plastic localization in pure aluminum are the perturbations of the initial dislocation density, in the alloys – perturbations of the dislocation density and the concentration of copper atoms. Perturbations of temperature field in a range of tens of kelvins are not so effective for plastic localization. In the alloy plastic localization intensity decreases with an increase of strain rate due to the thermally activated nature of the dislocation motion
DEFF Research Database (Denmark)
Schyth, Brian Dall; Bramsen, Jesper Bertram; Pakula, Malgorzata Maria
2012-01-01
but often only examining the expression of specific immunologically relevant genes in selected cell populations typically blood cells from treated animals or humans. Assays using a relevant physiological state in biological models as read-out are not common. Here we use a fish model where the innate...
Modeling of Local Magnetic Field Enhancements within Solar Flux Ropes
Romashets, E; Vandas, M; Poedts, Stefaan
2010-01-01
To model and study local magnetic-field enhancements in a solar flux rope we consider the magnetic field in its interior as a superposition of two linear (constant alpha) force-free magnetic-field distributions, viz. a global one, which is locally similar to a part of the cylinder, and a local torus-shaped magnetic distribution. The newly derived solution for a toroid with an aspect ratio close to unity is applied. The symmetry axis of the toroid and that of the cylinder may or may not coinci...
Nociceptive Effects of Locally Treated Metoprolol
Directory of Open Access Journals (Sweden)
Nursima Cukadar
2015-06-01
Results: Metoprolol, an antagonist, significantly decreased the thermal latency and mechanical thresholds with dose and time dependent manner. However, dobutamine, an agonist, enhanced the latency and thresholds dose and time dependent. Conclusions: This results suggest that in contrast to dobutamine, locally treated metoprolol may cause hyperalgesic and allodynic actions. In addition, our results can demonstrate that peripheral beta-adrenergic receptors can play important roles in nociceptive process. [Cukurova Med J 2015; 40(2.000: 258-266
Relativistic effects in local inertial frames including parametrized-post-Newtonian effects
International Nuclear Information System (INIS)
Shahid-Saless, B.; Ashby, N.
1988-01-01
We use the concept of a generalized Fermi frame to describe relativistic effects, due to local and distant sources of gravitation, on a body placed in a local inertial frame of reference. In particular we have considered a model of two spherically symmetric gravitating point sources, moving in circular orbits around a common barycenter where one of the bodies is chosen to be the local and the other the distant one. This has been done using the slow-motion, weak-field approximation and including four of the parametrized-post-Newtonian (PPN) parameters. The position of the classical center of mass must be modified when the PPN parameter zeta 2 is included. We show that the main relativistic effect on a local satellite is described by the Schwarzschild field of the local body and the nonlinear term corresponding to the self-interaction of the local source with itself. There are also much smaller terms that are proportional, respectively, to the product of the potentials of local and distant bodies and to the distant body's self-interactions. The spatial axes of the local frame undergo geodetic precession. In addition we have an acceleration of the order of 10/sup -11/ cm sec -2 that vanish in the case of general relativity, which is discussed in detail
Integrated modeling and characterization of local crack chemistry
International Nuclear Information System (INIS)
Savchik, J.A.; Burke, M.S.
1995-01-01
The MULTEQ computer program has become an industry wide tool which can be used to calculate the chemical composition in a flow occluded region as the solution within concentrates due to a local boiling process. These results can be used to assess corrosion concerns in plant equipment such as steam generators. Corrosion modeling attempts to quantify corrosion assessments by accounting for the mass transport processes involved in the corrosion mechanism. MULTEQ has played an ever increasing role in defining the local chemistry for such corrosion models. This paper will outline how the integration of corrosion modeling with the analysis of corrosion films and deposits can lead to the development of a useful modeling tool, wherein MULTEQ is interactively linked to a diffusion and migration transport process. This would provide a capability to make detailed inferences of the local crack chemistry based on the analyses of the local corrosion films and deposits inside a crack and thus provide guidance for chemical fixes to avoid cracking. This methodology is demonstrated for a simple example of a cracked tube. This application points out the utility of coupling MULTEQ with a mass transport process and the feasibility of an option in a future version of MULTEQ that would permit relating film and deposit analyses to the local chemical environment. This would increase the amount of information obtained from removed tube analyses and laboratory testing that can contribute to an overall program for mitigating tubing and crevice corrosion
Integrated modeling and characterization of local crack chemistry
International Nuclear Information System (INIS)
Savchik, J.A.; Burke, M.S.
1996-01-01
The MULTEQ computer program has become an industry wide tool which can be used to calculate the chemical composition in a flow occluded region as the solution within concentrates due to a local boiling process. These results can be used to assess corrosion concerns in plant equipment such as steam generators. Corrosion modeling attempts to quantify corrosion assessments by accounting for the mass transport processes involved in the corrosion mechanism. MULTEQ has played an ever increasing role in defining the local chemistry for such corrosion models. This paper will outline how the integration of corrosion modeling with the analysis of corrosion films and deposits can lead to the development of a useful modeling tool, wherein MULTEQ is interactively linked to a diffusion and migration transport process. This would provide a capability to make detailed inferences of the local crack chemistry based on the analyses of the local corrosion films and deposits inside a crack and thus provide guidance for chemical fixes to avoid cracking. This methodology is demonstrated for a simple example of a cracked tube. This application points out the utility of coupling MULTEQ with a mass transport process and the feasibility of an option in a future version of MULTEQ that would permit relating film and deposit analyses to the local chemical environment. This would increase the amount of information obtained from removed tube analyses and laboratory testing that can contribute to an overall program for mitigating tubing and crevice corrosion
Marsh, Herbert W.; Kuyper, Hans; Morin, Alexandre J. S.; Philip, D. Parker; Seaton, Marjorie
2014-01-01
We offer new theoretical, substantive, statistical, design, and methodological insights into the seemingly paradoxical negative effects of school- and class-average achievement (ACH) on academic self-concept (ASC) the big-fish-little-pond-effect (BFLPE; 15,356 Dutch 9th grade students from 651
Directory of Open Access Journals (Sweden)
Peida Zhan
2018-04-01
Full Text Available In joint models for item response times (RTs and response accuracy (RA, local item dependence is composed of local RA dependence and local RT dependence. The two components are usually caused by the same common stimulus and emerge as pairs. Thus, the violation of local item independence in the joint models is called paired local item dependence. To address the issue of paired local item dependence while applying the joint cognitive diagnosis models (CDMs, this study proposed a joint testlet cognitive diagnosis modeling approach. The proposed approach is an extension of Zhan et al. (2017 and it incorporates two types of random testlet effect parameters (one for RA and the other for RTs to account for paired local item dependence. The model parameters were estimated using the full Bayesian Markov chain Monte Carlo (MCMC method. The 2015 PISA computer-based mathematics data were analyzed to demonstrate the application of the proposed model. Further, a brief simulation study was conducted to demonstrate the acceptable parameter recovery and the consequence of ignoring paired local item dependence.
MFAM: Multiple Frequency Adaptive Model-Based Indoor Localization Method.
Tuta, Jure; Juric, Matjaz B
2018-03-24
This paper presents MFAM (Multiple Frequency Adaptive Model-based localization method), a novel model-based indoor localization method that is capable of using multiple wireless signal frequencies simultaneously. It utilizes indoor architectural model and physical properties of wireless signal propagation through objects and space. The motivation for developing multiple frequency localization method lies in the future Wi-Fi standards (e.g., 802.11ah) and the growing number of various wireless signals present in the buildings (e.g., Wi-Fi, Bluetooth, ZigBee, etc.). Current indoor localization methods mostly rely on a single wireless signal type and often require many devices to achieve the necessary accuracy. MFAM utilizes multiple wireless signal types and improves the localization accuracy over the usage of a single frequency. It continuously monitors signal propagation through space and adapts the model according to the changes indoors. Using multiple signal sources lowers the required number of access points for a specific signal type while utilizing signals, already present in the indoors. Due to the unavailability of the 802.11ah hardware, we have evaluated proposed method with similar signals; we have used 2.4 GHz Wi-Fi and 868 MHz HomeMatic home automation signals. We have performed the evaluation in a modern two-bedroom apartment and measured mean localization error 2.0 to 2.3 m and median error of 2.0 to 2.2 m. Based on our evaluation results, using two different signals improves the localization accuracy by 18% in comparison to 2.4 GHz Wi-Fi-only approach. Additional signals would improve the accuracy even further. We have shown that MFAM provides better accuracy than competing methods, while having several advantages for real-world usage.
MFAM: Multiple Frequency Adaptive Model-Based Indoor Localization Method
Directory of Open Access Journals (Sweden)
Jure Tuta
2018-03-01
Full Text Available This paper presents MFAM (Multiple Frequency Adaptive Model-based localization method, a novel model-based indoor localization method that is capable of using multiple wireless signal frequencies simultaneously. It utilizes indoor architectural model and physical properties of wireless signal propagation through objects and space. The motivation for developing multiple frequency localization method lies in the future Wi-Fi standards (e.g., 802.11ah and the growing number of various wireless signals present in the buildings (e.g., Wi-Fi, Bluetooth, ZigBee, etc.. Current indoor localization methods mostly rely on a single wireless signal type and often require many devices to achieve the necessary accuracy. MFAM utilizes multiple wireless signal types and improves the localization accuracy over the usage of a single frequency. It continuously monitors signal propagation through space and adapts the model according to the changes indoors. Using multiple signal sources lowers the required number of access points for a specific signal type while utilizing signals, already present in the indoors. Due to the unavailability of the 802.11ah hardware, we have evaluated proposed method with similar signals; we have used 2.4 GHz Wi-Fi and 868 MHz HomeMatic home automation signals. We have performed the evaluation in a modern two-bedroom apartment and measured mean localization error 2.0 to 2.3 m and median error of 2.0 to 2.2 m. Based on our evaluation results, using two different signals improves the localization accuracy by 18% in comparison to 2.4 GHz Wi-Fi-only approach. Additional signals would improve the accuracy even further. We have shown that MFAM provides better accuracy than competing methods, while having several advantages for real-world usage.
A generative, probabilistic model of local protein structure
DEFF Research Database (Denmark)
Boomsma, Wouter; Mardia, Kanti V.; Taylor, Charles C.
2008-01-01
Despite significant progress in recent years, protein structure prediction maintains its status as one of the prime unsolved problems in computational biology. One of the key remaining challenges is an efficient probabilistic exploration of the structural space that correctly reflects the relative...... conformational stabilities. Here, we present a fully probabilistic, continuous model of local protein structure in atomic detail. The generative model makes efficient conformational sampling possible and provides a framework for the rigorous analysis of local sequence-structure correlations in the native state...
Evers, J.B.; Vos, J.; Chelle, M.; Andrieu, B.; Fournier, C.; Struik, P.C.
2007-01-01
The outgrowth of tiller buds in Poaceae is influenced by the ratio of red to far-red light irradiance (R:FR). At each point in the plant canopy, R:FR is affected by light scattered by surrounding plant tissues. This paper presents a three-dimensional virtual plant modelling approach to simulate
Bermúdez, María; Neal, Jeffrey C.; Bates, Paul D.; Coxon, Gemma; Freer, Jim E.; Cea, Luis; Puertas, Jerónimo
2016-04-01
Flood inundation models require appropriate boundary conditions to be specified at the limits of the domain, which commonly consist of upstream flow rate and downstream water level. These data are usually acquired from gauging stations on the river network where measured water levels are converted to discharge via a rating curve. Derived streamflow estimates are therefore subject to uncertainties in this rating curve, including extrapolating beyond the maximum observed ratings magnitude. In addition, the limited number of gauges in reach-scale studies often requires flow to be routed from the nearest upstream gauge to the boundary of the model domain. This introduces additional uncertainty, derived not only from the flow routing method used, but also from the additional lateral rainfall-runoff contributions downstream of the gauging point. Although generally assumed to have a minor impact on discharge in fluvial flood modeling, this local hydrological input may become important in a sparse gauge network or in events with significant local rainfall. In this study, a method to incorporate rating curve uncertainty and the local rainfall-runoff dynamics into the predictions of a reach-scale flood inundation model is proposed. Discharge uncertainty bounds are generated by applying a non-parametric local weighted regression approach to stage-discharge measurements for two gauging stations, while measured rainfall downstream from these locations is cascaded into a hydrological model to quantify additional inflows along the main channel. A regional simplified-physics hydraulic model is then applied to combine these inputs and generate an ensemble of discharge and water elevation time series at the boundaries of a local-scale high complexity hydraulic model. Finally, the effect of these rainfall dynamics and uncertain boundary conditions are evaluated on the local-scale model. Improvements in model performance when incorporating these processes are quantified using observed
Pengembangan Model Outdoor Learning melalui Project Berbasis Local Wisdom dalam Pembelajaran Fisika
Directory of Open Access Journals (Sweden)
Indah kurnia Putri Damayanti
2017-12-01
Full Text Available Abstrak Penelitian ini bertujuan untuk: (1 menghasilkan model outdoor learning melalui project berbasis local wisdom yang layak digunakan dalam pembelajaran fisika, (2 mengetahui keefektifan penggunaan model outdoor learning melalui project berbasis local wisdom. Penelitian pengembangan ini menggunakan metode pengembangan R & D (Research dan Development. Pada tahap Development, peneliti mengadopsi model 4D, yaitu Define, Design, Develop, dan Disseminate. Hasil penelitian menunjukkan bahwa model outdoor learning melalui project berbasis local wisdom yang dikembangkan layak digunakan dari segi produk pendukung pembelajaran yang memenuhi kriteria sangat tinggi menurut para ahli, praktis menurut guru dan peserta didik. Lembar observasi yang memenuhi kriteria valid dan reliabel berdasarkan hasil ICC dan tes hasil belajar yang memenuhi kriteria valid dan reliabel berdasarkan hasil Quest. Selain itu, model outdoor learning melalui project berbasis local wisdom lebih efektif digunakan dalam pembelajaran fisika dilihat dari hasil analisis multivariate dan GLMMDs yang memperoleh nilai signifikansi 0,000 dan MD yang tinggi. AbstractThis research was aimed to: (1 produce outdoor learning via project based suitable local wisdom model used in physics learning, (2 know the effectiveness in using outdoor learning via project based local wisdom model. This developing research used a R & D method (Research and Development. On Development step, the researcher adopted 4D model, they were Define, Design, Develop, dan Dissemination. The results showed that the developed outdoor learning via project based local wisdom model was suitable to be used in terms of learning support product that was in very high category according expert, practical according teacher and students. In addition the observation sheet was in valid criteria and reliabel based on ICC and the learning outcome test was in valid criteria and reliabel based on Quest. Besides, outdoor learning via
Modeling non-locality of plasmonic excitations with a fictitious film
Kong, Jiantao; Shvonski, Alexander; Kempa, Krzysztof
Non-local effects, requiring a wavevector (q) dependent dielectric response are becoming increasingly important in studies of plasmonic and metamaterial structures. The phenomenological hydrodynamic approximation (HDA) is the simplest, and most often used model, but it often fails. We show that the d-function formalism, exact to first order in q, is a powerful and simple-to-use alternative. Recently, we developed a mapping of the d-function formalism into a purely local fictitious film. This geometric mapping allows for non-local extensions of any local calculation scheme, including FDTD. We demonstrate here, that such mapped FDTD simulation of metallic nanoclusters agrees very well with various experiments.
DEFF Research Database (Denmark)
Te Boekhorst, Bernard C M; Jensen, Linda B; Colombo, Stefano
2012-01-01
in lipopolysaccharide-activated RAW 264.7 cells in vitro. The severity of collagen antibody-induced arthritis in DBA/1J mice was assessed by paw scoring and compared to the degree of magnetic resonance imaging (MRI)-quantified joint effusion and bone marrow edema. Two intra-articular treatments per joint...... and femoral head remained unchanged. When the siRNA dose was 5 or 10µg, there was no difference between the specific and the non-specific siRNA treatment groups. These findings suggest that MRI is a promising method for evaluation of early disease progression and treatment in murine arthritis models...
Algebraic models of local period maps and Yukawa algebras
Bandiera, Ruggero; Manetti, Marco
2018-02-01
We describe some L_{∞} model for the local period map of a compact Kähler manifold. Applications include the study of deformations with associated variation of Hodge structure constrained by certain closed strata of the Grassmannian of the de Rham cohomology. As a by-product, we obtain an interpretation in the framework of deformation theory of the Yukawa coupling.
VCE Model of Community, Local, Regional Food Systems
Niewolny, Kim
2016-01-01
This document is a chart illustrating the Virginia Cooperative Extension model for food systems at the community, local and regional level. This chart shows an interrelationship between basic and applied research, leveraging of resources and opportunities, communication and marketing, assessment, evaluation and impact, knowledge, skills, and social change, facilitation of partnerships, and also teaching.
Bi-local holography in the SYK model: perturbations
Energy Technology Data Exchange (ETDEWEB)
Jevicki, Antal; Suzuki, Kenta [Department of Physics, Brown University,182 Hope Street, Providence, RI 02912 (United States)
2016-11-08
We continue the study of the Sachdev-Ye-Kitaev model in the Large N limit. Following our formulation in terms of bi-local collective fields with dynamical reparametrization symmetry, we perform perturbative calculations around the conformal IR point. These are based on an ε expansion which allows for analytical evaluation of correlators and finite temperature quantities.
General Business Model Patterns for Local Energy Management Concepts
Energy Technology Data Exchange (ETDEWEB)
Facchinetti, Emanuele, E-mail: emanuele.facchinetti@hslu.ch; Sulzer, Sabine [Lucerne Competence Center for Energy Research, Lucerne University of Applied Science and Arts, Horw (Switzerland)
2016-03-03
The transition toward a more sustainable global energy system, significantly relying on renewable energies and decentralized energy systems, requires a deep reorganization of the energy sector. The way how energy services are generated, delivered, and traded is expected to be very different in the coming years. Business model innovation is recognized as a key driver for the successful implementation of the energy turnaround. This work contributes to this topic by introducing a heuristic methodology easing the identification of general business model patterns best suited for Local Energy Management concepts such as Energy Hubs. A conceptual framework characterizing the Local Energy Management business model solution space is developed. Three reference business model patterns providing orientation across the defined solution space are identified, analyzed, and compared. Through a market review, a number of successfully implemented innovative business models have been analyzed and allocated within the defined solution space. The outcomes of this work offer to potential stakeholders a starting point and guidelines for the business model innovation process, as well as insights for policy makers on challenges and opportunities related to Local Energy Management concepts.
General Business Model Patterns for Local Energy Management Concepts
International Nuclear Information System (INIS)
Facchinetti, Emanuele; Sulzer, Sabine
2016-01-01
The transition toward a more sustainable global energy system, significantly relying on renewable energies and decentralized energy systems, requires a deep reorganization of the energy sector. The way how energy services are generated, delivered, and traded is expected to be very different in the coming years. Business model innovation is recognized as a key driver for the successful implementation of the energy turnaround. This work contributes to this topic by introducing a heuristic methodology easing the identification of general business model patterns best suited for Local Energy Management concepts such as Energy Hubs. A conceptual framework characterizing the Local Energy Management business model solution space is developed. Three reference business model patterns providing orientation across the defined solution space are identified, analyzed, and compared. Through a market review, a number of successfully implemented innovative business models have been analyzed and allocated within the defined solution space. The outcomes of this work offer to potential stakeholders a starting point and guidelines for the business model innovation process, as well as insights for policy makers on challenges and opportunities related to Local Energy Management concepts.
Analytical local electron-electron interaction model potentials for atoms
International Nuclear Information System (INIS)
Neugebauer, Johannes; Reiher, Markus; Hinze, Juergen
2002-01-01
Analytical local potentials for modeling the electron-electron interaction in an atom reduce significantly the computational effort in electronic structure calculations. The development of such potentials has a long history, but some promising ideas have not yet been taken into account for further improvements. We determine a local electron-electron interaction potential akin to those suggested by Green et al. [Phys. Rev. 184, 1 (1969)], which are widely used in atom-ion scattering calculations, electron-capture processes, and electronic structure calculations. Generalized Yukawa-type model potentials are introduced. This leads, however, to shell-dependent local potentials, because the origin behavior of such potentials is different for different shells as has been explicated analytically [J. Neugebauer, M. Reiher, and J. Hinze, Phys. Rev. A 65, 032518 (2002)]. It is found that the parameters that characterize these local potentials can be interpolated and extrapolated reliably for different nuclear charges and different numbers of electrons. The analytical behavior of the corresponding localized Hartree-Fock potentials at the origin and at long distances is utilized in order to reduce the number of fit parameters. It turns out that the shell-dependent form of Green's potential, which we also derive, yields results of comparable accuracy using only one shell-dependent parameter
To an effective local Langlands correspondence
Bushnell, Colin J
2014-01-01
Let F be a non-Archimedean local field. Let \\mathcal{W}_{F} be the Weil group of F and \\mathcal{P}_{F} the wild inertia subgroup of \\mathcal{W}_{F}. Let \\widehat {\\mathcal{W}}_{F} be the set of equivalence classes of irreducible smooth representations of \\mathcal{W}_{F}. Let \\mathcal{A}^{0}_{n}(F) denote the set of equivalence classes of irreducible cuspidal representations of \\mathrm{GL}_{n}(F) and set \\widehat {\\mathrm{GL}}_{F} = \\bigcup _{n\\ge 1} \\mathcal{A}^{0}_{n}(F). If \\sigma \\in \\widehat {\\mathcal{W}}_{F}, let ^{L}{\\sigma }\\in \\widehat {\\mathrm{GL}}_{F} be the cuspidal representation matched with \\sigma by the Langlands Correspondence. If \\sigma is totally wildly ramified, in that its restriction to \\mathcal{P}_{F} is irreducible, the authors treat ^{L}{\\sigma} as known. From that starting point, the authors construct an explicit bijection \\mathbb{N}:\\widehat {\\mathcal{W}}_{F} \\to \\widehat {\\mathrm{GL}}_{F}, sending \\sigma to ^{N}{\\sigma}. The authors compare this "naïve correspondence" with the L...
Local yield stress statistics in model amorphous solids
Barbot, Armand; Lerbinger, Matthias; Hernandez-Garcia, Anier; García-García, Reinaldo; Falk, Michael L.; Vandembroucq, Damien; Patinet, Sylvain
2018-03-01
We develop and extend a method presented by Patinet, Vandembroucq, and Falk [Phys. Rev. Lett. 117, 045501 (2016), 10.1103/PhysRevLett.117.045501] to compute the local yield stresses at the atomic scale in model two-dimensional Lennard-Jones glasses produced via differing quench protocols. This technique allows us to sample the plastic rearrangements in a nonperturbative manner for different loading directions on a well-controlled length scale. Plastic activity upon shearing correlates strongly with the locations of low yield stresses in the quenched states. This correlation is higher in more structurally relaxed systems. The distribution of local yield stresses is also shown to strongly depend on the quench protocol: the more relaxed the glass, the higher the local plastic thresholds. Analysis of the magnitude of local plastic relaxations reveals that stress drops follow exponential distributions, justifying the hypothesis of an average characteristic amplitude often conjectured in mesoscopic or continuum models. The amplitude of the local plastic rearrangements increases on average with the yield stress, regardless of the system preparation. The local yield stress varies with the shear orientation tested and strongly correlates with the plastic rearrangement locations when the system is sheared correspondingly. It is thus argued that plastic rearrangements are the consequence of shear transformation zones encoded in the glass structure that possess weak slip planes along different orientations. Finally, we justify the length scale employed in this work and extract the yield threshold statistics as a function of the size of the probing zones. This method makes it possible to derive physically grounded models of plasticity for amorphous materials by directly revealing the relevant details of the shear transformation zones that mediate this process.
DEFF Research Database (Denmark)
Øjelund, Henrik; Sadegh, Payman
2000-01-01
be obtained. This paper presents a new approach for system modelling under partial (global) information (or the so called Gray-box modelling) that seeks to perserve the benefits of the global as well as local methodologies sithin a unified framework. While the proposed technique relies on local approximations......Local function approximations concern fitting low order models to weighted data in neighbourhoods of the points where the approximations are desired. Despite their generality and convenience of use, local models typically suffer, among others, from difficulties arising in physical interpretation...... simultaneously with the (local estimates of) function values. The approach is applied to modelling of a linear time variant dynamic system under prior linear time invariant structure where local regression fails as a result of high dimensionality....
Local Model Predictive Control for T-S Fuzzy Systems.
Lee, Donghwan; Hu, Jianghai
2017-09-01
In this paper, a new linear matrix inequality-based model predictive control (MPC) problem is studied for discrete-time nonlinear systems described as Takagi-Sugeno fuzzy systems. A recent local stability approach is applied to improve the performance of the proposed MPC scheme. At each time k , an optimal state-feedback gain that minimizes an objective function is obtained by solving a semidefinite programming problem. The local stability analysis, the estimation of the domain of attraction, and feasibility of the proposed MPC are proved. Examples are given to demonstrate the advantages of the suggested MPC over existing approaches.
Mathematical models and methods of localized interaction theory
Bunimovich, AI
1995-01-01
The interaction of the environment with a moving body is called "localized" if it has been found or assumed that the force or/and thermal influence of the environment on each body surface point is independent and can be determined by the local geometrical and kinematical characteristics of this point as well as by the parameters of the environment and body-environment interactions which are the same for the whole surface of contact.Such models are widespread in aerodynamics and gas dynamics, covering supersonic and hypersonic flows, and rarefied gas flows. They describe the influence of light
Application of modeling to local chemistry in PWR steam generators
International Nuclear Information System (INIS)
Fauchon, C.; Millett, P.J.; Ollar, P.
1998-01-01
Localized corrosion of the SG tubes and other components is due to the presence of an aggressive environment in local crevices and occluded regions. In crevices and on vertical and horizontal tube surfaces, corrosion products and particulate matter can accumulate in the form of porous deposits. The SG water contains impurities at extremely low levels (ppb). Low levels of non-volatile impurities, however, can be efficiently concentrated in crevices and sludge piles by a thermal hydraulic mechanism. The temperature gradient across the SG tube coupled with local flow starvation, produces local boiling in the sludge and crevices. Since mass transfer processes are inhibited in these geometries, the residual liquid becomes enriched in many of the species present in the SG water. The resulting concentrated solutions have been shown to be aggressive and can corrode the SG materials. This corrosion may occur under various conditions which result in different types of attack such as pitting, stress corrosion cracking, wastage and denting. A major goal of EPRI's research program has been the development of models of the concentration process and the resulting chemistry. An improved understanding should eventually allow utilities to reduce or eliminate the corrosion by the appropriate manipulation of the steam generator water chemistry and or crevice conditions. The application of these models to experimental data obtained for prototypical SG tube support crevices is described in this paper. The models adequately describe the key features of the experimental data allowing extrapolations to be made to plant conditions. (author)
Chen, Chien-Ho; Sheu, Ming-Thau; Wu, An-Bang; Lin, Keng-Ping; Ho, Hsiu-O
2005-12-08
In this study, topical minoxidil solutions supplemented with TPGS in cosolvent systems of various compositions consisting of water, alcohol, and polyethylene glycol 400 were designed to evaluate the efficacy of promoting hair growth after topical application and the safety in terms of the amount of minoxidil absorbed through the skin into the circulation using C57BL/6J mice as a model. The commercial product of 2% Regaine) was used as the positive control. The role, which sulfotransferase activity plays in hair growth with treatment using minoxidil, was determined as well. The results revealed that the addition of 0.5% TPGS was able to enhance the proliferation of hair, but an increase in the amount of TPGS to 2% led to deterioration in the enhancement of hair growth. At the higher added amount (2.0%) of TPGS, the promotion of hair growth was slightly reduced for both cosolvent formulations F1 (100% water) and F3 (100% PEG 400), whereas it was reduced to a greater extent for the cosolvent formulations F8-F10. In comparison, the influences of cosolvent compositions with TPGS amounts of 0.0 and 2.0% on the promotion of hair growth were similar. On the contrary, variability in the promotion of hair growth by different solvent formulations was minimal when the added amount of TPGS was 0.5%. In general, a relationship between hair growth and sulfotransferase activities after topical application of 2% Regaine and minoxidil formulations containing various amounts of TPGS was not demonstrated. Plasma concentrations of minoxidil with 2% Regaine were found to be greater than those of 2% minoxidil in those cosolvent formulations containing various amounts of TPGS, while showing insignificant differences among those 10 cosolvent formulations with a fixed amount of TPGS. A tendency for the plasma concentration of minoxidil to increase after the topical administration of minoxidil formulations containing the higher amount of TPGS (2%) was noted.
Applying Four Different Risk Models in Local Ore Selection
International Nuclear Information System (INIS)
Richmond, Andrew
2002-01-01
Given the uncertainty in grade at a mine location, a financially risk-averse decision-maker may prefer to incorporate this uncertainty into the ore selection process. A FORTRAN program risksel is presented to calculate local risk-adjusted optimal ore selections using a negative exponential utility function and three dominance models: mean-variance, mean-downside risk, and stochastic dominance. All four methods are demonstrated in a grade control environment. In the case study, optimal selections range with the magnitude of financial risk that a decision-maker is prepared to accept. Except for the stochastic dominance method, the risk models reassign material from higher cost to lower cost processing options as the aversion to financial risk increases. The stochastic dominance model usually was unable to determine the optimal local selection
Four-parameter analytical local model potential for atoms
International Nuclear Information System (INIS)
Fei, Yu; Jiu-Xun, Sun; Rong-Gang, Tian; Wei, Yang
2009-01-01
Analytical local model potential for modeling the interaction in an atom reduces the computational effort in electronic structure calculations significantly. A new four-parameter analytical local model potential is proposed for atoms Li through Lr, and the values of four parameters are shell-independent and obtained by fitting the results of X a method. At the same time, the energy eigenvalues, the radial wave functions and the total energies of electrons are obtained by solving the radial Schrödinger equation with a new form of potential function by Numerov's numerical method. The results show that our new form of potential function is suitable for high, medium and low Z atoms. A comparison among the new potential function and other analytical potential functions shows the greater flexibility and greater accuracy of the present new potential function. (atomic and molecular physics)
Simplified local density model for adsorption over large pressure ranges
International Nuclear Information System (INIS)
Rangarajan, B.; Lira, C.T.; Subramanian, R.
1995-01-01
Physical adsorption of high-pressure fluids onto solids is of interest in the transportation and storage of fuel and radioactive gases; the separation and purification of lower hydrocarbons; solid-phase extractions; adsorbent regenerations using supercritical fluids; supercritical fluid chromatography; and critical point drying. A mean-field model is developed that superimposes the fluid-solid potential on a fluid equation of state to predict adsorption on a flat wall from vapor, liquid, and supercritical phases. A van der Waals-type equation of state is used to represent the fluid phase, and is simplified with a local density approximation for calculating the configurational energy of the inhomogeneous fluid. The simplified local density approximation makes the model tractable for routine calculations over wide pressure ranges. The model is capable of prediction of Type 2 and 3 subcritical isotherms for adsorption on a flat wall, and shows the characteristic cusplike behavior and crossovers seen experimentally near the fluid critical point
Modeling local chemistry in PWR steam generator crevices
International Nuclear Information System (INIS)
Millett, P.J.
1997-01-01
Over the past two decades steam generator corrosion damage has been a major cost impact to PWR owners. Crevices and occluded regions create thermal-hydraulic conditions where aggressive impurities can become highly concentrated, promoting localized corrosion of the tubing and support structure materials. The type of corrosion varies depending on the local conditions, with stress corrosion cracking being the phenomenon of most current concern. A major goal of the EPRI research in this area has been to develop models of the concentration process and resulting crevice chemistry conditions. These models may then be used to predict crevice chemistry based on knowledge of bulk chemistry, thereby allowing the operator to control corrosion damage. Rigorous deterministic models have not yet been developed; however, empirical approaches have shown promise and are reflected in current versions of the industry-developed secondary water chemistry guidelines
The pion form factor within the hidden local symmetry model
International Nuclear Information System (INIS)
Benayoun, M.; David, P.; DelBuono, L.; Leruste, P.; O'Connell, H.B.
2003-01-01
We analyze a pion form factor formulation which fulfills the Analyticity requirement within the Hidden Local Symmetry (HLS) Model. This implies an s-dependent dressing of the ρ-γ VMD coupling and an account of several coupled channels. The corresponding function F π (s) provides nice fits of the pion form factor data from s=-0.25 to s=1 GeV 2 . It is shown that the coupling to KK has little effect, while ωπ 0 improves significantly the fit probability below the φ mass. No need for additional states like ρ(1450) shows up in this invariant-mass range. All parameters, except for the subtraction polynomial coefficients, are fixed from the rest of the HLS phenomenology. The fits show consistency with the expected behaviour of F π (s) at s=0 up to O(s 2 ) and with the phase shift data on δ 1 1 (s) from threshold to somewhat above the φ mass. The ω sector is also examined in relation with recent data from CMD-2. (orig.)
Papaya Development Model As A Competitive Local Superior Commodity
Directory of Open Access Journals (Sweden)
Reny Sukmawani
2014-12-01
Full Text Available The aim of this research is to study the comparative advantage and papaya competitive and to design its development model by using the approach of local base agriculture development. This research uses survey method. The resulting research shows that papaya is a base commodity that has comparative advantage and competitive. The development papaya in the district of Sukabumi is quite good bases on eight superior creations. But in order to be the main sector in economic development and has a competition, the development of papaya must concern to its influence factors. In supporting papaya development as a competitive local superior commodity, it needs to be done some efforts are as follows: (1 increase a skillful worker; (2 improve business management; (3 increase papaya productivity by using technology and study papaya planted technology in specific local superior commodity; (4 develop the involvement of the business relation; (5 provide market information and information technology network; and (6 improve infrastructures.
Local and non-local effects of spanwise finite perturbations in erodible river bathymetries
Musa, Mirko; Hill, Craig; Guala, Michele
2015-11-01
Laboratory experiments were performed to study the effect of axial-flow hydrokinetic turbine models on an erodible river bed under live-bed conditions. Results indicate that the presence of an operating turbine rotor creates a blockage in the mean flow which produces a remarkable geomorphic signature in the migrating bedforms. These impacts affect a local area downstream of the turbines when placed symmetrically with respect to the cross section of the channel. On the other hand, more interesting results are observed with an asymmetric installation of the turbines. This configuration demonstrates a stronger effect on the mean flow, resulting in a larger plan-wise distortion of the mean topography and differential migration patterns of bedforms. Different turbine installation arrangements and hub heights above the mean bed were investigated, focusing mainly on the perturbation of sediment transport characteristics influenced by the turbine wake. Additional results with spanwise modulated submerged walls explore the possibility to control river topography harvesting this type of geomorphic destabilization.
Magnetomechanical local-global effects in magnetostrictive composite materials
Elhajjar, Rani F.; Law, Chiu T.
2015-10-01
A constitutive model for magnetostrictive composite materials (MCMs) that describes the relations among stress, strain, magnetic field, and magnetization Liu and Zheng (2005 Acta Mech. Sin. 21 278-85) is implemented for multiphysics simulation for analysis of non-periodic or non-uniform microstructure effects. The multiphysics models that capture designed and actual microstructural details are used for predicting the responses of magnetostrictive composite materials under various mechanical and magnetic loading conditions. The approach overcomes the limitation with strain gages in the investigation of magnetostrictive strain due to stress localization around magnetostrictive phases. Three-dimensional digital image correlation (3D-DIC) is used to measure the displacements and strain in the composites under fluctuating magnetic fields. The specimens are prepared using epoxy and particulate magnetostrictive materials with the particles in the range of approximately 20 to 300 microns range. We examine the displacement and strain fields obtained and compare the results to those obtained from fiber Bragg grating (FBG) measurements. The coupling coefficients obtained from this method were in agreement with those measured using other techniques. The validated model allows us to predict the effect of curing, preload, microstructure alignment and particle shape on the magnetostrictive strains.
Magnetomechanical local-global effects in magnetostrictive composite materials
International Nuclear Information System (INIS)
Elhajjar, Rani F; Law, Chiu T
2015-01-01
A constitutive model for magnetostrictive composite materials (MCMs) that describes the relations among stress, strain, magnetic field, and magnetization Liu and Zheng (2005 Acta Mech. Sin. 21 278–85) is implemented for multiphysics simulation for analysis of non-periodic or non-uniform microstructure effects. The multiphysics models that capture designed and actual microstructural details are used for predicting the responses of magnetostrictive composite materials under various mechanical and magnetic loading conditions. The approach overcomes the limitation with strain gages in the investigation of magnetostrictive strain due to stress localization around magnetostrictive phases. Three-dimensional digital image correlation (3D-DIC) is used to measure the displacements and strain in the composites under fluctuating magnetic fields. The specimens are prepared using epoxy and particulate magnetostrictive materials with the particles in the range of approximately 20 to 300 microns range. We examine the displacement and strain fields obtained and compare the results to those obtained from fiber Bragg grating (FBG) measurements. The coupling coefficients obtained from this method were in agreement with those measured using other techniques. The validated model allows us to predict the effect of curing, preload, microstructure alignment and particle shape on the magnetostrictive strains. (paper)
Adaptation of Mesoscale Weather Models to Local Forecasting
Manobianco, John T.; Taylor, Gregory E.; Case, Jonathan L.; Dianic, Allan V.; Wheeler, Mark W.; Zack, John W.; Nutter, Paul A.
2003-01-01
Methodologies have been developed for (1) configuring mesoscale numerical weather-prediction models for execution on high-performance computer workstations to make short-range weather forecasts for the vicinity of the Kennedy Space Center (KSC) and the Cape Canaveral Air Force Station (CCAFS) and (2) evaluating the performances of the models as configured. These methodologies have been implemented as part of a continuing effort to improve weather forecasting in support of operations of the U.S. space program. The models, methodologies, and results of the evaluations also have potential value for commercial users who could benefit from tailoring their operations and/or marketing strategies based on accurate predictions of local weather. More specifically, the purpose of developing the methodologies for configuring the models to run on computers at KSC and CCAFS is to provide accurate forecasts of winds, temperature, and such specific thunderstorm-related phenomena as lightning and precipitation. The purpose of developing the evaluation methodologies is to maximize the utility of the models by providing users with assessments of the capabilities and limitations of the models. The models used in this effort thus far include the Mesoscale Atmospheric Simulation System (MASS), the Regional Atmospheric Modeling System (RAMS), and the National Centers for Environmental Prediction Eta Model ( Eta for short). The configuration of the MASS and RAMS is designed to run the models at very high spatial resolution and incorporate local data to resolve fine-scale weather features. Model preprocessors were modified to incorporate surface, ship, buoy, and rawinsonde data as well as data from local wind towers, wind profilers, and conventional or Doppler radars. The overall evaluation of the MASS, Eta, and RAMS was designed to assess the utility of these mesoscale models for satisfying the weather-forecasting needs of the U.S. space program. The evaluation methodology includes
Evidence of Non-local Chemical, Thermal and Gravitational Effects
Directory of Open Access Journals (Sweden)
Hu H.
2007-04-01
Full Text Available Quantum entanglement is ubiquitous in the microscopic world and manifests itself macroscopically under some circumstances. But common belief is that it alone cannot be used to transmit information nor could it be used to produce macroscopic non- local effects. Yet we have recently found evidence of non-local effects of chemical substances on the brain produced through it. While our reported results are under independent verifications by other groups, we report here our experimental findings of non-local chemical, thermal and gravitational effects in simple physical systems such as reservoirs of water quantum-entangled with water being manipulated in a remote reservoir. With the aids of high-precision instruments, we have found that the pH value, temperature and gravity of water in the detecting reservoirs can be non-locally affected through manipulating water in the remote reservoir. In particular, the pH value changes in the same direction as that being manipulated; the temperature can change against that of local environment; and the gravity apparently can also change against local gravity. These non-local effects are all reproducible and can be used for non-local signalling and many other purposes. We suggest that they are mediated by quantum entanglement between nuclear and/or electron spins in treated water and discuss the implications of these results.
THE EFFECT OF LOCAL ANESTHETICS ON TEAR PRODUCTION
African Journals Online (AJOL)
that local anesthetics measure only basic secretion thus reducing normal tear production/secretion, which is both reflex and basic. This could be attributed to the fact that local anesthetics have an adrenergic potentiating effects and because lacrimal fluid receive a preganglionic parasympathetic supply from lacrimal muscles ...
Non-local Effects of Conformal Anomaly
Meissner, Krzysztof A.; Nicolai, Hermann
2018-03-01
It is shown that the nonlocal anomalous effective actions corresponding to the quantum breaking of the conformal symmetry can lead to observable modifications of Einstein's equations. The fact that Einstein's general relativity is in perfect agreement with all observations including cosmological or recently observed gravitational waves imposes strong restrictions on the field content of possible extensions of Einstein's theory: all viable theories should have vanishing conformal anomalies. It is shown that a complete cancellation of conformal anomalies in D=4 for both the C^2 invariant and the Euler (Gauss-Bonnet) invariant can only be achieved for N-extended supergravity multiplets with N ≥ 5.
Council Appointed Mayors in Spain: Effects on Local Democracy
Directory of Open Access Journals (Sweden)
María Jesús García García
2017-03-01
Full Text Available This paper deals with the influence of having council appointed mayors on local governments. Five elements of local government systems are considered: the electoral system and its influence on the political composition of the local government; the local government structure and the distribution of functions and powers between mayor and council; the role of political parties; scrutiny of the executive and accountability; and citizen participation. This analysis highlights the effect that a council appointed mayor system has in terms of accountability and legitimacy, transparency and efficiency. KEYWORDS Local government systems, directly elected mayors, local governance, council appointed mayors, Local Government Structure; Political Parties; Citizen Participation; Accountability. El presente artículo toma en consideración los efectos que el sistema de elección del Alcalde tiene sobre la democracia local, basándose en la consideración cinco aspectos: el sistema electoral y su influencia en la composición política de las administraciones locales; la estructura de la administración local y la distribución de funciones entre los alcaldes y el pleno municipal; el papel de los partidos políticos; los mecanismos de control del ejecutivo local y la participación ciudadana. El estudio subraya especialmente la incidencia que el sistema de elección del alcalde por los concejales tiene en relación con los principios de responsabilidad, legitimidad, transparencia y eficiencia de la gestión local. PALABRAS CLAVE Gobierno local, elección directa de los alcaldes, elección indirecta de los alcaldes, estructura del gobierno local, partidos políticos, participación ciudadana, responsabilidad política.
Improved Application of Local Models to Steel Corrosion in Lead-Bismuth Loops
International Nuclear Information System (INIS)
Zhang Jinsuo; Li Ning
2003-01-01
The corrosion of steels exposed to flowing liquid metals is influenced by local and global conditions of flow systems. The present study improves the previous local models when applied to closed loops by incorporating some global condition effects. In particular the bulk corrosion product concentration is calculated based on balancing the dissolution and precipitation in the entire closed loop. Mass transfer expressions developed in aqueous medium and an analytical expression are tested in the liquid-metal environments. The improved model is applied to a pure lead loop and produces results closer to the experimental data than the previous local models do. The model is also applied to a lead-bismuth eutectic (LBE) test loop. Systematic studies illustrate the effects of the flow rate, the oxygen concentration in LBE, and the temperature profile on the corrosion rate
Strong Local-Nonlocal Coupling for Integrated Fracture Modeling
Energy Technology Data Exchange (ETDEWEB)
Littlewood, David John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Silling, Stewart A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mitchell, John A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Seleson, Pablo D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bond, Stephen D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Parks, Michael L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Turner, Daniel Z. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Burnett, Damon J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ostien, Jakob [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Gunzburger, Max [Florida State Univ., Tallahassee, FL (United States)
2015-09-01
Peridynamics, a nonlocal extension of continuum mechanics, is unique in its ability to capture pervasive material failure. Its use in the majority of system-level analyses carried out at Sandia, however, is severely limited, due in large part to computational expense and the challenge posed by the imposition of nonlocal boundary conditions. Combined analyses in which peridynamics is em- ployed only in regions susceptible to material failure are therefore highly desirable, yet available coupling strategies have remained severely limited. This report is a summary of the Laboratory Directed Research and Development (LDRD) project "Strong Local-Nonlocal Coupling for Inte- grated Fracture Modeling," completed within the Computing and Information Sciences (CIS) In- vestment Area at Sandia National Laboratories. A number of challenges inherent to coupling local and nonlocal models are addressed. A primary result is the extension of peridynamics to facilitate a variable nonlocal length scale. This approach, termed the peridynamic partial stress, can greatly reduce the mathematical incompatibility between local and nonlocal equations through reduction of the peridynamic horizon in the vicinity of a model interface. A second result is the formulation of a blending-based coupling approach that may be applied either as the primary coupling strategy, or in combination with the peridynamic partial stress. This blending-based approach is distinct from general blending methods, such as the Arlequin approach, in that it is specific to the coupling of peridynamics and classical continuum mechanics. Facilitating the coupling of peridynamics and classical continuum mechanics has also required innovations aimed directly at peridynamic models. Specifically, the properties of peridynamic constitutive models near domain boundaries and shortcomings in available discretization strategies have been addressed. The results are a class of position-aware peridynamic constitutive laws for
Energy Technology Data Exchange (ETDEWEB)
Wakatani, Yoshifumi; Yamanaka, Yoshiro (Central Research Inst. of electric Power Industry, Tokyo (Japan))
1982-05-01
The recent negotiation of enterprisers and local people concerning the location of power stations tends to extend for long periods because of diversified arguing points and the information exchange of high density, and also to be complicated by the interrelation with other points. It is a large problem to seek the policy of such negotiation for enterprisers to respond to local people. In this study, as the first step, the policy and action appeared in location negotiations and the development of the negotiations were analyzed on the cases of location, and two kinds of the model analysis were carried out, taking fishery compensation negotiation as the object among them. The knowledge was obtained about what response to local fishery associations is effective to promote the location. The classification of location negotiation and the factors affecting the development of negotiation were investigated. It was shown to be effective to divide the process of location negotiation into five stages of advancement. The model analysis was carried out according to game theory and by gaming simulation method. The results are reported.
International Nuclear Information System (INIS)
Wakatani, Yoshifumi; Yamanaka, Yoshiro
1982-01-01
The recent negotiation of enterprisers and local people concerning the location of power stations tends to extend for long period because of diversified arguing points and the information exchange of high density, and also to be complicated by the interrelation with other points. It is a large problem to seek the policy of such negotiation for enterprisers to respond to local people. In this study, as the first step, the policy and action appeared in location negotiations and the development of the negotiations were analyzed on the cases of location, and two kinds of the model analysis were carried out, taking fishery compensation negotiation as the object among them. The knowledge was obtained about what response to local fishery associations is effective to promote the location. The classification of location negotiation and the factors affecting the development of negotiation were investigated. It was shown to be effective to divide the process of location negotiation into five stages of advancement. The model analysis was carried out according to game theory and by gaming simulation method. The results are reported. (Kako, I.)
Local models of Gauge Mediated Supersymmetry Breaking in String Theory
Garcia-Etxebarria, I; Uranga, Angel M; Garcia-Etxebarria, Inaki; Saad, Fouad; Uranga, Angel M.
2006-01-01
We describe local Calabi-Yau geometries with two isolated singularities at which systems of D3- and D7-branes are located, leading to chiral sectors corresponding to a semi-realistic visible sector and a hidden sector with dynamical supersymmetry breaking. We provide explicit models with a 3-family MSSM-like visible sector, and a hidden sector breaking supersymmetry at a meta-stable minimum. For singularities separated by a distance smaller than the string scale, this construction leads to a simple realization of gauge mediated supersymmetry breaking in string theory. The models are simple enough to allow the explicit computation of the massive messenger sector, using dimer techniques for branes at singularities. The local character of the configurations makes manifest the UV insensitivity of the supersymmetry breaking mediation.
Local Refinement of the Super Element Model of Oil Reservoir
Directory of Open Access Journals (Sweden)
A.B. Mazo
2017-12-01
Full Text Available In this paper, we propose a two-stage method for petroleum reservoir simulation. The method uses two models with different degrees of detailing to describe hydrodynamic processes of different space-time scales. At the first stage, the global dynamics of the energy state of the deposit and reserves is modeled (characteristic scale of such changes is km / year. The two-phase flow equations in the model of global dynamics operate with smooth averaged pressure and saturation fields, and they are solved numerically on a large computational grid of super-elements with a characteristic cell size of 200-500 m. The tensor coefficients of the super-element model are calculated using special procedures of upscaling of absolute and relative phase permeabilities. At the second stage, a local refinement of the super-element model is constructed for calculating small-scale processes (with a scale of m / day, which take place, for example, during various geological and technical measures aimed at increasing the oil recovery of a reservoir. Then we solve the two-phase flow problem in the selected area of the measure exposure on a detailed three-dimensional grid, which resolves the geological structure of the reservoir, and with a time step sufficient for describing fast-flowing processes. The initial and boundary conditions of the local problem are formulated on the basis of the super-element solution. This approach allows us to reduce the computational costs in order to solve the problems of designing and monitoring the oil reservoir. To demonstrate the proposed approach, we give an example of the two-stage modeling of the development of a layered reservoir with a local refinement of the model during the isolation of a water-saturated high-permeability interlayer. We show a good compliance between the locally refined solution of the super-element model in the area of measure exposure and the results of numerical modeling of the whole history of reservoir
A realistic model for quantum theory with a locality property
International Nuclear Information System (INIS)
Eberhard, P.H.
1987-04-01
A model reproducing the predictions of relativistic quantum theory to any desired degree of accuracy is described in this paper. It involves quantities that are independent of the observer's knowledge, and therefore can be called real, and which are defined at each point in space, and therefore can be called local in a rudimentary sense. It involves faster-than-light, but not instantaneous, action at distance
Asymptotically exact solution of a local copper-oxide model
International Nuclear Information System (INIS)
Zhang Guangming; Yu Lu.
1994-03-01
We present an asymptotically exact solution of a local copper-oxide model abstracted from the multi-band models. The phase diagram is obtained through the renormalization-group analysis of the partition function. In the strong coupling regime, we find an exactly solved line, which crosses the quantum critical point of the mixed valence regime separating two different Fermi-liquid (FL) phases. At this critical point, a many-particle resonance is formed near the chemical potential, and a marginal-FL spectrum can be derived for the spin and charge susceptibilities. (author). 15 refs, 1 fig
Devaraju, N; Bala, Govindasamy; Modak, Angshuman
2015-03-17
In this paper, using idealized climate model simulations, we investigate the biogeophysical effects of large-scale deforestation on monsoon regions. We find that the remote forcing from large-scale deforestation in the northern middle and high latitudes shifts the Intertropical Convergence Zone southward. This results in a significant decrease in precipitation in the Northern Hemisphere monsoon regions (East Asia, North America, North Africa, and South Asia) and moderate precipitation increases in the Southern Hemisphere monsoon regions (South Africa, South America, and Australia). The magnitude of the monsoonal precipitation changes depends on the location of deforestation, with remote effects showing a larger influence than local effects. The South Asian Monsoon region is affected the most, with 18% decline in precipitation over India. Our results indicate that any comprehensive assessment of afforestation/reforestation as climate change mitigation strategies should carefully evaluate the remote effects on monsoonal precipitation alongside the large local impacts on temperatures.
A local mixing model for deuterium replacement in solids
International Nuclear Information System (INIS)
Doyle, B.L.; Brice, D.K.; Wampler, W.R.
1980-01-01
A new model for hydrogen isotope exchange by ion implantation has been developed. The basic difference between the present approach and previous work is that the depth distribution of the implanted species is included. The outstanding feature of this local mixing model is that the only adjustable parameter is the saturation hydrogen concentration which is specific to the target material and dependent only on temperature. The model is shown to give excellent agreement both with new data on H/D exchange in the low Z coating materials VB 2 , TiC, TiB 2 , and B reported here and with previously reported data on stainless steel. The saturation hydrogen concentrations used to fit these data were 0.15, 0.25, 0.15, 0.45, and 1.00 times atomic density respectively. This model should be useful in predicting the recycling behavior of hydrogen isotopes in tokamak limiter and wall materials. (author)
EFFECTS OF LOCAL DISSIPATION PROFILES ON MAGNETIZED ACCRETION DISK SPECTRA
International Nuclear Information System (INIS)
Tao, Ted; Blaes, Omer
2013-01-01
We present spectral calculations of non-LTE accretion disk models appropriate for high-luminosity stellar mass black hole X-ray binary systems. We first use a dissipation profile based on scaling the results of shearing box simulations of Hirose et al. to a range of annuli parameters. We simultaneously scale the effective temperature, orbital frequency, and surface density with luminosity and radius according to the standard α-model. This naturally brings increased dissipation to the disk surface layers (around the photospheres) at small radii and high luminosities. We find that the local spectrum transitions directly from a modified blackbody to a saturated Compton scattering spectrum as we increase the effective temperature and orbital frequency while decreasing midplane surface density. Next, we construct annuli models based on the parameters of a L/L Edd = 0.8 disk orbiting a 6.62 solar mass black hole using two modified dissipation profiles that explicitly put more dissipation per unit mass near the disk surface. The new dissipation profiles are qualitatively similar to the one found by Hirose et al., but produce strong near power-law spectral tails. Our models also include physically motivated magnetic acceleration support based once again on scaling the Hirose et al. results. We present three full-disk spectra, each based on one of the dissipation prescriptions. Our most aggressive dissipation profile results in a disk spectrum that is in approximate quantitative agreement with certain observations of the steep power-law spectral states from some black hole X-ray binaries.
Effective Management for National or Local Policy Objectives?
DEFF Research Database (Denmark)
Winter, Søren; Skou, Mette; Beer, Frederikke
This research considers the role of local policies and management in affecting street-level bureaucrats’ actions in implementing national policy mandates. The focus on sanctioning behavior by social workers provides a strong test of these effects, given that the behaviors are both visible and have...... workers with a better fit with the goals of the organization increases workers’ compliance with local policy goals, but only when these diverge from national ones! Increasing staff capacity and information provision have simpler effects in fostering more compliance with the national policy mandate among...... workers. Managers’ addressing adverse selection problems seems more effective than coping with moral hazard. The combination of local politicians’ influence on the formation of local policy goals and managers’ influence in getting workers to comply with those indicates a very important role for policy...
DEFF Research Database (Denmark)
Jeong, Cheol-Ho
2011-01-01
resistivity and the absorber thickness on the difference between the two surface reaction models are examined and discussed. For a porous absorber backed by a rigid surface, the local reaction models give errors of less than 10% if the thickness exceeds 120 mm for a flow resistivity of 5000 Nm-4s. As the flow...... incidence acoustical characteristics of typical building elements made of porous materials assuming extended and local reaction. For each surface reaction, five well-established wave propagation models, the Delany-Bazley, Miki, Beranek, Allard-Champoux, and Biot model, are employed. Effects of the flow...... resistivity doubles, a decrease in the required thickness by 25 mm is observed to achieve the same amount of error. For an absorber backed by an air gap, the thickness ratio between the material and air cavity is important. If the absorber thickness is approximately 40% of the cavity depth, the local reaction...
Droplet localization in the random XXZ model and its manifestations
Elgart, A.; Klein, A.; Stolz, G.
2018-01-01
We examine many-body localization properties for the eigenstates that lie in the droplet sector of the random-field spin- \\frac 1 2 XXZ chain. These states satisfy a basic single cluster localization property (SCLP), derived in Elgart et al (2018 J. Funct. Anal. (in press)). This leads to many consequences, including dynamical exponential clustering, non-spreading of information under the time evolution, and a zero velocity Lieb-Robinson bound. Since SCLP is only applicable to the droplet sector, our definitions and proofs do not rely on knowledge of the spectral and dynamical characteristics of the model outside this regime. Rather, to allow for a possible mobility transition, we adapt the notion of restricting the Hamiltonian to an energy window from the single particle setting to the many body context.
Brain MRI Tumor Detection using Active Contour Model and Local Image Fitting Energy
Nabizadeh, Nooshin; John, Nigel
2014-03-01
Automatic abnormality detection in Magnetic Resonance Imaging (MRI) is an important issue in many diagnostic and therapeutic applications. Here an automatic brain tumor detection method is introduced that uses T1-weighted images and K. Zhang et. al.'s active contour model driven by local image fitting (LIF) energy. Local image fitting energy obtains the local image information, which enables the algorithm to segment images with intensity inhomogeneities. Advantage of this method is that the LIF energy functional has less computational complexity than the local binary fitting (LBF) energy functional; moreover, it maintains the sub-pixel accuracy and boundary regularization properties. In Zhang's algorithm, a new level set method based on Gaussian filtering is used to implement the variational formulation, which is not only vigorous to prevent the energy functional from being trapped into local minimum, but also effective in keeping the level set function regular. Experiments show that the proposed method achieves high accuracy brain tumor segmentation results.
Modeling Shock Induced Plasticity in Copper Single Crystal: Numerical and Strain Localization Issues
International Nuclear Information System (INIS)
Shehadeh, M
2011-01-01
Multiscale dislocation dynamics plasticity (MDDP) simulations are carried out to address the following issues in modeling shock-induced plasticity: 1- the effect of finite element (FE) boundary conditions on shock wave characteristics and wave-dislocation interaction, 2- the effect of the evolution of the dislocation microstructure on lattice rotation and strain localization. While uniaxial strain is achieved with high accuracy using confined boundary condition, periodic boundary condition yields a disturbed wave profile due the edge effect. Including lattice rotation in the analysis leads to higher dislocation density and more localized plastic strain. (author)
Directory of Open Access Journals (Sweden)
Abílio Amiguinho
2005-01-01
Full Text Available The process of socio-educational territorialisation in rural contexts is the topic of this text. The theme corresponds to a challenge to address it having as main axis of discussion either the problem of social exclusion or that of local development. The reasons to locate the discussion in this last field of analysis are discussed in the first part of the text. Theoretical and political reasons are there articulated because the question is about projects whose intentions and practices call for the political both in the theoretical debate and in the choices that anticipate intervention. From research conducted for several years, I use contributions that aim at discuss and enlighten how school can be a potential locus of local development. Its identification and recognition as local institution (either because of those that work and live in it or because of those that act in the surrounding context are crucial steps to progressively constitute school as a partner for development. The promotion of the local values and roots, the reconstruction of socio-personal and local identities, the production of sociabilities and the equation and solution of shared problems were the dimensions of a socio-educative intervention, markedly globalising. This scenario, as it is argued, was also, intentionally, one of transformation and of deliberate change of school and of the administration of the educative territoires.
Modelling local government unit credit risk in the Republic of Croatia
Directory of Open Access Journals (Sweden)
Petra Posedel
2012-12-01
Full Text Available The objective of this paper is to determine possible indicators that affect local unit credit risk and investigate their effect on default (credit risk of local government units in Croatia. No system for the estimation of local unit credit risk has been established in Croatia so far causing many practical problems in local unit borrowing. Because of the specific nature of the operations of local government units and legislation that does not allow local government units to go into bankruptcy, conventional methods for estimating credit risk are not applicable, and the set of standard potential determinants of credit risk has to be expanded with new indicators. Thus in the paper, in addition to the usual determinants of credit risk, the hypothesis of the influence of political factors on local unit credit risk in Croatia is also tested out, with the use of a Tobit model. Results of econometric analysis show that credit risk of local government units in Croatia is affected by the political structure of local government, the proportion of income tax and surtax in operating revenue, the ratio of net operating balance, net financial liabilities and direct debt to operating revenue, as well as the ratio of debt repayment and cash, and direct debt and operating revenue.
A comprehensive multi-local-world model for complex networks
International Nuclear Information System (INIS)
Fan Zhengping; Chen Guanrong; Zhang Yunong
2009-01-01
The nodes in a community within a network are much more connected to each other than to the others outside the community in the same network. This phenomenon has been commonly observed from many real-world networks, ranging from social to biological even to technical networks. Meanwhile, the number of communities in some real-world networks, such as the Internet and most social networks, are evolving with time. To model this kind of networks, the present Letter proposes a multi-local-world (MLW) model to capture and describe their essential topological properties. Based on the mean-field theory, the degree distribution of this model is obtained analytically, showing that the generated network has a novel topological feature as being not completely random nor completely scale-free but behaving somewhere between them. As a typical application, the MLW model is applied to characterize the Internet against some other models such as the BA, GBA, Fitness and HOT models, demonstrating the superiority of the new model.
Convection with local thermal non-equilibrium and microfluidic effects
Straughan, Brian
2015-01-01
This book is one of the first devoted to an account of theories of thermal convection which involve local thermal non-equilibrium effects, including a concentration on microfluidic effects. The text introduces convection with local thermal non-equilibrium effects in extraordinary detail, making it easy for readers newer to the subject area to understand. This book is unique in the fact that it addresses a large number of convection theories and provides many new results which are not available elsewhere. This book will be useful to researchers from engineering, fluid mechanics, and applied mathematics, particularly those interested in microfluidics and porous media.
Environmental pollution has sex-dependent effects on local survival
Eeva, Tapio; Hakkarainen, Harri; Laaksonen, Toni; Lehikoinen, Esa
2006-01-01
Environmental pollutants cause a potential hazard for survival in free-living animal populations. We modelled local survival (including emigration) by using individual mark–recapture histories of males and females in a population of a small insectivorous passerine bird, the pied flycatcher (Ficedula hypoleuca) living around a point source of heavy metals (copper smelter). Local survival of F. hypoleuca females did not differ between polluted and unpolluted environments. Males, however, showed a one-third higher local-survival probability in the polluted area. Low fledgling production was generally associated with decreased local survival, but males in the polluted area showed relatively high local survival, irrespective of their fledgling number. A possible explanation of higher local survival of males in the polluted area could be a pollution-induced change in hormone (e.g. corticosterone or testosterone) levels of males. It could make them to invest more on their own survival or affect the hormonal control of breeding dispersal. The local survival of males decreased in the polluted area over the study period along with the simultaneous decrease in heavy metal emissions. This temporal trend is in agreement with the stress hormone hypothesis. PMID:17148387
One-loop Yukawa Couplings in Local Models
Conlon, Joseph P; Palti, Eran; 10.1007
2010-01-01
We calculate the one-loop Yukawa couplings and threshold corrections for supersymmetric local models of branes at singularities in type IIB string theory. We compute the corrections coming both from wavefunction and vertex renormalisation. The former comes in the IR from conventional field theory running and in the UV from threshold corrections that cause it to run from the winding scale associated to the full Calabi-Yau volume. The vertex correction is naively absent as it appears to correspond to superpotential renormalisation. However, we find that while the Wilsonian superpotential is not renormalised there is a physical vertex correction in the 1PI action associated to light particle loops.
One-loop Yukawa couplings in local models
Energy Technology Data Exchange (ETDEWEB)
Conlon, Joseph P. [Rudolf Peierls Center for Theoretical Physics, Oxford (United Kingdom); Balliol College, Oxford (United Kingdom); Goodsell, Mark [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Palti, Eran [Centre de Physique Theorique, Ecole Polytechnique, CNRS, Palaiseau (France)
2010-07-15
We calculate the one-loop Yukawa couplings and threshold corrections for supersymmetric local models of branes at singularities in type IIB string theory. We compute the corrections coming both from wavefunction and vertex renormalisation. The former comes in the IR from conventional field theory running and in the UV from threshold corrections that cause it to run from the winding scale associated to the full Calabi-Yau volume. The vertex correction is naively absent as it appears to correspond to superpotential renormalisation. However, we find that while the Wilsonian superpotential is not renormalised there is a physical vertex correction in the 1PI action associated to light particle loops. (orig.)
One-loop Yukawa couplings in local models
International Nuclear Information System (INIS)
Conlon, Joseph P.; Goodsell, Mark; Palti, Eran
2010-07-01
We calculate the one-loop Yukawa couplings and threshold corrections for supersymmetric local models of branes at singularities in type IIB string theory. We compute the corrections coming both from wavefunction and vertex renormalisation. The former comes in the IR from conventional field theory running and in the UV from threshold corrections that cause it to run from the winding scale associated to the full Calabi-Yau volume. The vertex correction is naively absent as it appears to correspond to superpotential renormalisation. However, we find that while the Wilsonian superpotential is not renormalised there is a physical vertex correction in the 1PI action associated to light particle loops. (orig.)
Composite PET and MRI for accurate localization and metabolic modeling
International Nuclear Information System (INIS)
Bidaut, L.
1991-01-01
This paper reports that in order to help in analyzing PET data and really take advantage of their metabolic content, a system was designed and implemented to align and process data from various medical imaging modalities, particularly (but not only) for brain studies. Although this system is for now mostly used for anatomical localization, multi-modality ROIs and pharmaco-kinetic modeling, more multi-modality protocols will be implemented in the future, not only to help in PET reconstruction data correction and semi-automated ROI definition, but also for helping in improving diagnostic accuracy along with surgery and therapy planning
Climate change and local pollution effects. An integrated approach
International Nuclear Information System (INIS)
Aaheim, H.A.; Kristin, A.; Seip, H.M.
1999-01-01
Few studies on measures for mitigation of damage caused by man-made emissions to the environment have tried to consider all major effects. We illustrate the importance of an integrated approach by estimating costs and benefits of a proposed energy saving program for Hungary, originally designed to reduce CO 2 emissions. The dominant benefit of implementing the program is likely to be reduced health damage from local pollutants. Also reduced costs of material damage and to a lesser extent vegetation damage contribute to make the net benefit considerable. Compared to the reduction in these local and regional effects, the benefits from reducing greenhouse gases are likely to be minor. Since local effects in general occur much earlier after measures have been implemented than effects of increased emissions of greenhouse gases, inclusion of local effects makes evaluation of climate policy less dependent on the choice of discount rate. In our opinion, similar results are likely for many measures originally designed to reduce emissions of greenhouse gases particularly in some areas in developing countries with high local pollution levels. Main uncertainties in the analysis, e.g. in the relationships between damage and pollution level, are discussed. 72 refs
The Integrated Model of Sustainability Perspective in Spermatophyta Learning Based on Local Wisdom
Hartadiyati, E.; Rizqiyah, K.; Wiyanto; Rusilowati, A.; Prasetia, A. P. B.
2017-09-01
In present condition, culture is diminished, the change of social order toward the generation that has no policy and pro-sustainability; As well as the advancement of science and technology are often treated unwisely so as to excite local wisdom. It is therefore necessary to explore intra-curricular local wisdom in schools. This study aims to produce an integration model of sustainability perspectives based on local wisdom on spermatophyta material that is feasible and effective. This research uses define, design and develop stages to an integration model of sustainability perspectives based on local wisdom on spermatophyta material. The resulting product is an integration model of socio-cultural, economic and environmental sustainability perspective and formulated with preventive, preserve and build action on spermatophyta material consisting of identification and classification, metagenesis and the role of spermatophyta for human life. The integration model of sustainability perspective in learning spermatophyta based on local wisdom is considered proven to be effective in raising sustainability’s awareness of high school students.
Towards a local learning (innovation) model of solar photovoltaic deployment
International Nuclear Information System (INIS)
Shum, Kwok L.; Watanabe, Chihiro
2008-01-01
It is by now familiar that in the deployment of solar photovoltaic (PV) systems, the cost dynamics of major system component like solar cell/module is subjected to experience curve effects driven by production learning and research and development at the supplier side. What is less clear, however, is the economics of system integration or system deployment that takes place locally close to the user, involving other market players, in the downstream solar PV value chain. Experts have agreed that suppliers of solar PV system must customize their flexible characteristics to address local unique users' and applications requirements and compete on price/performance basis. A lack of understanding of the drivers of the economics of system customization therefore is a deficiency in our understanding of the overall economics of this renewable energy technology option. We studied the non-module BOS cost for grid-connected small PV system using the experience curve framework. Preliminary analysis of PV statistics of the US from IEA seems to suggest that learning in one application type is taking place with respect to the cumulative installation among all types of grid-connected small PV projects. The effectiveness of this learning is also improving over time. A novel aspect is the interpretation of such experience curve effect or learning pattern. We draw upon the notion of product platform in the industrial management literature and consider different types of local small-scale grid-tied PV customization projects as adapting a standard platform to different idiosyncratic and local application requirements. Economics of system customization, which is user-oriented, involves then a refined notion of inter-projects learning, rather than volume-driven learning by doing. We formalized such inter-projects learning as a dynamic economy of scope, which can potentially be leveraged to manage the local and downstream aspect of PV deployment. This dynamic economy may serve as a focus
Xie, Wenrui; Chen, Sisi; Strong, Judith A; Li, Ai-Ling; Lewkowich, Ian P; Zhang, Jun-Ming
2016-08-17
Some forms of chronic pain are maintained or enhanced by activity in the sympathetic nervous system (SNS), but attempts to model this have yielded conflicting findings. The SNS has both pro- and anti-inflammatory effects on immunity, confounding the interpretation of experiments using global sympathectomy methods. We performed a "microsympathectomy" by cutting the ipsilateral gray rami where they entered the spinal nerves near the L4 and L5 DRG. This led to profound sustained reductions in pain behaviors induced by local DRG inflammation (a rat model of low back pain) and by a peripheral paw inflammation model. Effects of microsympathectomy were evident within one day, making it unlikely that blocking sympathetic sprouting in the local DRGs or hindpaw was the sole mechanism. Prior microsympathectomy greatly reduced hyperexcitability of sensory neurons induced by local DRG inflammation observed 4 d later. Microsympathectomy reduced local inflammation and macrophage density in the affected tissues (as indicated by paw swelling and histochemical staining). Cytokine profiling in locally inflamed DRG showed increases in pro-inflammatory Type 1 cytokines and decreases in the Type 2 cytokines present at baseline, changes that were mitigated by microsympathectomy. Microsympathectomy was also effective in reducing established pain behaviors in the local DRG inflammation model. We conclude that the effect of sympathetic fibers in the L4/L5 gray rami in these models is pro-inflammatory. This raises the possibility that therapeutic interventions targeting gray rami might be useful in some chronic inflammatory pain conditions. Sympathetic blockade is used for many pain conditions, but preclinical studies show both pro- and anti-nociceptive effects. The sympathetic nervous system also has both pro- and anti-inflammatory effects on immune tissues and cells. We examined effects of a very localized sympathectomy. By cutting the gray rami to the spinal nerves near the lumbar sensory
The Optimization of the Local Public Policies’ Development Process Through Modeling And Simulation
Directory of Open Access Journals (Sweden)
Minodora URSĂCESCU
2012-06-01
Full Text Available The local public policies development in Romania represents an empirically realized measure, the strategic management practices in this domain not being based on a scientific instrument capable to anticipate and evaluate the results of implementing a local public policy in a logic of needs-policies-effects type. Beginning from this motivation, the purpose of the paper resides in the reconceptualization of the public policies process on functioning principles of the dynamic systems with inverse connection, by means of mathematical modeling and techniques simulation. Therefore, the research is oriented in the direction of developing an optimization method for the local public policies development process, using as instruments the mathematical modeling and the techniques simulation. The research’s main results are on the one side constituted by generating a new process concept of the local public policies, and on the other side by proposing the conceptual model of a complex software product which will permit the parameterized modeling in a virtual environment of these policies development process. The informatic product’s finality resides in modeling and simulating each local public policy type, taking into account the respective policy’s characteristics, but also the value of their appliance environment parameters in a certain moment.
Developmental Local Government as a Model for Grassroots Socio ...
African Journals Online (AJOL)
In the past five decades of political independence in Nigeria, local ... governments places a strong limitation on local autonomy and governance at the local level. ... negatively affecting grassroots socio-economic development in the Country.
Saini, Harsh; Raicar, Gaurav; Dehzangi, Abdollah; Lal, Sunil; Sharma, Alok
2015-12-07
Protein subcellular localization is an important topic in proteomics since it is related to a protein׳s overall function, helps in the understanding of metabolic pathways, and in drug design and discovery. In this paper, a basic approximation technique from natural language processing called the linear interpolation smoothing model is applied for predicting protein subcellular localizations. The proposed approach extracts features from syntactical information in protein sequences to build probabilistic profiles using dependency models, which are used in linear interpolation to determine how likely is a sequence to belong to a particular subcellular location. This technique builds a statistical model based on maximum likelihood. It is able to deal effectively with high dimensionality that hinders other traditional classifiers such as Support Vector Machines or k-Nearest Neighbours without sacrificing performance. This approach has been evaluated by predicting subcellular localizations of Gram positive and Gram negative bacterial proteins. Copyright © 2015 Elsevier Ltd. All rights reserved.
Effects of local and global network connectivity on synergistic epidemics
Broder-Rodgers, David; Pérez-Reche, Francisco J.; Taraskin, Sergei N.
2015-12-01
Epidemics in networks can be affected by cooperation in transmission of infection and also connectivity between nodes. An interplay between these two properties and their influence on epidemic spread are addressed in the paper. A particular type of cooperative effects (called synergy effects) is considered, where the transmission rate between a pair of nodes depends on the number of infected neighbors. The connectivity effects are studied by constructing networks of different topology, starting with lattices with only local connectivity and then with networks that have both local and global connectivity obtained by random bond-rewiring to nodes within a certain distance. The susceptible-infected-removed epidemics were found to exhibit several interesting effects: (i) for epidemics with strong constructive synergy spreading in networks with high local connectivity, the bond rewiring has a negative role in epidemic spread, i.e., it reduces invasion probability; (ii) in contrast, for epidemics with destructive or weak constructive synergy spreading on networks of arbitrary local connectivity, rewiring helps epidemics to spread; (iii) and, finally, rewiring always enhances the spread of epidemics, independent of synergy, if the local connectivity is low.
Locally supersymmetric D=3 non-linear sigma models
International Nuclear Information System (INIS)
Wit, B. de; Tollsten, A.K.; Nicolai, H.
1993-01-01
We study non-linear sigma models with N local supersymmetries in three space-time dimensions. For N=1 and 2 the target space of these models is riemannian or Kaehler, respectively. All N>2 theories are associated with Einstein spaces. For N=3 the target space is quaternionic, while for N=4 it generally decomposes, into two separate quaternionic spaces, associated with inequivalent supermultiplets. For N=5, 6, 8 there is a unique (symmetric) space for any given number of supermultiplets. Beyond that there are only theories based on a single supermultiplet for N=9, 10, 12 and 16, associated with coset spaces with the exceptional isometry groups F 4(-20) , E 6(-14) , E 7(-5) and E 8(+8) , respectively. For N=3 and N ≥ 5 the D=2 theories obtained by dimensional reduction are two-loop finite. (orig.)
Understanding local residents of Korea using nuclear effective safety
International Nuclear Information System (INIS)
Chung, Yun Hyung; Lee, Gey Hwi; Hah, Yeonhee; Kim, Beom Jun
2010-01-01
The risk perception gap between experts and lay people is based on the use of different concept on risk. It is getting increasingly important for nuclear practitioners to understand the lay people's subjective perception on nuclear safety. We proposed the nuclear effective safety index (NESI) which is based on data of the public survey of local inhabitants. We extracted the four factors for effective safety indicators; communication, trust, plant emergency response capability, and personal emergency coping skills. The latest NESI was 41.54, which was increased from 38.22 but still low. The three-year data of NESI showed the differences between genders and between sites as well as trend. The survey of antecedents of effective safety showed some meaningful events and profound differences between plant employees and local inhabitants. The NESI can be utilized as useful communication tool between the local inhabitants and nuclear practitioners. (authors)
Modelling of Local Necking and Fracture in Aluminium Alloys
International Nuclear Information System (INIS)
Achani, D.; Eriksson, M.; Hopperstad, O. S.; Lademo, O.-G.
2007-01-01
Non-linear Finite Element simulations are extensively used in forming and crashworthiness studies of automotive components and structures in which fracture need to be controlled. For thin-walled ductile materials, the fracture-related phenomena that must be properly represented are thinning instability, ductile fracture and through-thickness shear instability. Proper representation of the fracture process relies on the accuracy of constitutive and fracture models and their parameters that need to be calibrated through well defined experiments. The present study focuses on local necking and fracture which is of high industrial importance, and uses a phenomenological criterion for modelling fracture in aluminium alloys. As an accurate description of plastic anisotropy is important, advanced phenomenological constitutive equations based on the yield criterion YLD2000/YLD2003 are used. Uniaxial tensile tests and disc compression tests are performed for identification of the constitutive model parameters. Ductile fracture is described by the Cockcroft-Latham fracture criterion and an in-plane shear tests is performed to identify the fracture parameter. The reason is that in a well designed in-plane shear test no thinning instability should occur and it thus gives more direct information about the phenomenon of ductile fracture. Numerical simulations have been performed using a user-defined material model implemented in the general-purpose non-linear FE code LS-DYNA. The applicability of the model is demonstrated by correlating the predicted and experimental response in the in-plane shear tests and additional plane strain tension tests
Localization effects in rare earth high Tc superconductors
International Nuclear Information System (INIS)
Badera, Nitu; Godbole, Bhavana; Srivastava, S.B.; Rathore, M.K.; Ganesa, V.
2006-01-01
The Y 1-x Gd x Ba 2 Cu 3 O 7-δ samples have been prepared for different concentration of Gd . We employ thermoelectric power technique, which is sensitive to changes at the Fermi surface to study these materials. Metallic diffusion model and two band model are used to evaluate the normal state properties of these materials. At concentrations above 5% clear wide linear regions have been observed suggesting good evidence for localized states. (author)
Methodology of investment effectiveness evaluation in the local energy market
Energy Technology Data Exchange (ETDEWEB)
Kamrat, W.
1999-07-01
The paper presents issues of investment effectiveness evaluation in the local energy market. Results of research presented in the paper are mainly proposing a concept of a methodology which allows the evaluation of investment processes in regional power markets at the decision-making stage. In this respect, selecting a rational investment strategy is an important stage of the entire investment process. In view of criteria of various nature, the construction of a methodology of investment effectiveness bears an especially important meaning for a local decision-maker or investor. It is of particular significance to countries that are undergoing a transition from a centrally planned economy to a market economy. (orig.)
The effect of local tramadol injection in post appendectomy pain
Alireza Khazaei; Farshid Arbabi-Kalati; Soheil Borumand; Reza Rooshanravan
2012-01-01
Background: It has been demonstrated that tramadol, asemisynthetic opioid, is an effective analgesic with systemic (central) and local (peripheral) anesthetic effects. The aim of this study was to compare the post-operative anesthetic effect of subcutaneous wound infiltration of tramadol with normal saline as placebo in the incision wounds after appendectomy and measuring the average need to petidine during the next 24 hours after the appendectomy. Materials and Method: This double blind stud...
International Nuclear Information System (INIS)
Cao, Duc; Moses, Gregory; Delettrez, Jacques
2015-01-01
An implicit, non-local thermal conduction algorithm based on the algorithm developed by Schurtz, Nicolai, and Busquet (SNB) [Schurtz et al., Phys. Plasmas 7, 4238 (2000)] for non-local electron transport is presented and has been implemented in the radiation-hydrodynamics code DRACO. To study the model's effect on DRACO's predictive capability, simulations of shot 60 303 from OMEGA are completed using the iSNB model, and the computed shock speed vs. time is compared to experiment. Temperature outputs from the iSNB model are compared with the non-local transport model of Goncharov et al. [Phys. Plasmas 13, 012702 (2006)]. Effects on adiabat are also examined in a polar drive surrogate simulation. Results show that the iSNB model is not only capable of flux-limitation but also preheat prediction while remaining numerically robust and sacrificing little computational speed. Additionally, the results provide strong incentive to further modify key parameters within the SNB theory, namely, the newly introduced non-local mean free path. This research was supported by the Laboratory for Laser Energetics of the University of Rochester
Energy Technology Data Exchange (ETDEWEB)
Cao, Duc; Moses, Gregory [University of Wisconsin—Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States); Delettrez, Jacques [Laboratory for Laser Energetics of the University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)
2015-08-15
An implicit, non-local thermal conduction algorithm based on the algorithm developed by Schurtz, Nicolai, and Busquet (SNB) [Schurtz et al., Phys. Plasmas 7, 4238 (2000)] for non-local electron transport is presented and has been implemented in the radiation-hydrodynamics code DRACO. To study the model's effect on DRACO's predictive capability, simulations of shot 60 303 from OMEGA are completed using the iSNB model, and the computed shock speed vs. time is compared to experiment. Temperature outputs from the iSNB model are compared with the non-local transport model of Goncharov et al. [Phys. Plasmas 13, 012702 (2006)]. Effects on adiabat are also examined in a polar drive surrogate simulation. Results show that the iSNB model is not only capable of flux-limitation but also preheat prediction while remaining numerically robust and sacrificing little computational speed. Additionally, the results provide strong incentive to further modify key parameters within the SNB theory, namely, the newly introduced non-local mean free path. This research was supported by the Laboratory for Laser Energetics of the University of Rochester.
Cao, Duc; Moses, Gregory; Delettrez, Jacques
2015-08-01
An implicit, non-local thermal conduction algorithm based on the algorithm developed by Schurtz, Nicolai, and Busquet (SNB) [Schurtz et al., Phys. Plasmas 7, 4238 (2000)] for non-local electron transport is presented and has been implemented in the radiation-hydrodynamics code DRACO. To study the model's effect on DRACO's predictive capability, simulations of shot 60 303 from OMEGA are completed using the iSNB model, and the computed shock speed vs. time is compared to experiment. Temperature outputs from the iSNB model are compared with the non-local transport model of Goncharov et al. [Phys. Plasmas 13, 012702 (2006)]. Effects on adiabat are also examined in a polar drive surrogate simulation. Results show that the iSNB model is not only capable of flux-limitation but also preheat prediction while remaining numerically robust and sacrificing little computational speed. Additionally, the results provide strong incentive to further modify key parameters within the SNB theory, namely, the newly introduced non-local mean free path. This research was supported by the Laboratory for Laser Energetics of the University of Rochester.
Mathematical Model of Synthesis Catalyst with Local Reaction Centers
Directory of Open Access Journals (Sweden)
I. V. Derevich
2017-01-01
Full Text Available The article considers a catalyst granule with a porous ceramic passive substrate and point active centers on which an exothermic synthesis reaction occurs. A rate of the chemical reaction depends on the temperature according to the Arrhenius law. Heat is removed from the pellet surface in products of synthesis due to heat transfer. In our work we first proposed a model for calculating the steady-state temperature of a catalyst pellet with local reaction centers. Calculation of active centers temperature is based on the idea of self-consistent field (mean-field theory. At first, it is considered that powers of the reaction heat release at the centers are known. On the basis of the found analytical solution, which describes temperature distribution inside the granule, the average temperature of the reaction centers is calculated, which then is inserted in the formula for heat release. The resulting system of transcendental algebraic equations is transformed into a system of ordinary differential equations of relaxation type and solved numerically to achieve a steady-state value. As a practical application, the article considers a Fischer-Tropsch synthesis catalyst granule with active cobalt metallic micro-particles. Cobalt micro-particles are the centers of the exothermic reaction of hydrocarbons macromolecular synthesis. Synthesis occurs as a result of absorption of the components of the synthesis gas on metallic cobalt. The temperature distribution inside the granule for a single local center and reaction centers located on the same granule diameter is found. It was found that there is a critical temperature of reactor exceeding of which leads to significant local overheating of the centers - thermal explosion. The temperature distribution with the local reaction centers is qualitatively different from the granule temperature, calculated in the homogeneous approximation. It is shown that, in contrast to the homogeneous approximation, the
Influence of local capillary trapping on containment system effectiveness
Energy Technology Data Exchange (ETDEWEB)
Bryant, Steven [University Of Texas At Austin, Austin, TX (United States). Center for Petroleum and Geosystems Engineering
2014-03-31
Immobilization of CO_{2} injected into deep subsurface storage reservoirs is a critical component of risk assessment for geologic CO_{2} storage (GCS). Local capillary trapping (LCT) is a recently established mode of immobilization that arises when CO_{2} migrates due to buoyancy through heterogeneous storage reservoirs. This project sought to assess the amount and extent of LCT expected in storage formations under a range of injection conditions, and to confirm the persistence of LCT if the seal overlying the reservoir were to lose its integrity. Numerical simulation using commercial reservoir simulation software was conducted to assess the influence of injection. Laboratory experiments, modeling and numerical simulation were conducted to assess the effect of compromised seal integrity. Bench-scale (0.6 m by 0.6 m by 0.03 m) experiments with surrogate fluids provided the first empirical confirmation of the key concepts underlying LCT: accumulation of buoyant nonwetting phase at above residual saturations beneath capillary barriers in a variety of structures, which remains immobile under normal capillary pressure gradients. Immobilization of above-residual saturations is a critical distinction between LCT and the more familiar “residual saturation trapping.” To estimate the possible extent of LCT in a storage reservoir an algorithm was developed to identify all potential local traps, given the spatial distribution of capillary entry pressure in the reservoir. The algorithm assumes that the driving force for CO_{2} migration can be represented as a single value of “critical capillary entry pressure” P_{c,entry}^{crit}, such that cells with capillary entry pressure greater/less than P_{c,entry}^{crit} act as barriers/potential traps during CO_{2} migration. At intermediate values of P_{c,entry}^{crit}, the barrier regions become more laterally extensive in the reservoir
Directory of Open Access Journals (Sweden)
Javier Macias-Guarasa
2012-10-01
Full Text Available This paper presents a novel approach for indoor acoustic source localization using sensor arrays. The proposed solution starts by defining a generative model, designed to explain the acoustic power maps obtained by Steered Response Power (SRP strategies. An optimization approach is then proposed to fit the model to real input SRP data and estimate the position of the acoustic source. Adequately fitting the model to real SRP data, where noise and other unmodelled effects distort the ideal signal, is the core contribution of the paper. Two basic strategies in the optimization are proposed. First, sparse constraints in the parameters of the model are included, enforcing the number of simultaneous active sources to be limited. Second, subspace analysis is used to filter out portions of the input signal that cannot be explained by the model. Experimental results on a realistic speech database show statistically significant localization error reductions of up to 30% when compared with the SRP-PHAT strategies.
Locality effects on bifurcation paradigm of L-H transition in tokamak plasmas
Directory of Open Access Journals (Sweden)
Boonyarit Chatthong
2015-12-01
Full Text Available The locality effects on bifurcation paradigm of L-H transition phenomenon in magnetic confinement plasmas are investigated. One dimensional thermal transport equation with both neoclassical and anomalous transports effects included is considered, where a flow shear due to pressure gradient component is included as a transport suppression mechanism. Three different locally driven models for anomalous transport are considered, including a constant transport model, pressure gradient driven transport model, and critical pressure gradient threshold transport model. Local stability analysis shows that the transition occurs at a threshold flux with hysteresis nature only if ratio of anomalous strength over neoclassical transport exceeds a critical value. The depth of the hysteresis loop depends on both neoclassical and anomalous transports, as well as the suppression strength. The reduction of the heat flux required to maintain H-mode can be as low as a factor of two, which is similar to experimental evidence.
Modeling amorphization of tetrahedral structures under local approaches
International Nuclear Information System (INIS)
Jesurum, C.E.; Pulim, V.; Berger, B.; Hobbs, L.W.
1997-01-01
Many crystalline ceramics can be topologically disordered (amorphized) by disordering radiation events involving high-energy collision cascades or (in some cases) successive single-atom displacements. The authors are interested in both the potential for disorder and the possible aperiodic structures adopted following the disordering event. The potential for disordering is related to connectivity, and among those structures of interest are tetrahedral networks (such as SiO 2 , SiC and Si 3 N 4 ) comprising corner-shared tetrahedral units whose connectivities are easily evaluated. In order to study the response of these networks to radiation, the authors have chosen to model their assembly according to the (simple) local rules that each corner obeys in connecting to another tetrahedron; in this way they easily erect large computer models of any crystalline polymorphic form. Amorphous structures can be similarly grown by application of altered rules. They have adopted a simple model of irradiation in which all bonds in the neighborhood of a designated tetrahedron are destroyed, and they reform the bonds in this region according to a set of (possibly different) local rules appropriate to the environmental conditions. When a tetrahedron approaches the boundary of this neighborhood, it undergoes an optimization step in which a spring is inserted between two corners of compatible tetrahedra when they are within a certain distance of one another; component forces are then applied that act to minimize the distance between these corners and minimize the deviation from the rules. The resulting structure is then analyzed for the complete adjacency matrix, irreducible ring statistics, and bond angle distributions
The plastic flow localization effect on crystalline material
International Nuclear Information System (INIS)
Pajot, A.
2011-01-01
Irradiation affects the mechanical properties of materials. In particular, an increase of yield strength followed by a decrease of ductility and a reduction of the elongation to fracture are observed above a threshold irradiation dose. The last two phenomena are correlated with the appearance of bands free of defects (clear bands) in which plastic deformation is confined. These bands also determine accumulation of dislocations at grain boundaries, thereby favouring local grain decohesion and possibly initiating fracture. Clear bands have an important impact on metal resistance, nevertheless our level of understanding is not sufficient to evaluate quantitatively their effect on the loss of ductility and reduction of elongation to fracture that are observed experimentally. A clear band is a microstructural defect, created when loading an irradiated material. Its complex interaction with defects on the nano scale affects the behaviour of the metal at the macroscopic scale. A full understanding implies the application of a multi scale modeling approach. This explains why, even though clear bands have first been
A non-local shell model of hydrodynamic and magnetohydrodynamic turbulence
Energy Technology Data Exchange (ETDEWEB)
Plunian, F [Laboratoire de Geophysique Interne et Tectonophysique, CNRS, Universite Joseph Fourier, Maison des Geosciences, BP 53, 38041 Grenoble Cedex 9 (France); Stepanov, R [Institute of Continuous Media Mechanics, Korolyov 1, 614013 Perm (Russian Federation)
2007-08-15
We derive a new shell model of magnetohydrodynamic (MHD) turbulence in which the energy transfers are not necessarily local. Like the original MHD equations, the model conserves the total energy, magnetic helicity, cross-helicity and volume in phase space (Liouville's theorem) apart from the effects of external forcing, viscous dissipation and magnetic diffusion. The model of hydrodynamic (HD) turbulence is derived from the MHD model setting the magnetic field to zero. In that case the conserved quantities are the kinetic energy and the kinetic helicity. In addition to a statistically stationary state with a Kolmogorov spectrum, the HD model exhibits multiscaling. The anomalous scaling exponents are found to depend on a free parameter {alpha} that measures the non-locality degree of the model. In freely decaying turbulence, the infra-red spectrum also depends on {alpha}. Comparison with theory suggests using {alpha} = -5/2. In MHD turbulence, we investigate the fully developed turbulent dynamo for a wide range of magnetic Prandtl numbers in both kinematic and dynamic cases. Both local and non-local energy transfers are clearly identified.
Dynamics Modeling and Analysis of Local Fault of Rolling Element Bearing
Directory of Open Access Journals (Sweden)
Lingli Cui
2015-01-01
Full Text Available This paper presents a nonlinear vibration model of rolling element bearings with 5 degrees of freedom based on Hertz contact theory and relevant bearing knowledge of kinematics and dynamics. The slipping of ball, oil film stiffness, and the nonlinear time-varying stiffness of the bearing are taken into consideration in the model proposed here. The single-point local fault model of rolling element bearing is introduced into the nonlinear model with 5 degrees of freedom according to the loss of the contact deformation of ball when it rolls into and out of the local fault location. The functions of spall depth corresponding to defects of different shapes are discussed separately in this paper. Then the ode solver in Matlab is adopted to perform a numerical solution on the nonlinear vibration model to simulate the vibration response of the rolling elements bearings with local fault. The simulation signals analysis results show a similar behavior and pattern to that observed in the processed experimental signals of rolling element bearings in both time domain and frequency domain which validated the nonlinear vibration model proposed here to generate typical rolling element bearings local fault signals for possible and effective fault diagnostic algorithms research.
Local effects of ECRH on argon transport at ASDEX upgrade
International Nuclear Information System (INIS)
Sertoli, Marco
2010-01-01
Future deuterium-tritium magnetically confined fusion power plants will most probably rely an high-Z Plasma Facing Components (PFCs) such as tungsten. This choice is determined by the necessity of low erosion of the first wall materials (to guarantee a long lifetime of the wall components) and by the need to avoid the too high tritium wall retention of typical carbon based PFCs. The experience gathered at the ASDEX Upgrade (AUG) tokamak has demonstrated the possibility of reliable and high performance plasma operation with a full tungsten-coated first wall. The observed accumulation of tungsten which can lead to excessive radiation losses is mitigated with the use of Electron Cyclotron Resonance Heating (ECRH). Although this impurity control method is routinely performed at AUG, the underlying physics principles are still not clear. This thesis aims an providing further knowledge an the effects of ECRH an the transport of impurities inside the core plasma. The transport of argon has been therefore investigated in-depth in purely ECR heated L-mode (low-confinement) discharges. Studies an impurity transport in centrally ECR heated nitrogen-seeded H-mode (high-confinement) discharges have also been performed. To this scope, a new crystal X-ray spectrometer of the Johann type has been installed an AUG for argon concentration and ion temperature measurements. New methods for the experimental determination of the total argon density through the integrated use of this diagnostic and of the Soft X-Ray (SXR) diode arrays have been developed. This gives the possibility of evaluating the full profiles of the argon transport coefficients from the linear flux-gradient dependency of local argon density. In comparison to classical χ 2 -minimization methods, the approach proposed here delivers transport coefficients intrinsically independent of the modelling of periodic relaxation mechanisms such as those Lied to sawtooth MHD (Magneto-Hydro-Dynamic) activity. Moreover, the good
Vardhan, Shreya; De Tomasi, Giuseppe; Heyl, Markus; Heller, Eric J.; Pollmann, Frank
2017-07-01
We study the effects of local perturbations on the dynamics of disordered fermionic systems in order to characterize time irreversibility. We focus on three different systems: the noninteracting Anderson and Aubry-André-Harper (AAH) models and the interacting spinless disordered t -V chain. First, we consider the effect on the full many-body wave functions by measuring the Loschmidt echo (LE). We show that in the extended or ergodic phase the LE decays exponentially fast with time, while in the localized phase the decay is algebraic. We demonstrate that the exponent of the decay of the LE in the localized phase diverges proportionally to the single-particle localization length as we approach the metal-insulator transition in the AAH model. Second, we probe different phases of disordered systems by studying the time expectation value of local observables evolved with two Hamiltonians that differ by a spatially local perturbation. Remarkably, we find that many-body localized systems could lose memory of the initial state in the long-time limit, in contrast to the noninteracting localized phase where some memory is always preserved.
International Nuclear Information System (INIS)
Kauch, Anna; Byczuk, Krzysztof
2012-01-01
The variational local moment approach (VLMA) solution of the single impurity Anderson model is presented. It generalizes the local moment approach of Logan et al. by invoking the variational principle to determine the lengths of local moments and orbital occupancies. We show that VLMA is a comprehensive, conserving and thermodynamically consistent approximation and treats both Fermi and non-Fermi liquid regimes as well as local moment phases on equal footing. We tested VLMA on selected problems. We solved the single- and multi-orbital impurity Anderson model in various regions of parameters, where different types of Kondo effects occur. The application of VLMA as an impurity solver of the dynamical mean-field theory, used to solve the multi-orbital Hubbard model, is also addressed.
Removal of semivolatiles from soils by steam stripping. 1. A local equilibrium model
International Nuclear Information System (INIS)
Wilson, D.J.; Clarke, A.N.
1992-01-01
A mathematical model for the in-situ steam stripping of volatile and semivolatile organics from contaminated vadose zone soils at hazardous waste sites is developed. A single steam injection well is modeled. The model assumes that the pneumatic permeability of the soil is spatially constant and isotropic, that the adsorption isotherm of the contaminant is linear, and that the local equilibrium approximation is adequate. The model is used to explore the streamlines and transit times of the injected steam as well as the effects of injection well depth and contaminant distribution on the time required for remediation
International Nuclear Information System (INIS)
Kumar, Munish; Kher, R K; Bhatt, B C; Sunta, C M
2007-01-01
Different models dealing with localized and semi-localized transitions, namely Chen-Halperin, Mandowski and the model based on the Braunlich-Scharmann (BS) approach are compared. It has been found that for recombination dominant situations (r > 1, the three models differ. This implies that for localized transitions under recombination dominant situations, the Chen-Halperin model is the best representative of the thermally stimulated luminescence (TSL) process. It has also been found that for the TSL glow curves arising from delocalized recombination in Mandowski's semi-localized transitions model, the double peak structure of the TSL glow curve is a function of the radiation dose as well as of the heating rate. Further, the double peak structure of the TSL glow curves arising from delocalized recombination disappears at low doses as well as at higher heating rates. It has also been found that the TSL glow curves arising from delocalized recombination in the semi-localized transitions model based on the BS approach do not exhibit double peak structure as observed in the Mandowski semi-localized transitions model
Modelling Local Attitudes to Protected Areas in Developing Countries
Directory of Open Access Journals (Sweden)
Chiara Bragagnolo
2016-01-01
Full Text Available During a time of intensifying competition for land, Protected Areas (PAs are coming under increasing pressure to justify their status. Positive local attitudes to a PA are a potentially important component of any such justification, especially in the developing world where human pressure on natural resources is often high. However, despite numerous studies our understanding of what drives positive attitudes to PAs is still exceedingly limited. Here, we review the literature on local attitudes towards PAs in developing countries. Our survey reveals a highly fragmented research area where studies typically lack an explicit conceptual basis, and where there is wide variation in choice of statistical approach, explanatory and response variables, and incorporation of contextual information. Nevertheless, there is a relatively high degree of concordance between studies, with certain variables showing strong associations with attitudes. We recommend that PA attitude researchers in developing countries adopt a more rigorous model building approach based on a clear conceptual framework and drawing on the extensive empirical literature. Such an approach would improve the quality of research, increase comparability, and provide a stronger basis to support conservation decision-making.
Local Side Effects of Sublingual and Oral Immunotherapy.
Passalacqua, Giovanni; Nowak-Węgrzyn, Anna; Canonica, Giorgio Walter
Sublingual immunotherapy (SLIT) is increasingly used worldwide, and several products have been recently registered as drugs for respiratory allergy by the European Medicine Agency and the Food and Drug Administration. Concerning inhalant allergens, the safety of SLIT is overall superior to that of subcutaneous immunotherapy in terms of systemic adverse events. No fatality has been ever reported, and episodes of anaphylaxis were described only exceptionally. Looking at the historical and recent trials, most (>90%) adverse events are "local" and confined to the site of administration. For this reason, a specific grading system has been developed by the World Allergy Organization to classify and describe local adverse events. There is an increasing amount of literature concerning oral desensitization for food allergens, referred to as oral immunotherapy. Also, in this case, local side effects are predominant, although systemic adverse events are more frequent than with inhalant allergens. We review herein the description of local side effects due to SLIT, with a special focus on large trials having a declared sample size calculation. The use of the Medical Dictionary for Regulatory Activities nomenclature for adverse events is mentioned in this context, as recommended by regulatory agencies. It is expected that a uniform classification/grading of local adverse events will improve and harmonize the surveillance and reporting on the safety of SLIT. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Numerical study of effect of oxygen fraction on local entropy ...
Indian Academy of Sciences (India)
This study considers numerical simulation of the combustion of methane with air, including oxygen and nitrogen, in a burner and the numerical solution of local entropy generation rate due to high temperature and velocity gradients in the combustion chamber. The effects of equivalence ratio () and oxygen percentage () ...
Strong expectations cancel locality effects: evidence from Hindi.
Directory of Open Access Journals (Sweden)
Samar Husain
Full Text Available Expectation-driven facilitation (Hale, 2001; Levy, 2008 and locality-driven retrieval difficulty (Gibson, 1998, 2000; Lewis & Vasishth, 2005 are widely recognized to be two critical factors in incremental sentence processing; there is accumulating evidence that both can influence processing difficulty. However, it is unclear whether and how expectations and memory interact. We first confirm a key prediction of the expectation account: a Hindi self-paced reading study shows that when an expectation for an upcoming part of speech is dashed, building a rarer structure consumes more processing time than building a less rare structure. This is a strong validation of the expectation-based account. In a second study, we show that when expectation is strong, i.e., when a particular verb is predicted, strong facilitation effects are seen when the appearance of the verb is delayed; however, when expectation is weak, i.e., when only the part of speech "verb" is predicted but a particular verb is not predicted, the facilitation disappears and a tendency towards a locality effect is seen. The interaction seen between expectation strength and distance shows that strong expectations cancel locality effects, and that weak expectations allow locality effects to emerge.
Strong expectations cancel locality effects: evidence from Hindi.
Husain, Samar; Vasishth, Shravan; Srinivasan, Narayanan
2014-01-01
Expectation-driven facilitation (Hale, 2001; Levy, 2008) and locality-driven retrieval difficulty (Gibson, 1998, 2000; Lewis & Vasishth, 2005) are widely recognized to be two critical factors in incremental sentence processing; there is accumulating evidence that both can influence processing difficulty. However, it is unclear whether and how expectations and memory interact. We first confirm a key prediction of the expectation account: a Hindi self-paced reading study shows that when an expectation for an upcoming part of speech is dashed, building a rarer structure consumes more processing time than building a less rare structure. This is a strong validation of the expectation-based account. In a second study, we show that when expectation is strong, i.e., when a particular verb is predicted, strong facilitation effects are seen when the appearance of the verb is delayed; however, when expectation is weak, i.e., when only the part of speech "verb" is predicted but a particular verb is not predicted, the facilitation disappears and a tendency towards a locality effect is seen. The interaction seen between expectation strength and distance shows that strong expectations cancel locality effects, and that weak expectations allow locality effects to emerge.
Effect of occupational exposure to local powdered tobacco (snuff) on ...
African Journals Online (AJOL)
The effect of occupational exposure to local powdered tobacco (snuff) on pulmonary function was studied. Snuff industry workers in Onitsha and Enugu markets were studied and compared with age-, weight-, and height-matched control not exposed to any known air pollutant. The pulmonary indices studied include; forced ...
Impedes to effective collection of local government revenue and ...
African Journals Online (AJOL)
However, the inability of these institutions to effectively collect revenue in Cameroon has hampered service delivery. Following the case of the Wum Central Council, the study holds that tax evasion and defaulting, migration and the diversion of revenue to other Local Government areas as well as underpayments of court ...
Electron localization in liquid hydrocarbons: The Anderson model
International Nuclear Information System (INIS)
Hug, Gordon L.; Mozumder, A.
2008-01-01
Anderson's model is applied for initial localization in liquid hydrocarbons (particularly n-alkanes) in conjunction with certain results of scaling theory. Medium connectivity is calculated using experimental X-ray data on liquid structure, from which critical disorder (W/V) c is computed, where W is diagonal disorder and V is the transfer energy. Actual W prevailing in the liquid is computed from anisotropic molecular polarizability. V is estimated by a heuristic procedure originating in scaling theory. These values are used to compute the percentage of initially delocalized states available for low-energy electrons in alkane liquids. This percentage decreases monotonically from methane (100%) to n-pentane and beyond (0%). In ethane and propane, the initial states are highly delocalized (97.6% and 83.9%, respectively). Subsequent trapping changes the situation as evidenced in mobility studies. Butane presents a partially, intermediate delocalized case (53.2%)
Onset patterns in a simple model of localized parametric forcing.
Porter, J; Tinao, I; Laverón-Simavilla, A; Rodríguez, J
2013-10-01
We investigate pattern selection at onset in a parametrically and inhomogeneously forced partial differential equation obtained by generalizing Mathieu's equation to include spatial interactions. No separation of scales is assumed. The proposed model is directly relevant to the case of parametrically forced surface waves, such as cross-waves, excited by the horizontal vibration of a fluid, where the forcing is localized to a finite region near the endwall or wavemaker. The availability of analytical solutions in the limit of piecewise constant forcing allows us investigate in detail the dependence of selected eigenfunctions on spatial detuning, forcing width, damping, boundary conditions, and container size. A wide range of onset patterns are located and described, many of which are rotated, modulated, or both, and deviate far from simple crosswise oriented standing waves. The linear selection mechanisms governing this multiplicity of potential onset patterns are discussed.
A note on local GUT models in F-theory
International Nuclear Information System (INIS)
Chen, C.-M.; Chung, Y.-C.
2010-01-01
We construct non-minimal GUT local models in the F-theory configuration. The gauge group on the bulk G S is one rank higher than the GUT gauge group. The line bundles on the curves are nontrivial to break G S down to the GUT gauge groups. We demonstrate examples of SU(5) GUT from G S =SU(6) and G S =SO(10), the flipped SU(5) from G S =SO(10), and the SO(10) GUT from G S =SO(12) and G S =E 6 . We obtain complete GUT matter spectra and couplings, with minimum exotic matter contents. GUT gauge group breaking to MSSM is achievable by instanton configurations.
Model for the local spiral structure of the galaxy
International Nuclear Information System (INIS)
Humphreys, R.M.
1976-01-01
The spatial distribution of the most luminous stars, associations, clusters, and H II regions in the region l = 270 0 to 30 0 reveal a major spiral arm, Sagittarius-Carina, which can be observed to 9 or 10 kpc from the sun in the direction l = 290 0 to 305 0 . Evidence is also presented for a spur at l = 305 0 to 310 0 on the inner side of the Saggitarius-Carina arm. The noncircular motions observed in the Carina and Sagittarius spiral features agree in both magnitude and direction and support the suggestion that Sagittarius-Carina is a major spiral arm. A model is presented for the local spiral structure with wide, massive, spiral arms which show fragmentation in our region of the Galaxy. On the basis of the optical spiral structure, the Milky Way is an Sc type spiral galaxy, perhaps of the M 101 type
A local non-parametric model for trade sign inference
Blazejewski, Adam; Coggins, Richard
2005-03-01
We investigate a regularity in market order submission strategies for 12 stocks with large market capitalization on the Australian Stock Exchange. The regularity is evidenced by a predictable relationship between the trade sign (trade initiator), size of the trade, and the contents of the limit order book before the trade. We demonstrate this predictability by developing an empirical inference model to classify trades into buyer-initiated and seller-initiated. The model employs a local non-parametric method, k-nearest neighbor, which in the past was used successfully for chaotic time series prediction. The k-nearest neighbor with three predictor variables achieves an average out-of-sample classification accuracy of 71.40%, compared to 63.32% for the linear logistic regression with seven predictor variables. The result suggests that a non-linear approach may produce a more parsimonious trade sign inference model with a higher out-of-sample classification accuracy. Furthermore, for most of our stocks the observed regularity in market order submissions seems to have a memory of at least 30 trading days.
Local stem cell depletion model for normal tissue damage
International Nuclear Information System (INIS)
Yaes, R.J.; Keland, A.
1987-01-01
The hypothesis that radiation causes normal tissue damage by completely depleting local regions of tissue of viable stem cells leads to a simple mathematical model for such damage. In organs like skin and spinal cord where destruction of a small volume of tissue leads to a clinically apparent complication, the complication probability is expressed as a function of dose, volume and stem cell number by a simple triple negative exponential function analogous to the double exponential function of Munro and Gilbert for tumor control. The steep dose response curves for radiation myelitis that are obtained with our model are compared with the experimental data for radiation myelitis in laboratory rats. The model can be generalized to include other types or organs, high LET radiation, fractionated courses of radiation, and cases where an organ with a heterogeneous stem cell population receives an inhomogeneous dose of radiation. In principle it would thus be possible to determine the probability of tumor control and of damage to any organ within the radiation field if the dose distribution in three dimensional space within a patient is known
Explosion localization and characterization via infrasound using numerical modeling
Fee, D.; Kim, K.; Iezzi, A. M.; Matoza, R. S.; Jolly, A. D.; De Angelis, S.; Diaz Moreno, A.; Szuberla, C.
2017-12-01
Numerous methods have been applied to locate, detect, and characterize volcanic and anthropogenic explosions using infrasound. Far-field localization techniques typically use back-azimuths from multiple arrays (triangulation) or Reverse Time Migration (RTM, or back-projection). At closer ranges, networks surrounding a source may use Time Difference of Arrival (TDOA), semblance, station-pair double difference, etc. However, at volcanoes and regions with topography or obstructions that block the direct path of sound, recent studies have shown that numerical modeling is necessary to provide an accurate source location. A heterogeneous and moving atmosphere (winds) may also affect the location. The time reversal mirror (TRM) application of Kim et al. (2015) back-propagates the wavefield using a Finite Difference Time Domain (FDTD) algorithm, with the source corresponding to the location of peak convergence. Although it provides high-resolution source localization and can account for complex wave propagation, TRM is computationally expensive and limited to individual events. Here we present a new technique, termed RTM-FDTD, which integrates TRM and FDTD. Travel time and transmission loss information is computed from each station to the entire potential source grid from 3-D Green's functions derived via FDTD. The wave energy is then back-projected and stacked at each grid point, with the maximum corresponding to the likely source. We apply our method to detect and characterize thousands of explosions from Yasur Volcano, Vanuatu and Etna Volcano, Italy, which both provide complex wave propagation and multiple source locations. We compare our results with those from more traditional methods (e.g. semblance), and suggest our method is preferred as it is computationally less expensive than TRM but still integrates numerical modeling. RTM-FDTD could be applied to volcanic other anthropogenic sources at a wide variety of ranges and scenarios. Kim, K., Lees, J.M., 2015. Imaging
Effect of water on the local electric potential of simulated ionic micelles
Energy Technology Data Exchange (ETDEWEB)
Brodskaya, Elena N.; Vanin, Alexander A., E-mail: alexvanin@yandex.ru [Institute of Chemistry, St. Petersburg State University, Universitetskiy pr. 26, Petrodvoretz, St. Petersburg 198504 (Russian Federation)
2015-07-28
Ionic micelles in an aqueous solution containing single-charged counter-ions have been simulated by molecular dynamics. For both cationic and anionic micelles, it has been demonstrated that explicit description of solvent has strong effect on the micelle’s electric field. The sign of the local charge alters in the immediate vicinity of the micellar crown and the electric potential varies nonmonotonically. Two micelle models have been examined: the hybrid model with a rigid hydrocarbon core and the atomistic model. For three molecular models of water (Simple Point Charge model (SPC), Transferable Intermolecular Potential 5- Points (TIP5P) and two-centered S2), the results have been compared with those for the continuum solvent model. The orientational ordering of solvent molecules has strong effect on the local electric field surprisingly far from the micelle surface.
Estimating Causal Effects of Local Air Pollution on Daily Deaths: Effect of Low Levels.
Schwartz, Joel; Bind, Marie-Abele; Koutrakis, Petros
2017-01-01
Although many time-series studies have established associations of daily pollution variations with daily deaths, there are fewer at low concentrations, or focused on locally generated pollution, which is becoming more important as regulations reduce regional transport. Causal modeling approaches are also lacking. We used causal modeling to estimate the impact of local air pollution on mortality at low concentrations. Using an instrumental variable approach, we developed an instrument for variations in local pollution concentrations that is unlikely to be correlated with other causes of death, and examined its association with daily deaths in the Boston, Massachusetts, area. We combined height of the planetary boundary layer and wind speed, which affect concentrations of local emissions, to develop the instrument for particulate matter ≤ 2.5 μm (PM2.5), black carbon (BC), or nitrogen dioxide (NO2) variations that were independent of year, month, and temperature. We also used Granger causality to assess whether omitted variable confounding existed. We estimated that an interquartile range increase in the instrument for local PM2.5 was associated with a 0.90% increase in daily deaths (95% CI: 0.25, 1.56). A similar result was found for BC, and a weaker association with NO2. The Granger test found no evidence of omitted variable confounding for the instrument. A separate test confirmed the instrument was not associated with mortality independent of pollution. Furthermore, the association remained when all days with PM2.5 concentrations > 30 μg/m3 were excluded from the analysis (0.84% increase in daily deaths; 95% CI: 0.19, 1.50). We conclude that there is a causal association of local air pollution with daily deaths at concentrations below U.S. EPA standards. The estimated attributable risk in Boston exceeded 1,800 deaths during the study period, indicating that important public health benefits can follow from further control efforts. Citation: Schwartz J, Bind MA
Preoperative localization of parathyroid adenomas is cost-effective
International Nuclear Information System (INIS)
Wilson, M.A.; Mack, E.; Rowe, B.; Perlman, S.B.
1986-01-01
The preoperative localization of parathyroid adenomas is cost-effective because it reduces anesthesia and surgery times. The technique is sensitive in single and double adenomas (90%), and some surgeons have modified their operative technique because of its introduction. The practical experience of one surgeon is presented, with similar patient subsets (n = 22) compared before and after use of a localization scan was instituted. The average operative time fell by 94%, from 2 hours 35 minutes to 1 hour 19 minutes. The reduction in operative time was possible because the surgeon did not seek to identify the remaining normal parathyroids when the scanned lesion was excised and proved to be the adenoma
Local effect of equilibrium current on tearing mode stability
International Nuclear Information System (INIS)
Cozzani, F.
1985-12-01
The local effect of the equilibrium current on the linear stability of low poloidal number tearing modes in tokamaks is investigated analytically. The plasma response inside the tearing layer is derived from fluid theory and the local equilibrium current is shown to couple to the mode dynamics through its gradient, which is proportional to the local electron temperature gradient under the approximations used in the analysis. The relevant eigenmode equations, expressing Ampere's law and the plasma quasineutrality condition, respectively, are suitably combined in a single integral equation, from which a variational principle is formulated to derive the mode dispersion relations for several cases of interest. The local equilibrium current is treated as a small perturbation of the known results for the m greater than or equal to 2 and the m = 1 tearing modes in the collisional regime, and the m greater than or equal to 2 tearing mode in the semicollisional regime; its effect is found to enhance stabilization for the m greater than or equal to 2 drift-tearing mode in the collisional regime, whereas the m = 1 growth rate is very slightly increased and the stabilizing effect of the parallel thermal conduction on the m greater than or equal to 2 mode in the semicollisional regime is slightly reduced
Directory of Open Access Journals (Sweden)
GVA Stadelmann
2008-07-01
Full Text Available It is a clinical challenge to obtain a sufficient orthopaedic implant fixation in weak osteoporotic bone. When the primary implant fixation is poor, micromotions occur at the bone-implant interface, activating osteoclasts, which leads to implant loosening. Bisphosphonate can be used to prevent the osteoclastic response, but when administered systemically its bioavailability is low and the time it takes for the drug to reach the periprosthetic bone may be a limiting factor. Recent data has shown that delivering bisphosphonate locally from the implant surface could be an interesting solution. Local bisphosphonate delivery increased periprosthetic bone density, which leads to a stronger implant fixation, as demonstrated in rats by the increased implant pullout force. The aim of the present study was to verify the positive effect on periprosthetic bone remodelling of local bisphosphonate delivery in an osteoporotic sheep model. Four implants coated with zoledronate and two control implants were inserted in the femoral condyle of ovariectomized sheep for 4 weeks. The bone at the implant surface was 50% higher in the zoledronate-group compared to control group. This effect was significant up to a distance of 400µm from the implant surface. The presented results are similar to what was observed in the osteoporotic rat model, which suggest that the concept of releasing zoledronate locally from the implant to increase the implant fixation is not species specific. The results of this trial study support the claim that local zoledronate could increase the fixation of an implant in weak bone.
Effect of localized polycrystalline silicon properties on solar cell performance
Leung, D.; Iles, P. A.; Hyland, S.; Kachare, A.
1984-01-01
Several forms of polycrystalline silicon, mostly from cast ingots, (including UCP, SILSO and HEM) were studied. On typical slices, localized properties were studied in two ways. Small area (about 2.5 sq mm) mesa diodes were formed, and localized photovoltaic properties were measured. Also a small area (about .015 sq mm) light spot was scanned across the cells; the light spot response was calibrated to measure local diffusion length directly. Using these methods, the effects of grain boundaries, or of intragrain imperfections were correlated with cell performance. Except for the fine grain portion of SILSO, grain boundaries played only a secondary role in determining cell performance. The major factor was intra-grain material quality and it varied with position in ingots and probably related to solidification procedure.
Opisthorchiasis in Northeastern Thailand: Effect of local environment and culture
Directory of Open Access Journals (Sweden)
Beuy Joob
2015-06-01
Full Text Available Opisthorchiasis is a kind of trematode infection. This parasitic infestation is a chronic hepatobiliary tract infection and can cause chronic irritation that will finally lead to cholangiocarcinoma. It is highly endemic in northeastern region of Thailand and contributes to many cholangiocarcinoma cases annually. The attempt to control the disease becomes a national policy. However, the sanitation becomes a major underlying factor leading to infection and meanwhile, the poverty and low education of the local people become an important concern. In this opinion, the authors discuss the effect of local environment and culture on opisthorchiasis in northeastern Thailand. Due to the pattern change of local environment, global warming and globalization, the dynamicity can be observed.
Contribution of local probes in the understanding of mechanical effect on localized corrosion
International Nuclear Information System (INIS)
Vignal, Vincent; Oltra, Roland; Mary, Nicolas
2004-01-01
Understanding the actual effects of mechanical stresses on the processes leading to pitting corrosion necessitates to develop both a mechanical approach and electrochemical experiments at a microscopic scale. Typical embrittlement can be observed after straining around MnS inclusions on a re-sulfurized 316 stainless steels and their corrosion sensitivity have been classified using the micro-capillary electrochemical cell technique. It has been shown that the numerical simulation of the location of stress gradients is possible before the local electrochemical analysis and could be a very interesting way to define the pitting susceptibility of micro-cracked areas during straining. (authors)
International Nuclear Information System (INIS)
Ijaz, H.; Asad, M.
2015-01-01
The use of composite laminates is increasing in these days due to higher strength and low density values in comparison of metals. Delamination is a major source of failure in composite laminates. Damage mechanics based theories are employed to simulate the delamination phenomena between composite laminates. These damage models are inherently local and can cause the concentration of stresses around the crack tip. In the present study integral type non-local damage formulation is proposed to avoid the localization problem associated to damage formulation. A comprehensive study is carried out for the models and classical local damage model are performed and results are compared with available experimental data for un IMS/924 Carbon/fiber epoxy composite laminate. (author)
Local thermodynamic mapping for effective liquid density-functional theory
Kyrlidis, Agathagelos; Brown, Robert A.
1992-01-01
The structural-mapping approximation introduced by Lutsko and Baus (1990) in the generalized effective-liquid approximation is extended to include a local thermodynamic mapping based on a spatially dependent effective density for approximating the solid phase in terms of the uniform liquid. This latter approximation, called the local generalized effective-liquid approximation (LGELA) yields excellent predictions for the free energy of hard-sphere solids and for the conditions of coexistence of a hard-sphere fcc solid with a liquid. Moreover, the predicted free energy remains single valued for calculations with more loosely packed crystalline structures, such as the diamond lattice. The spatial dependence of the weighted density makes the LGELA useful in the study of inhomogeneous solids.
Modeling local extinction in turbulent combustion using an embedding method
Knaus, Robert; Pantano, Carlos
2012-11-01
Local regions of extinction in diffusion flames, called ``flame holes,'' can reduce the efficiency of combustion and increase the production of certain pollutants. At sufficiently high speeds, a flame may also be lifted from the rim of the burner to a downstream location that may be stable. These two phenomena share a common underlying mechanism of propagation related to edge-flame dynamics where chemistry and fluid mechanics are equally important. We present a formulation that describes the formation, propagation, and growth of flames holes on the stoichiometric surface using edge flame dynamics. The boundary separating the flame from the quenched region is modeled using a progress variable defined on the moving stoichiometric surface that is embedded in the three-dimensional space using an extension algorithm. This Cartesian problem is solved using a high-order finite-volume WENO method extended to this nonconservative problem. This algorithm can track the dynamics of flame holes in a turbulent reacting-shear layer and model flame liftoff without requiring full chemistry calculations.
Modelling the flow structure in local scour around bridge pier
International Nuclear Information System (INIS)
Ghani, U.
2014-01-01
Bridge pier scouring is an important issue of any bridge design work. If it is not taken into account properly, then results will be disastrous. A number of bridges have failed due to clear water local scouring of piers. This research paper presents a numerical model study in which an attempt has been made to explore the flow variables which exist in and around a scoured bridge pier. A finite volume based model of bridge pier was developed using 3D (Three Dimensional) numerical code FLUENT and GAMBIT. After validation process, different discharge values were considered and its impact on three dimensional characteristics of flow such as stream-wise velocities on longitudinal and transverse sections, turbulance circulation cells, and boundary shear stresses was investigated. It was observed that increasing the discharge results in more turbulance around the pier on its downstream side and turbulence properties are intensified in such a situation. However, the primary velocities on the downstream side remain almost unchanged. The results have been presented in the form of contours, vector of primary velocities and x-y plots of bed shear stresses. This study can be used for enhanced understanding of flow features and improvement of formulae for prediction of scour holes around piers. (author)
Irving, J.; Koepke, C.; Elsheikh, A. H.
2017-12-01
Bayesian solutions to geophysical and hydrological inverse problems are dependent upon a forward process model linking subsurface parameters to measured data, which is typically assumed to be known perfectly in the inversion procedure. However, in order to make the stochastic solution of the inverse problem computationally tractable using, for example, Markov-chain-Monte-Carlo (MCMC) methods, fast approximations of the forward model are commonly employed. This introduces model error into the problem, which has the potential to significantly bias posterior statistics and hamper data integration efforts if not properly accounted for. Here, we present a new methodology for addressing the issue of model error in Bayesian solutions to hydrogeophysical inverse problems that is geared towards the common case where these errors cannot be effectively characterized globally through some parametric statistical distribution or locally based on interpolation between a small number of computed realizations. Rather than focusing on the construction of a global or local error model, we instead work towards identification of the model-error component of the residual through a projection-based approach. In this regard, pairs of approximate and detailed model runs are stored in a dictionary that grows at a specified rate during the MCMC inversion procedure. At each iteration, a local model-error basis is constructed for the current test set of model parameters using the K-nearest neighbour entries in the dictionary, which is then used to separate the model error from the other error sources before computing the likelihood of the proposed set of model parameters. We demonstrate the performance of our technique on the inversion of synthetic crosshole ground-penetrating radar traveltime data for three different subsurface parameterizations of varying complexity. The synthetic data are generated using the eikonal equation, whereas a straight-ray forward model is assumed in the inversion
International Nuclear Information System (INIS)
Ermann, L; Shepelyansky, D L
2014-01-01
We study numerically the frequency modulated kicked nonlinear rotator with effective dimension d=1,2,3,4. We follow the time evolution of the model up to 10 9 kicks and determine the exponent α of subdiffusive spreading which changes from 0.35 to 0.5 when the dimension changes from d = 1 to 4. All results are obtained in a regime of relatively strong Anderson localization well below the Anderson transition point existing for d = 3, 4. We explain that this variation of the exponent is different from the usual d− dimensional Anderson models with local nonlinearity where α drops with increasing d. We also argue that the renormalization arguments proposed by Cherroret N et al (arXiv:1401.1038) are not valid for this model and the Anderson model with local nonlinearity in d = 3. (paper)
Effect of conductor geometry on source localization: Implications for epilepsy studies
International Nuclear Information System (INIS)
Schlitt, H.; Heller, L.; Best, E.; Ranken, D.; Aaron, R.
1994-01-01
We shall discuss the effects of conductor geometry on source localization for applications in epilepsy studies. The most popular conductor model for clinical MEG studies is a homogeneous sphere. However, several studies have indicated that a sphere is a poor model for the head when the sources are deep, as is the case for epileptic foci in the mesial temporal lobe. We believe that replacing the spherical model with a more realistic one in the inverse fitting procedure will improve the accuracy of localizing epileptic sources. In order to include a realistic head model in the inverse problem, we must first solve the forward problem for the realistic conductor geometry. We create a conductor geometry model from MR images, and then solve the forward problem via a boundary integral equation for the electric potential due to a specified primary source. One the electric potential is known, the magnetic field can be calculated directly. The most time-intensive part of the problem is generating the conductor model; fortunately, this needs to be done only once for each patient. It takes little time to change the primary current and calculate a new magnetic field for use in the inverse fitting procedure. We present the results of a series of computer simulations in which we investigate the localization accuracy due to replacing the spherical model with the realistic head model in the inverse fitting procedure. The data to be fit consist of a computer generated magnetic field due to a known current dipole in a realistic head model, with added noise. We compare the localization errors when this field is fit using a spherical model to the fit using a realistic head model. Using a spherical model is comparable to what is usually done when localizing epileptic sources in humans, where the conductor model used in the inverse fitting procedure does not correspond to the actual head
The role of local repulsion in superconductivity in the Hubbard-Holstein model
Lin, Chungwei; Wang, Bingnan; Teo, Koon Hoo
2017-01-01
We examine the superconducting solution in the Hubbard-Holstein model using Dynamical Mean Field Theory. The Holstein term introduces the site-independent Boson fields coupling to local electron density, and has two competing influences on superconductivity: The Boson field mediates the effective electron-electron attraction, which is essential for the S-wave electron pairing; the same coupling to the Boson fields also induces the polaron effect, which makes the system less metallic and thus suppresses superconductivity. The Hubbard term introduces an energy penalty U when two electrons occupy the same site, which is expected to suppress superconductivity. By solving the Hubbard-Holstein model using Dynamical Mean Field theory, we find that the Hubbard U can be beneficial to superconductivity under some circumstances. In particular, we demonstrate that when the Boson energy Ω is small, a weak local repulsion actually stabilizesthe S-wave superconducting state. This behavior can be understood as an interplay between superconductivity, the polaron effect, and the on-site repulsion: As the polaron effect is strong and suppresses superconductivity in the small Ω regime, the weak on-site repulsion reduces the polaron effect and effectively enhances superconductivity. Our calculation elucidates the role of local repulsion in the conventional S-wave superconductors.
The effect of sadness on global-local processing.
von Mühlenen, Adrian; Bellaera, Lauren; Singh, Amrendra; Srinivasan, Narayanan
2018-05-04
Gable and Harmon-Jones (Psychological Science, 21(2), 211-215, 2010) reported that sadness broadens attention in a global-local letter task. This finding provided the key test for their motivational intensity account, which states that the level of spatial processing is not determined by emotional valence, but by motivational intensity. However, their finding is at odds with several other studies, showing no effect, or even a narrowing effect of sadness on attention. This paper reports two attempts to replicate the broadening effect of sadness on attention. Both experiments used a global-local letter task, but differed in terms of emotion induction: Experiment 1 used the same pictures as Gable and Harmon-Jones, taken from the IAPS dataset; Experiment 2 used a sad video underlaid with sad music. Results showed a sadness-specific global advantage in the error rates, but not in the reaction times. The same null results were also found in a South-Asian sample in both experiments, showing that effects on global/local processing were not influenced by a culturally related processing bias.
The role of local repulsion in superconductivity in the Hubbard–Holstein model
Energy Technology Data Exchange (ETDEWEB)
Lin, Chungwei, E-mail: clin@merl.com; Wang, Bingnan; Teo, Koon Hoo
2017-01-15
Highlights: • There exists an optimal Boson energy for superconductivity in Hubbard–Holstein model. • The electron-Boson coupling is essential for superconductivity, but the same coupling can lead to polaron insulator, which is against superconductivity. • The local Coulomb repulsion can sometimes enhance superconductivity. - Abstract: We examine the superconducting solution in the Hubbard–Holstein model using Dynamical Mean Field Theory. The Holstein term introduces the site-independent Boson fields coupling to local electron density, and has two competing influences on superconductivity: The Boson field mediates the effective electron-electron attraction, which is essential for the S-wave electron pairing; the same coupling to the Boson fields also induces the polaron effect, which makes the system less metallic and thus suppresses superconductivity. The Hubbard term introduces an energy penalty U when two electrons occupy the same site, which is expected to suppress superconductivity. By solving the Hubbard–Holstein model using Dynamical Mean Field theory, we find that the Hubbard U can be beneficial to superconductivity under some circumstances. In particular, we demonstrate that when the Boson energy Ω is small, a weak local repulsion actually stabilizes the S-wave superconducting state. This behavior can be understood as an interplay between superconductivity, the polaron effect, and the on-site repulsion: As the polaron effect is strong and suppresses superconductivity in the small Ω regime, the weak on-site repulsion reduces the polaron effect and effectively enhances superconductivity. Our calculation elucidates the role of local repulsion in the conventional S-wave superconductors.
A Local Poisson Graphical Model for inferring networks from sequencing data.
Allen, Genevera I; Liu, Zhandong
2013-09-01
Gaussian graphical models, a class of undirected graphs or Markov Networks, are often used to infer gene networks based on microarray expression data. Many scientists, however, have begun using high-throughput sequencing technologies such as RNA-sequencing or next generation sequencing to measure gene expression. As the resulting data consists of counts of sequencing reads for each gene, Gaussian graphical models are not optimal for this discrete data. In this paper, we propose a novel method for inferring gene networks from sequencing data: the Local Poisson Graphical Model. Our model assumes a Local Markov property where each variable conditional on all other variables is Poisson distributed. We develop a neighborhood selection algorithm to fit our model locally by performing a series of l1 penalized Poisson, or log-linear, regressions. This yields a fast parallel algorithm for estimating networks from next generation sequencing data. In simulations, we illustrate the effectiveness of our methods for recovering network structure from count data. A case study on breast cancer microRNAs (miRNAs), a novel application of graphical models, finds known regulators of breast cancer genes and discovers novel miRNA clusters and hubs that are targets for future research.
Effects of local mass anomalies in Eoetvoes-like experiments
International Nuclear Information System (INIS)
Talmadge, C.; Aronson, S.H.; Fischbach, E.
1986-01-01
We consider in detail the effects of local mass anomalies in Eoetvoes-like experiments. It is shown that in the presence of an intermediate-range non-gravitational force, the dominant contributions to both the sign and magnitude of the Eoetvoes anomaly may come from nearby masses and not from the earth as a whole. This observation has important implications in the design and interpretation of future experiments, and in the formulation of unified theories incorporating new intermediate-range forces
Exploring the effect of diffuse reflection on indoor localization systems based on RSSI-VLC.
Mohammed, Nazmi A; Elkarim, Mohammed Abd
2015-08-10
This work explores and evaluates the effect of diffuse light reflection on the accuracy of indoor localization systems based on visible light communication (VLC) in a high reflectivity environment using a received signal strength indication (RSSI) technique. The effect of the essential receiver (Rx) and transmitter (Tx) parameters on the localization error with different transmitted LED power and wall reflectivity factors is investigated at the worst Rx coordinates for a directed/overall link. Since this work assumes harsh operating conditions (i.e., a multipath model, high reflectivity surfaces, worst Rx position), an error of ≥ 1.46 m is found. To achieve a localization error in the range of 30 cm under these conditions with moderate LED power (i.e., P = 0.45 W), low reflectivity walls (i.e., ρ = 0.1) should be used, which would enable a localization error of approximately 7 mm at the room's center.
Eddy-Kuroshio Interactions: Local and Remote Effects
Jan, Sen; Mensah, Vigan; Andres, Magdalena; Chang, Ming-Huei; Yang, Yiing Jang
2017-12-01
western North Pacific, is important in redistributing ocean energy and, in turn, shaping the large scale ocean circulation. This study focuses on the processes underlying the interaction of nonlinear mesoscale eddies with the Kuroshio, which have not yet been thoroughly investigated in the literature. Using pressure-sensor equipped echo sounder and satellite observations interpreted in the context of semi-idealized numerical simulations, this study find (1) locally, eddy arrivals modify velocity structure in the Kuroshio first, followed by changes in sea level and isopycnal depths leading to seesaw-like variations of the sea level and density slopes across the Kuroshio, and (2) modeled remote effects, i.e., Kuroshio intrusions, manifest in the Luzon Strait and on the East China Sea shelf and depend on the eddies' impingement latitude, strength, and polarity.
Quantitative localization microscopy: effects of photophysics and labeling stoichiometry.
Directory of Open Access Journals (Sweden)
Robert P J Nieuwenhuizen
Full Text Available Quantification in localization microscopy with reversibly switchable fluorophores is severely hampered by the unknown number of switching cycles a fluorophore undergoes and the unknown stoichiometry of fluorophores on a marker such as an antibody. We overcome this problem by measuring the average number of localizations per fluorophore, or generally per fluorescently labeled site from the build-up of spatial image correlation during acquisition. To this end we employ a model for the interplay between the statistics of activation, bleaching, and labeling stoichiometry. We validated our method using single fluorophore labeled DNA oligomers and multiple-labeled neutravidin tetramers where we find a counting error of less than 17% without any calibration of transition rates. Furthermore, we demonstrated our quantification method on nanobody- and antibody-labeled biological specimens.
Thiess Buettner
1999-01-01
Despite spatial rigidity of collectively negotiated wages the local unemployment rate is found to have a significant negative impact on wages. This impact is shown to be consistent with both the wage-curve hypothesis and modern Phillips-curve modelling. Spatial contiguity effects are found in wages and unemployment and their neglect leads to an underestimation of the effect of local unemployment. Yet, the impact of local unemployment on wages turns out to be quite low as compared to studies f...
Localization of effective actions in open superstring field theory
Maccaferri, Carlo; Merlano, Alberto
2018-03-01
We consider the construction of the algebraic part of D-branes tree-level effective action from Berkovits open superstring field theory. Applying this construction to the quartic potential of massless fields carrying a specific worldsheet charge, we show that the full contribution to the potential localizes at the boundary of moduli space, reducing to elementary two-point functions. As examples of this general mechanism, we show how the Yang-Mills quartic potential and the instanton effective action of a Dp/D( p - 4) system are reproduced.
Gogol-Prokurat, Melanie
2011-01-01
If species distribution models (SDMs) can rank habitat suitability at a local scale, they may be a valuable conservation planning tool for rare, patchily distributed species. This study assessed the ability of Maxent, an SDM reported to be appropriate for modeling rare species, to rank habitat suitability at a local scale for four edaphic endemic rare plants of gabbroic soils in El Dorado County, California, and examined the effects of grain size, spatial extent, and fine-grain environmental predictors on local-scale model accuracy. Models were developed using species occurrence data mapped on public lands and were evaluated using an independent data set of presence and absence locations on surrounding lands, mimicking a typical conservation-planning scenario that prioritizes potential habitat on unsurveyed lands surrounding known occurrences. Maxent produced models that were successful at discriminating between suitable and unsuitable habitat at the local scale for all four species, and predicted habitat suitability values were proportional to likelihood of occurrence or population abundance for three of four species. Unfortunately, models with the best discrimination (i.e., AUC) were not always the most useful for ranking habitat suitability. The use of independent test data showed metrics that were valuable for evaluating which variables and model choices (e.g., grain, extent) to use in guiding habitat prioritization for conservation of these species. A goodness-of-fit test was used to determine whether habitat suitability values ranked habitat suitability on a continuous scale. If they did not, a minimum acceptable error predicted area criterion was used to determine the threshold for classifying habitat as suitable or unsuitable. I found a trade-off between model extent and the use of fine-grain environmental variables: goodness of fit was improved at larger extents, and fine-grain environmental variables improved local-scale accuracy, but fine-grain variables
Robust MR spine detection using hierarchical learning and local articulated model.
Zhan, Yiqiang; Maneesh, Dewan; Harder, Martin; Zhou, Xiang Sean
2012-01-01
A clinically acceptable auto-spine detection system, i.e., localization and labeling of vertebrae and inter-vertebral discs, is required to have high robustness, in particular to severe diseases (e.g., scoliosis) and imaging artifacts (e.g. metal artifacts in MR). Our method aims to achieve this goal with two novel components. First, instead of treating vertebrae/discs as either repetitive components or completely independent entities, we emulate a radiologist and use a hierarchial strategy to learn detectors dedicated to anchor (distinctive) vertebrae, bundle (non-distinctive) vertebrae and inter-vertebral discs, respectively. At run-time, anchor vertebrae are detected concurrently to provide redundant and distributed appearance cues robust to local imaging artifacts. Bundle vertebrae detectors provide candidates of vertebrae with subtle appearance differences, whose labels are mutually determined by anchor vertebrae to gain additional robustness. Disc locations are derived from a cloud of responses from disc detectors, which is robust to sporadic voxel-level errors. Second, owing to the non-rigidness of spine anatomies, we employ a local articulated model to effectively model the spatial relations across vertebrae and discs. The local articulated model fuses appearance cues from different detectors in a way that is robust to abnormal spine geometry resulting from severe diseases. Our method is validated by 300 MR spine scout scans and exhibits robust performance, especially to cases with severe diseases and imaging artifacts.
Xu, Peng; Tian, Yin; Lei, Xu; Hu, Xiao; Yao, Dezhong
2008-12-01
How to localize the neural electric activities within brain effectively and precisely from the scalp electroencephalogram (EEG) recordings is a critical issue for current study in clinical neurology and cognitive neuroscience. In this paper, based on the charge source model and the iterative re-weighted strategy, proposed is a new maximum neighbor weight based iterative sparse source imaging method, termed as CMOSS (Charge source model based Maximum neighbOr weight Sparse Solution). Different from the weight used in focal underdetermined system solver (FOCUSS) where the weight for each point in the discrete solution space is independently updated in iterations, the new designed weight for each point in each iteration is determined by the source solution of the last iteration at both the point and its neighbors. Using such a new weight, the next iteration may have a bigger chance to rectify the local source location bias existed in the previous iteration solution. The simulation studies with comparison to FOCUSS and LORETA for various source configurations were conducted on a realistic 3-shell head model, and the results confirmed the validation of CMOSS for sparse EEG source localization. Finally, CMOSS was applied to localize sources elicited in a visual stimuli experiment, and the result was consistent with those source areas involved in visual processing reported in previous studies.
A Stochastic Unit Commitment Model for a Local CHP Plant
DEFF Research Database (Denmark)
Ravn, Hans V.; Riisom, Jannik; Schaumburg-Müller, Camilla
2005-01-01
Local CHP development in Denmark has during the 90’s been characterised by large growth primarily due to government subsidies in the form of feed-in tariffs. In line with the liberalisation process in the EU, Danish local CHPs of a certain size must operate on market terms from 2005. This paper...
A space-jump derivation for non-local models of cell-cell adhesion and non-local chemotaxis.
Buttenschön, Andreas; Hillen, Thomas; Gerisch, Alf; Painter, Kevin J
2018-01-01
Cellular adhesion provides one of the fundamental forms of biological interaction between cells and their surroundings, yet the continuum modelling of cellular adhesion has remained mathematically challenging. In 2006, Armstrong et al. proposed a mathematical model in the form of an integro-partial differential equation. Although successful in applications, a derivation from an underlying stochastic random walk has remained elusive. In this work we develop a framework by which non-local models can be derived from a space-jump process. We show how the notions of motility and a cell polarization vector can be naturally included. With this derivation we are able to include microscopic biological properties into the model. We show that particular choices yield the original Armstrong model, while others lead to more general models, including a doubly non-local adhesion model and non-local chemotaxis models. Finally, we use random walk simulations to confirm that the corresponding continuum model represents the mean field behaviour of the stochastic random walk.
Evaluation of local site effect from microtremor measurements in Babol City, Iran
Rezaei, Sadegh; Choobbasti, Asskar Janalizadeh
2018-03-01
Every year, numerous casualties and a large deal of financial losses are incurred due to earthquake events. The losses incurred by an earthquake vary depending on local site effect. Therefore, in order to conquer drastic effects of an earthquake, one should evaluate urban districts in terms of the local site effect. One of the methods for evaluating the local site effect is microtremor measurement and analysis. Aiming at evaluation of local site effect across the city of Babol, the study area was gridded and microtremor measurements were performed with an appropriate distribution. The acquired data was analyzed through the horizontal-to-vertical noise ratio (HVNR) method, and fundamental frequency and associated amplitude of the H/V peak were obtained. The results indicate that fundamental frequency of the study area is generally lower than 1.25 Hz, which is acceptably in agreement with the findings of previous studies. Also, in order to constrain and validate the seismostratigraphic model obtained with this method, the results were compared with geotechnical, geological, and seismic data. Comparing the results of different methods, it was observed that the presented geophysical method can successfully determine the values of fundamental frequency across the study area as well as local site effect. Using the data obtained from the analysis of microtremor, a microzonation map of fundamental frequency across the city of Babol was prepared. This map has numerous applications in designing high-rise building and urban development plans.
Comprehensive modelling for approaching the Kyoto targets on a local scale
International Nuclear Information System (INIS)
Pietrapertosa, F.; Macchiato, M.; Salvia, M.
2003-01-01
This study aimed to evaluate the effectiveness of the MARKAL comprehensive model in the development of coherent medium-term strategies and sound climate protection policies at local level. The local case study (Val d'Agri, Basilicata region, Italy) discusses the possible role of local communities in the achievement of the national objectives derived by the Kyoto Protocol, investigating the traditional sectors responsible for air pollution and providing a full picture of the main energy and material flows. A scenario analysis was performed to analyse the response of the modelled system to the introduction of an exogenous constraint on carbon dioxide (CO 2 ) emissions. The main effects are presented with reference to fuel mix, technology choice, real market prices and reduced costs of competing options. The comparison of the solutions obtained for the different scenarios is useful to point out the effects of the CO 2 constraint on the total system cost and on the emission levels of other atmospheric pollutants. A further multiobjective optimisation was performed to analyse the effects of combined environmental constraints (CO 2 and particulate) on the overall system cost as well as in terms of marginal costs. (author)
Comprehensive modelling for approaching the Kyoto targets on a local scale
Energy Technology Data Exchange (ETDEWEB)
Pietrapertosa, F. [Istituto di Metodologie per l' Analisi Ambientale, Tito Scalo (Italy); Universita degli Studi della Basilicata, Potenza (Italy). Dipartimento di Ingegneria e Fisica dell' Ambiente; Cosmi, C.; Marmo, G. [Istituto di Metodologie per l' Analisi Ambientale, Tito Scalo (Italy); Istituto Nazionale di Fisica della Materia, Napoli (Italy); Macchiato, M. [Universita Federico II, Napoli (Italy). Dipartimento di Scienze Fisiche; Salvia, M. [Istituto di Metodologie per l' Analisi Ambientale, Tito Scalo (Italy)
2003-06-01
This study aimed to evaluate the effectiveness of the MARKAL comprehensive model in the development of coherent medium-term strategies and sound climate protection policies at local level. The local case study (Val d'Agri, Basilicata region, Italy) discusses the possible role of local communities in the achievement of the national objectives derived by the Kyoto Protocol, investigating the traditional sectors responsible for air pollution and providing a full picture of the main energy and material flows. A scenario analysis was performed to analyse the response of the modelled system to the introduction of an exogenous constraint on carbon dioxide (CO{sub 2}) emissions. The main effects are presented with reference to fuel mix, technology choice, real market prices and reduced costs of competing options. The comparison of the solutions obtained for the different scenarios is useful to point out the effects of the CO{sub 2} constraint on the total system cost and on the emission levels of other atmospheric pollutants. A further multiobjective optimisation was performed to analyse the effects of combined environmental constraints (CO{sub 2} and particulate) on the overall system cost as well as in terms of marginal costs. (author)
Effectiveness of local air quality measures; Effectiviteit van likale luchtkwaliteitsmaatregelen
Energy Technology Data Exchange (ETDEWEB)
Van Bommel, R.; Van de Poll, T. [Royal Haskoning DHV, Amersfoort (Netherlands)
2013-12-15
This article examines the effects of local air quality measures which are calculated by order of the city of Utrecht. The conclusions are that environmental zones and other local measures contribute to meet the targets and improve public health. It is also explained why this is the case, and the question is raised whether or not national measures would be better [Dutch] Dit artikel gaat in op de effecten van lokale maatregelen die zijn berekend in opdracht van de gemeente Utrecht. De conclusie: milieuzones en andere lokale maatregelen dragen bij aan het halen van normen en leveren gezondheidswinst op. Er wordt uitgelegd waarom dat zo is en de vraag wordt gesteld of landelijke maatregelen niet beter zijn.
DEFF Research Database (Denmark)
Tanderup, Kari; Fokdal, Lars Ulrik; Sturdza, Alina
2016-01-01
-center patient series (retroEMBRACE). Materials and methods This study analyzed 488 locally advanced cervical cancer patients treated with external beam radiotherapy ± chemotherapy combined with IGABT. Brachytherapy contouring and reporting was according to ICRU/GEC-ESTRO recommendations. The Cox Proportional...... Hazards model was applied to analyze the effect on local control of dose-volume metrics as well as overall treatment time (OTT), dose rate, chemotherapy, and tumor histology. Results With a median follow up of 46 months, 43 local failures were observed. Dose (D90) to the High Risk Clinical Target Volume...
Richards, Michael D; Goltz, Herbert C; Wong, Agnes M F
2018-01-01
Classically understood as a deficit in spatial vision, amblyopia is increasingly recognized to also impair audiovisual multisensory processing. Studies to date, however, have not determined whether the audiovisual abnormalities reflect a failure of multisensory integration, or an optimal strategy in the face of unisensory impairment. We use the ventriloquism effect and the maximum-likelihood estimation (MLE) model of optimal integration to investigate integration of audiovisual spatial information in amblyopia. Participants with unilateral amblyopia (n = 14; mean age 28.8 years; 7 anisometropic, 3 strabismic, 4 mixed mechanism) and visually normal controls (n = 16, mean age 29.2 years) localized brief unimodal auditory, unimodal visual, and bimodal (audiovisual) stimuli during binocular viewing using a location discrimination task. A subset of bimodal trials involved the ventriloquism effect, an illusion in which auditory and visual stimuli originating from different locations are perceived as originating from a single location. Localization precision and bias were determined by psychometric curve fitting, and the observed parameters were compared with predictions from the MLE model. Spatial localization precision was significantly reduced in the amblyopia group compared with the control group for unimodal visual, unimodal auditory, and bimodal stimuli. Analyses of localization precision and bias for bimodal stimuli showed no significant deviations from the MLE model in either the amblyopia group or the control group. Despite pervasive deficits in localization precision for visual, auditory, and audiovisual stimuli, audiovisual integration remains intact and optimal in unilateral amblyopia.
A model for cell type localization in the migrating slug of ...
Indian Academy of Sciences (India)
PRAKASH
. Localization of the three major cell types within the migrating slug stage is a dynamic process (Sternfeld 1992;. A model for cell type localization in the migrating slug of Dictyostelium discoideum based on differential chemotactic sensitivity to ...
Full-wave modeling of ICRF waves: global and quasi-local descriptions
International Nuclear Information System (INIS)
Dumont, R. J.
2007-01-01
Waves in the Ion Cyclotron Range of Frequencies (ICRF) undergo significant space dispersion as they propagate in magnetic fusion plasmas, making it necessary to incorporate non-local effects in their physical description. Full-wave codes are routinely employed to simulate ICRF heating experiments in tokamaks. The vast majority of these codes rely on a description of the plasma based on a 'quasi-local' derivation of the dielectric tensor, i.e. assuming that the range of space dispersion remains small compared to the system dimensions. However, non-local effects caused by wide particle orbits are expected to play a significant role in current and future experiments featuring wave-driven fast ions, fusion-born alpha particles... Global formalisms have thus been proposed to include these effects in a more comprehensive fashion. Based on a description of the particle dynamics in terms of action-angle variables, a full-wave code, named EVE, is currently under development. Its first version, presented here, incorporates quasi-local expressions valid to second order in Larmor radius, derived from the more general Hamiltonian formalism. The obtained tool has the advantage of being compatible with the current requirements of integrated modeling, and lends itself to direct comparisons with existing codes
Toy models for wrapping effects
International Nuclear Information System (INIS)
Penedones, Joao; Vieira, Pedro
2008-01-01
The anomalous dimensions of local single trace gauge invariant operators in N = 4 supersymmetric Yang-Mills theory can be computed by diagonalizing a long range integrable Hamiltonian by means of a perturbative asymptotic Bethe ansatz. This formalism breaks down when the number of fields of the composite operator is smaller than the range of the Hamiltonian which coincides with the order in perturbation theory at study. We analyze two spin chain toy models which might shed some light on the physics behind these wrapping effects. One of them, the Hubbard model, is known to be closely related to N = 4 SYM. In this example, we find that the knowledge of the effective spin chain description is insufficient to reconstruct the finite size effects of the underlying electron theory. We compute the wrapping corrections for generic states and relate them to a Luscher like approach. The second toy models are long range integrable Hamiltonians built from the standard algebraic Bethe ansatz formalism. This construction is valid for any symmetry group. In particular, for non-compact groups it exhibits an interesting relation between wrapping interactions and transcendentality.
Stability and supersymmetry: Models with local gauge symmetry
International Nuclear Information System (INIS)
Curtright, T.; Ghandour, G.
1978-01-01
Renormalization group analysis is used to show the supersymmetric point in the effective coupling constant space is an unstable fixed point for several model gauge theories. The physical significance of this result is discussed in terms of the stability of the semiclassical ground state. In perturbation theory the supersymmetric point appears to be surrounded by regions in the coupling space representing three classes of theories: class one consists of theories for which the effective potential V has no apparent lower bound for large (pseudo)scalar field expectations; class two theories have lower bounds and radiatively induced absolute minima for V with nonzero field expectations; class three theories apparently have an absolute minimum of V at the origin of field space. Thus radiatively induced breaking of gauge invariance occurs for theories in classes one and two, but perturbatively the class one theories appear to have no ground states. Class three theories have ground states in which all gauge invariance remains intact. For the supersymmetric limits of the models examined the origin is known to be neutrally stable in field space, permitting an ambiguous breakdown of gauge invariance but not supersymmetry. This phenomenon is discussed in some detail. Calculations are performed in both Lorentz covariant and noncovariant gauges with a detailed comparison between gauges of the relevant one-loop diagrams
Directory of Open Access Journals (Sweden)
Z. Hashemiyan
2016-01-01
Full Text Available Properties of soft biological tissues are increasingly used in medical diagnosis to detect various abnormalities, for example, in liver fibrosis or breast tumors. It is well known that mechanical stiffness of human organs can be obtained from organ responses to shear stress waves through Magnetic Resonance Elastography. The Local Interaction Simulation Approach is proposed for effective modelling of shear wave propagation in soft tissues. The results are validated using experimental data from Magnetic Resonance Elastography. These results show the potential of the method for shear wave propagation modelling in soft tissues. The major advantage of the proposed approach is a significant reduction of computational effort.
Packo, P.; Staszewski, W. J.; Uhl, T.
2016-01-01
Properties of soft biological tissues are increasingly used in medical diagnosis to detect various abnormalities, for example, in liver fibrosis or breast tumors. It is well known that mechanical stiffness of human organs can be obtained from organ responses to shear stress waves through Magnetic Resonance Elastography. The Local Interaction Simulation Approach is proposed for effective modelling of shear wave propagation in soft tissues. The results are validated using experimental data from Magnetic Resonance Elastography. These results show the potential of the method for shear wave propagation modelling in soft tissues. The major advantage of the proposed approach is a significant reduction of computational effort. PMID:26884808
Localizing gravity on Maxwell gauged CP1 model in six dimensions
International Nuclear Information System (INIS)
Kodama, Yuta; Kokubu, Kento; Sawado, Nobuyuki
2008-01-01
We shall consider a 3-brane embedded in six-dimensional space-time with a negative bulk cosmological constant. The 3-brane is constructed by a topological soliton solution living in two-dimensional axially symmetric transverse subspace. Similar to most previous works of six-dimensional soliton models, our Maxwell gauged CP 1 brane model can also achieve localizing gravity around the 3-brane. The CP 1 field is described by a scalar doublet and derived from the O(3) sigma model by projecting it onto two-dimensional complex space. In that sense, our framework is more effective than other solitonic brane models concerning gauge theory. We shall also discuss the linear stability analysis for our new model by fluctuating all fields.
Conversion to biofuel based heating systems - local environmental effects
International Nuclear Information System (INIS)
Jonsson, Anna
2003-01-01
One of the most serious environmental problems today is the global warming, i.e.climate changes caused by emissions of greenhouse gases. The greenhouse gases originate from combustion of fossil fuels and changes the atmospheric composition. As a result of the climate change, the Swedish government has decided to make a changeover of the Swedish energy system. This involves an increase of the supply of electricity and heating from renewable energy sources and a decrease in the amount electricity used for heating, as well as a more efficient use of the existing electricity system. Today, a rather large amount electricity is used for heating in Sweden. Furthermore, nuclear power will be phased out by the year 2010 in Sweden. Bio fuels are a renewable energy source and a conceivable alternative to the use of fossil fuels. Therefore, an increase of bio fuels will be seen the coming years. Bio fuels have a lot of environmental advantages, mainly for the global environment, but might also cause negative impacts such as depletion of the soils where the biomass is grown and local deterioration of the air quality where the bio fuels are combusted. These negative impacts are a result of the use of wrong techniques and a lack of knowledge and these factors have to be improved if the increase of the use of bio fuels is to be made effectively. The aim of this master thesis is to evaluate the possibilities for heating with bio fuel based systems in housing areas in the municipalities of Trollhaettan, Ulricehamn and Goetene in Vaestra Goetalands County in the South West of Sweden and to investigate which environmental and health effects are caused by the conversion of heating systems. The objective is to use the case studies as examples on preferable bio fuel based heating systems in different areas, and to what environmental impact this conversion of heating systems might cause. The housing areas for this study have been chosen on the basis of present heating system, one area
Coherent density fluctuation model as a local-scale limit to ATDHF
International Nuclear Information System (INIS)
Antonov, A.N.; Petkov, I.Zh.; Stoitsov, M.V.
1985-04-01
The local scale transformation method is used for the construction of an Adiabatic Time-Dependent Hartree-Fock approach in terms of the local density distribution. The coherent density fluctuation relations of the model result in a particular case when the ''flucton'' local density is connected with the plane wave determinant model function be means of the local-scale coordinate transformation. The collective potential energy expression is obtained and its relation to the nuclear matter energy saturation curve is revealed. (author)
Finite Element Analysis of the Amontons-Coulomb's Model using Local and Global Friction Tests
International Nuclear Information System (INIS)
Oliveira, M. C.; Menezes, L. F.; Ramalho, A.; Alves, J. L.
2011-01-01
In spite of the abundant number of experimental friction tests that have been reported, the contact with friction modeling persists to be one of the factors that determine the effectiveness of sheet metal forming simulation. This difficulty can be understood due to the nature of the friction phenomena, which comprises the interaction of different factors connected to both sheet and tools' surfaces. Although in finite element numerical simulations friction models are commonly applied at the local level, they normally rely on parameters identified based on global experimental tests results. The aim of this study is to analyze the applicability of the Amontons-Coulomb's friction coefficient identified using complementary tests: (i) load-scanning, at the local level and (ii) draw-bead, at the global level; to the numerical simulation of sheet metal forming processes.
Autonomous tracked robots in planar off-road conditions modelling, localization, and motion control
González, Ramón; Guzmán, José Luis
2014-01-01
This monograph is framed within the context of off-road mobile robotics. In particular, it discusses issues related to modelling, localization, and motion control of tracked mobile robots working in planar slippery conditions. Tracked locomotion constitutes a well-known solution for mobile platforms operating over diverse challenging terrains, for that reason, tracked robotics constitutes an important research field with many applications (e.g. agriculture, mining, search and rescue operations, military activities). The specific topics of this monograph are: historical perspective of tracked vehicles and tracked robots; trajectory-tracking model taking into account slip effect; visual-odometry-based localization strategies; and advanced slip-compensation motion controllers ensuring efficient real-time execution. Physical experiments with a real tracked robot are presented showing the better performance of the suggested novel approaches to known techniques. Keywords: longitudinal slip, visual odometry, slip...
Directory of Open Access Journals (Sweden)
Ernst Schetselaar
2017-12-01
Full Text Available 3D geological modeling of lithogeochemical and geological data provides insight into the role of the sulfide ore horizon and associated footwall hydrothermal alteration in localizing shear strain in the Flin Flon volcanogenic massive sulfide deposits, Canada, as deformation evolved from brittle-ductile to ductile regimes during collisional stages of the 1.9–1.8 Ga Trans-Hudson orogeny. 3D spatial characterization of hydrothermal alteration based on the Ishikawa index (AI and normative corundum percentages outline sericite + chlorite-rich high strain zones, consisting of Al-enriched and Na-depleted felsic and mafic volcanic rocks in the footwall of the sulfide ore horizon. The hydrothermal vent complex, from which these sheared alteration zones originated, was stacked together with the ore horizon by W-vergent thrust faults during an early collisional deformation regime, imbricating molasse-type clastic sediments with the ore-hosting volcanic and volcaniclastic rocks of the Flin Flon arc assemblage. Chlorite-rich planar zones marked by high values of the Carbonate–chlorite–pyrite index (CCPI are laterally more extensive and outline a later system of ductile shear zones, in which phyllosilicates, quartz and chalcopyrite in stringer zones localized shear strain and enhanced transposition of the hydrothermal vent stockwork. The contrasting deformation styles of these two thrusting events and their localization within the ore horizon and hydrothermal vent stockwork have important implications for vectoring towards undiscovered ore in this mature mining camp that are possibly also relevant to other strongly deformed VMS ore systems.
Geometric effects of 90-degree vertical elbows on local two-phase flow parameters
International Nuclear Information System (INIS)
Yadav, M.; Worosz, T.; Kim, S.
2011-01-01
This study presents the geometric effects of 90-degree vertical elbows on the development of the local two-phase flow parameters. A multi-sensor conductivity probe is used to measure local two-phase flow parameters. It is found that immediately downstream of the vertical-upward elbow, the bubbles have a bimodal distribution along the horizontal radius of the pipe cross-section causing a dual-peak in the profiles of local void fraction and local interfacial area concentration. Immediately downstream of the vertical-downward elbow it is observed that the bubbles tend to migrate towards the inside of the elbow's curvature. The axial transport of void fraction and interfacial area concentration indicates that the elbows promote bubble disintegration. Preliminary predictions are obtained from group-one interfacial area transport equation (IATE) model for vertical-upward and vertical-downward two-phase flow. (author)
Benchmark of the local drift-kinetic models for neoclassical transport simulation in helical plasmas
Huang, B.; Satake, S.; Kanno, R.; Sugama, H.; Matsuoka, S.
2017-02-01
The benchmarks of the neoclassical transport codes based on the several local drift-kinetic models are reported here. Here, the drift-kinetic models are zero orbit width (ZOW), zero magnetic drift, DKES-like, and global, as classified in Matsuoka et al. [Phys. Plasmas 22, 072511 (2015)]. The magnetic geometries of Helically Symmetric Experiment, Large Helical Device (LHD), and Wendelstein 7-X are employed in the benchmarks. It is found that the assumption of E ×B incompressibility causes discrepancy of neoclassical radial flux and parallel flow among the models when E ×B is sufficiently large compared to the magnetic drift velocities. For example, Mp≤0.4 where Mp is the poloidal Mach number. On the other hand, when E ×B and the magnetic drift velocities are comparable, the tangential magnetic drift, which is included in both the global and ZOW models, fills the role of suppressing unphysical peaking of neoclassical radial-fluxes found in the other local models at Er≃0 . In low collisionality plasmas, in particular, the tangential drift effect works well to suppress such unphysical behavior of the radial transport caused in the simulations. It is demonstrated that the ZOW model has the advantage of mitigating the unphysical behavior in the several magnetic geometries, and that it also implements the evaluation of bootstrap current in LHD with the low computation cost compared to the global model.
A local-world node deleting evolving network model
International Nuclear Information System (INIS)
Gu Yuying; Sun Jitao
2008-01-01
A new type network growth rule which comprises node addition with the concept of local-world connectivity and node deleting is studied. A series of theoretical analysis and numerical simulation to the LWD network are conducted in this Letter. Firstly, the degree distribution p(k) of this network changes no longer pure scale free but truncates by an exponential tail and the truncation in p(k) increases as p a decreases. Secondly, the connectivity is tighter, as the local-world size M increases. Thirdly, the average path length L increases and the clustering coefficient decreases as generally node deleting increases. Finally, trends up when the local-world size M increases, so as to k max . Hence, the expanding local-world can compensate the infection of the node deleting
A local-world node deleting evolving network model
Energy Technology Data Exchange (ETDEWEB)
Gu Yuying [Department of Mathematics, Tongji University, Shanghai 200092 (China); Sun Jitao [Department of Mathematics, Tongji University, Shanghai 200092 (China)], E-mail: sunjt@sh163.net
2008-06-16
A new type network growth rule which comprises node addition with the concept of local-world connectivity and node deleting is studied. A series of theoretical analysis and numerical simulation to the LWD network are conducted in this Letter. Firstly, the degree distribution p(k) of this network changes no longer pure scale free but truncates by an exponential tail and the truncation in p(k) increases as p{sub a} decreases. Secondly, the connectivity is tighter, as the local-world size M increases. Thirdly, the average path length L increases and the clustering coefficient
Connecting Global to Local Parameters in Barred Galaxy Models
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
Key words. Galaxies: barred—orbits—global and local parameters. .... series near the stable Lagrange point L1, which coincides with the origin. Doing so, .... Toomre, A. 1981, In: The Structure and Evolution of Normal Galaxies, (eds) S. M. Fall,.
Contraceptive Efficacy and Local Effects of Bioceramic IUD in Rat
Institute of Scientific and Technical Information of China (English)
WANG Yan; ZHANG Yuanzhen; YAN Yuhua; CHEN Weimin; LIU Wenhui; ZU Meiping
2006-01-01
The contraceptive efficacy and local effects of bioceramic IUD in rat were studied. The experiment was divided into four groups: bioceramic IUD group; stainless steel IUD group; operation control group; normal control group. All IUD samples were put into uterus of rats. The experimental results show that the alumina bioceramic has a strong contraceptive effect for those rats. In bioceramic IUD group the endometrial inflammation reaction was as mild as that in stainless IUD group during the early days (30 days ) and gradually abated with time during the late days (60 days ). The experiments show that the alumina bioceramic has a good biocompatibility and contraceptive effects and hint at the alumina bioceramic IUD may become a more safety reproduction family planning IUD.
Globally and locally supersymmetric effective theories for light fields
Brizi, Leonardo; Scrucca, Claudio A
2009-01-01
We reconsider the general question of how to characterize most efficiently the low-energy effective theory obtained by integrating out heavy modes in globally and locally supersymmetric theories. We consider theories with chiral and vector multiplets and identify the conditions under which an approximately supersymmetric low-energy effective theory can exist. These conditions translate into the requirements that all the derivatives, fermions and auxiliary fields should be small in units of the heavy mass scale. They apply not only to the matter sector, but also to the gravitational one if present, and imply in that case that the gravitino mass should be small. We then show how to determine the unique exactly supersymmetric theory that approximates this effective theory at the lowest order in the counting of derivatives, fermions and auxiliary fields, by working both at the superfield level and with component fields. As a result we give a simple prescription for integrating out heavy superfields in an algebrai...
A Local Land Use Competition Cellular Automata Model and Its Application
Directory of Open Access Journals (Sweden)
Jun Yang
2016-06-01
Full Text Available Cellular automaton (CA is an important method in land use and cover change studies, however, the majority of research focuses on the discovery of macroscopic factors affecting LUCC, which results in ignoring the local effects within the neighborhoods. This paper introduces a Local Land Use Competition Cellular Automata (LLUC-CA model, based on local land use competition, land suitability evaluation, demand analysis of the different land use types, and multi-target land use competition allocation algorithm to simulate land use change at a micro level. The model is applied to simulate land use changes at Jinshitan National Tourist Holiday Resort from 1988 to 2012. The results show that the simulation accuracies were 64.46%, 77.21%, 85.30% and 99.14% for the agricultural land, construction land, forestland and water, respectively. In addition, comparing the simulation results of the LLUC-CA and CA-Markov model with the real land use data, their overall spatial accuracies were found to be 88.74% and 86.82%, respectively. In conclusion, the results from this study indicated that the model was an acceptable method for the simulation of large-scale land use changes, and the approach used here is applicable to analyzing the land use change driven forces and assist in decision-making.
Directory of Open Access Journals (Sweden)
Kam-Yiu Lam
2015-01-01
Full Text Available In this paper, we propose a novel pervasive business model for sales promotion in retail chain stores utilizing WLAN localization and near field communication (NFC technologies. The objectives of the model are to increase the customers’ flow of the stores and their incentives in purchasing. In the proposed model, the NFC technology is used as the first mean to motivate customers to come to the stores. Then, with the use of WLAN, the movements of the customers, who are carrying smartphones, within the stores are captured and maintained in the movement database. By interpreting the movements of customers as indicators of their interests to the displayed items, personalized promotion strategies can be formulated to increase their incentives for purchasing future items. Various issues in the application of the adopted localization scheme for locating customers in a store are discussed. To facilitate the item management and space utilization in displaying the items, we propose an enhanced R-tree for indexing the data items maintained in the movement database. Experimental results have demonstrated the effectiveness of the adopted localization scheme in supporting the proposed model.
The effects of local blowing perturbations on thermal turbulent structures
Liu, Can; Araya, Guillermo; Leonardi, Stefano; Castillo, Luciano
2013-11-01
Blowing is an active flow control technique with several industrial applications, particularly in film cooling of turbine blades. In the past, the effects of localized blowing have been mostly analyzed on the velocity field and its influence of the flow parameters and turbulence structures (Krogstad and Kourakine, 2000). However, little literature can be found on the effects of blowing on the coherent thermal structures. In the present study, an incompressible turbulent channel flow with given steady blowing at the wall is simulated via DNS by means of five spanwise holes. The Reynolds number based on the friction velocity and half channel height is approximately Re = 394 and the molecular Prandtl number is Pr = 0.71. Temperature is considered a passive scalar with isothermal conditions at the wall. Different blowing amplitudes and perturbing angles (with respect to the streamwise direction) are applied to find out their effects on the turbulent thermal structures by means of a two-point correlation analysis. In addition, local reduction and increase of drag are connected to vorticity. The corresponding influence of perturbing amplitudes and angles on the energy budget of thermal fluctuations and turbulent Prandtl numbers are also shown and discussed.
Globally and locally supersymmetric effective theories for light fields
International Nuclear Information System (INIS)
Brizi, Leonardo; Gomez-Reino, Marta; Scrucca, Claudio A.
2009-01-01
We reconsider the general question of how to characterize most efficiently the low-energy effective theory obtained by integrating out heavy modes in globally and locally supersymmetric theories. We consider theories with chiral and vector multiplets and identify the conditions under which an approximately supersymmetric low-energy effective theory can exist. These conditions translate into the requirements that all the derivatives, fermions and auxiliary fields should be small in units of the heavy mass scale. They apply not only to the matter sector, but also to the gravitational one if present, and imply in that case that the gravitino mass should be small. We then show how to determine the unique exactly supersymmetric theory that approximates this effective theory at the lowest order in the counting of derivatives, fermions and auxiliary fields, by working both at the superfield level and with component fields. As a result we give a simple prescription for integrating out heavy superfields in an algebraic and manifestly supersymmetric way, which turns out to hold in the same form both for globally and locally supersymmetric theories, meaning that the process of integrating out heavy modes commutes with the process of switching on gravity. More precisely, for heavy chiral and vector multiplets one has to impose respectively stationarity of the superpotential and the Kaehler potential.
Local field effects and metamaterials based on colloidal quantum dots
International Nuclear Information System (INIS)
Porvatkina, O V; Tishchenko, A A; Strikhanov, M N
2015-01-01
Metamaterials are composite structures that exhibit interesting and unusual properties, e.g. negative refractive index. In this article we consider metamaterials based on colloidal quantum dots (CQDs). We investigate these structures taking into account the local field effects and theoretically analyze expressions for permittivity and permeability of metamaterials based on CdSe CQDs. We obtain inequality describing the conditions when material with definite concentration of CQDs is metamaterial. Also we investigate how the values of dielectric polarizability and magnetic polarizability of CQDs depend on the dots radius and properties the material the quantum dots are made of. (paper)
Can the hadron effective interaction be local in inclusive process
International Nuclear Information System (INIS)
Logunov, A.A.; Mestvirishvily, M.A.; Petrov, V.A.
1974-01-01
The behaviour of the inclusive spectrum fsub(ab→c) in the asymptotic region is discussed. On the basis of the Jost-Lehmann-Dyson representation it is shown that inclusive processes are described by some structure functions, depending only on ν, q 2 (ν=2psub(b)(psub(a)-psub(c)); q 2 =(psub(a)-psub(c)) 2 ) under certain restrictions on the J-L-D spectral functions. As these dynamical characteristics (structure functions) do not depend on the sum(psub(a)+psub(c)), the effective interaction of hadrons ''a'' and ''c'' is as if local
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.
Integrated Modeling of the Human-Natural System to Improve Local Water Management and Planning
Gutowski, W. J., Jr.; Dziubanski, D.; Franz, K.; Goodwin, J.; Rehmann, C. R.; Simpkins, W. W.; Tesfastion, L.; Wanamaker, A. D.; Jie, Y.
2015-12-01
Communities across the world are experiencing the effects of unsustainable water management practices. Whether the problem is a lack of water, too much water, or water of degraded quality, finding acceptable solutions requires community-level efforts that integrate sound science with local needs and values. Our project develops both a software technology (agent-based hydrological modeling) and a social technology (a participatory approach to model development) that will allow communities to comprehensively address local water challenges. Using agent-based modeling (ABM), we are building a modeling system that includes a semi-distributed hydrologic process model coupled with agent (stakeholder) models. Information from the hydrologic model is conveyed to the agent models, which, along with economic information, determine appropriate agent actions that subsequently affect hydrology within the model. The iterative participatory modeling (IPM) process will assist with the continual development of the agent models. Further, IPM creates a learning environment in which all participants, including researchers, are co-exploring relevant data, possible scenarios and solutions, and viewpoints through continuous interactions. Our initial work focuses on the impact of flood mitigation and conservation efforts on reducing flooding in an urban area. We are applying all research elements above to the Squaw Creek watershed that flows through parts of four counties in central Iowa. The watershed offers many of the typical tensions encountered in Iowa, such as different perspectives on water management between upstream farmers and downstream urban areas, competition for various types of recreational services, and increasing absentee land ownership that may conflict with community values. Ultimately, climate change scenarios will be incorporated into the model to determine long term patterns that may develop within the social or natural system.
Training effectiveness evaluation model
International Nuclear Information System (INIS)
Penrose, J.B.
1993-01-01
NAESCO's Training Effectiveness Evaluation Model (TEEM) integrates existing evaluation procedures with new procedures. The new procedures are designed to measure training impact on organizational productivity. TEEM seeks to enhance organizational productivity through proactive training focused on operation results. These results can be identified and measured by establishing and tracking performance indicators. Relating training to organizational productivity is not easy. TEEM is a team process. It offers strategies to assess more effectively organizational costs and benefits of training. TEEM is one organization's attempt to refine, manage and extend its training evaluation program
International Nuclear Information System (INIS)
Ehrhardt, J.
1995-02-01
As one of the main objectives of the MARIA project (''Methods for Assessing the Radiological Impact of Accidents'') initiated by the Commission of the European Communities the program package COSYMA (''COde SYstem from MARIA'') for assessing the radiological and economic off-site consequences of accidental releases of radioactive material to the atmosphere has been jointly developed by the Kernforschungszentrum Karlsruhe (KfK), FRG, and the National Radiological Protection Board (NRPB), UK. COSYMA includes models and data for assessing a broad spectrum of accident consequences, and they are implemented in independent modules. The subject of this report are those modules, which incorporate models and data for assessing individual and collective risks for deterministic and stochastic health effects. It describes the models implemented, the mathematical algorithms and the required data. Examples are given and explained for the input and output part of the modules. (orig.)
Zou, W; Ouyang, H
2016-02-01
We propose a multiple estimation adjustment (MEA) method to correct effect overestimation due to selection bias from a hypothesis-generating study (HGS) in pharmacogenetics. MEA uses a hierarchical Bayesian approach to model individual effect estimates from maximal likelihood estimation (MLE) in a region jointly and shrinks them toward the regional effect. Unlike many methods that model a fixed selection scheme, MEA capitalizes on local multiplicity independent of selection. We compared mean square errors (MSEs) in simulated HGSs from naive MLE, MEA and a conditional likelihood adjustment (CLA) method that model threshold selection bias. We observed that MEA effectively reduced MSE from MLE on null effects with or without selection, and had a clear advantage over CLA on extreme MLE estimates from null effects under lenient threshold selection in small samples, which are common among 'top' associations from a pharmacogenetics HGS.
Ecotoxicological effects extrapolation models
Energy Technology Data Exchange (ETDEWEB)
Suter, G.W. II
1996-09-01
One of the central problems of ecological risk assessment is modeling the relationship between test endpoints (numerical summaries of the results of toxicity tests) and assessment endpoints (formal expressions of the properties of the environment that are to be protected). For example, one may wish to estimate the reduction in species richness of fishes in a stream reach exposed to an effluent and have only a fathead minnow 96 hr LC50 as an effects metric. The problem is to extrapolate from what is known (the fathead minnow LC50) to what matters to the decision maker, the loss of fish species. Models used for this purpose may be termed Effects Extrapolation Models (EEMs) or Activity-Activity Relationships (AARs), by analogy to Structure-Activity Relationships (SARs). These models have been previously reviewed in Ch. 7 and 9 of and by an OECD workshop. This paper updates those reviews and attempts to further clarify the issues involved in the development and use of EEMs. Although there is some overlap, this paper does not repeat those reviews and the reader is referred to the previous reviews for a more complete historical perspective, and for treatment of additional extrapolation issues.
Local Politics and Portfolio Management Models: National Reform Ideas and Local Control
Bulkley, Katrina E.; Henig, Jeffrey R.
2015-01-01
Amid the growth of charter schools, autonomous schools, and private management organizations, an increasing number of urban districts are moving toward a portfolio management model (PMM). In a PMM, the district central office oversees schools that operate under a variety of governance models. The expansion of PMMs raises questions about local…
DEFF Research Database (Denmark)
Christensen, Andreas Aagaard
During the last decade digital modelling tools for environmental impact assessment have become increasingly interactive, agile and user-oriented. This has made it possible to implement models in situ, using them in live scenario situations with local stakeholders. As a result modelling tools......- and long term environmental impact of landscape management. This opens up a number of questions regarding the status and consequence of scientific data and modelled impact estimates as compared to locally held knowledge and expertise. It also opens up questions regarding how the injection of modelling...... for modelling the effect of agricultural land use decisions on nitrogen emission to the environment at landscape scales. Recently Danish authorities proposed to shift the scale of regulation from national regulatory instruments to a more local level to better fit relevant socio-political and agro-environmental...
RANS modeling of scalar dispersion from localized sources within a simplified urban-area model
Rossi, Riccardo; Capra, Stefano; Iaccarino, Gianluca
2011-11-01
The dispersion of a passive scalar downstream a localized source within a simplified urban-like geometry is examined by means of RANS scalar flux models. The computations are conducted under conditions of neutral stability and for three different incoming wind directions (0°, 45°, 90°) at a roughness Reynolds number of Ret = 391. A Reynolds stress transport model is used to close the flow governing equations whereas both the standard eddy-diffusivity closure and algebraic flux models are employed to close the transport equation for the passive scalar. The comparison with a DNS database shows improved reliability from algebraic scalar flux models towards predicting both the mean concentration and the plume structure. Since algebraic flux models do not increase substantially the computational effort, the results indicate that the use of tensorial-diffusivity can be promising tool for dispersion simulations for the urban environment.
Lumped Mass Modeling for Local-Mode-Suppressed Element Connectivity
DEFF Research Database (Denmark)
Joung, Young Soo; Yoon, Gil Ho; Kim, Yoon Young
2005-01-01
connectivity parameterization (ECP) is employed. On the way to the ultimate crashworthy structure optimization, we are now developing a local mode-free topology optimization formulation that can be implemented in the ECP method. In fact, the local mode-freeing strategy developed here can be also used directly...... experiencing large structural changes, appears to be still poor. In ECP, the nodes of the domain-discretizing elements are connected by zero-length one-dimensional elastic links having varying stiffness. For computational efficiency, every elastic link is now assumed to have two lumped masses at its ends....... Choosing appropriate penalization functions for lumped mass and link stiffness is important for local mode-free results. However, unless the objective and constraint functions are carefully selected, it is difficult to obtain clear black-and-white results. It is shown that the present formulation is also...
Many-body localization proximity effects in platforms of coupled spins and bosons
Marino, J.; Nandkishore, R. M.
2018-02-01
We discuss the onset of many-body localization in a one-dimensional system composed of a XXZ quantum spin chain and a Bose-Hubbard model linearly coupled together. We consider two complementary setups, depending whether spatial disorder is initially imprinted on spins or on bosons; in both cases, we explore the conditions for the disordered portion of the system to localize by proximity of the other clean half. Assuming that the dynamics of one of the two parts develops on shorter time scales than the other, we can adiabatically eliminate the fast degrees of freedom, and derive an effective Hamiltonian for the system's remainder using projection operator techniques. Performing a locator expansion on the strength of the many-body interaction term or on the hopping amplitude of the effective Hamiltonian thus derived, we present results on the stability of the many-body localized phases induced by proximity effect. We also briefly comment on the feasibility of the proposed model through modern quantum optics architectures, with the long-term perspective to realize experimentally, in composite open systems, Anderson or many-body localization proximity effects.
Zhandun, V.; Zamkova, N.; Ovchinnikov, S.; Sandalov, I.
2017-11-01
To accurately translate the results obtained within density functional theory (DFT) to the language of many-body theory we suggest and test the following approach: the parameters of the formulated model are to be found from the requirement that the model self-consistent electron density and density of electron states are as close as possible to the ones found from the DFT-based calculations. The investigation of the phase diagram of the model allows us to find the critical regions in magnetic properties. Then the behavior of the real system in these regions is checked by the ab initio calculations. As an example, we studied the physics of magnetic moment (MM) formation due to substitutions of Si by Fe-atoms or vice versa in the otherwise non-magnetic alloy α-FeSi2. We find that the MM formation is essentially controlled by the interaction of Fe atoms with its next nearest atoms (NNN) and by their particular arrangement. The latter may result in different magnetic states at the same concentrations of constituents. Moreover, one of arrangements produces the counterintuitive result: a ferromagnetism arises due to an increase in Si concentration in Fe1-xSi2+ x ordered alloy. The existing phenomenological models associate the destruction of magnetic moment only with the number of Fe-Si nearest neighbors. The presented results show that the crucial role in MM formation is played by the particular local NNN environment of the metal atom in the transition metal-metalloid alloy.
Tests of local Lorentz invariance violation of gravity in the standard model extension with pulsars.
Shao, Lijing
2014-03-21
The standard model extension is an effective field theory introducing all possible Lorentz-violating (LV) operators to the standard model and general relativity (GR). In the pure-gravity sector of minimal standard model extension, nine coefficients describe dominant observable deviations from GR. We systematically implemented 27 tests from 13 pulsar systems to tightly constrain eight linear combinations of these coefficients with extensive Monte Carlo simulations. It constitutes the first detailed and systematic test of the pure-gravity sector of minimal standard model extension with the state-of-the-art pulsar observations. No deviation from GR was detected. The limits of LV coefficients are expressed in the canonical Sun-centered celestial-equatorial frame for the convenience of further studies. They are all improved by significant factors of tens to hundreds with existing ones. As a consequence, Einstein's equivalence principle is verified substantially further by pulsar experiments in terms of local Lorentz invariance in gravity.
Global existence of solutions to a tear film model with locally elevated evaporation rates
Gao, Yuan; Ji, Hangjie; Liu, Jian-Guo; Witelski, Thomas P.
2017-07-01
Motivated by a model proposed by Peng et al. (2014) for break-up of tear films on human eyes, we study the dynamics of a generalized thin film model. The governing equations form a fourth-order coupled system of nonlinear parabolic PDEs for the film thickness and salt concentration subject to non-conservative effects representing evaporation. We analytically prove the global existence of solutions to this model with mobility exponents in several different ranges and present numerical simulations that are in agreement with the analytic results. We also numerically capture other interesting dynamics of the model, including finite-time rupture-shock phenomenon due to the instabilities caused by locally elevated evaporation rates, convergence to equilibrium and infinite-time thinning.
Chen, Xing; Jeong, Su-Jong
2018-02-01
To meet the growing demand for food, land is being managed to be more productive using agricultural intensification practices, such as the use of irrigation. Understanding the specific environmental impacts of irrigation is a critical part of using it as a sustainable way to provide food security. However, our knowledge of irrigation effects on climate is still limited to daytime effects. This is a critical issue to define the effects of irrigation on warming related to greenhouse gases (GHGs). This study shows that irrigation led to an increasing temperature (0.002 °C year-1) by enhancing nighttime warming (0.009 °C year-1) more than daytime cooling (-0.007 °C year-1) during the dry season from 1961-2004 over the North China Plain (NCP), which is one of largest irrigated areas in the world. By implementing irrigation processes in regional climate model simulations, the consistent warming effect of irrigation on nighttime temperatures over the NCP was shown to match observations. The intensive nocturnal warming is attributed to energy storage in the wetter soil during the daytime, which contributed to the nighttime surface warming. Our results suggest that irrigation could locally amplify the warming related to GHGs, and this effect should be taken into account in future climate change projections.
Effects of weak localization in quasi-one-dimensional electronic system over liquid helium
Kovdrya, Y Z; Gladchenko, S P
2001-01-01
One measured rho sub x sub x magnetoresistance of a quasi-one-dimensional electronic system over liquid helium within gas scattering range (1.3-2.0 K temperature range). It is shown that with increase of magnetic field the magnetoresistance is reduced at first and them upon passing over minimum it begins to increase from rho sub x sub x approx B sup 2 law. One anticipated that the negative magnetoresistance detected in the course of experiments resulted from the effects of weak localization. The experiment results are in qualitative conformity with the theoretical model describing processes of weak localization in single-dimensional nondegenerate electronic systems
Doehmann, M.; Brune, S.; Nardini, L.; Rybacki, E.; Dresen, G.
2017-12-01
Strain localization is an ubiquitous process in earth materials observed over a broad range of scales in space and time. Localized deformation and the formation of shear zones and faults typically involves material softening by various processes, like shear heating and grain size reduction. Numerical modeling enables us to study the complex physical and chemical weakening processes by separating the effect of individual parameters and boundary conditions. Using simple piece-wise linear functions for the parametrization of weakening processes allows studying a system at a chosen (lower) level of complexity (e.g. Cyprych et al., 2016). In this study, we utilize a finite element model to test two weakening laws that reduce the strength of the material depending on either the I) amount of accumulated strain or II) deformational work. Our 2D Cartesian models are benchmarked to single inclusion torsion experiments performed at elevated temperatures of 900 °C and pressures of up to 400 MPa (Rybacki et al., 2014). The experiments were performed on Carrara marble samples containing a weak Solnhofen limestone inclusion at a maximum strain rate of 2.0*10-4 s-1. Our models are designed to reproduce shear deformation of a hollow cylinder equivalent to the laboratory setup, such that material leaving one side of the model in shear direction enters again on the opposite side using periodic boundary conditions. Similar to the laboratory tests, we applied constant strain rate and constant stress boundary conditions.We use our model to investigate the time-dependent distribution of stress and strain and the effect of different parameters. For instance, inclusion rotation is shown to be strongly dependent on the viscosity ratio between matrix and inclusion and stronger ductile weakening increases the localization rate while decreasing shear zone width. The most suitable weakening law for representation of ductile rock is determined by combining the results of parameter tests with
Effect of localized hypoxia on Drosophila embryo development.
Directory of Open Access Journals (Sweden)
Zhinan Wang
Full Text Available Environmental stress, such as oxygen deprivation, affects various cellular activities and developmental processes. In this study, we directly investigated Drosophila embryo development in vivo while cultured on a microfluidic device, which imposed an oxygen gradient on the developing embryos. The designed microfluidic device enabled both temporal and spatial control of the local oxygen gradient applied to the live embryos. Time-lapse live cell imaging was used to monitor the morphology and cellular migration patterns as embryos were placed in various geometries relative to the oxygen gradient. Results show that pole cell movement and tail retraction during Drosophila embryogenesis are highly sensitive to oxygen concentrations. Through modeling, we also estimated the oxygen permeability across the Drosophila embryonic layers for the first time using parameters measured on our oxygen control device.
Learning to Localize Sound with a Lizard Ear Model
DEFF Research Database (Denmark)
Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob
The peripheral auditory system of a lizard is strongly directional in the azimuth plane due to the acoustical coupling of the animal's two eardrums. This feature by itself is insufficient to accurately localize sound as the extracted directional information cannot be directly mapped to the sound...
Developmental Local Government as a Model for Grassroots Socio ...
African Journals Online (AJOL)
DR Nneka
Indexed African Journals Online (AJOL) www.ajol.info. Vol. 4(2), S/No 14, ... Enugu State University of Science and Technology, Enugu. Enugu State, Nigeria ... As the third tier of government, local governments are entitled to a statutory ..... with other stakeholders (Federal, State and the private sector) in implementing the.
Simulation of local instabilities with the use of reduced order models
International Nuclear Information System (INIS)
Dykin, V.; Demaziere, C.; Lange, C.; Hennig, D.
2011-01-01
The development of an advanced reduced order model (ROM) with four heated channels, taking into account local, regional and core-wide oscillations, is described. The ROM contains three sub-models: a neutron-kinetic model (describing neutron transport), a thermal- hydraulic model (describing the coolant flow) and a heat transfer model (describing heat transfer between the fuel and the coolant). All these three models are coupled to each other, using two feedback mechanisms: void feedback and doppler feedback. Each of the sub-models is described by a set of reduced ordinary differential equations, derived from the corresponding time space-dependent partial differential equations by using different types of approximations and mathematical techniques. All three models were developed from past ROMs and, subsequently, were modified in order to fit the purpose of our investigations. One of the novelties of the present ROM is that it takes into account the effect of the first three neutronic modes, namely the fundamental, the first and the second azimuthal modes, as well as the effect of local oscillations on these modes. In order to have a proper representation of both azimuthal modes, a four heated channel ROM was developed. Another modification, compared to earlier work, is the determination of the coupling reactivity coefficients for both void fraction and fuel temperature, which were calculated explicitly by evaluating cross-section perturbations with the help of the SIMULATE-3 and the CORESIM codes. The ROM was thereafter applied to a channel instability event that occurred at the Swedish Forsmark-1 BWR in 1996/1997. The time signals for each of the modes were generated from the ROM and compared with the measurements, performed at the plant. Some qualitative comparison between the ROM and the measurements was made. The results could bear some significance in understanding the instability event and its coupling mechanism to core-wide oscillations. (author)
Efficient modeling of photonic crystals with local Hermite polynomials
International Nuclear Information System (INIS)
Boucher, C. R.; Li, Zehao; Albrecht, J. D.; Ram-Mohan, L. R.
2014-01-01
Developing compact algorithms for accurate electrodynamic calculations with minimal computational cost is an active area of research given the increasing complexity in the design of electromagnetic composite structures such as photonic crystals, metamaterials, optical interconnects, and on-chip routing. We show that electric and magnetic (EM) fields can be calculated using scalar Hermite interpolation polynomials as the numerical basis functions without having to invoke edge-based vector finite elements to suppress spurious solutions or to satisfy boundary conditions. This approach offers several fundamental advantages as evidenced through band structure solutions for periodic systems and through waveguide analysis. Compared with reciprocal space (plane wave expansion) methods for periodic systems, advantages are shown in computational costs, the ability to capture spatial complexity in the dielectric distributions, the demonstration of numerical convergence with scaling, and variational eigenfunctions free of numerical artifacts that arise from mixed-order real space basis sets or the inherent aberrations from transforming reciprocal space solutions of finite expansions. The photonic band structure of a simple crystal is used as a benchmark comparison and the ability to capture the effects of spatially complex dielectric distributions is treated using a complex pattern with highly irregular features that would stress spatial transform limits. This general method is applicable to a broad class of physical systems, e.g., to semiconducting lasers which require simultaneous modeling of transitions in quantum wells or dots together with EM cavity calculations, to modeling plasmonic structures in the presence of EM field emissions, and to on-chip propagation within monolithic integrated circuits
AN INVESTIGATION OF LOCAL EFFECTS ON SURFACE WARMING WITH GEOGRAPHICALLY WEIGHTED REGRESSION (GWR
Directory of Open Access Journals (Sweden)
Y. Xue
2012-07-01
Full Text Available Urban warming is sensitive to the nature (thermal properties, including albedo, water content, heat capacity and thermal conductivity and the placement (surface geometry or urban topography of urban surface. In the literature the spatial dependence and heterogeneity of urban thermal landscape is widely observed based on thermal infrared remote sensing within the urban environment. Urban surface warming is conceived as a big contribution to urban warming, the study of urban surface warming possesses significant meaning for probing into the problem of urban warming.The urban thermal landscape study takes advantage of the continuous surface derived from thermal infrared remote sensing at the landscape scale, the detailed variation of local surface temperature can be measured and analyzed through the systematic investigation. At the same time urban environmental factors can be quantified with remote sensing and GIS techniques. This enables a systematic investigation of urban thermal landscape with a link to be established between local environmental setting and surface temperature variation. The goal of this research is utilizing Geographically Weighted Regression (GWR to analyze the spatial relationship between urban form and surface temperature variation in order to clarify the local effects on surface warming, moreover to reveal the possible dynamics in the local influences of environmental indicators on the variation of local surface temperature across space and time. In this research, GWR analysis proved that the spatial variation in relationships between environmental setting and surface temperature was significant with Monte Carlo significance test and distinctive in day-night change. Comparatively, GWR facilitated the site specific investigation based on local statistical technique. The inference based on GWR model provided enriched information regarding the spatial variation of local environment effect on surface temperature variation which
Zheng, Qiang; Li, Honglun; Fan, Baode; Wu, Shuanhu; Xu, Jindong
2017-12-01
Active contour model (ACM) has been one of the most widely utilized methods in magnetic resonance (MR) brain image segmentation because of its ability of capturing topology changes. However, most of the existing ACMs only consider single-slice information in MR brain image data, i.e., the information used in ACMs based segmentation method is extracted only from one slice of MR brain image, which cannot take full advantage of the adjacent slice images' information, and cannot satisfy the local segmentation of MR brain images. In this paper, a novel ACM is proposed to solve the problem discussed above, which is based on multi-variate local Gaussian distribution and combines the adjacent slice images' information in MR brain image data to satisfy segmentation. The segmentation is finally achieved through maximizing the likelihood estimation. Experiments demonstrate the advantages of the proposed ACM over the single-slice ACM in local segmentation of MR brain image series.
A comparison of non-local electron transport models relevant to inertial confinement fusion
Sherlock, Mark; Brodrick, Jonathan; Ridgers, Christopher
2017-10-01
We compare the reduced non-local electron transport model developed by Schurtz et al. to Vlasov-Fokker-Planck simulations. Two new test cases are considered: the propagation of a heat wave through a high density region into a lower density gas, and a 1-dimensional hohlraum ablation problem. We find the reduced model reproduces the peak heat flux well in the ablation region but significantly over-predicts the coronal preheat. The suitability of the reduced model for computing non-local transport effects other than thermal conductivity is considered by comparing the computed distribution function to the Vlasov-Fokker-Planck distribution function. It is shown that even when the reduced model reproduces the correct heat flux, the distribution function is significantly different to the Vlasov-Fokker-Planck prediction. Two simple modifications are considered which improve agreement between models in the coronal region. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Knowledge transfer for learning robot models via local procrustes analysis
CSIR Research Space (South Africa)
Makondo, N
2015-11-01
Full Text Available Learning of robot kinematic and dynamic models from data has attracted much interest recently as an alternative to manually defined models. However, the amount of data required to learn these models becomes large when the number of degrees...
Effects of Spatial Localization on Microbial Consortia Growth.
Directory of Open Access Journals (Sweden)
Michael Venters
Full Text Available Microbial consortia are commonly observed in natural and synthetic systems, and these consortia frequently result in higher biomass production relative to monocultures. The focus here is on the impact of initial spatial localization and substrate diffusivity on the growth of a model microbial consortium consisting of a producer strain that consumes glucose and produces acetate and a scavenger strain that consumes the acetate. The mathematical model is based on an individual cell model where growth is described by Monod kinetics, and substrate transport is described by a continuum-based, non-equilibrium reaction-diffusion model where convective transport is negligible (e.g., in a biofilm. The first set of results focus on a single producer cell at the center of the domain and surrounded by an initial population of scavenger cells. The impact of the initial population density and substrate diffusivity is examined. A transition is observed from the highest initial density resulting in the greatest cell growth to cell growth being independent of initial density. A high initial density minimizes diffusive transport time and is typically expected to result in the highest growth, but this expected behavior is not predicted in environments with lower diffusivity or larger length scales. When the producer cells are placed on the bottom of the domain with the scavenger cells above in a layered biofilm arrangement, a similar critical transition is observed. For the highest diffusivity values examined, a thin, dense initial scavenger layer is optimal for cell growth. However, for smaller diffusivity values, a thicker, less dense initial scavenger layer provides maximal growth. The overall conclusion is that high density clustering of members of a food chain is optimal under most common transport conditions, but under some slow transport conditions, high density clustering may not be optimal for microbial growth.
Directory of Open Access Journals (Sweden)
Naledzani Rasila
2012-09-01
Full Text Available South Africa’s population has risen from 40.5 million in 1996 to 44.8 million in 2001 and to 51.77 in 2011. Africans are in majority making 79.2% of the whole population. About 22.3% of blacks have received no schooling with the unemployment rate of the blacks at 28.1%. Most of these unemployed and uneducated blacks are found in rural areas. This compelled government to introduce Developmental Local government. Developmental Local government refers to the layer of public service that has the capacity to deliver and account to the people in a responsive, accountable, and efficient manner. It is also described as a sphere that encourages community participation in matters of governance and developmental initiatives. However, Developmental Local government is hindered by continuous growth of population which is likely to lead to overpopulation. Overpopulation is characterised by lack of basic resources such as water and food. Developmental Local government on the other hand is expected to deliver on these needs. Lack of fulfilment of goals of Developmental Local government is attributed to lack of effective communication between local government and community members. Although population growth is not attributed only to high birth rate, governments around the continent have introduced measures to encourage healthy reproductive life. However, this needs community members that are self-motivated to be active participants in government initiatives. This is not achievable as there is an indication of lack of effective communication. This paper’s main focus is the provision of effective communication model at local sphere which will see community members working together with government on matters of their own development including initiatives to preserve limited resources amid the challenges of overpopulation. This paper is based on the qualitative study on effectiveness of communication in Mutale local municipality on the enhancement of
Three-dimensional modelling of slope stability using the Local Factor of Safety concept
Moradi, Shirin; Huisman, Sander; Beck, Martin; Vereecken, Harry; Class, Holger
2017-04-01
Slope stability is governed by coupled hydrological and mechanical processes. The slope stability depends on the effective stress, which in turn depends on the weight of the soil and the matrix potential. Therefore, changes in water content and matrix potential associated with infiltration will affect slope stability. Most available models describing these coupled hydro-mechanical processes either rely on a one- or two-dimensional representation of hydrological and mechanical properties and processes, which obviously is a strong simplification in many applications. Therefore, the aim of this work is to develop a three-dimensional hydro-mechanical model that is able to capture the effect of spatial and temporal variability of both mechanical and hydrological parameters on slope stability. For this, we rely on DuMux, which is a free and open-source simulator for flow and transport processes in porous media that facilitates coupling of different model approaches and offers flexibility for model development. We use the Richards equation to model unsaturated water flow. The simulated water content and matrix potential distribution is used to calculate the effective stress. We only consider linear elasticity and solve for statically admissible fields of stress and displacement without invoking failure or the redistribution of post-failure stress or displacement. The Local Factor of Safety concept is used to evaluate slope stability in order to overcome some of the main limitations of commonly used methods based on limit equilibrium considerations. In a first step, we compared our model implementation with a 2D benchmark model that was implemented in COMSOL Multiphysics. In a second step, we present in-silico experiments with the newly developed 3D model to show the effect of slope morphology, spatial variability in hydraulic and mechanical material properties, and spatially variable soil depth on simulated slope stability. It is expected that this improved physically
Controlling effect of geometrically defined local structural changes on chaotic Hamiltonian systems.
Ben Zion, Yossi; Horwitz, Lawrence
2010-04-01
An effective characterization of chaotic conservative Hamiltonian systems in terms of the curvature associated with a Riemannian metric tensor derived from the structure of the Hamiltonian has been extended to a wide class of potential models of standard form through definition of a conformal metric. The geodesic equations reproduce the Hamilton equations of the original potential model through an inverse map in the tangent space. The second covariant derivative of the geodesic deviation in this space generates a dynamical curvature, resulting in (energy-dependent) criteria for unstable behavior different from the usual Lyapunov criteria. We show here that this criterion can be constructively used to modify locally the potential of a chaotic Hamiltonian model in such a way that stable motion is achieved. Since our criterion for instability is local in coordinate space, these results provide a minimal method for achieving control of a chaotic system.
Semi-local invariance in Ising models with multi-spin interaction
International Nuclear Information System (INIS)
Lipowski, A.
1996-08-01
We examine implications of semi-local invariance in Ising models with multispin interaction. In ergodic models all spin-spin correlation functions vanish and the local symmetry is the same as in locally gauge-invariant models. The d = 3 model with four-spin interaction is nonergodic at low temperature but the magnetic symmetry remains unbroken. The d = 3 model with eight-spin interaction is ergodic but undergoes the phase transition and most likely its low-temperature phase is characterized by a nonlocal order parameter. (author). 7 refs, 1 fig
Local and omnibus goodness-of-fit tests in classical measurement error models
Ma, Yanyuan; Hart, Jeffrey D.; Janicki, Ryan; Carroll, Raymond J.
2010-01-01
We consider functional measurement error models, i.e. models where covariates are measured with error and yet no distributional assumptions are made about the mismeasured variable. We propose and study a score-type local test and an orthogonal
Network model of top-down influences on local gain and contextual interactions in visual cortex.
Piëch, Valentin; Li, Wu; Reeke, George N; Gilbert, Charles D
2013-10-22
The visual system uses continuity as a cue for grouping oriented line segments that define object boundaries in complex visual scenes. Many studies support the idea that long-range intrinsic horizontal connections in early visual cortex contribute to this grouping. Top-down influences in primary visual cortex (V1) play an important role in the processes of contour integration and perceptual saliency, with contour-related responses being task dependent. This suggests an interaction between recurrent inputs to V1 and intrinsic connections within V1 that enables V1 neurons to respond differently under different conditions. We created a network model that simulates parametrically the control of local gain by hypothetical top-down modification of local recurrence. These local gain changes, as a consequence of network dynamics in our model, enable modulation of contextual interactions in a task-dependent manner. Our model displays contour-related facilitation of neuronal responses and differential foreground vs. background responses over the neuronal ensemble, accounting for the perceptual pop-out of salient contours. It quantitatively reproduces the results of single-unit recording experiments in V1, highlighting salient contours and replicating the time course of contextual influences. We show by means of phase-plane analysis that the model operates stably even in the presence of large inputs. Our model shows how a simple form of top-down modulation of the effective connectivity of intrinsic cortical connections among biophysically realistic neurons can account for some of the response changes seen in perceptual learning and task switching.
Vibration analysis of rotating nanobeam systems using Eringen's two-phase local/nonlocal model
Khaniki, Hossein Bakhshi
2018-05-01
Due to the inability of differential form of nonlocal elastic theory in modelling cantilever beams and inaccurate results for some type of boundaries, in this study, a reliable investigation on transverse vibrational behavior of rotating cantilever size-dependent beams is presented. Governing higher order equations are written in the framework of Eringen's two-phase local/nonlocal model and solved using a modified generalized differential quadrature method. In order to indicate the influence of different material and scale parameters, a comprehensive parametric study is presented. It is shown that increasing the nonlocality term leads to lower natural frequency terms for cantilever nanobeams especially for the fundamental frequency parameter which differential nonlocal model is unable to track appropriately. Moreover, it is shown that rotating speed and hub radius have a remarkable effect in varying the mechanical behavior of rotating cantilever nanobeams. This study is a step forward in analyzing nanorotors, nanoturbines, nanoblades, etc.
Developing Local Scale, High Resolution, Data to Interface with Numerical Hurricane Models
Witkop, R.; Becker, A.
2017-12-01
In 2017, the University of Rhode Island's (URI's) Graduate School of Oceanography (GSO) developed hurricane models that specify wind speed, inundation, and erosion around Rhode Island with enough precision to incorporate impacts on individual facilities. At the same time, URI's Marine Affairs Visualization Lab (MAVL) developed a way to realistically visualize these impacts in 3-D. Since climate change visualizations and water resource simulations have been shown to promote resiliency action (Sheppard, 2015) and increase credibility (White et al., 2010) when local knowledge is incorporated, URI's hurricane models and visualizations may also more effectively enable hurricane resilience actions if they include Facility Manager (FM) and Emergency Manager (EM) perceived hurricane impacts. This study determines how FM's and EM's perceive their assets as being vulnerable to quantifiable hurricane-related forces at the individual facility scale while exploring methods to elicit this information from FMs and EMs in a format usable for incorporation into URI GSO's hurricane models.
Quantifying Local, Response Dependence between Two Polytomous Items Using the Rasch Model
Andrich, David; Humphry, Stephen M.; Marais, Ida
2012-01-01
Models of modern test theory imply statistical independence among responses, generally referred to as "local independence." One violation of local independence occurs when the response to one item governs the response to a subsequent item. Expanding on a formulation of this kind of violation as a process in the dichotomous Rasch model,…
A review of recent advances in numerical modelling of local scour problems
DEFF Research Database (Denmark)
Sumer, B. Mutlu
2014-01-01
A review is presented of recent advances in numerical modelling of local scour problems. The review is organized in five sections: Highlights of numerical modelling of local scour; Influence of turbulence on scour; Backfilling of scour holes; Scour around complex structures; and Scour protection ...
International Nuclear Information System (INIS)
Thierry, F.
2003-02-01
The aim of this work is to propose an evolution of nuclear (R7T7-type) glass alteration modeling. The first part of this thesis is about development and validation of the 'r(t)' model. This model which predicts the decrease of alteration rates in confined conditions is based upon a coupling between a first-order dissolution law and a diffusion barrier effect of the alteration gel layer. The values and the uncertainties regarding the main adjustable parameters of the model (α, Dg and C*) have been determined from a systematic study of the available experimental data. A program called INVERSION has been written for this purpose. This work lead to characterize the validity domain of the 'r(t)' model and to parametrize it. Validation experiments have been undertaken, confirming the validity of the parametrization over 200 days. A new model is proposed in the second part of this thesis. It is based on an inhibition of glass dissolution reaction by silicon coupled with a local description of silicon retention in the alteration gel layer. This model predicts the evolutions of boron and silicon concentrations in solution as well as the concentrations and retention profiles in the gel layer. These predictions have been compared to measurements of retention profiles by the secondary ion mass spectrometry (SIMS) method. The model has been validated on fractions of gel layer which reactivity present low or moderate disparities. (author)
A probabilistic model for robust acoustic localization based on an auditory front-end
May, T.; Par, van de S.L.J.D.E.; Kohlrausch, A.G.; Boone, M.
2009-01-01
Although extensive research has been done in the field of localization, the degrading effect of reverberation and the presence of multiple sources on localization performance has remained a major issue. The classical approach to localize an acoustic source in the horizontal space is to search for
Solution chemistry of Mo(III) and Mo(IV): Thermodynamic foundation for modeling localized corrosion
International Nuclear Information System (INIS)
Wang Peiming; Wilson, Leslie L.; Wesolowski, David J.; Rosenqvist, Joergen; Anderko, Andrzej
2010-01-01
To investigate the behavior of molybdenum dissolution products in systems that approximate localized corrosion environments, solubility of Mo(III) in equilibrium with solid MoO 2 has been determined at 80 deg. C as a function of solution acidity, chloride concentration and partial pressure of hydrogen. The measurements indicate a strong increase in solubility with acidity and chloride concentration and a weak effect of hydrogen partial pressure. The obtained results have been combined with literature data for systems containing Mo(III), Mo(IV), and Mo(VI) in solutions to develop a comprehensive thermodynamic model of aqueous molybdenum chemistry. The model is based on a previously developed framework for simulating the properties of electrolyte systems ranging from infinite dilution to solid saturation or fused salt limit. To reproduce the measurements, the model assumes the presence of a chloride complex of Mo(III) (i.e., MoCl 2+ ) and hydrolyzed species (MoOH 2+ , Mo(OH) 2 + , and Mo(OH) 3 0 ) in addition to the Mo 3+ ion. The model generally reproduces the experimental data within experimental scattering and provides a tool for predicting the phase behavior and speciation in complex, concentrated aqueous solutions. Thus, it provides a foundation for simulating the behavior of molybdenum species in localized corrosion environments.
Testing of motor unit synchronization model for localized muscle fatigue.
Naik, Ganesh R; Kumar, Dinesh K; Yadav, Vivek; Wheeler, Katherine; Arjunan, Sridhar
2009-01-01
Spectral compression of surface electromyogram (sEMG) is associated with onset of localized muscle fatigue. The spectral compression has been explained based on motor unit synchronization theory. According to this theory, motor units are pseudo randomly excited during muscle contraction, and with the onset of muscle fatigue the recruitment pattern changes such that motor unit firings become more synchronized. While this is widely accepted, there is little experimental proof of this phenomenon. This paper has used source dependence measures developed in research related to independent component analysis (ICA) to test this theory.
Nonlinear local electrovascular coupling. I: A theoretical model.
Riera, Jorge J; Wan, Xiaohong; Jimenez, Juan Carlos; Kawashima, Ryuta
2006-11-01
Here we present a detailed biophysical model of how brain electrical and vascular dynamics are generated within a basic cortical unit. The model was obtained from coupling a canonical neuronal mass and an expandable vasculature. In this proposal, we address several aspects related to electroencephalographic and functional magnetic resonance imaging data fusion: (1) the impact of the cerebral architecture (at different physical levels) on the observations; (2) the physiology involved in electrovascular coupling; and (3) energetic considerations to gain a better understanding of how the glucose budget is used during neuronal activity. The model has three components. The first is the canonical neural mass model of three subpopulations of neurons that respond to incoming excitatory synaptic inputs. The generation of the membrane potentials in the somas of these neurons and the electric currents flowing in the neuropil are modeled by this component. The second and third components model the electrovascular coupling and the dynamics of vascular states in an extended balloon approach, respectively. In the first part we describe, in some detail, the biophysical model and establish its face validity using simulations of visually evoked responses under different flickering frequencies and luminous contrasts. In a second part, a recursive optimization algorithm is developed and used to make statistical inferences about this forward/generative model from actual data. Copyright 2006 Wiley-Liss, Inc.
Business model innovation for Local Energy Management: a perspective from Swiss utilities
Directory of Open Access Journals (Sweden)
Emanuele Facchinetti
2016-08-01
Full Text Available The successful deployment of the energy transition relies on a deep reorganization of the energy market. Business model innovation is recognized as a key driver of this process. This work contributes to this topic by providing to potential Local Energy Management stakeholders and policy makers a conceptual framework guiding the Local Energy Management business model innovation. The main determinants characterizing Local Energy Management concepts and impacting its business model innovation are identified through literature reviews on distributed generation typologies and customer/investor preferences related to new business opportunities emerging with the energy transition. Afterwards, the relation between the identified determinants and the Local Energy Management business model solution space is analyzed based on semi-structured interviews with managers of Swiss utilities companies. The collected managers’ preferences serve as explorative indicators supporting the business model innovation process and provide insights to policy makers on challenges and opportunities related to Local Energy Management.
Herrera, Victoria LM; Colby, Aaron H; Tan, Glaiza AL; Moran, Ann M; O’Brien, Michael J; Colson, Yolonda L; Ruiz-Opazo, Nelson; Grinstaff, Mark W
2016-01-01
Aim: To evaluate the tumor localization and efficacy pH-responsive expansile nanoparticles (eNPs) as a drug delivery system for pancreatic peritoneal carcinomatosis (PPC) modeled in nude rats. Methods & materials: A Panc-1-cancer stem cell xeno1graft model of PPC was validated in vitro and in vivo. Tumor localization was tracked via in situ imaging of fluorescent eNPs. Survival of animals treated with paclitaxel-loaded eNPs (PTX-eNPs) was evaluated in vivo. Results: The Panc-1-cancer stem cell xenograft model recapitulates significant features of PPC. Rhodamine-labeled eNPs demonstrate tumor-specific, dose- and time-dependent localization to macro- and microscopic tumors following intraperitoneal injection. PTX-eNPs are as effective as free PTX in treating established PPC; but, PTX-eNPs result in fewer side effects. Conclusion: eNPs are a promising tool for the detection and treatment of PPC. PMID:27078118
Local versus global interactions in nonequilibrium transitions: A model of social dynamics
González-Avella, J. C.; Eguíluz, V. M.; Cosenza, M. G.; Klemm, K.; Herrera, J. L.; San Miguel, M.
2006-04-01
A nonequilibrium system of locally interacting elements in a lattice with an absorbing order-disorder phase transition is studied under the effect of additional interacting fields. These fields are shown to produce interesting effects in the collective behavior of this system. Both for autonomous and external fields, disorder grows in the system when the probability of the elements to interact with the field is increased. There exists a threshold value of this probability beyond which the system is always disordered. The domain of parameters of the ordered regime is larger for nonuniform local fields than for spatially uniform fields. However, the zero field limit is discontinous. In the limit of vanishingly small probability of interaction with the field, autonomous or external fields are able to order a system that would fall in a disordered phase under local interactions of the elements alone. We consider different types of fields which are interpreted as forms of mass media acting on a social system in the context of Axelrod’s model for cultural dissemination.
Effects of Radiofrequency Induced local Hyperthermia on Normal Canine Liver
International Nuclear Information System (INIS)
Suh, Chang Ok; Loh, John J. K.; Seong, Jin Sil
1991-01-01
In order to assess the effects of radiofrequency-induced local hyperthermia on the normal liver, histopathologic findings and biochemical changes after localized hyperthermia in canine liver were studied. Hyperthermia was externally administered using the Thermotron RF-8 (Yamamoto Vinyter Co., Japan; Capacitive type heating machine) with parallel opposed electrodes. Thirteen dogs were used and allocated into one control group (N=3) and two treatment groups according to the treatment temperature. Group I (N=5) was heated with 42.5±0.5.deg.C for 30 minutes, and Group(N=5) was heated with 45±0.5.deg.C for 15-30 minutes. Samples of liver tissue were obtained through a needle biopsy immediately after hyperthermia and 7, 14 and 28 days after treatment and examined for SGOT, SGPT and alkaline phosphatase. Although SGOT and SGPT were elevated after hyperthermia in both groups (three of five in each group), there was no liver cell necrosis or hyperthermia related mortality in Group I. A hydropic swelling of hepatocytes was prominent histologic finding. Hyperthermia with 45.deg.C for 30 minutes was fatal and showed extensive liver cell necrosis. In conclusion, liver damage day heat of 42.5±0.5.deg.C for 30 minutes is reversible, and liver damage by heat of 45±0.5.deg.C for 30 minutes can be fatal or irreversible. However, these results cannot be applied directly to human trial. Therefore, in order to apply hyperthermic treatment on human liver tumor safely, close observation of temperature with proper thermometry is mandatory. Hyperthermic treatment should be confined to the tumor area while sparing a normal liver as much as possible
Magnetic Island Growth A comparison of local and global effects
International Nuclear Information System (INIS)
Lloyd, S.S.; Gardner, H.J.
2003-01-01
In stellarators a hot plasma is confined to a torus by a magnetic field with both toroidal and poloidal components generated by external currents. Plasma currents develop to balance the pressure gradient with a J x B force which in turn change the shape of confining magnetic field. Self-consistent equilibrium magnetic fields and plasma currents for some H-1NF configurations were calculated using the HINT code. This code relaxes a simplified set of resistive MHD equations on a coordinate grid until an equilibrium is reached [1]. Islands can occur in the equilibrium magnetic field, surrounding field lines with low-order rational rotational transform. The island widths are influenced by four types of currents. External currents determine the vacuum island widths. Global resonant and non-resonant currents increase linearly with plasma pressure and can act in or out of phase to the external currents. Local resonant currents are caused by the presence of an island and reinforce or counteract the island depending on the field strength gradient [2]. We compare the impact of local resonant and global non-resonant currents by comparing the results of HINT for several related configurations of H-1NF. Two configurations with slightly different rotational transforms (but otherwise very similar parameters) will have very different resonant plasma currents but nearly identical non-resonant plasma currents. Comparing the effect of the currents of the two configurations on island width gives an insight into the different contributions of resonant and non-resonant plasma currents to island growth or self-healing
The effect of local tramadol injection in post appendectomy pain
Directory of Open Access Journals (Sweden)
Alireza Khazaei
2012-02-01
Full Text Available Background: It has been demonstrated that tramadol, asemisynthetic opioid, is an effective analgesic with systemic (central and local (peripheral anesthetic effects. The aim of this study was to compare the post-operative anesthetic effect of subcutaneous wound infiltration of tramadol with normal saline as placebo in the incision wounds after appendectomy and measuring the average need to petidine during the next 24 hours after the appendectomy. Materials and Method: This double blind study was carried out on 60 patients over 15 years old. Patients were randomly divided in two equal groups. At the end of procedure after repairing fascia 100mg of tramadol that was diluted with water for injection up to 10 cc in one syringe or 10 cc of normal saline in another syringe was infiltrated subcutaneously by surgeon before suturing the skin. The intensity of pain (NRS was recorded in the recovery room, after 6 and 24 hours post-operation as well as total amount of administered petidine in the same period. At the end of study the intensity of pain in the mentioned times and the average use of petidine compared in two groups. Results: A significant difference was noted in the severity of pain between two groups in recovery time, 6 and 24 hours afetr operation that was lower in tramadol group (p<0.0001. Also the average use of petidine was significantly lower in tramadol group in 24 hours (p<0.05. The average severity of pain by NRS in recovery was 5.36 for control (N and 3.08 for tramadol (T groups; and after 6 hours it was 5.36 for (N and 3.36 for (T and after 24 hours reached to 3.08 for (N and 2.08 for (T and the average number of injected 25mg ampoules of petidine was 1.56 in (N and 0.76 in (T.Conclusion: Local wound infiltration of tramadol is a good choice for reduction of post appendectomy pain and decreasing need for high potent opioid analgesics
Nonlinear simulations of particle source effects on edge localized mode
Energy Technology Data Exchange (ETDEWEB)
Huang, J.; Tang, C. J. [College of Physical Science and Technology, Sichuan University, Chengdu 610065 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Chen, S. Y., E-mail: sychen531@163.com [College of Physical Science and Technology, Sichuan University, Chengdu 610065 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Southwestern Institute of Physics, Chengdu 610041 (China); Wang, Z. H. [Southwestern Institute of Physics, Chengdu 610041 (China)
2015-12-15
The effects of particle source (PS) with different intensities and located positions on Edge Localized Mode (ELM) are systematically studied with BOUT++ code. The results show the ELM size strongly decreases with increasing the PS intensity once the PS is located in the middle or bottom of the pedestal. The effects of PS on ELM depend on the located position of PS. When it is located at the top of the pedestal, peeling-ballooning (P-B) modes can extract more free energy from the pressure gradient and grow up to be a large filament at the initial crash phase and the broadening of mode spectrum can be suppressed by PS, which leads to more energy loss. When it is located in the middle or bottom of the pedestal, the extraction of free energy by P-B modes can be suppressed, and a small filament is generated. During the turbulence transport phase, the broader mode spectrum suppresses the turbulence transport when PS is located in the middle, while the zonal flow plays an important role in damping the turbulence transport when PS is located at the bottom.
Stucki, S; Orozco-terWengel, P; Forester, B R; Duruz, S; Colli, L; Masembe, C; Negrini, R; Landguth, E; Jones, M R; Bruford, M W; Taberlet, P; Joost, S
2017-09-01
With the increasing availability of both molecular and topo-climatic data, the main challenges facing landscape genomics - that is the combination of landscape ecology with population genomics - include processing large numbers of models and distinguishing between selection and demographic processes (e.g. population structure). Several methods address the latter, either by estimating a null model of population history or by simultaneously inferring environmental and demographic effects. Here we present samβada, an approach designed to study signatures of local adaptation, with special emphasis on high performance computing of large-scale genetic and environmental data sets. samβada identifies candidate loci using genotype-environment associations while also incorporating multivariate analyses to assess the effect of many environmental predictor variables. This enables the inclusion of explanatory variables representing population structure into the models to lower the occurrences of spurious genotype-environment associations. In addition, samβada calculates local indicators of spatial association for candidate loci to provide information on whether similar genotypes tend to cluster in space, which constitutes a useful indication of the possible kinship between individuals. To test the usefulness of this approach, we carried out a simulation study and analysed a data set from Ugandan cattle to detect signatures of local adaptation with samβada, bayenv, lfmm and an F ST outlier method (FDIST approach in arlequin) and compare their results. samβada - an open source software for Windows, Linux and Mac OS X available at http://lasig.epfl.ch/sambada - outperforms other approaches and better suits whole-genome sequence data processing. © 2016 The Authors. Molecular Ecology Resources Published by John Wiley & Sons Ltd.
International Nuclear Information System (INIS)
Kravtsov, V E; Yudson, V I
2013-01-01
We consider the distribution function P(|ψ| 2 ) of the eigenfunction amplitude at the center-of-band (E = 0) anomaly in the one-dimensional tight-binding chain with weak uncorrelated on-site disorder (the one-dimensional Anderson model). The special emphasis is on the probability of the anomalously localized states (ALS) with |ψ| 2 much larger than the inverse typical localization length ℓ 0 . Using the recently found solution for the generating function Φ an (u, ϕ) we obtain the ALS probability distribution P(|ψ| 2 ) at |ψ| 2 ℓ 0 ≫ 1. As an auxiliary preliminary step, we found the asymptotic form of the generating function Φ an (u, ϕ) at u ≫ 1 which can be used to compute other statistical properties at the center-of-band anomaly. We show that at moderately large values of |ψ| 2 ℓ 0 , the probability of ALS at E = 0 is smaller than at energies away from the anomaly. However, at very large values of |ψ| 2 ℓ 0 , the tendency is inverted: it is exponentially easier to create a very strongly localized state at E = 0 than at energies away from the anomaly. We also found the leading term in the behavior of P(|ψ| 2 ) at small |ψ| 2 ≪ ℓ −1 0 and show that it is consistent with the exponential localization corresponding to the Lyapunov exponent found earlier by Kappus and Wegner. (paper)
Non local-thermodynamical-equilibrium effects in the simulation of laser-produced plasmas
Klapisch, M.; Bar-Shalom, A.; Oreg, J.; Colombant, D.
1998-05-01
Local thermodynamic equilibrium (LTE) breaks down in directly or indirectly driven laser plasmas because of sharp gradients, energy deposition, etc. For modeling non-LTE effects in hydrodynamical simulations, Busquet's model [Phys. Fluids B 5, 4191 (1993)] is very convenient and efficient. It uses off-line generated LTE opacities and equation of states via an effective, radiation-dependent ionization temperature Tz. An overview of the model is given. The results are compared with an elaborate collisional radiative model based on superconfigurations. The agreements for average charge Z* and opacities are surprisingly good, even more so when the plasma is immersed in a radiation field. Some remaining discrepancy at low density is attributed to dielectronic recombination. Improvement appears possible, especially for emissivities, because the concept of ionization temperature seems to be validated.
Non local-thermodynamical-equilibrium effects in the simulation of laser-produced plasmas
International Nuclear Information System (INIS)
Klapisch, M.; Bar-Shalom, A.; Oreg, J.; Colombant, D.
1998-01-01
Local thermodynamic equilibrium (LTE) breaks down in directly or indirectly driven laser plasmas because of sharp gradients, energy deposition, etc. For modeling non-LTE effects in hydrodynamical simulations, Busquet close-quote s model [Phys. Fluids B 5, 4191 (1993)] is very convenient and efficient. It uses off-line generated LTE opacities and equation of states via an effective, radiation-dependent ionization temperature T z . An overview of the model is given. The results are compared with an elaborate collisional radiative model based on superconfigurations. The agreements for average charge Z * and opacities are surprisingly good, even more so when the plasma is immersed in a radiation field. Some remaining discrepancy at low density is attributed to dielectronic recombination. Improvement appears possible, especially for emissivities, because the concept of ionization temperature seems to be validated. copyright 1998 American Institute of Physics
First status report on regional and local ground-water flow modeling for Richton Dome, Mississippi
International Nuclear Information System (INIS)
Andrews, R.W.; Metcalfe, D.E.
1984-03-01
Regional and local ground-water flow within the principal hydrogeologic units in the vicinity of Richton Dome is evaluated by developing conceptual models of the flow regime within these units at three different scales and testing these models using a three-dimensional, finite-difference flow code. Semiquantitative sensitivity analysis is conducted to define the system response to changes in the conceptual model, particularly the hydrologic properties. The effects of salinity on the flow field are evaluated at the refined and local scales. Adjoint sensitivity analysis is applied to the conceptualized flow regime in the Wilcox aquifer. All steps leading to the final results and conclusions are incorporated in this report. The available data utilized in this study is summarized. The specific conceptual models, defining the areal and vertical averaging of lithologic units, aquifer properties, fluid properties, and hydrologic boundary conditions, are described in detail. The results are delineated by the simulated potentiometric surfaces and tables summarizing areal and vertical boundary fluxes, Darcy velocities at specific points, and ground-water travel paths. These results are presented at regional, refined, and local (near-dome) scales. The reported work is the first stage of an ongoing evaluation of the Richton Dome as a potential repository for high-level radioactive wastes. The results and conclusions should thus be considered preliminary and subject to modification with the collection of additional data. However, this report does provide a useful basis for describing the sensitivity and, to a lesser extent, the uncertainty of the present conceptualization of ground-water flow in the vicinity of Richton Dome. 25 references, 69 figures, 15 tables
A hybrid plume model for local-scale dispersion
Energy Technology Data Exchange (ETDEWEB)
Nikmo, J.; Tuovinen, J.P.; Kukkonen, J.; Valkama, I.
1997-12-31
The report describes the contribution of the Finnish Meteorological Institute to the project `Dispersion from Strongly Buoyant Sources`, under the `Environment` programme of the European Union. The project addresses the atmospheric dispersion of gases and particles emitted from typical fires in warehouses and chemical stores. In the study only the `passive plume` regime, in which the influence of plume buoyancy is no longer important, is addressed. The mathematical model developed and its numerical testing is discussed. The model is based on atmospheric boundary-layer scaling theory. In the vicinity of the source, Gaussian equations are used in both the horizontal and vertical directions. After a specified transition distance, gradient transfer theory is applied in the vertical direction, while the horizontal dispersion is still assumed to be Gaussian. The dispersion parameters and eddy diffusivity are modelled in a form which facilitates the use of a meteorological pre-processor. Also a new model for the vertical eddy diffusivity (K{sub z}), which is a continuous function of height in the various atmospheric scaling regions is presented. The model includes a treatment of the dry deposition of gases and particulate matter, but wet deposition has been neglected. A numerical solver for the atmospheric diffusion equation (ADE) has been developed. The accuracy of the numerical model was analysed by comparing the model predictions with two analytical solutions of ADE. The numerical deviations of the model predictions from these analytic solutions were less than two per cent for the computational regime. The report gives numerical results for the vertical profiles of the eddy diffusivity and the dispersion parameters, and shows spatial concentration distributions in various atmospheric conditions 39 refs.
Embodying, calibrating and caring for a local model of obesity
DEFF Research Database (Denmark)
Winther, Jonas; Hillersdal, Line
Interdisciplinary research collaborations are increasingly made a mandatory 'standard' within strategic research grants. Collaborations between the natural, social and humanistic sciences are conceptualized as uniquely suited to study pressing societal problems. The obesity epidemic has been...... highlighted as such a problem. Within research communities disparate explanatory models of obesity exist (Ulijaszek 2008) and some of these models of obesity are brought together in the Copenhagen-based interdisciplinary research initiative; Governing Obesity (GO) with the aim of addressing the causes...
A Local Search Modeling for Constrained Optimum Paths Problems (Extended Abstract
Directory of Open Access Journals (Sweden)
Quang Dung Pham
2009-10-01
Full Text Available Constrained Optimum Path (COP problems appear in many real-life applications, especially on communication networks. Some of these problems have been considered and solved by specific techniques which are usually difficult to extend. In this paper, we introduce a novel local search modeling for solving some COPs by local search. The modeling features the compositionality, modularity, reuse and strengthens the benefits of Constrained-Based Local Search. We also apply the modeling to the edge-disjoint paths problem (EDP. We show that side constraints can easily be added in the model. Computational results show the significance of the approach.
Fermion local charged boson model and cuprate superconductors
International Nuclear Information System (INIS)
Sinha, K.P.; Kakani, S.L.
2002-01-01
One of the most exciting developments in Science in past few years is the discovery of high temperature superconductivity (HTSC) in cuprates. It has been observed that the superconducting state in these cuprates is rather normal compared to the anomalous normal state. This discovery has led to deluge of experimental and theoretical researches all along the world. These cuprates are close to metal-insulator transition and the stability of the insulating and metallic phase depends on the degree of doping. Measurements of physical properties of these systems have revealed many anomalous results both in the superconducting and normal states, e.g. d-wave superconducting gap, the presence of pseudo gap in the normal state, static or dynamic striped structure of CuO 2 planes etc. These have posed serious theoretical challenges towards formulating the mechanisms of pairing and explanation of anomalous behaviour. Several theoretical proposals have been advanced and only a few are likely to survive in the teeth of some reliable experimental data. A combined mechanism mediated by phonons and lochons (local charged bosons, local pairs or bipolarons) for the pairing of fermions (holes or electrons) belonging to a wide band provides a microscopic explanation of anomalous normal state properties of HTSC cuprates and vindicates features of the phenomenological marginal Fermi liquid formulation. In the present review article detailed features of combined lochon and phonon mediated pairing mechanism are presented and a contact with the normal and superconducting state properties of HTSC in YBa 2 Cu 3 O x does indicate pair hopping between planes via such resonant centres lying in between the CuO 2 planes. (author)
Central Limit Theorem for Exponentially Quasi-local Statistics of Spin Models on Cayley Graphs
Reddy, Tulasi Ram; Vadlamani, Sreekar; Yogeshwaran, D.
2018-04-01
Central limit theorems for linear statistics of lattice random fields (including spin models) are usually proven under suitable mixing conditions or quasi-associativity. Many interesting examples of spin models do not satisfy mixing conditions, and on the other hand, it does not seem easy to show central limit theorem for local statistics via quasi-associativity. In this work, we prove general central limit theorems for local statistics and exponentially quasi-local statistics of spin models on discrete Cayley graphs with polynomial growth. Further, we supplement these results by proving similar central limit theorems for random fields on discrete Cayley graphs taking values in a countable space, but under the stronger assumptions of α -mixing (for local statistics) and exponential α -mixing (for exponentially quasi-local statistics). All our central limit theorems assume a suitable variance lower bound like many others in the literature. We illustrate our general central limit theorem with specific examples of lattice spin models and statistics arising in computational topology, statistical physics and random networks. Examples of clustering spin models include quasi-associated spin models with fast decaying covariances like the off-critical Ising model, level sets of Gaussian random fields with fast decaying covariances like the massive Gaussian free field and determinantal point processes with fast decaying kernels. Examples of local statistics include intrinsic volumes, face counts, component counts of random cubical complexes while exponentially quasi-local statistics include nearest neighbour distances in spin models and Betti numbers of sub-critical random cubical complexes.
Local impact effects on concrete target due to missile: An empirical and numerical approach
International Nuclear Information System (INIS)
Ranjan, Rajiv; Banerjee, Sauvik; Singh, R.K.; Banerji, Pradipta
2014-01-01
Highlights: • Local impact effect of hard missile on reinforced concrete targets has been studied. • Review of empirical formulation for predicting local response carried out. • Numerical simulation of experimental test of Kojima (1991) carried out. • Divergence of FE results with those obtained using emperical formulations. • Close match of numerical simulation results with experimental data. - Abstract: Concrete containment walls and internal concrete barrier walls of a Nuclear Power Plant safety related structures are often required to be designed for externally and internally generated missiles. Potential missiles include external extreme wind generated missiles, aircraft crash and internal accident generated missiles such as impact due to turbine blade failure and steel pipe missiles resulting from pipe break. The objective of the present paper is to compare local missile impact effects on reinforced concrete target using available empirical formulations with those obtained using LS-DYNA numerical simulation. The use of numerical simulations for capturing the transient structural response has become increasingly used for structural design against impact loads. They overcome the limits of applicability of the empirical formulae and also provide information on stress and deformation fields, which may be used to improve the resistance of the concrete. Finite element (FE) analyses of an experimental impact problem reported by Kojima (1991) are carried out that are able to capture the missile impact effects; in terms of local and global damage. The continuous surface cap model has been used for modelling concrete behaviour. A range of missile velocity has been considered to simulate local missile impact phenomenon and modes of failure and to capture the concrete response from elastic to plastic fracture. A comparison is then made between the empirical formulations, numerical simulation results, and available experimental results of slab impact tests
Numerical modeling of local scour around hydraulic structure in sandy beds by dynamic mesh method
Fan, Fei; Liang, Bingchen; Bai, Yuchuan; Zhu, Zhixia; Zhu, Yanjun
2017-10-01
Local scour, a non-negligible factor in hydraulic engineering, endangers the safety of hydraulic structures. In this work, a numerical model for simulating local scour was constructed, based on the open source code computational fluid dynamics model OpenFOAM. We consider both the bedload and suspended load sediment transport in the scour model and adopt the dynamic mesh method to simulate the evolution of the bed elevation. We use the finite area method to project data between the three-dimensional flow model and the two-dimensional (2D) scour model. We also improved the 2D sand slide method and added it to the scour model to correct the bed bathymetry when the bed slope angle exceeds the angle of repose. Moreover, to validate our scour model, we conducted and compared the results of three experiments with those of the developed model. The validation results show that our developed model can reliably simulate local scour.
Cost-effectiveness of modern radiotherapy techniques in locally advanced pancreatic cancer.
Murphy, James D; Chang, Daniel T; Abelson, Jon; Daly, Megan E; Yeung, Heidi N; Nelson, Lorene M; Koong, Albert C
2012-02-15
Radiotherapy may improve the outcome of patients with pancreatic cancer but at an increased cost. In this study, the authors evaluated the cost-effectiveness of modern radiotherapy techniques in the treatment of locally advanced pancreatic cancer. A Markov decision-analytic model was constructed to compare the cost-effectiveness of 4 treatment regimens: gemcitabine alone, gemcitabine plus conventional radiotherapy, gemcitabine plus intensity-modulated radiotherapy (IMRT); and gemcitabine with stereotactic body radiotherapy (SBRT). Patients transitioned between the following 5 health states: stable disease, local progression, distant failure, local and distant failure, and death. Health utility tolls were assessed for radiotherapy and chemotherapy treatments and for radiation toxicity. SBRT increased life expectancy by 0.20 quality-adjusted life years (QALY) at an increased cost of $13,700 compared with gemcitabine alone (incremental cost-effectiveness ratio [ICER] = $69,500 per QALY). SBRT was more effective and less costly than conventional radiotherapy and IMRT. An analysis that excluded SBRT demonstrated that conventional radiotherapy had an ICER of $126,800 per QALY compared with gemcitabine alone, and IMRT had an ICER of $1,584,100 per QALY compared with conventional radiotherapy. A probabilistic sensitivity analysis demonstrated that the probability of cost-effectiveness at a willingness to pay of $50,000 per QALY was 78% for gemcitabine alone, 21% for SBRT, 1.4% for conventional radiotherapy, and 0.01% for IMRT. At a willingness to pay of $200,000 per QALY, the probability of cost-effectiveness was 73% for SBRT, 20% for conventional radiotherapy, 7% for gemcitabine alone, and 0.7% for IMRT. The current results indicated that IMRT in locally advanced pancreatic cancer exceeds what society considers cost-effective. In contrast, combining gemcitabine with SBRT increased clinical effectiveness beyond that of gemcitabine alone at a cost potentially acceptable by
Mild focal cerebral ischemia in the rat. The effect of local temperature on infarct size
DEFF Research Database (Denmark)
Hildebrandt-Eriksen, Elisabeth S; Christensen, Thomas; Diemer, Nils Henrik
2002-01-01
. The effect of local temperature at the occlusion site in this model was furthermore tested. Thirty-three Wistar rats were subjected to 30 min of simultaneous common carotid artery and distal middle cerebral artery occlusion or sham treatment. Animals were magnetic resonance-scanned repeatedly between day one...... and day 14 after surgery, then sacrificed, and paraffin brain sections stained. All animals scanned 24 h after reperfusion showed an area of edema in the affected cortex, which later was identified as an infarct. Animals with a temperature of 33.9 +/- 1.5 degrees C at the MCA site (hypothermic) showed...... smaller infarcts (14.4 +/- 10 mm3) than animals with normothermic local temperature (36.7 +/- 0.2 degrees C, 57.7 +/- 26.4 mm3). Infarct size was maximal on day 3 after ischemia but decreased as edema subsided. Infarct volumes from histology and magnetic resonance imaging correlated well. The model...
Yu, Jinyun; Chen, Tingjin; Xie, Zhizhi; Liang, Pei; Qu, Honglin; Shang, Mei; Mao, Qiang; Ning, Dan; Tang, Zeli; Shi, Mengchen; Zhou, Lina; Huang, Yan; Yu, Xinbing
2015-07-01
Caused by the consumption of raw or undercooked freshwater fish containing infective metacercariae of Clonorchis sinensis, human clonorchiasis remains a major public health problem in China. In previous study, we had expressed enolase from C. sinensis (CsENO) on the surface of Bacillus subtilis spore and the recombinant spore induced a pronounced protection in terms of reduced worm burden and eggs per gram feces, suggesting B. subtilis spore as an ideal vehicle for antigen delivery by oral treatment and CsENO as a promising vaccine candidate against clonorchiasis. In the current study, we detected CsENO-specific IgG and IgA levels both in serum and in intestinal mucus from rats orally administrated with B. subtilis spore surface expressing CsENO by ELISA. Lysozyme levels in serum and in intestinal mucus were analyzed too. In addition, IgA-secreting cells in intestine epithelium of the rats were detected by immunohistochemistry assay. The intestinal villi lengths of duodenum, jejunum, and ileum were also measured. Rats orally treated with B. subtilis spore or normal saline were used as controls. Our results showed that, compared with the control groups, oral administration of B. subtilis spore expressing CsENO induced both systemic and local mucosal immune response. The recombinant spores also enhanced non-specific immune response in rats. The spores had no side effect on liver function. Moreover, it might facilitate food utilization and digestion of the rats. Our work will pave the way to clarify the involved mechanisms of protective efficacy elicited by B. subtilis spore expressing CsENO and encourage us to carry out more assessment trails of the oral treated spore to develop vaccine against clonorchiasis.
International Nuclear Information System (INIS)
Sawada, Y.; Sugiyama, Y.; Iga, T.; Hanano, M.
1987-01-01
Tracer distribution kinetics in the determination of local cerebral blood flow (LCBF) were examined by using three models, i.e., venous equilibrium, tube, and distributed models. The technique most commonly used for measuring LCBF is the tissue uptake method, which was first developed and applied by Kety. The measurement of LCBF with the 14 C-iodoantipyrine (IAP) method is calculated by using an equation derived by Kety based on the Fick's principle and a two-compartment model of blood-tissue exchange and tissue concentration at a single data point. The procedure, in which the tissue is to be in equilibrium with venous blood, will be referred to as the tissue equilibration model. In this article, effects of the concentration gradient of tracer along the length of the capillary (tube model) and the transverse heterogeneity in the capillary transit time (distributed model) on the determination of LCBF were theoretically analyzed for the tissue sampling method. Similarities and differences among these models are explored. The rank order of the LCBF calculated by using arterial blood concentration time courses and the tissue concentration of tracer based on each model were tube model (model II) less than distributed model (model III) less than venous equilibrium model (model I). Data on 14 C-IAP kinetics reported by Ohno et al. were employed. The LCBFs calculated based on model I were 45-260% larger than those in models II or III. To discriminate among three models, we propose to examine the effect of altering the venous infusion time of tracer on the apparent tissue-to-blood concentration ratio (lambda app). A range of the ratio of the predicted lambda app in models II or III to that in model I was from 0.6 to 1.3
Global effects of local food-production crises: a virtual water perspective.
Tamea, Stefania; Laio, Francesco; Ridolfi, Luca
2016-01-25
By importing food and agricultural goods, countries cope with the heterogeneous global water distribution and often rely on water resources available abroad. The virtual displacement of the water used to produce such goods (known as virtual water) connects together, in a global water system, all countries participating to the international trade network. Local food-production crises, having social, economic or environmental origin, propagate in this network, modifying the virtual water trade and perturbing local and global food availability, quantified in terms of virtual water. We analyze here the possible effects of local crises by developing a new propagation model, parsimonious but grounded on data-based and statistically-verified assumptions, whose effectiveness is proved on the Argentinean crisis in 2008-09. The model serves as the basis to propose indicators of crisis impact and country vulnerability to external food-production crises, which highlight that countries with largest water resources have the highest impact on the international trade, and that not only water-scarce but also wealthy and globalized countries are among the most vulnerable to external crises. The temporal analysis reveals that global average vulnerability has increased over time and that stronger effects of crises are now found in countries with low food (and water) availability.
Interagency Modeling Atmospheric Assessment Center Local Jurisdiction: IMAAC Operations Framework
2010-03-01
proposed model ( Daft & Lengel, 1986). All six Ohio LINC Cities were interviewed face- to-face providing the basis for the research evaluating...Cincinnati, DHS should work in partnership with Cincinnati Urban Area Leadership to convene a randomly selected, but statistically-significant, UASI...response system. Internal document. Daft , R. L. & Lengel, R. H. (1986). Organizational Information Requirements, Media Richness and Structural
Acting Locally: A Guide to Model, Community and Demonstration Forests.
Keen, Debbie Pella
1993-01-01
Describes Canada's efforts in sustainable forestry, which refers to management practices that ensure long-term health of forest ecosystems so that they can continue to provide environmental, social, and economic benefits. Describes model forests, community forests, and demonstration forests and lists contacts for each of the projects. (KS)
A ductile fracture analysis using a local damage model
Energy Technology Data Exchange (ETDEWEB)
Benseddiq, N. [Laboratoire de Mecanique et de Rheologie de Tours, Ecole Nationale d' Ingenieurs du Val de Loire (ENIVL), Rue de la Chocolaterie, 41000 Blois Cedex (France)], E-mail: nbensedd@polytech-lille.fr; Imad, A. [Laboratoire de Mecanique de Lille (UMR CNRS 8107), USTL, Ecole Polytechnique Universitaire de Lille Cite Scientifique, Avenue P. Langevin, 59655 Villeneuve d' Ascq Cedex (France)
2008-04-15
In this study, the Gurson-Tvergaard-Needleman (GTN) model is used to investigate ductile tearing. The sensitivity of the model parameters has been examined from literature data. Three types of parameters have been reported: the 'constitutive parameters'q{sub 1}, q{sub 2} and q{sub 3}, the 'initial material and nucleation parameters' and the 'critical and final failure parameters'. Each parameter in this model has been analysed in terms of various results in the literature. Both experimental and numerical results have been obtained for notched round and CT specimens to characterize ductile failure in a NiCr steel (12NC6) with a small initial void volume fraction f{sub 0} (f{sub 0}=0.001%). Ductile crack growth, defined by the J-{delta}a curve, has been correctly simulated using the numerical calculations by adjusting the different parameters of the GTN model in the calibration procedure.
Primary assembly of soil communities: disentangling the effect of dispersal and local environment.
Ingimarsdóttir, María; Caruso, Tancredi; Ripa, Jörgen; Magnúsdóttir, Olöf Birna; Migliorini, Massimo; Hedlund, Katarina
2012-11-01
It has long been recognised that dispersal abilities and environmental factors are important in shaping invertebrate communities, but their relative importance for primary soil community assembly has not yet been disentangled. By studying soil communities along chronosequences on four recently emerged nunataks (ice-free land in glacial areas) in Iceland, we replicated environmental conditions spatially at various geographical distances. This allowed us to determine the underlying factors of primary community assembly with the help of metacommunity theories that predict different levels of dispersal constraints and effects of the local environment. Comparing community assembly of the nunataks with that of non-isolated deglaciated areas indicated that isolation of a few kilometres did not affect the colonisation of the soil invertebrates. When accounting for effects of geographical distances, soil age and plant richness explained a significant part of the variance observed in the distribution of the oribatid mites and collembola communities, respectively. Furthermore, null model analyses revealed less co-occurrence than expected by chance and also convergence in the body size ratio of co-occurring oribatids, which is consistent with species sorting. Geographical distances influenced species composition, indicating that the community is also assembled by dispersal, e.g. mass effect. When all the results are linked together, they demonstrate that local environmental factors are important in structuring the soil community assembly, but are accompanied with effects of dispersal that may "override" the visible effect of the local environment.
Zavodsky, Bradley; Case, Jonathan L.; Gotway, John H.; White, Kristopher; Medlin, Jeffrey; Wood, Lance; Radell, Dave
2014-01-01
Local modeling with a customized configuration is conducted at National Weather Service (NWS) Weather Forecast Offices (WFOs) to produce high-resolution numerical forecasts that can better simulate local weather phenomena and complement larger scale global and regional models. The advent of the Environmental Modeling System (EMS), which provides a pre-compiled version of the Weather Research and Forecasting (WRF) model and wrapper Perl scripts, has enabled forecasters to easily configure and execute the WRF model on local workstations. NWS WFOs often use EMS output to help in forecasting highly localized, mesoscale features such as convective initiation, the timing and inland extent of lake effect snow bands, lake and sea breezes, and topographically-modified winds. However, quantitatively evaluating model performance to determine errors and biases still proves to be one of the challenges in running a local model. Developed at the National Center for Atmospheric Research (NCAR), the Model Evaluation Tools (MET) verification software makes performing these types of quantitative analyses easier, but operational forecasters do not generally have time to familiarize themselves with navigating the sometimes complex configurations associated with the MET tools. To assist forecasters in running a subset of MET programs and capabilities, the Short-term Prediction Research and Transition (SPoRT) Center has developed and transitioned a set of dynamic, easily configurable Perl scripts to collaborating NWS WFOs. The objective of these scripts is to provide SPoRT collaborating partners in the NWS with the ability to evaluate the skill of their local EMS model runs in near real time with little prior knowledge of the MET package. The ultimate goal is to make these verification scripts available to the broader NWS community in a future version of the EMS software. This paper provides an overview of the SPoRT MET scripts, instructions for how the scripts are run, and example use
Suardana, I. Nyoman; Redhana, I. Wayan; Sudiatmika, A. A. Istri Agung Rai; Selamat, I. Nyoman
2018-01-01
This research aimed at describing the effectiveness of the local culture-based 7E learning cycle model in improving students' critical thinking skills in chemistry learning. It was an experimental research with post-test only control group design. The population was the eleventh-grade students of senior high schools in Singaraja, Indonesia. The…
Unstable spiral waves and local Euclidean symmetry in a model of cardiac tissue
International Nuclear Information System (INIS)
Marcotte, Christopher D.; Grigoriev, Roman O.
2015-01-01
This paper investigates the properties of unstable single-spiral wave solutions arising in the Karma model of two-dimensional cardiac tissue. In particular, we discuss how such solutions can be computed numerically on domains of arbitrary shape and study how their stability, rotational frequency, and spatial drift depend on the size of the domain as well as the position of the spiral core with respect to the boundaries. We also discuss how the breaking of local Euclidean symmetry due to finite size effects as well as the spatial discretization of the model is reflected in the structure and dynamics of spiral waves. This analysis allows identification of a self-sustaining process responsible for maintaining the state of spiral chaos featuring multiple interacting spirals
Unstable spiral waves and local Euclidean symmetry in a model of cardiac tissue.
Marcotte, Christopher D; Grigoriev, Roman O
2015-06-01
This paper investigates the properties of unstable single-spiral wave solutions arising in the Karma model of two-dimensional cardiac tissue. In particular, we discuss how such solutions can be computed numerically on domains of arbitrary shape and study how their stability, rotational frequency, and spatial drift depend on the size of the domain as well as the position of the spiral core with respect to the boundaries. We also discuss how the breaking of local Euclidean symmetry due to finite size effects as well as the spatial discretization of the model is reflected in the structure and dynamics of spiral waves. This analysis allows identification of a self-sustaining process responsible for maintaining the state of spiral chaos featuring multiple interacting spirals.
van der Ent, R.; Van Beek, R.; Sutanudjaja, E.; Wang-Erlandsson, L.; Hessels, T.; Bastiaanssen, W.; Bierkens, M. F.
2017-12-01
The storage and dynamics of water in the root zone control many important hydrological processes such as saturation excess overland flow, interflow, recharge, capillary rise, soil evaporation and transpiration. These processes are parameterized in hydrological models or land-surface schemes and the effect on runoff prediction can be large. Root zone parameters in global hydrological models are very uncertain as they cannot be measured directly at the scale on which these models operate. In this paper we calibrate the global hydrological model PCR-GLOBWB using a state-of-the-art ensemble of evaporation fields derived by solving the energy balance for satellite observations. We focus our calibration on the root zone parameters of PCR-GLOBWB and derive spatial patterns of maximum root zone storage. We find these patterns to correspond well with previous research. The parameterization of our model allows for the conversion of maximum root zone storage to root zone depth and we find that these correspond quite well to the point observations where available. We conclude that climate and soil type should be taken into account when regionalizing measured root depth for a certain vegetation type. We equally find that using evaporation rather than discharge better allows for local adjustment of root zone parameters within a basin and thus provides orthogonal data to diagnose and optimize hydrological models and land surface schemes.
Hybrid Scheme for Modeling Local Field Potentials from Point-Neuron Networks.
Hagen, Espen; Dahmen, David; Stavrinou, Maria L; Lindén, Henrik; Tetzlaff, Tom; van Albada, Sacha J; Grün, Sonja; Diesmann, Markus; Einevoll, Gaute T
2016-12-01
With rapidly advancing multi-electrode recording technology, the local field potential (LFP) has again become a popular measure of neuronal activity in both research and clinical applications. Proper understanding of the LFP requires detailed mathematical modeling incorporating the anatomical and electrophysiological features of neurons near the recording electrode, as well as synaptic inputs from the entire network. Here we propose a hybrid modeling scheme combining efficient point-neuron network models with biophysical principles underlying LFP generation by real neurons. The LFP predictions rely on populations of network-equivalent multicompartment neuron models with layer-specific synaptic connectivity, can be used with an arbitrary number of point-neuron network populations, and allows for a full separation of simulated network dynamics and LFPs. We apply the scheme to a full-scale cortical network model for a ∼1 mm 2 patch of primary visual cortex, predict laminar LFPs for different network states, assess the relative LFP contribution from different laminar populations, and investigate effects of input correlations and neuron density on the LFP. The generic nature of the hybrid scheme and its public implementation in hybridLFPy form the basis for LFP predictions from other and larger point-neuron network models, as well as extensions of the current application with additional biological detail. © The Author 2016. Published by Oxford University Press.
CMB anomalies and the effects of local features of the inflaton potential
Energy Technology Data Exchange (ETDEWEB)
Cadavid, Alexander Gallego [Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); ICRANet, Pescara (Italy); Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia); Romano, Antonio Enea [Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); University of Torino, Department of Physics, Turin (Italy); Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia); Gariazzo, Stefano [University of Torino, Department of Physics, Turin (Italy); INFN, Sezione di Torino, Turin (Italy); Instituto de Fisica Corpuscular (CSIC-Universitat de Valencia), Paterna, Valencia (Spain)
2017-04-15
Recent analysis of the WMAP and Planck data have shown the presence of a dip and a bump in the spectrum of primordial perturbations at the scales k = 0.002 Mpc{sup -1}, respectively. We analyze for the first time the effects of a local feature in the inflaton potential to explain the observed deviations from scale invariance in the primordial spectrum. We perform a best-fit analysis of the cosmic microwave background (CMB) radiation temperature and polarization data. The effects of the features can improve the agreement with observational data respect to the featureless model. The best-fit local feature affects the primordial curvature spectrum mainly in the region of the bump, leaving the spectrum unaffected on other scales. (orig.)
Alfano-Sobsey, Edie; Kennedy, Bobby; Beck, Frank; Combs, Brian; Kady, Wendy; Ramsey, Steven; Stockweather, Allison; Service, Will
2006-04-01
Respiratory-protection programs have had limited application in local health departments and have mostly focused on protecting employees against exposure to tuberculosis (TB). The need to provide the public health workforce with effective respiratory protection has, however, been underscored by recent concerns about emerging infectious diseases, bioterrorism attacks, drug-resistant microbes, and environmental exposures to microbial allergens (as in recent hurricane flood waters). Furthermore, OSHA has revoked the TB standard traditionally followed by local health departments, replacing it with a more stringent regulation. The additional OSHA requirements may place increased burdens on health departments with limited resources and time. For these reasons, the North Carolina Office of Public Health Preparedness and Response and industrial hygienists of the Public Health Regional Surveillance Teams have developed a training program to facilitate implementation of respiratory protection programs at local health departments. To date, more than 1,400 North Carolina health department employees have been properly fit-tested for respirator use and have received training in all aspects of respiratory protection. This article gives an overview of the development and evaluation of the program. The training approach presented here can serve as a model that other health departments and organizations can use in implementing similar respiratory-protection programs.
RIPH: A Model for Representing the Reality in the Global and Local Television
Directory of Open Access Journals (Sweden)
Saket Hosseynov
2013-03-01
Full Text Available The world is witnessing great changes, and these changes are comprehensible in the realm of performance of "identity", "boundary", "geographic concept” (place and "time". Identities are now segmented, boundaries passed over, and places and time compressed. Television is one of the effective factors in making this happen. However, it seems like television, which itself is one of the evidences of globalization, has now acquired new characteristics. With a little care while reading texts related to globalization and media, we realize the four words "reality", "identity", "power" and "hyper-reality" are constantly repeated in these texts, and very few people doubt the close relationship between television and these topics. Facing such a situation, and to understand the characteristics of the global television, this article plans to start on the basis of a theoretic called "RIPH Model". Based on the presumption that the role and place of television in forming the cultural shapes must not be exaggerated, it tries to present an outlook of the activities of the local and global televisions in the age of globalization and share the outcomes with 20 Iranian experts through interviews. RIPH is the short form which stands for the four words "reality", "identity", "power" and "hyper-reality". These are the concepts with new definitions that have changed our views about life on the Planet Earth, and this article studies the factors related to global and local televisions in the frame of an innovative model suggested by the researcher called "The Lozenge of the Performance of the Global and Local Televisions (RIPH Model", by investigating the relations between television and the above-mentioned concepts.
Gaudart, Jean; Touré, Ousmane; Dessay, Nadine; Dicko, A Lassane; Ranque, Stéphane; Forest, Loic; Demongeot, Jacques; Doumbo, Ogobara K
2009-04-10
The risk of Plasmodium falciparum infection is variable over space and time and this variability is related to environmental variability. Environmental factors affect the biological cycle of both vector and parasite. Despite this strong relationship, environmental effects have rarely been included in malaria transmission models.Remote sensing data on environment were incorporated into a temporal model of the transmission, to forecast the evolution of malaria epidemiology, in a locality of Sudanese savannah area. A dynamic cohort was constituted in June 1996 and followed up until June 2001 in the locality of Bancoumana, Mali. The 15-day composite vegetation index (NDVI), issued from satellite imagery series (NOAA) from July 1981 to December 2006, was used as remote sensing data.The statistical relationship between NDVI and incidence of P. falciparum infection was assessed by ARIMA analysis. ROC analysis provided an NDVI value for the prediction of an increase in incidence of parasitaemia.Malaria transmission was modelled using an SIRS-type model, adapted to Bancoumana's data. Environmental factors influenced vector mortality and aggressiveness, as well as length of the gonotrophic cycle. NDVI observations from 1981 to 2001 were used for the simulation of the extrinsic variable of a hidden Markov chain model. Observations from 2002 to 2006 served as external validation. The seasonal pattern of P. falciparum incidence was significantly explained by NDVI, with a delay of 15 days (p = 0.001). An NDVI threshold of 0.361 (p = 0.007) provided a Diagnostic Odd Ratio (DOR) of 2.64 (CI95% [1.26;5.52]).The deterministic transmission model, with stochastic environmental factor, predicted an endemo-epidemic pattern of malaria infection. The incidences of parasitaemia were adequately modelled, using the observed NDVI as well as the NDVI simulations. Transmission pattern have been modelled and observed values were adequately predicted. The error parameters have shown the smallest
Directory of Open Access Journals (Sweden)
Demongeot Jacques
2009-04-01
Full Text Available Abstract Background The risk of Plasmodium falciparum infection is variable over space and time and this variability is related to environmental variability. Environmental factors affect the biological cycle of both vector and parasite. Despite this strong relationship, environmental effects have rarely been included in malaria transmission models. Remote sensing data on environment were incorporated into a temporal model of the transmission, to forecast the evolution of malaria epidemiology, in a locality of Sudanese savannah area. Methods A dynamic cohort was constituted in June 1996 and followed up until June 2001 in the locality of Bancoumana, Mali. The 15-day composite vegetation index (NDVI, issued from satellite imagery series (NOAA from July 1981 to December 2006, was used as remote sensing data. The statistical relationship between NDVI and incidence of P. falciparum infection was assessed by ARIMA analysis. ROC analysis provided an NDVI value for the prediction of an increase in incidence of parasitaemia. Malaria transmission was modelled using an SIRS-type model, adapted to Bancoumana's data. Environmental factors influenced vector mortality and aggressiveness, as well as length of the gonotrophic cycle. NDVI observations from 1981 to 2001 were used for the simulation of the extrinsic variable of a hidden Markov chain model. Observations from 2002 to 2006 served as external validation. Results The seasonal pattern of P. falciparum incidence was significantly explained by NDVI, with a delay of 15 days (p = 0.001. An NDVI threshold of 0.361 (p = 0.007 provided a Diagnostic Odd Ratio (DOR of 2.64 (CI95% [1.26;5.52]. The deterministic transmission model, with stochastic environmental factor, predicted an endemo-epidemic pattern of malaria infection. The incidences of parasitaemia were adequately modelled, using the observed NDVI as well as the NDVI simulations. Transmission pattern have been modelled and observed values were adequately
Gaudart, Jean; Touré, Ousmane; Dessay, Nadine; Dicko, A lassane; Ranque, Stéphane; Forest, Loic; Demongeot, Jacques; Doumbo, Ogobara K
2009-01-01
Background The risk of Plasmodium falciparum infection is variable over space and time and this variability is related to environmental variability. Environmental factors affect the biological cycle of both vector and parasite. Despite this strong relationship, environmental effects have rarely been included in malaria transmission models. Remote sensing data on environment were incorporated into a temporal model of the transmission, to forecast the evolution of malaria epidemiology, in a locality of Sudanese savannah area. Methods A dynamic cohort was constituted in June 1996 and followed up until June 2001 in the locality of Bancoumana, Mali. The 15-day composite vegetation index (NDVI), issued from satellite imagery series (NOAA) from July 1981 to December 2006, was used as remote sensing data. The statistical relationship between NDVI and incidence of P. falciparum infection was assessed by ARIMA analysis. ROC analysis provided an NDVI value for the prediction of an increase in incidence of parasitaemia. Malaria transmission was modelled using an SIRS-type model, adapted to Bancoumana's data. Environmental factors influenced vector mortality and aggressiveness, as well as length of the gonotrophic cycle. NDVI observations from 1981 to 2001 were used for the simulation of the extrinsic variable of a hidden Markov chain model. Observations from 2002 to 2006 served as external validation. Results The seasonal pattern of P. falciparum incidence was significantly explained by NDVI, with a delay of 15 days (p = 0.001). An NDVI threshold of 0.361 (p = 0.007) provided a Diagnostic Odd Ratio (DOR) of 2.64 (CI95% [1.26;5.52]). The deterministic transmission model, with stochastic environmental factor, predicted an endemo-epidemic pattern of malaria infection. The incidences of parasitaemia were adequately modelled, using the observed NDVI as well as the NDVI simulations. Transmission pattern have been modelled and observed values were adequately predicted. The error
Scale Factor Study for 1:30 Local Scour Model
2016-08-01
establishes the worst- case scour depth for the current bridge configuration and the proposed pier nose extension. INTRODUCTION : Extensive research has been...used in the general physical model. A flat test section, approximately 32 ft long and 34–45 ft wide, was molded to a uniform elevation . Stilling...discharge calculation from the flow uniformity checks. The water surface elevation was controlled with the adjustable lift gate at the downstream
A conformal invariant model of localized spinning test particles
International Nuclear Information System (INIS)
Duval, C.; Centre National de la Recherche Scientifique, 13 - Marseille; Fliche, H.H.; Centre National de la Recherche Scientifique, 13 - Marseille
1977-02-01
A purely classical model of massless test particle with spin s is introduced as the dynamical system defined by the 10 dimensional 0(4,2) co-adjoint orbit with Casimir numbers (s 2 ,0,0). The Mathisson Papapetrou et al. equations of motion in a gravitational field are recovered, and moreover the particle appears to travel on null geodesics. Several implications are discussed
Rajabioun, Mehdi; Nasrabadi, Ali Motie; Shamsollahi, Mohammad Bagher
2017-09-01
Effective connectivity is one of the most important considerations in brain functional mapping via EEG. It demonstrates the effects of a particular active brain region on others. In this paper, a new method is proposed which is based on dual Kalman filter. In this method, firstly by using a brain active localization method (standardized low resolution brain electromagnetic tomography) and applying it to EEG signal, active regions are extracted, and appropriate time model (multivariate autoregressive model) is fitted to extracted brain active sources for evaluating the activity and time dependence between sources. Then, dual Kalman filter is used to estimate model parameters or effective connectivity between active regions. The advantage of this method is the estimation of different brain parts activity simultaneously with the calculation of effective connectivity between active regions. By combining dual Kalman filter with brain source localization methods, in addition to the connectivity estimation between parts, source activity is updated during the time. The proposed method performance has been evaluated firstly by applying it to simulated EEG signals with interacting connectivity simulation between active parts. Noisy simulated signals with different signal to noise ratios are used for evaluating method sensitivity to noise and comparing proposed method performance with other methods. Then the method is applied to real signals and the estimation error during a sweeping window is calculated. By comparing proposed method results in different simulation (simulated and real signals), proposed method gives acceptable results with least mean square error in noisy or real conditions.
Local stem cell depletion model for radiation myelitis
International Nuclear Information System (INIS)
Yaes, R.J.; Kalend, A.
1988-01-01
We propose a model for normal tissue damage based on the assumption that adult mammalian stem cells have limited mobility and, consequently, for each organ, there is a maximum volume (the critical volume, Vc), that can be repopulated and repaired by a single surviving stem cell. This concept is applied to a simple, 1-dimensional model of the spinal cord, where the critical volume is a slice of thickness, t, assumed to be small compared to lengths of spinal cord usually irradiated clinically. The probability of myelitis is explicitly obtained as a function of the dose, dose per fraction, length of cord irradiated, slice thickness, number of stem cells per slice and parameters alpha and beta of the stem cell survival curve. The complication probability is expressed as a triple negative exponential function of dose analogous to the double negative exponential function for tumor control, resulting in a steep dose-response curve with short tails in both the high dose and low dose regions. We show that the model predictions are compatible with the experimental data for radiation myelitis in the rat. We discuss how this concept can be applied to other organs such as skin and to organs composed of structurally and functionally distinct subunits, such as the kidney
NASA SPoRT Initialization Datasets for Local Model Runs in the Environmental Modeling System
Case, Jonathan L.; LaFontaine, Frank J.; Molthan, Andrew L.; Carcione, Brian; Wood, Lance; Maloney, Joseph; Estupinan, Jeral; Medlin, Jeffrey M.; Blottman, Peter; Rozumalski, Robert A.
2011-01-01
The NASA Short-term Prediction Research and Transition (SPoRT) Center has developed several products for its National Weather Service (NWS) partners that can be used to initialize local model runs within the Weather Research and Forecasting (WRF) Environmental Modeling System (EMS). These real-time datasets consist of surface-based information updated at least once per day, and produced in a composite or gridded product that is easily incorporated into the WRF EMS. The primary goal for making these NASA datasets available to the WRF EMS community is to provide timely and high-quality information at a spatial resolution comparable to that used in the local model configurations (i.e., convection-allowing scales). The current suite of SPoRT products supported in the WRF EMS include a Sea Surface Temperature (SST) composite, a Great Lakes sea-ice extent, a Greenness Vegetation Fraction (GVF) composite, and Land Information System (LIS) gridded output. The SPoRT SST composite is a blend of primarily the Moderate Resolution Imaging Spectroradiometer (MODIS) infrared and Advanced Microwave Scanning Radiometer for Earth Observing System data for non-precipitation coverage over the oceans at 2-km resolution. The composite includes a special lake surface temperature analysis over the Great Lakes using contributions from the Remote Sensing Systems temperature data. The Great Lakes Environmental Research Laboratory Ice Percentage product is used to create a sea-ice mask in the SPoRT SST composite. The sea-ice mask is produced daily (in-season) at 1.8-km resolution and identifies ice percentage from 0 100% in 10% increments, with values above 90% flagged as ice.
Local Stability Conditions for Two Types of Monetary Models with Recursive Utility
Miyazaki, Kenji; Utsunomiya, Hitoshi
2009-01-01
This paper explores local stability conditions for money-in-utility-function (MIUF) and transaction-costs (TC) models with recursive utility.A monetary variant of the Brock-Gale condition provides a theoretical justification of the comparative statics analysis. One of sufficient conditions for local stability is increasing marginal impatience (IMI) in consumption and money. However, this does not deny the possibility of decreasing marginal impatience (DMI). The local stability with DMI is mor...
Local and global dynamical effects of dark energy
Chernin, A. D.
Local expansion flows of galaxies were discovered by Lemaitre and Hubble in 1927-29 at distances of less than 25-30 Mpc. The global expansion of the Universe as a whole was predicted theoretically by Friedmann in 1922-24 and discovered in the 1990s in observations at truly cosmological distances of more than 1 000 Mpc. On all these spatial scales, the flows follow a (nearly) linear velocity-distance relation, known now as Hubble's law. This similarity of local and global phenomena is due to the universal dark energy antigravity which dominates the cosmic dynamics on both local and global spatial scales.
The effect of urban design parameters on the local microclimate
Energy Technology Data Exchange (ETDEWEB)
Kakoniti, Androula; Georgiou, Gregoria; Neophytou, Marina [Department of Civil and Environmental Engineering, University of Cyprus, 1678 Nicosia (Cyprus); Marakkos, Konstantinos [Department of Aerospace Engineering, University of Manchester, M60 1QD, Manchester (United Kingdom)
2015-01-22
Two-dimensional steady-state simulations have been performed using the standard k-e turbulence model coupled with the heat transfer models available in the CFD software FLUENT 6.1, in order to examine the impact of radiation on the Urban Heat Island phenomenon. Specifically, the impact of radiation in three typical urban areas of Cyprus during the summer period is examined. The first geometry considered represents a typical suburban area and is termed as the reference geometry. The second geometry represents an area at the centre of a town with higher buildings and relatively narrower roads. The third geometry, on the other hand, describes a suburban area with wider roads and larger houses than the reference model. Computed values for air temperature in the urban street canyon have indicated that the increase in temperature associated with radiative heat transfer can be reduced by optimising the canyon geometry and, ultimately, help to mitigate the human thermal discomfort. The present study has also revealed that the selection of construction materials can be optimised to offer further reductions in the air temperature of the urban environment. It can be concluded that the combined effect of these remedies can lead to reductions in the energy consumption for building air-conditioning over the summer period.
Energy Technology Data Exchange (ETDEWEB)
Heroux, Michael Allen; Teranishi, Keita
2014-06-01
Recovery from process loss during the execution of a distributed memory parallel application is presently achieved by restarting the program, typically from a checkpoint file. Future computer system trends indicate that the size of data to checkpoint, the lack of improvement in parallel file system performance and the increase in process failure rates will lead to situations where checkpoint restart becomes infeasible. In this report we describe and prototype the use of a new application level resilient computing model that manages persistent storage of local state for each process such that, if a process fails, recovery can be performed locally without requiring access to a global checkpoint file. LFLR provides application developers with an ability to recover locally and continue application execution when a process is lost. This report discusses what features are required from the hardware, OS and runtime layers, and what approaches application developers might use in the design of future codes, including a demonstration of LFLR-enabled MiniFE code from the Matenvo mini-application suite.
A supersymmetric standard model from a local E6 GUT
International Nuclear Information System (INIS)
Braam, Felix Klaus
2012-02-01
In this thesis we have investigated to what extent the exceptional Lie-group E 6 can serve as unified gauge group. In the presence of the full E 6 matter content, unifcation can be realized by increasing the degree of gauge symmetry above some intermediate scale. We found that a full E 6 gauge invariant theory is disfavoured by phenomenological observations like proton stability and the smallness of flavour changing neutral currents. An appropriate framework to embed E 6 into a model for particle physics are higher dimensional orbifold constructions, where E 6 is the gauge group in the bulk and the intermediate symmetry group is the common subset of E 6 subgroups residing at the fixed-points of the orbifold. In this way the degree of symmetry in four space-time dimensions is reduced, such that the operators leading to the aforementioned dsastrous phenomenological consequences can be forbidden independently. In order to derive the implications of the model for the current experiments at the Large Hadron Collider (LHC), we developed an automated spectrum generator. It uses Monte-Carlo Markov-Chain techniques to cope with the high dimensionality of the space of input parameters and the complex interdependencies in the evolution of the Lagrangian parameters from the orbifold compactification scale to the TeV scale. For the spectra obtained with this program, we performed Monte-Carlo simulations of the production and decay of the Z ' boson stemming from the additional U(1) ' , using our own implementation of the model into the event generator WHIZARD.
Local Recurrence in Rectal Cancer: Anatomic Localization and Effect on Radiation Target
International Nuclear Information System (INIS)
Syk, Erik; Torkzad, Michael R.; Blomqvist, Lennart; Nilsson, Per J.; Glimelius, Bengt
2008-01-01
Purpose: To determine the sites of local recurrence after total mesorectal excision for rectal cancer in an effort to optimize the radiation target. Methods and Materials: A total of 155 patients with recurrence after abdominal resection for rectal cancer were identified from a population-based consecutive cohort of 2,315 patients who had undergone surgery by surgeons trained in the total mesorectal excision procedure. A total of 99 cross-sectional imaging studies were retrieved and re-examined by one radiologist. The clinical records were examined for the remaining patients. Results: Evidence of residual mesorectal fat was identified in 50 of the 99 patients. In 83 patients, local recurrence was identified on the imaging studies. All recurrences were within the irradiated volume if the patients had undergone preoperative radiotherapy or within the same volume if they had not. The site of recurrence was in the lower 75% of the pelvis, anatomically below the S1-S2 interspace for all patients. Only 5 of the 44 recurrences in patients with primary tumors >5 cm from the anal verge were in the lowest 20% of the pelvis. Six recurrences involved the lateral lymph nodes. Conclusion: These data suggest that a lowering of the upper limit of the clinical target volume could be introduced. The anal sphincter complex with surrounding tissue could also be excluded in patients with primary tumors >5 cm from the anal verge
Directory of Open Access Journals (Sweden)
Chang-bae Moon
2011-01-01
Full Text Available Although there have been many researches on mobile robot localization, it is still difficult to obtain reliable localization performance in a human co-existing real environment. Reliability of localization is highly dependent upon developer's experiences because uncertainty is caused by a variety of reasons. We have developed a range sensor based integrated localization scheme for various indoor service robots. Through the experience, we found out that there are several significant experimental issues. In this paper, we provide useful solutions for following questions which are frequently faced with in practical applications: 1 How to design an observation likelihood model? 2 How to detect the localization failure? 3 How to recover from the localization failure? We present design guidelines of observation likelihood model. Localization failure detection and recovery schemes are presented by focusing on abrupt wheel slippage. Experiments were carried out in a typical office building environment. The proposed scheme to identify the localizer status is useful in practical environments. Moreover, the semi-global localization is a computationally efficient recovery scheme from localization failure. The results of experiments and analysis clearly present the usefulness of proposed solutions.
Directory of Open Access Journals (Sweden)
Chang-bae Moon
2010-12-01
Full Text Available Although there have been many researches on mobile robot localization, it is still difficult to obtain reliable localization performance in a human co-existing real environment. Reliability of localization is highly dependent upon developer's experiences because uncertainty is caused by a variety of reasons. We have developed a range sensor based integrated localization scheme for various indoor service robots. Through the experience, we found out that there are several significant experimental issues. In this paper, we provide useful solutions for following questions which are frequently faced with in practical applications: 1 How to design an observation likelihood model? 2 How to detect the localization failure? 3 How to recover from the localization failure? We present design guidelines of observation likelihood model. Localization failure detection and recovery schemes are presented by focusing on abrupt wheel slippage. Experiments were carried out in a typical office building environment. The proposed scheme to identify the localizer status is useful in practical environments. Moreover, the semi-global localization is a computationally efficient recovery scheme from localization failure. The results of experiments and analysis clearly present the usefulness of proposed solutions.
Local Balancing System from the Business Model Canvas Perspective
Directory of Open Access Journals (Sweden)
Matusiak Bożena Ewa
2016-01-01
Full Text Available The paper presents an overall view of the business model (BM for the e-balance system for: balancing energy production and consumption in energy efficient, smart neighbourhoods (the e-balance project, FP7-SMARTCITIES-2013 along with its functionalities, based upon the Osterwalder’s canvas methodology. Additionally, this is the second, after two years of work, more incisive evaluation of the BM from the user’s and demo site’s perspective (Bronsbergen, the Netherlands. The aim of this paper is to present results and assess the above mentioned BM in the face its commercialisation and applicability to Europe.
Model analysis of local oxygen delivery with liposome-encapsulated hemoglobin.
Matsumoto, Takeshi; Mano, Katsuhiko; Ueha, Ryohei; Naito, Hisashi; Tanaka, Masao
2009-03-01
Liposome-encapsulated hemoglobins (LHs) are comparable to red blood cells (RBCs) in terms of oxygen (O(2))-carrying capacity. The smaller particle size of LHs than of platelets allows their homogeneous dispersion in circulating plasma. In this study, we evaluated the effect of LH transfusion on arterial O(2) delivery through vascular trees by simulation. A mathematical model was established on the basis of the coronary arterial anatomy, the conservation of flow and RBC flux, and Poiseuille's law. The Fåhraeus-Lindqvist, Fåhraeus, and phase separation effects were considered in the model. By assuming steady perfusion, the arterial flow and O(2) delivery were calculated for five model trees undergoing the isovolumic replacement of RBCs (0.3 mg hemoglobin (Hb)/mL) with LHs (0.2 mg Hb/mL) or a plasma volume expander (PVE). The RBC-LH exchange increased both the total flow and the total O(2) flux but had almost no effect on the relative distribution of O(2) flux. In contrast, the RBC-PVE exchange decreased the total O(2) flux and increased the proportion of regions receiving a relatively low O(2) supply. Thus, LH transfusion may compensate for an enhanced bias in RBC-associated O(2) flux under hemodilution and is expected to be beneficial for both total and local O(2) delivery.
Power Balance Modeling of Local Helicity Injection for Non-Solenoidal ST Startup
Weberski, J. D.; Barr, J. L.; Bongard, M. W.; Fonck, R. J.; Perry, J. M.; Reusch, J. A.
2017-10-01
A zero-dimensional power balance model for predicting Ip(t) for Local Helicity Injection (LHI) discharges has been used to interpret experimental results from recent experimental campaigns using high-field-side (HFS) helicity injection. This model quantifies LHI's effective drive (Veff) through helicity balance while enforcing the Taylor relaxation current limit and tracking inductive effects to determine Ip(t) . Recent analysis of HFS LHI discharges indicate LHI is the dominant source of drive and provides Veff up to 1.3 V while geometric effects and inductive drive provide < 0.1 V throughout much of the discharge. In contrast to previous analysis of low-field-side (LFS) LHI discharges, which were driven by Veff = 0.3 V and 2.0 V from geometric effects and inductive drive. A significant remaining uncertainty in the model is the resistive dissipation of LHI discharges. This requires greater understanding of LHI confinement scaling and impurity content, which are currently under investigation. However, the model and experimental Ip(t) exhibit good agreement for parameters consistent with previous experimental findings. Extrapolation of plasma parameters and shaping from recent experiments allow for the model to project the performance of LHI systems. These projections indicate Ip 0.3 MA can be accessed on Pegasus via HFS LHI through changes to injector geometry to provide more Veff. This regime can be accessed via a LFS system by increasing the Taylor relaxation current limit early in the discharge. Work supported by US DOE Grants DE-FG02-96ER54375 and DE-SC0006928.
Directory of Open Access Journals (Sweden)
Alexander M. Chernysh
2018-01-01
Full Text Available Modifiers of membranes cause local defects on the cell surface. Measurement of the rigidity at the sites of local defects can provide further information about the structure of defects and mechanical properties of altered membranes.The purpose of the study: a step-by-step study of the process of a nonlinear deformation of red blood cells membranes under the effect of modifiers of different physico-chemical nature.Materials and methods. The membrane deformation of a viscoelastic composite erythrocyte construction inside a cell was studied by the atomic force spectroscopy. Nonlinear deformations formed under the effect of hemin, Zn2+ ions, and verapamil were studied.Results. The process of elastic deformation of the membrane with the indentation of a probe at the sites of local defects caused by modifiers was demonstrated. The probe was inserted during the same step of the piezo scanner z displacement; the probe indentation occured at the different discrete values of h, which are the functions of the membrane structure. At the sites of domains, under the effect of the hemin, tension areas and plasticity areas appeared. A mathematical model of probe indentation at the site of membrane defects is presented.Conclusion. The molecular mechanisms of various types of nonlinear deformations occurring under the effect of toxins are discussed. The results of the study may be of interest both for fundamental researchers of the blood cell properties and for practical reanimatology and rehabilitology.
Astrometric and Timing Effects of Gravitational Waves from Localized Sources
Kopeikin, Sergei M.; Schafer, Gerhard; Gwinn, Carl R.; Eubanks, T. Marshall
1998-01-01
A consistent approach for an exhaustive solution of the problem of propagation of light rays in the field of gravitational waves emitted by a localized source of gravitational radiation is developed in the first post-Minkowskian and quadrupole approximation of General Relativity. We demonstrate that the equations of light propagation in the retarded gravitational field of an arbitrary localized source emitting quadrupolar gravitational waves can be integrated exactly. The influence of the gra...
Quantum non-locality vs. quasi-local measurements in the conditions of the Aharonov-Bohm effect
International Nuclear Information System (INIS)
Gulian, Armen M
2014-01-01
Theoretical explanation of the Meissner effect involves proportionality between current density and vector potential, which has many deep consequences. As noticed by de Gennes, superconductors in a magnetic field 'find an equilibrium state where the sum of kinetic and magnetic energies is minimum' and this state 'corresponds to the expulsion of the magnetic field'. This statement still leaves an open question: from which source is the superconducting current acquiring its kinetic energy? A naïve answer, perhaps, is from the energy of the magnetic field. However, one can consider situations (Aharonov-Bohm effect), where the classical magnetic field is locally absent in the area occupied by the current. Experiments demonstrate that despite the local absence of the magnetic field, current is, nevertheless, building up. From what source is it acquiring its energy then? Locally, only a vector potential is present. How does the vector potential facilitate the formation of the current? Is the current formation a result of a truly non-local quantum action, or does the local action of the vector potential have experimental consequences? We discuss possible experiments with a hybrid normal-metal superconductor circuitry, which can clarify this puzzling situation. Experimental answers will be important for further developments.
Modeling of heat transfer into a heat pipe for a localized heat input zone
International Nuclear Information System (INIS)
Rosenfeld, J.H.
1987-01-01
A general model is presented for heat transfer into a heat pipe using a localized heat input. Conduction in the wall of the heat pipe and boiling in the interior structure are treated simultaneously. The model is derived from circumferential heat transfer in a cylindrical heat pipe evaporator and for radial heat transfer in a circular disk with boiling from the interior surface. A comparison is made with data for a localized heat input zone. Agreement between the theory and the model is good. This model can be used for design purposes if a boiling correlation is available. The model can be extended to provide improved predictions of heat pipe performance
Local probing by use of transparent model materials
Philippe, P.
2017-12-01
The present contribution emphasizes on two distinct examples the benefit with using transparent materials that enable direct visualization within different types of model systems. Our first use of transparent materials investigates the elementary mechanisms involved in soil erosion based on three key ingredients: a) cohesive model materials (i.e. glass beads bonded by solid bridges); b) optical techniques (Refractive Index Matching and Planar Laser Induced Fluorescence [1,2]) ; c) specific mechanical tests to estimate the mechanical strength of the solid bonds. Then, critical shear-stress at erosion onset can be related to tensile strength considering an extension of the classical Shields' number [3,4].Our second example uses a transparent elasto-visco-plastic fluid (Carbopol) as a model of debris flows. Different geometrical configurations allow for an accurate investigation of the flow over an obstacle [5] or a cavity [6], inducing the existence of a dead-zone and consequently of a frontier between solid-like and fluid-like regions that is of particular relevance for debris flows mobilization and deposition. Practically, the hydrodynamics of the flow is investigated by means of high-resolution optical velocimetry (PIV) and underlines a non-monotonous evolution of the shear rate, which increases from zero at the solid-liquid interface, passes through a peak (sometimes leveling off at its maximum value), and returns to zero in a plug zone sufficiently far above the cavity or the obstacle. [1] Philippe P., and Badiane M. Phys. Rev. E 87, 042206 (2013). [2] Dijksman J.A., Rietz F., Lorincz K.A., van Hecke M., and Losert W. Review of Scientific Instruments 83(1), 011301 (2012). [3] Badr S., Gauthier G., and Gondret P. Phys. Fluids 26:023302 (2014). [4] Brunier-Coulin F., Cuéllar P., and Philippe P. Phys. Rev. Fluids 87, 2: 034302 (2017). [5] Luu L.-H., Philippe P., and Chambon G. Phys. Rev. E 91, 013013 (2015). [6] Luu L.-H., Philippe P.; and Chambon G. Journal of
Fight against the greenhouse effect. From the local to the international action
International Nuclear Information System (INIS)
Mousel, M.
2002-01-01
In the fight against the greenhouse gases emissions, the local government are directly concerned. This sheet aims to explain the greenhouse effect, the kyoto protocol, the french national policy and to orientate the local actions. (A.L.B.)
The Effects of Hearing Aids on Localization of White Noise by Blind Subjects.
Bergen, Bruce R.
1980-01-01
An investigation was conducted to observe the effects of hearing aids on the ability of 20 blind veterans to localize white noise. In all cases, Ss performed more poorly on a localization task while wearing a hearing aid. (Author)
Estimating the Cumulative Ecological Effect of Local Scale Landscape Changes in South Florida
Hogan, Dianna M.; Labiosa, William; Pearlstine, Leonard; Hallac, David; Strong, David; Hearn, Paul; Bernknopf, Richard
2012-01-01
Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential, and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1) assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation of potential future LU patterns and incorporate EV into decision making.
Evaluation of sub grid scale and local wall models in Large-eddy simulations of separated flow
Sam Ali Al; Szasz Robert; Revstedt Johan
2015-01-01
The performance of the Sub Grid Scale models is studied by simulating a separated flow over a wavy channel. The first and second order statistical moments of the resolved velocities obtained by using Large-Eddy simulations at different mesh resolutions are compared with Direct Numerical Simulations data. The effectiveness of modeling the wall stresses by using local log-law is then tested on a relatively coarse grid. The results exhibit a good agreement between highly-resolved Large Eddy Simu...
The effect of interacting dark energy on local measurements of the Hubble constant
International Nuclear Information System (INIS)
Odderskov, Io; Baldi, Marco; Amendola, Luca
2016-01-01
In the current state of cosmology, where cosmological parameters are being measured to percent accuracy, it is essential to understand all sources of error to high precision. In this paper we present the results of a study of the local variations in the Hubble constant measured at the distance scale of the Coma Cluster, and test the validity of correcting for the peculiar velocities predicted by gravitational instability theory. The study is based on N-body simulations, and includes models featuring a coupling between dark energy and dark matter, as well as two ΛCDM simulations with different values of σ 8 . It is found that the variance in the local flows is significantly larger in the coupled models, which increases the uncertainty in the local measurements of the Hubble constant in these scenarios. By comparing the results from the different simulations, it is found that most of the effect is caused by the higher value of σ 8 in the coupled cosmologies, though this cannot account for all of the additional variance. Given the discrepancy between different estimates of the Hubble constant in the universe today, cosmological models causing a greater cosmic variance is something that we should be aware of.
The effect of interacting dark energy on local measurements of the Hubble constant
Energy Technology Data Exchange (ETDEWEB)
Odderskov, Io [Department of Physics and Astronomy, University of Aarhus, Ny Munkegade 120, Aarhus C (Denmark); Baldi, Marco [Dipartimento di Fisica e Astronomia, Alma Mater Studiorum Università di Bologna, viale Berti Pichat 6/2, I-40127, Bologna (Italy); Amendola, Luca, E-mail: isho07@phys.au.dk, E-mail: marco.baldi5@unibo.it, E-mail: l.amendola@thphys.uni-heidelberg.de [Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany)
2016-05-01
In the current state of cosmology, where cosmological parameters are being measured to percent accuracy, it is essential to understand all sources of error to high precision. In this paper we present the results of a study of the local variations in the Hubble constant measured at the distance scale of the Coma Cluster, and test the validity of correcting for the peculiar velocities predicted by gravitational instability theory. The study is based on N-body simulations, and includes models featuring a coupling between dark energy and dark matter, as well as two ΛCDM simulations with different values of σ{sub 8}. It is found that the variance in the local flows is significantly larger in the coupled models, which increases the uncertainty in the local measurements of the Hubble constant in these scenarios. By comparing the results from the different simulations, it is found that most of the effect is caused by the higher value of σ{sub 8} in the coupled cosmologies, though this cannot account for all of the additional variance. Given the discrepancy between different estimates of the Hubble constant in the universe today, cosmological models causing a greater cosmic variance is something that we should be aware of.
Modeling Shocks Detected by Voyager 1 in the Local Interstellar Medium
Energy Technology Data Exchange (ETDEWEB)
Kim, T. K.; Pogorelov, N. V. [Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 35805 (United States); Burlaga, L. F. [NASA Goddard Space Flight Center, Code 673, Greenbelt, MD 20771 (United States)
2017-07-10
The magnetometer (MAG) on Voyager 1 ( V1 ) has been sampling the interstellar magnetic field (ISMF) since 2012 August. The V1 MAG observations have shown draped ISMF in the very local interstellar medium disturbed occasionally by significant enhancements in magnetic field strength. Using a three-dimensional, data-driven, multi-fluid model, we investigated these magnetic field enhancements beyond the heliopause that are supposedly associated with solar transients. To introduce time-dependent effects at the inner boundary at 1 au, we used daily averages of the solar wind parameters from the OMNI data set. The model ISMF strength, direction, and proton number density are compared with V1 data beyond the heliopause. The model reproduced the large-scale fluctuations between 2012.652 and 2016.652, including major events around 2012.9 and 2014.6. The model also predicts shocks arriving at V1 around 2017.395 and 2019.502. Another model driven by OMNI data with interplanetary coronal mass ejections (ICMEs) removed at the inner boundary suggests that ICMEs may play a significant role in the propagation of shocks into the interstellar medium.
Comprehensive personal witness: a model to enlarge missional involvement of the local church
Directory of Open Access Journals (Sweden)
Hancke, Frans
2013-06-01
Full Text Available In the The Split-Level Fellowship, Wesley Baker analysed the role of individual members in the Church. He gave a name to a tragic phenomenon with which Church leaders are familiar. Although true of society in general it is especially true of the church. Baker called the difference between the committed few and the uninvolved many, Factor Beta. This reality triggers the question: Why are the majority of Christians in the world not missionally involved through personal witness and which factors consequently influence personal witness and missional involvement? This article explains how the range of personal witness and missional involvement found in local churches are rooted in certain fundamental factors and conditions which are mutually influencing each other and ultimately contribute towards forming a certain paradigm. This paradigm acts as the basis from which certain behavioural patterns (witness will manifest. The factors influencing witness are either described as accelerators or decelerators and their relativity and mutual relationships are considered. Factors acting as decelerators can severely hamper or even annul witness, while accelerators on the other hand, can have an immensely positive effect to enlarge the transformational influence of witness. In conclusion a transformational model is developed through which paradigms can be influenced and eventually changed. This model fulfils a diagnostic and remedial function and will support local churches to enlarge the individual and corporate missional involvement of believers.
Global Qualitative Flow-Path Modeling for Local State Determination in Simulation and Analysis
Malin, Jane T. (Inventor); Fleming, Land D. (Inventor)
1998-01-01
For qualitative modeling and analysis, a general qualitative abstraction of power transmission variables (flow and effort) for elements of flow paths includes information on resistance, net flow, permissible directions of flow, and qualitative potential is discussed. Each type of component model has flow-related variables and an associated internal flow map, connected into an overall flow network of the system. For storage devices, the implicit power transfer to the environment is represented by "virtual" circuits that include an environmental junction. A heterogeneous aggregation method simplifies the path structure. A method determines global flow-path changes during dynamic simulation and analysis, and identifies corresponding local flow state changes that are effects of global configuration changes. Flow-path determination is triggered by any change in a flow-related device variable in a simulation or analysis. Components (path elements) that may be affected are identified, and flow-related attributes favoring flow in the two possible directions are collected for each of them. Next, flow-related attributes are determined for each affected path element, based on possibly conflicting indications of flow direction. Spurious qualitative ambiguities are minimized by using relative magnitudes and permissible directions of flow, and by favoring flow sources over effort sources when comparing flow tendencies. The results are output to local flow states of affected components.
Directory of Open Access Journals (Sweden)
Bartjan W Pennink
2013-01-01
Full Text Available To build a strong local economy, good practice tells us that each community should undertake a collaborative, strategically planned process to understand and then act upon its own strengths, weaknesses, opportunities and threats. From this perspective we start with the local communities but how is this related to the perspective from the Helix model in which three actors are explicitly introduced: the Government, the Industry and the Universities? The purpose of local economic development (LED is to build up the economic capacity of a local area to improve its economic future and the quality of life for all. To support the Local Economic Development in remote areas, a program has been developed based on the LED frame work of the world bank. This approach and the experiences over the past years with this program are described in the first part. In the second part of the paper, We analyse work done with that program with the help of the social capital concept and the triple helix model. In all cases it is important to pay attention to who is taken the initiative after the first move (and it is not always the governance as actor and for the triple helix we suggest that the concepts of (national Government, Industry and University need a translation to Local Governance Agency, Cooperation or other ways of cooperation of local communities and Local Universities. Although a push from outside might help a local region in development the endogenous factors are also needed. Keywords: Triple Helix model, Local Economic Development, Local Actors, Double Triangle within the Helix Model
Foufoula-Georgiou, E.; Ganti, V. K.; Dietrich, W. E.
2009-12-01
Sediment transport on hillslopes can be thought of as a hopping process, where the sediment moves in a series of jumps. A wide range of processes shape the hillslopes which can move sediment to a large distance in the downslope direction, thus, resulting in a broad-tail in the probability density function (PDF) of hopping lengths. Here, we argue that such a broad-tailed distribution calls for a non-local computation of sediment flux, where the sediment flux is not only a function of local topographic quantities but is an integral flux which takes into account the upslope topographic “memory” of the point of interest. We encapsulate this non-local behavior into a simple fractional diffusive model that involves fractional (non-integer) derivatives. We present theoretical predictions from this nonlocal model and demonstrate a nonlinear dependence of sediment flux on local gradient, consistent with observations. Further, we demonstrate that the non-local model naturally eliminates the scale-dependence exhibited by any local (linear or nonlinear) sediment transport model. An extension to a 2-D framework, where the fractional derivative can be cast into a mixture of directional derivatives, is discussed together with the implications of introducing non-locality into existing landscape evolution models.
Dynamical generation of gauge bosons of hidden local symmetries in nonlinear sigma models
International Nuclear Information System (INIS)
Koegerler, R.; Lucha, W.; Neufeld, H.; Stremnitzer, H.
1988-01-01
We demonstrate how quantum corrections generate a kinetic term for the (at tree-level non-propagating) gauge fields of hidden local symmetries in nonlinear sigma models in four space-time dimensions. (orig.)
Local effects in flow-accelerated corrosion wall thinning
International Nuclear Information System (INIS)
Pietralik, J.
2006-01-01
'Full text:' There is enough evidence that flow conditions play the dominant role locally in Flow-Accelerated Corrosion (FAC) under certain conditions, e.g., in CANDU feeders. While chemistry and materials set the overall potential for FAC, which can be low or high, flow conditions determine the local distribution of wall thinning. This relationship is not new and recent accurate measurements of FAC rate of a plant feeder bend confirm that the relationship between flow local conditions expressed by local mass transfer coefficient and FAC rate in CANDU feeder bends is close. There is also a lot of other direct and indirect, experimental and laboratory evidence about this relationship. This knowledge can be useful for minimizing inspection, predicting new locations for inspection, predicting the location with the highest FAC rate for a given piping component, e.g., feeder element, and determining what components or feeders and to what extent they should be replaced. It applies also to heat exchangers and steam generators. The objective of this paper is to examine the relationship between FAC rate and local flow parameters. For FAC, the most important flow parameter is mass transfer coefficient. The mass transfer coefficient describes the intensity of the transport of corrosion products from the oxide-water interface into the bulk water. Therefore, this parameter can be used for predicting the local distribution of FAC rate. It could also be used in planning experiments because time-varying surface roughness can explain the time-dependence of FAC rates. The paper presents plant and laboratory evidence about the relationship. In addition, it shows correlations for mass transfer coefficient in components that are highly susceptible to FAC. The role of surface roughness, wall shear stress, and local turbulence is also discussed. (author)
Anderson localization through Polyakov loops: Lattice evidence and random matrix model
International Nuclear Information System (INIS)
Bruckmann, Falk; Schierenberg, Sebastian; Kovacs, Tamas G.
2011-01-01
We investigate low-lying fermion modes in SU(2) gauge theory at temperatures above the phase transition. Both staggered and overlap spectra reveal transitions from chaotic (random matrix) to integrable (Poissonian) behavior accompanied by an increasing localization of the eigenmodes. We show that the latter are trapped by local Polyakov loop fluctuations. Islands of such ''wrong'' Polyakov loops can therefore be viewed as defects leading to Anderson localization in gauge theories. We find strong similarities in the spatial profile of these localized staggered and overlap eigenmodes. We discuss possible interpretations of this finding and present a sparse random matrix model that reproduces these features.
Biophysical models of radiobiological effects
International Nuclear Information System (INIS)
Obaturov, G.M.
1984-01-01
Models of radiation effect on biological structures and objects are presented. Physical and molecular models based on target theory and DNA or chromosome injuries, respectively, and reparation ''saturation'' theory, are considered
Modeling of fuel vapor jet eruption induced by local droplet heating
Sim, Jaeheon
2014-01-10
The evaporation of a droplet by non-uniform heating is numerically investigated in order to understand the mechanism of the fuel-vapor jet eruption observed in the flame spread of a droplet array under microgravity condition. The phenomenon was believed to be mainly responsible for the enhanced flame spread rate through a droplet cloud at microgravity conditions. A modified Eulerian-Lagrangian method with a local phase change model is utilized to describe the interfacial dynamics between liquid droplet and surrounding air. It is found that the localized heating creates a temperature gradient along the droplet surface, induces the corresponding surface tension gradient, and thus develops an inner flow circulation commonly referred to as the Marangoni convection. Furthermore, the effect also produces a strong shear flow around the droplet surface, thereby pushing the fuel vapor toward the wake region of the droplet to form a vapor jet eruption. A parametric study clearly demonstrated that at realistic droplet combustion conditions the Marangoni effect is indeed responsible for the observed phenomena, in contrast to the results based on constant surface tension approximation
[Experimental model of severe local radiation injuries of the skin after X-rays].
Kotenko, K V; Moroz, B B; Nasonova, T A; Dobrynina, O A; LIpengolz, A A; Gimadova, T I; Deshevoy, Yu B; Lebedev, V G; Lyrschikova, A V; Eremin, I I
2013-01-01
The experimental model of severe local radiation injuries skin under the influence of a relatively soft X-rays on a modified device RAP 100-10 produced by "Diagnostica-M" (Russia) was proposed. The model can be used as pre-clinical studies in small experimental animals in order to improve the treatment of local radiation injuries, especially in the conditions of application of cellular therapy.
Genuine tripartite entangled states with a local hidden-variable model
International Nuclear Information System (INIS)
Toth, Geza; Acin, Antonio
2006-01-01
We present a family of three-qubit quantum states with a basic local hidden-variable model. Any von Neumann measurement can be described by a local model for these states. We show that some of these states are genuine three-partite entangled and also distillable. The generalization for larger dimensions or higher number of parties is also discussed. As a by-product, we present symmetric extensions of two-qubit Werner states
Rand, B C C; Penn-Barwell, J G; Wenke, J C
2015-10-01
Systemic antibiotics reduce infection in open fractures. Local delivery of antibiotics can provide higher doses to wounds without toxic systemic effects. This study investigated the effect on infection of combining systemic with local antibiotics via polymethylmethacrylate (PMMA) beads or gel delivery. An established Staphylococcus aureus contaminated fracture model in rats was used. Wounds were debrided and irrigated six hours after contamination and animals assigned to one of three groups, all of which received systemic antibiotics. One group had local delivery via antibiotic gel, another PMMA beads and the control group received no local antibiotics. After two weeks, bacterial levels were quantified. Combined local and systemic antibiotics were superior to systemic antibiotics alone at reducing the quantity of bacteria recoverable from each group (p = 0.002 for gel; p = 0.032 for beads). There was no difference in the bacterial counts between bead and gel delivery (p = 0.62). These results suggest that local antibiotics augment the antimicrobial effect of systemic antibiotics. Although no significant difference was found between vehicles, gel delivery offers technical advantages with its biodegradable nature, ability to conform to wound shape and to deliver increased doses. Further study is required to see if the gel delivery system has a clinical role. ©2015 The British Editorial Society of Bone & Joint Surgery.
Multi-site evaluation of the JULES land surface model using global and local data
Directory of Open Access Journals (Sweden)
D. Slevin
2015-02-01
Full Text Available This study evaluates the ability of the JULES land surface model (LSM to simulate photosynthesis using local and global data sets at 12 FLUXNET sites. Model parameters include site-specific (local values for each flux tower site and the default parameters used in the Hadley Centre Global Environmental Model (HadGEM climate model. Firstly, gross primary productivity (GPP estimates from driving JULES with data derived from local site measurements were compared to observations from the FLUXNET network. When using local data, the model is biased with total annual GPP underestimated by 16% across all sites compared to observations. Secondly, GPP estimates from driving JULES with data derived from global parameter and atmospheric reanalysis (on scales of 100 km or so were compared to FLUXNET observations. It was found that model performance decreases further, with total annual GPP underestimated by 30% across all sites compared to observations. When JULES was driven using local parameters and global meteorological data, it was shown that global data could be used in place of FLUXNET data with a 7% reduction in total annual simulated GPP. Thirdly, the global meteorological data sets, WFDEI and PRINCETON, were compared to local data to find that the WFDEI data set more closely matches the local meteorological measurements (FLUXNET. Finally, the JULES phenology model was tested by comparing results from simulations using the default phenology model to those forced with the remote sensing product MODIS leaf area index (LAI. Forcing the model with daily satellite LAI results in only small improvements in predicted GPP at a small number of sites, compared to using the default phenology model.
Directory of Open Access Journals (Sweden)
Ahmet Tolunay
2014-10-01
Full Text Available Voluntary cooperation and the support of stakeholders carry a major importance in the development of Model Forests. The identification of the support level of local organizations as stakeholders in the Bucak Model Forest initiative, located in the Mediterranean region of Turkey, constitutes the theme of this study. Within this scope, the views of the stakeholders comprising local government units (LGUs, non-governmental organizations (NGOs, village councils (VCs, professional organizations (POs and forest products enterprises (FPEs located in the district of Bucak were collected by utilizing a survey technique. The data were analysed by using non-parametric statistical analyses due to the absence of a normal distribution. The results show that the information provided about the Model Forest concept to the stakeholders located in the district on the Bucak Model Forest initiative was identified as a factor impacting the support level. Moreover, it was also observed that the stakeholders were more willing to provide advisory support rather than financial support. NGOs and VCs were identified as stakeholders who could not provide financial support due to their restricted budgets. We discuss the benefits for a Model Forest initiative of establishing international cooperation to strengthen the local and regional sustainable development process.
Cost-effectiveness on a local level: whether and when to adopt a new technology.
Woertman, Willem H; Van De Wetering, Gijs; Adang, Eddy M M
2014-04-01
Cost-effectiveness analysis has become a widely accepted tool for decision making in health care. The standard textbook cost-effectiveness analysis focuses on whether to make the switch from an old or common practice technology to an innovative technology, and in doing so, it takes a global perspective. In this article, we are interested in a local perspective, and we look at the questions of whether and when the switch from old to new should be made. A new approach to cost-effectiveness from a local (e.g., a hospital) perspective, by means of a mathematical model for cost-effectiveness that explicitly incorporates time, is proposed. A decision rule is derived for establishing whether a new technology should be adopted, as well as a general rule for establishing when it pays to postpone adoption by 1 more period, and a set of decision rules that can be used to determine the optimal timing of adoption. Finally, a simple example is presented to illustrate our model and how it leads to optimal decision making in a number of cases.
Shahriar, M.; Deb, Ujjwal Kumar; Rahman, Kazi Afzalur
2017-06-01
Microalgae based biofuel is now an emerging source of renewable energy alternative to the fossil fuel. This paper aims to present computational model of microalgae culture taking effect of solar irradiance and corresponding temperature in a photo bioreactor (PBR). As microalgae is a photosynthetic microorganism, so irradiance of sunlight is one of the important limiting factors for the proper growth of microalgae cells as temperature is associated with it. We consider the transient behaviour of temperature inside the photo bioreactor for a microalgae culture. The optimum range of temperature for outdoor cultivation of microalgae is about 16-35°c and out of this range the cell growth inhibits. Many correlations have already been established to investigate the heat transfer phenomena inside a tubular PBR. However, none of them are validated yet numerically by using a user defined function in a simulated model. A horizontal tubular PBR length 20.5m with radius 0.05m has taken account to investigate the temperature effect for the growth of microalgae cell. As the solar irradiance varies at any geographic latitude for a year so an empirical relation is established between local solar irradiance and temperature to simulate the effect. From our simulation, we observed that the growth of microalgae has a significant effect of temperature and the solar irradiance of our locality is suitable for the culture of microalgae.
Global and local Joule heating effects seen by DE 2
Heelis, R. A.; Coley, W. R.
1988-01-01
In the altitude region between 350 and 550 km, variations in the ion temperature principally reflect similar variations in the local frictional heating produced by a velocity difference between the ions and the neutrals. Here, the distribution of the ion temperature in this altitude region is shown, and its attributes in relation to previous work on local Joule heating rates are discussed. In addition to the ion temperature, instrumentation on the DE 2 satellite also provides a measure of the ion velocity vector representative of the total electric field. From this information, the local Joule heating rate is derived. From an estimate of the height-integrated Pedersen conductivity it is also possible to estimate the global (height-integrated) Joule heating rate. Here, the differences and relationships between these various parameters are described.
The effect of faulty local detectors on a detection network
International Nuclear Information System (INIS)
Mirjalily, G.; Emadi, S.
2002-01-01
Distributed detection theory has received increasing attention recently. Development of multiple sensors for signal detection results in improved performance and increased reliability. in a detection network, each local sensor decides locally whether a signal is detected or not. The local decisions are sent to the fusion center, where the final decision is made. In this paper, a theoretic approach is considered to data fusion when one of the sensors is faulty. If the fusion center does not have any knowledge of this fault, the performance of the system is different than its normal performance. The changes in the error probabilities depend on the type of the fault and on the threshold value of the fission center test. We derived some expressions of the changes in the values of error probabilities. For some type of faults, the system false alarm probability increases significantly, whereas for some other faults, the system detection probability decreases significantly. To illustrate the results, a numerical example is also given
Revised nonstochastic health effects models
International Nuclear Information System (INIS)
Yaniv, S.S.; Scott, B.R.
1991-01-01
In 1989, the U.S. Nuclear Regulatory Commission (NRC) published a revision of the 1985 report, Health Effects Models for Nuclear Power Plant Accident Consequence Analysis, NUREG/CR-4214, that included models for early occurring and continuing nonstochastic effects, cancers and thyroid nodules, and genetic effects. This paper discusses specific models for lethality from early occurring and continuing effects. For brevity, hematopoietic-syndrome lethality is called hematopoietic death; pulmonary-syndrome lethality is called pulmonary death; and gastrointestinal syndrome lethality is called gastrointestinal death. Two-parameter Weibull risk functions are recommended for estimating the risk of hematopoietic, pulmonary, or gastrointestinal death. The risks are obtained indirectly by using hazard functions; as a result, this type of approach has been called hazard-function modeling and the models generated are called hazard-function models. In the 1989 NUREG/CR-4214 report, changes were made in the parameter values for a number of effects, and the models used to estimate hematopoietic and pulmonary deaths were substantially revised. Upper and lower estimates of model parameters are provided for all early health effects models. In this paper, we discuss the 1989 models for hematopoietic and pulmonary deaths, highlighting the differences between the 1989 and 1985 models. In addition, we give the reasons for which the 1985 models were modified
Dynamics of spiral waves in a cardiac electromechanical model with a local electrical inhomogeneity
International Nuclear Information System (INIS)
Mesin, Luca
2012-01-01
Highlights: ► I study spirals in a model of electromechanical coupling in a cardiac tissue. ► The model is anisotropic and includes an electrical heterogeneity. ► Mechanical deformation is described under the active strain hypothesis. ► Joint effect of inhomogeneity and deformation influences spiral dynamics. ► Conductivity of stretch activated current is the parameter most affecting spirals. - Abstract: Joint effect of electrical heterogeneity (e.g. induced by ischemia) and mechanical deformation is investigated for an anisotropic, quasi–incompressible model of cardiac electromechanical coupling (EMC) using the active strain approach and periodic boundary conditions. Three local inhomogeneities with different geometry are simulated. Under a specific stimulation protocol, the heterogeneities are able to induce spirals. The interplay between the dimension of the electrical inhomogeneity, the EMC and the mechano-electrical feedback provided by the stretch activated current (SAC) determines the dynamics of the spiral waves of excitation, which could extinguish (in the case of low SAC), or be stable (with the tip rotating inside the inhomogeneity), or drift and be annihilated (in the case of high SAC).
Directory of Open Access Journals (Sweden)
Pawlowski Marcin
2012-11-01
Full Text Available Abstract Background Computational models of protein structures were proved to be useful as search models in Molecular Replacement (MR, a common method to solve the phase problem faced by macromolecular crystallography. The success of MR depends on the accuracy of a search model. Unfortunately, this parameter remains unknown until the final structure of the target protein is determined. During the last few years, several Model Quality Assessment Programs (MQAPs that predict the local accuracy of theoretical models have been developed. In this article, we analyze whether the application of MQAPs improves the utility of theoretical models in MR. Results For our dataset of 615 search models, the real local accuracy of a model increases the MR success ratio by 101% compared to corresponding polyalanine templates. On the contrary, when local model quality is not utilized in MR, the computational models solved only 4.5% more MR searches than polyalanine templates. For the same dataset of the 615 models, a workflow combining MR with predicted local accuracy of a model found 45% more correct solution than polyalanine templates. To predict such accuracy MetaMQAPclust, a “clustering MQAP” was used. Conclusions Using comparative models only marginally increases the MR success ratio in comparison to polyalanine structures of templates. However, the situation changes dramatically once comparative models are used together with their predicted local accuracy. A new functionality was added to the GeneSilico Fold Prediction Metaserver in order to build models that are more useful for MR searches. Additionally, we have developed a simple method, AmIgoMR (Am I good for MR?, to predict if an MR search with a template-based model for a given template is likely to find the correct solution.
Improving UWB-Based Localization in IoT Scenarios with Statistical Models of Distance Error.
Monica, Stefania; Ferrari, Gianluigi
2018-05-17
Interest in the Internet of Things (IoT) is rapidly increasing, as the number of connected devices is exponentially growing. One of the application scenarios envisaged for IoT technologies involves indoor localization and context awareness. In this paper, we focus on a localization approach that relies on a particular type of communication technology, namely Ultra Wide Band (UWB). UWB technology is an attractive choice for indoor localization, owing to its high accuracy. Since localization algorithms typically rely on estimated inter-node distances, the goal of this paper is to evaluate the improvement brought by a simple (linear) statistical model of the distance error. On the basis of an extensive experimental measurement campaign, we propose a general analytical framework, based on a Least Square (LS) method, to derive a novel statistical model for the range estimation error between a pair of UWB nodes. The proposed statistical model is then applied to improve the performance of a few illustrative localization algorithms in various realistic scenarios. The obtained experimental results show that the use of the proposed statistical model improves the accuracy of the considered localization algorithms with a reduction of the localization error up to 66%.
The effects of local culture on hospital administration in West Sumatra, Indonesia.
Semiarty, Rima; Fanany, Rebecca
2017-02-06
Purpose Problems in health-care leadership are serious in West Sumatra, Indonesia, especially in hospitals, which are controlled locally. The purpose of this paper is to present the experience of three hospitals in balancing the conflicting demands of the national health-care system and the traditional model of leadership in the local community. Design/methodology/approach Three case studies of the hospital leadership dynamic in West Sumatra were developed from in-depth interviews with directors, senior administrators and a representative selection of employees in various professional categories. Findings An analysis of findings shows that traditional views about leadership remain strong in the community and color the expectations of hospital staff. Hospital directors, however, are bound by the modern management practices of the national system. This conflict has intensified since regional autonomy which emphasizes the local culture much more than in the past. Research limitations/implications The research was carried out in one Indonesian province and was limited to three hospitals of different types. Practical implications The findings elucidate a potential underlying cause of problems in hospital management in Indonesia and may inform culturally appropriate ways of addressing them. Originality/value The social and cultural contexts of management have not been rigorously studied in Indonesia. The relationship between local and national culture reported here likely has a similar effect in other parts of the country.
Ozkaya, Efe; Yilmaz, Cetin
2017-02-01
The effect of eddy current damping on a novel locally resonant periodic structure is investigated. The frequency response characteristics are obtained by using a lumped parameter and a finite element model. In order to obtain wide band gaps at low frequencies, the periodic structure is optimized according to certain constraints, such as mass distribution in the unit cell, lower limit of the band gap, stiffness between the components in the unit cell, the size of magnets used for eddy current damping, and the number of unit cells in the periodic structure. Then, the locally resonant periodic structure with eddy current damping is manufactured and its experimental frequency response is obtained. The frequency response results obtained analytically, numerically and experimentally match quite well. The inclusion of eddy current damping to the periodic structure decreases amplitudes of resonance peaks without disturbing stop band width.
Implementation of SNS Model for Intrusion Prevention in Wireless Local Area Network
DEFF Research Database (Denmark)
Isah, Abdullahi
The thesis has proposed and implemented a so-called SNS (Social network security) model for intrusion prevention in the Wireless Local Area Network of an organization. An experimental design was used to implement and test the model at a university in Nigeria.......The thesis has proposed and implemented a so-called SNS (Social network security) model for intrusion prevention in the Wireless Local Area Network of an organization. An experimental design was used to implement and test the model at a university in Nigeria....
Safeguards system effectiveness modeling
International Nuclear Information System (INIS)
Bennett, H.A.; Boozer, D.D.; Chapman, L.D.; Daniel, S.L.; Engi, D.; Hulme, B.L.; Varnado, G.B.
1976-01-01
A general methodology for the comparative evaluation of physical protection system effectiveness at nuclear facilities is presently under development. The approach is applicable to problems of sabotage or theft at fuel cycle facilities. The overall methodology and the primary analytic techniques used to assess system effectiveness are briefly outlined
Safeguards system effectiveness modeling
International Nuclear Information System (INIS)
Boozer, D.D.; Hulme, B.L.; Daniel, S.L.; Varnado, G.B.; Bennett, H.A.; Chapman, L.D.; Engi, D.
1976-09-01
A general methodology for the comparative evaluation of physical protection system effectiveness at nuclear facilities is presently under development. The approach is applicable to problems of sabotage or theft at fuel cycle facilities. In this paper, the overall methodology and the primary analytic techniques used to assess system effectiveness are briefly outlined
Safeguards system effectiveness modeling
International Nuclear Information System (INIS)
Bennett, H.A.; Boozer, D.D.; Chapman, L.D.; Daniel, S.L.; Engi, D.; Hulme, B.L.; Varnado, G.B.
1976-01-01
A general methodology for the comparative evaluation of physical protection system effectiveness at nuclear facilities is presently under development. The approach is applicable to problems of sabotage or theft at fuel cycle facilities. In this paper, the overall methodology and the primary analytic techniques used to assess system effectiveness are briefly outlined
The charge-asymmetric nonlocally determined local-electric (CANDLE) solvation model
Energy Technology Data Exchange (ETDEWEB)
Sundararaman, Ravishankar; Goddard, William A. [Joint Center for Artificial Photosynthesis, Pasadena, California 91125 (United States)
2015-02-14
Many important applications of electronic structure methods involve molecules or solid surfaces in a solvent medium. Since explicit treatment of the solvent in such methods is usually not practical, calculations often employ continuum solvation models to approximate the effect of the solvent. Previous solvation models either involve a parametrization based on atomic radii, which limits the class of applicable solutes, or based on solute electron density, which is more general but less accurate, especially for charged systems. We develop an accurate and general solvation model that includes a cavity that is a nonlocal functional of both solute electron density and potential, local dielectric response on this nonlocally determined cavity, and nonlocal approximations to the cavity-formation and dispersion energies. The dependence of the cavity on the solute potential enables an explicit treatment of the solvent charge asymmetry. With four parameters per solvent, this “CANDLE” model simultaneously reproduces solvation energies of large datasets of neutral molecules, cations, and anions with a mean absolute error of 1.8 kcal/mol in water and 3.0 kcal/mol in acetonitrile.
A probabilistic model for robust localization based on a binaural auditory front-end
May, T.; Par, van de S.L.J.D.E.; Kohlrausch, A.G.
2011-01-01
Although extensive research has been done in the field of machine-based localization, the degrading effect of reverberation and the presence of multiple sources on localization performance has remained a major problem. Motivated by the ability of the human auditory system to robustly analyze complex
Non-local model analysis of heat pulse propagation and simulation of experiments in W7-AS
International Nuclear Information System (INIS)
Iwasaki, Takuya; Itoh, Sanae-I.; Yagi, Masatoshi; Itoh, Kimitaka; Stroth, U.
1999-01-01
A new model equation which includes the non-local effect in the hear flux is introduced to study the transient transport phenomena. A non-local heat flux, which is expressed in terms of the integral equation, is superimposed on the conventional form of the heat flux. This model is applied to describe the experimental results from the power switching [U. Stroth et al.: Plasma Phys. Control. Fusion 38 (1996) 1087] and the power modulation experiments [L. Giannone et al.: Nucl. Fusion 32 (1992) 1985] in the W7-AS stellarator. A small fraction of non-local component in the heat flux is found to be very effective in modifying the response against an external modulation. The transient feature of the transport property, which are observed in the response of heat pulse propagation, are qualitatively reproduced by the transport simulations based on this model. A possibility is discussed to estimate the correlation length of the non-local effect experimentally by use of the results of transport simulations. (author)
Effect of processing (sprouting and fermentation) of five local ...
African Journals Online (AJOL)
CLEMENT O BEWAJI
protein digestibility and mineral element composition of five local varieties were studied. ... Processed sorghum seeds or flour were found to be important sources of ... digestible than the proteins of other similar cooked cereals such as wheat and ... covered and kept for 72 hours away from light for fermentation to occur.
Effects of surprisal and locality on Danish sentence processing
DEFF Research Database (Denmark)
Balling, Laura Winther; Kizach, Johannes
2017-01-01
An eye-tracking experiment in Danish investigates two dominant accounts of sentence processing: locality-based theories that predict a processing advantage for sentences where the distance between the major syntactic heads is minimized, and the surprisal theory which predicts that processing time...
Local socio-economic effects of protected area conservation: The ...
African Journals Online (AJOL)
Some villagers have benefited from pilot development projects organized by financial and environmental organizations. Other local people benefited from other livelihood activities related to the conservation management of the forest. Most participants were aware of the ecosystem services of the forests (94.3%) and the ...
Lepton flavour violation in RS models with a brane- or nearly brane-localized Higgs
Beneke, M.; Moch, P.; Rohrwild, J.
2016-05-01
We perform a comprehensive study of charged lepton flavour violation in Randall-Sundrum (RS) models in a fully 5D quantum-field-theoretical framework. We consider the RS model with minimal field content and a ;custodially protected; extension as well as three implementations of the IR-brane localized Higgs field, including the non-decoupling effect of the KK excitations of a narrow bulk Higgs. Our calculation provides the first complete result for the flavour-violating electromagnetic dipole operator in Randall-Sundrum models. It contains three contributions with different dependence on the magnitude of the anarchic 5D Yukawa matrix, which can all be important in certain parameter regions. We study the typical range for the branching fractions of μ → eγ, μ → 3 e, μN → eN as well as τ → μγ, τ → 3 μ and the electron electric dipole moment by a numerical scan in both the minimal and the custodial RS model. The combination of μ → eγ and μN → eN currently provides the most stringent constraint on the parameter space of the model. A typical lower limit on the KK scale T is around 2 TeV in the minimal model (up to 4 TeV in the bulk Higgs case with large Yukawa couplings), and around 4 TeV in the custodially protected model, which corresponds to a mass of about 10 TeV for the first KK excitations, far beyond the lower limit from the non-observation of direct production at the LHC.
Directory of Open Access Journals (Sweden)
Liyun Su
2012-01-01
Full Text Available We introduce the extension of local polynomial fitting to the linear heteroscedastic regression model. Firstly, the local polynomial fitting is applied to estimate heteroscedastic function, then the coefficients of regression model are obtained by using generalized least squares method. One noteworthy feature of our approach is that we avoid the testing for heteroscedasticity by improving the traditional two-stage method. Due to nonparametric technique of local polynomial estimation, we do not need to know the heteroscedastic function. Therefore, we can improve the estimation precision, when the heteroscedastic function is unknown. Furthermore, we focus on comparison of parameters and reach an optimal fitting. Besides, we verify the asymptotic normality of parameters based on numerical simulations. Finally, this approach is applied to a case of economics, and it indicates that our method is surely effective in finite-sample situations.
Breakdown of local information processing may underlie isoflurane anesthesia effects.
Wollstadt, Patricia; Sellers, Kristin K; Rudelt, Lucas; Priesemann, Viola; Hutt, Axel; Fröhlich, Flavio; Wibral, Michael
2017-06-01
The disruption of coupling between brain areas has been suggested as the mechanism underlying loss of consciousness in anesthesia. This hypothesis has been tested previously by measuring the information transfer between brain areas, and by taking reduced information transfer as a proxy for decoupling. Yet, information transfer is a function of the amount of information available in the information source-such that transfer decreases even for unchanged coupling when less source information is available. Therefore, we reconsidered past interpretations of reduced information transfer as a sign of decoupling, and asked whether impaired local information processing leads to a loss of information transfer. An important prediction of this alternative hypothesis is that changes in locally available information (signal entropy) should be at least as pronounced as changes in information transfer. We tested this prediction by recording local field potentials in two ferrets after administration of isoflurane in concentrations of 0.0%, 0.5%, and 1.0%. We found strong decreases in the source entropy under isoflurane in area V1 and the prefrontal cortex (PFC)-as predicted by our alternative hypothesis. The decrease in source entropy was stronger in PFC compared to V1. Information transfer between V1 and PFC was reduced bidirectionally, but with a stronger decrease from PFC to V1. This links the stronger decrease in information transfer to the stronger decrease in source entropy-suggesting reduced source entropy reduces information transfer. This conclusion fits the observation that the synaptic targets of isoflurane are located in local cortical circuits rather than on the synapses formed by interareal axonal projections. Thus, changes in information transfer under isoflurane seem to be a consequence of changes in local processing more than of decoupling between brain areas. We suggest that source entropy changes must be considered whenever interpreting changes in information
Prediction Of Formability In Sheet Metal Forming Processes Using A Local Damage Model
International Nuclear Information System (INIS)
Teixeira, P.; Santos, Abel; Cesar Sa, J.; Andrade Pires, F.; Barata da Rocha, A.
2007-01-01
The formability in sheet metal forming processes is mainly conditioned by ductile fracture resulting from geometric instabilities due to necking and strain localization. The macroscopic collapse associated with ductile failure is a result of internal degradation described throughout metallographic observations by the nucleation, growth and coalescence of voids and micro-cracks. Damage influences and is influenced by plastic deformation and therefore these two dissipative phenomena should be coupled at the constitutive level. In this contribution, Lemaitre's ductile damage model is coupled with Hill's orthotropic plasticity criterion. The coupling between damaging and material behavior is accounted for within the framework of Continuum Damage Mechanics (CDM). The resulting constitutive equations are implemented in the Abaqus/Explicit code, for the prediction of fracture onset in sheet metal forming processes. The damage evolution law takes into account the important effect of micro-crack closure, which dramatically decreases the rate of damage growth under compressive paths
International Nuclear Information System (INIS)
Lazzaro, E.; Comisso, L.; Valdettaro, L.
2010-01-01
In tokamaks magnetic islands arise from an unstable process of tearing and reconnecting of helical field lines across rational surfaces. After a linear stage the magnetic instability develops through three characteristic nonlinear stages where increasingly complex topological alterations occur in the form of the magnetic islands. The problem of response of reconnection process to the injection of an external current suitably localized is addressed using a four-field model in a plane slab plasma, with a novel extension to account consistently of the relevant neoclassical effects, such as bootstrap current and pressure anisotropy. The results found have implications on the interpretation of the possible mechanism of present day experimental results on neoclassical tearing modes as well as on the concepts for their control or avoidance.
Pyle, M. L.; Walter, W. R.
2017-12-01
Discrimination between underground explosions and naturally occurring earthquakes is an important endeavor for global security and test-ban treaty monitoring, and ratios of seismic P to S-wave amplitudes at regional distances have proven to be an effective discriminant. The use of the P/S ratio is rooted in the idea that explosive sources should theoretically only generate compressional energy. While, in practice, shear energy is observed from explosions, generally when corrections are made for magnitude and distance, P/S ratios from explosions are higher than those from surrounding earthquakes. At local distances (chemical explosions at the Nevada National Security Site (NNSS) designed to improve our understanding and modeling capabilities of shear waves generated by explosions. Phase I consisted of 5 explosions in granite and Phase II will move to a contrasting dry alluvium geology. We apply a high-resolution 2D attenuation model to events near the NNSS to examine what effect path plays in local P/S ratios, and how well an earthquake-derived model can account for shallower explosion paths. The model incorporates both intrinsic attenuation and scattering effects and extends to 16 Hz, allowing us to make lateral path corrections and consider high-frequency ratios. Preliminary work suggests that while 2D path corrections modestly improve earthquake amplitude predictions, explosion amplitudes are not well matched, and so P/S ratios do not necessarily improve. Further work is needed to better understand the uses and limitation of 2D path corrections for local P/S ratios.
Biophysical models of radiobiological effects
International Nuclear Information System (INIS)
Obaturov, G.M.
1987-01-01
Radiobiological effect models at different organization levels, developed by the author, are presented. Classification and analysis of concepts and biophysical models at molecular, genetic and cellular levels, developed by Soviet and foreign authors in comparison to inherent models, are conducted from the viewpoint of system approach to radiobiological processes and of modelling principles. Models are compared with each other, limits of their applicability and drawbacks are determined. Evaluation of the model truthfulness is conducted according to a number of criteria, ways of further investigations and experimental examination of some models are proposed
Park, Sohyun
2018-02-01
We examine the origin of two opposite results for the growth of perturbations in the Deser-Woodard (DW) nonlocal gravity model. One group previously analyzed the model in its original nonlocal form and showed that the growth of structure in the DW model is enhanced compared to general relativity (GR) and thus concluded that the model was ruled out. Recently, however, another group has reanalyzed it by localizing the model and found that the growth in their localized version is suppressed even compared to the one in GR. The question was whether the discrepancy originates from an intrinsic difference between the nonlocal and localized formulations or is due to their different implementations of the subhorizon limit. We show that the nonlocal and local formulations give the same solutions for the linear perturbations as long as the initial conditions are set the same. The different implementations of the subhorizon limit lead to different transient behaviors of some perturbation variables; however, they do not affect the growth of matter perturbations at the sub-horizon scale much. In the meantime, we also report an error in the numerical calculation code of the former group and verify that after fixing the error the nonlocal version also gives the suppressed growth. Finally, we discuss two alternative definitions of the effective gravitational constant taken by the two groups and some open problems.
LDR vs. HDR brachytherapy for localized prostate cancer: the view from radiobiological models.
King, Christopher R
2002-01-01
Permanent LDR brachytherapy and temporary HDR brachytherapy are competitive techniques for clinically localized prostate radiotherapy. Although a randomized trial will likely never be conducted comparing these two forms of brachytherapy, a comparative radiobiological modeling analysis proves useful in understanding some of their intrinsic differences, several of which could be exploited to improve outcomes. Radiobiological models based upon the linear quadratic equations are presented for fractionated external beam, fractionated (192)Ir HDR brachytherapy, and (125)I and (103)Pd LDR brachytherapy. These models incorporate the dose heterogeneities present in brachytherapy based upon patient-derived dose volume histograms (DVH) as well as tumor doubling times and repair kinetics. Radiobiological parameters are normalized to correspond to three accepted clinical risk factors based upon T-stage, PSA, and Gleason score to compare models with clinical series. Tumor control probabilities (TCP) for LDR and HDR brachytherapy (as monotherapy or combined with external beam) are compared with clinical bNED survival rates. Predictions are made for dose escalation with HDR brachytherapy regimens. Model predictions for dose escalation with external beam agree with clinical data and validate the models and their underlying assumptions. Both LDR and HDR brachytherapy achieve superior tumor control when compared with external beam at conventional doses (LDR brachytherapy as boost achieves superior tumor control than when used as monotherapy. Stage for stage, both LDR and current HDR regimens achieve similar tumor control rates, in agreement with current clinical data. HDR monotherapy with large-dose fraction sizes might achieve superior tumor control compared with LDR, especially if prostate cancer possesses a high sensitivity to dose fractionation (i.e., if the alpha/beta ratio is low). Radiobiological models support the current clinical evidence for equivalent outcomes in localized
Wu, Helen W; Backman, Desiree; Kizer, Kenneth W
The US Department of Agriculture Supplemental Nutrition Assistance Program-Education (SNAP-Ed) funds state programs to improve nutrition and physical activity in low-income populations through its Nutrition Education and Obesity Prevention grants. States vary in how they manage and structure these programs. California substantially restructured its program in 2012 to universally position local health departments (LHDs) as the programmatic lead in all jurisdictions. This study sought to determine whether California's reorganization aligned with desirable attributes of decentralized public management. This study conducted 40 in person, semistructured interviews with 57 local, state, and federal SNAP-Ed stakeholders between October 2014 and March 2015. Local respondents represented 15 counties in all 7 of California's SNAP-Ed regions. We identified 3 common themes that outlined advantages or disadvantages of local public management, and we further defined subthemes within: (1) coordination and communication (within local jurisdictions, across regions, between local and state), (2) efficiency (administrative, fiscal, program), and (3) quality (innovation, skills). We conducted qualitative content analysis to evaluate how respondents characterized the California experience for each theme, identifying positive and negative experiences. California's LHD model offers some distinct advantages, but the model does not exhibit all the advantages of decentralized public management. Strategic planning, partnerships, subcontracting, and fiscal oversight are closer to communities than previously. However, administrative burden remains high and LHDs are limited in their ability to customize programs on the basis of community needs because of state and federal constraints. California's use of a universal LHD model for SNAP-Ed is novel. Recent federal SNAP-Ed changes present an opportunity for other states to consider this structure. Employing small-scale approaches initially (eg
Directory of Open Access Journals (Sweden)
Y. Abdallah Mohamed
2015-06-01
Full Text Available Scour around bridge supports such as abutments can result in structural collapse and loss of life and property, so there is a need to control and minimize the local scour depth. In this paper, numerical and experimental studies were carried out to investigate the effect of different relative radii of the bridge abutment provided with collar on local scour depth. A 3-D numerical model is developed to simulate the scour at bridge abutment using SSIIM program. This model solves 3-D Navier–Stokes equations and a bed load conservation equation. The k–ε turbulence model is used to solve the Reynolds-stress term. It was found the curvature shape of bridge abutment provided with collar could share to reduce the local scour depth by more 95%. In addition, the results of simulation models agree well with the experimental data.
Optimization modeling of U.S. renewable electricity deployment using local input variables
Bernstein, Adam
For the past five years, state Renewable Portfolio Standard (RPS) laws have been a primary driver of renewable electricity (RE) deployments in the United States. However, four key trends currently developing: (i) lower natural gas prices, (ii) slower growth in electricity demand, (iii) challenges of system balancing intermittent RE within the U.S. transmission regions, and (iv) fewer economical sites for RE development, may limit the efficacy of RPS laws over the remainder of the current RPS statutes' lifetime. An outsized proportion of U.S. RE build occurs in a small number of favorable locations, increasing the effects of these variables on marginal RE capacity additions. A state-by-state analysis is necessary to study the U.S. electric sector and to generate technology specific generation forecasts. We used LP optimization modeling similar to the National Renewable Energy Laboratory (NREL) Renewable Energy Development System (ReEDS) to forecast RE deployment across the 8 U.S. states with the largest electricity load, and found state-level RE projections to Year 2031 significantly lower than thoseimplied in the Energy Information Administration (EIA) 2013 Annual Energy Outlook forecast. Additionally, the majority of states do not achieve their RPS targets in our forecast. Combined with the tendency of prior research and RE forecasts to focus on larger national and global scale models, we posit that further bottom-up state and local analysis is needed for more accurate policy assessment, forecasting, and ongoing revision of variables as parameter values evolve through time. Current optimization software eliminates much of the need for algorithm coding and programming, allowing for rapid model construction and updating across many customized state and local RE parameters. Further, our results can be tested against the empirical outcomes that will be observed over the coming years, and the forecast deviation from the actuals can be attributed to discrete parameter
Lasa, A.; Borodin, D.; Canik, J. M.; Klepper, C. C.; Groth, M.; Kirschner, A.; Airila, M. I.; Borodkina, I.; Ding, R.; Contributors, JET
2018-01-01
Experiments at JET showed locally enhanced, asymmetric beryllium (Be) erosion at outer wall limiters when magnetically connected ICRH antennas were in operation. A first modeling effort using the 3D erosion and scrape-off layer impurity transport modeling code ERO reproduced qualitatively the experimental outcome. However, local plasma parameters—in particular when 3D distributions are of interest—can be difficult to determine from available diagnostics and so erosion / impurity transport modeling input relies on output from other codes and simplified models, increasing uncertainties in the outcome. In the present contribution, we introduce and evaluate the impact of improved models and parameters with largest uncertainties of processes that impact impurity production and transport across the scrape-off layer, when simulated in ERO: (i) the magnetic geometry has been revised, for affecting the separatrix position (located 50-60 mm away from limiter surface) and thus the background plasma profiles; (ii) connection lengths between components, which lead to shadowing of ion fluxes, are also affected by the magnetic configuration; (iii) anomalous transport of ionized impurities, defined by the perpendicular diffusion coefficient, has been revisited; (iv) erosion yields that account for energy and angular distributions of background plasma ions under the present enhanced sheath potential and oblique magnetic field, have been introduced; (v) the effect of additional erosion sources, such as charge-exchange neutral fluxes, which are dominant in recessed areas like antennas, has been evaluated; (vi) chemically assisted release of Be in molecular form has been included. Sensitivity analysis highlights a qualitative effect (i.e. change in emission patterns) of magnetic shadowing, anomalous diffusion, and inclusion of neutral fluxes and molecular release of Be. The separatrix location, and energy and angular distribution of background plasma fluxes impact erosion
Modelling irradiation effect of EUROFER
International Nuclear Information System (INIS)
Boutard, J.-L.; Dudarev, S.; Victoria, M.
2006-01-01
In fusion power reactor, the properties that controlled the behaviour of materials are affected at the atom scale: (i) the crystalline structure is locally destroyed where a displacement cascade occurs, (ii) the chemical bond is affected by transmutation products such as He and H, (iii) an radiation induced microstructure will take place due the diffusion of these point defects and impurities EFDA has launched a programme since 2002 to develop and validate modelling tools to predict the radiation effects in the reference ferritic martensitic steel Eurofer. Up to now, the effort has been devoted (i) to validate the multi-scale modelling approach based on ab-initio energetics map of point defects and He, (iii) to develop inter-atomic potentials for Molecular Dynamics simulation of displacement cascades and dislocation dynamics. Formation and migration energies and diffusion mechanisms of small vacancy (n< ) and interstitial clusters (n< ) were computed with the ab-initio code SIESTA and used to successfully predict via Kinetic Monte Carlo the experimental recovery stages of radiation damage in ultra high purity Fe. A complete He and point defect energetics mapping was ab-initio determined in Fe-C and used to reproduce via Rate Theory He-desorption from pre-implanted specimens. A developed '' magnetic '' potential is capable of transferring the magnetic properties of Fe due to the 3d-electron correlation to the scale of the Molecular Dynamics. An inter-atomic potential is being developed to reproduce the thermodynamics of the Fe-Cr system. The program will now be devoted (i) to develop atom-scale reference kinetic methods to predict the phase - stability of the Fe-Cr thermally and under irradiation (ii) to predict at the atom scale the core structure and dynamics of screw dislocation and their collective behaviour at the meso-scale, using Discrete Dislocation Dynamics (iii) to validate at the relevant scale using the multi-beam CEA-CNRS facility JANNUS. JANNUS allows
Effect of antigen on localization of immunologically specific B cells
International Nuclear Information System (INIS)
Ponzio, N.M.; Chapman, J.M.; Thorbecke, G.J.
1976-01-01
Studies were conducted to demonstrate homing of memory B cells to sites of antigen localization in lymph nodes, using functional criteria to detect local presence of memory cells at varying intervals after intravenous injection. Cell suspensions were prepared from spleens of donor mice injected with complete Freund's adjuvant. Recipient mice were injected with Escherichia coli endotoxin and immune or normal spleen cells and were gamma-irradiated. Results indicated that passively transferred unilateral B cell memory was established. The development over a period of several days of this difference between left and right lymph nodes suggests that recirculating memory B cells are being progressively selected by antigen in the lymph node, rather than that this difference is due to a specific exit of cells from the circulation towards the antigen
The Effectiveness of Social Media Implementation at Local Government Levels
Directory of Open Access Journals (Sweden)
Elvira NICA
2014-12-01
Full Text Available The purpose of this article is to gain a deeper understanding of the management of social me-dia at the local government level, the availability of opportunities for citizen dialogue on govern-ment websites, and the impact that social net-working applications have on e-government. The results of the current study converge with prior research on the growing awareness amongst government practitioners regarding the relevance of social media, the use of social media for feed-back on service quality, and privacy and security commitments in e-government. The literature on the use of information technology to transform government, the potential for online government information to contribute to citizen engagement, and the rapid growth in local government use of social media is relevant to this discussion.
Real-time prediction of respiratory motion based on a local dynamic model in an augmented space.
Hong, S-M; Jung, B-H; Ruan, D
2011-03-21
Motion-adaptive radiotherapy aims to deliver ablative radiation dose to the tumor target with minimal normal tissue exposure, by accounting for real-time target movement. In practice, prediction is usually necessary to compensate for system latency induced by measurement, communication and control. This work focuses on predicting respiratory motion, which is most dominant for thoracic and abdominal tumors. We develop and investigate the use of a local dynamic model in an augmented space, motivated by the observation that respiratory movement exhibits a locally circular pattern in a plane augmented with a delayed axis. By including the angular velocity as part of the system state, the proposed dynamic model effectively captures the natural evolution of respiratory motion. The first-order extended Kalman filter is used to propagate and update the state estimate. The target location is predicted by evaluating the local dynamic model equations at the required prediction length. This method is complementary to existing work in that (1) the local circular motion model characterizes 'turning', overcoming the limitation of linear motion models; (2) it uses a natural state representation including the local angular velocity and updates the state estimate systematically, offering explicit physical interpretations; (3) it relies on a parametric model and is much less data-satiate than the typical adaptive semiparametric or nonparametric method. We tested the performance of the proposed method with ten RPM traces, using the normalized root mean squared difference between the predicted value and the retrospective observation as the error metric. Its performance was compared with predictors based on the linear model, the interacting multiple linear models and the kernel density estimator for various combinations of prediction lengths and observation rates. The local dynamic model based approach provides the best performance for short to medium prediction lengths under relatively
Directory of Open Access Journals (Sweden)
Jose F Abisambra
Full Text Available BACKGROUND: Alzheimer's disease (AD is a chronic neurodegenerative disorder and the most common form of dementia. The major molecular risk factor for late-onset AD is expression of the epsilon-4 allele of apolipoprotein E (apoE, the major cholesterol transporter in the brain. The low-density lipoprotein receptor (LDLR has the highest affinity for apoE and plays an important role in brain cholesterol metabolism. METHODOLOGY/PRINCIPAL FINDINGS: Using RT-PCR and western blotting techniques we found that over-expression of APP caused increases in both LDLR mRNA and protein levels in APP transfected H4 neuroglioma cells compared to H4 controls. Furthermore, immunohistochemical experiments showed aberrant localization of LDLR in H4-APP neuroglioma cells, Abeta-treated primary neurons, and in the PSAPP transgenic mouse model of AD. Finally, immunofluorescent staining of LDLR and of gamma- and alpha-tubulin showed a change in LDLR localization preferentially away from the plasma membrane that was paralleled by and likely the result of a disruption of the microtubule-organizing center and associated microtubule network. CONCLUSIONS/SIGNIFICANCE: These data suggest that increased APP expression and Abeta exposure alters microtubule function, leading to reduced transport of LDLR to the plasma membrane. Consequent deleterious effects on apoE uptake and function will have implications for AD pathogenesis and/or progression.
Local blockage of EMMPRIN impedes pressure ulcers healing in a rat model.
Zhao, Xi-Lan; Luo, Xiao; Wang, Ze-Xin; Yang, Guo-Li; Liu, Ji-Zhong; Liu, Ya-Qiong; Li, Ming; Chen, Min; Xia, Yong-Mei; Liu, Jun-Jie; Qiu, Shu-Ping; Gong, Xiao-Qing
2015-01-01
Excessive extracellular matrix degradation caused by the hyperfunction of matrix metalloproteinases (MMPs) has been implicated in the failure of pressure ulcers healing. EMMPRIN, as a widely expressed protein, has emerged as an important regulator of MMP activity. We hypothesize that EMMPRIN affects the process of pressure ulcer healing by modulating MMP activity. In the rat pressure ulcer model, the expression of EMMPRIN in ulcers detected by Western blot was elevated compared with that observed in normal tissue. To investigate the role of EMMPRIN in regulating ulcer healing, specific antibodies against EMMPRIN were used via direct administration on the pressure ulcer. Local blockage of EMMPRIN resulted in a poor ulcer healing process compared with control ulcers, which was the opposite of our expectation. Furthermore, inhibiting EMMPRIN minimally impacted MMP activity. However, the collagen content in the pressure ulcer was reduced in the EMMPRIN treated group. Angiogenesis and the expression of angiogenic factors in pressure ulcers were also reduced by EMMPRIN local blockage. The results in the present study indicate a novel effect of EMMPRIN in the regulation of pressure ulcer healing by controlling the collagen contents and angiogenesis rather than MMPs activity.
Directory of Open Access Journals (Sweden)
Samuel B Biitir
2015-06-01
Full Text Available Property rates and business operating license fees constitute the major revenue sources for local government authorities. Accurate assessment of these revenues enhances the revenue base and effectiveness of their generation. Assessment of property rates and business operating license fees have been identified as one of the limiting factors that inhibit the revenue potential of local government authorities. Assessment must obey the principles of taxation such as efficiency, equity and fairness, adequacy, administrative feasibility and political acceptability. Over the years, the Sekondi-Takoradi Metropolitan Assembly (STMA acknowledges that, it has had problems in ensuring equity and fairness in the assessment of property rates and business operating license fees. The paper reports on a computer modelling study carried out to introduce measure to ensure equity and fairness in assessing tax objects. A computer application has been developed with quantitative measures to evaluate and assess equity in tax assessment. A test run of the system has been successful and a pilot test is currently being implemented by STMA.
DEFF Research Database (Denmark)
Koch-Ciobotaru, Cosmin; Isleifsson, Fridrik Rafn; Gehrke, Oliver
2012-01-01
This paper presents a model predictive controller developed in order to minimize the cost of grid energy consumption and maximize the amount of energy consumed from a local photovoltaic (PV) installation. The usage of as much locally produced renewable en