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Sample records for additional external constraints

  1. Integrated reservoir characterization: Improvement in heterogeneities stochastic modelling by integration of additional external constraints

    Doligez, B.; Eschard, R. [Institut Francais du Petrole, Rueil Malmaison (France); Geffroy, F. [Centre de Geostatistique, Fontainebleau (France)] [and others

    1997-08-01

    The classical approach to construct reservoir models is to start with a fine scale geological model which is informed with petrophysical properties. Then scaling-up techniques allow to obtain a reservoir model which is compatible with the fluid flow simulators. Geostatistical modelling techniques are widely used to build the geological models before scaling-up. These methods provide equiprobable images of the area under investigation, which honor the well data, and which variability is the same than the variability computed from the data. At an appraisal phase, when few data are available, or when the wells are insufficient to describe all the heterogeneities and the behavior of the field, additional constraints are needed to obtain a more realistic geological model. For example, seismic data or stratigraphic models can provide average reservoir information with an excellent areal coverage, but with a poor vertical resolution. New advances in modelisation techniques allow now to integrate this type of additional external information in order to constrain the simulations. In particular, 2D or 3D seismic derived information grids, or sand-shale ratios maps coming from stratigraphic models can be used as external drifts to compute the geological image of the reservoir at the fine scale. Examples are presented to illustrate the use of these new tools, their impact on the final reservoir model, and their sensitivity to some key parameters.

  2. Matching Games with Additive Externalities

    Branzei, Simina; Michalak, Tomasz; Rahwan, Talal;

    2012-01-01

    fully expressive representations of externalities in matchings require exponential space, in this paper we propose a compact model of externalities, in which the influence of a match on each agent is computed additively. In this framework, we analyze many-to-many and one-to-one matchings under neutral...

  3. How long do external capital constraints matter?

    Stucki, Tobias

    2009-01-01

    Start-ups mostly have only limited internal financing. Post-entry performance should thus strongly depend on the availability of new external capital. In this study we analyze the impact of financial constraints on the performance of Swiss start-ups. Since we use cohort data, we have for some start-ups data at different points in time. This allows us to analyze whether the effect of the availability of external capital on firm performance changes with increasing age of the firms. To measure t...

  4. External and internal constraints on eukaryotic chemotaxis.

    Fuller, Danny; Chen, Wen; Adler, Micha; Groisman, Alex; Levine, Herbert; Rappel, Wouter-Jan; Loomis, William F

    2010-05-25

    Chemotaxis, the chemically guided movement of cells, plays an important role in several biological processes including cancer, wound healing, and embryogenesis. Chemotacting cells are able to sense shallow chemical gradients where the concentration of chemoattractant differs by only a few percent from one side of the cell to the other, over a wide range of local concentrations. Exactly what limits the chemotactic ability of these cells is presently unclear. Here we determine the chemotactic response of Dictyostelium cells to exponential gradients of varying steepness and local concentration of the chemoattractant cAMP. We find that the cells are sensitive to the steepness of the gradient as well as to the local concentration. Using information theory techniques, we derive a formula for the mutual information between the input gradient and the spatial distribution of bound receptors and also compute the mutual information between the input gradient and the motility direction in the experiments. A comparison between these quantities reveals that for shallow gradients, in which the concentration difference between the back and the front of a 10-mum-diameter cell is <5%, and for small local concentrations (<10 nM) the intracellular information loss is insignificant. Thus, external fluctuations due to the finite number of receptors dominate and limit the chemotactic response. For steeper gradients and higher local concentrations, the intracellular information processing is suboptimal and results in a smaller mutual information between the input gradient and the motility direction than would have been predicted from the ligand-receptor binding process. PMID:20457897

  5. INTERNAL FINANCIAL CONSTRAINTS, EXTERNAL FINANCIAL CONSTRAINTS AND INVESTMENT CHOICE: EVIDENCE FROM PAKISTANI FIRMS

    Dr. Muhammad AZAM; Syed Anum SHAH

    2011-01-01

    The purpose of this study is to analyze the impact of internal and external financial constraints on investmentchoice. The data have been taken from 9 major sectors (52 listed firms in the Karachi Stock Exchange) namely; Pharmaceutical & Bio Technology, Textile, Sugar, Tobacco, Chemicals, Oil and Gas, Fixed line Telecommunication, Industrial metal and Mining, and Cement sectors for the time period 2004 to 2010 on annual basis. Multiple regression analysis has been done to examine the rela...

  6. Design for Additive Manufacturing: Trends, opportunities, considerations, and constraints

    Thompson, Mary Kathryn; Moroni, Giovanni; Vaneker, Tom;

    2016-01-01

    The past few decades have seen substantial growth in Additive Manufacturing (AM) technologies. However, this growth has mainly been process-driven. The evolution of engineering design to take advantage of the possibilities afforded by AM and to manage the constraints associated with the technology...... has lagged behind. This paper presents the major opportunities, constraints, and economic considerations for Design for Additive Manufacturing. It explores issues related to design and redesign for direct and indirect AM production. It also highlights key industrial applications, outlines future...

  7. INTERNAL FINANCIAL CONSTRAINTS, EXTERNAL FINANCIAL CONSTRAINTS AND INVESTMENT CHOICE: EVIDENCE FROM PAKISTANI FIRMS

    Dr. Muhammad AZAM

    2011-10-01

    Full Text Available The purpose of this study is to analyze the impact of internal and external financial constraints on investmentchoice. The data have been taken from 9 major sectors (52 listed firms in the Karachi Stock Exchange namely; Pharmaceutical & Bio Technology, Textile, Sugar, Tobacco, Chemicals, Oil and Gas, Fixed line Telecommunication, Industrial metal and Mining, and Cement sectors for the time period 2004 to 2010 on annual basis. Multiple regression analysis has been done to examine the relationship among firm’s size, dividend payout ratio, firm’s age, and investment. The empirical findings show that there is positive relationship between the firms’ size and investment while a negative relationship exists between firms’ age and investment. It also reports that there is negative relationship between dividend payout ratio and the investment. This shows that if a firm grows old or high dividend payout ratio then it will tend to spend less for expansion as compared to the young firms.

  8. Soil carbon mineralization following biochar addition associated with external nitrogen

    Rudong Zhao

    2015-12-01

    Full Text Available Biochar has been attracting increasing attention for its potentials of C sequestration and soil amendment. This study aimed to understand the effects of combining biochar with additional external N on soil C mineralization. A typical red soil (Plinthudults was treated with two biochars made from two types of plantation-tree trunks (soil-biochar treatments, and was also treated with external N (soil-biochar-N treatments. All treatments were incubated for 42 d. The CO2-C released from the treatments was detected periodically. After the incubation, soil properties such as pH, microbial biomass C (MBC, and microbial biomass N (MBN were measured. The addition of biochar with external N increased the soil pH (4.31-4.33 compared to the soil treated with external N only (4.21. This was not observed in the comparison of soil-biochar treatments (4.75-4.80 to soil only (4.74. Biochar additions (whether or not they were associated with external N increased soil MBC and MBN, but decreased CO2-C value per unit total C (added biochar C + soil C according to the model fitting. The total CO2-C released in soil-biochar treatments were enhanced compared to soil only (i.e., 3.15 vs. 2.57 mg and 3.23 vs. 2.45 mg, which was attributed to the labile C fractions in the biochars and through soil microorganism enhancement. However, there were few changes in soil C mineralization in soil-biochar-N treatments. Additionally, the potentially available C per unit total C in soil-biochar-N treatments was lower than that observed in the soil-biochar treatments. Therefore, we believe in the short term, that C mineralization in the soil can be enhanced by biochar addition, but not by adding external N concomitantly.

  9. Timeline-Based Space Operations Scheduling with External Constraints

    Chien, Steve; Tran, Daniel; Rabideau, Gregg; Schaffer, Steve; Mandl, Daniel; Frye, Stuart

    2010-01-01

    We describe a timeline-based scheduling algorithm developed for mission operations of the EO-1 earth observing satellite. We first describe the range of operational constraints for operations focusing on maneuver and thermal constraints that cannot be modeled in typical planner/schedulers. We then describe a greedy heuristic scheduling algorithm and compare its performance to both the prior scheduling algorithm - documenting an over 50% increase in scenes scheduled with estimated value of millions of dollars US. We also compare to a relaxed optimal scheduler showing that the greedy scheduler produces schedules with scene count within 15% of an upper bound on optimal schedules.

  10. 1-Skeletons of the Spanning Tree Problems with Additional Constraints

    V. A. Bondarenko

    2015-10-01

    Full Text Available In this paper, we study polyhedral properties of two spanning tree problems with additional constraints. In the first problem, it is required to find a tree with a minimum sum of edge weights among all spanning trees with the number of leaves less than or equal to a given value. In the second problem, an additional constraint is the assumption that the degree of all nodes of the spanning tree does not exceed a given value. The recognition versions of both problems are NP-complete. We consider polytopes of these problems and their 1-skeletons. We prove that in both cases it is a NP-complete problem to determine whether the vertices of 1-skeleton are adjacent. Although it is possible to obtain a superpolynomial lower bounds on the clique numbers of these graphs. These values characterize the time complexity in a broad class of algorithms based on linear comparisons. The results indicate a fundamental difference between combinatorial and geometric properties of the considered problems from the classical minimum spanning tree problem.

  11. Influence of external constraints on the stability of sintering of bi-porous materials

    The constitutive behavior of a material with bimodal pore distribution is considered in the presence of external constraints and loading. For analysis, numerical methods of the continuum mechanics of sintering are utilized. The effects of partial constraining of the external surface of powder specimens subjected to sintering are studied. The evolution of volume fractions of small and large pores is analyzed. The sensitivity of large and small pore volume fraction kinetics to constraining/loading path is determined

  12. Potential External (non-DOE) Constraints on U.S. Fuel Cycle Options

    Steven J. Piet

    2012-07-01

    The DOE Fuel Cycle Technologies (FCT) Program will be conducting a screening of fuel cycle options in FY2013 to help focus fuel cycle R&D activities. As part of this screening, performance criteria and go/no-go criteria are being identified. To help ensure that these criteria are consistent with current policy, an effort was initiated to identify the status and basis of potentially relevant regulations, laws, and policies that have been established external to DOE. As such regulations, laws, and policies may be beyond DOE’s control to change, they may constrain the screening criteria and internally-developed policy. This report contains a historical survey and analysis of publically available domestic documents that could pertain to external constraints on advanced nuclear fuel cycles. “External” is defined as public documents outside DOE. This effort did not include survey and analysis of constraints established internal to DOE.

  13. The internal and external constraints of data protection on competition law in the EU

    Costa-Cabral, Francisco; Lynskey, Orla

    2015-01-01

    Personal data has both an economic and a dignitary value. This begs the question of whether competition law should respect the dual nature of personal data, given that the regulation of competition is chiefly dictated by economic concerns. This article addresses that question by mapping the potential intersections between EU data protection law and competition law. In particular, it argues that data protection law exercises an internal and an external constraint on competition law. On the one...

  14. Co-digestion of municipal sludge and external organic wastes for enhanced biogas production under realistic plant constraints.

    Tandukar, Madan; Pavlostathis, Spyros G

    2015-12-15

    A bench-scale investigation was conducted to select external organic wastes and mixing ratios for co-digestion with municipal sludge at the F. Wayne Hill Water Resources Center (FWHWRC), Gwinnett County, GA, USA to support a combined heat and power (CHP) project. External wastes were chosen and used subject to two constraints: a) digester retention time no lower than 15 d; and b) total biogas (methane) production not to exceed a specific target level based on air permit constraints on CO2 emissions. Primary sludge (PS), thickened waste activated sludge (TWAS) and digested sludge collected at the FWHWRC, industrial liquid waste obtained from a chewing gum manufacturing plant (GW) and dewatered fat-oil-grease (FOG) were used. All sludge and waste samples were characterized and their ultimate digestibility was assessed at 35 °C. The ultimate COD to methane conversion of PS, TWAS, municipal sludge (PS + TWAS; 40:60 w/w TS basis), GW and FOG was 49.2, 35.2, 40.3, 72.7, and 81.1%, respectively. Co-digestion of municipal sludge with GW, FOG or both, was evaluated using four bench-scale, mesophilic (35 °C) digesters. Biogas production increased significantly and additional degradation of the municipal sludge between 1.1 and 30.7% was observed. Biogas and methane production was very close to the target levels necessary to close the energy deficit at the FWHWRC. Co-digestion resulted in an effluent quality similar to that of the control digester fed only with the municipal sludge, indicating that co-digestion had no adverse effects. Study results prove that high methane production is achievable with the addition of concentrated external organic wastes to municipal digesters, at acceptable higher digester organic loadings and lower retention times, allowing the effective implementation of CHP programs at municipal wastewater treatment plants, with significant cost savings. PMID:25979784

  15. The additive and interactive effects of parenting and children's personality on externalizing behaviour

    Prinzie, P; Onghena, P; Hellinckx, W; Grietens, H; Ghesquiere, P; Colpin, H

    2003-01-01

    Parenting practices have been previously linked to childhood externalizing behaviour However little attention has been given to the potential effect of individual personality differences among children on this relation. The current study assesses the additive effects of children's personality charac

  16. The impact of internal and external constraint on the index of safe organization of execution area production of works

    Didenko, L. M.; Rybalka, К. А.; Ragimov, C. U.

    2015-01-01

    Purpose. To determine the parameters of the zone of construction and installation work for reconstruction of the industrial building and a rational application of means of mechanization involved in this process and to create the necessary conditions for quality and safe construction and installation of work subject to various constraints (internal or external constraint) imposed by the conditions of reconstruction. To identify the effect of the parameters of the zone of works at the rate of s...

  17. Can an energy balance model provide additional constraints on how to close the energy imbalance?

    Wohlfahrt, Georg; Widmoser, Peter

    2013-01-01

    Elucidating the causes for the energy imbalance, i.e. the phenomenon that eddy covariance latent and sensible heat fluxes fall short of available energy, is an outstanding problem in micrometeorology. This paper tests the hypothesis that the full energy balance, through incorporation of additional independent measurements which determine the driving forces of and resistances to energy transfer, provides further insights into the causes of the energy imbalance and additional constraints on ene...

  18. Internal stabilization and external $L_p$ stabilization of linear systems subject to constraints

    Saberi, Ali; Stoorvogel, Anton A.; Shi, Guoyong; Sannuti, Peddapullaiah

    2001-01-01

    Having studied during the last decade several aspects of several control design problems for linear systems subject to magnitude and rate constraints on control variables, during the last two years the research has broadened to include magnitude constraints on control variables as well as state variables. Recent work by Han et al. (2000), Hou et al. (1998) and Saberi et al. (2002) considered linear systems in a general framework for constraints including both input magnitude constraints as we...

  19. Externalities

    Verhoef Erik T.

    1997-01-01

    This paper discusses the concept of ‘externalities ‘. It starts with a brief discussion of market failures in the neoclassical economic framework. It then proceeds to a definition of externalities, thereby distinguishing external effects from other sorts of ‘unpriced effects ‘. Finally, some attention is paid to the relation, and tension, between efficiency and equity impacts of externalities.

  20. Constraints on an additional Z' gauge boson versus the W, the top and the Higgs masses

    We analyse the restrictions on the mass and the mixing of an additional Z' gauge boson that follow from the recent LEP measurements taking into account standard model (SM) radiative corrections. We find that these restrictions depend sharply on the assumed values for the SM structural parameters, the most important of which are MW and mtop. The constraints become stronger for lighter W and heavier top. (orig.)

  1. Accurate and robust registration of high-speed railway viaduct point clouds using closing conditions and external geometric constraints

    Ji, Zheng; Song, Mengxiao; Guan, Haiyan; Yu, Yongtao

    2015-08-01

    This paper proposes an automatic method for registering multiple laser scans without a control network. The proposed registration method first uses artificial targets to pair-wise register adjacent scans for initial transformation estimates; the proposed registration method then employs combined adjustments with closing conditions and external triangle constraints to globally register all scans along a long-range, high-speed railway corridor. The proposed registration method uses (1) closing conditions to eliminate registration errors that gradually accumulate as the length of a corridor (the number of scan stations) increases, and (2) external geometric constraints to ensure the shape correctness of an elongated high-speed railway. A 640-m high-speed railway viaduct with twenty-one piers is used to conduct experiments using our proposed registration method. A group of comparative experiments is undertaken to evaluate the robustness and efficiency of the proposed registration method to accurately register long-range corridors.

  2. Dust Around Herbig Ae Stars: Additional Constraints from their Photometric and Polarimetric Variability

    Krivova, N. A.; Ilin, V. B.; Fischer, O.

    1996-01-01

    For the Herbig Ae stars with Algol-like minima (UX Ori, WW Vul, etc), the effects of circumstellar dust include: excess infrared emission, anomalous ultraviolet extinction, the 'blueing' of the stars in minima accompanying by an increase of intrinsic polarization. Using a Monte-Carlo code for polarized radiation transfer we have simulated these effects and compared the results obtained for different models with the observational data available. We found that the photometric and polarimetric behavior of the stars provided essential additional constraints on the circumstellar dust models. The models with spheroidal shell geometry and compact (non-fluffy) dust grains do not appear to be able to explain all the data.

  3. The external debt-servicing constraint and public-expenditure composition in sub-Saharan Africa

    Fosu, Augustin

    2010-01-01

    In the light of the current global financial and economic crises, how would governments in sub-Saharan Africa (SSA) allocate their budgets across sectors in response to a binding debt-servicing constraint? Within a framework of public-expenditure choice, the present paper estimates constraint-consistent debt-service ratios and employs them in Seemingly Unrelated Regression involving five-year panel for up to 35 African countries over 1975-94, a period preceding the Highly Indebted Poor Coun...

  4. Denitrification potential enhancement by addition of external carbon sources in a pre-denitrification process

    PENG Yong-zhen; MA Yong; WANG Shu-ying

    2007-01-01

    The aim of this study is to investigate the denitrification potential enhancement by addition of external carbon sources and to estimate the denitrification potential for the predenitrification system using nitrate utilization rate(NUR)batch tests.It is shown that the denitrification potential Can be substantially increased with the addition of three external carbon sources,i.e.methanol,ethanol,and acetate.and the denitrification rates of ethanol,acetate,and methanol reached up to 9.6,12,and 3.2 mgN/(gVSS·h),respectively,while mat of starch wastewater was only 0.74 mgN/(gVSS·h).By comparison,ethanol was found to be the best extemal carbon source.NUR batch tests with starch wastewater and waste ethanol were carried out.The denitrification potential increased from 5.6 to 16.5 mg NO.-N/L owing to waste ethanol addition.By means of NUR tests,the wastewater characteristics and kinetic parameters can be estimated.which are used to determine the denitrification potential of wastewater,to calculate the denitrification potential of the plant and to predict the nitrate effluent quality,as well as provide information for developing carbon dosage conlxol strategy.

  5. The Internal and External Constraints on Foreign Policy in India - Exploring culture and ethnic sensitivities

    Schmidt, Johannes Dragsbæk

    The main argument of this contribution is that the distinction between internal and external is at best blurred and in reality does not make much sense in the case of India’s foreign policy. It may start and end at the border and determined by negotiations, diplomacy or brute force but there is no...... ethnicity and outline the main approaches involved; to give an overview of how external factors impact foreign policy conduct and give an overview about India’s role in defining international norms and regulations; finally the paper gives some theoretical markers, suggestions and tentative concluding...

  6. Fuzzy Control of Nitrate Recirculation and External Carbon Addition in A/O Nitrogen Removal Process

    马勇; 彭永臻; 王淑莹; 王晓莲

    2005-01-01

    Nitrogen and phosphorous concentrations of effluent water must be taken into account for the design and operation of wastewater treatment plants. In addition, the requirement for effluent quality is becoming strict.Therefore, intelligent control approaches are recently required in removing biological nutrient. In this study, fuzzy control has been successfully applied to improve the nitrogen removal. Experimental results showed that a close relationship between nitrate concentration and oxidation-reduction potential (ORP) at the end of anoxic zone was found for anoxic/oxic (A/O) nitrogen removal process treating synthetic wastewater. ORP can be used as online fuzzy control parazneter of nitrate recirculation and external carbon addition. The established fuzzy logic controller that includes two inputs and one output can maintain ORP value at-86 mV and -90 mV by adjusting the nitrate recirculation flow and external carbon dosage respectively to realize the optimal control of nitrogen removal, improving the effluent quality and reducing the operating cost.

  7. Employment, real wages and external constraint: the case of Brazil and Chile.

    Cortazar R

    1986-01-01

    ILO pub-WEP pub. Working paper, economic analysis of the impact of economic policy responses to external debt on employment and wages in Brazil and Chile - discusses trends in minimum wages, unemployment and underemployment; reviews the economic implications and social implications of reduced consumer demand, export promotion, import substitution, devaluation and export of capital. Graphs, references, statistical tables.

  8. Can an energy balance model provide additional constraints on how to close the energy imbalance?

    Wohlfahrt, Georg; Widmoser, Peter

    2013-02-15

    Elucidating the causes for the energy imbalance, i.e. the phenomenon that eddy covariance latent and sensible heat fluxes fall short of available energy, is an outstanding problem in micrometeorology. This paper tests the hypothesis that the full energy balance, through incorporation of additional independent measurements which determine the driving forces of and resistances to energy transfer, provides further insights into the causes of the energy imbalance and additional constraints on energy balance closure options. Eddy covariance and auxiliary data from three different biomes were used to test five contrasting closure scenarios. The main result of our study is that except for nighttime, when fluxes were low and noisy, the full energy balance generally did not contain enough information to allow further insights into the causes of the imbalance and to constrain energy balance closure options. Up to four out of the five tested closure scenarios performed similarly and in up to 53% of all cases all of the tested closure scenarios resulted in plausible energy balance values. Our approach may though provide a sensible consistency check for eddy covariance energy flux measurements. PMID:24465072

  9. Research on additional external exposure dose rate measurement by in-situ HPGe γ spectrometer

    A spectrometric method for additional exposure dose rate (external dose rate due to γ-ray emitted by artificial nuclides) measurement is introduced. The principle of this method is that: strip off the spectrum attributed to the natural radionuclides from the gamma spectrum collected by in situ HPGe spectrometer, and get the spectrum attributed to the artificial radionuclides, then integrate the stripped spectrum with corresponding spectrum-dose conversion function (G(E) function) values to acquire additional exposure dose rate. Standard spectrums attributed to nuclides in U series, Th series and 40K were calibrated by in situ HPGe spectrometer at airborne pads, and the interference caused by other nuclides was eliminated by the inverse matrix calculations. The natural compositions in the spectrum is stripped according to the standard spectrums. Six standard γ-ray sources were used to acquire the response functions of the HPGe spectrometer, then the G(E) function was calculated by the least square method. Finally, the utility of this method was verified by in situ experiment, and the factors that influence the precision of the results are discussed. (author)

  10. Investigation of air-breathing, hypersonic missile configurations within external box constraints

    Starkey, Ryan Peter

    2000-12-01

    Aspects relating to the aerodynamic, geometric, and propulsive design and analysis of missile-class, waverider-based hypersonic vehicles are explored. A quasi-one-dimensional engine model, including the effects of fuel injection, mixing, chemical production rates, heat transfer, and viscous losses is developed and utilized to assess the effects of finite rate hydrocarbon chemistry on optimized missile configurations. Resultant optimized single and double engine missile designs are shown for changes in fuel mixing length, fuel mixing efficiency, fuel injector location, and assumed fuel mass fraction. The effects of these different design conditions on the cruise range are explored, as well as perturbations around these design points for optimized vehicles. Aerodynamics are evaluated using a newly developed modified shock-expansion method. Missiles are optimized for steady-state trim conditions at the beginning of cruise using parallelized genetic algorithm optimization software developed for this study. All missile designs are assumed to reach cruising altitude and velocity through the use of an external rocket booster. The missile is geometrically constrained to fit within the 0.61 m x 0.61 m x 4.27 m [2 foot x 2 foot x 14 foot] box limits for a Naval vertical launch tube and has a desired cruise range of 750 km [400 nm] at Mach 6. Investigations are also shown for the effects of various modeling assumptions: (1) shock-expansion method versus a new modified shock-expansion aerodynamic method, (2) boundary layer assumptions, (3) assumed combustor temperature profile versus finite rate chemistry computations, and (4) ratio of specific heats assumptions. An overall analysis and optimization toolkit is developed for quick calculation of hypersonic aerodynamics and propulsion with added insight into externally constrained vehicles. Results show that the optimized combustor designs were extremely sensitive to small changes in flow conditions and that high

  11. Constraints on additional Z' gauge bosons from a precise measurement of the Z mass

    González García, Mª Concepción; Furtado Valle, José Wagner

    1990-01-01

    We analyze the constraints on the mass and mixing of a superstring-inspired E6 Z' neutral gauge boson that follow from the recent precise Z mass measurements and show that they depend very sensitively on the assumed value of the W mass and also, to a lesser extent, on the top-quark mass.

  12. Comparative evaluation of tableting compression behaviors by methods of internal and external lubricant addition: Inhibition of enzymatic activity of trypsin preparation by using external lubricant addition during the tableting compression process

    Otsuka, Makoto; Sato, Mitsuyo; Matsuda, Yoshihisa

    2001-01-01

    This study evaluated tableting compression by using internal and external lubricant addition. The effect of lubricant addition on the enzymatic activity of trypsin, which was used as a model drug during the tableting compression process, was also investigated. The powder mixture (2% crystalline trypsin, 58% crystalline lactose, and 40% microcrystalline cellulose) was kneaded with 5% hydroxypropyl cellulose aqueous solution and then granulated using an extruding granulator equipped with a 0.5-...

  13. Update on the use of dissolved oxygen addition to monitor the effectiveness of noble metal applications in external manifolds

    Electrochemical corrosion potential (ECP) measurements in a Mitigation Monitoring System (MMS) ECP manifold have historically been a primary indicator of the effectiveness of an On-Line NobleChem™ (OLNC) application, with the MMS ECP intended to measure the catalytic effect of noble metal deposited on the ECP manifold surface. In some plants ECP measurements made on untreated surfaces prior to an OLNC application were significantly lower than what would be expected for stainless steel under reactor bulk chemistry conditions. This is due to the consumption and depletion of bulk liquid dissolved oxygen (DO) in the lines supplying reactor water to these external ECP measurement locations. This phenomenon degrades the ability to use these external manifolds to confirm noble metal deposition. Previous papers have described how the injection of an oxygen-rich stream to the MMS supply stream (DO Addition) can be used to re-establish the capability of external ECP measurements to monitor the catalytic behavior of platinum deposited during an OLNC injection. This paper will provide an update of how this method is being successfully used in operating BWRs to monitor OLNC injections. The paper will outline the overall approach used to characterize the catalytic behavior of external ECP manifolds before and after the noble metal application and present plant data collected during DO Additions performed under various conditions. (author)

  14. A novel approach for phosphorus recovery and no wasted sludge in enhanced biological phosphorus removal process with external COD addition.

    Xia, Cheng-Wang; Ma, Yun-Jie; Zhang, Fang; Lu, Yong-Ze; Zeng, Raymond J

    2014-01-01

    In enhanced biological phosphorus removal (EBPR) process, phosphorus (P) in wastewater is removed via wasted sludge without actual recovery. A novel approach to realize phosphorus recovery with special external chemical oxygen demand (COD) addition in EBPR process was proposed. During the new operating approach period, it was found that (1) no phosphorus was detected in the effluent; (2) with an external addition of 10 % of influent COD amount, 79 % phosphorus in the wastewater influent was recovered; (3) without wasted sludge, the MLVSS concentration in the system increased from 2,010 to 3,400 mg/L and kept stable after day 11 during 24-day operating period. This demonstrates that the novel approach is feasible to realize phosphorus recovery with no wasted sludge discharge in EBPR process. Furthermore, this approach decouples P removal and sludge age, which may enhance the application of membrane bioreactor for P removal. PMID:24122666

  15. Modeling the Effect of External Carbon Source Addition under Different Electron Acceptor Conditions in Biological Nutrient Removal Activated Sludge Systems.

    Hu, Xiang; Wisniewski, Kamil; Czerwionka, Krzysztof; Zhou, Qi; Xie, Li; Makinia, Jacek

    2016-02-16

    The aim of this study was to expand the International Water Association Activated Sludge Model No. 2d (ASM2d) to predict the aerobic/anoxic behavior of polyphosphate accumulating organisms (PAOs) and "ordinary" heterotrophs in the presence of different external carbon sources and electron acceptors. The following new aspects were considered: (1) a new type of the readily biodegradable substrate, not available for the anaerobic activity of PAOs, (2) nitrite as an electron acceptor, and (3) acclimation of "ordinary" heterotrophs to the new external substrate via enzyme synthesis. The expanded model incorporated 30 new or modified process rate equations. The model was evaluated against data from several, especially designed laboratory experiments which focused on the combined effects of different types of external carbon sources (acetate, ethanol and fusel oil) and electron acceptors (dissolved oxygen, nitrate and nitrite) on the behavior of PAOs and "ordinary" heterotrophs. With the proposed expansions, it was possible to improve some deficiencies of the ASM2d in predicting the behavior of biological nutrient removal (BNR) systems with the addition of external carbon sources, including the effect of acclimation to the new carbon source. PMID:26783836

  16. The Disciplinary Constraints of SLA and TESOL: Additive Bilingualism and Second Language Acquisition, Teaching and Learning

    May, Stephen

    2011-01-01

    For over 15 years now, various commentators have highlighted the 'monolingual bias' inherent in SLA and TESOL research, which invariably constructs bi/multilingualism in deficit terms. In contrast, these critics have advocated an additive bilingual approach to SLA and TESOL, albeit, not as yet to any great effect. In this paper, I explore why so…

  17. External Carbon Source Addition as a Means to Control an Activated Sludge Nutrient Removal Process

    Isaacs, Steven Howard; Henze, Mogens; Søeberg, Henrik; Kymmel, Mogens

    1994-01-01

    denitrification momentarily occurs. This approach serves to increase the denitrification rate on demand, thereby allowing the accumulation of nitrate and nitrite during periods of peak nitrogen loading to be reduced or avoided. A pilot plant demonstration of the control strategy using acetate as COD source is...... provided, showing a marked improvement in effluent water quality as compared to the uncontrolled case. An examination of the resulting denitrification rates illustrates the direct proportionality between these rates and the rate of COD addition....

  18. Intensified nitrogen removal in immobilized nitrifier enhanced constructed wetlands with external carbon addition.

    Wang, Wei; Ding, Yi; Wang, Yuhui; Song, Xinshan; Ambrose, Richard F; Ullman, Jeffrey L

    2016-10-01

    Nitrogen removal performance response of twelve constructed wetlands (CWs) to immobilized nitrifier pellets and different influent COD/N ratios (chemical oxygen demand: total nitrogen in influent) were investigated via 7-month experiments. Nitrifier was immobilized on a carrier pellet containing 10% polyvinyl alcohol (PVA), 2.0% sodium alginate (SA) and 2.0% calcium chloride (CaCl2). A batch experiment demonstrated that 73% COD and 85% ammonia nitrogen (NH4-N) were degraded using the pellets with immobilized nitrifier cells. In addition, different carbon source supplement strategies were applied to remove the nitrate (NO3-N) transformed from NH4-N. An increase in COD/N ratio led to increasing reduction in NO3-N. Efficient nitrification and denitrification promoted total nitrogen (TN) removal in immobilized nitrifier biofortified constructed wetlands (INB-CWs). The results suggested that immobilized nitrifier pellets combined with high influent COD/N ratios could effectively improve the nitrogen removal performance in CWs. PMID:27396293

  19. Prospective randomised trial on the role of HDR-brachytherapy in addition to external beam radiotherapy for central bronchial carcinoma

    Objective: In a prospective, randomised trial we investigated the influence of additional High-Dose-Rate-(HDR)-brachytherapy on tumor control and overall survival of patients suffering from inoperable central lung tumors treated with loco-regional external beam radiotherapy (EB-RT). Special attention was given to dose limiting side effects. Methods: Patients randomised in group A received loco-regional EB-RT up to 50 Gy (5 x 2 Gy per week), followed by a boost of 10 Gy also 2 Gy 5 times a week to the primary and adjacent lymphonodular metastases. Patients in group B additionally received an endoluminal HDR-afterloading-radiotherapy (192Ir) with 10 Gy calculated for 5 mm depth one week before and three weeks after EB-RT. Due to the advanced tumor stage, none of the patients received surgery before irradiation. Patients treated with chemotherapy were excluded from the study. Results: Until February 1996 all of 98 patients were evaluated. Both groups are comparable regarding age, gender, Karnofsky Performance State, tumor stage (mostly stage IIIb and IV) and histology. Squamous cell carcinoma (SCC) were found in 69%, whereas the rest consisted of adeno carcinoma (15%), large cell carcinoma (6%) and non small cell carcinoma (NSCLC) (10%), all subsets equally distributed between group A and B. Local control in group A (n=42) lasted for a median of 12 weeks, in group B (n=56) for a median of 21 weeks, a difference which is just significant (p≤0,05). The median overall survival was nearly identical (28 weeks). The subgroup of SCC, however, showed a median survival of 33 (group A) versus 40 weeks (group B), a difference which is not significant (p≤0.09), but might indicate an advantage for this histological group. The most serious side effect was fatal bleeding with 15% in group A and 21% in group B. Conclusions: At present, this study reveals improved local control by a boost of 2x10 Gy 192Ir-HDR-AL in addition to definitive EB-RT (group B) compared to EB-RT alone

  20. Diastereoselective Addition of α-Metalated Sulfoxides to Imines Revisited: Mechanism, Computational Studies, and the Effect of External Chiral Ligands

    Pedersen, Brian; Rein, Tobias; Søtofte, Inger;

    2003-01-01

    six-membered "flat chair") was probed by quantum mechanical calculations, which underpinned the idea of using external chiral ligands to enhance the diastereoselectivity of otherwise moderately selective reactions. In this way, the diastereomeric ratio of the product 3a could be raised from (84 : 16...

  1. Effect of Feed Additive on Base of L-carnitine in Drinking Water on Internal and External Egg Quality

    Cyril Hrnčár; Martin Gašparovič; Ján Weis; Henrieta Arpášová; Veronika Pistová; Martin Fik; Jozef Bujko

    2016-01-01

    The objective of present study was to investigate the effect of feed additive on base of L-carnitine (30%) on some parameters of egg quality. Totally 40 White Leghorn laying hens were divided in two groups: control group (n=20) received drinking water without any additives and experimental group (n=20) received feed additive in dose 1 ml per 1.2 l of drinking water for a period of 5 days in 2 week intervals from 26 to 56 week of age. Hens in both groups were feeding ad libitum with commercial...

  2. Constraint on Additional Planets in Planetary Systems Discovered through the Channel of High-magnification Gravitational Microlensing Events

    Shin, I -G; Choi, J -Y; Hwang, K -H; Jung, Y K; Park, H

    2015-01-01

    High-magnification gravitational microlensing events provide an important channel of detecting planetary systems with multiple giants located at their birth places. In order to investigate the potential existence of additional planets, we reanalyze the light curves of the eight high-magnification microlensing events for each of which a single planet was previously detected. The analyzed events include OGLE-2005-BLG-071, OGLE-2005-BLG-169, MOA-2007-BLG-400, MOA-2008-BLG-310, MOA-2009-BLG-319, MOA-2009-BLG-387, MOA-2010-BLG-477, and MOA-2011-BLG-293. We find that including an additional planet improves fits with $\\Delta\\chi^2 < 80$ for seven out of eight analyzed events. For MOA-2009-BLG-319, the improvement is relatively big with $\\Delta\\chi^2 \\sim 143$. From inspection of the fits, we find that the improvement of the fits is attributed to systematics in data. Although no clear evidence of additional planets is found, it is still possible to constrain the existence of additional planets in the parameter spa...

  3. Synergetic effects of pulse constraints and additives in electrodeposition of nanocrystalline zinc: Corrosion, structural and textural characterization

    Pulse electrodeposition was to produce nanocrystalline (nc) zinc from alkaline non-cyanide electrolyte with primary and secondary additives. The combined effect of pulse parameters (ON-time (TON), OFF-time (TOFF), pulse peak current density (IP)) and additives on the corrosion properties (evaluated using electrochemical techniques) of zinc electrodeposits are elucidated in terms of surface morphology (using scanning electron microscope), topography and root mean square (RMS) roughness (using atomic force microscope), crystallite size, its orientations and relative texture co-efficient (RTC, %) were evaluated using X-ray diffraction. The corrosion resistance of zinc electrodeposits obtained at constant TON and IP enhanced (i.e., low Icorr and high Rct values) with increased TOFF. At constant TOFF and IP, the Icorr values increased and Rct values decreased with TON while the former decreases and latter increases with IP at constant TON and TOFF. The inclusion of primary and secondary additives into the electrolyte produced nc zinc electrodeposits at 5 Adm-2, showed enhanced protective properties (Icorr-16 μA cm-2 and Rct-481.8 Ω cm-2). Fine grained due to high negative overpotential, reduced roughness and higher percentage of basal plane [0 0. 2] orientation have major impact for the enhanced corrosion resistances.

  4. Influence of Zeolite Additive on the Properties of Plaster Used for External Walls from Autoclaved Aerated Concrete

    Georgijus SEZEMANAS

    2013-05-01

    Full Text Available Enclosures that had been built from elements of autoclaved aerated concrete (AAC often are covered with plasters. Some adhesion problems between plasters and surface exist during the mechanized covering of surfaces of the mentioned enclosures with plaster. Some dispersible additives (vinyl acetate polymer or derivatives of acrylic acid esters are used to improve the adhesion. Another problem is the increased water absorption of AAC elements, therefore water retarding additives (cellulose esters are used in the mixture of plasters. Due to insufficient amount of water in the mixture of plasters, the hydration of cement minerals slows down. Influence of the natural zeolite – clinoptilolite on the properties of plaster is analyzed in this work. It was found that this additive effectively absorbs water and thus, ensures adequate hydration of cement minerals. When in the mixture of plaster the sand is changed by clinoptilolite in amount of 15 % the structure slightly compacts, the compressive and flexural strength of hardened plaster increase by 47 % and 12 % respectively and the adhesion to a surface of the AAC element increases by 44 %. Drying shrinkage, water vapor resistance factor and coefficient of capillary absorption remain unchanged.DOI: http://dx.doi.org/10.5755/j01.ms.19.2.4441

  5. Synergetic effects of pulse constraints and additives in electrodeposition of nanocrystalline zinc: Corrosion, structural and textural characterization

    Chandrasekar, M.S. [Indian Institute of Technology-Madras, Chennai 36 (India); Shanmugasigamani [Central Electrochemical Research Institute, Karaikudi 6 (India); Malathy, Pushpavanam, E-mail: malathypush@yahoo.com [Alagappa Chettiar College of Engineering and Technology, Karaikudi 6 (India)

    2010-11-01

    Pulse electrodeposition was to produce nanocrystalline (nc) zinc from alkaline non-cyanide electrolyte with primary and secondary additives. The combined effect of pulse parameters (ON-time (T{sub ON}), OFF-time (T{sub OFF}), pulse peak current density (I{sub P})) and additives on the corrosion properties (evaluated using electrochemical techniques) of zinc electrodeposits are elucidated in terms of surface morphology (using scanning electron microscope), topography and root mean square (RMS) roughness (using atomic force microscope), crystallite size, its orientations and relative texture co-efficient (RTC, %) were evaluated using X-ray diffraction. The corrosion resistance of zinc electrodeposits obtained at constant T{sub ON} and I{sub P} enhanced (i.e., low I{sub corr} and high R{sub ct} values) with increased T{sub OFF}. At constant T{sub OFF} and I{sub P}, the I{sub corr} values increased and R{sub ct} values decreased with T{sub ON} while the former decreases and latter increases with I{sub P} at constant T{sub ON} and T{sub OFF}. The inclusion of primary and secondary additives into the electrolyte produced nc zinc electrodeposits at 5 Adm{sup -2}, showed enhanced protective properties (I{sub corr}-16 {mu}A cm{sup -2} and R{sub ct}-481.8 {Omega} cm{sup -2}). Fine grained due to high negative overpotential, reduced roughness and higher percentage of basal plane [0 0. 2] orientation have major impact for the enhanced corrosion resistances.

  6. Effects of additional external weight on posture and movement adaptations to fatigue induced by a repetitive pointing task.

    Cantú, Hiram; Emery, Kim; Côté, Julie N

    2014-06-01

    Fatigue and additional weight are risk factors of injuries by falls. Posture and trunk movement changes occur with fatigue induced by a repetitive pointing task. These changes facilitate arm movement but they may also jeopardize postural stability. When equilibrium is challenged, e.g. with additional weight, strategies that represent less postural threat could develop with fatigue. Nineteen participants performed two sessions (without, with 20% body weight added load (Load)) of a repetitive pointing task until shoulder fatigue (8 on Borg CR-10). There was no difference in time to fatigue between the two sessions. Anterior deltoid, biceps and upper trapezius muscle activity significantly increased with fatigue. Peak medial-lateral center-of-pressure (CoP) velocity and the mean vertical position of the reaching shoulder were both significantly lower with fatigue, though these fatigue-induced decreases were smaller with the added load. Reach-to-reach variability in CoP displacement significantly increased with fatigue, and more so with the added load. With fatigue, significant contralateral shifts occurred at the reaching shoulder and elbow joints, and ranges of motion (RoM) significantly increased at most joints but not at the center-of-mass (CoM). Conversely, Load main effects were mostly seen in CoM dependent measures. Significantly increased variability in mean and range values was seen with fatigue and Load in most of our kinematic and CoP dependent measures, with the most notable effects on CoM dependent measures. Findings suggest that the postural control system adapts to combined perturbing factors of fatigue and added load, likely by using parallel control mechanisms. PMID:24786737

  7. The low-energy theorem for the forward Compton amplitude of a stationary composite system and the FW additive external electromagnetic interaction

    It is shown that the low-energy theorem for the forward Compton amplitude of a stationary composite system in states with nonzero internal orbital angular momentum can only be verified with the use of the FW additive external electromagnetic interaction to order 1/M3 together with the relativistic c.m. variables to order 1/M2, contrary to what is usually believed. The theorem is also explicitly demonstrated even when both the constituent particles of the composite system are electrically charged. (author)

  8. Temperature, pressure, and electrochemical constraints on protein speciation: Group additivity calculation of the standard molal thermodynamic properties of ionized unfolded proteins

    J. M. Dick

    2006-01-01

    Full Text Available Thermodynamic calculations can be used to quantify environmental constraints on the speciation of proteins, such as the pH and temperature dependence of ionization state, and the relative chemical stabilities of proteins in different biogeochemical settings. These calculations depend in part on values of the standard molal Gibbs energies of proteins and their ionization reactions as a function of temperature and pressure. Because these values are not generally available, we calculated values of the standard molal thermodynamic properties at 25°C and 1 bar as well as the revised Helgeson-Kirkham-Flowers equations of state parameters of neutral and charged zwitterionic reference model compounds including aqueous amino acids, polypeptides, and unfolded proteins. The experimental calorimetric and volumetric data for these species taken from the literature were combined with group additivity algorithms to calculate the properties and parameters of neutral and ionized sidechain and backbone groups in unfolded proteins. The resulting set of group contributions enables the calculation of the standard molal Gibbs energy, enthalpy, entropy, isobaric heat capacity, volume, and isothermal compressibility of unfolded proteins in a range of proton ionization states to temperatures and pressures exceeding 100°C and 1000 bar. This approach provides a useful frame of reference for thermodynamic studies of protein folding and complexation reactions. It can also be used to assign provisional values of the net charge and Gibbs energy of ionized proteins as a function of temperature and pH. Using these values, an Eh-pH diagram for a reaction representing the speciation of extracellular proteins from Pyrococcus furiosus and Bacillus subtilis was generated. The predicted predominance limits of these proteins correspond with the different electrochemical conditions of hydrothermal vents and soils. More comprehensive calculations of this kind may reveal pervasive

  9. Solar System constraints on Renormalization Group extended General Relativity: The PPN and Laplace-Runge-Lenz analyses with the external potential effect

    Rodrigues, Davi C; de Almeida, Álefe O F

    2016-01-01

    General Relativity extensions based on Renormalization Group effects are motivated by a known physical principle and constitute a class of extended gravity theories that have some unexplored unique aspects. In this work we develop in detail the Newtonian and post Newtonian limits of a realisation called Renormalization Group extended General Relativity (RGGR). Special attention is taken to the external potential effect, which constitutes a type of screening mechanism typical of RGGR. In the Solar System, RGGR depends on a single dimensionless parameter $\\bar \

  10. Constraints on the location of a putative distant massive body in the Solar System and on the External Field Effect of MOND from recent planetary data

    Iorio, Lorenzo

    2011-01-01

    We analytically work out the long-term variations caused on the motion of a planet orbiting a star by a distant, pointlike massive object X (Planet X/Nemesis/Tyche). It turns out that, apart from the semimajor axis $a$, all the other Keplerian orbital elements of the perturbed planet experience long-term variations which are complicated functions of the orbital configurations of both the planet itself and of X. A numerical integration of the equations of motion of the perturbed planet yielding the temporal evolution of all its orbital elements successfully confirms our analytical results. We infer constraints on the minimum distance $d_{\\rm X}$ at which the putative body X can exist by comparing, first, our prediction of the long-term variation of the longitude of the perihelion $\\varpi$ to the latest empirical determinations of the corrections $\\Delta\\dot\\varpi$ to the standard Newtonian/Einsteinian secular precessions of several planets of the solar system recently obtained. Independent teams of astronomers...

  11. Additional androgen deprivation makes the difference. Biochemical recurrence-free survival in prostate cancer patients after HDR brachytherapy and external beam radiotherapy

    Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus [University Medical Center Hamburg-Eppendorf, Martini-Clinic Prostate Cancer Center, Hamburg (Germany); Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf [University Medical Center Hamburg-Eppendorf, Department of Radiation oncology, Hamburg (Germany)

    2015-04-01

    The role of additional androgen deprivation therapy (ADT) in prostate cancer (PCa) patients treated with combined HDR brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) is still unknown. Consecutive PCa patients classified as D'Amico intermediate and high-risk who underwent HDR-BT and EBRT treatment ± ADT at our institution between January 1999 and February 2009 were assessed. Multivariable Cox regression models predicting biochemical recurrence (BCR) were performed. BCR-free survival was assessed with Kaplan-Meier analyses. Overall, 392 patients were assessable. Of these, 221 (56.4 %) underwent trimodality (HDR-BT and EBRT and ADT) and 171 (43.6 %) bimodality (HDR-BT and EBRT) treatment. Additional ADT administration reduced the risk of BCR (HR: 0.4, 95 % CI: 0.3-0.7, p < 0.001). D'Amico high-risk patients had superior BCR-free survival when additional ADT was administered (log-rank p < 0.001). No significant difference for BCR-free survival was recorded when additional ADT was administered to D'Amico intermediate-risk patients (log-rank p = 0.2). Additional ADT administration improves biochemical control in D'Amico high-risk patients when HDR-BT and EBRT are combined. Physicians should consider the oncological benefit of ADT administration for these patients during the decision-making process. (orig.) [German] Der Nutzen einer zusaetzlichen Hormonentzugstherapie (ADT, ''androgen deprivation therapy'') fuer Patienten mit Prostatakarzinom (PCa), welche mit einer Kombination aus HDR-Brachytherapie (HDR-BT) und perkutaner Bestrahlung (EBRT) behandelt werden, ist weiterhin ungeklaert. Fuer diese Studie wurden konsekutive, nach der D'Amico-Risikoklassifizierung in ''intermediate'' und ''high-risk'' eingeteilte Patienten ausgewaehlt, die zwischen Januar 1999 und Februar 2009 in unserem Institut eine kombinierte Therapie aus HDR-BT, EBRT ± ADT erhalten haben. Eine

  12. Salários e tecnologia num modelo de crescimento com restrição externa Wages and technology in a growth model with external constraints

    Marcus Dutra

    2006-04-01

    Full Text Available O modelo proposto formaliza uma preocupação que se encontra cada vez com mais freqüência na literatura, a saber, a de que trabalhadores que não têm acesso a condições adequadas de capacitação, saúde e motivação tendem a aprender menos, reduzindo a velocidade de inovação em produtos e processos na firma. Na medida em que a competitividade internacional repousa crescentemente na inovação e/ou na imitação rápida de tecnologia, um nível baixo de desenvolvimento humano implicará oportunidades de crescimento perdidas. Assim, o modelo assume que, até certo valor crítico do salário real, aumentos de salário real produzem aumentos de competitividade e da taxa de crescimento com equilíbrio externo, tornando compatíveis o crescimento econômico e a distribuição da renda, inclusive num contexto de abertura e de intensa concorrência internacional.The model formalizes a topic that the economic literature addresses with increasing frequency, namely that workers who have no access to adequate levels of education, health and motivation tend to learn more slowly and this in turn reduces the rate of innovation in products and processes in the firm. To the extent that international competitiveness increasingly relies on innovation and imitation of technology, a low level of human development will render lost opportunities for growth. Thus, the model assumes that - up to a certain critical level of the real wage - increases in real wages lead to a higher rate of growth consistent with balance-of-payments equilibrium, which makes compatible growth and income distribution even in contexts of external openness and intense international competition.

  13. Constraint Differentiation

    Mödersheim, Sebastian Alexander; Basin, David; Viganò, Luca

    2010-01-01

    We introduce constraint differentiation, a powerful technique for reducing search when model-checking security protocols using constraint-based methods. Constraint differentiation works by eliminating certain kinds of redundancies that arise in the search space when using constraints to represent...... experimentation. Our results show that constraint differentiation substantially reduces search and considerably improves the performance of OFMC, enabling its application to a wider class of problems....

  14. Constraints on Anaphoric Determiners

    Zuber, Richard

    2010-01-01

    Some constraints on functions from sets and relations to sets are studied. Such constraints are satisfied by anaphoric functions, that is functions denoted by anaphoric determiners. These constraints are generalisations of anaphor conditions known from the study of simpler cases of nominal anaphors. In addition a generalisation of the notion of conservativity as applied to anaphoric functions is proposed. Two classes of anaphoric determiners found in NLs are discussed as examples.

  15. Removing Propagation Redundant Constraints in Redundant Modeling

    Choi, Chiu Wo; Lee, Jimmy Ho-Man; Stuckey, Peter J.

    2004-01-01

    A widely adopted approach to solving constraint satisfaction problems combines systematic tree search with various degrees of constraint propagation for pruning the search space. One common technique to improve the execution efficiency is to add redundant constraints, which are constraints logically implied by others in the problem model. However, some redundant constraints are propagation redundant and hence do not contribute additional propagation information to the constraint solver. Redun...

  16. Software Architecture: Architecture Constraints

    Tibermacine, Chouki

    2014-01-01

    International audience In this chapter, we introduce an additional, yet essential, concept in describing software architectures : architecture constraints. We explain the precise role of these entities and their importance in object-oriented, component-based or service-oriented software engi-neering. We then describe the way in which they are specified and interpreted. An architect can define architecture constraints and then associate them to architectural descriptions to limit their stru...

  17. Constitutional Constraints

    Fallon, Richard Henry

    2009-01-01

    The main ambition of "Constitutional Constraints" is to open up the subject of constitutional constraints on government officials, including Presidents and Supreme Court Justices, as a topic for discussion within the field of Constitutional Theory. The subject has so far received little comprehensive discussion in the law reviews, in part because of a division between scholarly approaches that treat constitutional law as a system of norms and political scientific theories that portray judges ...

  18. External costs of electric power generation systems. Nuclear fuel cycle in ExternE

    In ExternE, external costs on mine steps such as mining and refining of uranium, conversion, enrichment, fuel production, power generation, reprocessing, wastes treatment, transportation, and construction and subdivision were evaluated. However, even treatment of same a step is not always carried out in own country. In order to conduct a fair evaluation, every country must elucidate performances of its specified sites. And, ExternE defines some important evaluation items (priority Impact) thought to largely affect the external cost formed at every stage in each power generation system. In addition, ExternE also considers on some impact routes of radioactive materials. On calculation result of external costs on the nuclear power generation, as its methodology is common, its evaluation results are not always realistic because of use of French data using Phase II when insufficiency of data in own country, use of supposed site condition, use of different time span for evaluating effect, and so forth. (G.K.)

  19. Motion constraint

    Raunhardt, Daniel; Boulic, Ronan

    2009-01-01

    In this paper, we propose a hybrid postural control approach taking advantage of data-driven and goal-oriented methods while overcoming their limitations. In particular, we take advantage of the latent space characterizing a given motion database. We introduce a motion constraint operating in the latent space to benefit from its much smaller dimension compared to the joint space. This allows its transparent integration into a Prioritized Inverse Kinematics framework. If its priority is high t...

  20. Strategic Planning under Severe Constraints in a State College

    Geisler, Jerry L.; Gilliard, Debbie J.

    2007-01-01

    This paper examines the difficulties of strategic planning under severe constraints in a state college. Constraints include the planning models available, the governance structure of the college and other externalities, and a not-for-profit model of constraints by Newman and Wallender. After presenting the planning challenges, we discuss…

  1. Searching for genomic constraints

    The authors have analyzed general properties of very long DNA sequences belonging to simple and complex organisms, by using different correlation methods. They have distinguished those base compositional rules that concern the entire genome which they call 'genomic constraints' from the rules that depend on the 'external natural selection' acting on single genes, i. e. protein-centered constraints. They show that G + C content, purine / pyrimidine distributions and biological complexity of the organism are the most important factors which determine base compositional rules and genome complexity. Three main facts are here reported: bacteria with high G + C content have more restrictions on base composition than those with low G + C content; at constant G + C content more complex organisms, ranging from prokaryotes to higher eukaryotes (e.g. human) display an increase of repeats 10-20 nucleotides long, which are also partly responsible for long-range correlations; work selection of length 3 to 10 is stronger in human and in bacteria for two distinct reasons. With respect to previous studies, they have also compared the genomic sequence of the archeon Methanococcus jannaschii with those of bacteria and eukaryotes: it shows sometimes an intermediate statistical behaviour

  2. Externalities of fuel cycles 'ExternE' project. Summary report

    There is a growing requirement for policy analysts to take account of the environment in their decision making and to undertake the specified cost-benefit analysis. Within the European Union this is reflected in the 5th Environmental Action Programme, and the Commission's White Paper entitled 'Growth, competitiveness, employment and the ways forward to the 21st century'. This has led to a need for evaluation of environmental externalities. The ExternE Project commenced in 1991 as the European part of a collaborative study between the European Commission and the US Department of Energy. It aims to be the first systematic approach to the evaluation of external costs of a wide range of different fuel cycles. The project will result in an operational accounting framework for the quantification and monetarisation of priority environmental and other externalities. This framework will allow the calculation of the marginal external costs and benefits for specific power plants, at specific sites using specified technologies. There are three major phases in the project. Phase I was undertaken in collaboration with the US Department of Energy. In this phase the teams jointly developed the conceptual approach and methodology and shared scientific information for application to a number of fuel cycles. On the European side work concentrated on the nuclear and coal fuel cycles which together were expected to raise many of the fundamental issues in fuel cycle analysis. The project is currently nearing completion of Phase 2. During this phase the methodology has been applied to a wide range of different fossil, nuclear and renewable fuel cycles for power generation and energy conservation options. Also a series of National Implementation Programmes are underway in which the methodology and accounting framework are being applied to reference sites throughout Europe. In addition the general methodology is being extended to address the evaluation of externalities associated with

  3. ExternE: Externalities of energy Vol. 1. Summary

    There is a growing requirement for policy analysts to take account of the environment in their decision making and to undertake the specified cost-benefit analysis. Within the European Union this is reflected in the 5th Environmental Action Programme, and the Commission's White Paper entitled 'Growth, competitiveness, employment and the ways forward to the 21st century'. This has led to a need for evaluation of environmental externalities. The ExternE Project commenced in 1991 as the European part of a collaborative study between the European Commission and the US Department of Energy. It aims to be the first systematic approach to the evaluation of external costs of a wide range of different fuel cycles. The project will result in an operational accounting framework for the quantification and monetarisation of priority environmental and other externalities. This framework will allow the calculation of the marginal external costs and benefits for specific power plants, at specific sites using specified technologies. There are three major phases in the project. Phase 1 was undertaken in collaboration with the US Department of Energy. In this phase the teams jointly developed the conceptual approach and methodology and shared scientific information for application to a number of fuel cycles. On the European side work concentrated on the nuclear and coal fuel cycles which together were expected to raise many of the fundamental issues in fuel cycle analysis. The project is currently nearing completion of Phase 2. During this phase the methodology has been applied to a wide range of different fossil, nuclear and renewable fuel cycles for power generation and energy conservation options. Also a series of National Implementation Programmes is underway in which the methodology and accounting framework are being applied to reference sites throughout Europe. In addition the general methodology is being extended to address the evaluation of externalities associated with

  4. Optimal capital stock and financing constraints

    Saltari, Enrico; Giuseppe, Travaglini

    2011-01-01

    In this paper we show that financing constraints affect the optimal level of capital stock even when the financing constraint is ineffective. This happens when the firm rationally anticipates that access to external financing resources may be rationed in the future. We will show that with these expectations, the optimal investment policy is to invest less in any given period, thereby lowering the desired optimal capital stock in the long run.

  5. External Beam Therapy (EBT)

    ... Physician Resources Professions Site Index A-Z External Beam Therapy (EBT) External beam therapy (EBT) is a ... follow-up should I expect? What is external beam therapy and how is it used? External beam ...

  6. Does the experience level of the radiologist, assessment in consensus, or the addition of the abduction and external rotation view improve the diagnostic reproducibility and accuracy of MRA of the shoulder?

    Aim: To prospectively evaluate the influence of observer experience, consensus assessment, and abduction and external rotation (ABER) view on the diagnostic performance of magnetic resonance arthrography (MRA) in patients with traumatic anterior-shoulder instability (TASI). Materials and methods: Fifty-eight MRA examinations (of which 51 had additional ABER views) were assessed by six radiologists (R1–R6) and three teams (T1–T3) with different experience levels, using a seven-lesion standardized scoring form. Forty-five out of 58 MRA examination findings were surgically confirmed. Kappa coefficients, sensitivity, specificity, and differences in percent agreement or correct diagnosis (p-value, McNemar's test) were calculated per lesion and overall per seven lesion types to assess diagnostic reproducibility and accuracy. Results: Overall kappa ranged from poor (k = 0.17) to moderate (k = 0.53), sensitivity from 30.6–63.5%, and specificity from 73.6–89.9%. Overall, the most experienced radiologists (R1–R2) and teams (T2–T3) agreed significantly more than the lesser experienced radiologists (R3–R4: p = 0.014, R5–R6; p = 0.018) and teams (T2–T3: p = 0.007). The most experienced radiologist (R1, R2, R3) and teams (T1, T2) were also consistently more accurate than the lesser experienced radiologists (R4, R5, R6) and team (T3). Significant differences were found between R1–R4 (p = 0.012), R3–R4 (p = 0.03), and T2–T3 (p = 0.014). The overall performance of consensus assessment was systematically higher than individual assessment. Significant differences were established between T1–T2 and radiologists R3–R4 (p<0.001, p = 0.001) and between T2 and R3 (p<0.001/p = 0.001) or R4 (p = 0.050). No overall significant differences were found between the radiologists' assessments with and without ABER. Conclusion: The addition of ABER does not significantly improve overall diagnostic performance. The radiologist

  7. ExternE: Externalities of energy Vol. 5. Nuclear

    Since the early 1970s, there has been increased interest in the environmental impacts that are caused by the generation of electricity. The comparative risk assessment studies at that time used mainly deaths and injuries as impact indicators. By the end of the 1980s studies changed to the assessment of the costs imposed on society and the environment that were not included in the market price of the energy produced, the so-called external costs. The preliminary studies that were published set the conceptual basis, grounded in neo-classical economics, for the valuation of the health and environmental impacts that could be assessed. As a consequence of the many questions raised by the methodologies employed by these early studies, Directorate General XII (DG XII) of the Commission of the European Communities established a collaborative research programme with the United States Department of Energy to identify an appropriate methodology for this type of work. Following the completion of this collaboration, the DG XII programme has continued as the ExternE project. The main objective of the work carried out at CEPN was to develop an impact pathway methodology for the nuclear fuel cycle that would be consistent with the methodologies developed for other fuel cycles, without loosing the nuclear-specific techniques required for a proper evaluation. In this way, comparisons between the different fuel cycles would be possible. This report presents the methodology and demonstration of the results in the context of the French nuclear fuel cycle. The United States team at Oak Ridge National Laboratory has previously issued a draft report on the results of their assessment. The French fuel cycle was broken down into 8 separate stages. Reference sites and 1990s technology were chosen to represent the total nuclear fuel cycle, as it exists today. In addition, the transportation of material between the sites was considered. The facilities are assessed for routine operation, except

  8. Morphological Disambiguation by Voting Constraints

    Oflazer, K; Oflazer, Kemal; Tur, Gokhan

    1997-01-01

    We present a constraint-based morphological disambiguation system in which individual constraints vote on matching morphological parses, and disambiguation of all the tokens in a sentence is performed at the end by selecting parses that receive the highest votes. This constraint application paradigm makes the outcome of the disambiguation independent of the rule sequence, and hence relieves the rule developer from worrying about potentially conflicting rule sequencing. Our results for disambiguating Turkish indicate that using about 500 constraint rules and some additional simple statistics, we can attain a recall of 95-96% and a precision of 94-95% with about 1.01 parses per token. Our system is implemented in Prolog and we are currently investigating an efficient implementation based on finite state transducers.

  9. The ExternE project: methodology, objectives and limitations

    This paper presents a summary of recent studies on external costs of energy systems, in particular the ExternE (External Costs of Energy) Project of the European Commission. To evaluate the impact and damage cost of a pollutant, one needs to carry out an impact pathway analysis; this involves the calculation of increased pollutant concentrations in all affected regions due to an incremental emission (e.g. μg/m3 of particles, using models of atmospheric dispersion and chemistry), followed by the calculation of physical impacts (e.g. number of cases of asthma due to these particles, using a dose-response function). The entire so-called fuel chain (or fuel cycle) is evaluated and compared on the basis of delivered end use energy. Even though the uncertainties are large, the results provide substantial evidence that the classical air pollutants (particles, NOx and SOx) from the combustion of fossil fuels impose a heavy toll, in addition to the cost of global warming. The external costs are especially large for coal; even for 'good current technology' they may be comparable to the price of electricity. For natural gas the external costs are about a third to a half of coal. The external costs of nuclear are small compared to the price of electricity (at most a few %), and so are the external costs of most renewable energy systems. (authors)

  10. Adaptive neural control for an uncertain robotic manipulator with joint space constraints

    Tang, Zhong-Liang; Ge, Shuzhi Sam; Tee, Keng Peng; He, Wei

    2016-07-01

    In this paper, adaptive neural tracking control is proposed for a robotic manipulator with uncertainties in both manipulator dynamics and joint actuator dynamics. The manipulator joints are subject to inequality constraints, i.e., the joint angles are required to remain in some compact sets. Integral barrier Lyapunov functionals (iBLFs) are employed to address the joint space constraints directly without performing an additional mapping to the error space. Neural networks (NNs) are utilised to compensate for the unknown robot dynamics and external force. Adapting parameters are developed to estimate the unknown bounds on NN approximations. By the Lyapunov synthesis, the proposed control can guarantee the semi-global uniform ultimate boundedness of the closed-loop system, and the practical tracking of joint reference trajectory is achieved without the violation of predefined joint space constraints. Simulation results are given to validate the effectiveness of the proposed control scheme.

  11. Efficient Searching with Linear Constraints

    Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff;

    2000-01-01

    We show how to preprocess a set S of points in d into an external memory data structure that efficiently supports linear-constraint queries. Each query is in the form of a linear constraint xd a0+∑d−1i=1 aixi; the data structure must report all the points of S that satisfy the constraint. This...... problem is called halfspace range searching in the computational geometry literature. Our goal is to minimize the number of disk blocks required to store the data structure and the number of disk accesses (I/Os) required to answer a query. For d=2, we present the first data structure that uses linear...... space and answers linear-constraint queries using an optimal number of I/Os in the worst case. For d=3, we present a near-linear-size data structure that answers queries using an optimal number of I/Os on the average. We present linear-size data structures that can answer d-dimensional linear...

  12. External priors for the next generation of CMB experiments

    Manzotti, Alessandro; Park, Youngsoo

    2015-01-01

    Planned cosmic microwave background (CMB) experiments can dramatically improve what we know about neutrino physics, inflation, and dark energy. The low level of noise, together with improved angular resolution, will increase the signal to noise of the CMB polarized signal as well as the reconstructed lensing potential of high redshift large scale structure. Projected constraints on cosmological parameters are extremely tight, but these can be improved even further with information from external experiments. Here, we examine quantitatively the extent to which external priors can lead to improvement in projected constraints from a CMB-Stage IV (S4) experiment on neutrino and dark energy properties. We find that CMB S4 constraints on neutrino mass could be strongly enhanced by external constraints on the cold dark matter density $\\Omega_{c}h^{2}$ and the Hubble constant $H_{0}$. If polarization on the largest scales ($\\ell<50$) will not be measured, an external prior on the primordial amplitude $A_{s}$ or the...

  13. Data assimilation with inequality constraints

    Thacker, W. C.

    If values of variables in a numerical model are limited to specified ranges, these restrictions should be enforced when data are assimilated. The simplest option is to assimilate without regard for constraints and then to correct any violations without worrying about additional corrections implied by correlated errors. This paper addresses the incorporation of inequality constraints into the standard variational framework of optimal interpolation with emphasis on our limited knowledge of the underlying probability distributions. Simple examples involving only two or three variables are used to illustrate graphically how active constraints can be treated as error-free data when background errors obey a truncated multi-normal distribution. Using Lagrange multipliers, the formalism is expanded to encompass the active constraints. Two algorithms are presented, both relying on a solution ignoring the inequality constraints to discover violations to be enforced. While explicitly enforcing a subset can, via correlations, correct the others, pragmatism based on our poor knowledge of the underlying probability distributions suggests the expedient of enforcing them all explicitly to avoid the computationally expensive task of determining the minimum active set. If additional violations are encountered with these solutions, the process can be repeated. Simple examples are used to illustrate the algorithms and to examine the nature of the corrections implied by correlated errors.

  14. Implementing Probabilistic Abductive Logic Programming with Constraint Handling Rules

    Christiansen, Henning

    2008-01-01

    probabilistic versions of abductive logic programming, the approach is characterized by higher generality and a flexible and adaptable architecture which incorporates integrity constraints and interaction with external constraint solvers. A PALP is transformed in a systematic way into a CHR program which serves...

  15. External constraints on monetary policy and the financial accelerator

    Mark Gertler; Simon Gilchrist; Fabio Natalucci

    2001-01-01

    We develop a small open economy macroeconomic model where financial conditions influence aggregate behavior. We use this model to explore the connection between the exchange rate regime and financial distress. We show that fixed exchange rates exacerbate financial crises by tieing the hands of the monetary authorities. We then investigate the quantitative significance by first calibrating the model to Korean data and then showing that it does a reasonably good job of matching the Korean exper...

  16. The Soft Cumulative Constraint

    Petit, Thierry

    2009-01-01

    This research report presents an extension of Cumulative of Choco constraint solver, which is useful to encode over-constrained cumulative problems. This new global constraint uses sweep and task interval violation-based algorithms.

  17. Optimality criteria design and stress constraint processing

    Levy, R.

    1982-01-01

    Methods for pre-screening stress constraints into either primary or side-constraint categories are reviewed; a projection method, which is developed from prior cycle stress resultant history, is introduced as an additional screening parameter. Stress resultant projections are also employed to modify the traditional stress-ratio, side-constraint boundary. A special application of structural modification reanalysis is applied to the critical stress constraints to provide feasible designs that are preferable to those obtained by conventional scaling. Sample problem executions show relatively short run times and fewer design cycle iterations to achieve low structural weights; those attained are comparable to the minimum values developed elsewhere.

  18. Automatic optimization of doses in external radiotherapy. Adaptation to a small informatics system. Addition of programmes for the determination of iso-effect curves and the computing of irradiation times

    The problem of computerized dose optimization in external radiotherapy was studied. An optimization by linear programming was developed, giving as homogeneous as possible a dose distribution in the target volume though without exceeding certain doses outside the tumour. By a set of modular programmes written in Fortran it is possible to optimize doses, plot iso-effect curves and compute irradiation time per beam and per session. This thesis is divided into two main sections. - Part one reviews the optimization criteria, describes the different mathematical methods and points out the originality of the method in the choice of object function. Finally the choices made for the informatics system used and the programmes established are presented. - Part two deals with the other programmes developed. The NSD and TDF formulae, from which the biological effect is calculated and the iso-effect curves are determined, are recalled. The irradiation time calculation depends on many parameters and especially the activity decay for cobalt sources. These elements are specified in the text and accounted for by different programmes. All the programmes described are now operational and are illustrated by examples. The programmes are conversational and have been made as simple as possible to use

  19. Estimating externalities of biomass fuel cycles, Report 7

    Barnthouse, L.W.; Cada, G.F.; Cheng, M.-D.; Easterly, C.E.; Kroodsma, R.L.; Lee, R.; Shriner, D.S.; Tolbert, V.R.; Turner, R.S.

    1998-01-01

    This report documents the analysis of the biomass fuel cycle, in which biomass is combusted to produce electricity. The major objectives of this study were: (1) to implement the methodological concepts which were developed in the Background Document (ORNL/RFF 1992) as a means of estimating the external costs and benefits of fuel cycles, and by so doing, to demonstrate their application to the biomass fuel cycle; (2) to develop, given the time and resources, a range of estimates of marginal (i.e., the additional or incremental) damages and benefits associated with selected impact-pathways from a new wood-fired power plant, using a representative benchmark technology, at two reference sites in the US; and (3) to assess the state of the information available to support energy decision making and the estimation of externalities, and by so doing, to assist in identifying gaps in knowledge and in setting future research agendas. The demonstration of methods, modeling procedures, and use of scientific information was the most important objective of this study. It provides an illustrative example for those who will, in the future, undertake studies of actual energy options and sites. As in most studies, a more comprehensive analysis could have been completed had budget constraints not been as severe. Particularly affected were the air and water transport modeling, estimation of ecological impacts, and economic valuation. However, the most important objective of the study was to demonstrate methods, as a detailed example for future studies. Thus, having severe budget constraints was appropriate from the standpoint that these studies could also face similar constraints. Consequently, an important result of this study is an indication of what can be done in such studies, rather than the specific numerical estimates themselves.

  20. External priors for the next generation of CMB experiments

    Manzotti, Alessandro [Chicago U., KICP; Dodelson, Scott [Chicago U., KICP; Park, Youngsoo [Arizona U.

    2015-12-08

    Planned cosmic microwave background (CMB) experiments can dramatically improve what we know about neutrino physics, inflation, and dark energy. The low level of noise, together with improved angular resolution, will increase the signal to noise of the CMB polarized signal as well as the reconstructed lensing potential of high redshift large scale structure. Projected constraints on cosmological parameters are extremely tight, but these can be improved even further with information from external experiments. Here, we examine quantitatively the extent to which external priors can lead to improvement in projected constraints from a CMB-Stage IV (S4) experiment on neutrino and dark energy properties. We find that CMB S4 constraints on neutrino mass could be strongly enhanced by external constraints on the cold dark matter density $\\Omega_{c}h^{2}$ and the Hubble constant $H_{0}$. If polarization on the largest scales ($\\ell<50$) will not be measured, an external prior on the primordial amplitude $A_{s}$ or the optical depth $\\tau$ will also be important. A CMB constraint on the number of relativistic degrees of freedom, $N_{\\rm eff}$, will benefit from an external prior on the spectral index $n_{s}$ and the baryon energy density $\\Omega_{b}h^{2}$. Finally, an external prior on $H_{0}$ will help constrain the dark energy equation of state ($w$).

  1. Regulating multiple externalities

    Waldo, Staffan; Jensen, Frank; Nielsen, Max;

    2016-01-01

    Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory instrume......Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory...

  2. ExternE National Implementation Finland

    Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P. [VTT Energy, Espoo (Finland); Hongisto, M. [Imatran Voima Oy, Vantaa (Finland); Siitonen, S. [Ekono Energy Ltd, Espoo (Finland); Johansson, M. [Finnish Environment Institute, Helsinki (Finland)

    1999-07-01

    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  3. ExternE National Implementation Finland

    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  4. External fixation of complex femoral shaft fractures

    Zlowodzki, M; Prakash, J. S.; Aggarwal, N. K.

    2006-01-01

    Conversion of temporary external fixation to an intramedullary nail within the first 2 weeks after a femoral shaft fracture is standard practice. However, due to financial constraints, in large parts of the world external fixation of femoral shaft fractures is often the definitive treatment. Out of 60 fractures, 47 were followed-up for a minimum period of 39 weeks. The average follow-up time was 75 weeks. Fourteen fractures were closed, and 33 open. Forty-four fractures united at an average o...

  5. On Constraint Programming

    Mathieu, Philippe; Keisu, Torbjörn

    1990-01-01

    This short note aims to present foundations for constraint logic programming. By logic programming, we understand in this paper the PROLOG paradigm. But it will be clear that we do reduce the problem to adding a new package to PROLOG. We argue that constraint logic programming should be defined as a new paradigm for programming: the LOGIC PROGRAMMING + SYMBOLIC COMPUTATION paradigm. Our system incorporates as a very basic, all the existing systems incorporating constraints i...

  6. Memoization of Coroutined Constraints

    Johnson, M; Johnson, Mark; Dörre, Jochen

    1995-01-01

    Some linguistic constraints cannot be effectively resolved during parsing at the location in which they are most naturally introduced. This paper shows how constraints can be propagated in a memoizing parser (such as a chart parser) in much the same way that variable bindings are, providing a general treatment of constraint coroutining in memoization. Prolog code for a simple application of our technique to Bouma and van Noord's (1994) categorial grammar analysis of Dutch is provided.

  7. External Radiation Therapy

    Full Text Available ... two different types. There's what we call external beam treatment, which is given from an x-ray ... sources, the difference being that in the external beam the treatment comes from outside the patient, whereas ...

  8. ASH External Web Portal (External Portal)

    Department of Transportation — The ASH External Web Portal is a web-based portal that provides single sign-on functionality, making the web portal a single location from which to be authenticated...

  9. Generalized Network Externality Function

    A. Paothong; G.S. Ladde

    2012-01-01

    In this work, we focus on the development of mathematical modeling of network externality processes. The introduction of the generalized network externality function provides a unified source of a tool for developing and analyzing the planning, policy and performance of the network externality process and network goods/services in a systematic way. This leads to fulfill all existing network externality assumptions as special cases. We study its properties and applications. This study provides...

  10. Preparation of a bifunctional pyrazosulfuron-ethyl imprinted polymer with hydrophilic external layers by reversible addition-fragmentation chain transfer polymerization and its application in the sulfonylurea residue analysis.

    Yang, Meixian; Zhang, Yingying; Lin, Shen; Yang, Xinlin; Fan, Zhijin; Yang, Lixia; Dong, Xiangchao

    2013-09-30

    A new bifunctional pyrazosulfuron-ethyl imprinted polymer was synthesized by the combination of molecular imprinting technology and living radical polymerization. In the synthesis, the pyrazosulfuron-ethyl imprinted polymer was obtained by the reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization followed by grafting poly(glyceryl monomethacrylate) (pGMMA) by the post-RAFT polymerization. In this research, we used polyethylene glycol (PEG) as the polymeric porogen in order to increase the porosity of the material which is a new porogen application in the precipitation polymerization. The imprinted polymer has selectivity for the template and ability of humic acids exclusion which has shown the merits of molecularly imprinted polymers and restricted access materials. An online solid-phase extraction/HPLC method for the analysis of three sulfonylurea residues in soil samples has been developed and validated. The recovery of 81-99% in the spiked levels of 40-200 μg kg(-1) was obtained and the limit of detection (LOD) and limit of quantification (LOQ) were less than 4.8 and 15.9 μg kg(-1) respectively. The results demonstrated that this bifunctional material can be used for the efficient pyrazosulfuron-ethyl extraction in the sulfonylurea residue analysis from environmental samples. PMID:23953454

  11. Investment Timing When External Financing Is Costly

    Hirth, Stefan; Uhrig-Homburg, Marliese

    2010-01-01

    This paper analyzes the investment timing of firms facing two dimensions of financing constraints: Liquidity constraints and capital market frictions inducing financing costs. We show that liquidity constraints are not sufficient to explain voluntary investment delay. However, when additionally...... considering financing costs, we can explain both voluntary delay and acceleration of investment. More precisely, we find that investment thresholds are U-shaped in liquid funds. For high-liquidity firms, investment thresholds are decreasing (i.e. accelerated investment takes place) in either dimension of...... financing constraint. In contrast, investment thresholds are increasing (i.e. investment is further delayed) in either form of financing constraint for low-liquidity firms. For intermediate levels of liquidity, investment thresholds are U-shaped in market frictions....

  12. Lessons learned from external hazards

    This paper presents a study performed by the European Clearinghouse of the Joint Research Centre on Operational Experience for nuclear power plants in cooperation with IRSN and GRS covering events reported by nuclear power plants in relation to external hazards. It summarizes the review of 235 event reports from 3 different databases. The events were grouped in 9 categories according to the nature of the external hazard involved, and the specific lessons learned and recommendations that can be derived from each of these categories are presented. Additional 'cross-cutting' recommendations covering several or all the external hazards considered are also discussed. These recommendations can be useful in preventing this type of events from happening again or in limiting their consequences. The study was launched in 2010 and therefore it does not cover the Fukushima event. This paper presents the main findings and recommendations raised by this study. (orig.)

  13. Food additives

    ... this page: //medlineplus.gov/ency/article/002435.htm Food additives To use the sharing features on this page, please enable JavaScript. Food additives are substances that become part of a food ...

  14. Theory of Constraints (TOC)

    Michelsen, Aage U.

    2004-01-01

    Tankegangen bag Theory of Constraints samt planlægningsprincippet Drum-Buffer-Rope. Endvidere skitse af The Thinking Process.......Tankegangen bag Theory of Constraints samt planlægningsprincippet Drum-Buffer-Rope. Endvidere skitse af The Thinking Process....

  15. Credit Constraints in Education

    Lochner, Lance; Monge-Naranjo, Alexander

    2012-01-01

    We review studies of the impact of credit constraints on the accumulation of human capital. Evidence suggests that credit constraints have recently become important for schooling and other aspects of households' behavior. We highlight the importance of early childhood investments, as their response largely determines the impact of credit…

  16. Creating Positive Task Constraints

    Mally, Kristi K.

    2006-01-01

    Constraints are characteristics of the individual, the task, or the environment that mold and shape movement choices and performances. Constraints can be positive--encouraging proficient movements or negative--discouraging movement or promoting ineffective movements. Physical educators must analyze, evaluate, and determine the effect various…

  17. Evaluating Distributed Timing Constraints

    Kristensen, C.H.; Drejer, N.

    In this paper we describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems.......In this paper we describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems....

  18. Constraint Reasoning Over Strings

    Koga, Dennis (Technical Monitor); Golden, Keith; Pang, Wanlin

    2003-01-01

    This paper discusses an approach to representing and reasoning about constraints over strings. We discuss how many string domains can often be concisely represented using regular languages, and how constraints over strings, and domain operations on sets of strings, can be carried out using this representation.

  19. The Antigone Constraint.

    Tuggy, David

    This paper presents a class of sentences that certain syntactic rules of English would be expected to produce, but that are not grammatical. The sentences all involve the raising of a sentential Noun Phrase (NP) and the subsequent application of some syntactic rule to that senential NP. A constraint, referred to as the Antigone Constraint, is…

  20. Temporal Concurrent Constraint Programming

    Nielsen, Mogens; Palamidessi, Catuscia; Valencia, Frank Dan

    2002-01-01

    The ntcc calculus is a model of non-deterministic temporal concurrent constraint programming. In this paper we study behavioral notions for this calculus. In the underlying computational model, concurrent constraint processes are executed in discrete time intervals. The behavioral notions studied...

  1. Relationship between protein structure and geometrical constraints

    Lund, Ole; Hansen, Jan; Brunak, Søren; Bohr, Jakob

    1996-01-01

    We evaluate to what extent the structure of proteins can be deduced from incomplete knowledge of disulfide bridges, surface assignments, secondary structure assignments, and additional distance constraints. A cost function taking such constraints into account was used to obtain protein structures...... using a simple minimization algorithm. For small proteins, the approximate structure could be obtained using one additional distance constraint for each amino acid in the protein. We also studied the effect of using predicted secondary structure and surface assignments. The constraints used in this...... approach typically may be obtained from low-resolution experimental data. When using a cost function based on distances, half of the resulting structures will be mirrored, because the resulting structure and its mirror image will have the same cost. The secondary structure assignments were therefore...

  2. Network Design with Node Degree Balance Constraints

    Pedersen, Michael Berliner; Crainic, Teodor Gabriel

    This presentation discusses an extension to the network design model where there in addition to the flow conservation constraints also are constraints that require design conservation. This means that the number of arcs entering and leaving a node must be the same. As will be shown the model has ...... applications within the design of transportation networks. The model is solved using a Tabu Search heuristic using a hybrid of the add/drop procedure and cycle-based neighbourhoods....

  3. Stochastic Image Registration with User Constraints

    Kolesov, Ivan; Lee, JeHoon; Vela, Patricio; Tannenbaum, Allen

    2013-01-01

    Constrained registration is an active area of research and is the focus of this work. This note describes a non-rigid image registration framework for incorporating landmark constraints. Points that must remain stationary are selected, the user chooses the spatial extent of the inputs, and an automatic step computes the deformable registration, respecting the constraints. Parametrization of the deformation field is by an additive composition of a similarity transformation and a set of Gaussia...

  4. Kernels for Global Constraints

    Gaspers, Serge

    2011-01-01

    Bessiere et al. (AAAI'08) showed that several intractable global constraints can be efficiently propagated when certain natural problem parameters are small. In particular, the complete propagation of a global constraint is fixed-parameter tractable in k - the number of holes in domains - whenever bound consistency can be enforced in polynomial time; this applies to the global constraints AtMost-NValue and Extended Global Cardinality (EGC). In this paper we extend this line of research and introduce the concept of reduction to a problem kernel, a key concept of parameterized complexity, to the field of global constraints. In particular, we show that the consistency problem for AtMost-NValue constraints admits a linear time reduction to an equivalent instance on O(k^2) variables and domain values. This small kernel can be used to speed up the complete propagation of NValue constraints. We contrast this result by showing that the consistency problem for EGC constraints does not admit a reduction to a polynomial...

  5. Constraint-based reachability

    Arnaud Gotlieb

    2013-02-01

    Full Text Available Iterative imperative programs can be considered as infinite-state systems computing over possibly unbounded domains. Studying reachability in these systems is challenging as it requires to deal with an infinite number of states with standard backward or forward exploration strategies. An approach that we call Constraint-based reachability, is proposed to address reachability problems by exploring program states using a constraint model of the whole program. The keypoint of the approach is to interpret imperative constructions such as conditionals, loops, array and memory manipulations with the fundamental notion of constraint over a computational domain. By combining constraint filtering and abstraction techniques, Constraint-based reachability is able to solve reachability problems which are usually outside the scope of backward or forward exploration strategies. This paper proposes an interpretation of classical filtering consistencies used in Constraint Programming as abstract domain computations, and shows how this approach can be used to produce a constraint solver that efficiently generates solutions for reachability problems that are unsolvable by other approaches.

  6. Renewable energy: Externality costs as market barriers

    This paper addresses the impact of environmentally based market failure constraints on the adoption of renewable energy technologies through the quantification in financial terms of the externalities of electric power generation, for a range of alternative commercial and almost-commercial technologies. It is shown that estimates of damage costs resulting from combustion of fossil fuels, if internalised into the price of the resulting output of electricity, could lead to a number of renewable technologies being financially competitive with generation from coal plants. However, combined cycle natural gas technology would have a significant financial advantage over both coal and renewables under current technology options and market conditions. On the basis of cost projections made under the assumption of mature technologies and the existence of economies of scale, renewable technologies would possess a significant social cost advantage if the externalities of power production were to be 'internalised'. Incorporating environmental externalities explicitly into the electricity tariff today would serve to hasten this transition process. (author)

  7. Renewable energy: Externality costs as market barriers

    This paper addresses the impact of environmentally based market failure constraints on the adoption of renewable energy technologies through the quantification in financial terms of the externalities of electric power generation, for a range of alternative commercial and almost-commercial technologies. It is shown that estimates of damage costs resulting from combustion of fossil fuels, if internalised into the price of the resulting output of electricity, could lead to a number of renewable technologies being financially competitive with generation from coal plants. However, combined cycle natural gas technology would have a significant financial advantage over both coal and renewables under current technology options and market conditions. On the basis of cost projections made under the assumption of mature technologies and the existence of economies of scale, renewable technologies would possess a significant social cost advantage if the externalities of power production were to be 'internalised'. Incorporating environmental externalities explicitly into the electricity tariff today would serve to hasten this transition process

  8. Sleep disturbances in chronic progressive external ophthalmoplegia.

    Smits, B.W.; Westeneng, H.J.; Hal, M.A. van; Engelen, B.G.M. van; Overeem, S.

    2012-01-01

    BACKGROUND: Chronic progressive external ophthalmoplegia (CPEO) is a relatively common mitochondrial disorder. In addition to extraocular muscle weakness, various other organs can typically be affected, including laryngeal and limb muscles, cerebrum, cerebellum, and peripheral nerves. Given this mul

  9. External radiation surveillance

    Antonio, E.J.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site.

  10. A constraint algorithm for singular Lagrangians subjected to nonholonomic constraints

    We construct a constraint algorithm for singular Lagrangian systems subjected to nonholonomic constraints which generalizes that of Dirac for constrained Hamiltonian systems. copyright 1997 American Institute of Physics

  11. New Constraints on Additional Satellites of the Pluto System

    Steffl, A. J.; Mutchler, M. J.; Weaver, H. A.; Stern, S. A.; Durda, D. D.; Terrell, D.; Merline, W. J.; Young, L. A.; Young, E. F; Buie, M. W.; Spencer, J. R.

    2005-01-01

    Observations of Pluto and its solar-tidal stability zone were made using the Advanced Camera for Surveys' (ACS) Wide Field Channel (WFC) on the Hubble Space Telescope on UT 2005 May 15 and UT 2005 May 18. Two small satellites of Pluto, provisionally designated S/2005 P 1 and S/2005 P 2, were discovered, as discussed by Weaver et al. (2006) and Stern et al. (2006a). Confirming observations of the newly discovered moons were obtained using the ACS in the High Resolution Channel (HRC) mode on 20...

  12. Theory and practice of internalization of external costs

    External costs are those parts of total costs which bypass the market. To internalize them means to confront economic agents with the true costs and benefits of their economic activities. The concept of internalization does not really meet the requirements of preserving ecological equilibrium. Defining ecological constraints fits the needs much better. Implicit in ecological constraints are shadow prices. To let them emerge, markets for tradable emission permits would be appropriate. Carbon dioxide is used as an example. (author) 7 refs

  13. Dynamics and causality constraints

    The physical meaning and the geometrical interpretation of causality implementation in classical field theories are discussed. Causality in field theory are kinematical constraints dynamically implemented via solutions of the field equation, but in a limit of zero-distance from the field sources part of these constraints carries a dynamical content that explains old problems of classical electrodynamics away with deep implications to the nature of physicals interactions. (author)

  14. Dynamics and causality constraints

    De Souza, M M

    2000-01-01

    The physical meaning and the geometrical interpretation of causality implementation in classical field theories are discussed. Local causality are kinematical constraints dynamically implemented via solutions of the field equations, but in a limit of zero-distance from the field sources part of these constraints carries a dynamical content that explains old problems of classical electrodynamics away and implies on deep implications to the nature of physical interactions.

  15. Essays on Collateral Constraints

    Brumm, Johannes

    2011-01-01

    This thesis consists of three self-contained papers. Chapter 1 provides a general introduction. In Chapter 2, I study the impact of collateral constraints on producers and thereby on aggregate output. In a theoretical paper, Kiyotaki and Moore (1997) show that collateral constraints that restrict the investment decisions of producers can strongly amplify and propagate aggregate shocks. However, the subsequent quantitative literature tends to find rather weak and non-robust effects of collater...

  16. Temporal Concurrent Constraint Programming

    Nielsen, Mogens; Valencia Posso, Frank Dan

    2002-01-01

    The ntcc calculus is a model of non-deterministic temporal concurrent constraint programming. In this paper we study behavioral notions for this calculus. In the underlying computational model, concurrent constraint processes are executed in discrete time intervals. The behavioral notions studied....... Furthermore, the expressive power of this fragment is illustrated by examples. Basic Research in Computer Science, Centre of the Danish National Research Foundation....

  17. Review of externality valuation

    Schleisner, Lotte

    1998-11-01

    This report covers the work done regarding assessment of externalities in the project `Investigation of Pricing Incentives in a Renewable Energy Strategy in Thailand`. The report gives a review of different valuation issues, which are used in different externality studies and focuses on why the numbers often are different for the same fuel cycles using different methodologies for assessment of the externalities. The review of externality valuation focuses in this report on the assessment of environmental externalities, and less attention is paid to the non-environmental externalities. The report points out different parameters, which are important to consider when externalities estimated for the same fuel cycle in different studies are compared. For instance some studies transfer dose-response functions and monetization values from other studies. It is in this case important to consider for each of the functions if it is possible to use functions from other studies, or if it is necessary to develop a function for a new region. An important parameter in estimating externalities based on earlier studies is the fact that some studies only include regional and local impacts and do not take the global impacts related to greenhouse gasses into account. Considerable uncertainty is related to the global externalities regarding time horizon for the greenhouse effect, choice of dose-response function and monetization values. Assumptions on famine and the monetization of human life may be the totally dominating factor estimating external costs. 7 studies have been chosen for further analysis and comparison in order to show the variation in external costs. The studies have been chosen in order to cover as well old, well-known studies as new, unknown, but interesting studies. Some of the new studies are based on results from earlier studies, while others implement new ideas concerning the methodology. (au) 21 refs.

  18. Combined Solar System and rotation curve constraints on MOND

    Hees, A; Angus, G W; Gentile, G

    2015-01-01

    The Modified Newtonian Dynamics (MOND) paradigm generically predicts that the external gravitational field in which a system is embedded can produce effects on its internal dynamics. In this communication, we first show that this External Field Effect can significantly improve some galactic rotation curves fits by decreasing the predicted velocities of the external part of the rotation curves. In modified gravity versions of MOND, this External Field Effect also appears in the Solar System and leads to a very good way to constrain the transition function of the theory. A combined analysis of the galactic rotation curves and Solar System constraints (provided by the Cassini spacecraft) rules out several classes of popular MOND transition functions, but leaves others viable. Moreover, we show that LISA Pathfinder will not be able to improve the current constraints on these still viable transition functions.

  19. Additive Manufacturing Infrared Inspection

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  20. The External Mind

    The External Mind: an Introduction by Riccardo Fusaroli, Claudio Paolucci pp. 3-31 The sign of the Hand: Symbolic Practices and the Extended Mind by Massimiliano Cappuccio, Michael Wheeler pp. 33-55 The Overextended Mind by Shaun Gallagher pp. 57-68 The "External Mind": Semiotics, Pragmatism...

  1. Swimmer's Ear (External Otitis)

    ... Can I Help a Friend Who Cuts? Swimmer's Ear (External Otitis) KidsHealth > For Teens > Swimmer's Ear (External Otitis) Print A A A Text Size ... Ryan awoke with a sharp pain in his ear — it really hurt! He remembered having ear infections ...

  2. Additivity dominance

    Paul Rozin

    2009-10-01

    Full Text Available Judgments of naturalness of foods tend to be more influenced by the process history of a food, rather than its actual constituents. Two types of processing of a ``natural'' food are to add something or to remove something. We report in this study, based on a large random sample of individuals from six countries (France, Germany, Italy, Switzerland, UK and USA that additives are considered defining features of what makes a food not natural, whereas ``subtractives'' are almost never mentioned. In support of this, skim milk (with major subtraction of fat is rated as more natural than whole milk with a small amount of natural vitamin D added. It is also noted that ``additives'' is a common word, with a synonym reported by a native speaker in 17 of 18 languages, whereas ``subtractive'' is lexicalized in only 1 of the 18 languages. We consider reasons for additivity dominance, relating it to omission bias, feature positive bias, and notions of purity.

  3. Misconceptions and constraints

    In theory, the sterile insect technique (SIT) is applicable to a wide variety of invertebrate pests. However, in practice, the approach has been successfully applied to only a few major pests. Chapters in this volume address possible reasons for this discrepancy, e.g. Klassen, Lance and McInnis, and Robinson and Hendrichs. The shortfall between theory and practice is partly due to the persistence of some common misconceptions, but it is mainly due to one constraint, or a combination of constraints, that are biological, financial, social or political in nature. This chapter's goal is to dispel some major misconceptions, and view the constraints as challenges to overcome, seeing them as opportunities to exploit. Some of the common misconceptions include: (1) released insects retain residual radiation, (2) females must be monogamous, (3) released males must be fully sterile, (4) eradication is the only goal, (5) the SIT is too sophisticated for developing countries, and (6) the SIT is not a component of an area-wide integrated pest management (AW-IPM) strategy. The more obvious constraints are the perceived high costs of the SIT, and the low competitiveness of released sterile males. The perceived high up-front costs of the SIT, their visibility, and the lack of private investment (compared with alternative suppression measures) emerge as serious constraints. Failure to appreciate the true nature of genetic approaches, such as the SIT, may pose a significant constraint to the wider adoption of the SIT and other genetically-based tactics, e.g. transgenic genetically modified organisms (GMOs). Lack of support for the necessary underpinning strategic research also appears to be an important constraint. Hence the case for extensive strategic research in ecology, population dynamics, genetics, and insect behaviour and nutrition is a compelling one. Raising the competitiveness of released sterile males remains the major research objective of the SIT. (author)

  4. Psychological constraints on egalitarianism

    Kasperbauer, Tyler Joshua

    2015-01-01

    Debates over egalitarianism for the most part are not concerned with constraints on achieving an egalitarian society, beyond discussions of the deficiencies of egalitarian theory itself. This paper looks beyond objections to egalitarianism as such and investigates the relevant psychological...... processes motivating people to resist various aspects of egalitarianism. I argue for two theses, one normative and one descriptive. The normative thesis holds that egalitarians must take psychological constraints into account when constructing egalitarian ideals. I draw from non-ideal theories in political...... philosophy, which aim to construct moral goals with current social and political constraints in mind, to argue that human psychology must be part of a non-ideal theory of egalitarianism. The descriptive thesis holds that the most fundamental psychological challenge to egalitarian ideals comes from what are...

  5. Additivity dominance

    Paul Rozin; Claude Fischler; Christy Shields-Argeles

    2009-01-01

    Judgments of naturalness of foods tend to be more influenced by the process history of a food, rather than its actual constituents. Two types of processing of a ``natural'' food are to add something or to remove something. We report in this study, based on a large random sample of individuals from six countries (France, Germany, Italy, Switzerland, UK and USA) that additives are considered defining features of what makes a food not natural, whereas ``subtractives'' are almost never mentioned....

  6. External Radiation Therapy

    Full Text Available ... for prostate cancer. They really boil down to two different types. There's what we call external beam ... and lay on the table. Count like, "One, two, three," up to 15. So, just about that ...

  7. External Radiation Therapy

    Full Text Available ... boil down to two different types. There's what we call external beam treatment, which is given from ... ready to go. Technician: Okay, Mr. Fabec, here we go. [beeping] Al Fabec: You keep your hands ...

  8. External Radiation Therapy

    Full Text Available ... completely contained in the prostate or when the patient is older the treatment that is frequently used ... external beam the treatment comes from outside the patient, whereas with the interstitial seed treatment the radioactive ...

  9. External Radiation Therapy

    Full Text Available ... older the treatment that is frequently used is radiation therapy. Gunnar Zagars, M.D.: There are different forms ... prostate. [beeping] Narrator: The more common form of radiation therapy is external beam. A typical treatment takes seven ...

  10. Evaluating External Communication.

    DeSantis, James R.

    1978-01-01

    Effective external communication by higher education institutions is described as an ongoing program, based on objective research, continuous informal feedback, and informed anticipation of changes in the environment that will force changes in the institution. (JMF)

  11. Initial external events: floods

    The initial external event, specifically flood in a Nuclear power plant, and the calculation necessary to determine the contribution of this type of event in a Probabilistic Safety Analysis, are presented. (M.I.)

  12. External Radiation Therapy

    Full Text Available ... prostate or when the patient is older the treatment that is frequently used is radiation therapy. Gunnar ... different types. There's what we call external beam treatment, which is given from an x-ray machine, ...

  13. External Radiation Therapy

    Full Text Available ... given from an x-ray machine, and there's a variety called interstitial implantation, which uses radioactive seeds. ... common form of radiation therapy is external beam. A typical treatment takes seven weeks. Gunnar Zagars, M. ...

  14. External Otitis (Swimmer's Ear)

    ... small area, as when pus accumulates in a boil (furuncle) or pimple. Malignant external otitis is a ... Aspergillus niger or Candida albicans, is less common. Boils are usually caused by Staphylococcus aureus . Certain people, ...

  15. External and internal audit

    Froňková, Hana

    2011-01-01

    Dissertation includes problems of internal and external audit. The goal of this work is on the basis teoretical knowledge and information got from experience, to do internal and external audit of fulfilment by drawings of financial subvence. The result of both made audits is final report.Work is composed from three parts, first part- theoretical-describes progress of internal audit, its essence and definitions, regulation frame, which characteristics ought to fulfil an internal auditor, then ...

  16. Constraint-based scheduling applying constraint programming to scheduling problems

    Baptiste, Philippe; Nuijten, Wim

    2001-01-01

    Constraint Programming is a problem-solving paradigm that establishes a clear distinction between two pivotal aspects of a problem: (1) a precise definition of the constraints that define the problem to be solved and (2) the algorithms and heuristics enabling the selection of decisions to solve the problem. It is because of these capabilities that Constraint Programming is increasingly being employed as a problem-solving tool to solve scheduling problems. Hence the development of Constraint-Based Scheduling as a field of study. The aim of this book is to provide an overview of the most widely used Constraint-Based Scheduling techniques. Following the principles of Constraint Programming, the book consists of three distinct parts: The first chapter introduces the basic principles of Constraint Programming and provides a model of the constraints that are the most often encountered in scheduling problems. Chapters 2, 3, 4, and 5 are focused on the propagation of resource constraints, which usually are responsibl...

  17. External trade development in 2010

    Český statistický úřad

    2011-01-01

    Analysis of the external trade development of the CR in total (turnover, export, import, trade balance). Main factors, which influence the external trade development. Territorial structure (by main blocks and selected countries) and commodity structure (by SITC, rev. 4) of the external trade. Comparisons of the CR external trade development with the external trade development of the other member states of the EU.

  18. External priors for the next generation of CMB experiments

    Manzotti, Alessandro; Dodelson, Scott; Park, Youngsoo

    2016-03-01

    Planned cosmic microwave background (CMB) experiments will improve what we know about neutrino physics, inflation, and dark energy. The low level of noise, together with improved angular resolution, will increase the signal-to-noise ratio of the CMB polarized data as well as the reconstructed lensing potential of large scale structure. Projected constraints on cosmological parameters are tight, but these can be improved even further with information from external experiments. Here, we examine quantitatively the extent to which external priors can lead to improvement in projected constraints from a CMB-Stage IV (S4) experiment on neutrino and dark energy properties. We find that CMB S4 constraints on neutrino mass could be strongly enhanced by external constraints on the cold dark matter density Ωch2 and the Hubble constant H0. If polarization on the largest scales (ℓenergy density Ωbh2. Finally, an external prior on H0 will help constrain the dark energy equation of state (w ).

  19. Ecosystems emerging. 5: Constraints

    Patten, B. C.; Straškraba, Milan; Jorgensen, S. E.

    2011-01-01

    Roč. 222, č. 16 (2011), s. 2945-2972. ISSN 0304-3800 Institutional research plan: CEZ:AV0Z50070508 Keywords : constraint * epistemic * ontic Subject RIV: EH - Ecology, Behaviour Impact factor: 2.326, year: 2011 http://www.sciencedirect.com/science/article/pii/S0304380011002274

  20. Combined Solar system and rotation curve constraints on MOND

    Hees, Aurélien; Famaey, Benoit; Angus, Garry W.; Gentile, Gianfranco

    2016-01-01

    The Modified Newtonian Dynamics (MOND) paradigm generically predicts that the external gravitational field in which a system is embedded can produce effects on its internal dynamics. In this communication, we first show that this external field effect (EFE) can significantly improve some galactic rotation curves fits by decreasing the predicted velocities of the external part of the rotation curves. In modified gravity versions of MOND, this EFE also appears in the Solar system and leads to a very good way to constrain the transition function of the theory. A combined analysis of the galactic rotation curves and Solar system constraints (provided by the Cassini spacecraft) rules out several classes of popular MOND transition functions, but leaves others viable. Moreover, we show that Laser Interferometer Space Antenna Pathfinder will not be able to improve the current constraints on these still viable transition functions.

  1. Metasurface external cavity laser

    Xu, Luyao; Curwen, Christopher A.; Hon, Philip W. C.; Chen, Qi-Sheng; Itoh, Tatsuo; Williams, Benjamin S.

    2015-11-01

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  2. Metasurface external cavity laser

    Xu, Luyao, E-mail: luyaoxu.ee@ucla.edu; Curwen, Christopher A.; Williams, Benjamin S. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, California 90095 (United States); Hon, Philip W. C.; Itoh, Tatsuo [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Chen, Qi-Sheng [Northrop Grumman Aerospace Systems, Redondo Beach, California 90278 (United States)

    2015-11-30

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  3. Checklists for external validity

    Dyrvig, Anne-Kirstine; Kidholm, Kristian; Gerke, Oke; Vondeling, Hindrik

    2014-01-01

    RATIONALE, AIMS AND OBJECTIVES: The quality of the current literature on external validity varies considerably. An improved checklist with validated items on external validity would aid decision-makers in judging similarities among circumstances when transferring evidence from a study setting to an....... The retrieved checklist items were assessed for (i) the methodology used in primary literature, justifying inclusion of each item; and (ii) the number of times each item appeared in checklists. RESULTS: Fifteen papers were identified, presenting a total of 21 checklists for external validity, yielding...... a total of 38 checklist items. Empirical support was considered the most valid methodology for item inclusion. Assessment of methodological justification showed that none of the items were supported empirically. Other kinds of literature justified the inclusion of 22 of the items, and 17 items were...

  4. Reduction of Constraints: Applicability of the Homogeneity Constraint for Macrobatch 3

    The Product Composition Control System (PCCS) is used to determine the acceptability of each batch of Defense Waste Processing Facility (DWPF) melter feed in the Slurry Mix Evaporator (SME). This control system imposes several constraints on the composition of the contents of the SME to define acceptability. These constraints relate process or product properties to composition via prediction models. A SME batch is deemed acceptable if its sample composition measurements lead to acceptable property predictions after accounting for modeling, measurement and analytic uncertainties. The baseline document guiding the use of these data and models is ''SME Acceptability Determination for DWPF Process Control (U)'' by Brown and Postles [1996]. A minimum of three PCCS constraints support the prediction of the glass durability from a given SME batch. The Savannah River Technology Center (SRTC) is reviewing all of the PCCS constraints associated with durability. The purpose of this review is to revisit these constraints in light of the additional knowledge gained since the beginning of radioactive operations at DWPF and to identify any supplemental studies needed to amplify this knowledge so that redundant or overly conservative constraints can be eliminated or replaced by more appropriate constraints

  5. Productivity Change and Externalities

    Kravtsova, Victoria

    2014-01-01

    This paper contributes to the analysis of the impact of externalities on the host country's total factor productivity by taking into account different dimensions of spillover effects. Namely, engagement in exporting and foreign ownership is generally perceived as being beneficial to individual...... on Hungary. While the country leads the group of post-socialist countries in the amount of attracted foreign direct investments (FDI) the effect of this policy on the economy remains unclear. The research finds that different externalities play a different role in productivity, technological and...

  6. External Liabilities and Crises

    Luis Catão; Gian Milesi-Ferretti

    2013-01-01

    We examine the determinants of external crises, focusing on the role of foreign liabilities and their composition. Using a variety of statistical tools and comprehensive data spanning 1970-2011, we find that the ratio of net foreign liabilities (NFL) to GDP is a significant crisis predictor, and the more so when it exceeds 50 percent in absolute terms and 20 percent of the country-specific historical mean. This is primarily due to net external debt--the effect of net equity liabilities is wea...

  7. Segmentation with Area Constraints

    Niethammer, Marc; Zach, Christopher

    2012-01-01

    Image segmentation approaches typically incorporate weak regularity conditions such as boundary length or curvature terms, or use shape information. High-level information such as a desired area or volume, or a particular topology are only implicitly specified. In this paper we develop a segmentation method with explicit bounds on the segmented area. Area constraints allow for the soft selection of meaningful solutions, and can counteract the shrinking bias of length-based regularization. We ...

  8. Overcoming Participation Constraints

    Hanming Fang; Peter Norman

    2005-01-01

    In incomplete information environments with transferable utility, efficient outcomes are generally implementable unless interim or ex post participation constraints are imposed on the problem. In this paper we show that linking a sufficiently large number of independent but possibly unrelated social decisions, a slightly perturbed Groves mechanism can implement an efficient outcome with probability arbitrarily close to one, while respecting all participation, incentive and balanced budget con...

  9. The NCL natural constraint language

    Zhou, Jianyang

    2012-01-01

    This book presents the Natural Constraint Language (NCL) language, a description language in conventional mathematical logic for modeling and solving constraint satisfaction problems. It uses illustrations and tutorials to detail NCL and its applications.

  10. Externalities - an analysis using the EU ExternE-results

    The EU project ExternE quantified the externalities for the different energy technologies. In this work, the ExternE results are used in a MARKAL-analysis for the Nordic countries. The analysis does not go into detail, but gives some interesting indications: The external costs are not fully covered in the Nordic energy systems, the present taxes and charges are not high enough. The emissions from the energy systems would be strongly reduced, if taxes/environmental charges were set at the level ExternE calculate. The emissions from power production would be reduced most. Renewable energy sources and natural gas dominate the energy systems in the ExternE case

  11. External Radiation Therapy

    Full Text Available ... D.: There are different forms of radiation for prostate cancer. They really boil down to two different types. There's what we call external beam treatment, which is given from an x-ray ... the prostate. [beeping] Narrator: The more common form of radiation ...

  12. Stochastic Control - External Models

    Poulsen, Niels Kjølstad

    2005-01-01

    This note is devoted to control of stochastic systems described in discrete time. We are concerned with external descriptions or transfer function model, where we have a dynamic model for the input output relation only (i.e.. no direct internal information). The methods are based on LTI systems and...

  13. External costs of electricity

    This article presents a synthesis of the ExternE project (External costs of Energy) of the European community about the external costs of power generation. Pollution impacts are calculated using an 'impact pathways' analysis, i.e. an analysis of the emission - dispersion - dose-response function - cost evaluation chain. Results are presented for different fuel cycles (with several technological variants) with their confidence intervals. The environmental impact costs are particularly high for coal: for instance, in France, for coal-fired power plants it is of the same order as the electricity retail price. For natural gas, this cost is about a third of the one for coal. On the contrary, the environmental impact costs for nuclear and renewable energies are low, typically of few per cent of the electricity price. The main part of these costs corresponds to the sanitary impacts, in particular the untimely mortality. In order to avoid any controversy about the cost evaluation of mortality, the reduction of the expectation of life due to the different fuel cycles is also indicated and the risks linked with nuclear energy are presented using several comparisons. (J.S.)

  14. External Radiation Therapy

    Full Text Available ... external beam treatment, which is given from an x-ray machine, and there's a variety called interstitial implantation, ... the treatment. You can't really feel the x-rays going into you and so they feel no ...

  15. External Radiation Therapy

    Full Text Available ... prostate or when the patient is older the treatment that is frequently used is radiation therapy. Gunnar Zagars, M.D.: There are different forms ... different types. There's what we call external beam treatment, which is given from an x-ray machine, ...

  16. Memoization in Constraint Logic Programming

    Johnson, Mark

    1994-01-01

    This paper shows how to apply memoization (caching of subgoals and associated answer substitutions) in a constraint logic programming setting. The research is is motivated by the desire to apply constraint logic programming (CLP) to problems in natural language processing that involve (constraint) interleaving or coroutining, such as GB and HPSG parsing.

  17. Network Externality: An Uncommon Tragedy

    S. J. Liebowitz; Stephen E. Margolis

    1994-01-01

    Economists have defined 'network externality' and have examined putative inframarginal market failures associated with it. This paper distinguishes between network effects and network externalities, where the latter are market failures. The authors argue that while network effects are important, network externalities are theoretically fragile and empirically undocumented. Some network externalities are merely pecuniary. Network ownership or transactions among network participants can internal...

  18. On the invariance properties of the Klein–Gordon equation with external electromagnetic field

    N D Sen Gupta

    2003-09-01

    Here we attempt to find the nature of the external electromagnetic field such that the KG equation with external electromagnetic field is invariant. Lie’s extended group method is applied to obtain the class of external electromagnetic field which admits the invariance of the KG equation. Though, the field potential only explicitly appears in the equation, the constraints for the invariance are only on the electromagnetic field.

  19. Constraints on Rindler Hydrodynamics

    Meyer, Adiel

    2013-01-01

    We study uncharged Rindler hydrodynamics at second order in the derivative expansion. The equation of state of the theory is given by a vanishing equilibrium energy density. We derive relations among the transport coefficients by employing two frameworks. First, by the requirement of having an entropy current with a non-negative divergence, second by studying the thermal partition function on stationary backgrounds. The relations derived by these two methods are consistent with each other. However, we find that the entropy current yields stronger constraints than the thermal partition function. We verify the results by studying explicit examples in flat and curved space-time geometries.

  20. Temporal Concurrent Constraint Programming

    Valencia, Frank Dan

    Concurrent constraint programming (ccp) is a formalism for concurrency in which agents interact with one another by telling (adding) and asking (reading) information in a shared medium. Temporal ccp extends ccp by allowing agents to be constrained by time conditions. This dissertation studies...... structures, robotic devises, multi-agent systems and music applications. The calculus is provided with a denotational semantics that captures the reactive computations of processes in the presence of arbitrary environments. The denotation is proven to be fully-abstract for a substantial fragment...

  1. External-Memory Multimaps

    Angelino, Elaine; Mitzenmacher, Michael; Thaler, Justin

    2011-01-01

    Many data structures support dictionaries, also known as maps or associative arrays, which store and manage a set of key-value pairs. A \\emph{multimap} is generalization that allows multiple values to be associated with the same key. For example, the inverted file data structure that is used prevalently in the infrastructure supporting search engines is a type of multimap, where words are used as keys and document pointers are used as values. We study the multimap abstract data type and how it can be implemented efficiently online in external memory frameworks, with constant expected I/O performance. The key technique used to achieve our results is a combination of cuckoo hashing using buckets that hold multiple items with a multiqueue implementation to cope with varying numbers of values per key. Our external-memory results are for the standard two-level memory model.

  2. Higher derivative theories with constraints: exorcising Ostrogradski's ghost

    We prove that the linear instability in a non-degenerate higher derivative theory, the Ostrogradski instability, can only be removed by the addition of constraints if the original theory's phase space is reduced

  3. Externalities in Urban Sustainability

    Erik T. Verhoef; Nijkamp, Peter

    2000-01-01

    This paper studies urban sustainability from the perspective ofexternalities. We develop a general spatialequilibrium model of a monocentric city, in which two types ofexternalities occur. On the one hand, pollution inthe industrial centre leads to a spatially differentiateddeterioration of the environmental quality in the residentialarea. On the other hand, the existence of the city is explained byagglomeration economies, represented as simpleMarshallian external benefits in production. We i...

  4. Frequency domain quantum optimal control under multiple constraints

    Shu, Chuan-Cun; Ho, Tak-San; Xing, Xi; Rabitz, Herschel

    2016-03-01

    Optimal control of quantum systems with complex constrained external fields is one of the longstanding theoretical and numerical challenges at the frontier of quantum control research. Here, we present a theoretical method that can be utilized to optimize the control fields subject to multiple constraints while guaranteeing monotonic convergence towards desired physical objectives. This optimization method is formulated in the frequency domain in line with the current ultrafast pulse shaping technique, providing the possibility for performing quantum optimal control simulations and experiments in a unified fashion. For illustrations, this method is successfully employed to perform multiple constraint spectral-phase-only optimization for maximizing resonant multiphoton transitions with desired pulses.

  5. Numerical strategy for model correction using physical constraints

    He, Yanyan; Xiu, Dongbin

    2016-05-01

    In this paper we present a strategy for correcting model deficiency using observational data. We first present the model correction in a general form, involving both external correction and internal correction. The model correction problem is then parameterized and casted into an optimization problem, from which the parameters are determined. More importantly, we discuss the incorporation of physical constraints from the underlying physical problem. Several representative examples are presented, where the physical constraints take very different forms. Numerical tests demonstrate that the physics constrained model correction is an effective way to address model-form uncertainty.

  6. Asteroseismic constraints for Gaia

    Creevey, O L

    2012-01-01

    Distances from the Gaia mission will no doubt improve our understanding of stellar physics by providing an excellent constraint on the luminosity of the star. However, it is also clear that high precision stellar properties from, for example, asteroseismology, will also provide a needed input constraint in order to calibrate the methods that Gaia will use, e.g. stellar models or GSP_phot. For solar-like stars (F, G, K IV/V), asteroseismic data delivers at the least two very important quantities: (1) the average large frequency separation and (2) the frequency corresponding to the maximum of the modulated-amplitude spectrum nu_max. Both of these quantities are related directly to stellar parameters (radius and mass) and in particular their combination (gravity and density). We show how the precision in , nu_max, and atmospheric parameters T_eff and [Fe/H] affect the determination of gravity (log g) for a sample of well-known stars. We find that log g can be determined within less than 0.02 dex accuracy for ou...

  7. Design with Nonlinear Constraints

    Tang, Chengcheng

    2015-12-10

    Most modern industrial and architectural designs need to satisfy the requirements of their targeted performance and respect the limitations of available fabrication technologies. At the same time, they should reflect the artistic considerations and personal taste of the designers, which cannot be simply formulated as optimization goals with single best solutions. This thesis aims at a general, flexible yet e cient computational framework for interactive creation, exploration and discovery of serviceable, constructible, and stylish designs. By formulating nonlinear engineering considerations as linear or quadratic expressions by introducing auxiliary variables, the constrained space could be e ciently accessed by the proposed algorithm Guided Projection, with the guidance of aesthetic formulations. The approach is introduced through applications in different scenarios, its effectiveness is demonstrated by examples that were difficult or even impossible to be computationally designed before. The first application is the design of meshes under both geometric and static constraints, including self-supporting polyhedral meshes that are not height fields. Then, with a formulation bridging mesh based and spline based representations, the application is extended to developable surfaces including origami with curved creases. Finally, general approaches to extend hard constraints and soft energies are discussed, followed by a concluding remark outlooking possible future studies.

  8. Supply Chain Optimized Strategies in the Mode of External Financing

    Wenyi; DU; Xingzheng; AI; Xiaowo; TANG

    2015-01-01

    In the circumstance that market demand is uncertain,it studies the decision-making problem of supply chain financial system consisting of the single supplier,a capital constraint retailer and a bank. Considering the mode of external financing,we obtain the optimal order decision of the capital constraint retailer,the optimal financing rate and the optimal wholesale price of the supplier and analyze the effects of owned capitals of retailer on the optimized decision-making of supply chain financial system. At last,it demonstrates the effectiveness of conclusion by numerical examples.

  9. Cosmographic Constraints and Cosmic Fluids

    Salvatore Capozziello

    2013-12-01

    Full Text Available The problem of reproducing dark energy effects is reviewed here with particular interest devoted to cosmography. We summarize some of the most relevant cosmological models, based on the assumption that the corresponding barotropic equations of state evolve as the universe expands, giving rise to the accelerated expansion. We describe in detail the ΛCDM (Λ-Cold Dark Matter and ωCDM models, considering also some specific examples, e.g., Chevallier–Polarsky–Linder, the Chaplygin gas and the Dvali–Gabadadze–Porrati cosmological model. Finally, we consider the cosmological consequences of f(R and f(T gravities and their impact on the framework of cosmography. Keeping these considerations in mind, we point out the model-independent procedure related to cosmography, showing how to match the series of cosmological observables to the free parameters of each model. We critically discuss the role played by cosmography, as a selection criterion to check whether a particular model passes or does not present cosmological constraints. In so doing, we find out cosmological bounds by fitting the luminosity distance expansion of the redshift, z, adopting the recent Union 2.1 dataset of supernovae, combined with the baryonic acoustic oscillation and the cosmic microwave background measurements. We perform cosmographic analyses, imposing different priors on the Hubble rate present value. In addition, we compare our results with recent PLANCK limits, showing that the ΛCDM and ωCDM models seem to be the favorite with respect to other dark energy models. However, we show that cosmographic constraints on f(R and f(T cannot discriminate between extensions of General Relativity and dark energy models, leading to a disadvantageous degeneracy problem.

  10. Unsustainable Groundwater Exploitation and Stochastic Regime Shifts: Converging Management Constraints

    Rao, Suresh; Park, Jeryang

    2014-05-01

    Increasing water security concerns arise from projected increases in competing freshwater demands, resulting from rapid urbanization, growing affluent population, and the need for increased production of food and bio-energy. These global trends in concert with the convergence of three groups of threats are likely to exacerbate freshwater security issues: (1) increasing dependency on effectively non-renewable groundwater ("peak water"); (2) increasing groundwater quality impairment("land-use intensification") from larger contaminant loads delivered from the vadose zone and surface water; and (3) increasing uncertainties in groundwater demand/supply from climate change ("stochastic risks"). Here, we present a conceptual framework for exploring water security threats, with a consideration of aquifers as complex hydrological systems with two stable states. Regime shifts in groundwater pumping -- from "sufficient" to "insufficient" -- result from changes in both internal system dynamics and external forcing from stochastic divers (non-stationary demands, hydro-climatic patterns). Examples from recent related work, in groundwater and surface water systems and ecosystems, are briefly reviewed as a prelude to presentation of model simulations of hypothetical scenarios of regime-shifts (tipping points) involving groundwater quantity and quality constraints. In addition to three types of widely recognized tipping points, we introduce a new type, stochastic tipping, that contributes to unexpected, undesirable regime shifts, resulting in inability to meet groundwater pumping needs, even when the perceived precariousness is small and the system is far from bifurcation point (deterministic tipping). Implications to sustainable groundwater management are discussed.

  11. Constraint Propagation as Information Maximization

    Abdallah, A Nait

    2012-01-01

    Dana Scott used the partial order among partial functions for his mathematical model of recursively defined functions. He interpreted the partial order as one of information content. In this paper we elaborate on Scott's suggestion of regarding computation as a process of information maximization by applying it to the solution of constraint satisfaction problems. Here the method of constraint propagation can be interpreted as decreasing uncertainty about the solution -- that is, as gain in information about the solution. As illustrative example we choose numerical constraint satisfaction problems to be solved by interval constraints. To facilitate this approach to constraint solving we formulate constraint satisfaction problems as formulas in predicate logic. This necessitates extending the usual semantics for predicate logic so that meaning is assigned not only to sentences but also to formulas with free variables.

  12. Graphene in external fields

    Feng, Sze-Shiang; Mochena, Mogus

    2010-01-01

    A general discussion of graphene in external electromagnetic field is provided. In general, the formulation is not Lorentz invariant because of Zeeman energy. But it can be restored approxiamtely in the case of strong magnetic field, the condition when quantum Hall effect is observed. Besides obtaining the well-known Hall conductance $\\frac{4q^2}{h}(L+1/2)$, we also predict that the sequence of Hall conductance $\\frac{4q^2}{h}L$,which contains the newly observed Hall conductance $\\frac{4q^2}{...

  13. Constraints On Cosmic Dynamics

    Mbonye, M R

    2003-01-01

    Observationally, the universe appears virtually critical. Yet, there is no simple explanation for this state. In this article we advance and explore the premise that the dynamics of the universe always seeks equilibrium conditions. Vacuum-induced cosmic accelerations lead to creation of matter-energy modes at the expense of vacuum energy. Because they gravitate, such modes constitute inertia against cosmic acceleration. On the other extreme, the would-be ultimate phase of local gravitational collapse is checked by a phase transition in the collapsing matter fields leading to a de Sitter-like fluid deep inside the black hole horizon, and at the expense of the collapsing matter fields. As a result, the universe succumbs to neither vacuum-induced run-away accelerations nor to gravitationally induced spacetime curvature singularities. Cosmic dynamics is self-regulating. We discuss the physical basis for these constraints and the implications, pointing out how the framework relates and helps resolve standing puzzl...

  14. Collateral constraints and macroeconomic asymmetries

    Luca Guerrieri; Matteo Iacoviello

    2013-01-01

    We show that a simple macroeconomic model with collateral constraints displays strong asymmetric responses to boom and bust periods. In a boom triggered by a rise in asset values, constraints become more and more relaxed, the collateral channel is weaker, and the response of aggregate consumption (and output) to a wealth shock is positive but small. In a recession, collateral constraints get tighter and tighter, the collateral channel gets stronger, and the response in consumption from a give...

  15. Adaptive constraints for feature tracking

    K. I. Hodges

    1999-01-01

    In this paper extensions to an existing tracking algorithm are described. These extensions implement adaptive tracking constraints in the form of regional upper-bound displacements and an adaptive track smoothness constraint. Together, these constraints make the tracking algorithm more flexible than the original algorithm (which used fixed tracking parameters) and provide greater confidence in the tracking results. The result of applying the new algorithm to high-resolution ...

  16. Environmental external effects from wind power based on the EU ExternE methodology

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1998-01-01

    The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective of...... the Danish part of the project is to implement the framework for externality evaluation, for three different power plants located in Denmark. The paper will focus on the assessment of the impacts of the whole fuel cycles for wind, natural gas and biogas. Priority areas for environmental impact...

  17. Registration of Long-Strip Terrestrial Laser Scanning Point Clouds Using RANSAC and Closed Constraint Adjustment

    Li Zheng

    2016-03-01

    Full Text Available The registration of long-strip, terrestrial laser scanning (TLS point clouds is a prerequisite for various engineering tasks, including tunnels, bridges, and roads. An artificial target-based registration method is proposed in this paper to automatically calculate registration parameters (i.e., rotation, translation of scanned pairs without initial estimations. The approach is based on the well-known Random Sample Consensus (RANSAC method and effectively searches the point cloud for corresponding returns from a system of artificial targets. In addition, Closed Constraint Adjustment (CCA is integrated into the registration method to significantly reduce the accumulative error. Experimental results demonstrate the robustness and feasibility of the proposed approach. It is a promising approach to register automatically long strips with limited external control points with satisfactory precision.

  18. External Link Policy | Division of Cancer Prevention

    The following graphic notice means that you are leaving the DCP Web site: (link is external)This external link provides additional information that is consistent with the intended purpose of DCP.The National Cancer Institute (NCI) cannot attest to the accuracy of a non-federal site.Linking to a non-federal site does not constitute an endorsement by HHS or any of its employees of the sponsors or the information and products presented on the site.You will be subject to the destination site |

  19. Automatic Planning of External Search Engine Optimization

    Vita Jasevičiūtė

    2015-07-01

    Full Text Available This paper describes an investigation of the external search engine optimization (SEO action planning tool, dedicated to automatically extract a small set of most important keywords for each month during whole year period. The keywords in the set are extracted accordingly to external measured parameters, such as average number of searches during the year and for every month individually. Additionally the position of the optimized web site for each keyword is taken into account. The generated optimization plan is similar to the optimization plans prepared manually by the SEO professionals and can be successfully used as a support tool for web site search engine optimization.

  20. ExternE: Externalities of energy Vol. 3. Coal and lignite

    methodological issues was reached on both sides of the Atlantic. Since 1993 the study has continued in Europe as the ExternE-Project, and now involves an international team of more than 30 organisations. The current study has three main objectives: 1. to design a unified methodology for quantifying the various social costs associated with the production and consumption of energy; 2. to use the methodology to evaluate the external costs of incremental use of different fuel cycles in different locations in the European Union; 3. to identify critical methodological issues and research requirements. At the same time as the publication of the present report, further reports are being published on the other major fuel cycles for electricity generation, including uranium, oil, gas, wind and hydro. A further volume, providing greater detail on the methodology used for assessment of the impacts of the fossil fuel cycles and their valuation is also being published. Additional reports on other fuel cycles, and implementation of the methodology in different countries will follow shortly. This document assesses the progress made in quantifying environmental and health damages associated with the coal and lignite fuel cycles. Estimates of impacts have been made following critical review of existing data and models rather than from original basic research. This review has been performed by a multi-disciplinary team including specialists in the fields of health, forestry, ecology, materials science, atmospheric chemistry and physics, energy technology, computer science and economics. Wherever possible we have used exactly the same methodology to quantify the same form of damage for each fuel cycle and for each location. However, some differences will be observed in the assessment of the fuel cycles considered in this report. These arise largely through the status of development of the methodology when certain parts of the work were completed. Wherever possible these differences have been

  1. Principles of Constraint Programming and Constraint Processing: A Review

    Van Der Beek, Peter; Walsh, Toby

    2004-01-01

    Review of Apt, Krzysztof. "Principles of Constraint Programming. Cambridge, England: Cambridge University Press. ISBN: 0- 521-825830. 420 pages, $50.00. Publication Date: August 2003. Review also of Dechter, Rina. "Constraint Processing. San Francisco: Morgan Kaufmann Publishers. ISBN 1-55860-890-7. 481 pages, $65.95. Publication Date: May 2003.

  2. EXTERNAL DEBTS SUSTAINABILITY, IMF POLICIES EFFECT AND TURKEY SAMPLE

    Faik A EL K

    2008-10-01

    Full Text Available It is generally recognized that developing countries need substantial amounts of net transfer of resources at early stages of development in order to close their savings and foreign exchange gaps. External3 borrowing is a core element in nearly all developing countries’ development strategies. Foreign loans can be used to finance public spending aimed at increasing growth, development, and security. Debt sustainability and holding the debt burden at a reasonable level are the two main cornerstones of achieving macroeconomic stability. Solvency is derived from the intertemporal budget constraint which shows sustainability of current policies. Generally, when the expected value of the future resources devoted to debt service equals the current debt stock, solvency condition is satisfied. Developing countries\\' debt is external debt incurred by Third World countries, generally in quantities beyond that country\\'s ability to repay. Unpayable debt is a term used to describe external debt where the interest on the debt exceeds the amount that the country produces, thus preventing the debt ever being repaid. IMF’ policies through to the World Economy have been changed in the globalization processes. Those policies have been applied in different countries When Turkish economy is taken into consideration it is seen that; it has high debt stocks, the need of external debt continues to increase and the external debt indicators give rise to the anxieties about the issue of external debt sustainability. This paper responds to take forward on external debt-related vulnerabilities and balance sheet risks.

  3. Sustainability constraints on UK bioenergy development

    Use of bioenergy as a renewable resource is increasing in many parts of the world and can generate significant environmental, economic and social benefits if managed with due regard to sustainability constraints. This work reviews the environmental, social and economic constraints on key feedstocks for UK heat, power and transport fuel. Key sustainability constraints include greenhouse gas savings achieved for different fuels, land availability, air quality impacts and facility siting. Applying those constraints, we estimate that existing technologies would facilitate a sustainability constrained level of medium-term bioenergy/biofuel supply to the UK of 4.9% of total energy demand, broken down into 4.3% of heat demands, 4.3% of electricity, and 5.8% of transport fuel. This suggests that attempts to increase the supply above these levels could have counterproductive sustainability impacts in the absence of compensating technology developments or identification of additional resources. The barriers that currently prevent this level of supply being achieved have been analysed and classified. This suggests that the biggest policy impacts would be in stimulating the market for heat demand in rural areas, supporting feedstock prices in a manner that incentivised efficient use/maximum greenhouse gas savings and targeting investment capital that improves yield and reduces land-take. (author)

  4. The Impact of Spatial Externalities: Skills, Education and Firm Productivity

    Wixe, Sofia

    2013-01-01

    This paper analyses the role of spatial externalities in explaining the average labour productivity of Swedish manufacturing firms. The empirical findings support MAR and Porter externalities as well as general urbanization economies, but not Jacobs externalities. In addition, the matching between the firm and the regional labour force is found to be productivity-enhancing. However, firm-specific characteristics, including the characteristics of the employees, are not to be forgotten. Especia...

  5. Axiomatics for the external numbers of nonstandard analysis

    Dinis, Bruno; Berg, Imme van den

    2016-01-01

    Neutrices are additive subgroups of a nonstandard model for the real numbers. An external number is the algebraic sum of a (hyper)real number and a neutrix. Due to the stability by some shifts, external numbers may be seen as mathematical models for orders of magnitude. The algebraic properties of external numbers gave rise to so-called solids, which are extensions of ordered fields, having a restricted distributivity law. However, necessary and sufficient conditions can be given for distribu...

  6. Financial Crisis and Financing Constraints of SMEs in Visegrad Countries

    Koráb, Petr; Pomenková, Jitka

    2014-01-01

    The paper investigates the access of small and medium-sized enterprises to external financing during the recent financial crisis via non-parametric density estimation. The kernel density estimation is applied on a firm-level measure of financing constraints and evaluates its distribution on a balanced panel of SMEs. For application and cross-country comparison we use panel data on Limited Liability enterprises in the Czech Republic, Poland, Slovakia and Hungary. Our results reveal asymmetric ...

  7. Generalizing Consistency and other Constraint Properties to Quantified Constraints

    Bordeaux, Lucas; Mancini, Toni

    2007-01-01

    Quantified constraints and Quantified Boolean Formulae are typically much more difficult to reason with than classical constraints, because quantifier alternation makes the usual notion of solution inappropriate. As a consequence, basic properties of Constraint Satisfaction Problems (CSP), such as consistency or substitutability, are not completely understood in the quantified case. These properties are important because they are the basis of most of the reasoning methods used to solve classical (existentially quantified) constraints, and one would like to benefit from similar reasoning methods in the resolution of quantified constraints. In this paper, we show that most of the properties that are used by solvers for CSP can be generalized to quantified CSP. This requires a re-thinking of a number of basic concepts; in particular, we propose a notion of outcome that generalizes the classical notion of solution and on which all definitions are based. We propose a systematic study of the relations which hold be...

  8. Nonlinear balance constraints in 3DVAR data assimilation

    ZHU; Jiang; YAN; Changxiang

    2006-01-01

    In many applications of 3DVAR, the balance constraints can be considered via two main approaches: weak constraint method which adds penalty terms to the cost function; and proper definition of the background error covariance matrix with non-zero cross-correlation sub-matrices. The weak constraint approach requires determining the weighting matrices of the penalty terms. The background error covariance approach does not require determining those additional weighting matrices. However, it is only applicable to those linear or linearized balance constraints. A novel approach is proposed based on the background error covariance approach by generalizing the so-called Derber-Bouttier formulation. An assimilation experiment of estimating temperature and salinity from the sea surface dynamic height observation is given to illustrate the proposed treatments of nonlinear balance constraints.

  9. Disk Dispersal: Theoretical Understanding and Observational Constraints

    Gorti, U; Sandor, Zs; clarke, C

    2015-01-01

    Protoplanetary disks dissipate rapidly after the central star forms, on time-scales comparable to those inferred for planet formation. In order to allow the formation of planets, disks must survive the dispersive effects of UV and X-ray photoevaporation for at least a few Myr. Viscous accretion depletes significant amounts of the mass in gas and solids, while photoevaporative flows driven by internal and external irradiation remove most of the gas. A reasonably large fraction of the mass in solids and some gas get incorporated into planets. Here, we review our current understanding of disk evolution and dispersal, and discuss how these might affect planet formation. We also discuss existing observational constraints on dispersal mechanisms and future directions.

  10. Disk Dispersal: Theoretical Understanding and Observational Constraints

    Gorti, U.; Liseau, R.; Sándor, Z.; Clarke, C.

    2016-05-01

    Protoplanetary disks dissipate rapidly after the central star forms, on time-scales comparable to those inferred for planet formation. In order to allow the formation of planets, disks must survive the dispersive effects of UV and X-ray photoevaporation for at least a few Myr. Viscous accretion depletes significant amounts of the mass in gas and solids, while photoevaporative flows driven by internal and external irradiation remove most of the gas. A reasonably large fraction of the mass in solids and some gas get incorporated into planets. Here, we review our current understanding of disk evolution and dispersal, and discuss how these might affect planet formation. We also discuss existing observational constraints on dispersal mechanisms and future directions.

  11. External Measures of Cognition

    Osvaldo Cairo

    2011-10-01

    Full Text Available The human brain is undoubtedly the most impressive, complex and intricate organ that has evolved over time. It is also probably the least understood, and for that reason, the one that is currently attracting the most attention. In fact, the number of comparative analyses that focus on the evolution of brain size in Homo sapiens and other species has increased dramatically in recent years. In neuroscience, no other issue has generated so much interest and been the topic of so many heated debates as the difference in brain size between socially defined population groups, both its connotations and implications. For over a century, external measures of cognition have been related to intelligence. However, it is still unclear whether these measures actually correspond to cognitive abilities. In summary, this paper must be reviewed with this premise in mind.

  12. Bevalac external beamline optics

    This handbook is intended as an aid for tuning the external particle beam (EPB) lines at the Lawrence Berkeley Laboratory's Bevalac. The information contained within will be useful to the Bevalac's Main Control Room and experimenters alike. First, some general information is given concerning the EPB lines and beam optics. Next, each beam line is described in detail: schematics of the beam line components are shown, all the variables required to run a beam transport program are presented, beam envelopes are given with wire chamber pictures and magnet currents, focal points and magnifications. Some preliminary scaling factors are then presented which should aid in choosing a given EPB magnet's current for a given central Bevalac field. Finally, some tuning hints are suggested

  13. Credit Constraints for Higher Education

    Solis, Alex

    2012-01-01

    This paper exploits a natural experiment that produces exogenous variation on credit access to determine the effect on college enrollment. The paper assess how important are credit constraints to explain the gap in college enrollment by family income, and what would be the gap if credit constraints are eliminated. Progress in college and dropout…

  14. Minimal Flavor Constraints for Technicolor

    Sakuma, Hidenori; Sannino, Francesco

    2010-01-01

    We analyze the constraints on the the vacuum polarization of the standard model gauge bosons from a minimal set of flavor observables valid for a general class of models of dynamical electroweak symmetry breaking. We will show that the constraints have a strong impact on the self-coupling and...

  15. CONCURRENT ENGINEERING WITH CONSTRAINT NETWORKS

    Steve Minnaar; Robert Reinecke

    2012-01-01

    Concurrent engineering is a systematic approach to the integrated, concurrent design of products and their related processes, including manufacture and support. It allows the consideration of all elements of the product's life cycle, from conception through disposal, including quality, cost, manufacturing, and customer requirements. Constraint networks as an approach to concurrent engineering provides considerable advantages over the conventional approaches to improve engineering. Constraint ...

  16. An Introduction to 'Creativity Constraints'

    Onarheim, Balder; Biskjær, Michael Mose

    2013-01-01

    Constraints play a vital role as both restrainers and enablers in innovation processes by governing what the creative agent/s can and cannot do, and what the output can and cannot be. Notions of constraints are common in creativity research, but current contributions are highly dispersed due to n...

  17. Constraint Programming for Context Comprehension

    Christiansen, Henning

    2014-01-01

    A close similarity is demonstrated between context comprehension, such as discourse analysis, and constraint programming. The constraint store takes the role of a growing knowledge base learned throughout the discourse, and a suitable con- straint solver does the job of incorporating new pieces...

  18. Optimizing selection with several constraints in poultry breeding.

    Chapuis, H; Pincent, C; Colleau, J J

    2016-02-01

    Poultry breeding schemes permanently face the need to control the evolution of coancestry and some critical traits, while selecting for a main breeding objective. The main aims of this article are first to present an efficient selection algorithm adapted to this situation and then to measure how the severity of constraints impacted on the degree of loss for the main trait, compared to BLUP selection on the main trait, without any constraint. Broiler dam and sire line schemes were mimicked by simulation over 10 generations and selection was carried out on the main trait under constraints for coancestry and for another trait, antagonistic with the main trait. The selection algorithm was a special simulated annealing (adaptative simulated annealing (ASA)). It was found to be rapid and able to meet constraints very accurately. A constraint on the second trait was found to induce an impact similar to or even greater than the impact of the constraint on coancestry. The family structure of selected poultry populations made it easy to control the evolution of coancestry at a reasonable cost but was not as useful for reducing the cost of controlling evolution of the antagonistic traits. Multiple constraints impacted almost additively on the genetic gain for the main trait. Adding constraints for several traits would therefore be justified in real life breeding schemes, possibly after evaluating their impact through simulated annealing. PMID:26220593

  19. Internalizing Externalities through Payments for Environmental Services

    Sudarsono Soedomo

    2012-08-01

    Full Text Available Forest ecosystems, including plantation forests, provide goods and services that are marketable and non-marketable. Positive externalities produced by forest ecosystems are rarely considered in pricing of marketable products that result in economic inefficiencies. Internalizing externalities is required to improve the economic efficiency. The traditional way to internalize an externality is by providing subsidies or imposing taxes. Recently, payments for environmental services  are receiving more attention as an instrument for internalizing externalities provided by forest ecosystems. This promising alternative to improve our environment needs to be studied more extensively. In this paper, it can be indicated theoretically that the Pigovian tax, as a traditional way of addressing environmental problems, is able to mimic the result derived from the employment of environmental services payment. The difference is that environmental services payment improves the welfare of environmental service producers, whereas the Pigovian tax reduces it. A positive Pigovian tax increases the optimal rotation, which is positively associated with environmental improvement, but certainly reduces forest owner's welfare. This difference should be taken into account in the public policymaking so that perverse incentive may be avoided. Payment for environmental services  as an additional income to forest growers, not as alternative source of income, is a potential tool to address simultaneously issues of environment and poverty that are frequently contested.Keywords: externalities, payments for environmental services, tax, perverse incentive, social welfare

  20. Infrared Kuiper Belt Constraints

    We compute the temperature and IR signal of particles of radius a and albedo α at heliocentric distance R, taking into account the emissivity effect, and give an interpolating formula for the result. We compare with analyses of COBE DIRBE data by others (including recent detection of the cosmic IR background) for various values of heliocentric distance R, particle radius a, and particle albedo α. We then apply these results to a recently developed picture of the Kuiper belt as a two-sector disk with a nearby, low-density sector (40< R<50 endash 90 AU) and a more distant sector with a higher density. We consider the case in which passage through a molecular cloud essentially cleans the solar system of dust. We apply a simple model of dust production by comet collisions and removal by the Poynting-Robertson effect to find limits on total and dust masses in the near and far sectors as a function of time since such a passage. Finally, we compare Kuiper belt IR spectra for various parameter values. Results of this work include: (1) numerical limits on Kuiper belt dust as a function of (R, a, α) on the basis of four alternative sets of constraints, including those following from recent discovery of the cosmic IR background by Hauser et al.; (2) application to the two-sector Kuiper belt model, finding mass limits and spectrum shape for different values of relevant parameters including dependence on time elapsed since last passage through a molecular cloud cleared the outer solar system of dust; and (3) potential use of spectral information to determine time since last passage of the Sun through a giant molecular cloud. copyright copyright 1999. The American Astronomical Society

  1. Vocabulary Constraint on Texts

    C. Sutarsyah

    2008-01-01

    Full Text Available This case study was carried out in the English Education Department of State University of Malang. The aim of the study was to identify and describe the vocabulary in the reading text and to seek if the text is useful for reading skill development. A descriptive qualitative design was applied to obtain the data. For this purpose, some available computer programs were used to find the description of vocabulary in the texts. It was found that the 20 texts containing 7,945 words are dominated by low frequency words which account for 16.97% of the words in the texts. The high frequency words occurring in the texts were dominated by function words. In the case of word levels, it was found that the texts have very limited number of words from GSL (General Service List of English Words (West, 1953. The proportion of the first 1,000 words of GSL only accounts for 44.6%. The data also show that the texts contain too large proportion of words which are not in the three levels (the first 2,000 and UWL. These words account for 26.44% of the running words in the texts.  It is believed that the constraints are due to the selection of the texts which are made of a series of short-unrelated texts. This kind of text is subject to the accumulation of low frequency words especially those of content words and limited of words from GSL. It could also defeat the development of students' reading skills and vocabulary enrichment.

  2. Automated constraint placement to maintain pile shape

    Hsu, Shu-Wei

    2012-11-01

    We present a simulation control to support art-directable stacking designs by automatically adding constraints to stabilize the stacking structure. We begin by adapting equilibrium analysis in a local scheme to find "stable" objects of the stacking structure. Next, for stabilizing the structure, we pick suitable objects from those passing the equilibrium analysis and then restrict their DOFs by managing the insertion of constraints on them. The method is suitable for controlling stacking behavior of large scale. Results show that our control method can be used in varied ways for creating plausible animation. In addition, the method can be easily implemented as a plug-in into existing simulation solvers without changing the fundamental operations of the solvers. © 2012 ACM.

  3. Constraint-Aided Product Design

    G. Mullineux

    2005-01-01

    Full Text Available The importance of supporting the early stages of design is widely accepted. In particular, the development of supportive tools and methods for modelling and analysis of evolving design solutions present a difficult challenge. One reason for this is the need to model both the product design and the design knowledge from which the design is created. There are a number of limitations with many existing techniques and an alternative approach that deals with the design constraints themselves is presented. Dealing directly with the constraints affords a more generalised approach that represents the process by which a product is designed. This enables modelling and reasoning about a product from an often abstract and evolving set of requirements. The constraint methodology is an iterative process where the design requirements are elaborated, the constraint rules altered, design ideas generated and tested as functional structures. The incorporation of direct search techniques to solve the constrained problem enables different solutions to be explored and allows the determination of ‘best compromises’ for related constraints. A constraint modelling environment is discussed and two example cases are used to demonstrate the potential of a constraint-aided approach for supporting important issues such as the design of product variants and product families. 

  4. Constraint Embedding Technique for Multibody System Dynamics

    Woo, Simon S.; Cheng, Michael K.

    2011-01-01

    Multibody dynamics play a critical role in simulation testbeds for space missions. There has been a considerable interest in the development of efficient computational algorithms for solving the dynamics of multibody systems. Mass matrix factorization and inversion techniques and the O(N) class of forward dynamics algorithms developed using a spatial operator algebra stand out as important breakthrough on this front. Techniques such as these provide the efficient algorithms and methods for the application and implementation of such multibody dynamics models. However, these methods are limited only to tree-topology multibody systems. Closed-chain topology systems require different techniques that are not as efficient or as broad as those for tree-topology systems. The closed-chain forward dynamics approach consists of treating the closed-chain topology as a tree-topology system subject to additional closure constraints. The resulting forward dynamics solution consists of: (a) ignoring the closure constraints and using the O(N) algorithm to solve for the free unconstrained accelerations for the system; (b) using the tree-topology solution to compute a correction force to enforce the closure constraints; and (c) correcting the unconstrained accelerations with correction accelerations resulting from the correction forces. This constraint-embedding technique shows how to use direct embedding to eliminate local closure-loops in the system and effectively convert the system back to a tree-topology system. At this point, standard tree-topology techniques can be brought to bear on the problem. The approach uses a spatial operator algebra approach to formulating the equations of motion. The operators are block-partitioned around the local body subgroups to convert them into aggregate bodies. Mass matrix operator factorization and inversion techniques are applied to the reformulated tree-topology system. Thus in essence, the new technique allows conversion of a system with

  5. Numerical parameter constraints for accurate PIC-DSMC simulation of breakdown from arc initiation to stable arcs

    Moore, Christopher; Hopkins, Matthew; Moore, Stan; Boerner, Jeremiah; Cartwright, Keith

    2015-09-01

    Simulation of breakdown is important for understanding and designing a variety of applications such as mitigating undesirable discharge events. Such simulations need to be accurate through early time arc initiation to late time stable arc behavior. Here we examine constraints on the timestep and mesh size required for arc simulations using the particle-in-cell (PIC) method with direct simulation Monte Carlo (DMSC) collisions. Accurate simulation of electron avalanche across a fixed voltage drop and constant neutral density (reduced field of 1000 Td) was found to require a timestep ~ 1/100 of the mean time between collisions and a mesh size ~ 1/25 the mean free path. These constraints are much smaller than the typical PIC-DSMC requirements for timestep and mesh size. Both constraints are related to the fact that charged particles are accelerated by the external field. Thus gradients in the electron energy distribution function can exist at scales smaller than the mean free path and these must be resolved by the mesh size for accurate collision rates. Additionally, the timestep must be small enough that the particle energy change due to the fields be small in order to capture gradients in the cross sections versus energy. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  6. A Comparative Study of Randomized Constraint Solvers for Random-Symbolic Testing

    Takaki, Mitsuo; Cavalcanti, Diego; Gheyi, Rohit; Iyoda, Juliano; dAmorim, Marcelo; Prudencio, Ricardo

    2009-01-01

    The complexity of constraints is a major obstacle for constraint-based software verification. Automatic constraint solvers are fundamentally incomplete: input constraints often build on some undecidable theory or some theory the solver does not support. This paper proposes and evaluates several randomized solvers to address this issue. We compare the effectiveness of a symbolic solver (CVC3), a random solver, three hybrid solvers (i.e., mix of random and symbolic), and two heuristic search solvers. We evaluate the solvers on two benchmarks: one consisting of manually generated constraints and another generated with a concolic execution of 8 subjects. In addition to fully decidable constraints, the benchmarks include constraints with non-linear integer arithmetic, integer modulo and division, bitwise arithmetic, and floating-point arithmetic. As expected symbolic solving (in particular, CVC3) subsumes the other solvers for the concolic execution of subjects that only generate decidable constraints. For the remaining subjects the solvers are complementary.

  7. A methodology for controlling motion and constraint forces in holonomically constrained systems

    Sapio, Vincent De, E-mail: vdesapio@hrl.com; Srinivasa, Narayan, E-mail: nsrinivasa@hrl.com [HRL Laboratories, LLC, Information and Systems Sciences Laboratory (United States)

    2015-02-15

    Holonomic constraints are ubiquitous in multibody systems. We present an approach to effectively address the control of holonomically constrained systems using a novel decomposition of task, constraint, and posture space. In addition to providing a natural approach for motion control in the presence of constraints, this scheme also allows for concurrent specification of desired constraint forces, given sufficient actuation. It does this by exposing both motion coordinates and constraint forces within the control formalism, allowing for substantial flexibility in control synthesis. Implementations are presented based on a partitioning of the constraint forces into controlled and uncontrolled subsets, as well as a specification of implicit conditions on the constraint forces. A number of examples demonstrate the practical efficacy of the approach. Finally, a system-level methodology for constraint management during robot interactions with the environment is presented.

  8. IRIS Toxicological Review of Methanol (Noncancer) (Revised External Review Draft)

    EPA is seeking additional public comment and external peer review of the scientific basis supporting the human health hazard and dose-response assessment of methanol (noncancer). Teleconference Details: The public may participate in th...

  9. Volumes and doses for external radiotherapy - Definitions and recommendations

    The report contains definitions of volume and dose parameters for external radiotherapy. In addition the report contains recommendations for use, documentation and minimum reporting for radiotherapy of the individual patient.(Author)

  10. Methods for quantifying environmental externalities

    The quantification of environmental externalities is a complex and often subjective task. The difficulty of reliably expressing complex and uncertain relationships between environmental pollutants and the resulting damages and then expressing these damages in dollar costs, results in a wide divergence of opinions regarding the appropriate environmental externality values. Below is a review of the generally accepted methods for incorporating environmental externalities into the resource evaluation process and for quantifying environmental externalities in terms of monetary values. Environmental externalities are open-quotes the cost of environmental damages caused by a project or activity for which compensation to affected parties does not occur.close-quote (Massachusetts Department of Public Utilities, 86-36-G, p. 77) An example of an environmental externality for the electric utility industry are the costs imposed on society of electric generating units uncontrolled (residual) emissions, e.g., the damage costs of acid rain caused by the sulfur dioxide emissions from Midwestern power plants. These costs are external since they are borne by society in general, not considered by the electric utilities in planning. Public awareness of the externality costs of acid rain has resulted in legislation requiring utilities to reduce their sulfur dioxide emissions and will cause electric utilities to reflect cost in their planning and in overall costs of electricity. Environmental externalities can be incorporated into utilities' resource planning processes in several ways. Two methods receiving the most attention are a weighting and ranking approach and the monetization of externalities, i.e., the expression of externality values in dollars. The monetization approach is more complex and has received wider acceptance from regulators. Consequently, this discussion focuses primarily on methods for monetizing externalities

  11. Form of ownership and financial constraints : panel data evidence from leverage and investment equations

    Schiantarelli, Fabio; Sembenelli, Alessandro

    1996-01-01

    The authors analyze whether form of ownership affects the substitutability of internal and external sources of finance. In particular, they test whether financial constraints are more severe for independent firms, and whether members of large national business groups suffer different constraints than subsidiaries of foreign multinational corporations. The results for leverage and investment equations estimated for a panel of Italian companies suggest that: a) independent firms face more sever...

  12. FINANCIAL DEVELOPMENT AND FINANCING CONSTRAINTS IN A DEVELOPING COUNTRY - THE CASE OF BANGLADESH

    Kang Kook Lee; Md. Rabiul Islam

    2009-01-01

    This paper examines the sensitivity of investment to available cash-stock, a measure for internal funds, for 192 listed non-financial firms of Bangladesh from 1992 to 2002. The empirical results show that smaller firms have greater financing constraints to investment than larger firms due to financial market imperfection and unequal access to external finance. We also find that financing constraints of investment by small firms are eased along with financial development. It is likely that fin...

  13. Endogenous business cycles: capital-labor substitution and liquidity constraint with increasing returns to scale

    Bosi, Stefano; Francesco MAGRIS

    1997-01-01

    It is well known from the literature that the introduction of financial constraints in economies with infinite-lived agents can be responsible for the occurrence of multiple equilibria and en- dogenous fluctuations. However, the question of the persistence of such phenomena when the constraints are progressively relaxed remains open. By departing from Cazzavillan, Lloyd-Braga and Pintus (1996) framework with heterogeneous agents and positive externalities in aggregate capital and labor, we sh...

  14. STABILITY OF MANIPULATOR CONFIGURATION UNDER EXTERNAL LOADING

    Klimchik, Alexandr; Pashkevich, Anatol; Chablat, Damien

    2012-01-01

    The paper is devoted to the analysis of robotic manipulator behavior under internal and external loadings. The main contributions are in the area of stability analysis of manipulator configurations corresponding to the loaded static equilibrium. In contrast to other works, in addition to usually studied the end-platform behavior with respect to the disturbance forces, the problem of configuration stability for each kinematic chain is considered. The proposed approach extends the classical not...

  15. On-site Labour Productivity of New Zealand Construction Industry: Key Constraints and Improvement Measures

    Serdar Durdyev

    2011-09-01

    Full Text Available Productivity is key to the survival and growth of any organisation, industry or nation. Some factors constrain the achievement of the set project objectives in the New Zealand building and construction industry and are responsible for the reported steady decline of productivity and performance. This study aims to identify the key constraints to on-site labour productivity and improvement measures. Using the descriptive survey method, views of some project managers, contractors and subcontractors in New Zealand were canvassed via pilot interviews and questionnaire surveys at the qualitative and quantity data gathering stages, respectively. Multi-attribute technique was used to analyse the quantitative data. Results showed that the key external constraints to on-site labour productivity comprise, in order of decreasing impact, statutory compliance, unforeseen events and wider external dynamics. The internal constraints, which contribute 67 percent of the onsite productivity issues, comprise reworks, level of skill and experience of the workforce, adequacy of method of construction, buildability issues, and inadequate supervision and coordination. . The factors underlying each broad category of external and internal constraints are reported. The relative levels of impact of the identified constraints are expected to guide the project team in addressing the constraints in a cost-effective manner.

  16. Expressing Preferences using Preference Set Constraint Atoms

    Brik, Alex; Remmel, Jeffrey B.

    2012-01-01

    This paper introduces an extension of Answer Set Programming called Preference Set Constraint Programming which is a convenient and general formalism to reason with preferences. PSC programming extends Set Constraint Programming introduced by Marek and Remmel (Marek and Remmel 2004) by introducing two types of preference set constraint atoms, measure preference set constraint atoms and pre-ordered preference set constraint atoms, which are extensions of set constraint atoms. We show that the ...

  17. SMEs, financial constraints and growth

    Ryan Banerjee

    2014-01-01

    The SME sector is often hailed as an important engine of economic growth. But recent research suggests that young rather than small firms are the main contributors to employment growth. This paper shows that young firms are also key contributors to profit growth across advanced economies. It them examines the impact of financial constraints on profitability across the age distribution of SMEs. We find that start-ups which report finance as their greatest constraint receive smaller new loans a...

  18. Developmental constraints on behavioural flexibility

    Holekamp, Kay E.; Swanson, Eli M.; Van Meter, Page E.

    2013-01-01

    We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotte...

  19. Collateral constraints and rental markets

    D'Albis, Hippolyte; Iliopulos, Eleni

    2013-01-01

    International audience We study a benchmark model with collateral constraints and heterogeneous discounting. Contrarily to a rich literature on borrowing limits, we allow for rental markets. By incorporating this missing market, we show that impatient agents choose to rent rather than to own the collateral in the neighborhood of the deterministic steady state. Consequently, impatient agents are not indebted and borrowing constraints play no role in local dynamics.

  20. Financial Constraints on Corporate Goodness

    Harrison Hong; Kubik, Jeffrey D.; Jose A. Scheinkman

    2012-01-01

    An influential thesis, dubbed "Doing well by doing good," argues that corporate social responsibility is profitable. But heterogeneity in firm financial constraints can induce a spurious correlation between profits and goodness even if the motives for goodness are non-profit in nature. We use two identification strategies to show that financial constraints are indeed an important driver of corporate goodness. First, during the Internet bubble, previously constrained firms experienced a tempor...

  1. Formal Verification under Unknown Constraints

    LI Guang-hui; LI Xiao-wei

    2005-01-01

    We present a formal method of verifying designs with unknown constraints (e. g. , black boxes) using Boolean satisfiability (SAT). This method is based on a new encoding scheme of unknown constraints, and solves the corresponding conjunctive normal form (CNF) formulas. Furthermore, this method can avoid the potential memory explosion, which the binary decision diagram (BDD) based techniques maybe suffer from, thus it has the capacity of verifying large designs. Experimental results demonstrate the efficiency and feasibility of the proposed method.

  2. Foundations of support constraint machines.

    Gnecco, Giorgio; Gori, Marco; Melacci, Stefano; Sanguineti, Marcello

    2015-02-01

    The mathematical foundations of a new theory for the design of intelligent agents are presented. The proposed learning paradigm is centered around the concept of constraint, representing the interactions with the environment, and the parsimony principle. The classical regularization framework of kernel machines is naturally extended to the case in which the agents interact with a richer environment, where abstract granules of knowledge, compactly described by different linguistic formalisms, can be translated into the unified notion of constraint for defining the hypothesis set. Constrained variational calculus is exploited to derive general representation theorems that provide a description of the optimal body of the agent (i.e., the functional structure of the optimal solution to the learning problem), which is the basis for devising new learning algorithms. We show that regardless of the kind of constraints, the optimal body of the agent is a support constraint machine (SCM) based on representer theorems that extend classical results for kernel machines and provide new representations. In a sense, the expressiveness of constraints yields a semantic-based regularization theory, which strongly restricts the hypothesis set of classical regularization. Some guidelines to unify continuous and discrete computational mechanisms are given so as to accommodate in the same framework various kinds of stimuli, for example, supervised examples and logic predicates. The proposed view of learning from constraints incorporates classical learning from examples and extends naturally to the case in which the examples are subsets of the input space, which is related to learning propositional logic clauses. PMID:25380338

  3. Phonotactic Constraints Are Activated across Languages in Bilinguals

    Freeman, Max R.; Blumenfeld, Henrike K.; Marian, Viorica

    2016-01-01

    During spoken language comprehension, auditory input activates a bilingual’s two languages in parallel based on phonological representations that are shared across languages. However, it is unclear whether bilinguals access phonotactic constraints from the non-target language during target language processing. For example, in Spanish, words with s+ consonant onsets cannot exist, and phonotactic constraints call for epenthesis (addition of a vowel, e.g., stable/estable). Native Spanish speakers may produce English words such as estudy (“study”) with epenthesis, suggesting that these bilinguals apply Spanish phonotactic constraints when speaking English. The present study is the first to examine whether bilinguals access Spanish phonotactic constraints during English comprehension. In an English cross-modal priming lexical decision task, Spanish–English bilinguals and English monolinguals heard English cognate and non-cognate primes containing s+ consonant onsets or controls without s+ onsets, followed by a lexical decision on visual targets with the /e/ phonotactic constraint or controls without /e/. Results revealed that bilinguals were faster to respond to /es/ non-word targets preceded by s+ cognate primes and /es/ and /e/ non-word targets preceded by s+ non-cognate primes, confirming that English primes containing s+ onsets activated Spanish phonotactic constraints. These findings are discussed within current accounts of parallel activation of two languages during bilingual spoken language comprehension, which may be expanded to include activation of phonotactic constraints from the irrelevant language. PMID:27242615

  4. ExternE transport methodology for external cost evaluation of air pollution

    Jensen, S. S.; Berkowicz, R.; Brandt, J.;

    The report describes how the human exposure estimates based on NERI's human exposure modelling system (AirGIS) can improve the Danish data used for exposure factors in the ExternE Transport methodology. Initially, a brief description of the ExternE Tranport methodology is given and it is summarised...... how the methodology has been applied so far in a previous Danish study. Finally, results of a case study are reported. Exposure factors have been calculated for various urban categories in the Greater Copenhagen Area...

  5. Breaking evolutionary constraint with a tradeoff ratchet.

    de Vos, Marjon G J; Dawid, Alexandre; Sunderlikova, Vanda; Tans, Sander J

    2015-12-01

    Epistatic interactions can frustrate and shape evolutionary change. Indeed, phenotypes may fail to evolve when essential mutations are only accessible through positive selection if they are fixed simultaneously. How environmental variability affects such constraints is poorly understood. Here, we studied genetic constraints in fixed and fluctuating environments using the Escherichia coli lac operon as a model system for genotype-environment interactions. We found that, in different fixed environments, all trajectories that were reconstructed by applying point mutations within the transcription factor-operator interface became trapped at suboptima, where no additional improvements were possible. Paradoxically, repeated switching between these same environments allows unconstrained adaptation by continuous improvements. This evolutionary mode is explained by pervasive cross-environmental tradeoffs that reposition the peaks in such a way that trapped genotypes can repeatedly climb ascending slopes and hence, escape adaptive stasis. Using a Markov approach, we developed a mathematical framework to quantify the landscape-crossing rates and show that this ratchet-like adaptive mechanism is robust in a wide spectrum of fluctuating environments. Overall, this study shows that genetic constraints can be overcome by environmental change and that cross-environmental tradeoffs do not necessarily impede but also, can facilitate adaptive evolution. Because tradeoffs and environmental variability are ubiquitous in nature, we speculate this evolutionary mode to be of general relevance. PMID:26567153

  6. Reheating Constraints to Inflationary Models

    Dai, Liang; Kamionkowski, Marc; Wang, Junpu

    2014-07-01

    Evidence from the BICEP2 experiment for a significant gravitational-wave background has focused attention on inflaton potentials V(ϕ)∝ϕα with α=2 ("chaotic" or "m2ϕ2" inflation) or with smaller values of α, as may arise in axion-monodromy models. Here we show that reheating considerations may provide additional constraints to these models. The reheating phase preceding the radiation era is modeled by an effective equation-of-state parameter wre. The canonical reheating scenario is then described by wre=0. The simplest α=2 models are consistent with wre=0 for values of ns well within the current 1σ range. Models with α=1 or α=2/3 require a more exotic reheating phase, with -1/31/3, unless ns is close to the lower limit of the 2σ range. For m2ϕ2 inflation and canonical reheating as a benchmark, we derive a relation log10(Tre/106 GeV)≃2000(ns-0.96) between the reheat temperature Tre and the scalar spectral index ns. Thus, if ns is close to its central value, then Tre≲106 GeV, just above the electroweak scale. If the reheat temperature is higher, as many theorists may prefer, then the scalar spectral index should be closer to ns≃0.965 (at the pivot scale k =0.05 Mpc-1), near the upper limit of the 1σ error range. Improved precision in the measurement of ns should allow m2ϕ2, axion monodromy, and ϕ4 models to be distinguished, even without precise measurement of r, and to test the m2ϕ2 expectation of ns≃0.965.

  7. Retrofitting Systems for External Walls

    Rose, Jørgen

    1997-01-01

    In this report, 9 different external and internal retrofitting systems are analyzed using numerical calculations. The analysis focuses on the thermal bridge effects in the different systems, and on this basis it is discussed whether internal or external retrofitting has the most advantages. The...... different systems are evaluated using 5 different types of existing walls....

  8. An overview of environmental externalities

    This paper describes the purpose of the conference on environmental externalities and provides illustrations and examples of incorporating these costs into the utility planning process. The topics of the paper include internalization, externalities, resistance to incorporation, reasons why they should be incorporated, and mechanisms for incorporation

  9. External coating of colonic anastomoses

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Rosenberg, Jacob

    2012-01-01

    Colon anastomotic leakage remains both a frequent and serious complication in gastrointestinal surgery. External coating of colonic anastomoses has been proposed as a means to lower the rate of this complication. The aim of this review was to evaluate existing studies on external coating of colonic...

  10. Utility planning and evaluating environmental externalities

    This discussion of environmental externalities in utility planning is divided into three parts. First, the pending Clean Air Act (CAA) Amendments contain market-based control provisions that internalize damage associated with SO2 and NOx air pollution. The amendments pose new challenges and risks for utility planners. The paper highlights several issues that have not received much attention. In particular, the need for short-term and long-term emissions allowance markets and the concept of emissions pooling. Conceptually, emissions pools would be similar to utility power pools. Since a utility may not know if it will exceed its annual emissions allowance until well into the year, a procedure for obtaining additional allowances could have value. Second, state regulators are taking a hard look at incorporating environmental externalities in the least-cost planning process. Generic methods available for incorporating externalities in the planning process are discussed. Third, a number of recent studies have referred to approaches for the direct valuation of externalities. Several of the more commonly used methods are described. Tables are presented that outline the applicability of the techniques and their strengths and weaknesses

  11. The Geometry of Algorithms with Orthogonality Constraints

    Edelman, A; Smith, S T; Edelman, Alan; Smith, Steven T.

    1998-01-01

    In this paper we develop new Newton and conjugate gradient algorithms on the Grassmann and Stiefel manifolds. These manifolds represent the constraints that arise in such areas as the symmetric eigenvalue problem, nonlinear eigenvalue problems, electronic structures computations, and signal processing. In addition to the new algorithms, we show how the geometrical framework gives penetrating new insights allowing us to create, understand, and compare algorithms. The theory proposed here provides a taxonomy for numerical linear algebra algorithms that provide a top level mathematical view of previously unrelated algorithms. It is our hope that developers of new algorithms and perturbation theories will benefit from the theory, methods, and examples in this paper.

  12. Comprehensive MRI simulation methodology using a dedicated MRI scanner in radiation oncology for external beam radiation treatment planning

    Paulson, Eric S., E-mail: epaulson@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 and Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 (United States); Erickson, Beth; Schultz, Chris; Allen Li, X. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 (United States)

    2015-01-15

    Purpose: The use of magnetic resonance imaging (MRI) in radiation oncology is expanding rapidly, and more clinics are integrating MRI into their radiation therapy workflows. However, radiation therapy presents a new set of challenges and places additional constraints on MRI compared to diagnostic radiology that, if not properly addressed, can undermine the advantages MRI offers for radiation treatment planning (RTP). The authors introduce here strategies to manage several challenges of using MRI for virtual simulation in external beam RTP. Methods: A total of 810 clinical MRI simulation exams were performed using a dedicated MRI scanner for external beam RTP of brain, breast, cervix, head and neck, liver, pancreas, prostate, and sarcoma cancers. Patients were imaged in treatment position using MRI-optimal immobilization devices. Radiofrequency (RF) coil configurations and scan protocols were optimized based on RTP constraints. Off-resonance and gradient nonlinearity-induced geometric distortions were minimized or corrected prior to using images for RTP. A multidisciplinary MRI simulation guide, along with window width and level presets, was created to standardize use of MR images during RTP. A quality assurance program was implemented to maintain accuracy and repeatability of MRI simulation exams. Results: The combination of a large bore scanner, high field strength, and circumferentially wrapped, flexible phased array RF receive coils permitted acquisition of thin slice images with high contrast-to-noise ratio (CNR) and image intensity uniformity, while simultaneously accommodating patient setup and immobilization devices. Postprocessing corrections and alternative acquisition methods were required to reduce or correct off-resonance and gradient nonlinearity induced geometric distortions. Conclusions: The methodology described herein contains practical strategies the authors have implemented through lessons learned performing clinical MRI simulation exams. In

  13. Comprehensive MRI simulation methodology using a dedicated MRI scanner in radiation oncology for external beam radiation treatment planning

    Purpose: The use of magnetic resonance imaging (MRI) in radiation oncology is expanding rapidly, and more clinics are integrating MRI into their radiation therapy workflows. However, radiation therapy presents a new set of challenges and places additional constraints on MRI compared to diagnostic radiology that, if not properly addressed, can undermine the advantages MRI offers for radiation treatment planning (RTP). The authors introduce here strategies to manage several challenges of using MRI for virtual simulation in external beam RTP. Methods: A total of 810 clinical MRI simulation exams were performed using a dedicated MRI scanner for external beam RTP of brain, breast, cervix, head and neck, liver, pancreas, prostate, and sarcoma cancers. Patients were imaged in treatment position using MRI-optimal immobilization devices. Radiofrequency (RF) coil configurations and scan protocols were optimized based on RTP constraints. Off-resonance and gradient nonlinearity-induced geometric distortions were minimized or corrected prior to using images for RTP. A multidisciplinary MRI simulation guide, along with window width and level presets, was created to standardize use of MR images during RTP. A quality assurance program was implemented to maintain accuracy and repeatability of MRI simulation exams. Results: The combination of a large bore scanner, high field strength, and circumferentially wrapped, flexible phased array RF receive coils permitted acquisition of thin slice images with high contrast-to-noise ratio (CNR) and image intensity uniformity, while simultaneously accommodating patient setup and immobilization devices. Postprocessing corrections and alternative acquisition methods were required to reduce or correct off-resonance and gradient nonlinearity induced geometric distortions. Conclusions: The methodology described herein contains practical strategies the authors have implemented through lessons learned performing clinical MRI simulation exams. In

  14. External costs related to power production technologies. ExternE national implementation for Denmark

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results; to aggregate these site- and technology-specific results to more general figures. The current report covers the results of the national implementation for Denmark. Three different fuel cycles have been chosen as case studies. These are fuel cycles for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant based on biogas. The report covers all the details of the application of the methodology to these fuel cycles aggregation to a national level. (au) EU-JOULE 3. 59 tabs., 25 ills., 61 refs

  15. External costs related to power production technologies. ExternE national implementation for Denmark

    Schleisner, L.; Sieverts Nielsen, P.

    1997-12-01

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results; to aggregate these site- and technology-specific results to more general figures. The current report covers the results of the national implementation for Denmark. Three different fuel cycles have been chosen as case studies. These are fuel cycles for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant based on biogas. The report covers all the details of the application of the methodology to these fuel cycles aggregation to a national level. (au) EU-JOULE 3. 59 tabs., 25 ills., 61 refs.

  16. Guidance for External Events Analysis

    This Guidance for External Events Analysis was developed under a contract with the Nordic PSA Group, and aims at creating a common framework for analysis of external events as part of a nuclear power plant Probabilistic Safety Assessment. Thus, the purpose of this Guidance is to constitute a common methodological guidance for the analysis of external events at Nordic nuclear power plants. This will make it possible for the utilities to perform these analyses in a cost-efficient way, assuring simultaneously the quality of the analyses. The Guidance is meant to clarify the scope of the analysis of external events, to provide guidance for the performance of the analysis, and to help in defining, subcontracting and reviewing the work. The analysis procedure includes four phases, addressing project planning, identification of external events, screening of events, and probabilistic analysis. The aim is first to do as complete an identification of potential single and combined external events as possible. Thereafter, as many external events as possible are screened out as early as possible. The screening capability is increased during the project, using the continuously acquired information on the events and on their effects on the plant

  17. Constraint multi-objective evolutionary algorithm based on artificial bee colony algorithm%约束多目标人工蜂群算法

    毕晓君; 王艳娇

    2013-01-01

    To improve the convergence and diversity of constraint multi-objective evolutionary algorithms, a novel constraintd multi-objective evolutionary algorithm, named CMABC, based on Artificial Bee Colony (ABC) algorithm is proposed. CMABC treats constraint conditions using external population storing feasible and unfeasible solutions. In addition, according to the feature of constraint multi-objective optimal problems, the update method of external and iterative population, and the ABC algorithm are improved. Experiment results show that the CMABC outperforms the state-of-the-art Multi-Objective Artificial Bee Colony (MOABC) algorithm and Hybrid Particle Swarm Optimization (HPSO) algorithm in terms of convergence and diversity matrics, which proves the superiority of CMABC in solving constraint multi-objective optimal problems.%为提高约束多目标进化算法的收敛性和解集分布性,提出一种基于人工蜂群算法的改进约束多目标进化算法CMABC.在利用外部种群分别存储较优可行解和不可行解处理约束条件的基础上,根据约束多目标问题的特点,对外部种群的更新方式、迭代种群的更新方式及人工蜂群算法进行改进.实验仿真结果表明,CMABC相对于目前性能较好的MOABC及HPSO具有一定优势,能够在保证良好收敛性的同时,使获得的Pareto最优解集具有更均匀的分布性和更广的覆盖范围,适合于约束多目标优化问题的求解.

  18. ESTIMATION OF EXTERNAL COSTS OF ELECTRICITY GENERATION USING EXTERNE MODEL

    Molnar, Sandor; Debrecin, N.; Kovacevic, T; Molnar, Melinda

    2008-01-01

    The external costs of electricity generation can be characterised by the resulting social and environmental impacts. The most significant impacts are the air pollutions impact on health, built in environment, crops, forests, agricultural areas and on global warming. The primary impact considered is the air pollution’s effect on human health. The monetised value of the health impact, the external costs are calculated for two regional coal power plants, the effects are examined on the EU level ...

  19. Magnetic nanoparticle motion in external magnetic field

    A set of equations describing the motion of a free magnetic nanoparticle in an external magnetic field in a vacuum, or in a medium with negligibly small friction forces is postulated. The conservation of the total particle momentum, i.e. the sum of the mechanical and the total spin momentum of the nanoparticle is taken into account explicitly. It is shown that for the motion of a nanoparticle in uniform magnetic field there are three different modes of precession of the unit magnetization vector and the director that is parallel the particle easy anisotropy axis. These modes differ significantly in the precession frequency. For the high-frequency mode the director points approximately along the external magnetic field, whereas the frequency and the characteristic relaxation time of the precession of the unit magnetization vector are close to the corresponding values for conventional ferromagnetic resonance. On the other hand, for the low-frequency modes the unit magnetization vector and the director are nearly parallel and rotate in unison around the external magnetic field. The characteristic relaxation time for the low-frequency modes is remarkably long. This means that in a rare assembly of magnetic nanoparticles there is a possibility of additional resonant absorption of the energy of alternating magnetic field at a frequency that is much smaller compared to conventional ferromagnetic resonance frequency. The scattering of a beam of magnetic nanoparticles in a vacuum in a non-uniform external magnetic field is also considered taking into account the precession of the unit magnetization vector and director. - Highlights: • There are three different modes of the unit magnetization vector precession for a free magnetic nanoparticle in uniform external magnetic field. • The high-frequency mode is similar to the conventional ferromagnetic resonance. The frequencies of the low-frequency modes can be two orders of magnitude lower. • The characteristic relaxation

  20. External effects in Swiss hydropower

    The article discusses the external costs and benefits of hydropower that are not internalised in normal book-keeping. Several negative and positive effects are discussed. The results of a study that addressed the difficult task of quantifying these external effects are presented. An assessment of the results gained shows that difficulties are to be met regarding system limits, methods of expressing the effects in monetary terms and ethical factors. The report also examines the consideration of external effects as a correction factor for falsified market prices for electricity

  1. Constraint Databases and Geographic Information Systems

    Revesz, Peter

    2007-01-01

    Constraint databases and geographic information systems share many applications. However, constraint databases can go beyond geographic information systems in efficient spatial and spatiotemporal data handling methods and in advanced applications. This survey mainly describes ways that constraint databases go beyond geographic information systems. However, the survey points out that in some areas constraint databases can learn also from geographic information systems.

  2. Applications of external beam PIXE at RMIT

    Moser, M.; Bubb, I. F.; Johnston, P. N.; El Bouanani, M.; Stannard, W. B.; Short, R. C.

    1998-04-01

    The development of an external Proton Induced X-Ray Emission (PIXE) facility for the 1 MV Tandetron accelerator based at the Royal Melbourne Institute of Technology has enabled the analysis of artefacts from the Museum of Victoria. Analyses of antique bullets, Egyptian glass samples, an Egyptian wall paint fragment and pigments from soils have been carried out. The results from the analysis of antique bullets determined the composition of blue spots on one bullet and aided in the conservation process. External PIXE analysis of two Egyptian glass samples enabled the partial determination of the colouring transition metals. Analysis of an Egyptian wall paint fragment and pigments from soils originating from the archaeological excavation of the town of Ismant el-Kharab as part of the Dakhleh Oasis Project revealed the necessity to find additional pigments to enable identification of the geographical origin of the wall paint.

  3. Applications of external beam PIXE at RMIT

    The development of an external proton induced X-ray emission (PIXE) facility for the 1 MV tandetron accelerator based at Royal Melbourne institute of technology has enabled the analysis of artefacts from the Museum of Victoria. Analyses of antique bullets, Egyptian glass samples, an Egyptian wall paint fragment and pigments from soils have been carried out. The results from the analysis of antique bullets determined the composition of blue spots on one bullet and aided in the conservation process. External PIXE analysis of two Egyptian glass samples enabled the partial determination of the colouring transition metals. Analysis of an Egyptian wall paint fragment and pigments from soils originating from the archaeological excavation of the town of Ismant el-Kharab as part of the Dakhleh Oasis Project revealed the necessity to find additional pigments to enable identification of the geographical origin of the wall paint. (orig.)

  4. Constraint programming and decision making

    Kreinovich, Vladik

    2014-01-01

    In many application areas, it is necessary to make effective decisions under constraints. Several area-specific techniques are known for such decision problems; however, because these techniques are area-specific, it is not easy to apply each technique to other applications areas. Cross-fertilization between different application areas is one of the main objectives of the annual International Workshops on Constraint Programming and Decision Making. Those workshops, held in the US (El Paso, Texas), in Europe (Lyon, France), and in Asia (Novosibirsk, Russia), from 2008 to 2012, have attracted researchers and practitioners from all over the world. This volume presents extended versions of selected papers from those workshops. These papers deal with all stages of decision making under constraints: (1) formulating the problem of multi-criteria decision making in precise terms, (2) determining when the corresponding decision problem is algorithmically solvable; (3) finding the corresponding algorithms, and making...

  5. Market dispatch incorporating stability constraints

    Stability aspects have often been incorporated in the electricity market dispatch/pricing procedure using trial-and-error methods, or approximated in the dispatch optimisation directly as a set of linear constraints on generation/transmission. This paper presents the preliminary experiences with the development of a market optimal power flow (OPF) model that incorporates both transient and voltage stability constraints. The resultant dispatch and prices are expected to exhibit the impact of accurately modelled stability limits that are hitherto largely unknown. This model allows integrated representation of both voltage and transient stability. It, however, entails very significant computational complexities. A complete resolution of all these issues is beyond the scope of this paper, although some initial thoughts to simplify computation are discussed. The importance of stability constraints on market dispatch and prices is discussed around a simple 9-bus system example. (author)

  6. External doses from radioactive fallout. Dosimetry and levels

    Woehni, T.

    1995-12-31

    The design, manufacture and calibration of a TL-based dosemeter for measurement of low level external photon radiation are presented. The dosemeter is based on CaF{sub 2} with 2 mm brass filter for energy compensation. It is able to resolve a 8% dose increase relative to natural background radiation. With this dosemeter external dose measurements were made in 6 villages in a heavily contaminated region in Russia (Chernobyl fallout), in order to assess external doses to the population. The results were analyzed in the light of additional existing information on radioactive deposition, social habits, decontamination measures and other influencing technical and physical factors. The observed dose values were lower than theoretical estimates of external doses based on published values for external dose levels relative to the level of contamination. 84 refs., 7 figs., 5 tabs.

  7. External doses from radioactive fallout. Dosimetry and levels

    The design, manufacture and calibration of a TL-based dosemeter for measurement of low level external photon radiation are presented. The dosemeter is based on CaF2 with 2 mm brass filter for energy compensation. It is able to resolve a 8% dose increase relative to natural background radiation. With this dosemeter external dose measurements were made in 6 villages in a heavily contaminated region in Russia (Chernobyl fallout), in order to assess external doses to the population. The results were analyzed in the light of additional existing information on radioactive deposition, social habits, decontamination measures and other influencing technical and physical factors. The observed dose values were lower than theoretical estimates of external doses based on published values for external dose levels relative to the level of contamination. 84 refs., 7 figs., 5 tabs

  8. Environmental externalities related to power production on biogas and natural gas based on the EU ExternE methodology

    Nielsen, Per Sieverts; Ibsen, Liselotte Schleisner

    This paper assesses the environmental impacts and external costs from selected electricity generation systems in Denmark. The assessment is carried out as part of the ExternE National Implementation, which is the second phase of the ExternE project and involves case studies from all Western Europ...

  9. Solving Functional Constraints by Variable Substitution

    Zhang, Yuanlin

    2010-01-01

    Functional constraints and bi-functional constraints are an important constraint class in Constraint Programming (CP) systems, in particular for Constraint Logic Programming (CLP) systems. CP systems with finite domain constraints usually employ CSP-based solvers which use local consistency, for example, arc consistency. We introduce a new approach which is based instead on variable substitution. We obtain efficient algorithms for reducing systems involving functional and bi-functional constraints together with other non-functional constraints. It also solves globally any CSP where there exists a variable such that any other variable is reachable from it through a sequence of functional constraints. Our experiments on random problems show that variable elimination can significantly improve the efficiency of solving problems with functional constraints.

  10. External proton and Li beams

    In the frame of a feasibility study to introduce proton therapy in Argentina in a collaborative agreement between the Physics and Radiobiology Departments of the National Atomic Energy Commission or Argentina and the Centre de Protontherapie de Orsay, France, external proton and Li beams were produced at the TANDAR accelerator in Buenos Aires. The specific aim of this work was to start radiobiology studies on cell cultures and small laboratory animals. In particular we seek to determine here the relative biological effectiveness, RBE, for proton and Li beams as a function of energy for different tumor and normal cell lines. The 24 MeV proton beam was diffused using a 25 μm gold foil and extracted through a Kapton window to obtain a homogeneous field (constant to 95%) of about 7 cm in diameter. Measurements were carried out with quasi-monoenergetic beams (of 20.2 ± 0.07 MeV, 2.9 ± 0.10 MeV y 1.5 ± 0.1 MeV for protons and 21.4 ± 0.4 MeV for Lithium). Proton fluence and Bragg peaks were measured. The dose delivered in each case was monitored on-line with a calibrated transmission ionization chamber. Three cell lines PDV, PDVC 57 and V 79 (as a reference) were irradiated with γ-rays, proton and lithium beams with linear energy transfer (LET) from 2 to 100 keV/μm. RBE values in the range of 1.2-5.9 were obtained. In addition preliminary studies on chromosomal aberrations and viability of alveolar macrophages were carried out. (author)

  11. External meeting: Geneva University

    2006-01-01

    Université de Genève Ecole de physique 24 quai Ernest Ansermet 1211 Genève 4 Tél : + 41 22 379 63 83 (secrétariat) Tél : + 41 22 379 62 56 (réception) Fax: + 41 22 379 69 22 Lundi 20 novembre 2006 COLLOQUIUM 17:00 - Auditoire Stückelberg Electrical correlation measurements in quantum nano-structures Dr. Stefan Oberholzer / Basel University Measuring the current-voltage characteristics of small conductors is widely used to characterize their electronic transport properties. In addition to such time-averaged measurements, correlation measurements between temporal fluctuations (noise) around the time-averaged mean current provide us with very important supplementary information about electrical transport. In this talk, I review our experimental work on shot noise, noise which originates from the granularity of charge and the diffraction of the electronic wave-function, and especially address the fundamental relation between electronic scattering experiments and the statistical properties of indist...

  12. External meeting: Geneva University

    2006-01-01

    Ecole de physique 24 quai Ernest Ansermet 1211 GENEVA 4 Tel: (022) 379 62 73 Fax: (022) 379 69 92 Monday 19 June 2006 17:00-Stückelberg Auditorium Quantum Optics and Quantum Information Processing with Superconducting Circuits Prof. A. Wallraff /ETH Zürich I will describe recent experiments with superconducting circuits in which we have demonstrated the coherent interaction of a two-level system and a single mode of a cavityfield. Such a feat was previously only realizable in atomic cavity quantum electrodynamics experiments. In our circuit we have generated coherent superpositions between asingle photon and a single superconducting qubit and have used photons to perform a quantum non-demolition measurement of the state of the qubit. This new regime ofmatter-light interaction in a circuit, allows us to both perform state of the art quantum optics experiments and to realize new elements for a quantum information processor. For additional information and publications please visit: http://www.solid.phys....

  13. Performance Targets and External Benchmarking

    Friis, Ivar; Hansen, Allan; Vámosi, Tamás S.

    Research on relative performance measures, transfer pricing, beyond budgeting initiatives, target costing, piece rates systems and value based management has for decades underlined the importance of external benchmarking in performance management. Research conceptualises external benchmarking as a...... market mechanism that can be brought inside the firm to provide incentives for continuous improvement and the development of competitive advances. However, whereas extant research primarily has focused on the importance and effects of using external benchmarks, less attention has been directed towards...... the conditions upon which the market mechanism is performing within organizations. This paper aims to contribute to research by providing more insight to the conditions for the use of external benchmarking as an element in performance management in organizations. Our study explores a particular type...

  14. Leveraging External Sources of Innovation

    West, Joel; Bogers, Marcel

    2014-01-01

    external innovations create value rather than how firms capture value from those innovations. Finally, the interaction phase considers both feedback for the linear process and reciprocal innovation processes such as cocreation, network collaboration, and community innovation. This review and synthesis......This paper reviews research on open innovation that considers how and why firms commercialize external sources of innovations. It examines both the “outside-in” and “coupled” modes of open innovation. From an analysis of prior research on how firms leverage external sources of innovation, it...... suggests a four-phase model in which a linear process—(1) obtaining, (2) integrating, and (3) commercializing external innovations—is combined with (4) interaction between the firm and its collaborators. This model is used to classify papers taken from the top 25 innovation journals, complemented by highly...

  15. External costs related to power production technologies. ExternE national implementation for Denmark

    Schleisner, L.; Sieverts Nielsen, P. [eds.

    1997-12-01

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results, to aggregate these site- and technology-specific results to more general figures. The current report covers the detailed information concerning the ExternE methodology. Importance is attached to the computer system used in the project and the assessment of air pollution effects on health, materials and ecological effects. Also the assessment of global warming damages are described. Finally the report covers the detailed information concerning the national implementation for Denmark for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant base on biogas. (au) EU-JOULE 3. 79 tabs., 11 ills., 201 refs.

  16. External costs related to power production technologies. ExternE national implementation for Denmark

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results, to aggregate these site- and technology-specific results to more general figures. The current report covers the detailed information concerning the ExternE methodology. Importance is attached to the computer system used in the project and the assessment of air pollution effects on health, materials and ecological effects. Also the assessment of global warming damages are described. Finally the report covers the detailed information concerning the national implementation for Denmark for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant base on biogas. (au) EU-JOULE 3. 79 tabs., 11 ills., 201 refs

  17. Introduction: Biological Constraints on Learning

    Burgos, José E

    2015-01-01

    This special section stemmed from a symposium on biological constraints on learning that was organized for the XVII Biennial Meeting of the International Society for Comparative Psychology in Bogotá, Colombia, September 2014.  The symposium sought to revisit the topic of biological constraints on learning.  Such is the aim of this special section as well, guided by the conviction that the topic demands further study.  Some of the most important researchers in the area were invited to contribu...

  18. Evolutionary Constraints to Viroid Evolution

    Santiago F. Elena

    2009-09-01

    Full Text Available We suggest that viroids are trapped into adaptive peaks as the result of adaptive constraints. The first one is imposed by the necessity to fold into packed structures to escape from RNA silencing. This creates antagonistic epistases, which make future adaptive trajectories contingent upon the first mutation and slow down the rate of adaptation. This second constraint can only be surpassed by increasing genetic redundancy or by recombination. Eigen’s paradox imposes a limit to the increase in genome complexity in the absence of mechanisms reducing mutation rate. Therefore, recombination appears as the only possible route to evolutionary innovation in viroids.

  19. Soft liquidity constraints and precautionary saving

    Emilio Fernandez-Corugedo

    2002-01-01

    The implications for consumption and saving behaviour are explored, when households are allowed to borrow, but face penalties which increase with the amount borrowed. It is shown that the introduction of this type of constraints (soft liquidity constraints) does not lead to consumers behaving very differently from consumers who face constraints which prevent them from borrowing at any time (hard liquidity constraints). However, when hard constraints are relaxed and become soft, the amount of ...

  20. Weak Dynamic Programming for Generalized State Constraints

    Bouchard, Bruno; Nutz, Marcel

    2012-01-01

    We provide a dynamic programming principle for stochastic optimal control problems with expectation constraints. A weak formulation, using test functions and a probabilistic relaxation of the constraint, avoids restrictions related to a measurable selection but still implies the Hamilton-Jacobi-Bellman equation in the viscosity sense. We treat open state constraints as a special case of expectation constraints and prove a comparison theorem to obtain the equation for closed state constraints.

  1. External recruitment versus internal promotion

    Chan, William

    1996-01-01

    This article analyzes the choice between internal promotion and external recruitment within the framework of an economic contest. Opening up the competition for a position to external candidates reduces the chance of promotion for existing workers and, therefore, their incentive to work. Increasing the prize for winning can maintain incentives but is limited by moral hazard and potentially disruptive office politics. Alternatively, a competitive handicap can be awarded to existing workers to ...

  2. Consumption externalities, coordination and advertising

    Pastine, Tuvana; Pastine, Ivan

    2001-01-01

    The aim of this Paper is to demonstrate that advertising can have an important function in markets with consumption externalities, apart from its persuasive and informative roles. We show that advertising may function as a device to coordinate consumer expectations of the purchasing decisions of other consumers in markets with consumption externalities. The implications of advertising as a coordinating device are examined in the pricing and advertising decisions of firms interacting strategic...

  3. Comsumption Externalities, Coordination, and Advertising

    Ivan Pastine; Tuvana Pastine

    2002-01-01

    The aim of this article is to demonstrate that advertising can have an important function in markets with consumption externalities apart from its persuasive and informative roles. We show that advertising may function as a device to coordinate consumer expectations of the purchasing decisions of other consumers in markets with consumption externalities. The implications of advertising as a coordinating device are examined in the pricing and advertising decisions of firms interacting strategi...

  4. Epidemic Spreading with External Agents

    Banerjee, Siddhartha; Gopalan, Aditya; Das, Abhik Kumar; Shakkottai, Sanjay

    2012-01-01

    We study epidemic spreading processes in large networks, when the spread is assisted by a small number of external agents: infection sources with bounded spreading power, but whose movement is unrestricted vis-\\`a-vis the underlying network topology. For networks which are `spatially constrained', we show that the spread of infection can be significantly speeded up even by a few such external agents infecting randomly. Moreover, for general networks, we derive upper-bounds on the order of the...

  5. Irrigation externalities: pricing and charges

    Gavan Dwyer; Robert Douglas; Deb Peterson; Jo Chong; Kate Maddern

    2006-01-01

    The Productivity Commission Staff Working Paper ‘Irrigation externalities: pricing and charges. by Gavan Dwyer, Robert Douglas, Deb Peterson, Jo Chong and Kate Maddern was released on 14 March 2006. The paper discusses the nature and causes of environmental change related to rural water use, and provides a taxonomy of the many diverse types. It also examines the issues surrounding possible charges on water use for water related externalities. There have been few attempts by water utilities to...

  6. Myiasis in female external genitalia

    Usha Kataria

    2013-01-01

    Full Text Available Myiasis is derived from the Greek word-"Myia", meaning "fly". The term was first introduced by Hope in 1840 and refers to the infestation of human beings with dipterous larvae (maggots. Presence of maggots on exposed parts is already known, but on covered parts like external genitalia it is very rare. We hereby describe a case of young unmarried female who presented with multiple sinuses over external genitalia along with maggots coming out of it.

  7. Myiasis in female external genitalia

    Usha Kataria; Sunita Siwach; Sanjeev Gupta

    2013-01-01

    Myiasis is derived from the Greek word-"Myia", meaning "fly". The term was first introduced by Hope in 1840 and refers to the infestation of human beings with dipterous larvae (maggots). Presence of maggots on exposed parts is already known, but on covered parts like external genitalia it is very rare. We hereby describe a case of young unmarried female who presented with multiple sinuses over external genitalia along with maggots coming out of it.

  8. Urban Sprawl and Transportation Externalities

    Randall G. Holcombe; Williams, DeEdgra W.

    2010-01-01

    One argument in support of minimizing urban sprawl is that sprawl creates transportation externalities. A problem with empirically examining the relationship between sprawl and transportation externalities is that sprawl is a difficult concept to quantify. This paper uses a measure of sprawl designed by Ewing, Pendall, and Chen (2002) to examine the relationship between sprawl and commute times, automobile ownership, miles driven, fatal auto accidents, air pollution, and highway expenditures....

  9. External photon beams: Physical aspects

    Radiotherapy procedures fall into two main categories: external beam radiotherapy and brachytherapy. In external beam radiotherapy the radiation source is at a certain distance from the patient and the target within the patient is irradiated with an external radiation beam. In brachytherapy (see Chapter 13) radiation sources are placed directly into the target volume (intracavitary or interstitial brachytherapy) or on to a target (surface mould or intraoperative radiotherapy). Most external beam radiotherapy is carried out with photon beams, some with electron beams and a very small fraction with more exotic particles such as protons, heavier ions or neutrons. This chapter deals with external photon beam radiotherapy. Photon external beams are all characterized by the same physical parameters, but fall into various categories depending on their origin, means of production and energy. There are two origins of photon beams: g rays, which originate from radioactive nuclei, and X rays, which originate in a target bombarded with energetic electrons. The X rays from a target consist of bremsstrahlung photons and characteristic photons. X rays are produced either in an X ray tube (superficial or orthovoltage X rays) or in a linac (megavoltage X rays)

  10. Molecular dynamics with coupling to an external bath

    Berendsen, H. J. C.; Postma, J. P. M.; van Gunsteren, W. F.; DiNola, A.; Haak, J. R.

    1984-10-01

    In molecular dynamics (MD) simulations the need often arises to maintain such parameters as temperature or pressure rather than energy and volume, or to impose gradients for studying transport properties in nonequilibrium MD. A method is described to realize coupling to an external bath with constant temperature or pressure with adjustable time constants for the coupling. The method is easily extendable to other variables and to gradients, and can be applied also to polyatomic molecules involving internal constraints. The influence of coupling time constants on dynamical variables is evaluated. A leap-frog algorithm is presented for the general case involving constraints with coupling to both a constant temperature and a constant pressure bath.

  11. Analysis of servo-constraint problems for underactuated multibody systems

    R. Seifried

    2013-02-01

    Full Text Available Underactuated multibody systems have fewer control inputs than degrees of freedom. In trajectory tracking control of such systems an accurate and efficient feedforward control is often necessary. For multibody systems feedforward control by model inversion can be designed using servo-constraints. So far servo-constraints have been mostly applied to differentially flat underactuated mechanical systems. Differentially flat systems can be inverted purely by algebraic manipulations and using a finite number of differentiations of the desired output trajectory. However, such algebraic solutions are often hard to find and therefore the servo-constraint approach provides an efficient and practical solution method. Recently first results on servo-constraint problems of non-flat underactuated multibody systems have been reported. Hereby additional dynamics arise, so-called internal dynamics, yielding a dynamical system as inverse model. In this paper the servo-constraint problem is analyzed for both, differentially flat and non-flat systems. Different arising important phenomena are demonstrated using two illustrative examples. Also strategies for the numerical solution of servo-constraint problems are discussed.

  12. External Costs Related to Power Production Technologies

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1997-01-01

    The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective of...

  13. Hexapod External Fixation of Tibia Fractures in Children.

    Iobst, Christopher A

    2016-06-01

    Most tibia fractures in children can be treated nonoperatively. For fractures that do require surgery, however, the most common methods of management include plating or flexible nail insertion. Some fracture patterns, such as periphyseal fractures, fractures with bone and/or soft tissue loss, or fractures with delayed presentation, are not easily amenable to these techniques. Hexapod external fixators are especially helpful in these difficult cases. The purpose of this review is to discuss the principles of performing hexapod circular external fixation applied to pediatric tibia fractures. Some of the additional capabilities of the hexapod external fixator will also be highlighted. PMID:27078228

  14. Credit constraints and durable consumption

    Herrala, Risto

    2010-01-01

    I find quantitative evidence of a significant effect for credit constraints on durable consumption during a post-deregulation consumer spending spree. The effect varied markedly across age and educational groups. Young households with low levels of education displayed high sensitivity to credit conditions. In contrast, older highly educated households were relatively immune to credit market developments.

  15. An Introduction to 'Creativity Constraints'

    Onarheim, Balder; Biskjaer, Michael Mose

    , we give an overview of the growing, but incohesive body of research into creativity and constraints, which leads us to introduce ‘creativity constraints’ as a unifying concept to help bridge these disjoint contributions to facilitate cross- disciplinary interchange. Finally, we suggest key topics and...

  16. Constraints on galaxy formation theories

    Szalay, A. S.

    1986-01-01

    The present theories of galaxy formation are reviewed. The relation between peculiar velocities, temperature fluctuations of the microwave background and the correlation function of galaxies point to the possibility that galaxies do not form uniformly everywhere. The velocity data provide strong constraints on the theories even in the case when light does not follow mass of the universe.

  17. Cultural Constraints on Literary Translation

    Wei Lou

    2009-01-01

    Translation is no longer considered a single, unified reproduction of the original but a kind of rewriting which reflects a certain ideology and literary norm and literary translation is no exception. This essay tends to explore the cultural constraints on literary translation.

  18. Intertemporal consumption and credit constraints

    Leth-Petersen, Søren

    2010-01-01

    There is continuing controversy over the importance of credit constraints. This paper investigates whether total household expenditure and debt is affected by an exogenous increase in access to credit provided by a credit market reform that enabled Danish house owners to use housing equity as...

  19. Credit Reporting and Financing Constraints

    Love, Inessa; Mylenko, Nataliya

    2003-01-01

    The authors combine firm-level data from the World Bank Business Environment Survey (WBES) with data on private and public credit registries to investigate whether the presence of a credit registry in a country is associated with lower financing constraints, as perceived by managers, and with higher share of bank financing. They find that the existence of private credit registries is assoc...

  20. Sterile neutrino constraints from cosmology

    Hamann, Jan; Hannestad, Steen; Raffelt, Georg G.;

    2012-01-01

    The presence of light particles beyond the standard model's three neutrino species can profoundly impact the physics of decoupling and primordial nucleosynthesis. I review the observational signatures of extra light species, present constraints from recent data, and discuss the implications of po...... of possible sterile neutrinos with O(eV)-masses for cosmology....

  1. Conjoined Constraints and Phonological Acquisition

    Bonilha, Giovana

    2003-01-01

    Since the start of Optimality Theory (Prince & Smolensky, 1993), research on phonological acquisition has explored the explanatory potential of constraint theories. This study, also based on Optimality Theory, attempts to analyze the acquisition of CVVC syllable structure by Brazilian Portuguese children and addresses the issue of Local Conjunction (Smolensky, 1995, 1997) in research that deals with problems of phonological acquisition.

  2. Constraint Programming versus Mathematical Programming

    Hansen, Jesper

    2003-01-01

    Constraint Logic Programming (CLP) is a relatively new technique from the 80's with origins in Computer Science and Artificial Intelligence. Lately, much research have been focused on ways of using CLP within the paradigm of Operations Research (OR) and vice versa. The purpose of this paper...

  3. Astrophysical Constraints on Dark Matter

    Tao, Charling

    2011-01-01

    Astrophysics gives evidence for the existence of Dark Matter and puts constraints on its nature. The Cold Dark Matter model has become "standard" cosmology combined with a cosmological constant. There are indications that "Cold" Dark Matter could be "warmer" than initially discussed. This paper reviews the main information on the Cold/Warm nature of Dark Matter.

  4. Strategic offloading of delayed intentions into the external environment.

    Gilbert, S. J.

    2014-01-01

    In everyday life, we often use external artefacts such as diaries to help us remember intended behaviours. In addition, we commonly manipulate our environment, for example by placing reminders in noticeable places. Yet strategic offloading of intentions to the external environment is not typically permitted in laboratory tasks examining memory for delayed intentions. What factors influence our use of such strategies, and what behavioural consequences do they have? This article describes four ...

  5. Asymmetric continuous-time neural networks without local traps for solving constraint satisfaction problems.

    Botond Molnár

    Full Text Available There has been a long history of using neural networks for combinatorial optimization and constraint satisfaction problems. Symmetric Hopfield networks and similar approaches use steepest descent dynamics, and they always converge to the closest local minimum of the energy landscape. For finding global minima additional parameter-sensitive techniques are used, such as classical simulated annealing or the so-called chaotic simulated annealing, which induces chaotic dynamics by addition of extra terms to the energy landscape. Here we show that asymmetric continuous-time neural networks can solve constraint satisfaction problems without getting trapped in non-solution attractors. We concentrate on a model solving Boolean satisfiability (k-SAT, which is a quintessential NP-complete problem. There is a one-to-one correspondence between the stable fixed points of the neural network and the k-SAT solutions and we present numerical evidence that limit cycles may also be avoided by appropriately choosing the parameters of the model. This optimal parameter region is fairly independent of the size and hardness of instances, this way parameters can be chosen independently of the properties of problems and no tuning is required during the dynamical process. The model is similar to cellular neural networks already used in CNN computers. On an analog device solving a SAT problem would take a single operation: the connection weights are determined by the k-SAT instance and starting from any initial condition the system searches until finding a solution. In this new approach transient chaotic behavior appears as a natural consequence of optimization hardness and not as an externally induced effect.

  6. Asymmetric continuous-time neural networks without local traps for solving constraint satisfaction problems.

    Molnár, Botond; Ercsey-Ravasz, Mária

    2013-01-01

    There has been a long history of using neural networks for combinatorial optimization and constraint satisfaction problems. Symmetric Hopfield networks and similar approaches use steepest descent dynamics, and they always converge to the closest local minimum of the energy landscape. For finding global minima additional parameter-sensitive techniques are used, such as classical simulated annealing or the so-called chaotic simulated annealing, which induces chaotic dynamics by addition of extra terms to the energy landscape. Here we show that asymmetric continuous-time neural networks can solve constraint satisfaction problems without getting trapped in non-solution attractors. We concentrate on a model solving Boolean satisfiability (k-SAT), which is a quintessential NP-complete problem. There is a one-to-one correspondence between the stable fixed points of the neural network and the k-SAT solutions and we present numerical evidence that limit cycles may also be avoided by appropriately choosing the parameters of the model. This optimal parameter region is fairly independent of the size and hardness of instances, this way parameters can be chosen independently of the properties of problems and no tuning is required during the dynamical process. The model is similar to cellular neural networks already used in CNN computers. On an analog device solving a SAT problem would take a single operation: the connection weights are determined by the k-SAT instance and starting from any initial condition the system searches until finding a solution. In this new approach transient chaotic behavior appears as a natural consequence of optimization hardness and not as an externally induced effect. PMID:24066045

  7. A class of constant modulus algorithms for uniform linear arrays with a conjugate symmetric constraint

    Zhang, L; Liu, W.; Langley, R.J.

    2010-01-01

    A class of constant modulus algorithms (CMAs) subject to a conjugate symmetric constraint is proposed for blind beamforming based on the uniform linear array structure. The constraint is derived from the beamformer with an optimum output signal-to-interference-plus-noise ratio (SINR). The effect of the additional constraint is equivalent to adding a second step to the original adaptive algorithms. The proposed approach is general and can be applied to both the traditional CMA and its all kind...

  8. Bank leverage cycles and the external finance premium

    Rannenberg, Ansgar

    2013-01-01

    By combining the approaches of Gertler and Karadi (2011) and Bernanke et al. (1999), I develop a DSGE model with leverage constraints both in the banking and in the non-financial firm sector. I calibrate this full model to US data. In a world with only a monetary policy and a productivity shock, the full model matches the relative volatility of the external finance premium, while a BGG model generates too low volatility. The full model also matches the procyclicality of bank leverage, unlike ...

  9. Approximating CSPs with Global Cardinality Constraints Using SDP Hierarchies

    Raghavendra, Prasad

    2011-01-01

    This work is concerned with approximating constraint satisfaction problems (CSPs) with an additional global cardinality constraints. For example, \\maxcut is a boolean CSP where the input is a graph $G = (V,E)$ and the goal is to find a cut $S \\cup \\bar S = V$ that maximizes the numberof crossing edges, $|E(S,\\bar S)|$. The \\maxbisection problem is a variant of \\maxcut with an additional global constraint that each side of the cut has exactly half the vertices, i.e., $|S| = |V|/2$. Several other natural optimization problems like \\minbisection and approximating Graph Expansion can be formulated as CSPs with global constraints. In this work, we formulate a general approach towards approximating CSPs with global constraints using SDP hierarchies. To demonstrate the approach we present the following results: Using the Lasserre hierarchy, we present an algorithm that runs in time $O(n^{poly(1/\\epsilon)})$ that given an instance of \\maxbisection with value $1-\\epsilon$, finds a bisection with value $1-O(\\sqrt{\\epsi...

  10. Efficient External Sorting on Flash Memory Embedded Devices

    Tyler Cossentine

    2013-03-01

    Full Text Available Many embedded system applications involve storing and querying large datasets. Existing research in thisarea has focused on adapting and applying conventional database algorithms to embedded devices.Algorithms designed for processing queries on embedded devices must be able to execute given the smallamount of available memory and energy constraints. Most embedded devices use flash memory to storelarge amounts of data. Flash memory has unique performance characteristics that can be exploited toimprove algorithm performance. In this paper, we describe the Flash MinSort external sorting algorithmthat uses an index, generated at runtime, to take advantage of fast random reads in flash memory. Thisalgorithm adapts to the amount of memory available and performs best in applications where sort keys areclustered. Experimental results show that Flash MinSort is two to ten times faster than previousapproaches for small memory sizes where external merge sort is not executable.

  11. Spreading history of the Arabian Sea: Some new constraints

    Chaubey, A.K.; Bhattacharya, G.C.; Murty, G.P.S.; Desa, M.

    Based on a new identification of magnetic anomalies, additional constraints are provided on the two episodes of spreading history of the Arabian Sea. Commencing at A27, the older phase ended at A21 and sprading of the younger phase started shortly...

  12. A Framework for Constraint-Programming based Configuration

    Queva, Matthieu Stéphane Benoit

    algorithm DnSTR is developed in order to solve the dynamic addition and retraction of table constraints at runtime. Finally, we present and evaluate a prototype implementation of ProCoLa and the configuration framework, including the integration in a development environment, tool support and interaction...

  13. External Debt and Economic Growth in Tunisia

    Nasfi Fkili Wahiba

    2014-12-01

    Full Text Available The objective of this study is to identify the effect of external debt on economic growth; we used the debt service as percentage of exports and debt indicators in the first and second degree. The econometric estimation showed that the sign of the coefficient of debt is positive and the debt squared is negative, and beyond a certain stock, the impact of debt on growth becomes negative and Tunisia must control its debts as additional increases will have adverse impacts on the economic performance of the country. Therefore, the borrowing should remain a necessity in cases of extreme emergency, not a solution to all economic problems experienced by the country.

  14. Tertiary oil recovery: potential application and constraints

    Geffen, C. A.

    1978-06-01

    The technology of tertiary oil recovery methods is described and potential economic and environmental constraints to future commercial application are identified. Oil recoverable by tertiary techniques represents a domestic resource of between 11- and 42-billion barrels. Estimates of additional oil supplies from tertiary methods by the year 2000 range from 1 to 8 million barrels per day, depending on the price of oil and the rate of technological development. The principal constraints to large-scale application of tertiary methods at the present time include environmental, economic and technological concerns. Regulatory action associated with the Clean Air Act Amendments of 1977 currently delay the expansion of thermal recovery operations in California and may discourage future projects. The high production costs of tertiary projects also hamper process implementation. Further testing and research is necessary to develop the technology of tertiary recovery methods and prove these techniques successful on a field-wide scale. To enable tertiary oil recovery to play a significant role in augmenting domestic energy supplies, further research and development is necessary. More accurate methods of determining reservoir structure and residual oil saturations are required, as well as means for assuring the technical feasibility and success of a tertiary method in different reservoir types. Technical process limitations must also be resolved. The severity of potential environmental impacts and constraints identified in this report should be determined. These concerns include the air pollutant emissions from steam generation in thermal processes; acceptable methods of brine disposal; damage due to runoff or accidental discharge of oil-rich chemicals into surface waters; the impacts of fluid injection on deep aquifers and the prevailing geological structure; and an adequate supply of high quality fresh water.

  15. Creativity from Constraints in Engineering Design

    Onarheim, Balder

    2012-01-01

    This paper investigates the role of constraints in limiting and enhancing creativity in engineering design. Based on a review of literature relating constraints to creativity, the paper presents a longitudinal participatory study from Coloplast A/S, a major international producer of disposable...... and ownership of formal constraints played a crucial role in defining their influence on creativity – along with the tacit constraints held by the designers. The designers were found to be highly constraint focused, and four main creative strategies for constraint manipulation were observed...

  16. Translating Pseudo-Boolean Constraints into CNF

    Aavani, Amir

    2011-01-01

    A Pseudo-Boolean constraint is a linear constraint over Boolean variables. This kind of constraints has been widely used in expressing NP-complete problems. This paper introduces a new algorithm for translating Pseudo-Boolean constraints into CNF clauses. The CNF produced by the proposed encoding has small size, and we also characterize the constraints for which one can expect the SAT solvers to perform well on the produced CNF. We show that there are many constraints for which the proposed encoding has a good performance.

  17. Learning Policies with External Memory

    Peshkin, Leonid; Meuleau, Nicolas; Kaelbling, Leslie

    2001-01-01

    In order for an agent to perform well in partially observable domains, it is usually necessary for actions to depend on the history of observations. In this paper, we explore a {\\it stigmergic} approach, in which the agent's actions include the ability to set and clear bits in an external memory, and the external memory is included as part of the input to the agent. In this case, we need to learn a reactive policy in a highly non-Markovian domain. We explore two algorithms: SARSA(\\lambda), wh...

  18. Schools' Logics of Action as Mediation and Compromise between Internal Dynamics and External Constraints and Pressures

    Ball, Stephen J.; Maroy, Christian

    2009-01-01

    This paper, based on 14 case studies of schools situated in six local urban spaces (within the urban agglomerations of Budapest, Charleroi, Lille, Lisbon, London and the Creteil/Paris region), will analyse the internal logics of action of these schools and show that they are conditioned by the interaction between internal (school narrative…

  19. Externalities and bailouts : hard and soft budget constraints in intergovernmental fiscal relations

    David E. Wildasin

    1997-01-01

    Subnational governments are assuming greater fiscal responsibility in many developing and transition countries. There is concern, however, that fiscal decentralization may weaken fiscal discipline -that local authorities may undertake commitments or incur debt obligations that subsequently result in massive central government support, in the form of extraordinary transfers, or bailouts. (Recent experience in major U.S. cities shows that these problems are not restricted to developing countrie...

  20. Planning grasps for object manipulation: integrating internal preferences and external constraints.

    Herbort, Oliver; Butz, Martin V

    2015-09-01

    Grasp selection for object manipulation depend on a person's preferences (e.g., comfortable grasp) and the object's shape (i.e., how the object can be grasped). Both have to be matched when planning to grasp an object. According to the simulation hypothesis, humans simulate the action outcome for each of the grasp options to select the best grasp. However, if an object offers many different grasp options, further processing is necessary to reduce the number of possibilities. According to the preference hypothesis, a preferred grasp is first computed and then adjusted to comply with the objects' shape, if necessary. To test the hypotheses, we asked participants to grasp knobs that could be grasped with two, four, or an unconstrained range of grasps. When participants chose among two or four options, planning time increased with the number of possible grasps which is in line with the simulation hypothesis. However, when grasps were unconstrained, planning times were as short as in the two-grasp condition, suggesting another--possibly preference-based--selection process in this case. In contrast to planning time, grasp choices were comparable regardless of the knob's shape. This suggests a common criterion most likely determined grasp selection in all conditions. PMID:26224266

  1. Thermal boundary conditions as constraints

    Fosco, C D; Roditi, I

    2006-01-01

    We introduce the boundary conditions corresponding to the imaginary-time (Matsubara) formalism for the finite-temperature partition function in $d+1$ dimensions as {\\em constraints} in the path integral for the vacuum amplitude (the zero-temperature partition function). We implement those constraints by using Lagrange multipliers, which are static fields, two of them associated to each physical degree of freedom. After integrating out the original, physical fields, we obtain an effective representation for the partition function, depending only on the Lagrange multipliers. The resulting functional integral has the appealing property of involving only $d$-dimensional, {\\em time independent} fields, looking like a non local version of the classical partition function. We analyze the main properties of this novel representation for the partition function, developing the formalism within the context of two concrete examples: the real scalar and Dirac fields.

  2. Water temperature constraint on Sonoluminescence

    Rahvar, S

    1999-01-01

    It is proposed that shock wave dynamics within the gas of a small bubble explain sonoluminescence, the emission of visible radiation. As the bubble radius oscillates, shock waves develop from spherical sound waves created inside the gas bubble. As any such shock propagates toward the center, it strengthens and, upon convergence and subsequent reflection, temperature of gas inside bubble increases dramatically in such a way that it can produce plasma. Since main radiation product in exploding epoch, nonadiabatic condition for imploding shock wave cool plasma and cause exploding shock wave can not sufficiently rise temperature to produce radiation. In this work we compare cooling time for plasma by bermsstrahlung radiation with collapsing time for the imploding shock wave . We find a constraint on radius of bubble with respect to temperature of water. This constraint condition explains experimental results as to, why the cold water is fine for SL.

  3. A Compendium of Chameleon Constraints

    Burrage, Clare

    2016-01-01

    The chameleon model is a scalar field theory with a screening mechanism that explains how a cosmologically relevant light scalar can avoid the constraints of intra-solar-system searches for fifth-forces. The chameleon is a popular dark energy candidate and also arises in $f(R)$ theories of gravity. Whilst the chameleon is designed to avoid historical searches for fifth-forces it is not unobservable and much effort has gone into identifying the best observables and experiments to detect it. These results are not always presented for the same models or in the same language, a particular problem when comparing astrophysical and laboratory searches making it difficult to understand what regions of parameter space remain. Here we present combined constraints on the chameleon model from astrophysical and laboratory searches for the first time and identify the remaining windows of parameter space. We discuss the implications for cosmological chameleon searches and future small-scale probes.

  4. The Viterbi Algorithm expressed in Constraint Handling Rules

    Christiansen, Henning; Have, Christian Theil; Lassen, Ole Torp; Petit, Matthieu

    The Viterbi algorithm is a classical example of a dynamic programming algorithm, in which pruning reduces the search space drastically, so that an otherwise exponential time complexity is reduced to linearity. The central steps of the algorithm, expansion and pruning, can be expressed in a concise...... and clear way in CHR, but additional control is needed in order to obtain the desired time complexity. It is shown how auxiliary constraints, called trigger constraints, can be applied to fine-tune the order of CHR rule applications in order to reach this goal. It is indicated how properties such as...... confluence can be useful for showing such optimized programs correct....

  5. Low Energy Constraints and Anomalous Triple Gauge Boson Couplings

    Zeppenfeld, Dieter

    1993-01-01

    Low energy (1-loop) constraints on anomalous triple gauge boson vertices (TGV's) are revisited and compared to the sensitivity achievable at LEP II and at future linear $e^+e^-$ colliders. The analysis is performed within the framework of an effective Lagrangian of gauge invariant dimension six operators with the gauge bosons and a single Higgs doublet field as the low energy degrees of freedom. The low energy data do not directly bound TGV's but they provide strong constraints on models which lead to anomalous gauge boson interactions in addition to other low energy effects.

  6. Random matrix ensembles with column/row constraints: I

    We analyze statistical properties of a complex system subjected to conditions which manifests through specific constraints on the column/row sum of the matrix elements of its Hermitian operators. The presence of additional constraints besides real-symmetric nature leads to new correlations among their eigenfunctions, hinders a complete delocalization of dynamics and affects the eigenvalues too. The statistical analysis of the latter indicates the presence of a new universality class analogous to that of a special type of Brownian ensemble appearing between Poisson and Gaussian orthogonal ensemble. (paper)

  7. First-and second-class constraints in super-BRST

    Using the recently obtained supersymmetric Becchi-Rouet-Stora-Tyutin transformations, the authors derive BRST- and supersymmetry-invariant equations which consist of the usual first- or second-class constraints plus ghost contributions. The ghost additions to the second-class constraints make them first-class

  8. Ply-based Optimization of Laminated Composite Shell Structures under Manufacturing Constraints

    Sørensen, Rene; Lund, Erik

    2012-01-01

    This work concerns a new ply-based parameterization for performing simultaneous material selection and topology optimization of fiber reinforced laminated composite structures while ensuring that a series of different manufacturing constraints are fulfilled. The material selection can either be......) with an additional constraint on the maximum allowable amount mass....

  9. Value Constraint and Monotone circuit

    Kobayashi, Koji

    2012-01-01

    This paper talks about that monotone circuit is P-Complete. Decision problem that include P-Complete is mapping that classify input with a similar property. Therefore equivalence relation of input value is important for computation. But monotone circuit cannot compute the equivalence relation of the value because monotone circuit can compute only monotone function. Therefore, I make the value constraint explicitly in the input and monotone circuit can compute equivalence relation. As a result...

  10. Quantum control with spectral constraints

    Pawela, Łukasz; Puchała, Zbigniew

    2012-01-01

    Various constraints concerning control fields can be imposed in the realistic implementations of quantum control systems. One of the most important is the restriction on the frequency spectrum of acceptable control parameters. It is important to consider the limitations of experimental equipment when trying to find appropriate control parameters. Therefore, in this paper we present a general method of obtaining a piecewise-constant controls, which are robust with respect to spectral constrain...

  11. Managing Restaurant Tables using Constraints

    Vidotto, Alfio; Brown, Kenneth N.; Beck, J. Christopher

    Restaurant table management can have significant impact on both profitability and the customer experience. The core of the issue is a complex dynamic combinatorial problem. We show how to model the problem as constraint satisfaction, with extensions which generate flexible seating plans and which maintain stability when changes occur. We describe an implemented system which provides advice to users in real time. The system is currently being evaluated in a restaurant environment.

  12. Liquidity constraints and entrepreneurial performance

    Hans K. Hvide; Møen, Jarle

    2007-01-01

    If entrepreneurs are liquidity constrained and cannot borrow to operate on an efficient scale, those with more personal wealth should do better than those with less wealth. We investigate this hypothesis using a unique dataset from Norway. Consistent with liquidity constraints being present, we find a strong positive relationship between founder prior wealth and start-up size. The relationship between prior wealth and start-up performance, as measured by profitability on assets, increases for...

  13. Bidding Markets with Financial Constraints

    Beker, Pablo; Hernando-Veciana, Angel

    2013-01-01

    We develop a model of bidding markets with financial constraints a la Che and Gale (1998b) in which two firms optimally choose their budgets. First, we provide an alternative explanation for the dispersion of markups and “money left on the table” across procurement auctions. Interestingly, this explanation does not hinge on significant private information but on di?erences, both endogenous and exogenous, in the availability of financial resources. Second, we explain why the empirical analysis...

  14. Integrating Gricean and Attentional Constraints

    Passonneau, Rebecca J.

    1995-01-01

    This paper concerns how to generate and understand discourse anaphoric noun phrases. I present the results of an analysis of all discourse anaphoric noun phrases (N=1,233) in a corpus of ten narrative monologues, where the choice between a definite pronoun or phrasal NP conforms largely to Gricean constraints on informativeness. I discuss Dale and Reiter's [To appear] recent model and show how it can be augmented for understanding as well as generating the range of data presented here. I argu...

  15. Intergenerational Ethics under Resource Constraints

    Geir B. Asheim

    2005-01-01

    When evaluating long-term policies, economists usually suggest to maximize the sum of discounted utilities. On the one hand, discounted utilitarianism was given a solid axiomatic foundation by Koopmans (Econometrica 1960). On the other hand, this criterion has questionable implications when applied to economic models with resource constraints. This raises the question: What ethical conditions for intergenerational distribution should and can be imposed? I use my discussion of such conditions ...

  16. Deepening Contractions and Collateral Constraints

    Jensen, Henrik; Ravn, Søren Hove; Santoro, Emiliano

    differential impact that occasionally non-binding constraints exert on the shape of expansions and contractions, we are also able to reconcile a more negatively skewed business cycle with a moderation in its volatility. Finally, our model can account for an intrinsic feature of economic downturns preceded by...... private credit build-ups: Financially driven expansions lead to deeper contractions, as compared to equally-sized non-financial expansions....

  17. Insider Ownership and Capital Constraints

    Hobdari, Bersant

    2007-01-01

    We analyze the impact of corporate governance structures on access to capital using a unique and rich panel data for a large and representative sample of Estonian firms over the period 1993 through 1999. We distinguish among five different governance structures and provide estimates on the impact of each of them on capital constraints. Our results indicate that: (i) separate regimes exist in investment behavior; (ii) the likelihood of being financially constrained is higher in firms that are ...

  18. Public investment under fiscal constraints

    Alessandro Missale; emanuele bacchiocchi; elisa borghi

    2009-01-01

    EU New Member States must comply with the Stability and Growth Pact (SGP) and the investment requirements implied by the Lisbon Agenda. However, the SGP rules may result in underinvestment or distortions in the allocation of public expenditure. This paper provides new evidence on the effects of debt sustainability and SGP fiscal constraints on government expenditure in fixed capital, education and health in OECD countries by estimating government expenditure reaction functions to public debt ...

  19. Controlled Synchronization Under Information Constraints

    Fradkov, Alexander L.; Andrievsky, Boris; Evans, Robin J.

    2007-01-01

    The class of controlled synchronization systems under information constraints imposed by limited information capacity of the coupling channel is analyzed. It is shown that the framework proposed in A. L. Fradkov, B. Andrievsky, R. J. Evans, Physical Review E 73, 066209 (2006) is suitable not only for observer-based synchronization but also for controlled master-slave synchronization via communication channel with limited information capacity. A simple first order coder-decoder scheme is propo...

  20. Isocurvature Constraints on Portal Couplings

    Kainulainen, Kimmo; Tenkanen, Tommi; Tuominen, Kimmo; Vaskonen, Ville

    2016-01-01

    We consider portal models which are ultraweakly coupled with the Standard Model, and confront them with observational constraints on dark matter abundance and isocurvature perturbations. We assume the hidden sector to contain a real singlet scalar $s$ and a sterile neutrino $\\psi$ coupled to $s$ via a pseudoscalar Yukawa term. During inflation, a primordial condensate consisting of the singlet scalar $s$ is generated, and its contribution to the isocurvature perturbations is imprinted onto the dark matter abundance. We compute the total dark matter abundance including the contributions from condensate decay and nonthermal production from the Standard Model sector. We then use the Planck limit on isocurvature perturbations to derive a novel constraint connecting dark matter mass and the singlet self coupling with the scale of inflation: $m_{\\rm DM}/{\\rm GeV}\\lesssim 0.2\\lambda_{\\rm s}^{\\scriptscriptstyle 3/8} \\left(H_*/10^{\\scriptscriptstyle 11}{\\rm GeV}\\right)^{\\scriptscriptstyle -3/2}$. This constraint is re...

  1. Analysis of Space Tourism Constraints

    Bonnal, Christophe

    2002-01-01

    Space tourism appears today as a new Eldorado in a relatively near future. Private operators are already proposing services for leisure trips in Low Earth Orbit, and some happy few even tested them. But are these exceptional events really marking the dawn of a new space age ? The constraints associated to the space tourism are severe : - the economical balance of space tourism is tricky; development costs of large manned - the technical definition of such large vehicles is challenging, mainly when considering - the physiological aptitude of passengers will have a major impact on the mission - the orbital environment will also lead to mission constraints on aspects such as radiation, However, these constraints never appear as show-stoppers and have to be dealt with pragmatically: - what are the recommendations one can make for future research in the field of space - which typical roadmap shall one consider to develop realistically this new market ? - what are the synergies with the conventional missions and with the existing infrastructure, - how can a phased development start soon ? The paper proposes hints aiming at improving the credibility of Space Tourism and describes the orientations to follow in order to solve the major hurdles found in such an exciting development.

  2. Cosmological constraints on neutrino oscillations

    Solar, atmospheric and terrestrial neutrino experiments have provided evidence for neutrino oscillations. These neutrino anomalies were successfully explained in terms of neutrino oscillations, the dominant channels being flavour neutrino oscillations. The role of sterile neutrinos and the active-sterile subdominant channels are being explored presently. Therefore, we discuss all cosmological effects of active-sterile neutrino oscillations on the early Universe evolution, and particularly the effects on the nucleosynthesis epoch. Numerical analysis of the cosmological production of He-4, Yp in the presence of νe ↔ νs, effective after νe decoupling from the equilibrium, was provided for the full neutrino oscillations parameter range. These neutrino oscillations lead always to an overproduction of He-4. We have obtained isohelium contours corresponding to different levels of He-4 overproduction, δYp/Yp, for initial population of the sterile state in the range 0 ≤ δNs ≤ 0.5. Cosmological constraints on oscillation parameters, obtained on the base of the calculated isohelium contours and Yp observational data, are discussed. We present the constraints corresponding toδNs = 0.0 and 0.5, and helium overproduction δYp/Yp = 3%. These cosmological constraints, being more stringent than the ones provided from the neutrino experimental data, provide valuable information for the impact of sterile neutrino in the neutrino anomalies and for the neutrino physics in general. (author)

  3. Infrared Constraint on Ultraviolet Theories

    Tsai, Yuhsin [Cornell Univ., Ithaca, NY (United States)

    2012-08-01

    While our current paradigm of particle physics, the Standard Model (SM), has been extremely successful at explaining experiments, it is theoretically incomplete and must be embedded into a larger framework. In this thesis, we review the main motivations for theories beyond the SM (BSM) and the ways such theories can be constrained using low energy physics. The hierarchy problem, neutrino mass and the existence of dark matter (DM) are the main reasons why the SM is incomplete . Two of the most plausible theories that may solve the hierarchy problem are the Randall-Sundrum (RS) models and supersymmetry (SUSY). RS models usually suffer from strong flavor constraints, while SUSY models produce extra degrees of freedom that need to be hidden from current experiments. To show the importance of infrared (IR) physics constraints, we discuss the flavor bounds on the anarchic RS model in both the lepton and quark sectors. For SUSY models, we discuss the difficulties in obtaining a phenomenologically allowed gaugino mass, its relation to R-symmetry breaking, and how to build a model that avoids this problem. For the neutrino mass problem, we discuss the idea of generating small neutrino masses using compositeness. By requiring successful leptogenesis and the existence of warm dark matter (WDM), we can set various constraints on the hidden composite sector. Finally, to give an example of model independent bounds from collider experiments, we show how to constrain the DM–SM particle interactions using collider results with an effective coupling description.

  4. Updating neutrino magnetic moment constraints

    B.C. Cañas

    2016-02-01

    Full Text Available In this paper we provide an updated analysis of the neutrino magnetic moments (NMMs, discussing both the constraints on the magnitudes of the three transition moments Λi and the role of the CP violating phases present both in the mixing matrix and in the NMM matrix. The scattering of solar neutrinos off electrons in Borexino provides the most stringent restrictions, due to its robust statistics and the low energies observed, below 1 MeV. Our new limit on the effective neutrino magnetic moment which follows from the most recent Borexino data is 3.1×10−11μB at 90% C.L. This corresponds to the individual transition magnetic moment constraints: |Λ1|≤5.6×10−11μB, |Λ2|≤4.0×10−11μB, and |Λ3|≤3.1×10−11μB (90% C.L., irrespective of any complex phase. Indeed, the incoherent admixture of neutrino mass eigenstates present in the solar flux makes Borexino insensitive to the Majorana phases present in the NMM matrix. For this reason we also provide a global analysis including the case of reactor and accelerator neutrino sources, presenting the resulting constraints for different values of the relevant CP phases. Improved reactor and accelerator neutrino experiments will be needed in order to underpin the full profile of the neutrino electromagnetic properties.

  5. Environmental externalities related to power production on biogas and natural gas based on the EU ExternE methodology

    Nielsen, Per Sieverts; Ibsen, Liselotte Schleisner

    1998-01-01

    European countries. The project use a “bottom-up” methodology to evaluate the external costs associated with a wide range of different fuel cycles. The project has identified priority impacts, where most are impacts from air emissions. Externalities due to atmospheric emissions are calculated through the......This paper assesses the environmental impacts and external costs from selected electricity generation systems in Denmark. The assessment is carried out as part of the ExternE National Implementation, which is the second phase of the ExternE project and involves case studies from all Western...

  6. Basic concept of new screening method for external event PSA

    After the TEPCO's Fukushima Daiichi nuclear power station accident, the importance of developing Probabilistic Safety Assessment (PSA) method is recognized not only for earthquakes in external events but also for broader external events. According to the external events assessment conducted by the U.S. Nuclear Regulatory Commission (NRC) in the 1980s, various external events were used to be selected by two screening methods first, and then estimated Core Damage Frequency (CDF) by the PSA method for the selected external events. However, at several nuclear power plant sites, there is a possibility to remain the too many external events that are not screened out by the above conventional screening methods because these depend on site and the feature of hazard. The purpose of this study is to propose a new screening method in addition to the conventional ones for external event PSA by focusing on failures of components for the fulfillment of CDF target value. In this paper, the proposed method was specifically applied to strong wind (i.e. typhoon), which has the highest frequency and the strongest wind velocity in Japan. As a result, we recognized the possibility of screening out typhoons from the view point of wind-resistant load although further investigation is necessary in terms of the safety functional failures of components. (author)

  7. Job Loss, Credit Constraints and Consumption Growth

    Thomas F. Crossley; Hamish W. Low

    2011-01-01

    We use direct evidence on credit constraints to study their importance for household consumption growth and for welfare. We distentangle the direct effect on consumption growth of a currently binding credit constraints from the indirect effect of a potentially binding credit constraint which generates consumption risk. Our data is focused on job losers. We find that less than 5% of job losers experience a binding credit constraint, but for those that do, they experience significant welfare lo...

  8. Breaking Weak Symmetries in Constraint Programming

    Martin, Roland

    2007-01-01

    Constraint programming (CP) is a powerful solving paradigm that is based on inference and search control algorithms and suitable for arbitrary/various NP-hard combinatorial problems beyond linearity. The flexibility of constraints - the working machines of a CP solver - allow a wide range of problems to be solved by constraint programming solvers. Constraint propagation and search control are to two main concepts that make CP an efficient solving strategy. The former identifies infeasible reg...

  9. Clustering trees with instance level constraints

    Struyf, Jan; Dzeroski, Saso

    2007-01-01

    Constrained clustering investigates how to incorporate domain knowledge in the clustering process. The domain knowledge takes the form of constraints that must hold on the set of clusters. We consider instance level constraints, such as must-link and cannot-link. This type of constraints has been successfully used in popular clustering algorithms, such as k-means and hierarchical agglomerative clustering. This paper shows how clustering trees can support instance level constraints. Clustering...

  10. Ant colony optimization and constraint programming

    Solnon, Christine

    2013-01-01

    Ant colony optimization is a metaheuristic which has been successfully applied to a wide range of combinatorial optimization problems. The author describes this metaheuristic and studies its efficiency for solving some hard combinatorial problems, with a specific focus on constraint programming. The text is organized into three parts. The first part introduces constraint programming, which provides high level features to declaratively model problems by means of constraints. It describes the main existing approaches for solving constraint satisfaction problems, including complete tree search

  11. Preferences in Constraint Satisfaction and Optimization

    Rossi, Francesca; University of Padova; Venable, Kristen Brent; Walsh, Toby

    2009-01-01

    We review constraint-based approaches to handle preferences. We start by defining the main notions of constraint programming, then give various concepts of soft constraints and show how they can be used to model quantitative preferences. We then consider how soft constraints can be adapted to handle other forms of preferences, such as bipolar, qualitative, and temporal preferences. Finally, we describe how AI techniques such as abstraction, explanation generation, machine learning, and prefer...

  12. Organizing for External Knowledge Sourcing

    Rabbiosi, Larissa; Reichstein, Toke

    2011-01-01

    The aim of this article is to provide an introduction to the special issue. We briefly consider the external knowledge sourcing and organizing for innovation literatures, which offer a background for the special issue, and we highlight their mutual dialogue. We then illustrate the main findings of...

  13. Femoral Reconstruction Using External Fixation

    Yevgeniy Palatnik

    2011-01-01

    Full Text Available Background. The use of an external fixator for the purpose of distraction osteogenesis has been applied to a wide range of orthopedic problems caused by such diverse etiologies as congenital disease, metabolic conditions, infections, traumatic injuries, and congenital short stature. The purpose of this study was to analyze our experience of utilizing this method in patients undergoing a variety of orthopedic procedures of the femur. Methods. We retrospectively reviewed our experience of using external fixation for femoral reconstruction. Three subgroups were defined based on the primary reconstruction goal lengthening, deformity correction, and repair of nonunion/bone defect. Factors such as leg length discrepancy (LLD, limb alignment, and external fixation time and complications were evaluated for the entire group and the 3 subgroups. Results. There was substantial improvement in the overall LLD, femoral length discrepancy, and limb alignment as measured by mechanical axis deviation (MAD and lateral distal femoral angle (LDFA for the entire group as well as the subgroups. Conclusions. The Ilizarov external fixator allows for decreased surgical exposure and preservation of blood supply to bone, avoidance of bone grafting and internal fixation, and simultaneous lengthening and deformity correction, making it a very useful technique for femoral reconstruction.

  14. Market Crashes without External Shocks

    Sergiu Hart; Yair Tauman

    2004-01-01

    It is shown here that market crashes and bubbles can arise without external shocks. Sudden changes in behavior coming after a long period of stationarity may be the result of endogenous information processing. Except for the daily observation of the market, there is no new information, no communication and no coordination among the participants.

  15. External costs and public opinion

    Public debate is strongly influencing the way individuals perceive pollution and risk issues. To take these perceptions into account in evaluating external costs, we propose an analysis of the social phenomenon which includes both the physical and symbolic exchanges simultaneously. The generalized social and political model then proposed should be considered a starting point (conceptual scheme) for analyzing individual perceptions. (author). 8 refs

  16. Lupus vulgaris of external nose

    Bhandary, Satheesh Kumar; Ranganna, B. Usha

    2008-01-01

    Lupus vulgaris is the commonest form of cutaneous tuberculosis which commonly involve trunk and buttocks. Lupus vulgaris affecting nose and face, are rarely reported in India. This study reports an unusual case of lupus vulgaris involving the external nose that showed dramatic outcome after six months of anti- tubercular treatment.

  17. Procedural design of exterior lighting for buildings with complex constraints

    Schwarz, Michael

    2014-09-23

    We present a system for the lighting design of procedurally modeled buildings. The design is procedurally specified as part of the ordinary modeling workflow by defining goals for the illumination that should be attained and locations where luminaires may be installed to realize these goals. Additionally, constraints can be modeled that make the arrangement of the installed luminaires respect certain aesthetic and structural considerations. From this specification, the system automatically generates a lighting solution for any concrete model instance. The underlying, intricate joint optimization and constraint satisfaction problem is approached with a stochastic scheme that operates directly in the complex subspace where all constraints are observed. To navigate this subspace efficaciously, the actual lighting situation is taken into account. We demonstrate our system on multiple examples spanning a variety of architectural structures and lighting designs. Copyright held by the Owner/Author.

  18. Connectivity in Secure Wireless Sensor Networks under Transmission Constraints

    Zhao, Jun; Gligor, Virgil

    2015-01-01

    In wireless sensor networks (WSNs), the Eschenauer-Gligor (EG) key pre-distribution scheme is a widely recognized way to secure communications. Although connectivity properties of secure WSNs with the EG scheme have been extensively investigated, few results address physical transmission constraints. These constraints reflect real-world implementations of WSNs in which two sensors have to be within a certain distance from each other to communicate. In this paper, we present zero-one laws for connectivity in WSNs employing the EG scheme under transmission constraints. These laws help specify the critical transmission ranges for connectivity. Our analytical findings are confirmed via numerical experiments. In addition to secure WSNs, our theoretical results are also applied to frequency hopping in wireless networks.

  19. Automatic Constraint Detection for 2D Layout Regularization

    Jiang, Haiyong

    2015-09-18

    In this paper, we address the problem of constraint detection for layout regularization. As layout we consider a set of two-dimensional elements where each element is represented by its bounding box. Layout regularization is important for digitizing plans or images, such as floor plans and facade images, and for the improvement of user created contents, such as architectural drawings and slide layouts. To regularize a layout, we aim to improve the input by detecting and subsequently enforcing alignment, size, and distance constraints between layout elements. Similar to previous work, we formulate the layout regularization as a quadratic programming problem. In addition, we propose a novel optimization algorithm to automatically detect constraints. In our results, we evaluate the proposed framework on a variety of input layouts from different applications, which demonstrates our method has superior performance to the state of the art.

  20. Cosmological constraints on Dark Matter models for collider searches

    Pree, Tristan du; Harris, Philip; Roskas, Christos

    2016-01-01

    Searches for Dark Matter at the LHC are commonly described in terms of simplified models with scalar, pseudo-scalar, vector and axial-vector mediators. In this work we explore the constraints imposed on such models from the observed Dark Matter relic abundance. We present these constraints over a range of mediator masses relevant for the LHC and for future, higher energy colliders. We additionally compute bounds from a photon line search for the decay of a pseudo-scalar mediator to di-photons that includes the mediator mass region near 750 GeV. Finally, we compare cosmological constraints with the reach of a possible future 100 TeV circular hadron collider, indirect, and direct detection experiments.

  1. Space group constraints on weak indices in topological crystalline insulators

    Varjas, Daniel; de Juan, Fernando; Lu, Yuan-Ming

    In this work we derive constraints on weak indices of topological insulators and superconductors coming from space group symmetry. Weak indices are topological invariants of lower dimensional slices of the Brillouin zone, notable examples are the Chern numbers in class A and weak ℤ2 indices in class AII in 3D. The components of the weak indices form a momentum space vector that transforms in a simple fashion under space group symmetries, using results of momentum space crystallography we find the allowed values for each Bravais lattice. Nonsymmorphic symmetries, such as screw axes and glide planes pose additional constraints. Accounting for both of these we find that most space groups experience some restriction, to the extent that some cannot support nontrivial weak topological insulators and superconductors at all. This result puts a strong constraint on candidates in the experimental and numerical search for topological materials based on the lattice structure alone.

  2. Revisiting constraints on uplifts to de Sitter vacua

    Bizet, Nana Cabo

    2016-01-01

    We revisit the issue of uplifting the potential to de Sitter (dS) vacua in type IIB flux compactifications of Kachru, Kallosh, Linde and Trivedi (KKLT). We shed light on some tension between two constraints on dS vacua in type IIB string theory. One is the well-known and much-discussed constraint which leads to the no-go theorem that can in principle be evaded. The other follows from 4-dimensional Einstein's equations, which has, however, been much less discussed in connection with the former constraint. In addition to the challenges previously posed, it is suggested that the uplifting scenarios, in particular, obstruct the evasion of the no-go theorem more strongly than one might have assumed.

  3. Exploring a type-theoretic approach to accessibility constraint modelling

    Pogodalla, Sylvain

    2008-01-01

    The type-theoretic modelling of DRT that [degroote06] proposed features continuations for the management of the context in which a clause has to be interpreted. This approach, while keeping the standard definitions of quantifier scope, translates the rules of the accessibility constraints of discourse referents inside the semantic recipes. In this paper, we deal with additional rules for these accessibility constraints. In particular in the case of discourse referents introduced by proper nouns, that negation does not block, and in the case of rhetorical relations that structure discourses. We show how this continuation-based approach applies to those accessibility constraints and how we can consider the parallel management of various principles.

  4. Comments on the nilpotent constraint of the goldstino superfield

    Ghilencea, D M

    2016-01-01

    Superfield constraints were often used in the past, in particular to describe the Akulov-Volkov action of the goldstino by a superfield formulation with $L=(\\Phi^\\dagger \\Phi)_D + [(f\\Phi)_F + h.c.]$ endowed with the nilpotent constraint $\\Phi^2=0$ for the goldstino superfield ($\\Phi$). Inspired by this, such constraint is often used to define the goldstino superfield even in the presence of additional superfields, for example in models of "nilpotent inflation". In this review we show that the nilpotent property is not valid in general, under the assumption of a microscopic (ultraviolet) description of the theory with linear supermultiplets. Sometimes only weaker versions of the nilpotent relation are true such as $\\Phi^3=0$ or $\\Phi^4=0$ ($\\Phi^2\

  5. A fuzzy multi-regional input–output optimization model for biomass production and trade under resource and footprint constraints

    Interest in bioenergy in recent years has been stimulated by both energy security and climate change concerns. Fuels derived from agricultural crops offer the promise of reducing energy dependence for countries that have traditionally been dependent on imported energy. Nevertheless, it is evident that the potential for biomass production is heavily dependent on the availability of land and water resources. Furthermore, capacity expansion through land conversion is now known to incur a significant carbon debt that may offset any benefits in greenhouse gas reductions arising from the biofuel life cycle. Because of such constraints, there is increasing use of non-local biomass through regional trading. The main challenge in the analysis of such arrangements is that individual geographic regions have their own respective goals. This work presents a multi-region, fuzzy input–output optimization model that reflects production and consumption of bioenergy under land, water and carbon footprint constraints. To offset any local production deficits or surpluses, the model allows for trade to occur among different regions within a defined system; furthermore, importation of additional biofuel from external sources is also allowed. Two illustrative case studies are given to demonstrate the key features of the model.

  6. Organizational Constraints on Corporate Public Relations Practitioners.

    Ryan, Michael

    1987-01-01

    Catalogs various internal constraints under which many public relations practitioners work, including constraints on (1) access to management; (2) information collection; (3) dissemination of timely, accurate information; and (4) the public relations mission. Reports that most practitioners see organizational constraints as more of a problem for…

  7. Learning and Parallelization Boost Constraint Search

    Yun, Xi

    2013-01-01

    Constraint satisfaction problems are a powerful way to abstract and represent academic and real-world problems from both artificial intelligence and operations research. A constraint satisfaction problem is typically addressed by a sequential constraint solver running on a single processor. Rather than construct a new, parallel solver, this work…

  8. Simulation of Water Vapor Condensation in a Partly Closed Structure: The Influence of the External Conditions of Temperature and Humidity

    Batina, Jean; Peyrous, René

    2013-01-01

    Our aim is to determine the more significant parameters acting on the water vapor condensation in a partly closed structure, submitted to external constraints (temperature and humidity) which induce convective movements and thermal variations inside. These constraints locally lead to condensation of the water vapor, initially contained in the air of the volume and/or on the walls. The inside bottom wall is remained dry. Condensed water quantities depend on: (1) dimensions of the structure, (2...

  9. Transcriptional Response of Escherichia coli to External Zinc

    Yamamoto, Kaneyoshi; Ishihama, Akira

    2005-01-01

    Transcriptional response of Escherichia coli to extracellular zinc was studied using DNA microarray and S1 mapping assays. Addition of external zinc induced the expression of zinc exporter ZntA and inhibited the expression of zinc importer ZnuC. In the continuous presence of zinc, ZnuC repression took place at lower zinc concentrations than ZntA induction. The microarray assay indicated that the addition of excess external zinc induces the expression of many genes that are organized in the re...

  10. Reassessment of external events in view of the Fukushima accident

    As a consequence of the EU stress tests following the Fukushima NPP accident, the Nordic BWR Owners Group (NOG) initiated an analysis related to the capability of Swedish and Finnish BWR plants to withstand potential effects from external flooding and other extreme natural events. A review of existing analyses was performed with the intention to identify and reassess assumptions and simplifications made, and to judge whether all significant aspects of external events had been identified and considered. A previous NOG project dealing with methodologies for analyzing certain external events was used as a reference. Additional analyses were performed within three sub-projects addressing extreme water levels in the Baltic Sea and Skagerrak, methodology for the analysis of multiple external events, and main heat sink accessibility. It was concluded that the outcome from the previous NOG project can still be used as a basis, but some issues requiring further analysis were also identified. (orig.)

  11. Pulsar constraints on screened modified gravity

    We calculate the rate of energy loss from compact astrophysical objects due to a scalar field in screened modified gravity models of the chameleon, dilaton and symmetron types. The cosmological evolution of the field results in a time-variation of the scalar charge of screened objects, implying the emission of scalar radiation. Focusing on binary objects, this leads to an additional decay in the orbital period complementing that due to the emission of gravitational waves. Using the Hulse–Taylor binary pulsar, the double pulsar PSR J0737–3039 and the pulsar-white dwarf system PSR J1738 + 033, we find a new observational bound on the time variation of the scalar charge of the Earth in the Milky Way. We then translate this into a new bound on the range of the scalar interaction in the Milky Way. Ultimately, we find that pulsar tests are not competitive with current observational constraints. (paper)

  12. Global constraints on heavy neutrino mixing

    Fernandez-Martinez, Enrique; Lopez-Pavon, Jacobo

    2016-01-01

    We derive general constraints on the mixing of heavy Seesaw neutrinos with the SM fields from a global fit to present flavour and electroweak precision data. We explore and compare both a completely general scenario, where the heavy neutrinos are integrated out without any further assumption, and the more constrained case were only 3 additional heavy states are considered. The latter assumption implies non-trivial correlations in order to reproduce the correct neutrino masses and mixings as observed by oscillation data and thus some qualitative differences can be found with the more general scenario. The relevant processes analyzed in the global fit include searches for Lepton Flavour Violating (LFV) decays, probes of the universality of weak interactions, CKM unitarity bounds and electroweak precision data. In particular, a comparative and detailed study of the present and future sensitivity of the different LFV experiments is performed. We find a mild $1-2\\sigma$ preference for non-zero heavy neutrino mixin...

  13. Technical basis document for external events

    This document supports the Tank Farms Documented Safety Analysis and presents the technical basis for the FR-equencies of externally initiated accidents. The consequences of externally initiated events are discussed in other documents that correspond to the accident that was caused by the external event. The external events include aircraft crash, vehicle accident, range fire, and rail accident

  14. Minimum weight design of helicopter rotor blades with frequency constraints

    Chattopadhyay, Aditi; Walsh, Joanne L.

    1989-01-01

    The minimum weight design of helicopter rotor blades subject to constraints on fundamental coupled flap-lag natural frequencies has been studied in this paper. A constraint has also been imposed on the minimum value of the blade autorotational inertia to ensure that the blade has sufficient inertia to autorotate in case of an engine failure. The program CAMRAD has been used for the blade modal analysis and the program CONMIN has been used for the optimization. In addition, a linear approximation analysis involving Taylor series expansion has been used to reduce the analysis effort. The procedure contains a sensitivity analysis which consists of analytical derivatives of the objective function and the autorotational inertia constraint and central finite difference derivatives of the frequency constraints. Optimum designs have been obtained for blades in vacuum with both rectangular and tapered box beam structures. Design variables include taper ratio, nonstructural segment weights and box beam dimensions. The paper shows that even when starting with an acceptable baseline design, a significant amount of weight reduction is possible while satisfying all the constraints for blades with rectangular and tapered box beams.

  15. A Variable Depth Search Algorithm for Binary Constraint Satisfaction Problems

    N. Bouhmala

    2015-01-01

    Full Text Available The constraint satisfaction problem (CSP is a popular used paradigm to model a wide spectrum of optimization problems in artificial intelligence. This paper presents a fast metaheuristic for solving binary constraint satisfaction problems. The method can be classified as a variable depth search metaheuristic combining a greedy local search using a self-adaptive weighting strategy on the constraint weights. Several metaheuristics have been developed in the past using various penalty weight mechanisms on the constraints. What distinguishes the proposed metaheuristic from those developed in the past is the update of k variables during each iteration when moving from one assignment of values to another. The benchmark is based on hard random constraint satisfaction problems enjoying several features that make them of a great theoretical and practical interest. The results show that the proposed metaheuristic is capable of solving hard unsolved problems that still remain a challenge for both complete and incomplete methods. In addition, the proposed metaheuristic is remarkably faster than all existing solvers when tested on previously solved instances. Finally, its distinctive feature contrary to other metaheuristics is the absence of parameter tuning making it highly suitable in practical scenarios.

  16. On Factorization Constraints for Branes in the H3+ Model

    Adorf, Hendrik; Flohr, Michael

    We comment on the brane solutions for the boundary H3+ model that have been proposed so far and point out that they should be distinguished according to the patterns regular/irregular and discrete/continuous. In the literature, mostly irregular branes have been studied, while results on the regular ones are rare. For all types of branes, there are questions about how a second factorization constraint in the form of a b-2/2-shift equation can be derived. Here, we assume analyticity of the boundary two-point function, which means that the Cardy-Lewellen constraints remain unweakened. This enables us to derive unambiguously the desired b-2/2-shift equations. They serve as important additional consistency conditions. For some regular branes, we also derive 1/2-shift equations that were not known previously. Case by case, we discuss possible solutions to the enlarged system of constraints. We find that the well-known irregular continuous AdS2 branes are consistent with our new factorization constraint. Furthermore, we establish the existence of a new type of brane: the shift equations in a certain regular discrete case possess a nontrivial solution that we write down explicitly. All other types are found to be inconsistent when using our second constraint. We discuss these results in view of the Hosomichi-Ribault proposal and some of our earlier results on the derivation of b-2/2-shift equations.

  17. External costs of future fusion plants

    Hamacher, T.; Cabal, H.; Hallberg, B.; Korhonen, R.; Lechon, Y.; Saez, R.M.; Schleisner, L

    2001-04-01

    In the framework of the Socio-Economic Research on Fusion (SERF), which was jointly conducted by the European Commission and the Fusion Associations, external costs of future fusion plants were calculated. All the damages that are not reflected in the market price are called external costs. The ExternE methodology was applied. External costs of the fusion power plants are found to be rather low, in the range of a few mEuro/kWh. Radiological impacts are only one source of external effects, but not the dominating one. External costs of fusion compare well with wind and solar energy.

  18. Village Chicken Husbandry Practice, Marketing and Constraints in Eastern Ethiopia

    Tarekegn, Getachew

    2015-12-01

    Full Text Available This experiment is designed to study the characteristics of village chicken husbandry practice, marketing and constraints in eastern Ethiopia. The study was conducted from July in four selected districts in the highlands of eastern Ethiopia (Haramaya, Kersa, Jarso and Meta. A total of 80 chicken owner households were randomly selected and interviewed using a structured questionnaire. Data on characteristics of village chicken production, feeds and feeding practices, housing, management of chicken and eggs, Marketing, diseases and constraints of village chicken production system were collected. Scavenging chicken production system is observed in all households of the districts. Average flock size of chickens in the study area was 9.4 birds and varied between 4 and 17 birds. In the present study, 82% of the households provide overnight housing within the family house for their chicken. Scavenging is the only feeding system encountered in all study districts with little grain supplementation. Most of the chicken are owned and managed by women (36.75%. Selling of unprocessed eggs and live chickens is mainly practiced. External parasites (mites, Coccidiosis and Newcastle disease were the most important and prevailing diseases in the study area with 39%, 38% and 34% incidence rates, respectively. The magnitude of occurrence of the parasites and diseases were higher in the wet season. Poor genetic quality, lack of extension service, inadequate veterinary service and poor management were the main constraints of village poultry production in the study area.

  19. The european commission externe project

    The Externe project, begun jointly in 1991 by the European Commission and the U.S. Department of Energy, consists in establishing an accounting framework for evaluating the external environmental costs of energy. So far, the project has concentrated on the main forms of energy used for producing electricity. The environmental costs of coal technologies, nuclear, gas, petroleum, and certain renewables (hydraulic, wind) have been evaluated for European locations. Some thirty research teams have been participating in the project in Europe. The project was originally prompted by the desire to establish a common concept based on physical, technical and economic evaluation methods, and on new clarified definitions of external costs that would be the same in the various countries and for future users. The external costs are thus evaluated: for newly installed equipment, with an ''incremental approach'' to marginal environmental cost; for a specific location; in proportion to the damage done to the environment, on the basis of willingness-to-pay monetary evaluation methods. The physical damage considered is the damage to health, materials, crops, forests, lakes, and rivers; but accidents, noise, unsightliness and potential impact on climatic change are also the subject of exploratory evaluations. The pollutants considered are the now classical SO2, NOx, CO2 particles, aerosols, ozone and radionuclides. Preliminary results have been presented and certain conclusions can already be drawn. In all, the Community project shows that substantial efforts have been made on a large scale, and that these are bearing their first significant, consistent results today. Even though these results may not provide a basis for deciding between one form of energy and another, they already give an indication of the limits within which the questions of internalizing external costs must be stated. The intent of the Community program to establish the Externe accounting framework in all the

  20. Conjure Revisited: Towards Automated Constraint Modelling

    Akgun, Ozgur; Hnich, Brahim; Jefferson, Chris; Miguel, Ian

    2011-01-01

    Automating the constraint modelling process is one of the key challenges facing the constraints field, and one of the principal obstacles preventing widespread adoption of constraint solving. This paper focuses on the refinement-based approach to automated modelling, where a user specifies a problem in an abstract constraint specification language and it is then automatically refined into a constraint model. In particular, we revisit the Conjure system that first appeared in prototype form in 2005 and present a new implementation with a much greater coverage of the specification language Essence.

  1. Constraint Specialisation in Horn Clause Verification

    Kafle, Bishoksan; Gallagher, John Patrick

    We present a method for specialising the constraints in constrained Horn clauses with respect to a goal. We use abstract interpretation to compute a model of a query-answer transformation of a given set of clauses and a goal. The effect is to propagate the constraints from the goal top-down and...... propagate answer constraints bottom-up. Our approach does not unfold the clauses at all; we use the constraints from the model to compute a specialised version of each clause in the program. The approach is independent of the abstract domain and the constraints theory underlying the clauses. Experimental...

  2. External costs of energy - do the answers match the questions? Looking back at 10 years of ExternE

    While the claim for 'getting prices right' is quite popular in conceptual policy papers, the implementation of appropriate internalisation strategies is still hampered by a lack of reliable external cost data. Great expectations were set into the ExternE project, a major research programme launched by the European Commission at the beginning of the 1990s to provide a scientific basis for the quantification of energy related externalities and to give guidance supporting the design of internalisation measures. After more than a decade of research, the ExternE label became a well recognised standard source for external cost data. Looking back into the ExternE history, the paper pursues how emerging new scientific insights and changing background assumptions affected external cost estimates and related recommendations to policy over time. Based on ExternE results, the usefulness and inherent limitations of external cost estimates for impact categories like climate change or nuclear waste disposal is discussed. The paper also gives examples on how external costs in spite of remaining uncertainties are successfully used to support environmental policy. (Author)

  3. A Maximal Tractable Class of Soft Constraints

    Cohen, D; Jeavons, P; Krokhin, A; 10.1613/jair.1400

    2011-01-01

    Many researchers in artificial intelligence are beginning to explore the use of soft constraints to express a set of (possibly conflicting) problem requirements. A soft constraint is a function defined on a collection of variables which associates some measure of desirability with each possible combination of values for those variables. However, the crucial question of the computational complexity of finding the optimal solution to a collection of soft constraints has so far received very little attention. In this paper we identify a class of soft binary constraints for which the problem of finding the optimal solution is tractable. In other words, we show that for any given set of such constraints, there exists a polynomial time algorithm to determine the assignment having the best overall combined measure of desirability. This tractable class includes many commonly-occurring soft constraints, such as 'as near as possible' or 'as soon as possible after', as well as crisp constraints such as 'greater than'. F...

  4. Percolation of spatially constraint networks

    Li, Daqing; Li, Guanliang; Kosmidis, Kosmas; Stanley, H. E.; Bunde, Armin; Havlin, Shlomo

    2011-03-01

    We study how spatial constraints are reflected in the percolation properties of networks embedded in one-dimensional chains and two-dimensional lattices. We assume long-range connections between sites on the lattice where two sites at distance r are chosen to be linked with probability p(r)~r-δ. Similar distributions have been found in spatially embedded real networks such as social and airline networks. We find that for networks embedded in two dimensions, with 24 it belongs to the universality class of percolation in regular lattices. For networks embedded in one dimension, we find that, for δ2 there is no percolation transition as in regular linear chains.

  5. Beyond the Constraints of Reality

    Hansen, Kim Toft

    horror (the affection on the body) and lastly the emotion of belief (“the idea that God exists”). In that sense, the poetics of horror can as well draw heavily upon the idea of mimetic aspects of fiction and, basically and correspondingly, Lucio Fulci’s cult film The Beyond is a core example of how...... horror draws upon another implication in the word ‘cult’, namely the religious cult. Both religion and horror deals with going beyond the constraints of reality....

  6. Ordinal Classification with Monotonicity Constraints

    Horváth, T.; Vojtáš, Peter

    Berlin: Springer, 2006 - (Perner, P.), s. 217-225. (Lecture Notes in Artificial Intelligence. 4065). ISBN 978-3-540-36036-0. [ICDM 2006. Industrial Conference on Data Mining /6./. Leipzig (DE), 14.07.2006-15.07.2006] R&D Projects: GA AV ČR 1ET100300517 Grant ostatní: VEGA(SK) 1/3129/06 Institutional research plan: CEZ:AV0Z10300504 Keywords : monotone * monotonicity constraints * classification * ordinal data Subject RIV: IN - Informatics, Computer Science

  7. External observer reflections on QBism

    Khrennikov, Andrei

    2015-01-01

    In this short review I present my personal reflections on QBism. I have no intrinsic sympathy neither to QBism nor to subjective interpretation of probability in general. However, I have been following development of QBism from its very beginning, observing its evolution and success, sometimes with big surprise. Therefore my reflections on QBism can be treated as "external observer" reflections. I hope that my representation of this interpretation of quantum mechanics (QM) has some degree of objectivity. It may be useful for researchers who are interested in quantum foundations, but do not belong to the QBism-community, because I tried to analyze essentials of QBism critically (i.e., not just emphasizing its advantages, as in a typical publication of QBists). QBists may be interested as well - in comments of an external observer who monitored development of this approach to QM during last 16 years. The second part of the paper is devoted to interpretations of probability, objective versus subjective, and view...

  8. MGR External Events Hazards Analysis

    The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses

  9. Parallel External Memory Graph Algorithms

    Arge, Lars Allan; Goodrich, Michael T.; Sitchinava, Nodari

    2010-01-01

    In this paper, we study parallel I/O efficient graph algorithms in the Parallel External Memory (PEM) model, one o f the private-cache chip multiprocessor (CMP) models. We study the fundamental problem of list ranking which leads to efficient solutions to problems on trees, such as computing lowest...... an optimal speedup of ¿(P) in parallel I/O complexity and parallel computation time, compared to the single-processor external memory counterparts....... common ancestors, tree contraction and expression tree evaluation. We also study the problems of computing the connected and biconnected components of a graph, minimum spanning tree of a connected graph and ear decomposition of a biconnected graph. All our solutions on a P-processor PEM model provide...

  10. Firm Search for External Knowledge

    Sofka, Wolfgang; Grimpe, Christoph

    2012-01-01

    to experience the negative performance effects of oversearch. Based on a comprehensive sample of almost 8,000 firms from ten European countries, we find that institutions matter considerably for firms' search activity. Higher market orientation of institutions increases the effectiveness of firms' search...... ignored the institutional context that provides or denies access to external knowledge at the country level. Combining institutional and knowledge search theory, we suggest that the market orientation of the institutional environment and the magnitude of institutional change influence when firms begin...... for external knowledge while higher magnitudes of institutional change decrease it. Our results provide important insights for management on how to adapt search strategies to the institutional context....

  11. MGR External Events Hazards Analysis

    L. Booth

    1999-11-06

    The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses.

  12. If you try, you’ll get by: Chinese private firms’ efficiency gains from overcoming financial constraints

    Galina Hale; Cheryl Long

    2010-01-01

    It appears to be common knowledge that external financing in China is mostly limited to state-owned firms and is hard to obtain for smaller private firms. In this paper we first confirm this pattern for more recent data and then investigate ways in which private firms overcome their financing constraints. We find that private firms reduce their need for external funds through more efficient management of inventory levels and accounts receivable. We further show that the low levels of inventor...

  13. File: protection against external risks

    A nuclear facility creates risks for its personnel, the public and environment that justify the surveillance that public authorities practice on it. But the phenomenons that develop outside the installation can request the safety of a nuclear facility. These sources of risks external to installations can be bound to human activities (plane crash) or be completely natural ( floods, seismic events) and this approach, even if the risk is exceptional, is a fundamental part of the safety. (N.C.)

  14. Mercosur’s external relations

    Manuel Cienfuegos Mateo

    2001-01-01

    The purpose of this study is a theoretical and practical analysis of Mercosur’s external relations. The article sets out the problems that the exercise of its international legal identity raises in international law and for the national rights of the member states and makes proposals de lege ferenda for its adequate integration into the international framework. From here, it proceeds to a series of general reflections on Mercosur’s international identity in light of the fact that its characte...

  15. External tank space debris considerations

    Elfer, N.; Baillif, F.; Robinson, J.

    1992-01-01

    Orbital debris issues associated with maintaining a Space Shuttle External Tank (ET) on orbit are presented. The first issue is to ensure that the ET does not become a danger to other spacecraft by generating space debris, and the second is to protect the pressurized ET from penetration by space debris or meteoroids. Tests on shield designs for penetration resistance showed that when utilized with an adequate bumper, thermal protection system foam on the ET is effective in preventing penetration.

  16. Atmospheric Externalities and Environmental Taxation.

    Sandmo, Agnar

    2010-01-01

    The paper reviews the theory of environmental taxation under first best and second best conditions. It argues that negative environmental externalities lead to reductions of the provision of public goods, while investment in abatement increases the supply of public goods. Together with optimal tax rules, the paper therefore also derives conditions for the optimal use of resources on abatement. After brief discussions of the dimensions of time and uncertainty, tax reform and the...

  17. Preference Externalities in Media Markets

    Simon P. Anderson; Waldfogel, Joel

    2015-01-01

    Media industries typically exhibit two fundamental features, high fixed costs and heterogeneity of consumer preferences. Daily newspaper markets, for example, tend to support a single product. In other examples, such as radio broadcasting, markets often support multiple differentiated offerings. Both contexts can deliver preference externalities, when the options and well-being for consumers depend on the number and mix of consumers according to their content preferences. This chapter present...

  18. External Mechanisms of Corporate Governance

    Radygin Alexandr; Entov Revold; Mejeraoups I.

    2007-01-01

    The aim of this research paper is to analyze those external corporate governance mechanisms, which either play a practical role or give an idea about the specifics of the Russian model. In the context of general institutional issues first of all market mechanisms are analyzed, which are “in built” into a modern system of corporate governance: financial arkets, corporate control market, bankruptcies. For the 2000’s, issues of improvement of the norms of voluntary regulation of corporate govern...

  19. External debt management in Romania

    Ramona DUMITRIU; Stefanescu, Razvan

    2013-01-01

    This paper approaches the evolution of Romania’s foreign debt in three periods of time: during Nicolae Ceausescu regime, in the transition period and the one which followed the adhesion to European Union. For all three periods the external debt management had to deal with different circumstances: the sharp increase of real interest rates from the 1980s, the lack of credibility on international financial markets from the 1990s or the recent global crisis. We conclude that political regime, the...

  20. ENDOSCOPIC DCR VERSUS EXTERNAL DCR

    Rukma

    2015-04-01

    Full Text Available PURPOSE: To compare success rates of endoscopic dacryocystorhinostomy (DCR and external DCR for acquired nasolacrimal duct obstruction (NLDO. MATERIALS AND METHODS: A prospective comparative non randomized study of 64 patients who presented with acquired NLD obstruction to a tertiary hospital. They were fully evaluated to ascertain the site of obstruction and patients with distal obstruction were included in the study. 34 patients underwent endoscopic DCR and 30 patients underwent external DCR RESULTS: 64 patients were included in the study and 72 procedures carried out. Success was achieved in 65 cases and failure in 7. Of the 7 failed cases, anatomical obstruction at the fistula site was found in 3, whereas functional failure was found in 4. In our patients, endoscopic DCR had a significantly higher success rate than external DCR, 95.23% versus 83.33% (P = 0.03. CONCLUSIONS: The success rate of Endoscopic DCR for acquired NLDO in our group of patients was 95.23%, with endoscopic surgery showing better results.

  1. Individuals' insight into intrapersonal externalities

    David J. Stillwell

    2012-07-01

    Full Text Available An intrapersonal externality exists when an individual's decisions affect the outcomes of her future decisions. It can result in decreasing or increasing average returns to the rate of consumption, as occurs in addiction or exercise. Experimentation using the Harvard Game, which models intrapersonal externalities, has found differences in decision making between drug users and control subjects, leading to the argument that these externalities influence the course of illicit drug use. Nevertheless, it is unclear how participants who behave optimally conceptualise the problem. We report two experiments using a simplified Harvard Game, which tested the differences in contingency knowledge between participants who chose optimally and participants who did not. Those who demonstrated optimal performance exhibited both a pattern of correct responses and systematic errors to questions about the payoff schedules. The pattern suggested that they learned explicit knowledge of the change in reinforcement on a trail-by-trial basis. They did not have, or need, a full knowledge of the historical interaction leading to each payoff. We also found no evidence of choice differences between participants who were given a guaranteed payment and participants who were paid contingent on their performance, but those given a guaranteed payment were able to report more contingency knowledge as the experiment progressed, suggesting that they explored more rather than settling into a routine. Experiment 2 showed that using a fixed inter-trial interval did not change the results.

  2. External indebtedness of Croatian banks

    Antun Jurman

    2005-06-01

    Full Text Available The paper analyses the main characteristics of the foreign assets and foreign liabilities of the banks that to a great extent include credit and deposit activities with non-residents – foreign physical persons and legal entities, mostly with foreign banks. The author in this paper analyses the size and trends of the Republic of Croatia’s external debt with regard to gross domestic product, import, export, international reserve of the Croatian National Bank (HNB, etc. The author also discusses external debt of the banks that have, during the past few years, contributed substantially to the overall external debt of the Republic of Croatia. The autor points out that the banks have used foreign sources mainly for placing citizens’ loans, and less for financing development projects and economy. Thus, the banks have “spent”, i.e. used up their credit capacity as well as the credit capacity of the Republic of Croatia. Regardless of the fact that the banks have improved the quality of their assets, maintained liquidity/solvency and made extremely good profits, there have not been positive effects of the multiplication of credits/loans and deposits nor have there been the awaited effects on the growth of the gross domestic product and employment that otherwise might have been achieved via different foreign resources investment policy

  3. Chance-Constrained Guidance With Non-Convex Constraints

    Ono, Masahiro

    2011-01-01

    Missions to small bodies, such as comets or asteroids, require autonomous guidance for descent to these small bodies. Such guidance is made challenging by uncertainty in the position and velocity of the spacecraft, as well as the uncertainty in the gravitational field around the small body. In addition, the requirement to avoid collision with the asteroid represents a non-convex constraint that means finding the optimal guidance trajectory, in general, is intractable. In this innovation, a new approach is proposed for chance-constrained optimal guidance with non-convex constraints. Chance-constrained guidance takes into account uncertainty so that the probability of collision is below a specified threshold. In this approach, a new bounding method has been developed to obtain a set of decomposed chance constraints that is a sufficient condition of the original chance constraint. The decomposition of the chance constraint enables its efficient evaluation, as well as the application of the branch and bound method. Branch and bound enables non-convex problems to be solved efficiently to global optimality. Considering the problem of finite-horizon robust optimal control of dynamic systems under Gaussian-distributed stochastic uncertainty, with state and control constraints, a discrete-time, continuous-state linear dynamics model is assumed. Gaussian-distributed stochastic uncertainty is a more natural model for exogenous disturbances such as wind gusts and turbulence than the previously studied set-bounded models. However, with stochastic uncertainty, it is often impossible to guarantee that state constraints are satisfied, because there is typically a non-zero probability of having a disturbance that is large enough to push the state out of the feasible region. An effective framework to address robustness with stochastic uncertainty is optimization with chance constraints. These require that the probability of violating the state constraints (i.e., the probability of

  4. ExternE: Externalities of energy Vol. 4. Oil and gas

    Awareness of the environmental damage resulting from human activity, particularly commencing energy use, has grown greatly in recent years. Effects such as global warming, ozone depletion and acid rain are now the subjects of much research and public debate. It is now known that these and other effects damage a wide range of receptors, including human health, forests, crops, freshwater ecosystems and buildings. Such damages are typically not accounted for by the producers and consumers of the good in question (in this case energy). They are thus referred to as 'external costs' or 'externalities', to distinguish them from the private costs which account for the construction of plant, cost of fuel, wages, etc. In recent years there has been a growing interest in the assessment of the environmental and health impacts of energy, and the related external costs. This concern is driven by a number of different factors: the need to integrate environmental concerns in decision making over the choice between different fuels and energy technologies; the need to evaluate the costs and benefits of stricter environmental standards; increased attention to the use of economic instruments for environmental policy, the need to develop overall indicators of environmental performance of different technologies; major changes in the energy sector, including privatisation, liberalisation of markets, reduction of subsidies, etc. An agreed methodology for calculation and integration of external costs has not been established. Earlier work is typically of a preliminary nature and tends to be deficient with respect to both the methods employed and the quality of models and data used. In consequence of this a collaborative project, the EC/US Fuel Cycles Study, was established between Directorate General XLI (Science, Research and Technology) of the European Commission and the United States Department of Energy. This ran for the period 1991 to 1993, and good agreement on a variety of

  5. Kyrgyzstan: Internal and External Course of Development

    Vadim Volovoj

    2015-03-01

    Full Text Available After collapse of the Soviet Union Central Asia (CA was not in the focus of academic society and big geopolitical players, Kyrgyzstan not being an exception. But today Russia is back to CA through the Eurasian Economic Union (EEU and Collective Security Treaty Organization (CSTO. Kyrgyzstan is a member of CSTO and is going to join the EEU. Therefore it is worth of broader analysis. This study tried to understand specifics of Kyrgyz internal and external course of development. It found that internal political process in Kyrgyzstan used to be very problematic. The country suffered a lot from two revolutions, caused by the authoritarian “family rule” of Askar Akaev and Kurmanbek Bakiev. After that Kyrgyzstan decided to change its system of government from presidential to parliamentary (or semi-presidential model. But this experiment did not bring peace and stability, additionally complicated by ethnic tension between Kyrgyz and Uzbek citizens. Possible recipe of success – bigger socio-economic responsibility of the government, but it is still not in place. After two people revolts Kyrgyzstan was near to become a “failed state”, but orientation towards strategic partnership with Russia and membership in the EEU can help it to survive politically and economically at the expense of Russian geopolitical ambitions, compensate internal political turbulence by external factor of stability. Moreover, close (also institutional cooperation with Moscow strengthens systemic power of Kyrgyzstan in its relations with the closest neighbors, such as Uzbekistan (not satisfied with the water policy of Bishkek and Afghanistan (poses real security threat of Islamic extremism and terrorism to Kyrgyzstan. To sum up, for the moment Kyrgyz internal politics is hardly predictable, also because of the parliamentary experiment, but definite external orientation towards Russia and the EEU creates some basis for stable long term development of the country.

  6. Design for Additive Manufacturing

    Bertran Comellas, Martí

    2012-01-01

    This Thesis, Design for Additive Manufacturing, has been mainly focused on the design process and the considerations to be taken into account when designing parts for Additive Manufacturing. It starts with an introduction to Additive Manufacturing, the different technologies and processes are described to let the readers understand their operating principle, materials used and their strengths and weaknesses. The applications of Additive manufacturing are also explained in the introductory ...

  7. Cognitive constraints on motor imagery.

    Dahm, Stephan F; Rieger, Martina

    2016-03-01

    Executed bimanual movements are prepared slower when moving to symbolically different than when moving to symbolically same targets and when targets are mapped to target locations in a left/right fashion than when they are mapped in an inner/outer fashion [Weigelt et al. (Psychol Res 71:238-447, 2007)]. We investigated whether these cognitive bimanual coordination constraints are observable in motor imagery. Participants performed fast bimanual reaching movements from start to target buttons. Symbolic target similarity and mapping were manipulated. Participants performed four action conditions: one execution and three imagination conditions. In the latter they indicated starting, ending, or starting and ending of the movement. We measured movement preparation (RT), movement execution (MT) and the combined duration of movement preparation and execution (RTMT). In all action conditions RTs and MTs were longer in movements towards different targets than in movements towards same targets. Further, RTMTs were longer when targets were mapped to target locations in a left/right fashion than when they were mapped in an inner/outer fashion, again in all action conditions. RTMTs in imagination and execution were similar, apart from the imagination condition in which participants indicated the start and the end of the movement. Here MTs, but not RTs, were longer than in the execution condition. In conclusion, cognitive coordination constraints are present in the motor imagery of fast (motor imagery. PMID:25758054

  8. OPTIMIZATION WITH LINEAR COMPLEMENTARITY CONSTRAINTS

    Joaquim Júdice

    2014-12-01

    Full Text Available A Mathematical Program with Linear Complementarity Constraints (MPLCC is an optimization problem where a continuously differentiable function is minimized on a set defined by linear constraints and complementarity conditions on pairs of complementary variables. This problem finds many applications in several areas of science, engineering and economics and is also an important tool for the solution of some NP-hard structured and nonconvex optimization problems, such as bilevel, bilinear and nonconvex quadratic programs and the eigenvalue complementarity problem. In this paper some of the most relevant applications of the MPLCC and formulations of nonconvex optimization problems as MPLCCs are first presented. Algorithms for computing a feasible solution, a stationary point and a global minimum for the MPLCC are next discussed. The most important nonlinear programming methods, complementarity algorithms, enumerative techniques and 0 - 1 integer programming approaches for the MPLCC are reviewed. Some comments about the computational performance of these algorithms and a few topics for future research are also included in this survey.

  9. Next generation cosmology: constraints from the Euclid galaxy cluster survey

    Sartoris, B.; Biviano, A.; Fedeli, C.; Bartlett, J. G.; Borgani, S.; Costanzi, M.; Giocoli, C.; Moscardini, L.; Weller, J.; Ascaso, B.; Bardelli, S.; Maurogordato, S.; Viana, P. T. P.

    2016-06-01

    We study the characteristics of the galaxy cluster samples expected from the European Space Agency's Euclid satellite and forecast constraints on parameters describing a variety of cosmological models. In this paper we use the same method of analysis already adopted in the Euclid Red Book, which is based on the Fisher matrix approach. Based on our analytical estimate of the cluster selection function in the photometric Euclid survey, we forecast the constraints on cosmological parameters corresponding to different extensions of the standard Λ cold dark matter model. Using only Euclid clusters, we find that the amplitude of the matter power spectrum will be constrained to Δσ8 = 0.0014 and the mass density parameter to ΔΩm = 0.0011. The dynamical evolution of dark energy will be constrained to Δw0 = 0.03 and Δwa = 0.2 with free curvature Ωk, resulting in a (w0, wa) figure of merit (FoM) of 291. In combination with Planck cosmic microwave background (CMB) constraints, the amplitude of primordial non-Gaussianity will be constrained to ΔfNL ≃ 6.6 for the local shape scenario. The growth factor parameter γ, which signals deviations from general relativity, will be constrained to Δγ = 0.02, and the neutrino density parameter to ΔΩν = 0.0013 (or Δ∑mν = 0.01). Including the Planck CMB covariance matrix improves dark energy constraints to Δw0 = 0.02, Δwa = 0.07, and a FoM = 802. Knowledge of the observable-cluster mass scaling relation is crucial to reach these accuracies. Imaging and spectroscopic capabilities of Euclid will enable internal mass calibration from weak lensing and the dynamics of cluster galaxies, supported by external cluster surveys.

  10. Invariance properties of the Dirac equation with external electro-magnetic field

    N D Sen Gupta

    2003-01-01

    In this paper, we attempt to obtain the nature of the external field such that the Dirac equation with external electro-magnetic field is invariant. The Poincar´e group, which is the maximal symmetry group for field free case, is constrained by the presence of the external field. Introducing infinitesimal transformation of x andψ, we apply Lie’s extended group method to obtain the class of external field which admit of the invariance of the equation. It is important to note that the constraints for the existence of invariance are explicity on the electric and magnetic field, though only potentials explicity appears in the equation.

  11. Testing multiple coordination constraints with a novel bimanual visuomotor task.

    Helene M Sisti

    Full Text Available The acquisition of a new bimanual skill depends on several motor coordination constraints. To date, coordination constraints have often been tested relatively independently of one another, particularly with respect to isofrequency and multifrequency rhythms. Here, we used a new paradigm to test the interaction of multiple coordination constraints. Coordination constraints that were tested included temporal complexity, directionality, muscle grouping, and hand dominance. Twenty-two healthy young adults performed a bimanual dial rotation task that required left and right hand coordination to track a moving target on a computer monitor. Two groups were compared, either with or without four days of practice with augmented visual feedback. Four directional patterns were tested such that both hands moved either rightward (clockwise, leftward (counterclockwise, inward or outward relative to each other. Seven frequency ratios (3∶1, 2∶1, 3∶2, 1∶1, 2∶3. 1∶2, 1∶3 between the left and right hand were introduced. As expected, isofrequency patterns (1∶1 were performed more successfully than multifrequency patterns (non 1∶1. In addition, performance was more accurate when participants were required to move faster with the dominant right hand (1∶3, 1∶2 and 2∶3 than with the non-dominant left hand (3∶1, 2∶1, 3∶2. Interestingly, performance deteriorated as the relative angular velocity between the two hands increased, regardless of whether the required frequency ratio was an integer or non-integer. This contrasted with previous finger tapping research where the integer ratios generally led to less error than the non-integer ratios. We suggest that this is due to the different movement topologies that are required of each paradigm. Overall, we found that this visuomotor task was useful for testing the interaction of multiple coordination constraints as well as the release from these constraints with practice in the presence of

  12. Cosmological Constraints from the Large Scale Weak Lensing of SDSS MaxBCG Clusters

    Zu, Ying; Rozo, Eduardo; Sheldon, Erin S; Tinker, Jeremy L; Becker, Matthew R

    2012-01-01

    We derive constraints on the matter density \\Om and the amplitude of matter clustering \\sig8 from measurements of large scale weak lensing (projected separation R=5-30\\hmpc) by clusters in the Sloan Digital Sky Survey MaxBCG catalog. The weak lensing signal is proportional to the product of \\Om and the cluster-mass correlation function \\xicm. With the relation between optical richness and cluster mass constrained by the observed cluster number counts, the predicted lensing signal increases with increasing \\Om or \\sig8, with mild additional dependence on the assumed scatter between richness and mass. The dependence of the signal on scale and richness partly breaks the degeneracies among these parameters. We incorporate external priors on the richness-mass scatter from comparisons to X-ray data and on the shape of the matter power spectrum from galaxy clustering, and we test our adopted model for \\xicm against N-body simulations. Using a Bayesian approach with minimal restrictive priors, we find \\sig8(\\Om/0.325...

  13. Constraints on the hadronic parameters in B nonleptonic decays into light pseudoscalar mesons

    The weak nonleptonic B decays into light pseudoscalar mesons are of much interest for the experimental determination of the CP violating parameters in the standard model. A difficult theoretical problem related to these decays is the description of the final state strong interactions, which generate additional complex phases in the decay amplitudes, besides the CP violating phases of the CKM matrix. For instance, the determination of the angle α of the unitarity triangle from the time dependent asymmetry in the B0 → π+ π- decay requires the knowledge of the ratio and the strong phase difference between the tree and the penguin amplitudes describing the process. This measurement is one of the main options of the ATLAS experiment at LHC. There are at present two quite opposite views about the origin and the magnitude of the strong phases in B nonleptonic decays. Calculations based on heavy quark effective theory and perturbative QCD indicate that these phases are small. On the other hand, arguments exploiting general features of high energy hadronic physics suggest that the strong phases might be appreciable. In an earlier paper we performed an analysis based on a dispersion representation in the external mass variable, combined with Regge model and flavour SU(3) symmetry. The results are consistent with the predictions of perturbative QCD, supporting the idea of hadron-parton duality. We derive in particular constraints on the tree and the penguin amplitudes of the B0 → π+ π- decay, of interest for the B physics program at LHC. (authors)

  14. Multioobjective inverse planning for external beam radiotherapy: decoupling the optimization and decision processes

    Inverse planning in radiation therapy is a trial and error process and many studies have been published which consider different algorithms, constraints, cases and objective functions. These planning algorithms combine in a specific way the objectives that are in conflict but do not provide the information that is necessary to obtain an optimal solution. Only in the last few years have significant increases in the availability of computing power enabled inverse planning to be performed to provide the information necessary to understand the possibilities of all dose distributions that can be obtained. We consider in this paper this multiobjective approach for external beam radiation therapy inverse planning that decouples the optimization and decision making processes. Inverse planning can now consider the number of beams, their orientation and optimal beam fluences and their dependence on importance factors. In this way it is possible to exploit the possibilities of advanced technologies such as intensity modulated radiation therapy (IMRT) or tomotherapy. Using data mining and visualization techniques a solution can be selected that requires, if possible, a small number of beams, and that also provides the required dose delivery to the target. Additionally, it allows reduction of the dose in the healthy tissue, especially in organs at risk, in such a way that the compromise we have to make for all the objectives in comparison to the best individual values is as small as possible. (author)

  15. Additives in yoghurt production

    Milna Tudor

    2008-02-01

    Full Text Available In yoghurt production, mainly because of sensory characteristics, different types of additives are used. Each group, and also each substance from the same group has different characteristics and properties. For that reason, for improvement of yoghurt sensory characteristics apart from addition selection, the quantity of the additive is very important. The same substance added in optimal amount improves yoghurt sensory attributes, but too small or too big addition can reduce yoghurt sensory attributes. In this paper, characteristics and properties of mostly used additives in yoghurt production are described; skimmed milk powder, whey powder, concentrated whey powder, sugars and artificial sweeteners, fruits, stabilizers, casein powder, inulin and vitamins. Also the impact of each additive on sensory and physical properties of yoghurt, syneresis and viscosity, are described, depending on used amount added in yoghurt production.

  16. Additive usage levels.

    Langlais, R

    1996-01-01

    With the adoption of the European Parliament and Council Directives on sweeteners, colours and miscellaneous additives the Commission is now embarking on the project of coordinating the activities of the European Union Member States in the collection of the data that are to make up the report on food additive intake requested by the European Parliament. This presentation looks at the inventory of available sources on additive use levels and concludes that for the time being national legislation is still the best source of information considering that the directives have yet to be transposed into national legislation. Furthermore, this presentation covers the correlation of the food categories as found in the additives directives with those used by national consumption surveys and finds that in a number of instances this correlation still leaves a lot to be desired. The intake of additives via food ingestion and the intake of substances which are chemically identical to additives but which occur naturally in fruits and vegetables is found in a number of cases to be higher than the intake of additives added during the manufacture of foodstuffs. While the difficulties are recognized in contributing to the compilation of food additive intake data, industry as a whole, i.e. the food manufacturing and food additive manufacturing industries, are confident that in a concerted effort, use data on food additives by industry can be made available. Lastly, the paper points out that with the transportation of the additives directives into national legislation and the time by which the food industry will be able to make use of the new food legislative environment several years will still go by; food additives use data by the food industry will thus have to be reviewed at the beginning of the next century. PMID:8792135

  17. Vicarious Michael Addition

    2006-01-01

    C-H bond can undergo vicarious Michael addition reaction (VMA) with doubleactivated double bond in the absence of strong base and catalyst under mild conditions.Intramolecular H-bonding, electron-withdrawing inductive effect, and steric hindrance at aposition of nucleophile facilitates C-H addition over N-H addition. By using VMA, high branching multiplicity, novel branching pattern, controllable density and distribution of functional groups can be envisioned for novel dendrimer synthesis.

  18. Wire + Arc Additive Manufacturing

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  19. Constraints on holographic cosmologies from strong lensing systems

    We use strongly gravitationally lensed (SGL) systems to put additional constraints on a set of holographic dark energy models. Data available in the literature (redshift and velocity dispersion) is used to obtain the Einstein radius and compare it with model predictions. We found that the ΛCDM is the best fit to the data. Although a preliminary statistical analysis seems to indicate that two of the holographic models studied show interesting agreement with observations, a stringent test lead us to the result that neither of the holographic models are competitive with the ΛCDM. These results highlight the importance of Strong Lensing measurements to provide additional observational constraints to alternative cosmological models, which are necessary to shed some light into the dark universe

  20. Constraints On Holographic Cosmological Models From Gamma Ray Bursts

    Rivera, Alexander Bonilla

    2016-01-01

    We use Gamma Ray Bursts (GRBs) data to put additional constraints on a set of holographic dark energy models. GRBs are the most energetic events in the Universe and provide a complementary probe of dark energy by allowing the measurement of cosmic expansion history that extends to redshifts greater than 6 and they are complementary to SNIa test. We found that the LCDM model is the best fit to the data, although a preliminary statistical analysis seems to indicate that the holographic models studied show interesting agreement with observations, except Ricci Scale CPL model. These results show the importance of GRBs measurements to provide additional observational constraints to alternative cosmological models, which are necessary to clarify the way in the paradigm of dark energy or potential alternatives.

  1. Skepticism, Contextualism, Externalism and Modality

    Ron Wilburn

    2006-12-01

    Full Text Available In this paper, I argue for the following claims. Contextualist strategies to tame or localize epistemic skepticism are hopeless if contextualist factors are construed internalistically. However, because efforts to contextualize externalism via subjunctive conditional analysis court circularity, it is only on an internalistic interpretation that contextualist strategies can even be motivated. While these claims do not give us an argument for skepticism, they do give us an argument that contextualism, as such, is not likely to provide us with an argument against skepticism.

  2. Matchings with Externalities and Attitudes

    Branzei, Simina; Michalak, Tomasz; Rahwan, Talal;

    2013-01-01

    Two-sided matchings are an important theoretical tool used to model markets and social interactions. In many real-life problems the utility of an agent is influenced not only by their own choices, but also by the choices that other agents make. Such an influence is called an externality. Whereas ...... where agents take different attitudes when reasoning about the actions of others. In particular, we study optimistic, neutral and pessimistic attitudes and provide both computational hardness results and polynomial-time algorithms for computing stable outcomes....

  3. Heat regenerative external combustion engine

    Duva, Anthony W.

    1993-10-01

    A heat regenerative external combustion engine is disclosed. The engine includes fuel inlet means which extends along the exhaust passage and/or combustion chamber in order to preheat the fuel, To provide for preheating by gases in both the combustion chamber and the exhaust passage, the combustion chamber is arranged annularly around the drive shaft and between the cylinders. This configuration also is advantageous in that it reduces the noise of combustion. The engine of the invention is particularly well-suited for use in a torpedo.

  4. EXTERNALITY EFFECTS OF HONEY PRODUCTION

    Arvane Vanyi, Georgina; Csapo, Zsolt; Karpati, Laszlo

    2012-01-01

    Bee-keeping and honey production has a long history in Hungary. Honey is an important and healthy food of people and it can be consumed without any human processing. The honey production has important role, too. Some researchers say that if honey bee will extinct the humanity in the world would also extinct. It is true since plant pollination by honey bees is very important. It is confirmed by researchers’ studies that plant pollination by honey bees has significant positive external impact...

  5. Fligt Dynamics Facility - External Interfaces

    Gonçalves, João Manuel Ribeiro

    2007-01-01

    Trabalho de projecto de mestrado , Engenharia Informática, Universidade de Lisboa, Faculdade de Ciências, 2007 O sistema Galileo consiste numa constelação de 30 satélites que disponibilizará diversos serviços, entre os quais, serviços de posicionamento e navegação alternativos aos actualmente disponibilizados pelo GPS. Neste projecto será concebido o componente External Interfaces que é parte integrante do elemento Flight Dynamics Facility (FDF), responsável pelo cálculo das órbitas e comp...

  6. Constraint Embedding for Multibody System Dynamics

    Jain, Abhinandan

    2009-01-01

    This paper describes a constraint embedding approach for the handling of local closure constraints in multibody system dynamics. The approach uses spatial operator techniques to eliminate local-loop constraints from the system and effectively convert the system into tree-topology systems. This approach allows the direct derivation of recursive O(N) techniques for solving the system dynamics and avoiding the expensive steps that would otherwise be required for handling the closedchain dynamics. The approach is very effective for systems where the constraints are confined to small-subgraphs within the system topology. The paper provides background on the spatial operator O(N) algorithms, the extensions for handling embedded constraints, and concludes with some examples of such constraints.

  7. Causality Constraints in Conformal Field Theory

    CERN. Geneva

    2015-01-01

    Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d-dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the (∂φ)4 coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinni...

  8. Causality constraints in conformal field theory

    Hartman, Thomas; Jain, Sachin; Kundu, Sandipan

    2016-05-01

    Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the (∂ ϕ)4 coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinning operators.

  9. Causality Constraints in Conformal Field Theory

    Hartman, Thomas; Kundu, Sandipan

    2015-01-01

    Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d-dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the $(\\partial\\phi)^4$ coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinning o...

  10. Integrating Gricean and Attentional Constraints

    Passonneau, R J

    1995-01-01

    This paper concerns how to generate and understand discourse anaphoric noun phrases. I present the results of an analysis of all discourse anaphoric noun phrases (N=1,233) in a corpus of ten narrative monologues, where the choice between a definite pronoun or phrasal NP conforms largely to Gricean constraints on informativeness. I discuss Dale and Reiter's [To appear] recent model and show how it can be augmented for understanding as well as generating the range of data presented here. I argue that integrating centering [Grosz et al., 1983] [Kameyama, 1985] with this model can be applied uniformly to discourse anaphoric pronouns and phrasal NPs. I conclude with a hypothesis for addressing the interaction between local and global discourse processing.

  11. Meditations on Quantified Constraint Satisfaction

    Chen, Hubie

    2012-01-01

    The quantified constraint satisfaction problem (QCSP) is the problem of deciding, given a structure and a first-order prenex sentence whose quantifier-free part is the conjunction of atoms, whether or not the sentence holds on the structure. One obtains a family of problems by defining, for each structure B, the problem QCSP(B) to be the QCSP where the structure is fixed to be B. In this article, we offer a viewpoint on the research program of understanding the complexity of the problems QCSP(B) on finite structures. In particular, we propose and discuss a group of conjectures; throughout, we attempt to place the conjectures in relation to existing results and to emphasize open issues and potential research directions.

  12. Default and Credit Constraint in General equilibrium

    Xavier Ragot; François Le Grand

    2011-01-01

    We study an economy where infinitely living agents face uninsurable shocks and are allowed default on their debt. After having defaulted, agents are excluded from the economy. We present a equilibrium definition allowing for both credit constraints and default inequilibrium. Indeed, existing theories introduce either default of credit constraint in general equilibrium, but never both. We prove that the optimal allocation includes both credit constraints and default, while the market allocatio...

  13. Extended Time Constraints for Generalized Sequential Patterns

    Fiot, Céline

    2006-01-01

    Version étendue de l'article soumis à la revue IJWET Mining temporal knowledge has many applications. Such knowledge can be all the more interesting as some time constraints between events can be pushed into during theminingtask. As well in data mining as in machine learning, some methods have been proposedto extract and manage such knowledge using temporal constraints. In particular some work has been done to mine generalized sequential patterns. However such constraints are often too cri...

  14. Integration of Declarative and Constraint Programming

    Hofstedt, Petra; Pepper, Peter

    2005-01-01

    Combining a set of existing constraint solvers into an integrated system of cooperating solvers is a useful and economic principle to solve hybrid constraint problems. In this paper we show that this approach can also be used to integrate different language paradigms into a unified framework. Furthermore, we study the syntactic, semantic and operational impacts of this idea for the amalgamation of declarative and constraint programming.

  15. Endogenous Liquidity Constraints in a Dynamic Contest

    Martin Grossmann

    2011-01-01

    In this article, I analyze the effects of future liquidity constraints on the investment behavior of two contestants with asymmetric prize valuations in a dynamic contest model. Contestants compete in two consecutive Tullock contests in order to win a contest prize in each period. The loser of the first-period contest can be liquidity constraint in the second period. The model reveals the following four main results: (i) Future liquidity constraints marginally affect today's intensity of comp...

  16. Geographic versus industry diversification: constraints matter

    Paul EHLING; Ramos, Sofia Brito

    2005-01-01

    This research addresses whether geographic diversification provides benefits over industry diversification. In the absence of constraints, no empirical evidence is found to support the argument that country diversification is superior. With short-selling constraints, however, the geographic tangency portfolio is not attainable by industry portfolios. Results with upper and lower constraints on portfolio weights as well as an out-of-sample analysis show that geographic diversification almost c...

  17. On the general constraints in single qubit quantum process tomography

    Bhandari, Ramesh; Peters, Nicholas A.

    2016-01-01

    We briefly review single-qubit quantum process tomography for trace-preserving and nontrace-preserving processes, and derive explicit forms of the general constraints for fitting experimental data. These forms provide additional insight into the structure of the process matrix. We illustrate this with several examples, including a discussion of qubit leakage error models and the intuition which can be gained from their process matrices. PMID:27188691

  18. On the general constraints in single qubit quantum process tomography

    Bhandari, Ramesh; Peters, Nicholas A.

    2016-01-01

    We briefly review single-qubit quantum process tomography for trace-preserving and nontrace-preserving processes, and derive explicit forms of the general constraints for fitting experimental data. These new forms provide additional insight into the structure of the process matrix. We illustrate their utility with several examples, including a discussion of qubit leakage error models and the intuition which can be gained from their process matrices.

  19. Photoactive devices including porphyrinoids with coordinating additives

    Forrest, Stephen R; Zimmerman, Jeramy; Yu, Eric K; Thompson, Mark E; Trinh, Cong; Whited, Matthew; Diev, Vlacheslav

    2015-05-12

    Coordinating additives are included in porphyrinoid-based materials to promote intermolecular organization and improve one or more photoelectric characteristics of the materials. The coordinating additives are selected from fullerene compounds and organic compounds having free electron pairs. Combinations of different coordinating additives can be used to tailor the characteristic properties of such porphyrinoid-based materials, including porphyrin oligomers. Bidentate ligands are one type of coordinating additive that can form coordination bonds with a central metal ion of two different porphyrinoid compounds to promote porphyrinoid alignment and/or pi-stacking. The coordinating additives can shift the absorption spectrum of a photoactive material toward higher wavelengths, increase the external quantum efficiency of the material, or both.

  20. Answer Set Programming with External Sources

    Redl, Christoph

    2012-01-01

    Answer Set Programming (ASP) is a well-known problem solving approach based on nonmonotonic logic programs and efficient solvers. To enable access to external information, HEX-programs extend programs with external atoms, which allow for a bidirectional communication between the logic program and external sources of computation (e.g., description logic reasoners and Web resources). Current solvers evaluate HEX-programs by a translation to ASP itself, in which values of external atoms are g...

  1. Externalities in Wage Formation and Structural Unemployment

    De La Croix, David

    1993-01-01

    A sectorial general equilibrium model in which externalities among sectors arise through wage envy is presented. Without externalities, equilibrium unemployment is only a function of the product market power of the firm and of demand uncertainty. With externalities, unemployment is higher. It is increasing with union power even though bargaining is efficient. Aggregate demand shock do not modify the magnitude of unemployment. However, when externalities are present, sectorial demand shocks mo...

  2. Toward an automaton Constraint for Local Search

    Jun He

    2009-10-01

    Full Text Available We explore the idea of using finite automata to implement new constraints for local search (this is already a successful technique in constraint-based global search. We show how it is possible to maintain incrementally the violations of a constraint and its decision variables from an automaton that describes a ground checker for that constraint. We establish the practicality of our approach idea on real-life personnel rostering problems, and show that it is competitive with the approach of [Pralong, 2007].

  3. Nonsingular cylindrical cloaks with internal–external invisible regions

    Two-dimensional nonsingular cloaks with internal and external invisible regions are presented. Objects can be hidden either in the internal cavity or the external concealment regions without being detected. Also in the latter case, the cloaked objects can receive incoming signals. In order to avoid the singularity (an infinitely large value of the constitutive parameters) which may appear at the inner boundary, the method of adjusting the principal stretches out of the cloaking plane is adopted. Detailed examples and their electromagnetic simulations are presented to validate the design. In addition, the effect of the material loss on the invisible property of the cloaks is also discussed

  4. 49 CFR 195.108 - External pressure.

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External pressure. 195.108 Section 195.108... PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on the pipe must be provided for in designing a pipeline system....

  5. Comments on the nilpotent constraint of the goldstino superfield

    Ghilencea, D. M.

    2016-04-01

    Superfield constraints were often used in the past, in particular, to describe the Akulov-Volkov action of the goldstino by a superfield formulation with L = (Φ†Φ) D + [(fΦ)F + h.c.] endowed with the nilpotent constraint Φ2 = 0 for the goldstino superfield (Φ). Inspired by this, such constraint is often used to define the goldstino superfield even in the presence of additional superfields, for example, in models of “nilpotent inflation”. In this review, we show that the nilpotent property is not valid, in general, under the assumption of a microscopic (ultraviolet (UV)) description of the theory with linear supermultiplets. Sometimes only weaker versions of the nilpotent relation are true such as Φ3 = 0 or Φ4 = 0 (Φ2≠0) in the infrared (far below the UV scale) under the further requirement of decoupling all additional scalars (coupling to sgoldstino), something not always possible (e.g. if light scalars exist). In such cases, the weaker nilpotent property is not specific to the goldstino superfield anymore. We review the restrictions for the Kahler curvature tensor and superpotential W under which Φ2 = 0 remains true in infrared, assuming linear supermultiplets in the microscopic description. One can reverse the arguments to demand that the nilpotent condition, initially an infrared property, be extended even in the presence of additional superfields, but this may question the nature of supersymmetry breaking or the existence of a perturbative UV description with linear supermultiplets.

  6. Technology for planning and scheduling under complex constraints

    Alguire, Karen M.; Pedro Gomes, Carla O.

    1997-02-01

    Within the context of law enforcement, several problems fall into the category of planning and scheduling under constraints. Examples include resource and personnel scheduling, and court scheduling. In the case of court scheduling, a schedule must be generated considering available resources, e.g., court rooms and personnel. Additionally, there are constraints on individual court cases, e.g., temporal and spatial, and between different cases, e.g., precedence. Finally, there are overall objectives that the schedule should satisfy such as timely processing of cases and optimal use of court facilities. Manually generating a schedule that satisfies all of the constraints is a very time consuming task. As the number of court cases and constraints increases, this becomes increasingly harder to handle without the assistance of automatic scheduling techniques. This paper describes artificial intelligence (AI) technology that has been used to develop several high performance scheduling applications including a military transportation scheduler, a military in-theater airlift scheduler, and a nuclear power plant outage scheduler. We discuss possible law enforcement applications where we feel the same technology could provide long-term benefits to law enforcement agencies and their operations personnel.

  7. On Factorization Constraints for Branes in the H3+ Model

    Adorf, Hendrik

    2008-01-01

    We comment on the brane solutions for the boundary H3+ model that have been proposed so far and point out that they should be distinguished according to the patterns regular/irregular and discrete/continuous. In the literature, mostly irregular branes have been studied, while results on the regular ones are rare. For all types of branes, there are questions about how a second factorization constraint in the form of a b^{-2}/2-shift equation can be derived. Here, we assume analyticity of the boundary two point function, which means that the Cardy-Lewellen constraints remain unweakened. This enables us to derive unambiguously the desired b^{-2}/2-shift equations. They serve as important additional consistency conditions. For some regular branes, we also derive 1/2-shift equations that were not known previously. Case by case, we discuss possible solutions to the enlarged system of constraints. We find that the well-known irregular continuous AdS_2 branes are consistent with our new factorization constraint. Furt...

  8. Coordinated Switching Control of the Excitation and Steam Valve System Based on State and Input Constraints

    Nan Jiang; Ting Liu; Haiyan He; Xin Li

    2015-01-01

    A single unit infinite system of the excitation and steam valve control was proposed based on Barrier Lyapunov theory of restrictive log type. The input amplitude constraint of the steam valve control was considered, and the coordinated nonlinear backstepping controller was designed by switching mechanism. At the same time, the generator rotor effect was considered to be an external unknown large disturbance on the output system, and the conservativeness of the simple estimates for the upper ...

  9. “Financial constraints to enterprise investments: an international analysis on financial accounts of OECD countries”

    Cinquegrana, Giuseppe; De Rita, Paola

    2012-01-01

    Since the ’80s, economic literature has stressed the importance of external financing on enterprises’ investment decisions; in particular the pecking order theory highlighted the existence of a hierarchy of financing sources, an approach that originates from the existence of asymmetric information between fund borrowers and lenders. The presence of effective financial constraints to the realisation of investments of productive units was reasserted in the work by Fazzari, Hubbard a...

  10. Additive and polynomial representations

    Krantz, David H; Suppes, Patrick

    1971-01-01

    Additive and Polynomial Representations deals with major representation theorems in which the qualitative structure is reflected as some polynomial function of one or more numerical functions defined on the basic entities. Examples are additive expressions of a single measure (such as the probability of disjoint events being the sum of their probabilities), and additive expressions of two measures (such as the logarithm of momentum being the sum of log mass and log velocity terms). The book describes the three basic procedures of fundamental measurement as the mathematical pivot, as the utiliz

  11. External Financing Costs and Banks Loan Supply: Does the Structure of the Bank Sector Matter?

    Charlotte Ostergaard

    2000-01-01

    This paper investigates whether banks loan supply depend on internally generated capital in a fashion that varies according to the size-structure of the bank sector. Banks may experience liquidity constraints if it is costly to raise uninsured funds and recent evidence suggests that external financing costs may be particularly high for small banks. Considering that retail loan markets are predominately local in nature, this paper ask whether the potential significance of individual-bank const...

  12. External noise when using biofuel

    The aim of this study has been to cover sources of noise dealing with all steps in a biofuel chain; producing, transporting, storing and firing the biofuel. When the availability of relevant test results from noise surveys is not so good and mostly badly documented, the study has been concentrated on estimation of external noise for planning and design purposes, from a prospective biofuel-fired plant. A synoptic tabulation of estimated acoustic power levels from different noise sources, has been done. The results from measurements of external noise from different existing combined power and heating plants are tabulated. The Nordic model for simulation of external noise has been used for a prospective plant - VEGA - designed by Vattenfall. The aim has been to estimate its noise pollutions at critical points at the nearest residential area (250 m from the fenced industry area). The software - ILYD - is easy to handle, but knowledge about the model is necessary. A requisite for the reliability is the access to measurements or estimations of different sources of noise, at different levels of octaves from 63 to 8000 Hz. The degree of accuracy increases with the number of broad band sources, that are integrated. Using ILYD with available data, a night limit of 40 dB(A) should be possible to fulfill with good degree of accuracy at VEGA, between 10 pm and 7 am, with good planning and under normal operation conditions. A demand for 35 dB(A) as a limit can be harder to fulfill, especially at mornings from 6 to 7. Noise from heavy vehicles within the plant area is classified as industrial noise and not as road traffic noise. This type of noise depends very much on the way of driving and assumed acceleration. Concerning wheel-mounted loaders, they may then only be used during daytime. The simulations show, that even at daytime from 7 to 6 pm, it would be possible to use an acoustically damped chipping machine, inside the power industry area. 31 refs, 13 figs, tabs, 8

  13. Food Additives and Hyperkinesis

    Wender, Ester H.

    1977-01-01

    The hypothesis that food additives are causally associated with hyperkinesis and learning disabilities in children is reviewed, and available data are summarized. Available from: American Medical Association 535 North Dearborn Street Chicago, Illinois 60610. (JG)

  14. Groups – Additive Notation

    Coghetto Roland

    2015-06-01

    Full Text Available We translate the articles covering group theory already available in the Mizar Mathematical Library from multiplicative into additive notation. We adapt the works of Wojciech A. Trybulec [41, 42, 43] and Artur Korniłowicz [25].

  15. Sparse Additive Models

    Ravikumar, Pradeep; Lafferty, John; Liu, Han; Wasserman, Larry

    2007-01-01

    We present a new class of methods for high-dimensional nonparametric regression and classification called sparse additive models (SpAM). Our methods combine ideas from sparse linear modeling and additive nonparametric regression. We derive an algorithm for fitting the models that is practical and effective even when the number of covariates is larger than the sample size. SpAM is closely related to the COSSO model of Lin and Zhang (2006), but decouples smoothing and sparsity, enabling the use...

  16. Additively Manufactured Propulsion System

    Dushku, Matthew; Mueller, Paul

    2012-01-01

    New high-performance, carbon-fiber reinforced polymer material allows additive manufacturing to produce pressure vessels capable of high pressures (thousands of pounds per square inch). This advancement in turn allows integral hybrid propulsion which is revolutionary for both CubeSats and additively-manufactured spacecraft. Hybrid propulsion offers simplicity as compared to bipropellant liquid propulsion, significantly better safety compared to solid or monopropellant hydrazine propulsion, an...

  17. External radiotherapy in thyroid cancer

    In the management of thyroid carcinoma (TC) of any histological type, surgery is the primary mode of treatment. The second modality for the management is treatment with radioactive iodine (131I), especially, when the tumor has the ability to concentrate 131I. External radiotherapy has a limited use in differentiated thyroid carcinoma (DTC). It is useful in the management of bulky residual tissue which is not completely resected, metastatic disease which does not concentrated radioiodine and as a palliative treatment for reliving pain in patients with distant metastases. The ER as an adjuvant treatment in both anaplastic and medullary carcinoma has a significant role to play and should be used more frequently than is presently being advocated and practiced

  18. External cavity quantum cascade laser

    In this paper we review the progress of the development of mid-infrared quantum cascade lasers (QCLs) operated in an external cavity configuration. We concentrate on QCLs based on the bound-to-continuum design, since this design is especially suitable for broadband applications. Since they were first demonstrated, these laser-based tunable sources have improved in performance in terms of output power, duty cycle, operation temperature and tuneability. Nowadays they are an interesting alternative to FTIRs for some applications. They operate at room temperature, feature a high spectral resolution while being small in size. They were successfully used in different absorption spectroscopy techniques. Due to their vast potential for applications in industry, medicine, security and research, these sources enjoy increasing interest within the research community as well as in industry. (topical review)

  19. An external drag measuring element

    Ringel, Mordechai; Levin, Daniel; Seginer, Arnan

    The accurate measurement of the axial-force component acting on small wind-tunnel models has traditionally made use of integral string balances, which eliminated many accuracy problems, such as friction and hysteresis, but also introduced interactions between the various force and moment sensing elements due to nonlinear elastic phenomena. The reduction of these interactions usually calls for complicated designs, expensive manufacturing, hard-to-handle calibration processes, and cumbersome data reduction programs. An approach is presented that is based on an external axial-force-measuring element and avoids the ill-conditioned design problems of integral balances. Other difficulties that are encountered, such as friction, misalignment, and relative motion between metric elements are considered, and their solution is examined. Calibration and test results show that the new approach duplicates and surpasses the results of much more complicated and expensive integral balances.

  20. External symmetry in general relativity

    We propose a generalization of the isometry transformations to the geometric context of the spin field theories where the local frames are explicitly involved. We define the external symmetry transformations as isometries combined with suitable tetrad gauge transformations and we show that these form a group which is locally isomorphic with the isometry one. We point out that the symmetry transformations leave invariant the field equations and have generators with specific spin terms that represent new physical observables. The examples we give are the generators of the central symmetry and those of the maximal symmetries of the de Sitter and anti-de Sitter spacetimes for which we derive the spin terms in different tetrad gauge fixings. (author)

  1. Handbook - Component modelling in analysis of external events

    The project deals with the modelling of components in connection with an external event, especially the modelling of area dependencies. A number of type components have been defined and analysed with respect to their sensitivity to external events. The focus has been on the interaction of the component with power supply and control. A systematic method is presented for adapting the type components to specific components, and the information needed for the adaptation is specified. The analysis has resulted in a fairly complete mapping of the required level of detail in the modelling of area dependencies of components. However, strongly conservative assumptions regarding the way safety components are affected by an external event are used in present PSA:s. Therefore, there is a risk that the detailed component model will result in unreasonably conservative risk assessments, making the basis for the ranking and selection of safety enhancing measures unreliable. Therefore, in addition to the detailed mapping of area dependencies, a realistic scenario analysis must be performed, describing how typical external events are handled by the plant, manually and via automatic functions. Only after this has been done, a true picture can be obtained of the sensitivity of components to external events. The analysis indicates that there are major differences in this sensitivity, depending on the mode of operation of the components. In general, a component that is activated (open/close or start/stop) is considerably more sensitive to an external event than a component that is to remain in its operating state (remain in operation). This fact can be used to simplify the analysis in some cases. Thus, if safety functions are activated early -before the interaction of it''s active component with the plant has become affected by the external event, then the operating mode 'No change' or 'Operation' is applicable, with the result that the logic model is simplified and the risk

  2. External costs of electricity generation

    The paper presents advantages connected with the use of electric energy and the hazards due to generation from various energy sources. In the analysis of fossil fuel power plants the latest plants are considered, provided with all emission abatement systems required by the regulations in force in USA and in the European Union. The perspectives of reduction of emissions over the next twenty years are taken into account and the actual emissions from various power plants during the last decade are reviewed. Based on the latest studies conducted by the international teams, e.g. within European Union program ExternE, the methods and data are presented for calculation of health damages due to fossil fuel burning and comparing with the effects of nuclear power plant operation. In all cases the whole chain of activities, from cradle to the grave, has been taken into account. Examples of the comparative analyses performed in EU countries are presented together with the results of analyses done in other countries known from objective approach to various options of power industry as Switzerland. Then the methodology proposed for Polish conditions is described. The analyses of emissions in normal operation compared with the values admissible according to health protection regulations shows that the emissions from modern coal fired power plants involve pollution to the admissible limits of about 100000 times more atmospheric air than the emissions from nuclear power plants. The health damages are similarly much greater for coal fired plants than for nuclear power. After a complex analysis of hazards due to all phases of power generation cycle it is found that nuclear power belongs to those energy sources that make it possible to generate electricity in a way involving the smallest damages to human health. (author)

  3. Virasoro constraint for Nekrasov instanton partition function

    Kanno, Shoichi; Zhang, Hong

    2012-01-01

    We show that Nekrasov instanton partition function for SU(N) gauge theories satisfies recursion relations in the form of U(1)+Virasoro constraints when {\\beta} = 1. The constraints give a direct support for AGT conjecture for general quiver gauge theories.

  4. Optimal Portfolio Choice with Wash Sale Constraints

    Astrup Jensen, Bjarne; Marekwica, Marcel

    2011-01-01

    We analytically solve the portfolio choice problem in the presence of wash sale constraints in a two-period model with one risky asset. Our results show that wash sale constraints can heavily affect portfolio choice of investors with unrealized losses. The trading behavior of such investors is to a...

  5. Review of Minimal Flavor Constraints for Technicolor

    S. Fukano, Hidenori; Sannino, Francesco

    2010-01-01

    We analyze the constraints on the the vacuum polarization of the standard model gauge bosons from a minimal set of flavor observables valid for a general class of models of dynamical electroweak symmetry breaking. We will show that the constraints have a strong impact on the self-coupling and...

  6. A Temporal Concurrent Constraint Programming Calculus

    Palamidessi, Catuscia; Valencia Posso, Frank Darwin

    2001-01-01

    The tcc model is a formalism for reactive concurrent constraint programming. In this paper we propose a model of temporal concurrent constraint programming which adds to tcc the capability of modeling asynchronous and non-deterministic timed behavior. We call this tcc extension the ntcc calculus...

  7. Supernova constraints on neutrino mass and mixing

    Srubabati Goswami

    2000-01-01

    In this article I review the constraints on neutrino mass and mixing coming from type-II supernovae. The bounds obtained on these parameters from shock reheating, -process nucleosynthesis and from SN1987A are discussed. Given the current constraints on neutrino mass and mixing the effect of oscillations of neutrinos from a nearby supernova explosion in future detectors will also be discussed.

  8. Constraint Satisfaction with Counting Quantifiers

    Madelaine, Florent; Stacho, Juraj

    2011-01-01

    We initiate the study of constraint satisfaction problems (CSPs) in the presence of counting quantifiers, which may be seen as variants of CSPs in the mould of quantified CSPs (QCSPs). We show that a single counting quantifier strictly between exists^1:=exists and exists^n:=forall (the domain being of size n) already affords the maximal possible complexity of QCSPs (which have both exists and forall), being Pspace-complete for a suitably chosen template. Next, we focus on the complexity of subsets of counting quantifiers on clique and cycle templates. For cycles we give a full trichotomy -- all such problems are in L, NP-complete or Pspace-complete. For cliques we come close to a similar trichotomy, but one case remains outstanding. Afterwards, we consider the generalisation of CSPs in which we augment the extant quantifier exists^1:=exists with the quantifier exists^j (j not 1). Such a CSP is already NP-hard on non-bipartite graph templates. We explore the situation of this generalised CSP on bipartite templ...

  9. Volcanological constraints of Archaean tectonics

    Thurston, P. C.; Ayres, L. D.

    1986-01-01

    Volcanological and trace element geochemical data can be integrated to place some constraints upon the size, character and evolutionary history of Archean volcanic plumbing, and hence indirectly, Archean tectonics. The earliest volcanism in any greenhouse belt is almost universally tholeitic basalt. Archean mafic magma chambers were usually the site of low pressure fractionation of olivine, plagioclase and later Cpx + or - an oxide phase during evolution of tholeitic liquids. Several models suggest basalt becoming more contaminated by sial with time. Data in the Uchi Subprovince shows early felsic volcanics to have fractionated REE patterns followed by flat REE pattern rhyolites. This is interpreted as initial felsic liquids produced by melting of a garnetiferous mafic source followed by large scale melting of LIL-rich sial. Rare andesites in the Uchi Subprovince are produced by basalt fractionation, direct mantle melts and mixing of basaltic and tonalitic liquids. Composite dikes in the Abitibi Subprovince have a basaltic edge with a chill margin, a rhyolitic interior with no basalt-rhyolite chill margin and partially melted sialic inclusions. Ignimbrites in the Uchi and Abitibi Subprovinces have mafic pumice toward the top. Integration of these data suggest initial mantle-derived basaltic liquids pond in a sialic crust, fractionate and melt sial. The inirial melts low in heavy REE are melts of mafic material, subsequently melting of adjacent sial produces a chamber with a felsic upper part underlain by mafic magma.

  10. Controlled synchronization under information constraints

    Fradkov, Alexander L.; Andrievsky, Boris; Evans, Robin J.

    2008-09-01

    A class of controlled synchronization systems under information constraints imposed by limited information capacity of the coupling channel is analyzed. It is shown that the framework proposed by Fradkov , [Phys. Rev. E 73, 066209 (2006)] is suitable not only for observer-based synchronization but also for controlled master-slave synchronization via a communication channel with limited information capacity. A simple first-order coder-decoder scheme is proposed and a theoretical analysis for multidimensional master-slave systems represented in the Lurie form (linear part plus nonlinearity depending only on measurable outputs) is provided. An output feedback control law is proposed based on the passification method. It is shown that for systems with passifiable linear part (satisfying the hyperminimum phase condition) the upper bound of the limiting synchronization error is proportional to the upper bound of the transmission error. As a consequence, both upper and lower bounds of the limiting synchronization error are proportional to the maximum rate of the coupling signal and inversely proportional to the information transmission rate (channel capacity). The results are applied to controlled synchronization of two chaotic Chua systems coupled via a controller and a channel with limited capacity. It is shown by computer simulation that, unlike for the case of observer-based synchronization, the hyperminimum phase property cannot be violated for controlled synchronization.

  11. External noise control in inherently stochastic biological systems.

    Zheng, Likun; Chen, Meng; Nie, Qing

    2012-11-01

    Biological systems are often subject to external noise from signal stimuli and environmental perturbations, as well as noises in the intracellular signal transduction pathway. Can different stochastic fluctuations interact to give rise to new emerging behaviors? How can a system reduce noise effects while still being capable of detecting changes in the input signal? Here, we study analytically and computationally the role of nonlinear feedback systems in controlling external noise with the presence of large internal noise. In addition to noise attenuation, we analyze derivatives of Fano factor to study systems' capability of differentiating signal inputs. We find effects of internal noise and external noise may be separated in one slow positive feedback loop system; in particular, the slow loop can decrease external noise and increase robustness of signaling with respect to fluctuations in rate constants, while maintaining the signal output specific to the input. For two feedback loops, we demonstrate that the influence of external noise mainly depends on how the fast loop responds to fluctuations in the input and the slow loop plays a limited role in determining the signal precision. Furthermore, in a dual loop system of one positive feedback and one negative feedback, a slower positive feedback always leads to better noise attenuation; in contrast, a slower negative feedback may not be more beneficial. Our results reveal interesting stochastic effects for systems containing both extrinsic and intrinsic noises, suggesting novel noise filtering strategies in inherently stochastic systems. PMID:23213267

  12. Constraints on Sterile Neutrino Dark Matter

    Abazajian, Kevork N; Abazajian, Kevork; Koushiappas, Savvas M.

    2006-01-01

    We present a comprehensive analysis of constraints on the sterile neutrino as a dark matter candidate. The minimal production scenario with a standard thermal history and negligible cosmological lepton number is in conflict with conservative radiative decay constraints from the cosmic X-ray background in combination with stringent small-scale structure limits from the Lyman-alpha forest. We show that entropy release through massive particle decay after production does not alleviate these constraints. We further show that radiative decay constraints from local group dwarf galaxies are subject to large uncertainties in the dark matter density profile of these systems. Within the strongest set of constraints, resonant production of cold sterile neutrino dark matter in non-zero lepton number cosmologies remains allowed.

  13. Externalities of fuel cycles 'ExternE' project. Economic valuation. Economical valuation: An impact pathway approach

    The EC/US study of the external costs of fuel cycles is designed to trace through all the environmental impacts arising from the use of a particular fuel, from the 'cradle' to the 'grave'; to quantify these impacts as far as possible (giving priority to those that are the considered the most important) and to value the damages arising from them in money terms as far as possible (again keeping to the priority listing established by the physical quantification). The fuel cycle has been identified as consisting of the following elements: activities -> emissions/burdens; emissions/burdens -> physical environmental impacts; physical impacts -> external environmental impacts; external impacts -> costs of these impacts. The activities consist of all the operations that are carried out in connection with the extraction transportation, use in electricity generation and finally disposal of the fuel. The emissions or burdens arising from the cycle result in physical impacts, which in turn imply certain environmental impacts. An illustration of a typical fuel cycle (coal) audits environmental impacts is given in Figures. The work of the fuels cycle study teams is to complete the valuation of the shaded areas but giving priority to those impacts that are likely to be quantitatively important. .Each fuel cycle is evaluated in a location-specific context, so that it refers to the impacts arising from the use of coal, or gas or whatever fuel is being considered at an actual plant that is operating. The purpose of this report on economic valuation is to: (a) examine the literature or economic valuation of environmental externalities in Europe; (b) assess its relevance to the fuel cycle study and (c) make recommendations on how the detailed analysis of the individual fuel cycles should use the economic valuation. It is important to recognize that the report is not a complete survey of all the research ever done on environmental valuation. Although as complete a survey of all the

  14. Model and algorithms of the fuzzy three-dimensional axial assignement problem with an additional constraint

    Chi-Jen Lin

    2015-11-01

    Full Text Available This study constructs a practical fuzzy three-dimensional axial assignment model, and proposes two efficient algorithms to solve the model. In our case, the model is applied to team performance management in a company to promote the performance of all members in a team. Two algorithms, namely the index-based branch and bound (B&B algorithm and the f-g trade-off algorithm, which is a hybrid of the trade-off and B&B concepts, are proposed. A numerical example is presented to illustrate these two algorithms. The computational results show that the proposed algorithms are sufficiently efficient and accurate. Two special cases are also discussed.

  15. Identifying constraints in the evolution of primate societies.

    Thierry, Bernard

    2013-05-19

    The evolutionary study of social systems in non-human primates has long been focused on ecological determinants. The predictive value of socio-ecological models remains quite low, however, in particular because such equilibrium models cannot integrate the course of history. The use of phylogenetic methods indicates that many patterns of primate societies have been conserved throughout evolutionary history. For example, the study of social relations in macaques revealed that their social systems are made of sets of correlated behavioural traits. Some macaque species are portrayed by marked social intolerance, a steep dominance gradient and strong nepotism, whereas others display a higher level of social tolerance, relaxed dominance and a weaker influence of kinship. Linkages between behavioural traits occur at different levels of organization, and act as constraints that limit evolutionary responses to external pressures. Whereas these constraints can exert strong stabilizing selection that opposes the potential changes required by the ecological environment, selective mechanisms may have the potential to switch the whole social system from one state to another by acting primarily on some key behavioural traits that could work as pacemakers. PMID:23569290

  16. Flavor Constraints on Split Fermion Models

    Lillie, Benjamin Huntington; Lillie, Ben; Hewett, JoAnne

    2003-01-01

    We examine the contributions to rare processes that arise in models where the Standard Model fermions are localized at distinct points in compact extra dimensions. Tree-level flavor changing neutral current interactions for the Kaluza-Klein (KK) gauge field excitations are induced in such models, and hence strong constraints are thought to exist on the size of the additional dimensions. We find a general parameterization of the model which does not depend on any specific fermion geography and show that typical values of the parameters can reproduce the fermion hierarchy pattern. Using this parameterization, we reexamine the contributions to neutral meson mixing, rare meson decays, and single top-quark production in $e^+e^-$ collisions. We find that is it possible to evade the stringent bounds for natural regions of the parameters, while retaining finite separations between the fermion fields and without introducing a new hierarchy. The resulting limits on the size of the compact dimension can be as low as TeV...

  17. Magneto-reheating constraints from curvature perturbations

    As additional perturbative degrees of freedom, it is known that magnetic fields of inflationary origin can source curvature perturbations on super-Hubble scales. By requiring the magnetic generated curvature to remain smaller than its inflationary adiabatic counterpart during inflation and reheating, we derive new constraints on the maximal field value today, the reheating energy scale and its equation of state parameter. These bounds end up being stronger by a few order of magnitude than those associated with a possible backreaction of the magnetic field onto the background. Our results are readily applicable to any slow-roll single field inflationary models and any magnetic field having its energy density scaling as aγ during inflation. As an illustrative example, massive inflation is found to remain compatible with a magnetic field today B0 = 5 × 10−15 G for some values of γ only if a matter dominated reheating takes place at energies larger than 105 GeV. Conversely, assuming γ = −1, massive inflation followed by a matter dominated reheating cannot explain large scale magnetic fields larger than 10−20 G today

  18. Magneto-reheating constraints from curvature perturbations

    Ringeval, Christophe [Centre for Cosmology, Particle Physics and Phenomenology, Institute of Mathematics and Physics, Louvain University, 2 Chemin du Cyclotron, 1348 Louvain-la-Neuve (Belgium); Suyama, Teruaki; Yokoyama, Jun' ichi, E-mail: christophe.ringeval@uclouvain.be, E-mail: suyama@resceu.s.u-tokyo.ac.jp, E-mail: yokoyama@resceu.s.u-tokyo.ac.jp [Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan)

    2013-09-01

    As additional perturbative degrees of freedom, it is known that magnetic fields of inflationary origin can source curvature perturbations on super-Hubble scales. By requiring the magnetic generated curvature to remain smaller than its inflationary adiabatic counterpart during inflation and reheating, we derive new constraints on the maximal field value today, the reheating energy scale and its equation of state parameter. These bounds end up being stronger by a few order of magnitude than those associated with a possible backreaction of the magnetic field onto the background. Our results are readily applicable to any slow-roll single field inflationary models and any magnetic field having its energy density scaling as a{sup γ} during inflation. As an illustrative example, massive inflation is found to remain compatible with a magnetic field today B{sub 0} = 5 × 10{sup −15} G for some values of γ only if a matter dominated reheating takes place at energies larger than 10{sup 5} GeV. Conversely, assuming γ = −1, massive inflation followed by a matter dominated reheating cannot explain large scale magnetic fields larger than 10{sup −20} G today.

  19. Flavor Constraints on Split Fermion Models

    We examine the contributions to rare processes that arise in models where the Standard Model fermions are localized at distinct points in compact extra dimensions. Tree-level flavor changing neutral current interactions for the Kaluza-Klein (KK) gauge field excitations are induced in such models, and hence strong constraints are thought to exist on the size of the additional dimensions. We find a general parameterization of the model which does not depend on any specific fermion geography and show that typical values of the parameters can reproduce the fermion hierarchy pattern. Using this parameterization, we reexamine the contributions to neutral meson mixing, rare meson decays, and single top-quark production in e+e- collisions. We find that is it possible to evade the stringent bounds for natural regions of the parameters, while retaining finite separations between the fermion fields and without introducing a new hierarchy. The resulting limits on the size of the compact dimension can be as low as TeV-1

  20. Flavor constraints on split fermion models

    We examine the contributions to rare processes that arise in models where the standard model fermions are localized at distinct points in compact extra dimensions. Tree-level flavor changing neutral current interactions for the Kaluza-Klein gauge field excitations are induced in such models, and hence strong constraints are thought to exist on the size of the additional dimensions. We find a general parametrization of the model which does not depend on any specific fermion geography and show that typical values of the parameters can reproduce the fermion hierarchy pattern. Using this parametrization, we reexamine the contributions to neutral meson mixing, rare meson decays, and single top-quark production in e+e- collisions. We find that it is possible to evade the stringent bounds for natural regions of the parameters, while retaining finite separations between the fermion fields and without introducing a new hierarchy. The resulting limits on the size of the compact dimension can be as low as TeV-1

  1. Behavioral constraints and the evolution of faithful social learning

    Alberto ACERBI; Pierre O. JACQUET; Claudio TENNIE

    2012-01-01

    Behavioral "traditions",i.e.behavioral patterns that are acquired with the aid of social learning and that are relatively stable in a group,have been observed in several species.Recently,however,it has been questioned whether non-human social learning is faithful enough to stabilize those patterns.The observed stability could be interpreted as a result of various constraints that limit the number of possible alternative behaviors,rather than of the fidelity of transmission mechanisms.Those constraints can be roughly described as "internal",such as mechanical (bodily) properties or cognitive limitations and predispositions,and "external",such as ecological availability or pressures.Here we present an evolutionary individual-based model that explores the relationships between the evolution of faithful social learning and behavioral constraints,represented both by the size of the behavioral repertoire and by the "shape" of the search space of a given task.We show that the evolution of high-fidelity transmission mechanisms,when associated with costs (e.g.cognitive,biomechanical,energetic,etc.),is only likely if the potential behavioral repertoire of a species is large and if the search space does not provide information that can be exploited by individual learning.Moreover we show how stable behavioral patterns ("traditions") can be achieved at the population level as an outcome of both high-fidelity and low-fidelity transmission mechanisms,given that the latter are coupled with a small behavioral repertoire or with a search space that provide substantial feedback.Finally,by introducing the possibility of environmental change,we show that intermediate rates of change favor the evolution of faithful social learning [Current Zoology 58 (2):307-318,2012].

  2. External Carbon Source Addition as a Means to Control an Activated Sludge Nutrient Removal Process

    Isaacs, Steven Howard; Henze, Mogens; Søeberg, Henrik; Kymmel, Mogens

    1994-01-01

    In alternating type activated sludge nutrient removal processes, the denitrification rate can be limited by the availability of readily-degradable carbon substrate. A control strategy is proposed by which an easily metabolizable COD source is added directly to that point in the process at which...... denitrification momentarily occurs. This approach serves to increase the denitrification rate on demand, thereby allowing the accumulation of nitrate and nitrite during periods of peak nitrogen loading to be reduced or avoided. A pilot plant demonstration of the control strategy using acetate as COD source is...

  3. Some additional Notes on external Features and on the jaw muscles of Orthragoriscus mola (L.)

    Roon, van J.M.

    1942-01-01

    In 1939 J. M. van Roon and J. J. ter Pelkwijk published some data on two specimens of Orthragoriscus mola (L.) stranded on the Dutch coast. Measurements of bones and muscles of the jaw were given on account of the functional treatise concerning the mechanism of the jaw of Orthragoriscus given by Van

  4. Topology optimization of structures with stress constraints: Aeronautical applications

    Topology optimization of structures is nowadays the most active and widely studied branch in structural optimization. This paper develops a minimum weight formulation for the topology optimization of continuum structures. This approach also includes stress constraints and addresses important topics like the efficient treatment of a large number of stress constraints, the approach of discrete solutions by using continuum design variables and the computational cost. The proposed formulation means an alternative to maximum stiffness formulations and offers additional advantages. The minimum weight formulation proposed is based on the minimization of the weight of the structure. In addition, stress constraints are included in order to guarantee the feasibility of the final solution obtained. The objective function proposed has been designed to force the convergence to a discrete solution in the final stages of the optimization process. Thus, near discrete solutions are obtained by using continuum design variables. The robustness and reliability of the proposed formulation are verified by solving application examples related to aeronautical industry.

  5. Cosmological constraints in the presence of ionizing and resonance radiation at recombination

    With the recent measurement of full sky cosmic microwave background (CMB) polarization from WMAP, key cosmological degeneracies have been broken, allowing tighter constraints to be placed on cosmological parameters inferred assuming a standard recombination scenario. Here we consider the effect on cosmological constraints if additional ionizing and resonance radiation sources are present at recombination. We find that the new CMB data significantly improve the constraints on the additional radiation sources, with log10[εα]10[εi]s are weakened to ns=0.98±0.03, with the ns=1 case now well inside the 95% c.l. The relaxation of constraints on tensor modes, scale invariance, dark energy and neutrino masses are also discussed

  6. Additives for the Axe

    2011-01-01

    On May 1,China will begin to ban the production and use of two food additives commonly used to "bleach" flour,benzoyl peroxide and calcium peroxide.The decision was made after 10 years of wrangling between the policy makers,manufacturers,scientists and consumers.The Ministry of Health said in a statement it was applying the ban in response to consumers’ concerns about chemical substances in food,and technical improvements that had made the two additives unnecessary in flour processing.Minister of Health Chen Zhu has also said

  7. From additivity to synergism

    Ritz, Christian; Streibig, Jens Carl

    2014-01-01

    Interest in synergistic or antagonistic effects through mixture experiments has grown immensely over the past two decades, not the least within in pharmacology and toxicology. Several definitions of reference models exist; one commonly used reference model is concentration or dose addition, which...... assumes compounds, when administrated simultaneously, do not interfere with each other at the site of action. We focus on statistical modelling that allows evaluation of dose addition. We will describe several statistical approaches that are suitable for analysis mixture data where synergistic or...

  8. Constraints on heavy Z' couplings from \\Delta S = 2 B^- -> K^- K^- \\pi^+ decay

    Fajfer, S.; Singer, P

    2001-01-01

    The heavy Z' boson with family nonuniversal couplings can introduce flavour changing effects. Constraints on nondiagonal Z' couplings coming from the \\mu-e conversion in a muonic atom, K^0 - \\bar{K^0} and B - \\bar{B} mixing, epsilon and epsilon'/ \\epsilon CP- violating coefficients have been already established. By using the OPAL upper bound of the branching ratio for the B^- -> K^- K^- \\pi^+ decay, we indicate additional constraints on the Z' couplings. We comment also on the constraints of ...

  9. Sloppy Addition and Multiplication

    Nannarelli, Alberto

    Sometimes reducing the precision of a numerical processor, by introducing errors, can lead to significant performance (delay, area and power dissipation) improvements without compromising the overall quality of the processing. In this work, we show how to perform the two basic operations, addition...

  10. Planck 2016 intermediate results. XLVII. Planck constraints on reionization history

    Adam, R; Ashdown, M; Aumont, J; Baccigalupi, C; Ballardini, M; Banday, A J; Barreiro, R B; Bartolo, N; Basak, S; Battye, R; Benabed, K; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bock, J J; Bonaldi, A; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Bucher, M; Burigana, C; Calabrese, E; Cardoso, J -F; Carron, J; Chiang, H C; Colombo, L P L; Combet, C; Comis, B; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Di Valentino, E; Dickinson, C; Diego, J M; Doré, O; Douspis, M; Ducout, A; Dupac, X; Elsner, F; Enßlin, T A; Eriksen, H K; Falgarone, E; Fantaye, Y; Finelli, F; Forastieri, F; Frailis, M; Fraisse, A A; Franceschi, E; Frolov, A; Galeotta, S; Galli, S; Ganga, K; Génova-Santos, R T; Gerbino, M; Ghosh, T; González-Nuevo, J; Górski, K M; Gruppuso, A; Gudmundsson, J E; Hansen, F K; Helou, G; Henrot-Versillé, S; Herranz, D; Hivon, E; Huang, Z; Ili_, S; Jaffe, A H; Jones, W C; Keihänen, E; Keskitalo, R; Kisner, T S; Knox, L; Krachmalnicoff, N; Kunz, M; Kurki-Suonio, H; Lagache, G; Lähteenmäki, A; Lamarre, J -M; Langer, M; Lasenby, A; Lattanzi, M; Lawrence, C R; Jeune, M Le; Levrier, F; Lewis, A; Liguori, M; Lilje, P B; López-Caniego, M; Ma, Y -Z; Macías-Pérez, J F; Maggio, G; Mangilli, A; Maris, M; Martin, P G; Martínez-González, E; Matarrese, S; Mauri, N; McEwen, J D; Meinhold, P R; Melchiorri, A; Mennella, A; Migliaccio, M; Miville-Deschênes, M -A; Molinari, D; Moneti, A; Montier, L; Morgante, G; Moss, A; Naselsky, P; Natoli, P; Oxborrow, C A; Pagano, L; Paoletti, D; Partridge, B; Patanchon, G; Patrizii, L; Perdereau, O; Perotto, L; Pettorino, V; Piacentini, F; Plaszczynski, S; Polastri, L; Polenta, G; Puget, J -L; Rachen, J P; Racine, B; Reinecke, M; Remazeilles, M; Renzi, A; Rocha, G; Rossetti, M; Roudier, G; Rubiño-Martín, J A; Ruiz-Granados, B; Salvati, L; Sandri, M; Savelainen, M; Scott, D; Sirri, G; Sunyaev, R; Suur-Uski, A -S; Tauber, J A; Tenti, M; Toffolatti, L; Tomasi, M; Tristram, M; Trombetti, T; Valiviita, J; Van Tent, F; Vielva, P; Villa, F; Vittorio, N; Wandelt, B D; Wehus, I K; White, M; Zacchei, A; Zonca, A

    2016-01-01

    We investigate constraints on cosmic reionization extracted from the Planck cosmic microwave background (CMB) data. We combine the Planck CMB anisotropy data in temperature with the low-multipole polarization data to fit {\\Lambda}CDM models with various parameterizations of the reionization history. We obtain a Thomson optical depth {\\tau}=0.058 +/- 0.012 for the commonly adopted instantaneous reionization model. This confirms, with only data from CMB anisotropies, the low value suggested by combining Planck 2015 results with other data sets and also reduces the uncertainties. We reconstruct the history of the ionization fraction using either a symmetric or an asymmetric model for the transition between the neutral and ionized phases. To determine better constraints on the duration of the reionization process, we also make use of measurements of the amplitude of the kinetic Sunyaev-Zeldovich (kSZ) effect using additional information from the high resolution Atacama Cosmology Telescope and South Pole Telescope...

  11. Model Additional Protocol

    Since the end of the cold war a series of events has changed the circumstances and requirements of the safeguards system. The discovery of a clandestine nuclear weapons program in Iraq, the continuing difficulty in verifying the initial report of Democratic People's Republic of Korea upon entry into force of their safeguards agreement, and the decision of the South African Government to give up its nuclear weapons program and join the Treaty on the Non-Proliferation of Nuclear Weapons have all played a role in an ambitious effort by IAEA Member States and the Secretariat to strengthen the safeguards system. A major milestone in this effort was reached in May 1997 when the IAEA Board of Governors approved a Model Protocol Additional to Safeguards Agreements. The Model Additional Protocol was negotiated over a period of less than a year by an open-ended committee of the Board involving some 70 Member States and two regional inspectorates. The IAEA is now in the process of negotiating additional protocols, State by State, and implementing them. These additional protocols will provide the IAEA with rights of access to information about all activities related to the use of nuclear material in States with comprehensive safeguards agreements and greatly expanded physical access for IAEA inspectors to confirm or verify this information. In conjunction with this, the IAEA is working on the integration of these measures with those provided for in comprehensive safeguards agreements, with a view to maximizing the effectiveness and efficiency, within available resources, the implementation of safeguards. Details concerning the Model Additional Protocol are given. (author)

  12. Constraints on lepton number violating short-range interactions from $|\\Delta L|=2$ processes

    Quintero, Nestor

    2016-01-01

    In this work we study the short-range contributions that induce effective lepton number violating (LNV) interactions. We obtain a full set of constraints on the effective short-range couplings from a large variety of low-energy $|\\Delta L|= 2$ processes of pseudoscalar mesons $K, D, D_s, B$, and $\\tau$-lepton. These constraints provide complementary and additional information to the one obtained from the neutrinoless double-$\\beta$ ($0\

  13. Collider Constraints and Prospects of a Scalar Singlet Extension to Higgs Portal Dark Matter

    Dupuis, Grace

    2016-01-01

    This work considers an extension of the Standard Model (SM) Higgs sector by a real, scalar singlet field, including applicability to a dark matter (DM) model with the addition of a Yukawa coupling to a Dirac fermion. The collider signatures and constraints on the mixed two-Higgs scenario are determined, including limits from Higgs production signals and exclusion searches, as well as constraints arising from the Higgs total and invisible widths. As there is overwhelming Higgs data which is co...

  14. a Chiral Schwinger Model, its Constraint Structure and Applications to its Quantization

    Bracken, Paul

    The Jackiw-Rajaraman version of the chiral Schwinger model is studied as a function of the renormalization parameter. The constraints are obtained and they are used to carry out canonical quantization of the model by means of Dirac brackets. By introducing an additional scalar field, it is shown that the model can be made gauge invariant. The gauge invariant model is quantized by establishing a pair of gauge fixing constraints in order that the method of Dirac can be used.

  15. A Chiral Schwinger model, its Constraint Structure and Applications to its Quantization

    Bracken, Paul

    2007-01-01

    The Jackiw-Rajaraman version of the chiral Schwinger model is studied as a function of the renormalization parameter. The constraints are obtained and they are used to carry out canonical quantization of the model by means of Dirac brackets. By introducing an additional scalar field, it is shown that the model can be made gauge invariant. The gauge invariant model is quantized by establishing a pair of gauge fixing constraints in order that the method of Dirac can be used.

  16. A Chiral Schwinger model, its Constraint Structure and Applications to its Quantization

    Bracken, Paul

    2007-01-01

    The Jackiw-Rajaraman version of the chiral Schwinger model is studied as a function of the renormalization parameter. The constraints are obtained and they are used to carry out canonical quantization of the model by means of Dirac brackets. By introducing an additional scalar field, it is shown that the model can be made gauge invariant. The gauge invariant model is quantized by establishing a pair of gauge fixing constraints, so the method of Dirac can be used.

  17. Functional Modeling of Constraint Management in Aviation Safety and Command and Control

    Woltjer, Rogier

    2009-01-01

    This thesis has shown that the concept of constraint management is instrumental in understanding the domains of command and control and aviation safety. Particularly, functional modeling as a means to address constraint management provides a basis for analyzing the performance of socio-technical systems. In addition to the theoretical underpinnings, six studies are presented.           First, a functional analysis of an exercise conducted by a team of electricity network emergency managers is...

  18. A New Optimal Control Algorithm for Quad-rotor Helicopter with State Constraints via Sliding-mode Control

    Zhao Jing

    2015-01-01

    Full Text Available This paper proposes a strategy of a new optimal sliding-mode control for flight control system with state constraints so that the system guarantees the optimal performance index. Besides, the strategy ensures strong robustness to the internal parametric uncertainty and the external disturbances. In order to have fast transient response speed as well as good tracking accuracy, the integral of the time multiplied by the absolute displacement tracking error is introduced as the performance index. By analyzing the state constraints which are specifically the velocity tracking error constraint and the acceleration tracking error constraint, and the performance index, the parameters of sliding-mode surface and control law are obtained. Finally, the authors conduct the semi physical simulation on Qball-X4 quad-rotor helicopter, showing the effectiveness of the proposed strategy.

  19. External auditory canal carcinoma treatment

    External auditory canal (EAC) carcinomas are relatively rare conditions lack on established treatment strategy. We analyzed a treatment modalities and outcome in 32 cases of EAC squamous cell carcinoma treated between 1980 and 2008. Subjects-17 men and 15 women ranging from 33 to 92 years old (average: 66) were divided by Arriaga's tumor staging into 12 T1, 5 T2, 6 T3, and 9 T4. Survival was calculated by the Kaplan-Meier method. Disease-specific 5-year survival was 100% for T1, T2, 44% for T3, and 33% for T4. In contrast to 100% 5-year survival for T1+T2 cancer, the 5-year survival for T3+T4 cancer was 37% with high recurrence due to positive surgical margins. The first 22 years of the 29 years surveyed, we performed surgery mainly, and irradiation or chemotherapy was selected for early disease or cases with positive surgical margins as postoperative therapy. During the 22-years, 5-year survival with T3+T4 cancer was 20%. After we started superselective intra-arterial (IA) rapid infusion chemotherapy combined with radiotherapy in 2003, we achieved negative surgical margins for advanced disease, and 5-year survival for T3+T4 cancer rise to 80%. (author)

  20. External plans for radiological emergency

    Since 1989, the National Institute of Nuclear Research in Mexico shares in the task of Food and Water Control corresponding to the FT-86 task force of External Plans for Radiological Emergency (PERE), in charge of the Veracruz Health Services. In the PERE preparation stage previous actions are necessary developed for the preparation and updating of this plan and the task organization with the purpose to maintaining standing and operable in any time and circumstance, the capability to response in the face of an emergency. This stage englobes activities which must be realized before to carry out the Plan as they are the specialized training of personnel which participates and the execution of exercises and simulacrums. Until 1998, training and exercises for this task had been realized under diverse possible sceneries but in conditions that simulated the presence of radioactive material. For this reason, it should be emphasized the training realized during the days 6th, 7th, 8th July, 1999, in the emergency planning zone of the Plan, which to carry out using radioactive material. The National Institute of Nuclear Research had in charge of the training. This work describes all the activities for the realization of this training. (Author)

  1. Clinical governance and external audit.

    Glazebrook, S G; Buchanan, J G

    2001-01-01

    This paper describes a model of clinical governance that was developed at South Auckland Health during the period 1995 to 2000. Clinical quality and safety are core objectives. A multidisciplinary Clinical Board is responsible for the development and publicising of sound clinical policies together with monitoring the effects of their implementation on quality and safety. The Clinical Board has several committees, including an organization-wide Continuous Quality Improvement Committee to enhance the explicit nature of the quality system in terms of structure, staff awareness and involvement, and to develop the internal audit system. The second stream stems from the Chief Medical Officer and clinical directors in a clinical management sense. The Audit Committee of the Board of Directors covers both clinical and financial audit. The reporting lines back to that committee are described and the role of the external auditor of clinical standards is explained. The aim has been to create a supportive culture where quality initiatives and innovation can flourish, and where the emphasis is not on censure but improvement. PMID:11422717

  2. Externalism, skepticism and epistemic luck

    Lazović Živan

    2011-01-01

    Full Text Available This paper deals with the concept of epistemic luck and its place within wider philosophical debates on knowledge and skepticism. Philosophers involved in these debates share an intuition that knowledge excludes luck. Starting from Prichard’s modal definition of luck and his distinction between two varieties of epistemic luck, namely veridic and reflective, the paper explores the internalist and externalist prospects for avoiding epistemic luck and skepticism. Externalism seems to be capable of both coping with the Gettier-type cases and eliminating at least veridic epistemic luck by introducing the so-called safety condition for knowledge. As such, it also responds to some versions of skepticism as the safety condition explains how it is possible to acquire knowledge without proving that the well known skeptical alternatives (e.g. a brain-in-a-vat are false. Thus, even though it does not eliminate the reflective epistemic luck or meta-epistemological skeptical challenge, the externalist approach to knowledge looks more plausible than the internalist, especially because it may allow an internalist justification to play its due role in acquiring knowledge.

  3. The external costs of electricity

    This article presents an overview of the ExtrenE project (external costs of electricity) of the European Commission (EC). The damage caused by pollution has been calculated through analyses of the impact pathways which involve an analysis of the emission - dispersion - dose-response function - monetary estimation chain. The results are introduced for various cycles of combustible fuels (with several technological variants), indicating the confidence intervals. The cost of the damage is particularly high for coal. For example, for the coal-fired power stations in France (with the emission levels of 1995) it is approximately equal to the sales price of electricity. For natural gas, the cost of damage is approximately one-third that of coal. On the other hand, the damage costs for nuclear fuel and most forms of renewable energy are low, at a maximum just a few percent of the electricity price. The greatest part of these costs arises from health impact, particularly premature death. In order to avoid the controversy inherent in making a monetary assessment of mortality, especially if this is imposed upon future generations, the reduction in life expectancy due to the various combustible cycles is also indicated and the risks of nuclear energy are put into perspective via several comparisons. (authors)

  4. Bone scanning in severe external otitis

    Levin, W.J.; Shary, J.H. 3d.; Nichols, L.T.; Lucente, F.E.

    1986-11-01

    Technetium99 Methylene Diphosphate bone scanning has been considered an early valuable tool to diagnose necrotizing progressive malignant external otitis. However, to our knowledge, no formal studies have actually compared bone scans of otherwise young, healthy patients with severe external otitis to scans of patients with clinical presentation of malignant external otitis. Twelve patients with only severe external otitis were studied with Technetium99 Diphosphate and were compared to known cases of malignant otitis. All scans were evaluated by two neuroradiologists with no prior knowledge of the clinical status of the patients. Nine of the 12 patients had positive bone scans with many scans resembling those reported with malignant external otitis. Interestingly, there was no consistent correlation between the severity of clinical presentation and the amount of Technetium uptake. These findings suggest that a positive bone scan alone should not be interpreted as indicative of malignant external otitis.

  5. Bone scanning in severe external otitis

    Technetium99 Methylene Diphosphate bone scanning has been considered an early valuable tool to diagnose necrotizing progressive malignant external otitis. However, to our knowledge, no formal studies have actually compared bone scans of otherwise young, healthy patients with severe external otitis to scans of patients with clinical presentation of malignant external otitis. Twelve patients with only severe external otitis were studied with Technetium99 Diphosphate and were compared to known cases of malignant otitis. All scans were evaluated by two neuroradiologists with no prior knowledge of the clinical status of the patients. Nine of the 12 patients had positive bone scans with many scans resembling those reported with malignant external otitis. Interestingly, there was no consistent correlation between the severity of clinical presentation and the amount of Technetium uptake. These findings suggest that a positive bone scan alone should not be interpreted as indicative of malignant external otitis

  6. A synthesis theory for the externally excited adaptive system /EEAS/

    Horowitz, I. M.; Smay, J. W.; Shapiro, A.

    1974-01-01

    The externally excited adaptive system (EEAS) is a two-degree-of-freedom feedback system with a nonlinearity which is saturated hard by an external periodic signal. Under certain conditions, the EEAS responds quasi-linearly to command and plant disturbance signals, permitting the development of a quantitative synthesis theory for satisfying system tolerances despite large plant uncertainty. The great advantage of the EEAS is its zero sensitivity to plant gain variations, a property it shares with the self-oscillating adaptive system (SOAS). The EEAS is, however, more flexible than the SOAS in satisfying the quasi-linearity constraints. The essential difference is that in the EEAS the loop transmission bandwidth is not rigorously tied to the 'carrier' signal, as it is in the SOAS. There is a class of problems for which the EEAS is superior to the purely linear system, which in turn is superior to the SOAS. The superiority of the EEAS over the SOAS is especially marked in the case of significant plant disturbances, which generally vitiate a SOAS design.

  7. QCD unitarity constraints on Reggeon Field Theory

    Kovner, Alex; Lublinsky, Michael

    2016-01-01

    We point out that the unitarity of QCD imposes meaningful constraints on a possible form of the QCD Reggeon Field Theory. We show that neither the BFKL nor JIMWLK nor Braun's Hamiltonian satisfy the said constraints. In a toy, zero transverse dimensional case we construct a model that satisfies the analogous constraint and show that at infinite energy it indeed tends to a "black disk limit" as opposed to the model with triple Pomeron vertex only, routinely used as a toy model in the literature

  8. QCD unitarity constraints on Reggeon Field Theory

    Kovner, Alex; Levin, Eugene; Lublinsky, Michael

    2016-08-01

    We point out that the s-channel unitarity of QCD imposes meaningful constraints on a possible form of the QCD Reggeon Field Theory. We show that neither the BFKL nor JIMWLK nor Braun's Hamiltonian satisfy the said constraints. In a toy, zero transverse dimensional case we construct a model that satisfies the analogous constraint and show that at infinite energy it indeed tends to a "black disk limit" as opposed to the model with triple Pomeron vertex only, routinely used as a toy model in the literature.

  9. Expressing Model Constraints Visually with VMQL

    Störrle, Harald

    OCL is the de facto standard language for expressing constraints and queries on UML models. However, OCL expressions are very difficult to create, understand, and maintain, even with the sophisticated tool support now available. In this paper, we propose to use the Visual Model Query Language (VMQL......) for specifying constraints on UML models. We examine VMQL's usability by controlled experiments and its expressiveness by a representative sample. We conclude that VMQL is less expressive than OCL, although expressive enough for most of the constraints in the sample. In terms of usability, however...

  10. Constraint satisfaction problems CSP formalisms and techniques

    Ghedira, Khaled

    2013-01-01

    A Constraint Satisfaction Problem (CSP) consists of a set of variables, a domain of values for each variable and a set of constraints. The objective is to assign a value for each variable such that all constraints are satisfied. CSPs continue to receive increased attention because of both their high complexity and their omnipresence in academic, industrial and even real-life problems. This is why they are the subject of intense research in both artificial intelligence and operations research. This book introduces the classic CSP and details several extensions/improvements of both formalisms a

  11. Modifier constraints in alkali ultraphosphate glasses

    Rodrigues, B.P.; Mauro, J.C.; Yue, Yuanzheng;

    2014-01-01

    In applying the recently introduced concept of cationic constraint strength [J. Chem. Phys. 140, 214501 (2014)] to bond constraint theory (BCT) of binary phosphate glasses in the ultraphosphate region of xR2O-(1-x)P2O5 (with x ≤ 0.5 and R = {Li, Na, Cs}), we demonstrate that a fundamental...... limitation of BCT can be overcome. The modifiers are considered to exist in either “isolated” or “crosslinking” sites, in line with the so-called modifier sub-network [J. Chem. Phys. 140, 154501 (2014)] and each site is associated with a certain number of constraints. We estimate the compositional dependence...

  12. Database queries and constraints via lifting problems

    Spivak, David I

    2012-01-01

    Previous work has shown a tight relationship between databases and categories. In the present paper we extend that connection to show that certain queries and constraints correspond to the algebro-topological notion of lifting problems. In our formulation, each so-called SPARQL graph pattern query corresponds to a lifting problem, and each solution to the query corresponds to a lift. We interpret constraints within the same formalism and then investigate some formal properties of queries and constraints, e.g. their behavior under data migration functors.

  13. Black hole thermodynamics from Euclidean horizon constraints.

    Carlip, S

    2007-07-13

    To explain black hole thermodynamics in quantum gravity, one must introduce constraints to ensure that a black hole is actually present. I show that for a large class of black holes, such "horizon constraints" allow the use of conformal field theory techniques to compute the density of states, reproducing the Bekenstein-Hawking entropy in a nearly model-independent manner. One standard string theory approach to black hole entropy arises as a special case, lending support to the claim that the mechanism may be "universal." I argue that the relevant degrees of freedom are Goldstone-boson-like excitations arising from the weak breaking of symmetry by the constraints. PMID:17678209

  14. Constraints on the parameters of the CKM matrix by End 1998

    Parodi, F; Stocchi, A

    1999-01-01

    A review of the current status of the Cabibbo-Kobayashi-Maskawa matrix (CKM) is presented. This paper is an update of the results published in [1]. The experimental constraints imposed by the measurements of \\epsilon_K, V_{ub}/V_{cb}, \\Delta m_d and from the limit on \\Delta m_d are used. Values of the constraints and of the parameters entering into the constraints, which restrict the range of the \\bar{\\rho} and \\bar{\\eta} parameters, include recent measurements presented at 1998 Summer Conferences and progress obtained by lattice QCD collaborations. The results are: \\bar{\\rho}=0.202 ^{+0.053}_{-0.059},\\bar{\\eta}=0.340 \\pm 0.035, from which the angles \\alpha, ^{+ 0.29}_{-0.28} ,\\sin 2 \\beta = 0.725 ^{+0.050}_{-0.060} ,\\gamma= (59.5^{+8.5}_{-7.5})^{\\circ}. Without using the constraint from \\epsilon_K, external measurements or theoretical inputs have been removed, in turn, from the constraints and their respective probability density functions have been obtained. Central values and uncertainties on these quantit...

  15. Early discharge after external anal sphincter repair

    Rosenberg, J; Kehlet, H

    1999-01-01

    PURPOSE: The aim of this study was to describe an accelerated-stay program for repair of the external anal sphincter. METHODS: Twenty consecutive patients undergoing overlapping repair of the external anal sphincter were included in the study. Effect parameters were length of hospitalization and....... CONCLUSION: We have described a safe accelerated-stay program (24 to 48 hours) for overlapping repair of external anal sphincter....

  16. External fixation in contemporary fracture management

    McCoy, G. F.; Orr, J. F.; Templeton, J.

    1987-01-01

    Important advances have been made within the last two decades in the field of fracture management. The development of the AO internal fixation system and the advances in cast bracing techniques are but two of the improvements worthy of mention. It is, however, in the field of external fixation of fractures that the greatest advances have been made. This paper traces the history of external fixation up to the present day and discusses, with examples, the application of external fixation in the...

  17. Internalizing Externalities through Payments for Environmental Services

    Sudarsono Soedomo

    2012-01-01

    Forest ecosystems, including plantation forests, provide goods and services that are marketable and non-marketable. Positive externalities produced by forest ecosystems are rarely considered in pricing of marketable products that result in economic inefficiencies. Internalizing externalities is required to improve the economic efficiency. The traditional way to internalize an externality is by providing subsidies or imposing taxes. Recently, payments for environmental services  are receiving ...

  18. Phase separation driven by external fluctuations

    García Ojalvo, Jordi; Lacasta Palacio, Ana María; Sancho, Jose Maria; Toral, R.

    1998-01-01

    The influence of external fluctuations in phase separation processes is analysed. These fluctuations arise from random variations of an external control parameter. A linear stability analysis of the homogeneous state shows that phase separation dynamics can be induced by external noise. The spatial structure of the noise is found to have a relevant role in this phenomenon. Numerical simulations confirm these results. A comparison with order-disorder noise induced phase transitions is also made.

  19. Energy security externalities and fuel cycle comparisons

    Externalities related to 'energy security' may be one way in which the full social costs of energy use diverge from the market prices of energy commodities. Such divergences need to be included in reckoning the full costs of different fuel cycles. In this paper we critically examine potential externalities related to energy security and issues related to the measurement of 2 these externalities, in the context of fuel cycle comparisons

  20. Risk analysis of external radiation therapy

    External radiation therapy is carried out via a complex treatment process in which many different groups of staff work together. Much of the work is dependent on and in collaboration with advanced technical equipment. The purpose of the research task has been to identify a process for external radiation therapy and to identify, test and analyze a suitable method for performing risk analysis of external radiation therapy